Patent Publication Number: US-7713282-B2

Title: Detachable atrial appendage occlusion balloon

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation-in-part of U.S. application Ser. No. 09/435,562 filed on Nov. 8, 1999, now U.S. Pat. No. 7,128,073 which is a continuation-in-part of U.S. application Ser. No. 09/187,200 filed on Nov. 6, 1998, now U.S. Pat. No. 6,152,144, issued Nov. 28, 2000, the disclosures of which are incorporated in their entirety herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to methods and devices for closing a body lumen or cavity and, in particular, for closing the left atrial appendage. 
     2. Description of the Related Art 
     Embolic stroke is the nation&#39;s third leading killer for adults, and is a major cause of disability. There are over 700,000 strokes per year in the United States alone. Of these, roughly 100,000 are hemoragic, and 600,000 are ischemic (either due to vessel narrowing or to embolism). The most common cause of embolic stroke emanating from the heart is thrombus formation due to atrial fibrillation. Approximately 80,000 strokes per year are attributable to atrial fibrillation. Atrial fibrillation is an arrhythmia of the heart that results in a rapid and chaotic heartbeat that produces lower cardiac output and irregular and turbulent blood flow in the vascular system. There are over five million people worldwide with atrial fibrillation, with about four hundred thousand new cases reported each year. Atrial fibrillation is associated with a 500 percent greater risk of stroke due to the condition. A patient with atrial fibrillation typically has a significantly decreased quality of life due, in part, to the fear of a stroke, and the pharmaceutical regimen necessary to reduce that risk. 
     For patients who develop atrial thrombus from atrial fibrillation, the clot normally occurs in the left atrial appendage (LAA) of the heart. The LAA is a cavity which looks like a small finger or windsock and which is connected to the lateral wall of the left atrium between the mitral valve and the root of the left pulmonary vein. The LAA normally contracts with the rest of the left atrium during a normal heart cycle, thus keeping blood from becoming stagnant therein, but often fails to contract with any vigor in patients experiencing atrial fibrillation due to the discoordinate electrical signals associated with AF. As a result, thrombus formation is predisposed to form in the stagnant blood within the LAA. 
     Blackshear and Odell have reported that of the 1288 patients with non-rheumatic atrial fibrillation involved in their study, 221 (17%) had thrombus detected in the left atrium of the heart. Blackshear J L, Odell J A., Appendage Obliteration to Reduce Stroke in Cardiac Surgical Patients With Atrial Fibrillation. Ann Thorac. Surg., 1996.61(2):755-9. Of the patients with atrial thrombus, 201 (91%) had the atrial thrombus located within the left atrial appendage. The foregoing suggests that the elimination or containment of thrombus formed within the LAA of patients with atrial fibrillation would significantly reduce the incidence of stroke in those patients. 
     Pharmacological therapies for stroke prevention such as oral or systemic administration of warfarin or the like have been inadequate due to serious side effects of the medications and lack of patient compliance in taking the medication. Invasive surgical or thorascopic techniques have been used to obliterate the LAA, however, many patients are not suitable candidates for such surgical procedures due to a compromised condition or having previously undergone cardiac surgery. In addition, the perceived risks of even a thorascopic surgical procedure often outweigh the potential benefits. See Blackshear and Odell, above. See also Lindsay B D., Obliteration of the Left Atrial Appendage: A Concept Worth Testing, Ann Thorac. Surg., 1996.61(2):515. 
     Despite the various efforts in the prior art, there remains a need for a minimally invasive method and associated devices for reducing the risk of thrombus formation in the left atrial appendage. 
     SUMMARY OF THE INVENTION 
     In accordance with one embodiment of the present invention, an adjustable occlusion device deployment system, for implanting an occlusion device within a tubular structure in the body is provided. The system includes an occlusion device, movable between a reduced cross section and an enlarged cross section, an inflation catheter, releasably attached to the occlusion device, and an anchoring system for the occlusion device. 
     In one embodiment, the anchoring system comprises an anchoring ribbon. In another embodiment, the anchoring system comprises a plurality of anchoring hooks. In some embodiments, the occlusion device comprises an occluding member, enlargeable from a reduced cross section to an enlarged cross section, and an anchoring member, enlargeable from a reduced cross section to an enlarged cross section. In some embodiments, the system also includes a two-way valve. 
     In accordance with another embodiment of the present invention, an occlusion device for occluding a tubular body structure is provided. The device includes an occluding member, enlargeable from a reduced cross section to an enlarged cross section, and an anchoring member, enlargeable from a reduced cross section to an enlarged cross section. In some embodiments, the device also includes at least one tissue attachment element on the occluding member. In some embodiments, the tissue attachment element comprises a tissue piercing element. 
     In accordance with another embodiment of the present invention, an occlusion device implantation system is provided. The system includes an inflation catheter, having an elongate flexible body with a proximal end and a distal end, and a radially expandable implant releasably connected to the distal end of the body. 
     In accordance with another embodiment of the present invention, a method of implanting a device in the left atrial appendage is provided. The method includes the steps of providing an inflation catheter, having an elongate flexible body with a proximal end and a distal end, and a device removably carried by the distal end, positioning at least a portion of the device in the left atrial appendage, enlarging the device under positive force or pressure, and anchoring the device in the left atrial appendage. 
     The systems and methods have several features, no single one of which is solely responsible for its desirable attributes. Without limiting the scope as expressed by the claims that follow, its more prominent features will now be discussed briefly. After considering this discussion, and particularly after reading the section entitled “Detailed Description of the Preferred Embodiments” one will understand how the features of the system and methods provide several advantages over traditional systems and methods. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of an occlusion device in accordance with the present invention. 
         FIG. 2  is a side elevational view of the occlusion device shown in  FIG. 1 . 
         FIG. 3  is a perspective view of an alternate embodiment of the present invention. 
         FIG. 4  is a side elevational view of the embodiment shown in  FIG. 3 . 
         FIG. 5  is a perspective view of a further embodiment of the present invention. 
         FIG. 6  is a side elevational view of the embodiment of  FIG. 5 . 
         FIG. 7  is a perspective view of a support structure for a further occlusion device in accordance with the present invention. 
         FIG. 7A  is a side elevational view of the device of  FIG. 7 . 
         FIG. 7B  is an end view taken along the line  7 B- 7 B of  FIG. 7A . 
         FIG. 8  is a schematic illustration of an inflatable balloon positioned within the occlusion device of  FIG. 7 . 
         FIG. 9  is a schematic view of a pull string deployment embodiment of the occlusion device of  FIG. 7 . 
         FIGS. 10 and 11  are side elevational schematic representations of partial and complete barrier layers on the occlusion device of  FIG. 7 . 
         FIG. 12  is a side elevational schematic view of an alternate occlusion device in accordance with the present invention. 
         FIG. 13  is a schematic view of a bonding layer mesh for use in forming a composite barrier membrane in accordance with the present invention. 
         FIG. 14  is an exploded cross sectional view of the components of a composite barrier member in accordance with the present invention. 
         FIG. 15  is a cross sectional view through a composite barrier formed from the components illustrated in  FIG. 14 . 
         FIG. 16  is a top plan view of the composite barrier illustrated in  FIG. 15 . 
         FIG. 17  is a schematic view of a deployment system in accordance with the present invention. 
         FIG. 17A  is an enlarged view of a releasable lock in an engaged configuration. 
         FIG. 17B  is an enlarged view as in  FIG. 17A , with the core axially retracted to release the implant. 
