Abstract:
The present invention provides devices and methods for closing a physical anomaly comprising two overlapping layers of tissue, such as a patent foramen ovale (“PFO”). A PFO is comprised of two overlapping layers of malformed interatrial septa, the septum primum and the septum secundum, that form a tunnel between the right atrium and the left atrium. The closure device includes two wings connected to a central arm. The device is delivered through the PFO tunnel in a substantially linear configuration such that the central arm is seated within the PFO tunnel, the first wing extends into the right atrium, and the second wing extends into the left atrium. Once implanted, the closure device is reconfigured such that the arm is seated within the PFO tunnel, the first wing folds against the septum secundum, and the second wing folds against the septum primum, thereby sealing the defect.

Description:
BACKGROUND 
       [0001]    Patent foramen ovale (“PFO”) is an anatomical interatrial communication with potential for right-to-left shunting of blood. Specifically, PFO is a flap-like opening between the atrial septa primum and secundum of the heart that persists after one year of age. In utero, the foramen ovale serves as a physiologic conduit for right-to-left shunting of blood in the fetal heart. After birth, with the establishment of pulmonary circulation, the increased left atrial blood flow and pressure presses the septum primum against the walls of the septum secundum, covering the foramen ovale and resulting in functional closure of the foramen ovale. This closure is usually followed by anatomical closure of the foramen ovale due to fusion of the septum primum to the septum secundum. 
         [0002]    If anatomical closure of the foramen ovale does not occur, a patent foramen ovale is created. A PFO results when either partial or no fusion of the septum primum and the septum secundum occurs. In the case of partial or no fusion, a persistent passageway or PFO track exists between the septum primum and the septum secundum. The passageway is typically parallel to the plane of the septum primum, and has a mouth that is generally oval in shape. Normally, the passageway is long and quite narrow. Because the mean left atrial pressure is typically higher than the mean right atrial pressure, the opening is usually held closed. However, at times, the mean right atrial pressure may exceed the mean left atrial pressure, causing the PFO track to open and allow the passage of blood (and possible blood clots) from the right atrium to the left atrium (and into systemic circulation). Although the PFO track is often held closed, the endothelialized surfaces of the tissues forming the PFO track prevent the tissues from healing together and permanently closing the PFO track. 
         [0003]    Studies have shown that a relatively large percentage of adults have a patent foramen ovale. It is believed that embolism via a PFO may be the cause of a significant number of ischemic strokes, particularly in relatively young patients. Such paradoxical embolism via PFO is considered in the diagnosis of patients who have suffered a stroke or transient ischemic attack (“TIA”) in the presence of a PFO and without another identified cause of ischemic attack. Blood clots that form in the venous circulation can embolize, and may enter the arterial circulation via the PFO, subsequently entering the cerebral circulation, resulting in an embolic stroke. Blood clots may also form in the vicinity of the PFO, and embolize into the arterial circulation and into the cerebral circulation. Patients suffering a cryptogenic stroke or TIA in the presence of a PFO are often considered for medical therapy to reduce the risk of a recurrent embolic event. Pharmacological therapy often includes oral anticoagulants or antiplatelet agents to block the formation of emboli. If pharmacotherapy is unsuitable, open heart surgery may be employed to close a PFO with stitches, for example. Like other open surgical procedures, this surgery is highly invasive, risky, requires general anesthesia, and may result in a lengthy recuperation. 
         [0004]    Nonsurgical closure of a PFO is possible with umbrella-like devices and a variety of similar mechanical closure devices originally developed for percutaneous closure of atrial septal defects (“ASD”), a condition where the septum primum is often under-developed and perforated. Many of the devices used for closure of an ASD, however, are often technically complex to manufacture and assemble, have a high septal profile, are difficult to deploy to a precise location, and are difficult to implant without deforming the atrial septa and PFO track. In addition, such devices may be difficult or impossible to reposition or retrieve in cases where the original positioning was unsatisfactory. Moreover, these devices are specially designed to close ASDs, or hole-like defects, and therefore are not optimally designed to close and seal a PFO, an overlapping, flap-like, passageway defect. Thus, when inserting an ASD device to close a PFO, the narrow opening and thin flap may form impediments to proper deployment of the device, resulting in residual leakage through the PFO. Even if an occlusive seal is formed, the device may be deployed in the PFO track at an angle, leaving some components insecurely seated against the septum and thereby increasing the risk of thrombus formation due to hemodynamic disturbances. 
         [0005]    Accordingly, there exists a need for instrumentation and techniques that facilitate more effective and efficient closure of aberrant, flap-like bodily openings such as patent foramen ovales. 
       SUMMARY 
       [0006]    This disclosure relates to a closure device for closing physical anomalies and defects, including a patent foramen ovale, an atrial septal defect, and various other septal and vascular defects. 
         [0007]    In one exemplary aspect, the present disclosure is directed to a device for closing a patent foramen ovale (PFO). The device may comprise a first arm, a second arm, a first wing, and a second wing. The first arm may include a first body portion and a first tab portion, wherein the first body portion may include a first passage extending longitudinally therethrough. The second arm may include a second body portion and a second tab portion, wherein the second body portion may include a second passage extending longitudinally therethrough. The second passage may be sized to slidably receive the first tab portion and the first passage may be sized to slidably receive the second tab portion. The first wing may be pivotally connected to the first arm and the second wing may be pivotally connected to the second arm. 
         [0008]    In another exemplary aspect, the present disclosure is directed to a device for closing a patent foramen ovale (PFO). The device may comprise a first arm and a second arm. The first arm may include proximal and distal ends, wherein the proximal end is pivotally connected to a first wing via a first hinge and the first hinge includes a first projection. The second arm may include proximal and distal ends, wherein the proximal end is pivotally connected to a second wing via a second hinge and the second hinge includes a second projection. The distal end of the first arm may be configured to engage the second projection to pivot the second wing with respect to the second arm, and the distal end of the second arm may be configured to engage the first projection to pivot the first wing with respect to the first arm. 
