Obstructive Uropathy case study

CONTENTSHISTORY.......................................................................................................................................................................1

PHYSICAL EXAM...........................................................................................................................................................3

SALIENT FEATURES.......................................................................................................................................................5

INITIAL IMPRESSION.....................................................................................................................................................5

DIFFERENTIAL DIAGNOSIS............................................................................................................................................5

Parapelvic cyst.........................................................................................................................................................5

Hydronephrosis of pregnancy..................................................................................................................................5

Abdominal aortic aneurysm.....................................................................................................................................5

Appendicitis.............................................................................................................................................................6

Gynaecological disorders (e.g., ovarian torsion, cyst)..............................................................................................6

Ectopic pregnancy...................................................................................................................................................6

Renal failure............................................................................................................................................................6

Bowel obstruction...................................................................................................................................................6

FINAL DIAGNOSIS:........................................................................................................................................................6

ETIOLOGY.....................................................................................................................................................................7

EPIDEMIOLOGY............................................................................................................................................................7

PATHOPHYSIOLOGY.....................................................................................................................................................8

CLINICAL COURSE.........................................................................................................................................................9

STEP-BY-STEP DIAGNOSTIC APPROACH.....................................................................................................................10

Laboratory Studies.................................................................................................................................................10

Urinalysis...........................................................................................................................................................10

Basic metabolic panel........................................................................................................................................10

Complete blood cell count................................................................................................................................10

Imaging Studies.....................................................................................................................................................11

Ultrasonography................................................................................................................................................11

Computerized tomography scan.......................................................................................................................11

Intravenous pyelography...................................................................................................................................11

Radionucleotide studies....................................................................................................................................12

Magnetic resonance imaging............................................................................................................................12

Retrograde urethrography................................................................................................................................12

Retrograde pyelography....................................................................................................................................12

Nephrostography..............................................................................................................................................12

Diagnostic Procedures...........................................................................................................................................12

Cystoscopy........................................................................................................................................................12

Cystoscopy with retrograde pyelography..........................................................................................................13

Histologic Findings.................................................................................................................................................13

Staging...................................................................................................................................................................13

PROGNOSIS................................................................................................................................................................13

PLAN OF MANAGEMENT............................................................................................................................................13

Medical Therapy....................................................................................................................................................13

Surgical Therapy....................................................................................................................................................14

Preoperative Details..............................................................................................................................................15

Intraoperative Details............................................................................................................................................15

Postoperative Details.............................................................................................................................................15

COMPLICATIONS........................................................................................................................................................15

RECOMMENDATION..................................................................................................................................................16

Follow up...............................................................................................................................................................16

Monitoring.............................................................................................................................................................16

Patient Instructions...............................................................................................................................................16

REFERENCES:..............................................................................................................................................................17

Case Report: Obstructive UropathyDecember 11, 2012

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HISTORY

Date of interview: December 4, 2012Time of Interview: 1:30 PMPlace of Interview: AUF MC

Identifying Data:

Patient TC is a 53 years old, female, Filipino, Born again, housewife and a resident of Pandacaqui resettlement. She was admitted for the 2nd time at AUFMC.

Date of Admission: November 29, 2012

Chief complaint: Difficulty urinating

History of Present Illness:

3 days prior to admission the patient experienced vomiting accompanied by fever and chills. The vomiting had occurred during nighttime for 3 days. It is described to be continues and the vomitus is watery and moderate in amount. She took 1 tablet of omeprazole but provided no relief. Fever occurred intermittently with the highest temperature reading of 38’c. It was managed by intake of 1 tablet paracetamol and provided temporary relief.

1 day prior to admission above signs and symptoms still persisted with accompanying symptom of dysuria with weak and interrupted stream. The patient described the pain to be 4/10 where in 10 is the most painful. Persistence of the above symptoms prompted the patient to consult at the ER of AUFMC and thus was admitted on the same day.

Past Medical History:

Immunizations: complete.Allergies: noneChildhood illnesses: unrecalledAdult illnesses: endometrial cancerHospitalizations:

- 1999, patient was admitted at A. Garcia hospital due to urinary tract infection.- November 22, 2012, patient was admitted at AUFMC due to fever, chills and vomiting.

Previous surgeries:- September 2012, patient was admitted at a private hospital in the US for hysterectomy


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Family History:

Patient’s parents are both dead, age and reason of death were unrecalled. She has 4 children who are all alive and apparently well.

