A catheter comprising an inner tubular member having a proximal end portion, a distal end portion and an exterior surface, wherein the inner tubular member further has at least one fluid lumen having a fluid flow port defined by the exterior surface along the distal end portion of the inner tubular member； an outer tubular member movable relative to the inner tubular member, the outer tubular member having a proximal end, a distal end and an interior surface directed toward the exterior surface of the inner tubular member； an expandable device disposed on the expandable member； an expandable member coupled to the distal end portion of the inner tubular member, and having the expandable member transitionable between a deflated configuration and an inflated configuration； a proximal seal extending from the interior surface of the outer tubular member toward the exterior surface of the inner tubular member, the proximal seal located proximal to the fluid flow port； a distal seal extending from the exterior surface of the inner tubular member toward the interior surface of the outer tubular member, the distal seal located distal to the fluid flow port； and a pressure chamber defined by the proximal seal, the distal seal, the exterior surface of the inner tubular member and interior surface of the outer tubular member, with the pressure chamber in fluid communication with the fluid lumen by the fluid flow port, wherein fluid introduced from the fluid lumen through the fluid flow port and into the pressure chamber applies a force on the proximal seal to urge the outer tubular member in a proximal direction to expose the expandable device for deployment from the expandable member.