         [0009]    In another exemplary aspect, the present disclosure is directed to a system for closing a patent foramen ovale (PFO) in a heart. The system may comprise a delivery catheter, a closure device, an outer tool, and an inner tool. The delivery catheter may have a lumen extending along a longitudinal axis. The closure device may be configured for delivery into the heart and for collapsible containment within the lumen. The closure device may comprise a first arm, a second arm, a first wing, and a second wing. The first arm may include a first body portion and a first tab portion, wherein the first body portion may include a first passage extending longitudinally therethrough. The second arm may include a second body portion and a second tab portion, wherein the second body portion may include a second passage extending longitudinally therethrough. The second passage may be sized to slidably receive the first tab portion and the first passage may be sized to slidably receive the second tab portion. The first wing may be pivotally connected to the first arm and the second wing may be pivotally connected to the second arm. The outer tool may be configured for attachment to the first body portion and have a lumen extending longitudinally through its length. The inner tool may be configured for attachment to the second tab portion. The lumen of the outer tool may be sized to receive a portion of the inner tool, wherein the inner tool is movable with respect to the outer tool to slide the second tab portion with respect to the first passage. 
         [0010]    In another exemplary aspect, the present disclosure is directed to a system for closing a patent foramen ovale (PFO) in a heart. The system may comprise a delivery catheter, a closure device, an outer tool, and an inner tool. The delivery catheter may have a lumen extending along a longitudinal axis. The closure device may be configured for delivery into the heart and for collapsible containment within the lumen. The closure device may comprise a first arm and a second arm. The first arm may include proximal and distal ends, wherein the proximal end is pivotally connected to a first wing via a first hinge and the first hinge includes a first projection. The second arm may include proximal and distal ends, wherein the proximal end is pivotally connected to a second wing via a second hinge and the second hinge includes a second projection. The distal end of the first arm may be configured to engage the second projection to pivot the second wing with respect to the second arm, and the distal end of the second arm may be configured to engage the first projection to pivot the first wing with respect to the first arm. The outer tool may be configured for attachment to the proximal end of the first arm and have a lumen extending longitudinally through its length. The inner tool may be configured for attachment to the distal end of the second arm. The lumen of the outer tool may be sized to receive a portion of the inner tool, wherein the inner tool is movable with respect to the outer tool to slide the distal end of the second arm with respect to the first hinge. 
         [0011]    In another exemplary aspect, the present disclosure is directed to a method for closing a patent foramen ovale (PFO) in a heart, where the PFO comprises a lumen between a septum primum and a septum secundum. The method may include the steps of: providing a closure device comprising a first wing, a first arm, a second arm, and a second wing; providing an assembly sheath having a lumen extending longitudinally through its length, the lumen sized and configured to contain the closure device in a collapsed configuration; providing a delivery catheter having a lumen extending longitudinally through its length, the lumen sized and configured to contain the assembly sheath; inserting the closure device into the lumen of the assembly sheath such that the closure device is in a collapsed configuration; advancing the delivery catheter into a desired location within the heart; connecting the assembly sheath to the delivery catheter; advancing the closure device through the assembly sheath into the delivery sheath; delivering the closure device at least partially within the PFO; withdrawing the delivery catheter such that the first arm and the second arm are positioned within the lumen of the PFO, the second wing is positioned in a left atrium of the heart, and the first wing is positioned in a right atrium of the heart; rotating the closure device such that the first wing and the second wing are about parallel to the septum secundum and the septum primum, respectively; and interlocking the first arm and second arm such that the second wing is positioned against the septum primum and the first wing is positioned against the septum secundum, wherein the first wing and the second wing exert force on the septum secundum and septum primum, respectively, to push overlapping layers of the septum secundum and the septum primum together to close the PFO. 
         [0012]    In another exemplary aspect, the present disclosure is directed to a method for closing a patent foramen ovale (PFO) between a septum primum and a septum secundum. The method may include the steps of: providing a first closure component including a first body portion connected between a first tab and a first wing, the first body portion including a first passage extending longitudinally therethrough; providing a second closure component including a second body portion connected between a second tab and a second wing, the second body portion including a second passage extending longitudinally therethrough; positioning the first and second body and tab portions into the patent foramen ovale; sliding the second tab portion within the first passage; sliding the first tab portion within the second passage; engaging the septum primum between the first and second body portions and the first wing; and engaging the septum secundum between the first and second body portions and the second wing. 
         [0013]    In another exemplary aspect, the present disclosure is directed to a method for closing a patent foramen ovale (PFO) between a septum primum and a septum secundum. The method may include the steps of: providing a first arm with proximal and distal ends, the proximal end pivotally connected to a first wing via a first hinge, the first hinge including a first projection; providing a second arm with proximal and distal ends, the proximal end pivotally connected to a second wing via a second hinge, the second hinge including a second projection; engaging the distal end of the first arm with the second projection to rotate the second wing with respect to the second arm; and engaging the distal end of the second arm with the first projection to rotate the first wing with respect to the first arm. 
         [0014]    Further aspects, forms, embodiments, objects, features, benefits, and advantages of the present invention shall become apparent from the detailed drawings and descriptions provided herein. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]    Aspects of the present disclosure are best understood from the following detailed description when read with the accompanying figures. It is emphasized that various features are not drawn to scale. In fact, the dimensions of the various features may be arbitrarily increased or reduced for clarity of discussion. In addition, the present disclosure may repeat reference numerals and/or letters in the various examples. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed. 
           [0016]      FIG. 1  is a perspective view of a first embodiment of the closure device. 
           [0017]      FIG. 2  is an exploded view of the arms of the first embodiment of the closure device. 
           [0018]      FIGS. 3   a - 3   c  are detailed views of the linkage between the arms of the first embodiment of the closure device.  FIG. 3   a  is a perspective view, and  FIGS. 3   b - 3   c  are cross-sectional side views. 
           [0019]      FIG. 4  is a perspective view of a hinge mechanism between the first arm and a first wing of the first embodiment of the closure device. In addition,  FIG. 4  is a perspective view of outer and inner connector members attached to portions of the first arm and the second arm, respectively. 
           [0020]      FIGS. 5-10  are perspective views illustrating a first embodiment of a compression apparatus and the preparation of the first embodiment of the closure device for delivery. 
           [0021]      FIGS. 11   a - 11   i  are partial cross-sectional views illustrating a second embodiment of a compression apparatus and the preparation of a first embodiment of the closure device for delivery. 
