A variety of pathologic conditions may result in ureteral stricture disease. These include urolithiasis, genitourinary infection, retroperitoneal fibrosis, radiation therapy, external trauma, and iatrogenic injury. Strictures below the pelvic brim can usually be managed effectively by ureteral reimplantation with or without bladder advancement. Proximal and midureteral strictures are more difficult to reconstruct. Treatment options include pyeloplasty, ureteroureterostomy, transureteroureterostomy, and ureteral reimplantation with Boari flap and renal mobilization. Long strictures frequently require ileal interposition, autotransplantation, or nephrectomy.
Potential complications of ileal interposition include metabolic acidosis, vitamin B 12 deficiency, short gut syndrome, hyperoxaluria, small bowel anastomotic stricture, and enterocutaneous fistula. Although autotransplantation avoids potential metabolic and bowel complications, graft loss from perioperative complications has been reported in up to 40% of cases.
Melnikoff first reported using the appendix to treat ureteral stricture disease in 1912. Multiple case reports and small case series have subsequently been published. Appendiceal interposition eliminates the risk of small bowel and vascular complications and decreases the likelihood of metabolic derangements. However, the narrow caliber of the appendix makes performing the anastomosis challenging and increases the risk of ureteroappendiceal anastomotic stricture. Using the appendix as a detubularized onlay flap maintains the potential advantages of interposition and decreases the aforementioned risks.
Reggio and colleagues reported the first laparoscopic appendiceal onlay flap ureteroplasty in 2009. The same institution subsequently published the results from a series of six patients undergoing the laparoscopic onlay procedure with subjective and objective success rates of 66% and 100%, respectively. No perioperative complications were encountered.
Alternatives to the appendiceal onlay procedure include small intestine (Yang-Monti) and colon transverse tubular reconfiguration with end-to-end anastomosis. Both procedures are associated with decreased risk of metabolic complications compared with ileal ureter reconstruction, but the potential for bowel leak and obstruction remain. As with appendiceal interposition, the narrow lumen of the reconfigured bowel segment makes performing the ureteral anastomosis difficult and may carry a higher risk of postoperative stricture.
Indications and Contraindications
Laparoscopic appendiceal onlay flap ureteroplasty should be considered for patients with right proximal or midureteral strictures longer than 1.5 cm. Individuals with shorter, nonischemic strictures may benefit from an initial attempt at endoureterotomy, given its decreased invasiveness and because failure does not preclude future reconstruction.
Patients having undergone an appendectomy are not candidates for the onlay flap procedure. Transverse tubular reconfiguration of the small intestines or colon is a feasible alternative in these patients or those with left-sided strictures.
The absolute contraindications are no different than for most laparoscopic procedures: uncorrected coagulopathy and untreated infection or sepsis. Relative contraindications include morbid obesity, prior abdominal surgery, and retroperitoneal radiotherapy.
Patient Preoperative Evaluation and Preparation
It is imperative to completely assess stricture location, length, and severity to counsel patients regarding the potential reconstructive options and their associated risks. Various diagnostic tools are available to characterize ureteral strictures, including excretory urography (computed tomography urography, intravenous pyelography) and antegrade and retrograde pyelography.
Patients referred with a ureteral stent can pose a diagnostic challenge if their stricture has not been fully worked up. It is prudent to delay reconstructive surgery because the stent can obscure the true extent of the stricture intraoperatively. Patients with normal renal function and no symptoms before stent placement should have the stent removed and should undergo urography 2 to 4 weeks later. If the patient had renal insufficiency or flank pain before stenting, then stent removal with nephrostomy tube placement should be considered.
A preoperative nuclear medicine scan should be performed in patients with long-standing obstruction and evidence of parenchymal atrophy on anatomic imaging. Patients with ipsilateral renal function less than 20% may be better served by a simple nephrectomy rather than a complex reconstructive procedure.
Operating Room Configuration and Patient Positioning for the Appendiceal Onlay Procedure
The primary surgeon and assistant stand to the left of the patient facing the abdomen. The scrub nurse stands on the opposite side of the patient. A minimum of two monitors should be available. One monitor is located across from the primary surgeon at chest level. The second monitor provides visualization for the scrub nurse and is positioned at the midabdomen behind the surgeon and assistant ( Fig. 29-1 ).
After induction of general anesthesia and intubation, an orogastric tube is placed by the anesthesia provider. The abdomen is then shaved if needed. The patient is placed in the modified decubitus position with the right flank elevated 30 degrees. The chest and pelvis are secured to the operating room table with wide cloth tape, and the right arm is draped over the chest and gently secured into place. Foam padding is used to prevent brachial plexus injury. A pillow is placed under the knees ( Fig. 29-2 ). A test roll is then performed by rotating the operating room table to the left to ensure that the patient is adequately secured. The patient is then prepared in a sterile fashion from the nipples to the genitalia.
Ureteral Stent Placement
Ureteral stent placement can be performed in a retrograde or antegrade fashion. It is my preference to place the stent at the beginning of the procedure. A flexible cystoscope is inserted into the bladder. The right ureteral orifice is cannulated with a guidewire over which a 7-French stent is placed. If fluoroscopy is not used, then the stent should be 2 cm longer than usual. Alternatively, a multilength stent can be placed. In women the stent can be deployed freehand. In men the pusher device will need to be used, either with fluoroscopic guidance or under direct visualization with the flexible cystoscope located within the posterior urethra adjacent to the stent as it is being deployed. After stent placement, a 16-French bladder catheter is inserted.
Trocar Placement
Once the stent and bladder catheter have been placed, the operating room table is rotated to the right away from the surgeon. While establishing the pneumoperitoneum, the assistant typically stands opposite the primary surgeon to the right of the patient. Either the Veress needle or Hasson technique is used to obtain peritoneal access at the level of the umbilicus. Pneumoperitoneum is initially established at 20 mm Hg to provide maximum abdominal distention. The first trocar placed is a 10-mm periumbilical port. Once the initial trocar has been placed, the intra-abdominal contents are inspected to ensure no vascular or bowel injury has occurred. The remaining ports are placed under direct visualization. These include a 12-mm port located along the right midclavicular line halfway between the periumbilical trocar and anterior superior iliac spine and a 5-mm subxiphoid trocar ( Fig. 29-3 ). The pneumoperitoneum is then decreased to 15 mm Hg. The operative table is then rotated to the left to facilitate passive retraction of the intra-abdominal contents by gravity.
Procedure (See )
Retroperitoneal Exposure
Once the ports have been placed, the retroperitoneum is exposed by incising the line of Toldt along the right pericolic gutter with either electrosurgical scissors or ultrasonic dissection ( Fig. 29-4 ). The lateral colonic peritoneal reflection is incised from below the right common iliac vessels to the hepatic flexure, which usually rests on the anterior aspect of the lower pole of the kidney ( Fig. 29-5 ). The peritoneum overlying the upper pole of the kidney need not be divided.
