Abstract:
A percutaneous catheter based method and apparatus for removably plugging a Patent Forman Ovale (PFO) in a patient&#39;s heart deploys a threaded surgical plug into the PFO. The plug is removably connected to a flexible connector. The plus is deployed in the PFO by advancing it through a catheter and rotating it into the PFO, then disengaging the flexible connector. The plug may be optionally removed by re-engaging the flexible connector and rotating the plug out of the PFO.

Description:
FIELD OF THE INVENTION 
     The present invention relates to a percutaneous catheter based method and apparatus for plugging a Patent Foramen Ovale formed in the heart of a human. 
     BACKGROUND OF THE INVENTION 
     The human cardio-pulmonary system, for oxygenating and circulating blood throughout the body, is dramatically different between normal adults and fetuses. In the adult circulatory system, blood is pumped from various parts of the body to the right side of the heart, and then through the pulmonary artery to the lungs. Following oxygenation at the lungs, the blood travels through the pulmonary veins to the left side of the heart, and is pumped from there through the aorta to the brain and other parts of the body. 
     During gestation, human fetuses do not breathe air. Rather, their blood is oxygenated by maternal blood through the placenta. Hence, not only is there no great need to divert all blood to the lungs upon every trip through the circulatory system, but additionally the fact that the lungs are collapsed makes it difficult for blood to flow and significantly raises the pressure in the pulmonary path of the circulatory system. To bypass the unnecessary trip to the lungs, blood in the fetal heart is shunted directly from the right chamber into the left chamber of the fetal heart through a valve-like opening in the wall separating the two sides of the heart, known as the Foramen Ovale. The blood is then pumped from the left side of the heart into the aorta and directly to the brain and other points in the fetal body. 
     After birth, the cardio-pulmonary system changes significantly. The lungs fill with air, reducing the resistance to blood flow through the lungs, and thus dramatically decreasing the pressure of the pulmonary path, i.e., the pulmonary artery and the right side of the heart. In this condition, the left side of the heart is maintained at a somewhat higher pressure than the right side, and the valve-like Foramen Ovale is forced closed, sealing off blood flow between the two sides of the heart. Eventually, fibrous tissue covers the closed Foramen Ovale and permanently seals it off. However, in twenty-five percent to thirty-five percent of adults, the Foramen Ovale remains open, or “patent.” This allows un-oxygenated blood to flow directly from the right side of the heart into the left side, where it is carried through the aorta directly to the brain and other parts of the body. This shunting of the blood directly from the right to the left side of the adult heart, thus by-passing its trip to the lungs, can occur whenever the pressure in the right side of the heart exceeds that in the left. This condition occurs upon heavy lifting or at other times of great physical exertion, or during a Valsalva maneuver (an abdominal constriction performed while holding one&#39;s breath). 
     Not only does the mixing of un-oxygenated blood with oxygenated blood dramatically reduce the efficiency of the cardiopulmonary system, it is believed to contribute to life-threatening ischemic strokes through paradoxical embolism. When blood clots in veins break off, or embolize, they normally travel through the right side of the heart and to the lungs, which act as a filter. The clots are thus normally filtered from the arteries, in particular the aorta and carotid arteries leading to the brain. In a paradoxical embolism, clots pass from a vein into an artery, such as through a Patent Foramen Ovale (PFO) or other atrial septal defect. If carried to the brain, the clots can obstruct the arterial blood supply, leading to an ischemic stroke. Once detected, the PFO condition requires either a regimen of anti-coagulants to prevent further clots, or closing of the PFO. 
     The traditional method of closing a PFO is open-heart surgery. This is expensive, complex, involves significant risk due to general anesthesia, infections, etc., and requires an extensive and painful recovery period. Catheter-based methods of closing a PFO are known in the art. Typically, these catheter-based solutions comprise a collapsed, expandable, or inflatable sealing element. The element is transferred through the catheter in a collapsed state, and is expanded upon deployment at the PFO within the heart. Such prior art devices typically deploy an expandable element on either side of the PFO, i.e., with a portion in both the left and right sides of the heart. Once deployed, the element is detached from the catheter and the catheter is withdrawn, leaving the element permanently in place. These prior art systems are deficient in that they depend on proper mechanical deployment of an element from a collapsed to an expanded state once positioned within the heart. If the element does not deploy, or deploys in an incorrect manner, it must be recompressed and withdrawn. Also, once inserted, the element is difficult or impossible to remove, since it has expanded on both sides of the PFO and cannot be removed. 
