Definition
• Arterial outpouching involving all 3 layers; an aneurysm denotes dilation of a vessel to 1.5 times its nl diameter. For the thoracic aorta, this value is ∼4.5 cm. Those b/w 1.1 & 1.5 times its nl diameter are considered dilated or ectatic.
• Pseudoaneurysm: Same but <3 layers
• Can occur at the root (annular aortic ectasia) &/or ascending aorta (50%), descending aorta (40%), aortic arch (10%), or thoracoabdominal aorta (10%). ∼25% of pt may also have an AAA.
• Most TAAs are caused by degenerative dz resulting in dilation of the aorta
• RFs: Similar to aortic dissection (see above)
• Average rate of expansion 0.10–0.42 cm/yr; TAA >6 cm has high rate of cx
Approach
• Often found incidentally on CT scan or echo; typically asymptomatic though they may have chest/back pain
• If HD unstable, assume rupture, call surgery
History
• For hx & RFs, see aortic dissection above
• May cause compressive sxs: Hoarseness (compression of recurrent laryngeal nerve), stridor (compression of trachea/bronchi), dyspnea (lung compression), dysphagia (esophageal compression), plethora/edema (SVC compression)
• Heart failure sxs may occur 2/2 aortic regurgitation from aortic root dilation
• Embolization of atherosclerotic debris w/ end-organ sxs may occur
• May lead to dissection (see sxs above) or rupture
Evaluation
• CTA: Good sens, quick, noninvasive
• MRI: Best for imaging aortic root
• TTE: Limited eval of root
• TEE: Better than TTE for evaluating the root
Treatment
• BP control: BB, ACEI, avoid intense exercise or Valsalva (ie, weight lifting)
• Lipid profile optimization
• Smoking cessation
• Open vs. endovascular repair (see indications for urgent cardiac surgery consultation below)
Disposition
• All pts w/ incidental Dx of TAA could be discharged, but should have prompt f/u w/ PCP or cardiologist for BP & lipid optimization as well as serial monitoring
Pearl
• Cx rates for TAAs depend on size
