Abstract:
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.

Description:
CROSS REFERENCES TO RELATED APPLICATIONS 
     This patent application is a continuation-in-part of application Ser. No. 10/748,452 entitled “Packaging System with Oxygen Sensor” filed Dec. 30, 2003, now U.S. Pat. No. 7,219,799, which claims benefit from the earlier filed U.S. Provisional Application No. 60/437,624 entitled “Packaging System with Oxygen Sensor”, filed Dec. 31, 2002, and is hereby incorporated into this application by reference as if fully set forth herein. This patent application is also a continuation-in-part of application Ser. No. 10/838,464 filed May 4, 2004, now U.S. Pat. No. 7,220,243 entitled “Gas Inflation/Evacuation System and Sealing System Incorporating a Compression Sealing Mechanism for Guidewire Assembly Having Occlusive Device”, which application in turn is a continuation-in-part of application Ser. No. 10/007,788 filed Nov. 6, 2001, entitled “Gas Inflation/Evacuation System for Guidewire Having Occlusive Device”, now U.S. Pat. No. 6,942,678 issued Sep. 13, 2005, and which are incorporated by reference as if fully set forth herein, and also a continuation-in-part of application Ser. No. 10/012,903 filed Nov. 6, 2001, entitled “Guidewire Occlusion System Utilizing Repeatably Inflatable Gas-Filled Occlusive Device”, now U.S. Pat. No. 6,932,828 issued Aug. 23, 2005, also incorporated by reference as if fully set forth herein. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to the field of packaging of sterile or oxygen-sensitive products, such as medical products and food products. More particularly, the present invention is directed to methods and arrangements for packaging oxygen-sensitive items, whereby a change in appearance of a material visually indicates the presence of oxygen inside the packaging. Additionally, the present invention relates generally to the field of vascular medical devices. More specifically, the present invention relates to a gas inflation/evacuation system and sealing system for selectively and repeatedly inflating an occlusive balloon and crimping an extended sealable section proximate the proximal end of a guidewire assembly during an occlusion procedure. 
     2. Description of the Prior Art 
     In certain applications, such as pharmaceutical storage or food processing, it is desirable to package the product in a controlled atmosphere or environment to ensure freshness, to promote proper chemical activity, or to prevent microbial contamination. The controlled atmosphere can be an inert gas such as nitrogen or carbon dioxide, or it could be a noble gas. In some applications, the controlled environment could be a vacuum. In those applications where a controlled atmosphere or environment is desirable, it may be beneficial to be able to determine that the desired controlled atmosphere or environment has not been compromised. The presence of oxygen in a previously evacuated sample indicates that atmospheric penetration has occurred and that the controlled atmosphere has been compromised. Thus, oxygen detection is one method for determining if a controlled atmosphere has been breached. 
     In the medical and food processing industries, it may be desirable to sterilize medical and food products after these products have been placed inside containers with controlled environments. The medical and food processing industries have sterilized some appropriate products with gamma radiation. Gamma radiation, which can be derived from cobalt 60, is lethal to bacteria and other microorganisms due to the effect that the radiation has on living cells. In addition, gamma radiation can be detrimental to some chemical systems and compositions. The dose or amount of radiation absorbed is typically measured in either Megarads or Kilograys, where 1 Megarad is equivalent to 10 Kilograys. In general, a 2.5 Megarad, or 25 Kilogray, dose of gamma radiation can be sufficient to kill most microorganisms. 
     Gamma radiation is composed of high energy photons with wavelengths generally shorter than about 0.1 nm. Gamma radiation is emitted from atomic nuclei during radioactive decay and generally follows the ejection of beta rays from the nucleus. X-rays are similar to gamma rays in the sense that both are highly energetic and penetrating forms of radiation. However, gamma rays usually have shorter wavelengths than X-rays, and as a result, gamma rays are slightly higher in energy than X-rays. 
     As a result of the increased use of gamma radiation sterilization and packaging in controlled environments, there is a need for oxygen-sensitive materials that can be placed inside medical and food product containers which can detect the presence of oxygen after the container has been irradiated, and possibly sterilized, with gamma radiation. 
     Currently, there are several types of oxygen, and oxidation, sensors designed to be used in packaging applications. See, for example, U.S. Pat. No. 4,526,752 to Perlman et al., U.S. Pat. No. 5,096,813 to Krumhar et al., U.S. Pat. No. 6,399,387 to Stenhom et al., and U.S. Pat. No. 6,325,974 to Ahvenainen et al. However, none of these patents are directed toward oxygen-sensitive materials that are activated by radiation. Furthermore, the above mentioned sensors are not suitable to form component parts for other devices. With the volume of medical devices and food products being produced, it would be desirable to provide an oxygen sensor that was easily stored in oxygen-rich environments and could be activated upon exposure to gamma radiation in the absence of oxygen. 
     The following additional background may be of assistance in understanding the present invention. Arterial disease involves damage that happens to the arteries in the body. Diseased arteries can become plugged with thrombus, plaque, or grumous material that may ultimately lead to a condition known as ischemia. Ischemia refers to a substantial reduction or loss of blood flow to the heart muscle or any other tissue that is being supplied by the artery and can lead to permanent damage of the affected region. While arterial disease is most commonly associated with the formation of hard plaque and coronary artery disease in the heart, similar damage can happen to many other vessels in the body, such as the peripheral vessels, cerebral vessels, due to the buildup of hard plaque or softer thrombus or grumous material within the lumen of an artery or vein. 
     A variety of vascular medical devices and procedures have been developed to treat diseased vessels. The current standard procedures include bypass surgery (where a new blood vessel is grafted around a narrowed or blocked artery) and several different types of nonsurgical interventional vascular medical procedures, including angioplasty (where a balloon on a catheter is inflated inside a narrowed or blocked portion of an artery in an attempt to push back plaque or thrombotic material), stenting (where a metal mesh tube is expanded against a narrowed or blocked portion of an artery to hold back plaque or thrombotic material), and debulking techniques in the form of atherectomy (where some type of high speed or high power mechanism is used to dislodge hardened plaque) or thrombectomy (where some type of mechanism or infused fluid is used to dislodge grumous or thrombotic material). In each of these interventional vascular medical procedures, a very flexible guidewire is routed through the patient&#39;s vascular system to a desired treatment location and then a catheter that includes a device on the distal end appropriate for the given procedure is tracked along the guidewire to the treatment location. 
     Although interventional vascular procedures avoid many of the complications involved in surgery, there is a possibility of complications if some of the plaque, thrombus or other material breaks free and flows downstream in the artery or other vessel, potentially causing a stroke, a myocardial infarction (heart attack), or other tissue death. One solution to this potential complication is to use some kind of occlusive device to block or screen the blood flowing downstream of the treatment location. Examples of catheter arrangements that use a pair of balloons as occlusive devices to create an isolated space in the blood vessel are described in U.S. Pat. Nos. 4,573,966, 4,636,195, 5,059,178, 5,320,604, 5,833,644, 5,925,016, 6,022,336 and 6,176,844. Examples of catheter arrangements that use a single balloon as an occlusive device either upstream or downstream of the treatment location are described in U.S. Pat. Nos. 5,171,221, 5,195,955, 5,135,482, 5,380,284, 5,688,234, 5,713,917, 5,775,327, 5,792,179, 5,807,330, 5,833,650, 5,843,022, 6,021,340, 6,159,195 and 6,248,121. An example of a catheter arrangement that uses a mechanically-expanded occlusive device is shown in U.S. Pat. No. 6,231,588. Occlusive balloons also have been used on non-over-the-wire catheters without any guidewire internal to the catheter as described, for example, in U.S. Pat. Nos. 4,838,268 and 5,209,727. 
     The use of an occlusive device as part of a vascular procedure is becoming more common in debulking procedures performed on heart bypass vessels. Most heart bypass vessels are harvested and transplanted from the saphenous vein located along the inside of the patient&#39;s leg. The saphenous vein is a long, straight vein that has a capacity more than adequate to support the blood flow needs of the heart. Once transplanted, the saphenous vein is subject to a buildup of plaque or thrombotic materials in the grafted arterial lumen. Unfortunately, the standard interventional vascular treatments for debulking are only moderately successful when employed to treat saphenous vein coronary bypass grafts. The complication rate for a standard balloon angioplasty procedure in a saphenous vein coronary bypass graft is higher than in a native vessel with the complications including embolization, “no-reflow” phenomena, and procedural related myocardial infarction. Atherectomy methods including directional, rotational, and laser devices are also associated with a high degree of embolization resulting in a greater likelihood of infarction. The use of stents for saphenous vein coronary bypass grafts has produced mixed results. Stents provide for less restenosis, but they do not eliminate the risk of embolization and infarction incurred by standard balloon angioplasty. 