     SUMMARY OF THE INVENTION 
     The present invention entails a method of plugging or sealing a Patent Foramen Ovale (PFO) formed in the heart. The method entails inserting a threaded plug into the PFO and rotating the threaded plug and securing the threaded plug in the PFO. 
     As embodied in one particular surgical procedure, the method further entails directing a guide wire into the heart and the PFO, and inserting a catheter over the guide wire and extending the catheter towards the PFO. Thereafter the threaded plug is secured to a carrier and the guide wire is threaded through both the carrier and the threaded plug. Thereafter, the carrier and threaded plug are moved towards the PFO. After the threaded plug has been secured within the PFO, the threaded plug is decoupled from the carrier. In one particular methodology of carrying out the above surgical procedure, a first member or flexible connector is secured to the threaded plug and both the carrier and the first member remain connected or secured to the threaded plug as it is advanced towards the PFO. In this particular embodiment of the invention, the first member or flexible connector is disconnected from the threaded plug first. Thereafter, the threaded plug is urged from the carrier. 
     In addition, the present invention entails a surgical kit for plugging or sealing an opening in the heart. The surgical kit includes a threaded plug adapted to be secured into the opening of the heart. Further, the surgical kit includes a carrier for holding the threaded plug and for delivering the threaded plug to the opening in the heart. Finally, the surgical kit includes a catheter for receiving the carrier and the threaded plug and permitting the carrier and the threaded plug to be moved through the catheter to the opening in the heart. 
     Finally, another aspect of the present invention entails a threaded plug for plugging an opening in the heart. The threaded plug basically comprises a tip and a circumferential lip spaced from the tip and adapted to lie adjacent the heart tissue surrounding the opening in the heart. There is provided a threaded portion disposed generally between the tip and the circumferential lip that includes a surrounding thread pattern formed on the outer surface of the threaded plug. The opening in the heart is plugged or sealed by rotating or screwing the threaded plug into the opening. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a cut-away view of the surgical kit of the present invention; 
     FIG. 1 a  is a section view of the surgical kit of the present invention; 
     FIG. 2 is a section view of the surgical kit of the present invention illustrating the sizer; 
     FIG. 3 is a section view of the :surgical kit of the present invention, depicting the insertion of the plug; 
     FIG. 4 is a section view of the surgical kit of the present invention, depicting the removal of the flexible connector; 
     FIG. 5 is a section view of the surgical kit of the present invention, with the plunger installed. 
     FIG. 6 is a section view of the surgical kit of the present invention, depicting the disengagement of the plug by the plunger; 
     FIG. 7 is a section view of the flexible connector, wrench, and plug, and a side view of the plug. 
     FIG. 8 a  is a section view of the plug immediately after insertion in the Patent Foramen Ovale; 
     FIG. 8 b  is a section view of the plug following insertion in the Patent Foramen Ovale, depicting the plug tip swelling; 
     FIG. 9 is a section view of a heart with a Patent Foramen Ovale, depicting the placement of the J-wire and catheter; 
     FIG. 10 is a section view of a heart with the sizer placed in the Patent Foramen Ovale. 
     FIG. 11 is a section view of a heart showing the advancement of the plug in the plug carrier, with the flexible connector and wrench additionally shown. 
     FIG. 12 is a section view of a heart depicting the deployment of the plug in the Patent Foramen Ovale, and indicating the operation of the wrench and flexible connector. 
     FIG. 13 is a section view of a heart showing the operation of the plunger to detach the plug carrier from the plug in the Patent Foramen Ovale. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     In one embodiment, the present invention comprises a surgical kit, indicated generally by the numeral  10 , for the minimally invasive, percutaneous introduction and deployment of a Patent Foramen Ovale (PFO) plug  26 . Plug  26  is introduced and deployed via a catheter, eliminating the need for open-heart surgery. The surgical kit  10  is depicted in the accompanying drawings, with its various constituent parts and configurations, in FIGS. 1 through 8. 
