What are surgical indications for thoracic aortic aneurysm?
Aortic aneurysm is a permanent localized dilatation of the aorta having a diameter at least 1.5 times that of expected normal diameter of that given aortic segment.
Initially, medical treatment with beta blockers has shown to reduce the rate of expansion and improved in survival (by reducing dp/dt & alter connective tissue metabolism).
Surgical therapy is often recommended prophylactically to prevent the morbidity and mortality associated with aneurysm rupture. However, the optimal timing of surgery for a thoracic aortic aneurysm is uncertain since the natural history is variable, particularly for aneurysms less than 50 mm in size. Many patients die of other cardiovascular causes before the aneurysm ruptures because majority of the patients have concomitant cardiovascular disease that increases the risks associated with surgery.
Indications for surgery include:
- The presence of symptoms (e.g. chest, back, flank, or abdominal pain, aortic insufficiency leading to heart failure)
- A diameter of 5 to 6 cm for an ascending aortic aneurysm and 6 to 7 cm for a descending aortic aneurysm
- Replacement before aortic size index (aortic diameter (cm) divided by body surface area (m2)) for the ascending of aorta is 2.75 cm/m2.
- Accelerated growth rate (>=1 cm per year) in aneurysms less than 5 cm in diameter
- Evidence of dissection
- In patients with aortic regurgitation of any severity and primary disease of the aortic root or ascending aorta (such as Marfan syndrome), the 2006 ACC/AHA valvular disease guidelines recommend aortic valve replacement and aortic root reconstruction when the degree of dilatation is 5 cm. The guidelines note that some have recommended surgery for this group at a lower level of dilatation (4.5 cm) or based on a rate of increase of 0.5 cm per year or greater in surgical centers with established expertise in repair of the aortic root and ascending aorta.