           [0022]      FIGS. 12-15  are schematic views illustrating the delivery of the first embodiment of the closure device within the atria. 
           [0023]      FIGS. 16   a  and  16   b  are partial cross-sectional view of a deployment handle accompanied by a perspective view of the hinge mechanism of the first wing during deployment of the wings. 
           [0024]      FIGS. 17-19  are schematic views illustrating the deployment of the first embodiment of the closure device within the atria. 
           [0025]      FIGS. 20   a - 20   c  are detailed perspective views illustrating the hinge mechanism of the first wing during deployment of the wings of the first embodiment of the closure device. 
       
    
    
     DETAILED DESCRIPTION 
       [0026]    For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiments, or examples, illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended. Any alterations and further modifications in the described embodiments, and any further applications of the principles of the invention as described herein are contemplated as would normally occur to one skilled in the art to which the invention relates. 
         [0027]    The present invention relates to a system and method for closing overlapping layers of tissue in a human or animal body. The various figures show embodiments of a closure device and methods of assembling and using the device to close a patent foramen ovale (“PFO”) in a patient&#39;s heart. One of ordinary skill in the art, however, would understand that similar embodiments could be used to close other passageways and openings in the body without departing from the general intent or teachings of the present invention. 
         [0028]      FIG. 1  illustrates a closure device  10  according to an exemplary embodiment of the present invention for closing a PFO. The closure device  10  includes a pair of wings  12 ,  14  and a pair of arms  16 ,  18 . The wing  12  is connected to the arm  16  via a hinge mechanism  20 , and the wing  14  is connected to the arm  18  via a hinge mechanism  22 . 
         [0029]    The wings  12 ,  14  each include sheets  24 ,  26 , respectively, bordered by support frames  28 ,  30 , respectively, having a predetermined shape configuration. The wings  12 ,  14  are expandable from an unexpanded configuration to an expanded configuration. The wings  12 ,  14  are constructed from structurally deformable materials that can elastically or plastically deform without compromising their integrity. The sheets are preferably made from a deformable biocompatible material. The sheets  24 ,  26  span smoothly and continuously across the support frames  28 ,  30 , respectively. The support frames  28 ,  30  may be made from a self-expanding biocompatible material, such as Nitinol or a resilient polymer, or an elastically compressed spring temper biocompatible material. Other materials having shape memory characteristics, such as particular metal alloys, may also be used. The shape memory materials allow the wings  12 ,  14  to be restrained in a low profile configuration during delivery and to resume and maintain their expanded shape in vivo after the delivery process. 
         [0030]    In the pictured embodiment in  FIG. 1 , the wings  12 ,  14  assume the predetermined shape of flat ellipses in the expanded state. The flat and substantially elliptical shape of the wings  12 ,  14  should not be considered a limiting feature of the invention, as other shapes and configurations of the wings  12 ,  14  are contemplated for other embodiments of the present invention. These may include, for example, round, rectangular, oblong, triangular, and square shapes for the frames  28 ,  30 , and flat or curved configurations for the sheets  24 ,  26 . 
         [0031]      FIG. 2  illustrates the arm  16  and the arm  18  being of substantially identical size and shape. In this embodiment, the arm  16  is shaped like an oblong paddle having a rounded end  32  and a rounded end  34 . The arm  16  includes a body portion  36  integrally and rigidly connected to a tab portion  38 . The arm  16  includes an upper surface  39 . In some embodiments, the body portion  36  and the tab portion  38  may share a continuous upper surface. The body portion  36  includes an aperture  40  extending from the upper surface  39  through the body portion and includes a passage  41  extending longitudinally through the body portion from an opening  37  to the aperture  40 . The body portion  36  is generally thicker than the tab portion  38 . In this embodiment, the aperture  40  is generally circular and sized for a portion of the hinge mechanism  20  to operate therein. In other embodiments, the aperture may have other shapes such as a square or an oval. 
         [0032]    The arm  18  is also shaped like an oblong paddle and includes a rounded end  42  and a rounded end  44 . The arm  18  includes a body portion  46  integrally and rigidly connected to a tab portion  48 . The arm  18  includes a lower surface  49 . In some embodiments, the body portion  46  and the tab portion  48  may share a continuous lower surface. The body portion  46  includes an aperture  50  extending from the lower surface  49  through the body portion and includes a passage  51  extending longitudinally through the body portion from an opening  47  to the aperture  50 . The body portion  46  is generally thicker than the tab portion  48 . In this embodiment, the aperture  50  is generally circular and sized for a portion of the hinge mechanism  22  to operate therein. In other embodiments, the aperture may have other shapes such as a square or an oval. 
         [0033]    The surfaces  39 ,  49  of the arms  16 ,  18 , respectively, can be smooth or textured. A textured or rough exterior surface may produce an inflammatory response upon contact with the septal tissue in vivo, thereby promoting faster tissue ingrowth and closure of the PFO track. Additionally or alternatively, the surfaces  39 ,  49  of the arms  16 ,  18 , respectively, may be porous to facilitate cell ingrowth. Additionally or alternatively, the surfaces  39 ,  49  of the arms  16 ,  18 , respectively, may be impregnated or coated with medication to promote cell ingrowth. 
         [0034]      FIG. 3   a  shows a detailed view of the central interconnection between the arm  16  and the arm  18 . The opening  37  of the arm  16  receives the end  44  of the arm  18 , and the tab  48  slides into the passage  41 . Simultaneously, the opening  47  of the arm  18  receives the end  34  of the arm  16 , and the tab  38  slides into the passage  51 . The interconnection of the tabs  38 ,  48  in the passages  51 ,  41 , respectively, causes the tabs to bend slightly inwardly. Thus, when inserted in the passages  51 ,  41 , the tabs  38 ,  48  exert a slightly outward force against the wall of the passage which serves to frictionally lock the arms  16 ,  18  in the connected configuration. 
