Aspiration catheter having a grooved inner surface and related systems and methods - Patents.com

Abstract

Disclosed herein are aspiration catheters having a grooved inner surface for removing clot material from a patient's vasculature, and associated systems and methods. In some embodiments, the aspiration catheter can include a proximal end, a distal end, and an inner surface defining a lumen. The inner surface includes at least one groove formed therein and extending from the distal end at least partially toward the proximal end. When clot material is aspirated through the aspiration catheter, the at least one groove can provide a leakage path for the passage of clot material to improve uptake of the clot material through the catheter and reduce clogging.

Description

[Technical field]

[0001] (CROSS REFERENCE TO RELATED APPLICATIONS) This application claims the benefit of U.S. Provisional Patent Application No. 63 / 304,748, entitled "ASPIRATION CATHETERS HAVING GROOVED INNER SURFACES, AND ASSOCIATED SYSTEMS AND METHODS," filed on January 31, 2022, and U.S. Provisional Patent Application No. 63 / 395,586, entitled "ASPIRATION CATHETERS HAVING GROOVED INNER SURFACES, AND ASSOCIATED SYSTEMS AND METHODS," filed on August 5, 2022, each of which is incorporated by reference in its entirety herein.

[0002] FIELD OF THEINVENTION The present technology generally relates to a clot treatment system that includes an aspiration catheter having a grooved or ribbed inner surface to promote increased clot entrapment into the aspiration catheter, reduce clogging of the aspiration catheter, increase / optimize flow rate in the aspiration catheter, and / or improve clot removal through the aspiration catheter. [Background technology]

[0003] Thromboembolism is characterized by the blockage of blood vessels. Thromboembolic disorders such as stroke, pulmonary embolism, heart attack, peripheral thrombosis, and atherosclerosis affect many people. These diseases are major causes of morbidity and mortality.

[0004] When an artery is occluded by a blood clot, tissue ischemia develops. Ischemia progresses to tissue infarction if the occlusion persists. If blood flow is rapidly restored, infarction does not develop or is severely limited. Failure to restore blood flow can lead to loss of limb, angina, myocardial infarction, stroke, and even death.

[0005] In the venous circulation, obstructive 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 vein thrombosis (DVT). DVT typically occurs when there is a tendency for blood to pool (e.g., long distance air travel, immobility, etc.) and for blood clots to form (e.g., cancer, recent surgery such as orthopedic surgery, etc.). DVT causes harm by (1) blocking the drainage of venous blood from the legs, resulting in swelling, ulcers, pain, and infection, and (2) acting as a reservoir for blood clots that travel to other parts of the body, including the heart, lungs, brain (stroke), abdominal organs, and / or extremities.

[0006] In the pulmonary circulation, unwanted substances can cause harm by obstructing the pulmonary arteries, a condition known as pulmonary embolism. If the obstruction is upstream in the main or great pulmonary artery bifurcation, it can severely impair the total blood flow within the lungs and therefore the total blood flow throughout the body, resulting in hypotension and shock. If the obstruction is downstream in the medium pulmonary artery bifurcation from the great pulmonary artery, it can prevent a significant portion of the lung from participating in gas exchange with the blood, resulting in low blood oxygen and a buildup of blood carbon dioxide.

[0007] There are many existing techniques for restoring blood flow through blocked blood vessels. In one common surgical technique, embolectomy, the vessel is incised and a balloon-tipped device (such as a Fogarty catheter) is introduced to the site of the blockage. The balloon is then inflated beyond the clot and used to pull the obstructing material back up to the incision point. The obstructing material is then removed by the surgeon. Although such surgical techniques are useful, exposing the patient to surgery can be traumatic and is best avoided if possible. Furthermore, the use of a Fogarty catheter can be problematic due to the risk that the catheter may damage the inner vessel wall as it is being pulled back.

