Patent Application
20120109180
The present invention relates generally to medical devices. More particularly the present invention relates to body lumen filter retrieval systems and methods for filtering a body lumen.
Vein thrombosis is a medical condition wherein a blood clot, or thrombus, has formed inside a vein. Such a clot often develops in the calves, legs, or lower abdomen, but can also affect other veins in the body. The clot may partially or completely block blood flow, and may break off and travel through the bloodstream. Commonly, the clot is caused by a pooling of blood in the vein, often when an individual is bed-ridden for an abnormally long duration of time, for example, when resting following surgery or suffering from a debilitating illness, such as a heart attack or traumatic injury. However, there are many other situations that cause the formation of a blood clot.
Vein thrombosis is a serious problem because of the danger that the clot may break off and travel through the bloodstream to the lungs, causing a pulmonary embolism. This is similar to a blockage of the blood supply to the lungs that causes severe hypoxia and cardiac failure, and frequently results in death. For many patients, anti-coagulant drug therapies may be sufficient to dissipate the clots. For example, patients may be treated with anticoagulants such as heparin and with thrombolytic agents such as streptokinase.
Unfortunately, some patients may not respond to such drug therapy or may not tolerate such therapy. Also, there may be other reasons why an anticoagulant is not desirable. For example, patients may have an acute sensitivity to heparin or may suffer from prolonged internal and/or external bleeding as a result of such drug therapies. Also, such drug therapies simply may be ineffective in preventing recurrent pulmonary emboli. In such circumstances, surgical procedures are required to reduce the occurrence of pulmonary emboli. Mechanical interruption of the inferior vena cava typically presents an effective method of preventing of pulmonary embolisms.
Other aspects and features of the present invention will become apparent from consideration of the following description in conjunction with the accompanying drawings.
In one aspect, a filter retrieval system includes a capture structure. The capture structure has an interior space bounded by an at least partially closed distal end and an open proximal end. The filter retrieval system includes an elongate retrieval member slidably disposable within at least a portion of the interior space. The elongate retrieval member includes a retrieval structure adapted to releasably engage at least a portion of a filter.
In another aspect, a filter retrieval system includes filter retrieval means including means for enclosing at least a portion of a filter in a collapsed state. The filter retrieval system includes means for engaging the filter at a deployment site. The means for engaging are configured to direct the filter into at least a portion of the filter retrieval means. The filter retrieval system includes means for delivering the filter retrieval means to the deployment site in a body lumen. The means for delivering has a proximal end and a distal end. The means for engaging is disposed near the distal end of the means for delivering.
In a further aspect, a method for retrieving a filter is disclosed. A filter retrieval system is advanced from an access site into a body lumen until a distal tip of the filter retrieval system approaches a deployment site. A retrieval structure is advanced towards a distal end of the filter retrieval system until the retrieval structure engages a filter. At least a portion of the filter is directed towards a distal end of the capture structure. The filter retrieval system with the filter is removed from the body lumen.
In order to describe the manner in which the above-recited and other advantages and features of the invention can be obtained, a more particular description of the invention briefly described above will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments of the invention and are not therefore to be considered to be limiting of its scope, the invention will be described and explained with additional specificity and detail through the use of the accompanying drawings.
FIG. 3A′ illustrates a top view of the filter retrieval system shown in
FIG. 3B′ illustrates a top view of the filter retrieval system shown in
It should be noted that the figures are not drawn to scale and that elements of similar structures or functions are generally represented by like reference numerals for illustrative purposes throughout the figures. It also should be noted that the figures are only intended to facilitate the description of embodiments of the present invention.
The various embodiments described herein extend generally to filter retrieval systems. By way of example only, implantable lumen filters, such as vena cava filters and other devices may be used to filter blood in blood vessels, which are discussed in reference to the vena cava filter retrieval systems. The various components of these filters and filter systems are also described. These components may include combinations of engagement portions, retrieval portions, and other components related to the vena cava filter retrieval system.