         [0035]    In an alternative embodiment, as shown in  FIG. 3   b , the arms  16 ′ and  18 ′ are substantially similar to arms  16  and  18  except for the differences to be described. The arms  16 ′ and  18 ′ can be interlocked as described above, but in this embodiment, a releasable locking mechanism  52  further secures the arms  16 ′,  18 ′ together. The locking mechanism  52  includes a set of mechanical connection structures configured as ridges. The mechanical connection structures comprise a set of ridges  54  extending from tab  38 ′ to interlock with a set of ridges  55  extending from the inferior surface of the passage  51 ′ and a set of ridges  56  extending from tab  48 ′ to interlock with a set of ridges  57  extending from the superior surface of passage  41 ′. The ridges  54  may also interlock with the ridges  56 . The ridges  54 ,  55 ,  56 ,  57  may be shaped to offer more resistance to the arms  16 ′,  18 ′ sliding apart from each other than is offered to the arms  16 ′,  18 ′ sliding toward each other. Nevertheless, the resistance imparted by the locking mechanism may be overcome, by sufficient force, to release the interconnection of the arms  16 ′,  18 ′ and allow the arms  16 ′,  18 ′ to separate. 
         [0036]    It is understood that the configuration of the releasable locking mechanism can include any of a variety of mechanical connection structures of various sizes, dimensions, shapes, and configurations. In addition, each individual tab  38 ′,  48 ′ and each individual passage  41 ′,  51 ′ may include a variety of mechanical connection structures of various sizes, dimensions, shapes, and configurations. For example, in an alternative embodiment illustrated in  FIG. 3   c , the mechanical connection structures on each tab  38 ′,  48 ′ and inside each passage  41 ′,  51 ′ may comprise hemispheric protrusions  58  and triangular, teeth-like protrusions  59  to offer more resistance to the arms  16 ′,  18 ′ sliding apart from each other than is offered to the arms  16 ′,  18 ′ sliding toward each other. The resistance imparted by the hemispheric protrusions  58  may be overcome, by sufficient force, to release the interconnection of the arms and allow the arms  16 ′,  18 ′ to partially separate. The triangular protrusions  59 , however, are shaped, configured, and positioned to prevent the arms  16 ′,  18 ′ from completely separating. It is understood that the configuration of the releasable locking mechanism can include any of a variety of mechanical connection structures of various sizes, dimensions, shapes, and configurations. 
         [0037]      FIG. 4  illustrates features of the closure device  10  that slidably draw the arms  16 ,  18  together and that cause the wings  12 ,  14  to move. As shown, an outer tool  70  is releasably connected to the body  36  of the arm  16 . The outer tool  70  is shaped as a hollow, cylindrical tube having a proximal end  72  (not shown) and a threaded distal end  74 . A threaded recess  76  is formed in the end  32  of the arm  16 . The outer tool  70  is releasably connected to the arm end  32  by threaded engagement of the threaded distal end  74  of the outer tool in the threaded recess  76 . In alternative embodiments, other connectors such as clamps, magnets, or spring-biased connectors may be used to connect the outer tool to the arm  16 . 
         [0038]    In  FIG. 4 , an inner tool  80  is shown releasably connected to the end  44  of the arm  18 . The inner tool  80  is configured as an elongate structure having a proximal end  82  (not shown) and a threaded distal end  84 . In various embodiments, the inner tool can be configured as a cable, a wire, or a rod, for example. A threaded recess  86  is formed in the end  44  of the arm  18 . The inner tool  80  is releasably connected to the arm end  44  by threaded engagement of the threaded distal end  84  of the inner tool in the threaded recess  86 . In alternative embodiments, other connectors such as clamps, magnets, or spring-biased connectors may be used to connect the inner tool to the arm  18 . The inner tool  80  is configured to be slidably received within the outer tool  70 . As will be explained in further detail below, moving the inner tool  80  within and relative to the outer tool  70  causes the tab  48  to slide within the passage  41  and the tab  38  to slide within the passage  51 . 
         [0039]      FIG. 4  also illustrates the hinge mechanism  20  attached to the arm  16 . The hinge mechanism  20  includes two hinge pins  90  and two hinge tips  92 . The two hinge pins  90  are straight, rod-like structures extending through the body  36  and into the aperture  40  of the arm  16  along a longitudinal axis  94 . One end of each hinge pin  90  is connected, either integrally or by a mechanical connector, to the support frame  28  of the wing  12 , and the opposite end of each hinge pin extends into the aperture  40 . Each hinge tip  92  is a projection shaped as a curved rod extending from each hinge pin  90  in a plane transverse or oblique to the axis  94 . 
         [0040]    The wing  12  is pivotally connected to the arm  16  and rotates around the axis  94  via the hinge mechanism  20 . As the physician exerts a pulling force on the proximal end  82  of the inner tool  80 , the tab  48  of the arm  18  slides within the passage  41  of the arm  16  in the direction of the pulling force. As the tab  48  slides into the passage  41 , the tab  38  of the arm  16  simultaneously slides within the passage  51  of the arm  18 , causing the arms  16 ,  18  to become interconnected. The hinge tips  92  are curved such that when the tab  48  is pulled by the inner tool  80  towards the end  32  of the arm  16 , the tab  48  extends into the aperture  40  and contacts convex portions of the curved hinge tips  92  to swivel the hinge tips  92  about the axis  94 , thereby causing the hinge pins  90  to rotate about the axis  94 . The rotation of the hinge pins  90  causes the simultaneous rotation of the wing  12  toward the arm  16 . 
         [0041]    The hinge mechanism  22 , as shown in  FIG. 1 , is configured to be substantially identical to the hinge mechanism  20 . The hinge mechanism  22  includes two hinge pins and two hinge tips that are substantially identical in both structure and function to the hinge pins  90  and the hinge tips  92 . The wing  18  is pivotally connected to the arm  16  via the hinge mechanism  22 . When the inner tool  80  is pulled and moved relative to the outer tool  70 , the tab  38  of the arm  16  slides within the passage  51  of the arm  18  in the direction opposite of the pulling force. The advancing end  34  of the tab  38  extends into the aperture  50  and contacts convex portions of the curved hinge tips of the hinge mechanism  22  to swivel the hinge tips and thereby cause the hinge pins to rotate. The rotation of hinge mechanism  22  causes the simultaneous rotation of the wing  14  toward the arm  18 . 
