IN-SITU EXTRACORPOREAL SHOCKWAVE LITHOTRIPSY OF DISTAL URETERAL STONES - PARAMETERS FOR THERAPEUTIC SUCCESS

Between January and December 1989, 123 patients with distal ureteral s tones were treated with in situ extracorporeal shockwave lithotripsy ( ESWL) using a modified HM3 Dornier lithotriptor. One hundred and three patients (83.7%) were stone-free, 20 patients (16.3%) had small resid ual stones (<1 mm(2)) that passed spontaneously. In situ ESWL treatmen t alone was successful in 88 of the 103 stone-free patients (85.4%). F ifty-six (54.4%) needed 1 ESWL session, 26 (25.2%) needed 2 ESWL sessi ons. Nineteen of the 123 patients (15.4%) needed auxiliary endourologi cal measures. The results of ESWL treatment were correlated to prether apeutically identified parameters such as stone size, radiopacity, out er contour, shape, inner structure, biochemical analysis of the stones and grade of dilatation of the upper urinary tract. The results prove that size (greater than or equal to 75 mm(2)), radiopacity and grade of dilatation have a direct correlation to the difficulty to disintegr ate ureteral stones.