Abstract:
A system and method for deploying an occluding device that can be used to remodel an aneurysm within the vessel by, for example, neck reconstruction or balloon remodeling. The system comprises an introducer sheath and an assembly for carrying the occluding device. The assembly includes an elongated flexible member having an occluding device retaining member for receiving a first end of the occluding device, a proximally positioned retaining member for engaging a second end of the occluding device and a support surrounding a portion of the elongated flexible member over which the occluding device can be postioned.

Description:
[0001]     This application is a Continuation-in-part of and claims priority to U.S. application Ser. No. 11/136,398, filed May 25, 2005, which is expressly incorporated herein by reference in its entirety. 
     
    
     FIELD OF THE INVENTION  
       [0002]     The invention generally relates to a system and method for delivering and deploying a medical device within a vessel, more particularly, it relates to a system and method for delivering and deploying an endoluminal therapeutic device within the vasculature of a patient to embolize and occlude aneurysms, particularly cerebral aneurysms.  
       BACKGROUND ART OF THE INVENTION  
       [0003]     Walls of the vasculature, particularly arterial walls, may develop areas of pathological dilatation called aneurysms. As is well known, aneurysms have thin, weak walls that are prone to rupturing. Aneurysms can be the result of the vessel wall being weakened by disease, injury or a congenital abnormality. Aneurysms could be found in different parts of the body with the most common being abdominal aortic aneurysms and brain or cerebral aneurysms in the neuromusculature. When the weakened wall of an aneurysm ruptures, it can result in death, especially if it is a cerebral aneurysm that ruptures.  
         [0004]     Aneurysms are generally treated by excluding the weakened part of the vessel from the arterial circulation. For treating a cerebral aneurysm, such reinforcement is done in many ways including: (i) surgical clipping, where a metal clip is secured around the base of the aneurysm; (ii) packing the aneurysm with small, flexible wire coils (micro-coils); (iii) using embolic materials to “fill” an aneurysm; (iv) using detachable balloons or coils to occlude the parent vessel that supplies the aneurysm; and (v) intravascular stenting.  
         [0005]     Intravascular stents are known in the medical arts for the treatment of vascular stenoses or aneurysms. Stents are prostheses that expand radially or otherwise within a vessel or lumen to provide support against the collapse of the vessel.  
         [0006]     In conventional methods of introducing a compressed stent into a vessel and positioning it within in an area of stenosis or an aneurysm, a guiding catheter having a distal tip is percutaneously introduced into the vascular system of a patient. The guiding catheter is advanced within the vessel until its distal tip is proximate the stenosis or aneurysm. A guidewire positioned within an inner lumen of a second, inner catheter and the inner catheter are advanced through the distal end of the guiding catheter. The guidewire is then advanced out of the distal end of the guiding catheter into the vessel until the distal portion of the guidewire carrying the compressed stent is positioned at the point of the lesion within the vessel. Once the compressed stent is located at the lesion, the stent may be released and expanded so that it supports the vessel.  
       SUMMARY OF THE INVENTION  
       [0007]     Aspects of the present invention include a system and method of deploying an occluding device within a vessel. The occluding device can be used to remodel an aneurysm within the vessel by, for example, neck reconstruction or balloon remodeling. The occluding device can be used to form a barrier that retains occlusion material such as a well known coil or viscous fluids, such as “ONYX” by Microtherapeutics, within the aneurysm so that introduced material will not escape from within the aneurysm. Also, during deployment, the length of the occluding device can be adjusted in response to friction created between the occluding device and an inner surface of a catheter. When this occurs, the deployed length and circumferential size of the occluding device can be changed as desired by the physician performing the procedure.  
         [0008]     An aspect of the present invention includes a system for supporting and deploying an occluding device. The system comprises an introducer sheath and an assembly for carrying the occluding device. The assembly includes an elongated flexible member having an occluding device retaining member for receiving a first end of the occluding device, a proximally positioned retaining member for engaging a second end of the occluding device and a support surrounding a portion of the elongated flexible member over which the occluding device can be positioned.  
         [0009]     Another aspect of the present invention includes a system for supporting and deploying an occluding device. The system comprises an assembly for carrying the occluding device. The assembly comprises an elongated member including a flexible distal tip portion, a retaining member for receiving a first end of the occluding device, and a support surrounding a portion of the elongated flexible member for supporting the occluding device.  
         [0010]     A further aspect of the present invention comprises a method of introducing and deploying an occluding device within a vessel. The method includes the steps of introducing an elongated sheath including an introducer sheath carrying a guidewire assembly into a catheter and advancing the guidewire assembly out of the sheath and into the catheter. The method also includes the steps of positioning an end of the catheter proximate an aneurysm, advancing a portion of the guidewire assembly out of the catheter and rotating a portion of the guidewire assembly while deploying the occluding device in the area of the aneurysm.  
