Management of Aortic Root Dilation
Surgical intervention is recommended for aortic root dilation when the diameter reaches ≥55 mm in most patients, ≥50 mm in patients with bicuspid aortic valves, and ≥45 mm in patients with Marfan syndrome, regardless of symptoms. 1
Assessment and Monitoring
Regular echocardiographic monitoring is essential for all patients with aortic root dilation, with frequency determined by the severity of dilation 1, 2:
- For diameters <40 mm: every 2 years
- For diameters ≥40 mm: annually or more frequently if rapid progression is noted
Initial evaluation should include transthoracic echocardiography (TTE) to assess aortic root dimensions, with CT or MRI recommended when TTE visualization is inadequate 1
Measurements should be indexed to body surface area (BSA) using appropriate nomograms, as normal aortic dimensions vary with age, gender, and body size 1
Monitor for rate of progression, with growth >0.5 cm/year considered rapid and warranting more frequent imaging and earlier intervention 1
Medical Management
Beta-blockers are first-line therapy for patients with Marfan syndrome to reduce the rate of aortic dilation by decreasing heart rate and myocardial contractility 1
Angiotensin receptor blockers (ARBs) are also effective in slowing aortic root growth in Marfan syndrome, with combination therapy of beta-blockers and ARBs being reasonable to maximize benefit 1
In non-Marfan patients with aortic regurgitation and hypertension, ACE inhibitors or dihydropyridine calcium channel blockers are recommended 1, 2
Beta-blockers should be used cautiously in patients with severe aortic regurgitation as they may increase regurgitant volume by prolonging diastole 1, 2
Surgical Indications
General Population:
- Aortic root/ascending aorta diameter ≥55 mm 1
- Rapid growth (>0.5 cm/year) regardless of absolute diameter 1
- Symptoms related to aortic dilation or associated aortic valve disease 1
Bicuspid Aortic Valve:
- Aortic root/ascending aorta diameter ≥50 mm 1
- Consider surgery at lower thresholds (>45 mm) if planning aortic valve replacement for valve dysfunction 1
Marfan Syndrome:
- Aortic root/ascending aorta diameter ≥45 mm 1
- Family history of aortic dissection at diameter <50 mm 1
- Desire for pregnancy with aortic diameter >40 mm (pregnancy should be discouraged if >40 mm) 1
Other Genetic Disorders:
- For Loeys-Dietz syndrome, consider earlier intervention (at 40-45 mm) due to higher risk of dissection 1
Surgical Approaches
Valve-sparing aortic root replacement (David or Yacoub procedure) should be considered in patients with preserved aortic valve leaflets, especially younger patients 1, 3
Composite valve-graft replacement (Bentall procedure) is appropriate when the aortic valve is diseased 1, 3
For isolated ascending aortic dilation without root involvement, supracoronary graft replacement may be sufficient 3
Lower thresholds for surgical intervention may be appropriate at experienced centers, particularly for the aortic root (5.0 cm) compared to the mid-ascending aorta (5.25 cm) 4
Special Considerations
Patients with Marfan syndrome require lifelong surveillance of the entire aorta, as dissection can occur in segments distal to a previously repaired aortic root 1
Women with Marfan syndrome contemplating pregnancy require careful counseling and more intensive monitoring, with consideration of prophylactic surgery if aortic diameter exceeds 40 mm 1
Athletes with aortic root dilation may require restriction from high-intensity isometric exercise and contact sports, particularly those with genetic aortopathies 5
First-degree relatives of patients with bicuspid aortic valves should undergo echocardiographic screening 1
Post-Surgical Management
After aortic root replacement, continued surveillance of the remaining aorta is essential, as patients remain at risk for aneurysm formation and dissection in other segments 1
Continued medical therapy with beta-blockers and/or ARBs is recommended after surgery, particularly in patients with Marfan syndrome 1