Some implantable lumen filters may be designed to capture and/or lyse particles of a particular size. An implantable lumen filter, when placed in a patient may prevent emboli of a particular size from reaching the pulmonary artery. Some implantable lumen filters may be placed in the inferior vena cava.
Some implantable lumen filters typically use jugular, antecubital, or other access sites for retrieval because they are typically not configured to be retrieved through the femoral access. Rather, some filters may include a distal retrieval structure, such as a hook.
Retrieval through the same access site through which the filter was deployed may be desired. For example, deployment and retrieval through a femoral access site may be desired. At least one embodiment of a filter retrieval system described herein may allow for retrieval of conventional filters through the same or other access site through which the filter was deployed.
Embodiments of a filter retrieval system may include a capture structure configured to enclose at least a portion of a filter. The capture structure may be located near the distal end of the filter retrieval system and may define an inner space by an at least partially closed distal end and an open distal end. In some embodiments, the distal end may be completely closed. At least a portion of the filter may be directed into the capture structure by an elongate retrieval member. The elongate retrieval member may engage the filter and/or position at least a portion of the filter within the capture structure using a retrieval structure, such as a hook. Some filters may include a proximal and/or a distal retrieval structure, such as a hook, that may be engaged by the retrieval structure. Other filters may not include a retrieval structure, but may be other engaged by the retrieval structure.
Referring now to the drawings,
The filter retrieval system 100 may include a retrieval component 113, the use of an embodiment of which is illustrated in
The filter retrieval systems described herein may be manufactured from any suitable material. For example, portions of a filter retrieval system may be, at least partially, formed from various materials such as biocompatible materials. Examples of such biocompatible materials for the filter retrieval systems can include a suitable hydrogel, hydrophilic polymer, biodegradable polymers, bioabsorbable polymers and bioneutral polymers. Examples of such polymers can include poly(alpha-hydroxy esters), polylactic acids, polylactides, poly-L-lactide, poly-DL-lactide, poly-L-lactide-co-DL-lactide, polyglycolic acids, polyglycolide, polylactic-co-glycolic acids, polyglycolide-co-lactide, polyglycolide-co-DL-lactide, polyglycolide-co-L-lactide, polyanhydrides, polyanhydride-co-imides, polyesters, polyorthoesters, polycaprolactones, polyesters, polyanydrides, polyphosphazenes, polyester amides, polyester urethanes, polycarbonates, polytrimethylene carbonates, polyglycolide-co-trimethylene carbonates, poly(PBA-carbonates), polyfumarates, polypropylene fumarate, poly(p-dioxanone), polyhydroxyalkanoates, polyamino acids, poly-L-tyrosines, poly(beta-hydroxybutyrate), polyhydroxybutyrate-hydroxyvaleric acids, other comparable materials, or combinations thereof. Other materials may include shape memory alloys, such as alloys of nickel titanium (nitinol). These materials may include at least one beneficial agent incorporated into the material and/or coated over at least a portion of the material.
The beneficial agents may be applied to filter retrieval systems that have been coated with a polymeric compound. Incorporation of the compound or drug into the polymeric coating of the filter retrieval systems can be carried out by dipping the polymer-coated implantable lumen filter into a solution containing the compound or drug for a sufficient period of time (such as, for example, five minutes) and then drying the coated implantable lumen filter, preferably by means of air drying for a sufficient period of time (such as, for example, 30 minutes). The polymer-coated filter retrieval systems containing the beneficial agent may then be used to retrieve an implantable lumen filter from a body vessel.