         [0011]     In another aspect an elongated flexible member supports and deploys an occluding device and the occluding device may be expanded and retracted based on input pressure. For example, air of fluid pressure may be applied to the occluding device via the flexible member to cause the occluding device to expand or retract. 
     
    
     BRIEF DESCRIPTION OF THE FIGURES  
       [0012]      FIG. 1  is a cross section of an occluding device delivery assembly and occluding device according to an aspect of the invention;  
         [0013]      FIG. 2  illustrates a catheter and introducer sheath shown in  FIG. 1 ;  
         [0014]      FIG. 3  is a partial cut away view of the introducer sheath of  FIG. 2  carrying a guidewire assembly loaded with an occluding device;  
         [0015]      FIG. 4  is a cross section of the guidewire assembly illustrated in  FIG. 3 ;  
         [0016]      FIG. 5  is a schematic view of the guidewire assembly of  FIG. 4 ;  
         [0017]      FIG. 6  is a second schematic view of the guidewire assembly of  FIG. 4 ;  
         [0018]      FIG. 7  illustrates the occluding device and a portion of the guidewire assembly positioned outside the catheter, and how a proximal end of the occluding device begins to deploy within a vessel;  
         [0019]      FIG. 8  illustrates a step in the method of deploying the occluding device;  
         [0020]      FIG. 9  illustrates the deployment of the occluding device according to an aspect of the present invention;  
         [0021]      FIG. 10  is a schematic view of a guidewire assembly according to another embodiment of the present invention; and  
         [0022]      FIG. 11  is a schematic view of the deployed occluding device after having been deployed by the guidewire assembly of  FIG. 10 .  
         [0023]      FIG. 12  illustrates an example of an expanded occluding device that expands responsive to pressure.  
         [0024]      FIG. 13  illustrates the occluding device of  FIG. 12  after a negative pressure is applied to the occluding device.  
         [0025]      FIG. 14  illustrates an example of release of the distal end of the occluding device while the proximal end of the occluding device remains attached to the delivery device.  
         [0026]      FIG. 15  illustrates an example of a partially deployed occluding device.  
         [0027]      FIG. 16  illustrates another example of a partially deployed occluding device.  
         [0028]      FIG. 17  illustrates the example of  FIG. 16  in which the occluding device is repositioned proximally in the blood vessel.  
         [0029]      FIG. 18  illustrates an example of an expanded occluding device.  
         [0030]      FIG. 19  illustrates the example of  FIG. 18  after the occluding device is repositioned within a blood vessel.  
         [0031]      FIG. 20  illustrates an example of the occluding device in a retracted state.  
         [0032]      FIG. 21  illustrates an example of repositioning the occluding device while the occluding device is retracted. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0033]     An occluding device delivery assembly having portions with small cross section(s) and which is highly flexible is described herein.  FIG. 1  illustrates an introducer sheath  10  according to an aspect of the present invention that receives, contains and delivers an occluding device  100  to a flexible micro-catheter  1  for positioning within the vasculature of an individual. The occluding device  100  can include those embodiments disclosed in copending U.S. patent application titled “Flexible Vascular Occluding Device”, U.S. Ser. No. 11/136,395, filed on May 25, 2005, which is expressly hereby incorporated by reference in its entirety.  
         [0034]     A distal end  12  of the introducer sheath  10  is sized and configured to be received within a hub  2  of the micro-catheter  1 , as shown in  FIGS. 1 and 2 . The hub  2  can be positioned at the proximal end of the micro-catheter  1  or at another location spaced along the length of the micro-catheter  1 . The micro-catheter  1  can be any known micro-catheter that can be introduced and advanced through the vasculature of a patient. In an embodiment, the micro-catheter has an inner diameter of 0.047 inch or less. In another embodiment, the micro-catheter has an inner diameter of about 0.027 inch to about 0.021 inch. In an alternative embodiment, the micro-catheter could have an inner diameter of about 0.025 inch. However, it is contemplated that the micro-catheter  1  can have an inner diameter that is greater than 0.047 inch or less than 0.021 inch. After the introducer sheath  10  is positioned within the catheter hub  2 , the occluding device  100  can be advanced from the introducer sheath  10  into the micro-catheter  1  in preparation for deploying the occluding device  100  within the vasculature of the patient.  
         [0035]     The micro-catheter  1  may have at least one fluid introduction port  6  located adjacent the hub  2  or at another position along its length. The port  6  is preferably in fluid communication with the distal end of the micro-catheter  1  so that a fluid, e.g., saline, may be passed through the micro-catheter  1  prior to insertion into the vasculature for flushing out air or debris trapped within the micro-catheter  1  and any instruments, such as guidewires, positioned within the micro-catheter  1 . The port  6  may also be used to deliver drugs or fluids within the vasculature as desired.  
