Campbell-Walsh Urology, 11th Edition

PART VIII

Upper Urinary Tract Obstruction and Trauma

49

Management of Upper Urinary Tract Obstruction

Stephen Y. Nakada; Sara L. Best

Questions

  1. Ureteropelvic junction (UPJ) obstruction in the neonate is most frequently found as a result of:
  2. maternal-fetal ultrasonography.
  3. voiding cystourethrography.
  4. diuretic renography.
  5. abdominal radiography.
  6. physical examination.
  7. Which study is diagnostic for functional obstruction at the UPJ?
  8. Retrograde pyelography
  9. Three-dimensional helical computed tomography (CT)
  10. Diuretic renography
  11. Renal ultrasound
  12. Renal angiography
  13. A 62-year-old man presents with left flank pain. Intravenous pyelography reveals delayed excretion and hydronephrosis to the level of a 2.5-cm calculus at the UPJ. Percutaneous stone extraction is accomplished without difficulty, but a postextraction nephrostogram reveals hydronephrosis to the level of the UPJ without residual stone. A follow-up nephrostogram 1 week later is unchanged. The best next step is:
  14. removal of the nephrostomy tube.
  15. diuretic renography.
  16. CT angiography.
  17. antegrade endopyelotomy.
  18. Whitaker pressure-perfusion test.
  19. The condition most predictive of failure after percutaneous endopyelotomy is:
  20. renal ptosis.
  21. ipsilateral stones.
  22. ipsilateral renal function.
  23. moderate to severe hydronephrosis.
  24. chronic flank pain.
  25. A 27-year-old woman has right flank pain, and her diuretic renography reveals UPJ obstruction and a differential renal function of 75:25 (L:R). The next best step is:
  26. CT angiography.
  27. stent placement.
  28. endopyelotomy.
  29. laparoscopic pyeloplasty.
  30. laparoscopic nephrectomy.
  31. The highest failure rate in treating UPJ obstruction is associated with:
  32. antegrade endopyelotomy.
  33. retrograde ureteroscopic endopyelotomy.
  34. balloon dilation.
  35. pyeloplasty.
  36. cautery balloon incision.
  37. The most appropriate location for endoscopic incision of a proximal ureteral stricture is:
  38. lateral.
  39. anterior.
  40. medial.
  41. posterior.
  42. anterolateral.
  43. The best treatment option for a patient with a functional left ureteroenteric anastomotic stricture is:
  44. metallic stent.
  45. balloon dilation.
  46. laser endoureterotomy.
  47. cautery wire balloon incision.
  48. open repair.
  49. The most common cause of retroperitoneal fibrosis is:
  50. methysergide.
  51. infection.
  52. lymphoma.
  53. breast cancer.
  54. immune-mediated aortitis.
  55. Retrocaval ureter results from:
  56. persistence of posterior cardinal veins.
  57. persistence of anterior cardinal veins.
  58. duplication of inferior vena cava.
  59. aberrance of lumbar veins.
  60. retroaortic renal veins.
  61. Transperitoneal laparoscopic pyeloplasty:
  62. is used rarely compared with the retroperitoneal approach.
  63. does not require water-tight, tension-free anastomosis.
  64. provides more working space than in the retroperitoneal approach.
  65. provides unfamiliar anatomy.
  66. does not require an external surgical drain.
  67. Surgical repair of ureteropelvic junction obstruction requires:
  68. a funnel-shaped transition between the renal pelvis and ureter.
  69. dependent drainage.
  70. water-tight anastomosis.
  71. tension-free anastomosis.
  72. all of the above.
  73. Contraindications for transureteroureterostomy include a history of:
  74. retroperitoneal fibrosis.
  75. urothelial malignancy.
  76. nephrolithiasis.
  77. a, b, and c.
  78. b and c.
