This article presents a review of the literature regarding surgical techniques and outcomes for reconstruction of strictures involving the upper ureter. The preoperative assessment for proximal ureteral stricture is briefly reviewed, followed by a discussion of ureteroureterostomy, transureteroureterostomy, ureterocalicostomy, bladder flaps, downward nephropexy, bowel interposition grafts, onlay or tubular grafting, renal autotransplantation, and nephrectomy. The future direction for reconstruction of the proximal ureter is proposed.
Key points
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The guiding surgical principle during ureteral reconstruction is creation of a tension-free, watertight anastomosis using absorbable sutures that is widely spatulated with preserved blood supply.
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Important factors when planning for ureteral reconstruction include length/location of the stricture, need for bowel interposition, and need to access the bladder.
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Urologists who repair proximal ureteral strictures should be familiar with ureteroureterostomy, transureteroureterostomy, downward nephropexy, ureterocalicostomy, bladder flap, psoas hitch, bowel interposition, and nephrectomy.
Introduction
Proximal ureteral strictures present a complex challenge to the urologist, often necessitating familiarity with a variety of surgical strategies for management. Because so many options exist for repair of the proximal ureteral stricture, consensus regarding optimal treatment can be elusive. The characteristics of each patient and surgeon’s experience combine to determine the surgical plan. When considering the repair of a proximal ureteral stricture, the urologist should be familiar with the techniques listed in Box 1 . The importance of understanding these surgical approaches is highlighted by the increased incidence of ureteral injury secondary to the advent of ureteroscopy and laparoscopy.
Ureteroureterostomy
Transureteroureterostomy
Downward nephropexy
Ureterocalicostomy
Bladder flap
Psoas hitch
Bowel interposition
Renal autotransplantation
Nephrectomy
Given the retroperitoneal location of the ureter, it is well protected from external trauma. It is therefore expected that ureteral trauma occurs in only 2.5% of all genitourinary injuries, most of which are caused by penetrating injury (61.5%–96.5%) within the proximal ureter (70%). In the acute trauma setting, it may be necessary to delay definitive reconstruction of ureteral injuries until the patient is stable. This delay may warrant well-established temporary damage control maneuvers, such as externalized single-J ureteral catheter placement or ligation of the proximal ureter with postoperative placement of a nephrostomy tube.
Introduction
Proximal ureteral strictures present a complex challenge to the urologist, often necessitating familiarity with a variety of surgical strategies for management. Because so many options exist for repair of the proximal ureteral stricture, consensus regarding optimal treatment can be elusive. The characteristics of each patient and surgeon’s experience combine to determine the surgical plan. When considering the repair of a proximal ureteral stricture, the urologist should be familiar with the techniques listed in Box 1 . The importance of understanding these surgical approaches is highlighted by the increased incidence of ureteral injury secondary to the advent of ureteroscopy and laparoscopy.
Ureteroureterostomy
Transureteroureterostomy
Downward nephropexy
Ureterocalicostomy
Bladder flap
Psoas hitch
Bowel interposition
Renal autotransplantation
Nephrectomy
Given the retroperitoneal location of the ureter, it is well protected from external trauma. It is therefore expected that ureteral trauma occurs in only 2.5% of all genitourinary injuries, most of which are caused by penetrating injury (61.5%–96.5%) within the proximal ureter (70%). In the acute trauma setting, it may be necessary to delay definitive reconstruction of ureteral injuries until the patient is stable. This delay may warrant well-established temporary damage control maneuvers, such as externalized single-J ureteral catheter placement or ligation of the proximal ureter with postoperative placement of a nephrostomy tube.
Preoperative evaluation
Numerous patient characteristics must be considered when deciding on the surgical approach to proximal ureteral strictures ( Box 2 ). The importance of a thorough patient history and physical examination cannot be overemphasized. A preoperative urinalysis and urine culture are mandatory with antibiotics as indicated. Mechanical bowel preparation should be performed for any patient who may potentially undergo an intestinal substitution of the ureter. In patients with intact bilateral kidneys, a functional study should be performed to establish differential renal function. Antegrade and/or retrograde ureterography are essential to determine the length and severity of the stricture. Excretory urography (nuclear or radiographic) is helpful in confirming obstruction in equivocal cases. If doubt remains regarding significant ureteral obstruction, a Whitaker test may be performed, although we have rarely resorted to this.
Number of previous failed endoscopic and/or open attempts
Length of stricture
Location of stricture
Function and drainage of each kidney
History of nephrolithiasis
Medical comorbidities
Life expectancy
History of malignancy
Previous radiation therapy
Bladder capacity
History of inflammatory bowel disease
We prefer routinely removing ureteral stents before ureteral reconstruction, thus using a nephrostomy for renal drainage. Removal of ureteral stents allows for delineation of normal versus fibrotic luminal assessment. If the stent is retained before surgery, we have found that it may interfere with identification of the stricture.