         [0036]      FIG. 3  illustrates the introducer sheath  10 , an elongated flexible delivery guidewire assembly  20  that is movable within the introducer sheath  10  and the occluding device  100 . As shown, the guidewire assembly  20  and the occluding device  100 , carried by the guidewire assembly  20 , have not been introduced into the micro-catheter  1 . Instead, as illustrated, they are positioned within the introducer sheath  10 . The introducer sheath  10  may be made from various thermoplastics, e.g., PTFE, FEP, HDPE, PEEK, etc., which may optionally be lined on the inner surface of the sheath or an adjacent surface with a hydrophilic material such as PVP or some other plastic coating. Additionally, either surface may be coated with various combinations of different materials, depending upon the desired results.  
         [0037]     The introducer sheath  10  may include drainage ports or purge holes (not shown) formed into the wall near the area covering the occluding device  100 . There may be a single hole or multiple holes, e.g., three holes, formed into introducer sheath  10 . These purge holes allow for fluids, e.g., saline, to readily escape from in between the introducer sheath  10  and the guidewire assembly  20  when purging the sheath prior to positioning the introducer sheath  10  in contact with the catheter hub  2 , e.g., to remove trapped air or debris.  
         [0038]     As shown in  FIG. 4 , the guidewire assembly  20  includes an elongated flexible guidewire  21 . The flexibility of the guidewire  21  allows the guidewire assembly  20  to bend and conform to the curvature of the vasculature as needed for positional movement of the occluding device  100  within the vasculature. The guidewire  21  may be made of a conventional guidewire material and have a solid cross section. Alternatively, the guidewire  21  can be formed from a hypotube. In either embodiment, the guidewire  21  has a diameter D 5  ranging from about 0.010 inch to about 0.020 inch. In an embodiment, the largest diameter of the guidewire  21  is about 0.016 inch. The material used for the guidewire  21  can be any of the known guidewire materials including superelastic metals, e.g., Nitinol. Alternatively, the guidewire  21  can be formed of metals such as stainless steel. Length L 4  of the guidewire can be from about 125 to about 190 cm. In an embodiment, the length L 4  is about 175 cm.  
         [0039]     The guidewire assembly  20  can have the same degree of flexion along its entire length. In an alternative embodiment, the guidewire assembly  20  can have longitudinal sections, each with differing degrees of flexion/stiffness. The different degrees of flexions for the guidewire assembly  20  can be created using different materials and/or thicknesses within different longitudinal sections of the guidewire  21 . In another embodiment, the flexion of the guidewire  21  can be controlled by spaced cuts (not shown) formed within the delivery guidewire  21 . These cuts can be longitudinally and/or circumferentially spaced from each other. The cuts can be formed with precision within the delivery guidewire  21 . Different sections of the delivery guidewire  21  can include cuts formed with different spacing and different depths to provide these distinct sections with different amounts of flexion and stiffness. In any of the above embodiments, the guidewire assembly  20  and the guidewire  21  are responsive to torque applied to the guidewire assembly  20  by the operator. As discussed below, the torque applied to the guidewire assembly  20  via the guidewire  21  can be used to release the occluding device  100  from the guidewire assembly  20 .  
         [0040]     The size and shape of the cuts formed within the delivery guidewire  21  may be controlled so as to provide greater or lesser amounts of flexibility. Because the cuts can be varied in width without changing the depth or overall shape of the cut, the flexibility of the delivery guidewire  21  may be selectively altered without affecting the torsional strength of the delivery guidewire  21 . Thus, the flexibility and torsional strength of the delivery guidewire  21  may be selectively and independently altered.  
         [0041]     Advantageously, longitudinally adjacent pairs of cuts may be rotated about 90 degrees around the circumference of the delivery guidewire  21  from one another to provide flexure laterally and vertically. However, the cuts may be located at predetermined locations to provide preferential flexure in one or more desired directions. Of course, the cuts could be randomly formed to allow bending (flexion) equally, non-preferentially in all directions or planes. In one embodiment, this could be achieved by circumferentially spacing the cuts.  
         [0042]     The flexible delivery guidewire  21  can include any number of sections having the same or differing degrees of flexion. For example, the flexible delivery guidewire  21  could include two or more sections. In the embodiment illustrated in  FIG. 4 , the flexible delivery guidewire  21  includes three sections, each having a different diameter. Each section can have a diameter of about 0.003 inch to about 0.025 inch. In an embodiment, the diameter of one or more sections can be about 0.010 inch to about 0.020 inch. A first section  22  includes a proximal end  23  that is located opposite the position of the occluding device  100 . The first section  22  can have a constant thickness along its length. Alternatively, the first section  22  can have a thickness (diameter) that tapers along its entire length or only a portion of its length. In the tapered embodiment, the thickness (diameter) of the first section  22  decreases in the direction of a second, transition section  24 . For those embodiments in which the guidewire  21  has a circular cross section, the thickness is the diameter of the section.  
