Gastrointestinal Blood Supply

What 5 branches come off of the SMA?

1.Inferior pancreaticoduodenal 2.Middle colic 3.Right colic 4.Ileocolic 5.Intestinal branches (15-18 branches)

What 3 major branches come off of the abdominal aorta to supply the GI tract?

Celiac trunk, SMA, IMA

What drains the right superior lobe of the liver? The caudate lobe? The left lobe?

Right superior hepatic vein Middle superior hepatic vein Left superior hepatic vein

Dual blood supply IMA - Iliac?

Superior rectal and middle and inferior rectals

Spinal arteries arise from _________, give rise to _________ arteries at each vertebral level. Spinal Artery of Adamkiewicz; supplies ________________, arises from _______ aorta between _________

posterior; radicular; inferior spinal cord; thoracic; T7 and T11

Splenic flexure is supplied by? Rectosigmoid junction is supplied by?

- Supplied by small branches of marginal artery of Drummond = vulnerable to under perfusion - Supplied by narrow branches of IMA

The celiac trunk supplies what? Main branches? (3)

-Supplies foregut structures (ie esophagus, stomach, liver, GB, spleen, part of duodenum, pancreas) -Common hepatic, splenic, left gastric

Embolism as a cause of mesenteric ischemia? Arterial thrombosis? Venous thrombosis? Non-occlusive ischemia?

1. embolism - typically LV thrombus/LA appendage that affects the jejunum 2. Arterial thrombus - at site of atherosclerosis 3. Venous thrombosis - venous clot seen in hyper-coagulable states/malignancy that leads to resistance to flow out of the mesentery 4. Non-occlusive - there is under perfusion (shock), typically in watershed areas of colon

Short gastric arteries? Susceptible to ischemia, why?

5-7 small branches that branch off of the splenic artery that supply the fundus and upper cardiac portions of the stomach. Because there is only blood supply from the splenic artery as opposed to the gastric and gastroepiploic arteries which have dual blood supplies.

Marginal artery of Drummond?

A continuous arterial circle or arcade along the inner border of the colon formed by the anastomoses of the terminal branches of the superior mesenteric artery (SMA) and inferior mesenteric artery(IMA).

Arcades and vasa recta?

Arcades: anastamoses of ileal/jejunal arteries Vasa recta: arteries extending from arcades

Watershed areas? 2 common sites?

Areas in the colon located between major vessels that are at risk for ischemia in shock/hypoperfusion; splenic flexure & rectosigmoid junction

Superficial mesenteric artery (SMA) arises where? Supplies what? Descends across what?

Arises around L1, usually behind the pancreas. Supplies midgut structures (ie small intestine, proximal colon, and pancreas). Descends across pancreas head and duodenum

Lumbar arteries branch off of the abdominal aorta where? What do they supply? (3)

At each lumbar vertebral level. They supply the anterior and lateral abdominal wall (anterior), true (intrinsic) back muscles and the spinal cord (posterior).

Gonadal arteries branch off of the abdominal aorta where? What do they supply? (2)

Between the SMA and IMA, around L2. Supply the gonads and the uterus

Renal arteries branch off of the abdominal aorta where? What do they supply? (3)

Between the SMA and IMA, around L2. Supply the kidneys, proximal ureter, and adrenal gland

Pringle's maneuver?

Clamping vessels of hepatoduodenal ligament to control liver bleeding. If bleeding continues, you know the bleed is in the IVC or hepatic veins.

Where do the right and left gastric veins and esophageal veins drain into?

Directly into the portal vein

Superior and inferior pancreaticoduodenal arteries supply?

Dual blood supply: Celiac trunk and SMA to supply both duodenum and pancreas

Hepatoduodenal ligament? Contains? (3)

Found on the free border of the lesser omentum and connects liver to the duodenum. Contains the proper hepatic artery (branch of common hepatic), portal vein, and common bile duct.

The renal veins from each kidney drain each into the ______. They pass _________ to the renal arteries. The left renal vein passes underneath the _____ on its way to the ____. The left gonadal vein drains into the ____________ whereas the right gonadal vein drains ______________.

IVC; anterior; SMA; IVC; left renal vein; directly into the IVC

What vein drains hindgut structures? What vein drains the spleen, body and tail of the pancreas, and stomach? What vein drains midgut structures?

Inferior mesenteric vein (IMV); Splenic vein; Superior mesenteric vein (SMV)

Ischemic colitis?

Ischemia of the colon

What is mesenteric ischemia? Ischemia of what structure is the most severe and often life threatening? Symptoms? Labs?

