Abstract:
Flow control elements can be injectably delivered through a needle (e.g., a fine hypodermic needle) or other tube and deployed into a blood vessel, percutaneously or laparoscopically, to effect the directional blood flow within the vessel. The valve (or other blood flow or occlusion control element) is delivered from outside the blood vessel directly to the chosen site within the blood vessel. The flow control elements are minimally invasive, reducing pain, discomfort and risk to the patient, while reducing the time the procedure takes to perform. In addition, the accuracy of deployment of the valve or other flow control element can be very precisely controlled.

Description:
REFERENCE TO PENDING PRIOR PATENT APPLICATION 
       [0001]    This patent application:
       (i) is a continuation-in-part of pending prior U.S. patent application Ser. No. 13/857,424, filed Apr. 5, 2013 by Arnold Miller et al. for METHOD AND APPARATUS FOR OCCLUDING A BLOOD VESSEL (Attorney&#39;s Docket No. AM-9), which patent application is (a) a continuation-in-part of prior U.S. patent application Ser. No. 13/348,416, filed Jan. 11, 2012 by Arnold Miller et al. for METHOD AND APPARATUS FOR TREATING VARICOSE VEINS (Attorney&#39;s Docket No. AM-0708), which patent application claims benefit of prior U.S. Provisional patent application Ser. No. 61/431,609, filed Jan. 11, 2011 by Arnold Miller for METHOD AND APPARATUS FOR TREATING VARICOSE VEINS (Attorney&#39;s Docket No. AM-7 PROV), and (b) claims benefit of prior U.S. Provisional Patent Application Ser. No. 61/620,787, filed Apr. 5, 2012 by Arnold Miller et al. for TEMPORARY ARTERIAL OCCLUSION FOR MILITARY AND CIVILIAN EXTREMITY TRAUMA (Attorney&#39;s Docket No. AM-9 PROV); and   (ii) claims benefit of pending prior U.S. Provisional Patent Application Ser. No. 61/643,092, filed May 4, 2012 by Raanan A. Miller et al. for INJECTABLE VALVE AND OTHER FLOW CONTROL ELEMENTS (Attorney&#39;s Docket No. AM-10 PROV), which patent application is hereby incorporated herein by reference.       
 
         [0004]    The five (5) above-identified patent applications are hereby incorporated herein by reference. 
     
    
     FIELD OF THE INVENTION 
       [0005]    This invention relates to surgical methods and apparatus in general, and more particularly to surgical methods and apparatus for treating blood vessels and other tubular structures. 
       BACKGROUND OF THE INVENTION 
       [0006]    Chronic venous disease is an extremely common disease in the general population. The most common cause of the disease is the development of venous valvular incompetence in the deep veins of the lower extremities. Not all of the causes of this valvular incompetence are known, but the development of clots within the veins (i.e., deep vein thrombosis) is one of the most common recognizable causes of valvular incompetence. The causes of deep vein thrombosis may be local within the veins themselves, such as trauma to a particular vein or slowing of the blood flow in these veins from lack or mobility (e.g., such as occurs during a long airplane flight), or systemic problems related to the blood coagulation, etc. 
         [0007]    These clots organize around the valves in the vein which are necessary for directing the flow of blood from the extremities to the heart, and destroy these valves. Over time (e.g., months to years), the clot obstructing the veins may recanalize, thereby allowing renewed blood flow. Venous flow in the lower extremities is controlled by muscular contraction. The combination of obstruction of the veins of the lower extremities, and valvular incompetence, results in the generation of high venous pressures within the lower extremities which, over time, results in the condition of chronic venous disease with swelling, pigmentation, ulceration, infection and progressive disability. 
         [0008]    The closer the incompetent valve is to the heart, the more severe the clinical consequences. Currently, treatment measures are aimed at alleviating the consequences of the high venous pressures, e.g., with leg elevation and/or compression stockings. 
