US20150142025A1 - Biodegradable blood vessel occlusion and narrowing - Google Patents

Abstract

A biodegradable blood vessel narrowing device, comprising: a biodegradable element; an anchoring element; wherein said anchoring element is anchored to a blood vessel wall and at least one external dimension of said biodegradable element is reduced upon biodegradation of said biodegradable element thereby pulling said blood vessel walls toward one another.

Description

FIELD AND BACKGROUND OF THE INVENTION
• The present invention, in some embodiments thereof, relates to blood vessel treatment and, more particularly, but not exclusively, to biodegradable devices and/or methods for blood vessel occlusion and narrowing.
• A malfunction in the ability of veins or arteries to supply or remove blood is associated with medical conditions such as varicose vein expansion, aneurisms, tumors, trauma and dissection of blood vessels.
• Varicose veins appear in 20-25% of women and 10-15% of men. Most varicose veins are considered a cosmetic condition rather than a medical condition; however, in some cases, hindered circulation may cause pain, disfiguring, swelling, discomfort, a tingling sensation, itching and/or a feeling of heaviness.
• Several techniques and procedures to treat varicose veins exist. Vein stripping involves tying off of the upper end of a vein and then removing the vein. Vein stripping is typically performed in an operating room under general anesthesia. Approximately 150,000 vein stripping surgeries are performed each year in the U.S. Vein stripping associated risks include risks linked to general anesthesia such as anesthesia allergies, infections etc. In addition, tissue around the stripped vein may become bruised and scarred causing a feeling of “tightness” in the leg. Damaged may cause numbness and paralysis of part of the leg.
• Endovenous laser treatment is typically performed done in-office under local anesthesia. Endovenous laser treatment uses intense heat to remove a vein, which may lead to an increased risk of developing blood clots. Treated veins can also become irritated and inflamed, leading to pain and swelling in the legs. The treated area can begin to tingle or become burned from the heat.
• Radiofrequency occlusion is typically performed done in-office under local anesthesia or in an ambulatory surgery setting. A small tube or catheter is used and threaded along the vein using ultrasound guidance. Local anesthetic is injected along the way to help ensure the patient's comfort throughout the procedure. Once the vein is canalized, sound waves are applied to heat and collapse the vein from the top, down. The vein will eventually result in a thin scar tissue and is absorbed by the body's natural processes. Following treatment with radiofrequency occlusion, a compression bandage is applied to the leg to aid in the healing process. This should be kept in place for a couple of days and then compression stockings are worn for another two to three weeks to continue to aid the healing process. Patients may walk shortly after treatment and most are able to resume normal activities or return to work after a few days provided they avoid heavy lifting and wear their compression stockings. There may be a chance of bleeding, infection or blood clots with radiofrequency occlusion as with many other procedures. A unique complication that is associated with radiofrequency occlusion, however, is skin burn due to the method of occlusion used during treatment.
• Ultrasound-guided sclerotherapy is typically performed done in-office under local anesthesia. Side effects that are applicable for standard sclerotherapy are also applicable to ultrasound-guided sclerotherapy, although the magnitude of certain complications, when they occur, may be greater. Standard sclerotherapy side effects include skin ulceration or necrosis, deep vein thrombosis, allergic reaction, arterial injection, pulmonary embolus, nerve injury, wound breakdown and wound inflammation.
• The artificial blocking of blood flow is known generically as “embolization” and/or “occlusion”. The embolization of a vessel in an organ may be used to treat a variety of maladies; typically though, embolization is used.
SUMMARY OF THE INVENTION
• According to an aspect of some embodiments of the present invention there is provided a biodegradable blood vessel narrowing device, comprising: a biodegradable element; an anchoring element sized and shaped to be anchored to a blood vessel wall when located in a blood vessel lumen; and at least one external dimension of the biodegradable element is reduced upon biodegradation of the biodegradable element thereby pulling the blood vessel walls toward one another. Optionally, the device occludes a blood vessel upon the device deployment in the blood vessel. Optionally, the device partially occludes a blood vessel upon the device deployment in the blood vessel. Optionally, the anchoring element is made of a shape memory alloy (SMA). Optionally, the anchoring element is made of a biocompatible polymer. Optionally, a degradation of the biodegradable element is initiated by external degradation means. Optionally, the anchoring element comprises a plurality of anchoring legs, each the anchoring leg having at least one anchoring tooth for anchoring to a blood vessel wall and a distance between at least two of respective the anchoring teeth shortens upon biodegradation of the biodegradable element. Optionally, the plurality of anchoring legs essentially encircles the biodegradable element. Optionally, the device further comprises a constriction element wherein the constriction element and upon biodegradation of the biodegradable element the constriction element applies pressure on the plurality of anchoring legs thereby bringing the plurality of anchoring legs to a closer proximity to one another. Optionally, the device further comprises a constriction element wherein the constriction element encircles the plurality of anchoring legs and the biodegradable element is positioned essentially inside the constriction element and upon biodegradation of the biodegradable element the constriction element applies pressure on the plurality of anchoring legs thereby pulling the plurality of anchoring legs. Optionally, the biodegradable element being positioned between at least one of the anchoring legs and a part of the device which is adjacent to