A system for use in a medical procedure includes a catheter defining a balloon lumen, at least one balloon that is secured to an outer surface of the catheter, and a regulator that is at least partially disposed within the balloon lumen. The regulator includes proximal and distal end portions, and defines a passage extending from the proximal end portion to the distal end portion. The distal end portion of the regulator includes an outer surface defining at least one opening that is in fluid communication with the passage. The at least one opening of the regulator is movable within the balloon lumen to control fluid communication between the passage and the at least one balloon.