Abstract:
This invention is a hole closure device ( 100 ) having at least two blood vessel engaging structures ( 106 ), preferably spikes, each comprising a base ( 102 ), at least one second, deformable structure ( 112 ) coupled to said at least two blood vessel engaging structures ( 106 ), having a first deformation state, and a second deformation state; wherein said at least one second deformable structures ( 106 ) urges said two blood vessel engaging structures ( 106 ) towards each other when going from said deformation state to said second deformation state; wherein said change in deformation state is at least partially mechanically decoupled from each of said blood vessel engaging structures ( 106 ).

Description:
RELATED APPLICATIONS 
     This application is a national phase filing of PCT/IB00/00302, filed Mar. 20, 2000. This application is a continuation in part of PCT applications PCT/IL99/00284, filed May 30, 1999 now U.S. Ser. No. 09/701,531, filed Nov. 28, 2000 PCT/IL99/00285, filed May 30, 1999 now U.S. Ser. No. 09/701,523, filed Nov. 28, 2000 PCT/IL99/00670 filed Dec. 8, 1999 and PCT/IL99/00674, filed Dec. 9, 1999 the disclosures of which are incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to hole closure devices for blood vessels. 
     BACKGROUND OF THE INVENTION 
     Many medical procedures require forming holes in blood vessels. After the procedure is completed, the holes must be closed, to prevent a fatal hemorrhage. Typically, such holes are closed using sutures, or by applying pressure against the hole. 
     U.S. Pat. No. 5,938,425 to Janzen et al., the disclosure of which is incorporated herein by reference, suggests sealing a hole by providing a sealing material outside of the hole. 
     U.S. Pat. No. 5,964,782 to Lafontaine et al., the disclosure of which is incorporated herein by reference, describes a catheter having hooks at its ends for bringing the sides of a hole together, for sealing by pressure or by electro-coagulation. 
     SUMMARY OF THE INVENTION 
     It is an object of some preferred embodiments of the invention to provide an implanted device for sealing holes in a blood vessel, the device having a smaller chance of retraction of spikes, barbs or other tissue engagement elements of the device, from the blood vessel, than devices of the prior art. 
     An aspect of some preferred embodiments of the invention relates to mechanically decoupling the spikes of a hole closure device from a part of the device that controls the device general geometry. Thus, the deformation of the spikes does not affect the device geometry and vice-versa. In a preferred embodiment of the invention, this results in a separation between the forces that change the device geometry to close the hole and the forces that maintain the spikes in side the blood vessel. This separation is expected to prevent the geometric distortion of the device from inadvertently retracting the spikes form the blood vessel. 
     In a preferred embodiment of the invention, the decoupling is achieved by assuring that energy stored by the device for closing the hole in the blood vessel is not stored in the spikes or in structures that spring-load the spikes. Thus, release of the energy is less likely to affect the hold of the spikes on the vessels. In plastically deformed devices, the spikes are configured so that the plastic deformation does not affect the spikes or parts of the device that spring-load the spikes. 
     An aspect of some preferred embodiments of the invention relates to providing a pivot bar for vessel-engaging spikes of a hole closure device. Preferably, the pivot bar is not part of the load bearing structure of the device. A potential advantage of using a pivot bar is that a spike can be rotated around the pivot bar without bending the spike and without and protrusion from the plane of the device and/or the surface of the blood vessel. Preferably, the pivot bar defines at its ends or along its length hinges (or weakened points) for controlling the twisting of the bar relative to the rest of the device, however, this is not necessary. 
     An aspect of some preferred embodiments of the invention relates to spacing the spike used to engage the blood vessel away from a hole in the blood vessel. Preferably, this results in a lower probability of the spike inadvertently retracting from the blood vessel. 
     An aspect of some preferred embodiments of the invention relates to a hole-closure device design, in which two concentric structures are provided, an inner structure for controlling the device geometry and an outer structure for supporting spikes and/or other means of engaging the blood vessel. Optionally, the spikes are coupled to the inner structure only through tab means provided to bend the spikes out of plane. 
