MULTI-LUMEN ASPIRATION CATHETERS, AND ASSOCIATED SYSTEMS AND METHODS

Disclosed herein are clot treatment systems including catheters having multiple lumens, and associated systems and methods. In some embodiments, a clot treatment system includes a catheter having a distal tip configured to be intravascularly positioned proximate to clot material within a blood vessel. The catheter can further include/define an aspiration lumen having a distal aspiration opening and an injection lumen having a distal injection opening. The clot treatment system can further include a pressure source fluidly coupled to the aspiration lumen, and a fluid source fluidly coupled to the injection lumen. The pressure source is configured to generate negative pressure within the aspiration lumen to aspirate at least a portion of the clot material through the distal aspiration opening. The fluid source is configured to inject a fluid through the injection lumen and out of the distal injection opening into the blood vessel.

TECHNICAL FIELD

The present technology generally relates to clot treatment systems including catheters having a primary aspiration lumen for aspirating clot material from within a blood vessel and a separate secondary injection lumen for injecting fluid into the blood vessel.

BACKGROUND

Thromboembolic events are characterized by an occlusion of a blood vessel. Thromboembolic disorders, such as stroke, pulmonary embolism, heart attack, peripheral thrombosis, atherosclerosis, and the like, affect many people. These disorders are a major cause of morbidity and mortality.

When an artery is occluded by a clot, tissue ischemia develops. The ischemia will progress to tissue infarction if the occlusion persists. Infarction does not develop or is greatly limited if the flow of blood is reestablished rapidly. Failure to reestablish blood flow can lead to the loss of limb, angina pectoris, myocardial infarction, stroke, or even death.

In the venous circulation, occlusive material can also cause serious harm. Blood clots can develop in the large veins of the legs and pelvis, a common condition known as deep venous thrombosis (DVT). DVT arises most commonly when there is a propensity for stagnated blood (e.g., long distance air travel, immobility, etc.) and clotting (e.g., cancer, recent surgery, such as orthopedic surgery, etc.). DVT causes harm by: (1) obstructing drainage of venous blood from the legs leading to swelling, ulcers, pain, and infection, and (2) serving as a reservoir for blood clots to travel to other parts of the body including the heart, lungs, brain (stroke), abdominal organs, and/or extremities.

In the pulmonary circulation, the undesirable material can cause harm by obstructing pulmonary arteries-a condition known as pulmonary embolism. If the obstruction is upstream, in the main or large branch pulmonary arteries, it can severely compromise total blood flow within the lungs, and therefore the entire body, and result in low blood pressure and shock. If the obstruction is downstream, in large to medium pulmonary artery branches, it can prevent a significant portion of the lung from participating in the exchange of gases to the blood resulting in low blood oxygen and buildup of blood carbon dioxide.

There are many existing techniques to reestablish blood flow through an occluded vessel. One common surgical technique, an embolectomy, involves incising a blood vessel and introducing a balloon-tipped device (such as the Fogarty catheter) to the location of the occlusion. The balloon is then inflated at a point beyond the clot and used to translate the obstructing material back to the point of incision. The obstructing material is then removed by the surgeon. Although such surgical techniques have been useful, exposing a patient to surgery may be traumatic and best avoided when possible. Additionally, the use of a Fogarty catheter may be problematic due to the possible risk of damaging the interior lining of the vessel as the catheter is being withdrawn.

Percutaneous methods are also utilized for reestablishing blood flow. A common percutaneous technique is referred to as balloon angioplasty where a balloon-tipped catheter is introduced to a blood vessel (e.g., typically through an introducing catheter). The balloon-tipped catheter is then advanced to the point of the occlusion and inflated to dilate the stenosis. Balloon angioplasty is appropriate for treating vessel stenosis, but it is generally not effective for treating acute thromboembolisms as none of the occlusive material is removed and the vessel will re-stenos after dilation. Another percutaneous technique involves placing a catheter near the clot and infusing streptokinase, urokinase, or other thrombolytic agents to dissolve the clot. Unfortunately, thrombolysis typically takes hours to days to be successful. Additionally, thrombolytic agents can cause hemorrhage and in many patients the agents cannot be used at all.

Various devices exist for performing a thrombectomy or removing other foreign material. However, such devices have been found to have structures which are either highly complex, cause trauma to the treatment vessel, or lack sufficient retaining structure and thus cannot be appropriately fixed against the vessel to perform adequately. Furthermore, many of the devices have highly complex structures that lead to manufacturing and quality control difficulties as well as delivery issues when passing through tortuous or small diameter catheters. Less complex devices may allow the user to pull through the clot, particularly with inexperienced users, and such devices may not completely capture and/or collect all the clot material.

DETAILED DESCRIPTION

The present technology is generally directed to clot treatment systems including catheters (e.g., aspiration catheters) having multiple lumens (e.g., dual lumens), and associated systems and methods. In some embodiments, a clot treatment system in accordance with the present technology includes a catheter having a distal tip configured to be intravascularly positioned proximate to clot material within a blood vessel. The catheter can further include/define an aspiration lumen having a distal aspiration opening and an injection lumen having a distal injection opening. The clot treatment system can further include a pressure source fluidly coupled to the aspiration lumen, and a fluid source fluidly coupled to the injection lumen. The pressure source is configured to generate negative pressure within the aspiration lumen to aspirate at least a portion of the clot material through the distal aspiration opening. The fluid source is configured to inject a fluid through the injection lumen and out of the distal injection opening into the blood vessel. In some embodiments, the distal injection opening is positioned proximal to the distal aspiration opening along the catheter.

The fluid can be a contrast fluid that permits visualization of a distal portion of the catheter including the distal tip under fluoroscopic imaging. The contrast fluid can enable an operator of the clot treatment system (e.g., a physician) to visualize a cause of occlusion of the aspiration lumen after aspiration. For example, the aspiration lumen may become occluded if (1) the distal tip of the catheter is positioned against a wall of the blood vessel and/or the blood vessel collapses during aspiration or (2) the clot material is not fully ingested into the distal tip and clogs the aspiration lumen. If the aspiration lumen is occluded by the wall of the blood vessel, the same or a different fluid can be injected through the injection lumen into the blood vessel to fill the blood vessel and/or the catheter can be retracted proximally until the aspiration lumen is no longer occluded (e.g., becomes unstuck from the wall of the vessel). If the aspiration lumen is occluded by the clot material, the catheter can be retracted proximally with the clot material captured thereby (e.g., stuck to the distal tip) from within the blood vessel and out of the patient.

Accordingly, the present technology permits the operator to directly visualize and determine the cause of an occlusion within the aspiration lumen (e.g., whether the catheter is engaged with and occluded by the wall of the blood vessel or occluded by clot material) via contrast fluid injected through the separate injection lumen. In contrast, many conventional clot removal techniques do not permit determination of the cause of an occlusion. For example, under fluoroscopy it can be difficult or impossible to tell what the cause of occlusion is because the area around the distal tip of the catheter (e.g., what the catheter is engaging) is not visible. In such systems, the catheter must be fully removed from the patient regardless of the cause of occlusion, cleaned, and subsequently reintroduced into the blood vessel. Using the present technology, if the catheter is merely engaged with the wall of the blood vessel, the operator can inject fluid through the injection lumen and/or slightly retract the catheter to release the wall of the blood vessel from the catheter and clear the occlusion. Notably, the operator need not retract the catheter fully from the patient to clear the occlusion-reducing procedure time. Additionally, the injection lumen is separate from the aspiration lumen such that fluid injection through the injection lumen minimizes the risk of reintroducing clot material into the blood vessel of the patient.

