Aortography

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Ascending Aortography

The Ascending Aorta is best visualized in the LAO projection. This view when focused on the aortic root nicely demonstrates 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 and some saphenous bypass grafts may also be accomplished in this projection. The RAO projection is best reserved for visualization of saphenous grafts but may also be used to demonstrate aortic insufficiency.

Technique

A 4-6 Fr 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 com 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 will have slight variation in 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 aort. A rate of rise of 0.4 cc/sec in order to prevent lunging of the catheter may be used. The pressure rate settings is typically 600 psi for a 6 Fr, 900 psi for a 5 Fr system and 1200 psi for a 4Fr system. Careful attention is required to remove air from the injector system prior to use to prevent catastrophic embolism during aortogrpahy.

Quantification of Aortic Insufficiency

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

1+  Brief and incomplete ventricualar opacification. Clears rapidly.

2+  Moderate opacification of the ventricle that clears in less that 2 cycles. Never greater than aortic root opacification. 

2+ AI Marfan Syndrome

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

3+ AI

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

4+ AI

Examples

Descending Aortic Dissection