Effectiveness of endourological management of ureteral stenosis in kidney transplant patients: EAU-YAU kidney transplantation working group collaboration

PURPOSE: Ureteral stenosis (US) in kidney transplant (KT) recipients is associated with poorer long-term graft survival. Surgical repair is the standard of care, and endoscopic treatment represents an alternative for stenosis < 3 cm. We aimed to determine the effectiveness and safety of endourological management of US in KT patients and predictors of failure. METHODS: A retrospective multicenter study was conducted in four European referral centers, including all KT patients with US managed endoscopically between 2009 and 2021. Clinical success was defined as the absence of upper urinary tract catheterization, surgical repair or transplantectomy during follow-up. RESULTS: A total of 44 patients were included. The median time to US onset was 3.5 months (IQR 1.9–10.8), the median length of stricture was 10 mm (IQR 7–20). Management of US involved balloon dilation and laser incision in 34 (79.1%) and 6 (13.9%) cases, respectively, while 2 (4.7%) received both. Clavien–Dindo complications were infrequent (10%); only one Clavien ≥ III complication was reported. Clinical success was 61% at last follow-up visit (median = 44.6 months). In the bivariate analysis, duckbill-shaped stenosis (vs. flat/concave) was associated with treatment success (RR = 0.39, p = 0.04, 95% CI 0.12–0.76), while late-onset stenosis (> 3 months post KT) with treatment failure (RR = 2.00, p = 0.02, 95% CI 1.01–3.95). CONCLUSIONS: Considering the acceptable long-term results and the safety of these procedures, we believe that the endoscopic treatment should be offered as a first-line therapy for selected KT patients with US. Those with a short and duckbill-shaped stenosis diagnosed within 3 months of KT seem to be the best candidates.