Characteristics of Adults Having Aortic Valve Replacement for Pure Aortic Regurgitation Involving a Congenitally Bicuspid Aortic Valve Unaffected by Infective Endocarditis or Aortic Dissection.

Few reports have appeared describing patients with a purely regurgitant congenitally bicuspid aortic valve (BAV) unassociated with active or healed infective endocarditis or with acute or healed aortic dissection. This report describes a large group of such patients who had replacement of the purely regurgitant BAV with or without concomitant resection of the ascending aorta. Operatively excised purely regurgitant BAVs were examined and then their clinical records were examined to confirm that the valves indeed were purely regurgitant. The patients were aged 21 to 86 years (median 50). Of the 133 patients, 114 (86%) were men. The degree of aortic regurgitation (AR) ranged from 1+ to 4+/4+. Of the 133 patients, 52 (39%) had simultaneous resection of the ascending aorta, its frequency varying inversely with the degree of AR. Histologic study of sections of the operatively excised aortas disclosed that 28 (54%) had a normal or nearly normal aorta (0-1+ loss of medial elastic fibers) and that 24 (46%) had an abnormal loss (grade 2+ -4+/4+). In conclusion, the congenitally BAV, unassociated with either infective endocarditis or aortic dissection, is a common cause of pure AR in adults in the Western World undergoing AVR for AR. About half the patients had a dilated ascending aorta and those resected were histologically abnormal half the time. Why one BAV becomes stenotic, another purely regurgitant, another the site of infective endocarditis, and another functions normally for an entire lifetime remains unclear.