Electrolytically severable joint for endovascular embolic devices

Description: TECHNICAL FIELD [Detailed description of the invention]

【0001】

[Technical field to which the invention belongs]

This application is filed on November 3, 1993, entitled "Electrolytically Separable Joints for Intravascular Embolic Equipment," US Patent Application No. 08 / 147,529 (June 13, 1995). It is a partial continuation application (issued as US Pat. No. 5,423,829), and the entire application is used as a reference.

【0002】

The present invention is a device for intravascular occlusion due to thrombosis in arteries, veins, aneurysms, vascular malformations, and arteriovenous fistulas. More specifically, the present invention is an improved sacrificial link between an intravascular device that has been introduced and intended to remain at the desired thrombus formation site and the device used to introduce this device. sacrificial link). The present invention further includes a method of introducing the tool and a method of electrolyzing the device thereof.

【0003】

[Conventional technology]

In North America, about 25,000 intracranial aneurysms rupture each year. The main purpose of treating a ruptured intracranial aneurysm is to prevent rebleeding. There are various methods for treating ruptured and unruptured aneurysms.

【0004】

Perhaps the most widely known of these techniques is the extravasational approach with surgery or microsurgery. This treatment is common for intracranial serous aneurysms. The method includes the steps of clipping the neck of the aneurysm, suturing and ligating the neck, or wrapping the entire aneurysm. Each of these techniques is performed by intrusive invation into the body and is performed from outside the aneurysm or target site. These surgical procedures typically require general anesthesia, craniotomy, brain retraction, and placement of clips around the neck of the aneurysm. Surgical procedures are often postponed while waiting for the patient to become medically stable. As a result, many patients die of the underlying disease or defect before the procedure begins.

【0005】

Another procedure, namely the extravasation-intravascular approach, involves surgically exposing the aneurysm or reaching the aneurysm stereotactically using a probe. The wall of the aneurysm is then perforated from the outside, and various techniques are used to occlude the inside to prevent it from rebleeding. Techniques used to occlude an aneurysm include electrical thrombus formation, adhesive thrombus formation, pig hair embolization, and ferromagnetic thrombus formation. These techniques are described in U.S. Pat. No. 5,122,136 of Guglielmi et al.

【0006】

A further approach is the least invasive, and is further described by Guglielmi et al. It is an intravascular approach. In this approach, the interior of the aneurysm is inserted by the use of a catheter as shown in Engelson (catheter guidewire), US Pat. No. 4,884,579, and further Engelson (catheter for guidewire tracking), US Pat. No. 4,739,768. To. These patents describe tools that utilize guidewires and catheters that allow access to the aneurysm from remote parts of the body. More specifically, by the use of a catheter with a highly flexible distal region and a guide wire that can be steered into the region of the aneurysm, embolic devices that can be delivered via this catheter are extravascular and An alternative to the extravascular-intravascular approach.

【0007】

The intravascular approach typically involves two major parts. The first part involves the introduction of a catheter into the aneurysm site using a tool as shown in the Engelson patent. The second part often involves filling the aneurysm in a particular or other way. For example, a balloon can be introduced into the aneurysm from the distal portion of the catheter, where the balloon is inflated, detached, and left to occlude the aneurysm. In this method, the causative artery is secured. The balloon is due to the difficulty of introducing the balloon into the aneurysm sac, due to the possibility of aneurysm rupture due to overinflation of the balloon within the aneurysm, and to the traction that occurs when the balloon is withdrawn. Due to the risks involved, it is preferably smaller.

【0008】

A particularly desirable embolization tool that can be introduced into an aneurysm using an intravascular placement technique is found in Ritchart et al., US Pat. No. 4,994,069. It describes a tool that can be introduced into an aneurysm via a catheter as described in Engelson above, i.e., typically a platinum / tungsten alloy coil with a very small diameter. These coils are often formed from wires with a diameter of 2-6 mils (0.051-0.15 mm). The diameter of the coil can be 10-30 mils (0.25-0.76 mm). These flexible and flexible coils can have any desired and appropriate length for the site to be occluded. For example, these coils can be used to fill an intracranial aneurysm. Within a short time after the aneurysm is filled with the embolic device, a thrombus is formed in the aneurysm and soon after it is replenished with a collagenous substance that significantly reduces the likelihood of aneurysm rupture.

