Embolic protection device

Abstract

An embolic protection device for deployment in a body vessel is provided, including a filtering body having a lip and extending therefrom to a tail and a frame connected to the lip for supporting the filtering body. The filtering body includes first and second openings formed therethrough, the first opening having a first area for maintaining fluid flowpaths through the device, the second opening having a second area for filtering emboli in the body vessel. The first area is greater than the second area.

Description

BACKGROUND

1. Field of the Invention

The invention relates generally to medical devices. More specifically, the invention relates to intravascular embolic protection devices.

2. Related Technology

Embolic protection devices are percutaneously placed in a body vessel to prevent emboli from traveling and creating an undesirable embolism, e.g., pulmonary embolism. For example, vena cava filters are used for trapping emboli in the vena cava filter to prevent pulmonary embolism. Also, anti-platelet agents and anticoagulants may be used to breakdown blood clots. Moreover, snares and baskets (e.g., stone retrieval baskets) are used for retrieving urinary calculi. Additionally, occlusion coils are commonly used to occlude aneurysms and accumulate thrombi in a body vessel.

Treatments for a stenotic lesion provide a potential in releasing blood clots and other thrombi plaque in the vasculature of the patient. One example is the treatment for a carotid artery stenosis. Generally, carotid artery stenosis is the narrowing of the carotid arteries, the main arteries in the neck that supply blood to the brain. Carotid artery stenosis (also called carotid artery disease) is a relatively high risk factor for ischemic stroke. The narrowing is usually caused by plaque build-up in the carotid artery.

Carotid angioplasty is a more recently developed treatment for carotid artery stenosis. This treatment uses balloons and/or stents to open a narrowed artery. Carotid angioplasty is a procedure that can be performed via a standard percutaneous transfemoral approach with the patient anesthetized using light intravenous sedation. At the stenosis area, an angioplasty balloon is delivered to predilate the stenosis in preparation for stent placement. The balloon is then removed and exchanged via catheter for a stent delivery device. Once in position, a stent is deployed across the stenotic area. If needed, an additional balloon can be placed inside the deployed stent for post-dilation to make sure the struts of the stent are pressed firmly against the inner surface of the vessel wall. During the stenosis procedure however, there is a risk of such blood clots and thrombi being undesirably released into the blood flow within the vasculature.

Therefore, embolic protection devices, such as occlusive devices and filters, have been developed to trap and to prevent the downstream travel of the blood clots and thrombi. The filters are typically advanced downstream of a site that is to be treated and then expanded into an opened state to increase the filter area. The blood clots and thrombi can be captured in the opened filter while blood is still able to flow therethrough.

However, filter devices may fail to completely open within the blood vessel, leaving gaps between the filter outer surface and the blood vessel inner surface. These gaps may permit the above-described blood clots and thrombi to flow past the filter, unoccluded. As a result, the unoccluded blood clots and thrombi may thereby compromise the blood flow at a location distal from the treatment site.

Thus, there is a need to improve the positioning the expanding of the filter device within the blood vessel to effectively capture the unoccluded blood clots and thrombi.

SUMMARY

In one aspect of the present invention, an embolic protection device for deployment in a body vessel is provided for filtering emboli in the body vessel. The device includes a filtering body having a lip and extending therefrom to a tail and a frame connected to the lip for supporting the filtering body. The filtering body includes first and second openings formed therethrough, the first opening having a first area for maintaining fluid flowpaths through the device, the second opening having a second area for filtering emboli in the body vessel. The first area is greater than the second area.

In another aspect of the invention, the first opening is one of a first plurality of openings located adjacent to the lip and the second opening is one of a second plurality of openings located adjacent to the tail. The filtering body further includes intermediate openings between the lip and the tail that are generally decreasing in size along a line extending from the lip to the tail. Additionally, the first, second, and intermediate openings are configured such that a fluid flowrate through the filtering body is substantially unhindered when openings adjacent to the tail become obstructed.

In yet another aspect, the frame includes a retrieval member extending from the frame to retrieve the embolic protection device from the body vessel. Furthermore, a tether is connected to an inner surface of the filtering body and is movable along an axis with respect to the connection means such as to create a collection area within the filtering body for collecting emboli. Additionally, a material promoting biofixation may be located around an outer surface of the filtering body to form a seal between the filtering body and the body vessel. More specifically, the material includes extracellular matrix that functions as a remodeling bioscaffold. Even more specifically, the material includes small intestinal submucosa.

