Patent Publication Number: US-8114145-B2

Title: Trigger wire system

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application is a divisional of application Ser. No. 10/447,406 filed May 29, 2003, issued on Sep. 28, 2010 at U.S. Pat. No. 7,803,177 which claims priority to U.S. Provisional Application Serial No. 60/392,682, filed Jun. 28, 2002, and of the same title, and U.S. Provisional Application Serial No. 60/384,056, filed May 29, 2002, entitled “Multi-Piece Prosthesis Deployment Apparatus.” All of the foregoing applications are hereby incorporated by reference. 
    
    
     BACKGROUND 
     This invention relates to a prosthesis deployment and more particularly to a trigger wire arrangement used on such devices to release a prosthesis when it is in a body lumen. 
     Deployment devices are used to deploy prostheses and in particular prostheses incorporating self expanding stents within lumens in the human body. This invention will generally be discussed in relation to the deployment of prostheses within the aorta but the invention is not so limited and may be used for other of deployment sites as well. 
     In some forms of deployment device trigger wires are used to retrain a prosthesis in a particular position on a deployment device or to retain self expanding stents of the prosthesis in a retracted state. In the region of the deployment device in which the prosthesis is carried, trigger wires can foul or catch with stents on the deployment device, particularly when the deployment device is bent to pass through convolutions in the lumen, therefore causing inaccurate deployment and perhaps jamming or breakage of the trigger wire. 
     Throughout this specification the term distal with respect to a prosthesis and a deployment device for prosthesis is the end of the prosthesis or deployment device which in use is furthest away in the direction of blood flow from the heart and the term proximal refers to the end of the prosthesis or deployment device which in use is nearest to the heart. When applied to other vessels corresponding terms such as caudal and cranial should be understood. 
     It is the object of this invention to provide an arrangement by which a trigger wire on a deployment device can be more safely routed to its destination or to at least provide a practitioner with a useful alternative. 
     BRIEF SUMMARY 
     In one form therefore, although this may not necessarily be the only or broadest form, the invention is said to reside in a trigger wire guide for a prosthesis deployment device, the prosthesis deployment device being of a type having a nose cone dilator located on a proximal end of the deployment device with an elongate catheter body coupled to the nose cone dilator with a guide wire lumen extending therethrough and a trigger wire guide concentric about the elongate catheter body that extends along at least a portion of the elongate catheter body, where the trigger wire guide comprises at least one trigger wire lumen formed within the trigger wire guide where the trigger wire lumen is separate and apart from the guide wire lumen and the trigger wire guide has an aperture, where at least one trigger wire is partially disposed within the at least one trigger wire lumen where the at least one trigger wire is configured to exit the aperture to engage the prosthesis, a stent of the prosthesis, or a suture retaining the prosthesis, and enter the same aperture to thereby retain a portion of the prosthesis adjacent to the trigger wire guide. 
     In an alternative embodiment, the invention comprises a prosthesis deployment device having a nose cone dilator with an elongate catheter body coupled to the nose cone dilator, the elongate catheter body having a guide wire lumen extending therethrough with a trigger wire guide concentric about the elongate catheter body and extending along at least a portion of the elongate catheter body, where the trigger wire guide comprises at least two trigger wire lumens formed within the trigger wire guide where each lumen is separate and apart from the guide wire lumen and at least two apertures in the trigger wire guide where at least one trigger wire is at least partially disposed within each of the at least two trigger wire lumens, where the at least two trigger wires are configured to exit each of the at least two apertures to engage the prosthesis, a stent of the prosthesis, or a suture retaining the prosthesis and enter the same aperture to thereby retain a portion of the prosthesis adjacent to the trigger wire guide. 
     In an alternative form the invention comprises a prosthesis deployment device comprising a nose cone dilator located on a proximal end of the deployment device with an elongate catheter body coupled to the nose cone dilator with the elongate catheter body having a guide wire lumen extending therethrough with a trigger wire guide concentric about the elongate catheter body extending along at least a portion of the elongate catheter body with the trigger wire guide comprising an enlarged proximal portion adjacent to the nose cone dilator with a distal portion of increasing diameter transition to the enlarged proximal portion having a maximum outer diameter less than the outer diameter of the enlarged proximal portion and three trigger wire lumens formed within the trigger wire guide with each lumen being separate from the guide wire lumen and extending at least partially within the trigger wire guide with at least three apertures in the trigger wire guide and with three trigger wires extending through the trigger wire guide with one trigger wire being at least partially disposed within each lumen and configured to exit the aperture to engage the prosthesis, a stent of the prosthesis, or a suture retaining the prosthesis and enter the same aperture to thereby retain a portion of the prosthesis adjacent to the trigger wire guide. 
