Medtronic Hancock II Gebrauchsanweisung Seite 24

Bioprosthesis
1. Device description
The Hancock™ II bioprostheses, Model T505 (aortic) and Model T510 (mitral) consist of porcine aortic valves that
have been preserved in buffered 0.2% glutaraldehyde, and fitted and secured to cloth-covered flexible stents.
Tissue fixation with 0.2% glutaraldehyde produces a virtually nonantigenic porcine valve.
The tissue is treated by a "T6" process that has been shown to mitigate porcine leaflet calcification in animal
studies.
The stents of the aortic and the mitral valves are constructed from a polymeric material.
The Hancock II bioprostheses are available in the sewing ring diameters and sizes shown in Table 1
through Table 3.
The inflow aspects of the aortic and mitral valves approximate the natural anatomy of the annuli. The aortic valve
stent and sewing ring are scalloped. The mitral valve stent and sewing ring are flat.
The stents are fitted with an annular ring and metal stent post markers to allow radiographic visualization. The
markers are placed close to the apex of each stent post to allow visualization of the relationship of the stent posts
to each other and to the aortic or ventricular wall.
The stents are covered with polyester fabric. The mitral valve sewing ring contains polyester felt, allowing for easy
needle penetration and low suture drag. The aortic valve sewing ring is scalloped to enable mounting within the
22 Instructions for Use English
annulus or in the supra-annular position. If preferred, a larger aortic valve can be used in a supra-annular position
to benefit patients with a small aortic root.
Disposable Cinch™ holders are sutured to both aortic and mitral bioprostheses. The holders incorporate a ratchet
mechanism. After the holder is attached to the handle, further handle rotation starts the ratchet mechanism. The
stent posts are drawn inward, easing implantation. The suture attaching the holder to the mitral bioprosthesis
prevents the surgeon's sutures from looping during implantation.
The disposable holders are designed to fit the reusable Medtronic Valve Handle, Model 7639. The handle is also
used with the Hancock™ II obturators, Model 7505 (aortic) and Model 7510 (mitral) for measuring the annulus.