Radiofrequency Ablation for Minimally-Invasive Repair of Mitral Valve Prolapse

The effects of intracardiac ablation have been well characterized (See Effects of RFA) and prior work has suggested that it can be used to repair mitral valve prolapse causing severe mitral regurgitation (MR).  Minimally invasive repair of mitral valve prolapse (MVP) causing severe mitral regurgitation (MR) should increase the rigidity of the valve leaflet, decrease the leaflet surface area, and decrease redundant chordal length. Ex-vivo studies suggest that direct application of radiofrequency ablation (RFA) to mitral leaflets and chordae can effect these repair goals to decrease MR.  We used a naturally occurring model of MVP (similar macroscopically and microscopically to primary MVP in humans) causing severe MR.  RFA was applied to the prolapsed leaflets of the mitral valve and any associated elongated chordae. Mitral regurgitant volume was calculated using the proximal isovelocity surface area method on pre- and post-ablation echocardiograms.  Subjects found to have anterior leaflet, posterior leaflet, and bileaflet MVP prolapse causing severe MR with a mean ejection fraction of 66±3%(±SD) underwent direct RFA. Echocardiograms performed before and after RFA demonstrated a 66.9±20.6% reduction in mitral regurgitant volume.  The first video below shows the severe MR prior to RFA application to leaflets and chordae.  The second video shows the degree of MR 6weeks after RFA applied.  One can note the qualitative decrease in MR that was quantified by doppler.

These data suggest that myxomatous mitral valve repair using radiofrequency energy delivered via catheter may be feasible. Further investigation is necessary to evaluate whether such a technique could be adapted to a percutaneous, closed chest, beating heart environment.

More information about this study can be found at:  http://www.lebanoncardiology.com/downloads/JLW%20JOIC%202008.pdf.

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