US20110082491A1 - Devices and methods for treating vascular malformations - Google Patents

Abstract

The invention is also directed to a device for treating an aneurysm which has a cover covering the neck of the aneurysm and a lateral portion extending into the aneurysm. The invention is also directed to a cover which is used to cover the neck of the aneurysm thereby isolating the aneurysm from the parental vessel.

Description

CROSS-REFERENCES TO RELATED APPLICATIONS
• The present application is a continuation in part of U.S. patent application Ser. No. 09/324,359 filed Jun. 2, 1999 which is hereby incorporated by reference for all purposes.
BACKGROUND OF THE INVENTION
• The present invention relates to treatment of abnormalities in a patient's to vascular system. A specific use of the present invention described below is for the treatment of cerebral aneurysms although the various aspects of the invention described below may also be useful in treating other abnormalities such as arteriovenous malformations (AVM), hypervascular tumors, cavernous carotid fistulas, fibroid tumors, and non-reversible sterilization via fallopial occlusion.
• Cerebral aneurysms are enlargements of the cerebral vasculature which protrude like a balloon from the wall of a cerebral artery. The cerebral aneurysm has a neck which leads to the parental vessel and a body or “dome” which can vary in diameter from 1-30 mm.
• The wall of the aneurysm is often weak and can rupture, leading to hemorrhage. Rupture of the aneurysm can kill the patient or leave the patient with permanent or transitory mental and physical deficits.
• Aneurysms are often treated to prevent rupture, leading to hemorrhage, or to prevent rebleeding of acutely ruptured aneurysms. A conventional method of treating aneurysms is to fill the aneurysm with coils. The coils are introduced into the aneurysm one at a time through a delivery catheter until the aneurysm is filled. The aneurysm eventually becomes a solid mass of coils and thrombus.
• A problem with the conventional method of using coils to fill aneurysms is that the aneurysm becomes a relatively solid mass due to coils and thrombus contained therein. The mass of coil and thrombus exerts pressure on adjacent areas of the brain which may lead to other problems. Another problem with the conventional method is that the coils must be delivered one at a time into the aneurysm which increases the procedure time and risk to the patient. For large aneurysms, up to twenty coils may be required to fill the aneurysm.
• It is an object of the invention to provide improved methods and devices for treating aneurysms. These and other objects of the invention will become evident from the description of the preferred embodiments described below.
SUMMARY OF THE INVENTION
• In a first aspect of the present invention, a method of treating an aneurysm is provided. An expandable structure is delivered through the vasculature in a collapsed position. Once the expandable structure is at the desired location, such as within a cerebral aneurysm, the expandable structure is expanded. The structure and advantages of the expandable structure are described below. The aneurysm wall is also reduced in size so that the aneurysm does not need to be completely filled in the conventional manner. The expandable shape is sized to be smaller than the aneurysm to permit reducing the size of the aneurysm by at least 30% percent.
• A preferred method of reducing the size of the aneurysm is to heat the aneurysmal wall, preferably to a temperature of at least 60° and preferably 60-80° C., which causes the aneurysmal wall to shrink. The aneurysm may be heated in any suitable manner and preferred methods are monopolar and bipolar RF, laser, microwave, and simple electrical resistance heating. In a preferred method, electrical energy is delivered to the expandable device itself to generate heat. A fluid may be introduced into the aneurysm to prevent clotting during heating and to provide thermal and/or electrical conductance. When using RF heating, for example, the fluid may be saline and more preferably hypertonic saline. Although it is preferred to heat the aneurysmal wall to reduce the size of the aneurysm, the aneurysm may also be reduced in size by chemical action.
• The expandable structure forms a matrix of filaments in the expanded condition. The matrix preferably forms a woven or braided structure, however the filaments may also be randomly oriented, parallel, or non-intersection filaments. The matrix'may be flexible filaments, such as platinum ribbon, extending randomly, radially or helically within an expandable, permeable, mesh-like enclosure. The material may also be an expandable material such as polymer, nitinol, stainless steel, tungsten or tantalum and alloys/composites thereof.
• The expandable device preferably fills a volume of at least 10% of the aneurysm volume, more preferably at least 40% and most preferably at least 60% of aneurysm volume. The expandable device preferably has internal filaments within the volume to quickly form a stable thrombus. An advantage of the expandable device is that a three-dimensional structure forms without requiring separate delivery of a cage and coils as described in International Application WO 99/07293. In another aspect, the expandable device has a deforming portion which plastically deforms when moving to the expanded position. The deformable portion holds the flexible filaments in the expanded position.
• The aneurysm may be reduced in size until the aneurysmal wall contacts the expandable structure so that the expandable structure stipports and reinforces the aneurysmal wall. In a particularly advantageous embodiment of the invention, the expandable structure itself is used to transmit energy to heat the aneurysmal wall which causes the aneurysmal wall to fuse to the expandable structure, thereby reinforcing the aneurysmal wall and preventing migration of the expandable structure into the parental vessel.
• In another aspect of the invention, the aneurysmal wall may be reduced in size together with the expandable device. In a preferred embodiment, the expandable structure is a soft mesh which easily collapses when the aneurysmal wall is shrunk.
• Various optional steps and structure may also be provided. For example, a sealant may be delivered into the aneurysm to ensure that the aneurysm is isolated from the parental artery. An advantage of the present invention is that the sealant is held within a matrix formed by the expandable device which holds the sealant in the aneurysm.
• The proximal portion of the expandable structure may be insulated to protect the neck of the aneurysm. The insulation may coat only the flexible filaments so that the structure is still permeable to fluid. Alternatively, the insulation may be impermeable to protect the neck from hot fluid slowly expelled into the aneurysm or to isolate the aneurysm entirely from the parental vessel.
