A NOVEL ANNULOPLASTY SYSTEM WITH RIGID AND FLEXIBLE ELEMENTS - INITIAL EXPERIMENTAL RESULTS IN SHEEP AND THE CASE FOR UNTREATED AUTOLOGOUS PERICARDIUM

Background and aims of the study. A precise annuloplasty is difficult to perform with pericardium as the ring material because unwanted plic ation of the pericardium itself typically occurs when the sutures are tied, A novel annuloplasty system has been developed which should allo w a predictably precise measured plication of the annulus without plic ation of the pericardium itself. A feasibility study was designed to e valuate this new concept, Methods: Three juvenile sheer underwent impl antation of a new annuloplasty system into the posterior mitral annulu s without tissue annulus plication, Small rigid titanium suture-platfo rms 7 x 3 x 1 mm with two-suture holes 3 mm apart were individually af fixed to tile posterior mitral tissue annulus each with a single horiz ontal mattress suture, A longitudinal strip of untreated autologous pe ricardium, corresponding to the perimeter dimension of the free edge o f the anterior leaflet, was sutured to the posterior annulus including both fibrous trigones, covering the suture-platforms with the mesothe lial surface up, using two different suture techniques. No postoperati ve anticoagulation was utilized. Serial transthoracic echocardiograms and necropsy at five to six weeks post implant were performed, Results : When the pericardium was affixed to the annulus with a continuous su ture exposing only the mesothelial surface to the blood, completely co vering the suture-platforms and their suture knots or folded in upon i tself as a tube above the suture-platforms, it appeared to maintain al l of its original implant dimensions and flexibility. There was no fun ctional or anatomical distortion of any part of the mitral apparatus; fibrotic reaction was minimal and there was no thrombus formation with this suture technique. Conclusions: This annuloplasty system combinin g rigid and flexible elements, 'melts' into the tissue annulus with a low profile, providing overall annular flexibility with nea shrinkage of the overlying untreated autologous pericardium, no distortion of an y part of the mitral apparatus, minimal fibrous reaction and no thromb us formation.