Acknowledgments
We thank the help from the staff of Tongji hospital affiliated with Tongji University, including the department of cardiac echocardiography, the department of cardiac angiography, and the animal laboratory management office. Without their help and professional guidance, we can’t finish this tough research project.
Conflicts of interest
The authors declare that there is no conflict of interest.
Author contribution
Yongxin Zhou supervised the research project, designed the Mitral stent system, executed the animal experiment, and modified the manuscript. Kaiqin Wu executed the animal experiment and wrote the manuscript. Shaorui Gu, Ttiancheng Lu, Zhenchuan Liu, Chenglai Dong, Xin Zhang, and Haitao Huang were involved in the animal experiments. Shaorui Gu and Tiancheng Lu also recorded and evaluated the experimental data.
Reference
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Figure Legends
Figure 1 Novel mitral valved stent for transcatheter implantation.
(A) Atrial side view of the valve prosthesis. (B) Ventricular side view of the valve prosthesis. (C-D) Lateral side view of the valve prosthesis. The main structure of the valve prosthesis was mainly divided into four parts, including the atrial flange and the ventricular portion, which are attached to two opposing extensions (star marker) and two opposing anchors (rectangular dotted lines). (E) The valve prosthesis is compressed within a delivery system, with recurrent strings (red arrow) hanging from each pair of anchors. Anchor (red triangle) is abducted at an angle by the string for grasping.
Figure 2 Preoperative echocardiography evaluation before the animal experiment
(A) The native mitral valve opening during the left ventricular diastole. (B)The native mitral valve closed during the left ventricular systole without valve regurgitation.
Figure 3 Representative fluoroscopy images after valved stent deployment
(A) The valve prosthesis was successfully deployed in the heart (asterisk labeled prosthesis), and the delivery system was removed and the ventricular angiography was performed with a pigtail catheter (arrow pointing to the pigtail catheter).
(B) Ventricular angiography showed that the valve prosthesis was closed normally in diastole. There is trace paravalvular leakage in this case. No obvious LVOT obstruction was observed. MV=Mitral valve, LV=Left ventricle, LA= Left atrium, Ao= Aorta.
Figure 4 Representative echocardiography images after valve deployment
The valve prosthesis was closed well during the left ventricular systole. (B) Valve prosthesis was opening during the left ventricular diastole. (LV=Left Ventricle, LA= Left Atrium)
Figure 5 Representative images of necropsy
(A)The pig heart atrium was removed to expose the valve prosthesis. The atrial flange of the valved stent is located on the mitral annulus.
(B) The left ventricle tissue was dissected to reveal the valve prosthesis and subvalvular structure. Both anchors successfully clamped the native leaflet (green arrow) and the valve prosthesis was stable in the mitral position. There were no LVOT obstruction, valve displacement, rupture of chordae tendineae or papillary muscle ischemia, or other subvalvular structural injury. The native mitral leaflets are sandwiched between anchors and the ventricular body of the stent.
(C) Careful examination of the valve prosthesis revealed no embolism or nitinol fracture. No leaflets rupture or dislocating was observed.
Tables
Table 1 Procedural data of animal experiments