Surgical Mitral Valve Replacement Utilizing Transcatheter Bioprosthetic Valve for Severe Mitral Annular Calcification

The patient was a 76-year-old woman with a known history of mitral stenosis. Her symptoms included worsening fatigue, malaise, and dyspnea with exertion. Echocardiography demonstrated a mitral valve area of 0.7 cm2 with a mean mitral valve gradient of 25 mm Hg, classifying this as severe mitral stenosis. The heavily calcified leaflets precluded a mitral valve repair and it was felt that the annular calcifications prohibited traditional mitral valve replacement. Thus, the authors proceeded with surgical mitral valve replacement with a transcatheter bioprosthetic valve.

The authors performed a median sternotomy and cardiopulmonary bypass was achieved. They began separating the left and right atria along Waterston’s groove, utilizing Sondergaard’s technique. A left atriotomy was performed and one can see the fibrotic anterior and posterior leaflets as well as the restricted mitral orifice. The leaflets, hypertrophied papillary muscle, and chordae structures were removed to relieve any left ventricular outflow tract obstruction. Additionally, the calcifications along the annular surface were removed.

A 26 mm balloon was introduced to aid in choosing the appropriately sized valve. The balloon was inflated and demonstrated a snug apposition. The authors proceeded to place pledgetted mitral annular sutures to secure the valve in place. They began at the anterior aspect and worked circumferentially around the annulus. As with any mitral valve procedure, careful suture placement is critical to prevent injury to structures such as the circumflex artery, the coronary sinus, and the noncoronary cusp of the aortic valve. In total, eight sutures were placed, leaving the atrial surface as shown by the red dotted line for future suture placement. They trimmed this to approximately match the circumference of the valve, while leaving a trapezoidal skirt that provided a sewing surface to the left atrium, as visually represented by this red dotted line. The arms of the felt were approximated and 4-0 Prolene was used to suture the ends of the felt around the valve. The felt was sutured to the metallic stent of the valve.

This technique provides a novel solution to suturing a valve in a heavily calcified and tenuous annulus. The valve was crimped to the balloon deployment device and carefully maneuvered into the mitral orifice, and the balloon was inflated to seat the valve in the optimal position. The left ventricle was filled with saline solution to assess for any insufficiency or leak. They then secured the valve in place with the previously placed annular sutures, starting on the anterior aspect to prevent canting. They worked their way to the posterior sutures, which were placed through the felt skirt of the valve.

Around the anterolateral commissure, they anchored in a felt buttress to prevent perivalvular leak. After tying the annular sutures, excess felt skirt material was removed. They reintroduced the balloon for a final inflation, and the left ventricle was filled to assess for any valvular incompetence. It was clear the valve was seated well with no obvious leak and good leaflet apposition.

The left atriotomy was closed and ventricular and atrial pacing wires were placed. The patient was weaned from bypass without concern and immediate on table TEE demonstrated low mitral valve gradients. The post placement 3D echocardiogram demonstrated a much-improved mitral valve orifice with clearance of the calcifications. There were no downstream effects on the aortic valve. The patient required pacemaker placement on postoperative day two for persistent bradycardia, however the remainder of her hospital stay was uneventful. They obtained a TTE prior to discharge, demonstrating appropriate valve placement with a mean gradient of 6 mm of Hg and an EF of 55-60%.

References

1. Baumgartner H, Hung J, Bermejo J, Chambers JB, Evangelista A, Griffin BP, et al. Echocardiographic assessment of valve stenosis: EAE/ASE recommendations for clinical practice. J Am Soc Echocardiogr. 2009;22(1):1-23.
2. Sondergaard T, Gotzsche M, Ottosen P, Schultz J. Surgical closure of interatrial septal defects by circumclusion. Acta Chir Scand 1955;109:188-196.

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