• The expandable device may have one or more expandable sections. In an embodiment, the expandable device has two expandable sections wherein energy is delivered to the dome with one of the sections while the second section is insulated to protect the neck.
• The expandable device may have a locking mechanism for locking the expandable device in the expanded position. The expandable device is naturally biased toward the collapsed position so that the operator may partially deploy the expandable device to determine whether the device has the appropriate size. If the device does not have the appropriate size, the device is collapsed and removed and another device having the appropriate size is introduced. The locking mechanism is then actuated when the user is satisfied with the size of the device.
• In still another aspect of the present invention, a catheter has a cover which is positioned over the neck of the aneurysm to isolate the aneurysm from the parental vessel. The aneurysm is then reduced in size as explained above while the cover isolates the aneurysm. The cover also protects the patient from hemorrhage by isolating the aneurysm from the parental vessel. The cover may be periodically moved to expel heated fluid into the parental vessel when heating and shrinking the aneurysm.
• In yet another aspect of the present invention, a coil is used to cover the neck of the aneurysm to regulate the flow of hot fluid out of the aneurysm and into the parental vessel. The pitch of the coil can be varied by the operator during deployment to allow faster or slower leakage of hot fluid out of the aneurysm and into the parent artery during heating.
• A catheter is also provided which has a low-impedance coil, such as flat copper ribbon or other suitable material, disposed in the catheter tip. Upon infusion of saline through the catheter and passage of RF energy through the coil, the saline is heated and conducts electrical energy to heat the fluid.
• These and other aspects and advantages of the invention will become evident from the following description, drawings and claims.
• Still another device for treating an aneurysm is provided which has a cover which covers the neck of the aneurysm to isolate the aneurysm from a parental vessel. The device also has a lateral extension which is coupled to the cover and extends into the aneurysm when the cover is positioned over the neck of the aneurysm.
• The cover is preferably a mesh and the lateral extension preferably forms 1-8 loops. The cover is preferably a substantially flat element which is positioned against a wall of the parental vessel around the neck of the aneurysm. The cover preferably extends no more than about 180 degrees around a longitudinal axis of the device when expanded so that branch vessels are not occluded by the cover. The extension is preferably expandable with one end connected to the cover and the other end sliding relative to the cover to permit the extension to expand and contract.
• The present invention describes still another device for treating an aneurysm which has the cover for covering the neck of an aneurysm. The cover is mounted to an expandable element and is covered by a retractable sheath. The sheath is preferably folded over itself at the distal end so that the cover is exposed as the sheath is pulled back over itself. The cover is preferably wrapped around the expandable member without overlapping folds, flaps or sections. The cover is preferably adhered to the parental vessel wall in any suitable manner such as with an adhesive. The cover may be a sheet of material or a metallic frame having impermeable layer attached thereto.
• Yet another device for treating an aneurysm is provided which has a plurality of filaments extending between proximal and distal hubs: The filaments preferably form a generally concave surface which covers a neck of an aneurysm when positioned in the aneurysm. The device may also have a concave side opposite the convex side. The filaments form overlapping loops when viewed along an axis through the hubs. The filaments are preferably in a relatively straight configuration when advanced through the delivery catheter to the aneurysm.
• Still another device for treating an aneurysm has a plurality of filaments, preferably 2-4 filaments, with the proximal ends of the filaments being coupled together and the distal end of the filaments being free. Each of the filaments preferably form a coil in the expanded position. The coils may have a central axis generally lying in the same plane.
BRIEF DESCRIPTION OF THE DRAWINGS
• FIG. 1 is a system for treating a patient's vascular system.
• FIG. 2 shows an expandable device in a collapsed position.
• FIG. 3 is a perspective view of the expandable device with the mesh removed.
• FIG. 4 is a cross-sectional view of the expandable device.
• FIG. 5 shows the expandable device in an aneurysm.
• FIG. 6 shows the expandable device detached from the delivery catheter.
• FIG. 7 shows the expandable device ofFIG. 6 with a sealant introduced into a portion of the expandable, device.
• FIG. 8 shows the sealant filling the aneurysm and the expandable device.
• FIG. 9 shows the expandable device having a proximal portion which is relatively impermeable to the sealant so that the sealant is retained in the aneurysm.
• FIG. 10 shows the expandable device filled with an expandable material such as random fibers or a coil.
• FIG. 11 shows another expandable device which is deployed with a balloon in a collapsed position.
• FIG. 12 shows the expandable device ofFIG. 11 in an expanded position.
• FIG. 13 shows the expandable device reduced in size and the expandable device having a proximal portion which is insulated to protect the neck of the aneurysm.
• FIG. 14 shows the expandable device ofFIG. 11 with simple resistance heating used to shrink a portion of the aneurysm into contact with the expandable device.
• FIG. 15 shows the use of simple resistance heating to shrink another portion of the aneurysm into contact with the expandable device.
• FIG. 16 shows a heating device.
• FIG. 17 shows a heating device with the tip curved.
• FIG. 18 shows the heating device used with the expandable device ofFIGS. 11-14.
• FIG. 19 shows the aneurysm shrunk into contact with the expandable device.
• FIG. 20 shows the expandable device reduced in size during shrinking of the aneurysm.
• FIG. 21 shows another expandable device having a locking mechanism for holding the device in the expanded position.
• FIG. 22 shows the expandable device ofFIG. 21 with the device in the expanded position.
• FIG. 23 shows the device ofFIGS. 21 and 22 released from the delivery catheter.
• FIG. 24 shows a catheter having a cover for isolating an aneurysm from the parental vessel.
• FIG. 25 is a cross-section of the catheter ofFIG. 21 along line A-A.
• FIG. 26 shows the catheter ofFIG. 21 with the cover having a curved shape.
• FIG. 27 shows the catheter ofFIG. 21 isolating an aneurysm.
• FIG. 28 shows the aneurysm reduced in size and a thrombogenic material and sealant introduced into the aneurysm.