     PCT Patent Publication No. WO 98/53761 entitled “A Prosthesis and a Method of Deploying a Prosthesis” discloses an introducer for a prosthesis which retains the prosthesis so that each end can be moved independently. These features and other features disclosed in PCT Patent Publication No. WO 98/53761 could be used with the present invention and the disclosure of PCT Patent Publication No. WO 98/53761 is herewith incorporated in its entirety into this specification. 
     PCT Patent Application Number PCT/US02/34348 entitled “Prostheses for Curved Lumens” discloses prostheses with arrangements for bending the prosthesis for placement into curved lumens. This feature and other features disclosed in PCT Patent Application No. PCT/US02/34348 could be used with the present invention and the disclosure of PCT Patent Application No. PCT/US02/34348 is herewith incorporated in its entirety into this specification. 
     Australian Provisional Patent Application No. PS3215 entitled “A Stent-Graft Fastening Arrangement” discloses arrangements for fastening stents onto grafts particularly for exposed stents. This feature and other features disclosed in Australian Provisional Patent Application Number No. PS3215 could be used with the present invention and the disclosure of Australian Provisional Patent Application Number No. PS3215 is herewith incorporated in its entirety into this specification. 
     Australian Provisional Patent Application No. PR9617 entitled “Improving Graft Adhesion” discloses arrangements on stent grafts for enhancing the adhesion of such stent grafts into walls of vessels in which they are deployed. This feature and other features disclosed in Australian Provisional Patent Application Number No. PR9617 could be used with the present invention and the disclosure of Australian Provisional Patent Application No. PR9617 is herewith incorporated in its entirety into this specification. 
     U.S. Pat. No. 5,387,235 entitled “Endovascular Transluminal Prosthesis For Repair Of Aneurysms” discloses apparatus and methods of retaining grafts onto deployment devices. These features and other features disclosed in U.S. Pat. No. 5,387,235 could be used with the present invention and the disclosure of U.S. Pat. No. 5,387,235 is herewith incorporated in its entirety into this specification. 
     U.S. Pat. No. 5,720,776 entitled “Stent Barb” discloses improved barbs with various forms of mechanical attachment to a stent. These features and other features disclosed in U.S. Pat. No. 5,720,776 could be used with the present invention and the disclosure of U.S. Pat. No. 5,720,776 is herewith incorporated in its entirety into this specification. 
     U.S. Pat. No. 6,206,931 entitled “Graft Prosthesis Materials” discloses graft prosthesis materials and a method for implanting, transplanting, replacing, and repairing a part of a patient and particularly the manufacture and use of a purified, collagen based matrix structure removed from a submucosa tissue source. These features and other features disclosed in U.S. Pat. No. 6,206,931 could be used with the present invention and the disclosure of U.S. Pat. No. 6,206,931 is herewith incorporated in its entirety into this specification. 
     Australian Provisional Patent Application No. PS3243 entitled “Thoracic Deployment Device” discloses introducer devices adapted for deployment of stent grafts particularly in the thoracic arch. This feature and other features disclosed in Australian Provisional Patent Application Number No. PS3243 could be used with the present invention and the disclosure of Australian Provisional Patent Application Number No. PS3243 is herewith incorporated in its entirety into this specification. 
     Australian Provisional Patent Application No. 2002950951 entitled “Asymmetric Stent Graft Attachment” discloses retention arrangements for retaining onto and releasing prostheses from introducer devices. This feature and other features disclosed in Australian Provisional Patent Application Number No. 2002950951 could be used with the present invention and the disclosure of Australian Provisional Patent Application Number No. 2002950951 is herewith incorporated in its entirety into this specification. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       This then generally describes the invention but to assist with understanding, reference will now be made to the accompanying drawings which show preferred embodiments of the invention. 