     The surgical kit  10  for plugging a PFO includes the plug  26  as particularly illustrated in FIG.  7 . To facilitate the delivery and securement of the plug  26  in the PFO, the surgical kit  10  may further include a J-wire  12 , a dilator  16 , a catheter  14 , a plug carrier  22 , a flexible connector  40  (sometimes referred to as a first member), and a tool or wrench  46  for manipulating the flexible connector  40  as shown in FIGS. 1 and 1A. Additionally, the surgical kit  10  may include a sizer  50 , as particularly shown in FIG. 2, and a plunger  60  (sometimes referred to as a second member), as depicted in FIGS. 5 and 6. As will be appreciated from subsequent portions of this disclosure, the plug carrier  22  is adapted to receive and hold the plug  26 , and to deliver the plug  26  to the site of the PFO. Additionally, the flexible connector is also adapted to be secured to the plug  26 . Together, the plug carrier  22  and the flexible connector  40  remain secured to the plug  26  as the plug  26 , is advanced through the catheter  14  towards the PFO. As will be further discussed, once the plug  26  is appropriately positioned adjacent the PFO of the heart, both the carrier  22  and flexible connector  40  are rotated, causing the plug to be screwed or secured within the PFO. Thereafter, both the plug carrier  22  and the flexible connector  40  are decoupled from the plug  26  and removed, along with the catheter, from the patient&#39;s body. The particulars of the decoupling procedure will be addressed subsequently herein. 
     Referring to the components of the surgical kit  10  and with particular reference to FIGS. 1 and 1A, the J-wire  10  is a thin, pliable wire formed of surgical steel or similar suitable material. During the procedure for plugging the PFO, the J-wire  12  is inserted into the patient&#39;s inferior vena cava at the right groin, and inserted through the inferior vena cava into the right atrium of the patient&#39;s heart, following well-known cardiac catheterization procedures. J-wire  12  is of solid material with sufficient density or other physical properties relative to the imaging technique used, e.g., x-ray fluoroscopy, ultrasound imaging, etc., that the J-wire  12  is readily discemable by the surgeon via the imaging system. In operation, the J-wire  12  provides guidance and alignment for the other elements of the surgical kit  10 , as other elements are introduced into the patient&#39;s body and advanced to the patient&#39;s heart and to the PFO by sliding over the J-wire  12 . 
     Dilator  16  is introduced into the patient&#39;s groin, and serves as a guide for the insertion and extraction of the remaining parts of the surgical kit  10 . Catheter  14  is a tube of pliable material that is inserted through the dilator  16  and advanced through the inferior vena cava into the patient&#39;s right atrium, around and enclosing J-wire  12 . It is contemplated that in normal applications, the catheter  14  is approximately 6 mm in diameter. The catheter  14 , in addition to J-wire  12 , serves as a guide for the insertion and extraction of the remaining components of the surgical kit  10 . Specifically, all other components can be threaded over J-wire  12  and advanced within the bore of the catheter  14 . 
     The plug carrier  22  serves to carry the plug  26  to the PFO in the patient&#39;s heart. The plug carrier  22  is a flexible tube that is deployed within the catheter  14  and around J-wire  12 . The distal end of the plug carrier  22  is configured and adapted to receive the plug  26  is a press fit relationship. A press fit means that the inner diameter of the plug carrier  22  is approximately the same as the outer diameter of the base portion of the plug  26 . When the plug  26  is inserted into the plug carrier  22 , it is frictionally held in place. At the proximate end of plug carrier  22  are formed two finger tabs  24  extending radially therefrom on opposite sides. As used herein, the “proximate end” of surgical kit  10  or any component thereof refers to the end nearest the surgeon in use, i.e., the end that remains outside of the patient&#39;s body. Similarly, as used herein, the “distal end” of surgical kit  10  or any component thereof refers to the end that is deployed inside the patient&#39;s heart. 
     The plug  26 , the flexible connector  40 , and the wrench  46  are discussed with reference to FIG. 7, depicting elevation and sectional views of these components isolated from the rest of surgical kit  10 . 
     The plug  26  is a surgical component that seals the PFO, and remains deployed within the patient&#39;s heart. Plug  26  comprises a base  27 , a circumferential lip  30 , a threaded portion  32 , and a tip  33 . The diameter of the plug  26  from the base  27  to the lip  30  is generally constant, and as described above, is approximately the same as the inner diameter of the distal end of the plug carrier  22 . When the plug  26  is disposed within the distal end of the plug carrier  22 , the portion of the plug  26  extending from the base  27  to the lip  30  is press-fitted within the plug carrier  22 . 
