Superior Mesenteric Artery

Question 1

THE SUPERIOR MESENTERIC ARTERY?

Answer 1

• The superior mesenteric artery (SMA) is a major artery of the abdomen.
• It arises from the abdominal aorta, and supplies arterial blood to the organs of the midgut –
• which spans from the major duodenal papilla (of the duodenum) to the proximal 2/3 of the transverse colon.

Question 2

Anatomical Position?

Answer 2

The superior mesenteric arises:

• anteriorly from the abdominal aorta at the level of the L1 vertebrae, immediately inferior to the origin of the coeliac trunk.
• it descends down the posterior aspect of the abdomen. At this point, it has several important anatomical relations:

Anterior to the SMA:

• pyloric part of the stomach, splenic vein and neck of the pancreas.

Posterior to the SMA:

• left renal vein, uncinate process of the pancreas and inferior part of the duodenum.

The uncinate process is the only part of the pancreas that hooks around the back of the SMA.

Question 3

Clinical Relevance: Occlusion of the Superior Mesenteric Artery?

Answer 3

Number of cause of superior mesenteric artery occlusion:

• including thrombosis, embolism, abdominal aortic aneurysm and aortic dissection.

Occlusion of the SMA restricts blood flow to the midgut:

• resulting in intestinal ischaemia. It is more common is the elderly, and most usually presents with abdominal pain.
• Treatment is surgical