     In order to overcome the shortcomings of these standard nonsurgical interventional treatments in treating saphenous vein coronary bypass graft occlusion, embolic protection methods utilizing a protective device distal to the lesion have been developed. The protective device is typically a filter or a balloon. Use of a protective device in conjunction with an atherectomy or thrombectomy device is intended to prevent emboli from migrating beyond the protective device and to allow the embolic particles to be removed, thereby subsequently reducing the risk of myocardial infarction. When the occlusive device is a balloon, the balloon is inserted and inflated at a point distal to the treatment site or lesion site. Therapy is then performed at the treatment site and the balloon acts to block all blood flow which prevents emboli from traveling beyond the balloon. Following treatment, some form of particle removal device must be used to remove the dislodged emboli prior to balloon deflation. U.S. Pat. No. 5,843,022 uses a balloon to occlude the vessel distal to a lesion or blockage site. The occlusion is treated with a high pressure water jet, and the fluid and entrained emboli are subsequently removed via an extraction tube. U.S. Pat. No. 6,135,991 describes the use of a balloon to occlude the vessel allowing blood flow and pressure to prevent the migration of emboli proximally from the treatment device. 
     There are various designs that have included an occlusive balloon on the end of a guidewire. U.S. Pat. Nos. 5,520,645, 5,779,688 and 5,908,405 describe guidewires having removable occlusive balloons on a distal end. U.S. Pat. No. 4,573,470 describes a guidewire having an occlusive balloon where the guidewire is bonded inside the catheter as an integral unit. U.S. Pat. Nos. 5,059,176, 5,167,239, 5,520,645, 5,779,688 and 6,050,972 describe various guidewires with balloons at the distal end in which a valve arrangement is used to inflate and/or deflate the balloon. U.S. Pat. No. 5,908,405 describes an arrangement with a removable balloon member that can be repeatedly inserted into and withdrawn from a guidewire. U.S. Pat. No. 5,776,100 describes a guidewire with an occlusive balloon adhesively bonded to the distal end with an adapter on the proximal end to provide inflation fluid for the occlusive balloon. 
     Except in the case of the normal cerebral anatomy where there are redundant arteries supplying blood to the same tissue, one of the problems with using an occlusive device in the arteries is that tissue downstream of the occlusive device can be damaged due to the lack of blood flow. Consequently, an occlusive device that completely blocks the artery can only be deployed for a relatively short period of time. To overcome this disadvantage, most of the recent development in relation to occlusive devices has focused on devices that screen the blood through a filter arrangement. U.S. Pat. Nos. 5,827,324, 5,938,672, 5,997,558, 6,080,170, 6,171,328, 6,203,561 and 6,245,089 describe various examples of filter arrangements that are to be deployed on the distal end of a catheter system. While a filter arrangement is theoretically a better solution than an occlusive device, in practice such filter arrangements often become plugged, effectively turning the filter into an occlusive device. The filter arrangements also are mechanically and operationally more complicated than an occlusive balloon device in terms of deployment and extraction. 
     As is the case in almost all angioplasty devices or stenting catheter devices where a balloon is used to expand the blood vessel or stent, most catheter occlusive balloons, as well as most guidewire occlusive balloons, utilize a liquid fluid, such as saline or saline mixed with a radiopaque marker, for fluoroscopic visualization (i.e., contrast) as the inflation medium. Generally, a liquid fluid medium for expanding vascular balloons has been preferred because the expansion characteristics of a liquid are more uniform and predictable, and because a liquid medium is easier to work with and more familiar to the doctors. In the case of angioplasty balloons, for example, high pressure requirements (up to 20 atmospheres) necessitate that the inflation fluid be an incompressible fluid for safety reasons. While having numerous advantages, liquid fluids do not lend themselves to rapid deflation of an occlusive balloon because of the high resistance to movement of the liquid in a long small diameter tube. In the context of angioplasty procedures, the balloon catheter has a much larger lumen than a guidewire. Consequently, rapid deflation is possible. In the context of a guidewire, however, liquid-filled occlusive balloons typically cannot be deflated in less than a minute and, depending upon the length of the guidewire, can take up to several minutes to deflate. Consequently, it is not practical to shorten the period of total blockage of a vessel by repeatedly deflating and then re-inflating a liquid-filled occlusive balloon at the end of a guidewire. 
     Gas-filled balloons have been used for intra-aortic occlusive devices where rapid inflation and deflation of the occlusive device is required. Examples of such intra-aortic occlusive devices are shown in U.S. Pat. Nos. 4,646,719, 4,733,652, 5,865,721, 6,146,372, 6,245,008 and 6,241,706. While effective for use as an intra-aortic occlusive device, these occlusive devices are not designed for use as a guidewire as there is no ability to track a catheter over the intra-aortic occlusive device. 
     An early catheter balloon device that utilized a gas as an inflation medium and provided a volume limited syringe injection system is described in U.S. Pat. No. 4,865,587. More recently, a gas-filled occlusive balloon on a guidewire is described as one of the alternate embodiments in U.S. Pat. No. 6,217,567. The only suggestion for how the guidewire of the alternate embodiment is sealed is a valve-type arrangement similar to the valve arrangement used in a liquid fluid embodiment. A similar gas-filled occlusive balloon has been described with respect to the Aegis Vortex™ system developed by Kensey Nash Corporation. In both U.S. Pat. No. 6,217,567 and the Aegis Vortex™ system, the gas-filled occlusive balloon is used for distal protection to minimize the risk of embolization while treating a blocked saphenous vein coronary bypass graft. Once deployed, the occlusive balloon retains emboli dislodged by the atherectomy treatment process until such time as the emboli can be aspirated from the vessel. No specific apparatus are shown or described for how the gas is to be introduced into the device or how the occlusive balloon is deflated. 
     Although the use of occlusive devices has become more common for distal embolization protection in vascular procedures, particularly for treating a blocked saphenous vein coronary bypass graft, all of the existing approaches have significant drawbacks that can limit their effectiveness. Liquid-filled occlusive balloons can remain in place too long and take too long to deflate, increasing the risk of damages downstream of the occlusion. Occlusive filters are designed to address this problem, but suffer from blockage problems and can be complicated to deploy and retrieve and may allow small embolic particles to migrate downstream. Existing gas-filled occlusive balloons solve some of the problems of liquid-filled occlusive balloons, but typically have utilized complicated valve and connection arrangements. It would be desirable to provide for an occlusive device that was effective, simple, quick to deploy and deflate, and that could overcome the limitations of the existing approaches. 
     It would be even more desirable if a medical device, such as an inflation/deflation system and a sealing system for occlusive balloons which systems are intended for use with a biocompatible gas and intended to avoid oxygen exposure could be stored and then used with confidence that they have not been exposed to oxygen. Moreover, it would be still more desirable if any unintended oxygen exposure could be readily visually detected immediately upon opening a sealed container in the course of medical treatment. 
     SUMMARY OF THE INVENTION 
     In some embodiments, the present invention is directed toward a method and packaging system or storage arrangement including a container and an oxygen-sensitive material that is suitable for detecting the presence of oxygen inside the container after the container has been irradiated with radiation. In addition, at least some of the oxygen-sensitive materials of the present invention can be incorporated into component parts for some other devices, such as medical devices. By using the oxygen-sensitive material as a component piece of a medical device, or other device, the device itself becomes an oxygen indicator, thereby removing any ambiguity regarding the contact of the device with the ambient atmosphere. Furthermore, some of the oxygen-sensitive materials of the present invention can be stored in oxygen-rich environments because they do not become “active” until the oxygen-sensor material has been exposed to radiation. In some embodiments, the oxygen-sensitive materials are activated in an oxygen-free environment. As used in this application, the term “activated” or “active” means that the oxygen-sensitive material will undergo a visual change when exposed to oxygen. Thus, the present invention creates an effective storage arrangement having means for detecting the presence of oxygen, and ultimately for determining a failure in packaging, in applications involving radiation sterilization. 
     In one embodiment of the present invention, a sealable container adapted to isolate the contents thereof from the ambient atmosphere is provided with an oxygen-sensitive material located within the sealable container. The oxygen-sensitive material can be any material that undergoes a visual change when in contact with oxygen after the oxygen-sensitive material has been irradiated with gamma radiation in an oxygen-free environment. 
     In another embodiment of the present invention, a medical device is provided that contains a structural element which is composed of an oxygen-sensitive polymeric material. The oxygen-sensitive polymeric material will visually indicate if the medical device has been exposed to oxygen. Thus, in this embodiment of the present invention, the product, i.e., the medical device and the oxygen-sensitive material, is a single unit. In a further embodiment of the present invention, a medical device comprising a polycarbonate material is provided. The polycarbonate material used in this embodiment of the present invention will visually indicate the presence of oxygen after being irradiated with gamma radiation if oxygen is present. 
