Studies on Inferior Mesenteric Arterial and Venous System in Rectal Surgery Part I. Morphological study of inferior mesenteric artery and vein

Origins, ramifications and courses of the inferior mesenteric arterial and venous system were statistically investigated in 120 cadavers of the Japanese. 1) The average distance between the bifurcation of the abdominal aorta and the origin of the inferior mesenteric artery was 4.4 cm. In 82.5% of all cases, the distance was between 3.6 cm and 5.5 cm. It was 0.5 cm longer in the male than the female on the average. 2) The number of the branches of the inferior mesenteric artery was; two in 47.5% of the cases, three in 38.3% and four in 14.2%. 3) The average distance between the origin of the inferior mesenteric artery and its first branch was 3.9 cm. In 78.3% of all cases, the distance was between 2.6 cm and 5.0 cm. 4) In 8.3% of all cases, the lack of the upper branch of the left colic artery was observed, while that of the lower branch was in 48.3%. 5) Most of the inferior mesenteric artery ascended almost vertically at the distance of 1.0 cm to 3.0 cm to the left from the left margin of the abdominal aorta at the level of the origin of the inferior mesenteric artery.