In yet another aspect of the present invention, the embolic protection device is utilized in an assembly for removing emboli from a body vessel. The assembly further includes an emboli dislodging catheter for dislodging the emboli from an inner wall of the body vessel and causing the emboli to flow downstream, thereby becoming trapped within the filter body. The assembly also includes an outer catheter for delivering the emboli dislodging catheter into the blood vessel and a guide wire slidably coupled with the embolic protection device to guide the embolic protection device within the body vessel.

Further objects, features and advantages of this invention will become readily apparent to persons skilled in the art after a review of the following description, with reference to the drawings and claims that are appended to and form a part of this specification.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an environmental side view of an embolic protection device in an opened state within a blood vessel in accordance with one embodiment of the present invention;

FIG. 2 is a cross-sectional view of the embolic protection device in FIG. 1 taken along line 2-2;

FIG. 3 is a cross-sectional view taken along line 3-3 in FIG. 1, which is adjacent to the proximal end of the filter;

FIG. 4 is a cross-sectional view of the embolic protection device in FIG. 1 taken along line 4-4;

FIG. 5 is a side view of the embolic protection device in a closed state within a blood vessel in accordance with another embodiment of the present invention;

FIG. 6 is a side view of yet another embodiment of the embolic protection device;

FIG. 7 is a side view of still another embodiment of the embolic protection device;

FIG. 8 is a side view of an embolic protection device utilized in an assembly for removing emboli from a blood vessel, in accordance with another embodiment of the present invention, before the emboli have been dislodged from the inner surface of the blood vessel; and

FIG. 9 is a side view of the embolic protection device shown in FIG. 8 after the emboli have been dislodged from the inner surface of the blood vessel.

DETAILED DESCRIPTION

Embodiments of the present invention generally provide embolic protection devices, embolic protection apparatus, and methods for capturing emboli in a body vessel during angioplasty for treatment of a stenosis. One particular stenosis is a carotid artery stenosis. The embodiments solve the concerns of current stenosis treatments, such as the relatively high risks of surgery and the potential release of emboli into the vasculature during the stenosis procedure. Embodiments of the present invention provide a relatively low risk approach to capturing emboli released during a stenosis procedure, e.g., balloon angioplasty.

Referring now to the drawings, FIG. 1 shows an embolic protection device 9 to be positioned within a body vessel, such as a blood vessel 12 having a blood flow in a direction generally indicated by reference numeral 14. More specifically, the embolic device 9 includes a filtering body 10 positioned downstream of emboli 16, such as blood clots and plaque fragments, to trap and to prevent the downstream travel of the emboli 16, thereby reducing the likelihood of downstream blood vessels becoming blocked. As will be discussed in more detail below, the filtering body 10 includes openings 18 that permit blood to flow through and that prevent the emboli 16 from doing the same.

The filtering body 10 is composed of any suitable material 19, a woven mesh or net configuration, but any suitable material may be used. More specifically, the filter material 19 is preferably configured to avoid rupture and to be disposed within the blood vessel 12. Furthermore, the filter material 19 is preferably sufficiently flexible such that the filtering body 10 is able to conform to various shapes and configurations, as may be needed to engage the blood vessel 12.

The filtering body 10 preferably includes a proximally-located lip portion 20 that is substantially opened to an opened state 22 for receiving the emboli 16. More specifically, the lip portion 20 opens in the radial direction such as to form a substantially fluid-tight seal 24 with the blood vessel 12. The seal 24 substantially prevents emboli 16 from flowing around the filtering body 10 and causing the above-described conditions.

The lip portion 20 is held in the opened state 22 by a frame 26 that extends around the perimeter of the lip portion 20. The frame 26 shown in the Figures is a rigid wire formed into a generally circular loop 28 and having an adjustable diameter such as to conform to the inner surface of the blood vessel 12. Additionally, as shown in FIG. 5, the circular loop 28 is collapsible into a closed state 36 to be easily moved within the blood vessel 12 when desirable, such as during deployment into and during removal from the blood vessel 12. When in the closed state 36, the filter 10 has relatively small radial dimensions, and thus a gap 40 exists between the circular loop 28 and the blood vessel 12. Alternatively, other suitable designs may also be used.

