A catheter includes a shaft extending from a proximal end to a distal end and a sheath which extends along the length of the catheter shaft. The sheath includes a compliant material and is expansile for fluid delivery from a distal end of the sheath to the proximal end of the catheter. The sheath is connected to a Luer on the proximal end of the catheter. Upon injection of fluid/particles through the Luer, the sheath expands to provide a temporary lumen which facilitates flow of fluid/particles from the proximal end of the catheter to an opening or opening adjacent to the distal end of the sheath and at or near the distal end of the catheter shaft for delivery of the fluid/particles into the vessel. Upon cessation of injection pressure, the sheath automatically contracts to provide a lower profile to easily accommodate repositioning/removal of the catheter.
