Bicuspid aortic valve repair adapted to aortic phenotype

External or subcomissural annuloplasty in bicuspid aortic valve repair: Which is better?

Patients with a bicuspid aortic valve (BAV) are at increased risk of valvular regurgitation compared to their counterparts with a tri-leaflet aortic valve. There is now increasing emphasis to offer BAV repair to mitigate the risks of prosthesis-related complications, including thromboembolism, hemorrhage and endocarditis, as well as structural valve deterioration and future reoperation with conventional valve replacement, particularly in younger populations. Furthermore, over the preceding two decades, our greater understanding of the functional anatomy of the BAV, pathophysiological mechanisms of BAV insufficiency, and the development of a functional classification of aortic regurgitation have significantly contributed to the evolution of aortic valve reconstructive surgery. In this commentary, we discuss a recent article from the Journal of Cardiac Surgery comparing external annuloplasty and subcommissural annuloplasty as techniques for BAV repair.

Commissural repositioning in bicuspid aortic valve repair: an in vitro acute model to explore and explain different results

OBJECTIVES

Commissural orientation <160° is a recognized risk factor for bicuspid aortic valve repair failure. Based on this observation, repairing this subtype of aortic valve by reorienting the 2 commissures at 180° has recently been proposed.

METHODS

Nine porcine hearts with aortic annulus diameters of 25 mm were selected. A pathological model of a Sievers 1 bicuspid aortic valve was obtained by suturing the coaptation line between the left and right leaflets. Each heart underwent reimplantation procedures both in the native (120°) and the reoriented (180°) configuration. After the operation, each sample was tested on a pulse duplicator at rest (heart rate 60 beats per min) and with mild exercise (heart rate 90 beats per min) conditions.

RESULTS

No statistically significant difference was noted in mean and peak transvalvular aortic gradients between the 2 configurations at rest (18.6 ± 5 vs 17.5 ± 4 for the mean aortic gradient; 42.8 ± 12.7 vs 36.3 ± 5.8 for the peak aortic gradient) but the group with the 120°-oriented commissures had significantly higher mean transaortic gradients compared to the group with the 180°-oriented commissures at initial exercise stress conditions (30.1 ± 9.1 vs 24.9 ± 3.8; p value 0.002).

CONCLUSIONS

The 180° commissural reorientation of the asymmetrical bicuspid aortic valve does not improve the transvalvular aortic gradient in an acute model at rest conditions, but it could do so under stress situations. Even if it is surgically more complex and time-consuming, this approach could be a good strategy to improve long-term results, particularly in young patients.

Comparison of bicuspid and tricuspid aortic valve repair

OBJECTIVES

The aim of this study was to compare the outcomes of tricuspid aortic valve (TAV) and bicuspid aortic valve (BAV) repair.

METHODS

We assessed mortality, freedom from reoperation and the rate of aortic valve regurgitation recurrence. Mortality in both groups was compared with expected survival, and risk factors for reoperation were identified.

RESULTS

From January 2010 to April 2020, a total of 368 elective aortic valve repair procedures were performed, including 223 (60.6%) in patients with TAV. The perioperative mortality was 0.7% in the BAV group and 3.6% in the TAV group (P = 0.079). Estimated survival at 5 years in the BAV versus TAV group was 97 ± 3% vs 80 ± 6%, respectively (P < 0.001). Freedom from reoperation at 5 years in the TAV versus BAV group was 96 ± 3% vs 93 ± 4%, respectively (P = 0.28). Grade 2 or more aortic valve regurgitation was noted in 9.9% of BAV patients and 11% of TAV patients (P = 0.66). Reoperation was predicted by cusp perforation [hazard ratio 15.86 (4.44-56.61); P < 0.001], the use of pericardial patch [hazard ratio 8.58 (1.96-37.53); P = 0.004] and aortic valve annulus diameter >27.5 mm [hazard ratio 3.07 (0.99-9.58); P = 0.053].

CONCLUSIONS

BAV repair is as durable as TAV repair. BAV is not a predictor of a higher rate of reoperations. BAV repair yields survival comparable to expected. Cusp perforation, aortic valve annulus diameter >27.5 mm and the use of pericardial patch adversely impact long-term outcome of aortic valve repair.