Patent Application
20100256669
Inferior vena cava (IVC) filters are devices configured for insertion into the inferior vena cava to capture particles that may be present in the blood stream which, if transported to, for example, the lungs could result in serious complications and even death. Typically, IVC filters are utilized in patients who have a contraindication to anticoagulation or in patients developing clinically apparent deep vein thrombosis (DVT) and/or pulmonary embolism (PE). Patients who have recently suffered from trauma, have experienced a heart attack (myocardial infarction), or who have undergone major surgical procedure (e.g., surgical repair of a fractured hip, etc.) may develop clinically apparent DVT. When a thrombus clot loosens from the site of formation and travels to the lung, it may cause PE, a life-threatening condition. An IVC filter may be placed in the circulatory system to intercept one or more clots and prevent them from entering the lungs. IVC filters are either permanent or retrievable.
There are many different configurations for IVC filters, including those that include a central hub from which extend a plurality of struts that form filter baskets having a conical configuration, such as disclosed in U.S. Pat. No. 6,258,026, which is incorporated by reference in its entirety into this application. Other IVC filter configurations utilize wires and/or frame members to form straining devices that permit flow of blood while trapping larger particles. IVC filters are generally configured for compression into a small size to facilitate delivery into the inferior vena cava and subsequent expansion into contact with the inner wall thereof. The IVC filter may later be retrieved from the deployed site by compressing the legs, frame members, etc., depending on the filter configuration. Typically, an IVC filter will include hooks or anchoring members for anchoring the filter in position within the inferior vena cava. The hooks may be more elastic than the legs or frame members to permit the hooks to straighten in response to withdrawal forces, which facilitate withdrawal from the endothelium layer of the blood vessel without risk of significant injury to the vessel wall.
The following references relate to IVC filters: U.S. Pat. No. 5,059,205; U.S. Pat. No. 5,893,869; U.S. Pat. No. 6,059,825; U.S. Pat. No. 6,497,709; U.S. Pat. No. 6,517,559; U.S. Pat. No. 6,623,506; US Publication No. 2002/0193828; US Publication No. 2004/0073252; US Publication No. 2004/0158273; US Publication No. 2004/0230220; US Publication No. 2005/0055045; and US Publication No. 2005/0131451, which are incorporated by reference in their entireties into this application.
Applicants have recognized that it would be desirable to provide an IVC filter that includes one or more members arranged helically along a longitudinal axis of the IVC filter, and embodiments of such an IVC filter are described herein.
Accordingly, blood vessel filters are described herein, having one or more members arranged helically along a longitudinal axis of the filter. In one embodiment, a blood vessel filter includes a plurality of legs extending radially outward from a proximal portion of the filter along a longitudinal axis, the legs including a hook on a distal end thereof, and a filament connecting the legs, the filament traveling in a first helical path around the legs along the longitudinal axis.
In another embodiment, a blood vessel filter includes an elongated wire member arranged helically along a longitudinal axis, wherein both a proximal free end of the elongated wire member and a distal free end of the elongated wire member are positioned at a proximal end of the filter, the elongated wire member radially expanding along a first helical path from the proximal free end of the elongated wire member to a distal end of the filter and radially decreasing along a second helical path from the distal end of the filter to the distal free end of the elongated wire member.
These and other embodiments, features and advantages will become more apparent to those skilled in the art when taken with reference to the following more detailed description of the invention in conjunction with the accompanying drawings that are first briefly described.
The following detailed description should be read with reference to the drawings, in which like elements in different drawings are identically numbered. The drawings, which are not necessarily to scale, depict selected embodiments and are not intended to limit the scope of the invention. The detailed description illustrates by way of example, not by way of limitation, the principles of the invention. This description will clearly enable one skilled in the art to make and use the invention, and describes several embodiments, adaptations, variations, alternatives and uses of the invention, including what is presently believed to be the best mode of carrying out the invention.
The filter embodiments discussed below may be used for insertion into the inferior vena cava or other blood vessels or cavities in a mammalian body. As used herein, the term “suture material” means a material that is, or could be, used as a suture thread by a surgeon, including, for example, synthetic polymers, polyglycolic acid (PGA), polydioxanone (PDS), polyglactin, nylon, polypropylene (prolene), silk, catgut, non-absorbable/non-biodegradable materials, and combinations thereof. Included in the term “suture material” are both monofilament and multifilament arrangements. Also, as used herein, the term “hook” denotes any suitable mechanism to connect the filter to the biological tissue such as, for example, a hook, a rod with barbs, double hooks, or arrow heads. Examples of hooks are provided in U.S. Pat. No. 6,258,026, which is incorporated by reference in its entirety into this application.
