Fluoroscopy-free minimally invasive ureteral stricture balloon dilatation: a retrospective safety and efficacy cohort study

Background: Traditional ureteral stricture balloon dilation was performed with fluoroscopic assistance. The use of a C-arm X-ray machine delivered hazardous radiation to both surgeons and patients. In attempt to eliminate the radiation hazard, we developed a F4.5/6.5 ureteroscope assisted intraoperative X-ray free balloon dilation surgical approach to treat ureteral stricture and to verify its safety and efficacy. Specifically, this method had not been previously reported in the literature. Methods: We demonstrated an intraoperative X-ray free balloon dilation with detailed step-by-step procedures description and video illustration. Clinical data of patients undergoing minimally invasive endourological treatment for ureteral stricture between February 2015 and November 2019 were retrospectively analyzed. All steps of X-ray free balloon dilation were carried out under direct vision of a ureteroscope, and two indwelling F7 ureteral stents were used for 3 months postoperatively. Preoperative, intraoperative, and postoperative clinical data were evaluated, and follow-up results were reported. Successful outcome was defined as disappearance of preoperative symptoms, relief of hydronephrosis and stable of renal function. Univariate and multivariate prognostic analyses were performed. Results: We identified 109 patients who received endourological treatment for ureteral stricture in our hospital's medical database. After excluding patients undergone simple catheter dilation, endoureterotomy and other treatment method, 76 patients received balloon dilation without intraoperative fluoroscopic guidance were included in our study. 4/76 patients report a grade II complication (urinary tract infections, UTIs) according to Clavien Dindo classification. In the 22.5 months median follow-up time, the one-year cumulative success rate and two-year cumulative success rate were 85.9% and 80.2% (61/76), respectively, and the majority (13/15, 86.7%) recurrence of ureteral stricture or hydronephrosis deterioration were found within two years after surgery. The longer stenotic lesion length (>5 mm) or multiple ureter stenosis and compromised blood supply of ureter were significantly associated with postoperative stenosis recurrence. Conclusions: X-ray free endoscopic balloon dilation is a safe and effective procedure that could be performed on patients with ureteral stenosis.