Patent Publication Number: US-2021186515-A1

Title: Method And System For Closure Of Cardiovascular Apertures

Description:
RELATED APPLICATIONS 
     This application claims priority to U.S. Provisional Application Ser. No. 62/677,392 filed May 29, 2018 entitled Method and System for Closure of Patent Foramen Ovale, which is hereby incorporated herein by reference in its entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     This invention relates to methods and systems for the repair of apertures and defects within the cardiovascular system. Such apertures or defects can include patent foramen ovale, atrial septal defect, left atrial appendage, pseudoaneurysm, and ventricle septal defect. 
     Atrial septal defect (ASD) is a heart defect in which blood flows directly between the atria (upper chambers) of the heart. The atrial septum forms the wall dividing the left atrium and right atrium. Defects in the septum are commonly congenital (e.g., primum, secondum, sinus venosus, etc.), but also may be iatrogenic, due to either transcatheter or surgical procedures. Ventricular septal defect (VSD) is a heart defect in which blood flows directly between the ventricles (lower chambers) of the heart. VSD may be congenital, iatrogenic, or related to myocardial ischemia and infarction. When the size of an ASD or VSD is clinically significant, volume overload of the chambers can result in heart failure and/or pulmonary hypertension from left-to-right shunting. Right-to-left shunting across an ASD or VSD can also result in systemic hypoxemia which leads to lower-than-normal oxygen levels in the arterial blood that supplies the brain, organs, and tissues. Transcatheter therapy of an ASD or VSD typically entails placing an oversized device (“clamshell”) inside the defect. 
     The foramen ovale is a small hole located in the septum (wall) of a heart between the two upper chambers of the heart, the right and left atriums. Before birth, a human does not use its lungs to get blood rich in oxygen. Instead, this blood comes from the mother&#39;s placenta and is delivered through the umbilical cord. The foramen ovale makes it possible for the blood to go from the veins to the right side of the fetus&#39; heart, and then directly to the left side of the heart. The foramen ovale normally closes as blood pressure rises in the left side of the heart after birth. Once it is closed, the blood flows to the lungs to get oxygen before it enters the left side of the heart and gets pumped to the rest of the body. 
     A patent foramen ovale (PFO) is a foramen ovale that did not close properly at birth, so there is still an opening or hole in the septum. In many cases, the PFO does not stay open at all times. Rather, the PFO behaves more like a flap that opens when there is higher pressure than normal in the right atrium. Whether the PFO is persistently or intermittently open, blood flow across the PFO between the right and left atria can occur. Normally, left atrial pressure is higher than right atrial pressure. Situations that can cause greater pressure in the right atrium include straining during bowel movements, coughing and sneezing. When the pressure gets high enough, blood may move through the PFO from the right atrium to the left atrium. 
     PFO is common and has been associated with occurrence of systemic embolization, which may result in transient or permanent disabling stroke. Closure of PFO may be performed surgically or, more commonly, with percutaneous methods. Such methods commonly rely on devices such as occluders, which straddle the PFO and surrounding structures to cease blood flow between the left and right atria. These devices work in most patients, but can be bulky, cause tissue erosion, and prohibit repeat use of the atrial septum as a conduit for future access to the left atrium from the right atrium. Access across the atrial septum is needed in the event that a patient may require procedures in the left atrium, such as left atrial appendage closure, mitral valve interventions, and ablation of arrhythmias, among other many procedures. 
     The left atrial appendage (LAA) is derived from the left wall of the primary atrium, which forms during the fourth week of embryonic development. It has developmental, ultrastructural, and physiological characteristics distinct from the left atrium proper. The LAA lies within the confines of the pericardium in close relation to the free wall of the left ventricle and thus its emptying and filling may be significantly affected by left ventricular function. Left atrial appendage occlusion (LAAO), also referred to as Left atrial appendage closure (LAAO) is a treatment strategy to reduce the risk of left atrial appendage blood clots from entering the bloodstream and causing a stroke in patients with non-valvular atrial fibrillation (AF). Left atrial appendage closure is an implant-based alternative to blood thinners. Successful closure of LAA is highly dependent on device sizing from within the structure, which can be highly irregular in shape and size. Leaks around LAAO devices are thus common. 
