Closure devices, related delivery methods, and related methods of use
A device for sealing a patent foramen ovale (PFO) in the heart is provided. The device includes a left atrial anchor adapted to be placed in a left atrium of the heart, a right atrial anchor adapted to be placed in a right atrium of the heart, and an elongate member adapted to extend through the passageway and connect the left and right atrial anchors. The right atrial anchor preferably includes a plurality of arms and a cover attached to the arms. The left atrial anchor preferably also includes a plurality of arms and preferably does not include a cover. Preferably, the elongate member has a first end fixedly connected to the left atrial anchor and a portion, proximal to the first end, passing through the right atrial anchor. Preferably, the elongate member is flexible.
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This invention relates to devices for closing a passageway in a body, for example a patent foramen ovale in a heart, related methods and devices for delivering such closure devices, and related methods of using such closure devices for sealing the passageway.
BACKGROUND OF THE INVENTION
Where anatomical closure of the foramen ovale does not occur, a patent foramen ovale (PFO) is created. A patent foramen ovale is a persistent, usually flap-like opening between the atrial septum primum (SP) and septum secundum (SS) of a heart. A patent foramen ovale results when either partial or no fusion of the septum primum (SP) to the septum secundum (SS) occurs. In the case of partial fusion, a persistent passageway exists between the superior portion of the septum primum (SP) and septum secundum (SS). It is also possible that more than one passageway may exist between the septum primum (SP) and the septum secundum (SS).
Studies have shown that a relatively large percentage of adults have a patent foramen ovale (PFO). It is believed that embolism via a PFO may be a cause of a significant number of ischemic strokes, particularly in relatively young patients. It has been estimated that in 50% of cryptogenic strokes, a PFO is present. Patients suffering a cryptogenic stroke or a transient ischemic attack (TIA) in the presence of a PFO often are considered for medical therapy to reduce the risk of a recurrent embolic event.
Pharmacological therapy often includes oral anticoagulants or antiplatelet agents. These therapies may lead to certain side effects, including hemorrhaging. If pharmacologic therapy is unsuitable, open heart surgery may be employed to close a PFO with stitches, for example. Like other open surgical treatments, this surgery is highly invasive, risky, requires general anesthesia, and may result in lengthy recuperation.
Nonsurgical closure of PFOs is possible with umbrella-like devices developed for percutaneous closure of atrial septal defects (ASD) (a condition where there is not a septum primum (SP)). Many of these conventional devices used for ASDs, however, are technically complex, bulky, and difficult to deploy in a precise location. In addition, such devices may be difficult or impossible to retrieve and/or reposition should initial positioning not be satisfactory. Moreover, these devices are specially designed for ASDs and therefore may not be suitable to close and seal a PFO, particularly because the septum primum (SP) overlaps the septum secundum (SS).
SUMMARY OF THE INVENTIONIn accordance with the invention, methods, tools, and devices for closing a passageway in a body, and more specifically closing a patent foramen ovale (PFO), are provided.
According to one aspect of the invention, a device for sealing a passageway in a human body is provided. The device comprises a first anchor adapted to be placed proximate a first end of the passageway, the first anchor including a plurality of first loop structures, each first loop structure having a first end connected to the first anchor and a second free end, a second anchor adapted to be placed proximate a second end of the passageway, and an elongate member adapted to extend through the passageway and connect the first and second anchors, the elongate member having a first end fixedly connected to one of the first and second anchors.
According to another aspect of the invention, a device for sealing a passageway in a human body comprises a first anchor adapted to be placed proximate a first end of the passageway, the first anchor including a plurality of first loop structures, each first loop structure having a first end connected to the first anchor and a second free end, a second anchor adapted to be placed proximate a second end of the passageway, and a flexible elongate member adapted to extend through the passageway and connect the first and second anchors, the elongate member capable of moving through the second anchor to vary a length of the elongate member between the first and second anchors.
