Apparatus, system, and method for vasculature obstruction removal

In embodiments of an obstruction removal device, system, and/or method, a removal tool and an expandable member are configured to be disposed at a distal end of a delivery tool. The removal tool may include peeler wires and hook wires that are configured to at least partially separate an obstruction from an inner surface of a vasculature. The expandable member is configured to at least partially surround the removal tool and is further configured to grasp at least one portion of the removal tool and the obstruction as the expandable member transitions from an expanded state to a contracted state when the delivery tool is removed from the vasculature to remove the removal tool and the obstruction from the vasculature.

TECHNICAL FIELD

The present invention generally relates to medical devices, and, more particularly, to medical devices for removing vascular obstructions.

BACKGROUND

Obstruction removal systems/devices may operate by lodging the obstruction in a component of the removal system. In some cases, the obstruction may dislodge. Dislodgement of the obstruction substantially increases the risk for potential complications, such as stroke or heart attack. Thus, it is desirable to secure the obstruction safely for removal from the body.

SUMMARY

An obstruction removal system is disclosed. In one or more embodiments, the obstruction removal system includes a guide catheter configured to be inserted within a vasculature and a delivery tool having a distal end configured to be inserted within the guide catheter and disposed proximate to an obstruction in the vasculature. The obstruction removal system further includes a removal tool disposed at the distal end of the delivery tool. In one or more embodiments, the removal tool includes peeler wires and hook wires that are configured to at least partially separate the obstruction from an inner surface of the vasculature. The obstruction removal system further includes an expandable member configured to at least partially surround the removal tool. The expandable member is configured to grasp at least one portion of the removal tool and the obstruction as the expandable member transitions from an expanded state to a contracted state when the delivery tool is removed from the vasculature to remove the removal tool and the obstruction from the vasculature.

More generally, an obstruction removal device is disclosed. In one or more embodiments, the obstruction removal device includes a removal tool and an expandable member configured to be disposed at a distal end of a delivery tool. The removal tool may include peeler wires and hook wires that are configured to at least partially separate an obstruction from an inner surface of a vasculature. The expandable member is configured to at least partially surround the removal tool and is further configured to grasp at least one portion of the removal tool and the obstruction as the expandable member transitions from an expanded state to a contracted state when the delivery tool is removed from the vasculature to remove the removal tool and the obstruction from the vasculature.

A method for removing an obstruction from a vasculature is also disclosed. In one or more embodiments, the method includes the steps of: inserting a guide catheter within the vasculature; extending a delivery tool through the guide catheter so that a distal end of the delivery tool is disposed proximate to the obstruction in the vasculature; engaging at least one portion of the obstruction in the vasculature with a removal tool disposed at the distal end of the delivery tool, the removal tool comprising peeler wires and hook wires that are configured to at least partially separate the obstruction from an inner surface of the vasculature; and grasping at least one portion of the removal tool and the obstruction with an expandable member that at least partially surrounds the removal tool as the expandable member transitions from an expanded state to a contracted state when the delivery tool is removed from the vasculature to remove the removal tool and the obstruction from the vasculature.

DETAILED DESCRIPTION

Reference will now be made in detail to the subject matter disclosed, which is illustrated in the accompanying drawings. Referring generally toFIGS. 1A through 3C, an obstruction removal system is described, in particular, an obstruction removal system configured to selectively deploy a removal tool at least partially surrounded by an expandable member in a vasculature to reduce the risks associated with removal of an obstruction. The expandable member may be used to prevent an obstruction from dislodging from the removal tool and passing to a potentially more dangerous area (e.g. causing a total blockage, blocking a portion of a vital vasculature, etc.). In this regard, a physician may determine whether an obstruction is prone to risk and selectively deploy the expandable member. Furthermore, the physician may deploy the expandable member at various locations away from the obstruction (e.g., clot), as needed.

FIGS. 1A through 1Fillustrate one or more embodiments of an obstruction removal system100. As shown inFIG. 1A, the obstruction removal system100includes a guide catheter104configured to be inserted through a vasculature102to a position proximate to an obstruction101. Referring now toFIG. 1B, the obstruction removal system100further includes an obstruction removal device110configured to be inserted through the guide catheter104. For example, the obstruction removal device110may be coupled or formed on/near a distal end of a delivery tool108(e.g., a guide wire and/or tube) configured to be inserted through the guide catheter104.