【0009】

Coilers such as those found in Ritchart et al., For example, mechanically disengage them from delivery tools as set forth in Palermo's US Pat. No. 5,250,071 or as described in Guglielmi et al. (US Pat. No. 5,122,136) above. It can be delivered to the vasculature site by a variety of methods, including by electrolytic withdrawal.

【0010】

Guglielmi et al. Demonstrate an embolus forming tool and procedures for using the tool. More specifically, Guglielmi et al. Fill a vascular cavity, such as an aneurysm, with an embolic device, such as a platinum coil, which coil is delivered through the vessel. The coil is then separated from its insertion tool by the application of a small current. Desirably, the insertion tool comprises a guide wire, which sacrificial is an electrolyzable sacrificial junction to the embolic device at its distal end. It is attached by joint). Guglielmi et al. Suggest that if the embolic tool is a platinum coil, the platinum coil can be 1-50 cm, or longer if desired. Proximal to the embolic coil is a guide wire, which is often constructed of stainless steel. The guide wire is clearly very gentle and is used to push the platinum embolic coil into the occluded vessel site. This patent describes various methods of connecting an embolic coil to a push-in guide wire. For example, the guide wire is tapered at its distal end, and the distal tip of the guide wire is soldered into the proximal end of the embolic coil. In addition, the stainless steel coil coaxially wraps around the distal tapered portion of the guidewire to give the guidewire strut strength. This coaxial stainless steel wire is joined to both the guide wire and the embolic coil. Insulators can be used to cover the portion of the stainless steel coil that provides strength. This arrangement provides two areas that must be electrolyzed before the embolic coil is separated from the guide wire.

【0011】

A further variant of the detachable coil of Guglielmi et al. Is a coil in which the distal tip of a stainless steel guidewire is not soldered to the proximal end of the embolic tool. Simple conical stainless steel wires are included, from stainless steel guide wires to embolic coils.

【0012】

Further variants found by Guglielmi et al. Include a thin thread-like extension between the guidewire core and the proximal end of the embolic coil. In this method, the guide wire does not extend to the embolic coil and instead relies on a separately introduced extension.

【0013】

US Pat. No. 5,354,295 (issued October 11, 1994), a partial continuation of the above Guglielmi et al. Patent, states that "the formation of thromboses in arteries, veins, aneurysms, vascular malformations and arteriovenous fistulas. Intravascular Electrolytic Detachable Wires and Improvements at the Tip for Intravascular Detachable Embolic Equipment for Mechanically Detachable and Electrolytically Detachable Embolic Tools. Embolic tools can be augmented by attaching filaments.

【0014】

Dr. Taki et al. Described a detachable coil with a copper link between the core wire and the coil, which is "Treatment of spontaneous carotid cavernous fistula with detachable microcoils", American Journal of Neuroradiology. , Vol. 14 (1993).

【0015】

[Problems to be Solved by the Invention]

None of the above techniques using electrolytically detachable embolic devices suggest the construction of sacrificial links described herein. INDUSTRIAL APPLICABILITY According to the present invention, the embolic device can be easily and quickly removed cleanly.

【0016】

An object of the present invention is to provide a guide wire with an improved sacrificial link between a removable embolic device and a core wire for introducing it in order to easily and quickly disengage the embolic device cleanly. is there.