According to a further aspect of the invention, the device for sealing a passageway in a human body comprises a first anchor adapted to be placed proximate a first end of the passageway, the first anchor including a plurality of first loop structures, each first loop structure having a first end connected to the first anchor and a second free end, a second anchor adapted to be placed proximate a second end of the passageway, the second anchor including a plurality of second loop structures, and a flexible elongate member adapted to extend through the passageway and connect the first and second anchors, the elongate member capable of moving through the second anchor to vary a length of the elongate member between the first and second anchors.
According to yet another aspect of the invention, a device for sealing a passageway in a human body comprises a first anchor adapted to be placed proximate a first end of the passageway, the first anchor including a plurality of first loop structures, each first loop structure having a first end connected to the first anchor and a second free end, a second anchor adapted to be placed proximate a second end of the passageway, and a flexible elongate member adapted to extend through the passageway and connect the first and second anchors, wherein the first anchor pivots relative to the elongate member and the second anchor pivots relative to the elongate member.
According to another aspect of the present invention, a device for sealing a passageway in a human body comprises a first anchor adapted to be placed proximate a first end of the passageway, the first anchor including a plurality of first loop structures, each first loop structure having a first end connected to the first anchor and a second free end, a second anchor adapted to be placed proximate a second end of the passageway, and a flexible elongate member adapted to extend through the passageway and connect the first and second anchors, wherein each of the first and second anchors is collapsible from a deployed state to a collapsed delivery state.
According to a further aspect of the present invention, a device for sealing a passageway in a human body comprises a first anchor adapted to be placed proximate a first end of the passageway, the first anchor including a plurality of first loop structures, each loop structure including an outer loop portion and a member connecting portions of outer loop portion, a second anchor adapted to be placed proximate a second end of the passageway, and an elongate member adapted to extend through the passageway and connect the first and second anchors, the elongate member having a first end fixedly connected to the first anchor.
According to yet another aspect of the invention, an assembly for sealing a passageway in a heart is provided. The assembly comprises a guide catheter capable of extending to the passageway, and a closure device capable of sealing the passageway, the closure device including a first anchor adapted to be placed proximate a first end of the passageway, the first anchor including a plurality of first loop structures, each first loop structure having a first end connected to the first anchor and a second free end, a second anchor adapted to be placed proximate a second end of the passageway, and a flexible elongate member adapted to extend through the passageway and connect the first and second anchors, wherein the closure device is positionable within the guide catheter in a first collapsed state and extendable from the guide catheter in a second deployed state.
According to another aspect of the invention, a method of sealing a passageway in a human body is provided. The method comprises placing a first anchor proximate a first end of the passageway, the first anchor including a plurality of first loop structures, placing a second anchor proximate a second end of the passageway, and moving the second anchor relative to the first anchor along a flexible elongate member disposed between the first and second anchors within the passageway.
According to a further aspect of the invention, a method of placing a closure device to seal a passageway in a human body is provided. The method comprises advancing a catheter into a first end of the passageway and out a second end of the passageway, advancing a first anchor of a closure device out of a distal end of the catheter, withdrawing the catheter through the passageway, positioning the first anchor adjacent the second end of the passageway, advancing a second anchor of the closure device out of the distal end of the catheter, positioning the second anchor of the closure device adjacent the first end of the passageway, and advancing a lock to a position adjacent the second anchor.
According to yet another aspect of the invention, a closure device for sealing a passageway in a heart is provided. The closure device comprises a left atrial anchor configured to close a first end of the passageway, a right atrial anchor configured to close a second end of the passageway, at least one of the left atrial anchor and the right atrial anchor including a plurality of loop structures, a flexible elongate member connecting the left and right atrial anchors, wherein the elongate member has a first end fixedly connected to the left atrial anchor and wherein the right atrial anchor is movable with respect to the elongate member, and a lock configured to prevent proximal movement of the right atrial anchor relative to the flexible elongate member.
According to another aspect of the invention, a system for sealing a passage in a heart is provided. The system comprises a delivery catheter capable of extending to a position near the passage, a closure device capable of sealing the passage, the device including a first anchor adapted to be placed proximate a first end of the passage, a second anchor adapted to be placed proximate a second end of the passage, and a flexible elongate member adapted to extend through the passage and connect the first and second anchors, and a cutting tool capable of extending over the flexible elongate member to a position near the second anchor.
