The importance of assessing the SMA margin in patients undergoing pancreaticoduodenectomy

Abstract

Aim: The purpose of this study is to examine the true incidence of superior mesenteric artery (SMA) positivity in patients who have superior mesenteric vein (SMV) positivity while undergoing pancreaticoduodenectomy (PD) for pancreatic adenocarcinoma (PDAC). Methods: All patients who underwent PD for PDAC between January 2005 and December 2011 were retrospectively identified from our database. Patients deemed resectable by NCCN guidelines, protocol CT scans, and endoscopic ultrasound were included. The PD specimen was inked using five colors to specifically identify and study the SMV and SMA margins. We also analyzed and compared R1-sub groups (R1A group- SMA and SMV positive; R1B group - SMV positive, SMA negative). Results: 98 patients underwent PD for resectable pancreatic adenocarcinoma. 75 patients (76.5%) were found to have negative surgical margin on final pathology (R0 group) while 23 patients (23.4%) had positive SMV margins (R1 group). In the R1 group, 11 patients (47.8%) were found to have positive SMA margin (R1A group) and 12 patients were SMV positive and SMA negative (R1B group). No statistically significant survival difference was noted between R0 and R1 or between R1-A and R1-B. Conclusion: This study demonstrates that with careful inking of the SMA and SMV margins, there is a high rate of concurrent SMA positivity in those patients that are SMV positive. There was no impact on survival. Accurate margin assessment is critical by careful examination and inking of the SMA and SMV margin.