• FIG. 29 shows only the thrombogenic material in the aneurysm.
• FIG. 30 shows another expandable device in a collapsed position.
• FIG. 31 shows the expandable device ofFIG. 30 in an expanded position.
• FIG. 32 is an alternative embodiment of the device ofFIGS. 30 and 31.
• FIG. 33 is another alternative embodiment of the device ofFIGS. 30 and 31.
• FIG. 34 shows a mesh structure for use with any of the expandable devices described herein.
• FIG. 35 shows a number of expandable device delivered to the aneurysm.
• FIG. 36 shows the aneurysm ofFIG. 35 reduced in size.
• FIG. 37 shows a coil for regulating flow between an aneurysm and a parent vessel.
• FIG. 38 shows the coil ofFIG. 37 with the windings spaced close together to further impede fluid flow between the aneurysm and the parent vessel.
• FIG. 39 shows another catheter for heating tissue.
• FIG. 40 is a cross-sectional view of the distal end of the catheter ofFIG. 39.
• FIG. 41 shows the tip of the catheter ofFIGS. 39 and 40 with holes at the distal end of the tip.
• FIG. 42 shows the tip of the catheter ofFIGS. 39 and 40 with holes along the side of the tip.
• FIG. 43 shows another device for treating an aneurysm.
• FIG. 44 shows the device ofFIG. 43 contained within a catheter for delivery to the aneurysm.
• FIG. 45 shows an extension of the device positioned in the aneurysm.
• FIG. 46 shows the device ofFIGS. 43-45 deployed with a cover over the neck of the aneurysm.
• FIG. 47 shows another device for treating an aneurysm.
• FIG. 48 shows the device ofFIG. 47 partially deployed with an expandable element:
• FIG. 49 shows the device ofFIG. 48 with the sheath full retracted and the expandable element expanded to move the cover over the neck of the aneurysm.
• FIG. 50 shows the device ofFIG. 47-49 fully deployed.
• FIG. 51 shows an alternative cover for the device ofFIGS. 47-49.
• FIG. 52 shows yet another device for treating aneurysms in a collapsed position.
• FIG. 53 is a side view of the device ofFIG. 52 in an expanded condition.
• FIG. 54 is a plan view of the device ofFIG. 52 in an expanded condition.
• FIG. 55 shows a catheter delivering the device ofFIGS. 52-54 to an aneurysm.
• FIG. 56 shows the device ofFIGS. 52-54 deployed in the aneurysm.
• FIG. 57 shows still another device for treating an aneurysm.
• FIG. 58 shows the device ofFIG. 57 deployed within an aneurysm.
• FIG. 59 shows a plan view of the device ofFIGS. 57 and 58.
• FIG. 60 shows an alternative to the device ofFIGS. 57-59.
• FIG. 61 shows another alternative to the device ofFIGS. 57-59.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
• Referring toFIG. 1, asystem2 for introducing anexpandable device4 into a cerebral aneurysm is shown. Afirst catheter6 extends through a penetration in the femoral artery and up to the carotid artery. Asecond catheter8 is advanced through thefirst catheter6 and into the cerebral vasculature to the site of the aneurysm or other abnormality. Adelivery catheter10 is then advanced through thesecond catheter8. Thecatheter10 delivers anexpandable device4 which partially fills the aneurysm as will be described below. Thesystem2 also has anenergy supply12 for heating the aneurysm to shrink the aneurysm as will be described below.
• After theexpandable device4 has been delivered to the aneurysm and expanded, the aneurysm is reduced in size as shown inFIG. 6. The aneurysm may be shrunk partially toward theexpandable device4, into engagement with theexpandable device4, or may even be shrunk until theexpandable device4 is also reduced in size. An advantage of shrinking the aneurysm is that the aneurysm does not need to be completely filled with coils in the conventional manner. The conventional method of filling the aneurysm with coils creates a relatively solid mass in the aneurysm which can press against adjacent structures leading to further problems. Theexpandable device4 is removably mounted to the end of a shaft5 in the manner described below so that theexpandable device4 may be released in the aneurysm. The expandable device may be released with a mechanical mechanism, a thermoadhesive bond, or an electrolytically or chemically severable bond.
• The aneurysm may be shrunk in any suitable manner and a preferred method is to heat the aneurysmal wall. Shrinking of the aneurysm may also be accomplished through chemical action. The aneurysmal wall is preferably heated to a temperature of 60-80° C. and preferably at least 70° C. Depending upon the size of the aneurysm, the aneurysmal wall is preferably heated for at least 10 seconds and generally between 10 seconds and 5 minutes.
• In the preferred system ofFIG. 1, theenergy supply12 supplies RF energy to heat and shrink the aneurysm. Theexpandable device4 is preferably configured as a mono-polar RF electrode14 and theenergy supply12 is preferably an RF generator. A suitable second electrode (not shown) is placed in contact with the patient's skin in the conventional manner. The aneurysm may, of course, be heated with the energy supply being a hot fluid, laser, microwave, bi-polar RF or a resistance heating device without departing from the scope of the invention.
• Referring toFIGS. 1 and 4, thecatheter8 has alumen16 coupled to a source offluid18 which is preferably a conductive fluid such as saline and more preferably hypertonic saline. Thelumen16 may also be coupled to a source ofsealant20 which may be used to seal the aneurysm as described below. The sealant may be any suitable sealant such as cyanoacrylates, ethylene vinyl-alcohol, cellulose acetate polymers, fibrin glues and other liquid-type tissue sealants. The sealants may also be bioperodable and/or bio-absorbable. Thelumen16 is also coupled to avacuum source22 for suctioning fluids and reducing the size of the aneurysm. A source ofcontrast24 is also provided for visualization of the aneurysm, vasculature and device positions. Avalve26 couples thelumen16 to thevarious sources18,20,22,24. Thedelivery catheter10 also has alumen28 which may be coupled to thesources18,20,22,24 and discussion of use of thelumen16 is equally applicable for thelumen28.
• Referring toFIGS. 2,3 and5, theexpandable device4 has first and second expandingsections30,32. Although it is preferred to provide both the first and second expandingsections30,32, theexpandable device4 may include only one expanding section or three or more expanding sections without departing from the scope of the invention. Thefirst section30 acts as theelectrode14 to deliver RF energy from theenergy source12 to the aneurysm. Thesecond section32 is insulated and does not transmit energy to the aneurysm so that the neck of the aneurysm is protected. Thesecond section32 is preferably coated with PTFE, polyamide, FED, or PFA to prevent RF energy transmission. Protecting the neck of the aneurysm also protects peripheral vessels adjacent the neck of the aneurysm.