at least one of the anchoring legs and upon degradation of the biodegradable element the distance between the at least one of the anchoring legs and the part. Optionally, the anchoring leg has a first leg part and a second leg part carrying the at least one anchoring tooth, the biodegradable element being positioned between the first leg part and the second leg part and upon degradation of the biodegradable element the distance between the first part and the second part shortens. Optionally, the biodegradable element encircles the plurality of anchoring legs thereby fastening the plurality of anchoring legs and a distance between the plurality of anchoring legs after degradation of the biodegradable element is shorter than a distance between the plurality of anchoring legs prior to degradation of the biodegradable element. Optionally, each of the plurality of anchoring legs further comprise a retention element and the plurality of anchoring legs have a twisted state in which the plurality of anchoring legs are twisted around one another and an untwisted state and a distance between the plurality of anchoring legs in the twisted state is bigger than a distance between the plurality of anchoring legs in the untwisted state and the biodegradable element encircles the plurality of anchoring legs in their twisted state thereby fastening the plurality of anchoring legs and the retention element restricts the movement of the biodegradable element and upon degradation of the biodegradable element the plurality of anchoring legs switch from a the twisted state to the untwisted state. Optionally, each of the plurality of anchoring legs is a spring shaped element. Optionally, the device further comprises an internal chamber wherein the device is capsule shaped and filling of the internal chamber enlarges an external dimension of the device to fit a blood vessel. Optionally, the biodegradable blood vessel narrowing device has an outer surface and the anchoring element comprises: a glue chamber internal to the capsule; a plurality of glue channels connecting the chamber to the capsule surface; and a bio-compatible glue; wherein the biocompatible glue flows from the glue chamber to the outer surface through the plurality of glue channels thereby gluing the biodegradable blood vessel narrowing device to a vessel wall. Optionally, the device further comprises a layer and the layer is positioned external to the glue chamber and internal to biodegradable element and upon degradation of the biodegradable element the layer applies pressure on the glue chamber thereby inserting the bio-compatible glue into the plurality of glue channels. Optionally, the device further comprises: a chamber internal to the biodegradable blood vessel narrowing device; a channel connecting the chamber to a surface of the capsule; wherein the channel transfers a bio-absorbable material between the chamber and an exterior of the capsule. Optionally, the device further comprises an occlusion element, wherein the occlusion element occludes a blood vessel.
• According to an aspect of some embodiments of the present invention there is provided a method for occluding and narrowing a blood vessel, comprising: deploying a biodegradable blood vessel narrowing device in a blood vessel; and attaching an anchoring element of the biodegradable blood vessel narrowing device to walls of the blood vessel; wherein narrowing of the blood vessel is mechanically linked to biodegradation of the biodegradable blood vessel narrowing device. Optionally, the method of further comprises applying external degradation means to the device for initiating biodegradation. Optionally, the method further comprises filling a chamber in the device with a bio-absorbable material. Optionally, the attachment of an anchoring element is performed by releasing bio-compatible glue from the biodegradable blood vessel narrowing device and gluing of the biodegradable blood vessel narrowing device to a blood vessel wall. Optionally, the method further comprises filling a glue chamber in the biodegradable blood vessel narrowing device with bio-compatible glue.
• Unless otherwise defined, all technical and/or scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the invention pertains. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of embodiments of the invention, exemplary methods and/or materials are described below. In case of conflict, the patent specification, including definitions, will control. In addition, the materials, methods, and examples are illustrative only and are not intended to be necessarily limiting.
BRIEF DESCRIPTION OF THE DRAWINGS
• Some embodiments of the invention are herein described, by way of example only, with reference to the accompanying drawings. With specific reference now to the drawings in detail, it is stressed that the particulars shown are by way of example and for purposes of illustrative discussion of embodiments of the invention. In this regard, the description taken with the drawings makes apparent to those skilled in the art how embodiments of the invention may be practiced.
• In the drawings:
• FIG. 1A is an illustration of a biodegradable blood vessel narrowing device with multiple anchoring legs in a twisted state, according to some embodiments of the present invention;
• FIG. 1B is an illustration of a biodegradable blood vessel narrowing device with multiple anchoring legs in an untwisted state, according to some embodiments of the present invention;
• FIG. 1C is an illustration of a biodegradable blood vessel narrowing device with multiple anchoring legs in an open state, according to some embodiments of the present invention;
• FIG. 1D is an illustration of a biodegradable blood vessel narrowing device with multiple anchoring legs in a closed state, according to some embodiments of the present invention;
• FIG. 2A is an illustration of a biodegradable blood vessel narrowing device with multiple anchoring legs having a biodegradable element between their first and second parts in a pre-degradation state, according to some embodiments of the present invention;
• FIG. 2B is an illustration of a biodegradable blood vessel narrowing device with multiple anchoring legs having a biodegradable element between their first and second parts in a degraded state, according to some embodiments of the present invention;
