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Just because the annou nc e me nt last week of the creation of a viable bacterium, whose entire genome had been entirely syn-

thesised from the basic chemical con-stituents of DNA, had been expected for some time (after all the new bac-terium came from the laboratory of the master scientist/publicist Craig Venter) doesn’t mean that it is any less momentous. Several years ago Craig Venter famously set the race for the first initial sequencing of the human genome alight by announcing that his privately-funded enterprise would sequence the human genome in three years at the time when the multina-tional collaborative, public-funded human genome project was plod-ding along three years into a planned ten years programme. The effect of Venter’s challenge was sufficient to galvanise the public consortium into revitalising their programme so that in the end both groups achieved the objectives at the same time. Since then Venter has made no secret of the next major objective of his lab which has now been reached, namely the crea-tion of a viable cell whose DNA has been entirely chemically synthesised. Of course many biologists rightly say that for years now the insertion into existing genomes of stretches of for-eign DNA, whether extracted from other organisms or synthesised from the base chemicals, has been rou-tine practice in the world of genetic engineering. In addition they point out that while Venter’s DNA was chemically manufactured according to a base sequence specified by scien-tists, the new genome still had to be inserted into an existing cell (specifi-cally Mycobacterium mycoides) from which existing native DNA had been removed, together with certain restric-tion enzymes which could otherwise have degraded the inserted synthetic nucleic acid. Nevertheless the demon-strated viability of Venter’s mycobac-terium is indeed momentous, if only because this is surely just the first of a long series of other organisms that will be created in the new discipline of synthetic biology. Automated sys-tems for the synthesis of specified

DNA sequences are continuing to be developed at an amazing rate (over the last decade the estimated cost of synthesising one DNA base pair has fallen from approximately $100 to around one US cent), so extension of the new science of synthetic biology to non-prokaryotic systems is only a matter of time. The real question is what the new technology will be used for. At the moment rough proposals

have been made regarding the future creation of synthetic genomes that will allow eukaryotic systems (algae look like being the first) to be able to carry out for, example, the photosynthetic absorption of CO2 from power sta-tions, or other vaguely defined worth-while causes such as the production of new drugs, vaccines or fuels. The real challenge of the recent announcement is not so much the

technology itself but rather the intel-lectual property questions around it. Craig Venter has already introduced patent claims on his technology which, if granted, could ultimately give his lab monopoly rights to the use of this genetic engineering. The outcry against this has just started.

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ContentsFRONT COVER PRODUCTS[32] Fee-for-use

cloud-based PACs[33] Closed loop

ventilation system[34] Point-of-care

imaging

FEATURES[6 - 11] PEDiATRiCS[6 - 8] Renal involvement and injury in obese children

[9 - 10] Single site laparoscopy in children

[11] Pediatrics: news in brief

[12 - 23] CARDiOlOgy[12] Scientific literature review — cardiology

[14 - 15] Doppler echo-cardiography in non-cardiac surgical patients: does it improve outcome?

[16 - 19] The changing paradigm of stress echo-cardiography: risk stratification, prognosis and patient outcomes

[19] Cardiology Book review: Clinical Cases Uncovered

[20 - 21] Getting to the heart of things: a review of modern diagnostic techniques

[22 - 23] Bringing lab PT/INR testing standards to POC and the home

[24 - 25] MEDiCAl iMAgiNg Europe’s first full-body PET/Mr system in operation

[28 - 30] ORThOPEDiCS SPECT-CT in imaging foot & ankle pathology: the demise of other co - registration techniques

REgUlARS[3] Editor’s letter

[26] News in brief

[31 - 34] Product News

[34] Calendar of upcoming events

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6 PEdiATriCs

The increasing prevalence of ESRD and childhood obesity The prevalence of end stage renal disease (ESRD) has approximately doubled over the past three decades [1], in parallel with the increasing preva-lence of obesity and insulin-resistance, which also occur in the pediatric population throughout the world [2]. Currently approximately one-fifth of children and adolescents in industrialised coun-tries are overweight or obese; obesity is thus a real threat not only to the health of children and adolescents, , but also for adults since the meta-bolic, cardiovascular and renal impacts of obesity, although generally not presenting symptomati-cally until adulthood, have their origins in child-hood [3]. This is alarming, since in most cases the condition of being overweight/obese earlier in life continues into adulthood, thus represent-ing a major contributor to the adult obesity epi-demic and to increased cardiovascular and renal morbidity and mortality in adult life.

Even if the vast majority of studies that have examined the association between obesity and kidney disease (KD) have been carried out in adults, a growing body of evidence suggests that childhood obesity also increases the risk of KD and its consequences, and that renal dys-function may start long before the appearance of hypertension or diabetes in adulthood [4].

From obesity and its metabolic complication to renal involvement and injuryThe so-called “obesity-related glomerulopathy” is clinically characterised by a higher serum albumin, moderate proteinuria (with a lower incidence of nephrotic-range proteinuria), lower serum cholesterol and minimal edema; morphologically it is defined as glomerulom-egaly with or without focal segmental glomer-ulosclerosis, due to functional and structural renal changes [5].

Currently there is increasing evidence that obesity may also damage the kidneys; in par-ticular, central adiposity seems to be impor-tant for renal function abnormalities, as it is strongly associated with diabetes and hyper-tension, the two most common causes of ESRD [6]. Moreover, the metabolic syndrome (MS), a major consequence of obesity, also seems to be an independent risk factor for both chronic kidney disease (CKD) and ESRD [4], with accumulating data supporting the hypoth-esis that increased insulin resistance (IR) and hyperinsulinemia are among the most impor-tant factors of MS contributing to renal injury [7] [Figure 1].

Insulin resistance/hyperinsulinemiaAccumulating data suggest that IR, as well as compensatory hyperinsulinemia, are independ-ently associated with an increase prevalence of CKD [8], and support the existence of sev-eral pathways linking IR and hyperinsulinemia with KD [Figure 2]. Insulin has been related to

the development of glomerular hyperperfusion and hyperfiltration, promotion of mesangial renal cell proliferation, increasing urinary albu-min excretion rate, and augmented activity of the renin-angiotensin-aldosterone system, thus contributing to hypertension. Moreover, insulin stimulates the production of pro-inflammatory cytokines by the adipose tissue and seems to be related to an impaired nitric oxide production or action, and to the altered oxidant/antioxidant status observed in obese subjects [9, 10].

Impaired glucose tolerance (IGT)Elevated plasma glucose levels were found to be significantly associated with an increased prevalence of both CKD and microalbuminu-ria, and with increased odds ratios of micro-albuminuria [11]. Hyperglycemia is directly related to hyperfiltration and renal hyperper-fusion, and it has been causally linked to vas-cular and glomerular dysfunction [12]. GFR values increase across the spectrum of hyper-glycemia among patients with IGT and newly diagnosed diabetes. The decline in GFR was greatest in patients with diabetes whereas it was only modest in those with normal or impaired glucose tolerance.

High blood pressure Obesity is associated with the activation of the renin-angiotensin-aldosterone system, increased sympathetic nervous system activity, IR and hyperinsulinemia, all of which contrib-ute to tubular sodium reabsorption, associated fluid retention and hypertension. A compensa-tory lowered renal vascular resistance, elevated

renal involvement and injury in obese childrenin recent years, the prevalence of end stage renal disease (Esrd) , including Esrd in the pediatric population, has been increasing in parallel with the rise of obes-ity and insulin-resistance. The clustering of cardiovascular risk factors (higher BMi, type 2 diabetes mellitus (T2dM), dyslipidemia, hypertension and insulin resistance (ir), has been well documented in obese children and adolescents, suggesting that the effects of obesity on target organs in adults, including the kidneys are initiated during childhood. by dr A. savino, dr P. Pelliccia, dr F. Chiarelli and dr A. Mohn

Figure 1. Obesity per se is a risk factor for renal complications. In addition, obesity is often associated with metabolic complications, such as diabetes, hypertension, dyslipidemia, and insulin resistance, which represent

well-known risk factors for the development of renal disease.

June 2010

7 June 2010

renal plasma flow, increased GFR and higher blood pressure are important in overcoming increased sodium reabsorption. In the presence of other risk factors, such as hyperlipidemia and hyperglycemia, these adaptive changes may provoke glomerulosclerosis, proteinuria and loss of nephron function, even before struc-tural changes are evident [13]. Furthermore, in obese subjects, visceral adipose tissue almost completely encapsulates the kidneys and pen-etrates into the sinuses of the medulla, causing compression and increased intrarenal pres-sure. Both increased intrarenal and abdominal pressure may contribute to obesity-associated hypertension [14, 15].

Hyperlipidemia Obesity is commonly associated with hyper-lipidemia and there is growing evidence that abnormalities in lipid metabolism contribute to renal disease progression. The mechanism has not been fully elucidated, but triglyceride-rich lipoproteins, free fatty acids (FFA) and metabo-lites, and albumin-loaded FFA seem to play a major role in renal cell injury. Hyperlipidemia also causes mesangial proliferation and expan-sion due to LDL cholesterol, development of glomerulosclerosis and progressive renal failure [16]. CKD patients also suffer from a secondary form of dyslipidemia, which contributes to the rate of progression of renal disease.

Metabolic syndrome (MS) Several studies investigating the relationship between factors of the MS and KD showed that it can to a large extent be explained by the fact

that most of the components of the metabolic syndrome, namely T2DM, hypertension, obes-ity and low HDL-cholesterol levels, apart from predisposing to cardiovascular disease are also strong independent risk factors for CKD [8]. Prospective data also suggest that the presence of the MS is independently related to a greater risk of developing CKD and microalbuminuria [17].

Obesity-related renal injury in childhoodThe sequelae of obesity, such as hypertension, dyslipidemia and hyperinsulinemia are increas-ingly being recognised in childhood. Clustering of cardiovascular risk factors is seen in children and adolescents, suggesting that adult conse-quences of obesity on target organs, includ-ing the kidney, are more likely to develop in young people. Growing evidence also suggests that childhood obesity may put young people at increased risk for KD and its consequences.One of the most important consequences of obesity is the development of a state of insulin resistance (IR). Obese children with a similar BMI can differ in their risk for complications on the basis of the degree of IR [18]. Hyperin-sulinemia influences blood pressure and serum lipoprotein concentrations, and often results in hypertension and dyslipidemia. The presence of these conditions, in addition to obesity, is thought to play key roles in the pathogenesis of obesity-related glomerulopathy. It is alarm-ing that metabolic and cardiovascular compli-cations are already found in obese prepuber-tal children, as IR and related consequences might be further exacerbated by the influence

of puberty, due to the physiological decrease in insulin sensitivity associated with normal development in puberty [19].

The association between hypertension and childhood overweight and obesity has been doc-umented in several studies [9]. In general, blood pressure values have been increasing in young people over the last decade, in parallel with the rise in obesity [20], and more children and ado-lescents are falling into hypertensive ranges. The risk of hypertension increases across the entire range of BMI values and is not defined by a simple threshold effect [21, 22]. Compared with normal weight children, those with a BMI >90th percentile were about three times more likely to have hypertension [23]. Low insulin sensitivity is also a well-known contributor to high blood pressure in children: an insulin-mediated effect on renal sodium reabsorption and on the sym-pathetic nervous system (SNS), with a state of hyperactivity characterised by increased heart rate, BP variability, increased levels of catecho-lamines and increased peripheral sympathetic nerve traffic, are the main mechanisms that have been suggested and described in obese children [24, 25].

The prevalence of microalbuminuria among severely obese children was found to be 10%, which is consistent with previous findings in obese adults. This was not related to BMI or

Figure 2. Through different pathways insulin resistance and hyperinsulinemia may lead to renal involvement and injury. (Na = sodium; Na-Cl = sodium chloride; RAAS = renin–angiotensin–aldosterone system; GFR =

glomerular filtration rate; IGF-1 = insulin-like growth factor-1; TGF-ß = transforming growth factor beta; CTGF = connective tissue growth factor; SNS = sympathetic nervous system; Ang II = angiotensin II; IL-1 = interleukin-1;

IL-6 = interleukin-6; TNF-a = tumor necrosis factor alfa; CRP = C reactive protein; NO = nitric oxide; IR = insulin resistance) (adapted from Savino et al., Horm Res 2010, in press)


classical cardiovascular risk factors, but there were significant associations with post-chal-lenge glucose, insulin levels and whole body insulin sensitivity index (WBISI), suggest-ing that even slight abnormalities in glucose metabolism may be a driving force for early vascular damage in the toxic environment of pediatric obesity [26]. Increased levels of microalbuminuria and ß2-microglobulinuria were also observed in obese children compared to those of normal weight, indicating early renal glomerular and tubular dysfunction as a consequence of childhood obesity [27]. The urinary albumin/creatinine ratio was associ-ated with metabolic disorders linked to obesity, and also with the clustering of features of the MS. The relationship between microalbuminu-ria and excess weight is more complicated in adolescents, since overweight adolescents, with presumably more coexisting cardiovascular risk factors, had a lower prevalence of micro-albuminuria [28, 29], probably due to the exist-ence of important confounding variables, e.g. orthostatic proteinuria. In any case, the associa-tion of microalbuminuria with cardiovascular risk factors differed according to BMI category, being strongly modified by overweight.

The increasing prevalence of overweight closely parallels the rise in type 2 diabetes among children and adolescent [30]. In 1994, T2DM accounted for one third of the newly diagnosed diabetes cases among 10 to 19 year olds [31], 90% of these subjects having BMI values at or above the 90th percentile for age and gender. IGT and IR are presenting early in life among overweight and obese children and adolescents [32, 33], suggesting that the metabolic process is acceler-ated in these individuals and that the transition between IGT and diabetes is shortened.

Obese children and adolescents have consistently been observed to have a more unfavorable lipid and lipoprotein profile than children and ado-lescents with a normal body weight, with signifi-cantly elevated total cholesterol concentrations, higher LDL cholesterol and TG concentrations and significantly lower HDL cholesterol con-centrations [34]. At-risk lipoprotein concentra-tions are of particular concern during the years of growth because they tend to continue into adulthood [35]. The best predictor of young adult total cholesterol concentration is a measurement taken 12 years earlier; approximately fifty percent of children and adolescents who had total cho-lesterol or LDL-cholesterol concentrations above the 75th percentile had elevated concentrations at follow-up in young adulthood [36].

ConclusionsExcess body weight is significantly associ-ated with an increased risk for KD, not only in adults, which is well documented, but also in obese children and adolescents. A higher BMI,

the presence of T2DM, hypertension and, of particular importance, IR, are strong independ-ent risk factors for CKD and ESRD, which may be present even among overweight and obese children and adolescents.

References1. USRDS: The United States Renal Data System. Am J

Kidney Dis 2003;42:1–230.2. Ogden CL et al. JAMA 2006;295:1549–1555.3. Wang Y et al. Adv Chronic Kidney Dis 2006;13:

336-351.4. Wahba IM, Mak RH. Clin J Am Soc Nephrol

2007;2:550-562.5. Kambham N et al. Kidney Int 2001;59:1498–1509.6. Pinto-Sietsma SJ et al for the PREVEND Study

Group. Am J Kidney Dis 2003;41(4):733-741.7. Sarafidis PA, Ruilope LM. Am J Nephrol

2006;26:232–244.8. Chen J et al. J Am Soc Nephrol 2003;14:469–477.9. Sarafidis PA, Ruilope LM. Am J Nephrol

2006;26:232–244.10. Savino A, Pelliccia P, Chiarelli F, Mohn A. Horm Res

2010; in press.11. Chen J et al. Ann Intern Med 2004;140:167-174.12. Soper CP, Barron JL, Hyer SL. Diabet Med

1998;15:1010–1014.13. Sandhu JS et al. JIACM 2004;5(4):335-338.14. Hall JE et al. Am J Med Sci 2002;324:127–137. 15. Hall JE. Hypertension 2003;41;625-633.16. Kasiske BL et al. Kidney Int 1998; 33: 667-72.17. Kurella M, Lo JC, Chertow GM. J Am Soc Nephrol

2005;16:2134–2140.18. Chiarelli F, Marcovecchio ML. Eur J Endocrinol

2008;159:S67–S7419. Caprio S et al. J Pediatr 1989;114:963–967.20. Muntner P et al. JAMA 2004;291:2107-2113.