Referring to
The legs 12 may be circumferentially spaced equidistant from one another or may be otherwise arranged in an unbalanced configuration. In one embodiment, the legs 12 have a length that is approximately equivalent to one another, but in other embodiments, the legs have different lengths. For example, a first set of legs 12 could have a first length and a second set of legs 12 could have a second length greater than the first length. In this example, each of the first set of legs could be positioned between successive second set of legs so that the lengths of the legs alternate between a first length and second length about the circumference of the filter. Of course, numerous alternate configurations are possible with respect to the lengths and arrangements of legs 12, as one skilled in the art would appreciate, and such alternate configurations are within the scope of the invention. The legs 12 of filter 10 are shown in an expanded configuration, defining an expanded perimeter of the filter 10. For delivery of the filter 10 to a blood vessel, the legs 12 are compressed to a collapsed configuration, defining a collapsed perimeter of the filter 10 smaller than the expanded perimeter of the filter 10.
Attached to the distal end of each of the legs 12 is a hook 16 in the embodiment shown in
A filament 14 connects the legs 12 along their length distal to the proximal end thereof attached to the hub 18, the filament 14 as shown in
Variations on attachment of the filament 14 to the legs 12 include attaching the filament to each leg 12, to alternating legs 12, to every third leg 12, etc. Although a single filament 14 is shown traveling along a helical path down the longitudinal axis L of filter 10, other embodiments are also possible. For example, two or more filaments 14 could be spaced apart and arranged in a helical path down the longitudinal axis of filter 10, two or more filaments 14 could be arranged in opposing helical paths, etc. In addition, while the filament 14 is shown in
In an alternative embodiment, shown here in
As shown in
In the preferred embodiments described herein, it is believed that further reduction in trauma on the blood vessel wall during removal can be achieved by having the hooks 160 attached respectively to elongated members 150 so that they can be retracted at least partly into the hollowed tubes 120 prior to retracting the entire filter 100 proximally during a recovery or repositioning procedure of the filter 100.
Referring to
Because the cone 304 is generally stationary, it tends to force the boss portion 170 to remain stationary and therefore the hollow tubes 120 are also stationary, while the elongated members 150 are being pulled downstream by virtue of the connection between the members 150 to the snareable member 180. This has the effect of retracting the elongated members 150 and hooks 160 (which are now deformed towards a generally linear configuration) into the tubes 120. Continued movement of the snare 302 downstream at a predetermined point will also pull the cone 304 downstream into the catheter tube 312, shown here in
It is believed that the designs of the embodiments exemplarily described and shown in FIGS. 1 and 2A-2F are advantageous for many reasons. First, the filament 14 and the plurality of extending appendages provide for two levels of blood filtration similar to that of the two-conical filter baskets of U.S. Pat. No. 6,007,558, which is incorporated by reference in its entirety into this application. Second, the use of the filament 14 allows for a smaller profile when the filter is compacted into a delivery catheter. Third, the use of filament 14 that is bio-resorbable within a period of time, e.g., 60-180 days, allows for retrieval of the filter 10 with just its appendages without the complication of entanglement with the suture filaments. Fourth, the use of deformable hooks, whether or not retractable into hollow tubes, allows for little or no trauma to the wall of the blood vessel.
Referring now to
In another embodiment, the outer boundary of the first helical path is within the outer boundary of the second helical path. In other embodiments, the first and second helical paths define alternating outer perimeters (e.g., a winding or loop of the first helical path is smaller than the adjacent windings or loops of the second helical path, but the next winding or loop of the first helical path (in a distal direction) is greater than the adjacent windings or loops of the second helical path). In all embodiments, the filter 20 has an expanded configuration with an expanded perimeter following deployment in a blood vessel, such as shown in
The hub 24 includes a base portion 26 and a retrieval member 28. In the embodiment shown, the retrieval member 28 has a hook-like configuration, although as known to one skilled in the art, there are many possible forms for the retrieval member, such as, for example, a loop, rod, shaft, etc., depending on the form of the removal device to be utilized. One example of a retrieval member is disclosed in U.S. Pat. No. 6,156,055, which is incorporated by reference in its entirety into this application. The hub 24 and elongated wire member 22 may be made of a material, such as, for example, stainless steel, shape memory metals, shape memory alloys, super elastic shape memory metal alloys, metal alloys, linear elastic shape memory alloy, shape memory polymers, polymers, and combinations thereof. The hub 24 and/or elongated wire member 22 may also be made of a bio-resorbable material such as, for example, such as, for example, the materials shown and described in U.S. Pat. No. 6,287,332 and U.S. Patent Application Publication No. 2002/0004060, which are incorporated by reference in their entireties into this application.
