Patent ID: 7422579

Claim:
A method of treating a lesion within a blood vessel that supplies blood to the heart, comprising: placing a non-occluding guide catheter proximate the ostium of the blood vessel; inserting an evacuation sheath within the guide catheter, the evacuation sheath having proximal and distal ends, an evacuation lumen, and at least one sealing surface proximate the distal end, the sealing surface being configured to seal against an inner surface of the blood vessel; positioning the sealing surface within the blood vessel proximal to the lesion to be treated; inserting a dilation catheter into the evacuation sheath, the dilation catheter having a dilation balloon; advancing the dilation catheter into the blood vessel to a position where the dilation balloon is proximal to the lesion to be treated; prior to advancing the dilation balloon across the lesion to be treated, deploying the at least one sealing surface to occlude normal antegrade flow within the blood vessel adjacent to the lesion to be treated; advancing the dilation balloon across the lesion to be treated; dilating the lesion to be treated with the dilation balloon; and subsequent to dilating the lesion, using active suction to induce retrograde flow within the blood vessel.