         [0042]    In order to introduce the closure device  10  into the atrial chambers through a minimally invasive, percutaneous procedure, the physician first compresses the closure device  10  into a configuration that is sized to pass within a standard intraluminal delivery catheter.  FIG. 5  illustrates a dumbbell-shaped compression apparatus  102  designed to compress the closure device  10  into a configuration that is sized for containment within an assembly sheath  104 . The compression apparatus  102  includes a proximal tube  106 , a proximal container  108 , a connecting tube  110 , a distal container  112 , and a distal flush port  114 . The assembly sheath  104  is an elongate, cylindrical, hollow tube having a proximal end (not shown) and a distal end  116 . The assembly sheath  104  is sized and configured to receive and contain the closure device  10  in a compressed state. The diameter of the assembly sheath  104  is sized such that the assembly sheath can flushly slide within the proximal tube  106 , but cannot advance into the connecting tube  110 . The distal end  116  of the assembly sheath  104  is removably and slidably engagable with the proximal tube  106 . The assembly sheath  104  possesses sufficient flexibility to flushly slide inside the proximal tube  106 , but also possesses sufficient axial stiffness to maintain the closure device  10  in a compressed state and to easily advance into a delivery sheath. 
         [0043]    The proximal container  108  and the distal container  112  are configured to be substantially identical in size and shape. In the embodiment pictured in  FIG. 5 , the containers  108 ,  112  are configured as rigid, hollow cylindrical drums. The containers  108 ,  112  are sized and configured to contain the closure device  10  in an expanded state. These containers  108 ,  112  include transparent upper walls  118   a ,  118   b  and opaque lower walls  120   a ,  120   b , respectively. The transparent upper walls  118   a ,  118   b  are removably or hingedly attached to the opaque lower walls  120   a ,  120   b . The transparent upper walls  118   a ,  118   b  allow the physician to visually observe and direct the compression of the closure device  10 . The containers  108 ,  112  each include proximal surfaces  122   a ,  122   b  and distal surface  124   a ,  124   b.    
         [0044]    The containers  108 ,  112  are connected by the connecting tube  110 , a rigid, cylindrical, hollow tube. The connecting tube  110  is sized and configured to slidably receive the closure device  10  in a compressed state. The connecting tube  110  extends perpendicularly between the distal surface  124   a  of the proximal container and the proximal surface  122   b  of the distal container, such that the lumens of the containers  108 ,  112  and the connecting tube  110  are centrally aligned and contiguous. The connecting tube  110  comprises a transparent hemi-cylindrical upper portion  126  and an opaque hemi-cylindrical lower portion  128  that are integrally connected to the transparent upper walls  118  and the opaque lower walls  120 , respectively. 
         [0045]    The proximal tube  106  is a rigid, cylindrical, hollow tube extending perpendicularly from the proximal surface  122   a  of the proximal container  108  such that the proximal tube  106  is coaxial with the connecting tube  110 . The proximal tube  106  comprises a transparent hemi-cylindrical upper portion  129  and an opaque hemi-cylindrical lower portion  130  that are integrally connected to the upper wall  118   a  and to the lower wall  120   a , respectively. It is understood that in alternative embodiments, any of the components described as opaque may be transparent or portions of components described as transparent may be opaque. The lumens of the proximal tube  106 , the proximal container  108 , the connecting tube  110 , and the distal container  112  are centrally aligned and contiguous. The proximal tube  106  is sized and configured to slidably receive and introduce the distal end  116  of the assembly sheath  104  into the lumen of the proximal container  108 . 
         [0046]    The distal flush port  114  is a rigid, cylindrical hollow tube extending from the distal surface  124   b  of the distal container  112  into the lumen of the distal container  112  such that the distal flush port  114  is coaxial with the connecting tube  110  and the proximal tube  106 . The distal flush port  114  comprises a transparent hemi-cylindrical upper portion  115   a  and an opaque hemi-cylindrical lower portion  115   b  that are integrally connected to the upper wall  118   b  and to the lower wall  120   b , respectively. 
         [0047]    To begin the compression process, the physician first detaches or hingedly separates the upper components  129 ,  118   a ,  126 ,  118   b ,  115   a  from the lower components  130 ,  120   a ,  128 ,  120   b ,  115   b  respectively. Then the physician inserts the closure device  10  into the compression apparatus  102  such that the arms  16 ,  18  are seated within the connecting tube  110  and the wings  12 ,  14  are positioned within the containers  108 ,  112 . Specifically, the wing  12  is positioned within the proximal container  108  and the wing  14  is positioned within the distal container  112 . Within the connecting tube  110 , the arms  16 ,  18  are connected such that the tab  48  extends at least partially within the passage  41  and the tab  38  extends at least partially within the passage  51 . The outer tool  70  and the inner tool  80  may be connected to the arm  16  and the arm  18 , respectively, in the manner described above. It is understood that this connection of the tools to the arms may be performed either before or while the closure device  10  is positioned in the compression apparatus  102 . The outer and inner tools  70 ,  80  extend through the proximal tube  106 , and the assembly sheath  104  is advanced over the outer and inner tools  70 ,  80  and into the proximal tube. 
         [0048]    Next, the physician reattaches the upper components  129 ,  118   a ,  126 ,  118   b ,  115   a  to the lower components  130 ,  120   a ,  128 ,  120   b ,  115   b  of the compression apparatus  102 . The interior of the compression apparatus  102  is flushed with saline through the distal flush port  114 . 
         [0049]    As  FIG. 6  illustrates, the compression process proceeds by advancing the outer tool  70  and thus the whole closure device  10  toward the distal flush port  114 . The wing  12  is forced to deform into a compressed state as it enters the connecting tube  110  while the wing  14  swings freely in the distal container  112 . The assembly sheath  104  is then advanced toward the connecting tube  110  until the assembly sheath abuts the connecting tube  110  within the proximal container  108 . 
         [0050]    As shown in  FIG. 7 , when the outer tool  70  is retracted, the wing  12  is drawn from the connecting tube  110  into the assembly sheath  104 . The first wing  12  maintains its compressed state as it is drawn into the assembly sheath  104 . 
         [0051]    As shown in  FIG. 8 , the outer tool  70  is further proximally retracted, the arms  16 ,  18  are drawn through the connecting tube  110  into the assembly sheath  104  and the wing  14  is deformed into a compressed shape as it passes through the connecting tube  110 . The wing  14  maintains its compressed state as it is drawn into the assembly sheath  104 . 
