Apparatus and methods provide
distal protection while accessing blood vessels within a patient's vasculature. A flexible sheath and
distal protection element, e.g., a
balloon or filter, are carried by a stiffening member. The sheath is lubricious and has a relatively
thin wall, thereby providing a collapsible / expandable guide for delivering fluids and / or instruments. The sheath is advanced into a
blood vessel in a contracted condition, expanded to an enlarged condition to define a lumen, and the
distal protection element is deployed within the vessel beyond the sheath. Fluids and / or instruments are introduced into the vessel via the sheath lumen, the distal protection element retaining the fluids and / or capturing emboli released by the instruments. Upon completing the procedure, the sheath, distal protection element, and stiffening member are removed from the vessel.