US20050273119A1 - Double spiral patent foramen ovale closure clamp - Google Patents

Abstract

The present invention provides a device which is adapted to press together the septum primum and the septum secundum between the atrial chambers to close any tunnel in the septum. The device in its preferred form has two clamping members, one on each side of the septum and a central connector which connects the two clamping members and passes through the tunnel. The device is configured to conform to the anatomy such that the tunnel is not substantially deformed by the device. The central connector, in its preferred form has two wires that are spaced apart so that the wires are proximate the lateral sides of the tunnel. The spacing allows the device to be centered at an appropriate location.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS
• This application claims priority toprovisional patent application 60/528,022 filed Dec. 9, 2003.
FIELD OF THE INVENTION
• The present invention relates to devices and methods which are used to close septal openings. In particular, this invention is directed to devices and methods which are used to close a patent foramen ovale (PFO) in the septum between the left atrium and right atrium.
BACKGROUND OF THE INVENTION
• A PFO, illustrated inFIGS. 1 and 2, is a persistent, one-way, usually flap-like opening in the wall between the right atrium and left atrium of the heart. Because left atrial (LA) pressure is normally higher than right atrial (RA) pressure, the flap usually stays closed. Under certain conditions, however, right atrial pressure can exceed left atrial pressure which creates the possibility that blood could pass from the right atrium to the left atrium and allow blood clots to enter the systemic circulation. It is desirable that this circumstance be reduced.
• The foramen ovale serves a desired purpose when a fetus is gestating in utero. Since blood is oxygenated through the umbilical chord, and not through the developing lungs, the circulatory system of a heart in a fetus allows the blood to flow through the foramen ovale as a physiologic conduit for right-to-left shunting. After birth, with the establishment of pulmonary circulation, the increased left atrial blood flow and pressure results in functional closure of the foramen ovale. This functional closure is subsequently followed by anatomical closure of the two over-lapping layers of tissue the septum secundum14 andseptum primum15. However, a PFO has been shown to persist in a number of adults.
• The presence of a PFO is generally considered to have no therapeutic consequence in otherwise healthy adults. However, patients suffering a stroke or transient ischemic attack (TIA) in the presence of a PFO and without another cause of ischemic stroke paradoxical embolism via a PFO is considered in the diagnosis. While there is currently no proof for a cause-effect relationship, many studies have confirmed a strong association between the presence of a PFO and the risk for paradoxical embolism or stroke. In addition, there is good evidence that patients with PFO and paradoxical embolism are at increased risk for future, recurrent cerebrovascular events.
• Accordingly, patients with an increased future risk are considered for prophylactic medical therapy to reduce the risk of a recurrent embolic event. These patients are commonly treated with oral anticoagulants, which have the potential for adverse side effects, such as hemorrhaging, hematoma, and interactions with a variety of other drugs. The use of these drugs can alter a person's recovery and necessitate adjustments in a person's daily living pattern.
• In certain cases, such as when anticoagulation is contraindicated, surgery may be necessary or desirable to close the PFO. The surgery would typically include suturing a PFO closed by attaching the septum secundum to the septum primum. This sutured attachment can be accomplished with either an interrupted or a continuous stitch and is a common way a surgeon shuts a PFO under direct visualization.
• Umbrella devices and a variety of other similar mechanical closure designs, developed initially for percutaneous closure of atrial septal defects (ASDs), have been used in some instances to close PFOs. These devices have the potential to allow patients to avoid the potential side effects often associated with anticoagulation therapies and the risks of invasive surgery. However, umbrella devices and the like which are designed for ASDs are not optimally suited for use as a PFO closure device.
