Technique for aortic valve annuloplasty using an intra-annular "hemispherical" frame

Abstract

Objective: A need exists for a stable annuloplasty method for aortic valve repair. On the basis of a "hemispherical" model of aortic valve geometry, a prototype annuloplasty frame was constructed and initially tested. Specific goals were to develop a clinically applicable transaortic implant technique and to evaluate the system in isolated and intact animal preparations.

Methods: Eight isolated porcine aortic roots were perfused from a water reservoir at a constant pressure of 100 mm Hg, and valve leak was measured by timed collection in a beaker. Baseline leak was negligible, and the 2 commissures adjacent to the right coronary leaflet were incised vertically to create severe valve insufficiency. Through a transverse aortotomy, a "hemispherical" annuloplasty frame was sutured to the aortic valve annulus with horizontal mattress sutures. The 3 posts of the frame were sutured first to the 3 subcommissural regions to align the device horizontally and vertically. The 3 frame curvatures then were sutured into the leaflet annuli using horizontal mattress "looping" sutures, supported with supra-annular pledgets. Post-repair valve leak was measured, and significance of the change was assessed with a 2-tailed paired t test. One survival implant was evaluated in an intact calf.

Results: Subcommissural incision disrupted annular geometry and created a valve leak of 1400 ± 847 mL/min (mean ± standard deviation). Suturing the 3-dimensional annuloplasty frame into the aortic valve annulus reestablished appropriate geometry of leaflet coaptation and restored valve competence, with a reduction in valve leak to 102 ± 86 mL/min (P = .004). After 6 weeks of chronic calf implantation, the frame was well healed and the native valve functioned normally.

Conclusions: Transaortic insertion of a "hemispherical" annuloplasty frame into severely disrupted and insufficient porcine aortic valves routinely and effectively restored valve competence. These data support the continued development and testing of this device as a stable method of annuloplasty during aortic valve repair.