Lymph node spread of gallbladder cancer from the perspective of embryologically-based anatomy and significance of the lymphatic basin along the embryonic right hepatic artery.

Lymph node metastasis from gallbladder cancer is often found in the pericholedochal area; however, these regional lymph nodes are not typically accompanied by arteries. We hypothesized that the artery accompanying pericholedochal lymph nodes was either the regressed embryonic right hepatic artery (eRHA) or an aberrant right hepatic artery (aRHA) remaining without regression. This study aimed to determine the artery supplying pericholedochal lymph nodes. We obtained serial tissue sections of resected specimens from 10 patients who underwent pancreaticoduodenectomy with combined resection of the superior mesenteric artery and vein and investigated the association between the distribution of enlarged lymph nodes and the course of blood vessels in each section. In 2 cases with aRHA, enlarged lymph nodes were distributed in the posterosuperior area, pancreaticoduodenal region and retroportal area along this artery. By contrast, no blood vessels accompanied enlarged lymph nodes in 8 patients exhibiting a normal hepatic artery branching pattern, although these nodes exhibited a distribution pattern similar to that of patients with the aRHA. Thus, the artery supplying pericholedochal lymph nodes appears to be either the regressed eRHA or an aRHA persisting without regression.