     Between the circumferential lip  30  and the tip  33 , is threaded portion  32 . Along the extent of threaded portion  32 , the diameter of the plug  26  gradually decreases from a maximum adjacent to the lip  30 , to a smaller diameter at the tip  33 . Additionally, shaped within the exterior of threaded portion  32  are approximately three to four turns of mechanical threads. When the plug  26  is deployed within the PFO and rotated by the surgeon, the threaded portion  32  of the plug  26  engages the tissue of the patient&#39;s cardiac septum, advancing the plug  26  into the PFO. Additionally, the threads on threaded portion  32  mechanically secure and retain the plug  26  in the patient&#39;s heart. In one embodiment, cilia  34  are formed in or disposed on the surface of circumferential lip  30  facing the threaded portion  32 . When the plug  26  is fully deployed in the PFO, these cilia provide increased friction between the lip  30  and the patient&#39;s heart tissue, thus additionally securing the plug  26  by resisting rotation in the removal direction. The plug  26  may be formed of DACRON®, TEFLON®, or any suitable material. In one alternate embodiment, at least the tip  33  portion of plug  26  is hydroscopically expanding, i.e., it swells or volumetrically expands when exposed to water or other fluids. This property may help seal the plug  26  in the patient&#39;s PFO soon after its surgical insertion therein, as depicted in FIG.  8 . FIG. 8A depicts the plug  26  of the present invention immediately following its insertion into a PFO in the patient&#39;s heart. The plug  26  has been advanced until the circumferential lip  30  is in contact with the tissue of the patient&#39;s cardiac septum. The tip  33  of the plug  26  extends through the PFO into the patient&#39;s left atrium. The subsequent swelling of the tip  33  is depicted in FIG.  8 B. 
     Referring again to FIG. 7, formed within the base  27  of plug  26  is a conical retrieval aperture  36 , which terminates in a tapped hole  38 . Extending from the tapped hole  38  through the tip  33  of the plug  26  is center hole  28 . The center hole  28  facilitates alignment of the plug  26  within the PFO, as the plug  26  is guided by the plug carrier  22  along J-wire  12 , previously located within the PFO. Retrieval aperture  36  has a generally tapered conical shape leading to tapped hole  38 . This shape facilitates the retrieval of the plug  26 , if necessary, after its deployment in the PFO by guiding the flexible connector  40  to the tapped hole  38 . 
     The flexible connector  40  comprises flexible connector shaft  42  and threaded end  44 , with center hole  43  running throughout. The flexible connector  40  is disposed within the plug carrier  22 , and is secured to the plug  26  by screwing the threaded end  44  into the tapped hole  38 . Thus positioned, flexible connector  40  secures the plug  26  to the plug carrier  22  (in addition to the press-fit of the lower portion of the plug  26  within the distal end of the plug carrier  22 ). The flexible connector shaft  42  in the embodiment illustrated has a square cross-section, although a variety of other shapes are possible. Shaft  42  could, for example, be triangular, rectangular, pentagonal, hexagonal, star-shaped, etc. Wrench  46  contains a connector hole  48  of the same size and shape as the cross-section of flexible connector  42 , for engaging and rotating the flexible connector shaft  42 . It will be appreciated that any cross-sectional shape of flexible connector shaft  42  and corresponding connector hole  48  in wrench  46  capable of inducing torque on the flexible connector  40 , as are well known in the art, will suffice and falls within the scope of the present invention. Referring back to FIGS. 1 and 1A, it will be noted that the flexible connector  40  extends past the proximate end of the plug carrier  22 , to allow the engagement of wrench  46  with the flexible connector shaft  42 . A center hole  43  extends throughout the length of the flexible connector  40 . This allows the assembled combination of the flexible connector  40  and the plug  26  to be aligned within the patient&#39;s body by sliding the assembly over J-wire  12 . 
     Deployment of the plug  26  and removal of the flexible connector  40  are depicted in FIGS. 3 and 4, showing the plug in relation to the Patent Foramen Ovale formed in the patient&#39;s atrial septum (AS). 
     The threaded end  44  of the flexible connector  40  and the threaded portion  32  of the plug  26  are threaded in the same direction. Thus, rotation of the flexible connector  40  by the wrench  46  in one direction, i.e., clockwise, first engages the threaded end  44  of the flexible connector  40  firmly within the tapped hole  38  of plug  26 , and then engages the threaded portion  32  of the plug  26  in the tissue surrounding the PFO in the patient&#39;s heart. Once the plug  26  is deployed within the PFO, turning the flexible connector  40  by the wrench  46  in the opposite direction disengages the threaded end  44  of the flexible connector  40  from the tapped hole  38  of the plug  26 , thus disconnecting the plug  26  from the flexible connector  40 , and allows removal of the flexible connector  40  from the assembly of surgical kit  10 . 