In embodiments, the obstruction removal device110may be at least partially housed within an intermediate catheter106(e.g., any suitable intermediate catheter, microcatheter, or any other suitable tube) during insertion. The intermediate catheter106may be used to contain and keep the obstruction removal device110from expanding within the guide catheter104. This may provide one or more advantages, such as, but not limited to, reducing friction between the obstruction removal device110and the guide catheter104, permitting the obstruction removal device110to be inserted through the distal opening of the guide catheter104, and preventing the obstruction removal device110from prematurely engaging with the obstruction101.

FIG. 1Cillustrates the obstruction removal device110deployed within the vasculature102in proximity to an obstruction101. The delivery tool108(e.g., a guide wire and/or tube) is configured to be inserted within the guide catheter104and disposed proximate to the obstruction101in the vasculature102. For example, the delivery tool108, carrying the end-mounted obstruction removal device110, may be fed through the guide catheter104using the intermediate catheter106to contain/sheathe the obstruction removal device110during its insertion.

Referring now toFIG. 1D, the intermediate catheter106may be configured to unsheathe the obstruction removal device110so that the obstruction removal device110can engage the obstruction101in the vasculature102. For example, after reaching a desired position within the vasculature102, the intermediate catheter106may be pulled back (and/or the delivery tool108may be pushed forward relative to the intermediate catheter106) to unsheathe the obstruction removal device110so that the obstruction removal device110can engage the obstruction101.

As shown inFIG. 2, the obstruction removal device110may include a removal tool112comprising peeler wires116and hook wires118that are configured to at least partially separate the obstruction101from an inner surface of the vasculature102. In embodiments, the peeler wires116comprise wire segments that extend from the distal end of the delivery tool108toward the inner surface of the vasculature102when the removal tool112is deployed within the vasculature102. The hook wires118comprise wire segments that extend from respective wire segments of the peeler wires116toward a central axis of the removal tool112. For example, the hook wires118may be curved toward the central axis of the removal tool112, thereby forming hook-like or barb-like structures that are configured to catch onto and secure the obstruction101after the peeler wires116separate the obstruction101from the inner surface of the vasculature102.

The obstruction removal device110may further include an expandable member114configured to at least partially surround the removal tool112. In embodiments, the expandable member114is configured to grasp at least one portion of the removal tool112and the obstruction101as the expandable member transitions from an expanded state to a contracted state, e.g., when the delivery tool108is withdrawn through the guide catheter104to remove the removal tool112and the obstruction101from the vasculature102.

As the removal tool112is pushed toward the obstruction, the peeler wires116begin separating the obstruction101from the inner surface of the vasculature102. At this stage, the expandable member114may also assist in separating the obstruction101from the inner surface of the vasculature102. In some implementations, the system may be torqued to aid in advancement of the removal tool112and/or expandable member114. Meanwhile the hook wires118are configured to catch onto and secure the obstruction101.

The intermediate catheter106may be pushed forward (and/or the delivery tool108may be pulled back) to at least partially re-sheathe the obstruction removal device110so that the removal tool112of the obstruction removal device110grasps the obstruction101. For example, as shown inFIG. 1E, after engaging the obstruction101with the removal tool112of the obstruction removal device110, the intermediate catheter106may be pushed forward (and/or the delivery tool108may be pulled back relative to the intermediate catheter106) to at least partially re-sheathe the obstruction removal device110so that the expandable member114compresses the removal tool112, thereby causing the removal tool112to grasp/clench the obstruction101.

As shown inFIG. 1F, the intermediate catheter106with the delivery tool108and obstruction removal device110are then pulled back through the guide catheter104to remove the obstruction101from the vasculature102. The delivery tool108with the obstruction removal device110(including removal tool112and expandable member114) and the obstruction101may be withdrawn through the intermediate catheter106, as depicted inFIG. 1F. Alternatively, the delivery tool108with the obstruction removal device110and the obstruction101may be pulled directly through the guide catheter104(without use of an intermediate catheter106).

As noted above, the expandable member114may be configured to transition between contracted/collapsed and expanded states. The expandable member114may be configured to transition between the contracted and expanded states in any suitable way, including, but not limited to, unsheathing the expandable member114to allow expansion and sheathing/re-sheathing the expandable member114to induce contraction.

The expanded state may allow the expandable member114to surround at least a portion of the removal tool112and/or the obstruction101. The contracted state may be suitable for insertion and removal of the obstruction removal device110(including expandable member114and removal tool112) through the guide catheter104and/or intermediate catheter106. For example, when the expandable member114is in the collapsed/contracted state, after surrounding at least a portion of the removal tool112and/or the obstruction101, the expandable member114and the removal tool112may be withdrawn through the guide catheter104and/or the intermediate catheter106to remove the obstruction101from the vasculature102.