       In the drawings: 
         FIG. 1  shows a typical deployment device incorporating a trigger wire guide of the present invention in the ready to deploy state; 
         FIG. 2  shows the embodiment in  FIG. 1  with a prosthesis partially deployed; 
         FIG. 3  shows schematically the problem to which the present invention is directed; 
         FIG. 4  shows schematically how the problem is overcome by the use of a trigger wire guide according to one embodiment of the invention; 
         FIG. 5  shows a detail of part of the deployment device incorporating the trigger wire guide of one embodiment of the present invention; 
         FIG. 6  shows a transverse cross section of the guide along the line  6 - 6 ′ shown in  FIG. 5 ; 
         FIG. 7  shows a cross sectional view of a deployment device incorporating a trigger wire guide of the present invention retaining self expanding stents of a prosthesis; 
         FIG. 8  shows a similar view to  FIG. 7  but with a different method of retaining the self expanding stents of the prosthesis; 
         FIG. 9  shows a detail of part of a deployment device incorporating the trigger guide wire of an alternative embodiment of the present invention; 
         FIG. 10  shows a cross-sectional view of the embodiment shown at  FIG. 9  at the region  10 ,  10 ′,  10 ″; 
         FIG. 11  shows a cross-sectional view of the embodiment shown in  FIG. 9  at the region  11 ,  11 ′,  11 ″; 
         FIG. 12  shows a detail of part of a deployment device incorporating the trigger guide wire of a further alternative embodiment of the present invention; 
         FIG. 13  shows a cross sectional view of the embodiment shown in  FIG. 12 ; 
         FIG. 14  shows a detail of part of a deployment device incorporating the trigger guide wire of a further alternative embodiment of the present invention; and 
         FIG. 15  shows a cross sectional view of the embodiment shown in  FIG. 14 . 
     
    
    
     DETAILED DESCRIPTION OF THE DRAWINGS AND THE PRESENTLY PREFERRED EMBODIMENTS 
     Now looking more closely to the drawings and in particular the embodiment shown in  FIGS. 1 and 2 , there is shown a prosthesis deployment device upon which the trigger wire guide of the present invention may be used. 
     The prosthesis deployment device of this invention comprises a guide wire catheter  1  extending between a distal end  20  and a proximal end  22  of the deployment device. In use the distal end  20  is adapted to remain outside the body of a patient and the proximal end  22  with its nose cone dilator  3  is adapted in use to be inserted into the arteries of a patient such as for treatment of an aortic aneurism. For such a treatment the deployment device is inserted through an incision into the femoral artery and through the iliac arteries to the aorta. The deployment device is usually deployed over a guide wire (not shown). There is a recess  24  between the nose cone dilator  3  and catheter body  26 . The recess  24  is adapted to retain a prosthesis  19  in a compressed state with a sheath  28  extending from a sheath termination point  30  to the nose cone dilator  3  and assisting in holding the prosthesis in the compressed state. The hollow guide wire catheter  1  extends from a distal syringe attachment point  32  to the nose cone dilator so that manipulation of the guide wire catheter with respect to the catheter body  26  will move the nose cone dilator with respect to the catheter body. Manipulation can be either rotational or longitudinal movement. 
     A pin vice  34  at the distal end of the deployment catheter  26  locks the position of the guide wire catheter  1  with respect to the deployment catheter  26 . 
     The deployment catheter  26  is surrounded by the sheath  28  extending from the sheath termination point  30  on the deployment catheter forward to the nose cone dilator  3 . The sheath termination  30  includes a side tube  36  which has a hypodermic syringe attachment point (not shown) so that angiographic contrast fluids can be supplied into the sheath termination to travel between the sheath  28  and the catheter body  1 . 
     The hypodermic syringe attachment point  32  at the distal end of the guide wire catheter is adapted for the supply of contrast angiographic fluid through the guide wire catheter to the nose cone dilator where it is adapted to be ejected through ports  4  in the sides of the nose cone dilator  3 . 
