Optimal ligation level of the primary feeding artery and bowel resection margin in colon cancer surgery: the influence of the site of the primary feeding artery.

PURPOSE: In colon cancer surgery, it is recommended that en bloc resection involving extended lymphadenectomy, characterized as a hemicolectomy, be performed by ligating the primary feeding artery at a high position and resecting proximal and distal with 5-cm to 10-cm bowel margins. However, there is little evidence to unequivocally support such extensive lymphovascular resection.
METHODS: The distribution of nodal metastases was obtained by the clearing method in 164 patients with colon cancer.
RESULTS: For pericolic spread, for pT1 tumors, the distance from the primary tumor to a diseased node was 2.5 cm; for pT2, the distance was less than 5 cm; for 97.0 percent of pT3 tumors and 93.3 percent of pT4 tumors with nodes involved, the distance was less than 7 cm. For central spread, for pT1 tumors, the rate of spread to central nodes was 0 percent; for pT2, the rate of spread was 20.0 percent to intermediate nodes (for tumors more than 5 cm from the feeding artery, the rate for central nodes was 0 percent); for pT3, the rate was 30.6 percent to intermediate nodes and 15.3 percent to main nodes; for pT4, the rate was 44.4 percent to intermediate nodes and 22.2 percent to main nodes. For curative resection cases with pT3 tumors more than 7 cm from the feeding artery, the rate to central nodes was 0 percent.
CONCLUSIONS: In T1 tumors, central node dissection is not required, but resection with proximal and distal 3-cm margins are required; in T2, central node dissection that includes the intermediate node should be performed in addition to resection with proximal and distal 5-cm margins. In T3 and T4, central node dissection that includes the main node should be performed in addition to resection with proximal and distal 7-cm margins. However, for T2 more than 5 cm from the primary feeding artery, and for T3 more than 7 cm from the primary feeding artery, proximal and distal resection alone may be adequate.