Patent Description:
This application claims the benefit of the following United States Provisional Applications:.

<CIT> (HORW-<NUM>-POl); <CIT> (HORW-<NUM>-P01); <CIT> (HORW-<NUM>-P01); and <CIT> (HORW-<NUM>-P02).

The disclosure generally relates to for the catheter-based removal of occlusions and unwanted matter from vessels, ducts and other cavities or lumens of an organism.

Current medical devices that are used for the removal of occlusions, such as thrombi from the vessels (such as those in the brain), have limitations that reduce their effectiveness, reliability, and ease of use. For example, current devices are designed exclusively for the vascular system, and may not be used for extraction of material from ducts, ureters, urethra, or other anatomical features. Current devices are not appropriate for use in large vascular structures such as aorta, vena cava and many peripheral vascular applications, and often do not work well with calcified, organized material due to inability of the wire structures often used to compress into the embolic material prior to an attempted extraction. Current devices often have a wire structure that must incorporate into a thrombus to remove a clot and provide poor distal protection from secondary emboli during thrombus extraction due to open ended stent retriever or partial grasping of thrombus. This may result in an intended thrombectomy procedure causing distal clot embolization and occlusion of previously patent arterial branches and collaterals. Current devices may be less effective when used with associated arterial stenoses due to device collapse and tendency for a stenosis to strip and debride thrombus from device as it is retracted through the stenotic vessel segment. Current devices often require operators to choose a predetermined device length at time of device insertion, but the chosen device length might not match the size of the target thrombus once the operator is in the vessel and provided a closer view of the target thrombus.

Current catheter-based methods and systems for the removal of foreign bodies from an artery, duct, ureter or other interior physical space, often require multiple co-axial (or concentric) sleeves or delivery catheters, some of which are intended for placement on the proximal side of an occlusion, some for direction through the occlusion for placement on the distal side of the occlusion, and still others for holding inflatable balloons, thrombus removal devices and the like. The presence of multiple catheters increases manufacturing complexity and cost, in addition to increasing complexity of usage during an intervention, with greater moving parts and the required ordering of operation aligned with the function of the multiple catheters. Current catheter-based methods and systems are also manufactured and deployed in the clinical setting with a specific catheter, meaning that if during an intervention a clinician wants to deploy ("load"), for example, a retrieval device having a different size than that first deployed in a vessel, the entire catheter-based tool must be withdrawn and a new catheter-based device with the preferred diameter loaded inserted. Additional limitations of the current catheter-based systems include, but are not limited to, a reliance on fixed-diameter instrumentation and/or inflatable bodies (e.g., balloons) for encapsulation of a foreign body or occlusion. As an example, catheters using an inflatable balloon for a distal body and/or proximal body may require that an interventionist pre-select a balloon model and size prior to entering a vessel or cavity because inflatable balloons have a manufactured minimum and maximum inflation diameter. Thus, if the incorrect balloon size is selected, or the clinical setting requires flexibility in the expansion or contraction diameter of the distal or proximal bodies, the intervention may be interrupted to allow for size adaptation of equipment. Incorrect sizing may also increase the likelihood for negative clinical sequelae, such as embolization and release of occlusive matter if, for example, distal protection is lost.

Therefore, there is a need for methods and systems of thrombus, or other matter, removal in which an object targeted for removal may be dynamically surrounded by a retrieval device, rather than incorporated into the target object, wherein the retrieval device can surround the target and may be physically adjusted to match the size of the target object while within the vessel or other cavity.

US Patent Application Publication Number <CIT> discloses a clot removal device having an expandable treatment member having a distal tip and a proximal end, a delivery wire having a distal end coupled to the proximal end of the expandable treatment member, and a flow restrictor carried along the delivery wire at a location that is separate and proximal from the expandable treatment member. The flow restrictor has a body with a distal section and a proximal section, the distal section being covered and the proximal section being uncovered. The expandable treatment member is moveable relative to the flow restrictor, and can be retracted into the distal section.

US Patent Application Publication Number <CIT> discloses a device and a method for increasing or restoring a flow in a body lumen. The device and the method may treat conditions like a stroke by removing a clot from a blood vessel and/or reopen the vessel. The device may have a plurality of engaging elements, wires that can link at least two engaging elements, a central wire, and proximal control element. The positions of the engaging elements and the distance there between can be adjusted to ensure the engagement of the clot or occlusion.

