Anomalous inferior mesenteric artery supplying the ascending, transverse, descending, and sigmoid colons

Abstract

We have encountered in our anatomical practice the first case and an extremely rare second case in which the ascending, transverse, descending, and sigmoid colons were supplied by the inferior mesenteric artery. The causes of colic artery anomalies are generally explained in conjunction with the development of the superior mesenteric artery, which is intimately related to embryonic elongation and midgut rotation. However, this embryological model was inapplicable to both cases. This difficulty motivated us to seek possible relationships with reported anomalous inferior mesenteric arteries in adults as well as their embryological causes. We consider that the aberrant right colic artery found in 2009 is an "intermesenteric artery" which anastomoses the superior (or its middle colic branch) and inferior mesenteric artery, but secondarily lost its origin from the superior mesenteric artery. The aberrant colic artery found in 2010 is a "middle-inferior mesenteric artery" in which the inferior mesenteric artery formed a common trunk with remnant middle mesenteric artery.

A case report of a rare ramification pattern and distribution area of the mesenteric arteries in a Japanese White rabbit (<i>Oryctolagus cuniculus</i>)

“…In the rare case reported here, however, the cranial mesenteric artery only gave rise to the caudal pancreaticoduodenal, jejunal and ileal arteries, whereas the caudal mesenteric artery gave origin to the ileocecocolic, middle colic, right colic, left colic and cranial rectal arteries. Although prior rabbit studies have not reported this untypical branching pattern [2,6,7,9], Abe et al [1] and Covanțev et al [4] reported a similar case in humans, in which the cranial mesenteric artery supplied the proximal small portion of the ascending colon and cecum [1], or cecum only [4] via the ileocecal artery. Furthermore, they also found that the caudal mesenteric artery supplied most of the colon via the right colic, cranial left colic and caudal left colic arteries [1], or via the right colic, middle colic, accessory middle colic, left colic and accessory left colic arteries [4].…”

“…In humans, several authors have reported rare ramification patterns of the cranial (=superior) and caudal (=inferior) mesenteric arteries [1,4,5,10,16]. For example, Kitamura et al [10] and Yamasaki et al [16] reported cases where the cranial and caudal mesenteric arteries emerged from the abdominal aorta as a common trunk.…”

“…Dave et al [5] described a duplicated caudal mesenteric artery with one arising from the celiac trunk, while the other originating from the cranial mesenteric artery. Moreover, Abe et al [1] and Covanțev et al [4] reported cases where the cranial mesenteric artery supplied the small intestine and cecum, while the caudal mesenteric artery supplied most of the colon. The embryological causes of such rare variations have also been discussed in detail in several previous reports [1,4,5,10,16].…”

“…However, some parts of these anastomotic branches may not always regress and thus may cause a variation in the branching pattern of the cranial and caudal mesenteric arteries and their branches in humans [1,5,10,16]. One of the embryological remnants of the anastomosis is referred to as the intermesenteric arteries, which have been observed between the middle and left colic arteries, or between the cranial mesenteric and left colic arteries, or between the cranial and caudal mesenteric arteries [12,15].…”

“…Abe et al [1] and Yamasaki et al [16] reported that the intermesenteric arteries may give origin to the colic arteries and cause an anatomical variation in the branching pattern of the colic arteries depending on the regression pattern of the intermesenteric arteries and their parent arteries. In the present case (Fig.…”