A guidewire occlusion system for use in vascular procedures includes a repeatably inflatable gas-filled occlusive device proximate a distal end of a tubular guidewire assembly having an extended sealable section proximate a proximal end. A gas inflation/evacuation system is removably connectable to the proximal end of the guidewire assembly and includes an evacuation system to evacuate air from the guidewire and an inflation system for introducing a gas under pressure into the guidewire to inflate the occlusive balloon a plurality of times. A sealing system is also removably connectable to the proximal end of the guidewire assembly and selectively seals the extended sealable section at one of a plurality of separate locations along the extended sealable section to form an airtight seal of the tubular guidewire. Each time a deflation of the occlusive device is desired to reestablish blood flow to the vessel downstream of the occlusive device, the extended sealable section is opened distal to the location of the last seal to quickly deflate the occlusive device.