【0017】

[Means for solving problems]

The present invention relates to a guide wire used in combination with a catheter to form a vascular occlusion, the guide wire being a core wire having a distal end and at least one so as not to undergo electrolytic separation in blood. A core wire insulated with a layer of adhesive polymer coating; a separable sacrificial separable link formed at the distal end of the core wire and undergoing electrolysis in blood; and the sacrificial link to the core wire. A separably connected elongated tip that extends distally beyond the core wire and is adapted to form the occlusion at a selected site within the blood vessel of the mammal. The tip is insulated with at least one layer of adhesive polymer coating just distal to the link to prevent the tip from undergoing electrolysis in the blood, and the sacrificial link is electrolyzed. It comprises a tip portion that is separable from the core wire at the time of target separation, and where the link has a circular cross section with a predetermined diameter, further such that the link has a length not exceeding the diameter. doing.

【0018】

In a preferred embodiment, the adhesive polymer coating consists of a material selected from polyfluorocarbons, polyxylene, polyethylene, polypropylene, polyurethanes, polyimides, and silicone polymers.

【0019】

In a preferred embodiment, the at least one adhesive polymer coating is polyfluorocarbon.

【0020】

In a preferred embodiment, the at least one adhesive polymer coating is polytetrafluoroethylene.

【0021】

In a preferred embodiment, the at least one adhesive polymer coating is polyxylene.

【0022】

In a preferred embodiment, the elongated tip is a coil.

【0023】

In a preferred embodiment, the elongated tip portion comprises a platinum alloy coil.

【0024】

The present invention also relates to a guide wire used in combination with a catheter to form a vascular obstruction, which is a core wire having a distal end and at least one so as not to undergo electrolytic separation in blood. A core wire that is insulated by a layer of two adhesive polymer coatings, located coaxially around the axis of the core wire, and electrically connected to a coil that is electrically insulated from the surrounding blood; formed on the coil. A separable sacrificial separable link that is and undergoes intensive electrolysis separation in the blood; and an elongated tip that is separably connected to the core wire by the sacrificial link. It extends distally beyond the core wire and is adapted to form the occlusion at a selected site within the vasculature of the mammal, the tip of which is electrolyzed in the blood. Immediately distal to the link, it is insulated with at least one layer of adhesive polymer coating and has a tip that is separable from the core wire during electrolytic separation of the sacrificial link. And here, the link has a circular cross section having a predetermined diameter, and the link further has a length not exceeding the diameter.

【0025】

In a preferred embodiment, the separate sacrificial link is a cut in the insulator on the coaxial coil.

【0026】

In a preferred embodiment, the separate sacrificial link is a groove created by laser scoring through the polymer coating.

【0027】

As described above, the present invention is a tool for forming a vascular occlusion at a selected site. Generally, the device comprises a guide wire having a distal tip, which can be introduced into a selected vascular site or cavity. The guidewire is joined to the distal tip or embolic device so that the vascular device can be electrolyzed away by applying an electric current to the core or guidewire. Improvements include the use of a separate sacrificial link between the core wire and the vascular device that allows for clean and quick disengagement from the guide wire. More specifically, the most desirable of the improved sacrificial joints is probably a narrow band cut from a coating (eg, a polymer coating attached to a metal substrate) by laser cutting. Focused electrolysis found at sacrificial sites reduces the overall likelihood of multiple electrolysis sites occurring and the release of large particles from those sites.

【0028】

There are several variations of sacrificial joints, including the use of a wide range of electrical insulation around the core wire, and any support coil, or a direct coating on the surface that undergoes electrolysis. The most desirable of the improved sacrificial joints is probably a narrow band cut from the coating (eg, a polymer coating attached to a metal substrate) by laser cutting.

【0029】

BEST MODE FOR CARRYING OUT THE INVENTION

Each of the separate sacrificial joints described below may be used in the equipment set forth in U.S. Pat. No. 5,122,136 of Guglielmi et al., The entire patent of which is incorporated by reference.

