Extracorporeal piezoelectric lithotripsy for complicated bile duct stones

Today, common bile duct stones are extracted endoscopically. After endoscopic sphincterotomy, nearly 90% of all stones can be removed with a Dormia basket or a mechanical lithotripter. Problems are encountered if there are larger stones or a duct stenosis. New conservative therapies do serve as an alternative to surgical intervention for those few patients in whom endoscopic measures have failed. Stone fragmentation can be achieved by extracorporeal shock wave lithotripsy, and remaining fragments can be removed endoscopically. So far, authors of most reports on the successful disintegration of common bile duct stones used the Dornier lithotripter. Stone localization is thus achieved with x-rays, and the shock waves are generated by an underwater spark discharge. We report on our experiences and results with extracorporeal piezoelectric shock wave lithotripsy (EPL) in 19 patients with complicated bile duct stones. With this lithotripter, stones are visualized by ultrasound, and shock waves are produced by a piezoelectric acoustic generator. Fragmentation was achieved in 84.2%, and complete stone removal in 78.9%. These results show that piezoelectric lithotripsy is also a useful method for the treatment of complicated bile duct stones, as has already been proved for the electrohydraulic- and electromagnetic-generated shock waves systems. However, the renunciation of general anesthesia and the need for analgesia or sedation in only 25% of the treatments render this lithotripter system attractive, especially for elderly and frail patients.