The significance of anatomical variation of the inferior mesenteric artery and its branches for laparoscopic radical resection of colorectal cancer: a review

Abstract

Currently, high or low ligation of the inferior mesenteric artery (IMA) is a controversial issue in laparoscopic radical surgery for colorectal cancer. High or low ligation of the IMA has both advantages and disadvantages, and the level of ligation during the left colon and/or rectum resection has been a dilemma for surgeons. One important factor influencing the surgeon's decision to ligate the IMA in a high or low position is the anatomical type of the IMA and its branches. Some studies confirm that the anatomy of the IMA and its branches is critical to the anastomotic blood supply and, therefore, influences the choice of surgical approach (level of ligation of the IMA). However, many vascular variations in the anatomy of the IMA and its branches exist. Herein, we have summarized the anatomical types of the IMA and its branches, finding that the classification proposed by Yada et al. in 1997 is presently accepted by most scholars. Based on Yada's classification, we further summarized the characteristics of the IMA's various anatomical types as a guide for high or low ligation in radical colorectal cancer surgery.

Keywords: Classification; Colorectal cancer; Inferior mesenteric artery; Laparoscopic resection of colorectal cancer; Left colonic artery; Riolan artery arch; Vascular anatomy.

Fig. 1

Laterjet’s classification of the branching type of the inferior mesenteric artery: type I (spread) and type II (fan)

Fig. 2

Predescu’s classification of the branching pattern of the IMA (IMA, inferior mesenteric artery; LCa, left colic artery; S trunk, sigmoid artery trunk; LC acc.a, middle left colonic artery MLCA or the inferior left colonic artery ILCA; SRa, superior rectal artery)

Fig. 3

Zebrowski classification: C, common artery; IM, inferior mesenteric artery; LC, left colonic artery; RST, rectosigmoid trunk; SR, superior rectal artery; ST, sigmoid trunk

Fig. 4

Wang’s classification of inferior mesenteric artery (IMA) branching types into A-C (AA, abdominal aorta; LCA, left colonic artery; SA, sigmoid artery; SRA, superior rectal artery)

Fig. 5

Classification of Patroni. Type I and type II represent diffuse or fan-shaped IMA branching patterns, respectively (Laterjet typing). Subgroup N represents IMV-LCA distances greater or less than 20 mm at the inferior margin of the pancreas, respectively; subgroup F represents IMV-LCA distances greater than 20 mm at the inferior margin of the pancreas, respectively

Fig. 6

Yada classification (I: LCA emanates from IMA independently; II: LCA and SA co-trunk; III: LCA, SA and SRA emanate from the same point; IV: LCA is absent)