Hiroki Kawashima1, Senju Hashimoto2, Eizaburo Ohno1, Takuya Ishikawa1, Tomomasa Morishima3, Hiroshi Matsubara4, Hiroyuki Sugimoto5, Koji Nonogaki6, Akira Kanamori7, Kazuo Hara8, Takamichi Kuwahara8, Masanao Nakamura1, Ryoji Miyahara1, Masatoshi Ishigami1, Masahiko Ando9, Yoshiki Hirooka10. 1. Department of Gastroenterology and Hepatology, Nagoya University Graduate School of Medicine, Nagoya, Japan. 2. Department of Liver, Biliary Tract and Pancreas Diseases, Fujita Health University, Toyoake, Japan. 3. Department of Gastroenterology, Konan Kousei Hospital, Konan, Japan. 4. Department of Gastroenterology, Toyohashi Municipal Hospital, Toyohashi, Japan. 5. Department of Gastroenterology, Handa City Hospital, Aichi, Japan. 6. Department of Gastroenterology, Daido Hospital, Nagoya, Japan. 7. Department of Gastroenterology, Ogaki Municipal Hospital, Gifu, Japan. 8. Department of Gastroenterology, Aichi Cancer Center Hospital, Nagoya, Japan. 9. Center for Advanced Medicine and Clinical Research, Nagoya University Hospital, Nagoya, Japan. 10. Department of Endoscopy, Nagoya University Hospital, Nagoya, Japan.
Abstract
OBJECTIVES: The time to recurrent biliary obstruction (TRBO) of unresectable distal malignant biliary obstruction is generally thought to be longer when a self-expandable metal stent (SEMS) with a thicker inner diameter is used for drainage, but the dependence on the inner diameter using a fully covered SEMS (FCSEMS) is uncertain. The objective of this multicenter prospective study was to compare TRBO and adverse events, such as cholecystitis and pancreatitis, in treatment of patients with unresectable malignant biliary obstruction using 8- and 10-mm diameter FCSEMS. METHODS: Eighteen tertiary-care centers participated in the study. Patients were allocated to the 8- and 10-mm diameter groups. TRBO, non-inferiority of the 8-mm FCSEMS, overall survival time, frequency and type of adverse events, and non-recurrent biliary obstruction (RBO) rate at the time of death were compared between the two groups. RESULTS: Median TRBO did not differ significantly between the 8-mm (n = 102) and 10-mm (n = 100) groups (275 vs 293 days, P = 0.971). The hazard ratio of the 8- to 10-mm groups was 0.90 (80% confidence interval, 0.77-1.04; upper limit lower than the acceptable hazard ratio [1.33] of the null hypothesis). Based on these findings, the 8-mm diameter stent was determined to be non-inferior to the 10-mm diameter stent. Survival time, incidence of adverse events and non-RBO rate at the time of death did not differ significantly between the two groups. CONCLUSIONS: Time to RBO with an 8-mm diameter FCSEMS was non-inferior to that with a 10-mm diameter FCSEMS. This finding is important for development of future SEMS.
OBJECTIVES: The time to recurrent biliary obstruction (TRBO) of unresectable distal malignant biliary obstruction is generally thought to be longer when a self-expandable metal stent (SEMS) with a thicker inner diameter is used for drainage, but the dependence on the inner diameter using a fully covered SEMS (FCSEMS) is uncertain. The objective of this multicenter prospective study was to compare TRBO and adverse events, such as cholecystitis and pancreatitis, in treatment of patients with unresectable malignant biliary obstruction using 8- and 10-mm diameter FCSEMS. METHODS: Eighteen tertiary-care centers participated in the study. Patients were allocated to the 8- and 10-mm diameter groups. TRBO, non-inferiority of the 8-mm FCSEMS, overall survival time, frequency and type of adverse events, and non-recurrent biliary obstruction (RBO) rate at the time of death were compared between the two groups. RESULTS: Median TRBO did not differ significantly between the 8-mm (n = 102) and 10-mm (n = 100) groups (275 vs 293 days, P = 0.971). The hazard ratio of the 8- to 10-mm groups was 0.90 (80% confidence interval, 0.77-1.04; upper limit lower than the acceptable hazard ratio [1.33] of the null hypothesis). Based on these findings, the 8-mm diameter stent was determined to be non-inferior to the 10-mm diameter stent. Survival time, incidence of adverse events and non-RBO rate at the time of death did not differ significantly between the two groups. CONCLUSIONS: Time to RBO with an 8-mm diameter FCSEMS was non-inferior to that with a 10-mm diameter FCSEMS. This finding is important for development of future SEMS.