IN-SITU EXTRACORPOREAL SHOCKWAVE LITHOTRIPSY OF MIDDLE AND LOWER URETERAL STONES - A BOOSTED, STENTLESS, VENTRAL TECHNIQUE

Objectives: To assess the outcome of a boosted, stentless, ventral in situ extracorporeal shockwave lithotripsy (ESWL) of middle and lower u reteric stones using a shockwave head from the opposite side of the st one using a Lithostar Siemens lithotriptor for stones larger than aver age size and of longer duration in place. The purpose was to attain a high clearance rate in a short time thereby avoiding auxiliary procedu res. Methods: A prospective study of 132 patients (134 stones) with mi ddle and lower ureteric stones >6 mm in place for more than 2 weeks we re treated with a Siemens Lithostar lithotriptor in the prone position with sedoanalgesia on an outpatient basis. No stents were planned ahe ad of treatment. The shock head from the opposite side of the stone tr ansversing only through the soft tissue of abdomen and pelvis was used routinely. Localization was done using fluoroscopy and snapshots and intravenous contrast was given when needed. The boosted sessions were done on day 1 (S1), day 2 (B1), day 7 (S2) and day 14 (S3) when needed or till adequate fragmentation after any session, even the first one. This procedure was evaluated at the 6th week of management or at adeq uate fragmentation and clearance if before that time. Results: This st udy inlcuded 115 males and 17 females with a mean age of 47 +/- 15 and 53 +/- 11 years. Stone size defined as the longest stone diameter as measured in plain film of the abdomen was 0.75-2.6 cm with a mean of 1 .1 cm. All but two stones were successfully fragmented. Only 12% neede d interference for developing obstruction and/or complication during t he planned treatment. 106 patients needed only SI or B1, 20 patients n eeded session 2, 6 patients needed session 3. Clearance was 43% by the 2nd day, 79% by the 7th day, 94% by the 14th day and 98.5% by the end of the 6th week. Conclusion: For larger ureteric stones a boosted ste ntless ventral shockwave lithotripsy for in situ middle and lower uret eric stones gave good results with short time clearance and without un usual side effects. The ventral application of shockwave from the oppo site side was found more convenient with the Siemens Lithostar lithotr iptor. We recommend this approach to be the initial procedure for midd le and lower ureteric stones when they are larger than average, of lon ger duration and/or expected to be of harder texture as an outpatient procedure under sedoanalgesia to minimize the need for auxiliary proce dures.