Personal and Social History:

Patient lives in Pandakati, Mexico, Pampanga right now. She works in US as a baby sitter since 2004 and comeback twice a year to visit family. Her husband is a tourist bus driver, carpenter, and polister and does swinging. The patient had studied up to high school. There is misunderstanding among sons which she explains as the source of stress. When she is stressed, she shouts to other family members to leave her alone.

Diet and Environment History

She eats 3 times a day. The most common is rice and consumes mostly vegetables and sometimes beef or chicken. The source of the food is from market. The source of the water is from refilling. She is nonsmoker, non-alcoholic, she has sedentary life style.

She lives in 2 room bungalow type house with her husband, one daughter, and 3 grandchildren. The house is well ventilated, lightened, with 1 bathroom. The garbage is collected by truck three times a week. There are no industries near the house. She has one dog in her home.

Review of Systems:

General: Confirms presence of weight loss. No weakness, fatigue, fever & chills.

Skin: Presence of pallor. No changes in the hair or nails. No rashes, pruritus, lumps, dryness and sores.

Head: No headache, injury, dizziness and lightheadedness

Eyes: Confirms wearing of eyeglasses. No redness, pain, irritation, excessive tearing, double vision, spots, glaucoma, cataracts & sensitivity to light.

Ears: No abnormal hearing, pain, tinnitus, vertigo, infection, discharge and hearing aids.

Nose and sinuses: No colds, nasal stuffiness, discharge, itching, hay fever, nosebleed, sore throat, and hoarseness.

Throat: No sore tongue, gum bleeding, dry mouth and difficulty swallowing.

Neck: No lumps, swollen glands, goiter, pain and neck stiffness.


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Breast: No lumps pain and discharge.

Respiratory: No cough, hemoptysis, wheezing, and difficulty of breathing.

Cardiovascular: No palpitations, rheumatic fever, hypertension, murmurs, chest pain, dyspnea, orthopnea and edema.

Gastrointestinal: Bowel movement: 3 times a day, stool semi solid, no trouble in swallowing, no heart burn. No belching, flatulence, jaundice and gall bladder problem. No nausea, no vomiting, no changes in bowel habit, no hemorrhoids, no constipation, no diarrhea, no abdominal pain, no food intolerance.

Urinary: Has burning sensation after voiding. Light yellow color urine. No nocturia, no frequency, no pain, no urgency, no UTI, no incontinence. No reduced force in urination, no hesitancy, no dribbling.

Genital: No hernias, no sores, no discharge, no pain, no masses, no STD. Peripheral Vascular: No leg cramps, no varicose veins, no intermittent claudication.

Musculoskeletal: No muscle or joint pains, no stiffness, no arthritis, no gout, no backache

Hematologic: No anemia, no easy bruising or bleeding, no transfusion reactions

Endocrine: No thyroid problems, no heat or cold intolerance, no excessive sweating, no excessive thirst or hunger, no polyuria, no change in glove or shoe size

Psychiatric: No nervousness, no depression, no memory loss, no suicidal attempts

Neurologic: No fainting, no weakness, no seizures, no numbness, no tingling, no tremors

PHYSICAL EXAM

General Survey: conscious, coherent to time place and person, stays in a sitting position, no effort when speaking, well kempt, and aptly groomed.

Vital Signs:

Temperature: 36.5Pulse rate: 84 bpmRespiratory Rate: 12 cpmBP: 160/90 mm HgHeight: 5'3"Weight: 110 lbsBMI: 19.48 kg/ m2 (Normal)


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Skin: no discoloration, no cyanosis, with a longitudinal incision scar from umbilicus to symphysis pubis, dry and warm to touch.

Nails: no clubbing, capillary refill count of 2 seconds

Eyes: pale palpebral conjunctiva, anicteric, pupils equally round and reactive to light and accommodation.

Ears: no ear deformities, with cerumen of minimal amount, non-tender, no discharges, tympanic membrane not inflamed

Nose and sinuses: symmetric with contiguous structures, no discharges, non-tender

Mouth: pinkish-moist oral mucosa, moist lips, no sores, tongue in midline.

Neck: no masses, no scars, no lesions, no neck vein distention, thyroid gland barely palpable, visible carotid artery pulsations, non-tender, no palpable nodes

Thorax: symmetric chest expansion, resonant on lung fields, clear breath sounds, normal tactile fremitus.