     In a method according to the present invention, an oxygen-sensitive storage arrangement is produced by placing an oxygen-sensitive material inside a sealable container. The oxygen-sensitive material can be any material that undergoes a visual change with oxygen after the oxygen-sensitive material has been irradiated with radiation. The atmospheric contents of the sealable container are then removed and the sealable container is sealed to isolate the oxygen-sensitive material inside the sealable container. The sealable container is then irradiated with an effective amount of radiation so that the oxygen-sensitive material will undergo a visual change if the oxygen-sensitive material contacts oxygen. 
     In another embodiment, the present invention is a gas inflation/evacuation system and sealing system for use with occlusive devices in vascular procedures. The gas inflation/evacuation system is removably connectible to the proximal end of a tubular guidewire assembly that has a distal portion and a proximal portion with an extended sealable section and includes an evacuation syringe to evacuate the tubular guidewire assembly and an inflation syringe or syringes for introducing a gas under pressure into the tubular guidewire assembly to inflate an occlusive balloon or other occlusive device proximate the distal end of the tubular guidewire assembly a plurality of times. A sealing system is also removably connectible to the proximal end of the tubular guidewire assembly and selectively seals the tubular guidewire assembly at one of a plurality of separate locations along the extended sealable section to form an airtight seal of the tubular guidewire assembly. Each time a deflation of the occlusive balloon is desired in order to reestablish blood flow to the vessel downstream of the occlusive balloon, the proximal end of the extended sealable section preferably is cut distal to the location of the last seal to quickly deflate the occlusive balloon. 
     The advantage of the gas inflation/evacuation system and sealing system of the present invention is that the occlusive device can be repeatably inflated and deflated a plurality of times during a vascular procedure in between which the proximal end of the tubular guidewire assembly is free of mechanical connections and obstructions and, therefore, the tubular guidewire assembly can function as a conventional exchange guidewire assembly for one or more over-the-wire catheters. Alternatively, the tubular guidewire assembly can be shorter in length for use with rapid exchange catheter systems. Unlike operation of existing liquid-filled occlusive devices, the present invention enables repeated and quick inflation and deflation which allows an operator to deploy the gas-filled occlusive device numerous times during a procedure for shorter periods of time, thereby reducing the risk of potential damage to downstream tissue. Unlike operation of other gas-filled occlusive devices, the simplicity of the present invention permits the tubular guidewire assembly to be used as a conventional exchange guidewire assembly. There are no complicated mechanical arrangements or valve systems internal to the tubular guidewire assembly that increase the cost, complexity, and potential for failure of the system. 
     In another preferred embodiment, the extended sealable section is an extended crimpable section and the sealing system includes a crimping mechanism. The extended crimpable section has a sufficient length to permit a plurality of crimps and cuts along the extended crimpable section and preferably has an outer diameter that is smaller than the outer diameter of the main body portion of the guidewire assembly. The crimping mechanism is used to crimp the extended crimpable section of the guidewire assembly to seal the guidewire assembly a plurality of times. Preferably, the gas inflation/evacuation system and the crimping mechanism and sealing mechanism of the sealing system constitute a handheld apparatus. Each time a deflation of the occlusive device is desired in order to reestablish blood flow to the vessel downstream of the occlusive device, the extended crimpable section is cut distal to the location of the last crimp so as to quickly deflate the occlusive device. Preferably, the extended crimpable section of the guidewire assembly is dimensioned and the crimping mechanism is arranged such that an effective outer diameter of the extended crimpable section at the location of a seal is no greater than the outer diameter of the main body portion of the guidewire assembly when the extended crimpable section is sealed. 
     In another alternate embodiment, the sealing mechanism is a plugging mechanism that selectively inserts a plug of material into the proximal end of the extended sealable section while maintaining an airtight seal between the guidewire assembly and the gas inflation/evacuation system. In one embodiment, the plug of material includes a wax/gel material and the sealing system includes wiping structure to remove excess wax/gel material from the outside of the extended sealable section once the wax/gel material has been inserted. In this embodiment, the extended sealable section may be opened either by cutting the extended sealable section distal to the location of the seal or by heating the proximal end of the extended sealable section. 
     In one embodiment for coronary vascular procedures, the guidewire assembly preferably has an effective length of at least 40 cm and more preferably at least 100 cm and an outer diameter of less than 0.060 inch and more preferably less than 0.018 inch, the extended sealable section has an effective length of at least 1 cm and more preferably at least 5 cm and an outer diameter of less than 0.050 inch and more preferably less than 0.012 inch, and the occlusive device (balloon) is deflated in less than two minutes and more preferably less than one minute. This embodiment is particularly adapted to provide distal embolization protection in debulking vascular interventional procedures, such as those involving a blocked saphenous vein coronary bypass graft. Alternatively, the guidewire assembly may be configured and dimensioned for use in peripheral vascular procedures or neurovascular procedures. 
     In a preferred embodiment, the inflation system of the gas inflation/evacuation system includes a plurality of individually actuatable syringes each containing a sufficient volume of biocompatible gas for a single inflation of the occlusive device so as to minimize the volume of biocompatible gas in the gas inflation/evacuation system in the event of a leak. The preferred embodiment is packaged in a sterile packaging that is assembled and packaged in a sealed chamber filled with a biocompatible gas such that any gas within the sterile packaging once packaged is only the biocompatible gas. In a particularly preferred embodiment, inflation/deflation systems and sealing systems are packaged in a container with the capability to detect undesired oxygen exposure, especially post radiation-sterilization, when a seal has been presumed to be effective. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Other objects of the present invention and many of the attendant advantages of the present invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, in which like reference numerals designate like parts throughout the figures thereof and wherein: 
         FIG. 1  is a schematic perspective view of one embodiment of a storage arrangement according to the present invention where a container and an oxygen-sensitive material are provided and where structures within the container have been made visible while hidden edges of the container are shown with phantom lines; 
         FIG. 2  is a side view of an oxygen-sensitive material attached to a background material that enhances the visual change of the oxygen-sensitive material; 
         FIG. 3  is a perspective view of one embodiment of a storage container of the present invention; 
         FIG. 4  is a view of a resealable container that can be used in the present invention; 
         FIG. 5  is a view of a foil pouch showing a plastic coating that can be heated to seal the foil pouch; 
         FIGS. 6 ,  6   a  and  6   b  are top views of two distal occlusion inflation devices each containing a component piece comprising an oxygen-sensitive material, with the device of  FIG. 6   b  having just been exposed to air and with the device of  FIG. 6   a  having been exposed to air for one week and thereby illustrating the color change associated with an oxygen-sensitive material of the present invention; 
         FIGS. 7 ,  7   a  and  7   b  are top views of two crimper devices that show a visual change associated with one embodiment of the present invention, with the device of  FIG. 7   b  having just been exposed to air and with the device of  FIG. 7   a  having been exposed to air for one week; 
         FIG. 8  is a schematic diagram of a guidewire occlusion system incorporating the present invention and operating in an evacuation mode; 
         FIG. 9  is a schematic diagram of the guidewire occlusion system shown in  FIG. 8  operating in an inflation mode; 
         FIG. 10   a  is a side view of the guidewire assembly shown in  FIG. 8 , and  FIG. 10   b  is an enlarged view of the portion of  FIG. 10   a  delineated by the circle  10   b;    
         FIGS. 11   a  and  11   b  are fragmentary cross sectional views of different manners of joining the extended sealable section to the main body portion at the proximal portion of the guidewire assembly of  FIG. 10   a;    
         FIGS. 12-14  are perspective views of three alternate embodiments of gas inflation/evacuation systems and the sealing systems used therewith; 
         FIG. 15  is an exploded view of the gas inflation/evacuation system of the alternate embodiment shown in  FIG. 14  and the associated sealing system; 
         FIG. 16  is a perspective view of the sealing system illustrated with the alternate embodiment shown in  FIG. 14 ; 
         FIG. 17  is a top view of a preferred embodiment of a gas inflation/evacuation system and sealing system of the present invention; 
         FIG. 18  is a perspective view of another alternate embodiment of a gas inflation/evacuation system and sealing system; 
         FIG. 19  is an end view of a crimping mechanism; 
         FIGS. 20 and 21  are two sectional views of the crimping mechanism of  FIG. 19 ,  FIG. 21  being a view taken along the line  21 - 21  of  FIG. 19 , and  FIG. 20  being a magnification of the portion of  FIG. 21  indicated by the dashed circle; 
         FIG. 22  is a cross sectional view of an alternate embodiment of a sealing system showing one embodiment of a plugging mechanism; 
         FIG. 23  is a schematic view of equipment including a sealed chamber for use in assembling and packaging the guidewire occlusion system; 
         FIG. 24  is a side view of a biocompatible packaging; 
         FIG. 25  is an exploded view of still another alternate embodiment of a gas inflation/evacuation system and sealing system; and, 
         FIG. 26  is a partially exploded view of the alternate embodiment of  FIG. 18  including the entire joinable housing assembly thereof. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     In one embodiment of the present invention, a packaging system or storage arrangement is provided that comprises a sealable container adapted to isolate the contents of the sealable container from the ambient atmosphere. In this embodiment, an oxygen-sensitive material is located inside the sealable container. The oxygen-sensitive material can undergo a visual change upon contact with oxygen after the oxygen-sensitive material has been irradiated with radiation in the absence of oxygen. In one embodiment, the visual change is a color change. In some embodiments, the sealable container can isolate a medical product from the ambient atmosphere, while in other embodiments the sealable container can isolate a food product. In one embodiment, the sealable container isolates a distal occlusion inflation device from the ambient atmosphere. In some embodiments, the oxygen-sensitive material comprises a polycarbonate material. In one embodiment, the polycarbonate material comprises Dow Calibre® 2081 polycarbonate material. In some embodiments, the sealable container is resealable, while in other embodiments the sealable container is not resealable. In some embodiments, the sealable container is substantially free of oxygen. In one embodiment, the sealable container is a foil pouch. 