• Currently available designs of septal closure devices present drawbacks, including that the implantation procedure is technically complex. Additionally, there are not insignificant complication rates due to thrombus, fractures of the components, conduction system disturbances, perforations of heart tissue, and residual leaks. Many devices have high septal profile and may include large masses of foreign material which may lead to unfavorable body adaptation of a device. Since ASD devices are designed to occlude a hole, many lack anatomic conformability to the PFO flap-like anatomy. That is, when inserting an ASD into the heart to close a PFO, the narrow opening and the thin flap may form impediments to proper deployment. Even if an occlusive seal is formed, the device may be deployed in the heart on an angle which could leave some components not securely seated against the septum. Finally, some septal closure devices are complex to manufacture, which may result in lack of consistency in product performance.
• Nitinol (an alloy of nickel and titanium) is known to be used in medical devices because of its biocompatablity and, especially, its unique properties. Nitinol is a member of a class of materials which exhibit shape memory characteristics. Specifically, nitinol has the ability to “remember” a shape and, after being deformed, will return to that shape once a certain temperature is reached. Hence, nitinol has been used to create medical devices that have a desired configuration in the body, e.g., a vena cava filter. The device is deformed into a delivery configuration (generally a reduced profile for delivery through a catheter). Once the device is delivered to the desired site, the nitinol changes configuration into the desired shape upon achieving a certain temperature. This is generally considered thermal responsive shape memory. Nitinol, and other materials, also exhibit superelastic shape memory. In this case, the nitinol can be restrained in a delivery configuration and then will return to the desired configuration as the device leaves the delivery catheter. Of course, some devices can be a combination of thermally induced shape memory and superelastic shape memory.
• The present invention is designed to address these and other deficiencies of the prior art septal closure devices.
SUMMARY OF THE INVENTION
• The present invention provides a device which is adapted to press together the septum primum and the septum secundum between the atrial chambers to close any tunnel in the septum. The device in its preferred form has two clamping members, one on each side of the septum and a central connector which connects the two clamping members and passes through the tunnel. The device is configured to conform to the anatomy such that the tunnel is not substantially deformed by the device. The central connector, in its preferred form has two wires that are spaced apart so that the wires are proximate the lateral sides of the tunnel. The spacing allows the device to be centered at an appropriate location.
• In a preferred form of the device, the clamping members are spirals which are formed from nitinol. The spirals may be constructed of wire, or alternatively, may be constructed of nitinol sheets which have been cut or shaped to form the spirals. The spirals may circle around more or less than 360 degrees and may have the a helical form. In one preferred embodiment the connector may be attached to the inner end of the wire that forms the spiral, in another, the connector may be attached to the outer end of the wire that forms the spiral. Of course, depending on the desired configuration, the connector may be connected to the inner location on one side of the device and the outer location on the other side of the device.
• The clamping member may be a spiral or some other structure or configuration which secures the septum together. For example, a plurality of wires may be used which could be spread out along the septum to provide the desired clamping force. Other shapes and orientations could be used which would spread the clamping force over a sufficient surface area to accomplish the desired effect.
• The connecting member may be two or more wires which are configured to spread apart in the PFO tunnel. The spacing of the wires is sized to center the device in the desired clamping location in the septum. In one preferred embodiment, the wires are joined at ends and bow apart from each other to fit within the PFO tunnel. Alternatively, the wires may form an S-shaped curve to improve the centering location. Other shapes and configurations are possible.
• In an alternate form the connecting member may be formed of thin wires that are wound into a helix (e.g., in the shape of a coil spring). The connecting member may have one or more helically wound wires that form the connecting member. The resultant connector may be shaped in the same manner as the other embodiments. In other embodiments, the connecting member may have an abrasive surface so that a healing response may be stimulated by the abrasive surface. Additionally, the abrasive surface may be directionally oriented. That is, if one were to feel the surface of the wire in one direction, the wire would feel smooth and in the other direction, the wire would feel abrasive or rough.