• The secondexpandable section32 may be permeable to fluid so that heated fluid in the aneurysm may be slowly expelled into the parental vessel to dissipate heat. Thesecond section32 may also have a fluidimpermeable portion36 adjacent the neck to further protect the neck of the aneurysm as shown inFIG. 9. The fluidimpermeable portion36 is preferably aflexible sheath38 having a ring or annular shape. The ring shape may interrupted at a radiallyinner portion39 so that heated fluid may still be slowly expelled into the parental vessel. Alternatively, thesheath38 may completely isolate the aneurysm from the parental vessel.
• The first and secondexpandable sections30,32 have a number offlexible filaments40 which move from the collapsed position ofFIG. 2 to the expanded position ofFIG. 5. Theflexible filaments40 are preferably woven or braided to form a substantially closed-form mesh structure42 in the expanded position. Thefilaments40 andmesh42 have the characteristics described below and are graphically depicted in the drawings for clarity. Apreferred mesh structure42 is also described with reference toFIG. 34 below.
• Referring again toFIGS. 2 and 3, thefilaments40 are positioned overdeformable elements48 which hold theflexible filaments40 in the expanded position. Referring toFIG. 3, thedeformable elements48 havecolumns50 extending betweencollars52,53 at the ends. Thedeformable elements48 are formed from tubes which have four cut-out sections54 to form thecolumns50. Thecollars52 are then attached to the ends of the tube. Thecolumns50 are bent outward slightly so that they will buckle outwardly when compressed. As will be described in further detail below, thedeformable elements48 are plastically deformed when moving to the expanded position to hold thefilaments40 in the expanded position. Thecolumns50 may also be designed with curved or sinusoidal shaped sections to improve flexibility.
• Referring toFIG. 4, the proximal anddistal collars52 are threaded to engage a threadedtip58 of aguidewire60 for manipulating theexpandable device4.Intermediate collars62 provide only throughholes to hold and guide theexpandable device4 on theguidewire60. When expanding thedevice4, theguidewire60 is pulled until thedevice4 is trapped between thedelivery catheter10 and the threadedtip58. Theguidewire60 is then rotated to engage thetip58 with the distal threadedcollar52. When thetip58 is threaded into engagement with thedistal collar52, theguidewire60 can be pulled to expand the device. When thedevice4 is partially expanded, thedeformable elements48 may still be within their elastic range so that theexpandable device4 will recover the collapsed position when tension is released on theguidewire60. The operator may then check to see if thedevice4 has the appropriate size and shape for the aneurysm before fully deploying the device. If the operator determines that thedevice4 is too small or too large, thedevice4 is collapsed and removed and another expandable device of appropriate size advanced to the aneurysm.
• When the operator is ready to deploy thedevice4, the operator pulls theguidew ire60 so that thedeformable elements48 undergo plastic deformation and move to the expanded position. Even if thedevice4 is moved to the expanded position, the operator may still retrieve the device by engaging theproximal collar53 with the threadedtip58 and withdrawing the device into thesecond catheter8.
• After theexpandable device4 has been moved to the expanded position, the aneurysm is then preferably reduced in size. In a preferred method, RF energy is delivered to the firstexpandable section30 through theguidewire60 and a conductive fluid, preferably hypertonic saline, is injected into the aneurysm through thelumen16 orlumen28,FIG. 6 shows the aneurysm reduced in size until the aneurysm engages thefirst section30. The threadedtip58 is then disengaged from thedevice4 leaving thedevice4 in the shrunken aneurysm.
• As an optional step, thesealant64 from the source ofsealant20 may also be introduced into the entire aneurysm (FIG. 8) or into just the second section32 (FIG. 7) to seal the aneurysm. An advantage of the present invention over conventional methods is that thesealant64 is contained within the closed-form mesh structure42 to prevent escape of thesealant64 into the parental vessel. Referring toFIG. 9, aproximal portion66 may be impermeable to further isolate the aneurysm from the parental vessel. A small amount of thesealant64 may also be delivered to completely isolate the aneurysm if necessary as shown at dotted-line68. The method of the present invention described above may, of course, be practiced with any suitable structure other than the structure ofFIGS. 1-9 without departing from the scope of the invention.
• Referring toFIGS. 11-15, anotherdelivery catheter70 is shown for use with the system ofFIG. 1. Thedelivery catheter70 is delivered through the first and second catheters described above. The catheter delivers anexpandable device4A to the aneurysm through the second catheter8 (seeFIG. 1).
• Thedelivery catheter70 has anexpandable member72, preferably aballoon74, for deploying theexpandable device4A. Thedevice4A is configured to retain the expanded position ofFIG. 12 after theballoon74 has been deflated. Thedelivery catheter70 has aninflation lumen72 coupled to a source ofinflation fluid74 for inflating the balloon (FIG. 1).
• Theexpandable device4A is preferably made of a number offlexible filaments76. Thefilaments76 are preferably woven or braided but may also be a number of non-woven filaments. Thefilaments76 may be any suitable material and a preferred material is platinum alloy (92% platinum, 8% tungsten) wire having a thickness of 0.005-0.003 inch.
• Theexpandable device4A may take any shape and may have a number of predetermined shapes which can be selected depending upon the shape of the aneurysm and the nature of the patient's vasculature. Referring toFIG. 12, theexpandable device4A has a simple spherical shape. Although theexpandable device4A is shown as spherical, theexpandable device4A preferably has a width to height ratio of more than 1.1, more preferably at least 1.2 and most preferably at least 1.8. The width and height are defined relative to the aneurysm (FIG. 12) and/or relative to alongitudinal axis76 of theexpandable device4A. The preferred dimensions provide a relatively large width so that theexpandable device4A cannot escape through the neck of the aneurysm after expansion. The height of theexpandable device4A provides clearance for shrinking the aneurysmal toward the expandable device. The width to height ratios are preferred dimensions for all of the embodiments described herein.
• Once theexpandable device4A has been delivered to the aneurysm, the aneurysm is preferably reduced in size in any manner described herein. A method of reducing the size of the aneurysm is to deliver energy to theexpandable device4A from theenergy source12. The energy may be delivered to the aneurysm by delivering RF energy to theexpandable device4A with one ormore wires80 passing through thesecond catheter8. During RF delivery, thesecond catheter8 may be used to deliver fluid, such as hypertonic saline, to the aneurysm.