         [0052]      FIG. 9  illustrates the entire closure device  10  positioned inside the assembly sheath  104  with both wings  12 ,  14  maintained in a compressed state. 
         [0053]      FIG. 10  illustrates the assembly sheath  104  separated from the compression apparatus  102 . The assembly sheath  104  contains the closure device  10  in a compressed state. 
         [0054]      FIGS. 11   a - 11   i  illustrate an alternative embodiment of a compression apparatus and the preparation of the first embodiment of the closure device for delivery. In this embodiment, the compression apparatus  140  includes a proximal tube  142 , a connecting bar  144 , and a distal tube  146 . The diameter of the assembly sheath  104  is sized such that the assembly sheath  104  can flushly slide within the proximal tube  142 , but cannot advance into the distal tube  146 . The distal end  116  of the assembly sheath  104  is removably and slidably engagable with the proximal tube  142 . The assembly sheath  104  possesses sufficient flexibility to flushly slide inside the proximal tube  142  such that the lumen of the assembly sheath  104  is coaxial with the lumen of the proximal tube  142 , but also possesses sufficient axial stiffness to maintain the closure device  10  in a compressed state and to easily advance into a delivery sheath. 
         [0055]    In the embodiment pictured in  FIGS. 11   a - 11   i , the proximal tube  142  and the distal tube  146  are configured as rigid, hollow, cylindrical tubes. The distal tube  146  is sized to have a length substantially similar to the length of the arms  16 ,  18  of the closure device when the arm  16  is connected to the arm  18 . The proximal tube  142  can have a shorter length than the length of the distal tube  146 . The proximal tube  142  comprises a transparent hemi-cylindrical upper portion  148   a  and an opaque hemi-cylindrical lower portion  150   a . The distal tube  146  comprises a transparent hemi-cylindrical upper portion  148   b  and an opaque hemi-cylindrical lower portion  150   b . The transparent upper portions  148   a ,  148   b  are removably or hingedly attached to the opaque lower portions  150   a ,  150   b , respectively. The transparent upper portions  148   a ,  148   b  allow the physician to visually observe and direct the compression of the closure device  10 . 
         [0056]    The proximal tube  142  and the distal tube  146  are connected by the connecting bar  144 , a rigid, elongate bar. The connecting bar  144  is sized to hold both the proximal tube  142  and the distal tube  146  at a distance apart from each other. The opaque lower portions  150   a ,  150   b  of the proximal tube  142  and distal tube  146 , respectively, are fixedly attached to the connecting bar  144  such that the proximal tube  142  is spaced a distance apart from the distal tube  146  and such that the lumens of the proximal tube  142  and the distal tube  146  are co-axial. The lumens of the assembly sheath  104 , the proximal tube  142 , and the distal tube  146  are all co-axial. 
         [0057]    To begin the compression process, the physician first detaches the transparent hemi-cylindrical upper portions  148   a ,  148   b  of the tubes  142 ,  146  from the opaque hemi-cylindrical lower portions  150   a ,  150   b  of the tubes  142 ,  146 , respectively. As shown in  FIG. 11   b , the physician then places the closure device  10  into the compression apparatus  140  such that the arms  16 ,  18  are seated within the distal tube  146  and the wings swing freely. Specifically, the wing  12  is positioned within the space between the proximal tube  142  and the distal tube  146 , and the wing  14  is positioned distal to the distal tube  146 . The outer tool  70  and the inner tool  80  may be connected to the arm  16  and the arm  18 , respectively in the manner described above. It is understood that this connection of the tools to the arms may be performed either before or while the closure device  10  is positioned in the compression apparatus  140 . Next, as shown in  FIG. 11   c , the physician reattaches the transparent components  148   a ,  148   b  of the compression apparatus  140  to the opaque components  150   a ,  150   b  of the compression apparatus  140 . 
         [0058]    As  FIG. 11   d  illustrates, when the physician advances the outer tool  70  toward the distal tube  146 , the outer tool  70  simultaneously advances the wing  12  within the distal tube  146 . As the wing  12  advances into the distal tube  146 , the wing  12  is forced to deform into a compressed state as it enters the distal tube  146  while the wing  14  swings freely distal to the distal tube  146 .  FIG. 11   e  shows that the assembly sheath  104  is then advanced through the proximal tube  142  and toward the distal tube  146  until the assembly sheath  104  abuts the distal tube  146 . 
         [0059]    As shown by  FIG. 11   f , when the physician proximally retracts the outer tool  70 , the wing  12  is drawn from the distal tube  146  into the assembly sheath  104  as the arms  16 ,  18  are drawn back into the distal tube  146 . The wing  12  maintains its compressed state as it is drawn into the assembly sheath  104 .  FIG. 11   g  illustrates that as the outer tool  70  is further proximally retracted, the arms  16 ,  18  are drawn through the distal tube  146  into the assembly sheath  104  and the wing  14  is forced to deform into a compressed shape as it passes through the distal tube  146 . The wing  14  maintains its compressed state as it is drawn into the assembly sheath  104 . 
         [0060]      FIG. 11   h  illustrates the entire closure device  10  positioned inside the assembly sheath  104  with both wings  12 ,  14  maintained in a compressed state while the assembly sheath is positioned against the distal tube  146 . 
         [0061]      FIG. 11   i  illustrates the assembly sheath  104  separated from the compression apparatus  140 . The assembly sheath  104  contains the closure device  10  in a compressed state. 
         [0062]    With the closure device  10  compressed within the assembly sheath  104  using any of the compression methods described above or known in the art, it is configured for placement within a heart.  FIG. 12  shows the two upper chambers in a human heart, the right atrium  152  and the left atrium  154 , separated by an interatrial septum containing a PFO track  156 . The interatrial septum includes a septum primum  158  and a septum secundum  160 . Though the anatomy of PFOs varies widely within the population, the septum primum  158  often extends to and overlaps with the septum secundum  160  as shown in  FIG. 12 . When a PFO is present, blood may travel through the PFO track  156  between the septum primum  158  and the septum secundum  160 . 