Ischemia of the intestines; Small intestine; "pain out of proportion to exam": usually sudden onset abdominal pain and cramping, no rebound tenderness/peritoneal signs, occult blood in stool; increased WBC, lactate, and acidosis

Splenic artery: located where and supplies what?

It branches off the celiac trunk to the left, posterior to the stomach and lies along the superior edge of the pancreas. Supplies the spleen, gastric fundus and pancreas.

Blood supply to the lesser curvature of the stomach? Greater curvature? Duodenum?

Left gastric artery Left and right gastroepiploic artery Gastroduodenal artery

The 6-18 inferior hepatic veins drain which lobes? (3)

Quadrate, caudate and right lobes.

SMA syndrome? Classic patient?

Rare cause of bowel obstruction. The SMA courses over distal 1/3 of duodenum (distal duodenum sits between the aorta and SMA; mesenteric fat keeps the SMA away from the duodenum). If the SMA is pressed down, there is obstruction of the bowel. A patient with recent massive weight loss because the fat pad shrinks

Cirrhosis of the liver can lead to?

Scarring of the liver can lead to impeded blood flow via the portal vein, resulting in portal HTN. Patient presents with esophageal varices, hemorrhoids, and caput medusae.

IMA supplies? 3 branches?

Supplies hindgut structures (descending colon, sigmoid colon, and rectum) 1. Left colic 2. Sigmoidal 3. Superior rectal

What structures converge to form the portal vein? Where does the portal vein run?

The splenic vein and IMV converge before joining with the SMV to form the portal vein. Posterior to the proper hepatic artery and common bile duct.

What veins drain the liver?

There are three hepatic veins that drain the liver along its superior aspect. The right, middle, and left hepatic veins

Phrenic arteries: branch off where? Travel along what? Supply what?

They are the first branches off of the abdominal aorta, left and right. Travel along inferior surface of diaphragm and supply the diaphragm and the adrenal gland.

Chronic mesenteric ischemia (intestinal angina): typical patient?

Usually older patient with other vascular disease; recurrent abdominal pain after eating thus, they develop fear of eating leading to weight loss

The common hepatic artery is the final branch of the __________. It courses to the ______ towards the liver and further divides into the ____________ and ____________ arteries. It supplies what? (5)

celiac trunk; right; proper hepatic; gastroduodenal; liver, gallbladder, stomach, duodenum and pancreas

There are ________ lumbar veins from each vertebral level. Usually unite to form the ___________ which on the right it becomes the _________ and on the left it becomes the __________.

four to five; ascending lumbar vein; azygos vein; hemiazygos vein

The common hepatic artery passes to the right of the stomach and gives off the _________ and ___________ arteries. The right gastroepiploic artery arises from the ______________ artery. The proper hepatic artery is part of the __________ and divides into right and left ____________.

gastroduodenal; proper hepatic; gastroduodenal; porta hepatis; hepatic arteries

The ileocolic artery is found within the _______ and supplies the ____________, specifically the junction between the _______ and the _______. It anastomoses with the ___________ artery.

mesentery; ascending colon; ileum; cecum; right colic

The right colic artery is found within the ________ and courses posterior to the ________ and supplies the ______________. It anastomoses with the _______ and ________ arteries.

mesentery; duodenum; right/ascending colon; middle; ileocolic

The sigmoidal branches are found within the _______ and anastomose with the _______ artery. It supplies the _________ (primarily) and the______________.

mesentery; left colic; sigmoid colon; left (descending) colon

The left colic artery is found within the _______ and anastomoses with the _______________ artery via the ___________ and the __________. It also anastomoses with the ____________. It supplies the ________________.

mesentery; middle colic (from SMA); marginal artery of Drummond; Arc of Riolan; sigmoidal branches; left (descending) colon

The middle colic artery is found within the _________ and anastomoses with the ____________ and ___________ arteries via the ______________ and _____________. What does it supply?

mesentery; right colic (from SMA); left colic (from IMA); marginal artery of Drummond; the Arc of Riolan; the transverse colon

The left gastric artery anastomoses with the __________ artery. It also sends a branch to the ________.

right gastric; esophagus

The inferior pancreaticoduodenal artery gives off anterior and posterior branches anastomoses with the anterior and posterior branches of the ______________. It courses around the C-loop of the _________ and ______________ and thus supplies the _________ and __________-.

superior pancreaticoduodenal artery; duodenum; head of the pancreas; pancreas; duodenum

The superior rectal artery is the _____________. It supplies the ______ (superior specifically). It anastomoses with ________ and the __________.

termination of the IMA; rectum; middle rectal; inferior rectal