Patent Description:
This invention relates to a system for endovascular treatment of blood clots obstructing passageways in the circulatory system.

Thromboembolism is the formation in a blood vessel of a clot (thrombus) that breaks loose (embolizes) and is carried by the blood stream to another location in the circulatory system resulting in a clot or obstruction at that new location. For example, a clot may embolize and plug a vessel in the lungs (pulmonary embolism), the brain (stroke), the gastrointestinal tract, the kidneys, or the legs. Thromboembolism is a significant cause of morbidity (disease) and mortality (death), especially in adults. A thromboembolism can be sudden and massive or it may be small and multiple. A thromboembolism can be any size and a thromboembolic event can happen at any time.

When a thrombus forms in the venous circulation of the body it often embolizes to the lungs. Such a thrombus typically embolizes from the veins of the legs, pelvis, or inferior vena cava and travels to the right heart cavities and then into the pulmonary arteries thus resulting in a pulmonary embolism.

A pulmonary embolism results in right heart failure and decreased blood flow through the lungs with subsequent decreased oxygenation of the lungs, heart and the rest of the body. More specifically, when such a thrombus enters the pulmonary arteries, obstruction and spasm of the different arteries of the lung occurs which further decreases blood flow and gaseous exchange through the lung tissue resulting in pulmonary edema. All of these factors decrease the oxygen in the blood in the left heart. As a result, the oxygenated blood supplied by the coronary arteries to the musculature of both the left and right heart is insufficient for proper contractions of the muscle which further decreases the entire oxygenated blood flow to the rest of the body. This often leads to heart dysfunction and specifically right ventricle dysfunction.

This condition is relatively common and has many causes. Some of the more common causes are prolonged inactivity such as bed rest, extended sitting (e.g., lengthy aircraft travel), dehydration, extensive surgery or protracted disease. Almost all of these causes are characterized by the blood of the inferior peripheral major circulatory system coagulating to varying degrees and resulting in permanent drainage problems.

There exist a number of approaches to treating thromboembolism and particularly pulmonary embolism. Some of those approaches include the use of anticoagulants, thrombolytics and endovascular attempts at removal of the emboli from the pulmonary artery. The endovascular attempts often rely on catheterization of the affected vessels and application of chemical or mechanical agents or both to disintegrate the clot. Invasive surgical intervention in which the emboli is removed by accessing the chest cavity, opening the embolized pulmonary artery and/or its branches and removing the clot is also possible.

The prior approaches to treatment, however, are lacking. For example, the use of agents such as anticoagulants and/or thrombolytics to reduce or remove a pulmonary embolism typically takes a prolonged period of time, e.g., hours and even days, before the treatment is effective. Moreover, such agents can cause hemorrhage in a patient.

And the known mechanical devices for removing an embolism are typically highly complex and prone to cause undue trauma to the vessel. Moreover, such known devices are difficult and expensive to manufacture.

Lastly, the known treatment methods do not emphasize sufficiently the goal of urgently restoring blood flow through the thrombus once the thrombus has been identified. In other words, the known methods focus primarily and firstly on overall clot reduction and removal instead of first focusing on relief of the acute blockage condition followed then by the goal of clot reduction and removal. Hence, known methods are not providing optimal patient care, particularly as such care relates to treatment of a pulmonary embolism.

<CIT> discloses an apparatus for increasing blood flow through a blood vessel including an elongate member, a first expandable member coupled to a distal portion of the elongate member and a second expandable member,.

The above described shortcomings of the existing systems and approaches for treating an occlusion in a lumen of a patient, such as a thromboembolism and particularly a pulmonary embolism, are improved upon by the occlusion management system of the present invention. These improvements are achieved by the occlusion management system of claim <NUM>. The occlusion management system comprises a catheter, a pusher, and a tubular member reversibly restrained in a compressed state within a lumen of the catheter and radially expanded from the compressed state upon retraction of the catheter relative to the pusher. Preferred embodiments of the system are provided in the dependent claims. Certain surgical methods are described with reference to the system of the present invention. Whilst these methods are not claimed, the system is capable of being used and is intended to be used in such methods.

The extraction member extending distally of a distal end of the cylindrical member has a diameter larger than a diameter of the cylindrical member.

These and other aspects, features and advantages of which embodiments of the invention are capable of will be apparent and elucidated from the following description of embodiments of the present invention, reference being made to the accompanying drawings, in which.