     A pseudoaneurysm, also known as a false aneurysm, occurs from rupture of a wall of cardiovascular structure, such as the aorta, left atrium, or left ventricle, among other areas. The rupture can be infectious, post-traumatic, related to myocardial ischemia or infarction, or iatrogenic. Pseudoaneurysms are collections of blood from the disruption of the structure that are contained by surrounding tissue. Because this tissue is relatively weak, the pseudoaneurysm is a risk of further rupture and can be life-threatening. Open cardiac surgery and transcatheter therapy can be used to treat such pseudoaneurysms. Surgery is often high risk due to underlying pathology that caused the pseudoaneurysm and may not be effective due to poor tissue integrity. The transcatheter approach involves devices that are typically circular or oval, and often not purpose built for treatment of pseudoaneurysms, which can be highly irregular in shape. Leaks around such devices used for pseudoaneurysm therapy thus are common. 
     Therefore, new methods and techniques for closure of these cardiac apertures are needed. 
     SUMMARY OF THE INVENTION 
     The present invention is generally directed to methods and devices for closing tissue apertures in a patient, such as patent foramen ovale, atrial septal defect, left atrial appendage, pseudoaneurysm, and ventricle septal defect. One embodiment is directed to a method of using a suturing device to place a suture and pledgets on each side of areas of tissue that are intended to be closed. 
     Another embodiment is directed to a device for placing a suture through target tissue, having a curved suture delivery tube that faces an apposition catheter. A suture wire is passed through the curved tube, through the tissue, and into an opening in the apposition catheter. A grasping device, such as a compressible mesh, is used in the apposition catheter to grab on to the end of the suture and pull it through the tissue until a knotted end of the suture wire (or attached button) contacts the tissue. 
     Another embodiment is directed to a device for placing a suture through target tissue, having a curved suture delivery tube that faces a pivoting arm. Target tissue is placed between the end of the curved suture delivery tube and an end of the arm, which is pivoted up against the tissue. A suture wire is passed through the curved tube, through the tissue, and into an end of the arm. The arm and the attached suture are retraced into the device, pulling the suture wire through the tissue until a knotted end of the suture wire (or attached button) contacts the tissue. 
     Another embodiment is directed to a patch delivery device for closing a tissue aperture. The device includes a pusher catheter that pushes a holding mechanism for a patch out of an outer guide catheter. The patch has a plurality of eyelets that are attached to previously placed suture wires around the tissue aperture. Once the patch is placed over the tissue aperture, the pusher catheter and holding mechanism are withdrawn and the suture wires are knotted to maintain the patch in place. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and other aspects, features and advantages of which embodiments of the invention are capable of will be apparent and elucidated from the following description of embodiments of the present invention, reference being made to the accompanying drawings, in which: 
         FIG. 1  illustrates a portion of a heart with a PFO. 
         FIG. 2  illustrates a device and method of suturing a PFO. 
         FIG. 3  illustrates a device and method of suturing a PFO. 
         FIG. 4  illustrates a device and method of suturing a PFO. 
         FIG. 5  illustrates a device and method of suturing a PFO. 
         FIG. 6  illustrates a device and method of suturing a PFO. 
         FIG. 7  illustrates a device and method of suturing a PFO. 
         FIG. 8  illustrates a device and method of suturing a PFO. 
         FIG. 9  illustrates a device and method of suturing a PFO. 
         FIG. 10  illustrates a device and method of suturing a portion of tissue. 
         FIG. 11  illustrates a device and method of suturing a portion of tissue. 
         FIG. 12  illustrates a device and method of suturing a portion of tissue. 
         FIG. 13  illustrates a device and method of suturing a portion of tissue. 
         FIG. 14  illustrates a device and method of suturing a portion of tissue. 
         FIG. 15  illustrates a device and method of suturing a portion of tissue. 
         FIG. 16  illustrates a device and method of suturing a portion of tissue. 
         FIG. 17  illustrates a device and method of suturing a portion of tissue. 
         FIG. 18  illustrates a device and method of suturing a portion of tissue. 
         FIG. 19  illustrates a device and method of suturing a portion of tissue. 
         FIG. 20  illustrates a device and method of suturing a portion of tissue. 
         FIG. 21  illustrates a device and method of suturing a portion of tissue. 
         FIG. 22  illustrates a device and method of patching a portion of tissue. 
         FIG. 23  illustrates a device and method of patching a portion of tissue. 
         FIG. 24  illustrates a device and method of patching a portion of tissue. 
         FIG. 25  illustrates a method of patching an atrial septal defect. 
         FIG. 26  illustrates a method of patching a left atrial appendage. 
