The analysis of ascending aortic dilatation in patients with a bicuspid aortic valve using the ratio of the diameters of the ascending and descending aorta

Background: A bicuspid aortic valve (BAV) is associated with premature valve dysfunction and abnormalities of the ascending aorta. The aim of our study was to assess the degree of ascending aortic dilatation by measuring the ratio of the dimension of the AAo to that of the descending aorta (DAo) using preoperative computerized tomography (CT). Methods: A review of our institutional clinical database identified 76 patients undergoing aortic valve replacement (AVR) and 73 control patients undergoing off-pump coronary artery bypass (OPCAB group) between September 2009 and April 2012. Results: There were 17 patients diagnosed with BAV (BAV group), and the remaining 59 patients had a tricuspid aortic valve (TAV group). The ratios of the dimensions of the AAo to that of the DAo (AAo/DAo) for each group were: BAV, 1.58 +/- 0.25; TAV, 1.32 +/- 0.11; and OPCAB, 1.29 +/- 0.12. Interestingly, the AAo/DAo of the BAV group was significantly larger than that of the other groups. Conclusions: Although progressive AAo dilatation for BAV is well documented, the diameter of the AAo is currently the only estimate of aortic dilatation. In this study, we report that the ratio of the AAo and DAo diameters in patients with BAV can be a new index for assessing the dilatation of the AAo and differentiating the patients with BAV from those with TAV.