CATHETERS HAVING STEERABLE DISTAL PORTIONS, AND ASSOCIATED SYSTEMS AND METHODS

Disclosed herein are clot removal systems including steerable catheters, and associated systems and methods. In some embodiments, a clot removal system includes (i) an aspiration catheter having a proximal region and a distal region and (ii) a handle coupled to the proximal region of the catheter and having an actuator. The distal region of the catheter can include a deflectable member, and the clot removal system can include a pull wire extending between the actuator and the deflectable member. Actuation of the actuator is configured to pull the pull wire to deflect the deflectable member to deflect the distal region relative to the proximal region. The deflection can facilitate steering of the catheter to hard-to-reach (e.g., tortuous) portions of the anatomy of a patient.

TECHNICAL FIELD

The present technology generally relates to clot removal systems including catheters (e.g., large bore aspiration catheters) having a steerable distal portion to, for example, facilitate positioning of the catheter in hard-to-reach regions of the vasculature of a patient.

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 inner 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 removal systems including aspiration catheters having a deflectable/steerable distal portion for improved flexibility through hard-to-reach (e.g., tortuous) vascular anatomy of a patient, and associated systems and methods. In some embodiments, a clot removal system in accordance with embodiments of the present technology includes (i) an aspiration catheter having a proximal region and a distal region and (ii) a handle coupled to the proximal region of the catheter and having an actuator. The distal region of the catheter can include a deflectable member, and the clot removal system can include a pull wire extending between the actuator and the deflectable member. Actuation of the actuator is configured to pull the pull wire to deflect the deflectable member to deflect the distal region relative to the proximal region. The deflection can facilitate steering of the catheter to the hard-to-reach portions of the anatomy of the patient.

In some embodiments, the deflectable member includes a proximal ring, a distal ring, and a tube portion extending between the proximal and distal rings. The proximal ring can include an annular member coupled (e.g., welded) thereto and configured to slidably receive the pull wire. The distal ring can be configured to be fixedly attached (e.g., welded) to the pull wire. The tube portion can include a plurality of openings (e.g., circumferentially extending openings) that define a plurality of ribs. The ribs can flex away from each other when the actuator is actuated to pull the pull wire. In some embodiments, the tube portion further includes a spine extending between the proximal and distal rings and generally aligned with the pull wire.

In some embodiments, the catheter further includes an intermediate region between the proximal and distal regions. The catheter can include a braid of wires extending along the proximal and distal regions, and a coil extending over the braid along the intermediate region.

In some aspects of the present technology, the catheter is configured to be steered to and positioned in difficult-to-reach regions of the anatomy of a patient while still having a relatively large size (e.g., 20 French, 24 French, greater than 24 French). More particularly, the catheter can have an improved torque response and flexibility compared to conventional catheters having the same size. For example, the braid can provide good torque response along the proximal and intermediate regions of the catheter. Additionally, the deflectable region can be configured (e.g., shaped, sized) to be positioned within and steered/flexed into the difficult-to-reach regions of the anatomy. Further, the coil can provide increased hoop strength at the intermediate region while still allowing the catheter to flex. For example, the coil can inhibit or even prevent kinking or other unwanted movement of the catheter when the catheter is aspirated during a clot removal procedure.

Certain details are set forth in the following description and inFIGS. 1-7Cto 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, 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. 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.

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.

FIGS. 1A and 1Bare partially schematic side and isometric views, respectively, of a clot removal system100in accordance with embodiments of the present technology. The clot removal system100can also be referred to as an aspiration assembly, a clot treatment system, and/or a thrombectomy system. Referring toFIGS. 1A and 1Btogether, the clot removal system100includes a tubing assembly110coupled to a catheter120via a handle130. In general, the clot removal system100(i) can include features generally similar or identical to those of the clot removal systems described in detail in U.S. patent application Ser. No. 16/536,185, filed Aug. 8, 2019, and titled “SYSTEM FOR TREATING EMBOLISM AND ASSOCIATED DEVICES AND METHODS,” which is incorporated herein by reference in its entirety, and/or (ii) can be used to treat/remove clot material from a patient (e.g., a human patient) using any of the methods described in detail therein.

Referring toFIG. 1A, the catheter120can include (i) a proximal region or portion121, (ii) an intermediate region122adjacent to and distal of the proximal region121, and (iii) a distal region123adjacent to and distal of the intermediate region122. Referring toFIG. 1B, the distal region123can further include a transition region124, a deflectable region125(e.g., a flexible region, steerable region, deformable region) distal of the transition region124, and a tip region126distal of the deflectable region125. Referring again toFIGS. 1A and 1Btogether, the catheter120further defines a lumen127extending therethrough from the proximal region121to the tip region126. The proximal region121defines a proximal terminus (obscured by the handle130inFIGS. 1A and 1B; e.g., a proximal terminus529shown inFIG. 5A) of the catheter120that can be positioned within the handle130, and the tip region126defines a distal terminus128of the catheter120.