         [0063]    The closure device  10  is introduced into the atria  152 ,  154  of the heart, preferably through a minimally invasive, percutaneous procedure. For example, the closure device  10  may be delivered to the atria via percutaneous methods using a delivery catheter. First, a peripheral vein, such as a femoral vein, is punctured with a needle. A wire is inserted through the needle into the vein, and the needle is removed. A dilator and an introducer sheath with at least one hemostatic valve is inserted through the puncture wound, the wire and the dilator are removed, and the sheath is secured in place while maintaining relative hemostasis. With the introducer sheath in place, a catheter containing a guidewire is introduced through the hemostatic valve of the introducer sheath and advanced along the peripheral vein, into the region of the inferior vena cava  151  and the right atrium  152 , and into the left atrium  154  through the PFO track  156 . The catheter is withdrawn while the guidewire is maintained in place. A delivery sheath  162  and a second dilator are simultaneously introduced into the introducer sheath and advanced over the guidewire to extend from the right atrium  152  into the left atrium  154  through the PFO track  156 . The second dilator and the guidewire are then withdrawn. It is understood that alternative procedures and methods may be used to place the delivery sheath  162  into the PFO track  156 , between septum primum  158  and a septum secundum  160 . 
         [0064]      FIG. 13  illustrates the delivery sheath  162 , containing the closure device  10 , positioned within the PFO track  156  between the septum primum  158  and septum secundum  160 . The delivery sheath  162  is an elongate hollow tube with a proximal end  164  and a distal end  166 . The distal end  166  of the delivery sheath  162  is positioned within the left atrium  154 . The delivery sheath  162  can be a standard delivery sheath as is known in the art or a variation thereof, provided that the delivery sheath  162  is sized to slidably accommodate the closure device  10  in a compressed configuration. The delivery sheath  162  can be constructed of a radiopaque material or carry radiopaque markers. The assembly sheath  104 , containing the closure device  10  in a compressed state, is connected to or aligned adjacent to the proximal end  164  of the delivery sheath  162 . The compressed closure device  10  is passed through the assembly sheath  104  into the delivery sheath  162  such that the wing  14  of the closure device  10  enters the delivery sheath  162  before the wing  12  of the closure device  10 . The closure device  10  is then advanced, still in the compressed configuration, toward the distal end  166  of the delivery sheath  162  until the wing  14  is seated within the distal end  166  of the delivery sheath  162 , as shown in  FIG. 13 . The wing  14  is housed within the distal end of the delivery sheath  162  and positioned within the left atrium  154 . The arms  16 ,  18  of the closure device  10  are housed within the delivery sheath  162  and positioned across the PFO track between the overlapping septum primum  158  and septum secundum  160 . The wing  12  is housed within the delivery sheath  162  and positioned within the right atrium  152 . 
         [0065]    As illustrated in  FIG. 14 , the closure device  10  is delivered into the atria by withdrawing the delivery sheath  162  from the heart while leaving the closure device  10  in place across the PFO track  156 . The delivery sheath  162  is withdrawn from the left atrium  154  into the right atrium  152 , and then is withdrawn from the heart entirely. The physician can maintain the position of the closure device  10  by holding the outer tool  70  steady relative to the delivery sheath  162  as the delivery sheath  162  is withdrawn from the heart. As the delivery sheath  162  is withdrawn and the closure device  10  is released from the delivery sheath  162 , the wings  12 ,  14  resume their predetermined expanded configurations in the form of ellipses. 
         [0066]    Thus, as shown in  FIG. 15 , the wing  14  is delivered within the left atrium, the arms  16 ,  18  are delivered within the PFO track, and the wing  12  is delivered within the right atrium. The operator then rotates the outer tool  70  to rotate the closure device  10  such that the surfaces of the wings  12 ,  14  are parallel to the atrial septal plane as defined by the septum primum  158  and the septum secundum  160 , as shown in  FIG. 17 . 
         [0067]      FIGS. 16   a  and  16   b  depict the physical mechanism by which the physician deploys the closure device  10 . Deployment of the closure device  10  is directed by maneuvering the inner tool  80  within the outer tool  70 . The physician controls the movements of the outer tool  70  and the inner tool  80  by using a deployment handle  170 . As shown in  FIG. 16   a , the deployment handle  170  has a proximal end  172  and a distal end  174 . The proximal end  72  of the outer tool  70  is fixedly attached to the distal end  174  of the deployment handle  170 . The deployment handle  170  includes a deployment lever  176 . The proximal end  82  of the inner tool  80  is fixedly attached to a swivel hinge  178  within the deployment lever  176 . 
         [0068]    As shown in  FIG. 16   b , when the physician pulls the deployment lever  176  towards the proximal end  172  of the deployment handle  170 , the swivel hinge  178  rotates toward the proximal end  172 , thereby pulling the inner tool  80  further inside the deployment handle  170  and causing the tab  48  of the arm  18  to slide within the passage  41  of the arm  16  toward the hinge mechanism  20 . 
         [0069]    As shown in  FIG. 20   a , when the tab  48  is pulled by the inner tool  80  towards the hinge mechanism  20 , the tab  48  contacts the convex portions of the hinge tips  92  and swivels the hinge tips  92  within the aperture  40  of the arm  16 , causing the hinge pins  90  to rotate. As shown in  FIGS. 17 and 20   b , the rotation of the hinge pins  90  causes the simultaneous rotation of the wing  12  toward the arm  16 . As the tab  48  slides into the passage  41 , the arms  16 ,  18  interconnect with each other, causing the tab  38  of the arm  16  to simultaneously slide within the passage  51  of the arm  18  toward the hinge mechanism  22  (not shown). When the tab  38  of the arm  16  contacts the convex portions of the hinge tips of the hinge mechanism  22 , the hinge tips swivel within the aperture  50  of the arm  18  and cause the hinge pins to rotate. The rotation of the hinge pins of the hinge mechanism  22  causes the simultaneous rotation of the wing  14  toward the arm  18 , as shown in  FIGS. 17 and 18 . 