     In another embodiment of the present invention, a medical device comprising a structural element is provided. The structural element comprises an oxygen-sensitive polymeric material that can visually indicate if the medical device has been exposed to oxygen. In one embodiment, the medical device is a distal occlusion inflation device. In some embodiments, the oxygen-sensitive polymeric material can visually indicate the presence of oxygen after the oxygen-sensitive polymeric material has been irradiated by an effective amount of radiation. In one embodiment, the oxygen-sensitive polymeric material comprises Dow Calibre® 2081. In some embodiments, the radiation is gamma radiation, while in other embodiments the radiation is X-ray radiation. When the oxygen-sensitive polymeric material comprises Dow Calibre® 2081, an effective amount of gamma radiation is from about 25 Kilograys to about 45 Kilograys. In some embodiments, the structural element is attached to a background material which enhances visibility of the visual indication of the presence of oxygen. 
     In another embodiment, a storage arrangement comprising a sealable container and an oxygen-sensitive material is provided. In this embodiment, the oxygen sensitive material will not function as an oxygen detector until the oxygen-sensitive material has been activated. In some embodiments, the oxygen-sensitive material can be activated by irradiating the oxygen-sensitive material with radiation in an oxygen-free environment. In one embodiment, the oxygen-sensitive material is activated by irradiating the material with gamma radiation. 
       FIG. 1  shows schematically one embodiment of a packaging system or storage arrangement according to the present invention. As shown in  FIG. 1 , a sealable container  101  (depicted representatively) isolates a product  103  (also depicted representatively) from the ambient atmosphere  104 . An oxygen-sensitive material  102  (illustrated representatively) is located inside the sealable container. The oxygen-sensitive material  102  can visually indicate the presence of oxygen inside the sealable container  101 . In one embodiment, the visual indication of the presence of oxygen will be a change in color of the oxygen-sensitive material  102 . The oxygen-sensitive material  102  of the present invention can be any material that will visually indicate the presence of oxygen after the oxygen-sensitive material  102  has been irradiated by radiation. A suitable choice for the oxygen-sensitive material  102  is a polycarbonate resin manufactured by Dow Chemical Company and sold under the trademark Dow Calibre® 2081. In one embodiment, when the oxygen-sensitive material  102  comprises Dow Calibre® 2081, the oxygen-sensitive material  102  will visually indicate the presence of oxygen after being irradiated with gamma radiation. A suitable amount of gamma radiation has been found to be from about 25 Kilograys to about 45 Kilograys. In other embodiments, the radiation used can be X-ray radiation. 
     The oxygen-sensitive material  102  as shown representatively in  FIG. 1  can be formed into any desirable shape for use in the present invention. In one embodiment, the shape of the oxygen-sensitive material is a rectangular chip. As shown in  FIG. 2 , the oxygen-sensitive material  102  optionally can be attached to a background material  110  to enhance the visibility of the visual change of the oxygen-sensitive material  102 . The background material can be composed of metal, plastic, paper, or any other suitable material that will enhance the visibility of the visual change. For example, a blue background material would make a yellow indicator appear green. Potential background materials could also have the word “exposed” written across the background material in a color such that upon contact with oxygen, the word “exposed” would become visible. As another option, the oxygen-sensitive material can be arranged to form at least one symbol that assists in interpreting the visual change of the oxygen-sensitive material. In embodiments that employ a background material  110 , the background material  110  can be attached to the oxygen-sensitive material  102  through the use of generally known adhesives or mechanical fasteners. 
     The sealable container of the present invention as shown representatively at  101  in  FIG. 1  can be composed of any substance that will transmit radiation and that is impermeable to gas, especially oxygen. Examples of suitable materials for the container are metals, glass, gas-impermeable plastics, gas-impermeable thermosets and rubbers, and gas-impermeable foil pouches. In one embodiment, the sealable container is a foil pouch of multi-layer construction comprising a silicone oxide treated PET layer, a foil layer, a biaxially oriented nylon layer, and a polyethylene layer. The gas-impermeable plastic containers of the present invention can be either rigid or flexible. Suitable plastic materials for the gas-impermeable plastic containers include, but are not limited to, gas-impermeable polyethylenes, polystyrenes, polycarbonates, nylons and polyethylene terephthalates. Potential thermoset and rubber materials for the sealable containers include gas-impermeable phenol formaldehydes, urea formaldehydes, natural rubbers and nitrile rubbers. 
     The sealable container  101  shown representatively in  FIG. 1  can be sealed by any conventional means known to be used in the packaging industries including thermal seals, adhesive seals, or airtight mechanical closures such as caps or lids; and the sealable container can be a container that is resealable or a container that is not resealable. As shown in  FIG. 3 , one specific embodiment of the sealable container  101  shown in  FIG. 1  is a gas-impermeable foil pouch  105  with a protective cardboard packaging  106 .  FIG. 4  shows another example comprising a resealable pouch  112  with closure means  114  on at least one end of the resealable pouch  112  that permits the resealable pouch  112  to be optionally resealed. When the sealable container is a gas-impermeable foil pouch  105 , a heat sealer can be used to heat plastic coatings located on the inside top and bottom of the foil pouch.  FIG. 5  shows one embodiment of foil pouch  105  with plastic coatings  116  located on the inside top and bottom of the foil pouch  105 . Heating will cause the plastic coatings on the top and bottom to flow together and seal the foil pouch  105 . 
     The product  103  contained within the sealable container  101  can be any product in which a controlled oxygen-free environment is desirable or necessary. Suitable products for the present invention include, but are not limited to, medical devices, pharmaceuticals, and food products. 
     In one embodiment, a storage arrangement is provided that comprises a sealable container  101  and an oxygen-sensitive material. In this embodiment, the oxygen-sensitive material will not function as an oxygen indicator until the oxygen-sensitive material has been activated. One method of activating the oxygen-sensitive material is by irradiating the material. In some embodiments, suitable forms of radiation for activating the oxygen-sensitive material include gamma radiation and X-ray radiation. In one embodiment, the oxygen-sensitive material comprises Dow Calibre® 2081 polycarbonate resin. When the oxygen-sensitive material comprises Dow Calibre® 2081, a dose of gamma radiation from about 25 Kilograys to about 45 Kilograys will activate the material. While not wanting to be limited to a particular theory, it is believed that the oxygen-sensitive property of the Dow Calibre® 2081 material is likely due to the dye used to color the material or the stabilizers used to protect the material from degradation. 
     In another embodiment of the present invention, a medical device within a container contains a component piece that is composed of an oxygen-sensitive polymeric material.  FIGS. 6   a  and  6   b  show one possible embodiment where a medical device  107  has a component piece that is composed of an oxygen-sensitive polymeric material. The medical device  107  is a distal occlusion inflation device available under the trademark GuardDOG which uses CO 2  as the inflation medium and which generally comprises a main body  108  and a crimper device  109 . In this embodiment, both the crimper device  109  and the main body  108  are composed of an oxygen-sensitive polymeric material. One reason for using an oxygen-sensitive polymeric material in this application is because the inflation medium needs to be relatively free from oxygen in order to prevent the release of oxygen or ambient air into the blood stream in the event that the distal occlusion inflation device would burst, thereby causing a potential embolism. By using CO 2  as the inflation medium, the inflation gas can be easily absorbed into the blood stream in the event that the inflation device fails. The oxygen-sensitive polymeric material permits the operator to confirm that the gas within the device that will be used to inflate the inflation device does not include any significant amount of oxygen prior to the use of the device. 
     In one embodiment, the oxygen-sensitive polymeric material is composed of Dow Calibre® 2081 polycarbonate resin. When a medical device with an oxygen-sensitive polymeric component piece comprising Dow Calibre® 2081 is irradiated with gamma radiation, in the absence of oxygen, the oxygen-sensitive material becomes activated and will undergo a visual change if oxygen contacts the material. In one embodiment, the visual change, or indication, is a color change. It has been found that from about 25 Kilograys to about 45 Kilograys of gamma radiation will activate Dow Calibre® 2081. 