In some embodiments, the proximal region121has a first length, the intermediate region122has a second length less than the first length, and the distal region123has a third length less than the first and second lengths. For example, the first length can be between about 50-100 millimeters (e.g., about 80 millimeters), the second length can be between about 10-50 millimeters (e.g., about 25 millimeters), and the third length can be between about 1.0-10 millimeters (e.g., about 4.2 millimeters). In some embodiments, the transition region124can have a length of between about 0.1-5.0 millimeters (e.g., about 0.6 millimeters), the deflectable region125can have a length of between about 1.0-10 millimeters (e.g., about 3.0 millimeters), and the tip region126can have a length of between about 0.1-5.0 millimeters (e.g., about 0.6 millimeters). In other embodiments, the lengths of one or more of the regions121-126can be different. In some embodiments, the catheter120can have varying flexibilities, shapes, thicknesses, and/or other properties in/along the various regions121-126.

In the illustrated embodiment, the handle130includes and/or is coupled to a valve132. The valve132can include a branch or side port133configured to fluidly couple the lumen127of the catheter120to the tubing assembly110, and can be integral with or coupled to the proximal region121of the catheter120. In some embodiments, the valve132is 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 valve132as various components such as delivery sheaths, pull members, guidewires, interventional devices, other aspiration catheters, and so on are inserted through the valve132to be delivered through the catheter120to a treatment site in a blood vessel. In some embodiments, the valve132can be a valve of the type disclosed in U.S. patent application Ser. No. 16/117,519, filed Aug. 30, 2018, and titled “HEMOSTASIS VALVES AND METHODS OF USE,” which is incorporated herein by reference in its entirety.

In the illustrated embodiment, the tubing assembly110fluidly couples the catheter120to a pressure source102, such as a syringe. The tubing assembly110can include one or more tubing sections112(individually labeled as a first tubing section112aand a second tubing section112b), at least one fluid control device114(e.g., a valve), and at least one connector116(e.g., a Toomey tip connector) for fluidly coupling the tubing assembly110to the pressure source102and/or other suitable components. In some embodiments, the fluid control device114is a stopcock that is fluidly coupled to (i) the side port133of the valve132via the first tubing section112aand (ii) the connector116via the second tubing section112b. The fluid control device114is externally operable by a user to regulate the flow of fluid therethrough and, specifically, from the lumen127of the catheter120to the pressure source102. In some embodiments, the connector116is a quick-release connector (e.g., a quick disconnect fitting) that enables rapid coupling/decoupling of the catheter120and the fluid control device114to/from the pressure source102.

In the illustrated embodiment, the handle130includes a housing134and an actuator136. The actuator136can be operably coupled to the catheter120and movable (e.g., rotatable) relative to the housing134to deflect (e.g., steer, flex) the deflectable region125from (i) a first position (e.g., an unflexed position, an aligned position) shown inFIG. 1Ain which the deflectable region125is generally aligned with the intermediate region122and/or the proximal region121to (ii) a second position (e.g., a flexed position) shown inFIG. 1Bin which the deflectable region125is deflected relative to the intermediate region122and/or the proximal region121. That is, the actuator136can be configured to deflect the deflectable region125away from a longitudinal axis generally aligned with the proximal region121and/or the intermediate region122. In some embodiments, the deflectable region125can have a bend angle Ain the second position (FIG. 1B) of greater than about 30 degrees, greater than about 50 degrees, greater than about 70 degrees, greater than about 90 degrees, or greater. In some embodiments, the bend angle A is about 90 degrees.

FIG. 2is an enlarged, partially cut-away side view of a portion of the proximal region121of the catheter120in accordance with embodiments of the present technology.FIG. 3Ais an enlarged, partially cut-away side view, andFIG. 3Bis an enlarged, partially cut-away isometric view, of a portion of the intermediate region122of the catheter120in accordance with embodiments of the present technology. Referring toFIGS. 1-3Btogether, the catheter120includes an outer sheath240and an inner liner242extending through/defining each of the regions121-126. The outer sheath240is positioned over (e.g., radially outside of) the inner liner242. The outer sheath240can also be referred to as an outer jacket, an outer shaft, or an outer layer, and the inner liner242can also be referred to as an inner layer, an inner sheath, or an inner shaft.

In some embodiments, the outer sheath240can be formed from a plastic material, elastomeric material, and/or thermoplastic elastomer (TPE) material. In some embodiments, the outer sheath240can 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 sheath240can have a varying hardness (e.g., durometer), thickness, flexibility, rigidity, and/or other property in one or more of the different regions121-126. For example, the outer sheath240can have (i) a first hardness along the proximal region121of between about 65 D-75 D (e.g., about 72 D), (ii) a second hardness along the intermediate region122of between about 30 D-40 D (e.g., about 35 D), (iii) a third hardness along the transition region124of between about 50 D-60 D (e.g., about 55 D), (iv) a fourth hardness along the deflectable region of between about 20 D-30 D (e.g., about 25 D), and (v) a fifth hardness along the tip region126of between about 50 D-60 D (e.g., about 55 D). In other embodiments, the outer sheath240can have a different hardness or other property along one or more of the regions121-126.

