A system and method for opening a lumen in an occluded blood vessel, e.g., a
coronary
bypass graft, of a living being. The system comprises an atherectomy catheter having
a working head, e.g., a rotary impacting impeller, and a debris extraction sub-system.
The atherectomy catheter is located within a guide catheter. The working head is
arranged to operate on, e.g., impact, the occlusive material in the occluded vessel
to open a lumen therein, whereupon some debris may be produced. The debris extraction
sub-system introduces an infusate liquid at a first flow rate adjacent the working
head and withdraws that liquid and some blood at a second and higher flow rate,
through the guide catheter to create a differential flow adjacent the working head,
whereupon the debris is withdrawn in the infusate liquid and blood for collection
outside the being's body. The introduction of the infusate liquid may also be used
to establish an unbalanced flow adjacent the working head to enable the atherectomy
catheter to be steered hydrodynamically. A guide wire having an inflatable balloon
on its distal end may be used with the atherectomy catheter to block the flow of
debris distally, while enabling distal tissues to be perfused with an oxygenating
liquid. At least one flow control port may be provided in the guide catheter to
prevent collapse of the vessel being revascularized. A cradle is provided to fix
the guide catheter and guide wire in position within the body of the being while
enabling the atherectomy catheter to be advanced along the guide wire and through
the guide catheter. The guide catheter includes a wear resistant coating and is
constructed so that its distal end includes plural sections of different outside
diameters, with the distal most section being of the smallest outside diameter.
A control console is provided to establish various modes of operation of the system
based on manual inputs via switches or voice commands via voice recognition circuitry.
A video panel displays the various modes of operation and instructions to the operator.