Comparison on the efficacy between partially covered self-expandable metal stent with enlarged head versus uncovered self-expandable metal stent for palliation of gastric outlet obstruction

Abstract

AIMS: Stent migration rarely occurs with uncovered SEMS (uSEMS), but tumor ingrowth is a problem. Tumor ingrowth can be expected to be prevented with covered SEMS, but migration poses a problem. If the proximal portion of the SEMS is enlarged so as to take on a funnel shape and covering material is applied at the mid-portion that is in contact with the SEMS, migration and tumor ingrowth can both be expected to be minimized. This study aimed to compare the efficacy between partially covered SEMS with enlarged head and uncovered SEMS for palliation of GOO. METHODS: From July 2009 to July 2016, 48 patients underwent duodenal SEMS insertion for palliation of GOO due to inoperable or advanced malignancy at Korea University Ansan Hospital. Enlarged-head SEMS and uncovered SEMS was inserted in 24 patients each. Technical feasibility and clinical outcomes were compared between the two types of SEMS. RESULTS: Technical success rate of enlarged-head SEMS and uSEMS was 100%(24/24) and 95.8%(23/24), respectively. Functional success rate was 91.7%(22/24) and 95.7%(22/23), respectively. Mean age of the patients was 71.7 ± 11.2 years. The reason for GOO was progression of pancreatic cancer (n = 20), gastric cancer (n = 9), gallbladder cancer (n = 7), cholangiocarcinoma (n = 5), CBD cancer (n = 5), AoV cancer (n = 1), and duodenal cancer (n = 1). Mean survival of enlarged-head SEMS group and uSEMS groups was 98.2 days (range 19-358 days) and 80.1 days (range 11-231 days), respectively. Mean stent patency of enlarged-head SEMS group and uSEMS groups was 89.6 days (range 13-358 days) and 69.9 days(range 2- 231 days), respectively (P = 0.34). With enlarged-head SEMS, distal migration did not occur, but proximal migration was observed in 1 case. Fracturing of the enlarged-head SEMS occurred in 2 cases and tumor ingrowth through the membrane in 2 cases. CONCLUSIONS: Although distal migration was prevented by shaping the SEMS to have enlarged-head, there was no difference in stent patency between the two types of SEMS.