Percutaneous cardiovascular valve replacement - Biomaterials and Devices for the Circulatory System - page 124

5.2.5 The CoreValve catheter
The catheter carries the heart valve prosthesis and delivers it at the deploy-
ment site. It has the fl exibility, tractability, and rigidity that are required to
navigate to the aortic annulus. The sheath and pusher antagonist move-
ments, carried out using the handle, allow the prosthesis to be loaded and
released (Fig. 5.5). For a simpler and safer procedure, the proximal PTFE-
Pebax sheath diameter is reduced to 12 Fr. The space required by the
compressed prosthesis is more signifi cant: the working Rilsan-Pebax distal
end has an 18 Fr diameter. The inner pusher has both plastic and metal
components. Two ways of delivering the prosthesis (controlled expansion
and high speed expansion) can be carried out thanks to an easy-to-use PVC
handle (Fig. 5.6). The different components are:

￿ a thumbwheel to carry out the controlled expansion;

￿ a threaded button to activate the high-speed expansion.

Reversed movements have to be executed to close the catheter by pushing
the sheath out of the handle.

Over-the-wire (0.035 ″ compatible)

Radiopaque tip

18 Fr value capsule

12 Fr flexible shaft

Radiopaque
marker

￿ ￿ ￿ ￿ ￿

5.5 Delivery catheter.

Proximal luer

C oreVa lve

Macro slide

Micro knob

Distal luer

5.6 Easy-to-use PVC handle.