• Referring to.FIGS. 14 and 15, simple resistance heating may also be used by moving thewires80 into contact with theexpandable device4A to conduct electricity therebetween as shown inFIG. 14. An advantage of the system is that different portions of the aneurysm can be heated to shrink the aneurysm as shown inFIGS. 14 and 15.
• Theexpandable device4A may be insulated at aproximal portion82 so that energy is delivered to the aneurysm dome rather than toward the neck and parental artery. Theflexible filaments76 may be coated with any suitable insulation, such as paraline, and may be applied by spraying, dipping or etching. Theexpandable device4A may also have theflexible sheath78 over the insulated region to further shield the neck of the aneurysm.
• Referring toFIGS. 16, aheating device84 is shown which may be used to heat and shrink the aneurysm. Theheating device84 is advanced into the aneurysm to heat fluid in the aneurysm thereby heating and shrinking the aneurysmal wall. Twoinsulated wires86,88 are wrapped around acore wire90 and covered with asheath92 along the proximal portion. Thesheath92 forms alumen94 therethough which may be coupled to thevarious sources18,20,22,24 described above withconnector96. The distal end of thewires86,88 form proximal anddistal electrodes98,100 for bipolar RF heating. Thecore wire90 is attached to thedistal electrode100.
• Anactuator102 is manipulated to change the distance between theelectrodes98,100 and to bend the tip in the manner shown inFIG. 17. Theactuator102 is coupled to thecore wire90. The device may be configured so that theelectrodes98,100 move toward another when theactuator102 is manipulated, or the device may be configured so that the tip curves as shown inFIG. 17. The tip may be curved to navigate tortuous vessels and may be curved during heating. In use, the distal end of thedevice84 is introduced into the aneurysm and theactuator102 is manipulated to curve the distal end. RF energy is then delivered and a fluid, such as hypertonic saline, is delivered through thesecond catheter8 or through thelumen94.
• Referring toFIGS. 18 and 19, the aneurysm may be shrunk into contact with the expandable device so that theexpandable device4A reinforces the aneurysmal wall to prevent rupture. The aneurysmal wall may also be shrunk further so that theexpandable device4A itself shrinks as shown inFIG. 20. After the aneurysm has been reduced in size, thesealant64 may also be delivered to further seal the aneurysm.
• Referring to FIGS.1 and21-24, anotherdelivery catheter110 for treating an aneurysm with thesystem2 ofFIG. 1 is shown. Thecatheter110 is advanced to the carotid artery and thesecond catheter8 is advanced through thefirst catheter6 to the aneurysm. Thedelivery catheter110 extends through thesecond catheter8 to deliver anexpandable device4B to the aneurysm. Thedelivery catheter110 has a lumen112 which may be coupled to one or more of thevarious sources18,20,22,24. Theexpandable device4B is coupled to theenergy source12 for heating and shrinking the aneurysm as will be described below.
• Theexpandable device4B is movable from the collapsed position ofFIG. 21 to the expanded position ofFIG. 22.Flexible filaments114 preferably form a woven or braidedmesh structure116 extending between first andsecond hubs118,120. Acentral post122 extends from thesecond hub120 and has alocking Mechanism124 which engages thefirst hub118 to hold theexpandable device4B in the locked position. Anactuator126, which is preferably a tapered rod128, has a threadedconnection130 with thecentral post122. Theactuator126 is pulled to move thelocking mechanism124 into engagement with thesecond hub120. Thelocking mechanism124 hasspring elements126 which are naturally biased to the position ofFIG. 23. Thespring elements126 are angled proximally so that they are displaced inwardly by thehub118 when thepost122 andspring elements126 pass through thehub118. After thespring elements126 have passed through thehub118 they assume their unbiased shape thereby locking thedevice4B in the expanded position. Thelocking mechanism124 may be any suitable locking mechanism.
• Theflexible filaments114 preferably bias thedevice4B toward the collapsed position so that the operator may partially expand the device to determine whether the device has the appropriate size. If the device is not the appropriate size, the device can be collapsed and withdrawn through thesecond catheter8. After theexpandable device4B has been expanded, the aneurysmal wall may then be shrunk in any manner described herein. In the preferred embodiment ofFIG. 21, the expandable device is a monopolar RF electrode with the energy source being an RF generator coupled to theactuator126. Theexpandable device4B may be insulated along aproximal portion116 to protect the neck, parental vessel and adjacent vessels as mentioned above. After the aneurysmal wall has been reduced in size, the sealant64 (FIG. 8) may be introduced to isolate the aneurysm from the parental vessel.
• In another aspect of the present invention, theexpandable devices4,4A, and4B may be filled with an expandablethrombogenic material130. Referring toFIG. 10, theexpandable device4 is filled with the compressible,thrombogenic material130 which may be randomly orientedfibers132 or coils134. When theexpandable device4 is expanded, thematerial130 expands to occupy the interior volume of the woven or braidedmesh structure42. Thematerial130 may be used with any of the expandable devices described herein without departing from the scope of the invention. When thematerial130 includes filaments136, the filaments136 may be helically, radially or randomly oriented within the interior volume of the mesh or braidedstructure42.
• Referring to FIGS.1 and24-27, anothercatheter140 for treating an aneurysm with the system ofFIG. 1 is shown. Thefirst catheter6 is introduced through the femoral artery and advanced to the carotid artery. Thesecond catheter8 is, advanced through thefirst catheter6 to the aneurysm. Thedelivery catheter140 is passed through thesecond catheter8 to the aneurysm to treat the aneurysm.
• Thedelivery catheter140 has alumen142 which is coupled to the sources of fluid, contrast, sealant andvacuum18,20,22,24. The distal end of thecatheter140 has acover144 which is positioned over the neck of the aneurysm as shown inFIG. 27. Thecover144 provides temporary isolation of the aneurysm from the parental vessel. Thecover144 is preferably a disc of relatively soft material such as silicone. Thecover144 is preferably configured to cover an area of about 0.8 mm²to 75 mm²and is relatively thin so that thecover144 does not impede flow through the parental vessel and so that thecover144 can distort to a small profile when passing through thesecond catheter8. Thecover144 is also preferably impermeable so that thecover144 can isolate the aneurysm from the parental vessel.