• In still other embodiments, the connecting member may include a film which extends between the connecting wires. The film may be comprised of and/or impregnated with biological and/or bioresorbable material. In another embodiment a joint may be formed at a location along the length of the connecting member. The joint reduces the trauma of the closure device within the PFO. The device may also have a hook or some other piercing element to maintain the PFO closure device in the desired location. Of course, each of the configurations could be used in combination.
• The device, in its preferred form, is adapted to be delivered through a catheter into the atria. The device is constrained into a delivery profile and introduced into a catheter for delivery to the heart. Once the catheter is located at the desired delivery site, the device is deployed into the site and changes shape into the desired configuration. The shape change could be a result of a thermally induced shape change or a change due to the superelastic character of the material. Once in the delivery location, the catheter is withdrawn.
BRIEF DESCRIPTION OF THE DRAWINGS
• FIG. 1 is a front elevational view from the left atrium of the atrial septum with patent foramen ovale (PFO);
• FIG. 2 is a cross-sectional view of the atrial septum ofFIG. 1;
• FIG. 3 is a bottom plan view of the double spiral patent foramen ovale closure clamp of the present invention showing the connecting central loop;
• FIG. 4 is a view in side elevation of the double spiral PFO closure clamp ofFIG. 3;
• FIG. 5A-5G show the steps for inserting the double spiral PFO closure clamp ofFIGS. 3 and 4;
• FIG. 6 is a front elevational view from the left atrium of the double spiral PFO closure clamp in place with the central loop in the PFO channel;
• FIG. 7 is a cross-sectional view of the atrial septum and double spiral PFO closure clamp ofFIG. 5;
• FIG. 8 is a perspective view of a jig for forming the double spiral PFO closure clamp of the present invention; and
• FIG. 9 is a top plan view of the jig ofFIG. 7 with spiral sections of the double spiral PFO closure clamp of the present invention wound thereon.
• FIG. 10 is a view in side elevation of a second embodiment of the double spiral PFO closure clamp of the present invention;
• FIG. 11 is a front elevational view from the right atrium of the double spiral PFO closure clamp ofFIG. 10;
• FIG. 12 is a front elevational view from the left atrium of the double spiral PFO closure clamp ofFIG. 10;
• FIG. 13 is a view in front elevation of a second embodiment of a central connector for a PFO closure clamp ofFIG. 10;
• FIGS. 14A and 14B are a plan view and a view in side elevation, respectively of a jig for forming the double spiral PFO closure clamp ofFIG. 10 with the central connector ofFIG. 13;
• FIGS. 15A and 15B are a plan are a plan view and a side elevation view, respectively, of the jig ofFIGS. 14A and 14B with the left atrial spiral section of the double spiral PFO closure clamp ofFIG. 10 and with one half of the central connector ofFIG. 13 formed thereon;
• FIGS. 16A and 16B are a plan view and a view in side elevation, respectively, of the jig ofFIGS. 14A and 14B with the right atrial spiral section of the double spiral PFO closure clamp ofFIG. 10 and with one half of the central connector ofFIG. 13 formed thereon;
• FIGS. 17A and 17B are a plan view and a side elevation view, respectively, of an expanded double spiral PFO closure clamp ofFIG. 10 with one half of the central connector forFIG. 13;
• FIGS. 18A and 18B are alternative embodiments of a center joint of the present invention using helically wound wire;
• FIGS. 19A-19F are alternative embodiments of a center joint of the present invention using special surface preparations;
• FIG. 20 is an alternative embodiment of a center joint of the present invention using a membrane;
• FIGS. 21A and 21B are alternative embodiments of a center joint of the present invention using a flexible joint; and
• FIGS. 22A and 22B are alternative embodiments of a center joint of the present invention in which piercing wires are used to secure the device at the desired location.
DESCRIPTION OF THE PREFERRED EMBODIMENT
• With reference toFIGS. 1 and 2, theatrial septum10 divides the left atrium and right atrium of the heart. The patent foramen ovale (PFO)channel12 extends between the left and right atria and is closed by aflap14 and15. Due to the overlap of the septum primum over the septum secundum, the PFO channel or tunnel extends substantially parallel to the surface of the atrial septum. The anatomical structure presents a problem when attempts are made to use conventional septal occluders with opposed, spaced, parallel sections (possibly spiral) are joined by a straight wire or bridge which is substantially perpendicular to the planes of engagement between the sections and the atrial septum. The straight wire or bridge deforms thechannel12 and often prevents proper closure even when the septum primum and the septum secundum are biased toward one another by the spiral sections of the occluder.