In the area adjacent to the lip portion 20, the filtering body 10 includes proximal openings 18a, each defining a fluid flowpath for blood to flow there through. Additionally, each of the proximal openings 18a includes a cross-sectional area 30, configured to permit unoccluded blood to flow there through. The proximal openings 18a are preferably circular and are relatively spaced-apart from each other, but may have any suitable shape and configuration.

The filtering body 10 also includes a distally-located tail portion 32 that is closed-off in order to trap the emboli 16 that flow into lip portion 20 of the filtering body 10. However, similarly to the lip portion 20, the tail portion 32 includes distal openings 18b, each defining a fluid flowpath for blood to flow therethrough. Additionally, each of the distal openings 18b defines a cross-sectional area 34 large enough configured to permit unoccluded blood to flow there through.

The filtering body 10 preferably has a generally decreasing radius such that a first cross-sectional area 21 of the filtering body 10 (FIG. 3) taken along a plane adjacent to the lip portion 20 is substantially larger than a second cross-sectional area 33 of the filtering body 10 (FIG. 4) taken along a second plane adjacent to the tail portion 32. More specifically, the filtering body 10 is generally cone-shaped such as to have a generally constantly decreasing radius along a longitudinal axis 35.

The cross-sectional area 30 of each of the proximal openings 18a is substantially greater than the cross-sectional area 34 of the distal openings 18b in order to maximize the occluding capacity of the filtering body 10 and to promote full expansion of the filtering body 10 within the blood vessel 12, as is discussed in more detail below.

Regarding the tail portion 32, the distal openings 18b are relatively small such as to cause a flow resistance that is sufficient to open the filtering body 10. More specifically, the distal openings 18b are sized and positioned with respect to each other such that the filtering body 10 provides a flow resistance when the tail portion 32 is folded. As shown in FIG. 5, when the filtering body 10 is in a closed state 36, such as when being initially deployed into the blood vessel 12, the filtering body 10 may become folded along creases 38 such that some of the openings 18 become blocked. Therefore, the distal openings 18b are sized and positioned with respect to each other such as to provide a flow resistance unless substantially all of the distal openings 18b are unobstructed. For example, the distal openings 18b define a second diameter 37 and the filtering body 10 defines a spacer distance 39 between adjacent openings 41, 43 of the distal openings 18b; the spacer distance 39 is preferably equal to or greater than one half of the second diameter 37 such as to provide a resistance that is sufficient to open the filtering body 10. Even more preferably, the spacer distance 39 is equal to or greater than the second diameter 37. As another example, the distal openings 18b define a second area 47 and the filtering body 10 defines a spacer area 51 between adjacent openings 41, 43 of the distal openings 18b; the spacer area 51 is preferably equal to or greater than one half of the second area 47 such as to provide a resistance that is sufficient to open the filtering body 10. Even more preferably, the spacer area 51 is equal to or greater than the second area 47.

However, the distal openings 18b are preferably not so small as to restrict blood flow there through when the tail portion 32 is fully opened and unobstructed. As discussed above, restricted blood flow can cause various undesirable medical conditions. Therefore, the distal openings 18b are large enough such as to not reduce blood flow through the filtering body 10.

The distal openings 18b are preferably located along an end face 42 of the filtering body 10 that is substantially perpendicular to the direction 14 of the blood flow. This configuration also causes the filtering body 10 to fully open because the openings along the end face 42 have a maximum effective area when positioned to be perpendicular to the blood flow direction 14. Therefore, the natural properties of fluid flow will cause the cause the end face 42 to be perpendicular to the blood flow direction 14, thus opening the filtering body 10 to its full length 44 and maximizing its trapping volume.

Regarding the lip portion 20, the proximal openings 18a are relatively large to act as overflow passages for the distal openings 18b if they become obstructed. As emboli 16 flow into the filtering body 10 and engage the tail portion 32, the distal openings 18b may become obstructed, thereby limiting the fluid flow through the tail portion 32. To compensate for this reduced flow are, the proximal openings 18a have the relatively large cross-sections 30. Therefore, the large proximal openings 18a substantially prevent flow loss across the embolic protection device 9.