         [0043]     The second, transition section  24  extends between the first section  22  and a third, distal section  26 . The second section  24  tapers in thickness from the large diameter of the first section  22  to the smaller diameter of the third section  26 . As with the first section  22 , the second section  24  can taper along its entire length or only a portion of its length.  
         [0044]     The third section  26  has a smaller thickness compared to the other sections  22 ,  24  of the delivery guidewire  21 . The third section  26  extends away from the tapered second section  24  that carries the occluding device  100 . The third section  26  can taper along its entire length from the second section  24  to the distal end  27  of the delivery guidewire  21 . Alternatively, the third section  26  can have a constant diameter or taper along only a portion of its length. In such an embodiment, the tapering portion of the third section  26  can extend from the second section  24  or a point spaced from the second section  24  to a point spaced from distal end  27  of the delivery guidewire  21 . Although three sections of the delivery guidewire  21  are discussed and illustrated, the delivery guidewire  21  can include more than three sections. Additionally, each of these sections can taper in their thickness (diameter) along all or only a portion of their length. In any of the disclosed embodiments, the delivery guidewire  21  can be formed of a shape memory alloy such as Nitinol.  
         [0045]     A tip  28  and flexible tip coil  29  are secured to the distal end  27  of the delivery guidewire  21  as shown in  FIGS. 4 and 5 . The tip  28  can include a continuous end cap or cover as shown in the figures, which securely receives a distal end of the tip coil  29 . Flexion control is provided to the distal end portion of the delivery guidewire  21  by the tip coil  29 . However, in an embodiment, the tip  28  can be free of the coil  29 . The tip  28  has a non-percutaneous, atraumatic end face. In the illustrated embodiment, the tip  28  has a rounded face. In alternative embodiments, the tip  28  can have other non-percutaneous shapes that will not injure the vessel in which it is introduced. As illustrated in  FIG. 4 , the tip  28  includes a housing  45  that securely receives the distal end of the guidewire  21  within an opening  46  in the interior surface of the housing  45 . The guidewire  21  can be secured within the opening by any known means.  
         [0046]     As shown in  FIG. 4 , the tip coil  29  surrounds a portion of the guidewire  21 .  
         [0047]     The tip coil  29  is flexible so that it will conform to and follow the path of a vessel within the patient as the tip  28  is advanced along the vessel and the guidewire  21  bends to follow the tortuous path of the vasculature. The tip coil  29  extends rearward from the tip  28  in the direction of the proximal end  23 , as shown.  
         [0048]     The tip  28  and coil  29  have an outer diameter D 1  of about 0.010 inch to about  0 . 018  inch. In an embodiment, their outer diameter D 1  is about 0.014 inch. The tip  28  and coil  29  also have a length L 1  of about 0.1 cm to about 3.0 cm. In an embodiment, they have a total length L 1  of about 1.5 cm.  
         [0049]     A proximal end  30  of the tip coil  29  is received within a housing  32  at a distal end  24  of a protective coil  35 , as shown in  FIGS. 1 and 4 . The housing  32  and protective coil  35  have an outer diameter D 2  of about 0.018 inch to about 0.038 inch. In an embodiment, their outer diameter D 2  is about 0.024 inch. The housing  32  and protective coil  35  have a length L 2  of about 0.05 cm to about 0.2 cm. In an embodiment, their total length L 2  is about 0.15 cm.  
         [0050]     The housing  32  has a non-percutaneous, atraumatic shape. For example, as shown in  FIG. 5 , the housing  32  has a substantially blunt profile. Also, the housing  32  can be sized to open/support the vessel as it passes through it. Additionally, the housing  32  can include angled sidewalls sized to just be spaced just off the inner surface of the introducer sheath  10 .  
         [0051]     The housing  32  and protective coil  35  form a distal retaining member that maintains the position of the occluding device  100  on the flexible guidewire assembly  20  and helps to hold the occluding device  100  in a compressed state prior to its delivery and deployment within a vessel of the vasculature. The protective coil  35  extends from the housing  32  in the direction of the proximal end  23  of the delivery guidewire  21 , as shown in  FIG. 4 . The protective coil  35  is secured to the housing  32  in any known manner. In a first embodiment, the protective coil  35  can be secured to the outer surface of the housing  32 . In an alternative embodiment, the protective coil  35  can be secured within an opening of the housing  32  so that the housing  32  surrounds and internally receives the distal end  51  of the protective coil  35  ( FIG. 4 ). As shown in  FIGS. 3 and 4 , the distal end  102  of the occluding device  100  is retained within the proximal end  52  so that the occluding device  100  cannot deploy while positioned in the sheath  10  or the micro-catheter  1 .  