     FIG. 2 depicts a sizer  50  deployed within the catheter  14 . Sizer  50  is a flexible elongate member that slides within catheter  14  and over J-wire  12 . At its distal end, sizer  50  is tapered. Along the tapered portion, a plurality of markers  52  are formed in sizer  50  at calibrated diameters, e.g., 3 mm, 4 mm, and 5 mm. Markers  52  may be metallic bands or may be otherwise formed so as to be conspicuously visible via the imaging system used during the procedure. By sliding the tapered portion of sizer  50  along the J-wire  12  and into the patient&#39;s PFO until the increasing diameter of sizer  50  precludes further advancement, the size of the PFO can be estimated by observing the relative position of the calibration markers  52 . In this way; the size of the PFO can be measured to a degree of accuracy sufficient to determine if it falls within a range of sizes for which the plug  26  will be effective. 
     FIGS. 5 and 6 depict the plunger  60  and its operation with the surgical kit  10  to extract the plug  26  from the plug carrier  22  following deployment in the PFO, for removal of the surgical kit  10 . After the plug  26  is secured in the patient&#39;s PFO (formed in the AS), the flexible connector  40  is disengaged and removed, as described above. The plunger  60  is then introduced and advanced within the plug carrier  22 , until it makes contact with plug  26 . The length of plunger  60  is fixed relative to the plug carrier  22  such that when the plunger  60  first contacts the plug  26 , the plunger finger tabs  62  extending radially therefrom at its proximate end are spaced a small distance from the proximate end of the plug carrier  22 . This distance corresponds generally to the length of the plug  26  extending between the base  27  and the circumferential lip  30 , i.e., the length of the plug  26  that is press-fitted into the distal end of the plug carrier  22 , as shown in FIG.  5 . When the plunger  60  is forced forward within the plug carrier  22 , e.g., by utilizing the plug carrier tabs  24  and plunger tabs  62  in a manner analogous to the actuation of a hypodermic syringe, the plunger  62 , abutting the plug  26  at its distal end, remains in a fixed position relative to the plug  26 , catheter  14 , and J-wire  12 , and the plug carrier  22  is drawn a small distance towards the proximate end of surgical kit  10 , thus disengaging it from the deployed plug  26 . This is depicted in FIG.  6 . 
     Turning to the method or process of inserting and securing the surgical plug  26  into a PFO in a patient&#39;s heart, reference is made to FIGS. 9-13. The surgical method of plugging a PFO described herein utilizes the surgical kit  10  described above. By using the surgical kit  10  and this surgical method, the need for thoracic surgery and its attendant risks, expense and recovery difficulties is obviated. 
     First the patient is positioned on a flouro-table, to enable the imaging device that will allow the surgeon to guide the catheter into the patient&#39;s heart and perform the method of the present invention. The patient is sedated and his or her right groin is prepared. The dilator  16  is introduced and secured to the patient. 
     The J-wire  12  of surgical kit  10  is then introduced into the inferior vena cava (IVC) at the right groin and guided up through the inferior vena cava into the right atrium of the patient&#39;s heart. The J-wire  12  is then positioned within the PFO in the patient&#39;s heart. The catheter  14  is then inserted around the J-wire  12 , and advanced up through the inferior vena cava and into the right atrium (RA) adjacent the PFO formed in the AS. The catheter  14  and J-wire  12  are depicted in FIG.  9 . 
     Referring to FIG. 10, sizer  50  is threaded onto the J-wire  12  and advanced through the catheter  14 , the tapered end thereof emerging from the catheter  14  in the patient&#39;s right atrium, and is guided by J-wire  12  into the PFO. The sizer  50  is advanced into the PFO until further motion is restricted by the increasing diameter of the tapered portion of the sizer  50 . The surgeon then observes calibrated markers  52  and their position relative to the PFO on the surgical imaging system. The surgeon estimates the size of the PFO, and makes a decision whether to proceed. If the PFO is not in a predetermined range, e.g., approximately 3 mm to approximately 5 mm, the method of the present invention may be contraindicated and the catheter is removed. On the other hand, if the PFO is determined to fall within the appropriate size range, the sizer  50  is withdrawn from the catheter  14  and the surgical procedure is continued. 
     As shown in FIG. 11, the plug  26 , press fitted into the distal end of the plug carrier  22 , and the flexible connector  40 , attached to the plug  26  and disposed within the plug carrier  22 , are advanced along the J-wire  12  and within the catheter  14  to a position adjacent to the PFO in the patient&#39;s heart. 