[0008] Percutaneous methods are also utilized to restore blood flow. A common percutaneous technique is called balloon angioplasty, in which a balloon-tipped catheter is introduced into a blood vessel (e.g., typically through an introducer catheter). The balloon-tipped catheter is then advanced to the point of occlusion and inflated to dilate the stenosis. Although balloon angioplasty is suitable for treating vascular stenosis, it is generally not effective for treating acute thromboembolism, since none of the occlusive material is removed and restenosis occurs after dilation. Another percutaneous technique involves placing a catheter near the clot and injecting streptokinase, urokinase, or other thrombolytic agents to dissolve the clot. Unfortunately, thrombolysis typically takes hours to days to be successful. Furthermore, thrombolytic agents can cause bleeding, and many patients cannot use thrombolytic agents at all.

[0009] Various devices exist for performing thrombectomy or removing other foreign bodies. However, such devices have been found to have structures that are either too complicated, cause trauma to the treated vessel, or lack sufficient retention structures and therefore lack the ability to be properly secured against the vessel and perform poorly. However, many of the devices have very complicated structures that lead to difficulties in manufacturing and quality control, as well as delivery problems when passing through tortuous or small diameter catheters. Less complicated devices may allow users, especially inexperienced users, to clear across the clot, but such devices may not completely capture and / or collect all the clot material. Summary of the Invention [Means for solving the problem]

[0010] The present technology relates generally to an aspiration catheter having a grooved inner surface for removing undesirable material from a patient, such as clot material from the patient's vasculature, and related systems and methods. In some embodiments, the aspiration catheter may include a proximal end, a distal end, and an inner surface defining a lumen. The inner surface includes at least one groove formed therein, the groove extending at least partially between the distal end and the proximal end. When clot material is aspirated through the aspiration catheter, the at least one groove may provide a leak path for the passage of the clot material to improve uptake of the clot material through the catheter and inhibit clogging.

[0011] In some embodiments, the lumen extends about a longitudinal axis and the at least one groove may circumferentially circumferentially around the longitudinal axis between the proximal and distal ends. Thus, the at least one groove may have a spiral / helical shape along the length of the aspiration catheter. In some aspects of the present technology, the spiral / helical shape of the at least one groove may generate a helical flow pattern within the lumen when clot material is aspirated through the aspiration catheter. The helical flow pattern may act to stretch and / or break up the clot material and may increase the rate at which the clot material is entrapped. [Brief description of the drawings]

