Apical lymph node dissection of the inferior mesenteric artery

It is controversial whether a high or low ligation of the inferior mesenteric artery (IMA) is superior. The former allows an extended lymph node clearance whereas the latter preserves the distal vascular supply via the left colic artery (LCA). Apical lymph node dissection of the IMA (ALMA) harvests nodal tissue along the IMA proximal to the LCA whilst performing a low ligation. This anatomically replicates the oncological benefit of high ligation and the vascular preservation of low ligation. Our study evaluates the nodal yield of ALMA and the short-term outcome of this technique.

We retrospectively studied 19 patients with sigmoid or rectal cancer who underwent curative surgical resection with ALMA. All ALMAs were performed with a standard technique previously described (Kobayashi et al., Surg Endosc 2005, 20:563-9; Sekimoto et al. Surg Endosc 2010, 25:861-6) . The lymph node yield from the dissection (the ALMA specimen) was compared with the total lymph node yield. Data on the LCA anatomy, time required to perform ALMA, complications and postoperative recovery were evaluated.

ALMA was successful in 18 patients. Median postoperative hospitalization was 5 (2-26) days without ALMA-related morbidity or mortality. The median lymph node yield was 20 (9-41) and a median of 14.3 (0-80)% were harvested with ALMA. Two patients not having neoadjuvant chemoradiotherapy had fewer than 12 lymph nodes, excluding nodes harvested from ALMA. The average time required for ALMA was 18 min.

ALMA is a safe and feasible technique, allowing extended lymphadenectomy without sacrificing the LCA. In this small group of patients none were upstaged due to cancerous involvement of the proximal nodes.