US Patent Application Publication Number <CIT> discloses a device and a method for increasing or restoring a flow in a body lumen. The device and the method may treat conditions related to a stroke, such as ischemic stroke, by removing an occlusion from a blood vessel and/or reopen a blood vessel. The device may comprise a tubing compartment, a central wire, and an engaging compartment. The engaging compartment may comprise a tubing compartment, a central wire, and an engaging compartment. The engaging compartment may comprise a distal engaging element and a proximal engaging element. A clot or occlusion present in the body lumen such as an artery may be engaged in and/or between the distal and proximal engaging elements. Further, the positions of one or both of the engaging elements and the distance therebetween can be adjusted to ensure the engagement of the clot or occlusion.

US Patent Application Publication Number <CIT> discloses an embolectomy device for removal of clots from vasculature, said device comprising: a proximal effecter characterized by a non-expanded configuration and an expanded configuration; a distal effecter characterized by a non-expanded configuration and an expanded configuration; said proximal effecter, in said expanded configuration is adapted for grasping a proximal portion of the target embolus; said proximal effecter, in said expanded configuration is adapted for grasping a distal portion of said target embolus; wherein both said effecters, when expanded, are oppositely positioned and are adapted to operate in concert, for trapping said clot such that said clot is (i) manipulatable along and/or around the main longitudinal axis of said vasculature in a predetermined set of motions; (ii) extracted out of said vasculature.

US Patent Number <CIT> discloses a method wherein an artery, vein, aneurysm, vascular malformation or arterial fistula is occluded through endovascular occlusion by the endovascular insertion of a platinum wire and/or tip into the vascular cavity. The vascular cavity is packed with the tip to obstruct blood flow or access of blood in the cavity such that the blood clots in the cavity and an occlusion is formed. The tip may be elongate and flexible so that it packs the cavity by being folded upon itself a multiple number of times, or may pack the cavity by virtue of a filamentary of fuzzy structure of the tip. The tip is then separated from the wire maechanically of by electrolytic separation of the tip from the wire. The wire and the microcatheter are thereafter removed leaving the tip embedded in the thrombus formed within the vascular cavity. Movement of wire in the microcatheter is more easily tracked by providing a radioopaque proximal marker on the microcatheter and a corresponding indicator marker on the wire. Electrothrombosis is facilitated by placing the ground electrode on the distal end of the microcatheter and flowing current between the microcatheter and the tip.

The present invention relates to the embodiments as characterized in the claims. Provided herein are occlusion removal devices of capturing and removing occlusions, thrombi, biological matter and foreign objects from anatomical systems, including the vascular system, ducts, ureters, urethra, or other anatomical features as characterized in the claims.

Embodiments of the present disclosure include an occlusion removal device comprising a first body releasably engaged to the delivery wire, wherein while engaged the first body remains fixed on the delivery wire and upon release moves axially along the delivery wire, and a second body mounted to the delivery wire. The first proximal body is oriented proximally to the second distal body. The proximal body and the distal body may be adapted to expand upon exiting a delivery catheter. The proximal is releasably engaged by a mechanically breakable connection. The proximal and distal bodies may be mesh, and may be made of nitinol.

These and other systems objects, features, and advantages of the present disclosure will be apparent to those skilled in the art from the following detailed description of the preferred embodiment and the drawings.

The disclosure and the following detailed description of certain embodiments thereof may be understood by reference to the following figures:.

The present invention relates to the embodiments as characterized in the claims. In embodiments of the present disclosure, the retrieval device, as shown in <FIG>, is a catheter-delivered tool used to remove a foreign body, such as a thrombus or clot, from an artery, vein, duct, or other interior physical space. The retrieval device may be interchangeably referred to herein as "the device" or a "removal device", the "removal" or "retrieval" of the foregoing may be modified by a variety of terms such as "thrombus," "occlusion," "foreign body," etc. The retrieval device may be used as a foreign body retriever and as a thrombectomy device in the arterial and venous system. The device may be used in the vascular system and in non-vascular structures such as ureters, ducts, airways, and any other accessible space that contains a material (biologic or foreign) that necessitates removal or retrieval.