         FIG. 18  is a perspective view of a flexible guide tube for use in the configurations of  FIG. 17  and/or  FIG. 19 . 
         FIG. 19  is a schematic view of an alternate deployment system in accordance with the present invention. 
         FIGS. 19A-19B  illustrate a removal sequence for an implanted device in accordance with the present invention. 
         FIG. 20  is a schematic cross sectional view through the distal end of a retrieval catheter having an occlusion device removably connected thereto. 
         FIG. 20A  is a side elevational schematic view of the system illustrated in  FIG. 20 , with the occlusion device axially elongated and radially reduced. 
         FIG. 20B  is a side elevational schematic view as in  FIG. 20A , with the occlusion device drawn part way into the delivery catheter. 
         FIG. 20C  is a schematic view as in  FIG. 20B , with the occlusion device and delivery catheter drawn into a transeptal sheath. 
         FIG. 21  is a schematic view of an alternate system in accordance with the present invention. 
         FIGS. 22A-C  are an enlarged cross-sectional view of the distal end of the system of  FIG. 21 . 
         FIG. 23  is an enlarged cross-sectional view of the distal end of the system of  FIG. 21 . 
         FIG. 24A  is a cross-sectional view of an implant and anchor element in accordance with the present invention. 
         FIG. 24B  is a side elevational view of the combined implant and anchor element in accordance with the present invention. 
         FIG. 24C  is a perspective view of the anchor element in accordance with the present invention. 
         FIG. 24D  is a perspective view of the combined implant and anchor element in accordance with the present invention. 
         FIG. 25  is a cross-sectional view of the system including the implant and anchor element in accordance with the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to  FIGS. 1 and 2 , there is illustrated one embodiment of the occlusion device  10  in accordance with the present invention. Although the present invention will be described primarily in the context of an occlusion device, the present inventors also contemplate omitting the fabric cover or enlarging the pore size to produce implantable filters or other devices which are enlargeable at a remote implantation site. 
     The occlusion device  10  comprises an occluding member  11  comprising a frame  14  and a barrier  15 . In the illustrated embodiment, the frame  14  comprises a plurality of radially outwardly extending spokes  17  each having a length within the range of from about 0.5 cm to about 2 cm from a hub  16 . In one embodiment, the spokes have an axial length of about 1.5 cm. Depending upon the desired introduction crossing profile of the collapsed occlusion device  10 , as well as structural strength requirements in the deployed device, anywhere within the range of from about 3 spokes to about 40 spokes may be utilized. In some embodiments, anywhere from about 12 to about 24 spokes are utilized, and, 18 spokes are utilized in one embodiment. 
     The spokes are advanceable from a generally axially extending orientation such as to fit within a tubular introduction catheter to a radially inclined orientation as illustrated in  FIG. 1  and  FIG. 2  following deployment from the catheter. In a self-expandable embodiment, the spokes are biased radially outwardly such that the occlusion member expands to its enlarged, implantation cross-section under its own bias following deployment from the catheter. Alternatively, the occlusion member may be enlarged using any of a variety of enlargement structures such as an inflatable balloon, or a catheter for axially shortening the occlusion member, as is discussed further below. 
     Preferably, the spokes comprise a metal such as stainless steel, Nitinol, Elgiloy, or others which can be determined through routine experimentation by those of skill in the art. Wires having a circular or rectangular cross-section may be utilized depending upon the manufacturing technique. In one embodiment, rectangular cross section spokes are cut such as by known laser cutting techniques from tube stock, a portion of which forms the hub  16 . 
     The barrier  15  may comprise any of a variety of materials which facilitate cellular in-growth, such as ePTFE. The suitability of alternate materials for barrier  15  can be determined through routine experimentation by those of skill in the art. The barrier  15  may be provided on either one or both axially facing sides of the occlusion member. In one embodiment, the barrier  15  comprises two layers, with one layer on each side of the frame  14 . The two layers may be bonded to each other around the spokes  17  in any of a variety of ways, such as by heat bonding with or without an intermediate bonding layer such as polyethylene or FEP, adhesives, sutures, and other techniques which will be apparent to those of skill in the art in view of the disclosure herein. The barrier  15  preferably has a thickness of no more than about 0.003″ and a porosity within the range of from about 5 μm to about 60 μm. 
     The barrier  15  in one embodiment preferably is securely attached to the frame  14  and retains a sufficient porosity to facilitate cellular ingrowth and/or attachment. One method of manufacturing a suitable composite membrane barrier  15  is illustrated in  FIGS. 13-16 . As illustrated schematically in  FIG. 13 , a bonding layer  254  preferably comprises a mesh or other porous structure having an open surface area within the range of from about 10% to about 90%. Preferably, the open surface area of the mesh is within the range of from about 30% to about 60%. The opening or pore size of the bonding layer  254  is preferably within the range of from about 0.005 inches to about 0.050 inches, and, in one embodiment, is about 0.020 inches. The thickness of the bonding layer  254  can be varied widely, and is generally within the range of from about 0.0005 inches to about 0.005 inches. In a preferred embodiment, the bonding layer  254  has a thickness of about 0.001 to about 0.002 inches. One suitable polyethylene bonding mesh is available from Smith and Nephew, under the code SN9. 
     Referring to  FIG. 14 , the bonding layer  254  is preferably placed adjacent one or both sides of a spoke or other frame element  14 . The bonding layer  254  and frame  14  layers are then positioned in-between a first membrane  250  and a second membrane  252  to provide a composite membrane stack. The first membrane  250  and second membrane  252  may comprise any of a variety of materials and thicknesses, depending upon the desired functional result. Generally, the membrane has a thickness within the range of from about 0.0005 inches to about 0.010 inches. In one embodiment, the membranes  250  and  252  each have a thickness on the order of from about 0.001 inches to about 0.002 inches, and comprise porous ePTFE, having a porosity within the range of from about 10 microns to about 100 microns. 
     The composite stack is heated to a temperature of from about 200° to about 300°, for about 1 minute to about 5 minutes under pressure to provide a finished composite membrane assembly with an embedded frame  14  as illustrated schematically in  FIG. 15 . The final composite membrane has a thickness within the range of from about 0.001 inches to about 0.010 inches, and, preferably, is about 0.002 to about 0.003 inches in thickness. However, the thicknesses and process parameters of the foregoing may be varied considerably, depending upon the materials of the bonding layer  254  the first layer  250  and the second layer  252 . 
     As illustrated in top plan view in  FIG. 16 , the resulting finished composite membrane has a plurality of “unbonded” windows or areas  256  suitable for cellular attachment and/or ingrowth. The attachment areas  256  are bounded by the frame  14  struts, and the cross-hatch or other wall pattern formed by the bonding layer  254 . Preferably, a regular window  256  pattern is produced in the bonding layer  254 . 
     The foregoing procedure allows the bonding mesh to flow into the first and second membranes  250  and  252  and gives the composite membrane  15  greater strength (both tensile and tear strength) than the components without the bonding mesh. The composite allows uniform bonding while maintaining porosity of the membrane  15 , to facilitate tissue attachment. By flowing the thermoplastic bonding layer into the pores of the outer mesh layers  250  and  252 , the composite flexibility is preserved and the overall composite layer thickness can be minimized. 
