The superior mesenteric artery is the name given to the upper visceral artery. It supplies blood to several important areas of the body.
What is the superior mesenteric artery?
The superior mesenteric artery is the upper visceral artery. It represents an unpaired branch of the aorta. This branch is located directly behind the outlet of the coeliac trunk (Haller’s tripod), so that the superior mesenteric artery forms the second unpaired branch of the abdominal aorta. The first unpaired branch is marked by the truncus coeliacus. The tasks of the superior visceral artery include supplying blood to several regions of the body. Occasionally, diseases also occur in the artery. This primarily includes mesenteric artery stenosis.
Anatomy and structure
The superior mesenteric artery originates behind the neck of the pancreas, between the renal arteries and the trunk of the coeliac trunk. Thereby, it is located approximately at the level of the first lumbar vertebra. In domestic animals, the origin of the artery is posterior to the coeliac artery and is called the cranial mesenteric artery, which means “cranial visceral artery.” There is a connection between the superior mesenteric artery and the inferior mesenteric artery via the Riolan anastomosis. The superior visceral artery arises from the aorta near the 1st lumbar vertebra. From there it runs in the anterior and inferior direction. In doing so, it passes by the neck portion of the pancreas as well as the splenic vein. Various structures are present between the aorta and the superior mesenteric artery. These include the processus uncinatus of the pancreas, the pars horizontalis of the duodenum, and the left renal vein (renal sinister vein). The upper visceral artery is accompanied on its way by the superior mesenteric vein, which is a tributary branch of the portal vein (vena portae). Following the passage of the pancreatic neck, there is a division of the superior mesenteric artery, which splits into several branches. Des are the middle colonic artery (Arteria colica media), the right colonic artery (Arteria colica dextra), the ileocolic artery (Arteria ileocolica), the anterior appendiceal artery (Arteria caecalis anterior), the posterior appendiceal artery (Arteria caecalis posterior) and the appendiceal appendix artery (Arteria appendicularis). The pancreaticoduodenal artery (Arteria pancreaticoduodenalis inferior) forms another important branch. This has a right and a left branch and, together with the branches of the right colonic artery, forms the marginal colic artery. This is located near the colon and provides blood supply to it.
Function and Tasks
The function of the superior mesenteric artery is to supply blood to various organs. These are the pancreas, duodenum, small intestine (intestinum tenue), ascending colon (colon), and transverse colon (colon transversum). Likewise, the upper visceral artery provides blood supply to the appendix vermiformis, which forms the vermiform appendix and is known for its infamous inflammations, often mistakenly called appendicitis. However, the worm-like appendix, which is about 10 centimeters long, represents only the outpouching of the appendix (caecum).
Diseases
Impairments of the superior mesenteric artery can cause health problems. Chief among these is mesenteric artery stenosis, also called mesenteric occlusive disease or mesenteric artery occlusion. This results in narrowing (stenosis) or even occlusion of the superior iliac artery. In the case of a complete occlusion of a mesenteric vessel, which is accompanied by necrosis of the affected intestinal region, physicians speak of an intestinal infarction or mesenteric infarction. Mesenteric occlusive disease is most commonly caused by local arterial thrombosis or arterial embolism in the superior mesenteric artery, inferior mesenteric artery, and coeliac trunk. There are certain risk factors that promote stenosis of the superior visceral artery.These include arteriosclerosis, cardiac arrhythmias as a source of embolism, and previous surgery on surrounding vessels such as surgery for an abdominal aortic aneurysm. Mesenteric artery stenosis is manifested by severe abdominal pain, which often takes a colicky course. After about six to eight hours, the pain initially improves again. However, doctors call this “deceptive peace” because a dangerous peritonitis forms afterwards, which leads to shock after a short time. Mesenteric artery stenosis can also take a chronic course. In this case, patients suffer from recurrent colicky abdominal pain, loss of appetite and weight loss. In the case of acute mesenteric artery occlusion, the first step is laparoscopy. If this results in the suspicion of intestinal obstruction, an abdominal incision (laparotomy) must be performed. If there is no necrosis, the blood clot is removed during the operation. In some cases, resection of ischemic-necrotic bowel areas may also be required. In cases of chronic obstruction of the superior mesenteric artery, the surgeon usually creates a bypass between the blood vessel and the aorta. A rare disease of the superior visceral artery is the superior mesenteric artery syndrome. This refers to a compression syndrome in which there is pain in the upper abdomen, nausea and vomiting. Because patients suffer from deficiency symptoms because of this, they are often mistakenly considered to have eating disorders. Superior mesenteric artery syndrome is also known as superior mesenteric artery syndrome, acute gastroduodenal obstruction, or Wilkie syndrome. In this condition, stenosis occurs in the distal duodenal region between the superior mesenteric artery and the aorta. The condition is caused by anatomic abnormalities, chronic weight loss, nutritional disturbances, or surgical intervention. Treatment is either conservative by weight gain or surgical.