Certain details are set forth in the following description and inFIGS.1-8Cto provide a thorough understanding of various embodiments of the present technology. In other instances, well-known structures, materials, operations, and/or systems often associated with intravascular procedures, clot removal procedures, catheters, fluoroscopic or other medical imaging techniques, and the like are not shown or described in detail in the following disclosure to avoid unnecessarily obscuring the description of the various embodiments of the technology. Moreover, although reference is primarily made to aspiration catheters and catheters for use in clot removal procedures, the catheters of the present technology can be other types of catheters and/or can be used in other types of medical procedures. Those of ordinary skill in the art will recognize, however, that the present technology can be practiced without one or more of the details set forth herein, and/or with other structures, methods, components, and so forth.

The accompanying Figures depict embodiments of the present technology and are not intended to be limiting of its scope unless expressly indicated. The sizes of various depicted elements are not necessarily drawn to scale, and these various elements may be enlarged to improve legibility. Component details may be abstracted in the Figures to exclude details such as position of components and certain precise connections between such components when such details are unnecessary for a complete understanding of how to make and use the present technology. Many of the details, dimensions, angles and other features shown in the Figures are merely illustrative of particular embodiments of the disclosure. Accordingly, other embodiments can have other details, dimensions, angles and features without departing from the present technology. In addition, those of ordinary skill in the art will appreciate that further embodiments of the present technology can be practiced without several of the details described below.

Moreover, although many of the devices and systems are described herein in the context of removing and/or treating clot material, the present technology can be used to remove and/or treat other unwanted material in addition or alternatively to clot material, such as thrombi, emboli, plaque, intimal hyperplasia, post-thrombotic scar tissue, etc. Accordingly, the terms “clot” and “clot material” as used herein can refer to any of the foregoing materials and/or the like.

With regard to the terms “distal” and “proximal” within this description, unless otherwise specified, the terms can reference a relative position of the portions of a catheter subsystem with reference to an operator and/or a location in the vasculature. Also, as used herein, the designations “rearward,” “forward,” “upward,” “downward,” and the like are not meant to limit the referenced component to a specific orientation. It will be appreciated that such designations refer to the orientation of the referenced component as illustrated in the Figures; the systems of the present technology can be used in any orientation suitable to the user.

In the Figures, identical reference numbers identify identical, or at least generally similar, elements. To facilitate the discussion of any particular element, the most significant digit or digits of any reference number refers to the Figure in which that element is first introduced. For example, catheter110is first introduced and discussed with reference toFIG.1A.

As used herein, unless expressly indicated otherwise, the terms “about,” “approximately,” “substantially” and the like mean within plus or minus 10% of the stated value. To the extent any materials incorporated herein by reference conflict with the present disclosure, the present disclosure controls. The headings provided herein are for convenience only and should not be construed as limiting the subject matter disclosed.

I. SELECTED EMBODIMENTS OF CLOT TREATMENT SYSTEMS

FIG.1is a partially schematic side view of a clot treatment system100in accordance with embodiments of the present technology. The clot treatment system100can also be referred to as an aspiration assembly, an aspiration and fluid injection assembly, a clot removal system, a thrombectomy system, and/or the like. In the illustrated embodiment, the clot treatment system100includes a catheter110(e.g., an elongate member, a tube, a sheath, a shaft, and/or the like) having a proximal end portion111and a distal end portion113. The catheter110further defines an aspiration lumen112(e.g., a first lumen, a primary lumen, a vacuum lumen, and/or the like) and one or more injection lumens114(e.g., a second lumen, a secondary lumen, a fluid injection lumen, an infusion lumen, and/or the like). The clot treatment system100further includes a first tubing assembly120fluidly coupled to the aspiration lumen112via a first port or first connector102and a second tubing assembly130fluidly coupled to the injection lumen114via a second port or second connector104. The first connector102can be coupled to the proximal end portion111of the catheter110and a valve101can be fluidly coupled to a proximal portion of the first connector102.

The valve101is fluidly coupled to the aspiration lumen112of the catheter110via the first connector102. In some embodiments, the valve101is a hemostasis valve that is configured to maintain hemostasis during a clot removal procedure by inhibiting or even preventing fluid flow in the proximal direction through the valve101as various components such as delivery sheaths, pull members, guidewires, interventional devices, other aspiration catheters, and so on are inserted through the valve101to be delivered through the aspiration lumen112of the catheter110to a treatment site in a blood vessel. In some embodiments, the valve101can be a valve of the type disclosed in U.S. Pat. No. 11,000,682, filed Aug. 30, 2018, and titled “HEMOSTASIS VALVES AND METHODS OF USE,” which is incorporated herein by reference in its entirety. For example, the valve101can include one or more actuators107(e.g., buttons) that are biased to a position in which a lumen of the valve101is closed and that are actuatable (e.g., depressible) by a user to open the lumen of the valve101. The first connector102includes a branch or side port103positioned to fluidly couple the aspiration lumen112of the catheter110to the first tubing assembly120.

In the illustrated embodiment, the first tubing assembly120fluidly couples the aspiration lumen112of the catheter110to a pressure source106(which can also be referred to as a source of negative pressure, an aspiration source, and/or the like), such as a syringe, electric pump, and/or the like. The first tubing assembly120can include one or more tubing sections122(individually labeled as a first tubing section122aand a second tubing section122b), at least one fluid control device124(e.g., a valve), and at least one third connector126(e.g., a Toomey tip connector) for fluidly coupling the tubing assembly120to the pressure source106and/or other suitable components. In some embodiments, the fluid control device124is a stopcock that is fluidly coupled to (i) the side port103of the first connector102via the first tubing section122aand (ii) the third connector126via the second tubing section122b. The fluid control device124is externally operable by a user to regulate the flow of fluid therethrough and, specifically, from the aspiration lumen112of the catheter110to the pressure source106. For example, the fluid control device124can be moved to a closed position to fluidly disconnect the pressure source106from the aspiration lumen112and moved to an open position to fluidly connect the pressure source106to the aspiration lumen112. In some embodiments, the third connector126is a quick-release connector (e.g., a quick disconnect fitting) that enables rapid coupling/decoupling of the catheter110and the fluid control device124to/from the pressure source106.

In the illustrated embodiment, the second connector104is coupled to the catheter110distal of the proximal end portion111. The second connector104can include a branch or side port108positioned to fluidly couple the injection lumen114of the catheter110to the second tubing assembly130. In the illustrated embodiment, the second tubing assembly130fluidly couples the injection lumen114of the catheter110to a fluid source109. The fluid source109can include/contain a fluid such as contrast (e.g., a dye loaded with particles that are visible under fluoroscopy), saline, blood and/or another fluid and, in some embodiments, includes a pressure for forcing the fluid through the injection lumen114(e.g., for injecting the fluid through the injection lumen114). For example, the fluid source109can comprise a syringe containing a contrast fluid, saline, heparin, anti-coagulant medications, and/or the like, and/or various mixtures thereof. The second tubing assembly130can include one or more tubing sections132coupled to a connector assembly134. The connector assembly134can include a fourth connector136configured to be coupled to the fluid source109and a valve138for selectively connecting the fluid source109to the injection lumen114.

