Aortography

# Ascending Aortography
The ascending aorta is best visualized in the 45 degrees LAO, 0 degrees cranial or causal projection. This view of the aortic root optimizes the evaluation of aortic insufficiency. Placement of the catheter in the ascending aorta prior to the great vessels demonstrates the aortic arch and the origin of the vessels which is useful in planing the approach prior to percutaneous revascularization of these vessels. Dissection of the ascending aorta as well as some visualization of anomalous coronary origins. Some operators prefer to engage saphenous bypass grafts in this projection.
The RAO projection is optimal for left ventriculography (30 degrees RAO and 0 degrees cranial) and visualization of saphenous grafts.

## Technique
A 4-6 F pigtail catheter is generally used to perform aortography. However, any non-end hole catheter may be used to perform the procedure. End hole catheters may risk aortic dissection or aortic valve damage during power injection. For aortic insufficiency quantification and bypass/anomalous vessel origination, the catheter is placed in the aortic root approximately 2 cm above the aortic valve. To delineate the great vessels, the catheter is placed proximal to the origin of the innominate artery. To optimize the origins of the vessels, the amount of LAO angulation is adjusted to maximize the elongation of the arch and the vessels.

## Settings
Optimal aortography requires the use of a power injector to adequately opacify and fill the aorta. Adjustable settings on the power injector include pressure and flow rates, volume, rate of pressure rise. Each patient may require slight variation in the settings based on the size of the root and the presence of any aneurysmal dilatation or insufficiency, catheter type and patient size. Generally, 20-25 ml/sec for 40-50 cc will be sufficient to image a normal aorta.
A rate of rise of 0.4 cc/sec should prevent forward lunging of the catheter. The pressure rate setting is typically 600 psi for a 6 F, 900 psi for a 5 F system and 1200 psi for a 4F system. Careful attention is required to remove air from the injector system prior to use to prevent catastrophic air embolism during aortograpahy.

# Quantification of Aortic Insufficiency
The pigtail catheter is placed a few centimeters above the aortic root.  Grading the amount of aortic regurgitation is based on the amount of opacification of the ventricle 2 complete cardiac cycles after injection compared to that of the aortic root.

## Normal (No Regurgitation)
There is no sign of ventricular opacification during and after contrast injection to aortic root.

## Grade 1
Brief and incomplete ventricular opacification. Clears rapidly.

## Grade 2
Moderate opacification of the ventricle that clears in less that 2 cycles. Never greater than aortic root opacification. Video below shows grade 2 aortic insufficiency in patient with marfan syndrome.

## Grade 3
Opacification of the ventricle equal to aortic root opacification within 2 cycles. Delayed clearing of ventricle over several cycles.

## Grade 4
Opacification of the ventricle almost immediately that is greater than that of the aortic root with delayed clearing of the ventricle.

# Additional Reading
- Braunwald's Heart Disease, Libby P, 8th ed., 2007, ISBN 978-1-41-604105-4
- Hurst's the Heart, Fuster V, 12th ed. 2008, ISBN 978-0-07-149928-6
- Willerson JT, Cardiovascular Medicine, 3rd ed., 2007, ISBN 978-1-84628-188-4

# Related Chapters
- Aortic insufficiency
- Aortic stenosis
- Aorta