What is the management for a dilated thoracic aorta?

Management of Ectatic Thoracic Aorta

The management of a dilated thoracic aorta requires aggressive blood pressure control with beta blockers as first-line therapy, followed by ACE inhibitors or ARBs, along with regular imaging surveillance and surgical intervention when specific size thresholds are reached. 1

Medical Management

Blood Pressure Control

• Beta blockers should be the foundation of medical therapy for patients with thoracic aortic aneurysms to reduce the rate of aortic dilatation, with a target heart rate of 60 beats per minute or less 1
• For patients with thoracic aortic aneurysm, blood pressure should be reduced with beta blockers and ACE inhibitors or ARBs to the lowest tolerated level 1
• Target blood pressure should be less than 140/90 mmHg for patients without diabetes and less than 130/80 mmHg for patients with diabetes or chronic renal disease 1
• Vasodilators should not be initiated prior to rate control to avoid reflex tachycardia that may increase aortic wall stress 1
• For patients with Marfan syndrome, an ARB (losartan) is reasonable to reduce the rate of aortic dilatation 1

Risk Factor Modification

• Stringent control of hypertension, lipid profile optimization, smoking cessation, and other atherosclerosis risk-reduction measures should be implemented 1
• Statin therapy is reasonable to achieve a target LDL cholesterol of less than 70 mg/dL for patients with atherosclerotic aortic aneurysm 1
• Smoking cessation is strongly recommended as it is a significant risk factor for aortic disease progression 1

Imaging Surveillance

Initial Evaluation

• When a thoracic aortic aneurysm is identified, assessment of the entire aorta is recommended at baseline and during follow-up 1
• Assessment of the aortic valve (especially for bicuspid aortic valve) is recommended when a thoracic aortic aneurysm is identified 1
• CT or MRI is recommended to confirm echocardiographic measurements, rule out aortic asymmetry, and determine baseline diameters for follow-up 1

Follow-up Imaging

• CT or MRI of the thoracic aorta is reasonable after a Type A or B aortic dissection or after prophylactic repair of the aortic root/ascending aorta 1
• For stable thoracic aortic aneurysms, imaging is recommended at 1,3,6, and 12 months post-diagnosis and, if stable, annually thereafter 1
• When following patients with imaging, utilization of the same modality at the same institution is reasonable for consistent comparison 1
• MRI provides adequate information for moderate-sized aneurysms that remain stable over time and avoids repeated radiation exposure 1

Surgical Management

Indications for Surgery

• For patients with ascending thoracic aortic aneurysm with a tricuspid aortic valve, surgery is recommended when the maximum diameter reaches ≥55 mm 1
• For patients with descending thoracic aortic aneurysm without heritable thoracic aortic disease, elective repair is recommended when diameter reaches ≥55 mm 1
• For thoracoabdominal aortic aneurysms, elective repair is recommended when the diameter reaches ≥60 mm 1
• Symptomatic aneurysms should be resected regardless of size 2, 3
• For patients with Marfan syndrome or familial thoracic aortic aneurysm, earlier intervention is recommended at 5.0 cm for the ascending and 6.0 cm for the descending aorta 3

Surgical Approach

• For descending thoracic aortic aneurysms when elective repair is indicated and anatomy is suitable, thoracic endovascular aortic repair (TEVAR) is recommended over open repair 1
• Valve-sparing aortic root replacement is recommended in patients with aortic root dilatation if performed in experienced centers and durable results are expected 1
• For patients with DTA aneurysm who undergo TEVAR with planned left subclavian artery coverage, revascularization of the left subclavian artery before TEVAR is recommended to reduce the risk of spinal cord ischemia and stroke 1

Special Considerations

Acute Aortic Syndromes

• Acute thoracic aortic dissection involving the ascending aorta should be urgently evaluated for emergent surgical repair due to high risk of life-threatening complications 1
• Acute thoracic aortic dissection involving the descending aorta should be managed medically unless life-threatening complications develop 1
• For patients with intramural hematoma, management is similar to aortic dissection in the corresponding aortic territory 1

Growth Rate and Risk Assessment

• The thoracic aorta grows slowly at an average rate of 0.1 cm/year (0.07 for ascending and 0.19 for descending) 2, 3
• Critical sizes for natural complications (rupture or dissection) are around 6.0 cm for the ascending aorta and 7.0 cm for the descending aorta 3
• Aneurysms 6.0 to 6.5 cm carry a 7% annual risk of rupture 1
• Aneurysms that grow at an annual rate >1 cm are more prone to rupture 1

Common Pitfalls and Caveats

• Failure to recognize that even non-Marfan aneurysms have a strong genetic basis; family members should be evaluated 2, 3
• Underestimating the importance of blood pressure control - for each 5 mmHg increment in systolic BP, there is a 3.9 kPa increase in wall stress 4
• Initiating vasodilator therapy before achieving adequate heart rate control, which can lead to reflex tachycardia and increased aortic wall stress 1
• Relying solely on transthoracic echocardiography for surveillance of aneurysms in the distal ascending aorta, aortic arch, or descending thoracic aorta, which is not recommended 1
• Failing to recognize that symptomatic aneurysms require surgical intervention regardless of size 2, 3