Fluoroless ureteroscopic lithotripsy for the definitive management of ureteral stones: a randomised, controlled trial

Abstract

Background: The purpose of this study is to determine the feasibilityand radiation reduction influoroless ureteroscopic lithotripsy (fL-URSL). Operative outcomes and complications are compared betweenfL-URSL and conventional URSL withfluoroscopy (cf-URSL). Methods:This single centre, prospective randomised controlled trialfrom 2017 to 2018, enlisted adults with unilateral ureteral stones.Patients with a history of ureteric stricture, complicated ureteralanatomy, no stone found on ureteroscopy and stone in solitary kidneywere excluded. Eligible patients were randomly assigned to fL-URSLor cf-URSL. In fL-URSL, guidewire insertion, endoscopicadvancement, stone identification, and placement of ureteral stent weredone under direct endoscopic view or tactile feedback. Standbyfluoroscopy was available during all operations. The primary outcomeswere radiation dosage andfluoroscopy time. Secondary outcomes wereendoscopic clearance, stone free rate, operative time, complication,need of auxiliary procedures, and complications. Results: The intended number of subjects in this randomised controlledtrial was 60 (with reported mean radiation dose of conventional URSL at46.4 mGy,fluoroless URSL at 1.1 mGy, power of study of 90% andpredicted dropout rate of 20%) and randomised in a 1:1 ratio. 30 cases inthe fL-URSL arm were compared with 28 cases in the cf-URSL arm.There was no significant difference in age (P=0.879), gender(P=0.397), location of stone (P=0.674), and maximum stone diameter(13.2+/- 11.3 mmvs8.9+/- 2.8 mm,P=0.054).There was a significant reduction of radiation dosage from 5.50+/-6.14 mGy in cf-URSL to 0.12+/- 0.65 mGy in fL-URSL(P=0.000). Thefluoroscopy time was reduced from 40.3+/- 43.1 sto 0.9+/- 4.9 s (P=0.000).There was no significant difference in outcome parameters between fL-URSL and cf-URSL. In fL-URSL and cfURSL the endoscopicclearance (100%vs96%,P=0.48), stone free rate (85.7%vs75.0%,P=0.313), operative time (33.2+/- 16.7 minvs32.9+/- 18.3 min,P=0.941), need for stent (P=0.187) and complications (P=0.730)did not differ significantly. In the cf-URSL arm,flush back of stonesoccurred in 3 patients and 1 patient had extravasation of contrast.There were no intraoperative complications in fL-URSL arm. Conclusions: Fluoroless URSL is safe and feasible alternative toreplace conventional URSL withfluoroscopy. Ureteral stone may bemanaged effectively with minimal ionizing radiation.