Specific embodiments of the disclosure will now be described with reference to the accompanying drawings. This disclosure and the invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete.

Methods and systems according to the present disclosure invention are broadly directed to treating a blood vessel or other body lumen. More particularly, the present disclosure is directed to systems and methods for disrupting, dissolving, and/or otherwise removing occlusive materials, such as thrombus, from a treatment site, such as a blood vessel.

With reference to <FIG>, in one embodiment of the present disclosure, an occlusion management system <NUM> employs a catheter <NUM> and a flow restoration member <NUM>. The flow restoration member <NUM> is radially expandable from a compressed delivery state, to a radially expanded, minimum energy state having at least, in part, a hollow cylindrical or tubular shape. A distal end <NUM> of a pusher <NUM> is attached to a proximal portion <NUM> of the flow restoration member <NUM>.

The flow restoration member <NUM> may be formed of a porous mesh or scaffold. The mesh or scaffold may be formed at least in part by a braid of filaments or fabricated by methods known in the art of stent manufacturing including but not limited to conventional machining, laser cutting, electrical discharge machining (EDM) and photo-chemical etching.

In operation, the pusher <NUM> and the attached compressed flow restoration member <NUM> are inserted into a lumen <NUM> of the catheter <NUM>. The catheter <NUM> is advanced through a lumen <NUM> of a patient, e.g. a blood vessel <NUM>, to a site within the lumen <NUM> at which occlusive material <NUM>, such as a thrombus or an embolus, is located. The catheter <NUM> is advanced in the direction of arrow <NUM> through the occlusive material <NUM> until a distal end <NUM> of the catheter <NUM> passes entirely through the occlusive material <NUM>, as shown in <FIG>.

With reference to <FIG>, the catheter <NUM> is then retracted relative to the pusher <NUM> and flow restoration member <NUM> in the direction of arrow <NUM>. As the flow restoration member <NUM> is exposed from the retracting distal end of the catheter <NUM>, the flow restoration member <NUM> radially expands within the occlusive material <NUM> to an intermediate diameter larger than a diameter of the member <NUM> in the compressed delivery state and smaller than a diameter of the member <NUM> in the expanded, minimum energy state. The structure and outer surface of the flow restoration member <NUM> is configured such that the mesh or scaffold of the flow restoration member <NUM> engages the occlusive material <NUM> when it is exposed from the constraint of the catheter <NUM>. As shown in <FIG>, the catheter <NUM> is retracted in the direction of arrow <NUM> to an extent that allows for the radial expansion of an entire length of the flow restoration member <NUM>.

As shown in <FIG>, when catheter <NUM> is retracted sufficiently to allow expansion of the entire length of the flow restoration member <NUM>, fluid or blood may enter the open, proximal portion <NUM> of the flow restoration member <NUM> in the direction of arrows <NUM>, flow through the hollow interior of the flow restoration member <NUM>, and exit through a open, distal portion <NUM> of the flow restoration member <NUM>. Thereby, allowing for a rapid restoration of blood flow through the lumen <NUM>.

As shown in <FIG>, the pusher <NUM> is then retracted relative to the catheter in the direction of the arrow <NUM>, thereby pulling the length of the flow restoration member <NUM> through the occlusive material <NUM>. The pusher <NUM> is retracted such that the flow restoration member <NUM> is pulled towards the distal end <NUM> of the catheter <NUM> and back into the lumen <NUM> of the catheter <NUM>. As the flow restoration member <NUM> is pulled through the occlusive material <NUM>, the occlusive material <NUM> engaged with the flow restoration member <NUM> is also pulled along and removed. Hence, while restoring flow through the lumen <NUM>, the flow restoration member <NUM> may also function to remove or extract at least a portion of the occlusive material <NUM> from the lumen <NUM>. Finally, the flow restoration member <NUM> and the engaged occlusive material <NUM> is pulled back into the lumen <NUM> of the catheter <NUM> and the system <NUM> is withdrawn from the patient.

As shown in <FIG>, the occlusion management system <NUM> may further employ an extraction member <NUM> for extraction or removal of the occlusive material <NUM>, such as an embolus. The extraction member <NUM> may have an umbrella-like configuration, as shown in <FIG>; a conical configuration, as shown in <FIG>; or a cup-like configuration, as shown in <FIG>. The extraction member <NUM> expands from a compressed diameter to an expanded diameter that is greater than a diameter of the expanded flow restoration member <NUM> and approximately equal to a diameter of the lumen <NUM>.

