Apparatus and methods are described for effective removal of emboli or
harmful fluids during vascular procedures, such as angiography, balloon
angioplasty, stent deployment, laser angioplasty, atherectomy,
intravascular ultrasonography and other therapeutic and diagnostic
procedures. A catheter with an occluder mounted at its distal end creates
an occlusion proximal to the lesion. The catheter provides a pathway for
introducing a treatment catheter. Prior to, during or subsequent to the
procedure, suction is activated to establish retrograde flow to remove
emboli from the site. Additionally, a thin catheter with a distal fluid
ejection nozzle maybe introduced distal to the treatment site to rinse
emboli from the treatment site. The suction flow and/or ejected fluid
flow may be varied in a pulsatile manner to simulate regular blood flow
and/or perturb settled emboli into being captured that may otherwise not
be collected. The method establishes a protective environment before any
devices enter the site to be treated.