DOUBLE MIDDLE COLIC ARTERIES IN A FEMALE CADAVER OF ASIAN ORIGIN-A CASE REPORT

Knowledge of variant vascular supply of the gastrointestinal tract is essential, especially in minimal access surgical procedures. We describe the rare variation of double middle colic arteries, the main right middle colic artery from the superior mesenteric artery and the accessory left middle colic artery from the celiac trunk in a female cadaver during dissection for undergraduate students. A pre-operative selective arteriogram is important to determine such anomalies prior to performing elective pancreatic resections


INTRODUCTION
The middle colic artery arises from the superior mesenteric artery near the lower border of the pancreas,courses through the transverse meso-colon to supply the transverse colon.The vessel branches at a variable distance (3-10 cm) from the colonic wall, anastomosing with the ascending branches of the right and left colic arteries to form the marginal artery of Drummond (Standring, 2005).Origin of the middle colic artery from the superior mesenteric artery is fairly constant at 78-99% (Garcia-Ruiz et al, 1996).The present case describes a rare variation of the double middle colic arteries in a female cadaver of about 60 years old of Asian origin.A middle colic artery originated from the superior mesenteric artery and another middle colic artery took origin from the celiac trunk.An undetected anomalous course of the middle colic artery could potentially cause its injury during pancreatoduodenectomy or retro-pancreatic dissection resulting in the transverse colon ischemia.

MATERIAL AND METHODS
During routine educational dissection of abdomen region for the first year undergraduate students of the academic year 2007-2008 in our department of anatomy, this rare variation of double middle colic arteries was observed in a female cadaver of about 60 years old of Asian origin.The arteries of the abdomen region were dissected following the standard dissection procedures.

RESULTS
In the female cadaver, the first middle colic artery (MCA-I) arose as a first branch of the superior mesenteric artery which gave a branch to the head of pancreas and then divided into two branches, the right and the left (

DISCUSSION
Garcia-Ruiz et al (1996) reported double middle colic arteries in the study of large series of cadaveric dissections.Middle colic arteries originate from the celiac trunk at a rate of 0.5% to 1% (Makowski et al, 2000, Yildirim et al, 2004;Michels et al, 1965).A middle colic artery originating from the celiac trunk was considered as evidence for the ventral longitudinal anastomosis of the primitive vitelline arteries in the embryo (Tandler, 1904).Middle colic arteries arising from the splenic trunk (Amonoo- Kuofi et al, 1995;Murokami et al, 1998) (Shoumura et al, 1991;Wadhwa and Barua, 2008) have been reported.Anomalous origin of the middle mesenteric artery from the aorta instead of the middle colic artery was reported by Yoshida et al (1993).In the presence of the anomalous middle colic artery from the celiac trunk passing behind the body of pancreas, attention should be paid during the pancreatic resections and in the interposition of the transverse colon for esophageal replacement in order to avoid serious bleeding and necrosis.Retro pancreatic middle colic arteries may spread the pancreatic malignancy to the transverse colon necessitating the resection of the transverse colon.Presence of an anomalous middle colic artery would need a higher level of lymph node dissection during transverse colonic resection for malignancy.These arterial variations need to be investigated by vascular studies prior to a major abdominal surgery.

Conflict of interest None
Funding None

Informed consent
Not applicable

Contributions
Chitra Ramasamy -Identification of the anatomical variations in the particular cadaver and preparation of the manuscript.Shakthi Kumaran Ramasamy -Dissection of the arteries and capturing images of the arteries Fig.1).The right branch of this middle colic artery (MCA-I) anastomosed with the upper branch of the right colic artery and supplied the hepatic flexure and right one third of the transverse colon.In the same cadaver, the celiac trunk had four branches, the left gastric artery, the common hepatic artery, the splenic artery and the second middle colic artery (MCA-II) (Fig.2).The middle colic artery originating from the celiac trunk passed behind the body of pancreas and then divided into right and left branches.The right branch of the MCA-II anatomosed with the left branch of MCA-I and supplied the middle one third of transverse colon.The left branch of MCA-II supplied the splenic flexure and upper part of the descending colon by anastomosing with the branch of the left colic artery from the inferior mesenteric artery.In the present case thus, the middle and left parts of the transverse colon and upper part of the descending colon had a vascular contribution from the celiac trunk

Figure 1 :
Figure 1: Showing double middle colic arteries, MCA I: Middle colic artery from the superior mesenteric artery, MCA II: Middle colic artery from the celiac trunk passing behind the neck of pancreas.

Figure 2 :
Figure 2: Origin of the middle colic artery from the celiac trunk, CT: Celiac trunk, CHA: Common hepatic artery, SA: Splenic artery, LGA: Left gastric artery, MCA II: Middle colic artery from the celiac trunk, P: Pancreas.