Cardiovascular: PMI on 5th intercostal space Left MCL, distinct S1 and S2, no murmurs, brisk carotid upstrokes.

Abdominal: Slightly globular, no pulsations, (+) colostomy drainage on left lower quadrant no effluent seen on bag, moist viscera with pinkish color, skin surrounding the bag is of good condition, no discoloration, redness nor ulcerations. Normoactive bowel sounds 5/ minute, tympanitic on the remaining quadrants, non-tender.

Extremities: (+) grade 2, pitting edema on lower extremities, full equal pulses, full ranges of motion, and no joint pains.

Neurologic:

Mental status: alert and cooperative, oriented, demonstrates good recall

Cranial nerves:

I - intact sense of smellII - normal visual acuity, pupils equally round and reactive to light and accommodationIII, IV, VI - (+) eye movements on all directions of gazeV - Intact chewing/ jaw clenchingVII - symmetric facial expressionsVIII - good hearing on both earsIX, X - gag reflex elicited, able to elevate soft palate, uvula at midlineXI - able to turn head to sides, can move shoulders against resistanceXII - no tongue deviation, ale to move freely


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Sensory: no deficits

Motor: no deficits, 5/5 on all extremities

Cerebellar: can perform rapid alternating movements, and fingers to nose.

SALIENT FEATURES

53 years old, female Vomiting accompanied by fever and chills Intermittent fever Dysuria with weak and interrupted stream History of urinary tract infection. Has burning sensation after voiding BP: 160/90 mm Hg

INITIAL IMPRESSION

On the basis of history and PE our initial impression is Obstructive Uropathy

DIFFERENTIAL DIAGNOSIS

Condition Differentiating signs/symptoms

Differentiating tests

Parapelvic cyst Usually asymptomatic. May appear similar to hydronephrosis but there is no obstruction present.

If a radiologist cannot differentiate on ultrasound, a nuclear renography scan or CT scan with intravenous contrast can rule out obstruction.

Hydronephrosis of pregnancy

Hydronephrosis is found in 43% to 100% of pregnant women and tends to progress throughout gestation; most patients are clinically asymptomatic.

If a patient is asymptomatic, no further testing is indicated.Renal ultrasonography is indicated if a patient has flank pain, pyelonephritis, or renal failure. Hydronephrosis beyond the level of the pelvic brim is a sign that obstruction from another cause may be present.Magnetic resonance urography is an emerging technique to evaluate the level of obstruction.

Abdominal aortic aneurysm

Haemodynamic instability, personal or family history of abdominal aneurysm, bilateral loin pain; pulsatile mass in the abdomen.

CT abdomen/pelvis with contrast will demonstrate aneurysm sac and extravasation of contrast if leaking.

Appendicitis Focal tenderness over Diagnosis usually clinical.


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McBurney's point. Patient often prefers to lie still to avoid pain on movement. Gradual onset of symptoms.

CT scan can identify an inflamed appendix.WBC and CRP often elevated.

Gynaecological disorders (e.g., ovarian torsion, cyst)

No haematuria; pain may be associated with menses.

Perform urine pregnancy test in all females of reproductive age before imaging.CT scan of the abdomen and pelvis may demonstrate ovarian pathology.Transvaginal ultrasound is first-choice investigation if a gynaecological cause is more likely than renal colic: may demonstrate ovarian torsion.

Ectopic pregnancy May be haemodynamically unstable; unilateral abdominal pain more pronounced than loin pain; may have features of peritonitis (e.g., guarding and rebound tenderness).

Positive pregnancy test and gestation of about 6 weeks with ectopic pregnancy.Transvaginal ultrasound reveals ectopic pregnancy, dilatation of fallopian tube and free fluid if present.

Renal failure No lower abdominal pain, no bladder distention; may be pruritic, have nausea or anorexia; may have other systemic illness or recent history of dehydration or fluid loss (e.g., post-surgery).

Catheterisation: minimal urine.Urea and creatinine: elevated urea and creatinine.

Bowel obstruction Bilious vomiting typically associated with small bowel obstruction; severe constipation; previous abdominal surgery or obstructed hernia present. May have concurrent dehydration and acute renal failure.

Abdominal x-ray may demonstrate dilated bowel loops.CT abdomen may show dilated loops of bowel and transition point if mechanical obstruction present.

