Abstract:
Apparatus for percutaneously occluding a hollow structure, said apparatus comprising:
       an occluder, said occluder comprising a first component and a second component, wherein said first component is configured so that it may assume (i) a diametrically-reduced configuration for disposition within the lumen of a hollow tube, and (ii) a diametrically-expanded configuration for disposition adjacent to the hollow structure, whereby to occlude the hollow structure, and further wherein said second component percutaneously connects said first component to a site remote from said first component.

Description:
REFERENCE TO PENDING PRIOR PATENT APPLICATIONS 
       [0001]    This patent application: 
         [0002]    (i) is a continuation-in-part of pending 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 
         [0003]    (ii) claims benefit of pending 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). 
     
    
       [0004]    The three (3) 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 the occlusion of blood vessels and the treatment of varicose veins. This invention also relates to a minimally invasive means for fastening mechanical structures to tissues or blood vessels, for example, for drug delivery. 
       BACKGROUND OF THE INVENTION 
     Varicose Veins in General 
       [0006]    There are three sets of veins in the legs: (i) superficial veins that lie under the skin and may be seen and felt when standing; (ii) deep veins that lie within the muscles and are not seen or felt; and (iii) perforating or connecting veins that join the two systems (i.e., the superficial veins and the deep veins). 
         [0007]    Veins lie within all tissues. Veins return blood to the heart. When muscles in the leg contract, blood is pumped back to the heart. Valves inside the veins direct the flow of blood back to the heart. 
         [0008]    The veins are relatively weak tubes. Under the skin there is no support for these veins, so that when the pressure in the veins is elevated, areas of weakness occur and the veins enlarge, both in size and length. In some cases the veins can become twisty and bulge significantly. This condition is commonly referred to as varicose veins. 
         [0009]    Very small varicose veins are sometimes called spider veins. Unlike the larger varicose veins, these spider veins lie in the skin. 
         [0010]    The cause of the increased pressure in the veins is due to the occurrence of “leaky” valves within the veins. The main valve is in the groin region, i.e., in the great sapheous vein near the sapheno-femoral junction. See  FIG. 1 , which shows a leg  5  of a patient, the femoral vein  10 , the great saphenous vein  15 , the sapheno-femoral junction  20 , and the main valve  25  in the great saphenous vein near the sapheno-femoral junction. Once this main valve in the saphenous vein becomes leaky, the pressure in the vein increases and the veins below the saphenous vein start to enlarge. This causes the next set of valves in the saphenous vein to leak. The raised pressure caused by the leaky valves in the saphenous vein is transmitted to the feeder veins, which distend and their valves also malfunction and become leaky. As this process carries on down the leg, many of the valves in the leg veins become incompetent, with high pressures occurring in the veins, especially on standing. 
         [0011]    Initially, the problem is primarily cosmetic. The veins bulge and look unsightly. However, there is commonly also discomfort in the legs upon standing. This discomfort is the result of the veins distending due to the increased pressure. 
         [0012]    With time, the high pressure in the veins is transmitted to the surrounding tissues and skin. Small veins within the skin (i.e., spider veins) enlarge and become visible. Blood cells may escape into the tissues and break down, causing areas of discoloration. Because the pressure in the tissues is high, the skin swells and the nutrition of the skin deteriorates. This lowers the local tissue resistance and allows infection to occur. Eventually skin may break down with the development of sores (i.e., ulcers). 
       Incidence of Varicose Veins 
       [0013]    Nearly 40 percent of women and 25 percent of men suffer from lower extremity venous insufficiency and associated visible varicose veins. Primary risk factors include heredity, gender, pregnancy and age. Most of these patients have long-standing leg symptoms which compromise their daily routine, with symptoms worsening during the day while the patients are at work or simply living their lives. Without varicose vein treatment, these symptoms can progress to a lifestyle-limiting condition. 
       Treatment of Varicose Veins 
       [0014]    Treatment of varicose veins is undertaken for relief of the symptoms, i.e., the removal of the unsightly veins and the prevention of the discomfort and late-stage manifestations described above. 
         [0015]    1. Non-Surgical Treatment. 
         [0016]    The simplest treatment is a non-surgical treatment directed against the high pressure in the varicose veins. More particularly, fitted elastic stockings, strong enough to overcome the increased pressure caused by the “leaky” valves, are used. These fitted elastic stockings control the symptoms and may prevent the veins from further enlargement, however, they are not curative. Good results require consistent, every-day use of the stockings. 
         [0017]    2. Surgical/Interventional Treatment. 
         [0018]    The aim of the surgical/interventional treatment is (i) the elimination of the cause of the high venous pressure (i.e., the “leaky” valves at the groin); and (ii) the removal of the unsightly veins. 
         [0019]    The early approach of “stripping” the saphenous vein (the main vein in the leg) as the sole manner of treatment has now been largely abandoned. This is because the “stripping” approach caused too much trauma and did not remove all of the superficial varicose veins: many of the superficial varicose veins were tributaries of the main superficial vein of the leg (i.e., the saphenous vein) that was stripped, and these tributary veins were not removed by this procedure. 
         [0020]    There are currently three basic approaches for treating varicose veins: chemical—sclerorosants and glues; venous ablation using thermal treatments; and open surgery. 
         [0021]    A. Sclerotherapy. 
         [0022]    Sclerotherapy (the use of sclerosants) is generally used for treating the smaller varicose veins and spider veins that do not appear to be directly associated with “leaky” valves. It is primarily a cosmetic procedure. 
         [0023]    In this approach, a sclerosant (i.e., a substance irritating to the tissues) is injected into the smaller varicose veins and spider veins, causing inflammation of the walls of these veins. As a result of this inflammation, the walls of the vein stick together and occlude the lumen of the vein so that no blood can pass through the vein. Eventually these veins shrink and disappear. 
         [0024]    The disadvantages of sclerotherapy include: (i) in the presence of high venous pressure (i.e., with leaky valves and the larger varicose veins), the results are uncertain and the recurrence rate is high; and (ii) the erroneous injection of the sclerosant into the surrounding tissues can result in damage to the surrounding tissues, with areas of discoloration of the skin and even ulceration. 
         [0025]    Recently, mixing the sclerosant with air to form a “foam” has been used to destroy the lining of the main vein (i.e., the saphenous vein) of the leg. To date, the results are somewhat unpredictable and there is a danger of the sclerosant escaping through the saphenous vein and into the deep veins and then embolizing into the lungs, which is harmful and dangerous for the patient. 
         [0026]    B. Venous Ablation. 
         [0027]    Venous ablation for varicose veins can be effected in two ways, i.e. percutaneously and endovenously. 
         [0028]    With the percutaneous approach, the superficial smaller varicose veins and spider veins are “heated” and coagulated by shining an external laser light through the skin. However, if the veins are too large, the amount of energy needed to destroy the veins may result in damage to the surrounding tissues. Percutaneous laser treatment is primarily an alternative to the sclerotherapy discussed above, and generally suffers from the same disadvantages described above with respect to sclerotherapy. 
         [0029]    With endovenous ablation, a special laser or radio-frequency (RF) catheter is introduced, with local anesthesia, through a needle puncture into the main superficial vein (i.e., the saphenous vein) of the leg. Entry is made in the region around the knee, and the catheter is passed up towards the groin, advancing to the site where the saphenous vein joins the deep veins at the site of the main “leaky” valves. Then, as the catheter is slowly withdrawn back through the vein, the laser light or radio-frequency (RF) energy heats up the wall of the vein, endoluminally coagulating the proteins and destroying the lining surface of the vein. The destruction of the lining surface of the vein causes the vein walls to adhere to one another, thereby eliminating the lumen within the vein and thus preventing the flow of blood. This is a process somewhat similar to sclerotherapy, but no substance is injected into the vein. This procedure takes care of the “leaky” valves and high venous pressures, however, the larger superficial varicose veins in the leg may still need to be removed. This may be done at the same time as the endovenous ablation or at a later time, either by open surgery (phlebectomy) or sclerotherapy. Placement of the laser or radio-frequency (RF) catheter is guided by ultrasound. 
         [0030]    The advantages of endovenous laser/radio-frequency (RF) therapy include: (i) it is a minimally invasive procedure and can be done with local anesthesia, either in an operating room or a physician&#39;s office; (ii) it does not require hospitalization; (iii) it does not require open surgery with incisions; (iv) recovery is easier than with open surgery, inasmuch as most patients are back at work within a day or two; and (v) some of the prominent varicosities may disappear and may not require a secondary procedure (i.e., either phlebectomy or sclerotherapy). 