• FIG. 2C is an illustration of a biodegradable blood vessel narrowing device with an encircling constriction element with an internal biodegradable element in an open state, according to some embodiments of the present invention;
• FIG. 2D is an illustration of a biodegradable blood vessel narrowing device with an encircling constriction element with an internal biodegradable element in a closed state, according to some embodiments of the present invention;
• FIG. 3A is an illustration of a biodegradable blood vessel narrowing device with spring shaped anchoring legs spaced by a biodegradable element in a pre-degradation state, according to some embodiments of the present invention;
• FIG. 3B is an illustration of a biodegradable blood vessel narrowing device with spring shaped anchoring legs spaced by a biodegradable element in a degraded state, according to some embodiments of the present invention;
• FIG. 4A is an illustration of a biodegradable blood vessel narrowing device with an occlusion element in a pre-degradation state, according to some embodiments of the present invention;
• FIG. 4B is an illustration of a biodegradable blood vessel narrowing device with an occlusion element in a degraded state, according to some embodiments of the present invention;
• FIG. 5A is an illustration of a biodegradable blood vessel narrowing device with a glue chamber in a pre-degradation state, according to some embodiments of the present invention;
• FIG. 5B is an illustration of a biodegradable blood vessel narrowing device with a glue chamber in a degraded state, according to some embodiments of the present invention;
• FIG. 6A is an illustration of a biodegradable blood vessel narrowing device with an empty internal chamber and a channel in a pre-degradation state, according to some embodiments of the present invention;
• FIG. 6B is an illustration of a biodegradable blood vessel narrowing device with a filled internal chamber and a channel in a pre-degradation state, according to some embodiments of the present invention;
• FIG. 6C is an illustration of a biodegradable blood vessel narrowing device with a filled internal chamber and a channel in a degraded state, according to some embodiments of the present invention;
• FIG. 7 is a flowchart of amethod700 for narrowing a blood vessel, according to some embodiments of the present invention; and
• FIG. 8 is an illustration of a blood clot cage, according to some embodiments of the present invention.
DESCRIPTION OF EMBODIMENTS OF THE INVENTION
• The present invention, in some embodiments thereof, relates to devices and methods for blood vessel occlusion and narrowing and, more particularly, but not exclusively, to biodegradable blood vessel narrowing devices and methods for occluding and narrowing a blood vessel using a biodegradable element.
• According to some embodiments of the present invention, there are provided a biodegradable blood vessel narrowing devices which anchor to a blood vessel wall and narrow the blood vessel upon a degradation of its biodegradable element. Such a biodegradable blood vessel narrowing device has a biodegradable scaffold or block, referred to herein as a biodegradable element and one or more anchoring elements for anchoring the biodegradable blood vessel narrowing device to the blood wall. For brevity, the one or more anchoring elements are referred to herein as an anchoring element. The anchoring element includes one or more anchoring legs, hooks and/or biocompatible glue. The anchoring element may be made of a shape memory alloy (SMA). Upon degradation of the biodegradable element the blood vessel the anchoring element changes its formation to pull the blood vessel walls inwardly, thereby narrowing the blood vessel. The anchored biodegradable blood vessel narrowing device is set to occlude the blood vessel completely and/or partially, immediately and/or overtime. Occlusion may be performed by an occlusion element that attaches to the blood vessel independently of the biodegradable blood vessel narrowing device and/or is attached to the biodegradable blood vessel narrowing device.
• Variations of the blood vessel narrowing device achieve the blood vessel narrowing with different configurations. The device may have anchoring legs, be capsule shaped, tube shaped and/or have anchoring springs. The biodegradable elements shape, number, position and/or relation with the anchoring element may differ between these variations. For example, the biodegradable element may include one or more biodegradable ring encircling anchoring legs. The anchoring legs are twisted around one another and are held in that state by the biodegradable ring. A retention element secures the ring in place and prevents and/or limits its movement. Upon degradation of the biodegradable ring the anchoring legs switch from twisted open state to an untwisted closed state. The legs are closer to each other in the untwisted closed state. With their movement towards one another the anchoring legs pull with them the blood vessel wall and narrow the blood vessel.
• A blood vessel narrowing device is inserted into a blood vessel in a state that fits the blood vessel shape and dimensions. The blood vessel narrowing device is then deployed in the blood vessel. The anchoring element attaches to the blood vessel walls. The attachment may be performed using biocompatible glue. When a bio-absorbable material is used it is first inserted into an internal chamber of the device. The insertion of the bio-absorbable material may bring the anchoring element into a position that allows its attachment to the blood vessel walls. Then the insertion means, for example a capillary, may be removed.
• Before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not necessarily limited in its application to the details of construction and the arrangement of the components and/or methods set forth in the following description and/or illustrated in the drawings and/or the Examples. The invention is capable of other embodiments or of being practiced or carried out in various ways.
• Before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not necessarily limited in its application to the details set forth in the following description or exemplified by the Examples. The invention is capable of other embodiments or of being practiced or carried out in various ways.
