Reporting the margin in pancreaticoduodenectomies: R0 versus R1.

Abstract

This study was conducted to analyze the changes in margin positivity in pancreaticoduodenectomies, on using a standardized protocol, which bread loafs the pancreas and duodenum in the axial plane for adenocarcinomas arising in the pancreatic head, ampulla, terminal common bile duct (CBD), and duodenum, and then to assess whether these tumor subsets involve the margins in different ways. The analysis was performed on 70 consecutive specimens, the pre-protocol specimens serving as the control group. Tumors originating from the pancreatic head, ampulla, terminal CBD, and duodenum showed a consistent increase in their R1 incidence, post-protocol. Ampullary tumors showed the greatest upward change in R1 positivity. The highest incidence of margin positivity was seen in pancreatic head adenocarcinomas (80%), then distal CBD tumors (60%), and finally the ampullary tumors (39%). In pancreatic head adenocarcinomas, R1 increased from 55% to 80%, distal CBD from 50% to 60%, and ampullary from 17% to 39%. Duodenal adenocarcinomas had no R1 in both pre- and post-protocol groups. The tumors also had different patterns of margin involvement. Ampullary tumors involved only the posterior margin, pancreatic adenocarcinomas involved the superior mesenteric vein (SMV) groove more often than the posterior margin, and distal CBD tumors involved the posterior margin and SMV groove equally. The size of the tumor made a significant difference in pancreatic head carcinomas with tumor size less than or equal to 2cm, showing an R1 incidence of 38%, while those above 2cm had an R1 incidence of 68%.