What is the treatment for a patient with a dilated aorta?

Treatment of Dilated Aorta

Surgery is recommended when the ascending aorta or aortic root reaches ≥55 mm in diameter for patients with a tricuspid aortic valve, with lower thresholds of ≥50 mm for bicuspid aortic valve and ≥50 mm for Marfan syndrome. 1

Initial Assessment and Surveillance Strategy

When a dilated aorta is identified, the entire aorta must be assessed at baseline and during follow-up to identify all affected segments 1. The specific surveillance approach depends on location and size:

Thoracic Aorta Surveillance

• Transthoracic echocardiography (TTE) is recommended at diagnosis to assess aortic valve anatomy, aortic root, and ascending aorta diameters 1
• Cardiac CT (CCT) or cardiac MRI (CMR) is recommended to confirm TTE measurements, rule out aortic asymmetry, and establish baseline diameters for follow-up 1
• CCT or CMR (not TTE) is recommended for ongoing surveillance of aneurysms in the distal ascending aorta, aortic arch, or descending thoracic aorta 1

Abdominal Aortic Aneurysm (AAA) Surveillance

• Duplex ultrasound (DUS) is the recommended modality for AAA surveillance 1
• Surveillance intervals for small AAA (30-55 mm): every 3 years for 30-39 mm, every 2 years for 40-44 mm, and annually for >45 mm 1
• Every 6 months for men with AAA 50-55 mm and women with AAA 45-50 mm 1

Medical Management

Blood Pressure Control

Strict blood pressure control is mandatory, targeting SBP 120-129 mmHg if tolerated, and definitely <140/90 mmHg. 1 This is the cornerstone of medical therapy to reduce aortic wall stress and slow progression.

Lipid Management

• LDL-C goal <1.4 mmol/L (55 mg/dL) with >50% reduction from baseline is recommended in patients with atherosclerotic peripheral arterial and aortic diseases 1

Beta-Blockers and ARBs

• Beta-blockers are first-line therapy for Marfan syndrome to reduce aortic root growth rate 1, 2
• Angiotensin receptor blockers (ARBs) effectively slow aortic root growth in Marfan syndrome, with combination beta-blocker plus ARB therapy being reasonable 2
• ACE inhibitors/ARBs may be considered in all patients with peripheral arterial disease regardless of blood pressure levels 1

Surgical Indications

Ascending Aorta and Aortic Root (Tricuspid Valve)

Surgery is recommended at ≥55 mm diameter. 1 However, lower thresholds apply in specific circumstances:

• Rapid growth ≥3 mm per year 1, 2
• Resistant hypertension 1
• Short stature (<1.69 m) 1
• Age <50 years 1
• Planned pregnancy 1
• Aortic coarctation 1
• Significant aortic valve regurgitation 1

Bicuspid Aortic Valve

Surgery is recommended at ≥50 mm diameter for the aortic root or ascending aorta 1, 2. If the patient already requires aortic valve replacement for severe stenosis or regurgitation, concomitant aortic repair should be performed if diameter is >45 mm 1.

Marfan Syndrome

Surgery is recommended at ≥50 mm diameter (external measurement) 1, 2. Additional factors prompting earlier intervention include:

• Rapid growth >0.5 cm per year 1, 2
• Family history of aortic dissection at diameter <50 mm 1
• Significant aortic regurgitation 1

For pregnant women with Marfan syndrome, surgical intervention is warranted if aortic diameter exceeds 40 mm before conception. 1, 2 All women with Marfan syndrome require frequent cardiovascular monitoring throughout pregnancy and puerperium 1, 2.

Descending Thoracic Aorta

Elective repair is recommended at ≥55 mm diameter for non-heritable thoracic aortic disease 1. When repair is indicated and anatomy is suitable, TEVAR (thoracic endovascular aortic repair) is recommended over open repair 1.

Thoracoabdominal Aortic Aneurysm (TAAA)

Elective repair is recommended at ≥60 mm diameter for degenerative TAAA 1.

Abdominal Aortic Aneurysm

Elective repair is recommended at ≥55 mm in men or ≥50 mm in women. 1 In ruptured AAA with suitable anatomy, endovascular repair is recommended over open repair to reduce perioperative morbidity and mortality 1.

Surgical Technique Selection

Valve-sparing aortic root replacement is recommended in patients with aortic root dilatation if performed in experienced centers and durable results are expected. 1, 2 This approach is particularly appropriate for young patients with aortic root dilation and tricuspid aortic valves using reimplantation or remodeling with aortic annuloplasty 1.

For patients requiring both valve and root replacement, the Bentall procedure (composite graft replacement) remains the most versatile approach, with operative mortality of approximately 2-4% at experienced centers 2, 3. Lifelong vitamin K antagonists (VKAs) are required for all patients with a Bentall procedure using a mechanical heart valve prosthesis. 1

Aortic Arch Involvement

Concomitant hemi-arch replacement should be considered in patients undergoing ascending aortic aneurysm repair if dilatation extends into the proximal aortic arch (>50 mm) 1.

Post-Operative Surveillance

After Endovascular Repair (TEVAR/EVAR)

Surveillance is recommended at 1,6, and 12 months, then yearly. 1 Imaging at 30 days post-procedure by CCT plus DUS/contrast-enhanced ultrasound (CEUS) is recommended to assess intervention success 1.

Re-intervention is mandatory for type I or type III endoleaks to achieve a seal 1.

After Open Repair

• Thoracic aorta: Early CCT within 1 month, then yearly CCT follow-up 1
• AAA: First follow-up imaging within 1 year, then every 5 years if findings are stable 1

Critical Pitfalls to Avoid

Do not use TTE alone for surveillance of distal ascending aorta, aortic arch, or descending thoracic aorta – these locations require CCT or CMR 1. TTE systematically underestimates dimensions in these segments.

Do not delay surgery in patients with rapid growth (≥3 mm/year) regardless of absolute diameter 1, 2. Rapid progression indicates unstable aortic wall pathology and warrants immediate surgical referral.

Do not perform elective AAA repair in patients with limited life expectancy (<2 years) 1. The perioperative risks outweigh potential benefits in this population.

Continue medical therapy (beta-blockers and/or ARBs) indefinitely after surgery, particularly in Marfan syndrome patients, as they remain at risk for aneurysm formation and dissection in other aortic segments 2.