     An aspect of some preferred embodiments of the invention relates to providing a hinge in a hole closure device. In a preferred embodiment of the invention, when the device distorts to close a hole, the distortion is controlled by the hinge, for example, being focused at the hinge or being prevented at the hinge. Preferably, the hinge is integral with the device. Alternatively, the device is formed of two or more parts attached to each other by the hinge. In a preferred embodiment of the invention, the device is designed for sealing an elongate cut in a blood vessel, by deforming between a substantially round configuration to a substantially ellipsoid configuration. 
     In a preferred embodiment of the invention, a multiple part device is provided, with all of the multiple parts being outside of the blood vessel and, preferably, being substantially equivalent in function. 
     An aspect of some preferred embodiments of the invention relates to a bi-stable hole closure device. In a preferred embodiment of the invention, the device has at least two stable states, a first state in which the device defines an open lumen through which a catheter, cannula or other tube may be provided and a second state in which the lumen is significantly contracted or even closed. 
     An aspect of some preferred embodiments of the invention relates to an elastic clip for closing a hole in a blood vessel. In a preferred embodiment of the invention, the clip is maintained in an open configuration, suitable for engaging a blood vessel, by inserting a spacer in the clip. After engaging the blood vessel, the spacer is moved or removed, so the clip can close. Preferably, the closure is elastic, super elastic or shape-memory based. Alternatively, the closure may be plastic, as a result of the application of force. 
     There is thus provided in accordance with a preferred embodiment of the invention, a hole closure device, comprising: 
     at least two blood vessel engaging structures, each comprising a base; 
     at least one second, deformable, structure, coupled to said at least two blood-vessel engaging structures and having a first deformation state and a second deformation state, wherein said at least one second deformable structure urges said two blood vessel engaging structures towards each other when going from said first deformation state to said second deformation state, 
     wherein, said change in deformation state is at least partially mechanically decoupled from each of said blood-vessel engaging structures, such that it does not effect a substantial deformation of said blood-vessel engaging structure relative to said base. 
     Preferably, said at least one second deformable structure comprises a deformable ring-like structure, adapted to enclose a blood vessel cannula-like tube in said first deformation state. Preferably, the device comprises a ring-like element on which said at least one deformable structure is mounted and wherein said at least one second deformable structure comprises at least two bending elements that couple said blood-vessel engaging structures to said ring-like element. Preferably, said ring-like element defines a lumen that has a substantially same radius in said deformation states. Alternatively, said blood vessel engaging structures each comprise at least one spike adapted for insertion into a wall of a blood vessel. 
     In a preferred embodiment of the invention, said blood vessel engaging structures each comprise at least two spikes adapted for insertion into a wall of a blood vessel. Preferably, said blood vessel engaging structures each comprise a pivot bar on which said spike is mounted. 
     In a preferred embodiment of the invention, said blood vessel engaging structures each comprise at least one tab, mounted on said pivot bar. Preferably, said tab comprises an anchor for holding said tab. Alternatively or additionally, said pivot bar comprises a hinge at either end. 
     In a preferred embodiment of the invention, said pivot bar is straight. Alternatively or additionally, said pivot bar is mounted on a spacer that spaces said pivot bar from said at least one second deformable structure. 
     In a preferred embodiment of the invention, said base is adapted for abutment against the blood vessel. Preferably, said bases are spaced apart a distance sufficient to prevent eversion of a blood vessel in which a hole is closed. Alternatively, said bases are spaced apart a distance sufficient to cause at least partial eversion of a blood vessel in which a hole is closed. 
     In a preferred embodiment of the invention, said at least one second deformable structure comprises at least two deformable structures connected by at least one joint. Preferably, said joint is elastic. Alternatively or additionally, said joint comprises a segment of a circle. 
     Alternatively, said joint is free turning for at least a range of angles. 
     In a preferred embodiment of the invention, said joint is integral with said at least two deformable structures. 
     In a preferred embodiment of the invention, said joint is formed by an interlocking of the two deformable structures. 
     In a preferred embodiment of the invention, said at least one deformable structure comprises a bar. 
