Effects of ureteral stents on risk of bacteriuria in renal allograft recipients

Background Placement of ureteral stents at the time of renal transplantation is thought to decrease the incidence of postoperative complications, such as anastomotic leakage and stenosis. However, stents may also predispose to post-transplantation urinary tract infection, which can lead to increased risks of graft dysfunction, sepsis, and death. The aim of this study was to analyze the risk of post-transplantation bacteriuria with ureteral stent placement in renal allograft recipients. Methods A retrospective single-center analysis was conducted to investigate the incidence of bacteriuria in all renal allograft recipients transplanted between January 2007 and March 2009. Recipients were categorized as in the nonstent group (NSTG) or the stent group (STG). Stent removal was performed per protocol at 6weeks, and all patients were followed for at least 1year post transplantation. In the NSTG, the incidence of bacteriuria was assessed at 0-6, 6-12, and 12weeks to 1year post transplantation. In the STG, bacteriuria was assessed prior to stent removal, 6weeks after stent removal, and thereafter until 1year post transplantation. Results A total of 395 renal allograft recipients, 183 in the NSTG and 212 in the STG groups, were studied. The overall incidence of bacteriuria within 1year post transplantation was similar between NSTG and STG (28.0 vs. 24.0%, P=0.38). No difference was found in the incidence of bacteriuria when NSTG and STG were compared at 0-6weeks or prior to stent removal (9.7% vs. 9.1%, P=0.81), at 6-12weeks, or 6weeks after stent removal (6.7% vs. 5.8%, P=0.75), and thereafter for 1year post transplantation (13.3% vs. 10.8%, P=0.46). The incidence of graft failure at 1year was similar in NSTG and STG (6.2% vs. 4.9%, P=0.6). Urinary anastomotic leakage occurred in none of the NSTG and 2 of the STG recipients. On multivariate analysis, risk factors for bacteriuria were female recipient gender (odds ratio [OR] 2.5, 95% confidence interval [CI] 1.5-4.3, P=0.001), delayed graft function (DGF) (OR 2.1, 95% CI 1.2-3.8, P=0.01), and postoperative Foley catheterization for >5days (OR 4.7, 95% CI 1.3-17.6, P=0.02). Conclusion Independent risk factors for bacteriuria following kidney transplantation include DGF, prolonged postoperative Foley catheterization, and recipient female gender, but not placement of ureteral stents.