【0030】

The first of such modifications is shown in FIG. The assembly 100 is generally formed from a guide or core wire 102 that tapers to a point at the distal end and is soldered to the proximal end of the vascular occlusion tool 104. The vascular occlusion tool 104 is a coil in this case. The entire core wire 102, except for the most distal exposed joint or sacrificial link 106, is polyfluorocarbon (eg, Teflon®), polyurethane, polyethylene, polypropylene, polyimide, or other suitable polymer. Covered with insulating material such as material. The link 106 is not covered with an electrical insulator and is formed from an electrolyzable and separable material in the blood. The core wire 102 is typically stainless steel and can be provided within a protective catheter (not shown). The stainless steel guide wire 102 typically has a diameter of about 10 mils to 30 mils (0.25 mm to 0.76 mm). The guide wire is often 50 cm to 300 cm in length from the insertion site outside the body to the sacrificial link 106.

【0031】

The sacrificial link 106 is a separate link. By "discrete" is preferably meant that the junction is substantially dissolved upon release of the vascular occlusion device 104. Alternatively, "separated" means that the length of the link 106 is less than or equal to the diameter of the sacrificial link 106, or the electrolytic surface present after the vascular occlusion device is released is substantially the diameter of the sacrificial link 106. It can mean that it is not larger than the surface of the circle it has.

【0032】

Figure 1 is also soldered at the proximal end and is typically designed to provide any strut strength for the guidewire assembly while not adversely affecting the flexibility of the taper of the core wire 102. The coil 108 is shown. Obviously, in the region where the support coil 108 is soldered to the core wire 102, there is no coating on the 102, which allows the solder to adhere to the metal surface. In addition, a pair of insulators, the sleeve 110 and the end plug 112, can be seen at the distal tip of the core wire 102. The sleeve 110 and end plug 112 are used to further remove contact between the stainless steel coil 108 and blood during the electrolyte removal step. Preferably, the end plug 112 and sleeve 110 form a housing around the coil 108 that is in close contact with each other and does not undergo electrical insulation or electrolysis. The end plug 112 and sleeve 110 in the figure are generally flat and form a plane perpendicular to the axis of the core wire 102.

【0033】

As described above, the distal end of the guide wire or core wire 102 is inserted into the solder joint 114 that forms the proximal end of the vascular occlusion tool 104.

【0034】

As described in more detail below, the separable sacrificial link 106 dissolves completely or substantially completely during electrolysis.

【0035】

FIG. 2 shows the most suitable modification of the tool of FIG. 1 having a guide wire or a core wire 102. The tool can be point-tapered at its distal end and, in this case, soldered to the proximal end of the coiled vascular occlusion tool 104. Similarly, the distal portion of the guide wire 102 having the stainless steel coil 108 around it is entirely surrounded within the end plug 107 and sleeve 109 to further protect the guide wire and the included stainless steel coil 108. To do. The main difference between the instrument in Figure 1 and the link assembly shown in Figure 2 is the use of the distal region that forms the bias. The combination of the end plug 107 and the sleeve 109 allows blood (and thus electrolytic current) to clearly access the sacrificial link (106). The end plug 112 and sleeve 110 in the figure are generally planar, but form a planar surface that is not perpendicular to the axis of the core wire 102.

【0036】

Obviously, the shape of this surface is not very important in itself, except to the extent that blood is reasonably freely accessible to the sacrificial junction 106. Curved end face modifications, slotted modifications, and other modifications are also considered in the present invention.

【0037】

FIG. 3 shows a variant of the tool shown in FIG. 1 or 2, where the core wire 102 is soldered to a solder junction 114 in the vascular occlusion tool 104 and down to a point with a sacrificial link 106. There is also a coil 108 provided to impart additional strut strength to the core wire 102. The end plug 112 is also found in this tool. An example of this modification is in the outer sleeve 116. In this variant, the outer sleeve extends to and contacts the solder joint 114 found at the end of the vascular occlusion tool 104. To allow the sacrificial link 106 to make electrical contact with the patient's blood, the sleeve 116 has many openings to allow contact between the blood and the sacrificial link 106. The opening 118 can be found in both the cross sections found in FIGS. 3 and 4. Cross sections of the end plug 112 and the sacrificial link 106 can also be found in FIG. The variants shown in FIG. 3 may have slightly more physical strength, but the electrolysis step may be slightly slower due to the smaller region through the opening 118.

