A pressure inhibitor for an intravascular catheter system includes a check valve and/or a pressure relief valve. The intravascular catheter system includes a handle assembly, an inner balloon, an outer balloon and a low pressure fluid line. The inner balloon and the outer balloon define an inter-balloon space therebetween. The low pressure fluid line extends between the handle assembly and the inter-balloon spaced The low pressure fluid line is in fluid communication with the inter-balloon space. The pressure inhibitor is positioned on the low pressure fluid line. The pressure inhibitor inhibits flow of a fluid to the inter-balloon space. The pressure inhibitor can be positioned within the handle assembly or outside of the handle assembly. A method of inhibiting flow of a fluid to the inter-balloon space includes positioning a pressure inhibitor on the low pressure fluid of an intravascular catheter system.