The inner liner242can be formed of a lubricious material that facilitates the movement (e.g., distal advancement, proximal retraction) of various components through the lumen127, such as delivery sheaths, pull members, guidewires, interventional devices, other aspiration catheters, and the like. In some embodiments, the inner liner242can be formed from a polymer material, a fluoropolymer material (e.g., polytetrafluoroethylene (PTFE)), and/or another material having a high degree of lubricity. In some embodiments, the inner liner242can define a diameter D (FIG. 2) of the lumen127, and the diameter D can be 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 diameter D is about 8 French, about 16 French, about 20 French, or about 24 French. In certain embodiments, the diameter D of the inner liner242is the same in each of the regions121-126while, in other embodiments, the diameter D can vary along one or more of the regions121-126.

The catheter120can further include a braid244extending along the proximal region121and the intermediate region122between the outer sheath240and the inner liner242. In some embodiments, the braid244terminates at or before the distal region123such that the braid244does not extend along the transition region124, the deflectable region125, or the tip region126. In the illustrated embodiment, the catheter120further includes a coil346(FIGS. 3A and 3B) extending at least partially along the intermediate region122between the braid244and the outer sheath240. In some embodiments, the coil346extends only along the intermediate region122and does not extend into the proximal region121or the distal region123.

The braid244can include wires, filaments, threads, sutures, fibers, or the like (collectively “wires248”) that have been woven or otherwise coupled, attached, formed, and/or joined together at a plurality of interstices249. Accordingly, the braid244can also be referred to as a braided structure, a braided filament structure, a braided filament mesh structure, a mesh structure, a mesh filament structure, and the like. In some embodiments, the wires248can comprise metals, polymers, and/or composite materials. In some embodiments, individual ones of the wires248can be rolled flat wires having a cross-sectional dimension of between about 0.0005-0.005 inch (e.g., about 0.002 inch) by about 0.002-0.005 inch (e.g., about 0.0033 inch).

In the illustrated embodiment, the coil346is a single wire wound around the braid244and the inner liner242along the intermediate region122. In other embodiments, the coil346can include more than one wire wound about the braid244. For example, the coil346can include multiple wires wound over one another and/or multiple wires wound to at least partially overlap one another to form a braided or overlapping coil structure on the braid244. In other embodiments, the coil346can be formed directly over the inner liner242, and the braid244can be formed over the coil346. The coil346can be formed from a metallic or other suitably strong material, such as nickel-titanium alloys (e.g. nitinol), platinum, cobalt-chrome alloys, stainless steel, tungsten, and/or titanium.

FIGS. 4A and 4Bare a distally-facing isometric view and an enlarged proximally-facing isometric view, respectively, of a deflectable member450of the deflectable region125of the catheter120in accordance with embodiments of the present technology. The deflectable member450can be positioned between the outer sheath240and the inner liner242(FIGS. 2-3B), which are both omitted inFIGS. 4A and 4Bfor clarity. In the illustrated embodiment, the deflectable member450includes a proximal ring452, a distal ring454, and a tube portion456extending between the proximal ring452and the distal ring454. The deflectable member450can be formed from a flexible metallic material—such as nickel-titanium alloys (e.g. nitinol), platinum, cobalt-chrome alloys, stainless steel, tungsten, and/or titanium—or another suitably strong and flexible material. Similarly, the deflectable member450can be manufactured (e.g., laser cut) as a single integral piece, or one or more of the proximal ring452, the distal ring454, and the tube portion456can be separately manufactured and then coupled (e.g., welded, tack welded, adhered, fastened) together.

FIGS. 4C and 4Dare isometric views of the proximal ring452and the distal ring454, respectively, in accordance with embodiments of the present technology. Referring toFIGS. 4A-4Ctogether, the proximal ring452can include an annular body462having an outer surface461and an inner surface463. An annular member464can be coupled (e.g., welded, tack welded, adhered, fastened) to the inner surface463of the annular member464and can define/include a lumen465. Referring toFIGS. 4A and 4Dtogether, the distal ring454can include an annular body468having an outer surface467and an inner surface469. Referring toFIGS. 4A-4Dtogether, the lumen465of the annular body462is configured to slidably receive a pull wire458(FIG. 4D). The pull wire458can be coupled (e.g., welded, tack welded, adhered, fastened) to the inner surface469of the distal ring454and can extend from the distal ring454to the handle130(FIG. 1), as described in greater detail below with reference toFIGS. 5A and 5B.

