Embolic protection device

Abstract

An embolic protection device is provided that include a hollow rail and a filter basket attached to the hollow rail. The filter basket includes a vessel wall apposition portion, a tapered portion, and an emboli collection portion. The vessel wall apposition portion of the filter basket has an expanded diameter that is larger than a diameter of an intended vessel. The tapered portion is attached to the vessel wall apposition portion, and decreases in diameter in a downstream direction of blood flow of the intended vessel. The emboli collection portion has an open end attached to the tapered portion and a closed end attached to the hollow rail, and a diameter of the emboli collection portion is less than the diameter of the intended vessel. The filter basket is configured to bypass blood flow through the tapered portion when blood flow through the emboli collection portion is inhibited.

Description

EMBOLIC PROTECTION DEVICEFIELD

[0001] The present disclosure generally relates to medical devices used in intravascular procedures, and more specifically, to embolic protection devices configured to maintain uninterrupted blood flow while capturing emboli.BACKGROUND

[0002] Intravascular procedures, such as angioplasty, stenting, and thrombectomy, often involve the manipulation of devices within the blood vessels. These procedures, while beneficial, carry a risk of generating emboli - small particles or clots that can travel within the bloodstream. If these emboli are allowed to travel downstream, they can potentially block blood vessels, leading to serious health conditions such as heart attack, stroke, or pulmonary embolism. The severity of these conditions depends on the vessel in which the emboli occur and their subsequent destination.

[0003] To mitigate the risk of emboli generation, embolic protection devices are commonly used. These devices typically consist of a filter that is placed within the blood vessel to capture any emboli that may be generated during the procedure. The filter is designed to allow blood to flow through while trapping the emboli, preventing them from traveling downstream.

[0004] However, a challenge with these devices is maintaining adequate blood flow through the filter as it becomes laden with emboli. The accumulation of emboli can lead to a substantial reduction or even complete blockage of blood flow through the filter. This can pose a health risk to the patient, particularly if the filter is placed in a vessel supplying blood to a major organ. Furthermore, reduced or obstructed flow can hinder the efficient transport of additional emboli into the filter for capture, potentially leading to emboli becoming suspended in the vessel where flow stagnation occurs.SUMMARY

[0005] According to an aspect of the inventive concepts, an embolic protection device is provided that include a hollow rail and a filter basket attached to the hollow rail. The filter basket includes a vessel wall apposition portion, a tapered portion, and an emboli collection portion. The vessel wall apposition portion of the filter basket has an expanded diameter that is larger than a diameter of an intended vessel. The tapered portion is attached to the vessel wall apposition portion, and decreases in diameter in a downstream direction of blood flow of the intended vessel. The emboli collection portion has an open end attached to the tapered portion and a closed end attached to the hollow rail, and a diameter of the emboli collection portion is less than the diameter of the intended vessel. The filter basket is configured to bypass blood flow through the tapered portion when blood flow through the emboli collection portion is inhibited.

[0006] The filter basket may further include a stiffness adding component attached between the vessel wall apposition portion and the hollow rail. The stiffness adding component may be defined by a portion of the filter basket coated with a polymer or metal. Alternatively, the stiffness adding component may be formed by attaching a secondary component to the vessel wall apposition portion.

[0007] A diameter of the emboli collection portion at an interface with the tapered portion may be 60% or less the expanded diameter of the vessel wall apposition portion.

[0008] The diameter of the emboli collection portion at an interface with the tapered portion may be 50% or less the expanded diameter of the vessel wall apposition portion.

[0009] A length of the emboli collection portion may be at least twice a combined length of the stiffness adding component, the vessel wall apposition portion and the tapered portion.

[0010] The length of the emboli collection portion may be at least two-and-half times a combined length of the stiffness adding component, the vessel wall apposition portion and the tapered portion.

[0011] The filter basket may be made of a braided material, or a sheeted fabric with holes formed therein. The filter basket may be made of constructed of metal, fabric, or polymers, or a combination of two or more thereof

[0012] The filter basket may be compressible and made of a shape memory material. The shape memory material may be nitinol.

[0013] The embolic protection device may further include radiopaque fullness markers on the emboli collection portion of the filter basket.

