Transcatheter aortic valve resection: new mechanical devices

Figures

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  Figure 1. The Aesulap II punch device resected the calcified aortic valves in the shortest amount of time in porcine (P<0.001) as well as in human experiments (P<0.001). However, it created more lesions compared to others (P=0.002). (A) Overall view of device with handle; (B) released resection head; (C) the distal element of device was re-clenched; (D) the resection chamber is closed. a: the mobile distal element with circular bald; b: the fixed proximal element.

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  Figure 2. The R&R II resection device resected a smaller number of cusps than the other two devices (P<0.001). The latter also resected with 158.4±66.1 mm2 a smaller area of the aortic valve (P=0.016). (A) overall view of device with pistol handle; (B) opened resection chamber (a: upper metal teeth blade of the resection chamber; b: lower cutting edge of the outer tube); (C) the inner tube is pulled down by moving the handle together; (D) closed chamber; (E,F) top view and lateral view of a captured aortic cusp.

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  Figure 3. The Randstad punch (A, designed by our group) removed the second largest amount of tissue with 250.9±92.7 mm2 in human studies (P<0.016) and created no damage in porcine studies (a: locking handle; b: connector for suction unit). (B,C,D) Punch resection head of the Randstad (c: punching cone; d: rounded abutment; e: external tube with integrated cutting edge; f: resection chamber of punching head); (E) the control handle (g: inlet for suction unit; h: the guide wire lumen).

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  Figure 4. Resection process and analysis of the native porcine aortic valve thereafter. (A) Transapical passage through the cusps with the device, positioning above aortic valve; (B) after sagittal dissection of the heart, view on resected aortic valve; (C,D) porcine heart after resection (a: not resected residual parts of the aortic cusps; b: resected aortic cusps).

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  Figure 5. Experimental setup with a custom-made metal flange designed to allow an optimal fixation of the calcified valves before resection experiments. (A) Upper part of the flange with cusps in place; (B) lower part; (C) assembled calcified human aortic valve chamber with a device delivery tube; (D) pre-resection view of the flange in supravalvular direction; (E) post-resection view of the flange in supravalvular direction.

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  Video 1. Transapical native aortic valve resection (in a human cadaver).

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  Figure 6. Inter-group analysis of all three devices (Aesculap II, R&R II and Randstad) of porcine native aortic valve resection experiments (r/c: resected area/resection chamber area). Differences between devices are indicated (*P<0.005).

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  Figure 7. Lesions caused by various resection devices. (A,B,C) By the Aesculap II device (a: anterior mitral leaflet, b: interventricular septum, c: left ventricular outflow tract); (D) damage at the aortic annulus (d) caused by R&R II device.