FINAL DIAGNOSIS:

On the basis of history and PE our initial impression is OBSTRUCTIVE UROPATHY.

ETIOLOGY

Causes of urinary obstruction include:


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prostate enlargement (in men), which may be benign or malignant stones (can be in the kidneys, ureter, or bladder) tumor (can be anywhere in or outside the urinary tract, compressing it) infection blood clots enlarged uterus in pregnant women weak bladder that cannot push the urine out (due to certain medications or neurologic

conditions) abnormal congenital structures (abnormal tissue that blocks the connection between the kidney

and the ureter, or within the urethra ), especially seen in children abnormal tissue that results from instrumentation of the urinary tract (also called strictures) foreign body trauma with pelvic fracture

EPIDEMIOLOGY

United States

No data are available on incidence and prevalence of urinary obstruction in unselected populations. Most epidemiologic studies of obstruction are in selected populations or autopsy studies. In large surveys of elderly men for symptoms of urinary obstruction, a prevalence of 20-35% has been estimated. Most (60%) of the men surveyed with moderately severe to severe symptoms of prostatism did not consult their physicians with these symptoms. Postmortem examinations have found hydronephrosis in 3.8% of adults and 2.0% of children.

Mortality/Morbidity

Urinary tract obstruction may lead to acute or chronic renal insufficiency or overt kidney failure. Obstruction may lead to a salt-losing nephropathy and urinary concentrating defects. Renal tubular acidosis (RTA) type IV, hyperkalemia, hypomagnesia, and hypophosphatemia are common sequelae of chronic obstruction. Although acute or chronic obstruction may cause urinary tract infection (UTI), other sequelae such as renal calculi, hypertension, and polycythemia are associated with a chronic setting. Ascites is a common sequela of neonatal obstruction syndrome. In cases of acute obstruction, a postobstructive diuresis following relief of the problem is well described.

Sex

In adults, incidence and etiology of urinary obstruction vary significantly with the age and sex of the patient.

•In young and middle-aged men, renal calculi are the most common cause of at least temporary urinary obstruction. Rare cases of obstructive uropathy due to seminal vesicle cyst and appendiceal mucocele have been reported.


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•In young and middle-aged women, gynecologic surgery, pregnancy, and cancers of pelvic organs are important etiologies of obstruction.

Age

Special considerations in pediatric patients include acquired or congential urethral stricture, congenital ureteropelvic junction (UPJ) or ureterovesical junction (UVJ) obstruction, vesicoureteral reflux, and urolithiasis.

After age 60 years, urinary obstruction is most common in men secondary to prostatic hypertrophy; prostate cancer accounts for occasional cases.

PATHOPHYSIOLOGY

Normal urine production in an adult is about 1.5-2 L/day. Urine flow depends on 3 factors—a pressure gradient from the glomerulus to the Bowman capsule, peristalsis of the renal pelvis and ureters, and the effects of gravity (ie, hydrostatic pressure).Obstruction of the urinary tract at any level eventually results in elevation of intraluminal ureteral pressure. With prolonged obstruction, ureteral peristalsis is overcome and increased hydrostatic pressures are transmitted directly to the nephron tubules.

As pressures in the proximal tubule and Bowman space increase, glomerular filtration rate (GFR) falls. After 12-24 hours of complete obstruction, intratubular pressure decreases to preobstruction levels. If complete obstruction is not relieved, a depressed GFR is maintained by decreases in renal blood flow mediated by thromboxane A2 and angiotensin II (AII). With continued obstruction, renal blood flow progressively falls, resulting in ischemia and incremental nephron loss. Thus, obstructive uropathy may lead to obstructive nephropathy. Several phases of obstructive nephropathy may be seen, including an early hyperemia and a late vasoconstriction followed by regulation of GFR post obstruction. Recovery of GFR depends on the duration and level of obstruction, preobstruction blood flow, and coexisting medical illness or infection.

Chronic urinary tract obstruction can lead to permanent damage to the urinary tract. Infravesical obstruction can lead to changes in the bladder, such as trabeculation, cellule formation, diverticula, bladder wall thickening, and, ultimately, detrusor muscle decompensation. Progressive back pressure on the ureters and kidneys can occur and can cause hydroureter and hydronephrosis. The ureter can then become dilated and tortuous, with the inability to adequately propel urine forward. Hydronephrosis can cause permanent nephron damage and renal failure. Urinary stasis along any portion of the urinary tract


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increases the risk of stone formation and infection, and, ultimately, upper urinary tract injury. Urinary tract obstruction can cause long-lasting effects to the physiology of the kidney, including its ability to concentrate urine.