In the illustrated embodiment, the catheter110includes (i) a proximal region115, (ii) an intermediate region116adjacent to and distal of the proximal region115, (iii) a distal region117adjacent to and distal of the intermediate region116, and (iv) a distal tip region118adjacent to and distal of the distal region117(collectively “the regions115-118”). The lengths of the regions115-118can differ from one another. For example, in some embodiments the proximal region115has a first length, the intermediate region116has a second length less than the first length, the distal region117has a third length greater than the second length but less than the first length, and the distal tip region118has a fourth length less than the first, second, and third lengths. Additionally, some or all of the regions115-118can have varying hardness, durometer, flexibility, rigidity, thickness, and/or other properties. For example, in some embodiments the catheter110has a first hardness along the proximal region115, a second hardness along the intermediate region116that is less than the first hardness, a third hardness along the distal region117that is less than the first hardness and the second hardness, and a fourth hardness in the distal tip region118that is greater than third hardness.

In some embodiments, the distal tip region118and/or another region of the catheter110includes a marker (e.g., marker band), such as a radiopaque marker configured to facilitate visualization of the position of the catheter110during a medical procedure (e.g., a clot removal procedure) using the catheter110. In some embodiments, all or a portion of the distal region117and/or the distal tip region118can be configured to assume a curved shape. For example, the distal region117can comprise a shape memory material that is heat-set or otherwise configured to have a predetermined curved shape. More specifically, the distal region117can be configured to deflect such that the catheter110has a pre-shaped portion (e.g., along some or all of the distal region117and/or the distal tip region118) as described in U.S. patent application Ser. No. 17/529,018, titled “CATHETERS HAVING SHAPED DISTAL PORTIONS, AND ASSOCIATED SYSTEMS AND METHODS,” and filed Nov. 17, 2021, which is incorporated by reference herein in its entirety.

In the illustrated embodiment, the clot treatment system100includes a dilator assembly140removably inserted through the valve101and the aspiration lumen112of the catheter110. The dilator assembly140can include an elongated dilator142coupled to a first connector or first cap144. The valve101can include a second connector or second cap143coupled to a proximal portion of the valve101. The first cap144can be releasably coupled/locked to the second cap143. Accordingly, inserting the dilator142into the catheter110can include moving the first cap144toward the second cap143. In some embodiments, the first cap144can mate with the second cap142to lock the dilator assembly140to the valve101when the dilator142is fully seated/positioned within the catheter110. In the fully seated position shown inFIG.1, the dilator142is configured to extend past a distal tip or distal terminus119of the catheter110. The dilator assembly140and the catheter110can be jointly advanced through the vasculature of a patient in this position with the dilator142providing an atraumatic distal or leading end during advancement. In some embodiments, the dilator assembly140can include features similar or identical to, and can function similarly or identically, to any of the dilator assemblies described in detail in U.S. patent application Ser. No. 18/156,944, titled “CLOT TREATMENT SYSTEMS WITH DILATOR LOCKING MECHANISMS, AND ASSOCIATED DEVICES AND METHODS,” and filed Jan. 19, 2023, which is incorporated by reference herein in its entirety.

The aspiration lumen112can extend from the first connector102to the distal terminus119of the catheter110and define a distal aspiration opening145. Accordingly, the distal aspiration opening145can be coplanar with the distal terminus119of the catheter110. The injection lumen114can extend from the second connector104toward the distal terminus119of the catheter110and define a distal injection opening146. In the illustrated embodiment, the injection lumen114terminates proximal to the distal terminus119such that the injection opening146is positioned proximal to the aspiration opening145. In other embodiments, the injection lumen114extends to the distal terminus119of the catheter110such that the aspiration opening145and the injection opening146are coplanar or substantially coplanar. In some embodiments, the aspiration lumen112has a larger dimension (e.g., diameter, radius, cross-sectional area) than a corresponding dimension of the injection lumen114. For example, the aspiration lumen112can have a diameter of about 0.270 inch and the injection lumen114can have a diameter of about 0.039 inch. Accordingly, the aspiration lumen112can have a diameter of about 7 times greater, about 5 times greater, about 2 times greater, or more than 7 times greater than the injection lumen114.

The aspiration lumen112can have a generally circular cross-sectional shape. The injection lumen114can have a generally circular cross-sectional shape, an elongate U-shaped cross-sectional shape, or other shape. In some embodiments, the injection lumen114comprises a single lumen while, in other embodiments, the injection lumen114comprises multiple (e.g., two, three, four, or more) parallel lumens. More particularly, for example,FIGS.2A-5Billustrate different configurations (e.g., shapes, sizes, positioning) of the injection lumen114in accordance with embodiments of the present technology.

FIG.2Ais a cross-sectional view of the catheter110ofFIG.1taken along the line2A-2A inFIG.1in accordance with embodiments of the present technology.FIGS.2B-2Dare proximally-facing perspective views of a distal portion of the catheter110ofFIGS.1and2Awith the dilator142ofFIG.1inserted therein in accordance with embodiments of the present technology. Referring toFIG.2A, the catheter110includes a wall250described in further detail below with reference toFIG.6. The wall250encloses/defines the aspiration lumen112. The injection lumen114can be formed in the wall250of the catheter110as described in greater detail below with reference toFIG.6.

Referring toFIGS.2A-2D, the aspiration lumen112has a generally circular cross-sectional shape, extends along a longitudinal axis L (FIG.2A), and is configured to receive the dilator142therethrough. In the illustrated embodiment, the injection lumen114has an elongate U-shaped cross-sectional shape. More particularly, referring toFIG.2A, the injection lumen114extends circumferentially through the wall250of the catheter110about the longitudinal axis L. In the illustrated embodiment, the injection lumen114extends about the longitudinal axis L by an angle A of about 120 degrees. In other embodiments, the injection lumen114can extend more or less circumferentially about the longitudinal axis L. For example, the angle A can be anywhere between about 110-140 degrees or between about 110-360 degrees.

Referring toFIGS.2B-2D, the aspiration lumen112terminates at the aspiration opening145at the distal terminus119of the catheter110, and the injection lumen114terminates at the injection opening146proximal of the distal terminus119of the catheter110. Referring toFIG.2B, the injection opening146can be spaced apart (e.g., spaced back) from the aspiration opening145by a distance D of between about 0.5-4.0 centimeters.

FIG.3is a cross-sectional view of the catheter110ofFIG.1taken along the line3-3inFIG.1in accordance with additional embodiments of the present technology. In the illustrated embodiment, the catheter110includes the wall250and a tubular member352coupled to, attached to, and/or integrally formed with the wall250. The wall encloses/defines the aspiration lumen112, and the tubular member352at least partially encloses/defines the injection lumen114. In some embodiments, the tubular member352is a separate circular tube or extrusion coupled to the wall250such that the injection lumen114has a generally tubular shape. In some embodiments, the tubular member352defines/encloses a first portion of the injection lumen114and the wall250encloses/defines a second portion of the injection lumen114such that the injection lumen114has a sector-like cross-sectional shape defined by the circular curvature of the tubular member352about the first portion and the circular curvature of the wall250about the second portion.

