Purpose: To evaluate the efficacy of oral dissolution therapy (ODT), shock wave lithotripsy (SWL), and combined SWL and ODT for medium-sized radiolucent renal stone (RLS).
Methods: A randomized controlled trial for patients with medium-sized RLS, 1-2.5 cm, ≤ 500 Hounsfield unit (HU). The ODT patients were counseled for oral potassiumsodium-hydrogen citrate (Uralyt-U®). The 2nd group underwent SWL and the last group had combined SWL and ODT. The primary outcome, stone-free rate (SFR) at 3 months, was assessed by non-contrast computed tomography (NCCT). We defined complete response (success) if no residual fragment were detected by NCCT; partial response (failure) if there was a decrease in stone size, but presence of residual stones; no response if there was no change or increase in stone size (failure).
Results: 150 patients completed follow-up. The SFR at 1st month and 3rd month were, respectively; 16% and 50% in the ODT group, 10% and 46% in the SWL group, and 35% and 72% patients in combined group with (p = 0.03 and 0.003, respectively. The overall SFR for all groups was 66%. Combined treatment and initial response in first month follow-up were independent factors predicting SFR. In addition, combined treatment significantly decreased the overall stone volume (p = 0.03) and the need for additional stone management procedures after 3 months (p = 0.01).
Conclusion: Combined ODT and SWL treatment constitutes the most rapid and effective therapeutic approach for medium-sized RLS, decreasing overall stone volume as well as the number of SWL sessions needed in comparison to SWL therapy, alone.
Keywords: Dissolution therapy; Radiolucent stones; Shock wave lithotripsy (SWL); Urolithiasis.