Embolic protection device

Abstract

The disclosed embolic protection device is designed for use in intravascular procedures. The device includes a braided structure that establishes contact with a vessel wall at both ends. The braided structure expands in diameter when compressed in length, providing additional force on the vessel wall to prevent device migration. The device also includes a telescoping tether with two attachment points to the braided structure. The tether controls the geometry of the braided structure, aiding in resisting migration of the device during the procedure. The device may also include an emboli collection portion that adopts a braided structure, with the basket and both anti-migration ends made from a single component. The braided structure and the telescoping tether work in conjunction to resist migration of the device in both distal and proximal directions.

Description

EMBOLIC PROTECTION DEVICEFIELD

[0001] The present disclosure generally relates to medical devices used in intravascular procedures, and more specifically, to embolic protection devices with anti-migration features designed to resist movement from an initially deployed location.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 presented in the use of embolic protection devices is their potential to migrate from an initially deployed location during the intravascular procedure. This migration is often attributed to the movement of a tether connected to the filter used for deployment and recapture. Inadvertent pushing or pulling of the tether while maneuvering other devices over it can unintentionally displace the filter.

[0005] The unintentional migration of the filter can result in several complications, including potential damage to nearby vessels or organs, or movement to a location where it can no longer effectively prevent emboli from migration downstream. To address this concern, modifications have been introduced in currently marketed embolic protection devices, typically aimed at increasing the radial force of the basket. This augmentation exerts more outward pressure on the vessel wall, thereby increasing friction and resistance against migration. Nevertheless, this approach has its drawbacks, as the increased radial force often makes the device more challenging to track, deploy and recapture.SUMMARY

[0006] According to an aspect of the inventive concepts, an embolic protection device is provided that includes a filter basket and a telescoping tether. The filter basket is configured to establish contact with a vessel wall at a proximal end portion of the filter basket, where the proximal end portion of filter basket expands in diameter when compressed in length. The telescoping tether is attached to the proximal end portion of the filter basket, and is configured to control a geometry of the proximal end portion of the filter basket.

[0007] The proximal end portion of the filter basket may be configured to naturally expand in diameter when compressed in length by the telescoping tether.

[0008] The telescoping tether may include an inner layer and an outer layer each connected to the proximal end portion of the filter basket, where the inner layer and the outer layer are movable relative to one another to control the length of the proximal end portion of the filter basket. The inner layer and outer layer of the tether may extend along a hollow rail that extends through a central axis of the filter basket. The telescoping tether may be configured to be locked in either an extended position or a retracted position, where the diameter of the proximal end portion of the filter basket is greater in the retracted position than in the extended position.

[0009] The filter basket may further include an emboli collection portion having a first end in fluid communication with the proximal end portion and having second end that is sealed, and a distal end portion connected to the second end of the emboli collection portion and having an expanded diameter configured to establish contact with the vessel wall. The distal end portion may be configured to naturally expand in diameter when compressed in length by migration of the embolic protection device while in contact with the vessel wall.

[0010] The filter basket may be made of a braided material.

[0011] The filter basket may be made of a sheeted fabric with holes formed therein.

[0012] The filter basket may be constructed of metal, fabric, or polymers, or a combination of two or more thereof.

[0013] The tether may be attached to the proximal end portion of the filter basket by connection elements, and the connection elements and the filter basket may be compressible for deployment through a catheter. The filter basket may be made of a shape memory material such as nitinol.

[0014] According to another aspect of the inventive concepts, an embolic protection device is provided that includes a hollow rail and a tether, where the tether includes an inner layer extending along the hollow rail, and an outer layer extending over the inner layer. The device further includes a filter basket including a barrel portion having an opening at a proximal end of the braided filter basket, and an emboli collection portion in fluid communication with the barrel portion. The device still further includes first connection elements connected between the outer tether and first portions of the barrel portion of the filter basket, and second connection elements connected between the inner tether and second portions of the barrel portion of the filter basket. The first portions of the barrel portion are located upstream of the second portions of the barrel portion relative to a direction of blood flow through the embolic protection device.

[0015] A distal end of the emboli collection portion may be sealed to the hollow rail, and the filter basket may further include a conical end portion extending downstream of the distal end of the emboli collection portion. The conical end portion may be configured to naturally expand in diameter when compressed in length by migration of the embolic protection device while in contact with a vessel wall.

[0016] A diameter of the emboli collection portion may be less than a diameter of the barrel portion.