CLINICAL COURSE

Pain secondary to stretching of the urinary collecting system is the most common symptom in acute obstruction. Prevalence of pain is related more to acuity of obstruction than degree of distention. Acute obstruction of the ureter by a calculus commonly results in an excruciating pain, commonly referred to as renal colic. This pain is described as unrelenting, radiating from the flank to lower abdomen and testicles or labia on the affected side.

By contrast, pathological processes that slowly obstruct, such as retroperitoneal tumors, are relatively pain free. Prostatic hypertrophy also may be associated with an obstructive uropathy that is relatively painless. It usually is identified when a superimposed acute obstruction occurs with the inability to void effectively; the resultant painful, distended bladder prompts a visit to an emergency physician.

Alterations in patterns of micturition often associated with more distal obstructions are early but frequently missed symptoms. Although anuria is dramatic and specific for obstruction, nocturia and polyuria are much more common presenting symptoms associated with renal concentrating defects due to partial obstruction. Bladder outlet obstruction leads to the symptoms of prostatism (eg, frequency, urgency, hesitancy, dribbling, decrease in voiding stream, the need to double void).

Acute and chronic renal failures are common complications of urinary obstruction. Obstructive nephropathy should be considered especially in uremic patients without a previous history of renal disease, hypertension, or diabetes.

Gross or microscopic hematuria often is associated with renal calculi, papillary necrosis, and tumors, all of which can cause obstruction.

Recurrent UTIs should always lead to an investigation for urinary obstruction.

New-onset or poorly controlled hypertension secondary to obstruction and increased renin-angiotensin has been reported.

Polycythemia secondary to increased erythropoietin production in the hydronephrotic kidney also has been reported.

History of recent gynecologic or abdominal surgery can give important clues to the etiology of urinary obstruction.

Pediatric patients may present with recurrent infections. Symptoms of voiding dysfunction such as enuresis, incontinence, or urgency should be sought.


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A thorough medication history should be elicited. A variety of drugs and toxins affect renal function. Bladder dysfunction is seen with a variety of xenobiotic drugs with antimuscarinic anticholinergic activity such as antihistamines, antipsychotics, and antidepressants. A variety of xenobiotics such as ethylene glycol, indinavir, methotrexate, phenylbutazone, or sulfonamides will induce crystal deposition throughout the tubulointerstium obstructing urine output. Additionally, drug-induced retroperitoneal fibrosis may obstruct ureteral function such as methysergide or other natural-occurring ergotamines.

In cases of both acute and chronic obstructive uropathy, occupational exposure history may be beneficial. For example, in textile manufactures, shipyard workers, roofers, or asbestos miners, retroperitoneal fibrosis due to asbestos-induced mesothelioma should be considered. Bladder cancer–induced outlet obstruction may occur in textile workers, rubber manufacturing workers, leather workers, painters, hairdressers, or drill press workers exposed to alpha- or beta-naphthylamine, 4-aminobiphenyl, benzidine, chlornaphazine, 4-chlor-o-toluidine, 2-chloroaniline, phenacetin compounds, benzidine azo dyes, or methylenedianiline.

STEP-BY-STEP DIAGNOSTIC APPROACH

Laboratory Studies

Urinalysis Urinalysis can provide useful information in evaluating for infection or hematuria. WBCs in the urine can indicate infection or inflammation. Nitrite- or leukocyte esterase–positive urine indicates infection. All urine that contains WBCs or is positive for nitrite or leukocyte esterase should be

sent for culture analysis and antibiotic susceptibility. RBCs in the urine can be present in infection, stones, or tumor. A urologist should

evaluate all patients with microscopic or gross hematuria to ensure that malignancy is not present. These patients require urine cytology and a full hematuria workup (cystoscopy, upper urinary tract imaging).

Urine pH is useful in the evaluation and workup of stones.

Basic metabolic panel Renal insufficiency is detected on a basic metabolic panel based on elevated BUN and

creatinine levels. This can result from bilateral renal obstructive processes or obstruction in a solitary kidney.