         [0009]    Because of technical challenges, attempts to replace (or repair) the incompetent venous valves surgically and by utilizing catheter-directed techniques remain in the research domain and have not yet achieved clinical acceptance. 
       SUMMARY OF THE INVENTION 
       [0010]    In one embodiment of the present invention, the clinical need is addressed with a device that provides a simplified method of placing a competent valve through a needle (e.g., a fine hypodermic needle) or other tube to within any incompetent vein, as diagnosed with modern imaging techniques, e.g., ultrasound or fluoroscopy. While replacement valves delivered through a blood vessel are potentially most useful in the venous system, they can also be deployed throughout the vascular and organ systems of the body. 
         [0011]    The present invention relates to various flow control elements that can be injectably delivered through a needle (e.g., a fine hypodermic needle) or other tube and deployed into a blood vessel, percutaneously or laparoscopically, whereby to effect the directional blood flow within the vessel. The valve (or other blood flow or occlusion control element) is delivered from outside the blood vessel directly to the chosen site within the blood vessel. 
         [0012]    The present invention is designed to be minimally invasive, reducing pain, discomfort and risk to the patient, while reducing the time the procedure takes to perform. In addition, the accuracy of deployment of the valve or other flow control element can be very precisely controlled. The procedure is performed with external imaging including, but not limited to, ultrasound, fluoroscopy and/or other visualization methods. The present invention does not require the use of tumescent anesthetic. 
         [0013]    In one preferred form of the invention, an injectable valve is positioned within the blood vessel. Once deployed within the blood vessel, the valve allows the blood to flow in one direction only, restricting blood flow in the reverse direction. Unique aspects of this valve include the way the valve is delivered and inserted into a blood vessel. 
         [0014]    In other preferred forms of the invention, other flow control elements may be injected within the blood vessel, e.g., a filter, an occluder, a balloon, a polymer occluder, a transvascular screw, a transvascular clamp, etc. 
         [0015]    In another preferred form of the invention, the injectable valve (or other flow control device) may be percutaneously or laparoscopically delivered to an artery through a needle (e.g., a fine hypodermic needle) or other tube, e.g., so as to replace a defective aortic valve. 
         [0016]    In yet another preferred form of the invention, the injectable valve (or other flow control device) may be cleared of thrombus periodically (or as needed) via an anti-coagulant coating, or via a thrombolytic agent deposited on the flow control device, or via the delivery of an anticoagulant compound or thrombolytic agent which is delivered externally to the vessel, but which flows through a channel or channels in the support frame of the flow control device and is delivered proximate to the flow control device. It should be appreciated that the anti-coagulant compound or thrombolytic agent may be replaced by other drugs for treating specific conditions associated with the vessel, organ or patient, e.g., to reduce pain or inflammation, or to deliver chemotherapeutic drugs, etc. 
         [0017]    In one preferred form of the invention, there is provided apparatus for controlling flow through a body lumen, the apparatus comprising:
       an injectable flow control device for disposition within the body lumen, the injectable flow control device comprising:
           a resilient frame for seating against the inside wall of the body lumen and compressible for disposition within a tube for delivery through the side wall of the body lumen to the interior of the body lumen, the resilient frame having an opening therein; and   a flow restrictor in contact with the resilient frame for restricting flow through the opening of the resilient frame.   
               
 
         [0021]    In another preferred form of the invention, there is provided apparatus for controlling flow through a body lumen, the apparatus comprising:
       an injectable flow control device for disposition within the body lumen, the injectable flow control device comprising:
           a balloon for seating against the inside wall of the body lumen and compressible for disposition within a tube for delivery through the side wall of the body lumen to the interior of the body lumen.   
               
 
         [0024]    In another preferred form of the invention, there is provided apparatus for controlling flow through a body lumen, the apparatus comprising:
       an injectable flow control device for disposition within the body lumen, the injectable flow control device comprising:
           a flowable material for solidifying against the inside wall of the body lumen, wherein at least one portion of the solidified material extends through the side wall of the body lumen, whereby to secure the solidified material in the body lumen.   
