A catheter can include a shaft an inflatable balloon having a proximal end that is anchored to an end of the shaft an elongate member that is separate from and disposed inside the shaft, extends into an interior chamber of the balloon, and is anchored to a distal end of the balloon and a spring member that exerts a distally-oriented longitudinal force on the elongate member, relative to the shaft, where the distally-oriented longitudinal force causes the balloon to be biased in an extended position, away from the end of the shaft. The catheter can further include a sheath that surrounds the shaft and balloon before a treatment procedure. The balloon can be configured to be advanced outside the sheath during a treatment procedure and inflated, and the spring member can be configured to facilitate deflation and withdrawal of the balloon into the sheath following the procedure.
