The impact of the Dornier Compact Delta lithotriptor on the management of primary ureteric calculi

OBJECTIVE: To assess the effectiveness of the Dornier Compact Delta lithotriptor on the management of in situ primary ureteric stones. PATIENTS AND METHODS: 137 patients with primary ureteric stones were treated at a tertiary urological center using the latest Dornier Compact Delta lithotriptor between January 1999 and January 2002. Effectiveness of lithotripsy, retreatment rate, reasons for failure and complications were assessed. RESULTS: 102 males and 35 females with primary ureteric stones underwent ESWL treatment at our center. 74 patients had upper, 37 middle and 26 lower ureteric locations respectively.Mean stone size was 10 mm (range 8-25 mm). Mean numbers of sessions required were 1.8 (range 1-3). The retreatment rate was 33% in upper ureteric, 29% in mid ureteric and 26% in lower ureteric locations respectively. Complete clearance rate at 3 months was 86% for upper ureteric, 79% for mid ureteric and 79% for lower ureteric. 29 patients had auxiliary treatment in the form of double J ureteric stenting or percutaneous nephrostomies. 26 patients failed treatment and underwent ureteroscopic or ante grade percutaneous removal. Stone size was the only significant factor correlating with failure. The mean size of stones in the successful group was 12 mm as compared to 17 mm in failure group. The likelihood of success following a failed second session (no disintegration or disintegration with fragments more than 6 mm) of treatment was 13.4%. Complications including, steinstrasse, colic, UTI and petechial haemorrhage were seen in 35 patients. One patient developed pyonephrosis and subsequently required nephrectomy. CONCLUSION: An electromagnetic shock wave lithotriptor using the EMSE-150 shock wave emitter is an effective in situ treatment of primary ureteric stones. Patients with large stone size are likely to have a higher retreatment rate, more auxiliary procedures and complications. Having a failed second treatment session, the likelihood of a successful outcome after third session of ESWL is poor.