High Lymph Node Dissection with Low Ligation: A Modified Technique for Left Colic Artery Preservation in Colorectal Cancer

The optimal level of inferior mesenteric artery (IMA) ligation in colorectal cancer remains controversial. High ligation allows complete D3 lymphadenectomy but sacrifices the left colic artery (LCA), raising concerns about anastomotic ischemia. This report presents a modified low ligation technique that achieves radical D3 dissection while preserving the LCA. The technique involves complete skeletonization of the IMA root with en bloc removal of surrounding lymphatic tissue while maintaining LCA continuity. Key procedural steps include: (1) medial-to-lateral mobilization, (2) exposure of the IMA origin, (3) para-IMA lymph node dissection along the vascular sheath, (4) preservation of the LCA and autonomic plexus, and (5) distal IMA division below the LCA bifurcation. Intraoperative images illustrate the dissected nodal field and preserved vasculature. This technique enables D3-level lymph node dissection comparable to high ligation, with clear visualization of the IMA root and preserved arterial supply. Thirty-five lymph nodes, including one metastatic node, were retrieved without compromising perfusion. This modified approach balances oncologic completeness with physiologic preservation and may serve as a practical model for achieving D3 lymphadenectomy with vascular preservation.