[0017] The first and second connection elements and the filter basket may be compressible for deployment through a catheter. The filter basket may be made of a shape memory material such as nitinol.BRIEF DESCRIPTION OF FIGURES

[0018] 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:

[0019] FIG. 1 is an image of an embolic protection device according to embodiments of the inventive concepts;

[0020] FIG. 2 is an image of the device of FIG. 1 in a partially deployed state according to embodiments of the inventive concepts;

[0021] FIG. 3 is an image of the device of FIG. 1 in an expanded state according to embodiments of the inventive concepts; and

[0022] FIG. 4 is an image of the device of FIG. 1 for refence in describing a distal antimigration feature according to embodiments of the inventive concepts.DETAILED DESCRIPTION

[0023] 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 description of 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.

[0024] 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.

[0025] 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.

[0026] The design and geometry of the filter play a pivotal role in the performance. The device typically includes a collection filter basket where the emboli are captured. The filter basket is designed to appose the vessel wall to ensure that no emboli can bypass the device. The filter basketmay 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.

[0027] In embodiments of the inventive concepts, the embolic protection device includes a proximal anti-migration feature. This feature may include a telescoping tether with attachment points to a filter basket. In the embodiment described herein, the filter basket is assumed to be a braided filter basket, but inventive concepts are not limited in this manner. For example, the filter basket may be formed a meshed structure, or of a fabric or other material having holes formed therein.

[0028] This tether may be designed to control the geometry of the braided filter basket, thereby aiding in resisting migration of the device during the procedure. The telescoping tether may be locked in either an extended position or a retracted position, allowing for control over the geometry of the braided structure and thus the force it exerts on a vessel wall.

[0029] In some embodiments of the inventive concepts, the filter basket of the embolic protection device includes a distal anti-migration feature. This may take the form of a braided cone that expands in diameter upon contact with the vessel wall, providing additional resistance to distal migration of the device.

[0030] In some embodiments of the inventive concepts, the filter basket of the embolic protection device includes both a proximal anti-migration feature and a distal anti-migration feature.

[0031] The embolic protection device of the embodiments may offer several potential benefits. For instance, the device may provide improved resistance to migration during intravascular procedures, potentially reducing the risk of complications associated with device migration. Additionally, the device may be easier to deploy and recapture compared to existing devices, potentially improving the ease and efficiency of intravascular procedures.

[0032] FIG. 1 is an image of an embolic protection device according to embodiments of the inventive concepts.

[0033] Referring to the example of FIG. 1, the primary components of the illustrated embolic protection device include a telescoping tether (1, 2, 3, 4), a braided filter basket (5, 6, 7, 8) and a hollow rail (9).

[0034] The hollow rail 9 supports the remaining components of the device, and allows the device to be conveyed along a guide wire for positioning in a target vessel and extraction from the target vessel. Using tools known in the art, the rail 9 may be conveyed along a guide wire within a catheter to ensure precise placement and retrieval of the device. As those skilled in the art will understand, the filter basket described below is in a collapsed state as it is conveyed within the catheter, and then expands into the state shown in FIG. 1 when deployed and released from the catheter. In some aspects, the hollow rail 9 may be sized to allow other interventional devices to be guided around (over the wire), next to (monorail) or within it.

[0035] In the example of FIG. 1, the braided filter basket includes a barrel portion 5, an emboli collection portion 6 having a closed end 7, and a distal conical portion 8. When deployed, the direction of blood flow is from left to right in the figure. As shown, the barrel portion 5 of the example tapers towards a central axis to the emboli collection portion 6. This allows blood flow through the tapered portion in the event that blood flow through the emboli collection portion is inhibited by emboli collected therein. However, the inventive concepts are not limited in this manner. For example, the outer walls of the emboli collection portion 6 may be aligned with the outer walls of the barrel portion 5 shown in FIG. 1. Regardless, the emboli collection portion 6 includes a closed end 7 to prevent escapement of the collected emboli. This may be achieved by connection to a hub of the hollow rail 9. As shown, the distal conical end portion 8 expands outwardly from the sealed end 7 of the emboli collection portion. From there, the hollow rail 9 may continue for a given distance.

[0036] It will be understood that a proximal end of the barrel portion 5 is open to allow blood flow and emboli (if any) to flow into the filter basket. On the other hand, at least the tapered portion of the barrel portion 5 and the emboli collection portion 6 are permeable to blood and impermeable to emboli. As those skilled in the art will understand, this is achieved by appropriately sizing apertures in the material of the filter basket.