• Referring toFIGS. 3-7, the double spiral PFO closure clamp of the present invention indicated generally at16 includes a leftatrial spiral section18 and an opposed rightatrial spiral section20 which are joined by an inclinedcentral loop22. The loops of each spiral extend progressively outward from the base loop in different planes, and theinnermost loops26 of the twospiral sections18 and20 are connected by the inclinedcentral loop22. The outermost free ends28 of thebase loops24 are provided withprotective balls30.
• With continued reference toFIGS. 3-7, in a preferred embodiment, the spirals that are disposed on each side of the septum and press against the septum with sufficient force to stabilize the device in the desired location. As illustrated, inner loops are connected and the outer loops are configured to compress against the septum. In an alternative configuration, not illustrated, the outer loops may be connected and the inner loops may be configured to press against the septum. In each embodiment, the center joint is configured to connect the loops and, according to several embodiments, the center joint is configured to center the device in the desired delivery location because the center joint is configured to spread out within the PFO tunnel and, as a result, become centered within the PFO tunnel.
• Theball30 of the rightatrial spiral section20 may be grasped and drawn into a protective sheath. As thefree end28 of the right atrial spiral section is drawn inwardly into the protective sheath, the coils of the spiral section straighten as they are drawn into the sheath until the inclinedcentral loop22 is reached. Then as the central loop enters the sheath, the sides of the central loop are compressed together, and as the central loop is enclosed by the sheath and moves inwardly, it draws the loops of the leftatrial spiral section18, beginning with theinnermost loop26, as a straight section into the sheath.
• FIG. 5A shows the double spiral PFO closure clamp in straightened form enclosed bysheath32. The tip of the sheath may be curved to assist the recovery of the curved loops of the double spiral PFO closure clamp. Here, the sheath is inserted through thePFO channel12 from the right atrium into the left atrium, and the left atrium, and inFIG. 5B, awire34 connected within the sheath to thefree end28 ofspiral section20 forces thespiral section18 out of the sheath so that it is deployed in the left atrium. Subsequently, as shown inFIG. 5C, the sheath andwire34 are withdrawn toward the right atrium to draw thespiral section18 against theatrial septum10.
• InFIG. 5D, after the inclinedcentral loop22 has been positioned within thesheath32 in thePFO channel12, the sheath is withdrawn to deploy and seat the inclined central loop in the PFO channel. Then, as shown inFIG. 5E, thewire34 ejects thespiral section20 into the right atrium against the atrial septum. InFIG. 5F, thewire34 is released from the free end of thespiral section20, and inFIG. 5G, thesheath32 andwire34 are withdrawn.
• Thespiral sections18 and20 are formed to be urged toward one another. Also, since the loops of eachopposed spiral section18 and20 are in different planes and since the inclinedcentral loop22 joins theinnermost loops26 of each spiral section, thespiral section18 will draw thespiral section20 against the atrial septum once it is deployed fromsheath32.
• FIGS. 6 and 7 show the double spiralPFO closure clamp16 in place with the inclinedcentral loop22 seated in the PFO channel. Thespiral sections18 and20 are not aligned but are offset so that the inclined central loop follows the PFO channel and does not deform thechannel12. However, enough of the two spiral sections overlap so that the septum primum and the septum secundum are engaged thereby and biased to a closed position.
• Since the inclinedcentral loop22 which joins thespiral sections18 and20 is seated in the PFO channel, it prevents shift or rotation of the spiral sections which might occur if a straight non-looped joined piece was used between the spiral sections.
• FIGS. 8 and 9 disclose ajig36 used to manufacture the double spiralPFO closure clamp16. The jig includes two stepped cone shapedsections38 and40 which are each used to form one of thespiral sections18 or20 and one half of the inclinedcentral loop22. Each stepped cone shaped section includes a plurality ofarcuate sections42,44,46, and48 of progressively decreasing size which terminate at a small,circular projection50. The front faces52,54,56, and58 of each of the arcuate sections is flat and supports aninclined mandrel60 having anarcuate side62. Thearcuate side62 faces left on the cone shapedsection38 and right on the cone shapedsection40. The front faces52 and58support projecting pins64 and66 respectively positioned above and below the arcuate side of themandrel60.