         [0031]    The disadvantages of endovenous laser/radio-frequency (RF) therapy include: (i) generally, only one leg is done at a time; (ii) the procedure typically requires significant volumes of local anesthetic to be injected into the patient in order to prevent the complications of the heat necessary to destroy the lining of the vein; (iii) if too much heat is applied to the tissue, there can be burning in the overlying skin, with possible disfiguring, including scarring; (iv) prior to the performance of a subsequent phlebectomy procedure, an interval of up to 8 weeks is required in order to evaluate the effectiveness of the venous ablation procedure; and (v) varicosities that remain after this interval procedure still require separate procedures (i.e., phlebectomy or sclerothapy). 
         [0032]    C. Open Surgery. 
         [0033]    The aim of open surgery is to eliminate the “leaky” valve at the junction of the superficial and deep veins (the cause of the high venous pressure in the leg), as well as the leaky valves in the tributaries of the saphenous vein that may enlarge over the years and result in a recurrence of the varicose veins. This open surgery is directed to removal of some or all of the affected veins. 
         [0034]    There is still some controversy as to how much of the saphenous vein needs to be removed for the best results. The current “teaching” is that removing the entire segment of saphenous vein in the thigh reduces the incidence of recurrence. However, the data for this is very weak. Removal of a very short segment of the proximal saphenous vein and the main tributaries at the sapheno-femoral junction is the alternative procedure and, provided that it is combined with removal of all visible varicosities, the results are very similar to removal of the entire thigh segment of the saphenous vein. The advantage of the latter procedure is the increased preservation of the saphenous vein which, in 50-60% or more of varicose vein patients, is not involved in the varicose vein process and is otherwise normal and hence usable for other procedures (such as a bypass graft in the heart or limbs). 
         [0035]    The surgery is performed in the operating room under light general or regional (spinal or epidural) anesthesia. An incision (e.g., 1-2 inch) is made in the groin crease and the veins dissected out and the proximal saphenous vein and tributaries excised. The wound is closed with absorbable sutures from within. Once this is completed, small (e.g., 2-4 mm) stab wounds are made over any unsightly varicose veins (these veins are marked out just prior to the surgery with the patient standing) and the varicose veins are completely removed. The small stab wounds associated with removal of the marked-out veins are generally so small that they typically do not require any stitches to close them. When all the previously marked-out veins are removed, the wounds are cleaned and a dressing applied. The leg is wrapped in elastic bandages (e.g., Ace wraps). 
         [0036]    In the post-operative care, the dressings and Ace wraps are usually changed in the doctor&#39;s office at the first post-operative visit, typically within 24 hours of the open surgical procedure. The patient and a family member or friend is instructed on proper care of the wounds. A simple dressing is applied to cover the small wounds in the legs for the next 2-3 days. After 2-3 days no further treatment is generally required. Recovery is generally rapid, with the patient returning to work within 5-7 days. 
         [0037]    The advantages of open surgery include: (i) varicose veins of both extremities can be done at a single operation, which generally takes 1-2 hours; (ii) the procedure typically does not require hospitalization and is an “out patient” procedure; (iii) the wounds are minimal, with minimal discomfort which is easily managed with oral analgesics (i.e., pain medicine); (iv) the results are generally excellent, with a minimum of recurrence (the results of open surgery remain the “gold standard” against which the sclerotherapy and laser/radio-frequency (RF) venous ablation therapies are compared); (v) recurrent or residual (i.e., those missed at surgery) veins are generally managed with sclerotherapy or phlebectomy under local anesthesia in a doctor&#39;s office or in an ambulatory procedure room; and (vi) the saphenous vein, if normal and without varicosities, is preserved and is therefore available for use (e.g., for bypass surgery) in the future if it should be needed. 
         [0038]    The disadvantages of open surgery include: (i) it is an open surgical procedure requiring an anesthetic (either general or regional), with its associated discomfort and with its attendant risks (which may depend on the health or age of the patient); and (ii) recovery generally takes 3-5 days. Thus it will be seen that varicose veins present a significant problem for many patients which must be addressed, and all of the current procedures for treating varicose veins suffer from a number of significant disadvantages. 
       SUMMARY OF THE INVENTION 
       [0039]    The present invention provides a new and improved approach for treating varicose veins and other blood vessels. 
         [0040]    More particularly, the present invention comprises the provision and use of a novel occluder which is used to occlude a vein (e.g., the proximal saphenous vein, the small saphenous vein, tributaries, the perforator veins, etc.) so as to restrict blood flow through the vein and thereby treat varicose veins below the point of occlusion. Significantly, the novel occluder is configured to be deployed using a minimally-invasive approach (i.e., either percutaneously or endoluminally), with visualization being provided by ultrasound and/or other visualization apparatus (e.g., CT, MRI, X-ray etc.). 
         [0041]    As a result, the novel treatment can be provided in a doctor&#39;s office, with minimal local anesthetic, and effectively no post-operative care. 
         [0042]    In one form of the invention, there is provided apparatus for occluding a blood vessel, the apparatus comprising: 
         [0043]    an occluder, the occluder being configured so that at least a portion of the occluder may assume (i) a diametrically-reduced configuration for disposition within the lumen of a tube, and (ii) a diametrically-expanded configuration for disposition adjacent to the blood vessel, such that when said at least a portion of the occluder is in its diametrically-expanded configuration adjacent to the blood vessel, the occluder will cause occlusion of the blood vessel. 
         [0044]    In another form of the invention, there is provided a method for occluding a blood vessel, the method comprising: 
         [0045]    providing apparatus comprising: 
         [0046]    an occluder, the occluder being configured so that at least a portion of the occluder may assume (i) a diametrically-reduced configuration for disposition within the lumen of a tube, and (ii) a diametrically-expanded configuration adjacent to the blood vessel, such that when said at least a portion of the occluder is in its diametrically-expanded configuration adjacent to the blood vessel, the occluder will cause occlusion of the blood vessel; and 
         [0047]    positioning the occluder adjacent to the blood vessel so as to cause occlusion of the blood vessel. 
         [0048]    In another form of the invention, there is provided apparatus for delivering a substance to a location adjacent to a blood vessel, the apparatus comprising: 
         [0049]    a carrier, the carrier being configured so that at least a portion of the carrier may assume (i) a diametrically-reduced configuration for disposition within the lumen of a tube, and (ii) a diametrically-expanded configuration for disposition adjacent to the blood vessel, such that when the substance is attached to the carrier and said at least a portion of the carrier is in its diametrically-expanded configuration adjacent to the blood vessel, the substance will be disposed adjacent to the blood vessel. 
         [0050]    In another form of the invention, there is provided a method for delivering a substance to a location adjacent to a blood vessel, the method comprising: 
         [0051]    providing apparatus comprising:
       a carrier, the carrier being configured so that at least a portion of the carrier may assume (i) a diametrically-reduced configuration for disposition within the lumen of a tube, and (ii) a diametrically-expanded configuration for disposition adjacent to the blood vessel, such that when the substance is attached to the carrier and said at least a portion of the carrier is in its diametrically-expanded configuration adjacent to the blood vessel, the substance will be disposed adjacent to the blood vessel; and       
 
         [0053]    positioning the carrier adjacent to the blood vessel so that the substance is disposed adjacent to the blood vessel. 
         [0054]    In another form of the invention, there is provided apparatus for percutaneously occluding a hollow structure, said apparatus comprising: 
         [0055]    an occluder, said occluder comprising a first component and a second component, wherein said first component is configured so that it may assume (i) a diametrically-reduced configuration for disposition within the lumen of a hollow tube, and (ii) a diametrically-expanded configuration for disposition adjacent to the hollow structure, whereby to occlude the hollow structure, and further wherein said second component percutaneously connects said first component to a site remote from said first component. 
         [0056]    In another form of the invention, there is provided a method for percutaneously occluding a hollow structure, the method comprising: 
         [0057]    providing apparatus comprising:
       an occluder, said occluder comprising a first component and a second component, wherein said first component is configured so that it may assume (i) a diametrically-reduced configuration for disposition within the lumen of a hollow tube, and (ii) a diametrically-expanded configuration for disposition adjacent to the hollow structure, whereby to occlude the hollow structure, and further wherein said second component percutaneously connects said first component to a site remote from said first component; and       
 
         [0059]    positioning said occluder adjacent to the hollow structure so as to occlude the hollow structure. 
         [0060]    In another form of the invention, there is provided an occluder for occluding a hollow structure, wherein the occluder is configured to be percutaneously delivered to an internal site and thereafter expanded so as to cause complete or partial occlusion of the hollow structure, and further wherein the occluder is configured so that the expansion of the occluder may thereafter be reversed in full or in part so as to completely or partially restore the hollow structure to its original condition. 
