7/26/2019 GT Anatomy

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GT Anatomy:

  Gallstone ileus results from the passage of a large gallstone (typically greater than 2.5 cm) through a

cholecystenteric fistula into the small bowel where it ultimately causes obstruction at the ileocecal valve.

Gas is seen within the gallbladder and biliary tree on abdominal X-ray due to the presence of the fistula,

and patients present with signs and symptoms of small bowel obstruction.

 

The hindgut encompasses the distal 1/3 of the transverse colon the descending colon the sigmoid colon andthe rectum. These structures receive their main arterial blood supply from the inferior mesenteric artery.

  Retroperitoneal hematoma in a stable patient is likely to occur due to pancreatic injury. Lt may present with

mild symptoms be asymptomatic or be masked by symptoms from other injuries related to trauma.

Abdominal CT is the diagnostic modality of choice. Frequently nonexpanding hematomas in this location

will be treated conservatively (i.e. non-operatively).

  The great majority of gastric ulcers occur at the lesser curvature, at the border between acid-secreting and

gastrin secreting mucosa. Left and right gastric arteries run along the lesser curvature and are likely to be

damaged, causing gastric bleeding.

  Cardiovascular dysphagia can result from pressure on the esophagus by a dilated left atrium. The left

atrium is commonly enlarged in patients with mitral stenosis and left ventricular failure.

  The esophagus is located between the trachea and the vertebral bodies in the superior thorax. It is typically

collapsed with no visible lumen on CT images of the chest.  The spleen is not a gut derivative it forms from the mesodermal dorsal mesentery. The splenic artery

however is a branch of the celiac trunk (the primary blood supply of the foregut)

  The third part of the duodenum courses horizontally across the abdominal aorta and inferior vena cava at

the level of the third lumbar vertebra. Here itis in close association with the uncinate process of the

 pancreas and the superior mesenteric vessels.

  On abdominal CT scans the pancreas can be identified by its head in close association with the second part

of the duodenum: by its body overlying the left kidney aorta, IVC and superior mesenteric vessels: and also

 by the tail lying in the splenorenal ligament.

  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 either from diminished mesenteric fat or pronounced lordosis

or surgical correction of scoliosis.

 

The gastroduodenal artery lies along the posterior wall of the duodenal bulb and is likely to be eroded by

 posterior duodenal ulcers. Ulceration into the gastroduodenal artery can be a source of life-threatening

hemorrhage.