Abstract: A steerable intravascular catheter includes a handle assembly having opposed proximal and distal end portions and defining a longitudinal axis therebetween. An elongated sheath extending from the distal end portion of the handle assembly has opposed proximal and distal end portions, and includes a tubular body wall forming a central lumen for accommodating the introduction of a device and a fluid lumen radially outward from and parallel to the central lumen. The distal end portion of the elongated sheath is deflectable relative to the proximal end portion of the elongated sheath. A rotatable actuation assembly is associated with the handle assembly for controlling deflection of the distal end portion of the elongated sheath. An inflatable occlusion balloon is positioned on an outer surface of the distal end portion of the elongated sheath. The fluid lumen of the elongated sheath is in fluid communication with an interior of the balloon.