• Referring now to the drawings,FIGS. 1-6 illustrate variations of a biodegradable bloodvessel narrowing device105,205,305,405,605.FIGS. 1A,2A,3A,4A,5A, and6A illustrate a pre-degradation state with thebiodegradable element110 and/or theconstriction element130 not yet degraded.FIGS. 1B,2B,3B,4B,5B and6C illustrate a degraded state with thebiodegradable element110 and/or theconstriction element130 partially and/or fully degraded.
• FIGS. 1A and 1B illustrate a biodegradable bloodvessel narrowing device105 with multiple anchoringlegs120 in atwisted state101A and untwistedstate101B, according to some embodiments of the present invention. The biodegradable bloodvessel narrowing device105 has multiple anchoringlegs120. In these examples four anchoringlegs120 are depicted. The anchoringlegs120 havesharp teeth122 used for anchoring thedevice105 to a blood vessel wall. Optionally, the anchoringlegs120 are made of an SMA such as copper-aluminium-nickel, nickel-titanium, zinc alloy, copper alloy, gold alloy and/or iron alloy. When the anchoringlegs120 are twisted, as inFIG. 1A, they are spread apart to touch opposing sides of a blood vessel wall. Thetwisted state101A is maintained by abiodegradable constriction element130. In this example the biodegradable constriction element is a loop which encircles the anchoringlegs120. Such aconstriction element130 is held in its position by one ormore retention elements135 on one or more of the anchoringlegs120, for example segments of the anchoringlegs120. Here, theretention element135 is shaped as an arch. Theconstriction element130 is made of a biodegradable material. As used herein, biodegradable material means a biodegradable, bio-absorbable and/or re-absorbable material for internal use, of a synthetic and/or natural source which can be degraded (i.e., broken down) and/or absorbed in a physiological environment such as by proteases. Biodegradability may depend on the availability of degradation substrates (i.e., biological materials or portion thereof which are part of the polymer), the presence of biodegrading materials (e.g., microorganisms, enzymes, proteins) and the availability of oxygen, carbon dioxide and/or other nutrients (for aerobic organisms, microorganisms and/or portions thereof). Examples of biodegradable material include, but are not limited to: a polyglycolic acid (PGA), Maxon—PGA, Tri-Methylene Carbonate (TMC), Vicryl PGA, Vicryl Polylactide, polylactic acid (PLA), polyglycolic acid (PLGA), Dexon olyglycolide, polycaprolactone (PCL), polydioxanone (PDO), Polydioxanone (PDS), polyethyleneglycol (PEG), PEG-DMA, Polyethylenimine (PEI), hyaluronic acid, catgut suture material, gelatin, cellulose, nitrocellulose, collagen, gelatin, albumin, fibrin, alginate, hydrogels, chitosan copolymers and/or other synthetic and naturally-occurring biodegradable materials and/or mixtures thereof. The biodegradable material may be a homo-polymer or a copolymer. When the biodegradable material of the constriction element degrades, theconstriction element135 is loosened and the anchoringlegs120 transfer from thetwisted state101A, as depicted inFIG. 1A, to the untwistedstate101B as depicted inFIG. 1B. Optionally, the change from thetwisted state101A to the untwistedstate101B is promoted by the shape memory of SMA anchoring legs120: TheSMA anchoring legs120 tend to be essentially straight and close to one another as a result of their shape memory. Without external pressure and/or retention theSMA anchoring legs120 tend to move to the untwistedstate101B. The anchoringlegs120 are closer to one another in the untwistedstate101B than in thetwisted state101A. Optionally the biodegradable bloodvessel narrowing device105 may have ablood clot cage890 as illustrated inFIG. 8. The biodegradation may be gradual. Gradual biodegradation may achieve a gradual narrowing of a blood vessel. The biodegradable bloodvessel narrowing device105 may occlude the blood vessel immediately and completely upon insertion and/or deployment. Optionally, the biodegradable bloodvessel narrowing device105 in atwisted state101A partially occludes the blood vessel upon insertion and/or deployment. Then, upon gradual transition to an untwistedstate101B the biodegradable bloodvessel narrowing device105 achieves a higher level of occlusion. Optionally, upon an essentially complete biodegradation of theconstriction element130, an essentially complete occlusion of the blood vessel is achieved by the biodegradable bloodvessel narrowing device105. Optionally, an accompanying occlusion device is used to achieve immediate occlusion and the biodegradable bloodvessel narrowing device105 narrows the blood vessel over time. Optionally, the accompanying occlusion device is removed when occlusion is achieved by the biodegradable bloodvessel narrowing device105.
• FIGS. 1C and 1D illustrate a biodegradable bloodvessel narrowing device105 with multiple anchoringlegs120 in anopen state101C and aclosed state101D, according to some embodiments of the present invention. The biodegradable bloodvessel narrowing device105 illustrated inFIGS. 1C and 1D is a variation of the biodegradable bloodvessel narrowing device105 depicted inFIGS. 1A and 1B respectively. One aspect of this correspondence is that the anchoringlegs120 are spread apart in theopen state101C and in thetwisted state101A. In thesestates101A,101C the anchoringlegs120 can touch opposing sides of a blood vessel wall. In this example the anchoringlegs120 are spread apart by abiodegradable element110. The anchoringlegs120 encircle thebiodegradable element110. Optionally, no retention element is required to hold thebiodegradable element110 between the anchoringlegs110. Optionally, thebiodegradable element110 contains one or more non degradable parts and/or a hollow chamber. The tendency of the anchoring legs to be in aclosed configuration101D may apply physical pressure towards thebiodegradable element110. In this example thebiodegradable element110 is shaped as a tube.