The beneficial agents that can be effective in preventing restenosis can be classified into the categories of anti-proliferative agents, anti-platelet agents, anti-inflammatory agents, anti-thrombotic agents, and thrombolytic agents. Anti-proliferative agents may include, for example, crystalline rapamycin. These classes can be further sub-divided. For example, anti-proliferative agents can be anti-mitotic. Anti-mitotic agents inhibit or affect cell division, whereby processes normally involved in cell division do not take place. One sub-class of anti-mitotic agents includes vinca alkaloids. Representative examples of vinca alkaloids include, but are not limited to, vincristine, paclitaxel, etoposide, nocodazole, indirubin, and anthracycline derivatives, such as, for example, daunorubicin, daunomycin, and plicamycin. Other sub-classes of anti-mitotic agents include anti-mitotic alkylating agents, such as, for example, tauromustine, bofumustine, and fotemustine, and anti-mitotic metabolites, such as, for example, methotrexate, fluorouracil, 5-bromodeoxyuridine, 6-azacytidine, and cytarabine. Anti-mitotic alkylating agents affect cell division by covalently modifying DNA, RNA, or proteins, thereby inhibiting DNA replication, RNA transcription, RNA translation, protein synthesis, or combinations of the foregoing.
Anti-platelet agents are therapeutic entities that act by (1) inhibiting adhesion of platelets to a surface, typically a thrombogenic surface, (2) inhibiting aggregation of platelets, (3) inhibiting activation of platelets, or (4) combinations of the foregoing. Activation of platelets is a process whereby platelets are converted from a quiescent, resting state to one in which platelets undergo a number of morphologic changes induced by contact with a thrombogenic surface. These changes include changes in the shape of the platelets, accompanied by the formation of pseudopods, binding to membrane receptors, and secretion of small molecules and proteins, such as, for example, ADP and platelet factor 4. Anti-platelet agents that act as inhibitors of adhesion of platelets include, but are not limited to, eptifibatide, tirofiban, RGD (Arg-Gly-Asp)-based peptides that inhibit binding to gpIIbIIIa or αvβ3, antibodies that block binding to gpIIaIIIb or αvβ3, anti-P-selectin antibodies, anti-E-selectin antibodies, compounds that block P-selectin or E-selectin binding to their respective ligands, saratin, and anti-von Willebrand factor antibodies. Agents that inhibit ADP-mediated platelet aggregation include, but are not limited to, disagregin and cilostazol.
Anti-inflammatory agents can also be used. Examples of these include, but are not limited to, prednisone, dexamethasone, hydrocortisone, estradiol, fluticasone, clobetasol, and non-steroidal anti-inflammatories, such as, for example, acetaminophen, ibuprofen, naproxen, and sulindac. Other examples of these agents include those that inhibit binding of cytokines or chemokines to the cognate receptors to inhibit pro-inflammatory signals transduced by the cytokines or the chemokines. Representative examples of these agents include, but are not limited to, anti-IL1, anti-IL2, anti-IL3, anti-IL4, anti-IL8, anti-IL15, anti-IL18, anti-GM-CSF, and anti-TNF antibodies.
Anti-thrombotic agents include chemical and biological entities that can intervene at any stage in the coagulation pathway. Examples of specific entities include, but are not limited to, small molecules that inhibit the activity of factor Xa. In addition, heparinoid-type agents that can inhibit both FXa and thrombin, either directly or indirectly, such as, for example, heparin, heparin sulfate, low molecular weight heparins, such as, for example, the compound having the trademark Clivarin®, and synthetic oligosaccharides, such as, for example, the compound having the trademark Arixtra®. Also included are direct thrombin inhibitors, such as, for example, melagatran, ximelagatran, argatroban, inogatran, and peptidomimetics of binding site of the Phe-Pro-Arg fibrinogen substrate for thrombin. Another class of anti-thrombotic agents that can be delivered is factor VII/VIIa inhibitors, such as, for example, anti-factor VII/VIIa antibodies, rNAPc2, and tissue factor pathway inhibitor (TFPI).
Thrombolytic agents, which may be defined as agents that help degrade thrombi (clots), can also be used as adjunctive agents, because the action of lysing a clot helps to disperse platelets trapped within the fibrin matrix of a thrombus. Representative examples of thrombolytic agents include, but are not limited to, urokinase or recombinant urokinase, pro-urokinase or recombinant pro-urokinase, tissue plasminogen activator or its recombinant form, and streptokinase.
