Mo1464 The Efficacy and Safety of Threaded Biliary Plastic ”Inside-Stent” for Malignant Hilar Obstruction

The Efficacy and Safety of Threaded Biliary Plastic ”Inside-Stent” for Malignant Hilar Obstruction Osamu Inatomi, Shigeki Bamba, Makoto Shioya, Yousuke Mochizuki, Takashi Nishimura, Yusuke Koizumi, Tomoyuki Tsujikawa, Akira Andoh, Yasuharu Saito, Yoshihide Fujiyama Division of Gastroenterology, Shiga University of Medical Science, Otsu, Japan; Division of Endoscopy, Shiga University of Medical Science, Otsu, Japan; Department of Infectious Response and Immune Control, Shiga University of Medical Science, Otsu, Japan INTRODUCTION/AIMS: Endoscopic indwelling stents have been widely used for the treatment of unresectable malignant bilialy obstruction. Plastic stents (PS) are easier to deliver and more economic than metallic stents (MS). However, the duration of PS patency is generally shorter than that of MS patency due to occlusion by food impaction resulting in ascending infection. To overcome the disadvantage, we firstly attach a nylon thread to the PS and then attempt the threaded stent placement above the sphincter of Oddi (the threaded “inside-stent”: TIS). In this study, we evaluated the safety and efficacy of TIS in malignant hilar obstruction compared to conventional PS and MS. PATIENTS AND METHODS: (1) Between April 2007 and September 2010, 38 patients with type I-IV (Bismuth classification) malignant hilar obstruction underwent the placement of endoscopic indwelling stents. The cases involved the TIS (n 10), conventional PS (n 18), and MS (n 10). To make TIS, nylon monofilament thread (size 3/0) was attached to the conventional PS (Flexima, Boston Scientific) by using puncher. The duration of patency, and complications were retrospectively evaluated in each group.(2) Three malignant hilar obstruction cases underwent TIS placement as a salvage threarpy after MS obstruction due to tumor ingrowth. We compared the patency of MS and TIS in the same cases. RESULTS: (1) All procedures were successful in each group. The median duration of patency in TIS group was significantly longer than that in conventional PS group (126.3 vs 42.1 days; P 0.025, Log-rank test) and not significant compared to MS group (126.3 vs 200.3 days, P 0.76). The removal of TIS was simple because the attached thread was appeared from the sphincter of Oddi except one case. In one patient, the thread was migrated into bile duct, but the stent was successfully removed by grasping forceps. There is no migration of the stent in any group.(2) The median duration of MS patency was 123 days compared to the TIS patency of 163 days (p 0.486). CONCLUSION: The placement of TIS is safe and effective compared to conventional PS for treatment of malignant hilar obstruction. Moreover, TIS is not inferior to MS. In addition, the patency of TIS was comparable to MS even used as a salvage therapy. In this context, TIS is useful not only for an initial therapy but also for a salvage threapy for the patients with malignant hilar obstruction.