<FIG> depicts the deployed retrieval device with a distal body <NUM>, which in this embodiment is a body mounted to the delivery wire <NUM> such that it remains in a fixed position. Referring to all embodiments disclosed herein, it should be noted that prior to deployment of the delivery wire <NUM>, a guide wire may be used to position any element of the system disclosed herein, including a delivery catheter <NUM>, guide catheter <NUM>, and delivery wire <NUM> into the preferred position within a vessel or other interior. The "bodies" referred to herein may be a mesh, and they may be made of nitinol or other suitable expandable biocompatible material. The mesh construct of the distal <NUM> and proximal <NUM> bodies may reduce the risk of distal embolization of portions of a clot since the mesh construct may capture embolic material within its interstices. The distal body <NUM> may, in embodiments, have differently-sized mesh or may comprise a selectively permeable material, or it may be non-permeable. A proximal body <NUM> is also shown. The proximal body <NUM> is mounted to the delivery wire <NUM> and is temporarily affixed thereto such that it remains in a fixed position. The temporary affixed aspect referred to above is releasable such that upon release the proximal body <NUM> may move along the wire, which is referred to herein as "axial movement" along the wire, while remaining engaged to the wire <NUM>. This aspect is referred to as being in "releasable engagement" or being "releasably engaged" to the delivery wire <NUM>. Such releasable engagement is achieved by using breakable connection <NUM>, is a mechanical connection that can be selectively disconnected by the clinician. The connection includes, without limitation, a breakable connection <NUM>, linking a proximal body <NUM> to the delivery wire <NUM>. The breakable connection <NUM> is preloaded onto the retrieval device in order to secure the proximal body <NUM> in a preferred location and/or configuration. The breakable connection may have a plurality of shapes and designs, including but not limited to a straight post extending from the delivery wire <NUM> to the proximal <NUM> or other body, a loop configuration of the breakable connection passing through the material of the proximal <NUM> or other body, and/or a "nail" configuration in which a straight post extends from the delivery wire to the proximal <NUM> or other body, wherein the post has an enlarged end, or nail head, within the body that may be eroded by the application of electric current to release the body. Embodiments of the present invention include a proximal <NUM> or other body that may be secured to the delivery wire <NUM> using more than one breakable connection <NUM>. In an example, a proximal body <NUM> may be secured with multiple breakable connections, each having a different length and a different release threshold, allowing the breakable connections to be sequentially released. In embodiments, more than one proximal body may be secured to the delivery wire <NUM> using a breakable connection <NUM>. Melting of a breakable connection may be caused by the application of electrical current, fluid, and/or chemical compounds. Breakable connection techniques and methods, including but not limited to those shown in <CIT>, <CIT>, <CIT>. and <CIT>, and <CIT>, may be used to release a proximal body and/or distal body, as described herein. Regarding the mechanically breakable connection as used herein, the breakable connection <NUM> may be made of a suture, brace, thread or other material that is able to be broken upon application of force to the breakable connection <NUM>. In embodiments, the distal motion of a catheter, such as the delivery catheter, with a force above the threshold holding force of the breakable connection <NUM> may cause the connection <NUM> to break or release, thus allowing the body <NUM> to move along the wire in the manners described herein. The "bodies" referred to herein may be of various geometric shapes including a disc or sphere. In embodiments, the distal body <NUM> and/or proximal body <NUM> may be an inflatable device, including but not limited to an inflatable balloon. In embodiments, a retrieval device, as described herein, may include a distal body <NUM> and a proximal body <NUM> made of differing materials, for example a proximal body <NUM> may be an inflatable balloon and a distal body <NUM>, on the same retrieval device, may be made of a mesh material. In embodiments, by adjusting the manufactured radial force, body diameter, and strength of the bodies, foreign body extraction, as described herein, may also be used for the removal of stones, pulmonary emboli, or some other type of obstruction. In embodiments, a proximal and/or distal body may have variable radial force, or stiffness across sub-regions of the body itself. For example, the upper hemisphere of a spherical body may have a difference radial force characteristic than the lower hemisphere of the body. In embodiments, the proximal and distal bodies may be substantially the same. In other embodiments, the proximal and distal bodies may be heterogeneous, having different compositions and characteristics including, without limitation, shape, size (e.g., thickness, diameter), configuration, pore size (e.g., mesh pore size), coating, or some other differing characteristic. In embodiments, the proximal and/or distal bodies may have anti-platelet, or some other type of, coatings to reduce adhesion and provide a less thrombogenic environment during clinical application. The proximal and/or distal bodies, and any material (e.g., wires) between these bodies, may be coated with control release agents including, but not limited to, thrombolytic agents.

The "delivery wire" <NUM> referred to herein may be a wire or a hypo tube. The delivery wire <NUM> may not require a coaxial system of catheters as disclosed herein in embodiments.

The "delivery catheter" <NUM> referred to herein may be referred to as a microcatheter, and may form a plurality of shape configurations based on the clinical application in which it is used, for example, which type of vessel the delivery catheter is used within, the vessel size, the vessel shape, or some other application characteristic. In embodiments, a delivery wire and/or hypo tube may be used within a microcatheter. For purposes of this disclosure, the microcatheter <NUM> is commonly called a "delivery catheter", although it should be understood that the terms can be used interchangeably.