• FIGS. 2A and 2B illustrate a biodegradable bloodvessel narrowing device205 with multiple anchoringlegs220 having a biodegradable element between their first224 andsecond parts226, according to some embodiments of the present invention.FIG. 2A illustrates anopen state201A of the anchoringlegs220. The biodegradable bloodvessel narrowing device105 illustrated inFIGS. 2A and 2B is a variation of the biodegradable bloodvessel narrowing device105 depicted inFIGS. 1A,1C and1B,1D respectively. The biodegradable bloodvessel narrowing device105 illustrated inFIG. 1C has four anchoringlegs220. Each leg has afirst part224 and asecond part226. Thesecond part226 of the anchoringleg220 carries an anchoringtooth222. The anchoringteeth222 anchor to the walls of a blood vessel. Optionally, anchoring of the anchoringteeth222 to blood vessel walls is performed without penetrating a blood vessel wall. Abiodegradable element210 is located between thefirst part224 and thesecond part226 of the anchoringlegs220 in anopen state201A. Upon the degradation of thebiodegradable element210, thebiodegradable element210 external dimensions become smaller and the first224 and second226 parts of the anchoringlegs220 get closer to one another. The walls of a blood vessel are pulled towards one another upon the degradation of thebiodegradable element210 as a result of the distance shortening between the first224 and second226 parts of the anchoringlegs220. Optionally, the change in the biodegradable element's210 external dimensions is promoted by the shape memory of anchoringlegs120 made of SMA.
• FIGS. 2C and 2D illustrate a biodegradable bloodvessel narrowing device205 with anencircling constriction element230 with an internalbiodegradable element210 in anopen state201C and in aclosed state201D, according to some embodiments of the present invention. In theopen state201C the anchoringlegs220 are further apart from one another compared to theclosed state201D. The biodegradable bloodvessel narrowing device105 illustrated inFIGS. 2C and 2D is a variation of the biodegradable bloodvessel narrowing device105 depicted inFIGS. 1A,1C,2A and1B,1D,2D respectively. In this example, theconstriction element230 encircles the anchoringlegs220. Optionally, theconstriction element230 encircles some of the anchoringlegs220. Optionally, the biodegradable bloodvessel narrowing device205 hasmultiple constriction elements230. Each of theconstriction elements230 encircles a group of anchoringlegs220. Optionally,multiple constriction elements230 may encircle the same anchoringlegs220, thereby creating an overlap between the groups of encircled anchoringlegs220. There is abiodegradable element210 inside theconstriction element230. Optionally, thebiodegradable element210 is completely internal to theconstriction element230, having essentially no part of thebiodegradable element210 exposed to the blood. Optionally, theconstriction element230 is made of a non permeable material which does not enable the degraded parts of thebiodegradable element210 to pass from theinternal side231 of theconstriction element230 to itsexternal side232 which is exposed to the blood. Optionally, thebiodegradable element210 is located in the center of theconstriction element230. Optionally, thebiodegradable element210 is positioned symmetrically in respect to the shape of theconstriction element230 in order to promote symmetric narrowing of blood vessel walls. Optionally, the biodegradable bloodvessel narrowing device205 is removed the blood vessel after the blood vessel is narrowed. Optionally, drugs affecting the blood vessel diameter are provided prior to, along with and/or after inserting and/or deploying the biodegradable bloodvessel narrowing device205.
• FIGS. 3A and 3B illustrate a biodegradable bloodvessel narrowing device305 with spring shaped anchoringlegs320A,320B, according to some embodiments of the present invention. In this example there are two anchoringlegs320A,320B, each shaped as a spring. Each of the spring shaped anchoringlegs320A,320B has anchoringteeth322. The anchoringteeth322 anchor the biodegradable bloodvessel narrowing device305 to ablood vessel wall340. Abiodegradable element310 spreads the spring shaped anchoringlegs320A,320B apart to create anopen state301A. The spring shaped anchoringlegs320A,320B tend to contract and wrap back together in aclosed state301B. The spring shaped anchoringlegs320A,320B apply pressure on thebiodegradable element310. Upon degradation of thebiodegradable element310 the spring shaped anchoringlegs320A,320B move towards one another creating aclosed state301B. In theclosed state301B the distance between the spring shaped anchoringlegs320A,320B is reduced. The movement of the spring shaped anchoringlegs320A,320B pulls the blood vessel walls toward each other which in turn narrow the blood vessel. Optionally, the spring shaped anchoringlegs320A,320B is made of a shape memory alloy SMA comprising: copper-aluminium-nickel, nickel-titanium, zinc alloy, copper alloy, gold alloy and/or iron alloy. Optionally, a retention element maintains the position of thebiodegradable element310 with respect to the spring shaped anchoringlegs320A,320B. Optionally, the biodegradable bloodvessel narrowing device305 has more than two anchoringlegs320A,320B. Optionally, the plurality of spring shaped anchoring legs is organized in groups of anchoring legs.
• FIGS. 4A and 4B illustrate a biodegradable bloodvessel narrowing device405 with anocclusion element450, according to some embodiments of the present invention. The biodegradable bloodvessel narrowing device405 illustrated inFIGS. 4A and 4B is a variation over the biodegradable bloodvessel narrowing device105 depicted inFIGS. 1A,1C and1B,1D respectively. In this example, there are no anchoring legs. Thebiodegradable element410 carries an anchoring element such as anchoringteeth422. When thebiodegradable element410 degrades the blood vessel walls are pulled therealong, narrowing the blood vessel. Optionally, theocclusion element450 is attached to the biodegradable bloodvessel narrowing device405. Optionally, the attached occlusion element is anchored to the blood vessel walls along with the biodegradable bloodvessel narrowing device405. Optionally, theocclusion element450 has a second anchoring element, such as anchoringteeth452. Optionally, the biodegradable bloodvessel narrowing device405 occludes a blood vessel even without theocclusion element450, and theocclusion element450 supplies an additional safety net for complete and/or immediate occlusion of a blood vessel. The biodegradable bloodvessel narrowing device405 narrows theblood vessel walls340,540,640,840 to fit the device's405 own dimensions, thereby occluding the blood vessel.