         FIG. 27  illustrates a method of patching a pseudoaneurysm. 
         FIG. 28  illustrates a method of patching a ventricle septal defect. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Specific embodiments of the invention will now be described with reference to the accompanying drawings. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. The terminology used in the detailed description of the embodiments illustrated in the accompanying drawings is not intended to be limiting of the invention. In the drawings, like numbers refer to like elements. 
     The present invention is generally directed to closure devices and methods of closings openings, such as patent foramen ovale, atrial septal defect, left atrial appendage, pseudoaneurysm, and ventricle septal defect. For simplicity, patent foramen ovale is discussed with reference to some figures of this specification, however it should be understood that any aperture or defect closure is possible, including the above examples. 
     As seen in the depiction of the heart  10  in  FIG. 1 , a PFO is an opening between the right atrium  12  and left atrium  14 , between the unattached superior limbus  16  and the septum primum  18 . This condition can be corrected by closing the PFO via a surgical procedure. In one embodiment, the device of U.S. Pat. No. 9,877,833 can be used for such a closure, the entirety of which is hereby incorporated by reference. The &#39;833 device uses self-knotting sutures for mitral valve repair, but not for PFO closure. 
     As best seen in  FIG. 2 , a guiding catheter  50 , inserted from a central venous access, is positioned such that its distal end is located proximate to the right atrial side of the superior limbus  16 . The superior limbus  16  is pierced and traversed by a crossing tool  52 , such as a needle, catheter, wire, or the like, which may be electrified. Next, the septum primum  18  is then traversed by same crossing tool  52  so that its distal end is positioned in the left atrium  14 . A delivery catheter  54  is advanced over the crossing tool  52  and through the superior limbus  16  and septum primum  18 , as seen in  FIG. 3 . 
     Referring to  FIG. 4 , a self-knotting suture  56  having a pledget  58  attached is advanced out a distal end of the guide catheter  50  and through the delivery catheter  54  so as to be positioned in the left atrium  14 . As seen in  FIG. 5 , the delivery catheter  54  is retracted from the superior limbus  16  and septum primum  18  and the guide catheter  50  is partially retracted to provide some space between it and the superior limbus  16  ( FIG. 6 ). 
     The suture  56  is retracted, causing the pledget to fold on the left atrial side of the septum primum  18 . Further retraction leads to apposition of the septum primum  18  and superior limbus  16  as seen in  FIGS. 5 and 6 . 
     A second pledget  58  is inserted and placed over the suture  56  to the right atrial side of superior limbus  16  ( FIG. 7 ). The suture  56  is knotted, followed by advancement of the knot to the right atrial pledget as seen in  FIG. 8 . A cutting tool is then delivered through the guiding catheter  50  to trim the suture. The entire method can then be repeated to insert additional self-knotting sutures in other areas of the PFO as shown in  FIG. 10 . 
     The previously described procedure, or other procedures utilizing sutures, can also be performed with the device  100  in  FIGS. 10-15  that can be used for suturing tissue in which both of its sides are at least initially accessible to the device  100  (e.g., the septum primum  18 ). These figures illustrate usage of the device  100  with only the septum primum  18  for simplicity, but it should be understood that the device  100  can be used to connected both the septum primum  18  and the superior limbus  16  together, as well as tissue located in other areas of the body. 
     The closure device  100  is composed of an outer guide catheter  102  that has a lumen within it that contains an apposition catheter  106  and a rim engagement catheter  104 . Preferably, the apposition catheter  106  and the rim engagement catheter  104  are separately moveable relative to each other and the apposition catheter  106  may include a groove along its length (seen in  FIG. 10 ) to accommodate the position of the rim engagement catheter  104  within the guide catheter  102 . 
     The rim engagement catheter  104  preferably has a tubular shape with a distal end that curves around so that the opening of the catheter  104  opens towards the apposition catheter  106 . In one embodiment, the rim engagement catheter  104  is composed of a flexible material that allows it to move between a straight configuration when retracted within the guide catheter  102  and a self-biased curved shape. In an alternate embodiment, the rim engagement catheter  104  maintains a curved shape but has a radius of curvature that is smaller than the profile or cross-sectional diameter of the outer guide catheter  102 . 
