Impact of positional relationship of commissures on cusp function after valve-sparing root replacement for regurgitant bicuspid aortic valve

OBJECTIVES: The aim of this study is to investigate the longitudinal valve function after valve-sparing root replacement in patients with bicuspid aortic valves (BAVs), in terms of both transvalvular pressure gradient (TVPG) and freedom from aortic regurgitation. METHODS: In this non-randomized retrospective study, two different approaches were chosen for correcting the circumferential orientation of commissures during aortic root reimplantation for Sievers type I BAV: (i) 180° orientation, in which both cusps occupy equal surface areas and (ii) preserving native commissural orientation. From 2005 to 2015, 41 consecutive patients with Sievers type I BAV undergoing valve-sparing root replacement were divided into two groups according to the techniques: native orientation group and 180° group. RESULTS: The native orientation group included 22 patients (age, 45.1 ± 13.6 years) and the 180° group included 19 patients (age, 36.6 ± 13.7 years; P = 0.053). There was no significant difference in preoperative variables between the two groups. Postoperative and follow-up echocardiography revealed the following: the average TVPG at the time of discharge in the native orientation and the 180° groups was 17.3 ± 6.6 and 21.7 ± 11.1 mmHg (P = 0.16), respectively, at peak and 10.0 ± 3.7 and 11.7 ± 6.0 mmHg (P = 0.33), respectively, at mean; at follow-up, the corresponding values were 19.1 ± 6.6 and 22.9 ± 10.6 mmHg (P = 0.24) at peak and 9.9 ± 3.8 and 13.2 ± 7.2 mmHg (P = 0.12) at mean. Thus, there was a trend towards higher TVPG in the 180° group. The difference between the preoperative and postoperative commissural angles was correlated with higher postoperative peak and mean TVPG (r = 0.53, P = 0.041, 95% confidence interval, 0.029-0.82 at peak and r = 0.58, P = 0.024, 95% confidence interval, 0.092-0.84 at mean). CONCLUSIONS: In terms of freedom from aortic regurgitation and valve function, similar outcomes were achieved in both despite different repair techniques used for fixation of commissures during valve-sparing aortic root replacement in BAV. However, attention should be paid to patients with 180° commissural reposition because of a trend towards higher TVPG.