Successful rescue of transplant ureteral obstruction by boari flap
Journal
Transplantation
Journal Volume
98
Journal Issue
7
Pages
e75-e76
Date Issued
2014
Author(s)
Abstract
Obstructive uropathy, which might affect 2% to 7.5% of renal transplant patients, remains one of the most important causes of morbidity after renal transplantation (1). Although conservative treatment with ureteric stenting could effectively treat most of the patients with ureteral stricture, definite surgical intervention would be required for those with complete ureteral obstruction. Reviewing 997 renal transplant recipients in a single transplant center, we identified five male patients, aged from 14 to 47 years, suffering from ureteral obstruction. Boari flap operations were successfully performed in all five cases to reestablish their urinary outflow. Among them, three had transplants from live donors and two from deceased donors. Two patients were actually having their second transplants and encountered with episodes of acute rejection before the ureteral complications. Of the five cases, one with live-donor transplantation developed massive urine leakage 10 days after transplantation and was identified with complete ureteral necrosis during the rescue operation. Otherwise, the remaining four patients had ureteral stricture and eventually total obstruction, although the initial nephrostomy drainage and ureter stenting were successfully conducted (Fig. 1A). The ureteral obstruction happened within 1 year (1–11 months) in four patients. However, one with frequent femoral vein cannulation and infection before transplantation developed progressive pelvic fibrosis and stricture of transplant ureter at 41 months after transplantation.FIGURE 1: A, Antegrade urography at post-transplant 5 months revealing total obstruction of the lower graft ureter just 2 weeks after removal of the first successful stenting double-J catheter. B, The Boari flap: the bladder was opened and then reformed as a muscular flap with submucosal tunneling for urinary reconstruction. A double-J catheter was placed in the lumen for stenting.The Boari flap operation was performed with meticulous dissection to expose the urinary bladder, graft kidney, and ureter. Intraoperative ultrasonography was used to locate of the ureteral stump and bladder by saline infusion into the percutaneous nephrostomy tube and Foley catheter, respectively. Color Doppler ultrasound was also used for localization of the iliac and renal vessels. The bladder was opened and then reformed as a muscular flap with submucosal tunneling (Fig. 1B). The bladder flap was reflected and anastomosed to the proximal ureteral stump in an end-to-end fashion. The flap was then tubularized and closed by two-layered continuous sutures with a stenting double-J catheter. Before Boari flap operations, all five patients experienced renal dysfunction; the serum creatinine level ranged from 2.9 to 17.5 (9.04±6.77) mg/dL. Their serum creatinine levels became stabilized at 1.3 to 2.3 (1.86±3.78) mg/dL 1 month after the operation. The difference in serum creatinine levels before and after operation reached statistical significance (P=0.0227). The hospital stay after operation ranged from 10 to 30 (17.4±9.0) days. No recurrence of ureteral stricture happened during a mean follow-up period of 31.4±11.7 months. So far, three of the five grafts have failed for nonurologic reasons: chronic rejection in two and poor compliance to medications in one. Ureteral stenosis is a common complication after renal transplantation, and most of the cases could be well managed by antegrade or retrograde double-J catheterization. However, in the presence of necrosis or a long-segment stricture of the transplant ureter, to reestablish the continuity of the urinary tract becomes a formidable challenge (2). Direct reanastomosis of a small ureteral defect could be successful, only if tension-free sutures could be placed. However, during the reoperation surgery, all the structures around the ureter are usually fixed; a tension-free reanastomosis would warrant extensive dissection and increase the risk of injury to the renal and iliac vessels. In 1894, Boari developed a bladder flap procedure to bridge over the ureteral defect caused by trauma or surgical excision of distal ureteral lesions (3). Its advantages over other reconstructive techniques were obvious and profound because the defected urinary tract could be restored without operating on the ipsilateral renal vasculature or contralateral ureter (4). Although Boari flap has been reported a century ago, surgeons seemed reluctant to do it because of the difficulty in dissection of the transplant kidney. Injury of the renal or iliac vessels could be incurred during the operation of Boari flap. We would suggest intraoperative Doppler ultrasonography for the localization of the vital structures in the operation field. In addition, ultrasonography could also be used to identify the ureteral stump and bladder. In our experience, no incidental injury to the iliac and renal vessels happened, and Boari flap was successfully conducted with minimal blood loss to reconstruct the urinary tract with sustained patency in every case. We believe that a pedicled flap of the bladder wall, which includes rich blood supply, offers an excellent chance for restoration of the distal ureteral defect after renal transplantation. In conclusion, for patients with transplant ureteral obstruction, Boari flap provided a good chance of recovery with good long-term results. Intraoperative Doppler ultrasonography could help forward the Boari flap operation by localization of the vascular and urinary structures. Po-Da Chen Chih-Yuan Lee Ching-Yao Yang Meng-Kun Tsai Department of Surgery National Taiwan University Hospital and National Taiwan University College of Medicine Taipei, Taiwan
SDGs
Publisher
Lippincott Williams and Wilkins
Type
letter