RESUMO
To evaluate the effect of SWL, anatomical influence on fragmentation and stone clearance. The success of Shock Wave Lithotripsy [SWL] arises from effective fragmentation and stone clearance. One hundred patients [65 males and 35 females] with lower calyceal stones treated with SWL were enrolled in the study and analyzed retrospectively, at Al-Azhar Lithotripsy Unit, Al-Hussein University Hospital. Stone was single in 90 patient and multiple in 10 patients. Regarding stone radiodensity, the stones were hyper dense in 35 patients, dense in 50 patients and radiolucent in 15 patients. Those patients were divided into two groups, Group I includes 60 patients, they were considered to be completely stone free 6 months after SWL, and forty patients were having residual stones in Group II. The mean size of stones in group I was 0.9cm in diameter, while in group II the mean size was 1.7cm. The PC angle, diameter of lower calyx infudibulum and lower pole calyceal pattern were determined from intravenous urography. Residual stones were found in 100% of patients with PC angle<90°, in 100% of patients with an infundibular diameter<4mm, and in 100% of patients with complex lower calyceal pattern. From the presenting results the PC angle, lower calyx infundibular diameter and anatomy of lower pole calyx SWL for lower calyceal stones