21. Lee WWR. Pediatric Diabetes 2007;8(9):76–87. 22. Sorof J, Daniels S. Hypertension 2002:40:441–447.23. Rosner B et al. Am J Epidemiol 2000;151:

1007-1019.24. Marcovecchio ML et al. J Hypertension

2006;24:2431–2436.25. Lurbe E et al. Hypertension 2008;51:635–641.26. Burgert TS et al. Int J Obesity 2006;30:273–280.27. Csernus K et al. Eur J Pediatr 2005;164:44–49.28. Bangstad HJ et al. Acta Paediatr 1993;82:857–862.29. Mueller PW, Caudill SP. Ren Fail 1999;21:293–302.30. Hannon TS, Rao G, Arslanian SA. Pediatrics

2005;116:473-480.31. Pinhas-Hamiel O et al. J Pediatr 1996;128:608-615.32. Sinha R et al. N Engl J Med 2002;346:802-810.33. Weiss R et al. Diab Care 2005;28:902-909.34. Friedland O et al. J Pediatr Endocrinol Metab

2002;15:1011-1016.35. Nicklas TA, Von Duvillard SP, Berenson GS. Int J

Sports Med 2002;23(1):S39-43.36. Webber LS et al. Am J Epidemiol 1991;133:704-714

The authorsAlessandra Savino MD, Piernicola Pelliccia MD, Francesco Chiarelli MD, PhD, Angelika Mohn MD, PhD.Department of Pediatrics University of Chieti Chieti, Italy

Correspondence to:Alessandra Savino, MDUniversity Department of PediatricsOspedale PoliclinicoVia dei Vestini 5, 66013 Chieti, ItalyTel. +390871358015 e-mail: [email protected]

8 PEdiATriCs June 2010

Cardiorenal syndromeMechanisms, risk and treatmentEdited by Adel E. Berbari and Giuseppe ManciaPublished by Humana Press, 2010, 320 pp, 159,95 €

Accelerated cardiovascular disease is a frequent complication of chronic kidney disease. Individuals with evidence of renal functional impairment are more likely to die of cardiovascular events than to progress to end stage renal disease. This relationship, which has been termed the cardiorenal syndrome, exists whether impairment of renal function is a consequence of primary renal parenchymal or primary heart disease. The mechanisms underlying the cardiorenal syndrome result from a complex interaction of traditional and uremia related cardiovascular risk factors. Prevention and management of car-diovascular disease include aggressive control of traditional risk factors as well novel approach to prevent or reverse uremia related processes. This book provides a comprehensive update analysis of our current understanding of the cardiorenal syndrome, including epidemiology, pathophysiologic mechanisms, and therapeutic approaches.

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BooK rEViEW

Videoscopic approaches to operations have allowed surgeons in every discipline to accom-plish the goals of the procedures without the large incisions traditionally necessary for expo-sure. These approaches have rapidly expanded over the last 20 years, and can be consid-ered as one of the most significant surgical advances of modern times, with documented benefits including reduced post-operative pain and convalescence with superior cos-mesis. The minimally invasive approaches to those operations with the most morbid inci-sions, such as cholecystectomy, fundoplication, splenectomy, nephrectomy and adrenalectomy offer patients a tremendous decrease in their physical investment.

While pediatric surgeons have trailed behind their colleagues carrying out surgery on adults in the widespread application of these approaches, the gap is now closing with the development of smaller instruments to facili-tate performing the procedures. The evolu-tion toward laparoscopy, however, was based on the premise of maintaining the basic prin-ciples of surgery including good visualisation, comfortable ergonomics and the ability to perform all the intended steps of the proce-dure without struggling. Accomplishing these goals requires well-triangulated separate instrument sites for retraction, exposure, dis-section, sewing and tying. Recently surgeons have begun to challenge the means of accom-plishing these goals and the goals of the

operation to allow for the entire videoscopic procedure to be carried out through a single incision in the umbilicus to further improve the cosmetic results for the patient.

Single site limitationsNarrow distances between instruments restrict the surgeon’s hands and limit the range of motion. The parallel alignment of instruments and scope limits triangulation and the range of view, by making the field of view dependent on the movements of the instruments. While there is only one incision, it is usually larger than any of those required for standard laparoscopy. The literature avail-able covers preliminary experience focus-ing on feasibility, and comparative data are still anticipated.

EquipmentSome equipment has been developed recently to overcome some of the aforementioned technical challenges. Several ports with multi-channel capacity have been launched on the market, allowing multiple instruments to be placed through a single access device. These offer some effective options for sur-geons when more then three working instru-ments are required. For example, we cur-rently perform single site cholecystectomies with a three channel port accomodating the camera and two working instruments, while an additional instrument is place alongside the port to retract the gall bladder.

In an effort to overcome the loss of triangu-lation, flexible instruments have been devel-oped to adjust the angle of the instrument to overcome the external parallel instruments. However, because the instruments are often crossed and the tip is at a different angle from the shaft, the instruments often require coun-ter-intuitive external movements by the sur-geon. Likewise, flexible laparoscopes are now available to allow a view outside the parallel of the instruments.

Despite these advances, we have found that single site appendectomy, cholecystectomy,

splenectomy and bowel procedures can be per-formed with standard laparoscopic equipment.

Pediatric considerationsGiven the rationale that a single incision may improve cosmesis, the margin of benefit may be less in pediatric surgery where scarring is typically less problematic and instrument sites are currently 3 mm or less. Many abdominal operations in small children and babies can be carried out with a 5 mm umbilical port and stab incisions so that 2.7 mm instruments can be placed directly through the abdominal wall. These incisions typically leave no per-ceptible defects in the skin after a few months [1]. Compared to the umbilicus of many small children, the adult umbilicus provides a rela-tively large skin surface for a longer incision to be hidden. The current single incision multi-ports require at least a 20 mm incision. This is larger than the umbilicus in virtually all infants and small children.

Single site approaches to infant operations that require no exteriorisation, such as pyloromyo-tomy, become quite inapplicable to single site techniques. For example, the circumumbilical open approach for pyloromyotomy leaves a fairly obvious surgical incision. The single site approach to this operation also leaves this scar in addition to adding technical disadvantages. Regardless, for the pediatric surgical popula-tion to participate in the evolution of mini-mally invasive surgery, we need to continue to challenge our limitations, borrow from expe-rience with adults, and apply the techniques where possible.

Published experienceSingle incision procedures have been reported in adults for appendectomy, cholecystectomy, gastrectomy, adrenalectomy, colorectal pro-cedures, bariatric procedures and urologic procedures. The number of procedures in children has been more limited but includes appendectomy, cholecystectomy, splenec-tomy, intestinal operations, gastrostomy and urologic procedures.

AppendectomyThe single incision laparoscopic approach in children was first reported in 1998. The described method included an infraumbili-cal trocar with a 10 mm operative telescope. The appendix was grasped with an instru-ment introduced through a channel in the scope allowing the appendix to be exteriorised and excised with a traditional extracorporeal method. A similar method was subsequently

single site laparoscopy in childrenLaparoscopy offers decreased post-operative pain and convalescence time with improved cosmesis compared to open procedures. single site laparoscopy repre-sents the next wave of minimally invasive surgery. This article reviews applications of single site procedures, the potential limitations and future directions in children.

by dr s. d. st. Peter

9PEdiATriCs June 2010

The set-up for bowel resection in Crohn’s disease, with two instruments passed through stab incisions in

the fascia on each side of the camera port.

reported in a series of 111 patients, which was the first to introduce the concern for surgical site infections with extracorporeal resection.

Utilising a grasper through the scope places the working instrument and field of view dependent on one another and such scopes are not widely available. We have over-come these limitations by placing a 5mm port through the centre of the umbilicus and using a stab incision through the fascia above or below this port for insertion of the working instrument. If the appendix requires more tenuous dissection, a second working instrument can be placed on the other side of the camera port providing triangulation similar to standard laparoscopy. Insufflation is maintained by small fascial incisions and keeping the flow at a high level. After the appendix is mobilised, connecting the fascial incisions allows for extracorporeal resection. If re-insufflation is required, one can par-tially close the fascia, insert a larger port or place a finger in the residual space, which is usually adequate to accomplish inspection and suctioning of the cecal fossa.

CholecystectomySingle umbilical cholecystectomy has the appeal of removing the visible incisions from the epigastrum. Wide triangulation has been the premise to usher in laparoscopy for safe gallbladder removal, which is attenuated sub-stantially with the single site approach. Flex-ible instruments have been utilised to facili-tate dissection. Recently, a few case series have emerged in children, which utilised spe-cialised equipment to perform the operation, with results comparable to those previously published with the standard laparoscopic approach [2-4]. We currently use standard instruments by placing two working instru-ments through two of the three channels offered by a multichannel port in scissor fashion so that the infundibulum is retracted laterally with the surgeon’s right hand and dissection is done with the left. We place a grasping instrument alongside the port to retract the gallbladder so the operation is done in the standard 3-instrument manner.

No prospective data exist in the literature on single site procedures, however a recent sys-tematic review of randomised controlled trials comparing laparoscopic and minilaparoscopic cholecystectomy found the same operating time, morbidity, analgesia use and convales-cence. The cosmetic advantage led to the con-clusion that smaller is not necessarily better, The lesson of the importance of good com-parative data should be learnt before allowing single site procedures to dominate the options for the patient.

Intestinal diseasesIn infants, we have previously applied the sin-gle umbilical incisions to numerous intesti-nal diseases without laparoscopic assistance, since the entire small bowel can be eviscer-ated through a small umbilical incision in these patients. Operations using only the umbilicus have been applied to conditions such as necrotising enterocolitis, jejunoileal atresia, midgut volvulus, meconium ileus and stomas.

In older patients, Meckel’s diverticulectomy and small bowel resection are simple tran-sumbilical operations due to the mobility of the intestine. A single grasper can be used to identify and grasp the area for resection and bring it up through the umbilicus for extracorporeal resection.

Ileocectomy is the operation where the sin-gle umbilical incision has intuitive advan-tages. Standard 3-port ileocectomy uses two working ports to mobilise the right colon and terminal ileum to allow for extracorpor-ealisation. The ultimate size of the umbili-cal incision is limited by the size of the mass being inverted, which is often large in Crohn’s disease. The necessity to open the umbili-cus offers the opportunity to make a larger incision in the beginning so two working

instruments can be placed with good trian-gulation. The umbical location allows for simple takedown of the hepatic flexure to ease extracorporealisation. Other proceduresThere are several of other procedures reported in the literature using the single incision approach in children, including single port laparoscopy-aided gastrostomy tube placement, varicocelectomy and neonatal ovarian cysts.

SummarySingle site laparoscopic operations appear to be the next generation of procedures with the potential to further minimise the impact that the operations have on patients. Currently, sound comparative data are lacking in the lit-erature. Given that the margin of advantage is likely to be small, and in any case certainly not comparable to the leap that occurred from open to laparoscopic surgery, we feel prospec-tive trials are warranted for these procedures. We are currently conducting three prospective randomised trials for appendectomy, cholecys-tectomy and splenectomy utilising a validated scar assessment tool during follow-up to ana-lyse whether the patients perceive the cosmetic benefits these operations are reported to offer.

References1. St Peter SD, Holcomb GW 3rd, Calkins CM, Mur-

phy JP, Andrews WS, Sharp RJ, Snyder CL, Ostlie DJ Open versus laparoscopic pyloromyotomy for pyloric stenosis: a prospective, randomized trial. Ann Surg 2006; 244(3): 363-70.

2. Ponsky TA, Diluciano J, Chwals W, et al. Early experience with single-port laparoscopic sur-gery in children. J Laparoendosc Adv Surg Tech 2009;19(4):551-553.

3. Rothenberg SS, Shipman K, Yoder S. Experience with modified single-port laparoscopic proce-dures in children. J Laparoendosc Adv Surg Tech 2009; 19(5): 1-4.

4. Dutta S. Early experience with single incision laparoscopic surgery: eliminating the scar from abdominal operations. J Ped Surgery 2009; 44: 1741-1745

The authorShawn D. St. Peter, MDDepartment of Pediatric Surgery,Children’s Mercy Hospital and Clinics,2401 Gillham Road,Kansas City, MO, USA 64108Tel: 816-983-6465Fax: 816-983-6885e-mail: [email protected]

Comments on this article?Feel free to post them at

www.ihe-online.com/comment/SS_laparascopy

10 PEdiATriCs June 2010

Improved cosmesis. The image above shows the umbilicus two weeks after an appendectomy.

The picture above shows how the multichannel port can be used with a working instrument right along side of it to replicate a standard 4 port technique.

11

Gene variant raises odds of mother-to-child HIV transmission

A correlation has been discovered between specific variants of the gene that codes for a key immune system protein, TLR9, and the risk of vertical transmission of HIV. Researchers writ-ing in BioMed Central’s open access Journal of Translational Medicine studied three hundred children born to HIV-positive mothers, find-ing that those who had either of two TLR9 gene variants were significantly more likely to acquire the virus.Anita De Rossi from the University of Padova, Italy, worked with a team of researchers to carry out the study using samples taken from children born between 1984 and 1996 to HIV infected mothers who had not received antiret-roviral prophylaxis. Two changes to the TLR9 gene have recently been linked to progression of HIV-1 disease and viral load in adult patients. This study found that children who have two copies of either of these polymorphisms are at significantly higher risk of catching HIV as they are born.TLR9 plays a pivotal role in the induction of first-line defense mechanisms of the innate immune system and triggers effective adaptive immune responses to different bacterial and viral pathogens. This study is the first to link changes in the protein to vertical HIV trans-mission. De Rossi said that the results con-firmed the relevance of innate immunity in perinatal HIV-1 infection, knowledge which-may be valuable in the development of new therapeutic strategies including the use the specific adjuvants.http://www.translational-medicine.com/

Genetic markers of adult obesity risk are associated with infancy weight gain and growth

In research pub-lished recently in PLoS Medicine, Ken Ong of Adden-brooke’s Hospital, Cambridge, and colleagues show an association between

greater early-infancy gains in weight and length and genetic markers for adult obesity risk. The proportion of overweight and obese

children is increasing across the globe. World-wide, 22 million children under five years old are considered by the World Health Organi-sation to be overweight. The authors suggest that weight gain and growth even in the first few weeks after birth may be the beginning of a pathway of greater adult obesity risk. How-ever, this research does not provide advice for parents on how to reduce their children’s obes-ity risk. It does suggest that ‘’failure to thrive’’ in the first six weeks of life is not simply due to a lack of provision of food by the baby’s caregiver but that genetic factors also contribute to early weight gain and growth.http://tinyurl.com/352u7af

Stem cell disruption induces craniosynostosisIn a study lead by Dr Wei Hsu, scientists at the University of Rochester Medical Center, USA have discovered a defect in cellular pathways of mice that provides a new explanation for the earliest stages of abnormal skull develop-ment in newborns, namely craniosynostosis. Mutations of the WNT and FGF signalling pathways set off a cascade of events that reg-ulate bone formation at the stem cell level, according to the article, published recently in Science Signaling. Abnormal head shape due to craniosynostosis affects about one in 2,500 individuals. It can restrict normal brain growth and result in neurodevelopment delays and elevated intracranial pressure. The chief cause, which is already known, is a defect in osteoblasts, but until now scientists did not know about a second mechanism for craniosynostosis, a result of a disruption of stem cells. Eight bones make up the cranium. Initially these individual plates of skull bone are sepa-rated by sutures. In humans the bone plates gradually fuse together, starting at birth and ending in the 30s. Two key events take place during the first 18 months of life that are critical to the proper formation of bone. The first, namely intramembranous ossification, is responsible for final development of the skull bones, jaw-bones and collarbones. The other process, namely endochondral ossification, controls development of the long bones in the body. During intramembranous ossification a type of stem cell – the mesenchymal cell – must transform into bone-forming osteoblast cells, which deposit the bone matrix. The majority of bone is made after the matrix hardens and entraps the osteoblasts.Hsu’s group discovered that the WNT and FGF signalling pathways determine the fate of the mesenchymal stem cells, and when these pathways are altered, the mesenchymal cells change to chondrocytes and induce endochon-dral ossification instead of intramembranous ossification. As a result of this switch, the skull sutures close prematurely.

While endochrondal ossification is essential to the development of cartilage and long bones, it has not previously been shown to play a role in normal skull development. This research, implies that endochondral ossification can induce skull deformities. Alterations of the mesenchymal stem cells have also been associated with osteoarthri-tis, osteoporosis and osteoponia, and mutations in either the WNT or FGF pathways are often detected in skeletal disorders and cancer. http://tinyurl.com/38a6owl

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Optical coherence tomography assessment of in vivo vascular response after implantation of overlapping bare-metal and drug-eluting stents.A randomised trial was designed using opti-cal coherence tomography (OCT) to assess coverage and apposition of overlapping bare-metal stents (BMS) and drug-eluting stents (DES) in human coronary arteries. Overlap-ping DES impair healing in animals. Optical coherence tomography allows accurate in vivo assessment of stent strut coverage and appo-sition. Seventy-seven patients with long coro-nary stenoses were randomised to overlapping sirolimus-eluting stents (SES), paclitaxel-elut-ing stents (PES), zotarolimus-eluting stents (ZES) or BMS. The primary goal of the study was to determine the rate of uncovered/malap-posed struts in overlap versus nonoverlap seg-ments, according to stent type, at 6-month follow-up with OCT. A total of 53,047 struts were analysed. As assessed by OCT the impact of DES on vascular healing was similar at overlapping and nonoverlapping sites. How-ever, strut malapposition, coverage pattern and neointimal hyperplasia differ significantly according to DES type. Guagliumi G et al. ODESSA Trial Investigators. JACC Cardiovasc Interv. 2010 May; 3(5): 531-9.