               
 
         [0027]    In another preferred form of the invention, there is provided a method for controlling flow through a body lumen, the method comprising:
       advancing a tube through the side wall of a body lumen; and   positioning an injectable flow control device within the body lumen, the injectable flow control device controlling flow through a body lumen.       
 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0030]    These and other objects and features of the present invention will be more fully disclosed or rendered obvious by the following detailed description of the preferred embodiments of the invention, which is to be considered together with the accompanying drawings wherein like numbers refer to like parts, and further wherein: 
           [0031]      FIGS. 1 and 2  are schematic views showing a novel valve formed in accordance with the present invention; 
           [0032]      FIGS. 3 and 4  are schematic views showing another novel valve formed in accordance with the present invention; 
           [0033]      FIG. 5  is a schematic view showing the novel valve of  FIGS. 1 and 2  disposed across a blood vessel; 
           [0034]      FIG. 6  is a schematic view showing another form of novel valve disposed across a blood vessel; 
           [0035]      FIGS. 7-15  are schematic views showing the novel valve of  FIGS. 1 and 2  being deployed across a blood vessel; 
           [0036]      FIG. 16  is a schematic view showing another form of novel valve formed in accordance with the present invention; 
           [0037]      FIG. 17  is a schematic view showing another form of novel valve formed in accordance with the present invention; 
           [0038]      FIG. 18  is a schematic view showing a novel filter formed in accordance with the present invention; 
           [0039]      FIGS. 19 and 20  are schematic views showing a novel occluder formed in accordance with the present invention; 
           [0040]      FIGS. 21-23  are schematic views showing a flow control device disposed across a blood vessel which can deliver fluidic compounds around the flow control device, whereby to prevent thrombus build-up around the flow control device; 
           [0041]      FIGS. 24 and 25  are schematic views showing another novel valve or occluder formed in accordance with the present invention; 
           [0042]      FIGS. 26 and 27  are schematic views showing the novel valve or occluder of  FIGS. 24 and 25  being deployed within a blood vessel; 
           [0043]      FIGS. 28-30  are schematic views showing a novel balloon formed in accordance with the present invention; 
           [0044]      FIGS. 31-33  are schematic views showing a novel polymer occluder formed in accordance with the present invention; 
           [0045]      FIGS. 34-36  are schematic views showing a novel transvascular screw formed in accordance with the present invention; and 
           [0046]      FIGS. 37-43  are schematic views showing a novel transvascular clamp formed in accordance with the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0047]      FIGS. 1 and 2  show a novel flow control device formed in accordance with the present invention. More particularly,  FIGS. 1 and 2  show a novel valve  5  which may be used to control flow in a blood vessel or other body lumen.  FIG. 1  shows valve  5  in an open configuration.  FIG. 2  shows valve  5  in a closed configuration. In a preferred embodiment of the present invention, valve  5  comprises a resilient frame  10  having an attached resilient flap  15 . Frame  10  and flap  15  have a generally circular configuration to match the cross-sectional geometry of a blood vessel. Frame  10  is designed such that it acts as a stop for flap  15 , thereby limiting movement of flap  15  in one direction. Frame  10  may be made of a thicker material than flap  15 , or of a different material than flap  15 , or the same material and/or thickness as flap  15 , etc. Frame  10  is designed to be attached to a blood vessel in such a way as to restrict, at least in part, movement of frame  10  vis-à-vis the blood vessel. Flap  15  may be attached to frame  10  via a hinge, solder, welding, etc., or flap  15  may be a contiguous part of frame  10  (i.e., flap  15  may be formed integral with frame  10 ). Flap  15  may comprise one or more movable components. 
         [0048]      FIG. 1  shows valve  5  in an open-valve configuration, allowing blood flow through valve  5 .  FIG. 2  shows valve  5  in a closed-valve configuration, whereby blood flow is impeded. 
