Transplant Ureteral Stenosis after Renal Transplantation: Risk Factor Analysis

Abstract

Introduction: The results of kidney transplants have improved dramatically in recent years, leading to reduced morbidity and mortality. Despite continuous improvements, urological complications occur at a rate of 2.6%–15%. Ureteral stenosis of graft ureters is the most common complication, with a probability of 0.5%–6.3%. This study aimed to determine the incidence of ureteral stenosis after kidney transplantation and identify risk factors that distinguish transplant patients with and without ureteral stenosis. Methods: This study retrospectively analyzed patients who had undergone kidney transplantation at the Department of Urology of the Friedrich-Alexander University Erlangen-Nuremberg between 2001 and 2015. Forty-seven patients developed ureteral stenosis during the operation. Most of the ureteral stenosis cases occurred in the first 4 months after transplantation. Kaplan-Meier analysis and the log-rank test were used to calculate the cumulative risk, and the Mann-Whitney U test was used nonparametrically. The significance level was set at p < 0.05. Results: Statistical analysis showed that residual diuresis (p = 0.008), cold ischemia time (CIT) (p = 0.040), the body mass index (p = 0.027), and donor serum creatinine value (p = 0.039) showed a significantly different distribution between recipients with or without ureteral stenosis after kidney transplantation. In multivariate Cox’s regression modeling, residual diuresis and the donor serum creatinine level were identified as the only independent predictors of patients’ stenosis-free survival. Conclusion: Urological complications not diagnosed and treated in time endanger the success of kidney transplantation. After evaluating the kidney transplantation data of the patients at the Transplant Center Erlangen-Nuremberg from 2001 to 2015, residual diuresis, CIT, the body mass index, and donor serum creatinine value were found to influence the development of ureteral stenosis.

Ureterovesical Anastomosis Complications in Kidney Transplantation: Definition, Risk Factor Analysis, and Prediction by Quantitative Fluorescence Angiography with Indocyanine Green

“…Urological complications occur frequently after renal transplantation. In the recently published literature, the incidences range between 3.6% and 15.5% [ 4 , 18 , 19 , 20 , 21 , 22 , 23 , 24 ], but rates up to 30% have been reported [ 3 , 25 ]. Their occurrence in immunosuppressed patients is associated with relevant morbidity, including negative implications for long-term graft survival [ 26 , 27 ], and even with an increased mortality rate [ 4 ].…”

“…The two most common subtypes of ureterovesical anastomosis complications are stenosis/stricture/obstruction and urinary leakage/fistula [ 25 ]. Stenosis occurs in about 3% [ 4 , 18 , 25 , 26 ] and leakage/fistula in 1–4% [ 4 , 20 , 24 , 25 , 28 ]. Management strategies are similar for all subtypes and include mainly ureteric stenting, but also surgical revision [ 29 , 30 , 31 ].…”

“…In the present study, the parameters time since dialysis initiation, type of donation, and need for postoperative dialysis were associated with post-transplant ureteral complications. As shown before, spending a long time on dialysis can lead to bladder atrophy, which increases the risk for ureterovesical anastomosis complications [ 18 , 38 ]. Further risk factors for general postoperative urological complications after kidney transplantation that have been identified in large retrospective case series include male recipient gender [ 21 , 26 , 27 , 33 ], technical aspects [ 1 , 4 , 27 , 28 ], cold ischemia time [ 18 ], extended criteria donors [ 39 ], donor age, and delayed graft function [ 40 ].…”

“…As shown before, spending a long time on dialysis can lead to bladder atrophy, which increases the risk for ureterovesical anastomosis complications [ 18 , 38 ]. Further risk factors for general postoperative urological complications after kidney transplantation that have been identified in large retrospective case series include male recipient gender [ 21 , 26 , 27 , 33 ], technical aspects [ 1 , 4 , 27 , 28 ], cold ischemia time [ 18 ], extended criteria donors [ 39 ], donor age, and delayed graft function [ 40 ]. In contrast to other studies [ 33 , 41 , 42 ], arterial multiplicity did not influence the development of ureterovesical anastomosis complications in our patient cohort, but this is most likely due to the limited number of patients expressing this feature here.…”

Acute renal failure after kidney transplantation due to mizoribine-induced ureteral stones

“…Ureteral obstruction can cause acute renal failure in the transplanted kidney [ 1 ]. Graft renal and ureteral stones are uncommon [ 2 ]. Mizoribine (MZR) prevents rejection during kidney transplantation by inhibiting lymphocyte proliferation and differentiation.…”