FIG.4is a proximally-facing perspective end-on view of the catheter110ofFIGS.1and/or3in accordance with additional embodiments of the present technology. In the illustrated embodiment, the catheter110includes the wall250which encloses defines the aspiration lumen112, and the injection lumen114is formed in the wall250of the catheter110as described in greater detail below with reference toFIG.6. The aspiration lumen112and the injection lumen114can both have a circular cross-sectional shape. In the illustrated embodiment, the aspiration lumen112terminates at the aspiration opening145at the distal terminus119of the catheter110, and the injection lumen114terminates at the injection opening146proximal of the distal terminus119of the catheter110.

FIG.5Ais a cross-sectional view of the catheter110ofFIG.1taken along the line5A-5A inFIG.1in accordance with additional embodiments of the present technology.FIG.5Bis a proximally-facing perspective end-on view of the catheter110ofFIGS.1and5Ain accordance with embodiments of the present technology. Referring toFIGS.5A and5B, the injection lumen114comprises multiple parallel injection lumens114(individually identified as first through third injection lumens114a-c, respectively). Referring toFIGS.1,5A, and5B, the injection lumens114can each be coupled to the second tubing assembly130via the second connector104to receive the fluid from the fluid source109. Referring toFIGS.5A and5B, the catheter110includes the wall250which encloses defines the aspiration lumen112, and the injection lumens114are formed in the wall250of the catheter110as described in greater detail below with reference toFIG.6. While three of the injection lumens114are illustrated inFIGS.5A and5Band are equally spaced circumferentially about the longitudinal axis L (FIG.5A) of the catheter110(e.g., by 120 degrees apart from one another), the catheter110can include more or fewer (e.g., two, four, five, more than five) of the injection lumens114and/or the injection lumens114can be spaced apart differently (e.g., irregularly). The aspiration lumen112and the injection lumens114a-ccan both have a circular cross-sectional shape. Referring toFIG.5B, in the illustrated embodiment the aspiration lumen112terminates at the aspiration opening145at the distal terminus119of the catheter110, and the first through third injection lumens114a-ceach terminate at a corresponding first through third injection opening146a-c, respectively, at the distal terminus119of the catheter110. In other embodiments, the injection openings146can be set back proximally from the distal terminus119of the catheter110.

FIG.6is a cross-sectional view of the catheter110taken along the line6-6inFIG.1in accordance with embodiments of the present technology. In the illustrated embodiment, the wall250of the catheter110comprises an outer sheath660and an inner liner662extending through/defining each of the regions115-118(FIG.1). The outer sheath660is positioned over (e.g., radially outside of) the inner liner662. The outer sheath660can also be referred to as an outer jacket, an outer shaft, an outer layer, or the like, and the inner liner662can also be referred to as an inner layer, an inner sheath, an inner shaft, or the like. In the illustrated embodiment, the catheter110further includes an inner coil layer664(e.g., a first coil layer) and an outer coil layer666(e.g., a second coil layer) extending over/about the inner coil layer664. The inner coil layer664and the outer coil layer666(collectively “the coil layers664,666”) can comprise a plurality of individual wires that are wound around the inner liner662. In some embodiments, the wires extend around the inner liner662in a helical or spiral pattern about the longitudinal axis L (FIGS.2A and5A) of the catheter110in a first direction to form the inner coil layer664, and the wires double back at or proximate to the distal terminus119(FIG.1) to extend about the inner coil layer664in a helical or spiral pattern about the longitudinal axis L in a second direction to form the outer coil layer666. The wires can thus self-terminate at and/or proximate to the distal terminus119of the catheter110where the wires transition from the inner coil layer664to the outer coil layer666. The coil layers664,666can extend along an entire length of the catheter110through each of the regions115-118(FIG.1), or can extend only partially along the length of catheter110(e.g., in the distal region117and the distal tip region118ofFIG.1). The coil layers664,666can be referred to collectively as a reinforcement structure or the like. In some embodiments, the catheter110can include features similar or identical to, and can function similarly or identically, to any of the catheters described in detail in U.S. patent application Ser. No. 18/463,960, titled “CATHETERS HAVING MULTIPLE COIL LAYERS, AND ASSOCIATED SYSTEMS AND METHODS,” and filed Sep. 8, 2023, which is incorporated by reference herein in its entirety.

The outer sheath660can be formed from a plastic material, elastomeric material, thermoplastic polyurethane (TPU), and/or thermoplastic elastomer (TPE) material. In some embodiments, the outer sheath660can be formed from a TPE manufactured by Arkema S.A., of Colombes, France, such as the TPEs manufactured under the trademark “Pebax.” In some embodiments, the outer sheath660can have a varying hardness (e.g., durometer), thickness, flexibility, rigidity, and/or other property in one or more of the different regions115-118as described in detail above with reference toFIG.1. The outer sheath660can define an outer diameter O of the catheter110. In some embodiments, the outer diameter O is greater than about 6 French, greater than about 10 French, greater than about 16 French, greater than about 20 French, greater than about 24 French, or greater. In some embodiments, the outer diameter O is about 8 French, about 16 French, about 20 French, about 24 French, or about 26 French. As used herein with reference to the outer diameter O, the term “about” means within plus or minus 1 French of the stated diameter.

The inner liner662defines/encloses the aspiration lumen112and, in some embodiments, can be formed of a lubricious material that facilitates the movement (e.g., distal advancement, proximal retraction) of various components through the aspiration lumen112, such as the dilator assembly140(FIG.1), delivery sheaths, pull members, guidewires, interventional devices, other aspiration catheters, and/or the like. In some embodiments, the inner liner662can be formed from a polymer material, a fluoropolymer material (e.g., polytetrafluoroethylene (PTFE)), and/or another material having a high degree of lubricity. The inner liner662defines an inner diameter D of the catheter110. The thicknesses of the outer sheath660, the inner liner662, and the coil layers664,666relative to one another and/or to the inner diameter D may not be to scale inFIG.6. For example, one of ordinary skill in the art will understand that the thicknesses of these components are shown for clarity but that the wall250of the catheter110can be relatively thin compared to the inner diameter D. The inner diameter D can be less than the outer diameter O of the catheter110by a thickness T of the wall250of the catheter110comprising the combined thicknesses of the outer sheath660, the inner liner662, and the coil layers664,666. In some embodiments, the thickness T is about between about 0.2-2.0 mm, between about between about 1.0-2.0 mm, between about 1.2-1.4 mm, about 1.3 mm, between about 1.0-3.0 mm, and/or the like. Accordingly, in some embodiments, the inner diameter D is greater than about 6 French, greater than about 10 French, greater than about 16 French, greater than about 20 French, greater than about 24 French, or greater. In some embodiments, the inner diameter D is about 8 French, about 16 French, about 20 French, about 24 French, or about 26 French. In some embodiments, the outer diameter O is about 24 French, and the inner diameter D is about 20 French (e.g., the thickness T is about 1.3 mm). As used herein with reference to the inner diameter D, the term “about” means within plus or minus 1 French of the stated diameter. Referring toFIGS.1and6, in some embodiments the inner diameter D of the inner liner662is the same in each of the regions115-118(FIG.1) while, in other embodiments, the inner diameter D can vary along one or more of the regions115-118.

In some embodiments, the inner liner662or the outer sheath660can be omitted. For example, the inner liner662can be omitted and the coil layers664,666can be coupled to (e.g., fused to) the outer sheath660.