One or more immunosuppressant agents may be used. Immunosuppressant agents may include, but are not limited to, IMURAN® azathioprine sodium, brequinar sodium, SPANIDIN® gusperimus trihydrochloride (also known as deoxyspergualin), mizoribine (also known as bredinin), CELLCEPT® mycophenolate mofetil, NEORAL® Cylosporin A (also marketed as different formulation of Cyclosporin A under the trademark SANDIMMUNE®), PROGRAM tacrolimus (also known as FK-506), sirolimus and RAPAMUNE®, leflunomide (also known as HWA-486), glucocorticoids, such as prednisolone and its derivatives, antibody therapies such as orthoclone (OKT3) and Zenapax®, and antithymyocyte globulins, such as thymoglobulins. In addition, a crystalline rapamycin analog, A-94507, SDZ RAD (a.k.a. Everolimus), and/or other immunosuppressants.
The capture structure 116 may be configured to receive at least a portion of a filter with the filter in a pre-deployed state (i.e. collapsed, longitudinally elongated, etc.). The capture structure 116 may be formed from a flexible material, such as silicone rubber, polyurethane, other flexible materials, or combinations thereof. The material can be similar to the material used in a balloon of a balloon catheter.
As mentioned above, the capture structure 116 may be expandable from a pre-capture state toward a capture state. The capture structure 116 is shown in
In still another configuration, the capture structure 116 can be mechanically opened and closed using a tether or actuator that extends from the proximal end 104 toward the distal end 106 of the delivery catheter 102. The tether or actuator can extend to one or more frame members pivotally coupled to the distal end of the capture structure. These frame members can be biased to either the pre-capture state or the capture state, such as through the frame members being formed of a shape memory alloy (SMA), such as but not limited to Nitinol, or through the inclusion of a biasing member coupled to the frame members. When the frame members are biased to the pre-capture state, movement of the actuator in either the proximal or distal direction, depending upon the particular configuration, can release the frame members to move outwardly. Upon capture of the filter, movement in the direction opposite to that used to allow outward movement of the frame members allows the biasing frame members to return to the pre-capture state. It will be understood that when the frame members are biased open, movement of the tether or actuator would be used to enable the biased outward movement and subsequent closing of the capture structure.
In still another configuration, the capture structure 116 can include at least one balloon chamber (not shown) that may be inflated to expand the capture structure and/or apply a capture force to a filter received within the capture structure 116 to prevent movement of the filter following retrieval. The one or more balloon chambers may be formed over all or at least a portion of the capture structure, with these balloon chambers optionally being selectively inflatable during the capturing process. In embodiments where the capture structure 116 is inflated, one or more lumens in the delivery catheter 102 may also be provided and fluidly communicate with the one or more balloon chambers. The inclusion of the balloon can optionally be combined with the other configurations described herein, such as the biased frame members, etc.
In use, the capture structure 116 may be disposed at and/or near the distal end 106 of the delivery catheter 102. The capture structure 116 may include a tapered proximal portion 122 which may taper toward the proximal end 116b.
The retrieval structure 118 may be operatively associated with the retrieval member 124, which may be movable. The retrieval member 124 may be configured to facilitate movement of the retrieval structure 118 along the filter retrieval system 100 between the proximal and distal ends 104, 106 of the filter retrieval system 100. For instance, the retrieval member 124 may be a wire attached to the retrieval structure 118 and extending out from the handle 114 to be controlled by the user at and/or near the proximal end 104.
In the present embodiment, the delivery catheter 102 may define a lumen 108 and may be used in combination with a guide wire 110. In other embodiments, the filter retrieval system 100 may be otherwise guided toward a filter. For instance, an imaging device, such as a fluoroscope, x-ray, and/or other imaging device may be used to guide the filter retrieval system toward the filter.
