Anatomy of the Superior Mesenteric Vein With Special Reference to the Surgical Management of First-order Branch Involvement at Pancreaticoduodenectomy

Objective: To describe our approach to resection of pancreatic head cancers, which involve 1 or both of the first-order branches of the superior mesenteric vein (SMV). Summary Background Data: In contrast to tumors which involve the proximal SMV, cancers in the inferior aspect of the pancreatic head or root of mesentery (mid gut carcinoid) may involve one of the 2 primary branches of the SMV (the ileal and jejunal branches), with or without involvement of the main trunk of the SMV. Such cases are associated with significant technical challenges. Methods: Our surgical approach is described and illustrated. Results: Isolated involvement of the jejunal branch of the SMV may be managed by division of this branch without reconstruction as long as the ileal branch is intact and of good caliber. Tumors which involve the ileal branch of the SMV, in the rare setting in which the jejunal branch is preserved, may also be managed by ligation and resection without reconstruction. Involvement of one of these first-order branches in association with more proximal involvement of the main trunk of the SMV may be successfully managed by ligation of one first-order branch and concurrent segmental resection and reconstruction of the other branch, and the main SMV trunk, with or without an interposition graft. Conclusion: Segmental resection of one of the 2 first-order branches of the SMV may be performed without venous reconstruction if mesenteric venous flow is preserved through the remaining first-order branch. Detailed knowledge of the vascular anatomy of the root of the mesentery is necessary for the performance of complex surgical procedures involving the pancreatic head and root of mesentery.