As described above with reference toFIGS.2A-5B, the injection lumen114can be formed in the wall250of the catheter110. For example, the injection lumen114can comprise a tube, extrusion, elongate member, and/or the like that is formed/positioned between the coil layers664,666, between the inner coil layer664and the inner liner662, and/or between the outer coil layer666and the outer sheath660.

More specifically,FIG.6illustrates with dashed lines various configurations in which the injection lumen114can be formed in the wall250of the catheter110, referenced as first through sixth injection lumens114a-f, respectively. In the illustrated embodiment, the first injection lumen114aextends between the outer sheath660and the outer coil layer666and has a generally U-like shape (e.g., as described in detail above with reference toFIGS.2A-2D). The second injection lumen114bextends between the coil layers664,666and has a generally U-like shape. The third injection lumen114cextends between the inner coil layer664and the inner liner662and has a generally U-like shape. The fourth injection lumen114dextends between the outer sheath660and the outer coil layer666and has a generally circular shape (e.g., as described in detail above with reference toFIGS.3-5B). The fifth injection lumen114eextends between the coil layers664,666and has a generally circular shape. And, the sixth injection lumen114fextends between the inner coil layer664and the inner liner662and has a generally circular shape. The catheter110can include one or multiple of the injection lumens114having any suitable shape and position relative to the wall250of the catheter110.

The injection lumen(s)114can be formed during manufacturing of the catheter110as, for example, described in detail in U.S. patent application Ser. No. 18/463,960, titled “CATHETERS HAVING MULTIPLE COIL LAYERS, AND ASSOCIATED SYSTEMS AND METHODS,” and filed Sep. 8, 2023, which is incorporated by reference herein in its entirety. For example, the injection lumen(s)114can be secured in position between the coil layers664,666during manufacturing by (i) positioning the injection lumen(s)114over the inner coil layer664after winding the wires of the inner coil layer664about the inner liner662and then (ii) further winding the wires over the injection lumen(s)114and the inner coil layer664to form the outer coil layer666. In some aspects of the present technology, the catheter110can be manufactured to include the injection lumen(s)114with a single machine setup due to the self-terminating ends of the coil layers664,666. In additional aspects of the present technology, the injection lumen(s)114can be formed within the catheter110without increasing or substantially increasing the thickness T of the wall250of the catheter110compared to conventional manufacturing methods.

Referring toFIG.1, in some embodiments the second tubing assembly130can be fluidly coupled to a source of filtered blood and the injection lumen114can be utilized to reinfuse the filtered blood into the vasculature of a patient. For example,FIG.9is a partially-schematic side view of the clot treatment system100configured as a clot aspiration and filtered blood reinfusion system in accordance with embodiments of the present technology. In the illustrated embodiment, the aspiration lumen112and the injection lumen114of the catheter110are fluidly coupled to an aspiration and blood filtering assembly940via the first tubing assembly120and the second tubing assembly130, respectively. The aspiration and blood filtering assembly940is configured to aspirate blood and clot material through the aspiration lumen112, filter the blood from the clot material, and reinfuse/return the filtered blood through the injection lumen114(which, accordingly, can be referred to as a reinfusion lumen).

In some embodiments, the aspiration and blood filtering assembly940comprises a first pressure source, a filter device, and a second pressure source. The first pressure source (e.g., a first syringe) can be fluidly coupled to the first tubing assembly120and activated to aspirate blood and clot material through the aspiration lumen112of the catheter110, through the first tubing assembly120, and into the first pressure source. The first pressure source can then be decoupled from the first tubing assembly120, fluidly coupled to an inlet of the filter device, and activated to drive the blood and clot material into the filter device through the inlet. The filter device can include one or more filters configured to filter the blood from the clot material. The second pressure source (e.g., a second syringe) can be fluidly coupled to an outlet of the filter device and activated to draw the filtered blood from the filter device into the second pressure source. The second pressure source can then be decoupled from the outlet of the filter device, fluidly coupled to the second tubing assembly130, and activated to drive the filtered blood through the second tubing assembly130, through the injection lumen114of the catheter110, and into the vasculature of the patient. Accordingly, in some embodiments the blood filtering assembly940can have some features generally similar or identical to and/or function generally similarly or identically to any of the aspiration and blood filtering devices described in detail in U.S. Pat. No. 11,559,382, filed Aug. 8, 2019, and titled “SYSTEM FOR TREATING EMBOLISM AND ASSOCIATED DEVICES AND METHODS,” which is incorporated herein by reference in its entirety.

In other embodiments, the aspiration and blood filtering assembly940can comprise one or more blood-filtering syringes or other devices configured to aspirate blood and clot material into the syringe via the aspiration lumen112and to filter the blood from the clot material for reinfusion through the reinfusion lumen114. For example, the aspiration and blood filtering assembly940can have some features generally similar or identical to and/or function generally similarly or identically to any of the blood-filtering syringes/devices described in detail in U.S. patent application Ser. No. 18/192,855, filed Mar. 30, 2023, and titled “BLOOD-FILTERING DEVICES FOR USE WITH CLOT TREATMENT SYSTEMS,” which is incorporated herein by reference in its entirety.

In other embodiments, the aspiration and blood filtering assembly940can be an at least partially automated system configured to aspirate blood and clot material through the aspiration lumen112, filter the clot material from the blood, and reinfuse/return the filtered blood through the injection lumen114. For example, the aspiration and blood filtering assembly940can comprise one or more pumps (e.g., syringe, electric pumps, etc.), one or more filters, and one or more tubing sections configured to carry out the aforementioned functions. In some embodiments, the aspiration and blood filtering assembly940can have some features generally similar or identical to and/or function generally similarly or identically to any of the automated aspiration thrombectomy and blood reinfusion systems described in detail in U.S. Provisional Patent Application No. 63/675,087, filed Jul. 24, 2024, and titled “AUTOMATED CLOT ASPIRATION AND BLOOD REINFUSION SYSTEMS, AND ASSOCIATED DEVICES AND METHODS,” which is incorporated herein by reference in its entirety.

In some aspects of the present technology, because the aspiration lumen112and the injection lumen114are integrated into the same catheter110, the system100can reduce the number of vascular access sites needed for a thrombectomy and blood reinfusion procedure as well as reducing the overall profile needed for the access site-improving procedure efficiency and reducing patient discomfort. Moreover, in some aspects of the present technology the aspiration and reinfusion operations of the aspiration and blood filtering assembly940can be independent such that the rate at which the aspiration and blood filtering assembly940aspirates material via the aspiration lumen112is independent from the rate at which the aspiration and blood filtering assembly940reinfuses filtered blood into the patient. That is, the rate at which fluid is removed from the patient need not be the same as the rate at which fluid is reintroduced into the patient such that the aspiration lumen112can be of different size (e.g., diameter) than the injection lumen114.

II. SELECTED EMBODIMENTS OF METHODS OF CLOT TREATMENT

FIG.7is a flow diagram of a process or method770of treating clot material (e.g., removing clot material) within a patient, such as a human patient, in accordance with embodiments of the present technology. Although some features of the method770are described in the context of the clot treatment system100ofFIG.1for the sake of illustration, one skilled in the art will readily understand that the method770can be carried out using other clot treatment systems.FIGS.8A-8Care sides views (e.g., fluoroscopic images) of the distal region117of the catheter110of the clot treatment system100at various stages of the method770in accordance with embodiments of the present technology. In some embodiments, some aspects (e.g., blocks) of the method770can be generally similar or identical to any of the clot removal procedures disclosed in U.S. Pat. No. 11,559,382, filed Aug. 8, 2019, and titled “SYSTEM FOR TREATING EMBOLISM AND ASSOCIATED DEVICES AND METHODS,” which is incorporated herein by reference in its entirety.