[0012] Many aspects of the present technology can be better understood with reference to the following drawings. The components in the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the present disclosure. [Figure 1] FIG. 1 is a partially schematic side view of a clot treatment system including a catheter in accordance with an embodiment of the present technology. [Figure 2A] 2A and 2B are an enlarged partial cutaway and a side isometric view, respectively, of a portion of the catheter of the system of FIG. 1 in accordance with an embodiment of the present technology. [Figure 2B]2A and 2B are an enlarged partial cutaway and a side isometric view, respectively, of a portion of the catheter of the system of FIG. 1 in accordance with an embodiment of the present technology. [Figure 3A] 3A and 3B are enlarged isometric and proximal-facing longitudinal views, respectively, of a distal portion of the catheter of FIG. 1 in accordance with an embodiment of the present technology. [Figure 3B] 3A and 3B are enlarged isometric and proximal-facing longitudinal views, respectively, of a distal portion of the catheter of FIG. 1 in accordance with an embodiment of the present technology. [Figure 3C] FIG. 3C is an internal view of a catheter, as viewed from within the lumen of the catheter, in accordance with an embodiment of the technology. [Figure 3D] FIG. 3D is a partially see-through isometric view of a catheter in accordance with an embodiment of the present technology. [Figure 4] FIG. 4 is a partially see-through isometric view of the catheter of FIG. 1 in accordance with an additional embodiment of the present technology. [Diagram 5] FIG. 5 is an internal view of the catheter of FIG. 1, as viewed from within the lumen of the catheter, in accordance with an additional embodiment of the present technology. [Figure 6A] 6A and 6B are enlarged isometric and cross-sectional side views, respectively, of a distal portion of the catheter of FIG. 1 in accordance with an additional embodiment of the present technology. [Figure 6B] 6A and 6B are enlarged isometric and cross-sectional side views, respectively, of a distal portion of the catheter of FIG. 1 in accordance with an additional embodiment of the present technology. [Figure 7A] 7A and 7B are side views of a distal portion of the clot treatment system of FIG. 1 during a procedure to remove clot material from within a patient's blood vessel in accordance with an embodiment of the present technology. [Figure 7B] 7A and 7B are side views of a distal portion of the clot treatment system of FIG. 1 during a procedure to remove clot material from within a patient's blood vessel in accordance with an embodiment of the present technology. [Figure 8A] 8A and 8B are proximally facing longitudinal and enlarged partially see-through side views, respectively, of a distal portion of the catheter of FIG. 1 having clot material entrapped therein, in accordance with an embodiment of the present technology. [Figure 8B] 8A and 8B are proximally facing longitudinal and enlarged partially see-through side views, respectively, of a distal portion of the catheter of FIG. 1 having clot material entrapped therein, in accordance with an embodiment of the present technology. [Figure 9A] 9A and 9B are perspective views of the clot treatment system of FIG. 1 traversing simulated paths to the right and left pulmonary arteries, respectively, in accordance with an embodiment of the present technology. [Figure 9B] 9A and 9B are perspective views of the clot treatment system of FIG. 1 traversing simulated paths to the right and left pulmonary arteries, respectively, in accordance with an embodiment of the present technology. [Figure 9C] Figures 9C and 9D are distally facing longitudinal views of the proximal portion of the catheter of Figure 1 illustrating the flow pattern during aspiration without internal grooves and with the groove arrangement shown in Figures 3A-3D, respectively, as the catheter traverses the simulated path to the right pulmonary artery shown in Figure 9A in accordance with an embodiment of the present technology. [Figure 9D] Figures 9C and 9D are distally facing longitudinal views of the proximal portion of the catheter of Figure 1 illustrating the flow pattern during aspiration without internal grooves and with the groove arrangement shown in Figures 3A-3D, respectively, as the catheter traverses the simulated path to the right pulmonary artery shown in Figure 9A in accordance with an embodiment of the present technology. [Figure 10A] FIG. 10A is a graph of measured flow rate through the catheter of FIG. 1 against the number of revolutions of the internal groove along the length of the catheter for a simulated path to the right pulmonary artery shown in FIG. 9A in accordance with an embodiment of the present technology. [Figure 10B] FIG. 10B is a graph of the corresponding measured time for aspirating an occlusive synthetic clot through a catheter in accordance with an embodiment of the present technology. [Figure 11A] FIG. 11A is a graph of the measured distance traveled by an occlusive synthetic clot versus the number of revolutions of the internal groove along the length of the catheter when the clot is aspirated through the catheter of FIG. 1 for a simulated path to the right pulmonary artery shown in FIG. 9A in accordance with an embodiment of the present technology. [Figure 11B] FIG. 11B is a graph of the corresponding measured clot rates according to an embodiment of the present technology. [Figure 12] FIG. 12 is a graph of the measured maximum force required to move an occlusive synthetic clot through the catheter of FIG. 1 versus the number of revolutions of the internal groove along the length of the catheter as the clot is aspirated through the catheter for a simulated path to the right pulmonary artery shown in FIG. 9A in accordance with an embodiment of the present technology. [Figure 13] FIG. 13 is a longitudinal view of a mandrel from which the catheter of FIG. 1 may be formed in accordance with an embodiment of the present technology. [Figure 14A] 14A and 14B are cross-sectional longitudinal and enlarged isometric views, respectively, of a mandrel upon which the catheter of FIG. 1 may be formed, in accordance with an additional embodiment of the present technology. [Figure 14B] 14A and 14B are cross-sectional longitudinal and enlarged isometric views, respectively, of a mandrel upon which the catheter of FIG. 1 may be formed, in accordance with an additional embodiment of the present technology. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] In order to provide a thorough understanding of various embodiments of the present technology, certain details are set forth in the following description and in FIGS. 1-14B. In other examples, well-known structures, materials, operations, and / or systems often associated with endovascular procedures, clot removal procedures, clot aspiration, catheters, and the like, are not shown or described in detail in the following disclosure to avoid unnecessarily obscuring the description of various embodiments of the present technology. However, one of ordinary skill in the art will recognize that the present technology may be practiced without one or more of the details described herein and / or with other structures, methods, components, and the like. Furthermore, although many of the devices and systems are described herein in the context of removing and / or treating clot material, the present technology may be used to remove and / or treat other undesirable material in addition to or as an alternative to clot material, such as thrombus, emboli, plaque, intimal hyperplasia, post-thrombotic scar tissue, and the like. Thus, the terms "clot" and "clot material" as used herein may refer to any of the aforementioned materials and / or the like.

