Absolute size thresholds for degenerative aneurysms: [1][3][5]
Ascending aorta/aortic root: ≥5.5 cm
Descending thoracic aorta: ≥6.0 cm (or 5.5 cm if favorable anatomy for TEVAR)
Thoracoabdominal aorta: ≥6.0 cm
Lower thresholds apply for: [3]
Marfan syndrome or genetic conditions: 4.0-5.0 cm depending on condition
Bicuspid aortic valve: 5.0-5.5 cm
Rapid growth: >0.5 cm/year
Concomitant cardiac surgery: >4.5 cm if undergoing aortic valve surgery
Immediate surgical evaluation: [5]
Any symptomatic aneurysm regardless of size (chest/back pain, dysphagia, hoarseness, hemoptysis)
Acute complications (dissection, rupture, malperfusion)
Post-Repair Surveillance
After TEVAR: CT at 1 month, 12 months, then annually if stable. [1]
After open repair: CT or MRI within 1 year, then every 5 years if no residual aortopathy. Annual imaging if residual disease or abnormal findings.