Rationale for en bloc vein resection in the treatment of pancreatic adenocarcinoma adherent to the superior mesenteric portal vein confluence

Objective Tumor invasion of the superior mesenteric-portal vein (SMPV) confluence is often considered a contraindication to pancreaticoduodenectomy for patients with malignant tumors of the pancreas or periampullary region. The authors sought to determine whether pancreaticoduodenectomy with en bloc resection of the SMPV confluence could be safely performed and whether tumors involving the SMPV confluence were associated with pathologic parameters suggesting poor prognosis. Summary Background Data Several centers have reported high rates of retroperitoneal margin positivity after pancreaticoduodenectomy for tumors of the pancreatic head and periampullary region. Positive-margin or incomplete resection is associated with early tumor recurrence and no survival benefit compared with palliative therapy. Tumor adherence to the lateral or posterior wall of the SMPV confluence often represents the only barrier to complete tumor resection at the time of pancreaticoduodenectomy. Methods Data on all patients undergoing pancreaticoduodenectomy for adenocarcinoma of the pancreas or periampullary region over a 3.5-year period were entered prospectively in a pancreatic tumor data base, To be considered for surgery, patients were required to fulfill the following computed tomography criteria for resectability: 1) the absence of extrapancreatic disease, 2) no tumor encasement of the superior mesenteric artery or celiac axis, and 3) a patent SMPV confluence. Tumor adherence to the superior mesenteric vein or SMPV confluence was assessed intraoperatively, and en bloc venous resection was performed when necessary to achieve complete tumor extirpation. Data on operative characteristics, morbidity, mortality, tumor size, nodal metastases, margin positivity, perineural invasion, and tumor DNA content were compared for patients who did and did not receive venous resection. Results Fifty-nine patients underwent pancreaticoduodenectomy, 36 without venous resection and 23 with en bloc resection of the SMPV confluence. No differences in median hospital stay, morbidity, mortality, tumor size, margin positivity, nodal positivity, or tumor DNA content were observed between groups. Conclusions When necessary, segmental resection of the SMPV confluence may be performed safely during pancreaticoduodenectomy for periampullary malignant tumors. Tumors invading the SMPV confluence are not associated with histologic parameters suggesting a poor prognosis. Our data suggest that venous involvement is a function of tumor location rather than an indicator of aggressive tumor biology.