Conclusions
For a decade, sutureless and rapid deployment aortic valves have provided a compromise between standard AVR and TAVI by favoring minimal surgical approach, reducing time procedure and limiting paravalvular leak. The sutureless Perceval-S aortic valve was designed to be surgeon-friendly and to make its implantation safe and reproducible. Our results corroborate its safety as early mortality was low and rate of implantation success, stroke, pacemaker requirement and post-operative hemodynamics were similar to those reported in the current literature19,21.
However, the sutureless feature of the Perceval-S is based on the specific design of an expandable nitinol stent which needs two anchoring sites: i) the first one, at the annulus level (inflow ring), ii) and the second one at the STJ level (outflow ring). These characteristics imply some procedural caution to avoid implantation pitfalls.
In order to prevent valve migration, the ratio between the aortic annulus and STJ diameters must be < 1.3, and the size of the aortic annulus must be < 27mm (according that the Perceval-S sizes are : S = 19-21mm, M = 21-23mm, L = 23-25mm, XL = 25-27mm). Moreover, in order to minimize paravalvular leak occurrence, the aortic annulus must be decalcified enough (but avoiding annulus lesion) to be flexible enough to be conformed to the valve by the radial force of the Perceval-S stent. It is also important that annulus has a circular shape and that the heights of the sub-commissural triangles are neither too high nor too unequal. Furthermore, the height of the nitinol struts obligates to slightly modify the surgical technique by performing a horizontal and higher aortotomy than with sutured prosthetic valves, which could reduce the accessibility and the exposition of the diseased aortic valve.
Pre-operative imaging (cardiac-CT or echocardiography) is helpful to assess the shape and size of the annulus as well as to choose the best surgical approach22. That allows to estimate the likelihood of Perceval-S implantation success, but despite of this, some anatomic features of the aortic annulus (shape, flexibility, sub-commissural triangle height, calcification, etc…) are unpredictable before surgery and could hamper Perceval-S implantation. In such situations, the surgeon should typically substitute a sutured valve, which is more time consuming and may be challenging, especially through a minimally invasive approach1–4.
In order to address unexpected anatomical features of the annulus, some techniques of annuloplasty have been described sporadically to decrease the risk of implantation failure. In a short series, Ferrari et al. described how they sneaked a purse string suture of 3-0 polypropylene all around the aortic annulus before implanting a rapid-deployment aortic valve (Intuity, Edwards Lifesciences, Irvine, CAL, USA). Before closing the aorta, the suture was snared to tighten the implanted valve and minimize both paravalvular leak and valve migration23. In BAV, Glauber et al. suggested to reduce the height of the three sub-commissural triangles by a mattress suture before implanting a Perceval-S valve, if the annulus was overly scalloped15. In his series of 13 patients with BAV, Durdu et al. described a similar SCAP technique to ours, used in order to decrease the height of the sub-commissural triangles and to circularize the annulus14.
The present study highlights three situations in which SCAP was particularly helpful: (i) in case of aortic annuli that were slightly too large or too flexible (ii) in case of elliptic or overly scalloped aortic annuli (frequent in BAV), (iii) and as a rescue trick in case of implantation failure. We used 34 SCAPs successfully spread over these three situations, which permitted to widen the field of use of the Perceval-S. For example, among the 25 XL-sized valves implanted (including nine BAV), 14 SCAPs were performed, otherwise we would not have succeeded to implant it. This may partially explain why we reported a remarkable proportion of XL-sized valves compared to the current literature21,24. SCAP also afforded an issue to address implantation failure in almost one third of patients involved. We did not notice significant reduction of the effective orifice area surface, nor an increase of severe mismatch rates in the Group SCAP. Thus, we can infer that SCAP did not significantly reduce the annulus size but rather that it improved its congruence with the valve.
Our study presents several limitations. First, this is a monocentric retrospective study not in intention to treat, as the surgeon decided to implant a Perceval-S according to his feeling. Moreover, we did not randomize patients with a group control, in which we would use a sutured valve instead of SCAP if needed. Finally, our follow up was too short to evaluate the long-term stability of SCAP, especially in BAVs, which are known to dilate by time.
This study shows that SCAP is a safe and useful technique that could improve the success rate of implantation of the Perceval-S sutureless aortic valve essentially by circularizing the aortic annulus and reducing the height of sub-commissural triangles. It might be particularly useful in presence of a BAV or in case of a first implantation failure, as rescue trick. Larger studies and longer follow-up periods are necessary.