Perfecting aortic valve repair is a process

In this issue, Jarral et al. [1] report experience with 53 tri-leaflet and 18 bicuspid aortic valve repairs (AVr), performed with internal ring annuloplasty over 5 years. Mean follow-up was 3.9 ± 1.1 years. This type of annuloplasty reflects Carpentier’s concept of suturing a geometric ring to the inflow region of the valve annulus [2, 3], and then reconstructing leaflet defects. In this case, the inflow area is the infra-annular aspect of the aortic valve. The HAART device was the first internal ring for this purpose, and a learning curve was encountered related to suture untying and leaflet abrasion by annular suture tails [4]. A ‘lateral suture fixation’ technique was developed to mitigate these problems [5]. To enhance lubricity and tight ring-to-annulus apposition, polypropylene annular suture was employed, since coated polyester suture was not available in European clinical trial centres. These technical modifications reduced 2-year repair failure from ∼10% in the clinical trials [4] to 4% in first US clinical applications [6]—a time-frame and previously published incidence that were similar to Jarral’s. Such a learning curve was analogous to that encountered initially for mitral repair [7], or during the developmental phase of other AVr techniques [8, Fig. 1B] (it should be clarified that early studies of AVr employed a 0–3+ Aortic Insufficiency (AI) scale, in which grade 2, moderate, reflected worse AI than current definitions of grade 2 using a 0–4+ scale. In early papers, exact definitions of AI grade also were poorly documented). Regulatory outcomes with ring annuloplasty compared favourably with existing large, well-documented series [9]. The Duke surgeons were early adopters of this technology, and their cases are among the first performed in the US after device approval. Surprisingly, however, polypropylene annular sutures seemed to possibly ‘fracture’ in 3–5% of patients, and this mechanism became the main cause of repair failure during this era [6] (as in Jarral’s series). After coming to this understanding 3 years ago, annular suture was changed to 3–0 braided polyester, coated with Teflon for lubricity. Importantly, annular suture disruption disappeared completely with this technical change, verifying polypropylene fracture as the probabe culprit of ‘ring dehiscence’. As a result, early repair failure fell to the 2% range in recent unpublished data, but improvement efforts continue, including (i) consistent ring positioning out of abrasive contact with leaflets; (ii) more secure bicuspid cleft closure and leaflet reconstruction [10]; and (iii) routine intraoperative topical antibiotics to eliminate rare cases of acute prosthetic endocarditis.