The effects of pretreatment oral hydration on extracorporeal shockwave lithotripsy outcomes: A randomized controlled trial.

Introduction: We sought to investigate the effects of pretreatment oral hydration on the outcomes of extracorporeal shockwave lithotripsy (ESWL).

Methods: Patients who undergoing ESWL for a single radio-opaque renal or proximal ureteric calculus ≤2 cm in size were randomized into two groups. The oral hydration group (OHG) administered 600 ml of water before ESWL, while the control group (CG) did not. The urine was held during ESWL to create a full bladder induced hydronephrosis. Both groups received the same ESWL protocol at four-week intervals and a maximum of three sessions. The primary outcome was stone-free rate (SFR) at 12 weeks and the secondary outcomes were the total number of shockwaves and the number of ESWL sessions.

Results: A total of 154 patients completed the study, 77 patients in each group; both groups were comparable in demographic data and stone characteristics. The SFR was 84.4% in the OHG and 68.8% in the CG group (p=0.036). Stone fragmentation in OHG was significantly higher than CG, 75.3% vs. 58.4% (p=0.040). OHG had more cases of artificial hydronephrosis (55.8% vs. 27.3%, p=0.001) and higher urine volume (375 [148] ml vs. 230 [110] ml, p<0.001). There were no statistically significant differences in the total number of shockwaves and the number of ESWL sessions. The auxiliary procedures in OHG were less than CG (15.6% vs. 31.2%, p=0.049).

Conclusions: Pretreatment oral hydration, together with holding urine during ESWL, has increased stone disintegration and SFR. This simple and safe technique improves the ESWL outcomes.