         [0061]    In another form of the invention, there is provided a method for occluding a hollow structure, wherein an occluder is percutaneously delivered to an internal site and thereafter expanded so as to cause complete or partial occlusion of the hollow structure, and further wherein the occluder is configured so that the expansion of the occluder may thereafter be reversed in full or in part so as to completely or partially restore the hollow structure to its original condition. 
         [0062]    In another form of the invention, there is provided apparatus for occluding a hollow structure, wherein the apparatus comprises an occluder, a device for percutaneously delivering the occluder to an internal site and deploying the occluder so that it completely or partially occludes the hollow structure, and a device for removing some or all of the occluder so as to completely or partially restore the hollow structure to its original condition. 
         [0063]    In another form of the invention, there is provided a method for treating a patient, wherein the method comprises percutaneously delivering an occluder to an internal site so that it completely or partially occludes the hollow structure, and further wherein the method comprises thereafter removing some or all of the occluder so as to completely or partially restore the hollow structure to its original condition. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0064]    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: 
           [0065]      FIG. 1  is a schematic view showing various aspects of the venous system of the leg; 
           [0066]      FIGS. 2-4  are schematic views showing an occluder occluding a blood vessel in accordance with one form of the present invention; 
           [0067]      FIG. 5  is a schematic view showing one possible construction for the occluder shown in  FIGS. 2-4 ; 
           [0068]      FIGS. 6 and 7  are schematic views showing an exemplary syringe-type inserter which may be used to deploy the occluder shown in  FIGS. 2-4 ; 
           [0069]      FIGS. 8-10  are schematic views showing an occluder occluding a blood vessel in accordance with another form of the present invention; 
           [0070]      FIGS. 11-14  are schematic views showing an occluder occluding a blood vessel in accordance with still another form of the present invention; 
           [0071]      FIGS. 15-17  are schematic views showing other possible constructions for the occluder of the present invention; 
           [0072]      FIGS. 18-20  are schematic views showing the occluders of the types shown in  FIGS. 15-17  occluding a blood vessel in accordance with yet another form of the present invention; 
           [0073]      FIGS. 21-24  are schematic views showing an occluder occluding a blood vessel in accordance with another form of the present invention; 
           [0074]      FIGS. 25-27  are schematic views showing an occluder occluding a blood vessel in accordance with still another form of the present invention; 
           [0075]      FIGS. 28 and 29  are schematic views showing an occluder occluding a blood vessel in accordance with yet another form of the present invention; 
           [0076]      FIGS. 30 and 31  are schematic views showing an occluder occluding a blood vessel in accordance with another form of the present invention; 
           [0077]      FIGS. 32 and 33  are schematic views showing an occluder occluding a blood vessel in accordance with still another form of the present invention; 
           [0078]      FIGS. 34 and 35  are schematic views showing a drug/cellular delivery body being attached to a blood vessel in accordance with one form of the present invention; 
           [0079]      FIGS. 36 and 37  are schematic views showing a drug/cellular delivery body being attached to a blood vessel in accordance with another form of the present invention; 
           [0080]      FIGS. 38 and 39  are schematic views showing a drug/cellular delivery body being attached to a blood vessel in accordance with still another form of the present invention; 
           [0081]      FIGS. 40 and 41  are schematic views showing a drug/cellular delivery body being attached to a blood vessel in accordance with yet another form of the present invention; 
           [0082]      FIGS. 42-48  are schematic views showing a two-part occluder formed in accordance with another form of the present invention; 
           [0083]      FIGS. 49-58  are schematic views showing installation apparatus which may be used to deploy the two-part occluder of  FIGS. 42-48 ; 
           [0084]      FIGS. 59-82  are schematic views showing the two-part occluder of  FIGS. 42-48  being deployed across a blood vessel using the installation apparatus of  FIGS. 49-58 ; 
           [0085]      FIGS. 83-86  are schematic views showing another two-part occluder formed in accordance with the present invention; 
           [0086]      FIGS. 87-90  are schematic views showing still another two-part occluder formed in accordance with the present invention; 
           [0087]      FIGS. 91-94  are schematic views showing yet another two-part occluder formed in accordance with the present invention; 
           [0088]      FIGS. 95-100  are schematic views showing another two-part occluder formed in accordance with the present invention; 
           [0089]      FIGS. 101-103  are schematic views showing a temporary occluder formed in accordance with the present invention; 
           [0090]      FIGS. 104-107  are schematic views showing another temporary occluder formed in accordance with the present invention; 
           [0091]      FIGS. 108-124  are schematic views showing still another temporary occluder formed in accordance with the present invention; 
           [0092]      FIGS. 125 and 126  are schematic views showing yet another temporary occluder formed in accordance with the present invention; 
           [0093]      FIGS. 127-142  are schematic views showing another temporary occluder formed in accordance with the present invention; 
           [0094]      FIGS. 143-148  are schematic views showing still another temporary occluder formed in accordance with the present invention; 
           [0095]      FIG. 149  is a schematic view showing yet another temporary occluder formed in accordance with the present invention; and 
           [0096]      FIG. 150  is a schematic view showing another temporary occluder formed in accordance with the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0097]    The present invention provides a new and improved approach for treating varicose veins and other blood vessels. 
         [0098]    More particularly, the present invention comprises the provision and use of a novel occluder which is used to occlude a vein (e.g., the proximal saphenous vein, the small saphenous vein, tributaries, the perforator veins, etc.) so as to restrict blood flow through the vein and thereby treat varicose veins below the point of occlusion. Significantly, the novel occluder is configured to be deployed using a minimally-invasive approach (i.e., either percutaneously or endoluminally), with visualization being provided by ultrasound and/or other visualization apparatus (e.g., CT, MRI, X-ray etc.). As a result, the novel treatment can be provided in a doctor&#39;s office, with minimal local anesthetic, and effectively no post-operative care. 
       Percutaneous Approach 
       [0099]    In the percutaneous approach, the occluder is delivered by percutaneously advancing the occluder through the skin, through intervening tissue and then across some or all of the blood vessel (e.g., the great saphenous vein near the sapheno-femoral junction) so as to occlude the blood vessel. This occlusion (or multiple of these occlusions) will thereby treat varicose veins. In one form of the invention, the occluder is configured to occlude the vein by compressing the vein and closing down its lumen; and in another form of the invention, the occluder is configured to occlude the vein by depositing a mass within the lumen of the vein so as restrict blood flow through the lumen of the vein. The occlusion of the lumen may be complete or partial. If the occlusion is partial, some blood may continue to flow in the vein. Such partial occlusion can act to relieve some of the pressure on the valve, thereby improving its function. In some applications, an occlusion of 70% or greater of the lumen may be desired and realized based on the current invention. In other applications, an occlusion of 80% or greater of the lumen may be desired and realized based on the current invention. In one embodiment, the occlusion pressure applied may be greater than 40 mm of mercury. In another embodiment of the present invention, the occlusion pressure may be greater than the pressure of the typical blood flow in the vein. 
         [0100]    Looking first at  FIGS. 2-4 , in one form of the invention, there is provided an occluder  30 . Occluder  30  comprises an elastic filament  35  which, in an unconstrained condition, comprises a generally non-linear configuration (e.g., a coiled mass) but which, when properly restrained, can maintain a linear configuration (e.g., in the narrow lumen  40  of a needle  45 , or where the filament is formed out of a shape memory material, by appropriately controlling its temperature and hence its shape); when the restraint is removed (e.g., the elastic filament  35  is extruded from the constraining lumen  40  of the needle  45 , or the temperature of the shape memory material is elevated such as by body heat), elastic filament  35  will return to its generally non-linear configuration, whereby to provide enlarged masses for occluding the vein. 
         [0101]    In one form of the invention, the occluder is formed out of a shape memory material (e.g., a shape memory alloy such as Nitinol, or a shape memory polymer), with the shape memory material being configured to provide superelasticity, or temperature-induced shape changes, or both). 
         [0102]    In one preferred method of use, the occluder  30  is installed in the narrow lumen  40  of a needle  45  ( FIG. 2 ), the needle is introduced percutaneously and advanced across the vein which is to be occluded (e.g., the great saphenous vein  15 ), a first length of the occluder is extruded from the needle on the far side of the vein so that a portion of the occluder is restored to a coiled mass configuration  50  on the far side of the vein ( FIG. 3 ), the needle is withdrawn back across the vein, and then the remainder of the occluder is extruded on the near side of the vein ( FIG. 4 ), whereupon the remainder of the occluder is restored to a coiled mass configuration  55 , with a portion  57  of the occluder extending across the lumen  60  of the vein  15 , and with the portions of the occluder on the far and near sides of the vein (i.e., the coiled masses  50  and  55 , respectively) being drawn toward one another under the coiling force inherent in the elastic filament so as to compress the vein there between and occlude its lumen  60 , whereby to restrict blood flow through the vein and thereby treat the varicose veins. 