         [0049]    Flap  15  and frame  10  may be formed by laser cutting, embossing, injection molding, or any other method known to those skilled in the art. In one preferred form of the invention, frame  10  also includes a plurality of resilient finger anchors  20  for attaching frame  10  to the wall of a blood vessel by penetrating through the wall of the blood vessel. It should be appreciated that frame  10  may comprise other elements for anchoring frame  10  to the wall of a blood vessel instead of, or in addition to, finger anchors  20 . 
         [0050]    In another preferred form of the invention, and looking now at  FIGS. 3 and 4 , valve  5  can include flexible finger anchors  20 , for example of Nitinol, which contact, or even conform to, the shape of the external wall of the blood vessel V, sandwiching the blood vessel V at least in part on either side, and exerting a force between finger anchors  20  and frame  10 . This embodiment of the invention enables the finger anchors to better support frame  10 , and distribute the pressure of the stopped blood across blood vessel V, thus preventing the valve  5  from moving or migrating within blood vessel V. 
         [0051]    Looking next at  FIGS. 5 and 6 , valve  5  is shown deployed inside a blood vessel V. In a preferred form of the present invention, valve  5  may be deployed with finger anchors  20  spanning the wall of blood vessel V and deploying external to blood vessel V, whereby to compress against the exterior of blood vessel V and secure valve  5  in position. See  FIG. 5 . A connector  25 , which may be formed as part of frame  10 , connects frame  10  (disposed inside of blood vessel V) and finger anchors  20  (disposed outside of blood vessel V), with connector  25  penetrating the wall of blood vessel V. 
         [0052]    In another preferred form of the present invention, and looking now at  FIG. 6 , there is shown a valve  5  which does not have finger anchors  20  disposed external to blood vessel V. In this form of the present invention, frame  10  includes anchors (or protruding elements)  30  disposed along the outer perimeter of frame  10 , which secure frame  10  of valve  5  to the internal wall of blood vessel V, thereby anchoring frame  10  (and hence valve  5 ) to the wall of blood vessel V. Compression of valve  5  against the internal wall of blood vessel V may also be sufficient to secure valve  5  within blood vessel V, in which case anchors  30  may be omitted. 
         [0053]    A novel feature of the present invention is the minimally invasive manner in which valve  5  is deployed within a blood vessel. The minimally invasive approach utilized by the present invention minimizes discomfort and trauma to the patient, and minimizes the risk of complications associated with surgical exposures. In one preferred form of the present invention, an anesthetic is delivered superficially and locally on the skin of the patient at the site of delivery of valve  5 . More particularly, and looking now at  FIGS. 7-9 , valve  5  may be percutaneously deployed into a blood vessel V using a hollow needle  35  or other tube (preferably sharpened so as to facilitate passage of the tube through the side wall of the blood vessel, as well as through any intervening tissue). Valve  5  is compressed (or rolled-up) so that it fits within the bore of hollow needle  35 . The frame  10 , as well as the finger anchors  20  (or anchors  30 ) of valve  5  are also compressed to fit into the needle. Alternatively, valve  5  may be compressed and contained within a sheath  40  which is inserted into the bore of hollow needle  35 . Sheath  40  affords additional control over the deployment process. 
         [0054]    In one preferred form of the present invention, and as seen in  FIGS. 8-14 , frame  10  and flap  15  are rolled up along a single axis (e.g., in the manner of rolling a pancake on itself), whereby to facilitate positioning valve  5  within needle  35 , i.e., by aligning the longitudinal axis of the rolled-up frame  10  and flap  15  with the longitudinal axis of hollow needle  35 . In this form of the invention, finger anchors  20  of valve  5  may be similarly rolled up about the same single axis as frame  10  and flap  15  or, alternatively, they may extend longitudinally, e.g., parallel to the axis of rolled-up frame  10  and flap  15 . 
