Abstract:
A guiding tool for controllable and reversible folding or deformation of a wound closure element before insertion into a percutaneous incision or puncture in the wall of e.g. a blood vessel, said incision or puncture being smaller than said wound closure element in an unfolded or undeformed state. It comprises a tubular member having a lumen. The lumen has inner walls provided with wound closure element guiding surfaces, adapted to reversibly reduce the spatial extension of a wound closure element during its passage through the guiding tool. A system for the introduction and securing of a wound closure element into a percutaneous incision or puncture in the wall of a vessel comprises such a guiding tool.

Description:
[0001]    The present invention relates generally to sealing of a percutaneous incision or puncture in the wall of a vessel, duct, lumen or hollow organ in the body of a living being, by positioning a sealing device in said incision or puncture, where the incision or puncture is smaller than said sealing device. In particular the invention relates to a guiding tool for enabling the correct positioning of such a sealing device, ensuring a leak-proof sealing.  
         BACKGROUND OF THE INVENTION  
         [0002]    In recent years a number of devices and apparatuses have been developed enabling the closure or occlusion of e.g. punctures in the femoral artery following catheterization. Instead of applying a pressure to the puncture site for a period of time sufficient for blood clot formation to occur, the new methods are e.g. based on providing a plug, commonly referred to as an “artery plug”, in the puncture. The plug is made of a resorbable material, such that it can be left in place until the tissue has recovered properly and the wound or puncture is healed. The plug can be made of collagen, and applied to the outside of a vessel against a counteracting element, also made of a resorbable material, introduced into the interior of the vessel. A locking means secures the collagen plug in place. A device of this kind is disclosed in U.S. Pat. No. 5,935,147 (Kensey et al). The sealing action is thus performed by the externally applied collagen plug. However, a certain percentage of applied plugs will not be leak-proof and often further compression by other devices or manually must be applied.  
           [0003]    Alternatively, a plug can be made of two members such that a first member is positioned within a vessel and acts as the occluding member, and a second member is positioned outside the vessel and locked to the first member by a locking means. In order to ensure leak-proof action, the first member is larger than the puncture in all directions, i.e. it will cover a surface larger than the area of the puncture. In order to make this possible, the first member is foldable. A device of this kind is disclosed in our own EP-application EP-00850184.3 (corresponding to U.S. patent application Ser. No. 09/704,726).  
           [0004]    The problem facing all systems wherein a folding or deformation of an element is needed in order to introduce the element into a vessel or through any tissue wherein the hole is smaller than the element itself, is that it can be difficult to achieve a reproducible unfolding, that accurately seals the hole from the inside. Also, in many cases the closure element is provided inside an introducer member such as a tube, in a folded state, already at the time of manufacture of the kit comprising all components. If the kit is stored for extended periods of time, and even for shorter times, the folded closure element most likely does not unfold properly at the time of use. To avoid the risk of permanent deformation, the closure element could be inserted into the introducer device by the physician, but this would require an extra manipulation, and it might be very difficult to maintain the sterility of the devices in such a case.  
         SUMMARY OF THE INVENTION  
         [0005]    Thus, in view of the problem with the prior art devices, it is the object of the present invention to improve the rate of successful sealing operations using wound closure devices, when foldable or deformable closure elements are introduced into a vessel through a hole, smaller than the element itself, and to enable the folding and unfolding operation to take place during the sealing operation, and to avoid manipulation of the closure element by the physician at the time of performing the sealing operation.  
           [0006]    This object is achieved by the provision of a guiding tool which in a controlled manner deforms or folds a wound closure element such that it after having been introduced through a puncture, unfolds and regains its original shape in a reproducible and controllable manner, and thereby provides adequate sealing at an excellent rate of success, this procedure taking place at the time of performing the sealing operation. The guiding tool according to the invention is defined in claim 1. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0007]    [0007]FIGS. 1 a - c  is a schematic illustration of a system for wound closure during operation thereof;  
         [0008]    [0008]FIG. 2 a  illustrates a first embodiment of the guiding tool of the invention in cross section;  
         [0009]    [0009]FIG. 2 b  is a view in longitudinal cross section of a second embodiment of the inventive guiding tool;  
         [0010]    [0010]FIG. 2 c  illustrates cross sections at A-E in FIG. 2 b;    
         [0011]    [0011]FIG. 2 d  is a perspective cut view in two different directions of a third preferred embodiment of the inventive guiding tool;  
         [0012]    [0012]FIG. 3 a  is a cross section view of a closure element; and  
         [0013]    [0013]FIG. 3 b  is a top view of a closure element. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0014]    [0014]FIGS. 1 a - c  illustrates the procedure of inserting a wound closure (occlusion) element  2  in a blood vessel  4  and clamping it by means of a locking member  6 . Thereby, an incision  8  is made in the blood vessel  4  in question, and an introducer tube  10  is inserted into the vessel  4 , see FIG. 1 a . Then, a folded, or in some other manner deformed closure element  2  is passed through said introducer tube  10  and into the vessel  4 . The closure element  2  is secured to e.g. a suture  12 , and some rigid elongated element  14  such as a steel pin or pusher rod (not shown) can be used to guide the closure element  2  through the tube  10  and into the vessel  4 , where it unfolds. Once the closure element  2  has unfolded inside the vessel  4 , the pusher rod and the introducer tube  10  are withdrawn from the vessel but maintained close to the exterior of the vessel  4 . Then, the closure element  2  is pulled back using the suture  12 , so as to be located in a position where it is held against the interior vessel wall  16 , FIG. 1 b . An essentially disk shaped locking element  18 , having a central hole, is provided on the suture  12 , the suture running through said hole, such that the locking member can be moved along the suture  12  to be brought into contact with the exterior vessel wall  20 . By the provision of suitable friction enhancing means  19  on the very distal end of the suture, the locking element can be pushed against the wall of the vessel while engaging the portion of the suture having higher friction, and thereby cause a locking of the closure element, FIG. 1 c . This principle is used in e.g. U.S. Pat. No. 5,916,236.  