【0038】

FIG. 5 shows another modification of the sacrificial joint of the present invention. The tool of this example also has a guide wire or core wire 120 that tapers into small dots that are soldered to the solder joint 114 at the end of the vascular occlusion tool 104. Again, similar to the equipment in FIGS. 1, 2, and 3, the core wire 120 is all insulated, such as Teflon® polymer or other suitable insulating polymer, except for the most distal portion 122. Coated with sex material. However, in this case, the sacrificial link 122 forming the distal end of the core wire 120 is surrounded by a release spring 124, similar to the tapered portion of the guide wire 120. The release spring 124 is attached to the guide wire body 120, but not to the solder joint 114 of the vascular occlusion tool 104. The discharge spring 124 is slightly compressed. However, there is some space between adjacent bends, as seen in the proper position on the core wire 120. In this way, the blood has access to the sacrificial link 122 between the adjacent bends of the release spring 124. When the sacrificial link 122 dissolves, the release spring 124 gradually pushes the vascular occlusion tool 104 away from the tip of the guide wire or core wire 120. If the release spring 124 needs to be welded or soldered to the core wire 120, the release spring 124 is completely insulated except where it is clearly connected to the core wire 120.

【0039】

FIG. 6 shows the invention in which the core wire 126 is tapered and soldered directly to the interior of the coil 128 at the solder joint 130 or to the joint 130 by being connected to a link. An example of modification of the tool is shown. The support spring 132 inside the coil 128 can be used in the same fashion as shown in FIGS. 1, 2, and 3. For safety, the coil 128 and the support spring 132 are fixed to the core wire 126. The coil 128 is also electrically connected to the core wire 126. The core wire 126, the coil 128, and the support spring 132 are all insulated so as to prevent electrolysis when a voltage is applied to the core wire 126. The exception to this isolation is the scribe or score mark 134, which forms a separate sacrificial link. The score mark 134 is shown in more detail with reference to FIG. In addition, in the effect of scribe or score mark 134 as shown in FIG. 6, electrolysis occurs only in a narrow area, and when coil 128 is completely separated by electrolysis at that time, other than core wire 126 or spring 128. There is little chance of electrolysis occurring at this location.

【0040】

The vascular occlusion tool 104 is shown as a coil in each of the above drawings. The vascular occlusion device can be a coil, braid, or other vascular occlusion tool that is already known. The vascular occlusion tool can be tied to the outside of the coil or, as desired, covered or connected with a fibrous material woven with the outer cover of the coil. Such fibrous aids can be described by Phelps et al., U.S. Patent Application No. 07 / 965,973 (issued January 17, 1995, U.S. Pat. No. 5,382,259), or "Vascular Occlusion with Fibrous Members Attached." It can be found in US Patent Application No. 07 / 771,013 entitled "Coil" (issued as US Pat. No. 5,226,911 on July 13, 1993), all of which are incorporated for reference.

【0041】

In addition to the use of shrink wrap tubing, including polyethylene, polypropylene, polyurethane, polyethylene terephthalate, polyvinyl chloride, etc. as the insulator on the core wire, another suitable thermoplastic resin is commonly known as parylene. There are various polymers based on para-xylylene (eg, polyxylylene, polyxylylene). These polymers are typically placed on the substrate by vapor phase polymerization of the monomers. The parylene N coating is produced by vaporization of the di (P-xylylene) dimer, pyrroleization, and condensation of vapors to produce the polymer, which is maintained at a relatively low temperature. In addition to parylene N, parylene C is derived from di (monochloro-P-xylylene) and parylene D is derived from di (dichloro-P-xylylene). There are various known methods for applying parylene to a substrate. Their use in surgical instruments is, for example, US Pat. No. 5,380,320 (JR). It is shown in US Pat. No. 5,174,295 (by Christian et al.), US Pat. No. 5,067,491 (by Taylor et al.), Etc. (by Morris et al.). Since the tools of the present invention are single-use tools, various parylenes are particularly suitable in the area of electrolyzably separable junctions as an external insulating layer. This is especially true when the covered utensil is anneled.