         [0055]    In use, and still looking at  FIGS. 7-9 , needle  35  is passed through the skin of the patient and then through blood vessel V at the desired location. Note that needle  35  extends transverse to blood vessel V at the desired location, and not parallel to the longitudinal axis of blood vessel V, since valve  5  is advanced transversely into blood vessel V and not endoluminally along blood vessel V. Needle  35  does not have to go through the skin of a patient if the procedure is performed laparoscopically. Note that in one preferred form of the invention, needle  35  passes through both the proximal and distal walls of blood vessel V. 
         [0056]    Looking now at  FIGS. 10 and 11 , there is shown a deployment element (or pusher)  45  that fits within sheath  40  and is used to push valve  5  through needle  35  while valve  5  is in its compressed state, as will hereinafter be discussed in greater detail. 
         [0057]    Looking next at  FIGS. 7-9 and 12-15 , needle  35  is advanced through the proximal wall of the blood vessel V, across the lumen of the blood vessel, and then through the distal wall of blood vessel V. Sheath  40  and valve  5  (in its compressed condition) are advanced together through the bore of needle  35  by maintaining pressure on the proximal end of valve  5  with pusher  45  while both sheath  40  and valve  5  are advanced distally through the bore of needle  35 . Needle  35  is then retracted proximally, whereby to expose sheath  40  ( FIG. 12 ). At this point, sheath  40  and finger anchors  20  of valve  5  protrude out of the distal wall of blood vessel V. 
         [0058]    Sheath  40  and needle  35  are then retracted while valve  5  is maintained in position using pusher  45 . See  FIGS. 13 and 14 . This causes resilient finger anchors  20  to open up on the distal side of blood vessel  20 . Sheath  40  and needle  35  continue to be retracted until sheath  40  and needle  35  have been completely retracted from blood vessel V, thereby allowing resilient frame  10  and resilient flap  15  of valve  5  to “open up” and deploy within the lumen of the blood vessel V, anchored in place by resilient finger anchors  20  disposed external to blood vessel V (i.e., on both the distal and proximal sides of the blood vessel). See  FIG. 15 . 
         [0059]    It should be appreciated that the number, configuration and geometry of finger anchors  20  may vary depending on the specific needs of the clinical application. By way of example but not limitation,  FIG. 16  shows a valve  5  having six finger anchors  20 , although fewer or more finger anchors  20  may be included if desired. 
         [0060]    Furthermore, it should be appreciated that resilient finger anchors  20  may be replaced by any structure, such as a disk for example, that opens up outside a blood vessel, whereby to anchor valve  5  within a blood vessel and secure valve  5  to the wall of the blood vessel. By way of example but not limitation, finger anchors  20  may comprise a Nitinol or plastic or polymer ball, a coiled spring, etc. Alternative embodiments are possible and will be evident to those skilled in the art in view of the present disclosure. 
         [0061]    In an alternative form of the present invention, and looking now at  FIG. 17 , an aperture  50  may be provided in flap  15  of valve  5 . Aperture  50  can be selectively sized so as to enable a desired amount of blood to flow back-and-forth through valve  5 . By way of example but not limitation, aperture  50  may be useful if a minimum amount of blood flow through the blood vessel is desired, while halting most of blood flow in a given direction. This permits a blood vessel to be perfused with flowing blood at all times, which may be advantageous in keeping a desired organ alive, or which may minimize the impact of a lack of blood flow in a particular direction in a blood vessel. 
         [0062]    A valve  5  having an aperture  50  formed in flap  15  ( FIG. 17 ) can be used to reduce the pressure of blood flow on the distal side of the valve, whereby to reduce blood pressure in the distal side of the valve, e.g., down the Saphenous vein if the valve is deployed next to the Sapheno-Femoral junction. 
         [0063]    If desired, a plurality of valves  5  may be deployed in a single blood vessel, or a plurality of valves  5  may be deployed in multiple blood vessels, so as to physiologically control blood flow and pressure within a blood vessel in a minimally invasive manner, and without requiring the destruction of, or physical removal of, the blood vessels. 
