Aorta Exam
The Quick and Dirty! (for quick review)
Probe: curvilinear
Position: supine
Acquisition:
Start with probe in the subxiphoid area with indicator pointing to the patient’s right
Sweep cephalad
Identify the celiac artery branches (splenic artery, common hepatic artery)
Sweep cephalad
Identify the SMA
Sweep cephalad
Identify the aortic bifurcation
Repeat in the long axis view
AAA: >3cm, from outer to outer wall
Indications
Concern for abdominal aortic aneurysm or aortic dissection
Flank, back, groin, abdominal, or chest pain
Pulsatile abdominal mass
Elderly (age >65) with history of smoking, hypertension, atherosclerosis
Hypertension, hypotension
Cardiac arrest
Acquisition
The Views
Aorta Short Axis
Aorta Long Axis
Celiac Trunk
Superior Mesenteric Artery (SMA)
Renal Arteries
Bifurfaction of Iliac Arteries
The Patient
Supine
The Probe
Phased Array
Curvilinear
Aorta Short Axis
Place the probe in the subxiphoid area with the probe marker pointing to the patient’s right.
Identify your landmarks!
Vertebral bodies: hyperechoic in the far field.
IVC: superior to the vertebral bodies, on the right of the aorta and have respiratory variability (aka, will change in size with inspiration)!
Aorta: sits on top of the vertebral body or slightly to the left.
Identify the celiac trunk
Sweep the transducer caudally, pushing hard enough to displace bowel gas.
The celiac trunk will be the first branch off of the aorta. The celiac trunk, common hepatic artery, and splenic artery form a "seagull sign!"
Identify the superior mesenteric artery (SMA)
Continue to sweep the transducer caudally, pushing hard enough to displace bowel gas.
The SMA is the second branch off of the aorta. In short axis, the echogenic area around the SMA is called the "donut sign!"
Identify the bifurcation of the iliac arteries
Continue to sweep the transducer caudally, pushing hard enough to displace bowel gas.
The aorta will bifurcate into the right and left iliac arteries, around the level of the umbilicus.
Aorta Long Axis
Place the probe in the subxiphoid area with the probe marker pointing to the patient’s head.
Rotate the probe until the vessel does not taper at the edges. Vessels should reach from leading edge to receding edge.
Slide your probe caudally. Identify the celiac branches and the SMA coming off of the aorta. They are usually about 1 cm apart from each other!
Slide your probe caudally to identify where the aorta bifurcates into the right and left iliac arteries.
Obtain an abdominal aortic diameter measurement
Take three measurements at the proximal, middle, and distal aorta in both the short and long axis
Proximal: around the celiac trunk
Middle: below the SMA
Distal: above the bifurcation
Measure at the widest point
Take measurements from outer wall to outer wall
Abdominal Aortic Aneurysm (AAA)
A diameter > 3cm is diagnostic of AAA. A diameter >5cm is an indication for emergent surgery!
In the image below, you can see evidence of wall thickening & calcifications.
Aortic Dissection
How to identify an aortic dissection
Place the probe at the suprasternal notch, angled slightly down
Identify the ascending and descending aorta
Assess for hyperechoic flaps
Visualize the abdominal aorta all the way to the aortic bifurcation.
Assess for hyperechoic flaps!
Tips and Tricks
Use the vertebral body as a landmark. The aorta should sit on top!
"Milk" the bowel to remove gas from the near field by applying slow constant pressure as you move your probe.
If you're still having trouble, you can reposition the patient
Have the patient bend their knees
Place the patient in left lateral decubitus
Rescue view may be obtained by going to the midaxillary line in either RUQ or LUQ
Just because it pulsates does not mean its arterial! Veins can appear pulsatile secondary to proximity to artery
Ultrasound G.E.L. Podcast
Want to learn more? Take a listen to a review of the literature!