The extraction member <NUM> may be attached directly to the flow restoration member <NUM> or to a separate structure that is deployed through the flow restoration member <NUM> either before or after deployment of the flow restoration member <NUM>. For example, as shown in <FIG>, a distal portion <NUM> of the extraction member <NUM> may be attached to a distal end <NUM> of a delivery element <NUM>. The delivery element <NUM> may be formed of a separate, transposable element that is located within a lumen of the pusher <NUM>. One or more tethers <NUM> may statically attach a proximal periphery <NUM> of the extraction member <NUM> to the delivery element <NUM> proximally of the distal end <NUM> of the delivery element <NUM>. The tethers <NUM> facilitate compression and retraction of the extraction member <NUM> back into the catheter <NUM>. Alternatively, the tethers <NUM> may be transposable independent of the delivery element <NUM>. For example, the tethers <NUM> may be attached to a coaxial tube located within the lumen of the pusher <NUM> around the delivery element <NUM>.

In operation, the extraction member can be deployed either prior to complete deployment of the flow restoration member <NUM> or after complete deployment of the flow restoration member <NUM>.

In certain embodiments, as shown in <FIG>, the extraction member <NUM> is a balloon <NUM> that is attached to a distal end <NUM> of a delivery element <NUM>. The delivery element <NUM> has a lumen formed therethrough for inflation and deflation of the balloon <NUM>. The balloon <NUM> having a diameter that is substantially equal to or greater than a diameter of the vessel <NUM>.

In certain other embodiments, as shown in <FIG>, the extraction member <NUM> is formed by a malecot-type formation of the distal end <NUM> of the delivery element <NUM>. The malecot-type formation may be covered with a fabric, polymer, or braided covering. The malecot-type formation has a diameter that is substantially equal to or greater than a diameter of the vessel <NUM>.

In certain other embodiments, as shown in <FIG> the extraction member <NUM> is formed of a braided structure having a disc-like form that is attached to a distal end <NUM> of a delivery element <NUM>. The disc-like structure has a diameter that is substantially equal to or greater than a diameter of the vessel <NUM>.

In one embodiment of the present invention, as shown in <FIG>, the delivery element <NUM> is not employed in the system <NUM> and extraction member <NUM> is attached directly to the flow restoration member <NUM> by the tethers <NUM>. More particularly, proximal ends of the tethers <NUM> are attached to the distal portion <NUM> of the flow restoration member <NUM> and distal ends of the tethers <NUM> are attached to the proximal periphery <NUM> of the extraction member <NUM>.

In operation, after the catheter <NUM> is advanced through the occlusive material <NUM> until a distal end <NUM> of the catheter <NUM> passes entirely through the occlusive material <NUM>, the catheter <NUM> is then retracted relative to the pusher <NUM>. As the extraction member <NUM> is exposed from the retracting distal end <NUM> of the catheter <NUM>, the extraction member <NUM> radially expands distally of the occlusive material <NUM>. As the catheter <NUM> is further retracted, the flow restoration member <NUM> radially expands within the occlusive material <NUM>.

After complete expansion of the flow restoration member <NUM>, the pusher <NUM> is retracted relative to the catheter, thereby pulling the flow restoration member <NUM> through the occlusive material <NUM> and pulling the extraction member <NUM> into and around the occlusive material <NUM>. The occlusive material <NUM> is thereby captured within the extraction member <NUM>. Retraction of the pusher <NUM> is continued until the flow restoration member <NUM> and extraction member <NUM> with captured occlusive material <NUM> are pulled back into the lumen <NUM> of the catheter <NUM>. The system <NUM> is then withdrawn from the patient.

The extraction member <NUM> may be formed at least in part by a braid of filaments or fabricated by methods known in the art of stent manufacturing including but not limited to conventional machining, laser cutting, electrical discharge machining (EDM) and photo-chemical etching.