• To form the double spiralPFO closure clamp16, an elongate length of wire is formed upon each of the cone shapedsections38 and40 as shown inFIG. 9. Each of these lengths ofwire68 and70 are preferably formed of shape memory material such as nitinol and are annealed after being wound in place on the stepped, cone shapedsections38 and40. The wire is wound clockwise on the cone shapedsection38 and counter-clockwise on the cone shapedsection40. Each length of wire begins at startingpin72 and extends around the projectingpin64 and thearcuate side62 to the projectingpin66. The wire extends behind the projectingpin66 and around thecircular projection50. At theflat face58, the wire drops and extends around thearcuate section48 to theflat face56 where the wire drops again to extend around thearcuate section44, and at theflat face52, the wire drops to extend around thearcuate section42 to aterminal post74. Thus the twospiral sections18 and20 ofFIG. 4 are formed. Once the two wire sections are processed on thejig36, they are removed from the core shapedsections38 and40 and one is inverted and rotated relative to the other so that the inclined, arcuate wire sections formed on themandrels60 may be welded together to form the inclinedcentral loop22. Now the free ends of each wire section which were held by the terminal pins74 are provided with theprotective balls30.
• With reference toFIGS. 10-12, a second embodiment of the double spiral PFO closure clamp of the present invention is indicated generally at76. The double spiralPFO closure clamp76 includes a rightatrial spiral section78 to contact the right side of the septum and an opposed leftatrial spiral section80 to contact the left side of the septum. These two spiral sections are joined by an inclinedcentral loop82 which rests in thePFO channel12. Unlike the offsetatrial spiral sections18 and20 of thePFO closure clamp16, theatrial spiral sections78 and80 of thePFO closure clamp76 are directly opposed in substantial alignment when they are deployed against the atrial septum. This is facilitated by connecting the large, outermost loop of each atrial spiral section to the inclinedcentral loop82.
• As shown byFIG. 11, theoutermost loop84 of the rightatrial spiral section78 is connected to the bottom of thecentral loop82 at86, and curves upwardly over the septum and then inwardly to form the smaller inner loops of the right atrial spiral section. These inner loops terminate at an innermostfree end88 provided with aprotective ball30.
• To form the leftatrial spiral section80 in opposed alignment with the right atrial spiral section, theoutermost loop90 is connected to the top of thecentral loop82 at92 as shown byFIG. 12. Theoutermost loop90 then curves downwardly over the septum and then inwardly to form the inner loops of the left atrial spiral section. These inner loops terminate at an innermostfree end94 provided with aprotective ball30.
• Theoutermost loops84 and90 are configured to position the left atrial spiral section and right atrial spiral section in aligned, opposed relationship.
• Instead of connecting the twospiral sections78 and80 with a central loop which rests in the PFO channel, the central loop can be replaced with the double “S” shapedconnector96 ofFIG. 13. This connector has rounded side surfaces98 and100 which engage the sides of the PFO channel, but theconnections86 and92 with theouter loops84 and90 of thespiral sections78 and80 are oriented in opposite directions by the configuration of the connector. Thus forces on the connector from the spirals which would tend to cause shifting of a round central loop are offset to oppose shifting of the connector.
• FIGS. 14A and 14B,15A and15B,16A and15B, and17A and17B show the manner in which the double spiral PFO closure clamp76 with the double “S” shapedconnector96 is formed. Asplit jig102 is used to form both the rightatrial spiral section78 and the leftatrial spiral section80. The jig includes two spaced steppedsections104 and106 having opposed arcuate steps which progressively decrease in size. Between the stepped sections are formed to form the double “S” shapedconnector96. These forms include apin108 which projects adjacent to around form110. Thisround form110 contacts a secondround form112 which is adjacent to asecond projection pin114. Spaced from but adjacent to theround forms110 and112 are two spacedarcuate forms116 and118. Centered between thearcuate forms116 and118 is around form120. Wireend retaining screws122,124, and126 are positioned outwardly from the steppedsections104 and106.