     An example of the visual change, which indicates the presence of oxygen, associated with this embodiment of the present invention can be seen in  FIGS. 6   a  and  6   b  by comparing the color of the main body  108  and the crimper device  109  of the medical device  107  shown in  FIG. 6   a  with the color of the main body  108  and the crimper device  109  of the medical device  107  shown in  FIG. 6   b , the stippling in  FIG. 6   a  representing a change in color from the showing in  FIG. 6   b.  The elapsed time, after exposure to oxygen, before a visible change can be detected is generally 1-8 hours, preferably 1-2 hours. As shown by  FIGS. 6   a  and  6   b , when a component piece of a medical device is composed of an oxygen-sensitive polymeric material, the device itself becomes an oxygen indicator, and any ambiguity about whether the device has been exposed to oxygen is removed. 
     The method for producing the storage arrangement of the present invention involves placing an oxygen-sensitive material  102 , for example, Dow Calibre® 2081 polycarbonate resin, inside a gas-impermeable sealable container  101 . In some embodiments, a product  103 , such as, for example, a medical product or food product, will also be placed into the sealable container  101 . In one embodiment, the sealable container is a foil pouch  105 . As discussed above, the oxygen-sensitive material  102  can be any material that visually indicates the presence of oxygen after exposure to radiation. As discussed above, the oxygen-sensitive material  102  can comprise a polycarbonate resin. Furthermore, the oxygen-sensitive material  102  may be formed into any desired shape or size depending upon the application. 
     Before being placed inside the sealable container, the oxygen-sensitive material  102  optionally can be attached to a background material  110  to enhance the visibility of the visual change. In addition, the oxygen-sensitive material  102 , and the optional background material  110 , can be either fixed inside the container or can be free-moving inside the container. By fixed inside the sealable container  101 , it is meant that the oxygen-sensitive material  102  is directly attached to the inside of the sealable container  101 . In embodiments where the oxygen-sensitive material is fixed inside the sealable container  101 , any conventional method of attachment, including adhesives and mechanical fasteners, may be used that does not interfere with the function of the oxygen-sensitive material  102 . Conversely, the term “free-moving” is intended to describe embodiments of the present invention where the oxygen-sensitive material  102  is not attached directly to the inside of the sealable container  101 . 
     The atmospheric contents of the sealable container  101  are then removed by either vacuum or by purging the sealable container  101  with an inert gas such as nitrogen, carbon dioxide, argon or helium. In one embodiment, a vacuum is used to remove the atmospheric contents because a higher percent of oxygen, or atmospheric gas, can be removed in a shorter period of time as compared to purging. If the atmospheric contents of the container are removed by a vacuum, the sealable container  101  may be subsequently filled with an inert gas. In some embodiments, the ability of the oxygen-sensitive materials  102  to visually indicate the presence of oxygen is not dependent upon the choice of inert gas used as the controlled environment. Furthermore, the oxygen-sensitive materials  102  of the present invention can also function in applications where the controlled environment is a vacuum. 
     Once the atmospheric contents have been removed from the sealable container  101 , the sealable container  101  will be substantially free of oxygen. As described above, the sealable container  101  can be filled with a substantially oxygen-free gas. The substantially oxygen-free gas can be nitrogen, helium, argon, carbon dioxide or some other inert gas. In some embodiments, the sealable container  101  is not filled with a substantially oxygen-free gas, and in those embodiments the controlled inert environment is a vacuum. The sealable container  101  is then sealed to isolate the oxygen-sensitive material  102  from the ambient atmosphere. As noted above, the sealable container  101  may be sealed by any conventional means known in the packaging industry including, but not limited to, thermal, adhesive or mechanical closures. In embodiments where the sealable container is a foil pouch  105 , a heat press can be used to seal the foil pouch. The choice of sealing means will generally be determined by the particular choice of container being employed in a specific application. 
     The sealed container, including any contents or products contained within the sealed container, can then be irradiated with an effective amount of radiation to activate the oxygen-sensitive material  102 . As discussed above, the sealable container can isolate foods, medical devices, pharmaceuticals, or other products from the ambient atmosphere. In some embodiments, the radiation used to activate the oxygen-sensitive material  102  is gamma radiation. In other embodiments of the present invention, the radiation used to activate the oxygen-sensitive material is X-ray radiation. In one embodiment, where the oxygen-sensitive material comprises Dow Calibre® 2081, an effective amount of gamma radiation to activate the oxygen-sensitive material has been found to be from about 25 Kilograys to about 45 Kilograys. 
     In the embodiment of the present invention where the oxygen-sensitive material  102  is Dow Calibre® 2081, the gamma radiation can visually change the oxygen-sensitive material  102  from a purple color to a yellow-gray color. In this embodiment, once this color change has occurred, the oxygen-sensitive material  102  has been activated. Once activated, the Dow Calibre® 2081 material will undergo a visual color change when exposed to oxygen. Prior to being activated, some of the oxygen-sensitive materials  102  of the present invention will not undergo a visual change when exposed to oxygen. As a result, some of the unactivated oxygen-sensitive materials of the present invention can be handled and stored in oxygen-rich environments. This feature of the oxygen-sensitive materials of the present invention facilitates easier storage and processing of the sensor materials as compared to other chemical oxygen indicators.  FIGS. 7   a  and  7   b  show one example of a visual change associated with one embodiment of the present invention involving crimper devices  109  formed of oxygen-sensitive material where the oxygen-sensitive material comprises Dow Calibre® 2081. The crimper device  109  shown in  FIG. 7   a  has been exposed to oxygen for one week, while the crimper device  109  shown in  FIG. 7   b  has just been removed from a substantially oxygen-free environment. The stippling in  FIG. 7   a  represents a change in color from the showing in  FIG. 7   b.    
     The embodiments are intended to be illustrative and not limiting. Additional embodiments are within the claims. Although the present invention has been described with reference to particular embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and the scope of the invention. 
     Referring now to  FIGS. 8 and 9 , the overall structure and operation of a guidewire occlusion system  20  incorporating the present invention will be described. The guidewire occlusion system  20  includes a guidewire assembly  22 , a sealing system  60 , and a gas inflation/evacuation system  80 . The preferred embodiments of the overall guidewire occlusion system  20  are described in further detail in the previously identified co-pending application Ser. No. 10/012,903 entitled “Guidewire Occlusion System Utilizing Repeatably Inflatable Gas-Filled Occlusive Device” filed Nov. 6, 2001, patented Aug. 23, 2005, as U.S. Pat. No. 6,932,828. 
     Guidewire assembly  22  is a tubular member that includes a proximal portion  24  and a distal portion  26 . As used in the present invention, the terms proximal and distal will be used with reference to an operator, such that a distal portion of the guidewire assembly  22 , for example, is the portion first inserted into a blood vessel, and the proximal portion remains exterior to the patient and is therefore closer to the operator. An extended sealable section  28  is provided proximate the proximal portion  24  of guidewire assembly  22 . Preferably, the extended sealable section  28  is an extended crimpable section comprised of a tubular segment having an outer diameter smaller than an outer diameter of a main body portion  30  of guidewire assembly  22 . Although the diameter of the extended crimpable section could be any size consistent with effective use as a guidewire, it will be understood that the smaller diameter allows for less force to be used in sealing the extended crimpable section and provides a crimped seal that is not too large when crimped. An occlusive balloon  32  is located along the distal portion  26  of guidewire assembly  22 . The occlusive balloon  32  is fluidly connected via a lumen  34  to the proximal end  36  of guidewire assembly  22 , with channels or holes  35  allowing for fluid communication between lumen  34  and occlusive balloon  32 . In a preferred embodiment, a flexible tip  38  is positioned at the distal end  40  of distal portion  26  of the guidewire assembly  22 . Preferably, distal portion  26  of guidewire assembly  22  includes a tapered portion  42  to increase the flexibility and transition properties of the distal portion  26  of guidewire assembly  22 . 
     Preferably, sealing system  60  is implemented as part of a handheld apparatus that also includes gas inflation/evacuation system  80 . Alternatively, sealing system  60  may be a handheld unit completely separate from the gas inflation/evacuation system  80 . Sealing system  60  includes a first aperture  62  into which the proximal end  36  of guidewire assembly  22  is insertable so as to operably position at least a portion of extended sealable section  28  in relation to sealing system  60 . Sealing system  60  further includes a second aperture  64  that is fluidly connectible to gas inflation/evacuation system  80 . The sealing system  60  includes means for selectively sealing the extended sealable section which in the preferred embodiment comprises a crimping mechanism  66  and a sealing mechanism  68 . A passageway  70  is defined from first aperture  62  to second aperture  64  and extends through both crimping mechanism  66  and sealing mechanism  68 . Preferably, at least a portion of the extended sealable section  28  is inserted into first aperture  62  a sufficient distance to engage crimping mechanism  66  and sealing mechanism  68 . 