[0014] The hollow rail may be configured for conveyance along a guide wire insertable in the intended vessel.BRIEF DESCRIPTION OF FIGURES

[0015] The above and other aspects and features of the inventive concepts will become readily apparent from the detailed description that follows, with reference to the accompanying drawings, in which:

[0016] Fig. 1 is a schematic representation of a prior art embolic protection filter within a blood vessel;

[0017] Fig. 2 is a schematic representation of an embolic protection device according to embodiments of the inventive concepts; and

[0018] Fig. 3 is a photographic image of an embolic protection device according to embodiments of the inventive concepts.DETAILED DESCRIPTION

[0019] In the following detailed description, for purposes of explanation and not limitation, representative embodiments disclosing specific details are set forth in order to provide a thorough understanding of the present teachings. However, it will be apparent to one having ordinary skill in the art having had the benefit of the present disclosure that other embodiments according to the present teachings that depart from the specific details disclosed herein remain within the scope of the appended claims. Moreover, descriptions of well-known apparatuses and methods may be omitted to avoid obscuring the descriptionof the example embodiments. Such methods and apparatuses are clearly within the scope of the present teachings. Further, throughout the drawings, like reference numbers refer to the same or similar elements.

[0020] The terminology used herein is for purposes of describing particular embodiments only, and is not intended to be limiting. The defined terms are in addition to the technical and scientific meanings of the defined terms as commonly understood and accepted in the technical field of the present teachings. As used in the specification and appended claims, the terms ‘a’, ‘an’ and ‘the’ include both singular and plural referents, unless the context clearly dictates otherwise. Thus, for example, ‘a device’ includes one device and plural devices. Further, for example, when one element is described as being “connected to” another element, the one element may be directly connected to the other element, or indirectly connected to the other element in an operative manner.

[0021] The present disclosure pertains to medical devices used in intravascular procedures, specifically to embolic protection devices. These devices are designed to capture emboli, or small particles or clots that can travel within the bloodstream, during intravascular procedures. The captured emboli are prevented from traveling downstream where they could potentially block blood vessels and lead to serious health conditions.

[0022] The design and geometry of the filter play a pivotal role in the performance. The filter typically includes a collection basket where the emboli are captured. The basket is designed to appose the vessel wall to ensure that no emboli can bypass the filter. The basket may be made of various materials, including metal, fabric, or polymers, and may be constructed in a braided or mesh pattern. Some filters may also incorporate shape memory materials, such as nitinol, which can return to their original shape after being collapsed for delivery into the vessel.

[0023] The embolic protection device of embodiments of the inventive concepts include a specially designed collection basket or filter basket. This filter basket may have a larger diameter portion on the inflow side to ensure proper apposition to the vessel wall and resistance against migration. The filter basket may then taper to a smaller diameter wherethe emboli are accumulated. This design allows for blood flow around the collected emboli, even as the basket fills, thereby maintaining adequate blood flow throughout the procedure.

[0024] The material make-up of the filter basket is not limited, and may include a metal, fabric, or polymers, or a combination thereof. For example, the filter basket may be made of a braided material. As another example, the filter basket may be made of a fabric with small holes formed therein. In some embodiments, the basket is made of a shape memory material such as nitinol, which can return to its original shape after being collapsed for delivery into the vessel.

[0025] The embolic protection device may also include a stiffness adding component attached to a hollow rail. This component may be created by selectively coating the basket with a polymer or metal in the area of the vessel wall apposition portion of the basket. Alternatively, the stiffness adding component may be created by attaching a secondary component such as a laser cut structure or a secondary braided structure to the vessel wall apposition portion of the basket.

[0026] In some embodiments, the embolic protection device may include radiopaque fullness markers on the emboli collection portion of the basket. These markers, visible under x-ray imaging, can alert a physician when the emboli load approaches the taper at the inflow portion of the filter. This feature can help ensure that the filter is not filled beyond the region where the flow is able to bypass the collection portion of the filter, which would impede the ability of the design to maintain flow.

[0027] FIG. 1 depicts a schematic view of a prior art embolic protection filter within a blood vessel. The blood vessel wall 1 is shown with the direction of blood flow 2 moving towards the prior art filter geometry 3. Emboli 4 are illustrated accumulating within the filter, leading to blocked blood flow 5 and reduced blood flow 6 around the filter. In some cases, as mentioned earlier herein, the filter geometry 3 may be unable to maintain adequate blood flow due to the accumulation of emboli 4. This can potentially lead to a decrease or complete blockage in the amount of blood reaching downstream organs, as well as stagnation prior to the filter, both of which can pose a health risk to the patient.

[0028] FIG. 2 is a schematic view of an embolic protection device 100 within a blood vessel according to embodiments of the inventive concepts. The blood vessel wall 1 is shown with the direction of blood flow 2 indicated by the illustrated arrow.