In one embodiment, one or more hooks for anchoring the filter 20 to a blood vessel wall may be attached to the elongated wire member 22 along its length at any point among the first or second helical path. The hook or hooks may be attached by any attachment method known to one skilled in the art (e.g., welding, adhesive bonding, solvent bonding, etc.). In one embodiment, the hook contains a linear portion connected to an arcuate portion that terminates in a point, as shown and described in U.S. Pat. No. 6,258,026. In one embodiment, the arcuate member has a cross-sectional area smaller than the cross-sectional area of the wire member. In the embodiment shown in
This invention has been described and specific examples of the invention have been portrayed. While the invention has been described in terms of particular variations and illustrative figures, those of ordinary skill in the art will recognize that the invention is not limited to the variations or figures described. For example, other materials can be incorporated with the filter such as, for example, bio-active agents such as blood de-clotting agent (e.g., heparin, warfarin, etc.). The bio-active agents can be incorporated into the filaments. Other bio-active agents may include, but are not limited to substances such as, for example, anti-proliferative/antimitotic agents including natural products such as vinca alkaloids (i.e. vinblastine, vincristine, and vinorelbine), paclitaxel, epidipodophyllotoxins (i.e. etoposide, teniposide), antibiotics (dactinomycin (actinomycin D) daunorubicin, doxorubicin and idarubicin), anthracyclines, mitoxantrone, bleomycins, plicamycin (mithramycin) and mitomycin, enzymes (L-asparaginase which systemically metabolizes L-asparagine and deprives cells which do not have the capacity to synthesize their own asparagine); antiplatelet agents such as G(GP) IIb/IIIa inhibitors and vitronectin receptor antagonists; anti-proliferative/antimitotic alkylating agents such as nitrogen mustards (mechlorethamine, cyclophosphamide and analogs, melphalan, chlorambucil), ethylenimines and methylmelamines (hexamethylmelamine and thiotepa), alkyl sulfonates-busulfan, nirtosoureas (carmustine (BCNU) and analogs, streptozocin), trazenes-dacarbazinine (DTIC); anti-proliferative/antimitotic antimetabolites such as folic acid analogs (methotrexate), pyrimidine analogs (fluorouracil, floxuridine, and cytarabine), purine analogs and related inhibitors (mercaptopurine, thioguanine, pentostatin and 2-chlorodeoxyadenosine {cladribine}); platinum coordination complexes (cisplatin, carboplatin), procarbazine, hydroxyurea, mitotane, aminoglutethimide; hormones (i.e. estrogen); anti-coagulants (heparin, synthetic heparin salts and other inhibitors of thrombin); fibrinolytic agents (such as tissue plasminogen activator, streptokinase and urokinase), aspirin, dipyridamole, ticlopidine, clopidogrel, abciximab; antimigratory; antisecretory (breveldin); anti-inflammatory: such as adrenocortical steroids (cortisol, cortisone, fludrocortisone, prednisone, prednisolone, 6α-methylprednisolone, triamcinolone, betamethasone, and dexamethasone), non-steroidal agents (salicylic acid derivatives i.e. aspirin; para-aminophenol derivatives i.e. acetominophen; indole and indene acetic acids (indomethacin, sulindac, and etodalac), heteroaryl acetic acids (tolmetin, diclofenac, and ketorolac), arylpropionic acids (ibuprofen and derivatives), anthranilic acids (mefenamic acid, and meclofenamic acid), enolic acids (piroxicam, tenoxicam, phenylbutazone, and oxyphenthatrazone), nabumetone, gold compounds (auranofin, aurothioglucose, gold sodium thiomalate); immunosuppressives: (cyclosporine, tacrolimus (FK-506), sirolimus (rapamycin), azathioprine, mycophenolate mofetil); angiogenic agents: vascular endothelial growth factor (VEGF), fibroblast growth factor (FGF); angiotensin receptor blockers; nitric oxide donors; anti-sense oligionucleotides and combinations thereof; cell cycle inhibitors, mTOR inhibitors, and growth factor receptor signal transduction kinase inhibitors; retenoids; cyclin/CDK inhibitors; HMG co-enzyme reductase inhibitors (statins); and protease inhibitors.
In addition, where methods and steps described above indicate certain events occurring in certain order, those of ordinary skill in the art will recognize that the ordering of certain steps may be modified and that such modifications are in accordance with the variations of the invention. Additionally, certain of the steps may be performed concurrently in a parallel process when possible, as well as performed sequentially as described above. Therefore, to the extent there are variations of the invention, which are within the spirit of the disclosure or equivalent to the inventions found in the claims, it is the intent that this patent will cover those variations as well. Finally, all publications and patent applications cited in this specification are herein incorporated by reference in their entirety as if each individual publication or patent application were specifically and individually put forth herein.
This application claims the benefit of priority to U.S. Application No. 60/742,148, filed Dec. 2, 2005, which is incorporated by reference into this application as if fully set forth herein.
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/US06/45738 | 11/28/2006 | WO | 00 | 6/17/2010 |
| Number | Date | Country | |
|---|---|---|---|
| 60742148 | Dec 2005 | US |
