Use of annulus washer after debridement: A new mitral valve replacement technique for patients with severe mitral annular calcification

Abstract

Extreme calcification of the mitral annulus (MAC) is a formidable challenge during mitral valve surgery, with the risk of serious and potentially fatal complications such as stroke, atrioventricular disruption, ventricular rup- ture, valve dehiscence, and periprosthetic leakage. 1 A vari- ety of surgical techniques have been developed that vary from avoiding or minimizing any decalcification 2 to exten- sive radical removal of the calcium bar followed by recon- struction of the atrioventricular annulus. 3-5 We describe our experience with an intermediate approach that involves limited debridement of the calcified annulus, allowing implantation of a good-sized prosthesis using a felt washer, sandwiched between the annulus and prosthesis, as a support. aortic calcification), and normothermic cardiopulmonary bypass were used in all patients. The mitral valve is approached transeptally. First the severity of the dis- ease and valvular dysfunction is reevaluated to finalize the surgical plan. This includes sizing the valve opening and estimating the debridement necessary to implant a good-sized valve. Exposure is optimized with a low threshold to extend the atrial septal incision to the dome of the left atrium and add a proximal aortotomy. The anterior leaflet is preserved and transposed posteriorly to support the annulus, and when doable, the posterior leaflet is released and also salvaged for support. Debridement is performed carefully piece by piece by rongeur, often using a dual ap- proach from the left atrium and aortic root. Great care is taken to avoid transmural defects in the atrioventricular groove or deep defects in the pos- terior wall muscle. Size and shape of the mitral opening are repeatedly reevaluated until it is deemed possible to place sutures and implant a pros- thesis of good size. In some cases this requires extensive debridement. The valve sutures are placed through or around the residual calcium and annu- lus, with pledgets on the ventricular side (Figure 1, A). Working through the aortotomy often allows better placement of valve sutures in the region of the central fibrous body. A 1- to 1.5-cm wide (1/2 inch) PTFE felt washer is inserted in between the annulus and sewing ring of the prosthesis from trigone to trigone posteriorly (Figure 1, B). The valve and the washer are tied down. The washer is then sutured to the atrial wall with a second suture line using running No. 4-0 polypropylene (Figure 1, C). Generous irrigation is performed repeatedly to clear the heart of loose pieces of calcium.