The endocoil stent for malignant biliary obstruction

The Endocoil (Instent, Inc., Eden Prairie, MN), first introduced in 1993, is a self-expandable nitinol stent made of a coil spring of nickel-titanium alloy. Advantages of the Endocoil in patients with malignant biliary obstruction were thought to include increased radial force with more rapid stricture dilation, inhibition of tumor ingrowth caused by the stent's coil framework with closed approximation of loops, and the possibility for endoscopic removal. Unfortunately, in subsequent reports of patients undergoing Endocoil placement, there have been significant problems with incomplete expansion or twisting during deployment, stent migration, and tumor ingrowth. This article reviews the available literature regarding Endocoil placement for malignant biliary obstruction and addresses the authors' experience at a tertiary referral center.