     Referring back to  FIGS. 1 and 2 , the occlusion device  10  may be further provided with a bulking element or stabilizer  194 . The stabilizer  194  may be spaced apart along an axis from the occluding member  11 . In the illustrated embodiment, a distal end  190  and a proximal end  192  are identified for reference. The designation proximal or distal is not intended to indicate any particular anatomical orientation or deployment orientation within the deployment catheter. As shown in  FIGS. 1 and 2 , the stabilizer  194  is spaced distally apart from the occluding member  11 . 
     For use in the LAA, the occluding member  11  has an expanded diameter within the range of from about 1 cm to about 5 cm, and, in one embodiment, about 3 cm. The axial length of the occluding member  11  in an expanded, unstressed orientation from the distal end  192  to the hub  16  is on the order of about 1 cm. The overall length of the occlusion device  10  from the distal end  192  to the proximal end  190  is within the range of from about 1.5 cm to about 4 cm and, in one embodiment, about 2.5 cm. The axial length of the stabilizer  194  between distal hub  191  and proximal hub  16  is within the range of from about 0.5 cm to about 2 cm, and, in one embodiment, about 1 cm. The expanded diameter of the stabilizer  194  is within the range of from about 0.5 cm to about 2.5 cm, and, in one embodiment, about 1.4 cm. The outside diameter of the distal hub  191  and proximal hub  16  is about 2.5 mm. 
     Preferably, the occlusion device  10  is provided with one or more retention structures for retaining the device in the left atrial appendage or other body cavity or lumen. In the illustrated embodiment, a plurality of barbs or other anchors  195  are provided, for engaging adjacent tissue to retain the occlusion device  10  in its implanted position and to limit relative movement between the tissue and the occlusion device. The illustrated anchors are provided on one or more of the spokes  17 , or other portion of frame  14 . Preferably, every spoke, every second spoke or every third spoke are provided with one or two or more anchors each. 
     The illustrated anchor is in the form of a barb, with one on each spoke for extending into tissue at or near the opening of the LAA. Depending upon the embodiment, two or three barbs may alternatively be desired on each spoke. In the single barb embodiment of  FIG. 7 , each barb is inclined in a proximal direction. This is to inhibit proximal migration of the implant out of the left atrial appendage. In this context, distal refers to the direction into the left atrial appendage, and proximal refers to the direction from the left atrial appendage into the heart. 
     Alternatively, one or more barbs may face distally, to inhibit distal migration of the occlusion device deeper into the LAA. Thus the implant may be provided with at least one proximally facing barb and at least one distally facing barb. For example, in an embodiment of the type illustrated in  FIG. 12 , discussed below, a proximal plurality of barbs may be inclined in a first direction, and a distal plurality of barbs may be inclined in a second direction, to anchor the implant against both proximal and distal migration. 
     One or more anchors  195  may also be provided on the stabilizer  194 , such that it assists not only in orienting the occlusion device  10  and resisting compression of the LAA, but also in retaining the occlusion device  10  within the LAA. Any of a wide variety of structures may be utilized for anchor  195 , either on the occluding member  11  or the stabilizer  194  or both, such as hooks, barbs, pins, sutures, adhesives, ingrowth surfaces and others which will be apparent to those of skill in the art in view of the disclosure herein. 
     In use, the occlusion device  10  is preferably positioned within a tubular anatomical structure to be occluded such as the left atrial appendage. In a left atrial appendage application, the occluding member  11  is positioned across or near the opening to the LAA and the stabilizer  194  is positioned within the LAA. The stabilizer  194  assists in the proper location and orientation of the occluding member  11 , as well as resists compression of the LAA behind the occluding member  11 . The present inventors have determined that following deployment of an occluding member  11  without a stabilizer  194  or other bulking structure to resist compression of the LAA, normal operation of the heart may cause compression and resulting volume changes in the LAA, thereby forcing fluid past the occluding member  11  and inhibiting or preventing a complete seal. Provision of a stabilizer  194  dimensioned to prevent the collapse or pumping of the LAA thus minimizes leakage, and provision of the barbs facilitates endothelialization or other cell growth across the occluding member  11 . 
     The stabilizer  194  is preferably movable between a reduced cross-sectional profile for transluminal advancement into the left atrial appendage, and an enlarged cross-sectional orientation as illustrated to fill or to substantially fill a cross-section through the LAA. The stabilizing member may enlarge to a greater cross section than the (pre-stretched) anatomical cavity, to ensure a tight fit and minimize the likelihood of compression. One convenient construction includes a plurality of elements  196  which are radially outwardly expandable in response to axial compression of a distal hub  191  towards a proximal hub  16 . Elements  196  each comprise a distal segment  198  and a proximal segment  202  connected by a bend  200 . The elements  196  may be provided with a bias in the direction of the radially enlarged orientation as illustrated in  FIG. 2 , or may be radially expanded by applying an expansion force such as an axially compressive force between distal hub  191  and proximal hub  16  or a radial expansion force such as might be applied by an inflatable balloon. Elements  196  may conveniently be formed by laser cutting the same tube stock as utilized to construct the distal hub  191 , proximal hub  16  and frame  14 , as will be apparent to those of skill in the art in view of the disclosure herein. Alternatively, the various components of the occlusion device  10  may be separately fabricated or fabricated in subassemblies and secured together during manufacturing. 
     As a post implantation step for any of the occlusion devices disclosed herein, a radiopaque dye or other visualizable media may be introduced on one side or the other of the occlusion device, to permit visualization of any escaped blood or other fluid past the occlusion device. For example, in the context of a left atrial appendage application, the occlusion device may be provided with a central lumen or other capillary tube or aperture which permits introduction of a visualizable dye from the deployment catheter through the occlusion device and into the entrapped space on the distal side of the occlusion device. Alternatively, dye may be introduced into the entrapped space distal to the occlusion device such as by advancing a small gauge needle from the deployment catheter through the barrier  15  on the occlusion device, to introduce dye. 
     Modifications to the occlusion device  10  are illustrated in  FIGS. 3-4 . The occlusion device  10  comprises an occlusion member  11  and a stabilizing member  194  as previously discussed. In the present embodiment, however, each of the distal segments  198  inclines radially outwardly in the proximal direction and terminates in a proximal end  204 . The proximal end  204  may be provided with an atraumatic configuration, for pressing against, but not penetrating, the wall of the left atrial appendage or other tubular body structure. Three or more distal segments  198  are preferably provided, and generally anywhere within the range of from about 6 to about 20 distal segments  198  may be used. In one embodiment, 9 distal segments  198  are provided. In this embodiment, three of the distal segments  198  have an axial length of about 5 mm, and 6 of the distal segments  198  have an axial length of about 1 cm. Staggering the lengths of the distal segments  198  may axially elongate the zone in the left atrial appendage against which the proximal ends  204  provide anchoring support for the occlusion device. 
     The occlusion device  10  illustrated in  FIGS. 3 and 4  is additionally provided with a hinge  206  to allow the longitudinal axis of the occlusion member  11  to be angularly oriented with respect to the longitudinal axis of the stabilizing member  194 . In the illustrated embodiment, the hinge  206  is a helical coil, although any of a variety of hinge structures can be utilized. The illustrated embodiment may be conveniently formed by laser cutting a helical slot through a section of the tube from which the principal structural components of the occlusion device  10  are formed. At the distal end of the hinge  206 , an annular band  208  connects the hinge  206  to a plurality of axially extending struts  210 . In the illustrated embodiment, three axial struts  210  are provided, spaced equilaterally around the circumference of the body. Axial struts  210  may be formed from a portion of the wall of the original tube stock, which portion is left in its original axial orientation following formation of the distal segments  198  such as by laser cutting from the tubular wall. 
