EXPERIMENTAL AND CLINICAL TRANSPLANTATION

Objectives: Urologic complications after kidney transplant are associated with significant morbidity, mortality, and prolonged hospital stay. An intervention or second surgical procedure is frequently required. Here, we report urologic complications in adult kidney recipients.

Materials and Methods: Since 2006, 171 adult kidney transplant procedures have been performed at the Gazi University Transplantation Center (Ankara, Turkey). Among these patients, there were 65 adult female (38%) and 106 adult male (62%) recipients. Donor source included 61 deceased donations (36%) and 110 living related donations (64%). The Haberal corner-saving technique was used for ureteroneocystostomy anastomosis. All recipients received a calcineurin-based triple immunosuppression regimen. All recipients also received trimethoprim/sulfamethoxazole prophylaxis for 3 months after transplant.

Results: In the 171 adult kidney recipients analyzed for urologic complications, mean age was 32.5 ± 14.1 years (median: 32.5 y; range, 18-67 y); mean donor age was 41 ± 14.2 years (median: 42 y). We focused on 3 specific urologic complications: urine leak, ureteric stenosis, and symptomatic vesicoureteral reflux. In our study group, urologic complications were encountered in 7 patients (4%), with 5 complications detected in the early period and 2 complications detected in the late period. No symptomatic vesicoureteral reflux complications were shown in this study group. Urologic complications did not result in any patient deaths or graft loss.

Conclusions: In this study, the Haberal corner-saving suture technique with double J stent seemed to have a protective effect for development of urologic complications.

Key words : Double J stent, Kidney transplant

Urologic complications remain a major source of morbidity and occasional mortality in renal transplant patients, despite a reduction in their incidence of at least one-half over the past 30 years. The incidence of ureteral complications after renal transplant varies from 2.9% to 21% with an associated 20% to 30% mortality rate according to previous reports.^1-6 The most common urologic complications after renal transplant are those involving the ureter.^1,2 Leaks or obstructions make up more than 90% of urologic problems after transplant; leaks occur because of ischemic or mechanical injury to the ureter and also technical difficulties with the anastomosis makeup.³ Ureteric obstructions may also be caused by twists, kinks, and technical difficulties with the anastomosis. In this study, we focused on 3 specific posttransplant urologic complications: urine leak, ureteric stenosis, and symptomatic vesicoureteral reflux.

Materials and Methods

The data of 213 total kidney transplant procedures since 2006 at Gazi University Transplantation Center (Ankara, Turkey) were reviewed, with pediatric renal transplant patients excluded. In total, 171 adult kidney transplants, which had been done by the same transplant team, were retrospectively analyzed, which included 65 female (38%) and 106 male (62%) recipients. Donor source included 61 deceased (36%) and 110 living related donations. All patients received calcineurin-based triple immunosuppression therapy.

A modified version of the Lich-Gregoir method with the Haberal corner-saving technique was used during anastomosis of ureterovesical reimplantation.⁷ In this method, the filled urinary bladder is incised so that mucosa protrudes at the site of incision. The graft ureter is anastomosed to the bladder mucosa, and anastomosis is covered by serosa and muscle layers with 5-0 polydioxanone stent. Routine double J stent (DJS; 4.8F, 16 cm) placement is performed intraoperatively for all cases. All patients receive antibiotic treatment with ceftriaxone (1 g every 12 h) until removal of drain. By postoperative day 5, the indwelling Foley catheter is usually removed, with the pelvic drain usually removed by postoperative day 4. During postoperative week 4, the DJS is removed under sedation on an outpatient basis by our Department of Urology.

Among 213 total renal transplant procedures, 171 adult kidney transplants were performed since 2006 at the Gazi University Transplantation Center (Ankara, Turkey). Mean recipient age was 32.5 ± 14.1 years (median: 32.5 y; range, 18-67 y), and mean donor age was 41 ± 14.2 years (median: 42 y).

In our patient group, urologic complications were shown in 7 patients (4%). Five of 7 complications were detected in the early period (< 3 mo), whereas 2 complications were detected in the late period (> 3 mo) after transplant. Early complications included urine leak (n = 3) and distal ureter stenosis (n = 2), and late complications included distal ureter necrosis (n = 1) and distal ureter stenosis (n = 1). No symptomatic vesicoureteral reflux complications were shown among the 171 recipients.

Two patients with urine leak were diagnosed at postoperative days 4 and 5 from biochemical examination of drain output. In 1 patient, a collection found in routine control postoperative day 17 showed urine yield. Therefore, percutaneous antegrade cystography was done, confirming the diagnosis. All 3 patients with urine leak were treated successfully with percutaneous nephrostomy by interventional radiology. Two patients with early-onset distal ureter stenosis were treated successful by interventional radiology with balloon dilatation.