         [0015]    It is important that the closure element unfolds in a reproducible way, such that it will contact the inner vessel wall around the circumference of the incision. If the closure element is delivered to the user in a folded state, in position inside the introducer, as a “kit” ready for use by a physician, and the kit has been stored on a shelf for some time, it may happen that the closure element has become permanently deformed, and will not assume the desired shape (which may be to regain its original shape) inside the vessel. Such an event would of course dramatically increase the risk that the closure element will not fulfill its function, and cause a leakage.  
         [0016]    Therefore, in accordance with the present invention, there is provided a guiding tool that is connectable to an introducer of the type discussed above, the closure element being provided in said guiding tool in an unfolded state. Thereby the actual deformation or folding of the closure element, necessary to enable insertion through the incision (which is smaller than the closure element) and into the blood vessel, is not performed until the time of performing the operation of inserting the closure element. In this way, the closure element will not be subjected to a prolonged deformation during storage.  
         [0017]    A first embodiment of the invention is illustrated in FIG. 2 a . It comprises a body in the shown embodiment in the form of an elongated tube like member  20  (although cylindrical outer symmetry is no requirement), having an inner lumen  22  that has a first diameter in the proximal end portion  24  and over a fraction of its length (up to the dotted line X), forming a space  26  in which an closure element (not shown) can be housed without being deformed. Over a second fraction of the length, from the dotted line X and up to the distal end  26  portion, the lumen becomes narrower, rendering the 22 lumen cone shaped over this portion. Finally there is a connection portion  28 , connectable to an introducer tube (such as the tube  10  in FIG. 1 a ). The exit diameter is equal to or slightly smaller than the inner diameter of the introducerbe, i.e. small enough to enable passing the closure element into the blood vessel.  
         [0018]    In FIG. 2 b  a second embodiment of the guiding tool according to the present invention is illustrated. It is adapted for a closure element  30  having the general shape shown in FIGS. 3 a  and  3   b . The closure element suitable for use with the illustrated embodiment of the guiding tool, has a thick mid portion  32 , that is generally elongated, and has peripheral wings  34  or edges, which are substantially thinner, and thus more flexible than the mid portion  32 . The peripheral shape is like a slightly distorted ellipse, but could in principle be circular, the wings  34  thereby forming rather a collar or a brim surrounding the mid portion. Other shapes are also possible. A suitable kind of closure element is disclosed and claimed in our copending EP-00850184.3. In view of its flexibility, the wings  34  or rim are foldable such that the entire element will have a smallest dimension in a folded state that fits well within an incision or puncture in a blood vessel, thereby enabling insertion into said vessel.  
         [0019]    Thus, the embodiment of the guiding tool according to the present invention shown in FIG. 2 b , comprises an essentially tubular element  42  having a proximal end  44  and a distal end  46  and a lumen  48  extending between said distal  46  end and said proximal end  44 . There is further a wound closure element introduction opening  50  in the proximal end  44 , and a wound closure element exit opening  52  in the distal end  46 . The distal end is shaped so as to be connectable to an introducer tube, like the one described above in connection with FIG. 1.  
         [0020]    The lumen  48  has inner walls  54  provided with wound closure element deformation surfaces  56 , adapted to deform a wound closure element during passage thereof, past said surfaces  56 , through the guiding tool, from an essentially undeformed or unfolded state to a deformed or folded state. The effect of this deformation/folding should be such that the overall dimension of the wound closure element is changed to render it capable of passing through the puncture in the blood vessel. Also, after passage through said incision or puncture it must regain a shape that is capable of providing a sealing action against the inner wall of the vessel.  
