Anatomical study of the left colic artery in laparoscopic-assisted colorectal surgery.

Background: It is important for lymph node dissection around the inferior mesenteric artery (IMA) with preservation of the left colic artery (LCA) to be aware of the track and the length of the LCA. We aimed to investigate the branching pattern and trajectory of LCA and measure the distances from the root of the IMA to the origin of the LCA (D mm) and from the origin of LCA to intersection of LCA and IMV (d mm) during laparoscopic left-sided colorectal operations.

Methods: We analyzed 106 patients who underwent laparoscope-assisted left-side colorectal surgery during laparoscopic surgery. The branching patterns among the IMA, LCA, and sigmoidal trunk were evaluated; the trajectory of LCA was examined; the D mm and d mm were measured using a length of silk in the surgical operation.

Results: In 59.5% patients, the LCA arose independently from the sigmoidal trunk (type A); in 8.5% patients, the LCA and sigmoidal trunk arose from the IMA at the same point (type B); in 29.2% patients, the LCA and sigmoidal trunk had a common trunk (type C); the LCA did not exist in 2.8% (type D).The D mm and d mm for all cases ranged from 15.0 to 65.3 mm (median, 43.1 mm) and from 20.3 to 46.2 mm (median, 34.8 mm), respectively. 74.8% of the LCA went straight upper left and upward to proximal part of descending colon (type I), 25.2% went to the lower left at first, then turned to travel straight upward to proximal part of descending colon (type II).

Conclusion: This study showed the anatomic variations of LCA during laparoscopic left-sided colorectal operation, which would help surgeons safely perform laparoscopic surgery in the left-side colon and rectum.