Treatment for Dilated Ascending Aorta
Surgical intervention is recommended for patients with a dilated ascending aorta when the diameter reaches ≥55 mm in patients with tricuspid aortic valve, ≥50 mm in patients with bicuspid aortic valve, and ≥45 mm in patients with Marfan syndrome. 1
Medical Management
- Blood pressure control is essential for all patients with aortic dilation, using any effective antihypertensive medication to reduce shear stress on the aortic wall 1
- Beta-blockers and angiotensin receptor blockers (ARBs) have conceptual advantages in reducing progression rate, but clinical studies have not definitively proven their benefit in non-Marfan patients 1
- In patients with Marfan syndrome, beta-blockers, ACE inhibitors, and ARBs may help reduce progression of aortic dilation 1
- Smoking cessation is important as current smoking has been associated with faster aneurysm expansion (approximately 0.4 mm/year) 1
- Competitive sports should be avoided in patients with enlarged aorta to prevent blood pressure spikes 1
Surveillance Recommendations
- For patients with aortic diameter >4.0 cm, regular imaging surveillance is recommended 1
- Imaging frequency should be determined by:
- Degree and rate of progression of aortic dilation
- Family history
- Presence of risk factors 1
- For aortic diameter >4.5 cm, annual imaging is recommended 1
- Consistent imaging modality should be used for serial measurements 1
- Echocardiography is recommended for initial assessment of aortic valve anatomy, function, and root dimensions 1
- CT or MRI is recommended to confirm measurements, evaluate for asymmetry, and establish baseline diameters 1
Surgical Indications Based on Aortic Diameter
Tricuspid Aortic Valve
- Surgery recommended when aortic diameter ≥55 mm 1
- Consider surgery at >52 mm in patients with low surgical risk 1
- Consider surgery at ≥45 mm when undergoing other cardiac surgery 1
Bicuspid Aortic Valve
- Surgery recommended when aortic diameter ≥50 mm 1
- Surgery recommended when aortic diameter ≥45 mm in patients undergoing aortic valve surgery 1
- Consider surgery at >50 mm if risk factors present (family history of dissection or growth rate ≥0.5 cm/year) 1
Marfan Syndrome
- Surgery recommended when aortic diameter ≥45 mm 1
Other Considerations for Earlier Intervention
- Family history of aortic dissection
- Rapid progression (≥0.5 cm/year)
- Presence of severe aortic valve disease
- Planned pregnancy
- Patient preference 1
- Short stature (<1.69 m)
- Resistant hypertension 1
Surgical Options
For Isolated Ascending Aorta Dilation
- Resection and graft replacement is the most commonly performed procedure 1, 2
- Reduction aortoplasty may be considered in selected cases with diameter <55 mm 3
For Aortic Root Involvement
- Valve-sparing aortic root replacement is recommended in experienced centers when durable results are expected 1
- Bentall procedure (composite replacement of aortic valve and ascending aorta) for patients with significant valve disease 4, 5
- Separate valve and ascending aortic replacement for patients without significant root dilation 1, 5
Pitfalls and Caveats
- Measurement technique matters: diameters should be measured perpendicular to the longitudinal axis of the aorta 1
- Different segments of the aorta have different normal diameters (sinus segment is normally 0.5 cm larger than ascending aorta) 1
- Rapid growth (≥0.5 cm/year) is an indication for earlier intervention regardless of absolute diameter 1
- Mechanical properties of the aortic wall deteriorate with age, potentially increasing risk of complications even at smaller diameters in elderly patients 6
- Anisotropy of aortic tissue (different strength in different directions) may influence risk of complications 6
- Endovascular stent grafts are not FDA-approved for treatment of ascending aortic aneurysms 1