Benefits of surrounding at least a portion of the removal tool112and/or the obstruction101with the expandable member114may include, but are not limited to, smaller cross-sectional area, reduced friction on a vessel wall, reduced likelihood of catching on an opening of the guide catheter104and/or intermediate catheter106, and reduced likelihood of obstruction dislodgement.

As shown inFIGS. 1A through 1F, the delivery tool108may be a guide wire or tube with the expandable member114and the removal tool112both fixed to the distal end of the guide wire or tube. Furthermore, the removal tool112may be fixedly/permanently coupled to the expandable member114. In other embodiments, such as the embodiments illustrated inFIGS. 3A through 3C, the removal tool112and the expandable member114are separable and/or moveable independent of one another. For example, the delivery tool108may include a guide wire108A disposed within a tube108B, where the removal tool112is fixed to the distal end of the guide wire108A, and the expandable member114is fixed to the distal end of the tube108B.

As shown inFIG. 3A, the guide wire108A may be configured to be at least partially extended from a distal end of the tube108B. In such embodiments, the guide wire108A may be configured to extend the removal tool112away from the expandable member114(by extending the guide wire108A further into the vasculature102and/or pulling the tube108B back). This may allow the removal tool112to at least partially separate the obstruction101from the inner surface of the vasculature102without interference from the expandable member114.

Referring now toFIG. 3B, the guide wire108A may be further configured to retract the removal tool112toward the expandable member114(by pulling the guide wire108A back into the tube108B and/or pushing the tube108B along the guide wire108A) so that the expandable member114at least partially surrounds the removal tool112and/or obstruction101after the removal tool112at least partially separates the obstruction101from the inner surface of the vasculature102. Then, as shown inFIG. 3C, the intermediate catheter106may be pushed forward and/or the delivery tool108(i.e., guide wire108A and tube108B) may be pulled back relative to the intermediate catheter106to at least partially re-sheathe the obstruction removal device110so that the expandable member114compresses the removal tool112, thereby causing the removal tool112to grasp the obstruction101. The intermediate catheter106with the delivery tool108, the obstruction removal device110(including removal tool112and expandable member114), and the obstruction101are then pulled back through the guide catheter104to remove the obstruction101from the vasculature102. Alternatively, the delivery tool108with the obstruction removal device110and the obstruction101may be pulled directly through the guide catheter104(without use of an intermediate catheter106).

Referring generally to embodiments of the obstruction removal system100disclosed herein, the expandable member114may be configured to transition between a first configuration and a second configuration, or between a contracted state and an expanded state, in any number of ways, including, but not limited to, unsheathing (e.g., withdrawal of the intermediate catheter106or extension through the guide catheter104), disengagement of locking members (e.g., wires, hooks, etc.) attached to the expandable member114, use of shape memory alloys (e.g., Nitinol), or the like. It is envisioned that when the expandable member is in an expanded state, the expandable member may take up a substantial portion of the cross-section of the vasculature102.

In embodiments, the expandable member114, removal tool112, and the obstruction101are withdrawn into the guide catheter104and removed from the vasculature102. In some embodiments, the expandable member114, removal tool112, and the obstruction101may be further withdrawn into the intermediate catheter106. The expandable member114may surround at least a portion of the obstruction101to prevent dislodging and may also assist in compressing the obstruction101into the guide catheter104and/or the intermediate catheter106(e.g., by tension, cinching, crimping, etc.).

Surrounding at least a portion of the removal tool112and/or obstruction101with the expandable member114may serve several functions including, but not limited to, reducing a likelihood that the removal tool112snags (e.g. on an inner surface/vessel wall of the vasculature102or an opening of the guide catheter104), reducing a profile of the obstruction101for removal through the guide catheter104and/or intermediate catheter106, and/or securing the obstruction101to prevent dislodgement from the removal tool112.

In embodiments, the expandable member114may comprise a wire mesh. Such a wire mesh may include wires made of a flexible material (e.g. nitinol, cobalt chromium, polymer mesh (e.g., PET or nylon), or the like), where the wires (e.g. 16 to 288 or more wires), have a certain diameter (e.g. from 0.0007 inches to 0.0050 inches), and have certain material properties (e.g. strength, coefficient of friction with blood, resistance to plastic deformation, etc.) suitable for engaging the obstruction101and/or removal tool112. The wire mesh can be can be single ply or multiple plies. Furthermore, the wire mesh may include various sets of wires (e.g. support wires with larger diameters, wires to engage a vessel wall, wires to engage a portion of the obstruction or obstruction removal device, radiopaque or radiodense wires, etc.).