Surgical principles
The guiding surgical principle during ureteral reconstruction is creation of a tension-free, watertight anastomosis using absorbable sutures that is widely spatulated with preserved blood supply, allowing good drainage to the bladder. Maintaining the continuity of the urothelium (ie, avoiding intestinal interposition) is advocated whenever possible for reconstruction of the ureter. The dissection of the nondiseased portions of the ureter should be minimized to avoid disrupting the ureteric adventitial sheath and its vascular supply. However, complete excision of the pathologic portions of the ureter is paramount to prevent recurrent strictures.
The urothelial anastomosis may be wrapped with omentum, peritoneum, or perinephric fat to reduce the risk of leakage and improve the vascular supply. An omental flap is harvested by dissecting the omentum from the greater curvature of the stomach. The resulting omental flap obtains its blood supply from the right or left gastroepiploic vessels.
Depending on the type of reconstruction, retroperitoneal and/or intraperitoneal drainage in combination with ureteral stent placement and bladder drainage are used routinely, but are not always performed. A passive drain may be preferable to suction drainage to prevent negative pressure on the anastomotic suture line. We prefer to use both drains and stents.
Incision
Important factors when planning the incision and surgical approach for ureteral reconstruction include the length/location of the stricture, the need for bowel interposition, and the need to access the bladder. These factors also guide the decision to perform the reconstruction via an intraperitoneal or extraperitoneal approach. If limited proximal ureteral dissection is planned without accessing the bladder, a flank, Gibson, or pararectal incision may be used. A midline incision is preferred for transureteroureterostomy or when the need for bowel interposition is anticipated. However, optimal extraperitoneal exposure of the ipsilateral ureter and bladder may be accomplished through a modified Gibson incision that extends from the tip of the twelfth rib inferiorly in a lazy-S configuration toward the pubic symphysis.
Ureteroureterostomy
Ureteroureterostomy is the preferred reconstruction method for short proximal ureteral strictures if a tension-free anastomosis is possible. It is critical to fully excise the strictured portion of the ureter until healthy epithelial edges are observed. The ureter is either transected obliquely (as initially described by Bovee in 1897) or spatulated for 10 to 15 mm to reduce the risk of anastomotic narrowing and subsequent stricture. Anastomosis is performed with either interrupted or continuous 4-0 or 5-0 absorbable suture.
Numerous maneuvers may be necessary to provide sufficient ureteral length for a tension-free repair. If the renal pelvis is enlarged, it is possible to achieve additional length by performing a Heineke-Mikulicz transverse incision of the superior and medial renal pelvis with closure in a longitudinal orientation. The distance achieved with this maneuver is determined by the size of the renal pelvis and the length of the pyelotomy. Renal mobilization and downward nephropexy to the quadratus lumborum or psoas muscle have been shown to provide an additional 4 cm of proximal ureteral length.
Although historical reports showed high complication rates from ureteroureterostomy, more contemporary series indicate long term patency rates beyond 90% with low morbidity.
Transureteroureterostomy
The first transureteroureterostomy (TUU) in a human was described by Higgins in 1935. TUU is performed by mobilizing the donor ureter proximally, ensuring preservation of the periureteral adventitia. A retroperitoneal tunnel is created across the midline anterior to the great vessels. Placement of the tunnel cephalad to the inferior mesenteric artery may avoid kinking depending on the length of donor ureter available. Mobilization of the recipient ureter is minimized and a 1.5-cm to 2-cm medial longitudinal ureterotomy is made. In cases involving a short donor ureter, the recipient ureter may be further mobilized toward the midline as necessary. The donor ureter is spatulated and the anastomosis is performed with interrupted or running 4-0 or 5-0 absorbable sutures over a stent placed from the donor kidney to the recipient ureter ( Fig. 1 ). Some investigators suggest that stent placement into both ureters reduces the risk of stenosis and leakage.
The length and location of a proximal ureteral stricture determine the feasibility of TUU (ie, the ability for the donor ureter to reach across the retroperitoneum). For this reason, TUU may be a useful option for patients with a proximal ureteral stricture located near the sacral margin in the context of a radiated, reoperative, or otherwise diseased pelvis. Contraindications to TUU include history of urothelial carcinoma, genitourinary tuberculosis, idiopathic retroperitoneal fibrosis, and nephrolithiasis because progression and/or recurrence of the causative condition can result in compromise of both renal units and subsequent renal failure. A rarely used alternative to TUU is transureteropyelostomy, which has a theoretic lower risk of recipient ureteral stricture, but with the additional risk of donor ureteral obstruction caused by kinking as it crosses the retroperitoneum.
Iwaszko and colleagues (2010) reported a series of 63 patients who underwent TUU, only 10 of whom underwent the procedure for stricture. The most common early complication was urinary leakage from the anastomosis (9.5%). Of the 10 who underwent TUU for stricture, the location the stricture was only reported in 1 patient (midureter). The complication rate was significantly higher for patients undergoing TUU for malignancy (47.6%) rather than benign reasons (11.9%). Of the 56 patients with follow-up imaging, patency was maintained in 96.4%. After TUU, the development of urolithiasis was seen in 8 patients (12.7%), 3 of whom had a previous history of urolithiasis. Six of those patients required percutaneous nephrolithotomy and 1 patient underwent ureteroscopic stone extraction.