• Thecatheter140 has anelectrode146 which is coupled to theenergy source12 with awire148 extending through thecatheter140. Theelectrode146 may be configured as a monopolar RF electrode for delivery of RF energy with a second electrode (not shown) in contact with the patient's skin. Alternatively, asecond electrode150 may be passed through thelumen142 to provide monopolar or bipolar RF with the first and/or second electrodes to146,150. Shrinking of the aneurysm may, of course, be accomplished with any of the methods described above. For example, the heating device84 (FIG. 16) may be advanced through thelumen142 to heat and shrink the aneurysm.
• Use of thedelivery catheter140 is now described, thedelivery catheter140 is advanced through thesecond catheter8 to the aneurysm. Thecover144 is positioned over the neck of the aneurysm and the aneurysm is heated to shrink the aneurysm. When using RF heating, fluid such as hypertonic saline may be infused into the aneurysm through thecatheter140 or second catheter8 (FIG. 1). Thecover144 may be flexible enough to deflect and permit hot fluid to be slowly expelled into the parental vessel. Alternatively, thecover144 may be periodically moved away from the neck so that hot fluid in the aneurysm may be slowly expelled into the parental vessel. The aneurysm may be reduced to an acceptable size or partially shrunk and filled with thethrombogenic material130 and sealant (FIG. 28) or just the material130 (FIG. 29). Although thedelivery catheter140, and particularly thecover144, have been described in connection with RF delivery, thecover144 may be incorporated into any of the other catheters described herein or any other catheter without departing from the scope of the invention.
• Referring toFIGS. 30-34, anotherexpandable device160 is shown for use with the system ofFIG. 1. Theexpandable device160 is advanced through thesecond catheter8 with adelivery catheter162. The expandable device has amesh166 which covers aspring160 made of a shape memory material. Theexpandable device160 is in the collapsed shape ofFIG. 30 when advanced through thesecond catheter8. After theexpandable device160 is within the aneurysm, awire161 or other device can be advanced to contact thedevice160 to heat the device and the aneurysm. Upon heating, the coil collapses to the shape ofFIG. 31 to move themesh166 to the expanded condition. Heating of the coil may be undertaken in any manner described herein. An advantage of thedevice160 is that the device may be heated together with the aneurysm to deploy thedevice160 while shrinking the aneurysm. Referring to.FIG. 32, anotherdevice160A is shown which is substantially the same as thedevice160 except thatspring160A expands in the middle.FIG. 33 shows still anotherdevice160B which has a smaller diameter in the middle to impede fluid flow through thespring160.
• Referring toFIG. 34, anothermesh42A is shown. Themesh42A may be used with any of the expandable devices described herein and the mechanism for expanding and holding themesh42A has been omitted fromFIG. 34 for clarity. Any of the actuating and delivery methods and devices described above or any other suitable device may be used with themesh42A. Themesh42A preferably has 10-50 filaments, more preferably 20-50 filaments, extending between first and second ends150,152. Thefilaments148 are preferably platinum alloy (such as 92% platinum, 8% tungsten). Thefilaments148 preferably form a tube in the collapsed position which has a diameter of no more than 0.020 inch but expands to a diameter of at least 0.200 inch at a central portion154.
• The devices described herein are preferably delivered to the aneurysm to occupy the remaining volume of the aneurysm after shrinking the aneurysm. Referring toFIGS. 35 and 36, a number ofdevices170 may be delivered to the aneurysm with one of thedevices171 being used to heat and shrink the aneurysm. Thedevices170 may be partially or completely insulated in the manner described above to protect the neck while heating and shrinking is accomplished with thedevice171. Thedevices170 and171 are shown spaced apart for clarity but, of course, will be closely packed together when filling the aneurysm. Thedevices170 and171 may be any of the expandable devices described herein or any other suitable device without departing from the scope of the invention.
• Referring toFIG. 37, another system for reducing the size of an aneurysm is shown. Acoil172 is used to regulate flow of fluid between the aneurysm and the parent vessel. Thecoil172 is particularly useful for holding heated fluid in the aneurysm to heat and shrink the aneurysm. Theheating device84 ofFIGS. 16 and 17, or any other suitable device for heating the aneurysm, is introduced into the aneurysm to heat and shrink the aneurysm. Thecoil172 is manipulated by pulling or pushing the coil to retract or deploy thecoil172 from the catheter8 (seeFIG. 1). The pitch of thecoil172 can be varied by pulling or pushing thecatheter8 relative to thecoil172. The windings of thecoil172 may be close together so that thecoil172 substantially impedes flow between the aneurysm and the parent vessel (FIG. 38) or may be spaced-apart to permit slow leakage of fluid into the parent vessel. Thecoil172 may be made of any suitable material and is preferably a shape-memory alloy such as nitinol.
• Referring toFIGS. 39 and 40, anothercatheter180 for heating and shrinking an aneurysm is shown. Thecatheter180 is preferably less than 5 Fr, more preferably 2-4 Fr, and most preferably about 3 Fr in size so that it is small and flexible enough to shrink select portions of the aneurysm as shown by dottedlines181 inFIG. 39. Thecatheter180 may, of course, be sized larger to shrink larger portions of the aneurysm or other tissue structures. Thecatheter180 has atip182 which is made of a heat-resistant, non-stick material (such as PTFE) so that the tip can contact the tissue during heating without sticking to the tissue. Thecatheter180 may also be a hypotube, guidewire or similar device without departing from the scope of the invention. Thetip182 forms achamber183 and hasholes186 formed therein for delivery of a conductive fluid as described below.
• Thecatheter180 has alumen184 which communicates with the,chamber183 in thetip182. Thelumen184 is coupled to the source of fluid18 (seeFIG. 1) which is preferably hypertonic saline. AnRF probe188 passes through thelumen184 and is coupled to the energy supply12 (seeFIG. 1) which is preferably an RF generator. TheRF probe188 has anelectrode189 positioned in the chamber while a second electrode (not shown) is positioned in contact with the patient's skin in the conventional manner. When the conductive fluid is delivered through thelumen184, electrical energy is conducted by the conductive fluid to heat the aneurysm. Theholes183 in thetip182 may be distributed around the tip182 (FIGS. 39 and 41), positioned at the distal end185 (FIG. 42) or along the sides187 (FIG. 43) of thetip182.