Referring toFIG.7, at block771the method770can include intravascularly advancing the catheter110of the clot treatment system100to at and/or proximate clot material within a blood vessel of a patient. In some embodiments, the catheter110is advanced through the blood vessel until the distal terminus119of the catheter110is positioned proximate to a proximal portion of the clot material. The position of the distal terminus119can be confirmed or located via visualization of a marker band or other marker positioned along the distal region117and/or along the distal tip region118using fluoroscopy or another imaging procedure (e.g., a radiographic procedure). In other embodiments, the distal terminus119can be positioned at least partially within the clot material or distal of the clot material. In some embodiments, the blood vessel can be a portion of left pulmonary artery, the temporal arteries, the inferior vena cava, or the right atrium. In some embodiments, the clot material can be a pulmonary embolism, deep vein thrombosis, clot in transit (CIT) within the right atrium, and/or the like.

Access to the pulmonary vessels can be achieved through the patient's vasculature, for example, via the femoral vein. In some embodiments, the clot treatment system100can include an introducer (e.g., a Y-connector with a hemostasis valve) that can be partially inserted into the femoral vein. A guidewire (e.g., a guidewire890shown inFIGS.8A-8C) can be guided into the femoral vein through the introducer and navigated through the right atrium, the tricuspid valve, the right ventricle, the pulmonary valve, and into the main pulmonary artery. Depending on the location of the clot material, the guidewire can be guided to one or more of the branches of the right pulmonary artery and/or the left pulmonary artery. In some embodiments, the guidewire can be extended entirely or partially through the clot material. In other embodiments, the guidewire can be extended to a location just proximal of the clot material. After positioning the guidewire, the catheter110and the dilator assembly140can be placed over the guidewire and advanced to the position proximate to the clot material. The guidewire can extend through the aspiration lumen112or the injection lumen114. The dilator assembly140can then be withdrawn from the aspiration lumen112. In some embodiments, the guidewire can then be withdrawn while, in other embodiments, the guidewire can remain and can be used to guide other catheters (e.g., delivery catheters, additional aspiration guide catheters), interventional devices, etc., to the treatment site. It will be understood, however, that other access locations into the venous circulatory system of a patient are possible and consistent with the present technology. For example, the user can gain access through the jugular vein, the subclavian vein, the brachial vein, or any other vein that connects or eventually leads to the superior vena cava. Use of other vessels that are closer to the right atrium of the patient's heart can also be advantageous as it reduces the length of the instruments needed to reach the clot material.

At block772, the method770can include injecting a contrast fluid (e.g., a contrast agent) through the injection lumen114of the catheter110to visualize a position and/or orientation of the distal region117and/or the distal tip region118of the catheter110within the blood vessel.FIG.8A, for example, illustrates the distal region117of the catheter110positioned within a blood vessel BV with the distal terminus proximal119to clot material CM within the blood vessel BV. Referring toFIGS.1and8A, the dilator assembly140has been removed from the aspiration lumen112(while the guidewire890extending through the aspiration lumen112or the injection lumen114remains) and a contrast fluid891has been injected into the blood vessel BV from the injection lumen114. More specifically, the contrast fluid891can be driven from the fluid source109, through the second tubing assembly130, through the injection lumen114, and out of the injection opening146into the blood vessel BV.

In some aspects of the present technology, an operator (e.g., physician) can inject only a bolus of the contrast fluid891having a relatively small volume through the injection lumen114for visualizing the position of the distal region117of the catheter110. For example, the injection lumen114can be small in dimension relative to the aspiration lumen112, and the injection opening146can be positioned at and/or proximate to the distal region117of the catheter110where visualization is desired. Accordingly, a smaller volume of the contrast fluid891can provide sufficient visualization, whereas a larger volume of the contrast fluid891would likely be needed to facilitate the same level of visualization if it were injected through, for example, the aspiration lumen112.

The contrast fluid891can enable an operator (e.g., a physician) viewing the fluoroscopic or other image to visualize a position of the distal region117of the catheter110within the blood vessel BV. The operator can determine from the image whether the catheter110is optimally placed prior to aspiration (block774). For example, the operator can determine that the catheter110is optimally located centrally within the blood vessel BV away from the walls of the blood vessel BV with the distal terminus119and the aspiration opening145proximate to the clot material CM. Optionally, based on the image, at block773the operator can reposition the distal region117of the catheter110within the blood vessel BV.

At block774, the method770can include aspirating the aspiration lumen112of the catheter110to, for example, aspirate a portion of the clot material into and through the aspiration lumen112. In some embodiments, the pressure source106is configured to generate (e.g., form, create, charge, build-up) a vacuum (e.g., negative relative pressure) and store the vacuum for subsequent application to the catheter110. For example, after positioning the catheter110proximate the clot material, a user can first close the fluid control device124before generating the vacuum in the pressure source106by, for example, withdrawing the plunger of a syringe coupled to the third connector126of the first tubing assembly120. In this manner, a vacuum is charged within the pressure source106(e.g., a negative pressure is maintained) before the pressure source106is fluidly connected to the aspiration lumen112of the catheter110. To aspirate the aspiration lumen112of the catheter110, the user can open the fluid control device124to fluidly connect the pressure source106to the aspiration lumen112and thereby apply or release the vacuum stored in the pressure source106to the aspiration lumen112.

Opening of the fluid control device124instantaneously or nearly instantaneously applies the stored vacuum pressure to the first tubing assembly120and the aspiration lumen112of the catheter110, thereby generating a suction pulse throughout the catheter110. In particular, the suction is applied at the distal tip region118of the catheter110through the aspiration opening145with the intent to suck/aspirate at least a portion of the clot material into the aspiration lumen112of the catheter110from within the blood vessel. In some aspects of the present technology, pre-charging or storing the vacuum in the pressure source106before applying the vacuum to the aspiration lumen112of the catheter110is expected to generate greater suction forces and corresponding fluid flow velocities at and/or near the distal tip region118of the catheter110compared to simply activating the pressure source106while it is fluidly connected to the catheter110. In other embodiments, the pressure source106can be activated while the fluid control device124is open to aspirate the clot material.

At decision block775, the method770can include determining whether the aspiration lumen112of the catheter110is occluded (e.g., clogged) after aspiration (block774). For example, if the aspiration lumen112does not become occluded during aspiration, blood and clot material will typically be aspirated proximally at least partially through the aspiration lumen112, through the first tubing assembly120, and into the pressure source106. The pressure source106and/or the first tubing assembly120can be at least partially transparent to enable the operator to visually confirm, by the presence of the blood and clot material, that the aspiration did not occlude the aspiration lumen112. For example, the pressure source106can be a clear syringe or clot container. In contrast, if the aspiration lumen112becomes occluded during aspiration, blood and clot material typically will not be aspirated through the aspiration lumen112—or only a small amount of blood and clot material will be—and blood and clot material will therefore not be visible to the operator, confirming that the aspiration lumen112is occluded. In such instances, a cavitation can form in the aspiration lumen112, the first tubing assembly120, and/or the pressure source106. In other embodiments, the clot treatment system100can include other devices or systems for detecting that the catheter110is occluded.