     A trigger wire arrangement which incorporates three trigger wires  11  as will be discussed in relation to the embodiment shown in  FIG. 5 , for instance, extends from a trigger wire release mechanism  42  and then the trigger wires extend between the deployment catheter  26  and the guide wire catheter  1  and then through the recess  24  to the proximal end of the prosthesis  19 . After the guide wires exit from the lumen between the central catheter  26  and the guide wire catheter  1  into the recess  24  they enter the trigger wire guide  7  until they exit through the aperture  13  ( FIG. 5 ) thereby preventing fouling of the trigger wires with a prosthesis which is held retained by the sheath  28 . The trigger wire release mechanism  42  has a thumb screw  41  which can be rotated to release the release mechanism to enable withdrawal of the three trigger wires  11 . 
     Another trigger wire  14  is deployed between the guide wire catheter  1  and the catheter body  26  and extends from a trigger wire release mechanism  38  to the distal end of the prosthesis  19  where the distal end of the prosthesis  19  is retained to the trigger wire  14  by a mooring loop  18 . The trigger wire release mechanism  38  has thumb screw  40  which can be rotated to release the trigger wire retention mechanism to withdraw the distal trigger wire  14  and hence release the distal mooring loop  18  to free the distal end of the prosthesis  19 . 
     As shown in  FIG. 2  the sheath  28  has been withdrawn by moving the sheath termination point  30  towards the distal end  20  of the prosthesis deployment device until the prosthesis  19  has been fully deployed except that at the proximal end the stents  17  are still retained by the loop  15  of trigger wire  11  (see  FIG. 7 ). The distal component of the trigger wire release mechanism  38  and mooring loop  18  also retains the distal end of the prosthesis  19 . The proximal end can be deployed, when the nose cone dilator has been manipulated so that the graft is in the correct position, by removal of the trigger wire  11  by actuation of the proximal trigger wire release mechanism  42  and then subsequently the distal end of the prosthesis  19  can be released by removal of the trigger wire  14  by actuation of the trigger wire release mechanism  38 . For some situations it may be preferable to release the distal end of the stent graft before the proximal end and in such a situation the distal trigger wire release mechanism  38  and the proximal trigger wire release mechanism  42  would be mounted in the opposite order. 
       FIG. 3  shows schematically the problem to which the present invention is directed and  FIG. 4  shows schematically how the problem is overcome by the use of a trigger wire guide according to one embodiment of the invention. The prosthesis deployment device is shown in a more realistic configuration as it would be in a curved lumen of a patient such as the thoracic arch of the patient at the stage of deployment as shown in  FIG. 2 . 
     As shown in  FIG. 3 , without the trigger wire guide of the present invention, the trigger wire or wires  11  extend from the lumen between the guide wire catheter  1  and the deployment catheter body  26  to a proximal mooring loop  18  for the prosthesis  19 . The proximal mooring loop  18  retains the exposed stents  17  adjacent the nose cone dilator  3  in a retracted condition. The guide wire does not follow, however, the curve of the guide wire catheter  1  but goes in a more straight line and in doing so fouls with the wall  25  of the prosthesis  19  and can be more difficult to withdraw when required and in serious cases can tangle with stents associated with the prosthesis and jam or break. 
     The problem is solved as shown in  FIG. 4  with the use of a trigger wire guide  7  extending along that portion of the guide wire catheter  1  which is within the recess  24 . By this arrangement the trigger wire  11  cannot foul with the prosthesis  19 . 
     In  FIGS. 5 to 7  a part of the prosthesis deployment device is shown and includes the guide wire catheter  1  which extends the length of the deployment device and at the proximal end of the guide wire catheter  1  is the nose cone dilator  3 . 
     Extending back from the nose cone dilator  3  and surrounding the guide wire catheter  1  is a trigger wire guide  7 . The trigger wire guide  7  is coaxial with the guide wire catheter  1  and includes three lumens  9  through which, in use, pass trigger wires  11 . 
     Just distal of the nose cone dilator  3  there are apertures  13  in the trigger wire guide  7  extending into each lumen  9  and out of which aperture  13  extends the guide wire  11  in a loop  15  so that it can engage the zig zag stents  17  of a prosthesis  19  (see  FIG. 7 ). The trigger wire  11  continues along the lumen  9  to terminate within the region of the nose cone dilator  3 . When it is desired to release the stent  17 , the trigger wire  11  is pulled out as is discussed in relation to  FIGS. 1 and 2 . 