         [0021]    In FIG. 2 b  there is also shown a pusher rod  51 , having a fork like configuration, that is used to push the closure element  30  through the introducer and into the blood vessel. This pusher rod is retracted once the element is properly located inside the vessel.  
         [0022]    In the embodiment shown in FIG. 2 b  the deformation surfaces  56  have a specific design, illustrated by a sequence in FIG. 2 c , which are cross section views through the lumen at the positions indicated with corresponding letters A, B, C, D, E in FIG. 2 b . Thus, there is one guiding surface  58  for each wing on the closure element  30 , and a guiding recess  60  in which the thicker mid portion  32  of the closure element  30  will run during its passage through the guiding tool. The guiding surfaces will initially have an orientation such that the wings  34  of the unfolded or undeformed closure element  30 , when inserted into the guiding tool in the introduction opening, will rest thereon in a position and orientation causing no deformation (referred to as a “horizontal” orientation; position A in FIG. 2 c ). Thereby the nominal shape of the closure element  30  is preserved also during extended storage. In a direction towards the exit opening, the guiding surfaces will gradually become elevated (A-B-C-D-E in FIG. 2 c ) from the initial, essentially horizontal orientation, and also curved such that they form what could be referred to as a “quasi-conical” lumen inside the tool. At the end of the lumen, near the exit opening, the guiding surfaces will have reached a state where the cross section of the lumen is essentially circular, and where the diameter corresponds to the inner diameter of the introducer tube.  
         [0023]    Preferably, there are guiding rails  62  provided above the guiding surfaces  58 , such that the wings or rims  34  of the closure element  30  will be kept down during the process of pushing it with the pusher rod through the guiding tool, thereby preventing inadvertent tilting or incorrect behavior of the closure element during the movement through said guiding tool. The rails are preferably integrated in the “roof” of the lumen. However, they can also be provided as an insert and attached by suitable means inside the lumen.  
         [0024]    In a further variation of the above described embodiment, the interior lumen of the guiding tool essentially has a cross section that exactly corresponds to the cross section of the closure element. This lumen would then form a guiding slot inside the tool, whereby the slot would be shaped so as to gradually change from a cross section corresponding to the above mentioned “horizontal orientation” to an essentially circular cross section, the diameter of which would be smaller than the incision through which the closure element is to be inserted. There must however be a space above the closure element for the access by the pushing rod needed for advancing the closure element through the tool and the introducer.  
         [0025]    The sequence A-E in FIG. 2 c  illustrates the folding process, and it is clearly seen that the closure element reaches a folded state where it conforms to the circular cross section of the introducer tube, which is connected to the guiding tool at the exit end thereof.  
         [0026]    Another embodiment of the guiding tool is shown in FIG. 2 d , showing perspective cuts through the device at two orientations perpendicular to each other. Like reference numerals are used for like elements in FIGS. 2 c  and  2   d . Like in the above described embodiment, this embodiment of the guiding tool comprises an essentially tubular element  42  having a proximal end  44  and a distal end  46  and a lumen  48  extending between said distal  46  end and said proximal end  44 . There is further a wound closure element introduction opening  50  in the proximal end  44 , and a wound closure element exit opening  52  in the distal end  46 . The distal end is shaped so as to be connectable to an introducer tube.  
         [0027]    Also in this embodiment, the lumen  48  has inner walls  54  also provided with wound closure element deformation surfaces  56 , adapted to deform a wound closure element during passage thereof, past said surfaces  56 , through the guiding tool, from an essentially undeformed state to a deformed state.  
         [0028]    However, the deformation surfaces have a different design in this embodiment. Namely, one wall of the inner lumen is flat such that the closure element can be placed essentially flat thereon, in an unfolded state, e.g. during shelf storage, corresponding to the “horizontal orientation” discussed above in connection with FIG. 2 b , but with the thicker mid portion facing upwards. Towards the exit opening the lumen is shaped as cone, much like in the first embodiment of FIG. 2 a , whereby the final diameter of the inner lumen corresponds to a diameter smaller than the diameter of the opening in the blood vessel through which the closure element is to be introduced. About half-way along the conical portion of the lumen, there are provided a pair of deflection surfaces  64 , having a “steeper” angle than the over-all cone angle of the lumen. These surfaces will engage the peripheral rim or collar portions of the closure element, such that they are deflected or bent downwards from the essentially flat initial position. Also, the pusher rod discussed above will cause the closure element not to lie completely flat, but slightly angled with the trailing edge at a slightly elevated position compared to the leading edge. Furthermore, said pusher rod will assist in keeping the leading edge forced against the flat surface.  
         [0029]    In order to facilitate correct positioning of the closure element during insertion, also in this case there may be provided guiding rails like those described above.  
         [0030]    The invention having been described with reference to preferred embodiments thereof can be subject to alterations and modifications by the man skilled in the art, and the scope of the invention is limited only by the appended claims.