         [0103]    As noted above, occluder  30  may be formed out of a shape memory material (e.g., a shape memory alloy such as Nitinol, or a shape memory polymer, etc.), with the shape memory material being configured to provide superelasticity, or temperature-induced shape changes, or both). 
         [0104]    In the form of the invention shown in  FIGS. 2-4 , occluder  30  is formed out of a single elastic filament  35 , and a shape transition (i.e., from substantially linear to a pair of opposing coiled masses  50 ,  55 ) is used to cause occlusion of the target blood vessel. In this respect it should be appreciated that the aforementioned coiled masses  50 ,  55  may comprise substantially random turns of the elastic filament arranged in a substantially three-dimensional structure (i.e., somewhat analogous to a ball of string), or the coiled masses  50 ,  55  may comprise highly reproducible structures such as loops, coils, etc., and these loops, coils, etc. may or may not assume a substantially planar structure. See, for example,  FIG. 5 , where coiled masses  50 ,  55  comprise highly reproducible loops and coils. 
         [0105]      FIGS. 6 and 7  show an exemplary syringe-type inserter  65  which may be used to deploy the novel occluder of the present invention. The syringe-type inserter  65  may contain one occluder  30  or multiple pre-loaded occluders  30 , e.g., where syringe-type inserter  65  comprises multiple occluders  30 , the occluders may be disposed serially within the syringe-type inserter, or they may be disposed parallel to one another within the syringe-type inserter (i.e., in the manner of a “Gatling gun” disposition), etc. When the syringe-type inserter  65  is activated, an occluder  30  is deployed out of the distal end of needle  45 . 
         [0106]    In  FIGS. 2-4 , occluder  30  is shown occluding the vein by compressing the vein between the two coiled masses  50 ,  55 , whereby to close down its lumen  60 . However, in another form of the invention, the occluder  30  can be used to occlude the vein without compressing the vein. This is done by depositing a coiled mass within the lumen of the vein, whereby to restrict blood flow through the lumen of the vein. More particularly, and looking now at  FIGS. 8-10 , in this form of the invention, the needle  45  is passed into the interior of the vein  15  and one coiled mass  50  of the occluder  30  is extruded into the lumen  60  of the vein ( FIG. 8 ) so as to occlude the lumen of the vein, the needle  45  is withdrawn to the near side of the vein ( FIG. 9 ), and then another coiled mass  55  is disposed on the near side of the vein ( FIG. 10 ), with the portion  57  of the occluder extending through the side wall of the vein so as to stabilize the occluder relative to the vein (i.e., so as to attach the occluder to the vein and prevent the occluder from moving relative to the vein). 
         [0107]      FIGS. 11-14  show another approach where a coiled mass of the occluder  30  is deposited within the interior of the blood vessel so as to obstruct blood flow through the vessel. More particularly, in this form of the invention, the needle  45  is passed completely through the vein ( FIG. 11 ), a coiled mass  50  of the occluder is deposited on the far side of the vein ( FIG. 12 ), the needle is withdrawn into the interior of the vein where another coiled mass  55  of the occluder is deposited ( FIG. 13 ), and then the needle is withdrawn to the near side of the vein where another coiled mass  70  of the occluder  30  is deposited ( FIG. 14 ). In this form of the invention, coiled mass  55  resides within the lumen  60  of the vein and obstructs blood flow while coiled masses  50  and  70  compress the vein inwardly and stabilize the disposition of the intraluminal coiled mass  55 . 
         [0108]      FIGS. 15 and 16  show occluders  30  formed out of a single strand of elastic filament. In  FIG. 15 , the occluder  30  comprises a relatively ordered coil where the turns  72  of the coil are unidirectional. In  FIG. 16 , the occluder  30  comprises another relatively ordered coil but where the turns rotate in opposite directions on different sides of a midpoint  75 . Of course, it should also be appreciated that the occluder  30  can be constructed so as to form a relatively disordered coil, i.e., where the strand of the filament follows a relatively random pattern (see, for example, the disordered coils illustrated in  FIGS. 8-10 ). Indeed, where it is desired that the mass of the reformed coil itself provide a flow obstruction (e.g., where the reformed coil is disposed intraluminally so as to impede blood flow through the vein), it is generally preferred that the elastic filament reform into a relatively disordered coil having a relatively random disposition, since this can provide a denser filament configuration. 
         [0109]      FIG. 17  shows an occluder  30  formed out of multiple strands of elastic filaments  35 . In one form of the invention, these multiple strands are joined together at a joinder  80 . Again, the coils (e.g., the aforementioned coiled masses  50 ,  55 ,  70 ) formed by these multiple strands can be relatively ordered or relatively disordered.  FIGS. 18 and 19  show how the multistrand occluder of  FIG. 17  can be used to occlude a vein by forming coiled masses  50 ,  55  to compress the side wall of the vein inwardly so as to restrict blood flow through the vein.  FIG. 20  shows how the multi-strand occluder  30  of  FIG. 17  can be used to occlude a vein by depositing a coiled mass  55  within the lumen  60  of the vein, whereby to restrict blood flow through the lumen of the vein. In  FIG. 20 , a number of the elastic filaments  35  are shown piercing the side wall of the vein so as to hold the coiled mass  55  in position within the lumen of the blood vessel. 
         [0110]      FIGS. 21-24  show another form of occluder  30  where the occluder is formed by structures other than a filament. By way of example but not limitation, the occluder  30  may comprise a transluminal section  85 , a far side lateral projection  90  and a near side lateral projection  95 , with the far side lateral projection  90  and the near side lateral projection  95  being held in opposition to one another so as to close down the lumen  60  of the vein  15 . Such an arrangement may be provided by many different types of structures, e.g., such as the “double T-bar” structure shown in  FIGS. 25-27  where the transluminal section  85  of the occluder  30  is formed out of an elastic material which draws the two opposing T-bars  90 ,  95  of the occluder together so as to provide vessel occlusion. Still other arrangements for connecting and drawing together a far side lateral projection  90  and a near side lateral projection  95  will be apparent to those skilled in the art in view of the present disclosure. By way of further example but not limitation, far side lateral projection  90  and near side lateral projection  95  may be connected together by a loop of suture, with the loop of suture being lockable in a reduced size configuration (i.e., so as to maintain occlusion) with a sliding locking knot. 
         [0111]    Furthermore, multiple occluders  30  may be used on a single blood vessel or tissue to occlude the blood vessel more completely, or to occlude a blood vessel in multiple regions, or to attach a material (e.g., a drug or cellular delivery element) in multiple places to the blood vessel. The occluders may be coated with a drug-eluting compound, or the occluders may be electrically charged to enhance or prevent clotting or to deliver a desired compound or agent to the blood vessel, etc. If desired, the location of the occluding or attachment element may be precisely controlled to deliver the desired compound or agent at a specific anatomical location. 
       Endoluminal Approach 
       [0112]    In the endoluminal approach, the occluder  30  is delivered to the occlusion site by endoluminally advancing the occluder up the vein using a catheter, and then deploying the occluder in the vein, with the occluder acting to occlude the vein and thereby treat varicose veins. In this form of the invention, the occluder is preferably passed through one or more side walls of the vein so as to stabilize the occluder relative to the vein. In one form of the invention, the occluder is configured to occlude the vein by depositing a mass within the lumen of the vein so as to restrict blood flow through the lumen of the vein; and in another form of the invention, the occluder is configured to occlude the vein by compressing the vein and closing down its lumen. 
         [0113]    More particularly, and looking now at  FIGS. 28 and 29 , a catheter  100  is used to endoluminally advance the occluder  30  up the interior of the vein  15  to a deployment site. Then one end of the occluder is passed through the side wall of the vein so as to deposit a coiled mass  50  of the occluder  30  outside the vein, and the remainder of the occluder is deposited as a coiled mass  55  within the lumen  60  of the vein, with a portion  57  of the occluder extending through the side wall of the vein so as to attach the occluder to the side wall of the vein and thereby stabilize the occluder relative to the vein. Thus, in this form of the invention, a coiled mass  55  of the occluder is deposited within the interior of the vein so as to restrict blood flow through the vein and thereby treat varicose veins. 
         [0114]      FIGS. 30 and 31  show how two separate occluders  30 , each used in the manner shown in  FIGS. 28 and 29 , can be used to increase the coiled mass of occluder contained within the lumen of the vein, whereby to increase the extent of occlusion of the lumen of the vein. 