Referring again toFIGS. 4A and 4Btogether, the tube portion456can include a plurality of openings451extending partially about a circumference of the tube portion456to define a spine453and a plurality of ribs455. In the illustrated embodiment, the spine453extends generally parallel to a longitudinal axis L (FIG. 4A) of the deflectable member450and is generally aligned with the annular member464and the pull wire458(FIG. 4D). That is, the pull wire458can extend through the tube portion456generally parallel to the spine453. In some embodiments, the openings451are generally elongate openings that extend (i) generally parallel to one another and (ii) circumferentially about the longitudinal axis L such that, for example, the ribs455have a generally similar or identical shape. The openings451and/or the ribs455can all have the same dimensions as shown inFIGS. 4A and 4Bwhile, in other embodiments, some or all of the openings451and/or the ribs455can have different dimensions and/or arrangements about the tube portion456. In some embodiments, the tube portion456can be a laser-cut hypo tube.

Referring toFIGS. 2-4Dtogether, in some embodiments the deflectable member450can be positioned between the outer sheath240and the inner liner242such that (i) the outer sheath240extends over/along the outer surface461of the proximal ring452, an outer surface of the tube portion456, and the outer surface467of the distal ring454and (ii) the inner liner242extends over/along the inner surface463of the proximal ring452, an inner surface of the tube portion456, and the inner surface469of the distal ring454. In some embodiments, some or all of the pull wire458can be coated with PTFE or another suitable material (e.g., a fluoropolymer material). For example, the PTFE material can be omitted where the pull wire458is attached to the distal ring454. The PTFE or other coating material can help inhibit the outer sheath240from adhering to the pull wire458—thereby allowing the pull wire458to be moved relative to the deflectable member450after the outer sheath240is applied thereover.

Referring toFIGS. 1-3Btogether, in some embodiments the transition region124and the tip region126can include only the outer sheath240and the inner liner242. In some embodiments, the transition region124and/or the tip region126can include a marker band (not shown), such as a radiopaque marker configured to facilitate visualization of the position of the catheter120during a medical procedure (e.g., a clot removal procedure) using the catheter120. For example, the transition region124and the tip region126can each include a radiopaque marker to facilitate visualization of the deflectable region125of the catheter120.

Referring toFIGS. 1-4Dtogether, in some embodiments, the catheter120can be formed about a mandrel or other elongate member. For example, the inner liner232can first be positioned about the mandrel. Then, the braid244can be formed (e.g., wound, braided) about the inner liner242around the mandrel (e.g., along the proximal and intermediate regions121,122) and/or the deflectable member450can be positioned about the inner liner242around the mandrel (e.g., along the deflectable region125). Next, the coil346can be wound around the mandrel about the braid244over the intermediate region122. Next, the outer sheath240can be positioned over the inner liner242, the braid244, the coil346, and the deflectable member450, and then heat shrunk or otherwise secured thereto. In some embodiments, the outer sheath240can be fused to the inner liner242, the braid244, the coil346, and/or the deflectable member450to secure these components of the catheter120together.

FIG. 5Ais a partially cross-sectional side view of the handle130and a portion of the proximal region121of the catheter120in accordance with embodiments of the present technology.FIG. 5Bis an enlarged cross-sectional isometric view of a portion of the handle130shown inFIG. 5A. Referring toFIGS. 5A and 5B, together, the housing134defines a proximal chamber570(e.g., a volume, lumen, compartment) and a distal chamber572that can be separated by the actuator136. The valve132can be coupled to the housing134(e.g., a proximal portion of the housing134) and positioned at least partially within the proximal chamber570.

In the illustrated embodiment, the handle130includes a hollow tube member574positioned at least partially within the proximal chamber570. The tube member574can include a proximal end portion571aand a distal end portion571bcoupled to (e.g., secured to) the actuator136. The tube member574can define a lumen573extending between the proximal and distal end portions571a-b, and the tube member574can have a threaded inner surface575extending at least partially along the lumen573. The actuator136can be a rotatable member, such as a wheel, grip wheel, or dial that is rotatable relative to the housing134to rotate the tube member574within the proximal chamber570.

In the illustrated embodiment, the handle130further includes a catheter support or guide576extending at least partially through (i) the distal chamber572, (ii) the actuator136(e.g., through a lumen in the actuator), (iii) the lumen573of the tube member574, and (iv) the proximal chamber570. In some embodiments, the catheter guide576defines a lumen577extending therethrough and includes a proximal flange portion578that can be secured to the housing134. In some embodiments, the catheter guide576is fixed to the housing134such that the catheter guide576does not rotate when the actuator136is actuated to move the tube member574. The proximal region121of the catheter120can extend into the handle130, through the lumen577in the catheter guide576, and to the valve132. The proximal terminus529of the catheter120can be fluidly coupled to the valve132. Accordingly, the catheter120, the catheter guide576, and the tube member574can be coaxially aligned. In other embodiments, the catheter guide576can be omitted.