  79. A 25-year-old man presents with right flank pain. He underwent a laparoscopic pyeloplasty, which failed within 1 year. Consequently, he underwent failed endopyelotomy. A CT scan shows a small, intrarenal pelvis and moderate cortical loss in the right kidney with a normal-appearing left kidney. A renogram reveals 35% differential function on the affected side, and a diuretic study demonstrates functional obstruction (> 30 min). The next step is:
  80. chronic internal ureteral stent.
  81. ileal ureter.
  82. Davis intubated ureterotomy.
  83. ureterocalicostomy.
  84. renal autotransplantation.
  85. Spiral flap procedures for UPJ obstruction are used:
  86. to bridge a shorter length stenosis.
  87. to treat crossing vessels.
  88. to bridge a longer length stenosis.
  89. for a small, intrarenal pelvis.
  90. only in the presence of greater than 30% ipsilateral renal function.
  91. Foley Y-V plasty is a suitable approach when encountering:
  92. high ureteral insertion.
  93. small intrarenal pelvis.
  94. anterior crossing vessel.
  95. duplication of collecting system.
  96. redundant renal pelvis.
  97. Which type of pyeloplasty is suitable when there is an aberrant crossing vessel?
  98. Foley Y-V plasty
  99. Culp-DeWeerd spiral flap
  100. Dismembered pyeloplasty
  101. Scardino-Prince vertical flap
  102. Ligation and transection of the crossing vessel
  103. Ileal ureter can be performed when the patient has:
  104. renal insufficiency (serum creatinine > 2 mg/dL).
  105. inflammatory bowel disease.
  106. bladder dysfunction.
  107. radiation enteritis.
  108. small intrarenal pelvis.
  109. A 55-year-old woman underwent left transperitoneal laparoscopic dismembered pyeloplasty over an internal ureteral stent. An abdominal drain was placed at surgery, and there was minimal drain output during the first 24 hours after surgery. Within 3 hours after Foley catheter removal, the patient's nurse noted a significant amount of fluid coming out of the drain site. The next step is to:
  110. change dressings frequently and continue observation.
  111. replace the urethral catheter.
  112. restrict fluid intake.
  113. remove the surgical drain.
  114. change the ureteral stent.
  115. In performing a psoas hitch, additional bladder mobility can be achieved by transection of the:
  116. contralateral superior vesical artery.
  117. ipsilateral inferior vesical artery.
  118. contralateral inferior vesical artery.
  119. ipsilateral superior vesical artery.
  120. ipsilateral gonadal artery.
  121. A 40-year-old woman with a history of hypertension and recurrent nephrolithiasis presents with a 5-cm proximal right ureteral stricture following an iatrogenic injury in a recent abdominal surgery. She has had an indwelling right nephrostomy tube for more than 6 months. Her baseline serum creatinine is 2.5 mg/dL. Renal scan shows split function of 65% in the right kidney. Her bladder capacity is found to be less than 300 mL. The next step is:
  122. ureteroureterostomy.
  123. Boari flap.
  124. transureteroureterostomy.
  125. ileal ureteral substitution.
  126. autotransplantation.
  127. During a psoas hitch, the structure particularly susceptible to injury is the:
  128. obturator nerve.
  129. iliohypogastric nerve.
  130. ilioinguinal nerve.
  131. sacral nerve.
  132. genitofemoral nerve.
  133. The technique that does not require normal bladder capacity, drainage, and function is the:
  134. ileal ureteral substitution.
  135. psoas hitch.
  136. ureteroneocystostomy.
  137. endoscopic incision of transmural ureter.
  138. Boari flap.