【0042】

One highly desirable variant of the invention is that at least the area near the electrolyzable joint is covered with parylene and a very narrow band is removed, for example using a laser. Form a sacrificial joint. Coatings smaller than about 0.001 inch (0.025 mm) are highly desirable, more preferably smaller than about 0.00075 inch (0.019 mm).

【0043】

More specifically, FIG. 8 shows a joint similar to that shown in FIG. 5 or 6. The tool has a guide wire or core wire 137 tapered to a small point that is incorporated into the solder joint 114 at the end of the vascular occlusion tool 104. As seen in FIG. 8, at least a portion of the core wire 137 is coated with parylene coating 139. The core wire 137 at the distal end of the figure seen in FIG. 8 can also be coated with parylene, if desired or if desired. Laser-scribed region 141 is prepared by cutting out the previously coated parylene using a laser. An ultraviolet excimer laser with appropriate power output is suitable. The width of the laser scribed area 141 is extremely narrow, typically about 0.010 inches (0.25 mm) or less, preferably about 0.005 inches (0.13). mm) or less. The laser scribed area 141 can be adjacent to the solder joint 114 or the weld joint; this results in a clean "tail" in the coil after it has been deployed. However, the laser scribed region 141 can be anywhere in the region.

【0044】

This procedure has proven reliable and produces good joints steadily with predictable deployment times.

【0045】

We also use a polyfluorocarbon spray, eg, a PTFE solid in a suitable solvent carrier, to create an insulating layer for the core wire portion of the assembly, especially the core wire portion proximal to the sacrificial junction. I found it useful to do.

【0046】

In the alternative method described above, at least a portion of the area of the assembly distal to the sacrificial junction is covered with one or more polymer coatings selected from the polymers listed above; this area is usually covered. There is no need to extend to the bushing or coil solder joints described above. The area of the core wire assembly proximal to the sacrificial junction can also be covered with a polymer coating selected from one or more of the polymers listed above; the insulating area is usually very much in the catheter. It does not have to extend far, but it does.

【0047】

FIG. 9 shows a typical layout including the separable sacrificial joint 106 of the present invention, as is commonly shown in the drawings above. In FIG. 9, to some extent a conventional Teflon® laminated or similarly insulated stainless steel guidewire assembly 140 may be provided within the protective catheter. As mentioned above, the stainless steel guide wire 140 has 10 to 30 mils (0.25 to 0.76). Can have a diameter of mm). In the embodiment shown in FIG. 9, the guidewire assembly 140 is tapered at its distal end to form a conical portion 142. The cone 142 joins an additional portion 144 that extends along the length of the guide wire 146. The portion 144 then gradually narrows towards the thinner portion 148. As mentioned above, the guidewire assembly 140 can be placed within the catheter body, and the length to the sacrificial link 106 is typically 50 cm to 200 cm. As shown in FIG. 1, the distal portion of the guidewire assembly 140 has an outer sleeve 150 (or a sleeve formed from other suitable insulating material) made of Teflon®. In addition, the distal part has a terminal plug 152, which can electrically isolate the guidewire from the blood, except for the separate sacrificial link 106. The proximal end of the vascular occlusion device 104 is typically a soldered tip or junction 114. Preferably, if the vascular occlusion device 104 is a coil, the vascular occlusion device forms a secondary loop after being released from the end of the catheter. The distal end of the vascular occlusion device 104 may also have a terminal plug or tip that prevents the aneurysm from being punctured when introduced into the aneurysm sac.

【0048】

As mentioned above, the coil or vascular occlusion device 104 can be pre-biased to form a columnar or conical envelope. However, the vascular occlusion tool 104 is very flexible, and its overall shape is easily deformed. The vascular occlusion tool 104, when inserted into a catheter (not shown), easily straightens and is axially placed within the catheter. The vascular occlusion device 104, once released from the tip of the catheter, can form the shape shown in FIG. 9 or can be gently deformed to fit the internal shape of the aneurysm.

