Types of patients requiring aortic root surgery (Bentall procedure)
Asymptomatic patients with thoracic aneurysms for whom the ascending aorta or aortic root diameter is 5.5 cm or greater are recommended to have surgical repair.
- Patients with Marfan syndrome or bicuspid aortic valve, or familial thoracic aortic aneurysm and dissection (patients with known family members with aneurysms or dissections) should undergo an elective operation at smaller diameters (4.0 to 5.0 cm) because they are at a higher risk for rupture or dissection compared to the general population.
- Patients with an aneurysm that grows more than 0.5 cm in a year in an aorta that is less than 5.5 cm in diameter should be considered for the operation.
- Patients undergoing aortic valve repair or replacement who have an ascending aorta or aortic root of greater than 4.5 cm should be considered for concomitant repair of the aortic root or replacement of the ascending aorta.
- Patients with symptoms (usually chest or back pain) suggestive of expansion of a thoracic aneurysm should be evaluated for prompt surgical intervention. Chest or back pain in the presence of an enlarged thoracic aorta is a predictor of aortic rupture and dissection.
- Patients who develop acute aortic dissection commonly present with sudden onset of severe chest or back pain. These patients require emergent surgery to prevent death.
Aneurysms of the ascending aorta and aortic sinuses may result in symptoms related to the aortic regurgitation (e.g., leaky aortic valve) that develops as a result of the progression of the aortic enlargement. The usual early symptom is shortness of breath with walking or exercise. These symptoms can progress to severe shortness of breath with limited exercise and finally lead to congestive heart failure.
Aortic root reconstruction and replacement
Aortic root reconstruction is performed when there is aneurismal enlargement or dissection of the aortic root. The ascending aorta is very often involved in this process, and it is replaced at the same time as the aortic root.
Ascending aortic replacement is performed for an aneurysm or dissection that is located exclusively in the ascending aorta. If the aortic arch is involved in the process, it can be replaced at the same time. Often aortic valve replacement or coronary artery bypass can be performed at the same time if needed.
The aortic root is replaced with a composite valve graft, which is a mechanical or biological valve attached to a synthetic artificial tube. There are a variety of mechanical valves to choose from that would attach to the synthetic tubes. The mechanical valves are available in different sizes to accommodate every possible anatomical variation of the aortic root. Invariably, these patients require blood thinners after the operation.
The combination of a biological valve and a synthetic tube (bioroot) is used in older patients or in younger patients who cannot receive or wish to avoid blood thinners. Usually, the valve is selected first and is attached to a synthetic tube manually.
In cases of aortic root endocarditis ( a severe infection of the aortic valve with the destruction of the native tissue) homografts (human cryopreserved roots) or xenografts (porcine roots) can be used to replace the aortic valve and the adjacent aortic root simultaneously.
The coronary arteries, which supply the heart with blood, arise from the aortic root. During aortic root replacement surgery, the coronary arteries are initially disconnected from the diseased tissue and then reconnected back to graft.