EXPERIMENTAL AND CLINICAL TRANSPLANTATION

Objectives: Renal transplant with double ureters is uncommon. However, with increasing numbers of en bloc and dual transplants from marginal donors, we frequently observe 2 ureters for implant. The current study reviewed our experience with 76 double-ureter renal transplants.

Materials and Methods: We performed a retro-spective analysis of renal transplant performed in 2 institutes from 1996 to 2011. We recorded the outcomes of renal transplants with double ureters including complications. We compared outcomes with renal transplants with single ureters.

Results: Irrespective of the technique used for implant, we recorded no significant risk of complications of double- compared with single-ureter renal transplants. There were no significant differences in patient and graft survival.

Conclusions: We believe that double-ureter transplant does not require additional risk discussion with the recipient because it is safe. However, when ureteral stents are used, we should ensure that a mechanism is in place for both stents to be removed postoperatively.

Key words : Complications, End-stage renal disease, Urology, Ureteral stent

Renal transplant is the preferred treatment for patients with end-stage kidney disease. Renal transplant improves quality of life and life expectancy. There is a large shortage of organs for transplant despite an increasing list of transplant recipients. To overcome this imbalance, transplant centers have relaxed donor selection criteria. However, there are few anatomic characteristics that are not modifiable such as multiple renal arteries, multiple renal veins, and a duplicate pelvicaliceal and ureteric system.

Double ureter is an uncommon anomaly, with a reported incidence from 1 in 100 to 500.^1,2This anomaly can be a complete duplicate pelvicalyceal ureteral system with 2 separate openings in the bladder or ureters that merge into a single ureter before entering the bladder.^2-4 However, because of the short length of ureter required during transplant, usually there are 2 ureters to implant. Double ureters often are asymptomatic in healthy individuals but are associated with a higher incidence of recurrent urinary tract infections, reflux, and stone formation.^5,6 After transplant, double ureters may be associated with a higher risk of infection, hydronephrosis, ureteral necrosis, and leakage.^7,8 The present multicenter study describes our experience and outcome of kidney transplants with double ureters. To our knowledge, this is the largest reported series.

Materials and Methods

Patients
Between January 1, 1996, and December 31, 2011, a total of 76 renal transplants with double ureters were performed at the Manchester Royal Infirmary, United Kingdom (n = 37) and the Sharif Medical City Hospital, Lahore, Pakistan (n = 39). These double-ureter transplants (group A) included 2 en bloc transplants from a pediatric donor, 2 transplants associated with simultaneous pancreas transplant, 1 horseshoe kidney, and 1 dual transplant. There were 43 living- and 33 deceased-donor transplants. Different techniques for ureteroneocystostomy were used including modified Lich-Grégoir (n = 13),⁹ mucosa-to-mucosa anastomosis with double-J ureteral stent in situ (n = 50), and without stent (n = 13). There were 19 patients who had single ureteroneocystostomy following anastomosis of the medial ureteral wall.¹⁰

We recorded donor and recipient basic demo-graphics, different techniques used for uretero-neocystostomy, postoperative short- and long-term complications, and patient and graft survival. We compared these results with our single ureter (group B) transplants performed during the past 10 years in both centers. Group B included 2365 renal transplants (Manchester, 1634 transplants; Sharif, 731 transplants). Comparison also was made with published data. The study was approved by the Ethical Review Committee of the Institute. All of the protocols conformed to the ethical guidelines of the 1975 Helsinki Declaration.

Statistical analyses
Data analysis were performed with statistical software (SPSS for Windows, Version 11.0, SPSS Inc., Chicago, IL, USA). The results were presented as median. Statistical significance between compared groups was estimated using independent sample t test and chi-square test. Kaplan-Meier method was used to calculate patient and graft survival rates. Log-rank test was used for comparison of survival curves. The results were considered significant when P < .05.