The handle130can further include a shuttle member580positioned at least partially in the lumen573of the tube member574over the catheter guide576(e.g., over an outer surface thereof). In some embodiments, the shuttle member580is a hollow member slidably positioned over the catheter guide576and movable relative to the catheter120. In the illustrated embodiment, the shuttle member580includes a threaded portion582having a threaded outer surface583and an anchor portion584extending from the threaded portion582. The threaded outer surface583is configured to engage the threaded inner surface575of the tube member574such that, for example, movement of the tube member574drives the shuttle member580to move through the lumen573over the catheter guide576and relative to the catheter120.

In the illustrated embodiment, the pull wire458extends along the catheter120into the handle130where it secured to the anchor portion584of the shuttle member580. More specifically, the pull wire458can extend from the distal ring454of the deflectable member450(FIG. 4D) and through/along the transition, intermediate, and proximal regions124,122,121of the catheter120(FIGS. 1A and 1B) to the handle130. For example, the pull wire458can be routed (i) through a lumen formed in the wall of the catheter120or (ii) simply between the outer sheath240and inner liner242(FIGS. 2-3B). In the illustrated embodiment, the pull wire458exits the catheter120and the catheter guide476(e.g., via openings therein) and enters the distal chamber572. From the distal chamber572, the pull wire458can extend through the actuator136and through the lumen573of the tube member574to the anchor portion584. As best seen inFIG. 5B, in some embodiments the pull wire458can be secured to anchor portion584via a screw581or other fastener. In some embodiments, the handle130can further include a biasing member585, such as a coil spring, coupled to and/or over the pull wire458. The biasing member585can be configured to smooth/distribute tension loads on the pull wire458during operation that might otherwise damage the pull wire458and/or various components of the handle130.

Referring toFIGS. 1A, 1B, and 4A-5Btogether, the deflectable region125(and correspondingly the deflectable member450) is in the first position and the handle130is in a corresponding first position in which the shuttle member580is positioned distally within the lumen473of the tube member574proximate to the actuator136and/or the distal end portion571bof the tube member574. To move the deflectable region125to the second (e.g., bent) position, a user can rotate the actuator136in a first direction to rotate the tube member574. The rotation of the tube member574can drive the shuttle member580to move proximally through the lumen573in a direction toward the proximal end portion571aof the tube member574via the engagement of the threaded outer surface583with the threaded inner surface575. That is, the handle130is configured to translate the rotational movement of the actuator136into linear movement of the shuttle member580. As the shuttle member580moves proximally, the shuttle member580pulls the pull wire458proximally and increases the tension therein. The pull wire458thus moves (e.g., slides) proximally through the lumen465in the annular member464of the deflectable member450and, because the pull wire458is fixedly attached to the distal ring454of the deflectable member450, the pull wire458urges the distal ring454proximally relative to the proximal ring452. This differential force causes the tube portion456of the deflectable member450to bend toward the second position shown inFIG. 1B. More specifically, because the pull wire458is aligned with the spine453of the deflectable member450, the spine453can define an inner radius of the bend while the ribs455flex away from one another, thereby increasing a size of the openings451. To return the deflectable region125from the second position to the first position, the user can rotate the actuator136in a second direction opposite the first direction to translate the shuttle member580distally through the lumen573to decrease the tension in the pull wire458, thereby allowing the deflectable member450to return to the relaxed position shown inFIGS. 4A and 4B.

In other embodiments, the handle130can include other features for moving/driving the shuttle member580through the housing134to tension the pull wire458. For example, the actuator136can be a slider, clip, or other actuator movable relative to the housing134.

Referring toFIGS. 1A-5Btogether, in some aspects of the present technology, the catheter120is configured to be steered to and positioned in difficult-to-reach regions of the anatomy of a patient while still having a relatively large size (e.g., 20 French, 24 French, greater than 24 French). More particularly, the catheter120can have an improved torque response and flexibility compared to conventional catheters having the same size. For example, the braid234can provide good torque response along the proximal and intermediate regions121,122of the catheter120. Moreover, the varying hardness (e.g., distally decreasing hardness) of the outer sheath240can provide (i) good torque response and/or pushability at the proximal region121and (ii) increased flexibility at the intermediate and distal regions122,123. Additionally, the deflectable region125is configured (e.g., shaped, sized) to be positioned within and steered/flexed into the difficult-to-reach regions of the anatomy. Further, the coil346can provide increased hoop strength at the intermediate region122while still allowing the catheter120to flex. For example, the coil346can inhibit or even prevent kinking or other unwanted movement of the catheter120when the lumen127is aspirated during a clot removal procedure.

FIGS. 6A and 6Bare a distally-facing isometric view and a side view, respectively, of a deflectable member650in accordance with additional embodiments of the present technology. The deflectable member650is configured to be positioned in the deflectable region125of the catheter120(FIG. 1) and can include some features generally similar or identical to the deflectable member450described in detail above with reference toFIGS. 4A-4D. For example, in the illustrated embodiment the deflectable member650includes a proximal ring652, a distal ring654, and a tube portion656extending between the proximal ring652and the distal ring654. The proximal ring652includes an annular member664coupled thereto and configured to slidably receive the pull wire458. The pull wire458can extend through the tube portion656and be fixedly secured (e.g., welded) to the distal ring654.

