Clinical Experience of Extracorporeal Shock Wave Lithotripsy with Modulith SL-20 in 750 Urinary Calculi

Yim, Jae Sung; Sul, Chong Koo

Abstract

PURPOSE: Extracorporeal shock wave lithotripsy(ESWL) has been established as the first line procedure of urinary stone treatment. We studied retrospectively to evaluate the effectiveness of ESWL.
MATERIALS AND METHODS
ESWL was performed in 750 cases with Modulith SL-20 electromagnetic lithotriptor from January, 1994 to June, 1997 in our Department of Urology.
RESULTS
Most patients were distributed between the fourth and sixth decades 72.5%), and male to female ratio was 1.47:1. There were 750 cases of urinary stones: 172 cases of renal stone(23.0%), 529 cases of ureteral stone(70.4%), 14 cases of renal and ureteral stone(1.9%), 35 cases(4.7%) of bladder stone, and range of size was 5mm-60mm in diameter The success rate according to stone location was 76.2% In renal stone, 98.1% in ureter stone, 84.3% in renal and ureteral stone, and 71.4% In bladder stone. The success rate according to stone size measured on the KUB and sonography was 98.0% in 5-10mm, 82.0% in 11-20mm, 46.4% in 21-30mm and 40.0% over 31mm. The average number of sessions was 2.8 sessions. Of 59 cases of staghorn calculi, 16 were treated without preoperative silicone ureteral stenting, while 43 were treated with preoperative silicone ureteral stunting. The complications were gross hematuria(69.6%), flank pain(13.4%), nausea & vomiting(8.4%), fever(1.9%), steinstrasse(1.2%), perirenal hematoma(0.7%) and uremia(0.1%). The failure rate was 8.8%. The causes of failure were large stone(2.67%), difficulty in eliminating lower caliceal stones(1.33%), bladder stone(1.33%), impact stone(1.07%), caliceal diverticulum(0.93%), infundibular stenosis(0.67%), steinstrasse(0.53%), ureterocele(0.13%), and patient's desire for operation(0.13%).
CONCLUSIONS
ESWL is considered to be a safe and non-invasive treatment method. ESWL therapy is less effective for stones larger than 2cm(43.4%), staghorn calculi(52.5%) or the presence of anatomical obstructions.