[0029] As shown in FIG. 2, the device includes a portion engage with the blood vessel wall 1, a portion that tappers inwardly towards a central axis of the blood vessel, and a portion have a diameter which is less than that of the portion engage with the blood vessel wall 1. The smaller diameter portion is utilized to capture emboli 4 within the embolic protection device 100. In the meantime, the tapper portion allows blood flow 7 to bypass around the accumulated emboli 4. This innovative filter geometry ensures that blood can continue to flow past the emboli 4, preventing blockage and maintaining circulation during intravascular procedures.

[0030] FIG. 3 is a photographic image of an embolic protection device 100 according to embodiments of the inventive concepts.

[0031] Referring to FIG. 3, the device 100 includes a hollow rail 101. The hollow rail 101 supports the remaining components of the device (collectively referred to herein as a filter basket), and allows the device to be conveyed along a guide wire 107 for positioning in a target vessel and extraction from the target vessel. Using tools known in the art, the rail 101 may be conveyed along a guide wire within a catheter to ensure precise placement and retrieval of the device 100. Here, the filter basket described below is in a collapse state as it is conveyed within the catheter, and then expands into the state shown in FIG. 3 when deployed and released from the catheter. In some aspects, the hollow rail 101 may be sized to allow other interventional devices to be guided around (over the wire), next to (monorail) or within it.

[0032] Attached to an upstream hub 101a of the hollow rail 101 is a stiffness adding component 102 that provides structural support and helps maintain the device's position against the blood vessel wall. In some cases, the stiffness adding component 102 may be created by selectively coating the proximal (upstream) portion of the filter basket with a polymer or metal. In other cases, the stiffness adding component 102 may be created by attaching a secondary component such as a laser cut structure or a secondary braidedstructure between the hollow rail 101 and a vessel wall apposition portion 103 of the filter basket. Regardless of its composition, the stiffness adding component 102 is permeable to both blood and emboli, thus allowing both to travel downstream into the remainder of the filter basket.

[0033] Attached to the stiffness adding component 102 is the vessel wall apposition portion 103 of the filter basket. The vessel wall apposition portion 103 is configured to create a seal against the blood vessel wall, preventing emboli from bypassing the filter basket. The expanded diameter of the vessel wall apposition portion 103 is greater than the diameter of the vessel, thereby exerting an outward force against the vessel wall which holds the device 100 in place within the vessel. In some aspects, a secondary component may be attached to the vessel wall apposition portion of the basket 103 to increase the outward force, further ensuring the seal against the blood vessel wall 1. The permeability to blood and emboli of the vessel wall apposition portion 103 is not limited, since it is pressed against the vessel wall.

[0034] Attached to the vessel wall apposition portion 103 is a tapered portion 104. As illustrated, the tapered portion 104 decreases in diameter in a downstream direction of the blood flow within the vessel. The tapered portion 104 is permeable to blood flowing downstream, but impermeable to emboli.

[0035] Attached to the tapered portion 104 is an emboli collection portion. Like the tapered portion 104, the emboli collection portion is permeable to blood flowing downstream, but impermeable to emboli.

[0036] The emboli collection portion 105 of the filter basket 105 is where emboli 4 are trapped and collected. In the meantime, the tapered portion 104 allows blood flow to bypass around the accumulated emboli 4. This innovative filter geometry ensures that blood can continue to flow past the emboli, preventing blockage and maintaining circulation during intravascular procedures.

[0037] In some cases, the basket, including the vessel wall apposition portion 103, the tapered region 104, and the emboli collection portion 105, may be made of a braided material, a sheet of material with small holes formed therein, or a shape memory materialsuch as nitinol. The material used for the basket may be metal, fabric, or polymers. It will be understood that apertures through the tapered regions 104 and emboli collection portion 105 are sized to allow the passage of blood therethrough, but block emboli from passing therethrough.

[0038] At the distal end of the device, a tapered / closed end 106 of the filter basket 106 is fixed to a downstream hub 10 lb of the hollow rail 107 to prevent emboli 4 from escaping . From there, the hollow rail 101 may continue for a given distance. As discussed previously, the hollow rail 101 extends along a guidewire 107 device 107, facilitating its navigation through the vascular system in maimers that are known in the art.

[0039] It will be appreciated that the size of the embolic protection device will depend on the diameter of the intended vessel in which it is to be used as well as the desired size of particulate to be captured. Nonetheless, in order to provide some dimensional context, some examples sizes of the device components are provided next. It is emphasized here that the inventive concepts are not limited to these particular examples, nor are the inventive concepts limited to the components having sizes relative to one another as represented by the examples.

