Functional Outcomes of Type I Bicuspid Aortic Valve Repair With Annular Stabilization: Subcommissural Annuloplasty Versus External Subannular Aortic Ring

Abstract

Background: In bicuspid aortic valve patients with nonaneurysmal root (<45 mm) and severe aortic insufficiency (AI), external subannular aortic ring (ESAR) is being increasingly utilized for annular stabilization, compared with traditional subcommissural annuloplasty (SCA). To this date, there is no comparative study assessing functional equivalence or superiority of ESAR over SCA.

Methods: From 2003 to 2017, 139 patients underwent type I bicuspid aortic valve repair, of which 50 patients underwent concomitant SCA and 24 underwent ESAR. Cases with suboptimal echocardiographic imaging were excluded, resulting in 38 patients in the SCA group and 20 patients in ESAR group. Intraoperative transesophageal echocardiography before and after procedure were retrospectively analyzed for 11 parameters in the functional aortic root complex.

Results: ESAR patients had larger preoperative annulus (28.3 ± 3.2 mm versus 29.8 ± 3.7 mm, p = 0.1) and left ventricular (LV) outflow tract (28.1 ± 3.5 mm versus 29.8 ± 4.0 mm, p = 0.1) diameters, with greater leaflet prolapse (3.4 ± 1.3 mm versus 4.3 ± 1.3, p = 0.02). In both groups, 100% freedom from AI greater than 1+ was achieved, with significant reduction of vena contracta (-3.0 ± 0.6 mm, p < 0.001; -3.2 ± 0.4 mm, p < 0.001) and level of eccentricity of AI jet (AI angle change: -24.3 ± 6.5 degrees, p = 0.002; -22.3 ± 7.2 degrees, p = 0.01). Reduction in LV dimensions (-7.1 ± 1.2 mm, p < 0.001; -8.9 ± 1.9 mm, p < 0.001), annulus (-3.4 ± 0.4 mm, p < 0.001; -5.1 ± 2.7 mm, p < 0.001), LV outflow tract (-2.3 ± 0.4 mm, p < 0.001; -4.4 ± 0.5 mm, p < 0.001), and degree of leaflet prolapse (-1.6 ± 0.4 mm, p = 0.005; -2.1 ± 0.4 mm, p = 0.001) was achieved in both groups. Comparison of postprocedure outcomes showed improved mean transvalvular gradients in ESAR (11.2 ± 5.7 mm Hg versus 7.1 ± 2.5 mm Hg, p = 0.003), with similar freedom from AI.

Conclusions: In addition to providing equivalent and excellent freedom from AI, ESAR also renders a more robust annular reduction than SCA, along with improved transvalvular gradients.