Ureterocalicostomy
Ureterocalicostomy (UC) is typically used for proximal ureteral strictures involving the ureteropelvic junction with an intrarenal pelvis and/or scarring of the renal hilum, thus preventing a widely patent anastomosis between the renal pelvis and ureter (typically seen following failure of previous pyeloplasty). Although UC is best suited for massively hydronephrotic kidneys with thinned parenchyma, it remains feasible with normal parenchymal thickness when a lower pole partial nephrectomy is performed to expose to the lower pole caliceal epithelium. The ureterocalicostomy is recommended by some to be the operation of choice for proximal ureteral obstructions in children with a horseshoe kidney. It has also proved to be a valuable option for managing ureteral necrosis following renal transplantation in which the native ureter is anastomosed to the lower pole calyx. We prefer this operation for salvage of failed robotic pyeloplasty ( Fig. 2 ).
A flank incision with partial resection of the 11th or 12th rib provides excellent exposure for the retroperitoneal approach to UC. The kidney is completely mobilized and the hilum is exposed. The strictured portion of the ureteropelvic junction and proximal ureter is excised. The renal pelvis is closed with 4-0 absorbable sutures at the level of the renal sinus. The lower pole of the kidney is widely amputated. The desire to preserve renal parenchyma by tunneling into the lower pole should be avoided because of the increased risk of stricture with this technique. Preservation of a flap of renal capsule during the amputation process may allow closure of the capsule following the anastomosis, but this is not necessary and has been postulated to increase the risk of postoperative anastomotic stricture.
The renal artery may be clamped to minimize bleeding and improve visibility during anastomotic suture placement. As an alternative, local ischemia with a Penrose drain secured around the lower pole, suture ligation of the parenchymal surface, and/or argon beam coagulation may be used to limit global renal ischemia and the potential for renal artery thrombosis.
After amputation of the lower pole, the spatulated ureter is sutured to the lower pole calyx using 5-0 absorbable interrupted sutures. If anastomotic tension is present, downward nephropexy from the inferior aspect of the kidney to the psoas muscle or quadratus lumborum with 2-0 nonabsorbable suture can be performed. Technical nuances of UC include vesicocalicostomy using a Boari flap and ileocalicostomy using an ileal ureter.
Only a few large series of UC exist in the literature. Osman and colleagues (2011) reported a case series of 22 patients who underwent UC. The investigators reported complete cure in 12 patients, improvement in 4, no change in 2, and failure in 4. Of the patients who failed, 2 underwent nephrectomy and 2 were managed with chronic double-J ureteral stents. One injury to the inferior vena cava and 1 colonic injury occurred among the 22 patients. Matlaga and colleagues (2005) reported a series of 11 patients who underwent UC for strictures measuring 0.5 to 3 cm with a mean follow-up of 10.1 months (range 5–32 months). None of these patients showed recurrent obstruction as measured by intravenous urography or nuclear renography.
Bladder flaps
Described by Van Hook in 1893 with human cadavers, Boari with canines in 1894, and with humans by Baidin in 1930 and Ockerblad in 1947, the use of bladder flaps continues to be an effective technique for complex ureteral reconstruction. Although most investigators describe the Boari bladder flap (BBF) for mid ureteral strictures, Mauck and colleagues (2011) showed equivalent patency rates between BBF cases performed for ureteral strictures above and below the cephalad border of the sacroiliac joint. Thus, in well-selected patients, long Boari flaps can be created that reach high into the abdomen enabling near panureteral reconstruction.
The potential length of the BBF is directly related to the patient’s preoperative bladder capacity, which can be assessed with cystometrogram, cystoscopy, voiding diary, and/or retrograde cystography. Although some investigators suggest that a minimum bladder capacity of 400 mL is required for BBF, other reports suggest a minimum of only 150 mL. However, no studies have objectively measured preoperative and postoperative subjective and objective bladder function following BBF.
The BBF is performed by first releasing the bladder from its anterior attachments to the abdominal wall (obliterated umbilical arteries and urachus) and posteriorly from the peritoneum. Ligation and division of the contralateral superior vesical pedicle provides improved mobility, but great care should be taken to avoid injury to the contralateral ureter. Ligation of the ipsilateral superior vesical pedicle risks compromise of the blood supply to the flap and should be avoided.
After bladder mobilization, the healthy ureter proximal to the stricture is mobilized and transected at the level of the stricture. The resulting ureteral defect is measured and an appropriately sized inverted U–shaped anterior cystotomy is made between stay sutures corresponding with the length of the defect. The length/width ratio of the bladder flap should be no more than 3:1 to preserve the vascular supply to the apex of the flap, and the base of the flap should be no less than 4 cm for the same reason. A spiral orientation provides additional length for small bladders or long flaps. Further length can be obtained by performing an adjunctive psoas hitch in a stepladder fashion between the flap and the psoas muscle or by making several transverse relaxing incisions on the flap. The tip of the flap is then anastomosed in a refluxing fashion to the healthy end of the ureter and the flap is tubularized over a stent in a running fashion with fine absorbable suture. The tubularization continues distally until the cystotomy is completely closed ( Fig. 3 ). A suprapubic tube is unnecessary unless the cystotomy closure is tenuous.