• FIGS. 5A and 5B illustrate a biodegradable bloodvessel narrowing device505 with a glue chamber, according to some embodiments of the present invention. The biodegradable bloodvessel narrowing device505 has aglue chamber560 and abiodegradable element510. Theglue chamber560 may be internal to thebiodegradable element510 as illustrated.Glue channels565 connect theglue chamber560 with theouter surface570 of the biodegradable bloodvessel narrowing device505. The biocompatible glue passes through theglue channels565. The bio-compatible glue reaches theouter surface570 of the biodegradable bloodvessel narrowing device505. The bio-compatible glue glues thedevice505 to a blood vessel wall after thedevice505 deployment in a blood vessel. The biodegradable bloodvessel narrowing device505 is depicted here in two states: with aglue chamber560 full of biocompatible glue and abiodegradable element510 as illustrated inFIG. 5A and with aglue chamber560 essentially empty of biocompatible glue and a degradedbiodegradable element510 as illustrated inFIG. 5B. Optionally, the biodegradable bloodvessel narrowing device505 is capsule shaped. Optionally, the biodegradable bloodvessel narrowing device505 hasmultiple glue chambers560.Multiple glue chambers560 may enable to reduce the distance between theglue chamber560 and theouter surface570, thereby reducing the force needed to inject the bio-compatible glue through theglue channels565 and/or the distance and/or time the glue has to pass before sticking to ablood vessel wall540. These may reduce the chances of aglue channel565 block occurrence. Optionally, the biocompatible glue is released by applying external pressure onto thedevice505.
• Optionally, the biocompatible glue is released by injecting a second material into theglue chamber560. The increase in fluid pressure forces the biocompatible into theglue channels565. The second material, which is optionally inserted into theglue chamber560, may be a fast bio-absorbable such as water, the patient's own blood etc. Optionally, the glue is released as a result of the pressure applied by the blood vessel walls on the biodegradable bloodvessel narrowing device505. Optionally, the glue release is dependent on degradation of thebiodegradable element510 and/or on absorption of a bio-absorbable material. Optionally, alayer575 is external to thebiodegradable element510. Theadditional layer575 may be made of a biocompatible polymer, a biocompatible material and/or an SMA. Upon degradation of thebiodegradable element510, thebiodegradable element510 essentially collapses towards the glue chamber. As a result thebiocompatible polymer575 shrinks and creates pressure towards the glue chamber, thereby releasing the bio-compatible glue. Thebiocompatible polymer layer575 may be partial or essentially completely cover thebiodegradable element510. Optionally, a bio-absorbable element may function in a similar to the biodegradable element with respect to the bio-compatible glue release. Using a bio-absorbable element instead, in combination with and/or in addition to abiodegradable element510 may reduce the glue release time. Optionally, the glue is not present in theglue chamber560 at the time ofdevice505 deployment. The biocompatible glue may be inserted into theglue chamber560 once thedevice505 is in a blood vessel in a similar manner to that illustrated inFIG. 6. The glue may be inserted to thedevice505 through the glue channels and/or through a different opening.
• FIGS. 6A,6B and6C illustrate a biodegradable bloodvessel narrowing device605 with an internal chamber468 and achannel685, according to some embodiments of the present invention. When the biodegradable bloodvessel narrowing device605 is deployed in a blood vessel theinternal chamber668 is typically empty. Once thedevice605 is deployed a biocompatible material is inserted through thechannel685. Thechannel685 connects theinternal chamber668 with thesurface670 of thedevice605. The channel may penetrate thedegradable element610. Optionally, anotherlayer675 of material may essentially encircle thebiocompatible element610. This layer may also be made of a biodegradable material, an SMA and/or a biocompatible polymer. The additional later675 may apply pressure on internal layers promoting their degradation, shape modification and/or insertion into channel, as illustrated inFIG. 5 by theadditional layer575. Optionally, thedegradable element610 has a hollow tube which fitschannel685. Optionally, thechannel685 extends beyond thesurface670 of the device. Optionally, thechannel685 is inserted after deployment. The biocompatible material may be a bio-absorbable material such as water and/or other biocompatible absorbable materials and/or a biodegradable material such as collagen and/or biodegradable materials as listed above inFIGS. 1A and 1B. The operator inserts biocompatible material into the internal chamber468 until the surface of thedevice605 anchors to theblood vessel walls640. Optionally, thedevice605 contains an occlusion agent for occluding the blood vessel. The occlusion may be complete and/or partial, i.e. some of the blood streaming through the blood vessel is blocked and some of the blood still flows through the blood vessel with the partially occludingdevice605. Optionally, more biocompatible material is inserted to create pressure on the blood vessel walls. Optionally, monitoring means such as a camera and/or a pressure detector are used to determine when to stop the biocompatible material insertion. Optionally, once the biocompatible material is contained in theinternal chamber668 thechannel685 is removed. When the biocompatible material and/or thebiodegradable element610 the blood vessel walls which are anchored to thedevice610 are pulled inward, thereby narrowing the blood vessel. Optionally, the biocompatible material in theinternal chamber668 is absorbed and/or degraded in a different pace compared to the degradation pace of thebiodegradable element610.
