A storable gas inflation/evacuation system and sealing system. The systems
are removably connectible to a proximal portion of a guidewire assembly
which has an occlusive balloon at a distal portion. The invention
includes provision for indicating the presence of oxygen which is
undesirable. The storable aspect concerns a sealable container isolating
systems components from ambient atmosphere and an oxygen-sensitive
material located within the sealable container. The oxygen-sensitive
material is initially inactive but activated by exposure to radiation so
as to visually change in response to post-radiation oxygen exposure.