In one embodiment of the present disclosure, as shown in <FIG>, the flow restoration member and the extraction member of the occlusion management system <NUM> are formed of a substantially continuous structure. For example, as shown in <FIG>, a distal portion <NUM> of a flow restoration member <NUM> is biased to evert to a relaxed state that turns in a proximal direction back towards a proximal portion <NUM> of the flow restoration member <NUM>, thereby forming an extraction member <NUM>. One or more tethers <NUM> are eccentrically coupled or attached to the distal portion <NUM> of a flow restoration member <NUM>. In certain embodiments, a radially expandable connector member <NUM> may hold ends of the filaments that may be present at the distal portion <NUM> of a flow restoration member <NUM>.

Proximal ends of the tethers <NUM> may extend proximally within the lumen <NUM> of the catheter <NUM> and may be manipulated by a physician in order to facilitate the formation of the everted distal portion <NUM> and extraction member <NUM> of the flow restoration member <NUM>. In certain embodiments, the tethers <NUM> do not extend to a proximal end of the system <NUM> but rather are connected to an elongate retraction member that in turn extends proximally for manipulation by a physician. As shown in <FIG>, the tethers <NUM> may further function to cut through the occlusive material <NUM> as the extraction member <NUM> is formed or when the pusher <NUM>, the flow restoration member <NUM>, and the extraction member <NUM> are retracted relative to the catheter <NUM>.

In certain embodiments, as shown in <FIG>, the flow restoration member <NUM> having everted distal portion <NUM> need not necessarily employ the tethers <NUM>.

In certain other embodiments, as shown in <FIG>, <FIG>, the mesh or scaffold structure forming the flow restoration member <NUM> employs an enlarged diameter distal portion <NUM> that does not necessarily evert. For example, <FIG> shows a partially deployed and <FIG> shows completely deployed flow restoration member <NUM> having a flared or expanded distal portion <NUM>. <FIG> shows the flow restoration member <NUM> having a bulbous, expanded distal portion <NUM> which may or may not employ a guide wire passage through a distal end.

In certain other embodiments, as shown in <FIG>, the extraction member <NUM> is a wireform attached to the delivery element, such as delivery element <NUM> described above, or alternatively attached directly to the flow restoration member <NUM> to form an expanded distal portion <NUM> of the flow restoration member <NUM>. The wire form may also be covered with a braid. As shown in <FIG>, operation of the occlusion management system <NUM> is substantially the same as described above regarding the occlusion management system <NUM> employing the extraction member <NUM>.

In one embodiment of the present disclosure, as shown in <FIG>, the pusher <NUM> may be formed of a wire, tube, or catheter.

In one embodiment of the present disclosure, as shown in <FIG>, a method for operation of system <NUM>, <NUM> is shown. First, retrieval of occlusive matter <NUM> includes first advancing a guidewire <NUM> through a lumen <NUM> to the site of the occlusive material <NUM> and through the occlusive material <NUM>. The catheter <NUM> is then advanced over the guidewire <NUM> to the site of the occlusive material <NUM> and through the occlusive material <NUM>, as shown in <FIG>. The guidewire <NUM> is withdrawn from the patient. As shown in <FIG>, the catheter <NUM> is then retracted relative to the pusher <NUM>, thereby allowing the flow restoration member <NUM> to expand to a more relaxed state and engage the occlusive material <NUM>.

In certain embodiments, as shown in <FIG>, the catheter <NUM> may be passed through a lumen of a sheath <NUM>. The sheath <NUM> may function to provide suction, vacuum, or irrigation, in the direction of arrows <NUM>, within the lumen <NUM> near the site of the occlusive material <NUM>. Alternatively, as shown in <FIG>, one or more holes <NUM> may be formed in the catheter <NUM> so that the suction, vacuum, or irrigation may originate from a proximal end of the catheter <NUM> and be simultaneously generated through the proximal portions of both the lumen <NUM> of the catheter <NUM> and the lumen of the sheath <NUM>.

With the assistance of such suction, vacuum, or irrigation, as shown in <FIG>, it may be possible for the flow restoration member <NUM> to sufficiently engage the occlusive material <NUM> such that the occlusive material <NUM> is released from the lumen <NUM> and can be extracted in substantially its entirety from the lumen <NUM> of the patient.

