Histologic abnormalities of the ascending aorta and pulmonary trunk in patients with bicuspid aortic valve disease: Clinical relevance to the Ross procedure

Objective: Bicuspid aortic valve disease is often associated with dilation of the aortic root and ascending aorta, This study examines the histologic features of the ascending aorta and main pulmonary artery of patients with and without aortic valve disease, Methods: Samples from ascending aorta and main pulmonary artery were obtained at the time of the operation from 20 p atients with bicuspid aortic valve and 11 patients with tricuspid aortic va lve disease. In addition, samples were also obtained from autopsy cases wit h normal aortic valve, The histologic changes were graded from 1 to 3 accor ding to severity of degenerative changes. Results: In the ascending aorta, the severity of cystic medial necrosis (P = .001), elastic fragmentation (P = .002), and changes in the smooth muscle cell orientation (P = .002) were significantly more severe in patients with bicuspid than in those with tri cuspid aortic valve disease, In the pulmonary trunk specimens, those 3 hist ologic features were also significantly more severe in patients with bicusp id than those with tricuspid valves (P = .001, P = .01, and P = .04, respec tively). Seventy-five percent of patients with bicuspid aortic valve diseas e had grade 3 degenerative changes, whereas only 14% of those patients with tricuspid aortic valve disease had similar degrees of degenerative changes . Conclusion: Patients with bicuspid aortic valve disease have more severe degenerative changes in the media of the ascending aorta and main pulmonary artery than patients with tricuspid aortic valve disease. These findings m ay explain root and ascending aortic dilation in patients with bicuspid aor tic valve disease and pulmonary autograft dilation in certain patients afte r the Ross procedure.