[0014] The terms used below should be interpreted in their broadest reasonable manner, even when used in conjunction with the detailed description of specific examples of embodiments of the present technology. In fact, certain terms may even be emphasized below. However, any terms intended to be interpreted in any limited manner are expressly and specifically defined as such in this detailed description section.

[0015] The accompanying figures depict embodiments of the present technology and are not intended to limit its scope unless expressly indicated. The sizes of the various depicted elements are not necessarily drawn to scale, and these various elements may be enlarged to improve legibility. Details of components may be abstracted in the figures to exclude details such as the location of components and specific precise connections between such components when such details are not necessary for a complete understanding of how to create and use the present technology. Many of the details, dimensions, angles, and other features shown in the figures are merely illustrative of certain embodiments of the present disclosure. Thus, other embodiments may have other details, dimensions, angles, and features without departing from the present technology. However, those skilled in the art will appreciate that further embodiments of the present technology may be practiced without some of the details described below.

[0016] With respect to the terms "distal" and "proximal" within this description, unless otherwise specified, these terms may refer to the relative location of portions of the catheter subsystem with respect to an operator and / or a location within the vasculature. Also, as used herein, designations such as "rear," "forward," "upper," "lower," etc. are not meant to limit the referenced components to a particular orientation. It will be understood that such designations refer to the orientation of the referenced components as illustrated in the figures. The systems of the present technology may be used in any orientation suitable to the user.

[0017] The headings provided herein are for convenience only and are not to be construed as limiting the subject matter disclosed.

[0018] I. SELECTED EMBODIMENTS OF THE CLOMATIC TREATMENT SYSTEM 1 is a partial schematic side view of a clot treatment system 100 in accordance with an embodiment of the present technology. The clot treatment system 100 may also be referred to as an aspiration assembly, a clot removal system, a thrombectomy system, etc. Although referred to as a clot treatment system and generally described in the context of removing clot material from a patient's vasculature, the system 100 may be used to treat and / or remove other undesirable material from a patient's vasculature, body conduits, and / or other lumens. For example, the system 100 may be used to treat and / or remove emboli, foreign bodies, wart formations, and other material from within a patient's vasculature, gallstones from a gallbladder, and / or other material from other body lumens.

[0019] In the illustrated embodiment, the clot treatment system 100 includes a tubing assembly 110 fluidly connected via a valve 102 to a catheter 120. The catheter 120 may be referred to as an aspiration catheter, a guide catheter, an aspiration guide catheter, or the like. In general, the clot treatment system 100 may (i) include features generally similar or identical to those described in detail in U.S. Patent Application No. 16 / 536,185, entitled "SYSTEM FOR TREATING EMBOLISM AND ASSOCIATED DEVICES AND METHODS," filed August 8, 2019, which is incorporated by reference herein in its entirety, and / or (ii) be used to treat / remove clot material from a patient (e.g., a human patient) using any of the methods described in detail therein.