The guide wire 110 can extend through the lumen 108 and extend from the lumen 108 through a distal tip 112 at and/or near the distal end 106. The lumen 108, for example, can have an inner diameter of about 1F to about 5F. The guide wire 110 may extend through the delivery catheter 102 from the proximal end 104 toward the distal end 106. The guide wire 110 may be accessible by a handle 114 at and/or near the proximal end 104 of the delivery catheter 102. The handle 114 may be configured to be grasped by a technician during insertion and/or removal of the delivery catheter 102.
The guide wire 110 may be used to guide a distal end 106 of the delivery catheter 102 toward the delivery site. The filter 120 may be disposed within the delivery catheter 102 in a collapsed state. While in the collapsed state, the filter 120 may be longitudinally elongated with respect to a deployed state.
The guide wire 110 may be removed after the distal end 106 of the delivery catheter 102 is located near the delivery site. Alternatively, the guide wire 110 may remain in the delivery catheter 102 during the filter retrieval process discussed above.
The retrieval structure 118 may extend out from the lumen 108 through an aperture 126, such as an elongated slot, slit, or groove, disposed along an outer wall of the delivery system at and/or near the distal end 106. The aperture 126 may extend from near the distal end 116a beyond the proximal end 116b of the capture structure 116.
The filter 120 may be inserted and retrieved through the radial vein access site 254c. Additionally, the filter 120 may be inserted and retrieved through the jugular vein access site 254b. Further, the filter 120 may be inserted and retrieved through the femoral artery access site 254a.
The filter 120 may be deployed near a deployment site 256. In the present embodiment, the deployment site 256 may include a location within the inferior vena cava. In other embodiments, other deployment sites may be used, such as the superior vena cava. For example, the deployment site 256 may include all larger veins.
As mentioned above, some body lumen filters typically use jugular, antecubital, or other access sites for retrieval because they are typically not configured to be retrieved through the femoral access. Retrieval through the same access site through which the filter was deployed may be desired. At least we one embodiment of a filter retrieval system may provide for retrieval through the same access site through which the filter was deployed.
Components of the filter retrieval system 100 may be sized and configured to position the proximal end 116b of the capture structure 116 beyond a distal end 320a of the filter 320 in a pre-capture state. For instance, the filter retrieval system 100 may be sized and configured to be inserted through at least one aperture 330. As illustrated in FIGS. 3A and 3A′, the filter retrieval system 100 is inserted in a pre-capture state through an aperture 330 near the center of the body lumen 121 and/or filter 320. In other embodiments, the filter retrieval system 100 may be inserted through any appropriate aperture 330 or may be otherwise positioned.
The filter 320 may be configured to travel between a deployed (i.e. pre-capture) state and a pre-deployed (i.e. captured) state. The interior space of the capture structure 116 may be configured to be about the same or less than the general size of the body 338 in the pre-deployed state. The deployed diameter of the body 338 may allow the filter 320 to expand to a diameter that substantially traverses the cross sectional area of the body lumen being treated.
The filter 320 can be made from similar materials and/or components of the filter retrieval system 100 or other materials and/or coatings. Apertures 330 can be formed in a precise pattern using a laser or other ablation techniques or by mechanical techniques. As shown, the filter 320 may include a retrieval mechanism 340. The retrieval mechanism 340 may be connected to the proximal end 320b of the filter 320. For instance, the retrieval mechanism 340 may be connected to the proximal end 320b by the body 338. A retrieval mechanism 340 connected to the proximal end 320b would typically be used to retrieve the filter 320 through an access site that is closer to the proximal end 320b than to the distal end 320a. However, as illustrated, the filter 320 may be removed through an access site that is closer to the proximal end 320b than to the distal end 320a using the body 338. In other embodiments, the filter 320 may include a retrieval mechanism 340 connected to the distal end 320a of the filter 320. In further embodiments, the filter 320 may not include a retrieval mechanism 340.
