Percutaneous intervention for mitral valve (MV) disease has been established as an alternative to open surgical MV repair in patients with prohibitive surgical risk. Multiple percutaneous approaches have been described and are in various stages of development. Edge-to-edge leaflet plication with the MitraClip (Abbott, Menlo Park, CA) is currently the only Food and Drug Administration-approved device specifically for primary or degenerative lesions. Use of the edge-to-edge clip for secondary mitral regurgitation is currently under investigation and may result in expanded indications. Echocardiography has significantly increased our understanding of the anatomy of the MV and provided us with the ability to classify and quantify the associated mitral regurgitation. For percutaneous interventions of the MV, transesophageal echocardiography imaging is used for patient screening, intraprocedural guidance, and confirmation of the result. Optimal outcomes require the echocardiographer and the proceduralist to have a thorough understanding of intra-atrial septal and MV anatomy, as well as an appreciation for the key points and potential pitfalls of each of the procedural steps. With increasing experience, more complex valvular pathology can be successfully percutaneously treated. In addition to two-dimensional echocardiography, advances in three-dimensional echocardiography and fusion imaging will continue to support the refinement of current technologies, the expansion of clinical applications, and the development of novel devices.
Highlights
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Echocardiography is key to determining mitral valve pathology and suitability for percutaneous repair.
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Two-dimensional and 3D echocardiography is invaluable for MitraClip procedural guidance, confirming success, and exclusion of complications.
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The role of interventional echocardiography will increase with the development of novel new devices.
Percutaneous intervention for mitral valve (MV) disease has been established as an alternative to open surgical MV repair, particularly in patients with increased surgical risk. Multiple percutaneous approaches have been described and are in various stages of development. Edge-to-edge leaflet plication with the MitraClip (Abbott, Menlo Park, CA) is currently the only Food and Drug Administration-approved device specifically for primary or degenerative lesions. Utilization of the edge-to-edge clip (E-EC) for secondary mitral regurgitation is currently under investigation and may result in expanded indications. During this procedure anterior and the posterior mitral leaflets are percutaneously “clipped” to convert the MV into a double orifice valve analogous to the surgically performed Alfieri stitch. Transesophageal echocardiography (TEE) imaging is integral to the success of the procedure. Its role extends from assessing suitability, procedural guidance, confirming success, and exclusion of complications.
Anatomical Perspective
Anatomically, the MV is part of an apparatus that includes leaflets, annulus, chordae tendineae, and the papillary muscles with the underlying myocardium. The MV has an anterior and a posterior leaflet, which are continuous with an anterolateral commissure and a posteromedial commissure where the leaflets merge. Centrally, the leaflets overlap by approximately 10 mm (coaptation height), and reduction of this overlap by annular dilatation or tethering of one or both leaflets may result in valvular incompetence. The leaflets are enclosed in a saddle-shaped annulus and attached to the papillary muscles via chordae tendineae. The anterolateral papillary muscle and the posteromedial papillary muscle support both leaflets. The lateral half of the MV including the lateral commissure is supported via chordae tendineae attached to the anterolateral papillary muscle. The medial half of the MV including the medial commissure is supported via chordae tendineae attached to the posteromedial papillary muscle. The central portion of each leaflet is relatively free of chordal insertion, making it an ideal location for E-EC placement. Leaflet attachments to the annulus are continuous with commissures formed where both leaflets merge. Echocardiographically, the MV is examined to assess its function, that is, competence during systole and nonrestriction during diastole. The anterior leaflet is longer than the posterior leaflet that has indentations along its free edge, giving it a scalloped appearance ( Figure 1 ). The degree of coaptation between the two leaflets determines the extent of mitral annular dilation that can be sustained without overt Mitral regurgitation (MR).