Other metabolic abnormalities can also be present in renal insufficiency.Hyperkalemia and acidosis may be present.

Complete blood cell count Leukocytosis indicates infection. Anemia can be due to acute processes (eg, blood loss) or chronic processes (eg, chronic

renal insufficiency, malignancy).


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Imaging Studies

Ultrasonography Ultrasonography of the kidneys and bladder is a useful imaging modality as an initial

study. It is a noninvasive inexpensive study that does not involve radiation exposure or depend on renal function. It is the initial study of choice in pregnant women.

In patients with intravenous pyelography (IVP) dye allergies or elevated creatinine levels, ultrasonography is a very useful source of imaging.

In children, this is often part of the initial workup for obstructive processes. Ultrasonography is sensitive in revealing renal parenchymal masses, hydronephrosis, a

distended bladder, and renal calculi. The accuracy of this imaging modality depends heavily on the experience of the

ultrasonographer. In adults, if the ultrasonography findings are abnormal in any way, additional imaging is

usually recommended. The combination of renal ultrasonography with flat-plate radiography of the kidneys, ureters, and bladder (KUB) is an inexpensive initial combination.

Computerized tomography scan A CT scan is very useful in providing anatomic detail and is often a first-line test in the

evaluation of a patient. A CT scan provides information regarding the urinary tract, as well as any possible

retroperitoneal or pelvic pathologic condition that can affect the urinary tract via direct extension or external compression.

A noncontrast CT scan should be obtained to assess for calculi. If calculi are found, flat-plate radiography of the abdomen (KUB) should be obtained to help determine calcium content and stone shape and to assist in monitoring the progress of the stone. Its progress can be observed with periodic simple radiography.

A contrasted CT scan is needed to provide information on renal pathology. If delayed contrast images are obtained, CT urography with 3-dimensional

reconstruction can provide excellent visualization of the entire upper urinary tracts. A CT scan can be used to identify or rule out any other intra-abdominal processes that can cause presenting symptoms (eg, appendicitis, cholecystitis, diverticulitis, abdominal aneurysms, ovarian cysts).

Intravenous pyelography IVP involves the injection of dye into the venous system and a series of KUB radiographs

over time. It can be performed in patients with a normal creatinine value (< 1.5 mg/dL) for

visualization of the upper urinary tract. It provides both anatomical and functional information.


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Delayed calyceal filling, delayed contrast excretion, prolonged nephrography results, and dilatation of the urinary tract proximal to the point of obstruction characterize obstruction.

IVP is superior to CT scan in revealing small urothelial upper tract lesions. If IVP is inadequate, retrograde pyelography can be performed to completely visualize

the renal pelvis or ureter. Patients with IVP dye allergy cannot undergo this test. A combination CT scans and IVP (CT/IVP) test is commonplace. With this combined

technique, both modalities can be used. CT urography, as mentioned above (see Computerized tomography scan), is also an excellent modality.

Radionucleotide studies: A renal scan can be performed to determine the differential function of the kidneys, as well as to demonstrate the concentrating ability, excretion, and drainage of the urinary tract. Lasix can be administered with the renal scan to verify delayed excretion and the presence of obstruction.

Magnetic resonance imaging MRI is not a first-line test used to evaluate the urinary tract. In patients who cannot tolerate a CT scan with contrast, an MRI with gadolinium can be

performed to reveal any enhancing renal lesions. MRI is useful in delineating specific tissue planes for surgical planning, as well as in

evaluating the presence or extent of a renal vein or inferior vena cava thrombus in cases of renal tumors.

MRI does not reveal urinary stones well so is not often used as a first-line test.

Retrograde urethrography: Radiographic dye is injected into the urethral meatus via Foley catheter at the distal urethra. Fluoroscopy is used to visualize the entire urethra for stricture or any abnormalities. This test can be particularly useful in working up lower urinary tract trauma.

Retrograde pyelography: similar to Cystoscopy with retrograde pyelography.

Nephrostography: This can be performed in patients who have a nephrostomy tube in place. Radiographic dye is injected antegrade through the nephrostomy tube. With fluoroscopy, any abnormalities or filling defects in the renal pelvis or ureter are visible. This can be safely performed even in patients with IVP contrast allergies.

Diagnostic Procedures

Cystoscopy : Cystoscopy is the placement of a small camera called a cystoscope through the urethral meatus and passing through the urethra into the bladder. Any abnormalities in the urethra, prostatic urethra, bladder neck, and bladder can be visualized. This can be performed in the office or in the operating room.


