Extracorporeal Shockwave Lithotripsy for Ureterolithiasis in Patients with Urinary Bilharziasis: Efficacy and Variables That Influence Treatment Outcome

Abstract

Objectives: Schistosomiasis affecting the ureter is commonly accompanied by ureteric dilatation with or without ureteric stricture and altered ureteric wall motility that can influence extracorporeal shockwave lithotripsy (ESWL) results. This study attempts to identify variables that may influence the outcome of ESWL in the treatment of ureterolithiasis in patients with urinary bilharziasis.Patients and Methods: Forty–three patients with urinary schistosomiasis and ureterolithiasis treated with ESWL were reviewed. The study data include characteristics of patients, stones, urinary tract treated and details of ESWL treatment.Results: Thirty–five patients (81.3%) were stone–free at 3 months. Multivariate analysis with logistic regression identified two significant variables that influenced treatment outcome, namely the presence of ureteric stricture (p = 0.004) and the ESWL voltage (p = 0.003). Ten ureteric strictures were encountered in 9 patients (21%), the majority of these were diagnosed post–ESWL when patients failed to pass well–fragmented stones in spite of pre–ESWL evaluation.Conclusions: In situ ESWL is a safe and effective first line of treatment for urinary stones in bilharzial ureters. The presence of concomitant bilharzial stricture is a significant variable which affects the treatment outcome. Every effort should be made to rule out and deal with possible complicating factors such as ureteric strictures in the pretreatment period.