Histopathologic Appraisal of Lymphatic and Connective Tissue Clearance in Resection of Pancreatic Head Cancer

Abstract

We have improved the 5-year survival rate from 9% to 29% by extending the range of lymphatic and connective tissue clearance (D2a) in resection of pancreatic head cancer. When D2a was performed, the long-term survivors were obtained mainly from the groups in which the positive nodes were absent or limited in the pancreaticoduodenal regions. Among these two groups, 40% of patients had cancer extension at a microscopic levels (microinvasion), in the nerve plexi or connective tissues beyound the pancreatic confines. The 5-year survival rate was around 40% even in the patients who had microinvasion around the superior mesenteric artery, celiac artery and aorta. Whereas, the long-term survival would be scarecely expected when the patients had either positive nodes beyond the pancreaticoduodenal region or microinvasion around the hepatic artery or inferior pancreatic head. These data lead us to conclude that the D2a-procedure is recommended for the selected patients with pancreatic head cancer.