         [0115]      FIGS. 32 and 33  show how an occluder  30  can be delivered endoluminally and used to compress the outer walls of the vein so as to occlude blood flow through the lumen of the vein. More particularly, in this form of the invention, the occluder  30  is advanced endoluminally through the vein to the deployment site, one end of the occluder is passed through one side wall of the vein so as to deposit a coiled mass  50  on one side of the vein and the other end of the occluder is passed through the other side wall of the vein so as to deposit another coiled mass  55  on the other side of the vein, with the two coiled masses being connected together by the intermediate portion  57  of the occluder and with the two coiled masses being drawn toward one another under the coiling force inherent in the elastic filament so as to apply compressive opposing forces on the two sides of the vein, whereby to compress the vein and close down its lumen. 
       Occlusion in Combination with Phlebectomy 
       [0116]    If desired, the novel occluder of the present invention can be used in conjunction with the removal of the large varicose veins (i.e., phlebectomy). The phlebectomy can be done at the same time as the occlusion of the vein or at another time. For this surgical procedure, minimal local anesthetic is needed. 
       Occluding Tubular Structures for Purposes Other than Treating Varicose Veins 
       [0117]    It will be appreciated that the novel occluder of the present invention can also be used to occlude tubular structures for purposes other than treating varicose veins. By way of example but not limitation, the novel occluder of the present invention can be used to occlude other vascular structures (e.g., to occlude arteries so as to control bleeding), or to occlude other tubular structures within the body (e.g., phallopian tubes, so as to induce infertility), etc. 
       Drug/Cellular Delivery Applications 
       [0118]    Furthermore, using the foregoing concept of minimally-invasive hollow tube penetration, and attachment and fixation of the device to the vessel wall, either percutaneously or endoluminally, the occluder  30  may be modified so as to allow drug/cellular delivery at fixed points within or adjacent to the vasculature or other hollow bodily structure. In this form of the invention, the device functions as a drug/cellular delivery stabilizer, and may or may not function as an occluder. See, for example,  FIGS. 34 and 35 , where an elastic filament  35 , having a drug/cellular delivery body  105  attached thereto, is advanced across a blood vessel  110  using a needle  115 , with the distal end of the elastic filament forming a coiled mass  120  on the far side of the blood vessel and the drug/cellular delivery body  105  being securely disposed within the lumen  125  of the blood vessel.  FIGS. 36 and 37  show a similar arrangement where a catheter  130  is used to deliver the device endoluminally.  FIGS. 38 and 39  show another arrangement wherein the device is delivered percutaneously so that the coiled mass is disposed inside lumen  125  of the blood vessel and the drug/cellular delivery body  105  is disposed outside the blood vessel, and  FIGS. 40 and 41  show how the device is delivered endoluminally so that the coiled mass is disposed inside lumen  125  of the blood vessel and the drug/cellular delivery body  105  is disposed outside the blood vessel. These drug/cellular delivery devices may be passive or active polymers or silicon-based or micro- and nanotechnology devices, or matrices of materials, etc. 
       Two-Part Occluder 
       [0119]    Looking next at  FIG. 42 , there is shown a two-part occluder  200  formed in accordance with the present invention. Two-part occluder  200  generally comprises a distal implant  205  and a proximal implant  210 . 
         [0120]    Distal implant  205  is shown in further detail in  FIGS. 43-46 . Distal implant  205  comprises a distal implant body  215  and a distal implant locking tube  220 . Distal implant body  215  comprises a tube  225  having a distal end  226 , a proximal end  227 , and a lumen  230  extending therebetween. Tube  225  is slit intermediate its length so as to define a plurality of legs  235 . A set of inwardly-projecting tangs  240  are formed in tube  225  between legs  235  and proximal end  227 . A set of windows  245  are formed in tube  225  between inwardly-projecting tangs  240  and proximal end  227 . Distal implant body  215  is preferably formed out of an elastic material (e.g., a shape memory material having superelastic properties such as Nitinol or superelastic polymers, including superelastic plastics) and constructed so that its legs  235  normally project laterally away from the longitudinal axis of tube  225  (e.g., in the manner shown in  FIGS. 43 and 44 ), however, due to the elastic nature of the material used to form distal implant body  215 , legs  235  can be constrained inwardly (e.g., within the lumen of a delivery needle, as will hereinafter be discussed) so that distal implant body  215  can assume a substantially linear disposition. See, for example,  FIG. 46 , which shows legs  235  moved inwardly relative to the position shown in  FIGS. 43 and 44 . However, when any such constraint is removed, the elastic nature of the material used to form distal implant body  215  causes legs  235  to return to the position shown in  FIGS. 43 and 44 . 
         [0121]    Distal implant locking tube  220  ( FIG. 45 ) comprises a generally tubular structure having a distal end  250 , a proximal end  260  and a lumen  262  extending therebetween. A set of windows  265  are formed in the distal implant locking tube  220 , with windows  265  being disposed distal to proximal end  260 . 
         [0122]    Distal implant locking tube  220  is disposed within lumen  230  of distal implant body  215 . When distal implant  205  is in its aforementioned substantially linear condition (i.e., with legs  235  restrained in an in-line condition), distal implant locking tube  220  terminates well short of tangs  240  of distal implant body  215 , so that the proximal end  227  of distal implant body  215  can move longitudinally relative to distal end  226  of distal implant body  215 . However, when the proximal end  227  of distal implant body  215  is moved distally a sufficient distance to allow full radial expansion of legs  235  (see  FIG. 42 ), locking tangs  240  of distal implant body  215  will be received within windows  265  of distal implant locking tube  220 , whereby to lock distal implant  205  in its radially-expanded condition (i.e., with legs  235  projecting laterally away from the longitudinal axis of tube  225 , e.g., in the manner shown in  FIGS. 43 and 44 ). Spot welds applied via openings  270  formed in the distal end  226  of distal implant body  215  serve to lock distal implant locking tube  220  to distal implant body  215 , whereby to form a singular structure (see  FIGS. 43 and 46 ). 
         [0123]    Looking next at  FIGS. 47 and 48 , proximal implant  210  comprises a tube  275  having a distal end  280 , a proximal end  285 , and a lumen  290  extending therebetween. Tube  275  is slit at its distal end so as to define a plurality of legs  295 . A set of inwardly-projecting tangs  300  are formed in tube  275  between legs  295  and proximal end  285 . Proximal implant  210  is preferably formed out of an elastic material (e.g., a shape memory material having superelastic properties such as Nitinol) and constructed so that its legs  295  normally project laterally away from the longitudinal axis of tube  275  (e.g., in the manner shown in  FIG. 47 ), however, legs  295  can be constrained inwardly (e.g., within the lumen of a delivery tube, as will hereinafter be discussed) so that proximal implant  210  can assume a substantially linear disposition. See, for example,  FIG. 48 , which shows legs  295  moved inwardly relative to the position shown in  FIG. 47 . However, when any such constraint is removed, the elastic nature of the material used to form proximal implant  210  causes legs  295  to return to the position shown in  FIG. 47 . 
         [0124]    As will hereinafter be discussed, distal implant  205  and proximal implant  210  are configured and sized so that tube  225  of distal implant body  215  can be received in lumen  290  of proximal implant  210 , with the expanded legs  235  of distal implant  205  opposing the expanded legs  295  of proximal implant  210  (see, for example,  FIG. 82 ), whereby to impose a clamping action on the side wall of a blood vessel (e.g., vein) disposed therebetween and thereby occlude the blood vessel, as will hereinafter be discussed in further detail (or, as an alternative, the opposing expanded legs of the proximal and distal implants could interdigitate to impose the clamping action). Furthermore, distal implant  205  and proximal implant  210  are configured and sized so that they may be locked in this position, inasmuch as inwardly-projecting tangs  300  of proximal implant  210  will project into windows  245  of distal implant  205 . 
         [0125]    Two-part occluder  200  is intended to be deployed using associated installation apparatus. This associated installation apparatus preferably comprises a hollow needle  305  ( FIG. 49 ) for penetrating tissue, a distal implant delivery tube  310  ( FIG. 50 ) for delivering distal implant  205  through hollow needle  305  to the far side of the blood vessel which is to be occluded, a composite guidewire  315  ( FIGS. 51-56 ) for supplying support to various components during delivery and deployment, a push rod  320  ( FIG. 57 ) for delivering various components over composite guidewire  315 , and a proximal implant delivery tube  330  ( FIG. 58 ) for delivering proximal implant  210  for mating with distal implant  205 , as will hereinafter be discussed. 
         [0126]    Hollow needle  305  ( FIG. 49 ) comprises a distal end  335 , a proximal end  340  and a lumen  345  extending therebetween. Distal end  335  terminates in a sharp point  350 . In one preferred form of the invention, hollow needle  305  comprises a side port  355  which communicates with lumen  345 . 
         [0127]    Distal implant delivery tube  310  ( FIG. 50 ) comprises a distal end  360 , a proximal end  365  and a lumen  370  extending therebetween. 