• With reference toFIGS. 15A and 15B, the leftatrial spiral section80 and one half of the double “S” shapedconnector96 are formed by winding wire in a clockwise direction on the steppedsections104 and106. Beginning at the wireend retaining screw124, the wire is passed around thepin108 and across theround forms110 and112 and then around theform112 and back to theround form120. The wire is then brought around theround form120 and then around thearcuate form116 to thepin114 to form one half of the double “S” shapedconnector96. From thepin114, the wire is wound in a clockwise direction from the bottom to the top of the steppedsections104 and106 and is then secured to the wireend retaining screw126. When the wire is thermal shape memory wire, it is annealed in place before the left atrial spiral section is removed from thejig102.
• As shown inFIGS. 16A and 16B, the rightatrial spiral section78 is formed in the reverse manner and is wound counter clockwise on the steppedsections104 and106. Beginning at the wireend retaining screw124, the wire is passed around thepin114, theround forms112 and110, theround form120 and anarcuate form118 to thepin108 to form the remaining half of the double “S” shapedconnector96. The wire is then wound in a counter clockwise direction from the bottom to the top of the steppedsections104 and106 and is then passed to the wireend retaining screw126.
• FIGS. 17A and 17B show the manner in which the twoatrial spiral sections78 and80 are joined to form the double spiralPFO closure clamp76. The two atrial spiral sections are oriented back to back to form the double “S” shapedconnector96, and are secured together at128 and130.
• The double spiralPFO closure clamp76 can be straightened with a tubular delivery device for delivery and may be delivered across the PFO by catheter using a pusher wire. The leftatrial spiral section80 is delivered first into the left atrium and flattened against the septum. The central double “S” shapedconnector96 is then unsheathed in the PFO channel, and finally the rightatrial spiral section78 is released against the septum in the right atrium.
• FIGS. 18A and 18B illustrate another embodiment of the center joint of the present invention. In this embodiment, the center joint is constructed of wire which has been wound to form aspiral200 that connects ends210 and220. The spiral wound wire is flexible enough to accommodate a variety of anatomical configurations for the PFO tunnel. In this manner the spiral wound wire will conform to the PFO tunnel and will bend as necessary to allow theends210 and220 to conform to the wall of the septum (not shown in this embodiment). The spirals are illustrate in an exaggerated and open manner. Preferably the wire will be tightly close together and have a small overall diameter. Alternatively, the wire may have athin wire strand225 disposed in the helical wire to ensure that the spiral does not expand beyond the length of the wire strand. Thewire225 allows the center joint to be flexible and conform to the PFO tunnel without expanding beyond the longitudinal distance of the wire strand. The ends210 and220 are illustrated as the wire elements of the CardioSeal device more specifically described in U.S. Pat. No. 5,629,766 which is incorporated by reference into this specification.
• FIG. 18B illustrates another embodiment of the center joint with a pair ofhelically wound wires230,240 that form the center joint.Ends245,247 of the device that contact the walls of the septum are illustrated as spirals. Of course, one skilled in the art would recognize the that the ends could be in a variety of configurations and dimensions, for example, spiral and CardioSeal configurations. The illustration exaggerates relative dimension of the center joint for clarity. In this embodiment, the center joint wires may also havewire strands250,252 disposed with the helically wound wire similar to the wire described in connection withFIG. 18A. In this embodiment, thestrands250,252 may have a bent configuration, such as illustrated so that the center joint is disposed at the desired (e.g., centered) location.
• FIGS. 19A-19F illustrate various configuration of the center joint which may be used with a PFO closure device. In these illustrations, the center joint is illustrated without the ends. That is, only the portion that would be disposed within and next to the PFO tunnel is illustrated. The ends (not illustrated) would be connected at the locations identified byreference numberal26. In these embodiments, different treatments are provided to the wires which assist in the positioning device and healing of the septum once the device is delivered.FIG. 19A illustrates twowires260,262 which are configured in an oval shape and are provided with a surface treatment which roughens the surface of the wires.FIG. 19B illustrates a magnified view of thewire262 and shows bumps orroughness264 on the wire. A variety of surface treatments may cause the roughness, for example, the wire may be electro-coated with a material that has a rougher surface. Alternatively, a mechanical knurling process may be used to roughen the surface. Finally, for example, the extrusion process of the wire manufacture may be modified to create a rough surface instead of a smooth. The rough surface may be randomly rough, as illustrated, or the rough surface may have a pattern, as would be typically achieved by a knurling or extrusion process. A rough surface in the center joint may provide certain advantages, for example, the rough surface may assure the center joint stays in place. Additionally, the roughened wires may stimulate a healing response by “irritating” the PFO tunnel in a manner that stimulates the body to heal and close the PFO tunnel.