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Cystoscopy with retrograde pyelography : Retrograde pyelography is performed in the operating room with a cystoscope in the bladder. Radiographic dye is injected into each ureteral orifice. Then, with the use of fluoroscopy, any ureteral or renal pelvis filling defects or abnormalities can be visualized. The contrast load does not interfere with renal function and can be used in patients with elevated creatinine levels. It can also be used in patients with an IVP dye allergy because the contrast remains extravascular.

Histologic Findings

When upper urinary tract obstruction occurs, the kidney undergoes interstitial fibrosis, with the accumulation of collagens and other extracellular matrix components.

Staging

No staging system exists for urinary tract obstruction.

PROGNOSIS

Obstructive uropathy can result in permanent renal damage, but the majority of patients recover completely if the obstruction is relieved promptly. Although benign prostatic hyperplasia (BPH) is a common cause of obstructive uropathy, most patients with BPH do not go on to develop obstruction. In a study of over 3000 men, 18 (2.4%) of the 737 men in the placebo group went on to develop acute urinary retention with a mean follow-up of 4.5 years. No men in the trial went on to develop renal insufficiency due to BPH.

PLAN OF MANAGEMENT

Medical Therapy

Consultation with a urologist should be obtained in patients with urinary tract obstruction, as in hydronephrosis or urinary retention. A patient with complete urinary tract obstruction; any type of obstruction in a solitary kidney; obstruction with fever or infection; or renal failure needs immediate attention by a urologist. Patients with pain that is uncontrolled with oral medications or with persistent nausea and vomiting that causes dehydration also need immediate urological attention.

A partial urinary tract obstruction in the absence of infection can be initially managed with analgesics and prophylactic antibiotics until a complete urologic evaluation is performed and definitive management is completed.

Antibiotics are often given for prophylaxis and should cover common urinary tract pathogens. Commonly used antibiotics include trimethoprim-sulfamethoxazole, nitrofurantoin, cephalosporins, and fluoroquinolones.


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Pain secondary to urinary tract obstruction is often managed with oxycodone, hydrocodone, acetaminophen, and nonsteroidal anti-inflammatory medications.

Surgical Therapy

The goal of surgical intervention is to completely relieve the urinary tract obstruction. This can be evaluated with reimaging to ensure that the obstruction is resolved, as well as renal function monitoring with a creatinine laboratory test. The recovery of renal function depends on the severity and duration of the obstruction.

Different interventions can be performed to temporarily relieve the point of obstruction. Surgical intervention is usually obtained once the point of obstruction is identified with radiographic imaging.

Lower urinary tract obstruction (bladder, urethra) can be relieved with the following:

Urethral catheter

o A urethral catheter (size 8F-24F) is a flexible external catheter that extends from the bladder through the urethra.

o A physician or nurse can place it. If catheter placement is difficult, a urologist may be needed to avoid urethral trauma. The urologist may need to perform urethral dilation, cystoscopy, or both to pass the catheter.

o The catheter can be left indwelling, or, as an alternative, the patient can perform clean intermittent catheterization.

o If blood is present at the urethral meatus after pelvic trauma and suspicion of urethral injury exists, a urologist should be consulted prior to catheter placement. Retrograde urethrography needs to be performed to rule out urethral injury.

Suprapubic tube or catheter: If a Foley catheter cannot be passed, a suprapubic tube can be placed percutaneously (at the bedside) or in an open fashion (in the operating room). A suprapubic tube is placed on the lower anterior abdominal wall, approximately 2 finger-breadths above the pubic symphysis. Ultrasound guidance should be used for bedside procedures to ensure proper placement without injury to adjacent structures. In patients with previous abdominal surgery, adhesions and scar tissue may have changed the normal bowel location, so an open approach may be preferred.

Upper urinary tract obstruction (ureter, kidney) can be relieved with the following:

Ureteral stent: A ureteral stent is a flexible tube that extends from the renal pelvis to the bladder. It can be placed during cystoscopy to relieve obstruction along any point in the ureter. A ureteral stent generally needs to be changed every 3 months.

