Abstract

Objective: To assess the effect of the gravity-related radiographic features on the success rate of extracorporeal shock wave lithotripsy (SWL) in renal stones.

Materials and methods: A total of 79 patients (mean age 47.34±12.9 year) who underwent SWL due to renal pelvis stones (mean area 162.58±130.31 mm²) between 2005 and 2008 were enrolled. Three angles on the pretreatment excretory urography were measured; the inner angle between the axis of the lower pole infundibular and ureteropelvic axis (angle 1), lower pole infundibular axis and main axis of pelvis-ureteropelvic junction point (angle 2), and lower pole infundibular axis and perpendicular line (angle 3). Age, number of session, stone burden, numbers of shock waves, and presence of hydronephrosis were defined for all patients. The significant predictors of stone-free rate after the application of SWL was defined.

Results: The success rate was 53.2%. All angles, number of sessions, stones burden, and number of shock waves were significant predictors of stone free rate. However, age, sex and the presence of hydronephrosis did not show similar effects.  

Conclusions: Gravity-related factors have significant role on the stone-free rate in patients treated with SWL for renal pelvis stones. These radiographic parameters may be used to determine the patients who will benefit from SWL.