Comparison of long-term clinical outcome between external and Internal pancreatic Stent in pancreatoduodenectomy

Abstract

Purpose: In our previous prospective randomized trial, external stent group showed higher rate of clinically relevant postoperative pancreatic fistula (POPF) compared with internal stent group in performing pancreaticojejunal anastomosis after pancreatoduodenectomy (PD). Thus, the purpose of this study was to determine the most appropriate pancreatic drainage method by investigating differences in long-term clinical outcome related with stent between external and internal pancreatic stent groups after postoperative 12 months. Methods: From August 2010 to January 2014, total 213 patients who underwent PD with duct to mucosa pancreaticojejunostomy were enrolled in this prospective randomized controlled trial (NCT01023594). Among them, 185 patients (97 external and 88 internal stent groups) have been taken follow-up and evaluated via outpatient clinic for 12 months. Their long-term clinical outcomes were compared, including late complications, volume status of remnant pancreas, pancreatic function, and quality of life. Results: Overall late complication rate for postoperative 12 months was 15.5 % (n=15) in external stent group and 18.2 % (n=16) in internal stent group (P=0.621). In the external group, there were 5 cases of complications associated with removal of stent including peritonitis after removal and acute abdominal pain resulted from unintended extraction. The internal stent was migrated from pancreaticojejunal anastomosis site within 3 months in 57 patients (64.8%). Even though there were 24 cases of abnormal migration of internal stent including pancreatic duct, intrahepatic duct, and hepaticojejunal anastomosis site, however, there were no associated complications identified for 12 months. Pancreatic duct diameter at postoperative 12 months was comparable between 2 groups (3.24±1.40mm vs. 3.30±1.46mm, P=0.806). There was no significant difference in comparison of patients with pancreatic ductal stricture or dilatation divided according to migration time of internal stent. The rate of patients with atrophy of the remnant pancreatic volume of more than 50 % after postoperative 12 months was 39.2 % in external group and 43.2 % in internal group (P=0.580). As factors associated with pancreatic exocrine or endocrine function, stool elastase level (63.6±88.3 vs. 73.7±109.9, P=0.571) and rate of patients with new-onset diabetes at postoperative 12 months (24.3% vs. 12.5%, P = 0.179) were also comparable. There were no significant differences in quality of life evaluated by EORTC QLQ-C30 and QLQ PAN26 between 2 groups at postoperative 12 months. Conclusion: External and internal stent showed comparable clinical outcomes in long-term follow-up as well as short-term results. The type of pancreatic stent can be selected by the operator according to their preference.