General demographics
There were 76 patients with double-ureter transplant included in this study. The general demographics of the donors and recipients were tabulated (Table 1 and 2). The graft functions were recorded for primary graft function, primary nonfunction, and delayed graft function. Acute tubular necrosis and episodes of rejection, type of rejection, and treatment were recorded. Delayed graft function was defined as having occurred when the patient required dialysis within 1 week following renal transplant. The diagnosis of acute tubular necrosis and rejection were based on the histology report following graft biopsy. Graft and transplant characteristics were tabulated (Table 3).

Complications
We recorded urologic and general postoperative complications in our double-ureter transplant group (group A). We compared urologic complications with our single-ureter kidney transplant group during the past 10 years (group B). This group included adult renal transplants irrespective of donor type and number of transplants. There was no statistically significant difference noted between these 2 groups. We also compared our double-ureter transplant group with published data for double-ureter transplant¹¹ and overall urologic complications irrespective of number of ureters (Table 4).^12,13 Other complications were tabulated (Table 5). The incidence of complications was not significantly different between the 2 techniques used for ureteroneocysto-stomy and was not different for groups with or without stent. There were 2 cases recorded that had only 1 stent removed at 6 weeks after surgery, which was due to lack of communication. In 1 patient, the missed stent was identified immediately and removed during the same admission, but in the second patient, it was highlighted at ultrasonography performed for deranged renal function.

Graft and patient survival
We recorded patient and graft survival for patients with double ureters and compared these data in the subgroups of living-related donor and deceased-donor transplants; we compared these results with our single-ureter transplant group (group B) (Figure 1 and 2).

Outcomes
No statistically significant difference was noted between the groups with single or double ureter with respect to postoperative complications, patient survival, and graft survival during mean follow-up 5 years following transplant.

The incidence of double ureter is rare.^1,2 Therefore, renal transplant with double ureters is not commonly performed. However, because of increasing numbers of extended criteria donations¹⁴ and improved techniques of organ procurement and transplant, there is an increased trend of transplanting en bloc kidneys from a pediatric donor^15,16 or dual transplant from elderly donors^17,18 to compensate for low nephron mass. With respect to ureteroneocystostomy, these kidneys are associated with the same challenges as with double-ureter kidney transplant.

The association of urinary complications with poor graft function is well established.^19,20 Different procedures and techniques have been used to minimize these complications. These procedures vary from U-stitch ureteroneocystostomy^21,22 to mucosa-to-mucosa anastomosis with or without the use of ureteral stents.^23-25 However, the outcome of kidney transplant with double ureters is not well studied.

Haferkamp and coworkers presented their series of 19 patients over 30 years who received renal transplants with double ureters including 1 en bloc transplant.¹¹ They reported 10.5% incidence of urinary complications, mainly ureteral stenosis. In comparison, we observed 5.5% incidence of urinary complications, with 1.5% incidence of ureteral stricture. This may be reflected by our current policy of using double J ureteral stents in all cases. Sulikowski and associates reported a small series of 12 patients over 20 years.7 In their series, they performed a distal anastomosis of the 2 ureters to make a single ostium for anastomosis. They reported a high incidence of temporary urinary fistula (33.33%), but overall there was no graft loss secondary to urinary complications. In our series, we had 19 bench reconstructions of ureters into a single common ostium. We had only 1 urinary leak from this subgroup. At the time of reimplant, it is important to carefully look at pelviureteric anatomy of the kidney to avoid missing a second ureter that later can present with urinary leak or urinoma. We had no case in the double-ureter transplant group in which a kidney transplant was lost secondary to urologic complications.

This study demonstrated no patient and graft survival disadvantage in recipients receiving renal transplant from kidneys with double ureters. It also demonstrated no difference between the techniques on implant at surgery. We believe that double-ureter transplant does not require additional risk discussion with the recipient because it is safe. However, when a stent is used, physicians should ensure that a mechanism is in place for both stents to be removed postoperatively. It is important to provide this information verbally to the patients and their families, so they can take responsibility in follow-up and communicate this important information to the medical team that will perform stent removal.

Volume: 13 Issue: 2 April 2015

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