Lymph node clearance after total mesorectal excision for rectal cancer: laparoscopic versus open approach

Background: Laparoscopic resection of the rectum is still under scrutiny for its adequacy of oncological clearance.

Aim: To assess lymph node yield after laparoscopic total mesorectal excision (TME) for rectal cancer as compared to the open approach.

Methods: 74 patients with middle and low rectal cancer were prospectively randomized in two groups. Group A included 39 patients who had an open TME (35 with low anterior resection of the rectum (LARR) and 4 with abdominoperineal resection of the rectum (APR)). In group B, there were 34 patients who had a laparoscopic TME (27 with LARR and 7 with APR). 10 of the LARR patients in group A and 14 of the LARR patients in group B had a defunctioning ileostomy. All operations were performed by one surgeon or under his supervision.

Results: Gender and age distribution were similar for both groups (group A: 23 males; mean age 69 (41-85); group B: 20 males; mean age 72 (31-84)). The mean distance of the tumor from the dentate line was 7.6 cm (1-12 cm) for group A and 6.1 cm (1-12 cm) for group B. Anastomosis was formed at a mean distance of 5.5 cm (1.5-8.5 cm) from the dentate line in group A and 3.5 cm (1-4.5 cm) in group B. At histology, in group A there were 5 T4 tumors, 9 T3, 10 T3+ (<1 mm distance from the circumferential resection margin), 13 T2 and 2 T1. In group B, there were 3 T4 tumors, 14 T3, 8 T3+, 7 T2 and 2 T1. Differences between groups were not significant. The mean number of lymph nodes retrieved in group A specimens was 19.2 (5-45) and in group B 19.2 (8-41) (p = 0.2). In group A, 3.9 (1-9) regional, 13.9 (3-34) intermediate and 1.5 (1-3) apical lymph nodes were retrieved. The respective values in group B were 3.7 (3-7), 14.4 (4-33) and 1.3 (1-3). Differences between groups were not significant. Also, the incidence of lymph node involvement by the tumor was not significantly different between groups (group A: 23; group B: 19).

Conclusions: Laparoscopic resection of the rectum can achieve similar lymph node clearance to the open approach. Also, distribution of the lymph nodes along the resected specimens is similar between the two approaches.