Subureteric injection for the treatment of vesicoureteral reflux in transplant kidneys.

Introduction: Treatment of de novo vesicoureteral reflux (VUR) into the transplanted kidney constitutes a clinical challenge. Herein, we present our data on patients who underwent endoscopic subureteric injection for the treatment of VUR following renal transplantation (RT) in our center.

Methods: The patients who underwent endoscopic subureteric injection for VUR into the transplanted kidney after RT in our department between 2008 and 2023 were reviewed retrospectively. Indication for subureteric injection, age, gender, laterality, number of injections, amount of material used, renal failure etiology, auxiliary procedures, and treatment success were noted. All interventions were performed by pediatric urologists who also perform RT.

Results: During a median followup of 27.5 (4-160) months, 22 patients (17 women, 77.2%) and 23 transplanted ureters (13 right, eight left, one bilateral) were treated with subureteric injections. In all patients, the indications for subureteric injection were recurrent febrile urinary tract infection (UTI), and the grades of VUR varied between I and IV. Patients received a median of 1.65 cc (0.7-2.7) dextranomer-hyaluronic acid copolymer. In total, 10 RTs (eight from living donors, two from cadaveric donors) were performed in another center, whereas 13 RTs were carried out in our center (eight from cadaveric donors and five from living donors). Among the patients who were transplanted in our center, the rate of subureteric injections due to de novo symptomatic VUR after RT was 2.2% (13/593 patients). After subureteric injections, five patients required a second injection due to the recurrence of VUR. Ureteroureterostomy (to the native ureter) was performed in two patients who had further UTIs after the second endoscopic treatment. Eventually, 19/21 patients (90.4%) benefited clinically from the endoscopic treatment and none of the patients underwent re-do ureteroneocystostomy. It is noteworthy that the etiology of renal failure was VUR nephropathy in seven (31.8%) patients.

Conclusions: Subureteric injection provides a high clinical success for the treatment of de novo VUR after RT.