• After the volume of the aneurysm has been reduced, the aneurysm may be treated in any other manner described herein. Furthermore, thecatheter180 ofFIGS. 39-43 may be used to heat tissue or fluid in connection with any of the other embodiments described herein and in particular as a substitute for thedevice84 ofFIGS. 16 and 17. Finally, thecatheter180 may be used to heat tissue for any other suitable purpose including those described above. For example, thecatheter180 may be useful in treating venous insufficiency, deep vein reflux or for vein stripping. Furthermore, thecatheter180 may be useful for treating urinary incontinence.
• While the above is a description of the preferred embodiments of the invention, various alternatives, modifications, and equivalents may be used. For example, the expandable device may take any other shape and the sealant may be any other suitable sealant. Furthermore, the dimensions and characteristics of any of the expandable members may be incorporated into any of the other expandable devices described herein without departing from the scope of the invention. Finally, the expandable devices are preferably used when shrinking the aneurysm but the expandable devices may have various features which may be useful when simply filling the aneurysm in the conventional manner.
• Referring toFIG. 43-46, anotherdevice200 for treating an aneurysm is shown. Thedevice200 has acover202 that covers the neck of the aneurysm. Thedevice200 also has alateral extension204 extending from thecover202 into the aneurysm. Thelateral extension204 positions thecover202 over the neck of the aneurysm and anchors thedevice200 to the aneurysm.
• Thecover202 may be any suitable structure such as a patch or tube so long as thecover202 is able to block the neck of the aneurysm to isolate the aneurysm from the parental vessel. Thecover202 is preferably substantially flat so that thecover202 can lie against the wall of the parental vessel around the neck of the aneurysm. In the preferred embodiment, thecover202 is preferably amesh patch206 made of a superelastic material such as nitinol. Themesh206 may have a coating orlayer208, such as expanded PTFE, which provides the properties and advantages of conventional graft materials. Thecover202 preferably extends no more than one half, and more preferably no more than one third, the circumference of the vessel. Stated another way, thecover202 preferably extends no more than 180 degrees and more preferably no more than 120 degrees around a longitudinal axis of the device when expanded. Of course, thecover202 may cover more or less of the parental vessel without departing from various aspects of the invention.
• Thelateral extension204 preferably forms 1-8loops210, and more preferably only one loop, extending from thecover202. Theloop210 is preferably formed by anelongate element212 such as a ribbon made of a superelastic or shape-memory material such as nitinol. Anend211 of theloop210 is attached to aguide214 which is attached to thecover202. Theterm loop210 is intended to include any filament, ribbon, wire or the like having two sides coupled to thecover202. The two sides do not have to touch or be adjacent one another to form aloop210 and, in fact, the loop could be made from a continuous coil wrapped into thecover202 so long as the coil generally forms 1-8individual loops210 extending into the aneurysm. Thelateral extension204 extends laterally from acatheter216 during deployment so that thecatheter216 can remain aligned with the vessel in the manner shown inFIG. 45.
• Theelongate element212 extends and slides through theguide214. Theelement212 has astop220 at one end that engages theguide214 to hold theextension204 in the expanded condition. Theelement212 is preferably biased toward the expanded position ofFIGS. 43 and 46 so that thestop220 naturally engages theguide214 when theelement212 is released. Theelement212 is coupled to afirst manipulator222 with a releasable connection such as a threadedconnection223 or an electrolytically severable bond. Thefirst manipulator222 is used to move and deploy thedevice200, and in particular theloop210, in the manner described below. As will be explained below, thedevice200 is preferably available in a number of different sizes with the size of theloop210 and the size of thecover202 being variable. The size of theloop210 and cover202 are selected based upon the geometry of the aneurysm and parental vessel.
• Thedevice200 is preferably delivered with thecatheter216. Thedevice200 is mounted within thecatheter216 and is advanced out of thecatheter216 and exposed as shown inFIGS. 44-46 when deploying thedevice200. Thedelivery catheter200 has afirst lumen224 in which is positioned thefirst manipulator222. Asecond manipulator226 holds thecover202 opposite thefirst manipulator222 for moving and deploying thedevice200. Asuture228 or any other releasable connection holds thecover202 to thesecond manipulator226. Thecatheter216 is preferably advanced over a guidewire230 which is positioned in a guidewire lumen232. Thecatheter216 preferably has a three-lumen configuration although fewer lumens may be used without departing from the scope of the invention.
• Thedevice200 may also be operated by delivering energy, such as RF energy, to thedevice200 as now described in connection with methods and systems of the invention. When delivering energy, such as RF energy, thecover202 preferably does not conduct energy to protect the parental vessel and neck of the aneurysm.
• Additional methods of the present invention are now described in connection with the preferred embodiment ofFIGS. 43-46 although other suitable devices may be used. Before introducing thedevice200 into the patient, the geometry of the aneurysm and parental vessel are determined so that the appropriate size of thedevice200 is used. For example, the size of theextension204 may be selected to be somewhat smaller than the aneurysm particularly when heat is used to shrink the aneurysm with RF energy or the like. Thedevice200 may also form a number of different shapes that are selected based on the geometry of the aneurysm.
• After selecting the appropriate size of thedevice200, thedevice200 is introduced into the patient with thecatheter216 in the manner described above and the methods and systems described above are specifically incorporated here. When thedevice200 is positioned at the aneurysm, the distal end of thecover202 and thelateral extension204 are advanced out of thecatheter216 by manipulating the first andsecond manipulators222,226. The first andsecond manipulators222,226 may be used to expand and retract the device200 a number of times when attempting to introduce the extension into the aneurysm. Once theextension204 is properly positioned within the aneurysm, theextension204 expands to occupy space within the aneurysm.