Spontaneous left main coronary artery dissection and the role of intravascular ultrasonography.Spontaneous left main coronary artery (LMCA) dissection is a rare event with an unknown incidence and high risk of sudden cardiac death. The diagnosis of LMCA dis-section is often challenging, given the limi-tations of 2-dimensional angiography. The 3-dimensional perspective of intravascular ultrasonography (IVUS) is often indispensa-ble in confirming or excluding the diagnosis

of spontaneous LMCA dissection. Two cases of spontaneous LMCA dissection with unique angiographic presentations are reported in this paper wherein IVUS was essential in defining the extent of LMCA involvement and facilitated the subsequent referral for emergent coronary artery bypass grafting. The two patients presented with acute coronary syndrome prompting coronary angiogra-phy, which was notable for an unusual angi-ographic appearance of the LMCA. Intravas-cular ultrasonography was performed in each case, revealing spontaneous LMCA dissection, enabling prompt diagnosis and facilitating definitive surgical intervention. Klein AJ et al. J Ultrasound Med. 2010 Jun; 29(6): 981-8.

Intravascular radiation therapy with a Re-188 liquid-filled balloon in patients with in-stent restenosis.This study evaluated the feasibility and safety of intravascular radiation therapy (IVRT) using a Re-188 filled balloon system in patients with in-stent stenosis. A total of 39 patients with in-stent restenosis were enrolled as the IVRT (22 patients) and control groups (17 patients) after a successful coronary angioplasty. For irradia-tion the angioplasty balloon was replaced by a noncompliant balloon of the same diameter, but 10 mm longer, with a proximal and distal radio-opaque marker to deliver the dose of 18 Gy at 1.0 mm depth from the surface of the bal-loon into the vessel wall. Angiographic follow-up was performed after 6 months. The length of the irradiated segment was between 9.14 and 22 mm and the diameter between 2.5 and 3 mm. In the IVRT group, two patients who did not receive antiplatelet therapy had myo-cardial infarction. Four patients who had pre-sented with stable angina earlier also had angi-ographically documented in-stent occlusion (two patients) and edge stenosis (two patients) of the target lesion and received angioplasty (18.1%). In the control group, three patients with recurrent angina and four asymptomatic patients had documented in-stent occlusion angiographically at 6 months and these seven patients underwent target lesion revasculari-zation (41.2%). The overall restenosis rate in the IVRT and control groups were 23.91 and 39.86%, respectively (P=0.013). No complica-tions were documented, except anginal pain and ST segment changes. The results indi-cate that the Re-188 liquid-filled balloon is feasible, safe and effective in patients with in-stent restenosis.Selcuk NA et al. Nucl Med Commun. 2010 May 20.

Doppler echo-cardiography in non-cardiac surgical

patients: does it improve outcomes?

Page 14

The changing paradigm of stress echo-cardiography:

risk stratification, prognosis and patient

outcomesPage 16

Getting to the heart of thingsPage 20

Bringing laboratory PT/INR testing standards to the Point-of-Care and

the homePage 22

June 2010


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Doppler-echocardiography is now generally accepted as an invaluable tool to assess cardiac compromised patients. All morphological and functional aspects of the cardiac chambers, including valves and the respective connec-tive tissue and major vessels, can be evaluated in a physiological approach. Furthermore, hemodynamic monitoring, revealing ventricu-lar function, insufficient preload or excessive afterloading conditions [1], may often be fine-tuned utilising Doppler echocardiography [2]. In mechanically ventilated ICU patients, the non-invasive transthoracic mode is often the preferred technique of choice.

Nevertheless, the transoesophageal approach is ideal, with much better visualisation possibili-ties. Although the transoesophageal approach is somewhat more invasive, it remains a safe technique. Recent, still unpublished, guide-lines from the European Society of Intensive Care Medicine strongly suggest only to use this technique with an advanced level of training in echocardiography.

Modern medicine is driven by endpoints and goals. Most often the outcome and length of stay in the ICU and in the hospital are part of these. A summary of the potential of Doppler-echocardiography to improve the outcome of critically ill patients is provided in this review.

From a morphological point of view, post-operative Doppler-echocardiography is par-ticularly useful in those patients with hemo-dynamic instability, high PEEP-ventilation, necessity of high doses of inotopic or vasopres-sor drugs, or any situation where inadequate perfusion is present, even with normal cardiac output. One look permits the evaluation of the function of both the left and right ventricles by combining different views. Furthermore, tis-sue Doppler imaging allows the assessment of regional or more global evaluation of the func-tion of these chambers [3,4]. The different tools

of Doppler-echocardiography provide insight into functional hemodynamics, in conjunction with other more invasively obtained data, on the condition that these data are integrated and interpreted by the human brain using a physio-logical approach. In this way, it is perfectly pos-sible to get information on systolic and diastolic function of the ventricles, the actual preloading conditions and even the afterload.

Echo-Doppler diagnostic toolThe unique combination of several echo-Doppler tools facilitates the correct interpre-tation of flows within a selected zone. These tools comprise: • two-dimensional imaging, offering insight

into morphology and function;• colour Doppler, exemplifying scattering and

directions of flows, within the selected area;• Doppler, providing information on direc-

tion, intensity and duration of flows. In addition the morphology of the Doppler pattern itself can provide indications of the pathology present;

• myocardial Doppler imaging, demonstrating the relative motion, direction and intensity of the investigated myocardial wall segment. In particular, this technique is useful when ana-lysing systolic and diastolic function of the left ventricle. Care should be taken that both systolic and diastolic characteristic Doppler waves are preload dependent.

The difficulty with Doppler-echocardiography concerns both acquiring the different images in conjunction with the correct interpreta-tion: both practical issues and knowledge must be combined to come to a correct evaluation [5]. Hence, correct interpretation can only be achieved when the physiological meaning is fully understood, applied and integrated with other data. This necessitates a prolonged learning curve, although the user need not be acquainted with all facets to permit a practical approach [6,7].

Immediate bedside hemodynamic informationPerforming a complete echocardiogram offers a full picture of the heart as cardiac muscle and the circulation pump. As with each other (invasive) hemodynamic monitoring tools, all tricks and flaws must be recognised to permit a comprehensive hemodynamic evaluation of a hemodynamically unstable patient.

In a hypotensive patient, a quick investigation of cardiac function at the level of the short axis view permits differentiation between a cardiac and a non-cardiac cause of hypotension [1]. A small left ventricle suggests hypovolemia [8] or a ventricle loaded with a high sympathomimetic intrinsic or extrinsic load [9,10]. In contrast, a dilated, barely contracting left ventricle needs inotropic support. Therefore, this initial short axis view and the cor-rect interpretation has a direct impact on bedside management and hence outcome.

The myocardial performance index (MPI) is a variable of both systolic and diastolic function [11], which is, however, load dependent. The fol-lowing formula allows calculation of this index:MPI = (ICT + IRT)/ET(ET, ejection time measured at the Doppler sig-nal of the aortic flow; ICT, isovolumic contrac-tion time; IRT, isovolumic relaxation time).Although this index has a prognostic power in cardiology practice, this index adds little infor-mation on the ICU patient in view of the load dependency. This was shown both in an animal experimental [12] and in a clinical [13] setting.

Another, more useful load-dependent variable is the systolic velocity of the mitral annulus, assessed with tissue Doppler imaging. Veloci-ties lower than 8 cm/s suggest decreased systo-lic function whereas velocities above 15 cm/s imply normal left ventricular systolic function. Both preload [4] and afterload [14] appear to have impact on the amplitude.

Rapid diagnosis of LV failure permits immedi-ate intervention, which is, indirectly, related to improved outcome [15,16].

Right ventricleA similar differentiation can be made with respect to the right ventricle. A normal right ventricle is depicted as a crescent-shaped struc-ture. A dilated right ventricle (i.e. right ventricu-lar diameter > 0,6 diameter of the left ventricle) suggests either right ventricular myocardial ischemia, or volume and/or pressure overload [1], with typical management approaches.

does it improve outcome?doppler echo-cardiography in non-cardiac surgical patients:

Echocardiography provides bedside and immediate insight in the post-operative iCU patient, whenever hemodynamic deterioration occurs. Both morphological and hemodynamic features can be diagnosed instantly and related to clinical practice. Furthermore, this tool is used as a functional hemodynamic monitoring device offering on line information on systolic function, preload and afterload of both the left and right sides of the heart.This review will provide an overview of the data available with respect to improving outcome utilising this particular technology. by dr Jan Poelaert

June 2010

15 June 2010

Assessment of flow across cardiac valves reveals transvalvular pressure gradients. Typically, a pressure gradient can be assessed from a tricus-pid regurgitant flow in order to calculate right ventricular systolic pressure (RVSP) correctly if right atrial pressure can be estimated [17,18].

The knowledge of the presence of a dilated right ventricle in conjunction with increase RVSP may also be important in the direct management of ventilator settings [19], optimisation of preload [20], or reduction of afterloading conditions [21-24], with indirect impact on outcome.

Myocardial ischemiaThe direct visualisation of the relative motion of the different wall segments provides an ideal window for detection of myocardial ischemia, on the condition that no other interfering factors occur and the regional wall motion abnormality is detected after previous normal motion of the segment in question. These two conditions suggest the difficulties which can be encountered when trying to detect myo-cardial ischemia with Doppler-echocardiog-raphy. Conversely, Doppler echocardiography is a perfect tool to confirm the localisation of an occluded coronary artery with respect to a malperfused myocardial region after a posi-tive ECG or ST segment monitoring, which alerted the clinician. Newer technologies are currently being developed utilising vector-related technology to allow early diagnosis of myocardial ischemia.

Preload and fluid responsivenessPreload is the first issue to be assessed whenever hypotension has to be managed, and has been related to improved outcome [25,26]. Clini-cally, the legs-up test is preferred for evaluating

optimal preloading conditions: it does no harm and provides immediate information about the filling status.

From a short axis view, the left ventricular end-diastolic area (LVEDA) < 5.5 cm² was shown to be associated with low preloading condi-tions. Although a purely static variable of load, the legs-up test brings this LVEDA as a truely dynamic descriptor of fluid responsiveness.

Other variables are used in conjunction with mechanical ventilation and they rely on the variation of intra-thoracic pressures with ventilation. Both inferior [27] and superior vena cava [28] variations with ventilation can be utilised. Care should be taken that these variables only provide insight into right ven-tricular preload. Acute right ventricular fail-ure in conjunction with a hyperdynamic left ventricle will be associated with an absence of ventilation-induced variation of the diam-eter. Commencing the echocardiographic investigation with the short axis view will already eliminate right ventricular dilata-tion. Variation of stroke volume exemplified by variations of the time-velocity-integral (TVI) will provide the same information [29], [Figure 1].

ConclusionsDoppler echocardiography provides immedi-ate insight into the morphological and hemo-dynamic functional aspects of cardiac and circulation-related issues. The most impor-tant advantage is that appropriate use leads to direct action depending on the findings, even with a limited number of views [30]. The adage ‘do not harm your patient’ can be followed by introducing the TTE tool in conjunction with

a really knowledgeable echocardiographer-intensivist. ICU clinicians responsible for the daily management of hemodynamically unstable patients should be convinced to uti-lise echocardiography as primary diagnostic and monitoring tool.

References1. Poelaert JI, Schupfer G. Chest 2005; 127: 379-3902. Vignon P et al. Crit Care 2007; 11: R433. Edvardsen T et al. Circulation 2002; 105: 2071-20774. Amà R et al. Anesthesia Analgesia 2004; 99: 332-85. Poelaert J, Mayo P. Intensive Care Med 20076. Cholley BP, Vieillard-Baron A, Mebazaa A. Intensive

Care Med 2006; 32: 9-107. Charron C et al. Intensive Care Med 2007;

33: 1712-88. Leung JM, Levine EH. Anesthesiology 1994;

81: 1102-99. Boden WE et al. Cathet Cardiovasc Diagn 1978; 4:

249-6310. Giacomin E et al. Cardiovasc Ultrasound 2008; 6: 911. Tei C et al. J Am Soc Echocardiogr 1997; 10: 169-7812. Haney MF et al. Acta Anaesthesiol Scand 2007; 51:

545-5213. Poelaert J et al. Acta Anaesthesiol Scand 2004; 48:

973-914. Borlaug BA et al. J Am Coll Cardiol 2007;

50: 1570-715. Faris R, Coats AJ, Henein MY. Am Heart J 2002;

144: 343-5016. Poelaert J, Roosens C. Crit Care 2007; 11: 16717. Sagie A et al. J Am Coll Cardiol 1994; 24: 446-5318. Yock P, Popp R. Circulation 1984; 70: 657-6219. Vieillard-Baron A et al. Am. J. Respir. Crit. Care

Med. 2002; 166: 1310-131920. Vieillard-Baron A et al. Am J Respir Crit Care Med

2003; 168: 671-621. Jardin F, Vieillard-Baron A. Intensive Care Med

2003; 29: 1426-3422. Schmitt J et al. Crit Care Med 2001; 29: 1154-115823. Poelaert J et al. . Chest 1993; 104: 214-924. Poelaert JI et al. J Cardiothorac Vasc Anesth 1992;

6: 438-4325. Feissel M et al. Intensive Care Med 2004; 30:

1834-726. Michard F, Teboul JL. Crit Care 2000; 4: 282-927. Barbier C et al. Intensive Care Med 2004; 30:

1740-628. Vieillard-Baron A et al. Anesthesiology 2001; 95:

1083-829. Slama M et al. Am J Physiol Heart Circ Physiol 2002;

283: H1729-3330. Beaulieu Y. Crit Care Med 2007; 35: S144-9

The authorJan Poelaert, MD, PhDDepartment of Anesthesiology and Perioperative MedicineAcute and Chronic PaintherapyUZ Brussel, VUBLaarbeeklaan 1011090 BrusselsBelgiumFigure 1. Systolic ventilation induced variation of flow, assessed at the level of the aortic valve.

16 CArdioLoGy

Stress echocardiography was first introduced in 1979 and represents the natural merger of car-diovascular stress testing with two-dimensional echocardiography. The rationale for its use is that either physical exercise (treadmill or bicy-cle) or pharmacologic (dobutamine or dipyri-damole/adenosine) stress will result in ischemia. Myocardial ischemia is manifested as a regional wall motion abnormality, which then serves as a marker for the location, severity and extent of obstructive coronary stenoses. The applications of stress echocardiography have broadened sub-stantially since its introduction as a diagnostic test for CAD. Primarily, the expanded applications of stress echocardiography relate to its prognostic efficacy and influence on clinical outcomes.

Table 1 summarises the different variables, important in identifying risk and predicting prognosis, which will be discussed in detail in the following sections.

Risk stratification and prognosis in patients with known or suspected ischemic heart disease.An important objective of noninvasive test-ing is to identify patients at risk for future cardiac events. The application of prognostic testing is based on the premise that in patients identified as being at highest risk for adverse outcomes, there can be intervention to alter the natural history of their disease process, thereby reducing subsequent risk.

We and others have demonstrated that the pres-ence of normal wall motion (peak wall motion score index, WMSI = 1.0) during stress echocar-diography confers a benign prognosis [1]. These low risk patients generally only require counseling in regard to risk factor modification.

Patients with mild to moderate wall motion abnormalities (peak WMSI = 1.1-1.7) have an intermediate risk of cardiac events. The ideal management strategy for these patients is unclear. Rather than an invasive management approach of catheterisation and revascularisation with its inherent risks, patients with an intermediate risk of cardiac events may, perhaps, experience low-ering of their risk for future cardiac events by aggressive risk factor modification, and referral

to catheterisation only for refractory symptoms. In addition, resting Ejection Fraction (EF) should have an important influence on the appropriate management approach in such patients. An initial noninvasive management strategy may be cost-effective and avoid unnecessary invasive proce-dures. Conversely, high risk patients with WMSI >1.7 and especially those with EF ≤45% are at a significant risk of cardiac events [Figure 1]. Such high risk patients should be appropriately referred for consideration of cardiac catheterisation and potential coronary revascularisation in order to modify and reduce their cardiac risk.