     In a preferred embodiment of the crimping mechanism  66  as shown in  FIGS. 19-21 , the crimping mechanism  66  comprises a handle  72  that actuates a pivotable cam arrangement  74  that crimps and then severs the extended sealable section  28  between a pair of rollers  76 ,  78  by mechanically flattening and pinching the extended sealable section  28  to the point of breaking. Preferably, the sealing mechanism  68  has a rotatable hemostatic valve positioned proximal to the crimping mechanism  66  along passageway  70 . Preferably, crimping mechanism  66  and sealing mechanism  68  are arranged coaxially with each other along a straight portion of passageway  70 . In this embodiment, when the proximal end  36  of guidewire assembly  22  is inserted into first aperture  62  until the proximal end  36  engages the hemostatic valve of sealing mechanism  68 , the extended sealable section  28  is properly positioned relative to the crimping mechanism  66 . 
     It will be seen that the relative distance between the engaging portions of sealing mechanism  68  and crimping mechanism  66  in this embodiment effectively defines the relative distances between a plurality of locations along extended sealable section  28  at which an airtight seal can be created, as shown in  FIGS. 8-9 . To permit multiple inflations and deflations of the occlusive balloon  32  of the guidewire assembly  22 , the length of the extended sealable section  28  should be greater than at least twice the distance between crimping mechanism  66  and sealing mechanism  68 . 
     The gas inflation/evacuation system  80  is connected via conduit  82  to the second aperture  64  of the sealing system  60 . The gas inflation/evacuation system  80  preferably includes a valve arrangement  84  that selectively couples one of an evacuation system which includes means for evacuating the guidewire assembly  22  and an inflation system which includes means for introducing a gas into the guidewire assembly  22  to the conduit  82 . The evacuation system includes an evacuation syringe  86  which is used to evacuate the guidewire assembly  22 , passageway  70 , and conduit  82 . The inflation system includes an inflation syringe  88  which contains a volume of a biocompatible gas sufficient to inflate the occlusive balloon  32  a plurality of times. Preferably, the biocompatible gas is carbon dioxide. Other biocompatible gasses that may be utilized with the present invention include oxygen, nitrogen, and nitrous oxide. Although not preferred, low viscosity biocompatible liquids or foams also may be used for inflation provided the surface tension of the fluid is sufficient to permit the rapid inflation and deflation contemplated by the present invention. Optionally, a pressure gauge  90  can be associated with the inflation syringe  88 . 
     In a preferred embodiment shown in  FIGS. 10   a ,  10   b ,  11   a  and  11   b , guidewire assembly  22  is constructed as described in further detail in the previously identified co-pending application Ser. No. 10/012,891 entitled “Guidewire Assembly Having Occlusive Device And Repeatably Crimpable Proximal End” filed Nov. 6, 2001, currently pending. The main body portion  30  is formed of a primary stainless steel hypotube having an outer diameter of 0.013 inch and an inner diameter of 0.007 inch. To accomplish passive deflation in the desired time of less than one minute when the extended sealable section  28  is cut, it is preferable that the main body portion  30  have an inner diameter of at least 0.002 inch. The extended sealable section  28  of guidewire assembly  22  is comprised of a crimp tube also formed of stainless steel and having an outer diameter of 0.009 inch to 0.015 inch and an inner diameter of at least 0.002 inch and preferably about 0.005 inch. The extended sealable section  28  is preferably a separate piece secured to the proximal portion  24  by a laser weld  44  (see  FIGS. 8 ,  9  and  10   a ) of sufficient strength. Alternatively, the extended sealable section  28  may be formed by centerless grinding or reducing the outer diameter of a portion of the proximal portion  24  of the main body portion  30  of guidewire assembly  22 . Still other embodiments may enable the extended sealable section to be a modified, treated or otherwise fabricated portion of the proximal portion  24  of the main body portion  30  of guidewire assembly  22  that is suitable for the particular sealing technique to be used. As shown in  FIG. 11   a , in one embodiment the distal end of the extended sealable section  28  is preferably centerless ground and press fit within a chamfered proximal end of the main body portion  30 . Alternatively, as shown in  FIG. 11   b , a chamfered crimp arrangement could be used. Still further, a separate joining/crimping tube or other tubular joining arrangements could be used. Preferably, a protective polymer coating  56  of polytetrafluoroethylene (PTFE) or a hydrophilic coating is applied by any of a number of known techniques such that the coating  56  surrounds the main body portion  30 . The protective polymer coating  56  is preferably about 0.0004+/−0.0003 inch thick such that the effective outer diameter of the main body portion  30  of guidewire assembly  22  is 0.0132-0.0144 inch. 
     In this embodiment, the extended sealable section  28  can be made of any material that when deformed and severed retains that deformation so as to form an airtight seal. When crimped and severed, it is preferable that the extended sealable section  28  not present a sharp, rigid point that is capable of piercing a gloved hand. It has been found that as long as the preferred embodiment is not gripped within less than one inch of the proximal end of the extended sealable section  28 , the severed proximal end of the extended sealable section  28  does not penetrate a standard surgical glove. In addition, the extended sealable section  28  must have sufficient strength in terms of high tensile and kink resistance to permit catheter devices to repeatedly pass over the extended sealable section  28 . 
     In this embodiment, the main body portion  30  is preferably secured to the distal portion  26  using a Ni—Ti alloy or stainless steel sleeve  46 , or of other suitable material, laser welded to the main body portion  30  at laser weld  48  and crimped to the distal portion  26  at crimp  50 . The distal portion  26  is preferably formed of a Ni—Ti alloy having an inner diameter of 0.0045 inch and an outer diameter that ranges from 0.014 inch to 0.0075 inch to form tapered portion  42 , preferably formed by a centerless grinding process. Preferably, the distal portion includes a pair of coil sections, proximal tip coil  52  and distal tip coil  54 , that are longitudinally spaced apart and adjacent to the holes  35  and that assist in providing a better surface for bonding the occlusive balloon  32  to the distal portion  26 . This arrangement also tends to increase the visibility of the location of the occlusive balloon  32  under fluoroscopy, as the occlusive balloon  32  filled with a biocompatible gas will be radiotranslucent when compared to the two coils  52  and  54 . Alternatively, a platinum markerband could be located around the distal portion  26  just proximal to the occlusive balloon  32  to serve as a radiopaque/MRI marker. The flexible tip  38  is a coiled tip attached to distal portion  26  distal to occlusive balloon  32 , preferably by a crimp. Alternatively, a sleeve could be welded to the flexible tip  38 , and the tapered portion  42  could then be inserted into this sleeve and crimped. 
     Alternatively, any number of other alloys or polymer materials and attachment techniques could be used in the construction of the guidewire assembly  22 , provided the materials offer the flexibility and torque characteristics required for a guidewire and the attachment techniques are sufficiently strong enough and capable of making an airtight seal. These materials include, but are not limited to, Ni—Ti, 17-7 stainless steel, 304 stainless steel, cobalt superalloys, or other polymer, braided or alloy materials. The attachment techniques for constructing guidewire assembly  22  include, but are not limited to, welding, mechanical fits, adhesives, sleeve arrangements, or any combination thereof. 
     The occlusive balloon  32  may be made of any number of polymer or rubber materials. Preferably, the occlusive balloon is preinflated to prestretch it so that expansion is more linear with pressure. Preferably, the pressure supplied by gas inflation/evacuation system  80  is designed to stay well within the elastic limit of the occlusive balloon  32 . A two-layer occlusive balloon arrangement, adding gas and/or liquid between balloon layers, may be used in an alternate embodiment to increase visibility of the distal end  40  of the distal portion  26  of the guidewire assembly  22  under fluoroscopy. 
