Full-root aortic valve replacement with stentless xenograft achieves superior regression of left ventricular hypertrophy compared to pericardial stented aortic valves

Abstract

Background: Full-root aortic valve replacement with stentless xenografts has potentially superior hemodynamic performance compared to stented valves. However, a number of cardiac surgeons are reluctant to transform a classical stented aortic valve replacement into a technically more demanding full-root stentless aortic valve replacement. Here we describe our technique of full-root stentless aortic xenograft implantation and compare the early clinical and midterm hemodynamic outcomes to those after aortic valve replacement with stented valves.

Methods: We retrospectively compared the pre-operative characteristics of 180 consecutive patients who underwent full-root replacement with stentless aortic xenografts with those of 80 patients undergoing aortic valve replacement with stented valves. In subgroups presenting with aortic stenosis, we further analyzed the intra-operative data, early postoperative outcomes and mid-term regression of left ventricular mass index.

Results: Patients in the stentless group were younger (62.6 ± 13 vs. 70.3 ± 11.8 years, p < 0.0001) but had a higher Euroscore (9.14 ± 3.39 vs.6.83 ± 2.54, p < 0.0001) than those in the stented group. In the subgroups operated for aortic stenosis, the ischemic (84.3 ± 9.8 vs. 62.3 ± 9.4 min, p < 0.0001) and operative times (246.3 ± 53.6 vs. 191.7 ± 53.2 min, p < 0.0001) were longer for stentless versus stented valve implantation. Nevertheless, early mortality (0% vs. 3%, p < 0.25), re-exploration for bleeding (0% vs. 3%, p < 0.25) and stroke (1.8% vs. 3%, p < 0.77) did not differ between stentless and stented groups. One year after the operation, the mean transvalvular gradient was lower in the stentless versus stented group (5.8 ± 2.9 vs. 13.9 ± 5.3 mmHg, p < 0.0001), associated with a significant regression of the left ventricular mass index in the stentless (p < 0.0001) but not in the stented group (p = 0.2).

Conclusion: Our data support that full-root stentless aortic valve replacement can be performed without adversely affecting the early morbidity or mortality in patients operated on for aortic valve stenosis provided that the coronary ostia are not heavily calcified. The additional time necessary for the full-root stentless compared to the classical stented aortic valve replacement is therefore not detrimental to the early clinical outcomes and is largely rewarded in patients with aortic stenosis by lower transvalvular gradients at mid-term and a better regression of their left ventricular mass index.

Figure 1

Surgical technique of full-root aortic xenograft implantation. The aorta is cross-clamped above the sino-tubular junction and transected at its level to inspect the aortic valve and root (a). The aortic valve is removed and the coronary ostia are dissected free from the aortic sinuses with a generous patch (b). The aortic stentless xenograft is implanted onto the surgical aortic annulus with 6 Prolene 4.0 running sutures beginning under the left coronary ostium in a clockwise manner (c). The coronary ostia are reimplanted into the stentless xenograft in a manner to avoid tension, torsion or kinking of the patient’s proximal coronary arteries (d). The implantation of the xenograft is completed by end-to-end anastomosis between the stentless xenograft and the mobilized distal aorta with a running Prolene 5.0 suture (e).

Figure 2

Projectedversuscalculated IEOA in patients with aortic stenosis operated before January 2013.A) The projected IEOA for patients in the stentless group (white bars) was compared to the calculated IEOA if they had received a stented pericardial valve 3–4 mm smaller (black bars). B) The projected IEOA for patients in the pericardial stented group (black bars) was compared to the calculated IEAO if they had received a full-root stentless aortic valve 3–4 mm larger (white bars). Blocks are means and bars are SD values. ***indicates p < 0.001 and ****p < 0.0001.

Figure 3

Post-operative transvalvular gradients in patients with aortic stenosis operated before January 2013.A) Maximum transvalvular gradients at one year after the operation for patients in the stentless compared in the pericardial stented group. B) Mean transvalvular gradients at one year after the operation for patients in the stentless compared in the pericardial stented group. Blocks are means and bars are SD values. ****indicates p < 0.0001.

Figure 4

Pre- and post-operative LVMI in patients with aortic stenosis operated before January 2013. The left ventricular mass index at one year after the operation was compared to the pre-operative value in the stented group (left panel) and in the stentless group (right panel) using the non- parametric Wilcoxon matched-pair signed rank test. Ns, non-significant, and ****indicates p < 0.0001.