Extent and severity of myocardial wall motion abnormality as predictors of prognosis. The prognostic utility of stress echocardi-ography derives from its ability to quantify the magnitude of “jeopardised” (i.e. poten-tially ischemic) myocardium during exercise or pharmacologic stress testing. Specifically, stress echocardiography measures two indices of ischemia: a) ischemic extent and b) maxi-mal severity. Ischemic extent reflects the area of myocardium (number of segments) that is abnormal, whereas maximal severity reflects the maximal magnitude of abnormal wall motion within a designated segment, both quantified at peak stress. Ischemic extent reflects the number of new stress-induced wall motion abnormali-ties, and corresponds roughly to the number of stenosed coronary arteries. Maximal sever-ity reflects the magnitude of ischemia within a designated myocardial segment and reflects the severity of a subtending coronary stenosis within a given coronary artery vascular terri-tory. Estimation of both ischemic extent and maximal severity variables by stress echocar-diography provides a functional depiction of a

risk stratification, prognosis and patient outcomesThe changing paradigm of stress echocardiography:

stress echocardiography has evolved considerably over the last three decades. The prognostic value of stress echocardiography is now well established, with the ability to risk-stratify patients into low (<1%), intermediate (1-5%) or high (>5%) risk groups. This article addresses the current role of stress echocardiography in stratifying risk, its influence on patient outcome and management decisions.

by dr s. s. yao, dr s. Bangalore, dr X. Zhang, & dr F. A. Chaudhry

June 2010

Table 1. Stress echocardiography variables important in identifying risk and predicting prognosis.

Abbreviations: LV = left ventricular; %MPHR = percent maximum predicted-heart rate; TID = transient ischemic cavity dilation; WMSI = wall motion

score index.

Achieved heart rate (%MPHR) / Heart rate reserve (exercise stress)

Heart rate when wall motion abnormality first seen (pharmacologic stress)

Resting left ventricular ejection fraction

Extent and severity of new wall motion abnormalities

Multi-vessel disease pattern (peak WMSI>1.7)

Transient ischemic LV cavity dilatation (TID)

Left atrial size

Right ventricular wall motion abnormalities

Figure 1. Cardiac event rate per year as a function of wall motion score index. The number of patients within each wall motion score index category is shown underneath each column (left). Statistical significance

increases as a function of wall motion score index result (right).

Two scenarios, one solution The Alere INRatio®2 PT/INR system provides a simple, reliable and practical point of care solution to improving the clinical effectiveness of Oral Anticoagulation Therapy. Healthcare Professionals can see results in seconds, allowing for immediate face to face dose adjustments in one appointment. Our system is so easy to use it can also empower patients to self-monitor their therapy in the comfort of their own home. Home testing with Alere INRatio®2 allows for more frequent testing which has been proven to increase time in therapeutic range and reduce the risk of clinical complications.1

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Alere INRatio®2 PT/INR Monitoring System

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“noninvasive” coronary angiogram, and accu-rate prognostic assessment of the amount of jeopardised myocardium.

We have demonstrated that prognostic risk stratification by stress echocardiography can be established using both separate and com-bined functions of the extent and severity of wall motion abnormalities [2]. Ideally, a con-tinuum of risk can be defined based upon varying degrees of extent and severity of wall motion abnormalities. Stable patients with nor-mal stress echocardiography or those with mild and non-extensive wall motion abnormalities (single vessel CAD or mild ischemia) are at low (<1%/year) to intermediate (1-5%/year) car-diac risk, and may be considered for an initial strategy of aggressive risk factor modification and optimal medical therapy.

On the contrary, patients manifesting severe and/or extensive stress-induced wall motion abnormalities are at intermediate-high car-diac risk (>4%/year) and should warrant con-sideration for referral to catheterisation and potential coronary revascularisation in order to modify and reduce their risk [Figure 2]. Moreover, a prognostic model of risk stratifica-tion is important since a defined threshold for aggressive management can be applied indi-vidually according to a given patient’s clinical characteristics and other co morbidities.

Prediction of MI vs cardiac death by stress echocardiography.Stress echocardiography is an effective tech-nique for differential risk stratification of patients for the outcome specific endpoints of cardiac death and non-fatal myocardial inf-arction (MI) [3]. Patients with EF <30% are at very high risk of cardiac death (>4%/year) and

these patients should be managed actively with aggressive medical management, assessment of viability, revascularisation if needed and early consideration of device therapy and cardiac resynchronisation therapy. In patients with EF ≥30%, peak wall motion score index can fur-ther risk-stratify this subgroup. There are three risk categories, namely a high-intermediate risk group (WMSI >1.7) (cardiac death rate 2.5-4%/year) who may benefit from aggressive medical management and consideration for revascular-isation; a low-intermediate risk group (WMSI 1.1-1.7) (cardiac death rate 1.0-2.5%/year) may benefit from aggressive medical man-agement and consideration for revascularisa-tion for symptom relief only. Finally there is a low-risk group (WMSI 1.0) (cardiac death rate

<1.0%/year) who may benefit from risk factor modification [Figure 3].

Impact of stress echocardiography on patient outcome Stress echocardiography is now an established technique for diagnosis, risk stratification and prognosis of patients with known or suspected coronary artery disease. However, the impact of stress echocardiography on patient outcomes and coronary revascularisation was previously unclear. In our study, we assessed 3121 patients (60 ± 13 years, 48% male) undergoing stress echocardiography (41% treadmill, 59% dob-utamine) [4]. Follow-up data were obtained (2.8 ± 1.1 years) for subsequent coronary angiography, revascularisation: percutaneous coronary intervention (PCI) or coronary artery bypass surgery (CABG), and confirmed hard events: non-fatal myocardial infarction (n = 76) or cardiac death (n = 83). Stress echocar-diography studies were normal (pWMSI = 1.0) in 66% and abnormal (pWMSI >1.0) in 34% of patients. Early coronary angiography (30 days following stress echocardiography) was performed in only 35 patients (1.7%) with nor-mal stress echocardiography and 267 patients (25.5%) with abnormal stress echocardiogra-phy (p<0.0001). Late coronary revascularisa-tion (2 years following stress echocardiogra-phy, PCI% or CABG%) occurred in 80 patients (2.8%, 1.1%) with pWMSI = 1.0, 123 patients (13.5%, 7.3%) with pWMSI = 1.1-1.7 and 102 patients (12.7%, 9.6%) with pWMSI >1.7 [Fig-ure 4]. Multivariate logistic regression analysis identified pWMSI as the strongest predictor of coronary angiography (RR 2.04, 95% CI 1.67-2.5), revascularisation (RR 1.91, 95% CI 1.68-2.17) and cardiac events (RR 2.45, 95% CI 2.09-2.88). All data were statistically significant

18 CArdioLoGy June 2010

Figure 2. Cumulative effect of ischemic extent and maximal severity (jeopardised myocardium) of wall motion abnormalities on event rate/year. Event rate increases as a curvilinear function of both extent

and severity combined.

Figure 3. Schematic for the risk stratification of patients undergoing stress echocardiography. CD, Cardiac death; CRT, cardiac resynchronisation therapy; EF, ejection fraction.

19

p <0.0001. Patients with markedly abnormal stress echocardiography (pWMSI >1.7) had a significantly higher cardiac event rate than those who did not undergo coronary revascu-larisation (9.6%/year vs. 2.9%/year, p < 0.05). Stress echocardiography is an effective gate-keeper for coronary angiography and revascu-larisation. A normal stress echocardiography study (pWMSI = 1.0) confers a benign prog-nosis (0.8%/year), and is associated with a low rate of early coronary angiography (1.7%) and late revascularisation (2.8% PCI, 1.1% CABG). Stress echocardiography impacts clinical deci-sion making in higher risk patients (pWMSI ≥1.1) with significantly increased coronary angiography, PCI and CABG rates. Patients with markedly abnormal stress echocardiogra-phy (pWMSI >1.7) were most likely to benefit from coronary revascularisation.

Conclusions Stress echocardiography has evolved during the past 30 years to become a mainstay in the diagnostic and prognostic armamentarium of clinical cardiologists. Stress echocardiography provides diagnostic and prognostic informa-tion in a broad range of patient subsets and plays an integral role in the management of patients with known or suspected CAD. Stress echocardiography has demonstrated significant incremental prognostic value when added to clinical and adjuvant testing information. Stress echocardiography is an essential tool in defining cardiac risk and in identifying patients who are most likely to benefit from additional invasive diagnostic testing. Stress echocardiography sig-nificantly influences clinical patient outcomes while impacting clinical decision making and use of limited cardiology resources.

Future developments In stress echocardiography future develop-ments are likely to be targeted at refinements in methodology and quantitation in order to increase reproducibility of interpretation, decrease subjectivity and improve accuracy.

These potential enhancements include the incorporation of myocardial strain, strain rate imaging, tissue Doppler and 3D/4D imaging. Furthermore, advances in myocardial con-trast echocardiography would ideally allow the simultaneous evaluation of myocardial function and perfusion.

References1. Yao S, Qureshi E, Sherrid MV, Chaudhry FA.

Practical applications in stress echocardiography: risk stratification and prognosis in patients with known or suspected ischemic heart disease. J Am Coll Cardiol 2003; 42: 1084-1090.

2. Yao S, Qureshi E, Syed A, Chaudhry FA. Novel stress echocardiographic model incorporating the

extent and severity of wall motion abnormality for risk stratification and prognosis. Am J Cardiol 2004; 94(6): 715-719.

3. Bangalore S, Yao S, Chaudhry FA. Prediction of myocardial infarction versus cardiac death by stress echocardiography. J Am Soc Echocardiogr 2009; 22(3): 261-7.

4. Yao S, Bangalore S, Shah A, Silva-Encisco J, Chaudhry FA. Impact of Stress Echocardiog-raphy on Patient Outcome: An Effective Gate-keeper for Coronary Angiography. Circulation 2008; 118S849 (abst).

The authors Siu-Sun Yao, MD, FASE, Sripal Bangalore, MD, Xiaoqian Zhang, MD, Farooq A. Chaudhry, MD, FASE

Department of Medicine, Division of Cardiology, St. Luke’s-Roosevelt Hospital Center, Columbia University College of Physicians and Surgeons, New York, NY, USA

Contact address: Farooq A. Chaudhry, MD, St. Luke’s-Roosevelt Hospital Center, Division of Cardiology, 1111 Amsterdam Avenue, New York, NY 10025. Tel (212) 523-4298. Fax (212) 523-5989. E-mail [email protected]

June 2010

Figure 4. Left: coronary angiography rate per year as a function of wall motion score index. The number of patients within each wall motion score index category is shown underneath each column. Right: coronary

revascularisation rate per year as a function of wall motion score index. The number of patients within each category is indicated below each column.

2 .

1 3 .

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Cardiology: Clinical Cases Uncoveredby Tim Betts, Jeremy Dwight, Sacha BullPub. by Wiley-Blackwell February 2010,256 pages, 28.80 e

Cardiology: Clinical Cases Uncovered is the ideal integrated text that helps in the recognition, understanding, investi-gation and management of many heart-related disorders and conditions. Written by three practising cardiologists, it uses a clinical approach to management problems with the help of 26 real-world cardiovascular cases. There is strong emphasis on high-quality figures, particularly 12-lead ECGs, as these play such a major role in the evaluation of the cardiac patient. Following a question-answer approach throughout the nar-rative, with self-assessment MCQs, EMQs and SAQs, the book includes sections on cardiac anatomy, physiology and pathology, which provide the essentials required to understand clinical cardiology. The book is ideal for medical students and junior doctors on the Foun-dation Programme, specialist nurses and nurse practitioners, and in general for those with plans for a career in cardiology.

WIlEyHoboken, NJ, USA www.ihe-online.com & search 45603

BooK rEViEW

20

Some 14 million people in Europe currently suffer from heart failure with the number predicted to increase to no fewer than 30 million by 2020. The medical impact of heart failure is huge — in partic-ular, the condition is associated with high mortality. After the first incident of cardiac decompensation, as many as around 40 percent of patients will die within one year. Of those who survive the first year only one third will actually live longer than a fur-ther 5 years. In addition to such alarming medical statistics, the social impact of heart failure is also significant and is understandably associated with immense costs, which put an additional financial strain on already tight healthcare budgets.

For all these reasons, the early detection and adequate treatment of cardiac diseases is of the greatest importance, since this is the only way to prevent subsequent damage to the myocar-dium and to avoid permanent limitations on the quality of life of the patient.

The latest developments in imaging and in vitro diagnostics offer new opportunities for

detecting heart failure not only much earlier but also with great precision.

Echocardiography: from 2D to 4D Ultrasound examination of the heart, i.e. echocar-diography, is the basic imaging technology (and also the least expensive one) in cardiology, and, in the vast majority of patients, plays the role of a “Gatekeeper” controlling access to eventual addi-tional diagnostic procedures that may be needed. The latest echocardiography systems now enable real-time three-dimensional images of the beat-ing heart so that the heart can be imaged as a whole organ easily and rapidly, and not just in 2D images, but in full volumes. The latest echocardi-ography systems can display and analyze the heart in full after a single heartbeat. Such echocardiog-raphy results are the prerequisite for other, more expensive examinations, which may be necessary. Echocardiography is widely available in hospi-tals and in nearly all cardiology practices, while newer imaging technologies such as cardiac CT or MRI, which may be indicated for further diag-nostic investigation are in general found mostly in larger facilities.

The heart in the magnet: cardiac MRIOne of the most recent imaging techniques being used to analyze the heart is magnetic resonance imaging (MRI), which, in addition to the fact that it does not involve the use of ionizing radia-tion, in contrast to CT, provides a comprehensive (and highly accurate) assessment of the heart. Cardiac magnetic resonance imaging (CMR) can also yield penetrating insights into the underly-ing pathology of a failing heart. Known as the gold standard for the assessment of cardiac func-tion, cardiac MRI is used as the most accurate non-invasive tool to measure parameters like ejec-tion fraction, based on which patients may get a drug therapy alone or even devices implanted (such as pacemakers or defibrillators). CMR also provides a special imaging approach for the visu-alization of even the smallest scars in the myo-cardium [Figure 1], which is important since the presence and extent of myocardial scarring

is a major risk factor for sudden cardiac death [Ref. 1]. It has been shown in many recent clini-cal studies, that CMR allows accurate assessment of myocardial scar formation with extremely high diagnostic accuracy. CMR is the best non-invasive approach to address this important clinical ques-tion [Ref. 2]. For this reason, a growing number of cardiologists are using the procedure to identify patients with severe heart failure who are in need of an implantable defibrillator, which protects against cardiac arrest through targeted shock delivery.Until recently, because of the high magnetic fields used in the technique, CMR was contraindicated in patients with pacemakers. Thanks to coopera-tive development between the manufacturers of MRI systems on the one hand and pacemaker devices on the other, MRI-conditional pacemak-ers* are beginning to become available (e.g. from Medtronic). Since MRI scanners may cause tra-ditional pacemakers to misinterpret MRI-gener-ated electrical noise and withhold pacing therapy or deliver unnecessary pacing therapy, the new generation of pacemakers include features that set the device into an appropriate mode for the MRI environment. Such pacemakers also include hardware modifications to the device and leads that are designed to reduce or eliminate the influ-ence of the MRI environment.At the practical level, MR examinations of the heart are no longer complicated or time-consum-ing. In general, a CMR examination for the evalu-ation of cardiac anatomy, function and scarring can now be carried out within 20 minutes.

Coronary vessels in view: cardiac CTComputed tomography (CT) has long had a valuable role in early disease detection over the years. Steady technological development over the years means that the latest generation of CT scanners can now carry out coronary CT angiography (CTA) with significantly reduced radiation dose [Figure 2]. The most recent inno-vation, namely the use of ECG-triggered high-pitch spiral data acquisition using dual source CT as implemented in the Definition Flash sys-tem from Siemens can carry out CTAs at radia-tion doses as low as below 1 mSv, which is less than in conventional coronary angiography. [Ref. 3] (By comparison, one mSv is less than half of the annual natural background radia-tion on earth, to which everyone is exposed).

Getting to the heart of things Not only is heart failure one of the single biggest causes of morbidity and mortality in man, but the incidence of the condition is steadily increasing. rising to this chal-lenge, innovative medical diagnostic techniques with ever greater performance are constantly being introduced so that early, unambiguous detection of the underlying condition is now possible, enabling the prompt initiation of targetted therapies. This article presents a brief review of the most relevant diagnostic techniques, their current status and their indications. By o. Ekinci, M.d.

Figure 1. Cardiovascular MRI provides a 40-fold higher voxel resolution when compared to the current

standard of myocardial scintigraphy and allows unprecedented visualization of even smallest areas of scar in the myocardium. The short axis image above shows contrast enhancement (white area) in the infe-

rior wall caused by myocardial infarction. Image source: Okan Ekinci, DKD Wiesbaden

June 2010 CArdioLoGy

* “MR-conditional” is a term used to indicate that a device may be used in the MRI environment under certain conditions, such as a particular type of MRI

scanner and scanner settings.