     The occlusion member  11  is provided with a proximal zone  212  on each of the spokes  17 . Proximal zone  212  has an enhanced degree of flexibility, to accommodate the fit between the occlusion member  11  and the wall of the left atrial appendage. Proximal section  212  may be formed by reducing the cross sectional area of each of the spokes  17 , which may be provided with a wave pattern as illustrated. 
     Each of the spokes  17  terminates in a proximal point  214 . Proximal point  214  may be contained within layers of the barrier  15 , or may extend through or beyond the barrier  15  such as to engage adjacent tissue and assist in retaining the occlusion device  10  at the deployment site. 
     Referring to  FIGS. 5 and 6 , a further variation on the occlusion device  10  illustrated in  FIGS. 1 and 2  is provided. The occlusion device  10  is provided with a proximal face  216  on the occlusion member  11 , instead of the open and proximally concave face on the embodiment of  FIGS. 1 and 2 . The proximal face  216  is formed by providing a proximal spoke  218  which connects at an apex  220  to some or all of the distal spokes  17 . The proximal spoke  218 , and corresponding apex  220  and distal spoke  17  may be an integral structure, such as a single ribbon or wire, or element cut from a tube stock as has been discussed. 
     Proximal spokes  218  are each attached to a hub  222  at the proximal end  192  of the occlusion device  10 . The barrier  15  may surround either the proximal face or the distal face or both on the occlusion member  11 . In general, provision of a proximal spoke  218  connected by an apex  220  to a distal spoke  17  provides a greater radial force than a distal spoke  17  alone, which will provide an increased resistance to compression if the occlusion member  11  is positioned with the LAA. 
     Referring to  FIGS. 7-12 , alternate structures of the occlusion device in accordance with the present invention are illustrated. In general, the occlusion device  10  comprises an occluding member but does not include a distinct stabilizing member as has been illustrated in connection with previous embodiments. Any of the embodiments previously disclosed herein may also be constructed using the occluding member only, and omitting the stabilizing member as will be apparent to those of skill in the art in view of the disclosure herein. 
     The occluding device  10  comprises a proximal end  192 , a distal end  190 , and a longitudinal axis extending therebetween. A plurality of supports  228  extend between a proximal hub  222  and a distal hub  191 . At least two or three supports  228  are provided, and preferably at least about ten. In one embodiment, sixteen supports  228  are provided. However, the precise number of supports  228  can be modified, depending upon the desired physical properties of the occlusion device  10  as will be apparent to those of skill in the art in view of the disclosure herein, without departing from the present invention. 
     Each support  228  comprises a proximal spoke portion  218 , a distal spoke portion  17 , and an apex  220  as has been discussed. Each of the proximal spoke portion  218 , distal spoke portion  17  and apex  220  may be a region on an integral support  228 , such as a continuous rib or frame member which extends in a generally curved configuration as illustrated with a concavity facing towards the longitudinal axis of the occlusion device  10 . Thus, no distinct point or hinge at apex  220  is necessarily provided. 
     At least some of the supports  228 , and, preferably, each support  228 , is provided with one or two or more barbs  195 . In the illustrated configuration, the occlusion device  10  is in its enlarged orientation, such as for occluding a left atrial appendage or other body cavity or lumen. In this orientation, each of the barbs  195  projects generally radially outwardly from the longitudinal axis, and is inclined in the proximal direction. One or more barbs may also be inclined distally, as is discussed elsewhere herein. In an embodiment where the barbs  195  and corresponding support  228  are cut from a single ribbon, sheet or tube stock, the barb  195  will incline radially outwardly at approximately a tangent to the curve formed by the support  228 . 
     The occlusion device  10  constructed from the frame illustrated in  FIG. 7  may be constructed in any of a variety of ways, as will become apparent to those of skill in the art in view of the disclosure herein. In one method, the occlusion device  10  is constructed by laser cutting a piece of tube stock to provide a plurality of axially extending slots in-between adjacent supports  228 . Similarly, each barb  195  can be laser cut from the corresponding support  228  or space in-between adjacent supports  228 . The generally axially extending slots which separate adjacent supports  228  end a sufficient distance from each of the proximal end  192  and distal end  190  to leave a proximal hub  222  and a distal hub  191  to which each of the supports  228  will attach. In this manner, an integral cage structure may be formed. Alternatively, each of the components of the cage structure may be separately formed and attached together such as through soldering, brazing, heat bonding, adhesives, and other fastening techniques which are known in the art. A further method of manufacturing the occlusion device  10  is to laser cut a slot pattern on a flat sheet of appropriate material, such as a flexible metal or polymer, as has been discussed in connection with previous embodiments. The flat sheet may thereafter be rolled about an axis and opposing edges bonded together to form a tubular structure. 
     The apex portion  220  which carries the barb  195  may be advanced from a low profile orientation in which each of the supports  228  extend generally parallel to the longitudinal axis, to an implanted orientation as illustrated, in which the apex  220  and the barb  195  are positioned radially outwardly from the longitudinal axis. The support  228  may be biased towards the enlarged orientation, or may be advanced to the enlarged orientation under positive force following positioning within the tubular anatomical structure, in any of a variety of manners. 
     For an example of enlarging under positive force, referring to  FIG. 8 , an inflatable balloon  230  is positioned within the occlusion device  10 . Inflatable balloon  230  is connected by way of a removable coupling  232  to an inflation catheter  234 . Inflation catheter  234  is provided with an inflation lumen for providing communication between an inflation media source  236  outside of the patient and the balloon  230 . Following positioning within the target body lumen, the balloon  230  is inflated, thereby engaging barbs  195  with the surrounding tissue. The inflation catheter  234  is thereafter removed, by decoupling the removable coupling  232 , and the inflation catheter  234  is thereafter removed. The balloon  230  may be either left in place within the occlusion device  10 , or deflated and removed by the inflation catheter  234 . 
     In an alternate embodiment, the supports  228  are radially enlarged such as through the use of a deployment catheter  238 . See  FIG. 9 . Deployment catheter  238  comprises a lumen for movably receiving a deployment element such as a flexible line  240 . Deployment line  240  extends in a loop  244  formed by an aperture or slip knot  242 . As will be apparent from  FIG. 9 , proximal retraction on the deployment line  240  while resisting proximal movement of proximal hub  222  such as by using the distal end of the catheter  238  will cause the distal hub  191  to be drawn towards the proximal hub  222 , thereby radially enlarging the cross-sectional area of the occlusion device  10 . Depending upon the material utilized for the occlusion device  10 , the supports  228  will retain the radially enlarged orientation by elastic deformation, or may be retained in the enlarged orientation such as by securing the slip knot  242  immovably to the deployment line  240  at the fully radially enlarged orientation. This may be accomplished in any of a variety of ways, using additional knots, clips, adhesives, or other techniques known in the art. 
     A variety of alternative structures may be utilized, to open or enlarge the occlusion device  10  under positive force. For example, Referring to  FIG. 9 , a pullwire  240  may be removably attached to the distal hub  191  or other distal point of attachment on the occlusion device  10 . Proximal retraction of the pullwire  240  while resisting proximal motion of the proximal hub  222  such as by using the distal end of the catheter  238  will cause enlargement of the occlusion device  10  as has been discussed. The pullwire  240  may then be locked with respect to the proximal hub  222  and severed or otherwise detached to enable removal of the deployment catheter  238  and proximal extension of the pullwire  240 . Locking of the pullwire with respect to the proximal hub  222  may be accomplished in any of a variety of ways, such as by using interference fit or friction fit structures, adhesives, a knot or other technique depending upon the desired catheter design. 
