Laparoscopic left hemicolectomy with inferior mesenteric vein sparing: a step-by-step surgical approach (with video).

Routine ligation of the inferior mesenteric vein (IMV) during laparoscopic left hemicolectomy is widely practiced but may predispose patients to venous congestion, ischemia, and anastomotic complications, especially in patients with a long remnant sigmoid colon. IMV preservation remains underutilized due to technical difficulty and the absence of standardized guidance. This video article presents a structured, step-by-step technique for laparoscopic left hemicolectomy with D3 lymphadenectomy and IMV preservation in a 64-year-old male with distal transverse colon adenocarcinoma. Key elements include meticulous IMV skeletonization with selective tributary ligation, targeted left colic artery division, and extracorporeal functional end-to-end anastomosis. The patient recovered uneventfully and was discharged on postoperative day 3. A 6-month colonoscopy confirmed a well-healed anastomosis without congestion or stricture. IMV-preserving left hemicolectomy is safe, oncologically sound, and technically reproducible. Maintaining venous drainage may reduce anastomotic congestion and support optimal healing, offering meaningful value in selected patients.