O. Ekinci, MD.

21 June 2010

Unlike a cardiac catheter examination, CT can not only visualize the coronary lumen, but also display deposits (plaque) in the coronary wall. The calcium load of the coronary vessels (known as the Calcium Score) can be quantified in CT without the use of contrast agent. An age-adapted increased calcium load of the coronary arteries is as much a risk factor as smoking or increased cholesterol. Recent studies have shown that high Calcium Score can modify predicted risk obtained from traditional risk strati-fication tools (e.g. Framingham Risk Score) alone, especially among patients in the intermediate risk category in whom clinical decision making is most uncertain [Ref. 4]. In practice, using the latest tech-nology coronary CT examinations can be carried out in less than a second and are therefore espe-cially useful in patients with cardiac arrhythmias and older patients since the short time-span means that the patients can breathe normally [Figure 3]. The procedure is also optimal and time-efficient for the physician, since now a single mouse click generates a meaningful image, where previously lengthy image processing was necessary.

Of course, such innovations inevitably have their price. However, it is important to realize that the appropriate use of these new technologies may save overall health care expenditure over the long term: thanks to better diagnostics, treat-ment can be initiated much sooner. As a conse-quence, quality of life can be preserved and loss of productivity avoided.

Minimally invasive therapy: intervention instead of surgery Some underlying diseases of heart failure — such as severe valvular disease — often require therapeutic interventions beyond drug therapy involving cardiologists and surgeons at the same time. The cardiac cath. lab of the future is already being implemented in some centers in the so-called Hybrid-ORs which, by bringing together the features of the surgical room with those of a cath lab, make possible innovative therapies, such as in the treatment of severe aortic valve steno-sis. Until now, valve replacement by open-heart surgery was the recommended therapy approach in these cases, but in many elderly patients with concomitant diseases this can be too risky. Inter-ventional implantation of an aortic valve pros-thesis has become an alternative in such patients, and can give rise to rapid improvement of cardiac parameters. In this procedure the valve pros-thesis is placed via the femoral artery or, if this is not possible, by a small incision in the apex of the heart. Such a ‘minimally invasive’ interven-tion puts much less stress on the patient, than an open heart operation. Overall, providing techni-cal equipment needed to accommodate multiple specialties in one lab may allow for better quality of care as well as better time and cost efficiency, both for the patient and the institution.

Drop by drop to diagnosis: biomarkersThe presence and course of heart failure can also be assessed using in vitro lab tests, through the use of new biomarkers which, especially

in emergency care, can influence and support clinical decisions. In heart failure the use of circulating B-Natriuretic peptide (BNP) is particularly relevant, since the level of this biomarker is a good indicator of the degree to which the cardiac function is impaired. BNP is used both for initial diagnosis and for ther-apy monitoring. Recent studies have shown that in the presence of other risk factors and known HF, BNP has also a prognostic value, i.e. patients with BNP above a certain level will be candidates for more aggressive risk management [Ref. 5].In many patients, a heart attack is the direct cause of cardiac insufficiency, so fast detec-tion of a myocardial infarction (MI) is extremely important in order to prevent severe myocardial damage and subsequent heart failure. To do this, more and more emergency rooms routinely use high sensi-tive troponin I tests as an early and precise indicator of MI [Ref. 6]. Significant time can be saved in this way so that the recom-mended therapy, such as the reopening of the occluded coronary artery by cardiac cathe-terization can be initiated immediately. Since, for every second that the coronary artery remains occluded muscle cells will die (in the classical dictum “time is muscle”) rapid intervention is of course vital.

References 1. Assomull et al. Cardiovascular Magnetic Reso-

nance, Fibrosis, and Prognosis in Dilated Cardio-myopathy. J Am Coll Cardiol 2006; 48: 1977-85.

2. Kim HW et al. Cardiovascular magnetic reso-nance in patients with myocardial infarction: cur-rent and emerging applications. J Am Coll Cardiol 2009 Dec 29;55(1):1-16

3. Achenbach et. al. Coronary computed tomography angiography with a consistent dose below 1 mSv using prospectively electrocardiogram-triggered high-pitch spiral acquisition. Eur Heart J. 2010 Feb;31(3):340-6

4. Polonsky TS et al. Coronary artery calcium score and risk classification for coronary heart disease prediction. JAMA 2010 Apr 28;303(16):1610-6.

5. McKie et al. The Prognostic Value of N-Termi-nal Pro–B-Type Natriuretic Peptide for Death and Cardiovascular Events in Healthy Normal and Stage A/B Heart Failure Subjects. J Am Coll Cardiol. 2010;55:2140–7.

6. Bonaca M et al. Prospective Evaluation of the Prognostic Implications of Improved Assay Per-formance With a Sensitive Assay for Cardiac Troponin I. J Am Coll Cardiol. 2010;55:2118–24

The authorA cardiologist by training, Okan Ekinci, M.D.,is a Cardiac Imaging Expert and Lecturer for Cardiovascular MRI at the Medical University of Vienna (Austria) and University College Dublin (Ireland).Contact: [email protected]

Figure 3. CTA image acquisition can be carried out in less than a second today, making breath-holding unnecessary. Even patients with arrhythmia can now be imaged as all data are captured within a single

heart-beat. Image courtesy of Erasmus Medical Center Rotterdam, NL.

Figure 2. The introduction of technological advances over the years has resulted in a steady decrease in the amount of ionizing radiation to which the patient is exposed in cardiac CT examinations. The above graph

shows dose levels of the multi-center multi-vendor PROTECTION I study involving 50 sites and 1965 coronary CTA exams (data from Hausleiter et al, JAMA 2009;30:500). The bars reflect the mean eff. radiation dose at each of the sites respectively. Most scanners on the market still require a mean effective dose between 6 and 37 mSv, whereas the most recent generation of scanners with high-pitch spiral scanning can perform at mean

doses of 1 mSv - a new benchmark (Flash, dotted line).

……Eff. dose of novelhigh-pitch spiral

imaging (<1 mSv)

Modified from:

22 CArdioLoGy

Warfarin is a commonly used medication for oral anticoagulant therapy (OAT) in patients predisposed to thromboembolism or thrombo-sis due to atrial fibrillation (AFIB), mechanical heart valve replacement or congenital throm-bophilia. Warfarin is a coumarin-based vitamin K antagonist, which decreases blood coagulation by inhibiting the enzyme vitamin K epoxide reductase. This enzyme recycles oxidised vitamin K to its reduced form after it has participated in the carboxylation of several blood coagulation proteins, mainly prothrombin and factor VI.

Patients taking warfarin require regular moni-toring using Prothrombin Time (PT) tests. PT and the derived International Normalised Ratio [INR] are measurements of the extrinsic pathway of coagulation and are used to deter-mine the clotting of blood, thus measuring the clinical effectiveness of OAT.

Warfarin is, unfortunately, a less-than-ideal medication due to its narrow therapeutic

window; it has a wide variability of responses from patient to patient due to metabolic rate, pharmacodynamics, lifestyle, compliance and its sensitivity to diet and drugs. These factors can markedly increase or decrease the level of effective anticoagulation for any given dose. As a result, patients treated with Warfarin have always been forced to not only comply with a difficult dosage regimen, but also undergo PT/INR testing, which can vary from as often as once a week to once every couple of months, to ensure that their regimen is adequate. Regular monitoring is required to minimise the risk of a thromboembolic event resulting from inad-equate anticoagulation, as well as the risk of bleeding due to overanticoagulation [1]. An INR result of less than 2 increases the risk of thromboembolism whilst an INR of more than 4.5 increases the risk of bleeding.

Typically, patients on OAT are required to have a venous blood sample taken on each appoint-ment at their local clinic, hospital or anticoag-ulation clinic. This sample is then sent to the laboratory for analysis. The PT/INR results are provided to the clinician and then telephoned to the patient, at which point they are given their daily dose regime. This process is not ideal as there are delays with reporting, it is time-consuming and costly for both the patient and healthcare professional.

Point-of-care testingOne way to improve the management of OAT, especially for those patients on chronic long-term warfarin therapy, is through the use of handheld point-of-care (POC) testing devices, such as the INRatio2 platform from Alere. Such devices allow lab-accurate INR/PT test

results to be generated in just 60 seconds dur-ing a clinic appointment. A small volume of fresh capillary whole blood obtained from a finger stick (as low as 10µL) placed on a disposable test strip that is inserted into the device provides results that are clearly visible on a digital display.

POC testing of INR/PT can eliminate the draw-backs associated with a centralised laboratory approach. The quicker turnaround means that results are not only available at a single patient visit, but enables patients and clinicians to engage in face-to-face testing and consultation of treatment regimes.

Clinicians and health authorities can also ben-efit from a reduction in short and long term healthcare expenditure as patients remain in the therapeutic range for longer, improving the clinical effectiveness of OAT, and have less side-effects from therapy. Hospital readmissions and treatment costs are significantly reduced, while a quicker turnaround of results requires fewer resources and simplifies workflow. Research has demonstrated, from the perspective of the healthcare provider, that a care model which utilises POC PT/INR testing devices would provide a cost-effective alternative to more tra-ditional care requiring venous blood sampling and laboratory analysis [2].

Home testing There are two recognised methods of home testing and monitoring of PT/INR:

1) Patient self-testing (PST). With PST, patients measure their own PT/INR with a home test-ing device and transmit the results to their clinician, often by telephone or via an online system. The clinician then determines the appropriate OAT dosage and provides instruc-tions to the patient on how to proceed.

2) Patient self-management (PSM). Using a home testing device, patients following PSM are able to measure their own PT/INR and, using an agreed protocol, interpret the results and adjust their OAT dosage themselves.

Local healthcare policy often determines whether it is the patient or their clinician who interprets the results and determines the dose of medication. For example, in Germany patients may adjust the medication dose themselves,

Bringing laboratory PT/iNr testing standards to point-of-care and the home

Two scenarios, one solution

oral anticoagulation therapy (oAT) is one of the most common medication regi-mens, with warfarin being by far the most frequently used drug. its narrow thera-peutic range however means that there is a risk on the one hand of bleeding caused by excess drug or, on the other hand, of thrombosis when there is subop-timal anticoagulation. Laboratory monitoring of oAT using prothrombin time (PT) tests is vital. one way to improve the management of oAT, especially for those patients on chronic long-term warfarin therapy, is through the use of handheld point-of-care (PoC) testing devices. This article describes such a system for the monitoring of PT/iNr.

by Evette duncan

June 2010

There is a risk of a thromboembolic event from inadequate anticoagulation unless warfarin therapy is

monitored regularly.

23 June 2010

while in the UK and the USA, this remains in the hands of a healthcare professional. Home testing however, is not suitable for every patient and selected patients must participate in a structured educational programme [1]. Patients must be able to understand and show compe-tency in the testing procedure, in addition to demonstrating a basic theoretical knowledge of blood coagulation, PT/INR interpretation and the adverse effects of over- or under-dosing. Documentation and results should always be communicated to healthcare professionals [1].

Devices such as the INRatio2 system can empower patients to become more knowledge-able and look after their own condition. By pro-viding the freedom of home testing, patients require fewer visits to specialist clinics saving time, money and improving the patient’s qual-ity of life. Home testing allows for more fre-quent PT/INR testing, proven to increase time in the therapeutic range [3], therefore reducing the risk of clinical complications.

Quality assured resultsThe INRatio2 monitoring device now has new heparin-insensitive test strips which have recently been CE marked. Heparin is a natu-rally occurring anticoagulant and is the most commonly used therapy for the initial man-agement of acute cardiovascular diseases prior to starting warfarin therapy. Due to its short half-life of one hour, heparin must be admin-istered regularly or as a continuous infusion. It is therefore only used until OAT with warfarin becomes effective, or in emergency and trauma situations. The heparin insensitivity of the INRatio2 monitoring system means that the management of OAT is improved, resulting in quicker initiation, stabilisation and bridging of warfarin therapy with overall cost saving.

It is important that POC monitoring devices offer high accuracy, precision and quality control (QC). The INRatio2 system utilises a unique 2-level quantitative on-board QC system and does not require any additional

control measures. The monitor uses the test strip’s 3-channel technology to perform the PT test and two QC tests (normal and therapeutic) simultaneously. This determines whether the controls are within range before the patient’s INR result is displayed. The unique technol-ogy of the INRatio strip enables the two QC tests to be performed alongside the test sample, following laboratory procedure and ensuring that accurate and reliable results are generated every time.

According to guidelines issued by the World Health Organisation (WHO), working throm-boplastins used in the prothrombin time (PT) test for the control of OAT must be calibrated against International Reference Preparations to determine the International Sensitivity Index (ISI) necessary to convert PT results into INR [4]. If correctly calibrated, results of tests from different testing devices are repro-ducible and comparable. The INRatio2 sys-tem adheres to these international standards by utilising a thromboplastin reagent with an ISI of 1.0.

SummaryPoint-of-care and home testing can significantly increase the time in the therapeutic range and improve a patient’s quality of life. Ultimately, devices such as the INRatio2 can improve the clinical effectiveness of OAT, preventing hospi-tal readmissions due to adverse complications and saving hospital expenditure and resources.

Healthcare professionals can now test and obtain results in 60 seconds, enabling them to immediately advise the patient in one appointment, thereby simplifying work-load, and saving time and resources. This saved time allows patients to have face-

to-face consultations with their healthcare professional, which can improve patient compliance and therefore increase the clinical effectiveness of OAT.

Patients can now be empowered to look after their own condition, as home testing allows for more frequent testing in the comfort of their own homes. This is proven to increase the time in the therapeutic range and results in fewer clinical complications. Waiting for results, venous blood sampling and regular clinic appointments are no longer necessary.

The Alere INRatio2 PT/INR monitoring system brings laboratory standards to point-of-care and the home

References1. Braun S, Spannagl M, Voller H. Patient self-test-

ing and self-management of oral anticoagula-tion. Anal Bioanal Chem 2009; 393:1463-1471

2. Lafata J et al. The Cost-Effectiveness of Dif-ferent Management Strategies for Patients on Chronic Warfarin Therapy. J Gen Intern Med 2000; 15(1): 31–37

3. Bernado A, Hahuber C, Horskotte D. Home pro-thrombin estimation. Thrombosis, embolism and bleeding 1992; 325-30

4. The World Health Organization. Regulation of in vitro diagnostic devices: Thromboplastin rea-gents. http://www.who.int/bloodproducts/ivd/thromboplastin_reagents/en/ (2010)

The authorEvette Duncan BScAlere International International Product [email protected] www.alere.com www.ihe-online.com & search 45602

The management of OAT, especially for those patients on chronic long term Warfarin therapy, is through the use of handheld point-of-care (POC) testing devices,

such as the INRatio2 platform from Alere.

MRI research highlights high-risk atherosclerotic plaque hidden in the vessel wallResearchers from the Boston University School of Medicine (BUSM), USA have shown that use of magnetic resonance imaging (MRI) in an ani-mal model can non-invasively identify danger-ous plaque. The findings, which appeared in the May issue of Circulation Cardiovascular Imag-ing, offer possible applications in the diagnosis and treatment of patients with atherosclerosis. Rupture of vulnerable atherosclerotic plaque, which often occurs without prior symptoms, is responsible for a substantial number of deaths and disabilities worldwide. Identification of atherosclerotic plaque with a high risk for disruption and thrombosis would allow pre-ventive therapy to be initiated before thrombi begin to clog arteries and cause stroke or MI. The BUSM researchers examined diagnostic

protocols in an animal (rabbit) model of human disease with procedures that never could have been applied to humans. Plaque disruption was stimulated at a precise time to allow MRI imag-ing before and after the rupture. According to researchers, plaque that was hidden within the vessel wall and pushing the vessel wall outward instead of occluding the lumen had a very high chance of forming a thrombus; plaque that caused vessel narrowing was almost always sta-ble, which could explain why the most danger-ous plaque generally escapes detection by X-ray angiography. The study finds accurate, non-inva-sive MRI can identify stable and unstable plaque. It also reports that enhanced gadolinium uptake, which is associated with histological findings of inflammation, tissue necrosis and the prolifera-tion of blood vessels in tissue not normally con-taining them, can predict dangerous plaque. http://www.bmc.org/

24 MEdiCAL iMAGiNG

It has been a long-held belief that combining an MRI scanner and a PET scanner would be technically impossible due to the incompat-ibility of the ultra-sensitive electronics of PET scanners with the powerful magnetic field generated by the MRI. Recent technological advances (see side-bar) have however now made such an integrated system a reality — the University Hospital of Geneva in Switzerland now houses Europe’s first combined full-body PET /MR system.

We performed the first scan in April 2010 and by the end of the April we had performed 25 patient examinations. Initially, we concentrated on oncology cases of patients originally sched-uled for a PET-CT study and we compared the results of the PET-MR studies with the PET-CT data. We believe the new combined PET-MRI technique will significantly improve our diag-nostic accuracy in areas where patients already undergo separate PET and MR studies as part of their workup such as in prostate cancers, breast cancer and head and neck cancers. Our early results show that bringing the two modalities together improves the quality and accuracy of diagnoses. The molecular imaging provided by

PET in conjunction with the anatomy and tis-sue characterisation of MRI will enable us to see the function and metabolism of tissue more precisely than ever before.