         [0052]     At the proximal end of the occluding device  100 , a bumper coil  60  and cap  62  prevent lateral movement of the occluding device  100  along the length of the guidewire  21  in the direction of the proximal end  23 , see  FIG. 3 . The bumper coil  60  and cap  62  have an outer diameter D 4  of about 0.018 inch to about 0.038 inch. In an embodiment, their outer diameter D 4  is about 0.024 inch. The cap  62  contacts the proximal end  107  of the occluding device  100  and prevents it from moving along the length of the guidewire  21  away from the protective coil  35 . The bumper coil  60  can be in the form of a spring that contacts and pressures the cap  62  in the direction of the protective coil  35 , thereby creating a biasing force against the occluding device  100 . This biasing force (pressure) aids in maintaining the secured, covered relationship between the distal end  102  of the occluding device  100  and the protective coil  35 . As with any of the coils positioned along the delivery guidewire  21 , the bumper coil  60  can be secured to the delivery guidewire  21  by soldering, welding, RF welding, glue, and/or other known adhesives.  
         [0053]     In an alternative embodiment illustrated in  FIG. 10 , the bumper coil  60  is not utilized. Instead, a proximal end  107  of the occluding device  100  is held in position by a set of spring loaded arms (jaws)  140  while positioned within the introducer sheath  10  or the micro-catheter  1 . The inner surfaces of the micro-catheter  1  and the introducer sheath  10  limit the radial expansion of the arms  140 . When the proximal end of the occluding device passes out of the micro-catheter  1 , the arms  140  would spring open and release the occluding device as shown in  FIG. 11 .  
         [0054]     In another example, the occluding device  100  in the introducer sheath  10  or the micro-catheter  1  may expand within a vessel under pressure.  FIG. 12  illustrates an example of an expanded occluding device  100  that expands responsive to pressure. Pressure may be applied through the micro-catheter  1  or the introducer sheath  10  as the occluding device  100  passes out of the micro-catheter  1 . The pressure may be exerted through application of air, fluid, or any material for increasing the internal pressure of the occluding device. The increase in pressure within the occluding device  100  when the occluding device  100  passes out of the micro-catheter  1  may cause the occluding device to expand within the vessel. Conversely, a negative pressure may be exerted at the occluding device  100 .  FIG. 13  illustrates the occluding device  100  of  FIG. 12  after a negative pressure is applied to the occluding device  100 . The negative pressure may be applied via the micro-catheter  1  or the introducer sheath  10  and may cause the occluding device  100  to retract or decrease in size. In one example, a negative pressure is exerted at the occluding device  100  after the occluding device  100  is passed out of the micro-catheter  1  and expanded in the vessel. The negative pressure causes the occluding device  100  to retract. Upon retraction, the occluding device  100  may be reduced in size. In another example, the occluding device  100  may be replaced back into the microcatheter  1  after retraction. The negative pressure may be applied in a variety of ways. For example, the negative pressure may be applied by suction of air from the micro-catheter  1  or by removal or suction of fluid from the micro-catheter  1 .  
         [0055]     Also, in another example, the occluding device  100  may be expanded, for example, by application of increased pressure within the occluding device. The increased pressure may be administered via the delivery device by, for example, injecting air or fluid via the delivery device to the occluding device  100 . The occluding device  100  may thus be expanded in a vessel such that the occluding device  100  may come into contact with the internal aspect of the wall of the vessel. In this way, at least a portion of the occluding device  100 , while in the expanded state, may contact the wall of the vessel.  
         [0056]     While in the expanded state, the occluding device  100  may be repositioned within the vessel.  FIG. 18  illustrates an example of an expanded occluding device  100 .  FIG. 19  illustrates the example of  FIG. 18  after the occluding device is repositioned within a blood vessel. In this example, the occluding device  100  may be expanded in a longitudinal axis along the vessel such that the occluding device  100  may move within the vessel while expanded. Pressure may be exerted by a user at a proximal end of the occluding device  100  such that the proximal end is moved distally within the vessel lumen. At the same time, frictional forces between the wall of the vessel and the more distal portions of the occluding device may prevent immediate movement of the more distal portions of the occluding device. When the pressure or force exerted at the proximal end exceeds a threshold level, the force may be transmitted to the more distal portions of the occluding device to cause the more distal portions of the occluding device to more distally in the lumen of the vessel. In this way, the occluding device may move distally in the vessel lumen and may be repositioned at a desired location within the vessel by the user.  FIG. 19  illustrates distal repositioning of the occluding device in a blood vessel.  
         [0057]     Similarly, the occluding device may be repositioned more proximally in the vessel lumen by the user. For example, the user may provide a force or pressure at a distal portion of the occluding device in a proximal direction. The distal portion of the occluding device may move proximally while frictional forces between the more proximal portions of the occluding device prevent initial movement of the more proximal portions of the occluding device. Hence, in this example, the occluding device compresses at a portion intermediate between the distal portion and the more proximal portions of the occluding device. When the pressure or force exerted by the user at the distal portion of the occluding device exceeds a threshold level that exceeds the frictional force preventing movement of the more proximal portions of the occluding device, the more proximal portions of the occluding device may move in a proximal direction responsive to the applied pressure or force. In this way, the occluding device may be repositioned proximally in the vessel.  
