Electrokinetic lithotripsy: safety, efficacy and limitations of a new formof ballistic lithotripsy

Objective To investigate the safety and efficacy of electro-kinetic lithotr ipsy (EKL), a ballistic lithotripter which uses high-energy magnetic fields to propel an impactor to fragment calculi. Patients and methods The records and radiographs of 121 patients who underw ent ureteroscopy using the EKL for stones in the upper (26), mid (26) or lo wer (67) ureter were reviewed retrospectively. Ureteroscopy was performed w ith an 8.5 F semi-rigid ureteroscope, through which a 3 F EKL probe was pas sed. Results A total of 148 stones (mean stone size 11.5 mm, range 6-40) in 121 patients were treated using the EKL. One patient was lost to follow-up. Of 148 stones, 147 (99.3%) were fragmented, including five that had resisted f ragmentation with either pulsed-dye laser or electrohydraulic lithotripsy. Despite this, only 45 of 56 patients (80%) with a single stone in the lower ureter were rendered stone-free after a single ureteroscopic procedure. Se ven patients in this group (12%) required shock-wave lithotripsy for fragme nts that had been propelled into the kidney, while four patients (7%) requi red repeat ureteroscopy for retained ureteric fragments. Complications were limited to minor ureteric perforations in two patients, both of which were treated with a stent. Conclusion EKL is an inexpensive and reliable endoscopic method which fragm ents nearly all urinary calculi. Its limitations include the propulsion of fragments and the need to use an offset, semi-rigid ureteroscope. We recomm end the use of a basket or graspers to remove fragments of greater than or equal to 4 mm after EKL.