Editorial

Is routine ultrasound necessary followingrenal transplantation in children?

Renal transplantation is the optimal treatmentfor end-stage renal disease, and Doppler ultra-sonography (DU) is commonly used to monitorfor postoperative complications in the allograft(1). DU is a readily available, non-invasiveimaging modality that in the immediate postop-erative period can help distinguish among vari-ous causes of allograft dysfunction. In the earlypostoperative period, renal DU can be used todetect problems such as renal artery or veinthrombosis or stenosis, ureteral problems, and/or perinephric fluid collections (1). The utilityand cost-effectiveness of routine, postoperativerenal DU as a screening test has not been wellestablished in pediatric kidney transplantation.Bou Matar et al. (2) have addressed this concernby examining retrospectively 113 consecutivepediatric renal transplant recipients who receivedroutine renal DU on postoperative day 3.Bou Matar et al. found that 37.5% (30) of the

80 routine renal DUs performed had abnormal-ities, most of which were minor. One patient witha dysfunctional bladder was noted to havehydronephrosis, which led to an intervention.The other 50 patients who underwent routineDU had normal findings. The cost of each DUwas $1080, and the incremental cost of screeningstrategy for the 80 DUs and 16 follow-up DUswas estimated to be $86 400. The cost of obtain-ing routine DU in the post-transplant period wasestimated to add 1.2% to the total cost of akidney transplant (2).The presence of no or mild abnormalities on

DU immediately following transplantation maybe valuable to know, even if no immediateintervention is indicated, as the DU can be auseful baseline examination. Chu and colleaguesretrospectively reviewed pediatric renal trans-plant recipients and found that nearly 50% hadhydronephrosis, and the presence of hydroneph-rosis, regardless of the grade, was associated withworse renal function. The hydronephrotic cohort

also had increased rates of VUR and rejection,suggesting that intervention may be indicated(3).Renal DU can also be used to measure the

resistive index (RI), a physiological value thatindirectly reflects the degree of resistance of theintrarenal vessels (4). Although Matar and col-leagues found no correlation between resistiveindices and subsequent problems in the post-transplant period, Barba and colleagues foundthat the RI at <24 h following kidney trans-plantation could be used to predict three andfive yr allograft survival (2, 4).Matar and colleagues have performed a pro-

vocative study evaluating the limited utility ofscreening Doppler ultrasonography in the imme-diate post-transplant period. An ideal screeningtest should be non-invasive, available, and inex-pensive. It could be argued that the additionalexpense of 1.2% is relatively low, given theinformation the DU provides following trans-plantation (2).The authors report that routine screening DUs

provided only one examination of unclear clin-ical consequence. Unfortunately, as the authorsacknowledge, retrospective review of the medicalrecord is limited by documentation. A baselineDU documenting the presence or absence ofhydronephrosis, fluid collections, elevated resis-tive indices, and/or altered perfusion could beinvaluable in the long-term management of thepatient.At this time, there may still be a role for

immediate postoperative screening DU, as it isrelatively inexpensive, provides a baselinestudy, and has the potential to provide theopportunity for early intervention in postoper-ative complications. Although Matar and col-leagues demonstrated few tangible interventionsduring the study period, the information thatcould direct subsequent care is still quitevaluable for the overall low incremental cost

Pediatr Transplantation 2012 � 2012 John Wiley & Sons A/S.

Pediatric TransplantationDOI: 10.1111/j.1399-3046.2012.01747.x

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relative to the transplant itself. Further studiesdelineating the role and predictive value ofscreening DU in the postoperative period areneeded before changes in practice can bedefinitively recommended.

Christina Nguyen1 and Ron Shapiro2

1Department of Pediatric Nephrology, Children�s Hospital

of Pittsburgh of UPMC, Pittsburgh, PA,2Department of Surgery, Thomas E. Starzl Transplantation

Institute, University of Pittsburgh, Pittsburgh, PA, USA

E-mail: shapiror@upmc.edu

References

1. Schwenger V, Hinkel UP, Nahm AM, et al. Color doppler

ultrasonography in the diagnostic evaluation of renal allo-

grafts. Nephron Clin Pract 2006: 104: c107–c112.

2. Bou Matar R, Warshaw B, Hymes L, et al. Routine Trans-

plant Doppler Ultrasonography Following Pediatric Kidney

Transplant. Pediatr Transplant 2012: doi: 10.1111/j.1399-

3046.2012.01712.x.

3. Chu L, Jacobs BL, Schwen Z, et al. Hydronephrosis in pedi-

atric kidney transplant: Clinical relevance to graft outcome. J

Pediatr Urol 2012: in press.

4. Barba J, Rioja J, Robles JE, et al. Immediate renal Doppler

ultrasonography findings (<24 h) and its association with graft

survival. World J Urol 2011: 29: 547–553.

Editorial

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