A Rare Branching Pattern of a Middle Mesenteric Artery Supplying the Head of the Pancreas and the Transverse Colon

<p><strong>Objective</strong>. The appearance of a middle mesenteric artery is a rare branching variation, with an incidence lower than 0.1%. Our case reports such an anatomical artery pattern which was discovered in a male Caucasian cadaver during routine educational dissection. This alternation is seldom encountered and may trouble diagnostic and surgical interventions.</p><p><strong>Case Report.</strong> The case of a Middle Mesenteric Artery is described, as a vessel originating from the Abdominal Aorta 3.3 cm below the origin of the Superior Mesenteric and 3.8 cm above the origin of the Inferior Mesenteric Artery. The middle mesenteric artery, directed upwards, gives two branches for supplying blood to the head of the pancreas. We first mention the thinner branch, corresponding to the posterior one of the inferior pancreaticoduodenal artery, and second the thicker branch corresponding to the anterior branch of the Inferior Pancreaticoduodenal Artery. The main artery continues its course between the two sheets of the mesocolon to supply the transverse colon, thus substituting the normal colic artery.</p><p><strong>Conclusion. </strong>The occurrence of a Middle Mesenteric Artery constitutes a very rare anatomic variation. We present, to our knowledge, the first case described where the Middle Mesenteric Artery provides blood to the pancreas.</p>

Middle mesenteric artery: contraindication to endovascular repair of an abdominal aortic aneurysm?

Middle mesenteric artery has been described in 1923. We report the observation of a patient with an abdominal aortic aneurysm who had this rare artery arising from the anterior wall of the aneurysmal sac. His inferior mesenteric artery was occluded at its origin from the aorta and the middle and the distal colon was vascularized only by the middle mesenteric artery. Occlusion of this artery would have been necessary before endovascular repair of the aneurysm. We were concerned about the risk of colic ischemia after the occlusion of the middle mesenteric artery, so we abandoned this approach and operated on the patient via a laparotomy. Based on a case report, we here report a literature overview on the repair of abdominal aortic aneurysm in the presence of a middle mesenteric artery.