     Referring to  FIGS. 10 and 11 , the occlusion device  10  may be provided with a barrier  15  such as a mesh or fabric as has been previously discussed. Barrier  15  may be provided on only one hemisphere such as proximal face  216 , or may be carried by the entire occlusion device  10  from proximal end  192  to distal end  190 . The barrier may be secured to the radially inwardly facing surface of the supports  228 , as illustrated in  FIG. 11 , or may be provided on the radially outwardly facing surfaces of supports  228 , or both. 
     A further embodiment of the occlusion device  10  is illustrated in  FIG. 12 , in which the apex  220  is elongated in an axial direction to provide additional contact area between the occlusion device  10  and the wall of the tubular structure. In this embodiment, one or two or three or more anchors  195  may be provided on each support  228 , depending upon the desired clinical performance. The occlusion device  10  illustrated in  FIG. 12  may also be provided with any of a variety of other features discussed herein, such as a partial or complete barrier  15 . In addition, the occlusion device  10  illustrated in  FIG. 12  may be enlarged using any of the techniques disclosed elsewhere herein. 
     Referring to  FIG. 17 , there is schematically illustrated a further aspect of the present invention. An adjustable implant deployment system  300  comprises generally a catheter  302  for placing a detachable implant  304  within a body cavity or lumen, as has been discussed. The catheter  302  comprises an elongate flexible tubular body  306 , extending between a proximal end  308  and a distal end  310 . The catheter is shown in highly schematic form, for the purpose of illustrating the functional aspects thereof. The catheter body will have a sufficient length and diameter to permit percutaneous entry into the vascular system, and transluminal advancement through the vascular system to the desired deployment site. For example, in an embodiment intended for access at the femoral artery and deployment within the left atrial appendage, the catheter  302  will have a length within the range of from about 50 cm to about 150 cm, and a diameter of generally no more than about 15 French. Further dimensions and physical characteristics of catheters for navigation to particular sites within the body are well understood in the art and will not be further described herein. 
     The tubular body  306  is further provided with a handle  309  generally on the proximal end  308  of the catheter  302 . The handle  309  permits manipulation of the various aspects of the implant deployment system  300 , as will be discussed below. Handle  309  may be manufactured in any of a variety of ways, typically by injection molding or otherwise forming a handpiece for single-hand operation, using materials and construction techniques well known in the medical device arts. 
     The implant  304  may be in the form of any of those described previously herein, as modified below. In general, the implant is movable from a reduced crossing profile to an enlarged crossing profile, such that it may be positioned within a body structure and advanced from its reduced to its enlarged crossing profile to obstruct bloodflow or perform other functions while anchored therein. The implant  304  may be biased in the direction of the enlarged crossing profile, may be neutrally biased or may be biased in the direction of the reduced crossing profile. Any modifications to the device and deployment system to accommodate these various aspects of the implant  304  may be readily accomplished by those of skill in the art in view of the disclosure herein. 
     In the illustrated embodiment, the distal end  314  of the implant  304  is provided with an implant plug  316 . Implant plug  316  provides a stopping surface  317  for contacting an axially movable core  312 . The core  312  extends axially throughout the length of the catheter body  302 , and is attached at its proximal end to a core control  332  on the handle  309 . 
     The core  312  may comprise any of a variety of structures which has sufficient lateral flexibility to permit navigation of the vascular system, and sufficient axial column strength to enable reduction of the implant  304  to its reduced crossing profile. Any of a variety of structures such as hypotube, solid core wire, “bottomed out” coil spring structures, or combinations thereof may be used, depending upon the desired performance of the finished device. In one embodiment, the core  312  comprises stainless steel tubing. 
     The distal end of core  312  is positioned within a recess or lumen  322  defined by a proximally extending guide tube  320 . In the illustrated embodiment, the guide tube  320  is a section of tubing such as metal hypotube, which is attached at the distal end  314  of the implant and extends proximally within the implant  304 . The guide tube  320  preferably extends a sufficient distance in the proximal direction to inhibit buckling or prolapse of the core  312  when distal pressure is applied to the core control  332  to reduce the profile of the implant  304 . However, the guide tube  320  should not extend proximally a sufficient distance to interfere with the opening of the implant  304 . 
     As will be appreciated by reference to  FIG. 17 , the guide tube  320  may operate as a limit on distal axial advancement of the proximal end  324  of implant  304 . Thus, the guide tube  320  preferably does not extend sufficiently far proximally from the distal end  314  to interfere with optimal opening of the implant  304 . The specific dimensions are therefore relative, and will be optimized to suit a particular intended application. In one embodiment, the implant  304  has an implanted outside diameter within the range of from about 5 mm to about 45 mm, and an axial implanted length within the range of from about 5 mm to about 45 mm. The guide tube  320  has an overall length of about 3 mm to about 35 mm, and an outside diameter of about 0.095 inches. 
     An alternate guide tube  320  is schematically illustrated in  FIG. 18 . In this configuration, the guide tube  320  comprises a plurality of tubular segments  321  spaced apart by an intervening space  323 . This allows increased flexibility of the guide tube  320 , which may be desirable during the implantation step, while retaining the ability of the guide tube  320  to maintain linearity of the core  312  while under axial pressure. Although three segments  321  are illustrated in  FIG. 18 , as many as 10 or 20 or more segments  321  may be desirable depending upon the desired flexibility of the resulting implant. 
     Each adjacent pair of segments  321  may be joined by a hinge element  325  which permits lateral flexibility. In the illustrated embodiment, the hinge element  325  comprises an axially extending strip or spine, which provides column strength along a first side of the guide tube  320 . The guide tube  320  may therefore be curved by compressing a second side of the guide tube  320  which is generally offset from the spine  325  by about 180°. A limit on the amount of curvature may be set by adjusting the axial length of the space  323  between adjacent segments  321 . In an embodiment having axial spines  325 , each axial spine  325  may be rotationally offset from the next adjacent axial spine  325  to enable flexibility of the overall guide tube  320  throughout a 360° angular range of motion. 
     Alternatively, the flexible hinge point between each adjacent segment  321  may be provided by cutting a spiral groove or plurality of parallel grooves in a tubular element in between what will then become each adjacent pair of segments  321 . In this manner, each tubular element  321  will be separated by an integral spring like structure, which can permit flexibility. As a further alternative, the entire length of the guide tube  320  may comprise a spring. Each of the forgoing embodiments may be readily constructed by laser cutting or other cutting from a piece of tube stock, to produce a one piece guide tube  320 . Alternatively, the guide tube  320  may be assembled from separate components and fabricated together using any of a variety of bonding techniques which are appropriate for the construction material selected for the tube  320 . 
     Various distal end  314  constructions may be utilized, as will be apparent to those of skill in the art in view of the disclosure herein. In the illustrated embodiment, the distal implant plug  316  extends within the implant  304  and is attached to the distal end of the guide tube  320 . The implant plug  316  may be secured to the guide tube  320  and implant  304  in any of a variety of ways, depending upon the various construction materials. For example, any of a variety of metal bonding techniques such as a welding, brazing, interference fit such as threaded fit or snap fit, may be utilized. Alternatively, any of a variety of bonding techniques for dissimilar materials may be utilized, such as adhesives, and various molding techniques. In one construction, the implant plug  316  comprises a molded polyethylene cap, and is held in place utilizing a distal cross pin  318  which extends through the implant  304 , the guide tube  320  and the implant plug  316  to provide a secure fit against axial displacement. 
