Percutaneous transvenous Melody valve-in-ring procedure for mitral valve replacement

Abstract

Objectives: The purpose of this study was to demonstrate the feasibility of percutaneous transvenous mitral valve-in-ring (VIR) implantation using the Melody valve in an ovine model.

Background: The recurrence of mitral regurgitation following surgical mitral valve (MV) repair in both adult and pediatric patients remains a significant clinical problem. Mitral annuloplasty rings are commonly used in MV repair procedures and may serve as secure landing zones for percutaneous valves.

Methods: Five sheep underwent surgical MV annuloplasty (24 mm, n = 2; 26 mm, n = 2; 28 mm, n = 1). Animals underwent cardiac catheterization with VIR implantation via a transfemoral venous, transatrial septal approach 1 week following surgery. Hemodynamic, angiographic, and echocardiographic data were recorded before and after VIR.

Results: VIR was technically successful and required <1 h of procedure time in all animals. Fluoroscopy demonstrated securely positioned Melody valves within the annuloplasty ring in all animals. Angiography revealed no significant MV regurgitation in 4 and moderate central MV regurgitation in the animal with the 28-mm annuloplasty. All animals demonstrated vigorous left ventricular function, no outflow tract obstruction, and no aortic valve insufficiency.

Conclusions: This study demonstrated the feasibility of a purely percutaneous approach to MV replacement in patients with preexisting annuloplasty rings. This novel approach may be of particular benefit to patients with failed repair of ischemic mitral regurgitation and in pediatric patients with complex structural heart disease.

Figure 1

Figure 1 shows the transvenous, transeptal approach to Melody Valve-in-Ring (VIR) delivery. In Figure 1A The Melody device is crimped on the delivery balloon and advanced from the femoral vein, across the atrial septum and positioned centrally in the annuloplasty ring. Figure 1B shows deployment of the Melody valve via balloon inflation. Figure 1C shows a follow-up left ventriculogram. There is no mitral regurgitation, and no left ventricular outflow tract obstruction. A device was used to close the small atrial septal defect.

Figure 2

The Melody device conformed to the “D-shape” of the annuloplasty ring upon Valve-in-Ring (VIR) implantation.

Figure 3

Three of the five animals had residual mitral regurgitation (MR) following the VIR procedure. The ECHO grade was trivial-to-mild for two animals (Figure 3A–3B) and moderate-to-severe for one animal (animal #5) [Figure 3C] in which a 28mm annuloplasty ring was used, requiring “over-dilation” of the Melody valve for secure anchoring. The mechanism of MR was via a central coaptation defect in the Melody device in all animals as shown above. There were no perivalvular leaks.

Figure 4

Left ventriculogram and aortogram status post Melody VIR implantation. There is no LV outflow tract obstruction (LVOTO) and no aortic valve insufficiency.

Figure 5

Necropsy pictures: In all animals, the Melody device was securely anchored within the annuloplasty ring, forming a tight circumferential seal. Figure 5 shows representative views from the left atrial and left ventricular sides.