The transgluteal approach to shockwave lithotripsy to treat distal ureter stones: a prospective, randomized, and multicenter study

Abstract

Purpose: We compared the outcomes of SWL to treat distal ureter stones with regard to the conventional prone and supine positions using the transgluteal approach through the greater sciatic foramen.

Methods: A prospective, randomized, single-blind, and multicenter study was conducted between October 2014 and July 2015. The inclusion criteria were radio-opaque distal ureter stones with a maximum diameter of 0.5-2 cm as measured on a CT scan. The included 160 patients were randomly assigned to two groups: the prone group (n = 80; treated in the conventional prone position) and the transgluteal group (n = 80; treated in the supine position using a transgluteal approach). In the latter group, the focused shock wave was transmitted through the greater sciatic foramen with the head positioned at a 40° angle to the vertical. "Stone-free" was defined as the complete clearance of stone fragments, assessed using a CT scan at 2 weeks after treatment. Overall satisfaction was self-reported using a 0-5 Likert scale.

Results: The overall efficacy was 66.9%. The stone-free rate was significantly higher in the transgluteal group (72.6%) than in the prone group (54.7%; odds ratio 2.413, 95% CI 1.010-5.761, P = 0.023). No serious adverse events due to treatment were observed in either group. The satisfaction score of the transgluteal group was 4.21 ± 0.81, and 83.6% were willing to repeat the same procedure if necessary.

Conclusions: SWL using the transgluteal approach via a supine position through the greater sciatic foramen was more effective than via the conventional prone position. Furthermore, this approach provided a comparably safe and satisfactory procedure.

Keywords: Lithotripsy; Patient positioning; Prone position; Supine position; Treatment outcome; Ureteral calculi.