If the aspiration lumen112is not occluded at decision block775, the method can proceed to decision block776, where the method770can include determining whether the clot material has been sufficiently removed from the blood vessel. If the clot material is sufficiently removed at block776, at block777, the method770can include proximally retracting the catheter110from the blood vessel and the patient. In some embodiments, retracting the catheter110from the blood vessel and the patient can include retracting the catheter110into the lumen of a funnel catheter or other outer catheter. The method770can then end at block778.

If the clot material is not sufficiently removed at block776, the method770can include returning to block774to again aspirate the aspiration lumen112of the catheter110with the intent to suck/aspirate at least another portion of the clot material into the aspiration lumen112of the catheter110from within the blood vessel. In other embodiments, the method770can return to blocks772or773to optimize the positioning of the catheter110within the blood vessel before again aspirating the aspiration lumen112of the catheter110. At block779, the method770optionally includes, advancing a clot treatment device through the catheter110(e.g., through the aspiration lumen112and/or the injection lumen114) for disrupting the remaining clot material before aspiration. In some embodiments, the clot treatment device can include features similar or identical to, and can function similarly or identically, to any of the clot treatment devices described in detail in U.S. Pat. No. 11,648,028, titled “METHODS AND APPARATUS FOR TREATING EMBOLISM,” and filed Jun. 26, 2020, and/or U.S. patent application Ser. No. 17/072,909, titled “SYSTEMS, DEVICES, AND METHODS FOR TREATING VASCULAR OCCLUSIONS,” and filed Oct. 16, 2020, each of which is incorporated by reference herein in its entirety.

If the aspiration lumen112is occluded at block775, the method770can proceed to decision block780. At decision block780, the method770can include injecting a contrast fluid through the injection lumen114to visualize a cause of the occlusion and, more specifically for example, to determine whether the occlusion is caused by (1) the distal terminus119of the catheter110being positioned against (e.g., stuck against) a wall of the blood vessel or (2) clot material at the distal terminus119of the catheter110clogging the aspiration lumen112of the catheter110. Regarding (1), rapid aspiration through the aspiration lumen112at block774can sometimes cause the blood vessel to collapse and/or for the aspiration through the aspiration opening145to be applied directly against the wall of the blood vessel rather than the clot material therein. Regarding (2), the clot material aspirated at block774can be large enough and/or of a consistency that it is not aspirated fully through the aspiration lumen112and instead is caught against the distal terminus119(e.g., partially within and partially outside the aspiration lumen112) and occludes the aspiration opening145. That is, the clot material can stick to the distal terminus119of the aspiration catheter as a “lollipop” or clump.

FIG.8Billustrates scenario (1) of block780with the distal terminus119of the catheter110positioned against and occluded by a wall of the blood vessel BV after aspiration of the aspiration lumen112(block774). Referring toFIGS.1and8B, the contrast fluid891has been injected into the blood vessel BV from the injection lumen114. The contrast fluid891enables the operator to visualize the distal region117of the catheter110and the surrounding anatomy in the fluoroscopic or other image. The operator of the clot treatment system100can determine from the image that the catheter110is occluded by the wall of the blood vessel BV rather than by the clot material. For example, the operator can determine that there is a lack of contrast fluid891distal to the distal terminus119of the catheter110—indicating that there is no room or flow distal to the catheter110and therefore that the blood vessel BV is collapsed and/or that the catheter110is occluded by the wall of the blood vessel BV or clot is occluding that portion of the anatomy. In some embodiments described in detail above, the injection opening146of the injection lumen114is set back proximally from the distal terminus119and the aspiration opening145of the catheter110. In some aspects of the present technology, this configuration can inhibit or even prevent the injection lumen114from becoming occluded by the wall of the blood vessel BV after aspiration. Accordingly, the contrast fluid891can be injected through and exit the injection lumen114even when the wall of the blood vessel BV occludes the aspiration lumen112. In additional aspects of the present technology, an operator (e.g., physician) need only inject a bolus of the contrast fluid891having a relatively small volume through the injection lumen114for visualizing the cause of the occlusion, as described in detail above.

At block781, the method770can then include further injecting a fluid through the injection lumen114and/or proximally retracting the catheter110until the aspiration lumen112is no longer occluded. For example, a fluid (e.g., a contrast fluid, saline, blood) can be injected through the injection lumen114to fill and expand the blood vessel to cause the wall of the blood vessel to release from the catheter110. The fluid can be the same or different than the fluid injected through the injection lumen at blocks772and/or780. In some aspects of the present technology, injecting the fluid through the separate injection lumen114rather than the aspiration lumen112reduces the risk of reintroducing any clot material captured within the aspiration lumen112into the blood vessel. Alternatively or additionally, the catheter110can be retracted proximally until the distal terminus119pulls away (e.g., becomes unstuck) from the wall of the blood vessel BV thereby clearing the occlusion. When the aspiration lumen112is no longer occluded, the unreleased vacuum pressure within the clot treatment system100will be applied to the no-longer-occluded aspiration lumen112thereby aspirating blood and/or clot material at least partially through the aspiration lumen112, through the first tubing assembly120, and into the pressure source106. The operator can therefore visualize that the aspiration lumen112is no longer occluded by visually confirming the presence of blood and/or clot material in the proximal components of the clot treatment system100and/or by reading a pressure gauge coupled to the clot treatment system, as described in detail above with reference to block775. When the aspiration lumen112is no longer occluded, the method770can return to any of blocks772-774to again position and then aspirate the aspiration lumen112.

FIG.8Cillustrates scenario (2) of block780with the distal terminus119of the catheter110occluded by the clot material CM after aspiration of the aspiration lumen112(block774). Referring toFIGS.1and8B, the contrast fluid891has been injected into the blood vessel BV from the injection lumen114. The contrast fluid891enables the operator to visualize the distal region117of the catheter110and the surrounding anatomy in the fluoroscopic or other image. The operator of the clot treatment system100can determine from the image that a portion of the clot material CM is captured on (e.g., stuck against) the distal terminus119of the catheter110and occludes the aspiration opening145. In some embodiments described in detail above, the injection opening146of the injection lumen114is set back proximally from the distal terminus119and the aspiration opening145of the catheter110. In some aspects of the present technology, this configuration can inhibit or even prevent the injection lumen114from becoming occluded by the clot material CM after aspiration. Accordingly, the contrast fluid891can be injected through and exit the injection lumen114even when the clot material CM occludes the aspiration lumen112.

At block782, the method770can then include proximally retracting the catheter110while maintaining aspiration to remove the clot material from the patient. The clot material is captured at and/or proximate to the aspiration opening145such that retraction of the catheter110also retracts the clot material. In some embodiments, retracting the catheter110and the captured clot material from the blood vessel and the patient includes retracting the catheter110and clot material into the lumen of a funnel catheter or other catheter.