         [0128]    Composite guidewire  315  ( FIGS. 51-56 ) comprises a guidewire rod  370  and a guidewire sheath  380 . Guidewire rod  370  comprises a distal end  385  and a proximal end  390 . Distal end  385  terminates in an enlargement  395 . Guidewire sheath  380  comprises a distal end  400 , a proximal end  405  and a lumen  410  extending therebetween. The distal end  400  of guidewire sheath  380  comprises at least one, and preferably a plurality of, proximally-extending slits  415 . Proximally-extending slits  415  open on the distal end of guidewire sheath  380  and allow the distal end of guidewire sheath  380  to radially expand somewhat. As will hereinafter be discussed, guidewire rod  370  and guidewire sheath  380  are configured and sized so that guidewire rod  370  can be received in lumen  410  of guidewire sheath  380 . Furthermore, when guidewire rod  370  is forced proximally relative to guidewire sheath  380 , the proximally-extending slits  415  in guidewire sheath  380  allow the distal end of the guidewire sheath  380  to expand somewhat so as to receive at least some of the enlargement  395  formed on the distal end of guidewire rod  370 . As this occurs, the distal end of guidewire sheath  380  will expand radially. 
         [0129]    Push rod  320  ( FIG. 57 ) comprises a distal end  420 , a proximal end  425  and a lumen  430  extending therebetween. 
         [0130]    Proximal implant delivery tube  330  ( FIG. 58 ) comprises a distal end  435 , a proximal end  440  and a lumen  445  extending therebetween. 
         [0131]    Two-part occluder  200  and its associated installation apparatus are preferably used as follows. 
         [0132]    First, hollow needle  305  (carrying distal implant delivery tube  310  therein, which in turn contains the composite guidewire  315  therein, upon which is mounted distal implant  205 ) is passed through the skin of the patient, through intervening tissue, and across the blood vessel (e.g., vein  450 ) which is to be occluded. See  FIGS. 59-61 . As this is done, any blood flowing out side port  355  can be monitored—excessive or pulsatile blood flow can indicate that hollow needle has accidentally struck an artery. 
         [0133]    Next, hollow needle  305  is retracted, leaving distal implant delivery tube  310  extending across the blood vessel. See  FIG. 62 . 
         [0134]    Then distal implant delivery tube  310  is retracted somewhat so as to expose the distal ends of composite guidewire, or rod,  315  and distal implant  205 . See  FIG. 63 . 
         [0135]    Next, composite guidewire  315 , push rod  320  and distal implant  205  are all moved distally, so as to advance the distal ends of composite guidewire  315  and the distal implant  205  out of the distal end of distal implant delivery tube  310 . As this occurs, legs  235  of distal implant  205  are released from the constraint of distal implant delivery tube  310  and expand radially. See  FIGS. 64 and 65 . 
         [0136]    Then, with push rod  320  being held in place against the proximal end of distal implant  205 , composite guidewire  315  is pulled proximally so as to bring the distal end of distal implant  205  toward the proximal end of distal implant  205 , whereby to cause locking tangs  240  of distal implant body  215  to enter windows  265  of distal implant locking tube  220 , whereby to lock legs  235  in their radially-expanded condition (see  FIG. 66 ). 
         [0137]    At this point, hollow needle  305 , distal implant delivery tube  310  and push rod  320  may be removed ( FIG. 67 ), leaving distal implant  205  mounted on composite guidewire  315 , with the legs  235  fully deployed on the far side of the blood vessel and the proximal end of distal implant  205  extending into the interior of the blood vessel ( FIG. 68 ). 
         [0138]    Next, proximal implant delivery tube  330  (carrying proximal implant  210  therein) is advanced down composite guidewire  315 , until the distal end of proximal implant delivery tube  330  sits just proximal to the blood vessel ( FIGS. 69-72 ). 
         [0139]    Then push rod  320  is used to advance the distal end of proximal implant  210  out of the distal end of proximal implant delivery tube  330 . As this occurs, legs  295  are released from the constraint of proximal implant delivery tube  330  and open radially. See  FIGS. 73-76 . 
         [0140]    Next, using push rod  320 , proximal implant  210  is pushed distally as distal implant  205  is pulled proximally using composite guidewire  315 . More particularly, guidewire rod  370  is pulled proximally, which causes enlargement  395  on the distal end of guidewire rod  370  to expand guidewire sheath  380  to a size larger than lumen  262  in distal implant locking tube  220 , which causes guidewire sheath  380  to move proximally, which causes proximal movement of distal implant  205 . As distal implant  205  and proximal implant  210  move together, their legs  235 ,  295  compress the blood vessel, thereby occluding the blood vessel. Distal implant  205  and proximal implant  210  continue moving together until inwardly-projecting tangs  300  of proximal implant  210  enter windows  245  of distal implant  205 , thereby locking the two members into position relative to one another. See  FIG. 77 . 
         [0141]    At this point push rod  320  and proximal implant delivery tube  330  are removed. See  FIG. 78 . 
         [0142]    Next, composite guidewire  315  is removed. This is done by first advancing guidewire rod  370  distally ( FIG. 79 ), which allows the distal end of guidewire sheath  380  to relax inwardly, thereby reducing its outer diameter to a size smaller than lumen  262  in distal implant locking tube  220 . As a result, guidewire sheath  380  can then be withdrawn proximally through the interior of two-part occluder  200 . See  FIG. 80 . Then guidewire rod  370  can be withdrawn proximally through the interior of two-part occluder  200 . See  FIG. 81 . 
         [0143]    The foregoing procedure leaves two-part occluder  200  locked in position across the blood vessel, with the opposing legs  235 ,  295  compressing the blood vessel, whereby to occlude the blood vessel. 
         [0144]      FIGS. 83-86  illustrate another two-part occluder  200 A having a distal implant  205 A and a proximal implant  210 A. Two-part occluder  200 A is generally similar to the aforementioned two-part occluder  200 , except that distal implant  205 A utilizes a unibody construction. 
         [0145]      FIGS. 87-90  illustrate another two-part occluder  200 B. Two-part occluder  200 B is generally similar to the aforementioned two-part occluder  200 A, except that distal implant  205 B utilizes a friction fit to lock distal implant  205 B to proximal implant  210 B. 
         [0146]      FIGS. 91-94  illustrate another two-part occluder  200 C having a distal implant  205 C and a proximal implant  210 C. Two-part occluder  200 C is generally similar to the aforementioned two-part occluder  200 , except that distal implant  205 C comprises a tube  225 C which receives and secures the proximal ends of legs  235 C. Legs  235 C are preferably elongated elements (e.g., bent wires) formed out of a superelastic shape memory material so as to provide the legs  235 C with the desired degree of elasticity. 
         [0147]      FIGS. 95-100  illustrate another two-part occluder  200 D having a distal implant  205 D and a proximal implant  210 D. Two-part occluder  200 D is generally similar to the aforementioned two-part occluder  200 , except that distal implant  205 D comprises a tube or rod  225 D which receives and secures the proximal ends of legs  235 D. Legs  235 D are preferably coils formed out of a superelastic shape memory material so as to provide the legs  235 D with the desired degree of elasticity. 
         [0148]    In the foregoing disclosure, there is a disclosed a composite guidewire  315  for use in delivering distal implant  205  and proximal implant  210  to the anatomy. As noted above, composite guidewire  315  is formed from two parts, i.e., a guidewire rod  370  and a guidewire sheath  380 . By providing composite guidewire  315  with this two-part construction, composite guidewire  315  can have its distal diameter enlarged or reduced as desired so as to permit composite guidewire  315  to bind to distal implant  205 , or be separable from the distal implant  205 , respectively. However, if desired, composite guidewire  315  can be replaced by an alternative guidewire which includes a mechanism for releasably binding the alternative guidewire to distal implant  205 . By way of example but not limitation, such an alternative guidewire may include screw threads, and distal implant  205  may include a screw recess, so that the alternative guidewire can be selectively secured to, or released from, the distal implant  205 , i.e., by a screwing action. 
       Temporary Blood Vessel Occlusion for Extremity Trauma 
       [0149]    Uncontrolled hemorrhage remains the most significant cause of death in victims who survive a major initial trauma, particularly in truncal and extremity injuries. A loss of 50% of blood volume without replenishment is frequently fatal, and a hypotensive patient, who has lost 30%-35% of blood volume and is in uncompensated shock, is generally close to death. 
         [0150]    Establishing and maintaining hemostasis at the site of an injury is an important consideration in the acute management of trauma patients. The tourniquet, with or without local compression, remains the time-honored method for controlling extremity bleeding following trauma. However, tourniquets are generally only useful for controlling bleeding in limbs, and even then tourniquets suffer from the disadvantage that they limit blood flow to the entire limb and cannot target individual blood vessels within the limb. It is estimated that of all military wounded whom ultimately succumb to their wounds, approximately 10-20% die from blood loss due to inadequate compression or tourniquet application. 