In the illustrated embodiment, the tube portion656includes a plurality of openings651(identified individually as first openings651aand second openings651b) extending partially about a circumference of the tube portion656to define a plurality of ribs655(identified individually as first ribs655aand second ribs655b). In some embodiments, the first openings651aare generally elongate openings that extend (i) generally parallel to one another and (ii) circumferentially about a longitudinal axis M of the deflectable member650such that, for example, the first ribs655ahave a generally similar or identical shape. Similarly, the second openings651bcan each have an elongate tapered shape and can extend (i) generally parallel to one another and (ii) circumferentially about the longitudinal axis M of the deflectable member650such that, for example, the second ribs655bhave a generally similar or identical shape. In the illustrated embodiment, the second ribs655bhave a smaller dimension (e.g. width) in a direction along the longitudinal axis M than the first ribs655a. Accordingly, the second ribs655bcan be relatively more flexible than the first ribs655a.

In some embodiments, the pull wire458can extend over/adjacent to the first ribs655a. Accordingly, referring toFIGS. 5-6Btogether, actuation of the actuator can136pull the pull wire458to urge the distal ring654proximally relative to the proximal ring652. This differential force causes the tube portion656of the deflectable member650to bend such that, for example, a portion of the first ribs655adefine an inner radius of the bend while the second ribs655bflex away from one another, thereby increasing a size of the second openings651b(e.g., and conversely decreasing a size of the first openings651a).

In some embodiments, all or a portion of the deflectable member650can be manufactured as a single integral piece. For example,FIG. 6Cis top view of flat pattern that can be cut to integrally form the proximal ring652and the tube portion656of the deflectable member650in accordance with embodiments of the present technology.FIG. 6Dis an enlarged top view of a portion of the pattern shown inFIG. 6C. Referring toFIGS. 6C and 6Dtogether, the pattern can be laser cut from a single piece of material (e.g., stainless steel), formed to have the three-dimensional tubular shape shown inFIGS. 6A and 6B, and then welded or otherwise adhered together to form the deflectable member650.

FIGS. 7A-7Care side views of a portion of the catheter120of the clot removal system100during a procedure for removing clot material PE (e.g., a pulmonary embolism) from within a blood vessel BV (e.g., a pulmonary blood vessel) of a patient (e.g., a human patient) in accordance with embodiments of the present technology. As noted above, in some embodiments the clot removal procedure illustrated inFIGS. 7A-7Ccan be generally similar or identical to any of the clot removal procedures disclosed in U.S. patent application Ser. No. 16/536,185, filed Aug. 8, 2019, and titled “SYSTEM FOR TREATING EMBOLISM AND ASSOCIATED DEVICES AND METHODS,” which is incorporated herein by reference in its entirety.

With reference toFIGS. 1A-7Atogether, the catheter120can be advanced through the patient toward and/or proximate to the clot material PE within the blood vessel BV (e.g., advanced to a treatment site within the blood vessel BV). In some embodiments, however, the blood vessel BV can include a hard-to-reach (e.g., tortuous) region, such as a region beyond a bend790in the blood vessel BV that can have a relatively small radius of curvature. The region of the blood vessel BV distal of the bend790can be difficult to reach due to the required approach angle, varying anatomy of the blood vessel BV, and/or irregularities due to illness of the patient.

Accordingly, with reference toFIGS. 1A-5B and 7Btogether, the deflectable region125can be moved fully or partially from the first position (FIG. 1A) to the second position (FIG. 1B) before and/or during further advancement of the catheter120toward the clot material PE. More specifically, the user can actuate (e.g., rotate) the actuator136of the handle to pull the pull wire458to deflect the deflectable member450to deflect the deflectable region125, as described in detail above. In some embodiments, the catheter120can be advanced through the blood vessel BV until the distal terminus128of the catheter120is positioned proximate to a proximal portion of the clot material PE. In some embodiments, the position of the distal terminus128can be confirmed or located via visualization of a marker band (not shown; e.g., in/along the tip region126) using fluoroscopy or another imaging procedure (e.g., a radiographic procedure). In other embodiments, the distal terminus128can be positioned at least partially within the clot material PE or distal of the clot material PE.

