Is it necessary to dissect the lymph nodes around an abnormal hepatic artery in D2 lymphadenectomy for gastric cancer?

BACKGROUND: Surgical resection remains the principal treatment for advanced gastric cancer. However, one of the difficulties in radical D2 lymphadenectomy is the identification of the vascular abnormalities around the stomach, especially abnormal hepatic artery. The hepatic artery arising from the superior mesenteric artery shows great variations, and whether or not the lymphatic tissues around the abnormal artery should be dissected is still controversial. METHOD: Eighty-six gastric cancer patients who underwent radical D2 lymphadenectomy by the same surgeon in our department in the past 2 years were included in this study. All patients underwent multislice spiral computed tomography angiography for preoperative evaluation of the abnormal hepatic artery arising from the superior mesenteric artery. Postoperative immunohistochemistry of the lymphoid tissues around the abnormal hepatic artery was performed using CK20 and CEA antibodies to determine the occurrence of lymph node micrometastasis around the abnormal artery. RESULTS: In our study, we found 14 cases with an abnormal hepatic artery arising from the superior mesenteric artery. The hepatic artery ran in front of the pancreas in 1 case and behind the pancreas in 13 cases. Immunohistochemical analyses revealed no micrometastasis in the lymphoid tissues surrounding the abnormal artery. CONCLUSIONS: Abnormal hepatic arteries arising from the superior mesenteric artery can be classified into pre-pancreas and post-pancreas types. Lymph nodes around the abnormal artery may not need to be dissected in radical D2 lymphadenectomy.