         [0070]    Further retraction of the inner tool  80  causes the tabs to further rotate the hinge tips. As shown in  FIG. 19  and partially shown in  FIG. 20   c , when the tabs  38 ,  48  have advanced as far as possible within the passages  51 ,  41 , respectively, the wing  12  swivels upward to press against the septum secundum  160  and the wing  14  swivels downward to press against the septum primum  158 . In addition, when the tabs  38 ,  48  have advanced as far as possible within the passages  51 ,  41 , respectively, the arms  16 ,  18  may be releasably interlocked together as described above, thereby locking the wing  12  against the septum secundum  160  and the wing  14  against the septum primum  158 . It should be noted that the septum secundum  160  and the septum primum  158  do not have to be tightly touching along their entire lengths to effect proper closure of the PFO. Instead, it may be sufficient that the septum secundum  160  and the septum primum  158  are only brought close enough to allow tissue ingrowth to eventually seal the defect. 
         [0071]    The physician may visually assess the delivery and deployment of the closure device by various methods including fluoroscopy, ultrasonography, and magnetic resonance imaging. For example, fluoro-visible dyes, such as radiopaque contrast, may be injected into the venous circulation and atria such that the venous vasculature and atrial chambers are visible using a fluoroscopic imaging device. Such a procedure, known as a type of venogram, allows the physician to localize a desired target location and to guide proper device positioning while performing the implantation procedure. In addition, an ultrasonic probe may be positioned in the patient&#39;s esophagus, within the patient&#39;s chest cavity, or on the patient&#39;s chest to image the heart. Moreover, the individual components of the closure device  10  and the delivery sheath  162  can include radiopaque fillers or markers that permit the physician to fluoroscopically visualize their location and orientation within the patient. Such radiopaque markers or fillers may be fabricated from noble metals such as platinum and gold, and may be attached to the closure device  10  using a variety of known methods such as adhesive bonding, lamination between two layers of polymers, or vapor deposition, for example. 
         [0072]    After deploying the closure device  10  across the PFO track, the physician can reposition the closure device  10  by rotating, retracting, or advancing the outer tool  70  by rotating, retracting, or advancing the deployment handle  170  itself. After final positioning of the closure device  10 , the inner tool  80  is disconnected from the closure device  10  by reverse threading the distal end  84  from the arm  18 , the outer tool  70  is disconnected from the closure device  10  by reverse threading the distal end  74  from the arm  16 , and both the inner tool  80  and the outer tool  70  are removed from the heart. 
         [0073]    In some instances it may be necessary for the physician to remove the closure device  10  from the heart. For example, the physician may need to remove the closure device  10  from the heart if the closure device  10  is not appropriately sized for the particular PFO track  156  and/or if the closure device  10  cannot adequately seal the PFO track  156 . The physician may use a suitable foreign body retrieval device, as is known in the art, to remove the closure device  10  from the heart. In some embodiments, the arm  16  has a retrieval formation such as a hook-like protrusion  96 , as shown in  FIG. 4 , disposed on the body  36  at the end  32 . The physician can retrieve the closure device  10  by using the foreign body retrieval device to snare or hook the arm  16  at the protrusion  96  and pull the arm  16  into a retrieval sheath. Pulling the arm  16  into the retrieval sheath will partially separate the arm  16  from the arm  18 , thereby disengaging the locked hinge mechanisms  20 ,  22  and allowing the wings  12 ,  14  to swivel freely within the atria  152 ,  154 , respectively. The physician can then pull the closure device  10  completely into retrieval sheath. As the physician retracts the wings  12 ,  14  into the retrieval sheath, the wings  12 ,  14  will assume compressed configurations. The physician can then retract the retrieval sheath to remove the entire closure device  10  from the patient&#39;s body. 
         [0074]    In one exemplary aspect, the present disclosure is directed to a system for closing a patent foramen ovale (PFO) in a heart. The system may comprise a delivery catheter, a closure device, an outer tool, and an inner tool. The delivery catheter may have a lumen extending along a longitudinal axis. The closure device may be configured for delivery into the heart and for collapsible containment within the lumen. The closure device may comprise a first arm, a second arm, a first wing, and a second wing. The first arm may include a first body portion and a first tab portion, wherein the first body portion may include a first passage extending longitudinally therethrough. The second arm may include a second body portion and a second tab portion, wherein the second body portion may include a second passage extending longitudinally therethrough. The second passage may be sized to slidably receive the first tab portion and the first passage may be sized to slidably receive the second tab portion. The first wing may be pivotally connected to the first arm and the second wing may be pivotally connected to the second arm. The outer tool may be configured for attachment to the first body portion and have a lumen extending longitudinally through its length. The inner tool may be configured for attachment to the second tab portion. The lumen of the outer tool may be sized to receive a portion of the inner tool, wherein the inner tool is movable with respect to the outer tool to slide the second tab portion with respect to the first passage. 
         [0075]    In another exemplary aspect, the present disclosure is directed to a system for closing a patent foramen ovale (PFO) in a heart. The system may comprise a delivery catheter, a closure device, an outer tool, and an inner tool. The delivery catheter may have a lumen extending along a longitudinal axis. The closure device may be configured for delivery into the heart and for collapsible containment within the lumen. The closure device may comprise a first arm and a second arm. The first arm may include proximal and distal ends, wherein the proximal end is pivotally connected to a first wing via a first hinge and the first hinge includes a first projection. The second arm may include proximal and distal ends, wherein the proximal end is pivotally connected to a second wing via a second hinge and the second hinge includes a second projection. The distal end of the first arm may be configured to engage the second projection to pivot the second wing with respect to the second arm, and the distal end of the second arm may be configured to engage the first projection to pivot the first wing with respect to the first arm. The outer tool may be configured for attachment to the proximal end of the first arm and have a lumen extending longitudinally through its length. The inner tool may be configured for attachment to the distal end of the second arm. The lumen of the outer tool may be sized to receive a portion of the inner tool, wherein the inner tool is movable with respect to the outer tool to slide the distal end of the second arm with respect to the first hinge. 
         [0076]    The devices, systems, and methods described herein provide an improved and more efficient system of PFO closure. Applicants note that the procedures disclosed herein are merely exemplary and that the services and methods disclosed herein may be utilized for numerous other medical processes and procedures. Although several selected embodiments have been illustrated and described in detail, it will be understood that they are exemplary, and that a variety of substitutions and alterations are possible without departing from the spirit and scope of the present invention, as defined by the following claims.