     In a preferred embodiment of the invention, at least one of said blood vessel engaging structures is radially external to said at least one deformable structure. Alternatively or additionally, at least one of said blood vessel engaging structures is radially internal to said at least one deformable structure. 
     There is also provided in accordance with a preferred embodiment of the invention, a hole closure device, comprising: 
     at least one pivot bar; 
     at least one spike mounted on said spike such that rotating said spike around said bar twists said pivot bar; and 
     a base to which said at least one bar is coupled and which base does not encompass said bar. Preferably, the device comprises at least one structure which supports said pivot bar and which couples said pivot bar to said base. 
     Alternatively or additionally, said base comprises a deformable ring-like element. Preferably, said base comprises at least two hinges at opposite ends of said base. 
     There is also provided in accordance with a preferred embodiment of the invention, a hole closure device, comprising: 
     a deformable ring-like structure; 
     a plurality of spikes coupled to said structure, each of said spike comprising a base; and 
     a coupling structure coupling said base to said ring-like structure, wherein said base is radially spaced from said ring-like structure by said coupling structure, at least the length of said spike. Preferably, said spikes are each mounted on a pivot bar. 
     There is also provided in accordance with a preferred embodiment of the invention, a hole closure device comprising: 
     a first body part comprising: 
     a plurality of blood-vessel engaging structures, adapted to remain outside a blood vessel; and 
     at least a first hinge part coupled to said plurality of blood vessel engaging structures; and 
     a second body part comprising: 
     a plurality of blood-vessel engaging structures adapted to remain outside a blood vessel; and 
     at least a second hinge part coupled to said plurality of blood vessel engaging structures, 
     wherein said first and said second hinge parts are adapted to interlock to form a hinge. 
     There is also provided in accordance with a preferred embodiment of the invention, a blood vessel clip, comprising: 
     at least two spikes; 
     at least one tab, perpendicular to at least one of said spikes; and 
     an elastic body connecting the two spikes, said body having a greater inner dimension away from said spike than nearer said spike. 
     There is also provided in accordance with a preferred embodiment of the invention, a bi-stable hole closure device, comprising: 
     at least two arms, coupled to each other at either end thereof, wherein: 
     a first one of said arms is less flexible than a second one of said arms, and wherein said second arm is adapted to have two stable states, one state in which the second arm is spaced from said first arm and one state in which said second arm is adjacent said first arm; and 
     a plurality of blood-vessel engaging elements mounted on each of said arms. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Particular embodiments of the invention will be described with reference to the following description of preferred embodiments in conjunction with the figures, wherein identical structures, elements or parts which appear in more than one figure are preferably labeled with a same or similar number in all the figures in which they appear, in which: 
     FIG. 1A is a plan view of a hole closure device in accordance with a preferred embodiment of the invention; 
     FIGS. 1B-1E illustrate the deployment of the device of FIG. 1, in accordance with a preferred embodiment of the invention; 
     FIG. 2A is a perspective view of a two part hole closure device, in accordance with a preferred embodiment of the invention; 
     FIGS. 2B and 2C show the device of FIG. 2A, during deployment, in accordance with a preferred embodiment of the invention; 
     FIGS. 3A-3C illustrate hole closure devices in accordance with preferred embodiments of the invention; 
     FIGS. 3D-3E illustrate a deployment of one of the devices of FIGS. 3A and 3B, in accordance with a preferred embodiment of the invention; 
     FIG. 3F illustrates an alternative, deployed, hole closure device in accordance with a preferred embodiment of the invention; 
     FIGS. 4A and 4B illustrate a blood vessel clip, in accordance with a preferred embodiment of the invention; and 
     FIGS. 5A and 5B illustrate a bi-stable hole closure device, in accordance with a preferred embodiment of the invention. 