         [0151]    Thus there is also a need for effective temporary blood vessel occlusion for military and civilian trauma cases. 
         [0152]    In addition to trauma applications, there are many instances where an occlusion device may be implanted and then, at a later time (e.g., days, months, years), may be removed. Examples of such uses of temporary occlusion devices include reversible occlusion of fallopian tubes, temporary occlusion of the saphenous vein during pregnancy and subsequent removal of the occlusion device at the conclusion of pregnancy so as to restore blood flow through, etc. 
         [0153]    The present invention also envisions deployment of temporary occlusion devices that can be left in the body permanently. 
         [0154]    The present invention also provides a novel temporary occlusion device (hereinafter sometimes referred to as a “temporary occluder”) that can be deployed percutaneously to temporarily occlude major blood vessels (e.g., arteries) until specialized care can be obtained to surgically control massive hemorrhage following civilian or military trauma. The novel temporary occluder of the present invention may be used as an alternative to a conventional tourniquet to control major extremity bleeding following trauma, providing a more effective, reliable and highly targeted method to control major blood vessel hemorrhage. Furthermore, unlike a conventional tourniquet, the temporary occluder of the present invention may be used even in the presence of soft tissue injury with minimal patient discomfort. Once deployed, minimal post-deployment supervision is required during the time required to transport the patient to the specialized care required to surgically repair the damaged blood vessel. The present invention requires accessing the damaged blood vessel (e.g., major artery) with a needle or other device, but this is typically within the level of expertise expected of the average military medic or civilian emergency medical technician. The utilization of ultrasound to identify and access the damaged blood vessel significantly simplifies the temporary occlusion procedure. Deployment comprises passing a portion of the temporary occluder across the blood vessel (e.g., artery) so that a distal portion of the temporary occluder bears against the outside surface of the blood vessel on the far side of the blood vessel, and positioning a proximal portion of the temporary occluder against the outside surface of the blood vessel on the near side of the blood vessel, or against the outside surface of the skin, whereby to establish an occluding compression across the blood vessel. Once deployed, removal of the temporary occluder may be performed in the specialized care center at the appropriate time. Following removal of the temporary occluder, hemostasis of the punctures caused by deployment of the temporary occluder across the blood vessel may be obtained with standard manual compression of the blood vessel, thus minimizing the need for further blood vessel repair. Alternatively, other means such as cauterization of the tissue, deploying a polymeric sealant, or deploying gauze or a pad, or positioning a coated stent in the vessel, may be used to arrest blood flow. 
         [0155]    Looking now at  FIGS. 101-103 , there is shown a temporary occluder  500  formed in accordance with the present invention. Temporary occluder  500  may be used percutaneously to temporarily occlude a blood vessel  505  disposed beneath the surface of skin  510 , wherein intervening tissue  512  is disposed between the surface of skin  510  and blood vessel  505 . 
         [0156]    Temporary occluder  500  generally comprises a distal portion  515  and a proximal portion  520 . Distal portion  515  generally comprises a cylindrical body  525  having a plurality of laterally-expandable legs  530  connected thereto. By way of example but not limitation, distal portion  515  may be formed out of a Nitinol cylinder having distal slits formed therein, whereby to form cylindrical body  525  and laterally-expandable legs  530 . Proximal portion  520  generally comprises a cylindrical body  535  having a plurality of laterally-expandable legs  540  connected thereto. By way of example but not limitation, proximal portion  520  may be formed out of a Nitinol cylinder having proximal slits formed therein, whereby to form cylindrical body  535  and laterally-expandable legs  540 . In one embodiment, each laterally-expandable leg  530 ,  540  is designed with an appropriate length to minimize penetration into any tissues which may reside adjacent to the blood vessel. In one embodiment, each laterally-expandable leg  530 ,  540  is less than about 20 mm in length. In one embodiment, the cylindrical bodies  525 ,  535  are both less than about 18 gauge. Distal portion  515  is sized to be concentrically received within proximal portion  520  (see  FIG. 101 ). In one preferred form of the invention, cylindrical body  535  of proximal portion  520  is approximately aligned with the distal ends of laterally-expandable legs  530  of distal portion  515 , and cylindrical body  525  of distal portion  515  is approximately aligned with the proximal ends of laterally-expandable legs  540  of proximal portion  520 . 
         [0157]    Temporary occluder  500  also comprises a flexible filament  545  having a distal end  550  and a proximal end  555  ( FIG. 103 ). Distal end  550  of flexible filament  545  is secured to cylindrical body  525  of distal portion  515 . 
         [0158]    Temporary occluder  500  is intended to be deployed using a needle  560 , or other tubular element. Needle  560  comprises a distal end  565 , a proximal end  570  and a lumen  575  extending therebetween. Needle  560  is sized to slidably receive temporary occluder  500  within its lumen  575 . 
         [0159]    In use, and looking now at  FIG. 101 , needle  560 , carrying temporary occluder  500  therein, with flexible filament  545  extending from proximal end  570  of needle  560 , is advanced through the skin  510  of the patient, through the intervening tissue  512 , and across the blood vessel  505  which is to be occluded. Then distal portion  515  of temporary occluder  500  is pushed out of needle  560  so that laterally-expandable legs  530  of distal portion  515  deploy on the far side of blood vessel  505 . As distal portion  515  of temporary occluder  500  is pushed out of needle  560 , cylindrical body  525  of distal portion  515  is set so that it is approximately aligned with cylindrical body  535  of proximal portion  520 . Then needle  560  is withdrawn proximally, allowing laterally-expandable legs  540  of proximal portion  520  to deploy on the near side of blood vessel  505 , with laterally-expandable legs  530  of distal portion  515  cooperating with laterally-expanding legs  540  of proximal portion  520  so as to occlude blood vessel  505  ( FIG. 102 ). Needle  560  may then be completely removed, leaving flexible filament  545  extending from the occlusion site up to the surface of the skin  510 . 
         [0160]    Thereafter, when occlusion of blood vessel  505  is no longer necessary, the proximal end  555  of flexible filament  545  (which extends above the surface of skin  510 ) is pulled proximally, whereby to pull distal portion  515  of temporary occluder  500  free of proximal portion  520  of temporary occluder  500 , and thereby restore normal blood flow through blood vessel  505  ( FIG. 103 ). 
         [0161]    In another embodiment of the present invention, the laterally-expandable legs  530 ,  540  may be replaced by resilient (e.g., polymer) disks or umbrella structures that can open laterally. 
         [0162]    In another form of the invention, and looking now at  FIGS. 104-107 , temporary occluder  500  omits the aforementioned flexible filament  545 , and instead provides an introducer  580  for deploying temporary occluder  500  out of needle  560  ( FIGS. 104 and 105 ). However, in this form of the invention, introducer  580  is withdrawn with needle  560 , leaving the deployed temporary occluder  500  isolated at the occlusion site. 
         [0163]    When occlusion of blood vessel  505  is no longer necessary, a guidewire  585  is passed down the lumen  590  of blood vessel  505  and through the deployed temporary occluder  500 . Then an appropriately-sized, non-compliant balloon  595  (e.g., an angioplasty balloon) is advanced, in its deflated state, over guidewire  585  until balloon  595  spans temporary occluder  500 . Then balloon  595  is expanded ( FIG. 106 ) so as to separate distal portion  515  of temporary occluder  500  from proximal portion  520  of temporary occluder  500 , thereby restoring normal blood flow through blood vessel  505 . Finally balloon  595  and guidewire  585  are withdrawn ( FIG. 107 ). 
         [0164]    The balloon  595  may also be made out of an elastomer, e.g., latex or silicone. The balloon  595  may be filled with water or a compound of higher molecular weight than air. The balloon  595  may also be inflated with a polymer that hardens in situ, for applications where it is desirable to permanently maintain occlusion of the blood vessel. Alternatively, balloon  595  may be inflated with a polymer that hardens in situ and thereafter bio-degrades over time. 
         [0165]    Looking next at  FIG. 108 , in another form of the invention, there is provided a temporary occluder  600 . Temporary occluder  600  generally comprises a filament  605  having a distal portion  610  attached thereto, and a proximal portion  615 . Distal portion  610  comprises a plurality of laterally-expanding legs  620  secured to distal portion  610 . 
         [0166]    Temporary occluder  600  is intended to be deployed using a needle, e.g., the aforementioned needle  560  ( FIG. 109 ). 
