A 32-year-old female presents to your office with severe nausea and recurrent bilious vomiting. Her symptoms initially began as postprandial epigastric pain and early satiety, but have progressed over the last two weeks. She works as an actress, and tells you that her symptoms only started when she "landed a role in a soap opera" and was inspired to lose 25 lbs. on a "crash diet". On physical exam, her abdomen is tender and slightly distended with high-pitched bowel sounds. Concerned about a small bowel obstruction, you admit the patient to the hospital. A laparotomy is performed, and it is observed that the angle between her superior mesenteric artery and her aorta is significantly decreased. Which of the following structures is most likely to be obstructed by the artery?

Question

A 32-year-old female presents to your office with severe nausea and recurrent bilious vomiting.  Her symptoms initially began as postprandial epigastric pain and early satiety, but have progressed over the last two weeks.  She works as an actress, and tells you that her symptoms only started when she "landed a role in a soap opera" and was inspired to lose 25 lbs.  on a "crash diet".  On physical exam, her abdomen is tender and slightly distended with high-pitched bowel sounds.  Concerned about a small bowel obstruction, you admit the patient to the hospital.  A laparotomy is performed, and it is observed that the angle between her superior mesenteric artery and her aorta is significantly decreased.  Which of the following structures is most likely to be obstructed by the artery?

Quizplus · Accepted Answer

The superior mesenteric artery (SMA) leaves the aorta at the level of L1 and supplies the intestine from the duodenum and pancreas to the left colic flexure. The transverse portion of the duodenum lies horizontally at the level of L3, between the aorta and superior mesenteric artery. Normally, the SMA and aorta form an approximately 45 degree angle. If this angle diminishes to less than 20 degrees, the transverse portion of the duodenum can get entrapped between the SMA and aorta, leading to symptoms of partial small bowel obstruction. This condition is called superior mesenteric artery syndrome. 11ec160b_357a_e3d0_9249_0fcaae26101a_MD0001_00 Narrowing of the aortomesenteric angle can occur with any condition that causes diminished mesenteric fat, including low body weight, recent weight loss, severe burns or other inducers of catabolism, and prolonged bed rest. It can also occur with pronounced lordosis or after surgical correction of scoliosis, as this procedure lengthens the spine resulting in decreased mobility of the SMA. Educational Objective: Superior mesenteric artery syndrome occurs when the transverse portion of the duodenum is entrapped between the SMA and aorta, causing symptoms of partial intestinal obstruction. This syndrome occurs when the aortomesenteric angle critically decreases, secondary to diminished mesenteric fat, pronounced lordosis, or surgical correction of scoliosis.

A 32-Year-Old Female Presents to Your Office with Severe Nausea