There is considerable interest in percutaneous closure of perivalvular leaks without the need for repeat surgery. Successful percutaneous closure of these defects requires extensive planning and coordination before and during the procedure. However, there is no standardized description of valve pathology in the presence of a prosthetic valve, which adds to the challenge of communication. Transesophageal echocardiography is ideally suited to guide percutaneous mitral valve procedures, because of the proximity of the mitral valve to the esophagus. Successful percutaneous procedures of the mitral valve require teamwork. Both the interventionalist and the echocardiographer must have great familiarity with mitral valve anatomy, structure, and function, and they must know how to effectively communicate with each other. The authors review the relevant periprocedural mapping of the mitral valve and provide guidance to echocardiographers and interventionalists on effective ways to communicate during percutaneous perivalvular mitral leak closures to accomplish a successful outcome.
Perivalvular regurgitation is a known complication of prosthetic valves. This phenomenon may occur for several reasons, some of which include improper valve implantation, infection, friable tissue, or excessive annular calcification at the site of the annuloplasty ring or valve attachment. Perivalvular leaks are often inconsequential, and patients remain asymptomatic. However, when significant, these perivalvular regurgitant lesions may cause symptoms of severe heart failure or hemolysis requiring rehospitalizations and blood transfusions. Surgical closure of perivalvular leaks is often advised in symptomatic patients, because this offers better long-term survival. However, surgical repair of perivalvular regurgitation is also associated with significant morbidity and mortality and may not be successful, because the original anatomic issues that caused the perivalvular leak persist. Thus, there is considerable interest in percutaneous closure of these leaks without the need for repeat surgery. Successful percutaneous closure of these defects requires extensive planning and coordination before and during the procedure. However, there is no standardized description of valve pathology in the presence of a prosthetic valve, which adds to the challenge of communication.
Transesophageal echocardiography (TEE) is ideally suited to guide percutaneous mitral valve procedures, because of the proximity of the mitral valve to the esophagus. As a result, TEE has become the primary form of imaging used to guide such interventions. Successful percutaneous procedures of the mitral valve require teamwork. Both the interventionalist and the echocardiographer must have great familiarity with mitral valve anatomy, structure, and function, and they must know how to effectively communicate with each other. In this report, we review the relevant periprocedural mapping of the mitral valve and provide guidance to echocardiographers and interventionalists on effective ways to communicate to accomplish a successful outcome.
Echocardiographic Native Mitral Valve Anatomy
Mitral valve leaflet anatomy was well described by Carpentier et al . The anterior and posterior leaflets of the mitral valve are subdivided into three segments or scallops, the posterior scallops being P1, P2, and P3 and the anterior scallops being A1, A2, and A3. The P1 and A1 scallops are closest to the left atrial appendage or the anterolateral commissure, and the P3 and the A3 scallops are closest to the posteromedial commissural ( Figure 1 A). This nomenclature is based on the “surgeon’s view,” with the mitral valve being viewed en face from the left atrial side.
Speaking the Same Language: How Do the Echocardiographer and the Interventionalist Describe the Anatomy of a Prosthetic Mitral Valve to Each Other?
The Carpentier classification allows uniform communication about the native mitral valve between the surgeon and the echocardiographer. However, the presence of a mitral prosthesis results in additional challenges in the nomenclature, because the native leaflets are no longer present. Traditionally, two-dimensional (2D) TEE has been used to locate perivalvular regurgitations; however this requires tremendous expertise and is time consuming. In addition, because of distortion of the mitral annulus in the presence of a prosthetic valve, the standard views used to image the mitral valve may not be completely accurate. Three-dimensional (3D) TEE has revolutionized imaging of the mitral valve. It is especially useful in the presence of a mitral prosthesis because it is relatively easy to perform and also provides the echocardiographer with the surgeon’s view of the mitral annulus. Three-dimensional TEE has been especially useful in the localization of mitral perivalvular leaks and guidance of percutaneous closure.
Currently, there is no standardized nomenclature to describe mitral valve pathology in the presence of a prosthetic mitral valve. With the recent upsurge of percutaneous treatments for mitral valve disease, it is imperative that the echocardiographer and interventionalist communicate using the same language, especially when a prosthetic valve is present.
Meloni et al . proposed one of the many methods used to describe the location of the perivalvular regurgitation of the mitral valve ( Figure 1 B). In this description, the mitral valve (as viewed from the left atrium with the left atrial appendage on the lateral aspect and aortic valve superiorly) is divided simply into four quadrants: anterior, septal, lateral, and posterior. The prosthetic perivalvular regurgitation is then described in terms of its location in the quadrants. Although this nomenclature is easily understood, it may be too simplistic, because each quadrant includes a large portion of the annulus. Thus, one may need to be more specific in the description of the exact location of the perivalvular regurgitation.
