Surgical threshold for bicuspid aortic valve aneurysm: a case for individual decision-making

The bicuspid aortic valve (BAV) affects 1-2% of the population and may be associated with important valvular disease and an increased risk of aortic root and/or ascending aortic aneurysm and dissection. BAV aortic aneurysm and dissection occur earlier in life than when these disorders are associated with a tricuspid aortic valve (TAV). Alterations in the aortic media and differences in aortic elastic properties and wall stress also accompany BAV aortopathy. With appropriate follow-up and timely surgery, population studies have documented a survival rate for patients with BAV no different from age-matched controls. Guidelines have previously recommended prophylactic aortic surgery at a smaller aortic aneurysm size for patients with BAV compared with aneurysms in patients with a TAV. Recent guidelines have presented differing indications regarding the appropriate timing of prophylactic surgery for BAV aneurysms, giving the recommendation for surgery when the aortic root and/or ascending aortic exceeds 5.5 cm (unless certain factors are present), the same size for which TAV-associated aortic aneurysm surgery is recommended. We review the pathophysiology of BAV aortopathy, the clinical history of BAV ascending aortic disease, areas of uncertainty and make a case for a patient-centered, individualised decision regarding the optimal timing of aortic aneurysm surgery in BAV disease.