• Energy may then be delivered to thelateral extension204 to shrink the aneurysm and/or simply adhere the extension to the aneurysmal wall thereby holding the cover in the proper position. The source of RF energy is coupled to thefirst manipulator222 for this purpose. Although the invention may be practiced with delivery of RF energy, various aspects may be practiced without delivering energy to the aneurysm. Thedevice200 is then released to permit thecover202 to expand as shown inFIG. 46. Thelateral extension204 helps to orient thecover202 into the proper position as thecover202 expands.
• Referring toFIGS. 47-50, still anotherdevice250 for treating an aneurysm is shown. Thedevice250 has acover252 wrapped around anexpandable element254 such as aninflatable balloon256. Theballoon256 is inflated through aninflation lumen257. Asheath258 extends over thecover252 to trap thecover252 between thesheath258 andexpandable element254. Thesheath258 is retracted to expose thecover252 when deploying thecover252 as explained below. Thesheath258 is preferably folded over itself at the distal end and is folded back and everted to expose thecover252. Thesheath258 is preferably made of a flexible material at the distal end such as a suitable polymer such as polyethylene. The guidewire may engage theexpandable element254 at aconnection259 so that the guidewire helps to stabilize thedevice250 during deployment.
• Thecover252 is preferably wrapped or collapsed by simply wrapping thecover252 around theexpandable element254. Thecover252 may overlap itself or may extend around only part of theexpandable element254. In the preferred embodiment, thecover252 is wrapped around theexpandable element254 without any overlapping flaps, folds or sections.
• Thecover252 is preferably adhered to the wall of the parental vessel around the neck of the aneurysm. Thecover252 may be adhered to the wall with any suitable method including glue or heat. Thecover252 may also be adhered to the wall using a conventional stent or with a support structure similar to a stent. In a preferred method, thecover252 is adhered to the parental vessel with abiocompatible adhesive260 such as cyanoacrylate applied to an outer surface of thecover252. Thesheath258 covers the adhesive260 during introduction and advancement of thedevice250. The adhesive260 may also be activated within the patient using light, heat, RF, radiation, chemical or other suitable activators.
• Referring toFIG. 51, anothercover262 is shown for use with thedevice250 wherein the same or similar reference numbers refer to the same or similar structure. Thecover262 has aframe264, preferably metallic, and animpermeable portion266 mounted to theframe264. Theimpermeable portion266 is preferably PTFE or expanded PTFE and is fused or sutured to theframe264. Theimpermeable portion266 covers the neck of the aneurysm to isolate the aneurysm.
• Referring toFIG. 52-56, anotherdevice300 for treating an aneurysm is shown. Thedevice300 has a number offilaments302 that extend from aproximal hub304 to adistal hub306. Thefilaments302 are preferably stainless steel, platinum or nitinol and thehubs304,306 are preferably platinum or a radiopaque polymer. Thefilaments302 are attached to thehubs304,306 by solder, weld or glue. Thedevice300 preferably includes 2-16filaments302 and more preferably about 8filaments302. Thefilaments302 may be integrally formed with one or both of thehubs304,306 or may be asingle filament302 which is wound around or adhered to thehubs304,306. Thedevice300 preferably assumes a generally dish-shaped structure having a generallyconvex side308 and aconcave side310 although thedevice300 may take any other suitable shape.
• Thedevice300 is advanced through acatheter312 with amanipulator314. Thedevice300 may, of course, be mounted within a sheath (not shown) which is then advanced through thecatheter312 as described above. Themanipulator314 may simply push thedevice300 or the device may be releasably attached to thedevice300 with a mechanical connection or an electrolytically severable bond. When thedevice300 exits thecatheter312, thedistal hub306 is naturally biased toward theproximal hub304 with thefilaments302 formingloops314 when expanded (seeFIG. 54).
• Thedevice300 may be coupled to a source of energy, such as a source of RF energy, which is delivered to heat thedevice300 to adhere thedevice300 to the aneurysm and/or shrink the aneurysm. The device may also be used with other methods of closing an aneurysm such as with a sealant or with conventional coils and the like. Thedevice300 prevents such embolic material from migrating out of the aneurysm.
• Referring toFIGS. 57-61, yet anotherdevice316 for treating an aneurysm is shown. Thedevice316 has amanipulator318 which may simply push thedevice316 through alumen320 in acatheter322 or may be releasably attached in any suitable manner. Thedevice316 has a plurality offilaments324 each having aproximal end326 and adistal end328. The proximal ends326 are coupled together at ahub330.
• Thefilaments324 are collapsed into a relatively straightened configuration when positioned in thecatheter322. When thefilaments326 are deployed out of thecatheter322, thefilaments324 expand to occupy space in the aneurysm. Thefilaments324 may expand into any suitable shape and preferably expand to form a number ofcoils328. Thecoils328 may be oriented in any manner and are preferably oriented with acentral axis330 of at least threecoils328 lying in acommon plane330. Thedevice316 may have 2-6coils328 andFIG. 59 shows three coils andFIGS. 60 and 61 show two different fourcoil328 configurations. Thedevice316 is deployed in substantially the same manner as the device described above. Thecatheter322 is advanced to the aneurysm and themanipulator318 moves thedevice316 out of the catheter and into the aneurysm as shown inFIG. 58.

Claims (5)

1-58. (canceled)

59. A method of treating an aneurysm, comprising the steps of:

providing a device having a plurality of filaments extending from a first hub, the plurality of filaments being movable from a collapsed position to an expanded position, the filaments being biased toward the expanded position;

introducing the device into an aneursym with the plurality of filaments in the collapsed position;

expanding the filaments after the introducing step so that the filament occupy space in the aneurysm and form a mesh which contacts the wall of the aneurysm;

releasing the device so that the device remains within the aneurysm with the mesh in contact with the wall of the aneurysm.

60. The method ofclaim 59, wherein:

the providing step is carried out with the device having a second hub, the plurality of filaments extending between the first and second hubs, the first and second hubs moving toward one another when the plurality of filaments move to the expanded position.

61. The method ofclaim 59, wherein:

the expanding step is carried out with the plurality of filaments expanding radially outward from the first hub.

62. The method ofclaim 59, wherein:

the expanding step is carried out with the plurality of filaments forming a mesh which expanding into contact with the aneurysm.

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