         [0058]     In another example, the occluding device  100  may be repositioned in a blood vessel while the occluding device  100  is in a retracted state.  FIG. 20  illustrates an example of the occluding device  100  in a retracted state. For example, negative pressure may be exerted at the occluding device  100  of  FIG. 12  to cause the occluding device  100  to decrease in size as illustrated in  FIG. 20 . The occluding device  100  as illustrated in  FIG. 20  is retracted and approximates the delivery device.  FIG. 21  illustrates an example of repositioning the occluding device  100  while the occluding device is retracted. As  FIG. 21  illustrates, the occluding device is moved in a distal direction. Similarly, the occluding device may also be repositioned in a proximal direction (not shown).  
         [0059]     Also, deployment of the occluding device may be performed in parts. For example, the occluding device  100  may have a distal end and a proximal end. Deployment of the occluding device may include release of a distal end followed by release of the proximal end of the occluding device. Alternatively, deployment of the occluding device may include release of the proximal end followed by release of the distal end. Also, deployment of the occluding device may include release of the proximal end and the distal end of the occluding device  100  at approximately the same time.  
         [0060]      FIG. 14  illustrates an example of release of the distal end of the occluding device  100  while the proximal end of the occluding device remains attached to the delivery device. As  FIG. 14  shows, the distal end of the occluding device  100  is deployed and abuts the wall of the blood vessel. The proximal end of the occluding device  100  is still attached to the delivery device. Release of the proximal end of the occluding device may be accomplished in a variety of ways as described herein.  
         [0061]     In addition, the partially deployed occluding device  100  as illustrated in  FIG. 14  may be repositioned in the blood vessel.  FIG. 15  illustrates an example of a partially deployed occluding device  100  in which the distal end of the occluding device  100  has been released from the delivery device while the proximal end of the delivery device  100  remains attached and non-deployed to the delivery device. In addition,  FIG. 15  demonstrates repositioning of the occluding device while partially deployed. As  FIG. 15  shows, the delivery device and occluding device  100  has been moved proximally in the blood vessel. Also,  FIG. 15  illustrates that the occluding device is partially deployed in the blood vessel such that the distal end of the occluding device is released from the delivery device while the proximal end of the occluding device  100  remains attached to the delivery device.  
         [0062]     Alternatively,the proximal end of the occluding device may be released from the delivery device while the distal end of the occluding device remains attached to the delivery device. The distal end of the occluding device may then be deployed or released from the delivery device at a subsequent time.  FIG. 16  illustrates an example of a partially deployed occluding device  100  in a blood vessel in which the proximal end of the occluding device  100  is released from the delivery device while the distal end of the occluding device remains attached to the delivery device. The proximal end of the occluding device  100  thus approximates the walls of the blood vessel.  
         [0063]      FIG. 17  illustrates the example of  FIG. 16  in which the occluding device  100  is repositioned proximally in the blood vessel. In this example, the occluding device is partially deployed such that the proximal end of the occluding device  100  is released from the delivery device while the distal end of the occluding device  100  is attached. The occluding device is then moved or repositioned to a more proximal location within the blood vessel. Alternatively, the occluding device may also be moved or repositioned to a more distal location within the blood vessel (not shown).  
         [0064]     In an alternative embodiment, the bumper coil  60  and cap  62  can be eliminated and the proximal end of the occluding device  100  can be held in position relative to the protective coil  35  by a tapered section of the guidewire  21 . In such an embodiment, the enlarged cross section of this tapered section can be used to retain the occluding device  100  in position along the length of the delivery guidewire  21  and prevent movement of the occluding device  100  in the direction of the proximal end  23 .  
         [0065]     As shown in  FIG. 4 , the guidewire assembly  20  includes a support  70  for the occluding device  100 . In a first embodiment, the support  70  can include an outer surface of the delivery guidewire  21  that is sized to contact the inner surface of the occluding device  100  when the occluding device  100  is loaded on the guidewire assembly  20 . In this embodiment, the outer surface of the delivery guidewire  21  supports the occluding device  100  and maintains it in a ready to deploy state. In another embodiment, illustrated in the Figures, the support  70  comprises a mid-coil  70  that extends from a location proximate the protective coil  35  rearward toward the bumper coil  60 . The mid-coil  70  extends under the occluding device  100  and over the delivery guidewire  21 , as shown in  FIG. 1 . The mid-coil  70  can be coextensive with one or more sections of the delivery guidewire  21 . For example, the mid-coil  70  could be coextensive with only the second section  24  of the delivery guidewire  21  or it could extend along portions of both the third section  26  and the second section  24  of the delivery guidewire  21 .  
