Comparison of a magnetic retrieval device vs. flexible cystoscopy for removal of ureteral stents in renal transplant patients: A randomized controlled trial

INTRODUCTION: Placement of a ureteral stent at the time of renal transplantation can reduce complications when compared to non-stented anastomoses. Removal by flexible cystoscopy can be associated with discomfort, risk for infection, and high costs. New magnetic stents offer a means of bypassing cystoscopy by use of a magnetic retrieval device. Our objective was to compare clinical and cost-related outcomes of conventional and magnetic stents in patients undergoing deceased donor renal transplantation. METHODS: Patients were randomized to receive either a conventional or a Black-Star^® magnetic stent. Clinical, procedural, and cost outcomes were assessed, and the Ureteral Stent Symptom Questionnaire (USSQ) was administered with the stent in situ and after stent removal. All variables were compared between groups. RESULTS: Forty-one patients were randomized to conventional (n=19) or Black-Star (n=22) stent. The total time for stent removal under cystoscopy was significantly longer compared to Black-Star removal (6.67±2.47 and 4.80±2.21 minutes, respectively, p=0.019). No differences were found in the USSQ domains between groups. Rates of urinary tract infections and surgical complications between groups were similar. Stent removal was well-tolerated in both groups. Black-Star stent use resulted in a cost savings of $304.02 Canadian dollars (CAD) per case. CONCLUSIONS: USSQ scores suggest that stent removal with the Black-Star magnetic stent is as equally well-tolerated as flexible cystoscopy by renal transplant patients. Black-Star stent removal was significantly faster than conventional stents. No differences in discomfort, infection rate, or complication rate were found. Use of the Black-Star stent resulted in an estimated annual savings of $27 360 CAD at our centre.