Different approaches to assessment of lymph nodes and surgical margin status in patients with ductal adenocarcinoma of the pancreas treated with pancreaticoduodenectomy

Abstract

To develop a method of gross examination of pancreaticoduodenectomy specimens with pancreatic ductal adenocarcinoma, allowing adequate assessment of the entire pancreatic surface as a surgical margin, which would not affect the lymph node yield. We retrospectively compared the R1 rates (i.e., proportions of patients with microscopic residual tumour at surgical margins) and lymph node yield in a series of 67 consecutive cases of pT3 ductal adenocarcinomas diagnosed in pancreaticoduodenectomy specimens during three different periods of time and sampled using three different approaches: (1) period 2006-2007, when the pancreatic surface (except for the transection margin and superior mesenteric artery margin) was not examined; (2) period January-September 2008, when the posterior pancreatic surface (posterior circumferential radial margin) was examined using an improved method based on sampling of 2.0-2.5 mm thick consecutive slices perpendicular to the duodenal axis; and (3) period October 2008 - June 2009, when the whole surface of the pancreatic head was sampled using the approach mentioned above. The R1 rates in three consecutive time periods were 23.5%, 40% and 53.8%, respectively. Median numbers of retrieved peripancreatic lymph nodes were 11.0, 12.0 and 14.0, respectively. The newly proposed approach allowed adequate assessment of the entire pancreatic head surface as a surgical margin and reduced the risk of under-detection of R1 status. Moreover, this approach did not affect the number of peripancreatic lymph nodes examined.