According to yet another aspect of the invention, a device for sealing a passageway in a human body is provided. The device comprises a first anchor adapted to be placed proximate a first end of the passageway, the first anchor including a plurality of first loop structures, each loop structure having a first end connected to the first anchor and a second free end, a second anchor adapted to be placed proximate a second end of the passageway, the second anchor including an element configured to engage a snare, and a flexible elongate member connecting the first and second anchors.
According to another aspect of the invention, a device for closing a passageway in a heart comprises a left atrial anchor adapted to be placed in a left atrium of the heart and including a plurality of uncovered arms, a right atrial anchor adapted to be placed in a right atrium of the heart and including a plurality of arms, a cover attached to the plurality of arms, and an element configured to engage a snare, and a flexible elongate member adapted to extend through the passageway and connect the left and right atrial anchors, the elongate member having a first end fixedly connected to the left atrial anchor and a second end releasably connected to the right atrial anchor.
According to yet another aspect of the invention, a device for closing a passageway in a heart comprises a left atrial anchor adapted to be placed in a left atrium of the heart and including a plurality of uncovered arms, a right atrial anchor adapted to be placed in a right atrium of the heart and including a plurality of arms and a cover attached to the plurality of arms, a flexible elongate member adapted to extend through the passageway and connect the left and right atrial anchors, the elongate member having a first end fixedly connected to the left atrial anchor, and a lock for preventing proximal movement of the right atrial anchor relative to the flexible elongate member.
According to another aspect of the invention, a device for closing a passageway in a heart comprises a left atrial anchor adapted to be placed in a left atrium of the heart and including a plurality of uncovered arms and at least one, member connecting each arm to the left atrial anchor, a right atrial anchor adapted to be placed in a right atrium of the heart and including a plurality of arms and a cover attached to the plurality of arms, and a flexible elongate member adapted to extend through the passageway and connect the left and right atrial anchors, the elongate member having a first end fixedly connected to the left atrial anchor and a second end releasably connected to the right atrial anchor.
According to a further aspect of the invention, a method for retrieving a device for sealing a passageway in a heart is provided. The method comprises advancing a snare catheter through a guide catheter toward the passageway covered by a second anchor of the device, engaging a portion of the second anchor with the snare, and drawing the second anchor into the guide catheter with the snare.
According to yet another aspect of the invention, a cutting tool for severing a flexible elongate member is provided. The cutting tool comprises a cutting tool body having a distal end and a proximal end, the cutting tool body capable of extending through a guide catheter, a guide member for guiding the flexible elongate member, the guide member including a distal opening through which the flexible elongate member enters the cutting tool and a lateral opening through which the flexible elongate member exits the cutting tool, and a cutting element surrounding the guide member, wherein the cutting element is movable relative to the guide member to cut the flexible elongate member as it exits the guide member through the lateral opening of the guide member.
Additional advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims.
The foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.
BRIEF DESCRIPTION OF THE DRAWINGSThe accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate several embodiments of the invention and together with the description, serve to explain the principles of the invention.
Reference will now be made in detail to embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.
The various Figures show embodiments of patent foramen ovale (PFO) closure devices, devices and methods for delivery of the PFO closure devices, and methods of using the device to close a PFO. The devices and related methods are described herein in connection with use in sealing a PFO. These devices, however, also are suitable for closing other openings or passageways, including other such openings in the heart, for example atrial septal defects, ventricular septal defects, and patent ductus arterioses, and openings or passageways in other portions of a body such as an arteriovenous fistula. The invention therefore is not limited to use of the inventive closure devices to close PFOs.
As embodied herein and shown in
As shown in
The tether 16 is preferably a high strength flexible polymeric material, such as a braid of polyester yarn. Preferably, such a braided yarn is approximately 0.010 to 0.025 inch in diameter, and most preferably is about 0.0175 inch. Suitable materials include, but are not limited to, multifilament yarns of ultra-high molecular weight polyethylene (UHMWPE) such as SPECTRA™ or DYNEEMA™. Other suitable materials include liquid crystal polymer (LCP) such as VECTRANT™, polyester, or other high strength fibers. Alternatively, the tether 16 could be formed of a high strength polymeric monofilament. The distal end of the tether 16 may be frayed and encapsulated with an adhesive to form a ball shape, which mechanically engages the hub 18, permanently connecting the distal end of the tether 16 to the left atrial anchor 12. Alternatively, the distal end of the tether 16 could be knotted and trimmed to yield a ball shape for engagement with hub 18 of left atrial anchor 12.
