Extended mesenteric excision in right hemicolectomy for carcinoma of the colon.

Between 1979 and 1989, 169 patients had a curative operation for right sided colonic cancer. A retrospective analysis of the incidence and degree of lymph node metastasis was performed in all and survival rate was determined in 144 patients who could be followed over a period of 5 years or more. In all patients, dissection involved the removal of right colon (i.e., caecum, ascending colon, and right side of transverse colon). Dissection of regional lymph nodes in 84 patients (group 1) involved the removal of mesocolic lymph nodes related to the segment of the removed intestine. In 60 patients (group 2) dissection was extended to the nodes situated anterior to mesenteric and retropancreatic vessels. Morbidity and mortality rates were similar in the two procedures. The number of lymph nodes and the level of apical node examined were significantly different in the two groups. The 5-year survival rates showed no statistically significant difference, but in group 2 three of the nine patients with metastasis to N4 nodes are free of disease, surviving at 7, 12 and 14 years, respectively. The principle of extensive lymph node dissection is proposed as a procedure that supplies more accurate staging and might reduce the incidence of loco-regional recurrence.