As shown in FIG. 2, intermediate openings 18c are located axially between the proximal and distal openings 18a, 18b such as to define flowpaths there through. The intermediate openings 18c are generally decreasing in size along the axial length 44 in the flow direction 14. Furthermore, the proximal openings 18a are generally more spaced-apart from each other than the distal openings 18b. Additionally, the intermediate openings 18c become generally less spaced-apart along the axial length 44 in the flow direction 14.

The proximal openings 18a may serve as continuously-used passages, such that blood continuously flows through the proximal openings 18a, whether the distal openings 18b are obstructed or unobstructed. However, due to the generally cone-shaped nature of the filtering body 10, the radially central portion of the filter receives the majority of the flow therethrough. More specifically, the natural fluid properties of the blood flow, such as friction between the blood flow and the blood vessel walls, cause the radially central portion of the blood vessel 12 to have a higher mass flow volume than the radially off-set portion of the blood vessel 12. Furthermore, the tapered shape of the filtering body 10 directs blood towards the tail portion 32 and thus towards the distal openings 34.

In addition to maximizing the trapping volume of and minimizing the flow losses through, the filtering body 10 also includes features that maximize the radial expansion of the embolic protection device 9. More specifically, to effectively form the seal 24 between the filtering body 10 and the blood vessel 12 and thus prevent emboli 16 from flowing past the filtering body 10, the embolic protection device 9 is configured such that blood flow causes the filtering body 10 to be radially opened until it engages the blood vessel 12 inner walls.

One such feature that radially opens the filtering body 10 is the generally cone-shaped design of the filtering body 10. More specifically, as shown in FIGS. 3 and 4, the filtering body 10 includes a radius 45a, 45b of generally diminishing size along the length 44 from the lip portion 20 to the tail portion 32. This shape causes blood flow along the direction 14 to create an axial force component 46 and a radial force component 48. More specifically, the axial force component 46 extends the filtering body 10 along its length 44, as discussed above. Furthermore, the radial force component 48 extends the filtering body 10 outwardly in the radial direction, towards the blood vessel 12 inner walls. Therefore, the cone-shaped nature of the filtering body 10 improves the seal 24 and increases the trapping volume of the device 9.

Another such feature that radially opens the filtering body 10 is a material promoting biofixation between the filtering body 10 and the body vessel 12. More specifically, an outer surface 49 of the filter includes a connective tissue 50 that causes biofixation between the outer surface of the filtering body 10 and the inner surface of the blood vessel 12, thereby sealing the respective components 10, 12 together. The connective tissue 50 is located on the frame 26 and on a portion of the filtering body 10 immediately adjacent to the lip portion 20, as shown in FIG. 1. Additionally, as shown in FIG. 6, the connective tissue 50 may be located on the outer surface 50 along a length 52 of the filtering body 10 such as to increase the surface area of the seal 24.

Reconstituted or naturally-derived collagenous materials can be used as the connective tissue 50 in the present invention to induce tissue growth by the blood vessel. Such materials that are at least bioresorbable will provide advantage in the present invention, with materials that are bioremodelable and promote cellular invasion and ingrowth providing particular advantage. The connective tissue 50 preferably includes an extracellular matrix (ECM).

Suitable bioremodelable materials can be provided by collagenous extracellular matrix materials (ECMs) possessing biotropic properties, including in certain forms angiogenic collagenous extracellular matrix materials. For example, suitable collagenous materials include ECMs such as submucosa, renal capsule membrane, dermal collagen, dura mater, pericardium, fascia lata, serosa, peritoneum or basement membrane layers, including liver basement membrane. Suitable submucosa materials for these purposes include, for instance, intestinal submucosa, including small intestinal submucosa, stomach submucosa, urinary bladder submucosa, and uterine submucosa.

As prepared, the submucosa material and any other ECM used may optionally retain growth factors or other bioactive components native to the source tissue. For example, the submucosa or other ECM may include one or more growth factors such as basic fibroblast growth factor (FGF-2), transforming growth factor beta (TGF-beta), epidermal growth factor (EGF), and/or platelet derived growth factor (PDGF). As well, submucosa or other ECM used in the invention may include other biological materials such as heparin, heparin sulfate, hyaluronic acid, fibronectin and the like. Thus, generally speaking, the submucosa or other ECM material may include a bioactive component that induces, directly or indirectly, a cellular response such as a change in cell morphology, proliferation, growth, protein or gene expression.