         [0064]    In yet another form of the present invention, and looking now at  FIG. 18 , flap  15  may comprise a filter  55  which can be deployed to “catch” (i.e., filter out) emboli and thereby prevent blood clots from getting to critical organs in the body (e.g., the heart, lungs, brain, etc.). In this form of the invention, filter  55  comprises a structure (e.g., a mesh, a permeable membrane, or any other filtering structure) which allows blood to flow through filter  55  but which will not permit larger structures (e.g., blood clots) to flow though filter  55 . Filter  55  may comprise a polymer that dissolves over time, leaving just an open frame  10  in the blood vessel, or the entire structure (i.e., frame  10  and filter  55 ) could be made of a resorbable material and resorb over time. 
         [0065]    It should be appreciated that filter  55  (or any other flow control device formed in accordance with the present invention) may be positioned at an angle relative to the blood flow, such that blood may flow across both sides of filter  55 . By way of example but not limitation, the degree to which a vessel is occluded may be defined by the angle between the blood flow and the plane of filter  55 , e.g., if the angle is  20  degrees, blood will flow through the blood vessel, even though an occlusion device (i.e., filter  55 ) may be deployed in the blood vessel. The angle of filter  55  (or other flow control device) relative to the flow of blood in the blood vessel may be adjusted externally to the blood vessel, or re-adjusted as needed over time, without having to penetrate the blood vessel. 
         [0066]    In still another embodiment of the present invention, and looking now at  FIGS. 19 and 20 , flap  15  may comprise a solid barrier  60  which prevents blood from flowing through frame  10 , whereby to completely occlude the blood vessel. Barrier  60  may be formed out of the same material as frame  10 , as a contiguous piece, or barrier  60  may comprise a material that is different in thickness, density, shape, etc. The angle of barrier  60 , relative to the direction of blood flow, can be used as a means of defining and selecting the level of occlusion of the blood vessel, and allowed blood flow through the blood vessel. 
         [0067]    In still another embodiment of the present invention, and looking now at  FIGS. 21-23 , frame  10  may be formed hollow, or frame  10  may contain one or more channels for transporting a liquid (e.g., a thrombolytic agent, a drug, etc.) from an injection port (or reservoir)  62 , though a conduit  63 , and into channels  64  formed in frame  10 , and then out of holes  66  formed in frame  10 , whereby to deliver the solution into blood vessel V (or other tubular structure). Injection port  62  is formed such that it can receive a needle (or other tube) which is inserted through the skin, whereby fluid can be injected into the flow control device. By way of example but not limitation, holes  66  may be of different sizes, e.g., holes  66  may be formed smaller when closer to injection port  62 , and holes  66  may be formed larger when further away from injection port  62 , so as to ensure uniform distribution of the fluid being injected into injection port  62  and ejected out holes  66 . If desired, a plurality of injection ports  62  may be provided (e.g., to supply a thrombolytic agent to both sides of the flow control device, and/or upstream and downstream of the flow control device, etc.). 
         [0068]    Channels  64  formed in frame  10  communicate with the hollow tube or blood vessel via holes  66  such that the injected fluid enters into channels  64  and passes out of holes  66  of the porous openings into any attached clot, thereby promoting dissolution of this clot and allowing the full function of the valve (or other flow control device). This ensures a long operating life for the valve  5  (or flow control device), generally much longer than is typically achieved. Injection port (or reservoir)  62  may contain the fluid for a period of time, slowly dispensing the fluid over a period of time in a controlled release, thereby preventing buildup of thrombus, or delivering a desired substance to the tubular structure for a desired period of time. Multiple injection ports (or reservoirs)  62  may be connected to frame  10 , enabling simplified access, or delivery of more fluid or fluids that may mix in channels  64  formed in frame  10 . 