As embodied herein and shown in
The unitary arm structure, including the arms 40, is preferably formed from a rolled sheet of binary nickel titanium alloy (also known as nitinol). The alloy is known in the art to have superior elastic properties. The geometry of the unitary arm structure may be formed either by laser cutting or chemical etching. A smooth and passive surface is created by electropolishing. Thermal processing is used to impart a parent shape, as is known in the art. A preferred parent shape is shown in
The arms 40, as shown in
The diameter (span) of the left atrial anchor 12 is primarily determined by the size of the unitary arm structure. In a PFO closure application, the span of the unitary arm structure is preferably from about 10 mm to about 40 mm, and is most preferably from about 15 mm to about 25 mm. The preferred span width of the entire loop 42 at its widest point is preferably from about 0.050 inch to about 0.150 inch, and is most preferably about 0.100 inch. The rolled sheet that forms the loop 42 is preferably between about 0.003 inch and about 0.006 inch uniform thickness, and is most preferably about 0.045 inch, with a width of the loop 42 between about 0.002 inch and about 0.015 inch. The loop 42 is preferably wider near the hub 18, and narrower further away. The struts 46, 47 of the web 44 are thinner than the material forming the loop 42, preferably between about 0.001 inch and about 0.004 inch in width and thickness. The only structure within the left atrium is the relatively small struts of the arms 40, which are preferably well apposed to the wall tissue by virtue of their imparted parent shape. These small struts will readily be incorporated into the tissue of the left atrium, resulting in an endothelialized non-thrombogenic surface.
At the center of the unitary arm structure forming the left atrial anchor 12 is a hole, through which the hub 18 is secured. The hub 18 is preferably a tube formed of radiopaque material such as platinum alloy, and is swaged in place, forming a mechanical interlock with the unitary arm structure that forms left atrial anchor 12. The hub 18 serves to engage the distal bulb 16a of the tether 16, as previously described.
To facilitate visualization during and following implantation of the PFO closure device 10, markers 48 are provided on the arms 40. Holes near the free ends of the arms 40 are formed into the geometry of the unitary arm structure. Markers 48 may include, for example, rivets formed from a radiopaque material such as platinum alloy. The markers 48 are positioned into the holes and swaged in place.
With regard to the shape of each arm 50, thermal processing is used to impart a parent shape, as is known in the art. A preferred parent shape is shown in
The arms 50 form a unitary arm structure that is centered about a hub 19. Hub 19 is tubular, and is preferably formed of a radiopaque material such as platinum alloy. The inner diameter of the hub 19 is slightly larger than the diameter of the tether 16, to allow for the right atrial anchor 14 to slide relative to the tether 16. The hub 19 is secured to the unitary arm structure that forms the right atrial anchor 14 by swaging. A shoulder at the distal end of hub 19 is inserted inside the right atrial anchor 14, and flared by swaging, thus interlocking the hub 19 to the unitary arm structure, as shown in
As embodied herein and shown in
Positioned proximally to right atrial anchor 14 on tether 16 is a lock 20. As embodied herein and shown in
Additionally, the cover 160 for the right atrial anchor 114, as shown in
As shown in
Alternatively, each arm 240 may include a separate safety line 264. For example, the end 265 of the line 264 could be adjacent the end of the tether 216 as described above, extend through the hub 218 and parallel to the arm 240 to the hole 266, and terminate in a knot or encapsulated fray at a hole (not shown) in the end of the tether 216, as previously described in connection with the distal end of the tether 216.