• Reference is now also made toFIG. 7 which is a flowchart of amethod700 for narrowing a blood vessel, according to some embodiments of the present invention. First, a biodegradable blood vessel narrowing device is deployed in ablood vessel705. Optionally, the blood vessel is occluded707. The occlusion may be performed by the biodegradable bloodvessel narrowing device105,205,305,405,505 and/or605. Optionally, the occlusion is performed by an independent occlusion device. Optionally, the deployed biodegradable blood vessel narrowing device is one of the variations illustrated inFIGS. 1A-6C and/or a combination thereof. Then, optionally, glue chamber is filled in the biodegradable blood vessel narrowing device is filled withbio-compatible glue710. Then, an anchoring element of said biodegradable blood vessel narrowing device is attached to theblood vessel walls715. The attachment may be performed by hooks, by biocompatible glue and/or other anchoring means. The anchoring element may attach to the blood vessel wall by itself upon deployment. For example, hooks on anchoring legs that are in close proximity to a blood vessel walls. Optionally, thedevice105,205,305,405,505 and/or605 is moved in the blood vessel to facilitate the attachment of the anchoring element to the blood vessel walls. Optionally, external means are applied to facilitate the attachment of the anchoring element to the blood vessel walls such as applying pressure on tissue around blood vessel. Optionally, a chamber in the biodegradable blood vessel narrowing device is filled with a bio-absorbable material. The filling of a chamber in the biodegradable blood vessel narrowing device with a bio-absorbable may be performed as illustrated inFIG. 6B. The bio-absorbable material fill may promote the anchoring of the device to the blood vessel walls by bringing the blood vessel walls and the anchoring means closer together. Then, optionally, external degradation means are applied to the biodegradable blood vessel narrowing device for initiatingbiodegradation720. External degradation means may be selected from: external pressure, light emission, sound waves, degradation promoting agent, chemical compound delivery and/or a laser beam. Optionally, a chamber in said device is filled with a bio-absorbable material.
• Reference is now also made toFIG. 8 which illustrates ablood clot cage890, according to some embodiments of the present invention. The blood clot cage is depicted here deployed in ablood vessel840. Theblood vessel840 has a front840A and arear side840B as defined by the blood flow which occurs from therear side840B to thefront side840A. Theblood clot cage890 may be positioned in front of the biodegradable narrowing device. Theblood clot cage890 assists in catching a blood clot that may be formed as a result of the blood vessel occlusion.
• It is expected that during the life of a patent maturing from this application many relevant SMA, biocompatible glues, bio-absorbable materials, biocompatible polymers, external degradation means, anchoring means will be developed and the scope of the terms SMA, biocompatible glue, bio-absorbable material, biocompatible polymer, external degradation mean, and/or anchoring mean are intended to include all such new technologies a priori.
• As used herein the term “about” refers to ±10%.
• The terms “comprises”, “comprising”, “includes”, “including”, “having” and their conjugates mean “including but not limited to”. This term encompasses the terms “consisting of” and “consisting essentially of”.
• The phrase “consisting essentially of” means that the composition or method may include additional ingredients and/or steps, but only if the additional ingredients and/or steps do not materially alter the basic and novel characteristics of the claimed composition or method.
• As used herein, the singular form “a”, “an” and “the” include plural references unless the context clearly dictates otherwise. For example, the term “a compound” or “at least one compound” may include a plurality of compounds, including mixtures thereof.
• The word “exemplary” is used herein to mean “serving as an example, instance or illustration”. Any embodiment described as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments and/or to exclude the incorporation of features from other embodiments.
• The word “optionally” is used herein to mean “is provided in some embodiments and not provided in other embodiments”. Any particular embodiment of the invention may include a plurality of “optional” features unless such features conflict.
• Throughout this application, various embodiments of this invention may be presented in a range format. It should be understood that the description in range format is merely for convenience and brevity and should not be construed as an inflexible limitation on the scope of the invention. Accordingly, the description of a range should be considered to have specifically disclosed all the possible subranges as well as individual numerical values within that range. For example, description of a range such as from 1 to 6 should be considered to have specifically disclosed subranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6 etc., as well as individual numbers within that range, for example, 1, 2, 3, 4, 5, and 6. This applies regardless of the breadth of the range.
• Whenever a numerical range is indicated herein, it is meant to include any cited numeral (fractional or integral) within the indicated range. The phrases “ranging/ranges between” a first indicate number and a second indicate number and “ranging/ranges from” a first indicate number “to” a second indicate number are used herein interchangeably and are meant to include the first and second indicated numbers and all the fractional and integral numerals therebetween.
• It is appreciated that certain features of the invention, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention, which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable subcombination or as suitable in any other described embodiment of the invention. Certain features described in the context of various embodiments are not to be considered essential features of those embodiments, unless the embodiment is inoperative without those elements.
• Although the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alternatives, modifications and variations that fall within the spirit and broad scope of the appended claims.
• All publications, patents and patent applications mentioned in this specification are herein incorporated in their entirety by reference into the specification, to the same extent as if each individual publication, patent or patent application was specifically and individually indicated to be incorporated herein by reference. In addition, citation or identification of any reference in this application shall not be construed as an admission that such reference is available as prior art to the present invention. To the extent that section headings are used, they should not be construed as necessarily limiting.