In one embodiment, as shown in <FIG>, in order to further assist in the generation and efficacy of such suction, vacuum, or irrigation, an annular balloon <NUM> may be attached to an exterior of the catheter <NUM> near the distal end <NUM> of the catheter <NUM>. The balloon <NUM> is sized so as to contact a circumference of an interior surface of the lumen <NUM>. Accordingly, the balloon <NUM> provides a seal against the flow of fluid, such as blood, through the lumen <NUM> and enhances the efficacy of the suction, vacuum, or irrigation. <FIG> shows the flow restoration member <NUM> of <FIG> being deployed through a catheter <NUM> having an inflated balloon <NUM> near the distal end <NUM> of the catheter <NUM>. In order to inflate and deflate the balloon <NUM>, inflation lumens may be formed within the wall of the catheter <NUM> according to techniques known in the art.

In one embodiment, as shown in <FIG>, an occlusion management system <NUM> employs a flow restoration member <NUM>, such as that described above with respect to the flow restoration members <NUM> or <NUM> that is advanceable through a proximal capture member <NUM>.

The proximal capture member <NUM> is radially expandable from compressed delivery state within a lumen <NUM> of a sheath <NUM>, to a radially expanded, minimum energy state having a generally cylindrical or tubular shape. When in the expanded minimum energy state, the proximal capture member <NUM> may have a diameter that is larger or substantially equal to the diameter of the patient's lumen <NUM> in which the system <NUM> will be employed.

The proximal capture member <NUM> is attached to a capture member pusher <NUM> that is also inserted through the lumen <NUM> of the sheath <NUM>. The proximal capture member <NUM> may be formed of a mesh or scaffold. The mesh or scaffold may be formed at least in part by a braid of filaments or fabricated by methods known in the art of stent manufacturing including but not limited to conventional machining, laser cutting, electrical discharge machining (EDM) and photo-chemical etching.

The flow restoration member <NUM> is attached to the pusher <NUM> and the flow restoration member <NUM> and the pusher <NUM> are positioned within the lumen <NUM> of the catheter <NUM>. The catheter <NUM> is, in turn, positioned within a lumen of the proximal capture member <NUM>. A diameter of the proximal capture member <NUM> may be approximately equal to or greater than a diameter of the lumen <NUM>.

In operation, the capture member pusher <NUM> and attached proximal capture member <NUM> are inserted into the lumen <NUM> of the sheath <NUM>. A guidewire may be advance through the occlusion material <NUM>, such as a thrombus or embolus. The sheath <NUM> is then advanced over the guidewire to a position proximal of the occlusion material <NUM>. The guidewire may but need not necessarily be retracted at this time.

As shown in <FIG>, the sheath <NUM> is retracted, in the direction of arrow <NUM>, proximally relative to the capture member pusher <NUM>, thereby exposing the proximal capture member <NUM> at a distal end <NUM> of the sheath <NUM> and allowing the proximal capture member <NUM> to radially expand from its collapsed state within the lumen <NUM> of the sheath <NUM>.

The pusher <NUM> and attached flow restoration member <NUM> are then inserted into the lumen <NUM> of the catheter <NUM>. As shown in <FIG>, the catheter <NUM> is then advanced through the lumen <NUM> of the sheath <NUM> and the lumen of the proximal capture member <NUM> until a distal end <NUM> of the catheter <NUM> is positioned distally of the occlusive material <NUM>. As shown in <FIG> and <FIG>, the catheter <NUM> is then retracted, in the direction of arrow <NUM>, proximally relative to the flow restoration member <NUM>, thereby exposing the flow restoration member <NUM> and allowing the flow restoration member <NUM> to radially expand from its collapsed state within the lumen <NUM> of the catheter <NUM>.

As shown in <FIG>, after complete expansion of the flow restoration member <NUM>, the pusher <NUM> is retracted relative to the catheter <NUM>, thereby pulling the flow restoration member <NUM> through the occlusive material <NUM> and pulling an extraction member, if present, into and around the occlusive material <NUM>. The occlusive material <NUM> is thereby captured within the flow restoration member <NUM> and extraction member, if present. Retraction of the pusher <NUM> is continued until the flow restoration member <NUM> and extraction member, if present, with captured occlusive material <NUM> are pulled at least partially back into the lumen <NUM> of the catheter <NUM>. The catheter <NUM> and the flow restoration member <NUM> and extraction member, if present, with captured occlusive material <NUM> are then pulled back into the lumen <NUM> of the proximal capture member <NUM>. The proximal capture member <NUM> is then pulled back into the lumen <NUM> of the sheath <NUM>. The system <NUM> is then withdrawn from the patient.

