When to operate on fusiform aneurysm of the distal aorta?

From the Guidelines

Surgery for a fusiform aneurysm of the distal aorta is generally recommended when the aneurysm reaches 5.5 cm in diameter for most patients, as indicated by the most recent guidelines 1.

Key Considerations

• The decision to operate should balance the risk of aneurysm rupture against the risks of surgical intervention, considering factors such as the patient's age, comorbidities, life expectancy, and overall surgical risk.
• Intervention is also indicated regardless of size if the aneurysm is rapidly growing (more than 0.5 cm in 6 months or 1 cm per year), if the patient experiences symptoms such as back or abdominal pain related to the aneurysm, or if there are signs of impending rupture, as suggested by recent guidelines 1.
• The surgical approach depends on the exact location of the aneurysm, with open repair being traditional but endovascular aortic repair (EVAR) increasingly preferred when anatomically suitable, although open repair may be advisable for young, healthy patients with unsuitable TEVAR anatomy and prolonged life expectancy 1.

Preoperative Management

• Preoperative management typically includes blood pressure control with beta-blockers (such as metoprolol 25-100 mg twice daily) or calcium channel blockers (such as amlodipine 5-10 mg daily) to maintain systolic blood pressure below 130 mmHg.

Surveillance

• Regular imaging surveillance with CT or MRI every 6-12 months is essential for aneurysms below the surgical threshold to monitor for growth or changes that would indicate the need for intervention.

Guidelines

• The American College of Cardiology and American Heart Association guidelines recommend repair when the diameter of the descending aorta is $5.5 cm (COR 1) 1.
• The European Society of Cardiology guidelines recommend open repair as the first-choice intervention for distal thoracic aortic (DTA) aneurysms in patients with unsuitable anatomy for TEVAR or connective tissue disorders 1.

From the Research

Decision to Operate on Fusiform Aneurysm of Distal Aorta

The decision to operate on a fusiform aneurysm of the distal aorta is based on several factors, including the size of the aneurysm, symptoms, and growth rate.

• Primary indications for intervention in patients with abdominal aortic aneurysms (AAAs) include development of symptoms, rupture, rapid aneurysm growth (> 5 mm/6 months), or presence of a fusiform aneurysm with maximum diameter of 5.5 cm or greater 2.
• Medical management is recommended for asymptomatic patients with AAAs < 5 cm in diameter and focuses on modifiable risk factors, including smoking cessation and blood pressure control 2.
• For fusiform aneurysms of the basilar trunk and vertebrobasilar junction, surgical intervention achieved greater survival than conservative management 3.
• The use of computational fluid dynamics and finite element analysis can help understand the unique pathophysiology and determine possible underlying mechanisms of instability of cerebral fusiform aneurysms 4.

Factors Influencing the Decision to Operate

Several factors can influence the decision to operate on a fusiform aneurysm of the distal aorta, including:

• Size of the aneurysm: aneurysms with a maximum diameter of 5.5 cm or greater are considered for intervention 2.
• Symptoms: development of symptoms such as abdominal or back pain, thromboembolization, atheroembolization, aortic rupture, or development of an arteriovenous or aortoenteric fistula 2.
• Growth rate: rapid aneurysm growth (> 5 mm/6 months) is considered an indication for intervention 2.
• Patient age and comorbidities: patients younger than 45 years of age showed statistically longer survival than those equal and older than 45 years 3.