In some aspects of the present technology, moving the deflectable region125to the second position helps the catheter120flex/bend around the bend790and into the hard-to-reach region of the blood vessel BV distal thereof. In some embodiments, before advancing the catheter120to the position shown inFIG. 7B, the catheter120can be rotated to align the deflectable region125with the bend790. In contrast, conventional catheters of the same size may be too stiff to easily position proximate the clot material PE. For example, such conventional catheters may “rainbow” over the clot material PE by following or tracking along the wall of the blood vessel BV at the outside of the bend790. In addition to the deflectable region125, both (i) the varying hardness of the outer sheath240(FIGS. 2-3B) and (ii) the flexibility of the braid244(FIGS. 2-3B) and the coil346(FIGS. 3B and 3C) can help the catheter120flex through the anatomy of the blood vessel BV to the desired position proximate the clot material PE.

Access to the pulmonary vessels can be achieved through the patient's vasculature, for example, via the femoral vein. In some embodiments, the clot removal system100can include an introducer (e.g., a Y-connector with a hemostasis valve; not shown) that can be partially inserted into the femoral vein. A guidewire (not shown) 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 PE, 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 PE. In other embodiments, the guidewire can be extended to a location just proximal of the clot material PE. After positioning the guidewire, the catheter120can be placed over the guidewire and advanced to the position proximate to the clot material PE as illustrated inFIG. 7B. 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, etc.), 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 sub clavian 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 PE.

With reference toFIGS. 1A, 1B, and 7Ctogether, the pressure source102is configured to generate (e.g., form, create, charge, build-up) a vacuum (e.g., negative pressure) and store the vacuum for subsequent application to the catheter120. For example, after positioning the catheter120proximate the clot material PE, a user can first close the fluid control device114before generating the vacuum in the pressure source102by, for example, withdrawing the plunger of a syringe coupled to the connector116. In this manner, a vacuum is charged within the pressure source102(e.g., a negative pressure is maintained) before the pressure source102is fluidly connected to the lumen127of the catheter120. To aspirate the lumen127of the catheter120, the user can open the fluid control device114to fluidly connect the pressure source102to the catheter120and thereby apply or release the vacuum stored in the pressure source102to the lumen127of the catheter120.

Opening of the fluid control device114instantaneously or nearly instantaneously applies the stored vacuum pressure to the tubing assembly110and the catheter120, thereby generating a suction pulse throughout the catheter120. In particular, the suction is applied at the tip region126of the catheter120to suck/aspirate at least a portion of the clot material PE into the lumen127of the catheter120, as shown inFIG. 7C. In one aspect of the present technology, pre-charging or storing the vacuum in the pressure source102before applying the vacuum to the lumen127of the catheter120is expected to generate greater suction forces and corresponding fluid flow velocities at and/or near the tip region126of the catheter120compared to simply activating the pressure source102while it is fluidly connected to the catheter120.

Sometimes, as shown inFIG. 7C, discharging the vacuum stored in the pressure source to aspirate the lumen127of the catheter120may remove substantially all (e.g., a desired amount) of the clot material PE from the blood vessel BV. That is, a single aspiration pulse may adequately remove the clot material PE from the blood vessel BV. In other embodiments, a portion of the clot material PE may remain in the blood vessel BV. In such instances, the user may wish to again apply vacuum pressure (conduct an “aspiration pass”) to remove all or a portion of the remaining clot material PE in the blood vessel BV. In such instances, the pressure source102can be disconnected from the tubing assembly110and drained (e.g., aspirated clot removal removed) before the pressure source102is reconnected to the tubing assembly110and activated once again. After removing a desired amount of the clot material PE, the catheter120can be withdrawn from the patient.

In some aspects of the present technology, the relatively great flexibility and torquability of the catheter120allow the catheter120to be positioned in difficult-to-reach areas of the blood vessel BV (or elsewhere in the vasculature of the patient) without decreasing the size of the lumen127and while keeping the lumen127of constant diameter throughout. It is expected that the increased size of the lumen127will provide greater suction forces over a smaller period of time (e.g., will provide a larger vacuum impulse). In some embodiments, the greater suction forces can facilitate the removal of clot material from a blood vessel of a patient even where the clot material is strongly lodged or attached within the blood vessel (e.g., a chronic clot). Accordingly, in contrast to conventional catheters, the catheter120can be used to generate greater aspirational forces for improved clot removal in hard-to-reach places of the vasculature. In additional aspects of the present technology, the coil336(FIGS. 3B and 3C) can provide a high hoop strength that inhibits or even prevents kinking or other unwanted movement of the catheter120when the pressure source102is used to generate a suction pulse at the distal region123of the catheter120.

Although described in the context of removing clot material from pulmonary blood vessels, in other embodiments the clot removal system100can be used to remove clot from other locations in the body of the patient. For example, the clot removal system100can used to aspirate or otherwise remove clot material (e.g., stationary or in transit) and/or vegetation from the heart (e.g., the right atrium, tricuspid valve, pulmonary valve), the vena cava, the renal arteries, and so on.

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

1. An aspiration catheter, comprising:a proximal region; anda distal region including a deflectable member, wherein the deflectable member includes—a proximal ring;a distal ring configured to be fixedly attached to a pull wire; anda tube portion extending between the proximal and distal rings, wherein the tube portion includes a plurality of openings extending therethrough to define a plurality of ribs, and wherein the ribs are configured to flex away from each other when the pull wire is pulled proximally.

