EARLY EXPERIENCE WITH EXTRACORPOREAL SHOCKWAVE DORNIER LITHOTRIPTOR COMPACT

One of the latest developments in extracorporeal shockwave lithotripsy (SWL) is a combination of an electromagnetic energy source with an upgraded parallel online ultrasound imaging for localization. The device is compact, requiring no significant installation or site preparation. Furthermore, it increases the margin of safety of SWL by virtue of the continuous ultrasound monitoring. A hundred sessions of SWL were performed on 88 patients using the Dornier Compact machine. Ninety three renal units having an average of 1.7 stones were treated (two had upper ureteric stones). Of the 135 stones, 2 (1.5%) were radiolucent and 4 (3%) were of faint opacity. Intravenous sedation was used in all patients except one 13-year-old patient, who required general anesthesia. Patients received an average of 2409 shocks per session, and the maximum power setting ranged from 1 to 6 (average 4.7). A plain film was obtained immediately before and after treatment. Early adverse effects were uncommon, and all were mild. Patients were followed by plain films at 2 weeks and 3 months. In 35 sessions (25 solitary and 10 multiple stones), the stones were considered completely fragmented; in 63 sessions, the stones (43 solitary and 20 multiple) were judged to be partial fragmented; and 2 sessions (solitary stones) resulted in poor fragmentation. The mean (+/-SD) stone dimension in the group with complete fragmentation was 9+/-4.8 (range 2-24) mm, compared with 11+/-6.3 (range 2-38) mm in those with no or partial fragmentation (P=0.0095). After 2 weeks, 23 of 69 systems (33%) were stone free, while 46 showed residual stones. At 3 months, 80% were stone free. Two lucent and three of four poorly opaque stones were treated successfully. Stone burden was the critical factor in determining the outcome. These data are in favor of the safety and efficacy of this device. Immediate radiographs may be inaccurate in predicting the final result of SWL.