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withdrawn in the infusate liquid and blood for collection outside the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.