The instant invention encompasses a catheter, comprising: a first expandable occlusion device and a second expandable occlusion device, expandable beyond a wall of the catheter, the first occlusion device and the second occlusion device spaced along the catheter for generating an occluded segment of the blood vessel between the first occlusion device and the second occlusion device when the first occlusion device and the second occlusion device are expanded, a lumen or catheter for removing uncontaminated blood from a location up-stream of a first expandable occlusion device; a lumen or catheter for reintroducing the uncontaminated blood into a subject downstream from the second expandable occlusion device; apparati encompassing the above technology; and methods of use incorporating same.