Referring to <FIG>, prior to deployment of the distal <NUM> and proximal <NUM> bodies (which are shown as being restrained or in their unexpanded form and thus having different reference numerals from the <FIG>, and <FIG>) the delivery catheter <NUM> surrounds the delivery wire and restrains both bodies <NUM>, <NUM>. In embodiments, a guide catheter <NUM> is navigated into place, in embodiments, over a guide wire, said guide wire in some embodiments being removed. The delivery catheter <NUM> may be passed through an object, such as a thrombus or clot <NUM>, the bodies <NUM>, <NUM> may be released from the delivery catheter <NUM> either by retracting the delivery catheter <NUM> or advancing the wire <NUM>, such that expandable bodies are no longer restrained by the delivery catheter <NUM>. The distal body <NUM> remains fixed to the delivery wire <NUM>, but the proximal body <NUM> (once released from its releasable engagement) can freely move along its axis and longitudinally along the delivery wire <NUM> when pushed by the delivery catheter <NUM>. Also, the delivery wire <NUM> "pushing" the body (<NUM> or <NUM> once expanded) must be understood as relative pushing. That is, the retraction of the delivery wire <NUM> while the delivery catheter <NUM> is kept in place may serve to move the proximal body <NUM> axially along the wire. The term "pushing" as is used herein will refer to both forms of movement mentioned above. Once the proximal and distal bodies are positioned adjacent to both sides of the clot (which has been referred to herein as "surrounded" or "surrounding" the clot) by movement of the proximal body <NUM>, the clot may be removed by retrieving the device from the cavity and pulling the clot free. The terms "clot," "thrombus," "occlusion," "occlusive substance" and "foreign body" may be used interchangeably herein.

In embodiments, the freedom of movement of the proximal body <NUM> on the delivery wire <NUM> axially may allow for the compression of the occlusive substance and obviate the need for pre-measuring or estimating the required distance between the distal and proximal bodies prior to entering the vessel <NUM>; sizing may take place in situ within the vessel <NUM> upon the interventionist encountering it.

In embodiments of the present disclosure, the retrieval device may consist of a distal body <NUM> and a proximal body <NUM>, each of which in embodiments may be collapsible geometric forms. Although the distal and proximal bodies are presented for diagrammatic purposes as spherical, the distal and proximal bodies may also be other geometric forms such as a disc, cone, oblong-shaped form, etc. As mentioned above, the distal and proximal bodies may be a mesh in structure. The mesh cell size may be manufactured to have different sizes based on factors such as the expected properties of the target foreign matter to be removed, such as the density of the matter. The distal body <NUM> is mounted on a delivery wire <NUM> such that it remains fixed. In embodiments, the mounting of the proximal body <NUM> occurs by running the wire through one of the mesh opening. In other embodiments, the proximal body <NUM> itself may have an opening through which the wire may pass. In either case of mounting the proximal body <NUM>, the body is able to slide along the wire in an axial direction along the wire. This may be referred to herein as "slidably mounted". As described above, the proximal body is detachable (thus releasably engaged) using mechanical control release format. In embodiments, the proximal body <NUM> will be slidable along the wire one released while the distal body <NUM> remains fixed. Still in other embodiments, the proximal body <NUM> may be comprised of multiple bodies, and the distal body <NUM> may be comprised of multiple bodies. The mesh material of the distal and proximal bodies may have advantages over other material types, including but not limited to inflatable balloons. Inflatable material may be susceptible to rupture, such as that caused by over inflation. The clinical setting may also be associated with complications related to the use of inflatable balloons within a lumen. For example, a calcified thrombus may increase the risk of balloon rupture. In another example, if an occlusion itself includes metallic material, this may also increase the risk of rupture or other malfunction of an inflatable balloon. Rupture of a balloon may in turn increase the risk of an air embolus forming within the vessel or cavity of intervention. In embodiments, the mesh material of the distal and proximal bodies may allow for the bodies to expand upon release to the diameter and configuration of the cavity in which it is placed, such as a vessel <NUM> in which a thrombus <NUM> is located. Such meshes may be made of a shape memory substance such as nitinol. For example, a body made of nitinol mesh may expand to a first dimension outside of a vessel <NUM> or catheter, but may be designed to expand to a continuum of smaller dimensions than the first dimensions corresponding to different lumen sizes. In this way the bodies may fit the unique variations in diameter found in a lumen at the point of release and/or point of placement near an occlusion, such as a thrombus. Mesh material may also allow for improved distal flow during an intervention. The irregularity and/or texture of the expanded mesh material may facilitate the mesh material becoming entangled or otherwise incorporated with a clot or occlusive substance, thereby increasing adhesion of the distal and/or proximal body with the occlusion and facilitating its removal.