At decision block783, the method can include determining whether the clot material has been sufficiently removed from the blood vessel. If the clot material is sufficiently removed at decision block783, at block784the method770can end. If the clot material is not sufficiently removed at decision block783, the method770can proceed to block785to again advance the catheter110, or a separate (e.g., new) catheter to at and/or proximate any of the clot material remaining within the blood vessel. In some embodiments, the catheter110can be cleaned (e.g., flushed) before being readvanced to the remaining clot material. The method can then return to block772to again position the catheter110, aspirate the aspiration lumen112, etc., to treat the remaining clot material.

In general, the method770permits the operator to directly visualize and determine the cause of an occlusion within the aspiration lumen112(e.g., whether the catheter110is engaged with and occluded by the wall of the blood vessel or occluded by clot material) via contrast fluid injected through the separate injection lumen114. In contrast, many conventional clot removal techniques do not permit determination of the cause of an occlusion. For example, under fluoroscopy it can be difficult or impossible to tell what the cause of occlusion (e.g., cavitation) is because the area around the distal tip of the catheter (e.g., what the catheter is engaging) is not visible. In such systems, the catheter must be fully removed from the patient regardless of the cause of occlusion, cleaned, and subsequently reintroduced into the blood vessel. In some aspects of the present technology, the injection lumen114can be used to inject contrast agent to directly visualize the cause of occlusion as described in detail above with reference to block781. If the catheter110is merely engaged with the wall of the blood vessel, the operator can inject fluid through the injection lumen114and/or slightly retract the catheter110to release the wall of the blood vessel from the catheter110and clear the occlusion. Notably, the operator need not retract the catheter110fully from the patient to clear the occlusion-reducing procedure time. Additionally, the injection lumen114is separate from the aspiration lumen112such that fluid injection through the injection lumen114minimizes the risk of reintroducing clot material into the blood vessel of the patient.

In some embodiments, the various blocks771-785of the method770can be performed in a different order, and/or some of the blocks771-785can be omitted. For example, in some embodiments blocks772and773can be omitted.

III. ADDITIONAL EXAMPLES

Several aspects of the present technology are set forth in the following examples:

1. A clot treatment system, comprising:a catheter having a distal tip configured to be intravascularly positioned proximate to clot material within a blood vessel, wherein the catheter includes an aspiration lumen having a distal aspiration opening and an injection lumen having a distal injection opening;a pressure source fluidly coupled to the aspiration lumen, wherein the pressure source is configured to generate negative pressure within the aspiration lumen to aspirate at least a portion of the clot material through the distal aspiration opening; anda fluid source fluidly coupled to injection lumen, wherein the fluid source is configured to inject a fluid through the injection lumen and out of the distal injection opening.

2. The clot treatment system of example 1 wherein the fluid is a contrast agent visible under fluoroscopic imaging.

3. The clot treatment system of example 1 wherein the fluid is filtered blood.

4. The clot treatment system of any one of examples 1-3 wherein the catheter extends along a longitudinal axis, wherein the catheter defines a wall, wherein the wall encloses the aspiration lumen, and wherein the injection lumen extends through the wall along the longitudinal axis.

5. The clot treatment system of example 4 wherein the injection lumen has a circular cross-sectional shape.

6. The clot treatment system of example 4 wherein the injection lumen has a generally U-like shape extending about the longitudinal axis.

7. The clot treatment system of example 6 wherein the injection lumen extends between about 110-140 degrees about the longitudinal axis.

8. The clot treatment system of any one of examples 1-7 wherein the injection lumen comprises multiple parallel lumens.

9. The clot treatment system of any one of examples 1-8 wherein the distal injection opening is positioned proximal to the distal aspiration opening.

10. The clot treatment system of example 9 wherein the distal aspiration opening is coplanar with the distal tip.

11. The clot treatment system of example 10 wherein the aspiration lumen has a first cross-sectional area, and wherein the injection lumen has a second cross-sectional area less than the first cross-sectional area.

12. A method of treating clot material within a blood vessel of a patient, the method comprising:intravascularly positioning a distal tip of a catheter proximate to the clot material within the blood vessel;generating, via an aspiration source, negative pressure within an aspiration lumen of the catheter;determining that the aspiration lumen is occluded;injecting a first fluid through an injection lumen of the catheter separate from the aspiration lumen to visualize that the aspiration lumen is occluded by either a wall of the blood vessel or the clot material;if the aspiration lumen is occluded by the wall of the blood vessel, injecting a second fluid through the injection lumen into the blood vessel and/or proximally retracting the catheter until the aspiration lumen is no longer occluded; andif the aspiration lumen is occluded by the clot material, proximally retracting the catheter and the clot material from within the blood vessel and out of the patient.

13. The method of example 12 wherein the first fluid is the same as the second fluid.

14. The method of example 12 or example 13 wherein the first fluid and the second fluid comprise a contrast fluid visible under fluoroscopic imaging.

15. The method of any one of examples 12-14 wherein the aspiration lumen terminates distally at the distal tip of the catheter, and wherein the injection lumen terminates distally proximal of the distal tip of the catheter.

16. The method of any one of examples 12-15 wherein, if the aspiration lumen is occluded by the wall of the blood vessel, the method further comprises again generating, via the aspiration source, negative pressure within the aspiration lumen of the catheter after the aspiration lumen is no longer occluded.

17. A method of treating clot material within a blood vessel of a patient, the method comprising:intravascularly positioning a distal tip of a catheter proximate to the clot material within the blood vessel;generating, via an aspiration source, negative pressure within an aspiration lumen of the catheter;determining that the aspiration lumen is occluded;injecting a first fluid through an injection lumen of the catheter separate from the aspiration lumen to visualize that the aspiration lumen is occluded by a wall of the blood vessel; andinjecting a second fluid through the injection lumen into the blood vessel and/or proximally retracting the catheter until the aspiration lumen is no longer occluded by the wall of the blood vessel.

18. The method of example 17 wherein the first fluid and the second fluid comprise a contrast fluid visible under fluoroscopic imaging.

19. The method of example 17 or example 18 wherein the method comprises injecting the second fluid through the injection lumen into the blood vessel until the aspiration lumen is no longer occluded by the wall of the blood vessel.

20. The method of any one of examples 17-19 wherein the method comprises proximally retracting the catheter until the aspiration lumen is no longer occluded by the wall of the blood vessel.

21. The method of any one of examples 17-20 wherein the method further comprises again generating, via the aspiration source, negative pressure within the aspiration lumen of the catheter after the aspiration lumen is no longer occluded by the wall of the blood vessel.

22. The method of any one of examples 17-21 wherein the aspiration lumen terminates distally at the distal tip of the catheter, and wherein the injection lumen terminates distally proximal of the distal tip of the catheter.

23. A method of treating clot material within a blood vessel of a patient, the method comprising:intravascularly positioning a distal tip of a catheter proximate to the clot material within the blood vessel;generating, via an aspiration source, negative pressure within an aspiration lumen of the catheter;determining that the aspiration lumen is occluded;injecting a first fluid through an injection lumen of the catheter separate from the aspiration lumen to visualize that the aspiration lumen is occluded by the clot material; andproximally retracting the catheter and the clot material from within the blood vessel and out of the patient.

24. The method of example 23 wherein proximally retracting the catheter and the clot material comprises proximally retracting the catheter and the clot material into the lumen of a funnel catheter and out of the patient.

25. The method of example 23 or example 24 wherein the aspiration lumen terminates distally at the distal tip of the catheter, and wherein the injection lumen terminates distally proximal of the distal tip of the catheter.