Correlation Between Radiographic Classification and Pathological Grade of Portal Vein Wall Invasion in Pancreatic Head Cancer

Objectives: A retrospective study was performed to clarify the correlation between radiographic type of portal vein (PV) invasion and pathological grade of PV wall invasion, and their correlation with postoperative prognosis. Background: In many patients with pancreatic cancer, PV resection is necessary to increase resectability and obtain cancer-free margins. Methods: We analyzed 671 patients who had undergone surgery for invasive adenocarcinoma of the pancreas between July 1981 and June 2010. Radiographic types of PV invasion of pancreatic head cancer were classified into A (normal), B (unilateral narrowing), C (bilateral narrowing), or D (complete obstruction with collateral veins), by portography or computed tomography. Pathological grades of PV wall invasion were classified as 0 (no invasion), 1 (tunica adventitia), 2 (tunica media), or 3 (tunica intima). Results: Four hundred and sixty-three patients underwent resection, and PV resection was performed in 297. Combined arterial vessel resection was performed in 16 cases. No significant difference in operative mortality was observed between PV preservation (0.6%) and PV-only resection (2.1%), and no operative deaths occurred after 1999. Radiographic classification of PV invasion correlated with incidence of pathological PV wall invasion. In pancreatic head carcinoma, no pathological PV wall invasion was observed in type A (n = 111). Pathological PV invasion was observed in 51% of type B (42/82), 74% of type C (72/97), and 93% of type D (63/68). Long-term survival (>5 years) was observed in types A and B, and grades 0 and 1 subgroups. Conclusions: Pancreatectomy with PV resection can be performed safely. Even in radiographic classification type B, pathological PV wall invasion was observed in 51% of patients. Long-term survival was observed in types A and B, and grades 0 and 1.