     The plug  26  is guided into the PFO, and is rotated by actuating the wrench  46  on the flexible connector shaft  42  in the forward direction, e.g., clockwise, to advance the plug  26  into the patient&#39;s PFO, as depicted in FIG.  12 . In one contemplated procedure, the flexible connector shaft  42  is rotated through approximately four complete revolutions or turns. This advances the plug  26  into the PFO by operation of the threads on threaded portion  32 , bringing the circumferential lip  30  of the plug  26  into flush contact with the septum in the right atrium. The surgeon verifies the security of attachment of the plug  26  by gently tugging or wiggling the flexible connector  40 , simultaneously feeling for motion and observing the deployed plug  26  via the surgical imaging system. 
     Thus deployed, the plug  26  is detached from the flexible connector  40  by rotating the flexible connector  40  in the opposite direction from that used to seat the plug  26 , e.g., counterclockwise. This rotation may be facilitated by use of the wrench  46 . It will be appreciated that in removing the flexible connector  40 , only the flexible connector shaft  42  is rotated; the plug carrier  22  is not allowed to rotate. This is in contrast to the advancement of the plug  26 , when the plug carrier  22  was allowed to rotate with the flexible connector shaft  42 . The flexible connector  40  is rotated until the threaded end  44  completely disengages from the taped hole  38  in the plug  26 , i.e., approximately 15 turns. The flexible connector  40  is then removed from the catheter  14 . 
     Referring now to FIG. 13, the plunger  60  is next advanced over the J-wire  12  and within the catheter  14  until it contacts the base  27  of the plug  26 . The plug  26  is then disengaged from the plug carrier  22  by pulling the plug carrier  22  off of the plug  26  via actuating the plunger  60 . Grasping the finger tabs  24  at the proximate end of the plug carrier  22 , and corresponding finger tabs  62  of the plunger  60 , the plug carrier  22  and plunger  62  are pulled together. Since the distal end of the plunger  60  is abutting the base  27  of the plug  26 , pulling the proximate end of the plunger  60  and the plug carrier  22  together results in pulling the plug carrier  22  off of the plug  26 , thus releasing plug  26  from its press fit in the distal end of the plug carrier  22 . The assembly comprising the catheter  14 , the plug carrier  22 , and the plunger  60  is then removed from the patient. 
     At this point, the security of the plug  26  within the PFO may be verified by having the patient cough and move from side to side. The surgeon observes the plug  26  via the surgical imaging system. 
     If for some reason the plug  26  is determined to be insecurely attached, improperly positioned, or manifests any other problem, the surgeon has the option of removing the plug  26 . This is accomplished by reintroducing the catheter  14 , the plug carrier  22 , and the flexible connector  40  into the patient&#39;s heart, advancing the assembly over the J-wire  12 . The plug carrier  22  is advanced to the base  27  of the plug  26 . The flexible connector  40  is then advanced along the J-wire  12 , entering the retrieval aperture  36  formed in the base  27  of the plug  26 . The conical shape of retrieval aperture  36  guides the threaded end  44  of the flexible connector  40  into the taped hole  38  in the plug  26 . The flexible connector shaft  42  is then rotated in a forward direction, e.g., clockwise, utilizing the wrench  46 . When the flexible connector is firmly attached to the plug  26 , the plug carrier  22  is advanced relative to the flexible connector  40 , engaging the base end of plug  26  within the distal end of the plug carrier  22  in a press fit relationship. The plug carrier  22  and flexible connector  40  are then together rotated in a reverse direction, e.g., counterclockwise, thus disengaging the plug  26  from the patient&#39;s PFO. When the plug  26  is disengaged, the entire assembly may be removed. 
     If, on the other hand, the surgeon is satisfied that the plug  26  is sufficiently securely deployed and plugging the PFO, the J-wire  12  and the dilator  16  are removed from the patient, and the opening in the inferior vena cava at the patient&#39;s groin is closed. The patient then faces a brief and relatively painless recovery period of a few weeks, as opposed to the extended and traumatic recovery required following open-heart surgery. 
     Although the present invention has been described herein with respect to particular features, aspects and embodiments thereof, it will be apparent that numerous variations, modifications, and other embodiments are possible within the broad scope of the present invention, and accordingly, all variations, modifications and embodiments are to be regarded as being within the spirit and scope of the invention.