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     FIG. 1A is a plan view of a hole closure device  100 , in accordance with a preferred embodiment of the invention. Device  100  comprises a body section  102  and a plurality of spike sections  106  attached to body section  102 . Although six such sections are shown, the number may vary depending on the use of the device, for example, being 2, 3, 4, 5, 7, 9 or more. In the exemplary device shown, body section  102  comprises two elongate elements  103 , attached together at their ends by hinges  104 . The design of hinges  104  is such that when device  100  is distorted for implantation to define a circular or elliptical lumen (See FIGS.  1 B- 1 C), a significant part of the distortion is concentrated at the hinges. 
     In the exemplary device shown, a spike section  106  comprises a pivot bar  108 , having a spike  110  mounted on one side and a tab  112  mounted on another side thereof. A spacing structure  114  spaces bar  108  from body section  102 . In an alternative device, the lumen of device  100  is defined by alternating ring segments and spike sections. Alternatively, the spike sections may be inside the ring segment, so they are not spaced away from the lumen of the device. 
     It should be noted that since tab  112  is coupled to bar  108 , it is not required that tab  112  be opposite spike  110  in order to control the positions of the spikes. Further, a plurality of spikes  110  and/or tabs  112  may be provided on each spike section  106 . Also, tab(s)  112  and spike(s)  110  do not all have to be in a same plane. Preferably, the tabs are not in a same plane as the spikes, so that when deployment is complete (FIG. 1E, below), the tabs can be flat with the surface of the blood vessel. Thus, the tabs may also be curved. 
     Although a straight bar is shown, the bar may be curved or angular. Thus, in some embodiments, the bar is radially expandable or can provide elastic force perpendicular to the bar, along the spike. 
     The spikes may be long or short (relative to the length of pivot bar  108  and the distance of bar  108  from body section  102 ). Although straight spikes are preferred, curved spikes, curved in either of the two directions perpendicular to the spike, may be used. As shown, bar  108  does not include designated twisting regions. Alternatively one or more such regions, which twist more or less than the rest of bar  108 , may be provided. In one example, a more easily twisting region is provided at each of the ends of bar  108 . Twisting areas may be, for example, thinner, narrower or include apertures. 
     FIGS. 1B-1E illustrate the deployment of device  100 , in accordance with a preferred embodiment of the invention. In FIG. 1B, device  100  is mounted on a cannula  122 , that pierces a blood vessel  120 . In a preferred embodiment of the invention, tabs  112  are held by a tab holding tube  126  against a contra-element tube  124 . Tab-holding tube  126  may include thinner portions  128  for defining a hollow between tube  126  and tube  124 , for the tabs. As spikes  110  are preferably pointed axially with the cannula, closure device  100  can be advanced along cannula  122  to engage blood vessel  120 , as shown. 
     FIG. 1C is a top view along the cannula axis, with the holding and contra tubes  124  and  126  not shown. Body section  102  of device  100  is shown distorted to define a lumen through which cannula  122  is provided. 
     FIG. 1D shows the effect of removing tab holding tube  126 , which allows the pivot bar  108  to partially twist back so that spikes  110  engage vessel  120  better. 
     In FIG. 1E, the cannula is removed, allowing body section  102  to revert to its previous geometry. Since spikes  110  are pulled along by body section  102  and engage vessel  120 , when body section  102  distorts back, the hole in vessel  120  is closed. 
     FIG. 2A is a perspective view of a multi-part hole closure device  200 , in accordance with a preferred embodiment of the invention. Device  200 , as shown, comprises only two parts  201  and  205 , however, a larger number of device segments could be provided as well, for example the device being formed of three or four links. Each of parts  201  and  205  comprises an elongate element  203  and a plurality of spike sections  206 , corresponding to the same parts in FIG.  1 C. Parts  201  and  205  have, at the ends of elements  203 , hinge parts, for example an eye  216  on part  201  and a hook  218  on part  205 . Hook  218  and eye  216  engage to form a hinge. Other interlocking element types may also be used. Alternative types of joints may be provided, for example crimp joints that are formed by crimping the hinge parts together or by deforming one or both of the hinge parts. It is noted that unlike hinge  104  of device  100 , the hinge of device  200  does not necessarily (although it may) store any elastic energy when the device is distorted. Rather, any such energy is preferably stored by bending body elements  203 . 
