Transfemoral Aortic Valve Implantation in a Patient With Mitral Bioprosthesis, Technical Features and Forethoughts

To the Editor,

Experience with transcatheter aortic valve implantation (TAVI) in patients with mechanical mitral valve prostheses has recently been published.^{1, 2, 3, 4} We present the case of a transfemoral transcatheter aortic valve (TAV) (Edwards Lifesciences, Irvine, California) implantation in a patient with a mitral bioprosthesis (MBP). The presence of an MBP is not an indication approved by the manufacturer, although several cases of transapical implantation have been reported.^{3, 4}

The patient was an 86-year-old woman with a history of stroke, permanent atrial fibrillation, and MBP (Biocor 27, St. Jude Medical, St. Paul, Minnesota) implantation which had been performed 11 years earlier. She presented with symptoms of heart failure (New York Heart Association functional class III) presenting evidence of severe aortic stenosis with a valve area of 0.75 cm², a peak gradient of 64mmHg, a mean gradient of 37mmHg, pulmonary hypertension, and good left ventricular function. Given her logistic EuroSCORE of 43%, a medical-surgical meeting was called in which it was decided to attempt transfemoral TAVI since the iliofemoral anatomy was favorable. The operation was performed under general anesthesia and with 3-dimensional transesophageal echocardiography (3D TEE) monitoring, following standard procedure.⁵ The baseline study showed an MBP strut protruding 9mm into the left ventricular outflow tract (LVOT), but with sufficient space in the LVOT (in theory) to accommodate the TAV (Figure 1). During the aortic valvuloplasty procedure, displacement of the balloon toward the aorta was observed without further deformation of the MBP (Figure 2; video 1). The TAV (Edwards SAPIEN XT 23) implantation was initiated with 60% of the valve in the LVOT to prevent displacement toward the aorta, which finally occurred but with a scant magnitude (4mm) (Figure 2, video 2). A good result was achieved with the TAV in the high position without occluding the coronary ostia and/or impairing the MBP (video 3). The patient was discharged 6 days after the implantation procedure with stable normal left ventricular function, a peak gradient of 16mmHg, and a mean gradient of 10mmHg. At 5 months after the procedure, the patient was in functional class I-II and both prostheses were functioning correctly.

Figure 1. Transesophageal echocardiogram. A, 2-dimensional transesophageal echocardiogram. B, 3-dimensional multiplanar reconstruction. C, 3-dimensional transesophageal echocardiogram. The initial study (1) showed a strut of the biological mitral prosthesis protruding into the left ventricular outflow tract (arrow, A1, B1, C1), deployment site (dashed line, B1), and the arrangement of the struts (triangles) in relation to left ventricular outflow tract (C1). After implantation (A2, B2, C2) the transcatheter aortic valve can be seen in the high position and the intact mitral bioprosthesis.

Figure 2. Fluoroscopy. Valvuloplasty (A1-A2) with displacement of the balloon (arrow) compared to the initial position (oval), and implantation (B1-B2), with less displacement (arrow) compared to the initial position (dashed line). The mitral bioprosthesis can be seen as a thin radiopaque ring.

To the best of our knowledge, this is the first case of transfemoral TAVI in the presence of an MBP. However, we should recall that the presence of an MBP makes this off-label usage. The limitations of MBPs are as follows³: a) the profile (height) of MBPs is higher than that of mechanical valves, mainly due to the posts or struts to which the leaflets attach, and they usually protrude into the LVOT (Figure 1); b) the structure and the leaflets of MBPs are more fragile than those of mechanic valves, and have the potential risk of damaging the MBP during the procedure; and c) MBPs are very radiotransparent, so that planning and monitoring the procedure using 3D TEE are essential to assess the relationship between the 2 prostheses, although implantation is still performed under fluoroscopic guidance.

Although the transapical approach is considered more stable due to the course of the catheter being shorter, a better implantation success rate has not been demonstrated. The new transfemoral delivery systems (Novaflex^®) provide greater stability during the delivery of the TAV and, as shown in our case, make complex procedures possible using the femoral access route.

The following technical aspects have to be considered during these interventions⁴: a) prior meticulous study of the LVOT to avoid damage to the MBP and guarantee space for the TAV implantation, which can be performed using TEE or preferably using 3D TEE or computed tomography; b) assessment of the behavior of the valvuloplasty balloon because a shift indicates possible displacement of the TAV during implantation. The measures proposed to minimize displacement are to begin the implantation procedure with at least 60% of the TAV in the LVOT or perform a countertraction maneuver if displacement is expected; c) monitoring the impact of the valvuloplasty procedure on the MBP and avoiding damaging the MBP leaflets with the guidewire; and d) slow inflation of the prosthesis to correct displacements and obtain the hourglass shape that secures the TAV in position. The majority of published cases have described a displacement of the TAV toward the aorta and dislocations in which the prosthesis has to be permanently secured to some point in the aorta have also been reported.⁴

In conclusion, the transfemoral implantation of a TAV in the presence of an MBP is a viable alternative to the transapical access route and is facilitated by new delivery devices that increase stability during implantation.

Conflicts of Interest

Dr. Salinas received a grant from the Sociedad Española de Cardiología for training in hemodynamics at national centers.

Appendix A. Supplementary material

Supplementary material associated with this article can be found in the online version available at doi:10.1016/j.rec.2011.12.019.

Appendix A. Supplementary data

 

 

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