     As seen in  FIG. 10 , a distal end of the guide catheter  102  is advance in proximity of the tissue to be sutured (e.g., septum primum  18 ) so that the distal face of the apposition catheter  106  is on one side of the tissue and the opening of the rim engagement catheter  104  is positioned on the opposite side of the tissue. In  FIG. 11 , the apposition catheter  106  is advanced distally so that both catheters  104 ,  106  are in relatively close proximity to each side of the tissue. 
     Next, a suture wire  110  is advanced through the internal lumen/passage of the rim engagement catheter  104 , passes through the tissue, and into passage  108  of the apposition catheter  106 . The suture wire  110  can include a needle connected to a degradable suture material or can be a needle connected to a rigid wire that is connected to a degradable suture. A rigid, elongated pusher device can also be used to help advance the suture wire  110  during a procedure. 
     As seen in  FIGS. 13-15 , once the suture wire  110  has passed through the tissue and into the passage  108 , a mesh  108 A at the distal end of the passage  108  compresses or contracts radially around the wire  110 , causing the wire to be captured or engaged. The mesh  108 A can be a generally flat disc shape that closes similar to an iris or can be a tubular shape that expands/compresses similar to a stent. Either shape of the mesh  110  can be controlled at a proximal end of the device  100  by a control wire. 
     Once engaged with the mesh  108 A, the apposition catheter  106  can be withdrawn into the guide catheter  102  so that the proximal end of the suite wire  110  engages the tissue. In one example embodiment, the proximal end of the suture wire  110  includes an attached pledget and a knot or enlarged stopper that prevents its proximal end from passing through the tissue. In another example seen in  FIGS. 16 and 17 , an enlarged button  112  is temporarily fixed at the distal end/opening of the rim engagement catheter  104 . When the suture wire  110  is pulled through the button  110  and reaches a knot or stopper on the end of the suture wire  110 , the button  112  is pulled off the rim engagement catheter  104 , preventing the suture wire  110  from being pulled through the tissue. 
     Finally, the suture wire  110  on the proximal side is either knotted or attached to a second button  112 , securing the suture wire  110  in place through the target tissue (e.g., through the septum primum  18  and superior limbus  16 ). Any suture wire  112  remaining proximal of the suture point can be cut away and the device  100  can be removed from the patient. 
       FIGS. 18-21  illustrate another embodiment of a suture device  120  that is similar to the previously described device  100 , having a guide catheter  102 , a rim engagement catheter  104 , and an apposition catheter  122 . Instead of being positioned directly under the opening of the rim engagement catheter  104 , the apposition catheter  122  is positioned to the side of the opening, as seen in  FIG. 18 , and further includes a movable arm  124  that can be positioned underneath a target tissue area. In one embodiment, the arm  124  has a has a bent shape (e.g., shape memory Nitinol bent in the proximal direction) that is connected at its proximal end to a control wire  128 , allowing a user to pull the wire  128  and thereby move/pivot the arm  124 . The distal end of the arm  124  includes a suture capturing member  126  that is configured to capture a suture wire  110 . For example, suture capturing member  126  can be a circular wire supporting a membrane that a suture wire  110  is capable of piercing. In another example, the suture capturing member  126  includes a circular/tubular mesh structure that can be selectively compressed or radially contracted on a suture wire  110  passing through. 
     The device initially is configured as seen in  FIG. 18 , with its arm  124  located in a lowered position. In  FIG. 19 , the device  120  is moved over target tissue (e.g., the septum primum  18  and superior limbus  16 ) so that the rim engagement catheter  104  and button  112  are positioned on a distal side of the tissue. The control wire  128  is pulled, causing the arm  124  to pivot upwards towards the tissue. The suture wire  110  is advanced through the rim engagement catheter  104 , through the button  112 , through the tissue, and through the suture capturing member  126 . 
     In  FIGS. 20 and 21 , the suture capturing member  126  is actuated (e.g., its mesh is contracted around the suture wire  110 ) and the control wire  128  is proximally pulled further, moving the arm  124  and the suture capturing member  126  into the apposition catheter  122 . In this respect, the suture wire  110  is also pulled into the lumen of the apposition catheter  122  until an end knot or stopper reaches the button  112 , causing it to detach from the rim engagement catheter  104  and abut the tissue. A second button or knot can be connected to the proximal portion of the suture wire  110  and advanced adjacent to the opposite side of the tissue. 
       FIGS. 22-24  illustrates an embodiment of a patch delivery device  140  used to patch or close an aperture within tissue. The delivery device  140  can be used with pre-implanted suture wires  110  (implanted either by hand or by one of the previously described devices), which assist in the implantation process as described further below. 