The clinical cases we have examined so far have already shown the advantages of being able to perfectly superimpose the PET over MRI images to detect lesions. Previously, this has not been possible because the two studies took place at different times, different conditions and different patient positions.

The results of the early cases examined so far by PET/MRI compare favourably with more traditional PET-CT studies performed in the same patients. PET-MR provided identical PET quality with the added value of perfectly matched MR images. These encouraging results confirm that both modalities function perfectly together and provide diagnostic quality results when used together in a hybrid system. The studies we performed so far showed that they benefitted from additional high definition MRI sequences providing soft tissue characterisa-tion that is not possible with CT images of traditional PET-CT scanners.

Europe’s first full-body PET/Mr systemscience-fiction becomes reality:

When the radiology department at the University Hospital of Geneva was approached in 2008 by a major international medical imaging company look-ing for a site to test its new imaging modality, it seemed like science fiction had become reality. The company had combined a magnetic resonance imaging (Mri) functionality with that of positron emission tomography (PET) into one single system capable of scanning the entire body. in this article Prof o. ratib describes the installation of Europe’s first PET/Mri at the University Hospital of Geneva and the early results that are being produced by the new system, its benefits as well as its future potential.

by Prof. o. ratib

Figure 1. Example of a whole body PET-CT and whole-body PET-MR acquired in a patient with lung metastases of a head and neck cancer.

June 2010

Osman Ratib is Professor and Head of Nuclear Medicine, as well as chair of the Department of Radiology at the University Hos-pital of Geneva, Switzerland. Dr Ratib is a board-certified cardiologist and radiologist who has gained an i n t e r n a t i o n a l reputation in the development of

computer-aided diagnosis in cardiac imag-ing and in the development of picture archiving and communication systems (PACS). He became one of the active figures in medical imaging research in Europe and is a member of several societies of com-puted radiology and telemedicine and the former president of the EuroPACS soci-ety. In July 1998 he moved to Los Ange-les where he was appointed as Professor and Vice Chairman of the Department of Radiology at University of California Los Angeles (UCLA). He was responsible for

coordinating the deployment of an enter-prise-wide strategy and infrastructure for image management and communication. In July 2005 he returned to Geneva to take the position of Head of Nuclear Medicine, responsible for new molecular and func-tional imaging techniques and, in particular, hybrid positron emission Tomography–computed tomography (PET-CT). His clini-cal activities and areas of expertise include cardiovascular magnetic resonance and CT imaging procedures, combined PET-CT imaging and advanced cardiovascular imag-ing. He obtained his medical degrees at the University of Geneva and a further degree in biophysics and a PhD in medical imaging from UCLA in 1989.

Osman Ratib, MD, PhD, FAHA, is Professor and Chief of Nuclear Medi-cine and chair of the

Department of Radiology at the University Hospital

of Geneva.

... The results of the early cases examined so far by PET/MRI compare favourably with more traditional PET-CT studies ...

25 June 2010

Advantages of combined PET/MRI for patientsThere are many immediate advantages for patients with the new system. Generally, patients receiving MRI and PET scans as part of their clinical work-up and follow-up undergo these two studies hours or even days apart, frequently requiring separate visits to the clinic. Now we can provide both studies and repeat scans, such as an MRI focus on areas identified in the PET scan, in one single visit. And for both patients and staff, MRI has the advantage of there being no exposure to ionising radiation, which is a particularly important benefit for our pediatric patients.

Combined PET/CT scanners have only been available in the past decade and they have already made a significant impact. However, we believe that PET/MR is the next quantum leap in imaging technology. Even though the PET/MR combination is promising for both cardi-ology and neurology applications, in Geneva we have decided to focus on the benefits it provides in oncology.

Although personalised medicine has been dis-cussed at symposia for years, PET/MR may help us close the gap between science fiction and reality by providing a means to track whether a drug is reaching a tumor and monitor on a cellular level whether it’s working and tailor the treatment plan for each patient accordingly.

Installation of the new systemDeveloping the combined PET/MRI sys-tem was certainly an exciting and challeng-ing project, but the work did not end with the development of the system itself. Like many hospitals, the University Hospitals of Geneva has infrastructure restrictions so it was diffi-cult to find a suitable and large enough space

within the hospital for the system or a way of transporting the new system to the hospital. In addition, construction of any new building to accommodate the new system could of course not disturb or interfere with the surrounding infrastructure of the hospital.

Fortunately, a small Swiss company was able to design a room-size container where the system was pre-installed. The unit was then transported directly to the hospital build-ing and the container positioned adjacent to the outside wall of the building. The only actual construction that was needed was a door between the building and the new container container.

Whole-body PET/MR in the US In parallel to the installation of the first PET/MRI in Europe in the University Hospital of Geneva, Switzerland, another combined sys-tem from Philips Healthcare was installed in the Translational and Molecular Imaging Institute (TMII) of the Mount Sinai Hospital in New York City, NY, USA. Founded in 1852, the Mount Sinai Medical Center is a 1,171-bed, tertiary-care teaching facility internationally acclaimed for excellence in clinical care. As a leader in cardiology research, Mount Sinai is specifically interested in PET/MR since the combination is expected to provide a more advanced understanding of the processes taking place in vascular beds. Multimodality imaging synergistically enhances the power of the separated modalities by automatically combining functional and anatomical infor-mation. The use of PET/MR scanners instead of PET/CT scanners would not only reduce the extra radiation dose to the patient but would also offer higher soft tissue contrast, allowing better visualisation and understanding of the underlying disease.

Under the leadership of Prof Zahi A. Fayad, who is the Professor of Radiology and Medi-cine (Cardiology) at Mount Sinai and is also Director of the Translational and Molecular Imaging Institute, the Mount Sinai Medical Center is currently performing a clinical and a preclinical study to test the performance of the new PET/MR scanner. The prelimi-nary images are already showing promising and valuable results and Prof. Fayad and col-leagues will soon begin a study to profile the development of vulnerable/high-risk athero-sclerotic plaque in patients with high risk of cardiovascular disease.

The authorOsman Ratib, MD, PhD, FAHA,Professor and Chief of Nuclear Medicine, Department of Radiology, University Hospital of Geneva, Geneva, Switzerland

The combination of PET/MRI (lower frame) can give more info than PET/CT (upper frame) without the

radiation dose issues associated with CT.

Building a whole-body PET/MR system

The new Philips PET/MR system (equipped with a 3 Tesla MRI and PET using latest Time of Flight (ToF) technology) is a sophis-ticated device, providing both MRI and PET modalitites. In order to accomplish the PET/MR imaging, the scanners are situated face-to-face, together with a translational bed that accurately positions the patient inside each scanner. However, the concept was not the arduous part. In this case, overcoming mag-netic interference was the greatest obstacle because a new magnetic shield was needed.

All current PET & PET/CT systems today use PMT (hotomultiplier tube) systems or ‘light sensors’. These PMT systems are incompatible in a magnetic field and will not operate in a PET/MR configuration. Philips research and engineering teams worked closely to develop a very novel, yet accurate shielding programme for the new system. As part of this development, it was neces-sary to ensure the PET and MRI devices were situated three metres apart, as increasing the distance reduced the mag-netic interference. As for the PMTs, each photomultiplier tube was fitted within a shield made of a nickel-iron alloy called mu metal. And finally, a laminated steel cover was installed at the side of the PET gantry that faces the MRI device to protect it against the magnetic field.

The greatest technical challenge in developing the new system was ensuring that the electron-ics of the PET scanner were not affected by the

powerful 3 Tesla magnet of the MRI system.

By first installing the PET/MRI system in a special off-site container and then shipping the container as a whole, there was minimal infra-stuctural disturbance to the University Hospital

of Geneva.

26 NEWs iN BriEF

Regional differences in C-section rate not a result of maternal request in CanadaFewer than two per cent of cesarean births in British Columbia, Canada were a result of mater-nal request, but the number of cesarean and assisted vaginal deliveries varied widely across health regions in B.C., according to a new study by University of British Columbia researchers.The UBC study examined all deliveries in B.C. between 2004 and 2007 and found an aver-age of 21.2 per 100 deliveries were first-time C-sections and 14.2 per 100 deliveries were assisted vaginal deliveries involving the use of forceps and/or vacuum devices. Dystocia – or abnormal or difficult childbirth – was the most common reason for cesarean deliveries (30 per cent), followed by non-reassuring fetal heart rate (19.1 per cent).Canada’s cesarean delivery rate has increased dramatically over the past two decades, reach-ing an all time high of 26.3 per cent of in-hos-pital deliveries in 2005-2006. Until recently, B.C. had the highest cesarean rate in the country, according to the Canadian Institute for Health Information. The study also found significant regional variations in cesarean and assisted vaginal delivery rates across B.C.’s 16 Health Services Delivery Areas that could not be explained by accounting for medical indica-tions for these procedures. Cesarean delivery rates ranged from 27.5 per cent in the South Vancouver Island area to 16.1 per cent in Kootenay Boundary. Assisted vaginal delivery rates ranged from 18.6 per cent in Vancouver to 8.6 per cent in East Kootenay.

The researchers suggest potential reasons may include the differences in practitioners’ responses to similar medical situations, such as dystocia, including how they interpret and respond to the condition, and how they factor the resources available to them into their decisions. http://www.ubc.ca/

Genes associated with throat cancer foundScientists from Singapore, China and USA have identified three new susceptibility genes in a genome-wide association study of nasopha-ryngeal carcinoma (NPC). The reseacrh , led by the Genome Institute of Singapore (GIS), a biomedical research institute of the Agency for

Science, Technology and Research (A*STAR), and the Sun Yat-Sen University Cancer Cen-tre, identified genetic risk factors of NPC that advance the understanding of the impor-tant role played by host genetic variation in influencing the susceptibility to this cancer. NPC is a type of cancer that forms in the epi-thelial lining of the nasopharynx. It is par-ticularly prevalent in southern China, with an occurrence rate about 25 times higher than that in most regions of the world. NPC is therefore referred to as the Cantonese Cancer.To search for the genetic risk factors for NPC, a comprehensive genetic analysis of the human genome in a large clinical sample of southern Chinese descent was carried out in approximately

5,000 patients and 5,000 controls. The research-ers found that the genetic variation within the human leukocyte antigen (HLA) and the three genes TNFRSF19, MDSIEVI1 and CDKN2A/2B can significantly influence a person’s risk of devel-oping NPC. The researchers also noticed that these three susceptibility genes for NPC have been reported to be involved in the development of leukemia, suggesting there might be some shared biological mechanism between the developments of these two diseases. This finding provides an important opportunity for biologists to understand the molecular mechanism underlying the develop-ment of this cancer, and its unusual pattern of high prevalence in southern China.http://www.a-star.edu.sg/ Researchers develop test to identify ‘best’ spermA team of researchers at Yale School of Medicine, USA led by Gabor Huszar, M.D have discov-ered a method to select sperm with the highest DNA integrity in a bid to improve male fertility. The method is comparable to that of the egg’s natural selection abilities. Past semen analysis focussed on sperm concentration and motility. It was assumed that if a man had a high sperm count and active sperm, he was fertile, but there was no information on the sperm’s fertility or its ability to attach to the female gamete. In an ideal case, the egg naturally selects the optimal sperm, but during in vitro fertilisation treat-ment of men who had only a few sperm, clini-cians did not know whether they were injecting the correct sperm into the egg for fertilisation. Huszar and his colleagues tested the idea that

binding sperm to hyaluronic acid selects sperm with high DNA integrity. They studied semen samples from 50 men, and a part of the sperm in the semen was allowed to bind to hyaluronic acid. These sperm were isolated, and the DNA chain integrity was compared to the original sperm in semen. The team used a reagent that stained sperm with high DNA integrity green, whereas sperm with fragmented DNA, and diminished DNA integrity were stained red. The nuclear and cytoplasmic attributes of various sperm were identified, and a key relationship between the ability of sperm to bind to hyaluronic acid and between high sperm genetic integrity was found, which enhances the sperm’s contribution to normal embryo development.http://tinyurl.com/34cnt7a

Many people with HIV start care too late

Despite growing evidence that the earlier people are diagnosed with HIV and get access to care, the better their clinical outcomes, many HIV-infected people in the United States and Canada are not receiving the care they need early enough. A recent study of nearly 45,000 patients in both countries highlighted this trend. Researchers analysed patients’ CD4 cell counts, a critical measure of immune system strength, when these patients first began clinical care for HIV from 1997 to 2007. Although the median CD4 count at first presentation increased annually over this period, from 256 cells/mm3

to 317 cells/mm3, it still remains below the level currently recommended for patients to start antiretroviral therapy, 350 cells/mm3. The median age at which patients first received HIV care increased over the study period from 40 to 43 years of age. http://tinyurl.com/2ufsj3n

June 2010

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THE MAGAzINE FoR HEALTHCARE DECIsIoN MAkERs

28 orTHoPEdiCs

Chronic disorders of the ankle and foot are a significant clinical challenge given the complex anatomy and function of the foot, which makes it difficult to localise origin of pain by routine clini-cal examination. In recent years, there has been a significant development of imaging techniques to aid the clinician in the management of this complex group of problems. Anatomical imag-ing (X-ray, MRI, Ultrasound and CT) and func-tional imaging (Bone scan, MRI and Ultrasound) techniques have been used in the management of patients with chronic foot pain.

The technique of co-registering anatomical and functional images of the feet has already been described [1] and more recently the clinical value of co-registering of bone single photon emission computed tomography (SPECT) images of the wrist with multislice CT images using software has been described [2,3]. CT images provide exquisite details of the bone anatomy whilst the bone scan provides the functional information. Combined SPECT/CT study proves to be an excellent tech-nique for the evaluation of complex bony pathol-ogy in the feet although at present MRI remains the most widely used technique for the evaluation of chronic foot pain. In this article, we describe the current techniques available for imaging pathol-ogy in the feet, describe our clinical experience with the new SPECT/CT technique, and discuss its potential applications.

Conventional radiography (X-ray)This remains the most widely used, accessible and cost effective imaging modality for evalua-tion and management of acute and chronic foot pain. This has a particularly important role in the management of acute trauma while its role in chronic injuries remains limited and at best complementary to other techniques.

Computed tomographyMultidetector computed tomography (MDCT)

acquires data that may be reconstructed in any plane; advances in technology allows sub-milli-metre resolution for the evaluation of the bones and related complications, articular cartilage lesions, and even limited assessment of tendon disease [4]. This enhances the ability to detect fractures, osteochondral lesions [4,5] and also provides high resolution images essential for presurgical planning. Whilst CT arthrography may prove to be superior to MR for the post-operative assessment of chondral repair [5], its role in the assessment of tendinous and liga-mentous pathologies in the feet has not been proven and remains the main limitation when compared to MRI or ultrasound [6].

Magnetic resonance imaging (MRI)This remains the imaging method of choice for complex ankle and foot pathology according

to the appropriateness criteria published by the American College of Radiology. Advances in the strength of magnets (>1.5 T ) and the imaging pro-tocols offer the potential of a better signal-to-noise ratio, improved resolution, and faster scan times [7]. MR imaging is routinely used in the evalua-tion of soft tissue pathology of the feet including tendinosis, bursitis, fasciitis and for the diabetic foot. It allows for the examination of the vascula-ture as well, which has been successfully used in the management of diabetes-related osteomyeli-tis. Optimal evaluation of tendinous pathology however remains elusive [8], and ultrasonography remains the investigation of choice in this popu-lation. The potential disadvantages of which one must be aware in MRI are metallic artifacts asso-ciated with hardware or micrometallic material in an operative bed, which are more pronounced in high field systems and worse with increasing field strength. Postoperative follow-up imaging in the presence of micrometallic artifacts may not be carried out using a high field system. Imaging parameters are not transferable from 1.5 to 3.0-T systems and must be modified to take advantage of the potential benefits of high field strength imag-ing [7,9]. Also, claustrophobia requiring the use of general anaesthesia has been seen in up to 10% of patients imaged in a closed high field MR system and obese patients frequently cannot be imaged in the constrained geometry of closed systems.

Ultrasonography Ultrasound is used in patients with foot pain, to examine the soft tissue and is often the preferred imaging modality when Morton’s neuroma or Achilles tendinosis is suspected [8]. Advan-tages of sonography include direct correlation of findings with the patient’s symptoms, com-parison to the asymptomatic ankle, dynamic imaging of the foot in multiple planes and posi-tions, wide availability, and lower cost of and portability of the equipment to the bedside of an unwell patient. Disadvantages of ultrasound include unfamiliarity with the scanning tech-nique and appearance of ultrasound pathology, operator dependence and limitation of imaging structures superficial to the bony cortex.

