The 170°/190° commissure positioning technique for bicuspid aortic valve repair using valve-sparing aortic root replacement

Bicuspid aortic valve (BAV) depicts a wide spectrum of anatomic configurations with varying degrees of sclerosis and calcification, number of raphes, and cusp asymmetry. Increased awareness of the varying geometries has led to changes in aortic valve repair and replacement strategies. One excellent example of such revolution in treating BAV disease is the increased adoption of the valve-sparing aortic root replacement (VSARR) procedure for incompetent BAVs.^, The VSARR procedure was originally developed to preserve the native aortic valve (AV) in patients with root aneurysm and is a reasonable treatment strategy for patients with aortic regurgitation. In patients with BAV whose AVs are free of severe calcification and otherwise amendable to repair, VSARR has been shown to reliably produce great outcomes after BAV repair. Specifically, a 180° approach has been proposed to create a symmetric BAV. This 180° reimplantation technique has been adopted because of its simplicity and the excellent results reported. However, most BAVs present in asymmetric morphologies. Herein, we describe an alternative approach, the 170°/190° commissure positioning technique, that can generate an almost perfectly symmetric BAV by accommodating the native geometry with minimal commissure and leaflet displacement.

Using the most common BAV morphology with left-right cusp fusion in an asymmetric geometry as an example (Figure 1, A), the aortic root is resected to preserve 1 mm of native aortic tissue above the annulus. The coronary buttons are dissected, harvested, and retracted in the standard fashion (Figure 2, A). After the 2 true commissures are retracted, horizontal mattress sutures are placed below the cusp attachment sites following a scalloped pattern (Figure 1, B). Note that 2 sutures should be placed underneath the true commissures. Six sutures are spaced evenly along the left-right fused cusp, and 4 sutures are placed along the noncoronary cusp. This suture placement technique practically distributes 210° to the fused cusp and 150° to the nonfused cusp, respecting the BAV's native geometry. To create a symmetric BAV in a 170°/190° geometry, the commissures need to be shifted toward the fused cusp by 10° each. This is achieved by resuspending the 2 commissures slightly off the 180° markings on the Dacron graft. Specifically, the 2 commissures are resuspended and fixed onto a straight Dacron graft by placing the fused cusp side of the sutures on the single black line or in the middle of the double black lines on the Dacron graft (Figure 1, B). If only single-line markings are made on the Dacron graft by 180° separation, the fused cusp side of the commissure sutures should be placed right at the 180° marking lines (Figure 2, B and C). The remaining 10 subannular sutures are then placed evenly onto the Dacron graft reflecting the same scalloped geometry of the native annulus (Figure 1, B and C). Next, running sutures are placed along the native aortic wall tissue to reimplant the BAV onto the straight Dacron graft. Finally, the left coronary button is reattached in the orthotopic position. Before completing the right coronary button anastomosis, AV competency is tested by clamping the distal Dacron graft while infusing cold saline down to the root. Manual palpation as well as visualization under direct transesophageal echocardiogram are performed to evaluate BAV competency. If indicated, additional AV cusp repair is performed to eliminate any residual regurgitation. After the right coronary button attachment, the VSARR is completed with a reimplanted BAV in the 170°/190° orientation, demonstrating a symmetric geometry.

This 170°/190° commissural positioning technique is novel, safe, and produces reliable results. This technique not only creates an almost perfectly symmetric BAV, maximizing valve hemodynamics, but it may also minimize the leaflet stress on the BAV cusps when the commissures are repositioned. We have performed this approach on 26 patients with BAV and experienced excellent outcomes. The average age was 49.4 ± 10.9 year old. Left-right cusp fusion was the predominant morphology (88.5%), followed by left-right/right-non (7.7%) and right-non cusp fusion (3.8%). We believe this 170°/190° symmetric geometry is able to generate favorable valvular hemodynamics. In fact, we have seen patients with perfectly functioning native BAVs that are in this 170°/190° morphology, which is the goal of this repair technique. Video 1 illustrates an example native 170°/190° BAV from a 60-year-old patient with excellent valve hemodynamics and kinematics without regurgitation or stenosis. We believe this BAV VSARR technique by respecting its native geometry while optimizing commissural positioning can positively impact and improve BAV repair durability long-term. Future biomechanical engineering analysis of this 170°/190° commissural positioning technique should be conducted to further understand leaflet and annulus stress after VSARR for BAVs.