Nephrostomy tube: A nephrostomy tube is a flexible tube that is placed through the back directly into the renal pelvis. If a ureteral stent cannot be placed cystoscopically in a retrograde fashion, a percutaneous nephrostomy tube can be inserted for relief of hydronephrosis. If


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needed, a ureteral stent can then be passed in an antegrade fashion through the nephrostomy tube tract.

The following are urologic emergencies that require immediate attention and intervention:

Complete urinary tract obstruction Any type of obstruction in a solitary kidney Obstruction with fever, infection, or both Renal failure Pain that is uncontrolled with oral medications Nausea and vomiting that causes dehydration

Preoperative Details

Before any surgical intervention or any manipulation of the urinary tract, broad-spectrum antibiotics should be initiated to prevent infection or urosepsis. Ideally, before any manipulation is performed, the urine should be sterile. However, this may not be possible in cases of emergent surgical intervention. Urine culture along with the administration of broad-spectrum antibiotics is important.

If cystoscopy and stent are needed emergently, coagulation is not a concern. If percutaneous drainage is necessary, coagulopathies should be corrected.

Intraoperative Details

Different interventions can be performed to temporarily relieve the point of obstruction. If the planned procedure cannot be performed safely or is not adequate in relieving urinary tract obstruction, other modes of urinary tract decompression can be tried.

Postoperative Details

When a patient has long-standing urinary tract obstruction that has been relieved, they may experience postobstructive diuresis. This physiologic diuresis is usually self-limiting and can be managed conservatively with fluid replacement and, if needed, electrolyte replacement. Postobstructive diuresis is defined as diuresis of more than 200 mL/h for at least 2 hours. Patients with severe diuresis should receive intravenous fluid replacement in the form of half normal saline at 80% of the hourly urine volume for the first 24 hours, then 50%. Postobstructive diuresis usually lasts 24-72 hours. Most cases are not severe enough to require this level of attention.

COMPLICATIONS

A patient with urinary tract obstruction should see a urologist promptly because of the serious complications that the obstruction can impose. The following are complications of obstructive uropathy:


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Infection, including cystitis (bladder infection), pyelonephritis (kidney infection), abscess formation, and urosepsis

Urinary extravasation with urinoma formation Urinary fistula formation Renal insufficiency or failure Bladder dysfunction secondary to a defunctionalized bladder Pain

RECOMMENDATION

Follow up

Definitive treatment at the point of obstruction is needed after the acute obstruction is resolved. Adults and children often have different etiologies of urinary tract obstruction. Thus, various definitive surgical treatment options are available for each condition. After definitive treatment is achieved, a final imaging study is obtained to verify complete relief of the obstruction. The type of study performed, as well as the timing of the study, is left to the discretion of the urologist.

For excellent patient education resources, visit eMedicine's Kidneys and Urinary System Center. Also, see eMedicine's patient education articles Intravenous Pyelogram, Cystoscopy, Magnetic Resonance Imaging (MRI), and CT scan.

Monitoring

The frequency and type of monitoring depends on the illness the patient has and what has been done. In chronic illness (e.g., in a patient with obstructive uropathy undergoing chemotherapy) routine stent or nephrostomy tube changes are needed every few weeks or months.

Patients who have undergone definitive treatment such as a transurethral resection of the prostate and whose renal function is normal may not require further follow-up after an initial check.

For ureteric stones, follow-up is needed until the stone passes or is surgically removed. A metabolic evaluation to look for an underlying reason for stone formation is advised in certain patient groups (children and those who have a strong family history of ureteric calculi or previous personal history). Follow-up for unilateral obstruction not due to stones is focused on the underlying condition and usually involves a multidisciplinary team approach.

Patient Instructions

Patients undergoing treatment of obstructive uropathy need to be alert to signs such as worsening flank pain, fever, dysuria, increasing weakness, or decrease in urine output. If patients have a catheter or nephrostomy tube, they will need to be taught routine care of these appliances. It is critical that patients


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understand when the condition has not been completely treated and that appropriate follow-up is arranged

REFERENCES:

Schwartz, S. I., & Brunicardi, F. C. (2010). Schwartz's principles of surgery (9th ed.). New York: McGraw-Hill, Medical Pub. Division.

http://bestpractice.bmj.com/best-practice/monograph/643/follow-up/prognosis.html http://emedicine.medscape.com/article/438890-overview http://renux.dmed.ed.ac.uk/EdREN/EdRENINFObits/Obstruction.html

Obstructive Uropathy case study

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