     In practice, medical personnel gain entry to the vessel lumen prior to use of the guidewire occlusion system  20 . The extended sealable section  28  of the proximal portion  24  of guidewire assembly  22  is inserted into first aperture  62  and connected via sealing mechanism  68 . The distal portion  26  of guidewire assembly  22  is inserted into the vessel lumen, and occlusive balloon  32  is inserted to a point distal to the vessel occlusion. Valve arrangement  84  is set for evacuation. Evacuation syringe plunger  92  of evacuation syringe  86  is slidably withdrawn removing any air from guidewire assembly  22 . Valve arrangement  84  is then set for inflation. Inflation syringe plunger  94  of inflation syringe  88  is slidably advanced inserting a volume of an inert gas into guidewire assembly  22 . The inert gas inflates occlusive balloon  32  as shown in  FIG. 9 . During inflation, the medical personnel monitor pressure gauge  90  to ensure that the inflation pressure does not exceed the burst rating of the occlusive balloon  32  and to gauge the relative size of the occlusive balloon  32  as it is inflated. Following inflation of occlusive balloon  32 , crimping mechanism  66  is employed to crimp the extended sealable section  28  of guidewire assembly  22 , thereby sealing the guidewire assembly  22  to maintain the occlusive balloon  32  in an inflated state. Sealing mechanism  68  is released and the extended sealable section  28  is removed from first aperture  62  such that the proximal portion  24  of the guidewire assembly  22  is free of mechanical or other obstructions and can function as a conventional guidewire. When the medical personnel decide to deflate the occlusive balloon  32 , the extended sealable section  28  is cut using a medical scissors or the like distal to the existing crimp in the extended sealable section  28 . When the medical personnel deem reinflation of the occlusive balloon  32  to be necessary, the extended sealable section  28  of the proximal portion  24  is reinserted into first aperture  62 . Sealing mechanism  68  is then reactivated and the evacuation/inflation process can be repeated. It will be understood that a crimping handle  72  may also be provided with a separate severing arrangement to cut the extended sealable section  28 . Alternatively, extended sealable section  28  may be scored or otherwise weakened in selected locations to assist in crimping or severing, including severing by repeated bending back and forth at one of the scored locations. In another embodiment, the extended sealable section  28  could be broken off rather than sheared by using a brittle metal for the extended sealable section that aids in the severing of the extended sealable section  28 . 
       FIG. 12  shows an alternative unitized gas inflation/evacuation system  80   a  and also an alternative sealing system  60   a.  Assembly body  96  contains individual inflation syringe  194  with inflation syringe plunger  98  and individual evacuation syringe  192  with evacuation syringe plunger  100 . Assembly body  96  contains pressure gauge  90 . Attached to assembly body  96  is support structure  182  which supports a sealing system  60   a  that includes crimping mechanism  66   a  and sealing mechanism  68   a.  Valve arrangement  84  is mounted on the surface of assembly body  96 . Assembly body  96  contains two fingergrip bores  184 . Attached to assembly body  96  is fingergrip  186 . In the preferred embodiment, the assembly body  96  is constructed of a suitable inert plastic polymer, although any polymer material used in construction of medical devices could be used. In another embodiment, the assembly body  96  can be constructed of suitable metal alloys or even of tempered glass or any combination thereof. 
       FIG. 13  shows an alternative gas inflation/evacuation system  80   b  in use with sealing system  60   a.  Valve arrangement  188  has three interconnect fittings  190   a ,  190   b  and  190   c . Attached to interconnect fitting  190   a  is evacuation syringe  192 . Evacuation syringe  192  includes evacuation syringe plunger  100 . Attached to interconnect fitting  190   b  is pressure gauge  90 . Pressure gauge  90  is fluidly interconnected to inflation syringe  194 . Inflation syringe  194  includes inflation syringe plunger  98 . Attached to the interconnect fitting  190   c  is sealing system  60   a  comprised of crimping mechanism  66   a  and sealing mechanism  68   a.  Preferably, one-way check valves  191  and  193  are respectively connected between interconnect fitting  190   a  and evacuation syringe  192  and between interconnect fitting  190   b  and inflation syringe  194  as a safety measure to ensure only one-way flow of the gas within the gas inflation/evacuation system  80   b.  One-way check valve  193  ensures that only the carbon dioxide gas is delivered out of the gas inflation/evacuation system and prevents any reinfusion of air that has been evacuated from the gas inflation/evacuation system. 
       FIGS. 14 and 15  show an alternative gas inflation/evacuation system  80   c  with sealing system  60 . Assembly body  118  contains inflation syringe  194  and evacuation syringe  192 . Inflation syringe  194  includes inflation syringe plunger  98 . Evacuation syringe  192  includes evacuation syringe plunger  100 . Knob  120  connected to valve arrangement  188  is mounted on the exterior of assembly body  118 . Pressure gauge  90  is contained within assembly body  118 . Assembly body  118  contains fingergrips  186 . Conduit  122  is attached to assembly body  118 . At the distal end of conduit  122  is sealing system  60  which is comprised of crimping mechanism  66  and sealing mechanism  68 . 
       FIG. 16  shows an embodiment of the sealing system. Specifically,  FIG. 16  shows sealing system  60  which is comprised of sealing mechanism  68  and crimping mechanism  66 . Crimping mechanism  66  is comprised of crimp body  126 , handle  72 , handle return  128 , and first aperture  62 . Sealing mechanism  68  is comprised of sealing body  132  and second aperture  64 . Sealing system  60  has a passageway  70  (see  FIGS. 8 and 9 ) fluidly interconnecting first aperture  62  and second aperture  64 . 
       FIG. 17  shows an alternative gas inflation/evacuation assembly  80   d  coupled to sealing system  60 . Valve arrangement  188  has a coupling  141  connected to conduit  82  and a port  138  that is attached via one-way check valve  191  and hose  140  to evacuation syringe  192 . Attached to an interconnect fitting  139  of the valve arrangement  188  is inflation manifold  142 . Inflation manifold  142  is connected to connector  146  and pressure gauge  90 . Inflation manifold  142  has three check valves  144   a ,  144   b  and  144   c . Check valves  144   a ,  144   b  and  144   c  are connected to respective inflation syringes  194   a ,  194   b  and  194   c  which have respective inflation syringe plungers  98   a ,  98   b , and  98   c . In this embodiment, evacuation syringe  192  is mounted behind pressure gauge  90 . As with the other embodiments, the distal end of conduit  82  is connected to sealing system  60 . Sealing system  60  is comprised of sealing mechanism  68  and crimping mechanism  66 . 
       FIG. 18  shows an alternative gas inflation/evacuation system  80   e  that is similar to the gas inflation/evacuation system  80   d  shown in  FIG. 17  except that the components are arranged in a common housing  150 . Common housing  150  has internal sealed channels that fluidly interconnect via valve arrangement  188  to evacuation syringe  192  and to inflation syringes  194   a ,  194   b  and  194   c  and pressure gauge  90 . Common housing  150  has structure  152  that defines chambers for the three inflation syringes  194   a ,  194   b  and  194   c . Common housing  150  also includes structure defining external fingergrips  186  and internal fingergrips  154  between adjacent portions of structure  152 . Common housing  150  also contains structure for integrating evacuation syringe  192  and pressure gauge  90  as part of the common housing  150 . An external knob  156  connects to the valve arrangement  188 . 
       FIGS. 25 and 26  show an alternative embodiment to that shown in  FIG. 18 . Rather than utilizing the common housing  150  with internal sealed channels, an assembled gas inflation/evacuation system  80   f , substantially similar to the gas inflation/evacuation system  80   d  shown in  FIG. 17 , is securely placed within a two-part housing such that the two-part housing provides a protective and functional casing around the gas inflation/evacuation system  80   f . As demonstrated in the exploded view of  FIG. 25 , the previously described components of the gas inflation/evacuation system  80   d  are assembled prior to fitting of the housing. In addition to the components described above with relation to  FIG. 17 , this exploded view shows two additional components: namely, tee connector  143  and coupling  145 . Tee connector  143  is intermediately connected to pressure gauge  90  at one end and connector  146  at the other end. Further, coupling  145  interconnects valve arrangement  188  to tee connector  143 . Upon completion of the component assembly, the assembled system is securely placed within a top housing half  151 , as shown in  FIG. 26 . Once secured, a compatible bottom housing half  153 , as also shown in  FIG. 26 , is joined with top housing half  151  to form the full housing. This joining of top housing half  151  and bottom housing half  153  can be achieved using a myriad of techniques, such as adhesive bonding, heat bonding, chemical bonding, pressure fittings, snap connectors, clip connectors, fasteners such as screws and bolts, and the like. 
     The embodiments shown in  FIGS. 17 ,  18 ,  25  and  26  allow for effective pressurization of occlusive balloon  32  at less than 2 atmospheres while reducing the total volume of gas that might be introduced into a patient in the event of a leak in the guidewire occlusion system  20 . Depending upon the desired inflation pressure and the total number of inflation cycles, the total amount of pressurized gas in a single inflation syringe such as  88  in  FIGS. 8 and 9  or  194  in  FIGS. 12-15  can be significant. If a leak were to occur, the entire contents of a single inflation syringe would be susceptible to that leak. By using a separate inflation syringe  194   a ,  194   b ,  194   c  for each inflation in the embodiments shown in  FIGS. 17 ,  18 ,  25  and  26 , these alternate embodiments provide a simple way of decreasing the total amount of pressurized gas that might be introduced into a patient in the event of a leakage in the guidewire occlusion system  20 . 
     A similar result could be achieved by manually attaching separate inflation syringes  194   a ,  194   b ,  194   c  and an evacuation syringe  192  directly to the sealing system  60  by way of a Luer lock or the like. While such an embodiment would not be as quick or convenient as the preferred embodiment, this alternative would eliminate the volume of gas required for the conduit  82  and within common housing  150 , as well as the need for a valve arrangement  188 . 