The peeler wires116that help to separate the obstruction101from the inner surface of the vasculature102may comprise metal wires (e.g., elastic or super-elastic Nitinol wire ranging in diameter from 0.001 inches to 0.010 inches, or more, in diameter). In embodiments, the peeler wires116and/or hook wires118may be made from round Nitinol wire, flat ribbon Nitinol wire, and/or cut from a Nitinol tube. In some embodiments, the peeler wires116are made of round wire segments to provide a smooth and atraumatic surface that does not damage the inner surface (vessel wall) of the vasculature102.

The removal tool112may include any number of peeler wires116and hook wires. In some embodiments, the removal tool112includes three to nine, or more, peeler wires116. Each peeler wire116may have at least one hook wire118extending or jutting out from the peeler wire116. Alternatively, only a subset of the peeler wires116may have hook wires118extending or jutting out for the purpose of securing the obstruction101after the obstruction101is removed from the inner surface of the vasculature102.

In some embodiments, the leading edge of the expandable member114may include the peeler wires116of the removal tool112that may extend distal to the leading edge, may be flush with the leading edge, or may be recessed. Alternatively, as shown inFIGS. 3A through 3C, the expandable member114and the removal tool112may be separable.

Any number of the presently disclosed elements may be suitable for imaging by a non-invasive imaging technology (e.g. X-ray, CT scans, etc.). For instance, the guide catheter104, intermediate catheter106, delivery tool108, removal tool112, expandable member114, and/or any additional components may comprise radiodense or radiopaque material (e.g. titanium, tungsten, barium sulfate, or zirconium oxide) suitable for insertion in a human body.

It is to be understood that any number of components of the obstruction removal system100may be attached by any suitable means including, but not limited to, welding, adhesive, mechanical fastening, interference fittings, etc. For example, the deliver tool108may be attached to the removal tool112and/or expandable member114by such means. Alternatively, or additionally, two or more of the components may be portions of a common structure (e.g., a common mold or print).

It is envisioned that there may be multiple orders in which one or more devices of the obstruction removal system100are deployed. Factors for determining an order may include, but are not limited to, vasculature properties (e.g. vasculature size, vasculature geometries, branches of the vasculature, vasculature wall strength, etc.), blood pressure, blood flow direction, duration of operation (i.e. does patient require a reduced operating time for safety concerns), size of obstruction, or the configuration of the obstruction removal device.

Referring generally toFIGS. 1A through 3C, a method of removing an obstruction from a vasculature102may include, but is not limited to, the steps of: deploying the guide catheter104through the patient's vasculature102to a position near the obstruction101; extending the delivery tool108with the end-mounted obstruction removal device110through the guide catheter104so that the distal end of the delivery tool108is disposed proximate to the obstruction101in the vasculature102(with/without the use of the intermediate catheter106); engaging at least one portion of the obstruction101in the vasculature102with the removal tool112of the obstruction removal device110; and grasping at least one portion of the removal tool112and the obstruction101with the expandable member114of the obstruction removal device110, where the expandable member114transitions from an expanded state to a contracted state when the delivery tool108is at least partially withdrawn into the guide catheter104and/or intermediate catheter106to remove the removal tool112and the obstruction101from the vasculature102.

It is to be understood that implementations of the methods disclosed herein may include one or more of the steps described herein. Further, such steps may be carried out in any desired order and, in some implementations, two or more of the steps may be carried out simultaneously with one another. Two or more of the steps disclosed herein may be combined in a single step, and in some implementations, one or more of the steps may be carried out as two or more sub-steps. Further, other steps or sub-steps may be carried in addition to, or as substitutes to one or more of the steps disclosed herein.

It is also to be understood that usage of terminology in the present disclosure is not intended to be limiting. For example, as used herein, an “obstruction” may refer to any vascular obstruction, including but not limited to, a blood clot, plaque (e.g. fat, cholesterol, etc.), internal structure/growth, foreign object, or the like.

Although the technology has been described with reference to the embodiments illustrated in the attached drawing figures, equivalents may be employed and substitutions made herein without departing from the scope of the technology as recited in the claims. Components illustrated and described herein are merely examples of a device and components that may be used to implement the embodiments of the present invention and may be replaced with other devices and components without departing from the scope of the invention. Furthermore, any dimensions, degrees, and/or numerical ranges provided herein are to be understood as non-limiting examples unless otherwise specified in the claims.