Reply to Irimie and Urbanski Aortic repair: Trade off between residual regurgitation and higher gradient

Dear Editor,

The trade-off between residual stenosis and regurgitation after Bicuspid Aortic Valve (BAV) repair should be considered when planning the operation. The modified technique of hybrid annuloplasty during BAV repair with significant attention to Venticulo- Aortic Junction (VAJ) remodelling utilizing both external and internal stabilization caused a remarkable discussion, with comments from Irimie and Urbanski [1, 2]. They put their attention to the necessary caution, which should be taken not to narrow the annulus too extensively, avoiding significant decrease of the AV orifice area, resulting in redo operation and risk of prosthesis mismatch. Certainly, that outcome should be avoided, and I believe my modification of annuloplasty is aiming at that as well. The success of this approach relates to ventricular aortic junction remodelling [3]. Its aim is to achieve a symmetrical 180° orientation of both fused and non-fused leaflet annuli. The fused leaflet annulus often needs significant reduction from 240° down to 180°. As a result, a significant mobility increase can be achieved, resulting in a low gradient, as shown by the BAV Repair Working Group [4]. The external annuloplasty covering the basal ring from the left fibrous triangle to the muscular septum provides additional stabilization of the internal annuloplasty ring. Consequently, there is a significant increase in fused leaflet mobility, resembling the result achieved with leaflet enlargement, preferred by Irimie and Urbanski. Both approaches may successfully result in transvalvular gradient amelioration. A higher gradient resulting from suboptimal fused leaflet mobility, on the other hand, hampers long-term durability, leading to valve stenosis. This may determine suboptimal long-term results, similar to the small diameter of the aortic annulus after its stabilization, as claimed by Irimie and Urbanski. Still, we have to be aware that too large an annulus may result in significant post-repair regurgitation. Interestingly, a correlation of annulus area and volume of residual aortic regurgitation (AR) has been found with Catdiac Magnetic Resonance (CMR) study [5]. Therefore, we should recognize the trade-off between avoiding stenosis and counteracting residual aortic regurgitation. It is essential to determine the optimal post-repair annulus size, which should be taken into consideration when planning repair. It may be advisable to include 2 validated specific leaflet metrics, like height of commissura or annulus–free edge ratio, both allowing optimal reduction of annulus while maintaining decent length of leaflet edge. This strategy may be successfully combined with leaflet replacement, which may represent ‘the best of two worlds’ operation [6].

Conflict of interest: none declared.

REFERENCES