     Referring first to  FIG. 22 , a plurality of suture wires  110  are first placed through areas of the tissue (e.g., septum primum  18 ) near an opening that is intended to be closed. These suture wires  120  may be placed via one of the other devices described in this specification and may optionally include buttons  112  as also described. In the present example embodiment, three suture wires  110  are used, but 2, 4, 5, 6, or other numbers are also possible. The suture wires  110  can be placed into the myocardium, across the wall surrounding the defect, or wholly within the targeted aperture. 
     The device  140  includes an outer guide catheter  102  with a distal end opening that is advanced near the target aperture location. Within the lumen of the guide catheter  102  is a holding mechanism  144  that distally abuts the end of a pusher catheter  142 . The holding mechanism  144  can be, for example, a plurality of elongated wires that form a “V” shape when compressed within the catheter  102 , with end tips  144 A that help retain a conically folded patch  141  within it. As seen in  FIG. 23 , the pusher catheter  142  can be distally advanced to move the holding mechanism  144  distally out of the guide catheter  102 , causing the arms of the holding mechanism  144  and the patch  141  to radially expand. 
     The previously-placed suture wires  110  are positioned through eyelets  141 A on the outer edge of the patch  141  to guide the patch  141  to a desired implantation position to cover the tissue aperture. The suture wires  110  preferably pass through the guide catheter  102  and back to the user at the proximal end of the device  140 . 
     The pusher catheter  142  advances the holding mechanism  144  and patch  141  until the patch  141  becomes relatively flat against the aperture of the tissue, as aligned by the suture wires  110 . As seen in  FIG. 24 , the pusher catheter  142  and the holding mechanism  144  can be withdrawn proximally back into the guide catheter  102 . The holding mechanism  144  may include a tether  146  fixed to its proximal end and extending back to a proximal end of the device  140  to assist in this retraction. Finally, the suture wires  110  can be tied proximal of the patch  141  to secure the patch  141  in place and/or additional buttons  112  can be advanced over the wires  110  to the patch  141 . 
     The patch  141  can be used to treat a variety of different conditions, particularly in the heart. For example,  FIG. 25  illustrates an atrial septal defect  24  (ASD) covered by the patch  141  from the perspective of the right atrium  12  and right ventricle  22 . The suture wires  110  can be placed circumferentially around the ASD  24  in a manner previously discussed in this specification, and then the patch  141  can be advanced via eyelets  141 A over the suture wires  110  and secured in place over the ASD  24 , preventing the passage of blood between atriums of the heart. As stated above, the suture wires  110  can be placed into the myocardium, across the wall surrounding the defect, or wholly within the targeted aperture. 
       FIG. 26  illustrates another example of a left atrial appendage  26  (LAA) that is closed by the patch  141  within a left atrium  14 . Similarly, the suture wires  110  can be placed circumferentially around the LAA  26  in a manner previously discussed in this specification, and then the patch  141  can be advanced via eyelets  141 A over the suture wires  110  and secured in place over the LAA  26 , preventing the passage of blood into the LAA  26 . The suture wires  110  can be placed into the myocardium, pericardial space, or wholly within the aperture. 
       FIG. 27  illustrates another example of a pseudoaneurysm  30  that is closed by the patch  141  within a left ventricle  28  of a heart. Again, the suture wires  110  can be placed circumferentially around the pseudoaneurysm  30  in a manner previously discussed in this specification, and then the patch  141  can be advanced via eyelets  141 A over the suture wires  110  and secured in place over the pseudoaneurysm  30 , preventing the passage of blood into the pseudoaneurysm  30 . 
       FIG. 28  illustrates another example of a ventricle septal defect  31  (VSD) that is closed by the patch  141  within a right ventricle  32 . The suture wires  110  can be placed circumferentially around the ventricle septal defect  31  in a manner previously discussed in this specification, and then the patch  141  can be advanced via eyelets  141 A over the suture wires  110  and secured in place over the ventricle septal defect  31 , preventing the passage of blood between the ventricles of the heart. 
     Although the invention has been described in terms of particular embodiments and applications, one of ordinary skill in the art, in light of this teaching, can generate additional embodiments and modifications without departing from the spirit of or exceeding the scope of the claimed invention. Accordingly, it is to be understood that the drawings and descriptions herein are proffered by way of example to facilitate comprehension of the invention and should not be construed to limit the scope thereof.