The Annals of Thoracic Surgery
Volume 111, Issue 4, April 2021, Pages 1359-1366
Presented at the Sixty-sixth Annual Meeting of the Southern Thoracic Surgical Association, Marco Island, FL, Nov 6-9, 2019.
Ming-Sing Si MD, John V. Conte MD, Jennifer C. Romano MD, Matthew A. Romano MD, Nicholas D. Andersen MD, Marc W. Gerdisch MD, John P. Kupferschmid MD, Andrew C. Fiore MD, Mamdouh Bakhos MD, Juan J. Bonilla MD, J. Ryan Burke MD, J. Scott Rankin MD, Lawrence M. Wei MD, Vinay Badhwar MD, Joseph W. Turek MD, PhD
Unicuspid aortic valves (Sievers type 2 bicuspid) are characterized by major fusion and clefting of the right-left coronary commissure, and minor fusion of the right-noncoronary commissure. Repair has been difficult because of two fusions, variable relative sinus sizes, and peripheral leaflet deficiencies or tears after balloon valvuloplasty.
Twenty unicuspid aortic valves patients underwent valve repair in nine institutions. Right-left major fusion and right-noncoronary minor fusion occurred in 17 of 20 (85%). Commissurotomy was performed on the minor fusion, and a bicuspid annuloplasty ring with circular base geometry and two 180-degree subcommissural posts was sutured beneath the annulus, equalizing the annular circumferences of the fused and nonfused cusps. The nonfused leaflet was plicated, and the cleft in the major fusion was closed linearly until leaflet effective heights and lengths became greater than 8 mm and equal, respectively.
Average age (mean ± SD) was 22.3 ± 12.3 years (range, 13 to 58), 12 of 20 (60%) were symptomatic, 10 of 20 (50%) required aortic aneurysm resection. Pre-repair hemodynamic data included mean systolic valve gradient 25.8 ± 12.9 mm Hg, aortic insufficiency grade 2.9 ± 1.2, and annular diameter 24.7 ± 3.3 mm. No mortality or major complications occurred. Post-repair annular (ring) size was 20.5 ± 1.3 mm, mean gradient fell to 16.2 ± 5.9 mm Hg, and aortic insufficiency grade decreased to 0.1 ± 0.3 (P < .001). At an average follow-up of 11 months (range, 1 to 22), all 20 patients were asymptomatic and had returned to full activity.
Aortic ring annuloplasty reduced annular diameter effectively, recruiting more leaflet to midline coaptation. Minor fusion commissurotomy and annular remodeling to 180-degree commissures converted UAV repair to a simple and reproducible procedure.
Si and coworkers have reported a remarkable success rate of unicuspid aortic valve repair. Their results attest to the safety and reproducibility of the repair technique described. Aortic annular dilatation, an important contributor to aortic incompetence (AI) was uniformly present in this cohort. Elimination of AI from a preoperative mean grade of 2.9 to a post-repair mean of 0.1 is indeed remarkable. Annular size reduction using the remodeling geometric ring annuloplasty was crucial in reducing the degree of AI. Optimization of the effective cusp height and achievement of bicuspid status with good commissural orientation (180 degrees) were crucial contributors to the success of the technique. Follow up is short (mean of 11 months) so we must await long term data. The notable problem though is for the smaller patient who requires an annuloplasty ring smaller than 19mm in whom this technique may not yet be applicable.
Interestingly, the abstract begins with an apparent morphological contradiction: “Unicuspid aortic valves (Sievers type 2 bicuspid) …”. Therein lies probably the most obvious limitation of the widely used Sievers classification: (mis)-classification of unicuspid aortic valve as a bicuspid valve. Several investigators have also pointed out additional drawbacks – a lack of predictability of repair, operative strategy, and post-repair outcome. Ultimately the principles underlying successful repair (at least in the short to medium term), very well demonstrated in this study, include addressing annular dilatation, achieving effective cusp height of at least 8mm, leaflet repair to address prolapse or retraction, and avoiding patch material in repairing the valve.