Analysis of Mitral Valve Motion in 4D Transesophageal Echocardiography for Transcatheter Aortic Valve Implantation

Transcatheter aortic valve implantation (TAVI) is used to treat aortic stenosis in high-risk patients that cannot undergo cardiac surgery. Because it is minimally-invasive, it could be beneficial to treat patients in better conditions as well. Because their expected lifetime is much longer, the long-term benefit of the TAVI implant must be ensured. If the TAVI stent is placed too far into the left ventricular outflow tract it can impair movement of the anterior mitral leaftlet. Case reports demonstrated endocarditis and leaflet damage due to such friction.

To predict possible complications, we identified mitral valve, aortic valve, and left ventricular outflow tract in 4D transesophageal echocardiography series using model-based segmentation. The segmentation model was a combined structure of the left heart with dynamic valves that was adapted as a whole. Valve dynamics were modeled using shape modes. In a leave-one-patient-out validation of 16 datasets, the respective mean segmentation error for mitral and aortic valve was

$$0.99\pm 1.16\,\mathrm {mm}$$

and

$$1.27\pm 1.68\,\mathrm {mm}$$

.

We further analyzed the overlap of the mitral leaflet trajectory with the target region for a possible TAVI implant in 18 patients. The overlap as a function of distance from the aortic annulus varied considerably with peak overlaps of 4.7 to 16.6 mm. Such information is potentially useful for procedure planning and device selection to avoid mitral valve impairment by TAVI.