[0037] At least a portion of the barrel portion 5 is configured to create a seal against the blood vessel wall, preventing emboli from bypassing the filter basket. An expanded diameter of the barrel portion 5 is greater than the diameter of the vessel, thereby exerting an outward force against the vessel wall which holds the device in place within the vessel. The permeability to blood and emboli of this portion of the barrel portion 5 is not limited, since it is pressed against the vessel wall.

[0038] Still referring to FIG. 1, the telescoping tether includes an outer layer 1, and inner layer 2, connection elements 3 coupled to the outer layer 1, and connection elements 4 connected to the inner layer 2. The inner layer 2 wraps around the hollow rail 9, and the outer layer 1 wraps around the inner layer 2. The inner layer 1 and the outer layer 2 are movable relative to one another along the length of hollow rail 9. As such, the connection elements 3 are movable back and forth along the length of the hollow rail 9, as are the connection elements 4.

[0039] As illustrated in FIG. 1, the connection elements 3 are connected to outer proximal portions of the barrel portion 5 of the filter basket. In other words, the connection elements 3 extend between the outer layer 1 of the telescoping tether and the outer proximal portions of the barrel portion 5. Further, the connection elements 4 are connected to outer distal portions of the barrel portion 5 of the filter basket. In other words, the connection elements 4 extend between the inner layer 2 of the telescoping tether and the outer distal portions of the barrel portion 5. The connection elements 3 and 4 are collapsable together with filter basket for deployment through a catheter or the like. When released from the catheter, the collection elements are expanded to the state shown in FIG. 1 by their connection with the naturally expanding barrel portion of the filter basket.

[0040] Also shown in FIG. 1 is distal conical portion 8 of filter basket. As will be described later, this portion of the filter basket serves a distal anti-migration feature of the emboli protection device.

[0041] FIG. 2 is an image of the device of FIG. 1 in a partially deployed state 11 according to embodiments of the inventive concepts. Here, the inner layer of the tether is extended relative to the outer layer of the tether.

[0042] Referring to FIG. 2, the outer telescoping connections and inner telescoping connections are moved away from each other (as represented by the arrows 10) to elongate the barrel portion of the braided filter basket, which in turn decreases the diameter of the barrel portion as indicted by reference number 11. The narrowed diameter may facilitate the deployment and recapture of the device.

[0043] In some cases, as shown in the example of FIG. 2, the distal anti-migration feature (i.e., the distal conical portion) may maintain its shape for proper vessel wall contact. This feature may be designed to resist migration of the device during the procedure by maintaining a constant force against the vessel wall. This will be discussed below in connection with FIG. 4.

[0044] FIG. 3 is an image of the device of FIG. 1 in an expanded state according to embodiments of the inventive concepts. Here, the inner layer of the tether is retracted relative to the outer layer of the tether.

[0045] The barrel portion of the braided filter basket will naturally expand in diameter when compressed in length. In embodiments of the inventive concepts, this natural diametrical expansion is leveraged to provide additional force on the vessel wall to prevent device migration during an intravascular procedure. The telescoping tether, comprising the inner layer and outer layer, may be manipulated by a user to bring the proximal and distal connection elements closer together as indicated by the arrows 13 of FIG. 3, thereby achieving diametrical expansion as represented by reference number 14 of FIG. 3. This diametrical expansion increases the forces applied to the vessel wall, thus inhibiting migration of the emboli protection device with the vessel. In this manner, the proximal anti-migration feature is achieved.

[0046] When the emboli protection device is to be extracted from the vessel, the telescoping tether may be utilized to release the pressure of the barrel portion against the vessel wall. This is accomplished by extending the inner layer of the tether relative to the outer layer of the tether as shown previously in FIG. 2.

[0047] In some embodiments, the telescoping tether is configured to be locked in either an extended position or a retracted position. When locked in the extended position (e.g., as in FIG. 2) the diameter of barrel portion of the filter basket is less than that of a vessel wall. When locked in the retracted position (e.g., FIG. 3), the diameter of barrel portion of the filter basket is greater than that of a vessel wall.

[0048] FIG. 4 is an image of the device of FIG. 1 for refence in describing the distal antimigration feature according to embodiments of the inventive concepts.

[0049] Referring to the right side of FIG. 4, the distal conical portion of the braided filter basket is compressed longitudinally by interaction with the vessel wall. In other words, the distal conical end portion is configured to naturally expand in diameter when compressed in length by migration of the embolic protection device while in contact with the vessel wall. This is represented by reference number 16 in the figure. The resultant increase in force applied to the vessel wall acts to inhibit migration of the emboli protection device in a downstream direction. That is, expansion may occur when the structure at the distal end of the device forms a cone that expands in diameter upon contact with the vessel wall.