         [0066]     The mid-coil  70  provides the guidewire assembly  20  with an outwardly extending surface that is sized to contact the inner surface of the occluding device  100  in order to assist in supporting the occluding device and maintaining the occluding device  100  in a ready to deploy state. Like the other coils discussed herein and illustrated in the figures, the coiled form of the mid-coil  70  permits the mid-coil  70  to flex with the delivery guidewire  21  as the delivery guidewire  21  is advanced through the vasculature of the patient. The mid-coil  70  provides a constant diameter along a length of the delivery guidewire  21  that is covered by the occluding device  100  regardless of the taper of the delivery guidewire  21  beneath the occluding device  100 . The mid-coil  70  permits the delivery guidewire  21  to be tapered so it can achieve the needed flexibility to follow the path of the vasculature without compromising the support provided to the occluding device  100 . The mid-coil  70  provides the occluding device  100  with constant support regardless of the taper of the delivery guidewire  21  prior to the occluding device  100  being deployed. The smallest diameter of the occluding device  100  when in its compressed state is also controlled by the size of the mid-coil  70 . Additionally, the diameter of the mid-coil  70  can be chosen so that the proper spacing, including no spacing, is established between the occluding device  100  and the inner wall of the micro-catheter  1  prior to deployment of the occluding device  100 . The mid-coil  70  can also be used to bias the occluding device  100  away from the delivery guidewire  21  during its deployment.  
         [0067]     In either embodiment, the support  70  can have an outer diameter D 3  of about 0.010 inch to about 0.018 inch. In an embodiment, the outer diameter D 3  is about 0.014 inch. The support  70  can also have a length L 3  of about 2.0 cm to about 30 cm. In an embodiment, the length L 3  of the support 70 is about 7 cm.  
         [0068]     The occluding device  100  may also be placed on the mid-coil  70  between an optional pair of radio-opaque marker bands located along the length of the guidewire assembly  20 . Alternatively, the protective coil  35 , bumper coil  60  and or mid-coil  70  can include radio-opaque markers. In an alternative embodiment, the guidewire assembly  20  may include only a single radio-opaque marker. The use of radio-opaque markers allows for the visualization of the guidewire assembly  20  and the occluding device  100  during placement within the vasculature. Such visualization techniques may include conventional methods such as fluoroscopy, radiography, ultra-sonography, magnetic resonance imaging, etc.  
         [0069]     The occluding device  100  can be delivered and deployed at the site of an aneurysm according to the following method and variations thereof. The delivery of the occluding device  100  includes introducing the micro-catheter  1  into the vasculature until it reaches a site that requires treatment. The micro-catheter  1  is introduced into the vasculature using a conventional technique such as being advanced over or simultaneously with a conventional vascular guidewire (not shown). The positioning of the micro-catheter  1  can occur before it receives the guidewire assembly  20  or while it contains the guidewire assembly  20 . The position of the micro-catheter  1  within the vasculature can be determined by identifying radio-opaque markers positioned on or in the micro-catheter  1 .  
         [0070]     After the micro-catheter  1  is positioned at the desired location, the guidewire is removed and the distal end of the introducer sheath  10  is inserted into the proximal end of the micro-catheter  1 , as shown in  FIG. 1 . In an embodiment, the distal end of the introducer sheath  10  is introduced through the hub  2  at the proximal end of the micro-catheter  1 . The introducer sheath  10  is advanced within the micro-catheter  1  until a distal tip of the introducer sheath  10  is wedged within the micro-catheter  1 . At this position, the introducer sheath  10  cannot be advanced further within the micro-catheter  1 . The introducer sheath  10  is then securely held while the delivery guidewire assembly  20  carrying the occluding device  100  is advanced through the introducer sheath  10  until the occluding device  100  is advanced out of the introducer sheath  10  and into the micro-catheter  1 .  
         [0071]     The guidewire assembly  20  and the occluding device  100  are advanced through the micro-catheter  1  until the tip coil  29  is proximate the distal end of the micro- catheter  1 . At this point, the position of the micro-catheter  1  and guidewire assembly  20  can be confirmed. The guidewire assembly  20  is then advanced out of the micro-catheter  1  and into the vasculature of the patient so that the proximal end  107  of the occluding device  100  is positioned outside the distal end of the micro-catheter  1  and adjacent the area to be treated. At any point during these steps, the position of the occluding device  100  can be checked to determine that it will be deployed correctly and at the desired location. This can be accomplished by using the radio-opaque markers discussed above.  
         [0072]     When the distal end  102  of the occluding device  100  is positioned outside the micro-catheter  1 , the proximal end  107  will begin to expand, in the direction of the arrows shown in  FIG. 7 , within the vasculature while the distal end  102  remains covered by the protective coil  35 . When the occluding device  100  is in the proper position, the delivery guidewire  21  is rotated (See  FIG. 8 ) until the distal end  102  of the occluding device  100  moves away from the protective coil  35  and expands within the vasculature at the desired location. The delivery guidewire  21  can be rotated either clockwise or counter clockwise as needed to deploy the occluding device  100 . In an embodiment, the delivery guidewire  21  may be rotated, for example, between two and ten turns in either or both directions. In another example, the occluding device may be deployed by rotating the delivery guidewire  21  clockwise for less than five turns, for example, three to five turns. After the occluding device  100  has been deployed, the delivery guidewire  21  can be retracted into the micro-catheter  100  and removed form the body.  
