Aorta Exam
Indications
- Flank, back, groin, abdominal, or chest pain
- Hypertension, hypotension
- Pulsatile abdominal mass
- Cardiac arrest
- Elderly (age >65) with history of smoking, hypertension
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
The Moves
Start subxiphoid and identify the Aorta and the IVC
Transverse plane with leading edge towards patient's RIGHT.
Identify the vertebral body in the transverse plane.
The IVC will be to the right of the Aorta and have resipratory variability
The Aorta sits ontop of the verterbral body or slightly to the left
The First Branch you will encouter will be the Celiac Trunk
Normal diameter of the aorta below the renal artery is <23mm (men) and <19mm (women).
Celiac Trunk
the Moves
Rotate back to short axis and move the transducer caudally pushing hard enough to displace bowel gas. Leading edge pointed towards patient's right.
Continue moving caudally. First bifurcation is the celiac trunk; look for the "seagull sign."
Superior Mesenteric Artery (SMA)
Save an image and include the "donut sign," the echogenic area around the SMA that is visible when viewed in the short axis.
The Moves
Continue caudally until the next branch (SMA) is visualized. Leading edge pointed towards patient's right.
Bifurcation of Iliac Arteries
The Moves
Continue caudally until the aorta bifurcates into the iliac arteries, around the level of the umbilicus. Leading edge pointed towards patient's right.
Aorta Long Axis
The Moves
Rotate the transducer. Leading edge pointed towards patient's head.
Rotate the probe until the vessel does not taper at the edges. Vessels should reach from leading edge to receding edge.
Impression and Medical Decision Making
Atherosclerosis
Abdominal Aortic Aneurysm (AAA)
> 30mm in diameter = AAA
Can see evidence of wall thickening & calcifications.
Dissection
Low Sensitivity by High Specificity for dissection. Look for internal flap.
Turn up the gain and look in short and long axis if concenred.
Tips and tricks
- Use the vertebral body as a landmark. Aorta should sit on top of VB
- "Milk" the bowel to remove gas from the near field by slow constant pressure
- Use Pulsed Wave Doppler to differentiate between artery and vein
- Measure Outer to Outer being careful to include thrombosed region which may appear hypoechoic rather than anechoic
- Rescue view may be obtained by going to the midaxillary line in either RUQ or LUQ
- Just because it pulastes does not mean its arterial, veins can appear pulsatile secondary to proximity to artery