The inner tube 38 of delivery catheter 32 may be formed from a suitable polymer, such as PEBAX 6333™, and have a preferred inner diameter of between about 0.020 inch and about 0.040 inch, most preferably about 0.030 inch, with a wall thickness of between about 0.003 inch and about 0.010 inch, and most preferably about 0.006 inch. The preferred dimensions of the inner tube 38 are such that it can engage and advance the lock 20 along the tether 16. The distal end 38b of the inner tube 38 preferably has a uniform inner and outer diameter. The proximal end of the inner tube 38 also includes a rigid sleeve 38a, formed of a hypotube surrounding the polymeric tube. The length of the rigid sleeve 38a is preferably between about 15 cm and about 30 cm, and is most preferably about 23 cm. The length of the inner tube 38, including the rigid sleeve 38a, is preferably between about 90 cm and about 110 cm, and is most preferably about 100 cm.
In
Prior to deployment of closure device 10, guide catheter 30 would be delivered by conventional techniques to the site of the PFO. Such conventional techniques may include the temporary use of a guide wire (not shown).
The delivery catheter 32 is further advanced relative to the guide catheter 30, deploying only the left atrial anchor 12, as shown in
The delivery catheter 32 and guide catheter 30 are withdrawn, pulling the left atrial anchor 12 against the opening of the PFO track, as shown in
As shown in
The guide catheter 30 and delivery catheter 32 are further withdrawn relative to the PFO track, until the distal end of the guide catheter 30 is well within the right atrium, as shown in
Once left atrial anchor 12 is positioned, right atrial anchor 14 may be deployed. As shown in
With the guide catheter 30 positioned in the right atrium, the right atrial anchor 14 is deployed by advancing the delivery catheter 32 relative to the guide catheter 30, as shown in
In the next step of this embodiment of a closure device delivery method, right atrial anchor 14 is advanced into contact with the right atrial septal wall, as shown in
The right atrial anchor 14 is advanced until it makes contact with the right atrial end of the PFO track, thus closing it off. The tether clip 34 is then repositioned back to abut the proximal end of the delivery catheter 32 to temporarily maintain the relative positions of the left and right atrial anchors 12, 14. A test of the effectiveness of the closure of the PFO track can then be performed, as described earlier. Note that the distal end of the delivery catheter 32 is not fully connected to the right atrial anchor 14, but is merely abutting it. This arrangement allows for the delivery catheter 32 to pivot relative to the right atrial anchor 14 when abutting the right atrial anchor 14, as shown in
Up to this point, the two primary components of the delivery catheter 32, the inner tube 38 and the outer tube 36, have been secured together by way of a touhy-borst fitting 33 in a y-adaptor 35 at the proximal end of the outer tube 36, as shown in
The lock 20, which is initially positioned on the tether 16, several cm proximal of the distal end of the tether 16, is now advanced distally to permanently secure the position of the right atrial anchor 14 relative to the tether 16. To advance the lock 20, the touhy-borst fitting 33 securing the inner tube 38 and the outer tube 36 is loosened. Then, the inner tube 38 is advanced while maintaining the position of the outer tube 36 against the right atrial anchor 14. To prevent creating slack on the tether 16, light tension is applied at its proximal end.
The lock 20 is advanced along the tether 16 under fluoroscopic visualization until it abuts the hub 19 of the right atrial anchor 14. At this point, the delivery catheter 32 is withdrawn several cm, and the PFO closure is re-assessed as discussed previously. In some instances, the right and left atrial anchors 12, 14 may need to be further tightened relative to each other. This can be done by re-advancing the inner tube 38 to the lock 20. The lock 20 is then incrementally advanced along the tether 16, shortening the length of the tether 16 between the left and right atrial anchors 12, 14.
At this point, the effectiveness of the closure and sealing of the PFO can be tested by conventional techniques, such as contrast visualization, or a Valsalva maneuver combined with injection of bubbles, visualized with (TEE) or intracardiac ultrasound.