         [0073]     In one alternative or additional deployment method, the distal end  102  of the occluding device  100  may be passed outside of the micro-catheter  1 . The occluding device  100  may be further advanced so that the proximal end  107  of the occluding device  100  passes outside of the micro-catheter. However, in this example, the proximal end  107  of the occluding device  100  expands responsive to the application of pressure to the inner surfaces of the occluding device  100 . The applied pressure may be from any source. Examples of pressure exerted in the occluding device  100  include, but are not limited to, infusion of fluid or air into the lumen of the occluding device.  
         [0074]     The increase in pressure in the occluding device may cause the occluding device  100  to expand. Expansion of the occluding device  100  may cause a disconnection of the proximal end  107  of the occluding device  100  and/or the distal end  102  of the occluding device  100  such that the occluding device may substantially fill the lumen of the vessel. Alternatively, the increase in pressure in the occluding device may expand the occluding device  100  without detachment of either the proximal end  107  or the distal end  102  of the occluding device  100 . In this example, the occluding device  100  may be expanded without detaching the occluding device  100  from the delivery system. The expanded occluding device  100  may be adjusted and moved within the vessel in the expanded state while connected to the delivery system. When the occluding device  100  is at a desired location in the vessel, the occluding device  100  may be released from the delivery system. Release of the occluding device  100  from the delivery system may be accomplished in a variety of ways as described herein.  
         [0075]     In addition, the coverage of the occluding device  100  may be adjusted while the occluding device is expanded and connected to the delivery system. For example, the occluding device  100  may be unsheathed from the micro-catheter  1  and expanded under pressure (e.g., from fluid or air) such that the occluding device  100  is expanded in the vessel. The position of the occluding device  100  may be further adjusted. Also, the pressure applied within the occluding device  100  may be adjusted to increase the size of the expanded occluding device  100  in the vessel. Relative adjustments of the size of the expanded occluding device  100  (i.e., by adjusting the amount of pressure applied to the occluding device  100 ) and of the position or location of the occluding device  100  permit control of coverage of the occluding device when placed in the vessel.  
         [0076]     Also, a negative pressure may be applied (e.g., air suction or removal of fluid from within the occluding device  100 ) to cause the occluding device to retract. The retracted occluding device  100  may further be placed back into the micro-catheter  1 . In one example, the occluding device  100  may be expanded and retracted as desired for movement or placement of the occluding device  100  within the vessel.  
         [0077]     In an alternative or additional deployment step shown in  FIG. 9 , friction between the occluding device  100  and inner surface of the micro-catheter  1  cause the distal end of the occluding device  100  to separate from the protective coil  35 . The friction can be created by the opening of the occluding device  100  and/or the mid-coil  70  biasing the occluding device  100  toward the inner surface of the micro-catheter  1 . The friction between the micro-catheter  1  and the occluding device  100  will assist in the deployment of the occluding device  100 . In those instances when the occluding device  100  does not open and separate from the protective coil  35  during deployment, the friction between occluding device  100  and the inner surface of the micro-catheter  1  will cause the occluding device  100  to move away from the protective coil  35  as the delivery guidewire  21  and the micro-catheter  1  move relative to each other. The delivery guidewire  21  can then be rotated and the occluding device  100  deployed within the vessel.  
         [0078]     After the occluding device  100  radially self-expands into gentle, but secure, contact with the walls of the vessel so as to occlude the neck of the aneurysm A, the micro-catheter  1  may be removed entirely from the body of the patient. Alternatively, the micro-catheter  1  may be left in position within vasculature to allow for the insertion of additional tools or the application of drugs near the treatment site.  
         [0079]     Known materials can be used in the present invention. One common material that can be used with the occluding device  100  and the guidewire  21  is Nitinol, a nickel-titanium shape memory alloy, which can be formed and annealed, deformed at a low temperature, and recalled to its original shape with heating, such as when deployed at body temperature in the body. The radio-opaque markers can be formed of radio-opaque materials including metals, such as platinum, or doped plastics including bismuth or tungsten to aid in visualization.  
         [0080]     The apparatus and methods discussed herein are not limited to the deployment and use within the vascular system but may include any number of further treatment applications. Other treatment sites may include areas or regions of the body such as organ bodies. Modification of each of the above-described apparatus and methods for carrying out the invention, and variations of aspects of the invention that are obvious to those of skill in the art are intended to be within the scope of the claims. Furthermore, no element, component or method step is intended to be dedicated to the public regardless of whether the element, component or method step is explicitly recited in the claims.