         [0069]    In yet another embodiment of the present invention, and looking now at  FIGS. 24-27 , valve  5  can be constructed so that it does not have finger anchors  20  residing outside of the blood vessel. In this form of the invention, frame  10  comprises spikes (or grips)  65  which allow frame  10  to grip the internal wall of the blood vessel, and/or to penetrate partially or fully through the wall of the blood vessel, whereby to anchor valve  5  in position. In this embodiment of the present invention, valve  5  is deployed within the interior of a blood vessel in a manner similar to that by which the embodiment of  FIGS. 7-15  is deployed, i.e., using a needle  35 , except that with this form of the invention, needle  35  (and/or sheath  40 ) need not penetrate the distal wall of blood vessel V, since valve  5  can be deployed entirely within the interior of blood vessel V. Thus, in this form of the invention, needle  35  only needs to penetrate the surface of the skin, intervening tissue lying between the surface of the skin and the blood vessel, and the proximal wall of the blood vessel. 
         [0070]    However, it should also be appreciated that, if desired, both finger anchors  20  and spikes  65  may be provided on frame  10  in order to secure valve  5  within a blood vessel. 
         [0071]    In still another embodiment of the present invention, and looking now at  FIGS. 28-30 , a balloon  70 , having anchor elements  75  (e.g., barbs, protrusions, roughened surfaces, etc.) disposed on its outer surface, may be percutaneously delivered (e.g., via needle  35 ) into blood vessel V, and then balloon  70  may be inflated via needle  35 , whereby to occlude blood vessel V. In this form of the invention, anchor elements  75  can enhance the adhesion of the balloon to the interior walls of blood vessel V (e.g., by a friction fit). Balloon  70  may be inflated with a fluid (e.g., air, saline, etc.), or balloon  70  may be filled with a solidifying polymer (or other materials) so that balloon  70  solidifies after it is expanded in place. 
         [0072]    Alternatively, and looking now at  FIGS. 31-33 , balloon  70  may be replaced with an occlusion element  80  which comprises a polymer matrix material (or glue) such that it forms a solid occlusion of only a portion of, or the entirety of, blood vessel V. Occlusion element  80  is formed directly at the site where needle  35  penetrates blood vessel V, so multiple occlusion elements  80  can be formed in the same (or multiple) blood vessels V. The polymer matrix may comprise Super Glue, Crazy Glue, or any other satisfactory material. The polymer matrix which comprises occlusion element  80  may be resorbable, and/or the polymer matrix may be temperature sensitive. Occlusion element  80  may also penetrate blood vessel V in at least two locations. 
         [0073]    As seen in  FIGS. 31-33 , if desired, occlusion element  80  may be anchored in position by polymer anchors  85 , which solidify, harden and penetrate through the wall of blood vessel V, whereby to fill the void created by needle  35  as it punctures blood vessel V. If desired, balloon  70  can be fabricated with protrusions which correspond to polymer anchors  85 , such that the balloon protrusions extend through the side wall of the blood vessel, whereby to anchor the balloon to the blood vessel. 
         [0074]    It should be appreciated that the flow control elements described above (i.e., valve  5 , frame  10 , flap  15 , filter  55 , barrier  60 , balloon  70 , occlusion element  80  and polymer anchors  85 ), and the anchoring elements discussed above (i.e., finger anchors  20 , connector  25 , anchors  30 , spikes  65  and anchor elements  75 ) may comprise, but are not limited to, the following: biocompatible metals (e.g., Nitinol, Titanium, etc.) or various polymers that may be hard, soft, and/or flexible, and which may be permanent or absorbable or bioresorbable. Examples of such polymers include, but are not limited to, PGA, PLA (Poly Lactic Acid), PCL, PLGA, PLC, PLLA, poly-lactide, Poly Hydroxy Alkanoates, polymer alkylene bis(dilactoyl)-methacrylate, Block Co-Polymers, or Silk derivatives. The surrounding structure may be made of a hard polymer (which may be more crystalline if desired), shape memory metals, or polymers. Additionally, the present invention may be formed out of Super Glue, Crazy Glue, CyanoAcrylate, ceramics, carbide materials, etc. 
         [0075]    The injectable flow control devices may be made of bio-compatible metals in combination with a polymer-polymer, or a polymer mixed with other compounds to optimize mechanical, inertness and other characteristics. 