【0049】

FIG. 10 shows the installation of the above-mentioned tool of the present invention in the blood vessel 156 having the tip of the catheter 158 placed near the neck 160 of the aneurysm 162. The vascular occlusion device 164 is delivered into the aneurysm 162 at least until the sacrificial link 106 is exposed beyond the distal tip of the catheter 158. At 0.1 to 6 volts, a positive current of about 0.01 to 2 mA is supplied to the guidewire 166 to form a thrombus in the aneurysm 162. The negative electrode 168 of the power source 170 is typically arranged in electrical contact with the skin.

【0050】

After the thrombus is formed and the aneurysm is closed, the vascular occlusion device 164 is removed from the guide wire 166 by electrolytic separation of the sacrificial link 106.

【0051】

The aneurysm 162 remains obstructed, as shown in FIG. 11, after the sacrificial link 106 is at least almost dissolved by electrolysis, typically within 2 minutes, most often within 1 minute. Then, the guide wire 166 and the catheter 158 are removed from the blood vessel 156.

【0052】

This process is typically performed under the control of fluoroscopy with local anesthesia. To treat an aneurysm in the brain, a transfemoral catheter is used and is usually introduced from the groin. If the vascular occlusion device 164 is made of platinum, it is unaffected by electrolysis. Only the exposed portion of the sacrificial link 106 is affected by electrolysis if the relevant portion of the guide wire and support coil is properly coated with an insulating cover at the distal end of the guide wire.

【0053】

Many changes and modifications can be made by one of ordinary skill in the art without departing from the spirit and scope of the invention. Therefore, it should be understood that the shape of the tip or distal platinum coil used in combination with the guide wire according to the invention has a variety of shapes and envelopes.

【0054】

The above embodiments are used only for the purposes of simplification and are not intended to limit the invention as defined by the following claims.

【0055】

[Effect of the invention]

The use of a guidewire with an improved separable sacrificial link allows the embolic device to be easily and quickly detached cleanly and electrolyzed from the guidewire.

[Simple explanation of drawings]

[Figure 1]

FIG. 5 is a side sectional view of a modified example of an electrolyzable sacrificial link between a core wire and an embolic tool according to the present invention.

[Figure 2]

FIG. 5 is a side sectional view of a modified example of an electrolyzable sacrificial link between a core wire and an embolic tool according to the present invention.

[Fig. 3]

FIG. 5 is a side sectional view of a modified example of an electrolyzable sacrificial link between a core wire and an embolic tool according to the present invention.

[Fig. 4]

It is sectional drawing of the modification shown in FIG.

[Fig. 5]

FIG. 5 is a side sectional view of a modified example of an electrolyzable sacrificial link between a core wire and an embolic tool according to the present invention.

[Fig. 6]

FIG. 6 is a side sectional view showing a modified example of an electrolyzable sacrificial link between a core wire and an embolic tool according to the present invention.

[Fig. 7]

It is an enlarged side view of the modification as seen in FIG.

[Fig. 8]

It is a side view of the assembly including the laser scribed sacrificial link of the present invention.

[Fig. 9]

It is a side view which shows the typical assembly including the sacrificial link used in this invention.

[Fig. 10]

The method of installing the vascular occlusion tool using the sacrificial link of the present invention is schematically shown.

[Fig. 11]

The method of installing the vascular occlusion tool using the sacrificial link of the present invention is schematically shown.

[Explanation of symbols]

100 assemblies 102, 120, 126, 137, 166 Guide wire or core wire 104, 164 Vascular occlusion tool 106, 122 Sacrificial links 108, 128 coils 107, 112, 152 End plug 109, 110, 116, 150 sleeves 114, 130 Solder joint 124 Release spring 132 Support spring 134 scribe or score mark 140 guide wire assembly 158 Catheter 156 Blood vessels 162 Aneurysm 168 Negative electrode 170 power supply