Apical lymph node dissection of the inferior mesenteric artery

Area of Science:

• Surgical Oncology
• Colorectal Surgery
• Surgical Anatomy

Background:

• The optimal ligation technique for the inferior mesenteric artery (IMA) in colorectal surgery remains debated, balancing oncological clearance with vascular supply preservation.
• High ligation offers extended lymph node dissection, while low ligation preserves the left colic artery (LCA) supply.
• Apical lymph node dissection of the IMA (ALMA) aims to achieve both extended lymphadenectomy and preservation of the LCA.

Purpose of the Study:

• To evaluate the lymph node yield of the ALMA technique.
• To assess the short-term outcomes, including safety and feasibility, of ALMA.
• To compare the oncological and vascular benefits of ALMA with traditional high and low ligation methods.

Main Methods:

• Retrospective analysis of 19 patients with sigmoid or rectal cancer undergoing curative resection with ALMA.
• Standardized ALMA technique applied.
• Comparison of lymph node yield from ALMA specimen versus total yield; evaluation of LCA anatomy, procedure time, complications, and recovery.

Main Results:

• ALMA was successfully performed in 18 patients.
• Median lymph node yield was 20 (range 9-41), with a median of 14.3% harvested via ALMA.
• Median postoperative hospitalization was 5 days, with no ALMA-related morbidity or mortality. Average procedure time for ALMA was 18 minutes.

Conclusions:

• ALMA is a safe and feasible surgical technique for extended lymphadenectomy in colorectal cancer.
• The technique successfully harvests nodal tissue proximally without compromising the LCA.
• In this cohort, no patients were upstaged due to involvement of proximal nodes, suggesting oncological adequacy.