Influence of colectomy type and resected specimen length on number of harvested lymph nodes

Background: The optimal (minimal) number of harvested nodes is still a matter of debate. We prospectivly evaluated the relation between specimen length and tumor location to the number of harvested nodes and rate of node positivity. Methods: Specimens of right hemicolectomy, left hemicolectomy, and subtotal colectomy were assessed for specimen length, overall number of harvested lymph nodes, and lymph node ratio. Results: Left hemicolectomies were performed in 106 patients, right hemicolectomies in 90, and subtotal colectomies in 9. The mean number of retrieved lymph nodes was significantly higher in patients with right and subtotal colectomies compared to left colectomies: 33, 44, and 24, respectively. Positive nodes were found in 34% of the patients with right hemicolectomies, 55% in the subtotal group, and 35% in the left hemicolectomy group (not statistically significant). The length of the resected specimen was significantly longer in patients with right and subtotal colectomies compared to left colectomy: 31, 83, and 19 cm, respectively, but the ratio of lymph nodes to the length of the specimen was not statistically different: 1.19, 0.58, and 1.55, respectively. Conclusions: It appears that the additional length of resection in right colectomies compared to left colectomies leads to an increase in the average number of resected nodes, a change that did not translate into an increase in the number of positive nodes, nor in the ratio of patients with positive nodes.