     The prosthesis is also shown in  FIG. 7 . In this embodiment the proximal stent  17  of the prosthesis  19  is a covered stent whereas in  FIG. 2  an uncovered proximal stent is shown. The principle of retention using the trigger wire  11  is the same however, except that in  FIG. 7 , the trigger wire  11  in its loop  15  passes through the graft material as well. 
     As an alternative to the use of the loop  15  to engage directly into the stent and graft material the arrangement as shown in  FIG. 8  can be used. In  FIG. 8  a piece of thread  16  such as a monofilament or woven suture material is used with a loop around the trigger wire  11 , the stent  17  and the graft material of the prosthesis  19  with a knot or a mooring loop  18 . The stent  17  and the graft material of the prosthesis  19  are released from the trigger wire  11  when the trigger wire is withdrawn. In such a situation the loop of thread  16  would stay attached to the stent  17  or the graft material of the prosthesis  19 . 
     In the embodiment shown in  FIGS. 9 ,  10  and  11 , it will be seen that a deployment device according to this embodiment includes a guide wire catheter  50  which extends along the length of the deployment device and at the proximal end of the guide wire catheter  50  is a nose cone dilator  52 . Extending back from the nose cone dilator and surrounding the guide wire catheter is a trigger wire guide generally shown as  54 . The trigger wire guide  54  is coaxial with the guide wire catheter  50  and includes an enlarged portion generally shown as  56  and a thinner tubular portion  58 . In the region of the tubular portion  58  there is an annular lumen between the guide wire catheter  50  and the tubular portion  58  through which the trigger wire or wires  11  pass. 
     In the region  56  adjacent the nose cone dilator  52  the trigger wires extend from a central annular lumen  62  which is continuous with the lumen  60  and then pass out through elongate apertures  64  in the form of a loop  66  and then continue on through the lumen  62 . The loop  66  is adapted to engage a stent or graft material of a prosthesis to hold the proximal end of the prosthesis in a retracted or constrained condition until it is desired to release it. Alternatively the trigger wire  1  can engage a suture tied to a stent of a prosthesis to hold it in a retracted or constrained condition until it is desired to release it. 
     When it is desired to release the prosthesis the trigger wire  11  is pulled out as was discussed in relation to  FIGS. 4 and 5 . 
     In this embodiment of the deployment device the tubular portion  58  extends back into the lumen  68  of the deployment catheter  70  so that no portion of the guide wire would be visible in the region of the deployment device into which the stent graft or prosthesis is received in use. 
       FIG. 12  shows a detail of part of a deployment device incorporating the trigger guide wire of a further alternative embodiment of the present invention and  FIG. 13  shows a cross sectional view of the embodiment shown in  FIG. 12 . 
     In this embodiment the guide wire catheter  80  of the deployment device has soldered or otherwise fastened along at least a part of its length an inverted V shape cross section component  82  which with the guide wire catheter defines a lumen  84  between them. In this case solder  83  is used to fasten the V shape cross section component  82  to the guide wire catheter. A trigger wire  85  can pass along the lumen  84  and exit in a loop  86  in the region  88  where the V shape cross section component  81  is not present. The loop  86  can engage a stent of a prosthesis to hold the stent until it is desired to release it or to engage a suture tied to a stent of a prosthesis. 
       FIG. 14  shows a detail of part of a deployment device incorporating the trigger guide wire of a further alternative embodiment of the present invention and  FIG. 15  shows a cross sectional view of the embodiment shown in  FIG. 14 . 
     In this embodiment the guide wire catheter  90  of the deployment device has a concentric metal tube  91  placed around it and crimped at points  92  and  93  to the guide wire catheter  90  to clamp it to the catheter and thereby with the guide wire catheter defining a lumen  94  for the passage of trigger wires. In this case there are three trigger wires but there could be only a single trigger wire or other configuration of trigger wires. The trigger wires  96  can pass along the lumen  94  and exit in loops  97  in the region  98  where there is a cut-out  99  in the crimped tube  91 . The loops  97  can engage a stent of a prosthesis to hold the stent until it is desired to release it or to engage a suture tied to a stent of a prosthesis. 
     Throughout this specification various indications have been given as to the scope of this invention but the invention is not limited to any one of these but may reside in two or more of these combined together. The examples are given for illustration only and not for limitation. 
     Throughout this specification unless the context requires otherwise the words comprise and include and variations such as comprising and including will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.