Valve-sparing aortic root replacement in bicuspid aortic valve: as good as in tricuspid?

Valve-sparing aortic root replacement (VSARR) using aortic valve (AV) reimplantation (David procedure) became an established treatment for patients with aortic root aneurysm with or without AV regurgitation presenting excellent short- and long-term results, especially in tricuspid AV (TAV) morphology [1, 2]. Despite the fact that repair of bicuspid AV (BAV) has been already proposed in 1991 by Cosgrove et al. [3], it has not been widely adopted yet and some concerns still persist about recurrent AV regurgitation or progression to aortic stenosis [4]. This is based on frequent association with significant cusp pathologies, such as prolapse, degeneration, calcification and fenestration [5]. In the case of BAV aortopathy the repair techniques become even more complex since presentation of a raphe and orientation of the commissures play an important role [6, 7]. Due to these reasons, VSARR in BAV generally requires complex cusp repair accomplished by restoring the normal root diameters and geometry using e.g. the AV reimplantation [5–7]. In this issue of the European Journal of Cardio-Thoracic Surgery, Levine et al. [8] describe their experience in 677 patients (BAV: n = 171 and TAV: n = 506) who underwent VSARR using AV reimplantation in 2 high-volume aortic centres. For better cohort balancing, a propensity score matching was performed leading to 156 matched pairs. The presented cohort is one of the largest published yet with a follow-up period up to 12 years. The early- and long-term outcomes are excellent with an in-hospital mortality of 0.6% and overall survival at 12 years of 93.5%. Survival was similar in TAV and BAV patients. Overall cumulative incidence of reoperation/reintervention was low with 5.5% over 12 years and no increased risk in BAV patients. Nevertheless, on landmark analysis, BAV patients had an increased incidence of reoperation/reintervention beginning at postoperative year 4 (BAV 12.5% vs TAV 1.8%, P = 0.003). In addition, BAV was not associated with AV deterioration over time. All these findings were confirmed in the propensity score matching groups. There are couple of important messages which can be derived from this study. First, the VSARR technique in experienced centres leads to excellent survival and durability. Second, higher incidence of reoperation/reintervention might be presented in the late years after BAV VSARR using David procedure; however, the rate is low enough that the benefits of this procedure outweigh the multiple risks of valve replacement. Third, the achievement of a strict 180° commissural orientation whenever possible is 1 key element for a durable VSARR, as described in the previous important studies [7, 9]. The El Khoury’s group even recommend using AV reimplantation technique in aortic root <45mm in BAV configuration to facilitate the strength 180° commissural orientation and herewith achieve excellent long-term durability [7]. This point might be somewhat controversial, and some other groups perceive this as a ‘overtreatment’ and recommend better using of functional ring annuloplasty (ventriculo-aortic junction and/or sinotubular junction) with sparing of the aortic root instead of performing VSARR [6, 9]. Finally, adopting of new valve analysis techniques, such as using an AV calliper, makes the procedure more reproducible and central plication based on effective cusp height measurement also leads to larger coaptation area and better long-term durability of repaired BAVs. Generally, this is one of the most important steps of AV repair/-sparing, which has been described by Schäfers et al. many years ago and very much promoted since then [10]. In summary, the VSARR using the AV reimplantation procedure offers the patient with BAV durable valve-sparing option comparable to that with TAV, while respecting the important rules of BAV repair (dedicated valve analysis and achievement of 180° orientation of commissures). Importantly, precise patient selection and indication, as well as proper discussion of risk of recurrent AR with consequent reoperation with the patient is mandatory. Further assessment of results, especially in BAV, is a warranty to improve our outcomes.