[0050] 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. 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.

[0051] As an example, in the case of venous use in which the veins are quite large, the barrel portion 5 may expand to 33 millimeters in diameter when not manipulated by the telescoping tether. The emboli collection portion 6 may be 12 to 16 millimeters in diameter, and the distal conical portion may expand to 30 millimeters in diameter. In this case, the unmanipulated length of the barrel portion 5 and the distal conical portion may each be 40 millimeters, and the length of the emboli collection portion 6 may be 100 millimeters. The length of the hollow rail 101 may be on the order of 200 centimeters.

[0052] In some embodiments, the device may include radiopaque fullness markers on the emboli collection portion 6 of the filter basket, visible under x-ray imaging. These markers can alert a physician when the emboli load approaches the taper at the inflow portion of the emboli collection portion 6, indicating that the filter may require emptying before proceeding with the procedure. In the case where the barrel 5 is tapered as described previously, 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.

[0053] In some embodiments, the barrel portion 5, the emboli collection portion 6, and the distal conical portion 8 are formed of a single continuous material or sheet of material. However, it will be understood that two or more of these portions may be formed from separate materials and then attached together.

[0054] 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 presentteachings 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 IS:

1. An embolic protection device, comprising: a filter basket configured to establish contact with a vessel wall at a proximal end portion of the filter basket, wherein the proximal end portion of filter basket expands in diameter when compressed in length; and a telescoping tether attached to the proximal end portion of the filter basket, wherein the telescoping tether is configured to control a geometry of the proximal end portion of the filter basket.

2. The embolic protection device of claim 1 , wherein the proximal end portion of the filter basket is configured to naturally expand in diameter when compressed in length by the telescoping tether.

3. The embolic protection device of claim 1, wherein the telescoping tether comprises an inner layer and an outer layer each connected to the proximal end portion of the filter basket, the inner layer and the outer layer movable relative to one another to control the length of the proximal end portion of the filter basket.

4. The embolic protection device of claim 3, wherein the inner layer and outer layer of the tether extend along a hollow rail that extends through a central axis of the filter basket.

5. The embolic protection device of claim 3, wherein the telescoping tether is configured to be locked in either an extended position or a retracted position, wherein the diameter of the proximal end portion of the filter basket is greater in the retracted position than in the extended position.

6. The embolic protection device of claim 1, wherein the filter basket further comprises: an emboli collection portion having first end in fluid communication with the proximal end portion, and having second end that is sealed; and a distal end portion connected to the second end of the emboli collection portion and having an expanded diameter configured to establish contact with the vessel wall.

7. The embolic protection device of claim 6, wherein the distal end portion is configured to naturally expand in diameter when compressed in length by migration of the embolic protection device while in contact with the vessel wall.

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

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

10. The embolic protection device of claim 1 , the filter basket is constructed of metal, fabric, or polymers, or a combination of two or more thereof.

11. The embolic protection device of claim 1, wherein the tether is attached to the proximal end portion of the filter basket by connection elements, and the connection elements and the filter basket are compressible for deployment through a catheter.

12. The embolic protection device of claim 11, wherein the filter basket is made of a shape memory material.

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

14. An embolic protection device, comprising: a hollow rail; a tether including an inner layer extending along the hollow rail, and an outer layer extending over the inner layer; a filter basket including a barrel portion having an opening at a proximal end of the braided filter basket, and an emboli collection portion in fluid communication with the barrel portion;first connection elements connected between the outer tether and first portions of the barrel portion of the filter basket; and second connection elements connected between the inner tether and second portions of the barrel portion of the filter basket, wherein the first portions of the barrel portion are located upstream of the second portions of the barrel portion relative to a direction of blood flow through the embolic protection device.

15. The embolic protection device of claim 14, wherein a distal end of the emboli collection portion is sealed to the hollow rail, and wherein the filter basket further includes a conical end portion extending downstream of the distal end of the emboli collection portion.

16. The embolic protection device of claim 6, wherein the conical end portion is configured to naturally expand in diameter when compressed in length by migration of the embolic protection device while in contact with a vessel wall.

17. The embolic protection device of claim 14, wherein a diameter of the emboli collection portion is less than a diameter of the barrel portion.

18. The embolic protection device of claim 14, wherein the first and second connection elements and the filter basket are compressible for deployment through a catheter.

19. The embolic protection device of claim 18, wherein the filter basket is made of a shape memory material.

20. The embolic protection device of claim 19, wherein the shape memory material is nitinol.

Images