2. The aspiration guide catheter of example 1 wherein the tube portion includes a spine extending in a direction between the proximal and distal rings, wherein the ribs extend away from the spine, and wherein the spine is configured to extend generally parallel to and over the pull wire.

3. The aspiration catheter of example 1 or example 2 wherein the proximal region and the distal region define a lumen having a diameter of 20 French or greater.

4. The aspiration catheter of any one of examples 1-3, further comprising an intermediate region between the proximal and distal regions, wherein the proximal region and the intermediate region include a braid of wires extending therethrough.

5. The aspiration catheter of example 4 wherein the intermediate region includes a wire coiled around the braid.

6. The aspiration catheter of any one of examples 1-5 wherein the tube portion extends along a longitudinal axis in a relaxed state, and wherein the openings extend circumferentially about the longitudinal axis and generally parallel to one another in the relaxed state.

7. The aspiration catheter of any one of examples 1-6 wherein the proximal ring includes an annular member configured to slidably receive the pull wire therethrough.

8. A clot removal system, comprising:an aspiration catheter including a proximal region and a distal region, wherein the distal region includes a deflectable member;a handle coupled to the proximal region of the aspiration catheter, wherein the handle includes an actuator; anda pull wire extending between the actuator and the deflectable member, wherein actuation of the actuator is configured to pull the pull wire to deflect the deflectable member to deflect the distal region of the aspiration catheter relative to the proximal region.

9. The clot removal system of example 8 wherein the aspiration catheter extends along an axis, and wherein the actuation of the actuator is configured to deflect the distal region of the aspiration catheter away from the axis by about 90 degrees or greater.

10. The clot removal system of example 8 or example 9 wherein the aspiration guide catheter has a size of 20 French or greater.

11. The clot removal system of any one of examples 8-10 wherein the deflectable member has a tubular shape that extends along a longitudinal axis, and wherein the deflectable member includes (a) a spine extending parallel to the longitudinal axis and (b) a plurality of ribs extending from the spine and circumferentially about the longitudinal axis.

12. The clot removal system of example 11 wherein the deflectable member has a distal portion and a proximal portion, and wherein the pull wire is attached to the distal portion of the deflectable member.

13. The clot removal system of example 12 wherein the actuation of the actuator is configured pull the distal portion proximally relative to the proximal portion.

14. The clot removal system of example 12 or example 13 wherein the ribs define a plurality of openings therebetween, and wherein the actuation of the actuator is configured pull the distal portion of the deflectable member proximally relative to the proximal portion to bend the spine and increase a size of the openings.

15. The clot removal system of any one of examples 8-14 wherein the aspiration catheter further includes—an intermediate region between the proximal and distal regions;an inner liner extending through the proximal, intermediate, and distal regions;a braid of wires extending through the proximal and intermediate regions over the inner liner;a wire extending through the intermediate region and coiled around the braid; andan outer liner extending through the proximal, intermediate, and distal regions over the inner liner, the braid, and the wire, wherein the deflectable member is positioned between the inner and outer liners in the distal region.

16. The clot removal system of example 15 wherein—the distal region further includes a proximal transition region, a distal tip region, and a deflectable region between the proximal transition region and the distal tip region;the deflectable member is positioned in the deflectable region;the outer liner has a first hardness in the proximal transition region, a second hardness in the deflectable region, and a third hardness in the distal tip region; andthe second hardness is less than the first hardness and less than the third hardness.

17. A method of removing clot material from a blood vessel, the method comprising:advancing an aspiration catheter through the blood vessel, wherein the aspiration catheter includes a distal portion and a proximal portion;actuating a handle coupled to the aspiration catheter to deflect the distal portion of the aspiration catheter away from a longitudinal axis of the proximal portion;positioning a distal tip of the aspiration catheter proximate to the clot material;activating a pressure source coupled to the aspiration catheter via a fluid control device, while the fluid control device is closed, to generate a vacuum in the pressure source; andopening the fluid control device to apply the vacuum to the aspiration catheter to thereby aspirate at least a portion of the clot material into the aspiration catheter.

18. The method of example 17 wherein actuating the handle to deflect the distal portion of the aspiration catheter includes deflecting the distal portion of the aspiration catheter away from the longitudinal axis in a deflection direction, and wherein the method further comprises rotating the aspiration catheter such that the deflection direction is at least partially aligned with a bend in the blood vessel.

19. The method of example 17 or example 18 wherein the aspiration catheter has a size of 20 French or greater.

20. The method of any one of examples 17-19 wherein the aspiration catheter includes a deflectable member positioned in the distal portion, and wherein actuating the handle includes rotating an actuator of the handle to pull a pull wire coupled to the deflectable portion proximally to deflect the deflectable member to deflect the distal portion of the aspiration catheter.