Cook Medical is touting a recent study that compares its Zilver Biliary Stent to the most commonly used device, the Wallstent from Boston Scientific. Essentially, the conclusion of the international multi-center study, published in Gastrointestinal Endoscopy, is that the two stents have very similar performance characteristics.
The MOZART study included a total of 241 patients in nine centers in the U.S., Canada and Europe with malignant biliary obstructions – a complication associated with several forms of cancers in which the bile ducts of the liver become blocked by tumors. Although plastic stents are cheaper than metal for this purpose, data suggests that plastic stents occlude more readily when compared to SEMS, necessitating repeat procedures.
The two biliary stents in the MOZART study differ significantly in design, materials and mechanism of expansion, but achieved equal patency by several measures. In usage of both stents fewer than a quarter became occluded after placement over the life of the study. Treating physicians, who had more experience with Boston Scientific's stent, reported positioning the Zilver was not difficult.
Cook Medical's Zilver Biliary Stent is made of flexible laser-cut nitinol tubing, which is inherently kink-resistant and allows for conforming to the ductal wall while providing reliable patency. Additionally, the interlocking design construction means the stent’s ends are atraumatic – potentially reducing the risk of ulceration or perforation. Four gold radiopaque markers at each end of the stent also provide added fluoroscopic visualization that can aid in more accurate placements.