In embodiments, when the proximal body <NUM> is released, it is free to move/slide on its axis along the delivery wire <NUM> in a longitudinal and/or rotational fashion. Referring to <FIG> when the distal body <NUM> is placed distal to the target thrombus <NUM> for retrieval and the proximal body <NUM> is placed proximal to the thrombus <NUM>, the distal and proximal bodies will straddle and contain the thrombus <NUM> intended for removal from the vessel. The proximal body <NUM> may now be advanced in the direction of the thrombus <NUM> in a variety of mechanical fashions. As shown in <FIG>, a coaxially placed microcatheter, also referred to herein as a "delivery catheter" <NUM>, may be pushed forward (once the proximal body is released) and used to physically advance the proximal body <NUM> to ultimately capture and compress the thrombus <NUM>. Alternatively, the delivery catheter <NUM> may be used to hold the proximal body <NUM> in a fixed position while the delivery wire <NUM> is withdrawn thus moving the fixed distal body <NUM> towards the proximal body <NUM> and ultimately capturing and compressing the thrombus <NUM>. As shown in <FIG>, once the thrombus <NUM> is captured/compressed between the distal body <NUM> and the proximal body <NUM>, the entire retrieval device may be removed from the patient via withdrawal of the delivery wire <NUM> by, for example, withdrawing the proximal and distal bodies with the compressed material back to, and against, the delivery catheter and then removing the delivery catheter, bodies and compressed material through the guide catheter. Once this is removed, the guide catheter may be withdrawn from the vessel.

In embodiments of the present disclosure, the retrieval device may be employed as part of the removal of an occlusive object or substance from a human vessel, such as performing arterial thrombectomy. This procedure may include the following generalized steps. <FIG> shows an occlusion in the proximal left internal carotid artery (ICA). <FIG> shows an embodiment having a guide catheter <NUM> with a balloon <NUM> ("balloon catheter"). In embodiments, suction may be applied through the guide catheter <NUM>, in effect utilizing the guide catheter <NUM> as a suction catheter, as a given intervention may require. The balloon <NUM> is deflated an inserted into the ICA over a guide wire <NUM>. <FIG> shows a delivery catheter <NUM> advanced through the balloon catheter over the guide wire <NUM>, which has been advanced. <FIG> shows a guide wire <NUM> being advanced through and distal to the occlusion <NUM>. <FIG> shows the delivery catheter <NUM> being advanced through and distal to the occlusion over the guide wire <NUM>. The guide wire <NUM> is then removed (not shown) and <FIG> shows the retrieval device (delivery with distal <NUM> and proximal <NUM> bodies mounted on a delivery wire <NUM> as described herein) inserted into the delivery catheter <NUM> and still retrained (unexpanded) in the delivery catheter <NUM>. In <FIG> the delivery catheter <NUM> has been withdrawn (moved relative to the delivery wire <NUM>) such that the proximal <NUM> and distal <NUM> bodies expand on either side of the occlusion <NUM>. The proximal body <NUM> having been released is then advanced distally (shown in <FIG>) by force of the delivery catheter <NUM> (either by pushing the delivery catheter <NUM> or by pulling the delivery wire <NUM> while restraining the position delivery catheter <NUM>). <FIG> shows withdrawal of the retrieval device from the ICA, balloon <NUM> still inflated to arrest anterograde flow.

The retrieval device may remove both organized and unorganized thrombi since, in embodiments, the bodies of the retrieval device do not need to be incorporated into the thrombus <NUM> to affect its removal. The retrieval device may also remove calcified, atherosclerotic material since, in embodiments, the bodies of the retrieval device do not need to be incorporated into the material to affect its removal. The retrieval device may be used centrally and peripherally by selecting the appropriate diameter and characteristics of the bodies, such as appropriate radial force or stiffness, appropriate shape, whether the bodies are substantially identical or homogenous, mesh opening size in the bodies, and the like.

The system and apparatus, as described herein, may have a plurality of sizes loaded within a common catheter, and a clinician may self-load, for example, different and/or additional proximal bodies, as described herein, rather than having to fully replace a deployed catheter for a second catheter-based device and system. This may reduce manufacturing costs and improve intervention efficiency.

