Abdominal Vasculature Notes Flashcards
What is an abdominal aortic aneurysm?
Dilatation of the aorta equal to or exceeding 3 cm in diameter; also known as AAA.
What is an aneurysm?
A localized widening or dilatation of a blood vessel.
What is aortic dissection?
Spontaneous longitudinal separation of the intima and media layers creating a false lumen.
What is arterial stenosis? What is it usually caused by?
- Narrowing or constriction of an artery
- Usually caused by atherosclerosis, arteriosclerosis, or fibrointimal hyperplasia.
What is arteriosclerosis?
Pathological thickening, hardening, and loss of elasticity of the arterial walls.
What is an arteriovenous fistula? What is this also known as?
- An abnormal connection between an artery and vein
- Also known as arteriovenous shunting.
What is atherosclerosis?
Disorder characterized by yellowish plaques of lipids and cellular debris in the medial and intimal layers of the arterial walls.
What is a berry aneurysm?
Small saccular aneurysm primarily affecting the cerebral arteries.
What is an ectatic aneurysm?
Dilatation of an artery compared with a more proximal segment; in the abdominal aorta, the ectatic dilatation does not exceed 3.0 cm.
What is a fusiform aneurysm?
Characterized by a uniform dilatation of the arterial walls; most common type of abdominal aortic aneurysm.
What is mesenteric ischemia?
Decrease in arterial supply to the intestinal system.
What is a mycotic aneurysm?
A saccular dilatation of a blood vessel caused by a bacterial infection.
What is a pseudoaneurysm? What is this also known as?
- Dilatation of an artery as a result of damage to one or more layers of the arterial wall caused by trauma or aneurysm rupture
- Also known as pulsatile hematoma.
What is a saccular aneurysm?
Dilatation of an artery characterized by a focal outpouching of one arterial wall; most often caused by trauma or infection.
What are the functions of the vascular system?
Arteries and arterioles carry blood away from the heart to organs and tissues to ensure oxygenation and metabolism.
What are the exceptions in the vascular system? (arteries)
Pulmonary artery and umbilical arteries in the fetus.
What is the role of arterioles? What are they responsible for?
- Main controllers of blood pressure and blood flow
- Responsible for waveform morphology.
What do capillaries do?
Connect the arterial and venous systems and exchange nutrients and waste.
What do veins and venules do?
Carry oxygen depleted blood toward the heart.
What are the exceptions for veins?
Pulmonary vein and umbilical vein of the fetus.
What is the structure of venous walls compared to arterial walls?
Venous walls are thinner and less elastic compared with arterial walls.
What is the tunica adventitia?
Outer layer of a blood vessel, comprised of elastic tissue surrounded by a thin fibrous layer.
What is the tunica media?
Middle muscle layer of a blood vessel, comprised of collagenous fiber and smooth muscle.
What is the tunica intima?
Inner layer of a blood vessel, composed of three layers giving it a smooth surface.
What is the origin of the abdominal aorta?
Originates at the diaphragm and courses inferiorly until it bifurcates into the right and left common iliac arteries.
What are the terminal branches of the abdominal aorta?
Common iliac arteries.
What does the common iliac artery bifurcate into?
External and internal (hypogastric) iliac arteries.
What does the external iliac artery become after passing beneath the inguinal ligament?
Common femoral artery.
What does the internal iliac artery bifurcate into?
Anterior and posterior divisions.
What is the celiac axis?
First major branch of the abdominal aorta, arising from the anterior aspect.
What does the celiac axis branch into? 3
Splenic, left gastric, and common hepatic arteries.
What is the superior mesenteric artery (SMA)?
Second major branch of the abdominal aorta, arising from the anterior surface inferior to the celiac axis.
What does the SMA supply? 6
- Jejunum
- Ileum
- Cecum
- Ascending colon
- Portions of the transverse colon
- Head of the pancreas.
What is the location of the main renal arteries? (R + L)
- Right renal artery arises from the anterior lateral aspect
- Left renal artery arises from the posterior lateral aspect.
How do the gonadal arteries course in relation to the psoas muscles?
Course parallel to the psoas muscle into the pelvis.
What is the inferior mesenteric artery (IMA)?
Where is it located on the abdominal aorta?
Last major branch of the abdominal aorta, superior to the aortic bifurcation.
What does the IMA supply? 4
- Left transverse colon
- Descending colon
- Upper rectum
- Sigmoid.
Where does the inferior phrenic artery arise from? What does it supply?