     FIG. 2B shows device  200  on a cannula  122 . The mounting method can be exactly the same as that of FIG.  1 B. 
     FIG. 2C is a top view along the cannula axis, with the holding and contra tubes  124  and  126  not shown. This figure is also very similar to FIG. 1C, with an important difference, a hinge  220  is provided by the interlocking of eye  216  and hook  218 . 
     FIGS. 3A-3C illustrate hole closure devices in accordance with preferred embodiments of the invention. 
     FIG. 3A illustrates a device  300 , in which a plurality of spikes  302  are defined to be outside of a structural ring  304  of the device. In some embodiments of the invention, ring  304  does not distort during deployment. A pair of tabs  306  are provided, each tab associated with two of spikes  302 , such that when the tabs are bent, the spikes also twist with them. Preferably, a bending strip  310  is provided as a hinge between tab  306  and ring  304 . It is noted that spikes  302  are coupled to ring  304  only via tab(s)  306 , so that they are substantially decoupled from ring  304 . Tab  306  may include an anchor, such as a hole  308 , for engagement during deployment. Spikes  302  preferably comprise a base portion  303  that is substantially wider than the spike. 
     FIG. 3B illustrates a device  320  which is a variant of device  300 , in which an inner ring  321  extends to the ends of device  320  and takes over the function of holes  308  and/or bending strip  310 . Tabs  326  are significantly shorter than tabs  306 . 
     FIG. 3C illustrates a simpler device  330 , in which a plurality of spikes  334  are mounted on a ring  332 . As shown, spikes  334  are wide at their base, preventing the spikes themselves from bending, when ring  332  is twisted. A particular feature of this device (and some of the previous devices) is that a lumen remains in the device even after the hole is closed. This lumen is useful if an attempt is made to insert a cannula again into the vessel, at the device location. The cannula would be able to enter through the lumen, without damaging the blood vessel. 
     FIGS. 3D-3E illustrate a deployment of one of devices  300 ,  320  or  330 , in accordance with a preferred embodiment of the invention. For description purposes, device  300  is assumed, however, all the devices may be similarly deployed. As in FIGS. 1B and 2B, a catheter  422  is inserted through ring  304  (catheter shown here with a guide wire  423 ). Tabs  306  are held in place between a tab holding tube  426  and a contra-element tube  424 . The bending of bending element  310  is preferably supported by a curved portion  427  of contra-element tube  424 . In this configuration, spikes  302  are pointed straight ahead and can easily engage vessel  120 . 
     In FIG. 3E, which shows a cross-section of vessel  120 , contra-element  426  is removed, releasing tabs  306 . Base portions  303  (FIG. 3A) therefore urge the spike-engaged lips of vessel  120  against each other. It is noted that in device  300  of FIG. 3A, these events (releasing and radial contraction) will occur even if catheter  422  is not removed. Once catheter  422  is removed, the lips of the hole in vessel  120  will be pressed against each other and prevent leakage. This mechanism may not be suitable for all blood vessels, for example being suitable for veins and the femoral artery, but not for the aorta in situations when a radial hole closure is desired. 
     It should be noted that whether or not the lips of vessel  120  are everted by device  300  can be controlled, for example, by extending spikes  302 (e.g., spacing apart base portions  303 ), eversion can be avoided. 
     It should also be noted that spikes  302  can be designed to penetrate vessel  102  to greater than the vessel wall thickness. Possibly, the spikes are made jagged at their edges, to allow them to engage both lips of the blood vessel, when deployed. 
     In device  300 , the energy required to distort device  300  to seal the hole in vessel  120  is stored in bending element  310  and, possibly to some extent in ring  304 . In contrast, in device  320 , the energy is stored in ring  321 . 
     FIG. 3F illustrates an alternative hole closing device  340 , similar to device  330 , as deployed on vessel  120 . Device  340  comprises a pair of tabs  346 , possibly including holes  348  and a plurality of spikes  342  (only their base is shown). Unlike device  330  of FIG. 3C, and similar to devices  300  and  320 , the spikes do not exactly face each others in pairs, allowing the spikes to be longer than half the distance between the spike bases. This also allows the spike bases to be close together, to promote eversion. 