<FIG> show embodiments having a structure to incorporate into the thrombus <NUM>, referred to herein as an "incorporation structure". In some embodiments, the incorporation structure is part of the delivery wire <NUM>, in others it is separate. Referring to <FIG>, the delivery wire <NUM> (which in all embodiments disclosed herein may be a hypo tube) comprises a segment having characteristics different from that of the main segment of the delivery wire <NUM>, or a structure mounted to the delivery wire <NUM> that may expand. In the case where the incorporation structure is part of the delivery wire <NUM>, the segment will be referred to herein as the "active segment" while the remainder of wire will be referred to as the "delivery segment". The active segment is the segment having a section intended to span the length of the thrombus <NUM>. In embodiments, the active segment comprises a cross-sectional shape that differs from the delivery segment. In embodiments, the delivery segment contains a suture material <NUM> between the proximal <NUM> and distal <NUM> bodies. The suture material <NUM> gathers and moves along the delivery wire <NUM> as the proximal body <NUM> is advanced. Once the proximal body <NUM> is in position, the suture material <NUM> will be gathered in the area between the two bodies which will enhance incorporation characteristics of the active area. Note that the active area in the above example is the area between the two bodies, which in this case, has suture material <NUM> gathered therebetween. As mentioned above, in embodiments the incorporation structure can be an additional expandable structure between the proximal <NUM> and distal <NUM> bodies that expands and incorporates into the thrombus <NUM>. The incorporation structure may comprise other mechanisms to enhance thrombus-incorporation, such as flanges, hooks, sutures, sinusoidal wire <NUM>, or some other material configuration.

In embodiments, the delivery wire <NUM> may include a distal body <NUM> that may be affixed, mounted, adhered or otherwise connected to a delivery wire <NUM> or hypo tube as described herein. Prior to deployment, such as a thrombectomy, the distal body <NUM> may be affixed, mounted, adhered or otherwise connected to the delivery wire <NUM> or hypo tube in a collapsed or compressed state. Compression of the distal body <NUM> may be provided by the delivery catheter <NUM>, and/or multiple catheters which surround the distal body <NUM> and delivery wire <NUM> (as described herein). Once the delivery catheter <NUM> is inserted through an object, such as a thrombus, the distal body <NUM> may be released from inside the delivery catheter <NUM> as described herein, thus expanding. Following removal of the delivery catheter <NUM>, suction may be applied to the thrombus or other blockage. (It is to be noted that a suction step, as described herein, may be applied to any of the embodiments of this disclosure, and may be applied through the guide catheter, access catheter, specialized suction catheter, or some other type of catheter). In an example, the Seldinger technique may be initiated using a large bore suction catheter that is advanced over the delivery wire <NUM> (or a guide wire) and positioned proximal to the thrombus <NUM>, with the distal body <NUM> distally positioned to the thrombus. Suction may be applied to remove all or a portion of the thrombus. The positioning of the distal body <NUM>, on the distal side of the thrombus, may be used to retract the thrombus in the direction of the suction device, thereby increasing the effectiveness of the suction device in removing the thrombus. The distal body <NUM> may also provide distal protection from distal embolization during the suction device's placement and/or during the suctioning procedure. Note that in the above example, a proximal body has not yet been included in the procedure. There are situations and thus embodiments where an optional proximal body <NUM> may be added to the procedure, for example, by slidably mounting a proximal body <NUM> to the delivery wire <NUM>. As such, in embodiments the inclusion of a proximal body <NUM> is optional.

In some clinical scenarios the suction procedure may result in only a partial removal of the thrombus <NUM> or other obstruction. In such scenarios, mechanical removal of the thrombus <NUM>, using a distal body and an added proximal bodyl02, may be advantageous and/or required. Following the application of suction within the guide catheter <NUM>, a proximal body <NUM> may be added to the delivery wire <NUM>, where this proximal body <NUM> is proximal to the thrombus <NUM> or other obstruction. Once the proximal body <NUM> is placed on the delivery wire <NUM>, it may be advanced towards the distal end of the delivery wire <NUM> by advancing the delivery wire <NUM>. In another example, the proximal body <NUM>, in a restrained position, may be advanced towards the distal end of the delivery wire <NUM> using a hypo tube that is placed within the delivery catheter <NUM> over the delivery wire. As the hypo tube is pushed towards the distal end of the delivery wire <NUM>, the proximal body <NUM> may be moved axially to a desired location. Once the proximal body <NUM> is in the desired physical position, relative to the thrombus <NUM> or other obstruction, the proximal body <NUM> may be released from inside the delivery catheter <NUM> to form the expanded proximal body <NUM> in a manner already described herein. The coaxially placed hypo tube may be pushed forwards and used to physically advance the proximal body <NUM> to ultimately capture and compress the thrombus <NUM>. Once the thrombus <NUM> is captured/compressed between the distal body <NUM> and the proximal body <NUM>, the entire retrieval device may be removed from the body via coaxially placed catheters/tubes thus permitting removal of the thrombus <NUM> from its prior resting place within the vessel.