The size of apertures 330 can vary along the length of filter 320. For example, the apertures 330 may increase or decrease in size as they approach the proximal end 104. The size of the apertures 330 may transition gradually or abruptly in a proximal or distal direction. The shape of the apertures 330 can be circular, rectangular, square, trapezoidal, oval, slit, or other shapes. The edges of the apertures 330 can be mechanically or chemically chamfered, etched, or polished to provide a smooth and/or rounded shoulder to streamline the passage of blood from within the conical shape portion of the filter 320 to outside of the filter 320. The filter 320 may be configured to capture and/or lyse a variety of particles. The aperture 330 can be sized to reduce stagnation and/or re-circulation of bodily fluids (i.e. blood) in and/or around the filter 320 while in use.
The filter 320 may be implanted in a body lumen of the patient. The filter 320 may be inserted and/or retrieved through an access site, such as femoral artery, jugular, or radial vein access sites (shown as 154a, 154b, 154c, respectively, in
Components of the filter retrieval system 100 may be sized and configured to position the proximal end 116b of the capture structure 116 beyond a distal end 320a′ of the filter 320′ in a pre-capture state. For instance, the filter retrieval system 100 may be sized and configured to be inserted through at least one aperture 330′. As illustrated in FIGS. 3B and 3B′, the filter retrieval system 100 is inserted in a pre-capture state through an aperture 330 near the inner surface of the body lumen 121. In other embodiments, the filter retrieval system 100 may be inserted through any appropriate aperture 330′.
As shown, the proximal end 116b of the capture structure 116 may be positioned beyond the distal end 320a of the filter 320 in a pre-capture state. As illustrated, the filter retrieval system 100 is inserted in a pre-capture state through an aperture 330 near the center of the body lumen 121 and/or filter 320. In other embodiments, the filter retrieval system 100 may be inserted through any appropriate aperture 330.
The retrieval component 113 may be positioned with respect to the filter 320. For example, the elongate retrieval member 124 may move the retrieval structure 118 to engage the filter 320. The retrieval structure 118 may engage a portion of the body 338. As shown, the retrieval structure 118 may engage a portion of the body 338 near the distal end 320a.
As shown, the proximal end 116b of the capture structure 116 may be positioned beyond the distal end 320a′ of the filter 320′ in a pre-capture state. As illustrated, the filter retrieval system 100 is inserted in a pre-capture state through an aperture 330′ near the inner surface of the body lumen 121. In other embodiments, the filter retrieval system 100 may be inserted through any appropriate aperture 330′.
The retrieval component 113 may be positioned with respect to the filter 320′. For example, the elongate retrieval member 124 may move the retrieval structure 118 to engage the filter 320. The retrieval structure 118 may engage a portion of the body 338. As shown, the retrieval structure 118 may engage a portion of the body 338 generally away from the distal end 320a′ (illustrated as closer to the proximal end 320b′ than the distal end 320a′).
At least a portion of the filter 120 may be directed into the capture structure 116. As shown, the entire filter 120 may be directed into the capture structure 116. The filter 120 may transition from a deployed state toward a captured state (i.e. collapsed, longitudinally elongated, etc.).
The capture structure 116 is shown transitioned from an expanded state toward a pre-capture state. As discussed above, the capture structure 116 may expand to receive at least a portion of the filter 120. In embodiments where the capture structure 116 may expand to receive at least a portion of the filter 120, the capture structure 116 may reduce in diameter after receiving at least a portion of the filter 120.
After at least a portion of the filter 120 has been directed into the capture structure 116, the filter retrieval system 100 may be removed from the deployment site (shown as 256 in
The invention is susceptible to various modifications and alternative means, and specific examples thereof have been shown by way of example in the drawings and are herein described in detail. It should be understood, however, that the invention is not to be limited to the particular devices or methods disclosed, but to the contrary, the invention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the claims.
This patent application claims the benefit of and priority to U.S. Provisional Patent Application having Ser. No. 61/138,386, filed on Dec. 17, 2008, the disclosure of which is incorporated herein by reference in its entirety.
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/US09/68259 | 12/16/2009 | WO | 00 | 12/12/2011 |
| Number | Date | Country | |
|---|---|---|---|
| 61138386 | Dec 2008 | US |
