Feasibility of an Updated Randomised Controlled Trial on Surgical Urolithiasis Treatments: The Pilot Trial for the German Endoscopic versus Shock Wave Therapy Study (GESS)

Data comparing treatments for urolithiasis are often outdated, with inconsistent results or poor methodological and reporting quality. We report a pilot study in preparation for a larger multicentre randomised controlled trial (RCT) comparing shockwave therapy and ureteroscopy in patients with a single urinary stone of ≤20 mm in the upper urinary tract. Primary objectives included screening completeness, patients’ willingness to participate, their remaining in the study, the suitability of the eligibility criteria, and the acceptability of the outcome measures. Screened individuals not invited to participate were those with no indication for active treatment among referred patients (n = 166), those who staff failed to screen (n = 99), and patients not meeting the inclusion criterion of a single stone (n = 422). Of the 176 patients invited, 116 refused to participate. Ultimately, we were able to recruit 60 patients within 34 mo. All patients underwent their allocated treatments. This pilot trial provides an in-depth analysis of the feasibility of an RCT on surgical treatments for upper urinary tract urolithiasis in a highly regulated health care system. The study procedures and outcome measures proved acceptable and feasible. On the basis of these data, we propose a pragmatic, multicentre RCT to deliver updated, high-level evidence on the efficacy of currently available treatments for urolithiasis. We performed a small pilot trial comparing current treatments in urolithiasis. We were able to prove the feasibility of a larger multi-institutional trial with regard to the time needed to recruit an adequate number of patients and the acceptability of the treatments and outcome measures. With this single-centre pilot trial we were able to prove the feasibility of a larger multicentre trial to compare current treatments (shockwave lithotripsy and ureteroscopy) for stones of ≤20 mm in the upper urinary tract.