Percutaneous cardiovascular valve replacement - Biomaterials and Devices for the Circulatory System - page 120

5.1 Edwards SAPIEN valve. A bovine pericardial valve is sewn within
a stainless steel frame.

5.2.1 The Edwards SAPIEN prosthesis

The Edwards SAPIEN valve is constructed from a tubular, slotted, stainless
steel stent with an attached bovine pericardial trileafl et valve. The stent has
a polyethylene terephthalate fabric skirt that decreases perivalvular leak.
A sewn fabric cuff covers the left ventricular portion of the prosthesis
(Fig. 5.1). Valves are supplied sterile in glutaraldehyde and require on-site
preparation. A mechanical crimping device is used to attach the prosthesis
onto a specially constructed valvuloplasty balloon catheter. It can be placed
by antegrade, retrograde, and transapical approaches. For the transarterial
approach, the occlusive fabric skirt must be mounted distally on the balloon
catheter. Two sizes of valve, depending on the aortic annulus diameter, are
available to date (23 mm and 26 mm).

￿ ￿ ￿ ￿ ￿

5.2.2 The CoreValve prosthesis

The CoreValve self-expanding frame is made from laser-cut nitinol tubing
(Fig. 5.2). Each level carries out a particular function:

￿ The upper part ( aortic level ) of the frame increases the prosthesis
fi xation to the aortic wall and aligns the system parallel to the blood
fl ow.

￿ The middle part ( commissural level ) carries the valve. It is constrained

to a given diameter corresponding to the optimal diameter of the tissue
valve. It holds the valve leafl ets in their functional position. The convex