The order of deployment of the proximal capture member <NUM> and flow restoration member <NUM> as described above may be reversed as seen fit by the physician. Furthermore, therapeutic agent(s) such as thrombolytics or anticoagulants may be infused through the lumen <NUM> of the sheath <NUM> or lumen <NUM> of catheter <NUM> during the course of the procedure.

In one embodiment, the occlusion management systems <NUM>, <NUM>, <NUM> is configured for removal of at least a portion of the occlusive material <NUM>, such as an embolus or thrombus, that is located at a bifurcation, trifurcation or multi-lumen plexus of the lumen <NUM>, such as a blood vessel. By way of example, as shown in <FIG> and <FIG>, a sheath <NUM>, through which multiple catheters <NUM> are inserted, is advanced through the lumen <NUM> to the bifurcation at which occlusive material <NUM> is present. The catheters <NUM> are independently advanced distally from the sheath <NUM> through the occlusive material <NUM> within the different lumens <NUM> of the bifurcation. Flow restoration and extraction of the occlusive material <NUM> is conducted as described above.

In certain embodiments, the flow restoration member <NUM>, <NUM>, <NUM>, extraction member <NUM>, <NUM>, and the proximal capture member <NUM> may comprise a braided mesh of filaments or wires <NUM>. The braids for the mesh components may have a generally constant braid angle over an entire length of the member or may be varied to provide different zones of pore size and radial stiffness.

The braided mesh may be formed over a mandrel as is known in the art of tubular braid manufacturing. A braid angle α (alpha), shown in <FIG>, may be controlled by various means known in the art of filament braiding. In certain embodiments, the braid angle α is, for example, between about <NUM> degrees and about <NUM> degrees. The tubular braided mesh may be further shaped using a heat setting process. As known in the art of heat setting nitinol wires, a fixture, mandrel or mold may be used to hold the braided tubular structure in its desired configuration then subjected to an appropriate heat treatment such that the resilient filaments of the braided tubular member assume or are otherwise shape-set to the outer contour of the mandrel or mold.

In certain embodiments, the filamentary elements of the mesh member may be held by a fixture configured to hold the member in a desired shape and heated to about <NUM>-<NUM> degrees Celsius for about <NUM> to <NUM> minutes to shape-set the structure. In certain embodiments, the braid may be a tubular braid of fine metal wires <NUM> such as Nitinol, platinum, cobalt-chrome alloys, 35N LT, Elgiloy, stainless steel, tungsten or titanium.

In certain embodiments, the member can be formed at least in part from a cylindrical braid of elastic filaments. Thus, the braid may be radially constrained without plastic deformation and will self-expand on release of the radial constraint to an unrestrained diameter or diameter at its lowest energy state. Such a braid of elastic filaments is herein referred to as a "self-expanding braid.

In certain embodiments, the thickness of the braid filaments is less that about <NUM> millimeters. In certain embodiments, the braid may be fabricated from wires <NUM> with diameters ranging from about <NUM> millimeters to about <NUM> millimeters. In certain embodiments, the braid may be fabricated from wires with diameters ranging from about <NUM> millimeters to about <NUM> millimeters.

In certain embodiments, the member has a high braid angle zone where the braid angle α is greater than about <NUM> degrees. More particularly, the higher braid angle portion or zone may have a braid angle α that is between <NUM> and <NUM> degrees. The high braid angle portion may have higher radial stiffness that may provide, for example, improved extraction of occlusive material <NUM>. Furthermore, as the member is retracted the portion of the member with a high braid angle elongates to a greater amount relative to the remainder of the member, thereby providing a longer surface for retraction through the occlusive material.

In certain embodiments, the system may comprise a braided member where the braid is formed from a mixture of more than one diameter wire <NUM>, as shown in <FIG>. A braid showing two wire diameters, wire 70a and wires 70b having a smaller diameter than the diameter of the wires 70a, is shown in <FIG>.

A braided member may also comprise a plurality of layers. In certain embodiments, the system may comprise a braided member where the braid configuration changes over the length of the member forming a tubular structure with two or more zones of different braid. The parameters that may be changed to manipulate the braid include but are not limited to braid angle α, combinations of different diameters of wire <NUM> (e.g. a combination of small and large diameters) and wire loading (e.g. alternating wire size in a <NUM> by <NUM> or <NUM> by <NUM> pattern). Changing the braid parameters allows for zones of different mechanical properties (e.g. radial stiffness and compliance) along one continuous braid. In certain embodiments, the member may have one zone with a braid angle α between about <NUM> degrees and <NUM> degrees and another zone with a braid angle α between about <NUM> degrees and <NUM> degrees. In certain embodiments, the member may have one zone with a radial stiffness that is at least about <NUM>% greater than the radial stiffness of a second zone.