One patient with late-onset distal ureter stenosis did not respond successfully to percutaneous nephrostomy and balloon dilatation and DJS by interventional radiology. Therefore, a second ureteroneocystostomy anastomosis was performed, which showed no further problems. A patient with ischemic necrosis was admitted to the hospital with deterioration of graft function 8 months after transplant. Radiologic work-up revealed collection next to the graft. Collection was drained, and a sample was taken by placing a pigtail catheter by radiology. Collection showed urine yield. Percutaneous nephrostomy was placed, and antegrade pyelography was performed. A diagnosis of distal ureter necrosis was made by display of no connection continuity from the graft pelvis renalis to the urine bladder. Therefore, the patient required surgical revision. For this patient, we used native ureter for ureteroureterostomy with ipsilateral native nephrectomy due to the unhealthy condition of the remaining graft ureter.

Despite a reduction in their incidence of at least one-half over the past 30 years, urologic complications remain a major source of morbidity, increased hospitalization, and occasional mortality in renal transplant recipients. Their frequency varies among centers with different practices from 2.9% to 21%.^1-6 The most common urologic complication after renal transplant involves the ureter. Urine leak and distal ureter stenosis make up 90% of complications.^1,2 Urine leak may occur at the ureteroneocystostomy site because of ischemia. Other less common causes of urine leak include surgical trauma of the ureter during organ retrieval or donor nephrectomy or increased urinary pressures caused by obstruction.^8-11 The reason for low incidence of urine leak (1.7%) in our study seems to be the Haberal suture technique with stenting of the ureterovesical anastomosis. We believe that it significantly lowered the need for surgical revision after renal transplant. We found that this technique clearly allowed edges of both sides of the ureter mucosa to be viewed, allowing us to make safer anastomosis.

Stenosis/stricture of the distal ureter or ureterovesical anastomosis is a relevant late complication in renal transplant patients. Its frequency increases with time (from 4.6% after 1 year to 9.7% after 5 years) after transplant¹¹ because of ischemia that progresses to fibrosis, severe rejection (including ureter), mechanical kinking, immunosuppression, and even BK virus infection.¹² Percutaneous or cystoscopic dilatation is recommended, with success rates up to 85%.^13,14In our series, distal ureteral stenosis was found to be as low as 1.7% (3 of 171 patients). Interventional radiology successfully allowed treatment by balloon dilatation without stenting in 2 of our 3 cases with stenosis. In 1 case, interventional radiology was not successful after several dilatations (3 times), and ureteroneocystostomy was performed successfully.

Distal ureter necrosis is rare but is the most serious complication of this category.^15,16 The causes of these complications are uncertain, although blood supply to the terminal ureter is clearly vulnerable as it is entirely derived from the main renal artery, but it also might be caused by technical difficulties with the anastomosis during organ retrieval or infection (cytomegalovirus or BK virus infection).^14-16 Frequent urinary tract and cytomegalovirus infections after transplant can also be likely causes and may have been the cause in our patient.^16-18 First-line therapy is a repeat ureterocystostomy or a ureteroureterostomy, depending on the recipient’s ureter. Our patient required the latter, with ipsilateral native nephrectomy performed in this patient.

The routine use of DJS in renal transplant in prevention of ureteral complications remains controversial. Although stents have been reported to break or migrate and to cause complications due to calcification and an increased incidence of urinary tract infections,^2,19 we did not see such complications related to use of the DJS. According to studies favoring stenting, routinely inserted DJS reduces the rate of urine leaks and early postoperative obstructions, showing less surgical revision in the long-term follow-up.^18-21 In contrast, no significant differences have been reported in the incidence of ureterovesical complications by using routine stenting versus no stenting.^22,23 We routinely use DJS, and we believe it has a protective effect to anastomosis.

Prompt treatment of urologic complications in our study group resulted in compensation of elevated biochemical parameters associated with renal graft dysfunction to normal levels; therefore, neither graft nor patient loss due to urologic complications occurred.

The literature suggests widely variable urologic complication rates. In this study, a DJS seems to have a protective effect against the development of urine leak and stenosis and symptomatic vesicoureteral reflux after transplant. The routine use of DJS with the modified Lich-Gregoire method and the Haberal corner-saving technique for ureteroneocystostomy anastomosis seem to decrease risk of urologic complications.

EPUB Before Print

FULL TEXT