Imaging

  1. See Figure 49-1. A 72-year-old man with malaise has this CT scan. The serum creatinine is mildly elevated. What is the best diagnosis?

FIGURE 49-1

  1. Retroperitoneal fibrosis
  2. Retroperitoneal hematoma
  3. Tuberculosis
  4. Retroperitoneal sarcoma
  5. Perianeurysmal fibrosis

Answers

  1. a. Maternal-fetal ultrasonography.The current widespread use of maternal ultrasonography has led to a dramatic increase in the number of asymptomatic newborns who are diagnosed with hydronephrosis, many of whom are subsequently found to have ureteropelvic junction obstruction.
  2. c. Diuretic renography.Provocative testing with a diuretic urogram may allow accurate diagnosis of UPJ obstruction. Renal ultrasound, CT scan, and retrograde pyelogram give anatomic assessments of the UPJ without quantitatively assessing urinary drainage and function.
  3. e. Whitaker pressure-perfusion test.When doubt remains as to the clinical significance of a dilated collecting system, placement of percutaneous nephrostomy allows access for pressure perfusion studies. In the pressure perfusion test, first described by Whitaker in 1973 and then modified in 1978, the renal pelvis is perfused with normal saline or dilute radiographic contrast solution, and the pressure gradient across the presumed area of obstruction is determined. Renal pelvic pressures in excess of 15 to 22 cm H2O are highly suggestive of a functional obstruction. Although diuretic renography is useful for diagnosis as well, the Whitaker test is ideal for this situation because a nephrostomy tube is already in situ.
  4. d. Moderate to severe hydronephrosis. Consideration of any of the less invasive alternatives to open operative intervention must take into account individual anatomy including, but not limited to, the degree of hydronephrosis, overall and ipsilateral renal function, and, in some cases, the presence of crossing vessels or concomitant calculi. One study found that endopyelotomy success rates were less than 50% when significant hydronephrosis and crossing vessels were identified preoperatively.
  5. b. Laparoscopic pyeloplasty.Evidence indicates that crossing vessels lower the success rate of endopyelotomy from several investigators. When such patients were culled from the pool of candidates available for treatment of UPJ obstruction, endopyelotomy success rates improved in most studies. A CT angiography would be necessary to assess this. However, laparoscopic pyeloplasty would be a straightforward minimally invasive option for this young patient. The kidney has too much function to remove at this stage.
  6. c. Balloon dilation. McClinton reported long-term follow-up data on balloon dilation of the UPJ, finding a success rate of only 42%, which was significantly lower than the initial publications would indicate.
  7. a. Lateral. Proximal ureteral strictures are incised laterally, similar to UPJ strictures. Posterior incision is offered to UPJ obstruction patients who have failed open pyeloplasty. Distal strictures are incised anteriorly, as are strictures of the middle ureter.
  8. e. Open repair.Several studies have linked poor outcomes with endoscopic management of left ureteroenteric strictures. This may be a result of diminished blood flow to the ureter because the left ureter requires more mobilization than the right side at the time of diversion. Although metallic stents show promise in limited studies, using open repair, reports demonstrate an 80% success.
  9. e. Immune-mediated aortitis.Growing evidence indicates that the majority of cases of retroperitoneal fibrosis are, in fact, immune-mediated aortitis. Regardless, the other conditions are relatively rare causes of retroperitoneal fibrosis.
  10. a. Persistence of posterior cardinal veins.Retrocaval ureter results from the persistence of the posterior cardinal veins.
  11. c. Provides more working space than that in the retroperitoneal approach.Transperitoneal laparoscopic pyeloplasty provides a larger working space relative to a retroperitoneoscopic approach. Together with more familiar anatomy, the transperitoneal approach is used most commonly in the laparoscopic urologic community to date.
  12. e. All of the above. For any surgical repair of UPJ obstruction, the resultant anastomosis should be widely patent and completed in a watertight fashion without tension. In addition, the reconstructed UPJ should allow a funnel-shaped transition between the pelvis and the ureter that is in a position of dependent drainage.
  13. d. a, b, and c. Relative contraindications include history of nephrolithiasis, retroperitoneal fibrosis, urothelial malignancy, chronic pyelonephritis, and abdominopelvic radiation.
  14. d. Ureterocalicostomy.Direct anastomosis of the proximal ureter to the lower calyceal system is a well-accepted salvage technique for the failed pyeloplasty and small renal pelvis.
  15. c. To bridge a longer length stenosis.Flap procedures can be useful in situations involving a relatively long segment of ureteral narrowing or stricture. Of the various flap procedures, a spiral flap can bridge a strictured or narrow area of longer length. The flap procedures are not appropriate in the setting of crossing vessels.
  16. a. High ureteral insertion.The Foley Y-V-plasty is designed for repair of a UPJ obstruction secondary to a high ureteral insertion. It is specifically contraindicated when transposition of lower pole vessels is necessary. In situations requiring concomitant reduction of redundant renal pelvis, this technique is also of little value.
  17. c. Dismembered pyeloplasty.In the presence of crossing aberrant or accessory lower pole renal vessels associated with UPJ obstruction, a dismembered pyeloplasty is the only method to allow transposition of the UPJ in relation to these vessels.
  18. e. Small intrarenal pelvis.In ileal segment usage, a small intrarenal pelvis is not contraindicated and an ileocalycostomy can be performed successfully.
  19. b. Replace the urethral catheter.If the drain output increases following the removal of the Foley catheter, the catheter should be replaced for several days to avoid vesicoureteral reflux up the stent in the operated ureter and decrease urinary extravasation.
  20. a. Contralateral superior vesical artery.In psoas hitch, transection of the contralateral superior vesical artery can be helpful to bridge the gap to the ipsilateral ureteral end, thereby achieving tension-free anastomosis.
  21. e. Autotransplantation.Ureteroureterostomy is inappropriate for a 5-cm upper ureteral defect. Boari flap is inappropriate for a small bladder capacity. Transureteroureterostomy is contraindicated in the patient with a history of recurrent nephrolithiasis. Ileal ureter is contraindicated in the presence of elevated serum creatinine above 2 mg/dL. Autotransplant is appropriate for this particular patient.
  22. e. Genitofemoral nerve.The genitofemoral nerve courses over the psoas muscle.
  23. d. Endoscopic incision of transmural ureter.Normal bladder function without significant outlet obstruction is crucial to the success of ileal ureteral substitution, psoas hitch, Boari flap, and ureteroneocystostomy.