In one embodiment, as shown in <FIG>, the flow restoration member may be formed by machining or laser cutting a stent-like pattern either directly in a tube or in a flat sheet that is subsequently formed into a tube. The sheet may be rolled or otherwise formed into a generally tubular configuration and then welded, soldered or joined in order to fix the tubular shape. <FIG> shows an exemplary flat pattern. <FIG> shows the tube form of the stent-like pattern and <FIG> shows the stent-like tube attached to the distal end of a pusher or deleviery element. In certain other embodiments, as shown in <FIG>, the extraction member <NUM> is a braided structure extension of flow restoration member <NUM> that has been everted and curled back on itself forming an expanded distal portion. In any of the above described embodiments, the system <NUM>, <NUM>, <NUM> may include additional devices or components to facilitate thrombus maceration or disruption including but not limited to mechanical maceration members (auger, drill bit, screw, impellor, burr, pick, etc.), vibration members, ultrasonic energy, radiofrequency energy, microwave energy, thermal energy, cavitiation, flow jets or perfusion apparatus. For example, in certain embodiments, the system <NUM>, <NUM>, <NUM> may comprise a boring member to facilitate penetration of the occlusive material <NUM>. In certain embodiments, the system <NUM>, <NUM>, <NUM> may comprise an auger device to facilitate retraction of the occlusive material <NUM>, such as thrombus along a central path coaxial with the flow restoration member <NUM>, <NUM>, <NUM>.

In any of the above described embodiments, the system <NUM>, <NUM>, <NUM> may include a drug or bioactive agent to enhance the thrombus extraction performance and/or reduce the propensity to produce clotting. In certain embodiments, the system <NUM>, <NUM>, <NUM> and more particularly the flow restoration member <NUM>, <NUM>, <NUM>, extraction member <NUM>, <NUM>, and the proximal capture member <NUM> may employ textures, surface features, coatings, or the like to enhance the engagement and/or attachment of the occlusive material <NUM>, such as thrombus. In certain embodiments, the device may include an antiplatelet agent, a lytic agent or an anticoagulant.

In any of the above described embodiments, a delivery system may be provided or integrated into the catheter <NUM> and/or sheath <NUM>, <NUM>. The delivery system may include an introducer sheath for access into the appropriate vein such as the subclavian vein, jugular vein, femoral vein or radial vein. In certain embodiments, the catheter <NUM> and/or sheath <NUM>, <NUM> may be placed through the introducer sheath to pass through the access vein such as the right subclavian vein or jugular vein into the superior vena cava through the right atrium through the tricuspid valve, through the right ventricle, through the pulmonic valve, to thrombus or occlusive embolus situated in the pulmonary artery or branches of the pulmonary artery. In some embodiments, the catheter <NUM> and/or sheath <NUM> may be placed through the introducer sheath to pass through the access vein such as the femoral vein into the inferior vena cava through the right atrium through the tricuspid valve, through the right ventricle, through the pulmonic valve, to thrombus or occlusive embolus situated in the pulmonary artery or branches of the pulmonary artery.

Claim 1:
An occlusion management system (<NUM>) for treating occlusive material within a blood vessel, comprising:
a catheter (<NUM>);
a pusher (<NUM>) having a proximal portion and a distal portion; and
a tubular flow restoration member (<NUM>) coupled to the distal portion of the pusher (<NUM>), wherein the flow restoration member (<NUM>) comprises a stent-like tube that is radially expandable from a compressed delivery state to a radially expanded, minimum energy state having at least, in part, a hollow cylindrical or tubular shape;
and wherein the system comprises an extraction member (<NUM>) attached directly to the flow restoration member (<NUM>) and configured to be deployed distally of the flow restoration member (<NUM>) to have a diameter larger than a diameter of the flow restoration member (<NUM>), wherein the extraction member (<NUM>) is configured to be pulled into and around the occlusive material, and wherein the extraction member (<NUM>) comprises a braid of filaments.