     The proximal end  324  of the implant  304  is provided with a releasable lock  326  for attachment to a release element such as pull wire  328 . Pull wire  328  extends proximally throughout the length of the tubular body  306  to a proximal pull wire control  330  on the handle  309 . 
     As used herein, the term pull wire is intended to include any of a wide variety of structures which are capable of transmitting axial tension or compression such as a pushing or pulling force with or without rotation from the proximal end  308  to the distal end  310  of the catheter  302 . Thus, monofilament or multifilament metal or polymeric rods or wires, woven or braided structures may be utilized. Alternatively, tubular elements such as a concentric tube positioned within the outer tubular body  306  may also be used as will be apparent to those of skill in the art. 
     In the illustrated embodiment, the pull wire  328  is releasably connected to the proximal end  324  of the implant  304 . This permits proximal advancement of the proximal end of the implant  304 , which cooperates with a distal retention force provided by the core  312  against the distal end of the implant to axially elongate the implant  304  thereby reducing it from its implanted configuration to its reduced profile for implantation. The proximal end of the pull wire  328  may be connected to any of a variety of pull wire controls  330 , including rotational knobs, levers and slider switches, depending upon the design preference. 
     The proximal end  324  of the implant  304  is thus preferably provided with a releasable lock  326  for attachment of the pullwire  328  to the deployment catheter. In the illustrated embodiment, the releasable lock is formed by advancing the pullwire distally around a cross pin  329 , and providing an eye or loop which extends around the core  312 . As long as the core  312  is in position within the implant  304 , proximal retraction of the pullwire  328  will advance the proximal end  324  of the implant  304  in a proximal direction. See  FIG. 17A . However, following deployment, proximal retraction of the core  312  such as by manipulation of the core control  332  will pull the distal end of the core  312  through the loop on the distal end of the pullwire  328 . The pullwire  328  may then be freely proximally removed from the implant  304 , thereby enabling detachment of the implant  304  from the deployment system  300  within a treatment site. See  FIG. 17B . 
     The implant deployment system  300  thus permits the implant  304  to be maintained in a low crossing profile configuration, to enable transluminal navigation to a deployment site. Following positioning at or about the desired deployment site, proximal retraction of the core  312  enables the implant  304  to radially enlarge under its own bias to fit the surrounding tissue structure. Alternatively, the implant can be enlarged under positive force, such as by inflation of a balloon or by a mechanical mechanism as is discussed elsewhere herein. Once the clinician is satisfied with the position of the implant  304 , such as by injection of dye and visualization using conventional techniques, the core  312  is proximally retracted thereby releasing the lock  326  and enabling detachment of the implant  304  from the deployment system  300 . 
     If, however, visualization reveals that the implant  304  is not at the location desired by the clinician, proximal retraction of the pull wire  328  with respect to the core  312  will radially reduce the diameter of the implant  304 , thereby enabling repositioning of the implant  304  at the desired site. Thus, the present invention permits the implant  304  to be enlarged or reduced by the clinician to permit repositioning and/or removal of the implant  304  as may be desired. 
     In an alternate construction, the implant may be radially enlarged or reduced by rotating a torque element extending throughout the deployment catheter. Referring to  FIG. 19 , the elongate flexible tubular body  306  of the deployment catheter  302  includes a rotatable torque rod  340  extending axially therethrough. The proximal end of the torque rod  340  may be connected at a proximal manifold to a manual rotation device such as a hand crank, thumb wheel, rotatable knob or the like. Alternatively, the torque rod  340  may be connected to a power driven source of rotational energy such as a motor drive or air turbine. 
     The distal end of the torque rod  340  is integral with or is connected to a rotatable core  342  which extends axially through the implant  304 . A distal end  344  of the rotatable core  342  is positioned within a cavity  322  as has been discussed. 
     The terms torque rod or torque element are intended to include any of a wide variety of structures which are capable of transmitting a rotational torque throughout the length of a catheter body. For example, solid core elements such as stainless steel, nitinol or other nickel titanium alloys, or polymeric materials may be utilized. In an embodiment intended for implantation over a guide-wire, the torque rod  340  is preferably provided with an axially extending central guidewire lumen. This may be accomplished by constructing the torque rod  340  from a section of hypodermic needle tubing, having an inside diameter of from about 0.001 inches to about 0.005 inches or more greater than the outside diameter of the intended guidewire. Tubular torque rods  340  may also be fabricated or constructed utilizing any of a wide variety of polymeric constructions which include woven or braided reinforcing layers in the wall. Torque transmitting tubes and their methods of construction are well understood in the intracranial access and rotational atherectomy catheter arts, among others, and are not described in greater detail herein. Use of a tubular torque rod  340  also provides a convenient infusion lumen for injection of contrast media within the implant  304 , such as through a port  343 . 
     The proximal end  324  of the implant  304  is provided with a threaded aperture  346  through which the core  342  is threadably engaged. As will be appreciated by those of skill in the art in view of the disclosure herein, rotation of the threaded core  342  in a first direction relative to the proximal end  324  of the implant  304  will cause the rotatable core  342  to advance distally. This distal advancement will result in an axial elongation and radial reduction of the implantable device  304 . Rotation of the rotatable core  342  in a reverse direction will cause a proximal retraction of the rotatable core  342 , thus enabling a radial enlargement and axial shortening of the implantable device  304 . 
     The deployment catheter  302  is further provided with an antirotation lock  348  between a distal end  350  of the tubular body  306  and the proximal end  324  of the implant  304 . In general, the rotational lock  348  may be conveniently provided by cooperation between a first surface  352  on the distal end  350  of the deployment catheter  302 , which engages a second surface  354  on the proximal end  324  of the implantable device  304 , to rotationally link the deployment catheter  302  and the implantable device  304 . Any of a variety of complementary surface structures may be provided, such as an axial extension on one of the first and second surfaces for coupling with a corresponding recess on the other of the first and second surfaces. Such extensions and recesses may be positioned laterally offset from the axis of the catheter. Alternatively, they may be provided on the longitudinal axis with any of a variety of axially releasable anti-rotational couplings having at least one flat such as a hexagonal or other multifaceted cross sectional configuration. 
     As schematically illustrated in  FIG. 19 , one or more projections  356  on the first surface  352  may engage a corresponding recess  358  on the second surface  354 . Any of a variety of alternative complementary surface structures may also be provided, as will be apparent to those of skill in the art in view of the disclosure herein. For example, referring to  FIG. 19A , the projection  356  is in the form of an axially extending pin for engaging a complimentary recess  358  on the proximal end  324  of the implant  304 .  FIG. 19B  illustrates an axially extending spline  356  for receipt within a complimentary axially extending recess  358 . The various pin, spline and other structures may be reversed between the distal end of tubular body  306  and the proximal end  324  of the implant  304  as will be apparent to those of skill in the art in view of the disclosure herein. 
     Upon placement of the implantable device  304  at the desired implantation site, the torque rod  340  is rotated in a direction that produces an axial proximal retraction. This allows radial enlargement of the radially outwardly biased implantable device  304  at the implantation site. Continued rotation of the torque rod  340  will cause the threaded core  342  to exit proximally through the threaded aperture  346 . At that point, the deployment catheter  302  may be proximally retracted from the patient, leaving the implanted device  304  in place. 
