A medical device includes a catheter, an expandable balloon on the distal portion of the catheter, and a sheath that is configured to enclose and protect the expandable balloon. The sheath extends within a sheath lumen of the catheter and out from the catheter through a distal opening of the sheath lumen. When in a deployed configuration, the sheath extends proximally to enclose at least a portion of the expandable balloon. The sheath may be axially movable within the sheath lumen of the catheter to actuate from the deployed configuration to a retracted configuration. In moving to the retracted configuration, the sheath may expose the outer surface of the expandable balloon.