     FIGS. 4A and 4B illustrate a blood vessel clip  430 , in accordance with a preferred embodiment of the invention. Clip  430  comprises a pair of spikes  432  coupled together by a body  431 . A pair of tabs  434  is provided. Preferably, tabs  434  act as tissue stops to prevent over insertion of spikes  432  in vessel  120 . Alternatively or additionally, tabs  434  act as anchor points which can be used to hold clip  430  and/or advance it. 
     In FIG. 4A, a spacer element  436  is provided inside clip  430 . Preferably, a contour  438  is provided in clip  430  to hold spacer element  436 , however this is not essential. Clip  430  is then advanced into vessel  120 , with one spike on either side of the opening in the vessel. Elastic energy for closing of the clip is preferably stored in body  431 . 
     In FIG. 4B, spacer element  436  is retracted to a more spacious part  440  of body  431 , allowing the spikes to move towards each other and close the hole in the blood vessel. After a short time, the clip may be removed. Alternatively, it is left in the body. 
     Alternatively to spacious part  440  being in the same plane as spikes  432 , part  440  may be at an angle, or even perpendicular to the plane of spikes  432 . Alternatively, no body part  440  is provided. Instead the spring action of body part  440  is provided by a flat spring. Although only two spike  432  are shown, a larger number, such as three or four may be provided, spaced apart along a line perpendicular to the figure plane. Alternatively to a body  431 , these spikes may be mounted on a pivot bar. 
     Spacer element  436  is preferably removed by moving it perpendicular to the spike. Preferably spacer element  436  is a perpendicular protrusion on an elongate delivery tool. 
     FIGS. 5A and 5B illustrate a bi-stable hole closure device  500 , in accordance with a preferred embodiment of the invention. 
     FIG. 5A shows device  500  in an open configuration, a thick arm  540  and a thin arm  502  defining a lumen, into which project a plurality of spikes  506 . In FIG. 5B, thin arm  502  is distorted to be concave, rather than convex, so that it substantially conforms to the curve of arm  504 , rather than mirroring it. Spikes  506  are embedded in a vessel  120 , so they are not shown. Various bi-stable mechanisms, which may be suitable, are described in PCT publication WO98/32412, the disclosure of which is incorporated herein by reference. 
     The above devices are preferably formed of stainless steel or a titanium alloy and use elastic, super elastic and/or shape-memory properties to distort when cannula  122  or other constraint is removed. Alternatively, the devices may be formed of a plastic material, especially a bio-absorbable material. Alternatively or additionally, the devices utilize a plastic deformation, for example deformation by an externally applied force. 
     The above devices can be adapted to a wide variety of blood vessels and/or other hollow body lumens, such as ducts, intestines, esophagus and trachea. It is noted however, that the devices of FIGS. 1 and 2 are better suited for an aorta, while the devices of FIGS. 3 and 5 are better suited for a femoral artery. The device of FIG. 4 is better suited for veins, where the pressure is lower. In a preferred embodiment of the invention, the hole closure devices are provided mounted on standard cannulas and catheters. 
     It will be appreciated that the above described methods of applying a vascular port and sealing a hole may be varied in many ways, including, changing the order of steps and the methods of distortion used. In addition, a multiplicity of various features, both of method and of devices have been described. It should be appreciated that different features may be combined in different ways. In particular, not all the features shown above in a particular embodiment are necessary in every similar preferred embodiment of the invention. Further, combinations of the above features are also considered to be within the scope of some preferred embodiments of the invention. Also within the scope of the invention are surgical kits which include sets of medical devices suitable for making a single or a small number of ports or sealing holes of various sizes. When used in the following claims, the terms “comprises”, “includes”, “have” and their conjugates mean “including but not limited to”. 
     It will be appreciated by a person skilled in the art that the present invention is not limited by what has thus far been described. Rather, the scope of the present invention is limited only by the following claims.