Referring to <FIG> and <FIG>, the proximal body may be moved along the delivery wire via application of force to a tether or multiple tethers. As shown in <FIG>, a single proximal tether <NUM> may be attached to the proximal body <NUM>, the proximal body <NUM> being slidably mounted and in releasable engagement to a delivery wire (or hypo tube), as described herein. The proximal tether <NUM> may be pulled to move the proximal body back, proximally along the wire <NUM> after the proximal body <NUM> has been released and positioned in the manner described herein. The proximal tether <NUM> may run parallel and within the delivery catheter (not shown) or, as shown in <FIG>, the proximal tether <NUM> may run within a hollowed-out portion of the delivery wire or hypo tube and emerge through an opening 117A. The proximal end <NUM> of the proximal tether <NUM> is accessible to the interventionist who can pull it to pull back, proximally to the proximal body <NUM> at least to the point adjacent to the opening 117A.

<FIG> shows a two-tether embodiment. As with the embodiment shown in <FIG>, the tethers may run parallel and within the delivery catheter (not shown) or, as shown in <FIG>, the proximal tether <NUM> and distal tether <NUM> may run within a hollowed-out portion of the delivery wire or hypo tube and emerge through openings 117A and 117B, where the proximal tether <NUM> emerges from opening 117A and the distal tether <NUM> emerges from opening 117B. Movement of the proximal body via the proximal tether, in the proximal direction, is the same as mentioned above. In this embodiment, the interventionist can pull the end of the distal tether <NUM> to move the proximal body <NUM> adjacent to the opening 117B, which results in a distal movement of the proximal body <NUM> without the need for distal movement via the delivery catheter as described herein.

In addition to the steps of deployment mentioned above, the following steps may also or alternatively be followed for using the retrieval device in embodiments. <FIG> shows the common carotid artery (CCA) having an occlusion therein <NUM>. A guide catheter <NUM> having a flow arrest balloon <NUM> is inserted into the CCA (in embodiments over a guide wire). <FIG> shows the flow arrest balloon <NUM> as deflated. <FIG> shows the advancement of an access catheter <NUM> distally through the guide catheter <NUM> (in embodiments over a guide wire (not shown)). <FIG> shows the distal advancement of a delivery catheter <NUM> via a guide wire <NUM> to the origin of the inclusion (i.e., the base of the thrombus <NUM>). <FIG> shows the flow arrest balloon <NUM> being temporarily inflated to arrest anterograde flow in the CCA as well as the delivery catheter <NUM> being advanced distal to the occlusion <NUM> via the guide wire <NUM> and, in this case, in Ml. The guide wire <NUM> is removed (not shown). The delivery wire <NUM> with restrained proximal <NUM> and restrained distal <NUM> bodies thereon is inserted into and through the delivery catheter <NUM> with the tip emerging the delivery catheter as shown in <FIG>. In this example, the delivery wire <NUM> has within it a proximal tether <NUM> and a distal tether <NUM>.

In <FIG>, the proximal <NUM> and distal <NUM> bodies are deployed distally to the occlusion <NUM>, the deployment being in the manner described herein. The delivery catheter <NUM> is withdrawn from patient to increase open luminal area in access catheter <NUM>, which allows for better suction when suction is applied to access catheter <NUM>. <FIG> also shows the proximal tether <NUM> and the distal tether <NUM>, as described herein, attached to the proximal body <NUM>. <FIG> also shows the deflation of flow arrest balloon <NUM> on the guide catheter <NUM> to end flow arrest. Due to mesh construct of the proximal <NUM> and distal <NUM> bodies which are now deployed, anterograde flow into vessels will be reestablished with protection (established via the expanded proximal <NUM> and distal <NUM> bodies) from distal embolization of occlusion when flow is reestablished. Suction may be applied to the access catheter <NUM> at this point. The proximal body <NUM> may be released from its releasable engagement <NUM> as described herein, while the distal body <NUM> remains fixed to the wire.

With both the proximal <NUM> and distal <NUM> bodies providing protection (most commonly initially in an M2 branch for an Ml occlusion or covering the Ml bifurcation for an ICA terminus) an interventionist may slowly pull the delivery wire <NUM> in a proximal direction. This will draw both bodies proximally (see <FIG>). The proximal <NUM> and distal <NUM> bodies will open to a larger diameter when they transition from Ml to M2 and in the process of being withdrawn proximally will begin the thrombectomy process (see <FIG>).