Nuclear medicineA bone scan is a highly sensitive technique which has been used in the diagnosis and man-agement of skeletal pathology for nearly three decades [10], and the role of bone scintigraphy in the management of specific conditions result-ing in foot pain has been described [11]. Whilst the sensitivity of the bone scan in the diagnosis of bony pathology in the foot remains high, spe-cificity remains suboptimal. SPECT studies have

the demise of other co-registration techniquessPECT-CT in imaging foot & ankle pathology:

Given the complex anatomy and function of the foot, the management of chronic pathologies of the ankle and foot remains a challenge. imaging plays a crucial role and recent appropriateness criteria have been published for the use of the currently available investigating modalities, which are broadly classified into anatomical and functional imaging methods. The recent introduction of sPECT/CT scanners which are capable of combining functional and anatomical images is an excit-ing and important development. This article describes our clinical experience with sPECT/CT and discusses its potential applications in the imaging of complex foot and ankle pathologies.

by dr H K Mohan, dr G Gnanasegaran, dr s Vijayanathan and dr i Fogelman

June 2010

Figure 1. Non union: 59 year old patient with previ-ous Talo-Navicular fusion complaining of continuing pain. Clinically joint immobile. X-rays not conclusive

On the delayed images there is focal increased tracer uptake (Arrow) in the right mid foot and on the blood pool images there is increased vascularity noted to this site. (Arrow) On the SPECT CT study this area

of uptake corresponds to non union of talo-navicular joint (CT image) causing continued pain post surgery

in the patient.

29 June 2010

demonstrated improved sensitivity and spe-cificity although only limited benefit has been shown in the evaluation of foot pathology.

Co registration of bone scan images with X-ray [1] and CT have been performed using software [3,12] and low dose CT systems [13]. More recently, hybrid systems capable of acquiring high-resolution multislice CT image sets that directly match SPECT findings in the same sitting have been developed. This is expected to further increase the diagnostic accuracy of this already highly sensitive but generally non specific study [14].

Potential applicationsPostoperative evaluation of joint fusion and related complicationsJoint arthrodesis has long been used for the treat-ment of painful mal-alignment or arthritis of the hind foot [15]. Successful osseous union after joint arthrodesis is usually expected to occur within six months of the procedure [16] and is confirmed if no joint motion is detected on clinical examina-tion and there is evidence of trabeculation across the arthrodesis site as observed on plain film radi-ographs. Delayed union is defined as a successful fusion 6 to 9 months after surgery. In patients who continue to suffer from pain following arthrod-esis, non-union is suspected. Other complications include development of arthritis in the adjacent joints due to biomechanical overload in about 30% of patients [17] and infection in about 3-5% of patients [19].

Post-operative assessment of the success of fusion has been routinely evaluated using X-ray and CT techniques. However, exact localisation of the site of the origin of pain in these patients remains suboptimal on X-ray and CT [18]. MRI would be unsuitable in this situation due to in situ metal hardware or the presence of microme-tallic artifacts and in diabetic patients in whom there is the additional risk of nephrogenic fibrosis associated with gadolinium contrast.

SPECT-CT would be a valuable technique for the evaluation of continuing pain in the con-text of arthodeses as sites of altered metabolic activity on the bone scan would allow a more focussed examination of the area on the CT study. This improves the accuracy of identify-ing non-union / malunion [Figure 1], subja-cent arthritis or infection as the cause for con-tinuing pain. A combination of SPECT/CT Bone scan / white cell study would be useful in confirming bone and soft tissue infection and also in monitoring response to treatment.

Talar osteochondral defect (OCD)Osteochondral lesions are a result of acute and sub-acute injuries of the articular cartilage and underlying subchondral bone resulting in the aseptic necrosis observed on histopathology. Although uncommon, this remains one of the treatable causes of unexplained chronic ankle pain [20]. Medial talar dome OCD is more common and bilateral lesions may occur in approximately 10% of cases [20].

The role of bone scintigraphy in the diagno-sis of talar OCD [21] has been described. CT scans provide high quality anatomical images for accurately assessing the location and size of the OCD lesions and the diagnostic value is very similar to an MRI study [22]. In addi-tion CT provides information as to loose frag-ments within the lesion which makes surgical intervention a necessity [23]. The combination of highly sensitive bone SPECT images with a highly specific CT study would provide the clinician with an excellent tool for the diagno-sis and management of talar OCD [Figure 2]. It would also be beneficial in the post opera-tive assessment particularly where MRI images may be difficult to interpret.

Achilles tendonitis, bursitis and plantar fasciitisMRI remains the imaging of choice in these conditions as it can demonstrate more anatom-ical detail including disruption of the soft tissue structures, associated soft tissue and reactive bone oedema [24]. Typically, plain radiogra-phy is not helpful, but is always done to rule out other conditions. Although the role of bone scintigraphy remains limited in this group of patients SPECT-CT may provide useful coin-cidental imaging information for the clinician. The SPECT study would demonstrate the met-abolic abnormalities associated with the bone (edema/enthesophyte trauma etc) whilst the CT would be useful in demonstrating the asso-ciated bony (calcaneal spurs) and soft tissue abnormalities (plantar fascia, Kager’s fat pad and retrocalcaneal bursa) [Fig ure 4].

Stress fracturePlain radiography although having poor sensitiv-ity remains the first investigation that is ordered

in patients with suspected stress fracture. Bone scan [25] and recently MRI have demonstrated high sensitivity in identifying early stress injury. [26] Interestingly Gaeta et al [27] in their recent article suggest that the earliest finding of abnor-mal repetitive stress may be osteopenia which can only be demonstrated by dedicated high resolution CT studies. In view of these recent findings, one would anticipate that SPECT/CT may find a more prominent role to play in the early diagnosis and management of patients with suspected stress fractures by combining the advantages of the two modalities [Figure 3].

Painful accessory bonesPotentially painful normal bony variants, such as accessory tarsal navicular and os trigonum, have been described with chronic foot pain [28]. The mechanism of pain in the presence of an accessory tarsal bone has been attributed to traumatic or degenerative changes at the synchondrosis or to soft-tissue inflammation. Symptomatic accessory tarsal bones have been studied with bone scanning and MRI. Symp-tomatic lesions are reported to show increased radiotracer uptake or marrow edema across the synchondrosis. SPECT/CT study provides an excellent technique for the evaluation of the cause of chronic pain in this situation with the SPECT study elegantly demonstrating any altered metabolic activity in the joint whilst the CT demonstrates the associated anatomical abnormalities [Figure 4].

Tarsal coalitionTarsal coalition is a rare deformity [29] that results from abnormal bridging (fibrous / carti-laginous or osseous) across two or more tarsal bones resulting in painful deformity of the hind foot with restricted motion. Calcaneonavicular and talocalcaneal (middle facet at the level of the

Figure 2. Osteochondral defect: 27 yr old male with pain in left hind foot – Previous history of fall. Delayed images show increased focal uptake of tracer in left

ankle medially with increased vascularity on the early images [Arrows pointing]. SPECT CT study confirms

focal uptake in the Talar dome and on the CT images (Arrow) there are cystic changes noted in keeping

with an osteochondral defect in the talus.

Figure 3. Stress fracture: 36 year old with previous left leg amputation in a road traffic accident underwent bone

scintigraphy to evaluate the cause of severe pain in the right mid foot. Delayed planar images show focal increased

uptake in the right ankle / mid foot with increased vascular-ity (Arrow) on the early blood pool images. SPECT images

confirm uptake in the midfoot which on the SPECT CT images correspond to a stress fracture.

sustentaculum tali) coalition are the most com-mon sites. CT, although often diagnostic and MRI are not the imaging studies of choice for tarsal coalition and plain radiography remains the main mode of investigation [30]. SPECT/CT may be an improved alternative to CT alone with addition of supplementary functional informa-tion from the bone scan [Figure 5]. The area of uptake on the SPECT study may also help guide intra articular injections.

Our experienceWe have assessed the additional value of SPECT/CT in 16 patients referred from a spe-cialist orthopedic clinic and it was observed that SPECT/CT provided additional informa-tion in 13/16 (81%) patients and was unhelpful in 3 (19%) cases. A specific diagnosis was made in 6/13 (46%) patients which included mal-union, osteochondral defect, osteomyelitis and inflammatory arthritis. More accurate localisa-tion of degenerative or post surgical changes was observed in the remaining 7 patients. When compared to conventional bone scin-tigraphy, SPECT/CT provides more specific information (malunion / non-union / stress fractures/ impingement etc) as well as allowing more accurate localisation of the abnormalities detected [31,32]. It was found that in more than 50% of patients, management was changed fol-lowing the findings of the SPECT/CT study and many patients did not undergo any fur-ther investigation. We have also demonstrated the value of SPECT/CT in the investigation of heel pain [33] in a patient with retrocalcaneal bursitis and plantar fasciitis.

The limitations of SPECT-CT imaging however are the additional radiation exposure and the increased cost compared to planar bone scintigra-phy. The ACR has previously made recommenda-tions regarding the appropriateness of each inves-tigation in evaluating pathology of the foot and ankle. The role of a bone scan however remains limited with best use seen in identifying patients with reflex sympathetic dystrophy syndrome. However, with the combination of functional and structural information in a single study, SPECT/CT may prove to be a very useful technique for the evaluation of foot pain especially in patients with previous surgery or in situ metal work. This would also reduce the inconvenience of extra hospital visits for patients who previously may have had a standalone bone scan and / or a CT study performed. This would also result in a more efficient use of resources and likely to be cost effective for the health provider. We believe that the ACR recommendations will need to be revis-ited to incorporate the role of SPECT/CT as more evidence becomes available as to its benefits.

Conclusion Imaging of chronic foot pain remains complex and challenging. Currently MR remains the favoured modality although with increasing evidence, SPECT/CT could prove to be a valuable addition to the imaging armamentarium, particularly in the evaluation of pathology following surgery or in patients not suitable for MR, and may also play a role in guiding intra-articular injections.

References1. Robinson AH et al.The Journal of Bone and Joint

Surgery 1998; 80(5):777-80.

2. Groves, A et al. Nuclear Medicine Communications: Volume 5(11)November 2004 1151-1155

3. Ashley M et al. Am J Roentgenol 2005; 184:1470.4. Haapamaki V et al. Am J Roentgenol 2004; 183:615.5. Schmid MR et al. Skeletal Radiol 2003; 32: 259.6. Choplin RH et al. Radiographics 2004; 24: 343.7. Gold GE et al. Am J Roentgenol 2004; 183: 1479.8. Premkumar A et al. Am J Roentgenol 2002; 178: 223.9. Gold GE et al. Am J Roentgenol 2004; 183: 343.10. Holder LE. J Bone and Joint Surg 1982; 64-A:139111. Groshar D et al. Semin Nucl Med 1998; 28: 6212. D Utsunomiya et al. Radiology 2005; 238:26413. Even-Sapir E et al. J Nucl Med 2007; 48: 31914. Romer W, et al. J Nucl Med 2006; 47: 1102.15. Graves SC: In Myerson MS (ed): Foot and Ankle

Disorders. Philadelphia, WB Saunders, pp. 1040 – 1058, 2000.

16. Catanzariti AR et al. J Am Podiatr Med Assoc 2005; 95: 34

17. Rammelt S et al. Orthopade 2006;35:428.18. Mitchell MJ et al. Am J Roentgenol 1995;

164: 1473.19. Graves SC et al. J Bone Joint Surg 1993; 75: 355.20. Ferkel RD et al. Orthop Clin N America 1994

25: 1721. Pavlov H. Radiologic Clin North Am 1990; 28: 991 22. Verhagen RA et al. J Bone Joint Surg Br 2005; 87 4123. Madi F et al. Pediatr Radiol 2005 35: 823.24. Joong MA, El-Khoury GY. Am Fam Physician

2007;76(7):975-83.25. Ammann W et al. Clin J Sport Medicine 1991;

1:115 26. Sijbrandij ES et al. Eur J Radiol 2002;43:45-56.27. Gaeta M et al. Radiology. 2005; 235: 553.28. Karasick D et al. Am J Roentgenol 1996;166:12529. Stormont DM et al. Clin Orthop Relat Res 1983;

181: 28.30. Crim JR et al. Am J Roentgenol 2004; 182: 323.31. Langroudi B et al. J Nucl Med 2007; 48 :122P32. Mohan H et al. Eur J Nucl Med Mol Imaging

2007;34: S166.33. Breunung N et al Clinical Nuclear Medicine 2008;

33: 705.

The authorsHosahalli K Mohan, M.D.1, Gopinath Gnanasegaran,M.D.1 Sanjay Vijayanathan, M.D. 2 Ignac Fogelman, M.D. 1

1Department of Nuclear Medicine, 2 Department of RadiologyGuys & St Thomas Hospitals NHS trust, London, United Kingdom

Correspondence to : Dr. Hosahalli.K.MohanDepartment of Nuclear Medicine,Ground Floor, New Guys House, Guys Hospital,St Thomas Street, London, SE1 9RT. UK.Tel: +44 207 1887188e-mail: [email protected]

30 June 2010

Figure 4. Painful accessory bone, Os Trigonum: 47 year old lady with pain in right ankle and known to have bilateral Os trigonum. There is increased uptake in the delayed images and increased vascularity on the early blood pool images noted within the poste-rior aspect of right ankle. (Arrow) On the SPECT-CT

study the increased tracer uptake is seen correspond-ing to the syndesmosis between the Os Trigonum and the Talus. (Arrow) Although the CT study shows only

minor asymmetrical sclerosis and irregularity along the joint margin, the increased uptake on the SPECT study

helps confirm the site of symptoms allowing appropriate surgical management.

orTHoPEdiCs

Figure 5. Tarsal coalition: 33 year old lady with right ankle pain. The delayed images of the ankles show increased tracer uptake within the right ankle (Arrow) which on the SPECT CT images corresponds to the

lateral aspect of the subtalar joint. The cortical irregu-larity and sclerosis along the margins in the medial aspect are consistent with the clinical suspicion of

a fibrous coalition. (Arrow) The increased uptake in the lateral aspect of the joint (Arrow) was thought

to be due to associated alteration in biomechanical load. This area was injected with steroids, which has

resulted in improvement of pain.

ProdUCT NEWs 31

Point-of-Care cartsOffering fresh solutions to today’s healthcare IT chal-lenges, Human-scale’s T line of point-of-care tech-nology carts pro-vides the first truly ergonomic com-puter-on-wheels solution. The award-winning T5 model combines unmatched mobil-ity and comfort with a high-per-formance power system for both laptops and PCs.

Designed to meet the ergonomic requirements of 99% of users in both sitting and standing postures, the T5 provides independent adjust-ability of the keyboard, monitor, work surface and overall cart height for maximum user comfort. In addition, its minimal footprint ensures effortless manoeuvrability in tight corridors, and around hospital beds and other compact spaces. The T5’s optional energy-conscious and quick-charging internal power system stays cool without a fan — which helps limit the spread of potentially infectious mate-rial — and offers up to 12 hours of continuous use between charges. Power reserves may be easily monitored from both a graphic compu-ter interface and a unique remote power man-agement system that relays information to a central location within the healthcare facility.

HUmANScAlE HEAltHcARE New york, Ny, USA www.ihe-online.com & search 45604

Bladder volume scannersThe BladderScan range of bladder vol-ume instruments are 3D ultrasound devices that quickly, accurately and non-invasively measure urinary bladder vol-ume and post-void residual (PVR).

Designed to be used by physi-cians or nurses, without the need for a sonogra-pher, Bladder-Scan bladder vol-ume instruments are easy to learn and use. There are several mod-els in the range — the Bladder-Scan BVI 9400 is

a portable, noninvasive version that quickly and accurately measures urinary bladder vol-ume and post-void residual (PVR) with 3D ultrasound. The BVI9400 instrument is par-ticularly easy to use — within seconds after the user releases the scan button, the system measures ultrasonic reflections on multiple planes inside the body and produces a three-dimensional image. Based on this image, the BVI 9400 calculates and displays the bladder volume. The measurement information can be printed via an onboard printer or trans-mitted to the clinican’s office or facility com-puter for viewing, printing or archiving using HIPAA-compliant ScanPoint technology.

VERAtHoN mEdIcAl EURoPEIjsselstein, The Netherlands www.ihe-online.com & search 45605

Capnography monitor

The Capnostream 20 system from Oridion is a portable bedside monitor, ideal for use in all hospital areas where patients are at risk of opi-oid-induced respiratory depression and arrest, especially for all sedation procedures and patient controlled analgesia (PCA). The sys-tem incorporates a set of superior algorithms that reduce alarms, improve workflow and provide clinical utility for improved patient safety. The system offers both capnography and pulse oximetry in one monitor.

oRIdIoN cAPNoGRAPHy INcNeedham, mA, USA www.ihe-online.com & search 45606

Contrast delivery system Designed as the ultimate in user-friendly operation in CT contrast delivery systems, the NEMOTO A-60 is a high pressure single head device mounted on a pedestal, which includes a touch screen remote monitor for injection-programming and storage. The control moni-tor provides several functionalities including a clear indication of the remaining volume, storage of up to 10 protocols for quick ref-erence and easy recall, the ability to deliver full syringe volume without changing preset

volume as well as a start/stop remote control, which ensures accurate scan timing that can be set in one second increments.

