Extracorporeal shock wave lithotripsy and methyl tert-butyl ether for gallbladder stones

Twenty-one patients with gallbladder stones of 1.1-2.6 cm in diameter were treated by extracorporeal shock wave lithotripsy (ESWL) combined with dissolution using methyl tert-butyl ether (MTBE). In 18 of 21 patients, ESWLs were followed by MTBE instillation through a catheter placed percutaneously via the liver and the gallbladder bed under ultrasonographic and fluoroscopic guidance. As a result, 15 of the 18 patients were cleared of their stones after 54 minutes to 3 hours of dissolution. In the other three cases initially treated by MTBE, ESWLs were added because of no dissolution or poor efficacy. Consequently, after additional 3-5 hours of instillation, complete dissolution in one and subtotal dissolution in two were achieved. Our preliminary results indicated that ESWL followed by MTBE dissolution in the management of cholesterol gallbladder stones was reasonable. On the one hand, ESWL can enhance dissolution by increasing the surface area of stone, and on the other hand MTBE can instantly clear the fragments created by ESWL, so that long-term bile acid intake and potential side effects caused by fragment migration might be avoided.