Valve sparing root replacement: the remodeling technique with external ring annuloplasty.

Abstract

A standardized approach to aortic valve repair is described associating a physiological remodeling of the root, with resuspension of cusp effective height and a subvalvular aortic annuloplasty using an external expansible ring. This device achieves a complete calibrated annuloplasty, in order to increase cups coaptation height and protect the repair. This is a video-atlas describing the surgical steps of a physiological and standardized approach to aortic valve repair, to treat an aortic root aneurysm associated with grade III to IV eccentric aortic insufficiency on a 41-year old patient with a tricuspid aortic valve (Video 1). Ideal valve sparing root replacement procedure should treat dilatation of the aortic annular base, while preserving dynamics of the aortic root with vortices (neosinuses of Valsalva), root expansibility (interleaflet triangles) as well as restoring cusp coaptation (1-5). Video 1 Valve sparing root replacement: the remodeling technique with external ring annuloplasty The two original valve sparing procedures - remodeling of the aortic root and reimplantation of the aortic valve - focused on root reconstruction to reduce the dilated root diameters in order to restore proper valve function (6,7). The reimplantation technique performs external subvalvular aortic annuloplasty but withdraws the sinuses of Valsalva and includes the interleaflet triangles within a graft tube, thus impairing root dynamics (8-11). In contrast, the remodeling technique provides more physiologic movements of the cusps within three reconstructed neo-sinuses, thus preserving root expansibility through the interleaflet triangles, but without addressing annular base dilation (8-13). In vitro and in vivo studies have documented that cusp motion and flow patterns across the reconstructed aortic root are more physiologic (I) after remodeling of the aortic root than after reimplantation of the aortic valve, and (II) after procedures using a prosthetic conduit fashioned with neo- sinuses of Valsalva than without (9-11). Numerous technical variations have aimed to associate preservation of aortic root dynamics with the treatment of dilated native annulus (14,15). This resulted in a lack of standardization and limited their widespread application. Furthermore, most failures with valve sparing techniques are due to residual cusp prolapse, either as a primary unrecognized lesion or secondary to an induced prolapse after root reconstruction (12,16). Schafers et al. proposed to address this issue with a dedicated caliper in order to restore cusp effective height up to 8-10 mm (1,4,12). Therefore we suggest a standardized approach of aortic valve repair addressing both the aorta and the valve, associating a physiological reconstruction of the aortic root according to the remodeling technique, with resuspension of cusp effective height and an expansible subvalvular ring annuloplasty (CAVIAAR technique) (Figure 1) (2,17-19). Figure 1 Remodeling of the aortic root associated to an external subvalvular aortic annuloplasty (CAVIAAR technique), combining advantages of the original remodeling and reimplantation techniques To address the need for a dedicated aortic annuloplasty device, we designed a new expansible aortic ring in order to achieve a complete and calibrated annuloplasty in diastole, while maintaining systolic expansibility of the aortic root (Extra-Aortic™, CORONEO, Inc., Montreal, QC, Canada) (19). As such, cusp coaptation height is increased, reducing stress on the cusps and protecting the repair.