         [0167]    In use, and looking now at  FIGS. 110-124 , when blood vessel  505  is to be occluded ( FIG. 110 ), filament  605  is loaded into lumen  575  of needle  560  so that distal portion  610  of temporary occluder  600  has its laterally-expanding legs  620  contained within distal end  565  of needle  560 . This may be accomplished by feeding the proximal end  625  ( FIG. 108 ) of filament  605  into distal end  565  of needle  560 , advancing proximal end  625  of filament  605  out of proximal end  570  of needle  560 , and then pulling on proximal end  625  of filament  605  so that laterally-expanding legs  620  are drawn into distal end  565  of needle  560 . Then needle  560 , carrying filament  605  and distal portion  610  therein, is advanced through skin  510  ( FIG. 111 ), through intervening tissue  512  ( FIG. 112 ) and then across the blood vessel  505  which is to be occluded, so that the distal end of needle  560  resides on the far side of the blood vessel ( FIG. 113 ). Then filament  605  is advanced distally so that laterally-expanding legs  620  of distal portion  610  are pushed out of distal end  565  of needle  560 , whereupon the laterally-expanding legs  620  expand ( FIG. 114 ). Then needle  560  is retracted, and proximal portion  615  of temporary occluder  600  is advanced distally along needle  560  and filament  605  so that proximal portion  615  of temporary occluder  600  presses against the outer surface of the skin  510 , whereby to compress blood vessel  505  and the intervening tissue  512  ( FIGS. 115 and 116 ). Then proximal portion  615  of temporary occluder  600  is locked or secured in place ( FIG. 117 ). At this point needle  560  may be completely withdrawn, leaving blood vessel  505  occluded ( FIG. 118 ). 
         [0168]    When occlusion is to be thereafter withdrawn, proximal portion  615  of temporary occluder  600  is removed ( FIG. 119 ), needle  560  is advanced back down filament  605  ( FIG. 120 ), through skin  510 , through intervening tissue  512 , through blood vessel  505  ( FIG. 121 ) and then over laterally-expanding legs  620  ( FIG. 122 ), causing laterally-expanding legs  620  to enter the interior of needle  560 , collapsing laterally-expanding legs  512  in the process. Then needle  560  is withdrawn ( FIG. 123 ), carrying filament  605  and distal portion  610  of temporary occluder  600  with it ( FIG. 124 ). 
         [0169]      FIGS. 125 and 126  show a temporary occluder  625  which comprises another form of the invention. Temporary occluder  625  is substantially the same as the two-part occluder  200 A shown in  FIGS. 83-86 , except that (i) temporary occluder  625  comprises a distal implant  630  having a distal implant body  635  of increased length sufficient to protrude above the surface of skin  510 , and a proximal implant  640  having a proximal implant body  645  of increased length sufficient to protrude above the surface of skin  510 , and (ii) temporary occluder  625  comprises fingers  650  on proximal implant body  645  allowing proximal implant  640  to be unlocked from distal implant  630  when desired. 
         [0170]      FIG. 127  shows a temporary occluder  655  which comprises another form of the invention. Temporary occluder  655  is substantially the same as the two-part occluder  200 A shown in  FIGS. 83-86 , i.e., it comprises a distal implant  660  and a proximal implant  665 , etc., except that in this form of the invention, the proximal end of distal implant  660  is threaded (not shown) as will hereinafter be discussed. 
         [0171]    In this form of the invention, when temporary occluder  655  is to be removed from the patient, a removal device  670  is advanced through skin  510  and intervening tissue  512  until the distal tip  675  of removal device  670  contacts the proximal end of proximal implant  665  ( FIG. 128 ). Ultrasound guidance may be used to facilitate such docking. Then a shaft  680  is extended out of removal device  670  and threaded into distal implant  660  ( FIGS. 128 and 129 ). Next, a pusher tube  685  is advanced over shaft  680  and unlatches proximal implant  665  from distal implant  660  ( FIGS. 130 and 131 ). Pusher tube  685  itself latches onto proximal implant  665  using latching grooves  690  formed in pusher tube  685 , which receive latches  695  of proximal implant  665  ( FIG. 132 ) so as to effect the desired connection. Then shaft  680  is pulled proximally, pulling distal implant  660  through pusher tube  685  and out of the patient ( FIGS. 133-137 ). Next, an external sheath  700  is extended down over pusher tube  685  ( FIG. 138 ) whereby to capture proximal implant  665 , within the external sheath, whereupon proximal implant  665  is removed from the surgical site by pulling pusher tube  685  out of the patient through external sheath  700  ( FIGS. 139 and 140 ). Finally, external sheath  700  is removed from the patient ( FIGS. 141 and 142 ). It should also be appreciated that various other means of attachment and securing the various elements will be apparent to those skilled in the art in view of the present disclosure. 
         [0172]    In another form of the invention, and looking now at  FIGS. 143-148 , a pair of balloons  705 , which may be made of a polymer, or a thin metal or other material, and may be made out of an elastomer, e.g., latex or silicone, are selectively inflated by an inflation line  710 , may be used to establish temporary occlusion of a blood vessel. More particularly, as seen in  FIGS. 143 and 144  a needle  560  is passed from the surface of the skin  510 , through intervening tissue  512  and through a blood vessel  505 . Then a deflated balloon  705  (and its inflation line  710 ) is passed through needle  560  and the needle is deployed on the far side of blood vessel  505  ( FIG. 145 ). Then needle  560  is retracted, paying out inflation line  710  as it goes ( FIG. 146 ). On the near side of blood vessel  505 , a second balloon  505  is positioned (in its deflated condition) on the near side of blood vessel  505 , and then needle  560 , paying out inflation line  710  as it goes, is retracted out of the tissue ( FIG. 147 ). Then inflation line  710  is used to inflate both balloons  705 , whereby to occlude blood vessel  505  ( FIG. 148 ). 
         [0173]    When temporary occlusion is to be withdrawn, balloons  705  are deflated using inflation line  710 , and then the two balloons are pulled free of the anatomy by pulling proximally on inflation line  710 . 
         [0174]    In another form of the invention, and looking now at  FIG. 149 , a balloon  705  may be positioned on the far side of the blood vessel, a cap  615  may be positioned about inflation line  710  at the surface of skin  510 , balloon  705  may be inflated and then tension pulled between inflated balloon  705  and cap  615  so as to occlude blood vessel  505 . 
         [0175]    When temporary occlusion is to be withdrawn, balloon  705  is deflated using inflation line  710 , and then balloon  705  is pulled free of the anatomy by pulling proximally on inflation line  710 . 
         [0176]    In still another form of the invention, and looking now at  FIG. 150 , a balloon  705  may be positioned on the near side of the blood vessel, and then inflated using inflation line  710  so as to bear against blood vessel  505  and thereby occlude the blood vessel. Thus, in this form of the invention, temporary occlusion can be achieved without penetrating the blood vessel. 
         [0177]    When temporary occlusion is to be withdrawn, balloon  705  is deflated using inflation line  710 , and then balloon  705  is pulled free of the anatomy by pulling proximally on inflation line  710 . 
         [0178]    The balloon(s)  705  may be filled with air, water or a compound of higher molecular weight than air. The balloon  705  may also be inflated with a polymer that hardens in situ, for applications where it is desirable to permanently maintain occlusion of the blood vessel. Alternatively, balloon  705  may be inflated with a polymer that hardens in situ and thereafter bio-degrades over time. 
         [0179]    In another embodiment of the present invention, the occluder may comprise a sealed tube having two regions that may be inflated into balloons. These balloon regions are expanded using air or liquid pressure. 
         [0180]    In the foregoing disclosure, there is described an occluder (permanent or temporary, utilizing various constructions) which occludes a hollow structure (e.g., a blood vessel). In this respect it should be appreciated that the occluder may be positioned directly against a surface (e.g., an outer surface) of the hollow structure, or the occluder may be positioned such that an intervening structure or structures (e.g., anatomical tissue) may reside between the occluder and the hollow structure which is to be occluded. In this latter situation, the occluder applies a force to the intervening structure or structures, whereby to occlude the hollow structure which is to be occluded. 
       Using the Temporary Occluder to Occlude Tubular Structures Other than Blood Vessels 
       [0181]    It will be appreciated that the temporary occluder of the present invention can also be used to occlude tubular structures other than blood vessels. By way of example but not limitation, the temporary occluder of the present invention can be used to occlude other structures within the body (e.g., tubes such as fallopian tubes and/or vas deferens for temporary or permanent sterilization, ducts such as bile ducts and cystic ducts for cholecystectomy, lymphatic vessels, including the thoracic duct, fistula tracts, etc.). 
       Modifications of the Preferred Embodiments 
       [0182]    It should be understood that many additional changes in the details, materials (e.g., shape memory polymers that are permanent or that dissolve over time, or carbon nanotube based), 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.