• Other configurations for the wires of the center joint are possible.FIGS. 19C and 19D illustrate an alternative treatment of the wire.FIG. 19C shows thewires270 and272 which are adapted to be delivered into the PFO tunnel and the wires include a roughness that is different in one direction than the other. That is, if one were to run the wire between a thumb and an index finger in one direction, it would be relatively smooth and in the other direction, it would feel more rough.FIG. 19D illustrates the directional “quills”275 which provide a smooth surface (downward as illustrated) and a rough surface (in the upward direction as illustrated). The direction of the quills may be configured to allow for convenient placement of the device within the PFO and for improved resistance to movement. The quills may be placed on the device in a variety of methods including a post extrusion process or directional knurling.
• In another configuration, illustrated inFIGS. 19E and 19F, the quills are provided having opposed direction. In this embodiment, thewires280 and282 havequills284 which are directed toward the center of the center joint. Similarly, thequills285, on the other side of the center joint, are also directed toward the center of the center joint. This configuration may allow for improved stability within the PFO once delivered. In each of the embodiments, the healing response may be improved using roughened or quilled surfaces for the center joint.
• FIG. 20 illustrates yet another configuration for the center joint that includes a fabric or mesh. The center joint is formed bywires290 and292, a mesh orfabric294 is secured to the wires using a variety of known techniques. The mesh itself could be a biological material that stimulates a biological response. Alternatively, the mesh may be impregnated with a chemical or biological agent that may stimulate a biological healing response. Finally, the mesh could be the vehicle to deliver an agent to the PFO tunnel.
• FIGS. 21A and 21B also illustrate alternative embodiments of the center joints which provide improved movement within the PFO tunnel for the center joint. Specifically, as illustrated inFIG. 21A, a “trailer hitch” design is used to improve the ability of the wires to conform within the PFO tunnel.Wires300,310 form a single wire center joint and are connected by a “trailer hitch”connection320. The connection is configured to allow improved movement of the wires so that the ends (not illustrated) can conform to the septal walls without unnecessary stress. In a modification of the embodiment illustrated inFIG. 21A is shown inFIG. 21B. In the embodiment illustrated, thewires330 and332 are joined atend26, which as in the other embodiments, will secure the end wire configuration that secures against septum. Similarly, the334 and336 are joined at the other side of the center joint. A pair of “trailer hitch”connections338 and340 are used to allow the movement of the wires in the center joint. The use ofconnection338 and340 may provide for sufficient flexibility to allow for thicker, more stable wires to be used as the center joint. The use of thicker, stiffer wires may allow for greater resistance from movement for the center joint.
• In the embodiment of the invention illustrated inFIG. 22A the wires that form the oval connection provide a length of wire that could pierce into the septal tissue to secure the center joint in the desire location and, as a result, stabilize the PFO closure device. In the embodiment illustrated,wires340 and342 are joined towires344 and346, respectively. Thejoints348 and350 may be welds or other joints that allow for the reduced profile that is desirable for delivery through a catheter. The ends352,354,356 and358 are designed to pierce the septum and allow for the improved stability described above.
• In a slightly modified configuration, the wires may be provided that are in a configuration illustrated inFIG. 22B. In this embodiment, joints360 and362 provide for the connection between the wires364-370. The wires, as illustrated, have a shape that provides the greatest longitudinal width at the joint. This has the benefit of being able to keep the center joint centered within the PFO. In each of the embodiments described in connection withFIGS. 22A and 22B, the closure device is secured by the piercing elements. The wires can be constructed of a metal or a polymer, and have a circular cross-section or some other form such as a rectangle or polygon.