Submucosa or other ECM materials of the present invention can be derived from any suitable organ or other tissue source, usually sources containing connective tissues. The ECM materials processed for use in the invention will typically include abundant collagen, most commonly being constituted at least about 80% by weight collagen on a dry weight basis. Such naturally-derived ECM materials will for the most part include collagen fibers that are non-randomly oriented, for instance occurring as generally uniaxial or multi-axial but regularly oriented fibers. When processed to retain native bioactive factors, the ECM material can retain these factors interspersed as solids between, upon and/or within the collagen fibers. Particularly desirable naturally-derived ECM materials for use in the invention will include significant amounts of such interspersed, non-collagenous solids that are readily ascertainable under light microscopic examination with specific staining. Such non-collagenous solids can constitute a significant percentage of the dry weight of the ECM material in certain inventive embodiments, for example at least about 1%, at least about 3%, and at least about 5% by weight in various embodiments of the invention.

The submucosa or other ECM material used in the present invention may also exhibit an angiogenic character and thus be effective to induce angiogenesis in a host engrafted with the material. In this regard, angiogenesis is the process through which the body makes new blood vessels to generate increased blood supply to tissues. Thus, angiogenic materials, when contacted with host tissues, promote or encourage the infiltration of new blood vessels. Methods for measuring in vivo angiogenesis in response to biomaterial implantation have recently been developed. For example, one such method uses a subcutaneous implant model to determine the angiogenic character of a material. See, C. Heeschen et al., Nature Medicine 7 (2001), No. 7, 833-839. When combined with a fluorescence microangiography technique, this model can provide both quantitative and qualitative measures of angiogenesis into biomaterials. C. Johnson et al., Circulation Research 94 (2004), No. 2, 262-268.

Further, in addition or as an alternative to the inclusion of native bioactive components, non-native bioactive components such as those synthetically produced by recombinant technology or other methods, may be incorporated into the submucosa or other ECM tissue. These non-native bioactive components may be naturally-derived or recombinantly produced proteins that correspond to those natively occurring in the ECM tissue, but perhaps of a different species (e.g. human proteins applied to collagenous ECMs from other animals, such as pigs). The non-native bioactive components may also be drug substances. Illustrative drug substances that may be incorporated into and/or onto the ECM materials used in the invention include, for example, antibiotics or thrombus-promoting substances such as blood clotting factors, e.g. thrombin, fibrinogen, and the like. These substances may be applied to the ECM material as a premanufactured step, immediately prior to the procedure (e.g. by soaking the material in a solution containing a suitable antibiotic such as cefazolin), or during or after engraftment of the material in the patient.

Submucosa or other ECM tissue used in the invention is preferably highly purified, for example, as described in U.S. Pat. No. 6,206,931 to Cook et al. Thus, preferred ECM material will exhibit an endotoxin level of less than about 12 endotoxin units (EU) per gram, more preferably less than about 5 EU per gram, and most preferably less than about 1 EU per gram. As additional preferences, the submucosa or other ECM material may have a bioburden of less than about 1 colony forming units (CFU) per gram, more preferably less than about 0.5 CFU per gram. Fungus levels are desirably similarly low, for example less than about 1 CFU per gram, more preferably less than about 0.5 CFU per gram. Nucleic acid levels are preferably less than about 5 μg/mg, more preferably less than about 2 μg/mg, and virus levels are preferably less than about 50 plaque forming units (PFU) per gram, more preferably less than about 5 PFU per gram. These and additional properties of submucosa or other ECM tissue taught in U.S. Pat. No. 6,206,931 may be characteristic of the submucosa tissue used in the present invention.

Referring back to FIG. 1, the frame 26 is connected to, or unitarily formed with, a connecting wire 54 that is slidably coupled to a guidewire 56 to effectively deliver the filtering body 10 into the blood vessel 12. More specifically, as is known in the art, the guidewire 56 is metal wire that is generally rigid in the axial direction and that is generally flexible in the radial direction such that the guidewire 56 can be easily directed through a network of blood vessels. Furthermore, a connecting sleeve 58 includes an outer surface that is fixedly connected to the connecting wire 54 and an inner surface that is able to slidably receive the guidewire 56.

