Abdominal Vessels Flashcards
When does the thoracic aorta become the abdominal aorta?
As it passes posterior to the diaphragm and enters the abdominal cavity
What is the maximum normal diameter of the abdominal AO?
< 3 cm
What is the first branch of the abdominal AO?
The celiac axis
What are the three vessels that branch off the celiac axis?
The splenic, common hepatic, and left gastric veins
What is the second branch of the abdominal AO?
The superior mesenteric artery
Where are the renal arteries located in relation to the SMA?
Distal to SMA
Where are the renal arteries located in relation to the iliac arteries?
Proximal to iliacs
What actions can a patient take to increase IVC diameter?
Valsalva maneuver and holding their breath
What actions can a patient take to decrease IVC diameter?
Take in a sniff of air
Valsalva
What are the three layers of a vessel wall?
Tunica intima, media, and adventitia
How do the walls of the AO and IVC differ?
AO has thick tunica media w/ more muscle layers, IVC has thin tunica media and less elasticity
What is the purpose of the valves of the venous system?
They provide unidirectional flow to the vena cava
How do the walls of the AO appear on ultrasound?
Bright and echogenic
Is the AO pulsatile?
Yes, AO is pulsatile
Where is the AO in relation to the spine?
Anterior and to the anatomic left
What AO branches can be seen on ultrasound?
Celiac axis, SMA, renal arteries, and iliac arteries
What landmarks divide the abdominal AO into proximal, mid, and distal segments?
Proximal: diaphragm to celiac
Mid: celiac to SMA
Distal: SMA to ILI BIF
What transducer is most commonly used in abdominal AO scanning?
Low frequency (3-5 MHz) with a curvilinear probe
What other transducer can be used for AO scanning?
Phased array (1-5 MHz)
How is the patient usually positioned during an AO scan?
Supine position
What are the 4 techniques to optimize AO images?
- Decrease depth caudally
- Decrease depth at iliacs
- Increase gain in larger patients
- Lower transducer frequency for better pen
What is responsible for the image artifact delineated by the indicator on the anatomic left of the patient?
Stomach
Is the diameter of the AO or IVC highly dynamic and variable with compression?
IVC
What are tributaries of the IVC characteristically seen on ultrasound?
Hepatic veins
What can be seen when scanning proximal IVC in transverse?
Liver and hepatic veins
What do the walls of the IVC appear like on ultrasound?
Thin with highly echogenic walls surrounding anechoic lumen
What vessel does the left renal artery come from?
AO
What organ does the left renal artery drain into?
Left kidney
How can you clear acoustic enhancement from bowel gas?
Drinking water or shifting positions
What does the SMA supply with blood?
Intestines
What are IVC tributaries typically seen with ultrasound?
Hepatic veins, common iliac veins, and renal veins
What are indications for diagnostic evaluation of abdominal AO?
Palpable or pulsatile mass
Pain in lower back, flank, abdomen.
Follow up for AAA or ab AO or iliac stent graft
What are indications a patient should undergo screening for AAA?
Male > 65
Female > 65 w/ cardiovascular risk
Pt > 50 w/ hx of peripheral vascular aneurysmal disease
HTN, smoking
What measurements should be included when scanning AO?
Prox, mid and distal AO in long
Transverse for width
Dimension of aneurysm if any
What are criteria for if a patient has AAA?
AO is > or = diameter of 3 cm
AO is 1.5x proximal infrerenal AO
Where do you get a lot of pt information before exam?
Ultrasound request form and pt chart
What information is in the assessment notes?
Physical exam, lab results
