gastrointestinal blood supply Flashcards
what are the three major branches of the abdominal aorta ?
celiac trunk
SMA
IMA
what are the main branches of the celiac trunk ?
common hepatic
splenic
left gastric
what is the blood supply of the lesser curvature of the stomach ?
left gastric and right gastric
what is the blood supply of the grater curvature of the stomach ?
supplied by the right and left gastroepiploic artery
where are gastric ulcers more commonly found ?
in the lesser curvature of the stomach
if there is a bleeding of a gastric ulcer what is the most likley associated artery ?
left gastric artery
what is the most likley source of bleeding of perforated posterior duodenal ulcers ?
gastroduodenal artery
what is the blood supply of the cardia and the fundus of the stomach ?
short gastric arteries
where do the short gastric arteries branch from ?
branch from the splenic artery - and hence the celiac trunk
when are the short gastric arteries vulnerable to ischemia ?
when there is occlusion of the splenic artery
no double blood supply
why is ischemia a rarer occasion when it comes to the greater and lesser curvature of the stomach ?
due to the presence of a double blood supply
what are the structures in the hepatoduodenal ligament ?
contains the portal triad
proper hepatic ligament
portal vein
common bile duct
what is the significance of the pringle’s maneuver ?
it consists of clamping the hepatoduodenal ligament in order to control liver bleeding
if bleeding is still not controlled after clamping then the source of bleeding is either from the IVC or hepatic veins
what does the SMA supply ?
all the midgut structures
what is the course of the SMA ?
descends across pancreas head and duodenum
what are the branches of the SMA ?
right colic
ileocoloic
middle colic
all on the left side of the colon
on the right side
jejunal and ilelal arteries forming the arcades
what are the arcades and vasa recta ?
arcades is the anastmosis between the ileal and jejunal arteries
the vasa recta are extensions from the arcades
what is SMA syndrome ?
rare cause of bowel obstruction
where the dital duodenum is squashed between the aorta and the SMA
what is the classic patient associated with SMA syndrome ?
a patient who had recently lost a lot of fat quickly
what does the IMA supply ?
hindgut
what are the major branches of the IMA ?
left colic
sigmoid arteries
superior rectal arteries
what are the areas having dual blood supply ?
1- between the celiac trunk and the SMA
through the pancreaticoduodenal arteries supplies the duodenum and the pancreas
2- between the SMA and IMA through the marginal artery of drummond
3- IMA and iliac , which occurs in the rectum, superior rectal merges with the middle rectal
what is mesenteric ischemia ?
ischemia of the intestines , the most dangerous form is when it involves the small intestines
what is ischemic colitis ?
ischemia of the colon which may spontaneously resolve
what are the causes of mesenteric ischemia ?
1- emboli from the heart ( most common), especially with atrial fibrillation , affect jejunum mostly
2- arterial thrombosis, usually at site of atherosclorsis
3- venous thrombosis
4- non occlusive ischemia due to underperfusion , usually affects watershed areas of colon
what are the symptoms of mesenteric ischemia and what are the findings associated ?
sudden onset abdominal pain
on exam : pain out of proportion to exam, mild tenderness , nothing sus but occult blood present
what are the lab findings associated witg mesenteric ischemia ?
increased WBC and increased lactate and acidosis
what is watershed areas ?
areas with a dual blood supply but get less blood so they are at a higher risk of ischemia in cases of shock or hypoperfusion
what are the watershed areas aslan ?
1- splenic flexure: supplied by IMA and SMA (marginal artery of drummond)
2- rectosigmoid junction: supplied by IMA and internal iliac
what is chronic mesenteric ischemia and what is the othername used for it ?
also called mesenteric angina
occurs in older patients who have a known history of CVD or peripheral artery disease
what are the symptoms of chronic mesenteric ischemia ?
recurrent abdominal pain after eating
fear of eating, leading to weight loss
patient with intestinal angina but with sudden worsening on top of history of recurrent pain ?
may suggest acute thrombosis on top of a vascular plaque