NEmoto KyoRINdo tokyo, Japan www.ihe-online.com & search 45607

Colour Doppler system By providing an ‘All-in-One’ solution for abdominal, OB&GYN, cardiac-vascular, small parts, pediatric, and musculoskel-etal applications, the iVis 60 EXPERT from Chison has set a new standard for an afford-able, all-digital shared service colour Dop-pler system. The innovative architecture of processing channels, matched with wide band probes, provides THI, compound imaging, and ensures stunning image quality without compromising the frame rate. The system

supports CFM, PW, CW, Directional Power, Colour-M, Panoramic, 3D, ECG, DICOM, and comprehensive cardiac, vascular, and OB packages. A workflow-oriented user interface, one-touch key quick operation, i-CINE, free-arm LCD, and three active probe connectors make the iVis 60 EXPERT a state-of-the-art imaging system for all users.

cHISoN mEdIcAl ImAGING coWuxi city, china www.ihe-online.com & search 45608

June 2010

Improved laryngoscopes The laryngoscopes from German manufacturer Rudolf Riester have been improved and made much more effi-cient and user-friendly.New single-use, dis-posable Macintosh and Miller laryngo-scope blades made from robust Makro-lon plastic are now available. In addition,

standard LED handles and plug-in pow-ered LED handles, are now available for use both with reusable and disposable laryn-goscope blades. LEDs offer a whiter, more intense light, and can operate for more than 20 000 hours.

RUdolPH RIEStERJungingen, Germany www.ihe-online.com & search 45589

Endoscope reprocessingA collaboration between the British companies BES Decon and Tristel has resulted in the development of instant-activation solutions based on a new formulation of Tristel’s unique chlo-rine dioxide chemis-try. The new solution is designed for use in

BES Decon’s CISA endoscope reprocessing sys-tem (ERS) and provides the option of using Tris-tel’s established and thoroughly proven chem-istry. This environmentally friendly solution delivers broad spectrum and sporicidal activity for rapid and effective endoscope decontami-nation and efficiently removes the biofilms that can build up within reprocessing systems. The new solution shortens cycle times to as little as 15 minutes, significantly improving instrument turnaround time and maximising endoscope use. The highly cost-effective CISA endoscope reprocessing system protects endoscopes from the open air and thus from potential cross-con-tamination, from the start of reprocessing right to the point of use with a patient.

tRIStEl SolUtIoNSSnailwell, cambs, UK www.ihe-online.com & search 45599

Cardiovascular monitoringThe Navigator system from Applied Physi-ology provides volumetric, vasoactive and

cardio active information, which is auto-matically compared with set targets to give a clear picture of the progress and status of the patient, and enable the patient response to interventions to be evaluated without the need for time-consuming calculations from multiple monitors. Designed for use in criti-cal care units or other environments where resuscitation, stabilisation and optimisation of hemodynamic and oxygen metabolism is required, the system is intended for use with a broad range of adult patients with unsta-ble circulations presenting to the intensive care unit (ICU) or critical care units, Such patients include those undergoing major sur-gery or suffering from septic shock, renal fail-ure, major burns, major trauma, cardiogenic shock, hypovolemic shock or drug overdose.

APPlIEd PHySIoloGySydney, Australia www.ihe-online.com & search 45601

Follow-up of lesions in CT images

LMS-Lung/Track is a software applica-tion for the evaluation and follow-up of lesions identified in CT images covering the chest. It provides quantitative assess-ment of response to therapy in oncol-ogy patients, including patients enrolled in clinical trials, and also facilitates the evaluation and follow-up of indeterminate lung nodules.

mEdIAN tEcHNoloGIESminneapolis, mN, USA www.ihe-online.com & search 45600

ProdUCT NEWs32 June 2010

FroNT CoVEr ProdUCTFee-for-use cloud-based PACS

The new eHealth PACS Services from Car-estream Health delivers all the functionality of PACS (image management, viewing, distri-bution and storage) while lowering users’ total cost of ownership by reducing their invest-ment in capital equipment, security technol-ogy and management personnel. Contracting with eHealth PACS Services enables health-care facilities to devote resources to patient care and front-end clinical applications, leav-ing Carestream to manage the PACS infra-structure, thus enabling the healthcare pro-viders to achieve lower overall costs. With the new system, healthcare providers connect to secure, remote data centres hosted and man-aged by Carestream Health. Patient informa-tion can be shared with authorised physicians over a simple Internet connection—without the need to build, maintain and upgrade a complex infrastructure. This service enables convenient remote reading for primary diag-noses, as well as the ability to obtain a second opinion from another radiologist or special-ist. The PACS service is an operating expense with a monthly fee based on the number of imaging exams produced each month. The cloud-based service eliminates the danger of obsolescence since Carestream Health con-tinuously maintains and upgrades its data centres and on-site technology. Patient data and exam information are synchronised so that identical information is available to all users, regardless of location. An optional fea-ture allows users to access advanced reading tools such as native 3D features and automatic registration of volumetric exams. Carestream Health’s encryption and security measures meet HIPAA rules as well as the rigorous patient privacy regulations used in other countries. The company’s eHealth Archiving Services stores DICOM and non-DICOM data, including patient demographic infor-mation, video files, X-ray imaging exams, laboratory and pathology reports, and other patient documents.

cAREStREAm HEAltHRochester, Ny, USA www.ihe-online.com & search 45596

ProdUCT NEWs 33

Pediatric supraglottic airways

The innovative i-gel supraglottic airway from Intersurgical is now available in four pediatric sizes as well as the current three adult sizes, thus making it applicable for use with patients down to 2kg in weight. Initially launched in 2007, the i-gel has since become the supraglottic airway of choice in hundreds of hospitals in Europe and throughout the world. The rapid and easy insertion of the device, together with the improved safety provided by the gastric chan-nel as well as low postoperative complications and high seal pressures, all provide significant benefits to both clinician and patient. In the first global study of the new pediatric sizes, the overall insertion success rate was 100%. Venti-lation was considered good or very good with-out any episodes of desaturation. In 33 of the 50 cases, the investigators considered that the patients would have to have been intubated had an i-gel system not been available. Because of its stability, the i-gel device allows the child to be placed in the lateral decubitis position so that caudal anaesthesia can be performed without causing a leak or the displacement of the laryn-geal device. For clinicians looking for a suitable supraglottic airway for pediatric anesthesia, the new airways offer an innovative alternative to the traditional laryngeal mask.

INtERSURGIcAl Wokingham, Berks, UK www.ihe-online.com & search 45587

Hyperthermia system for tumor therapy

Hyperthermia is the therapy used to heat tumors and is based on the principle that heat can preferentially dam-age cancer cells. Hyper-thermia also increases the effect of radiation therapy in the treat-ment of some tumors that are recurrent or progressive despite conventional therapy. While it has been known for hundreds

of years that fevers can kill cancer cells, only recently has technology been developed that can control and focus heat specifically on tumors. Hyperthermia treatments are typically given in radiation oncology departments between one to three times a week either before or after radia-tion therapy. The BSD-500 hyperthermia system is indicated for use alone or in conjunction with radiation therapy in the palliative management of certain solid surface or subsurface malignant tumors (e.g., melanoma, squamous or basal-cell carcinoma, adenocarcinoma, or sarcoma) that are progressive or recurrent despite conventional therapy. Studies using BSD’s hyperthermia sys-tems in conjunction with radiation therapy have shown that 37.4% of patients had a complete tumor regression while an additional 24.5% had greater than 50% tumor regression and a total of 83.7% of patients had some tumor regression after hyperthermia therapy. The primary types of tumors included in the study were recurrent chest wall, recurrent head and neck, recurrent melanoma and recurrent sarcoma.

BSd mEdIcAlSalt lake city, Ut, USA www.ihe-online.com & search 45594

Combined defibrillator monitor

The Rescue Life combined defibrillator/monitor device is designed to be used by both out-of-hospital and hospital users. With its innovative design, the portable device has a brilliant high contrast, wide-angle TFT LCD colour display that allows the simultaneous visualisation of up to 3 ECG channels. Information such as heart rate, SpO2 values, alarms and operational func-tions are clearly displayed even in low visibil-ity conditions. In AED or Advisory mode, text messages and voice prompts guide the operator during the CPR procedure. Users can choose between ergonomic reusable paddles, suitable for manual defibrillation in both adult and pae-diatric patients or disposable pads for AED defi-brillation. Both are equipped with a single fast lock connection for reliable rescue operations.

PRoGEttImocalieri, Italy www.ihe-online.com & search 45588

June 2010

FroNT CoVEr ProdUCTClosed loop ventilation system

The result of 16 years intensive develop-ment, the newly launched INTELLiV-ENT-ASV device incorporates the world’s first fully closed loop ventilation technol-ogy and is now available for clinical use. Optimised ventilation therapy in inten-sive care generally requires the continual adjustment of parameters so that the patient can be weaned off the device as quickly as possible. Unfortunately in most cases it is not possible for personnel to stay permanently at the patient’s bedside. As a result, in many cases settings are only adjusted whenever some alarm threshold indicates a change in lung physiology. This situation looks set to change from now on with the introducton of the new closed loop ventilation system for oxy-genation and ventilation which covers all applications from intubation till extuba-tion. By bringing expert knowledge to the bedside, even in the absence of experts, the new system gives clinicians assistance on complex decision making by display-ing complex information in an intuitive way. Adjustments are made automatically following carefully established protocols based on the measurement of lung physi-ology, respiratory monitoring, capnogra-phy (etCO2) and pulse oximetry (SpO2). By reducing the burden of regular manual adjustments through the application of lung protective rules and the use of set-tings adapted to each individual patient, the overall time of ventilation can be reduced. This lowers stress for the entire staff, increases the availability of staff at the bedside and reduces the potential for mistakes and errors.

HAmIltoN mEdIcAl Bonaduz, Switzerland www.ihe-online.com & search 45595

Soft tissue probe for in vivo imaging using OCTThe VivoSight Multi-Beam optical coherence tomography (OCT) imaging system from Michelson Diagnostics can now be used with a probe developed especially for imaging soft tissue that allows in vivo imaging of oral and gynecological tissue. The OCT system provides sub-surface cross-sectional images at a far higher resolution than is possible with ultra-sound, CT or MRI, and much deeper and wider than is possible with confocal microscopy.

The new soft tissue probe provides the same unprecedented imaging quality as the existing topical probe, giving real-time, in vivo images at better than 7.5 µm lateral resolution. The probe is 9 cm long and provides both 2D and 3D images over a 5 mm x 5 mm area. For sterile applications, the probe is used with a dispos-able transparent sheath which covers the probe, handle and upper connecting cable. Several studies suggest that the new probe should be

particularly useful to clinicians in the diagno-sis and treatment of oral and cervical cancers. For example, ex vivo trials on excised oral tissue have already shown that the system can visu-alise structures such as the epidermal/dermal junction and areas of cellular crowding that are characteristic of early stage tumors. A blinded assessment of OCT images of 125 excised oral lesions showed that a sensitivity of 80 per cent and specificity of 81 per cent could be obtained in the diagnosis of oral cancer. It is expected that in vivo imaging will give even better results and could even eliminate the need for a biopsy.

mIcHElSoN dIAGNoStIcSorpington, Kent, UK www.ihe-online.com & search 45590

Five MP Grayscale monitorThe Radiforce GS520 monitor displays radiological images using a high resolu-tion image matrix with a perfect (1:1) pixel representa-tion. Fine structures are shown precisely, making the moni-tor ideal for thorax and mammography applications. The use

of a 13.5 bit Look-Up-Table avoids unwanted artefacts which could otherwise emerge after calibration, so that the image data are shown without any crushing of greyscales or loss of quality. The system has a pallet with 13771 grey-scales and incorporates a sensor for automatic and constant brightness.

EIzoIshikawa, Japan www.ihe-online.com & search 45591

ProdUCT NEWs34 June 2010

FroNT CoVEr ProdUCTPoint-of-care imaging

Roughly the size of a smart phone, the new Vscan scanner from GE Healthcare is a pocket-sized visualisation tool developed to provide physi-cians with imag-ing capabilities at the point-of-care. The system houses power-ful, ultra-smart

ultrasound technology that enables physi-cians to provide more rapid diagnoses by enhancing the physical exam. By leveraging GE’s high-quality black and white image technology and colour-coded blood-flow imaging in a device that weighs less than 500g, the system provides image quality that until recently was only available with a console ultrasound. The device can easily be taken from room to room and can be used in many clinical, hospital or primary care set-tings. The ability to take a quick look inside the body using Vscan may help clinicians detect disease earlier and could prove invalu-able in today’s busy practice environments such as those involving primary care physi-cians, specialists in cardiology, critical and emergency care and women’s health. Oper-ated via an intuitive user interface that is con-trolled using the thumb, the new system has applications in the examination of abdomi-nal, cardiac (adult and pediatric), urological, fetal/OB and pediatric cases. It is also suitable for thoracic/pleural motion and fluid detec-tion and for basic patient examination in primary care and in special care areas.

GE HEAltHcARE chalfont St Giles, Bucks, UK www.ihe-online.com & search 45592

CALENdAr oF EVENTsJuly 24 – 27, 2010

15th World Congress

on Heart Disease

Vancouver, B.C., Canada

Tel. +1 310 657 8777

Fax +1 310 659 4781

e-mail: [email protected]

www.cardiologyonline.com

August 24-26, 2010

Medifest South Africa 2010

Capetown, South Africa

Tel. +91 11 30580444


www.vantagemedifest.com

Aug. 28 – Sept. 1, 2010

ESC Congress 2010

Stockholm, Sweden

Tel. +33 492 947 600

Fax +33 492 947 601

www.escardio.org/congresses/

esc-2010

September 14-15, 2010

MHealth 2010

Dubai, UAE

Tel. +44 20 7067 1830

www.m-healthconference.com

September 15-17, 2010

Medical Fair Asia 2010

Suntec Singapore

Tel: + 65 6332 9620

Fax: +65 6332 9655 / 6337

4633

e-mail:

[email protected]

www.medicalfair-asia.com

October 5-7, 2010

Clinical Excellence Asia

Marina Bay Sands, Singapore

www.iirme.com/clinicalasia

October 9-13, 2010

23rd ESICM Annual Congress

Barcelona, Spain

Tel. +32 2 559 03 55

Fax +32 2 527 00 62


www.esicm.org

October 13-16, 2010

CMEF Autumn 2010

Shenyang, Liaoning Province, China

Tel. +86 10 6202 8899 ext 3825

Fax +86 20 6235 9314

e-mail:

[email protected]

http://en.cmef.com.cn/

October 9-13, 2010

EANM 2010 - Annual Congress

of the European Association of

Nuclear Medicine

Vienna, Austria

Tel. +43 1 212 80 30

Fax +43 1 212 80 309


http://eanm10.eanm.org/

October 18-21, 2010

Phar/MedExpo 2010

Amman, Jordan

Tel. +962 6 552 7066

Fax +962 6 552 7311


www.me-medexpo.com

November 17-20, 2010

MEDICA

Düsseldorf, Germany


www.medica.de

Nov. 28 – Dec. 3, 2010

RSNA 2010

Chicago, IL, USA

Tel. +1 630 571 2670

www.rsna.org

December 10-12, 2010

Medifest India 2010

New Delhi, India

Tel. +91 11 30580444


www.vantagemedifest.com

January 24-27, 2011

Arab Health 2011

Dubai, UAE

Tel. +971 4 336 5161


www.arabhealthonline.com

February 24-27, 2011

International Conference on Pre-

hypertension & Cardio Metabolic

Syndrome

Vienna, Austria

Tel. +41 22 5330948

Fax +41 22 5802953

e-mail:

[email protected]

www.prehypertension.org

March 3-7, 2011

ECR 2011

Vienna, Austria

Tel. +43 1 533 40 64 - 0

Fax +43 1 533 40 64 - 448


http://myESR.org

dates and descriptions of future events have been obtained from usually reliable official industrial sources. iHE cannot be held

responsible for errors, changes or cancellations.

For more events see www.ihe-online.com/events/

By being able to employ every clinical advancement.Cardiology Solutions from Siemens.

Cardiovascular diseases are the leading cause of death worldwide. And the number of chronic cardiovascular disease patients is rising. The consequence? An increasing demand for best possible quality of care in the most effective and efficient way. We offer you a comprehensive portfolio along the entire cardiovascular care continuum. Siemens commitment to excellence provides best-in-class support for your diagnostic and therapeutic decisions within your department, across your institution – and beyond.www.siemens.com/cardiology

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