Biomedical Engineering Reference
In-Depth Information
5.3 Photos of two percutaneous valves commercially available in Europe. Top,
the Edwards Lifesciences SAPIEN
TM
Transcatheter Aortic Heart Valve. Bottom,
the Medtronic CoreValve
Õ
Transcatheter Aortic Valve. (SAPIEN
TM
is a
trademark of Edwards Lifesciences Corporation. Reprinted with permission of
Edwards Lifesciences LLC, All Rights Reserved. CoreValve
Õ
is a registered
trademark of Medtronic CV Luxembourgh S.a.r.l. Reprinted with permission of
Medtronic, Inc. All Rights Reserved.)
consistency of results postoperatively. Nonetheless, the use of a stentless valve
seems to minimize prosthesis±patient mismatch, which may ultimately lead to
longer durability for the patient (Flameng et al., 2010).
Some stented valve designs endeavor to improve the effective orifice area of
the valve by placing the valve above the aortic annulus, rather than directly in
the annulus. This supra-annular position requires a different shape to the stent of
the valve, as shown in Fig. 5.5 (Carpentier and Lane, 1984). At the extreme,
Lane has designed a valve which fits entirely in the sinuses of valsalva, resulting
in a trilobal shape, rather than a circular design (Lane, 2002). Such a design
offers a theoretical improvement in orifice area of 17% over a similarly sized
circular valve. Preclinical testing of this valve demonstrated improved hemo-
dynamics over the PERIMOUNT
Õ
valve design, when tested in the adolescent
sheep model (Flameng et al., 2008). Figure 5.6 shows a valve fabricated with a
trilobal shape.
