Three-Dimensional Fixation: Pathological Protocol Following Pancreaticoduodenectomy with Portal Vein Resection for Pancreatic Cancer

Background: Although existing histopathologic protocols for pancreatic cancer have been standardized, the relevance between prognosis and resection margin clearance is still controversial. Reconstruction of specimens as in situ to appropriately assess the margin is desirable in these protocols. Methods: The three-dimensional fixation protocol defined specimen handling of pancreaticoduodenectomy (PD) with portal vein (PV) resection. The superior mesenteric artery (SMA) margin of the specimen was tidily fixed around an artificial SMA as if in an in situ setting. In this prospective study, patients undergoing PD with PV resection for pancreatic cancer in 2016 were enrolled. To evaluate the feasibility of the three-dimensional fixation protocol, the SMA margin distance and PV involvement of tumor assessed by computed tomography (CT) were compared with those assessed by pathology. Results: Thirty-three patients with/without preoperative chemotherapy were enrolled. The entire cohort did not present with high-quality diagnostic assessment of the medial margins around SMA and PV (correct estimation, 58% and 73%, respectively). In contrast, in 16 patients undergoing upfront surgery, the concordance value of the SMA margin, which assesses the agreement between CT and pathology measures, was 0.48 (moderate agreement). The PV involvement examined by imaging was significantly associated with that by pathology (P = 0.013). Conclusions: The three-dimensional fixation protocol was applicable to all cases undergoing PD with PV resection. Focusing on the patients with upfront surgery demonstrated the feasibility of accurate pathological assessment of medial margins. We propose this protocol as a promising standard for the assessment of true surgical margin status.