Claims (25)

What is claimed is:

1. A biodegradable blood vessel narrowing device, comprising:

a biodegradable element;

an anchoring element sized and shaped to be anchored to a blood vessel wall when located in a blood vessel lumen; and

at least one external dimension of said biodegradable element is reduced upon biodegradation of said biodegradable element thereby pulling said blood vessel walls toward one another.

2. The device ofclaim 1, wherein said device occludes a blood vessel upon said device deployment in said blood vessel.

3. The device ofclaim 1, wherein said device partially occludes a blood vessel upon said device deployment in said blood vessel.

4. The device ofclaim 1, wherein said anchoring element is made of a shape memory alloy (SMA).

5. The device ofclaim 1, wherein said anchoring element is made of a biocompatible polymer.

6. The device ofclaim 1, wherein a degradation of said biodegradable element is initiated by external degradation means.

7. The device ofclaim 1, wherein said anchoring element comprises a plurality of anchoring legs, each said anchoring leg having at least one anchoring tooth for anchoring to a blood vessel wall and a distance between at least two of respective said anchoring teeth shortens upon biodegradation of said biodegradable element.

8. The device ofclaim 7, wherein said plurality of anchoring legs essentially encircles said biodegradable element.

9. The device ofclaim 7, further comprising a constriction element wherein said constriction element and upon biodegradation of said biodegradable element said constriction element applies pressure on said plurality of anchoring legs thereby bringing said plurality of anchoring legs to a closer proximity to one another.

10. The device ofclaim 7, further comprising a constriction element wherein said constriction element encircles said plurality of anchoring legs and said biodegradable element is positioned essentially inside said constriction element and upon biodegradation of said biodegradable element said constriction element applies pressure on said plurality of anchoring legs thereby pulling said plurality of anchoring legs.

11. The device ofclaim 7, wherein said biodegradable element being positioned between at least one of said anchoring legs and a part of said device which is adjacent to at least one of said anchoring legs and upon degradation of said biodegradable element the distance between said at least one of said anchoring legs and said part.

12. The device ofclaim 7, wherein said anchoring leg has a first leg part and a second leg part carrying said at least one anchoring tooth, said biodegradable element being positioned between said first leg part and said second leg part and upon degradation of said biodegradable element the distance between said first part and said second part shortens.

13. The device ofclaim 7, wherein said biodegradable element encircles said plurality of anchoring legs thereby fastening said plurality of anchoring legs and a distance between said plurality of anchoring legs after degradation of said biodegradable element is shorter than a distance between said plurality of anchoring legs prior to degradation of said biodegradable element.

14. The device ofclaim 7, wherein each of said plurality of anchoring legs further comprise a retention element and said plurality of anchoring legs have a twisted state in which said plurality of anchoring legs are twisted around one another and an untwisted state and a distance between said plurality of anchoring legs in said twisted state is bigger than a distance between said plurality of anchoring legs in said untwisted state and said biodegradable element encircles said plurality of anchoring legs in their twisted state thereby fastening said plurality of anchoring legs and said retention element restricts the movement of said biodegradable element and upon degradation of said biodegradable element said plurality of anchoring legs switch from a said twisted state to said an untwisted state.

15. The device ofclaim 7, wherein each of said plurality of anchoring legs is a spring shaped element.

16. The device ofclaim 1, further comprising an internal chamber wherein said device is capsule shaped and filling of said internal chamber enlarges an external dimension of said device to fit a blood vessel.

17. The device ofclaim 1, wherein said biodegradable blood vessel narrowing device has an outer surface and said anchoring element comprises:

a glue chamber internal to said capsule;

a plurality of glue channels connecting said chamber to said capsule surface; and

a bio-compatible glue;

wherein said biocompatible glue flows from said glue chamber to said outer surface through said plurality of glue channels thereby gluing said biodegradable blood vessel narrowing device to a vessel wall.

18. The device ofclaim 17, further comprising a layer and said layer is positioned external to said glue chamber and internal to biodegradable element and upon degradation of said biodegradable element said layer applies pressure on said glue chamber thereby inserting said bio-compatible glue into said plurality of glue channels.

19. The device ofclaim 1, further comprising:

a chamber internal to said biodegradable blood vessel narrowing device; and

a channel connecting said chamber to a surface of said capsule;

wherein said channel transfers a bio-absorbable material between said chamber and an exterior of said capsule.

20. The device ofclaim 1, further comprising an occlusion element, wherein said occlusion element occludes a blood vessel.

21. A method for occluding and narrowing a blood vessel, comprising:

deploying a biodegradable blood vessel narrowing device in a blood vessel; and

attaching an anchoring element of said biodegradable blood vessel narrowing device to walls of said blood vessel;

wherein narrowing of said blood vessel is mechanically linked to biodegradation of said biodegradable blood vessel narrowing device.

22. The method ofclaim 21, further comprising applying external degradation means to said device for initiating biodegradation.

23. The method ofclaim 21, further comprising filling a chamber in said device with a bio-absorbable material.

24. The method ofclaim 21, wherein said attachment of an anchoring element is performed by releasing bio-compatible glue from said biodegradable blood vessel narrowing device and gluing of said biodegradable blood vessel narrowing device to a blood vessel wall.

25. The method ofclaim 21, further comprising filling a glue chamber in said biodegradable blood vessel narrowing device with bio-compatible glue.

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