- Arises from the anterior aspect of the abdominal aorta
- Supplying the inferior portion of the diaphragm.
What do lumbar arteries supply?
Abdominal wall and spinal cord.
Where is the median sacral artery located in relation to the inferior mesenteric artery and the aortic bifurcation?
Located inferior to the inferior mesenteric artery and superior to the aortic bifurcation.
What is the gastroduodenal artery (GDA)? Where is it located?
- Branch of the common hepatic artery
- Located between the superior portion of the duodenum and the anterior surface of the pancreatic head.
What is the common hepatic artery? What is it termed now?
- A branch of the celiac axis that gives rise to the gastroduodenal artery
- Now termed the proper hepatic artery.
What does the left gastric artery supply?
Supplies the left side of the lesser curvature of the stomach.
What is the inferior vena cava (IVC)?
Formed at the junction of the right and left common iliac veins, carrying oxygen-depleted blood from the body to the right atrium.
What are the main venous tributaries of the IVC? 6
- Lumbar veins
- Right gonadal vein
- Renal veins
- Right suprarenal vein
- Inferior phrenic vein
- Hepatic veins.
What do common iliac veins drain?
Blood from the lower extremities and pelvis.
What is the role of renal veins?
Course anterior to the renal arteries and drain blood from the kidneys.
What do hepatic veins do?
Lie at the boundaries of the hepatic segments and course toward the IVC.
What does the MPV drain? How much blood does it supply to the liver? (5)
- Drains the gastrointestinal tract
- Pancreas
- Spleen
- Gallbladder
- Providing approximately 70% to 75% of the liver’s blood supply.
Where does the splenic vein join? what does it form?
Joins the superior mesenteric vein to form the main portal vein.
What does the superior mesenteric vein form with the splenic vein? How does it course with in terms of the SMA?
Courses parallel to the superior mesenteric artery and joins the splenic vein to form the main portal vein.
What is the normal adult diameter of the abdominal aorta?
10 mm or less.
What causes an increase in the caliber of the abdominal aorta?
Inspiration and following a meal.
What organs drain into the abdominal aorta? 3
- Spleen
- Pancreas
- Portion of the stomach.
Where is the abdominal aorta located? (in relation to the left kidney, Left renal artery + vein, neck/body of the pancreas)
- Anterior to the left kidney
- Anterior to left renal artery and vein
- Posterior to the neck/body of the pancreas.
What is the course of the superior mesenteric vein?
Courses parallel to the superior mesenteric artery.
What does the superior mesenteric vein join to form?
The main portal vein.
What is the normal adult diameter of the superior mesenteric vein?
10 mm or less.
What does the inferior vena cava lie adjacent to?
The abdominal aorta.
What is the size of the normal abdominal aorta?
Should not exceed 3 cm in diameter.
What is the typical diameter of the inferior vena cava?
Usually less than 2.5 cm, should not exceed 3.7 cm.
What is the sonographic appearance of the abdominal aorta?
Anechoic tubular structure with thin hyperechoic wall margins.
What is the recommended fasting time for adults before an ultrasound of the renal arteries?
6 to 8 hours.
What transducer frequency is recommended for adults?
3.0 to 5.0 MHz.
What patient position is usually used for examination?
Supine position.
What should be documented when evaluating an abdominal aortic aneurysm?
Measurements from outer edge to outer edge in the anterior posterior and transverse planes.
What is a common risk factor for abdominal aortic aneurysm?
Arteriosclerosis.
What is the average growth rate of an abdominal aortic aneurysm?
2 mm/year.
What is the clinical finding of an abdominal aortic aneurysm?
Pulsatile abdominal mass.
What is the sonographic finding of an abdominal aortic aneurysm?
Typically fusiform-shaped dilatation of the aorta.
What is the risk of rupture for an abdominal aortic aneurysm measuring 6 cm?
16% within 5 years.
What is a pseudoaneurysm?
Trauma to the arterial wall permits the escape of blood into surrounding tissues.
What is the clinical finding of a ruptured aneurysm?
Severe abdominal pain and hypotension.
What is the sonographic finding of a ruptured aneurysm?
Asymmetrical or unilateral paraaortic hypoechoic mass.
What is the typical appearance of an abdominal aortic dissection?
Thin hyperechoic membrane within the aorta.
What is a common symptom of mesenteric ischemia?
Postprandial pain.
What is a common finding in arteriovenous shunts?
Presence of a bruit or ‘thrill’.
What can cause edema in the inferior vena cava?
Thrombosis.
