Minimally Invasive Mitral Valve-in-Ring Explant for Prosthetic Stenosis

This video shows the technical challenges of explanting a valve-in-ring mitral valve.

The patient was a 40-year-old woman who presented with a failed mitral valve repair in which a P2 triangular resection and 28 mm Edwards Physio 2 ring were used 5 years prior via a limited sternotomy at an outside institution. Her original operation was complicated by cardiogenic shock requiring mechanical support and inotropic support.

The patient’s left ventricular ejection fraction (LVEF) decreased from 55% to 15% after the mitral valve repair operation. The patient was referred to the author with severe mitral regurgitation, depressed LVEF of 15%, and a normal coronary angiogram. She was evaluated at the author’s center for permanent mechanical circulatory support versus repeat mitral valve replacement. The authors proposed a transcatheter valve-in-ring approach to her mitral regurgitation under the premise that her left ventricle could remodel, which could in time facilitate a definitive operation.

Three years after her original mitral valve repair, the patient underwent a valve-in-ring procedure using a 26 mm Edwards S3 valve with a right groin femoral venous approach with transseptal puncture. The procedure was uneventful with complete resolution of the mitral regurgitation, yet a mean transvalvular mitral gradient of 7 mmHg with a heart rate of 90 bpm.

The patient had a full recovery from this procedure showed immediate improvement of her symptoms. She was placed on warfarin and aspirin after the procedure. She was closely followed with echocardiography, and 2 years after the valve-in-ring placement she was found to have an elevated mean gradient across her mitral valve of 18 mmHg with moderate regurgitation and a heart rate of 110 bpm, which was a few months later accompanied by dyspnea on exertion of 1 flight of stairs and 2 hospital admissions for volume overload. The patient had been on maximal beta-blocker therapy up to this point.

This time, the patient’s echocardiogram showed favorable ventricular remodeling, with an LVEF of 40%. She was offered a repeat mitral valve replacement using a mechanical valve.

The approach taken was a right minithoracotomy at the fourth intercostal space with a right groin cutdown for femoral-femoral bypass. Her heart was arrested using del Nido cardioplegia (1000 ml initially and a 300 ml redose at 80 minutes).

The lung adhesions to the pleura were taken down, and the pericardium was opened 2 cm above the phrenic nerve. Dense adhesions of the heart to the pericardium were taken down, and the heart was arrested using a deployable (Cygnet®) clamp. The left atrium was opened at the interatrial groove, and the atrial lift retractor (USB Medical) was positioned exposing the mitral valve.

Inspection of the valve showed no obvious thrombosis. All three leaflets moved, but one was more rigid and curled open. The annuloplasty ring was not visible as it was covered with pannus.

Using a 15-blade scalpel on a very long handle, the pannus of over the annuloplasty ring was unroofed and each suture holding the ring removed. Once all the ring sutures were removed, a plaque elevator was used to free the ring from the annulus. Immediately below this plane, one could see the cage of the S3 valve densely adhered to the leaflets of the mitral valve. Using Metzenbaum scissors, a 15-blade scalpel, and Bovie cautery at 20 of energy, the native leaflets were freed from the cage of the S3 valve, facilitating removal of the valve-in-ring complex.

The annulus was sized to a 25 mm mechanical valve (ON-X, CryoLife). The valve was seated without problems, and the mean transvalvular gradient after cardiotomy was 3 mmHg without paravalvular leaks.

The patient had an uneventful recovery, achieving a therapeutic INR on postoperative day 6 when she was discharged home.

Transcatheter mitral valve-in-valve, and valve-in-ring operations have become more common since the concept was first reported in 2007 (1). Since then, multiple experiences have been published demonstrating feasibility of implantation via an apical or transseptal approach (2-5). Although initially utilized as a therapeutic option in elderly high-risk individuals, it has become more widespread and used in patients of different age. The use of the valve-in-valve implantation is FDA approved, whereas the valve-in-ring approach is not. The author’s patient presented with acute on chronic heart failure, with an LVEF of 15%, elevated creatinine with a history of ventricular fibrillation and a secondary prevention intracardiac defibrillator implanted, and a calculated STS mortality risk of 8.3%. The valve-in-ring implantation was successful, and it led to positive remodeling of the ventricle allowing her reoperative valve replacement.

Many have published on the technical feasibility of implanting valves in valves and in rings. There is little data to support the mid- and long-term durability of this procedure, yet its ease of use and the quick reversal of mitral regurgitation or stenosis make it ideal in high-risk individuals. In younger patients, this therapeutic should not be viewed as a definitive therapy, but as a bridge to clinical improvement and LV remodeling requiring definitive surgery at a later point.

The adoption of transcatheter therapies in the aortic space and the emerging therapies for the mitral space are creating the next wave of “new surgical procedures” that the community of cardiothoracic surgeons will have to master, and that is the explantation of long-term indwelling transcatheter hardware as in this case. Our training programs and current work force will need to adapt to face these new scenarios.

References

1. Walther T, Falk V, Dewey T, et al. Valve-in-a-valve concept for transcatheter minimally invasive repeat xenograft implantation. J Am Coll Cardiol. 2007;50(1):56-60.
2. Cheung A, Webb JG, Barbanti M, et al. 5-year experience with transcatheter transapical mitral valve-in-valve implantation for bioprosthetic valve dysfunction. J Am Coll Cardiol. 2013;61(17):1759-1766.
3. Ye J, Cheung A, Yamashita M, et al. Transcatheter aortic and mitral valve-in-valve implantation for failed surgical bioprosthetic valves: an 8-year single-center experience. JACC Cardiovasc Interv. 2015;8(13):1735-1744.
4. Coylewright M, Cabalka AK, Malouf JA, et al. Percutaneous mitral valve replacement using a transvenous, transseptal approach: transvenous mitral valve replacement. JACC Cardiovasc Interv. 2015;8(6):850-857.
5. Eleid MF, Cabalka AK, Williams MR, et al. Percutaneous transvenous transseptal transcatheter valve implantation in failed bioprosthetic mitral valves, ring annuloplasty, and severe mitral annular calcification. JACC Cardiovasc Interv. 2016;9(11):1161-1174.

Dr Castillo-Sang is a speaker for Edwards Lifesciences and proctor for Cryolife ONX.