     By modification of the decoupling mechanism to allow the core  342  to be decoupled from the torque rod  340 , the rotatable core  342  may be left within the implantable device  304 , as may be desired depending upon the intended deployment mechanism. For example, the distal end of the core  342  may be rotatably locked within the end cap  326 , such as by including complimentary radially outwardly or inwardly extending flanges and grooves on the distal end of the core  342  and inside surface of the cavity  322 . In this manner, proximal retraction of the core  342  by rotation thereof relative to the implantable device  304  will pull the end cap  326  in a proximal direction under positive force. This may be desirable as a supplement to or instead of a radially enlarging bias built into the implantable device  304 . 
     In the embodiment illustrated in  FIG. 19 , or any other of the deployment and/or removal catheters described herein, the distal end of the tubular body  306  may be provided with a zone or point of enhanced lateral flexibility. This may be desirable in order allow the implant to seat in the optimal orientation within the left atrial appendage, and not be restrained by a lack of flexibility in the tubular body  306 . This may be accomplished in any of a variety of way, such as providing the distal most one or two or three centimeters or more of the tubular body  306  with a spring coil configuration. In this manner, the distal end of the tubular body  306  will be sufficiently flexible to allow the implant  304  to properly seat within the LAA. This distal flex zone on the tubular body  306  may be provided in any of a variety of ways, such as by cutting a spiral slot in the distal end of the tubular body  306  using laser cutting or other cutting techniques. The components within the tubular body  306  such as torque rod  340  may similarly be provided with a zone of enhanced flexibility in the distal region of the tubular body  306 . 
     The implantable device  304  may also be retrieved and removed from the body in accordance with a further aspect of the present invention. One manner of retrieval and removal will be understood in connection with  FIGS. 20 through 20   c . Referring to  FIG. 20 , a previously implanted device  304  is illustrated as releasably coupled to the distal end of the tubular body  306 , as has been previously discussed. Coupling may be accomplished by aligning the tubular body  306  with the proximal end  324  of the deployed implant  304 , under fluoroscopic visualization, and distally advancing a rotatable core  342  through the threaded aperture  346 . Threadable engagement between the rotatable core  342  and aperture  346  may thereafter be achieved, and distal advancement of core  342  will axially elongate and radially reduce the implant  304 . 
     The tubular body  306  is axially moveably positioned within an outer tubular delivery or retrieval catheter  360 . Catheter  360  extends from a proximal end (not illustrated) to a distal end  362 . The distal end  362  is preferably provided with a flared opening, such as by constructing a plurality of petals  364  for facilitating proximal retraction of the implant  304  as will become apparent. Petals  364  may be constructed in a variety of ways, such as by providing axially extending slits in the distal end  362  of the delivery catheter  360 . In this manner, preferably at least about three, and generally at least about four or five or six petals or more will be provided on the distal end  362  of the delivery catheter  360 . Petals  364  manufactured in this manner would reside in a first plane, transverse to the longitudinal axis of the delivery catheter  360 , if each of such petals  364  were inclined at 90 degrees to the longitudinal axis of the delivery catheter  360 . 
     In one application of the invention, a second layer of petals  365  are provided, which would lie in a second, adjacent plane if the petals  365  were inclined at 90 degrees to the longitudinal axis of the delivery catheter  360 . Preferably, the second plane of petals  365  is rotationally offset from the first plane of petals  364 , such that the second petals  365  cover the spaces  367  formed between each adjacent pair of petals  365 . The use of two or more layers of staggered petals  364  and  365  has been found to be useful in retrieving implants  304 , particularly when the implant  304  carries a plurality of tissue anchors  195 . 
     The petals  364  and  365  may be manufactured from any of a variety of polymer materials useful in constructing medical device components such as the delivery catheter  360 . This includes, for example, polyethylene, PET, PEEK, PEBAX, and others well known in the art. The second petals  365  may be constructed in any of a variety of ways. In one convenient construction, a section of tubing which concentrically fits over the delivery catheter  360  is provided with a plurality of axially extending slots in the same manner as discussed above. The tubing with a slotted distal end may be concentrically positioned on the catheter  360 , and rotated such that the space between adjacent petals  365  is offset from the space between adjacent petals  364 . The hub of the petals  365  may thereafter be bonded to the catheter  360 , such as by heat shrinking, adhesives, or other bonding techniques known in the art. 
     The removal sequence will be further understood by reference to  FIGS. 20   a  through  20   c . Referring to  FIG. 20   a , the radially reduced implant  304  is proximally retracted part way into the delivery catheter  360 . This can be accomplished by proximally retracting the tubular body  306  and/or distally advancing the catheter  360 . As illustrated in  FIG. 20   b , the tubular body  306  having the implant  304  attached thereto is proximally retracted a sufficient distance to position the tissue anchors  195  within the petals  364 . The entire assembly of the tubular body  306 , within the delivery catheter  360  may then be proximally retracted within the transeptal sheath  366  or other tubular body as illustrated in  FIG. 20   c . The collapsed petals  364  allow this to occur while preventing engagement of the tissue anchors  195  with the distal end of the transeptal sheath  366  or body tissue. The entire assembly having the implantable device  304  contained therein may thereafter be proximally withdrawn from or repositioned within the patient. 
     In accordance with an embodiment of the present invention, an occlusion device implantation system  400  having a detachable implant  404  and anchoring device  406  is provided. With reference to  FIG. 21 , the system  400  comprises a deployment catheter  408 , having an elongate tubular flexible body  409  with a proximal end  410  and a distal end  411 . An inflation catheter  412  is also provided having an elongate flexible body  413  with a proximal end  414  and a distal end  415 . Inflation catheter extends within tubular body  409  of deployment catheter  408 . The inflation catheter may include a rotatable core  416  and a radially expandable implant  404  is releasably connected to the distal end of the body  413 . Inflatable implant  404  is connected by way of a removable coupling  418  to inflation catheter  412 . Inflation catheter  412  is provided with an inflation lumen  420  for providing communication between an inflation media source  422  outside of the patient and the implant  404 . 
     The tubular body  409  is further provided with a handle  424  generally on the proximal end  410  of the catheter  408 . The tubular body  413  is also further provided with a handle  425  generally on the proximal end of the catheter  412 . The handles  424 ,  425  permits manipulation of the various aspects of the implant deployment system  400 , as will be discussed below. Handles  424 ,  425  may be manufactured in any of a variety of ways, typically by injection molding or otherwise forming a handpiece for single-hand operation, using materials and construction techniques well known in the medical device arts. 
     The implantation system  400  is shown in highly schematic form, for the purpose of illustrating the functional aspects thereof. The catheter body will have a sufficient length and diameter to permit percutaneous entry into the vascular system, and transluminal advancement through the vascular system to the desired deployment site. For example, in an embodiment intended for access at the femoral artery and deployment within the left atrial appendage, the catheter  408  will have a length within the range of from about 50 cm to about 150 cm, and a diameter of generally no more than about 15 French. Further dimensions and physical characteristics of catheters for navigation to particular sites within the body are well understood in the art and will not be further described herein. 
     With reference to  FIGS. 22A-C  and  23 , the distal end of inflation catheter  412  is shown in detail. The elongate flexible tubular body  413  of the inflation catheter  412  includes a rotatable torque rod  426  extending through the deployment catheter  408 . The proximal end of the torque rod  426  may be connected at a proximal manifold to a manual rotation device such as a hand crank, thumb wheel, rotatable knob or the like. Alternatively, the torque rod  426  may be connected to a power driven source of rotational energy such as a motor drive or air turbine. The distal end of the torque rod  426  extends axially through the implant  404  and connects to removable coupling  418 . 