     In alternate embodiments, the sealing system could include means for selectively sealing involving techniques other than crimping to accomplish multiple airtight seals along the course of the extended sealable section  28 . One alternate embodiment, as portrayed in  FIG. 22 , would involve the insertion of some form of sealant material  158  into the proximal end of the extended sealable section  28 , such as wax, plastic, polymer or metal inserts or plugs. Conduit  82  is attached to a plugging mechanism  162  through the conduit aperture  160 . In this embodiment, sealant material  158  is confined by sealant confinement layer  164  residing within plugging mechanism  162 . Preferably for this embodiment, sealant material  158  is a wax or gel that is flowable at higher temperatures and might be melted during sterilization of the sealing system. Sealant confinement layer  164  is a foil layer or thin layer of non-meltable material capable of confining a flowable material during any sterilization process or exposure to higher temperature. The proximal end of extended sealable section  28  is inserted through first aperture  62  until it is past operational O-ring  166  or some other form of sealable/deformable material such as a silicone puncture seal or similar membrane seal. When it is desired to seal the extended sealable section  28 , the extended sealable section  28  is further inserted past a sealant O-ring  168 , then through sealant confinement layer  164 , and finally into sealant material  158 . Sealant material  158  is deposited in the proximal end of extended sealable section  28 , thus preventing the guidewire assembly  22  from being evacuated. Extended sealable section  28  can then be slidably withdrawn through the sealant O-ring  168 , through the operational O-ring  166 , and through the first aperture  62 , thereby effectively disengaging the guidewire assembly  22  from the plugging mechanism  162 . The O-rings  166  and  168  serve as wiping structures to remove excess sealant material from the outside of the extended sealable section  28 . Other alternate embodiments involve heating the extended sealable section  28  when it is formed of metal or polymer material so as to create a constriction, or applying electrical or magnetic energy to arc or weld material within the extended sealable section  28  to create a constriction. In one embodiment, the equivalent of a spot welder could be used in place of the crimping mechanism  66  to accomplish the same purpose of sealing, and then severing the extended sealable section  28 . Alternative embodiments could use other sealing techniques to seal the guidewire assembly  22 . These methods could include, but are not limited to, ones utilizing a heat source to melt the extended sealable section, ones using a heat source to apply a glue or gel, methods involving insertion of a plug material, methods using magnetics to manipulate a sealing material, or methods utilizing small occlusive devices. 
     Depending on the sealing method specified in an embodiment, different deflation techniques can be utilized. For the preferred embodiment, the extended sealable section  28  is of sufficient length to allow deflation through the shearing, breaking or opening of the extended sealable section  28  distal to the sealant material  158  located in the proximal end of the extended sealable section  28 . By having sufficient length of the extended sealable section  28 , the guidewire assembly  22  can be coupled to the gas inflation/evacuation system  80  (or  80   a - 80   f ) multiple times, allowing the occlusive balloon  32  to be inflated and deflated multiple times. Other embodiments will use methods of deflation including melting the sealant material  158 , removing a plug of sealant material  158 , and various other methods not requiring the extended sealable section  28  to be sheared. 
     In one embodiment, the guidewire occlusion system  20  is preferably pre-assembled and packaged in an environment consisting of an appropriate biocompatible gas.  FIG. 23  shows equipment with which the guidewire occlusion system  20  is assembled and packaged. The guidewire occlusion system  20  is assembled and packaged in a sealed chamber  170 . Sealed chamber  170  is equipped with a venting duct  171 , sealed handling ports  173 , and an atmosphere control system  175 . The venting duct  171  and atmosphere control system  175  provide the overall system for maintaining a biocompatible gas atmosphere within the sealed chamber  170 . Sensory readings within the sealed chamber  170  provide the atmosphere control system  175  with the data needed to adjust the biocompatible gas levels within the sealed chamber  170 . Stored biocompatible gas is introduced into the sealed chamber  170  through the venting duct  171 . Assembling and packaging of the guidewire occlusion system  20  and/or any of the pre-assembled components is achieved with the use of the sealed handling ports  173 . The ports  173  are sterilized and sealed so that an assembler or packager positioned outside the sealed chamber  170  can access the contents of the chamber without introducing contamination through actual human contact or through the introduction of undesirable gases and airborne contaminants. These ports  173  could be constructed of flexible glove-like attachments, as shown, or they could be robotic devices operable within the sealed chamber  170  through controls external to the sealed chamber  170 . The equipment could be two or more sealed chambers. 
     After a guidewire assembly  22 , a sealing system  60  (or  60   a ) and a gas inflation/evacuation system  80  (or  80   a - 80   f ) are placed in a sealed chamber  170 , they are assembled to form the guidewire occlusion system  20  and placed into biocompatible packaging  174  ( FIG. 24 ). Biocompatible packaging  174  is hermetically sealed so that the internal volume of both biocompatible packaging  174  and guidewire occlusion system  20  is composed solely of biocompatible gas. A preferred embodiment of the biocompatible packaging  174  is shown in  FIG. 24 . The biocompatible packaging  174  is preferably in the form of a foil pouch. This foil pouch is made from a medical packaging film with the following laminates: an 8.75 micron foil layer, an adhesive layer, a white polyethylene layer, and a 12 micron PET layer. The foil pouch has a preferred total thickness of approximately 3.6 millimeters, and a minimum bond strength of one pound. In addition, the preferred barrier properties of the film will be an oxygen transmission &lt;0.01 cc/100 sq. in/24 hr. (73 degrees F., 0% RH) ASTM 3985, and moisture vapor transmission &lt;0.01 gm H2O/100 sq. in/24 hr. (100 degrees F., 90% RH) ASTM F1249. It will be understood by those skilled in the art that this biocompatible foil pouch can be contained and/or attached within an outer packaging or container, such as a cardboard box, a plastic container, or the like. Such an outer packaging will facilitate shipping, labeling, storage, and handling of the biocompatible packaging  174  and its contents. 
     In practice, medical personnel gain access to the vessel lumen through which the guidewire assembly  22  will travel. The guidewire occlusion system  20  is removed from biocompatible packaging  174 . Flexible tip  38  is inserted in the vessel lumen and is manipulated to a point beyond the vessel occlusion. Valve arrangement  84  (or  188 ) is adjusted to the evacuation position and evacuation syringe plunger  92  (or  100 ) is slidably withdrawn to remove any gas present in the guidewire assembly  22 . Valve arrangement  84  (or  188 ) is then adjusted to the inflation position and inflation syringe plunger  94  (or  98 ,  98   a ,  98   b ,  98   c ) is slidably inserted causing occlusive balloon  32  to inflate. 
     Following inflation of occlusive balloon  32 , handle  72  of the crimping mechanism  66  (or the handle of  66   a ) is depressed causing roller  76  and roller  78  to crimp and preferably sever the extended sealable section  28  of guidewire assembly  22 . Severing of the extended sealable section  28  serves as an immediate verification of the creation of an effective seal. Sealing mechanism  68  (or  68   a ) can be released and guidewire assembly  22  can be completely removed from the sealing system  60  (or  60   a ) allowing the occlusive balloon  32  to remain inflated while occlusive substance treatment occurs. Following treatment, the extended sealable section  28  can be sheared or broken off, resulting in the deflation of the occlusive balloon  32 . If occlusive treatment is complete, guidewire assembly  22  can be removed from the vessel lumen. If additional treatment is required, extended sealable section  28  can be reattached to sealing system  60  (or  60   a ) through first aperture  62 . Sealing mechanism  68  (or  68   a ) can be retightened and the evacuation/inflation process can be repeated. 
     In a preferred embodiment of the present invention, the guidewire assembly  22  is utilized as the guidewire for an atherectomy or thrombectomy procedure of the type described in U.S. Pat. Nos. 5,370,609 or 5,496,267, the disclosures of both of which are hereby incorporated by reference. In each of these procedures, the guidewire assembly  22  is introduced into the patient, the occlusive balloon  32  is inflated, and then the atherectomy or thrombectomy catheter arrangement is slid over the proximal end  36  of the guidewire assembly  22  and advanced until it is proximate and proximal to the location of the occlusive balloon. The procedure is performed for a time period consistent with the desired maximum length for blockage of the particular vessel at which time the extended sealable section  28  of the guidewire assembly  22  may be severed to deflate the occlusive balloon  32 , thereby reestablishing blood flow within the vessel. Depending upon the nature of the procedure, the catheter arrangement may be removed from the vessel or left in place. Preferably, an evacuation of any plaque material or other debris dislodged by the therapy is accomplished before deflation of the occlusive balloon  32 . The occlusive balloon  32  is reinflated prior to reinitiation of the procedure. 
     The present invention may be embodied in other specific forms without departing from the essential attributes thereof; therefore, the illustrated embodiments should be considered in all respects as illustrative and not restrictive, reference being made to the appended claims rather than to the foregoing description to indicate the scope of the invention. 
     Various modifications can be made to the present invention without departing from the apparent scope thereof.