Claims (35)

1. A device adapted to press together the septum primum and the septum secundum between the atrial chambers, the device comprising:

two clamping members, one on each side of the septum and a central connector which connects the two clamping members and passes through the tunnel wherein the central connector includes two wires that are spaced apart at a portion of their length so that the wires are proximate the lateral sides of the tunnel so that the device may be centered in a passage between the atrial chambers.

2. The device ofclaim 1 wherein at least one of the clamping members include elongate wire members that are spiral shaped.

3. The device ofclaim 2, wherein the central connector is connected to at least one clamping member at an inner part of the spiral shape.

4. The device ofclaim 2, wherein the central connector is connected to at least one clamping member at the outer part of the spiral shape.

5. The device ofclaim 2, wherein the force applied to the septum primum and septum secundum is created by the spiral shape of the elongate member.

6. The device ofclaim 1 wherein the clamping members are formed from nitinol.

7. The device ofclaim 1, wherein the central connector is formed from nitinol.

8. The device ofclaim 1, wherein the central connector is adapted to center the device in the lateral direction along a longitudinal passageway.

9. The device ofclaim 2, wherein the claimping members are constructed of nitinol sheets which have been shaped to form the spirals.

10. The device ofclaim 2 wherein the spirals circle around more than 360 degrees.

11. The device ofclaim 10 wherein the spirals have a helical form.

12. The device ofclaim 1, wherein the clamping members are formed by a plurality of wires and the wires are adapted to spread out along the septum to provide a desired clamping force.

13. A connecting member for a PFO closure device configured to join two end pieces adapted to be disposed along a Patent Foramen Ovale tunnel, the connecting member comprising at least one wire that forms an S shaped curve wherein the outermost lateral sides of the S shaped curves are configured to be adjacent the lateral sides of the Patent Foramen Ovale tunnel.

14. The connecting member for a PFO closure device ofclaim 13 wherein the connecting member includes a wire that is helically wound to minimize trauma to the PFO tissue.

15. The connecting member for a PFO closure device ofclaim 14 wherein the connecting member includes a helically wound wire wrapped around a central wire that provides stability to the connecting member.

16. The connecting member for a PFO closure device ofclaim 13 wherein the connecting member includes whiskers to facilitate the implantation of the device at an implantation location.

17. The connecting member for a PFO closure device ofclaim 13 wherein the surface of the connecting member is roughened to facilitate implantation of the device at an implantation location.

18. The connecting member for a PFO closure device ofclaim 17 wherein the surface of the connecting member is roughened such that friction along the wire from movement in one direction is higher than movement along the wire in the opposite direction.

19. The connecting member for a PFO closure device ofclaim 13 wherein at least one of the wires includes at least two wire segments joined at a location such that the wires are able to move with respect to on another.

20. The connecting member for a PFO closure device ofclaim 19 werein the at least two wires are joined by a trailer hitch-type joint.

21. A connecting member configured to join two end pieces adapted to be disposed along a Patent Foramen Ovale tunnel, the connecting member comprising at least two wires that are joined at each end and spread apart between the ends, wherein wires are adapted to spread out a predetermined amount that is less than a predetermined distance between the lateral sides of a Patent Foramen Ovale tunnel.

22. The connecting member for a PFO closure device ofclaim 21 wherein the connecting member includes a wire that is helically wound to minimize trauma to the PFO tissue.

23. The connecting member for a PFO closure device ofclaim 22 wherein the connecting member includes a helically wound wire wrapped around a central wire that provides stability to the connecting member.

24. The connecting member for a PFO closure device ofclaim 21 wherein the connecting member includes whiskers to facilitate the implantation of the device at an implantation location.

25. The connecting member for a PFO closure device ofclaim 21 wherein the surface of the connecting member is roughened to facilitate implantation of the device at an implantation location.

26. The connecting member for a PFO closure device ofclaim 25 wherein the surface of the connecting member is roughened such that friction along the wire from movement in one direction is higher than movement along the wire in the opposite direction.

27. The connecting member for a PFO closure device ofclaim 21 wherein at least one of the wires includes at least two wire segments joined at a location such that the wires are able to move with respect to on another.

28. The connecting member for a PFO closure device ofclaim 27 wherein the at least two wires are joined by a trailer hitch-type joint.

29. The connecting member for a PFO closure device ofclaim 21 wherein the at least two wire are adapted to have a hook to pierce the tissue where the device is intended to be implanted.

30. The connecting member for a PFO closure device ofclaim 21 further comprising a membrane attached to the connecting member.

31. The connecting member for a PFO closure device ofclaim 21 wherein the connecting member includes a surface coating that promotes tissue growth.

32. The connecting member for a PFO closure device ofclaim 13 further comprising a membrane attached to the connecting member.

31. The connecting member for a PFO closure device ofclaim 13 wherein the connecting member includes a surface coating that promotes tissue growth.

33. The device ofclaim 1 further including a membrane attached to the connecting member.

34. The device ofclaim 1 wherein the connecting member includes a surface coating that promotes tissue growth.

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