     The terms torque rod or torque element are intended to include any of a wide variety of structures which are capable of transmitting a rotational torque throughout the length of a catheter body. For example, solid core elements such as stainless steel, nitinol or other nickel titanium alloys, or polymeric materials may be utilized. In an embodiment intended for implantation over a guide-wire, the torque rod  426  is preferably provided with an axially extending central guidewire lumen. This may be accomplished by constructing the torque rod  426  from a section of hypodermic needle tubing, having an inside diameter of from about 0.001 inches to about 0.005 inches or more greater than the outside diameter of the intended guidewire. Tubular torque rods  340  may also be fabricated or constructed utilizing any of a wide variety of polymeric constructions which include woven or braided reinforcing layers in the wall. Torque transmitting tubes and their methods of construction are well understood in the intracranial access and rotational atherectomy catheter arts, among others, and are not described in greater detail herein. Use of a tubular torque rod  426  also provides a convenient infusion lumen for injection of contrast media within the implant  404 , such as through a port  420 . 
     With reference to  FIGS. 22A-C , coupling  418  preferably comprises a two-way valve  442  for inflating and deflating implant  404 . The two-way valve  442  includes a first tubular body  444  and a second tubular body  446 . The first tubular body  444  has a proximal end  448  and a distal end  450  and preferably comprises a single lumen  452 . Tubular body  446  can move longitudinally within the first lumen  452  of tubular body  444 . The second tubular body  446  has a proximal end  456  and a distal end  458 . A skive  462  is preferably provided on the tubular body  446  for inflation and deflation. A safety stop  464  is also positioned at the distal end  458  of tubular body  446 . The inner diameter of the second tubular body is tapped to match the screw on the distal end of the torque shaft  426 . 
     Referring to  FIG. 23 , an alternative embodiment of the distal end of inflation catheter  412  is shown. The first tubular body  444  has a proximal end and a distal end and preferably comprises two lumens  452  and  454 . Tubular body  446  can move longitudinally within the lumen  454  of tubular body  444 . A skive  462  is preferably provided on the tubular body  446 . Initially, the tubular body  442  is positioned inside the first tubular body  444 , so the skives  460 ,  462  are aligned. 
     The implant  404  is preferably bonded on the tubing; however, any other known means for attaching a balloon to tubing may be used as known to those of skill in the art. The torque rod  426  is positioned inside the first lumen  452  of the tubing and can move freely within the tubing preferably in both the radial and longitudinal directions. The implant  404  and inflation catheter  412  are connected by screwing the distal tip of the torque rod  426  into tubular body  446 . The inflation catheter also preferably has two lumens which are complementary to the lumens of tubing  444 . 
     The two-way valve is locked and sealed by pulling back on torque rod  426  after inflating the implant  404 . The catheter  412  is detached from the implant  404  and removable coupling  418  by twisting the torque rod  426 . 
     A pin  466  is preferably provided within the second lumen of the catheter at its distal tip and also engages the second lumen  454  of the tubing of the coupling  418 . The pin  466  stops the implant  404  from turning during detachment. After the implant is inflated to a desired diameter, by pulling on the rotatable core  416  while holding the delivery catheter  408  against the balloon, the tubing  446  is pulled inside the tubing  444  and the skive  460  is sealed by the plastic tubing  444 . The implant  404  can be detached by unscrewing the torque rod  426  from the delivery catheter. 
     In other embodiments, the complimentary cross sections can be other shapes, such as a triangle, square, hexagon, ellipse, circle with one or more complimentary intruding and extruding pins, splines, flanges, grooves or other structures disclosed elsewhere herein, or any other regular or irregular polygon that allows the rotatable core  416  to apply a rotational torque to the implant  404 . 
     In general, the implant is movable from a reduced crossing profile to an enlarged crossing profile, such that it may be positioned within a body structure and advanced from its reduced to its enlarged crossing profile to obstruct bloodflow or perform other functions while anchored therein. The implant  404  may be biased in the direction of the enlarged crossing profile, may be neutrally biased or may be biased in the direction of the reduced crossing profile. Any modifications to the device and deployment system to accommodate these various aspects of the implant  404  may be readily accomplished by those of skill in the art in view of the disclosure herein. 
     Throughout this application the applicants have used the terms implant and occlusion device. One of ordinary skill in the art will appreciate that all of the disclosures herein are applicable to a wide variety of structures that include both implants that may or may not also be occlusion devices. Routine experimentation will demonstrate those limited circumstances under which certain disclosures and combinations thereof are not beneficial. 
     Any of a variety of balloon materials may be used, ranging in physical properties from latex for a highly compliant, low pressure system to PET for a noncompliant high pressure and consequently high radial force system for implant  404 , as is understood in the balloon angioplasty arts. 
     Implant  404  is preferably provided with a tissue anchor as shown in  FIGS. 24A-D . The tissue anchor  406  comprises a retention structure for retaining or anchoring the implant in the patient&#39;s body. The tissue anchor in the illustrated embodiment comprises a tubular body having an axial length of about 5 inches, and a 0.003 in. wall thickness. The ribbon is preferably laser cut and formed into a circular shaped collar. One or preferably, a plurality of hooks, are laser cut on the ribbon. The collar is then mounted on the balloon. Two or more barbs  470  may be provided by laser cutting a pattern in the wall of the tube, and bending each barb such that it is biased radially outwardly as illustrated. 
     Alternatively, one or more barbs may face distally, to inhibit distal migration of the occlusion device deeper into the LAA. Thus the implant may be provided with at least one proximally facing barb and at least one distally facing barb. For example, in an embodiment of the type illustrated in  FIG. 24C , discussed below, a proximal plurality of barbs may be inclined in a first direction, and a distal plurality of barbs may be inclined in a second direction, to anchor the implant against both proximal and distal migration. 
     The tissue anchor may be made from any of a variety of biocompatible metals such as stainless steel, Nickel Titanium, Nitinol, Elgiloy or others known in the art. Polymeric anchors such as HDPE, nylon, PTFE or others may alternatively be used. 
     The anchoring element is designed to easily collapse over the balloon to be pulled inside the delivery catheter. 
     With reference to  FIG. 25 , a delivery catheter is shown including detachable implant  404  and anchoring element  406 . Implant  404  is shown in a deflated position. The implant deployment system  400  thus permits the implant  404  to be maintained in a low crossing profile configuration, to enable transluminal navigation to a deployment site. 
     As will be appreciated by reference to  FIG. 25 , the guide tube  440  of catheter  408  may operate as a limit on distal axial advancement of the proximal end of implant  404 . Thus, the guide tube  440  preferably does not extend sufficiently far proximally from the distal end  411  to interfere with optimal opening of the implant  404 . The specific dimensions are therefore relative, and will be optimized to suit a particular intended application. 
     Following positioning within the target body lumen, the implant  404  is inflated, thereby engaging barbs  470  with the surrounding tissue. The inflation catheter  412  is thereafter removed, by decoupling the removable coupling  418  as previously discussed. 
     While particular forms of the invention have been described, it will be apparent that various modifications can be made without departing from the spirit and scope of the invention. Accordingly, it is not intended that the invention be limited, except as by the appended claims.