An apparatus including a cannula having a dimension suitable for insertion into a blood vessel and an expandable body coupled thereto, the expandable body comprising a first expandable member and a second expandable member to isolate a length of the vessel upon expansion within the blood vessel. The expandable body having an intermediate expandable member along a working length between the first expandable member and the second expandable. A method including introducing a cannula and an expandable body coupled thereto into a blood vessel at a point coextensive with a treatment site and expanding a first expandable member and a second expandable member of the expandable body to isolate a length of the vessel adjacent the treatment site. The method further including delivering a treatment agent to a vessel region between the first expandable member and the second expandable member while inflating and deflating an intermediate expandable member.