         [0076]    In another form of the present invention, and looking now at  FIGS. 34-36 , a transvascular screw  90  may be used to occlude blood vessel V. Transvascular screw  90  may comprise an implantable biocompatible resorbable or non-resorbable polymer, or plastic, or silk, or a hard metal or other material. In use, transvascular screw  90  (or multiple transvascular screws  90 ) is screwed across blood vessel V so as to pull the proximal wall and the distal wall of the blood vessel V together, whereby to occlude blood vessel V. Transvascular screw  90  may also comprise a second transvascular screw (or mechanism) disposed within the interior of transvascular screw  90 , such that the distal and proximal ends of transvascular screw  90  can be selectively expanded by actuating the second transvascular screw (or mechanism) whereby to help lock transvascular screw  90  to the side wall of blood vessel V. The pitch of the threads disposed on the outer surface of transvascular screw  90 , or the diameter of the threads of transvascular screw  90 , may also be variable, whereby to control occlusion strength or other characteristics of the occlusion. 
         [0077]    In still another form of the present invention, and looking now at  FIGS. 37-43 , a transvascular clamp  95  is provided for effecting occlusion of a blood vessel V. 
         [0078]    Transvascular clamp  95  comprises a shaft  100  having a plurality of distal fingers  105  and a plurality of proximal fingers  110 . In one preferred form of the invention, shaft  100  is threaded and fingers  105 ,  110  are threadingly engaged with shaft  100 , such that rotation of shaft  100  in a direction causes fingers  105 ,  110  to pivot outward. Shaft  100  terminates in a coupling  115  disposed at the proximal end of shaft  100 . Coupling  115  comprises a threaded bore, whereby to releasably attach a rod  120  to coupling  115 . When rod  120  is rotated in a first direction, shaft  100  advances distally. When rod  120  is rotated in a second, opposite direction, rod  120  disengages from coupling  115 . Fingers  105  can be folded against shaft  100  of transvascular clamp  95  so as to assume a compact configuration for percutaneous delivery (e.g., via a needle  35 ) to a blood vessel V. In use, transvascular clamp  95  is disposed in sheath  40  with fingers  105 ,  110  folded against shaft  100  of transvascular clamp  95  (i.e., transvascular clamp  95  is in its compact configuration), and sheath  40  is disposed within the bore of hollow needle  35 . Hollow needle  35 , sheath  40  and transvascular clamp  95  are advanced through the skin of the patient and through the proximal and distal walls of blood vessel V, whereby to span the lumen of blood vessel V with shaft  100  of transvascular clamp  95 . Next, sheath  40  and needle  35  are retracted proximally. When needle  35  and sheath  40  are removed by retracting proximally, the distal fingers  105  of transvascular clamp  95  open up, either independently (e.g., via a spring action) or by rotating shaft  100 . When the needle is retracted to expose the proximal fingers  110 , proximal fingers  110  of occlusion device  95  open up, either independently (e.g., via a spring action) or by rotating shaft  100 . Once the fingers  105 ,  110  are exposed, shaft  100  is rotated further so that the fingers  105 ,  110  are brought together across blood vessel V, whereby to occlude blood vessel V. Rod  120  is then rotated in the opposite direction to disengage rod  120  from coupling  115 , leaving the implanted transvascular clamp  95  disposed across the blood vessel V. 
         [0079]    Shaft  100  may be made of metal or polymers that may absorb or remain permanently. This and other occlusion devices described above may be used in conjunction with sclerosants, glues, laser and RF ablation probes to protect the deep vein system as well as protect the patient from embolization threats. The occlusion device may be used to occlude the vein at a site of interest and the glues or other elements may be used to occlude an entire portion of a blood vessel. 
       Modifications Of The Preferred Embodiments 
       [0080]    It should be understood that many additional changes in the details, materials, steps and arrangements of parts, which have been herein described and illustrated in order to explain the nature of the present invention, may be made by those skilled in the art while still remaining within the principles and scope of the invention.