[0040] As an example, in the case of venous use in which the veins are quite large, the vessel wall apposition portion 103 may expand to 33 millimeters in diameter, while the emboli collection portion 105 may be 12 to 16 millimeters in diameter. In this case, the combined length of the stiffness adding component 102, the vessel wall apposition portion103 and the tapered portion 104 may be 40 millimeters, and the length of the emboli collection portion 105 may be 100 millimeters. The length of the hollow rail 101 may be on the order of 200 centimeters.

[0041] In some example embodiments of the inventive concepts, the diameter of the emboli collection portion 105 at its interface with the tapered portion 104 is 60% or less the expanded diameter of the vessel wall apposition portion 103. In other embodiments, the diameter of the emboli collection portion 105 at its interface with the tapered portion104 is 50% or less the expanded diameter of the vessel wall apposition portion 103.

[0042] Also, in some example embodiments of the inventive concepts, the length of the emboli collection portion 105 is at least twice the combined length of the stiffness adding component 102, the vessel wall apposition portion 103 and the tapered portion 104. In other embodiments of the inventive concepts, the length of the emboli collection portion 105 is at least two-and-half times the combined length of the stiffness adding component 102, the vessel wall apposition portion 103 and the tapered portion 104.

[0043] In some aspects, the device may include radiopaque fullness markers on the emboli collection portion of the basket 105, visible under x-ray imaging. These are represented by the white dots 108 superimposed in the photo of FIG. 3. These markers can alert a physician when the emboli load approaches the taper at the inflow portion of the emboli collection portion 108, indicating that the filter may require emptying before proceeding with the procedure. This feature can help ensure that the filter is not filled beyond the region where the flow is able to bypass the collection portion 105 of the filter, which would impede the ability of the design to maintain flow.

[0044] In some embodiments, the vessel wall apposition portion 103, the tapered portion 104 and the emboli collection portion 105 are formed of a single continuous braided material. However, it will be understood that two or more of these portions may be formed from separate materials and then attached together.

[0045] While the invention has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive; the invention is not limited to the disclosed embodiments. Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims. While representative embodiments are disclosed herein, one of ordinary skill in the art will appreciate that many variations that are in accordance with the present teachings are possible and remain within the scope of the appended claim set. The invention therefore is not to be restricted except within the scope of the appended claims.

Claims

WHAT IS CLAIMED:

1. An embolic protection device comprising a hollow rail and a filter basket attached to the hollow rail, the filter basket comprising: a vessel wall apposition portion having an expanded diameter that is larger than a diameter of an intended vessel; a tapered portion attached to the vessel wall apposition portion, the tapered portion decreasing in diameter in a downstream direction of blood flow of the intended vessel; and an emboli collection portion having an open end attached to the tapered portion and a closed end attached to the hollow rail, wherein a diameter of the emboli collection portion is less than the diameter of the intended vessel, wherein the filter basket is configured to bypass blood flow through the tapered portion when blood flow through the emboli collection portion is inhibited.

2. The embolic protection device of claim 1, wherein the filter basket further includes a stiffness adding component attached between the vessel wall apposition portion and the hollow rail.

3. The embolic protection device of claim 2, wherein the stiffness adding component is defined by a portion of the filter basket coated with a polymer or metal.

4. The embolic protection device of claim 1, wherein a diameter of the emboli collection portion at an interface with the tapered portion is 60% or less the expanded diameter of the vessel wall apposition portion.

5. The embolic protection device of claim 1, wherein diameter of the emboli collection portion at an interface with the tapered portion is 50% or less the expanded diameter of the vessel wall apposition portion.

6. The embolic protection device of claim 2, wherein a length of the emboli collection portion is at least twice a combined length of the stiffness adding component, the vessel wall apposition portion and the tapered portion.

7. The embolic protection device of claim 2, wherein a length of the emboli collection portion is at least two-and-half times a combined length of the stiffness adding component, the vessel wall apposition portion and the tapered portion.

8. The embolic protection device of claim 2, wherein the stiffness adding component is formed by attaching a secondary component to the vessel wall apposition portion.

9. The embolic protection device of claim 1, wherein the filter basket is made of a braided material.

10. The embolic protection device of claim 1, wherein the filter basket is made of a sheeted fabric with holes formed therein.

11. The embolic protection device of claim 4, filter basket may be constructed of metal, fabric, or polymers, or a combination of two or more thereof.

12. The embolic protection device of claim 1, wherein the filter basket is compressible and made of a shape memory material.

13. The embolic protection device of claim 12, wherein the shape memory material is nitinol.

14. The embolic protection device of claim 1, further comprising radiopaque fullness markers on the emboli collection portion of the filter basket.

15. The embolic protection device of claim 1, wherein the hollow rail is configured for conveyance along a guide wire insertable in the intended vessel.

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