Abstract 2711: Mid-Term Efficacy of Percutaneous Mitral Valve Repair: A Real-Time Three-Dimensional Echocardiographpic Study in an Ovine Model
Background. Percutaneous catheter-based mitral annuloplasty (PTMA) is a newly-developed technique that exploits the anatomic proximity of the coronary sinus (CS) to the mitral valve apparatus. Durability of these procedures must be established.
Purpose. To assess 3-dimensional (3D) geometry of the mitral annulus (MA) in normal sheep 20 weeks after PTMA implantation.
Methods. A PTMA device was implanted percutaneously in the CS of 10 normal sheep. All animals were followed for 20 weeks with real-time 3D echocardiography (RT3DE)(Sonos 7500). The setting of PTMA was optimized to reduce the MV area and the anterior-posterior (A-P) diameter (Figure A⇓). RT3DE examination was done before, immediately after, and 20 weeks after implantation. Custom 3D software was used to elucidate MA geometry with manual tracing of 16 points at mid-systole. The MA area and the diameters in 4 directions, as shown in Figure B⇓, were measured. The angle α, defined in Figure C⇓, was measured as the index of the saddle shaped MA.
Results. No significant hemodynamic, pathologic or mechanical complications were observed during implantation or follow-up. MA area (4.8±0.9 cm2 to 3.7±0.9 cm2) and A-P diameter (21.4±3.0 mm to 17.6±2.4 mm) were reduced immediately after the procedure (both p<0.05). The angle α decreased after the procedure (142.0±11.5 to 128.3±15.6, p<0.05). These changes remained stable over the 20 week follow-up. The diameters in other 3 directions did not change after the procedure.
Conclusions. RT3DE demonstrated that PTMA provided reduced MA area and A-P diameter as well as emphasized the physiologic curved shape of MA. These changes remained stable for 20 weeks after the device implantation.