A catheterization device with vents is disclosed which serves to prevent a build-up of air pressure within a closed protective sheath. The vents may be in the form of small openings and may be situated at the distal portion of the catheterization device. The small openings may optionally be covered. They may be on the protective sheath itself or they may be on a distal terminus body connected to the protective sheath. Sample openings include an attached valve which connects the inside of the protective sheath with the external environment, a gas permeable membrane, or a slitted membrane forming 4 flaps.