Petersen, Bret T.

Background and Study Aims. Endoscopic placement of self-expanding metal stents (SEMSs) is indicated for palliation of inoperable malignant biliary obstruction. A fully covered biliary SEMS (WallFlex Biliary RX Boston Scientific, Natick, USA) was assessed for palliation of extrahepatic malignant biliary obstruction.Patients and Methods. 58 patients were included in this prospective, multicenter series conducted under an FDA-approved IDE. Main outcome measurements included (1) absence of stent occlusion within six months or until death, whichever occurred first and (2) technical success, need for reintervention, bilirubin levels, stent patency, time to stent occlusion, and adverse events.Results. Technical success was achieved in 98% (57/58), with demonstrated acute removability in two patients. Adequate clinical palliation until completion of followup was achievedin 98% (54/55) ofevaluablepatients, with 1 reintervention due to stent obstruction after 142 days. Mean total bilirubin decreased from 8.9 mg/dL to 1.2 mg/dL at 1 month. Device-related adverse events were limited and included 2 cases of cholecystitis. One stent migrated following radiation therapy.Conclusions. The WallFlex Biliary fully covered stent yielded technically successful placement with uncomplicated acute removal where required, appropriate reduction in bilirubin levels, and low rates of stent migration and occlusion. This SEMS allows successful palliation of malignant extrahepatic biliary obstruction.

Surgical removal of gallstones is performed about 500 000 times per year in the United States. Although the usual cost ranges from $5000 to more than $10 000 per patient, the operative mortality is less than 1% for otherwise healthy persons. Nonsurgical dissolution of gallstones is often possible, but many gallstones contain calcium compounds that slow or prevent dissolution using the direct content cholesterol solvent, methyl tertbutyl ether (MTBE). Extracorporeal shock wave lithotripsy (ESL) has potential clinical utility for facilitating dissolution and possibly allowing spontaneous or induced passage of small fragments via the bile ducts and intestines. Obstacles to be overcome include predictable fragmentation of multiple stones up to 3 cm in diameter so that all particles are small enough to be rapidly dissolved or pass safely through the bile ducts (⩽ 3 mm). This must be achieved using biologically tolerable shock wave dosages without requiring general anesthesia within one or two treatment sessions. Acute and chronic safety, patient acceptance, and cost must be competitive with surgical treatment. Initial experience suggests that only solitary noncalcified stones (10% of patients with stones) have a high probability of success using ESL plus oral bile acid dissolution therapy. Improving ESL technology and direct contact fragment dissolution using MTBE should increase the clinical utility of shock wave lithotripsy of gallstones.