Once a satisfactory closure of the PFO track is confirmed, the tether 16 may be cut at a position near the right atrial anchor 14. A cutting tool 80 is used to perform this step. An embodiment of a cutting tool 80 is illustrated in
The cuttings element 90 surrounds a tether guide 86, preferably formed from metallic hypotubing, with an outer diameter close to the inner diameter of the cutting element 90. The tether guide 86 incorporates a distal opening 82. A lateral opening 84 is a short distance, preferably about 1 mm to about 5 mm proximal of the distal opening 82. The tether guide 86 is secured about the distal end of a central wire 98. The central wire 98, preferably made of stainless steel, extends proximally through the outer tube 96 to the proximal end of the cutting tool 80. The distal portion of the central wire 98 is enlarged to fill the inside diameter of the tether guide 86. The distal end of the central wire 98 further incorporates a bevel 88. Central wire 98 moves axially and rotationally relative to outer tube 96. At the proximal end of the cutting tool (not shown) is a handle mechanism, which facilitates controlled relative rotation and longitudinal movement between the central wire 98 and thee outer tube 96.
The initial position of the cutting element 90 is just proximal to the lateral opening 84 in the tether guide 86, as shown in
In use, the cutting tool 80 is loaded over the proximal end of the tether 16, as Shown in
There are several points during the delivery of closure device 10 where device 10 can be completely removed from the patient. This may be necessary if, for example, device 10 is not creating a complete seal due to any of a number of causes, including, for example, the selected device being too small.
For example, after deployment of the left atrial arm 12, but before deployment of the right atrial arm 14 (the position shown in
Alternatively, the device 10 may be retrieved after deployment of the right atrial anchor 14, but before advancement of the lock 20 (the position shown in
The various described embodiments of closure devices and methods and tools for their delivery are suitable for closure of a wide variety of PFOs. For example, PFOs with a relatively long overlap between the septum primum (SP) and septum secundum (SS) may be suitably closed, as shown in
Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. The specification and examples are exemplary, with a true scope and spirit of the invention being indicated by the following claims.
Claims
1-90. (canceled)
91. A system for sealing a passage in a heart, the system comprising:
- a delivery catheter capable of extending to a position near the passage;
- a closure device capable of sealing the passage, the device including a first anchor adapted to be placed proximate a first end of the passage, a second anchor adapted to be placed proximate a second end of the passage, and a flexible elongate member adapted to extend through the passage and connect the first and second anchors; and
- a cutting tool capable of extending over the flexible elongate member to a position near the second anchor.
92. The system of claim 91, wherein the cutting tool includes a guide member for guiding the flexible elongate member.
93. The system of claim 92, wherein the guide member includes a distal opening through which the flexible elongate member enters the cutting tool and a lateral opening through which the flexible elongate member exits the cutting tool.
94. The system of claim 92, wherein the cutting tool further includes a cutting element disposed around the guide member.
95. The system of claim 94, wherein the cutting element is movable relative to the guide member to cut the flexible elongate member as it exits the guide member through a lateral opening of the guide member.
96. The system of claim 91, further comprising a guide catheter capable of extending to a position near the passage.
97. The system of claim 91, further comprising a loading tube.
98. The system of claim 97, wherein the closure device is positionable within the loading tube in a collapsed state.
99. The system of claim 91, wherein the second anchor includes a plurality of second loop structures.
100-108. (canceled)
109. The system of claim 94, wherein the cutting element is formed of stainless steel.
110. The system of claim 94, wherein the cutting element includes a sharpened distal edge.
111. The system of claim 94, wherein the cutting tool includes a handle mechanism configured to move the cutting element relative to the guide member.
112. The system of claim 111, wherein the handle mechanism is configured to rotate the cutting element.
113. The system of claim 111, wherein the handle mechanism is configured to advance the cutting element distally.
Type: Application
Filed: Sep 16, 2006
Publication Date: Mar 22, 2007
Applicant: St. Jude Medical, Cardiology Division, Inc. (Minnetonka, MN)
Inventors: David Blaeser (Champlin, MN), Jerome Grudem (Rogers, MN), Scott Olson (Princeton, MN), Mark Christianson (Darwin, MN), Scott Hanson (Savage, MN), Edward Anderson (Hopkins, MN), Patrick Russo (Vadnais Heights, MN), Dennis Wahr (Ann Arbor, MI)
Application Number: 11/522,193
International Classification: A61B 17/08 (20060101);