During delivery of the device 9 into the blood vessel 12, the guidewire 56 is first directed into the blood vessel 12 along the path of to a desired location, such as downstream of the site of a thrombus or a blood clot. Next, the device 9, being in the closed state 36, is slidably moved along the guidewire 56 via the connecting sleeve 58 until reaching the desired location. The device 9 is then expanded into the opened state 22 by any suitable means known in the art, such as by a catheter or other means.

Referring now to FIGS. 8 and 9, an assembly 100 for removing plaque and other stenotic lesions 102 from the blood vessel 12 is shown. The stenotic lesions 102 are fixed to the inner surface blood vessels 12, causing constricted areas 104 and thereby restricting bloodflow therethrough. The assembly 100 includes an emboli dislodging catheter, such as a balloon 106 that inflates to expand the flowpath of the blood vessel 12. More specifically, the balloon 106 expands to break-up the stenotic lesions 102 and cause fragments thereof to flow downstream as emboli 16.

During delivery of the balloon 106 into the blood vessel 12, an outer catheter 108 delivers the balloon 106 to the constricted area 104 in a deflated state 110, as is known in the art. The balloon 106 is then radially expanded by injecting a fluid, such as saline solution, into the balloon 106 via an inflating tube 112 fluidly connected thereto. The balloon 106 is then in an expanded state 114 to contact and break-up the stenotic lesions 102, thereby expanding the constricted area 104. The fragments of the stenotic lesions 102 then float downstream into the embolic protection device 9. Alternatively to the balloon, the emboli dislodging catheter may be any other suitable design for dislodging emboli, such as a scraping component or an expandable device.

The embolic protection device 9 is preferably expanded before the inflation balloon 106, so that the emboli 16 are prevented from bypassing the filter body 10. Additionally, the connecting wire 54 and the guidewire 56 in the Figures are received within the inflating tube 112, within a conduit that is fluidly-separated from the inflating chamber of the balloon, to control the delivery and the expansion of the embolic protection device 10.

Referring now to FIG. 7, another alternative embodiment of the present invention is shown. The embolic protection device 9 in FIG. 7 includes a tether 60 that is connected to the inner surface of the filtering body 10 and that is slidable along the longitudinal axis 35 with respect to the connecting wire 54 to create a collection area 62 within the filtering body 10 for collecting emboli 16. More specifically, as the tether 60 is pulled against the direction 14 of the blood flow, the portion of the filtering body 10 that is connected to the tether 60 likewise moves against the blood flow. This movement creates an area, the collection area 62, within the filtering body 10 that is furthest downstream from the emboli 16, causing the emboli 16 collect within the collection area 62.

The tether 60 is preferably connected to a radially central portion 64 of the tail 32 such that the collection area 62 is radially off-set from the longitudinal axis 35. More specifically, the central portion of the tail 32 is pulled backwards such that the collection area 62 is a ring-shaped area surrounding the central portion 64. This configuration causes the emboli 16 to collect around the central portion 64 and leaves the central portion 64 substantially unobstructed. A plurality of tethers 60 may be used to create more collection areas.

It is therefore intended that the foregoing detailed description be regarded as illustrative rather than limiting, and that it be understood that it is the following claims, including all equivalents, that are intended to define the spirit and scope of this invention.

Claims

1. An embolic protection device for filtering emboli in a body vessel in which blood flows in a first direction along a blood flow path, the body vessel defining a central longitudinal axis, the device comprising: a filtering body having a lip including a perimeter, the filtering body extending therefrom to a tail having an end face, the filtering body being configured to be folded into a closed state for delivery or retrieval and expanded into an open state for filtering emboli, the filtering body having a first plurality of openings formed therethrough and positioned generally spaced apart from each other and a second plurality of openings formed therethrough and positioned generally spaced apart from each other, the first plurality of openings being located adjacent to the lip, the second plurality of openings being located along the end face of the tail of the filtering body, the end face having a substantially perpendicular orientation that is substantially perpendicular to the first direction of the blood flow, the filtering body providing a flow resistance when the tail is folded, the substantially perpendicular orientation of the end face causing the filtering body to fully open into the open state when placed in the body vessel in the blood flow path, the first plurality of openings each having a first area for maintaining fluid flowpaths through the device and the second plurality of openings each having a second area for filtering emboli in the body vessel, wherein the first area is greater than the second area in both the closed state and the open state, and wherein the first plurality of openings is generally more spaced apart from each other than the second plurality of openings; anda frame connected to the lip for supporting the filtering body, wherein the frame includes a wire formed into a loop that extends around the perimeter of the lip, wherein the frame perpendicularly opens in a radial direction along a plane perpendicular to the central longitudinal axis defining an opened state of the frame;wherein the device further comprises a material promoting biofixation between the filtering body and the body vessel; andwherein the material promoting biofixation includes extracellular matrix material that functions as a remodeling bioscaffold between an outer surface of the filtering body and an inner surface of the body vessel.