Once the distal body <NUM> opens at the Ml bifurcation, both superior and inferior M2 protection has been established (see <FIG> and <FIG>). Using a proximal tether <NUM> and a distal tether <NUM> that connect to the proximal body <NUM> and exit from the delivery wire <NUM> either via an opening in the outer surface or via the opening on the end of the delivery wire <NUM> (see <FIG> and <FIG>), the proximal body <NUM> can be moved along the Ml and possibly ICA lumen back and forth (i.e., proximally and distally axially along the delivery wire) by pulling the ends of the tethers <NUM>, <NUM> as described herein and as desired by the clinician to mobilize occlusion and loosen and draw it proximally towards the suction device. If the initial placement of the proximal body <NUM> is determined to be too far in the distal direction, the interventionist may use the proximal tether <NUM> that is attached to the proximal body <NUM> to pull the proximal body <NUM> back in the proximal direction to place it farther from the distal end of the retrieval device. This allows the interventionist to adjust the proximal body's position along the wire <NUM> instead of only being able to advance the proximal body <NUM> in the distal direction. In an example, the proximal body <NUM> may have a Kevlar tether that exits the delivery wire (or hypo tube) <NUM> at an opening distance about <NUM>-<NUM> proximal to the proximal side of the proximal body <NUM> to which it is attached. Therefore, while the two bodies are initially adjacent to each other, the proximal body <NUM>, once electrolytic ally detached, can be withdrawn a distance proximally along the delivery wire <NUM> axis <NUM>-<NUM> by pulling on the proximal tether <NUM>. (All distances herein may be adjusted according to the need). It may be advanced by pushing it forward with the delivery catheter <NUM> and/or a second, distal tether <NUM> may exit the wire at opening 117B distally to the proximal body <NUM> which when pulled can pull the proximal body <NUM> distally back towards the distal body and adjacent to the opening 117B. Therefore, by pulling proximal tether <NUM> and/or the distal tether <NUM> the proximal body <NUM> may slide backwards and forwards along the delivery wire <NUM>. In this example, this configuration provides the proximal body <NUM> with <NUM>-<NUM> of travel distance back and forth along the delivery wire <NUM>. Despite anterograde flow, the distal body <NUM> may provide protection against distal embolization of loosened/floating occlusion thus eliminating/reducing the risk of distal embolization of this material (see <FIG>).

Once the thrombus <NUM> has been removed/evacuated through the access catheter <NUM>, the proximal and distal bodies can be removed by withdrawing them through the delivery catheter <NUM>. This process will also mechanically draw any thrombus <NUM> that sits on the tip of the access catheter <NUM> (cleans the catheter tip) into the catheter <NUM> so that it does not embolize off the catheter tip and back into the intracranial circulation (see <FIG>).

Claim 1:
A medical device for removing an occlusion from a vessel, comprising:
a delivery catheter (<NUM>) and a delivery wire (<NUM>);
said delivery catheter (<NUM>) comprising an internal lumen that extends through said delivery catheter (<NUM>), said internal lumen of said delivery catheter (<NUM>) adapted to receive said delivery wire (<NUM>) therein,
said delivery wire (<NUM>) comprising a distal end region, said delivery wire (<NUM>) disposed in said internal lumen of said delivery catheter (<NUM>), wherein said delivery wire (<NUM>) further comprising a first body (<NUM>) releasably engaged to said delivery wire (<NUM>) at a first position on said delivery wire (<NUM>), said releasable engagement of said first body (<NUM>) to said delivery wire (<NUM>) comprising a breakable mechanical connection (<NUM>) of said first body (<NUM>) to said delivery wire (<NUM>), wherein, while engaged, said first body (<NUM>) remains fixed on said delivery wire (<NUM>), said breakable mechanical connection (<NUM>) comprising a threshold holding force,
said delivery wire (<NUM>) further comprising a second body (<NUM>) fixed to said delivery wire (<NUM>) at a second position on said delivery wire (<NUM>), said second position comprising a position proximate said distal end region of said delivery wire (<NUM>) and, thereby distal from said first position of said first body (<NUM>),
said first body (<NUM>) further adapted to disengage from said delivery wire (<NUM>) and axially move along said delivery wire (<NUM>) in a distal direction toward said second body (<NUM>) when said delivery catheter (<NUM>) is axially moved in a distal direction relative to said delivery wire (<NUM>), said delivery catheter (<NUM>) being configured to contact said first body (<NUM>) and to apply a force to said first body (<NUM>) that is greater than said threshold holding force to break said breakable mechanical connection (<NUM>).