Imaging

  1. a. Retroperitoneal fibrosis.There is increased soft tissue in the retroperitoneum, which obscures and effaces the planes between the inferior vena cava and the aorta. Tuberculosis causes calcification and stricturing in the kidneys and collecting systems, and tuberculous iliopsoas abscess extends along the iliopsoas muscles. Retroperitoneal hematoma and sarcoma are not centered solely around the aorta and the inferior vena cava. In perianeurysmal fibrosis, a retroperitoneal fibrosis-like picture occurs in association with an abdominal aortic aneurysm; the aorta is of normal caliber in this case.

Chapter review

  1. Intrinsic UPJ obstruction is a result of an aperistaltic segment in which the normal spiral arrangement of the muscle bundles is replaced by longitudinal muscle bundles and fibrous tissue.
  2. A crossing vessel has the most detrimental effect on the success of an endopyelotomy.
  3. UPJ obstruction may coexist with vesicoureteral reflux.
  4. A multicystic kidney is distinguished from a UPJ obstruction on ultrasound by the "cyst" being connected in hydronephrosis as opposed to being distinct in a multicystic dysplastic kidney.
  5. A Whittaker test is performed by perfusing the renal pelvis at 10 mL/min. Pressures less than 15 cm H2O suggest a nonobstructed system. Pressures greater than 22 cm H2O suggest an obstructed system, and pressures between the two are indeterminate.
  6. The indications for repair of a UPJ include symptoms, impairment of renal function, stones, infection, and hypertension.
  7. In neonates, unilateral hydronephrosis when carefully followed results in 7% of patients requiring a pyeloplasty.
  8. Generally, kidneys with less than 15% function are not salvageable in adult patients.
  9. A long segment stricture (> 2 cm) is generally not successfully managed by the endopyelotomy method. An endopyelotomy cannot be performed safely by any route until access across the UPJ is established.
  10. The majority of endopyelotomy failures occur within the first year. Success rates for endopyelotomy in properly selected patients range between 60% and 80%.
  11. High-grade hydroureteronephrosis and crossing vessels have a detrimental effect on the success rate of endopyelotomy.
  12. When bleeding occurs following an endopyelotomy, one should have a low threshold to precede to angiography to thrombose the severed vessel.
  13. Seventy percent of failures following laparoscopic pyeloplasty occur in the first 2 years.
  14. When repairing a retrocaval ureter, the ureter is transected and relocated ventral to the vena cava.
  15. Lower ureteral strictures are incised in an anterior medial direction; upper ureteral strictures are incised in a lateral or posterior lateral direction.
  16. With ureteral strictures, one must always rule out malignancy.
  17. There is no significant difference in preserving renal function in the adult when reimplanting the ureter into the bladder by either a refluxing or antirefluxing method.
  18. Most patients with long-term urinary conduits will have an element of hydronephrosis that is not secondary to obstruction.
  19. Retroperitoneal fibrosis secondary to malignancy is often indistinguishable from idiopathic retroperitoneal fibrosis and can be identified only with appropriate biopsy that identifies islands of tumor cells.
  20. The initial management of retroperitoneal fibrosis is generally with steroids. Steroids are more likely to be beneficial if there is evidence of active inflammation as indicated by an elevated erythrocyte sedimentation rate, leukocytosis, and infiltration of lymphocytes on biopsy.
  21. In addition to steroids, azathioprine, cyclophosphamide, cyclosporine, colchicine, and tamoxifen have been used to treat retroperitoneal fibrosis with some success.
  22. Generally, 25% renal function is required to keep a repair of the UPJ or ureter open.
  23. For any surgical repair of UPJ obstruction, the resultant anastomosis should be widely patent and completed in a watertight fashion without tension. In addition, the reconstructed UPJ should allow a funnel-shaped transition between the pelvis and the ureter that is in a position of dependent drainage.