Given the limitations of this nomenclature, another method used to describe the mitral valve anatomy and location of the perivalvular leak was proposed by Mahjoub et al . and by the American Society of Echocardiography. One can use fluoroscopic guidance to view the prosthetic mitral valve in terms of the face of a clock, with the aortic valve at the 12 o’clock position and the left atrial appendage at the 9 o’clock position ( Figure 2 A). Using these landmarks, the face of the clock can also be applied to the transesophageal echocardiographic images. When this method is used, one can unify the nomenclature for the interventionalist and the echocardiographer when describing the location of the perivalvular leak ( Figure 2 B). The different “numbers of the clock” can be easily obtained by the different transesophageal echocardiographic planes ( Figure 2 C): for instance, 12 o’clock and 6 o’clock on the surgeon’s clock view of the mitral prosthesis correspond to a transesophageal echocardiographic 135° transesophageal view. Similarly, the 45° view corresponds to the 3 o’clock and 9 o’clock positions on the surgeon’s clock. It is important to recognize that when the mitral valve is viewed from the left atrium (as in 3D TEE), the aortic valve is at the 12 o’clock position, and the left atrial appendage is on the left-hand side of the screen at the 9 o’clock position. This is in contrast to when the mitral valve is viewed from the left ventricular side (as in the short-axis view of the mitral valve on transthoracic echocardiography). Now the clock is reversed. The left atrial appendage is still at 9 o’clock but is on the right-hand side of the image ( Figure 3 ).
Another method to describe the location of the perivalvular regurgitation is to visualize the prosthetic mitral valve in terms of the location of the scallops of a native mitral valve. In this method, the native mitral annulus and scallop anatomy is superimposed on the prosthetic mitral valve. One can then describe the location of the perivalvular regurgitation in terms of the Carpentier nomenclature ( Figure 2 D). There are some surgeons who may prefer to use this methodology in describing the location of a perivalvular leak, because of their familiarity with this nomenclature. It should be noted that the leak is described in terms of the anatomic location of the adjacent native mitral valve scallop if that scallop were present. This methodology can be applied to any prosthesis because the description does not describe prosthetic leaflets but rather the location of the leak relative to the native mitral scallop. There is yet a fourth method used to describe the location of the perivalvular leak, in which the mitral valve is divided into eight different sections.
Any of the aforementioned methods to describe the location of a perivalvular leak is acceptable. Some may prefer the clock method, which is more specific, over the four-quadrant method, because the latter nomenclature may not be specific enough. Others may prefer the anatomic scallop method because of familiarity with this nomenclature. The most important step is for the echocardiographer and the interventionalist to establish in advance which method of communication will be used.
Speaking the Same Language: How Do the Echocardiographer and the Interventionalist Describe the Anatomy of a Prosthetic Mitral Valve to Each Other?
The Carpentier classification allows uniform communication about the native mitral valve between the surgeon and the echocardiographer. However, the presence of a mitral prosthesis results in additional challenges in the nomenclature, because the native leaflets are no longer present. Traditionally, two-dimensional (2D) TEE has been used to locate perivalvular regurgitations; however this requires tremendous expertise and is time consuming. In addition, because of distortion of the mitral annulus in the presence of a prosthetic valve, the standard views used to image the mitral valve may not be completely accurate. Three-dimensional (3D) TEE has revolutionized imaging of the mitral valve. It is especially useful in the presence of a mitral prosthesis because it is relatively easy to perform and also provides the echocardiographer with the surgeon’s view of the mitral annulus. Three-dimensional TEE has been especially useful in the localization of mitral perivalvular leaks and guidance of percutaneous closure.
Currently, there is no standardized nomenclature to describe mitral valve pathology in the presence of a prosthetic mitral valve. With the recent upsurge of percutaneous treatments for mitral valve disease, it is imperative that the echocardiographer and interventionalist communicate using the same language, especially when a prosthetic valve is present.
Meloni et al . proposed one of the many methods used to describe the location of the perivalvular regurgitation of the mitral valve ( Figure 1 B). In this description, the mitral valve (as viewed from the left atrium with the left atrial appendage on the lateral aspect and aortic valve superiorly) is divided simply into four quadrants: anterior, septal, lateral, and posterior. The prosthetic perivalvular regurgitation is then described in terms of its location in the quadrants. Although this nomenclature is easily understood, it may be too simplistic, because each quadrant includes a large portion of the annulus. Thus, one may need to be more specific in the description of the exact location of the perivalvular regurgitation.
Given the limitations of this nomenclature, another method used to describe the mitral valve anatomy and location of the perivalvular leak was proposed by Mahjoub et al . and by the American Society of Echocardiography. One can use fluoroscopic guidance to view the prosthetic mitral valve in terms of the face of a clock, with the aortic valve at the 12 o’clock position and the left atrial appendage at the 9 o’clock position ( Figure 2 A). Using these landmarks, the face of the clock can also be applied to the transesophageal echocardiographic images. When this method is used, one can unify the nomenclature for the interventionalist and the echocardiographer when describing the location of the perivalvular leak ( Figure 2 B). The different “numbers of the clock” can be easily obtained by the different transesophageal echocardiographic planes ( Figure 2 C): for instance, 12 o’clock and 6 o’clock on the surgeon’s clock view of the mitral prosthesis correspond to a transesophageal echocardiographic 135° transesophageal view. Similarly, the 45° view corresponds to the 3 o’clock and 9 o’clock positions on the surgeon’s clock. It is important to recognize that when the mitral valve is viewed from the left atrium (as in 3D TEE), the aortic valve is at the 12 o’clock position, and the left atrial appendage is on the left-hand side of the screen at the 9 o’clock position. This is in contrast to when the mitral valve is viewed from the left ventricular side (as in the short-axis view of the mitral valve on transthoracic echocardiography). Now the clock is reversed. The left atrial appendage is still at 9 o’clock but is on the right-hand side of the image ( Figure 3 ).
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