2. An embolic protection device as in claim 1, the filtering body further including a third plurality of intermediate openings located between the lip and the tail, the intermediate openings generally decreasing in size along a line extending from the lip to the tail.

3. An embolic protection device as in claim 2, wherein the first plurality of openings is configured such that a fluid flowrate through the filtering body is substantially unhindered when the second plurality of openings becomes obstructed.

4. An embolic protection device as in claim 1, wherein the second plurality of openings is radially closer than the first plurality of openings to the central longitudinal axis of the body vessel.

5. An embolic protection device as in claim 1, the filtering body having a generally tapered shape.

6. An embolic protection device as in claim 1, wherein the first area is at least two times larger than the second area.

7. An embolic protection device as in claim 1, the frame further including a retrieval member extending proximally therefrom to retrieve the embolic protection device from the body vessel.

8. An embolic protection device as in claim 1, further comprising a tether connected to the tail of the filtering body and being movable along the longitudinal axis to create a collection area within the filtering body for collecting emboli.

9. An embolic protection device as in claim 8, wherein the collection area is radially offset from the longitudinal axis.

10. An embolic protection device as in claim 1, wherein the material encircles the filtering body outer surface adjacent to the lip of the filter.

11. An embolic protection device as in claim 10, wherein the material is substantially located only along a portion of the filtering body adjacent to the lip of the filter.

12. An embolic protection device as in claim 1, wherein the extracellular matrix material includes small intestinal submucosa.

13. An embolic protection device as in claim 1, wherein each of the first and second plurality of openings is generally circular in shape.

14. An assembly for removing emboli from a body vessel in which blood flows in a first direction along a blood flow path, the body vessel defining a central longitudinal axis, the assembly comprising: an emboli dislodging catheter configured for dislodging the emboli from an inner wall of the body vessel;an outer catheter for delivering the emboli dislodging catheter into the body vessel; an embolic protection device positioned distally of the emboli dislodging catheter for collecting the dislodged emboli in the body vessel, the embolic protection device including a filtering body having a lip including a perimeter, the filtering body extending therefrom to a tail having an end face, the filtering body being configured to be folded into a closed state for delivery or retrieval and expanded into an open state for filtering emboli, the filtering body having a first plurality of openings formed therethrough and positioned generally spaced apart from each other and a second plurality of openings formed therethrough and positioned generally spaced apart from each other, the first plurality of openings being located adjacent to the lip, the second plurality of openings being located along the end face of the tail of the filtering body, the end face having a substantially perpendicular orientation that is substantially perpendicular to the first direction of the blood flow, the filtering body providing a flow resistance when the tail is folded, the substantially perpendicular orientation of the end face causing the filtering body to fully open into the open state when placed in the body vessel in the blood flow path, the first plurality of openings each having a first area for maintaining fluid flowpaths through the device and the second plurality of openings each having a second area for filtering emboli in the body vessel, wherein the first area is greater than the second area in both the closed state and the open state, and wherein the first plurality of openings is generally more spaced apart from each other than the second plurality of openings; anda frame connected to the lip for supporting the filtering body, wherein the frame includes a wire formed into a loop that extends around the perimeter of the lip, wherein the frame perpendicularly opens in a radial direction along a plane perpendicular to the central longitudinal axis defining an opened state of the frame;wherein the device further comprises a material promoting biofixation between the filtering body and the body vessel; andwherein the material promoting biofixation includes extracellular matrix material that functions as a remodeling bioscaffold between an outer surface of the filtering body and an inner surface of the body vessel; anda guide wire slidably coupled with the embolic protection device to guide the embolic protection device within the body vessel.

15. An assembly as in claim 14, further comprising a connecting wire unitarily formed with the frame, the connecting wire being slidably coupled to the guidewire for effective delivery of the embolic protection device into the blood vessel.