The effect of inclined position on stone free rates in patients with lower caliceal stones during SWL session.

OBJECTIVE: To compare the outcomes of shock wave lithotripsy (SWL) combined with inclined position and SWL alone in patients with lower pole calyx stones.

METHODS: Seven hundred forty patients who underwent SWL treatment for lower pole renal stones with a total diameter of 2 cm or less were prospectively randomized into two groups. They were comparable in terms of age, sex, and stone diameters. Patients with lower calyceal stones (4-20 mm) were randomized to SWL (368 patients) or SWL with simultaneous inclination (372 patients) with 30o head down Trendelenburg position). Shock wave and session numbers were standardized according to stone size. Additional standardized shock waves were given to patients with stone fragments determined by kidney urinary bladder film and ultrasound at weeks 1, 4, 10.

RESULTS: The overall stone free rate (SFR) was 73% (268/368) in patients with SWL alone and 81% (300/372) in SWL with inclination at the end of 12th week (p = 0.015). No significant adverse events were noted in both treatment groups.

CONCLUSION: Simultaneous inclination of patients during SWL session increase SFR in lower caliceal stones significantly compared to SWL treatment alone.