Mitral annuloplasty using an intra-annular ring

The final step in mitral valve repair is usually the implantation of an annuloplasty ring which remodels the dilated annulus and improves the long-term durability of repair. Conventional annuloplasty rings remain as a permanent foreign body on the atrio-ventricular annulus, thus presenting an increased risk for thromboembolic complications. Furthermore, currently available conventional rings are adapted for the adult population, with no annuloplasty ring specifically developed for the paediatric population. A new intra-annular ring that undergoes gradual degradation by hydrolysis has been developed for use both in adults and in children. The resultant inflammatory reaction induces fibrosis, thereby remodelling the posterior mitral annulus. Contrary to the conventional rings that are implanted 'onto' the annulus, the intra-annular ring is implanted 'into' the annulus, and hence prevents direct contact with the circulating blood, thereby reducing the risk of thrombo-embolic complications and negating the need for anticoagulation. This annuloplasty ring also permits normal growth of the valve orifice in the paediatric population. This article aims to present the intra-annular implantation technique and the rationale for a biodegradable annuloplasty ring in mitral valve repair.