[0020] In the illustrated embodiment, the catheter 120 includes a proximal region or portion 122 and a distal region or portion 124 adjacent and distal to the proximal portion 122. The catheter 120 further defines a lumen 121 extending completely therethrough from the proximal portion 122 to a distal tip portion 124. The proximal portion 122 defines a proximal end 123 of the catheter 120, and the distal portion 124 defines a distal tip or end 125 of the catheter 120. In the illustrated embodiment, the distal portion 124 includes a marker band 126, such as a radiopaque marker, configured to facilitate visualization of the location of the catheter 120 during a medical procedure (e.g., a clot removal procedure) using the catheter 120. In some embodiments, the catheter 120 can have a length L of about 20 to 50 inches, about 30 to 40 inches, about 35 inches, or the like.

[0021] The valve 102 is fluidly coupled to a lumen 121 of the catheter 120 and may be integral with or coupled to a proximal portion 122 of the catheter 120. In some embodiments, the valve 102 is a hemostatic valve configured to maintain hemostasis during a clot removal procedure by inhibiting or preventing proximal fluid flow through the valve 102 as various components, such as delivery sheaths, tensioning members, guidewires, interventional devices, other aspiration catheters, etc., are inserted through the valve 102 and delivered to a treatment site in a blood vessel through the catheter 120. The valve 102 includes a bifurcation or side port 104 configured to fluidly couple the lumen 121 of the catheter 120 to the tubing assembly 110. In some embodiments, the valve 102 may be a valve of the type disclosed in U.S. patent application Ser. No. 16 / 117,519, filed Aug. 30, 2018, entitled "HEMOSTASIS VALVES AND METHODS OF USE," the entirety of which is incorporated herein by reference.

[0022] In the illustrated embodiment, the tubing assembly 110 fluidly connects the catheter 120 to a pressure source 106, such as a syringe (e.g., an automatic pressure locking syringe). The tubing assembly 110 may include (i) one or more tubing sections 112 (individually identified as a first tubing section 112a and a second tubing section 112b), (ii) at least one fluid control device 114 (e.g., a valve), and (iii) at least one connector 116 (e.g., a Toomey tip connector) for fluidly connecting the tubing assembly 110 to the pressure source 106 and / or other suitable components. In some embodiments, the fluid control device 114 is a stopcock that is fluidly connected (i) to the side port 104 of the valve 102 via the first tubing section 112a and (ii) to the connector 116 via the second tubing section 112b. The fluid control device 114 is externally operable by a user to regulate the flow of fluid therethrough, specifically from the lumen 121 of the catheter 120 to the pressure source 106. For example, the fluid control device 114 can be actuated to fluidly connect and disconnect the pressure source 106 from the lumen 121 of the catheter 120. In some embodiments, the connector 116 is a quick release connector (e.g., a quick disconnect fitting) that enables rapid coupling / disconnection of the catheter 120 and the fluid control device 114 to / from the pressure source 106.

[0023] 2A and 2B are enlarged partial cutaway side and isometric views, respectively, of a portion of the catheter 120 of FIG. 1 in accordance with an embodiment of the present technology. Referring together to FIGS. 2A and 2B, the catheter 120 includes an outer sheath 230 and an inner liner 232. The outer sheath 230 is positioned over (e.g., radially outward of) the inner liner 232. The outer sheath 230 may also be referred to as an outer jacket, outer shaft, or outer layer, and the inner liner 232 may also be referred to as an inner layer, inner sheath, or inner shaft. In the illustrated embodiment, the catheter 120 further includes (i) a braid 234 extending between the outer sheath 230 and the inner liner 232, and (ii) a coil 236 extending between the outer sheath 230 and the braid 234. In some embodiments, the braid 234 and the coil 236 extend along the entire length L (FIG. 1) of the catheter 120. In some embodiments, the inner liner 232 may be omitted, but the outer sheath 230 and / or another component of the catheter 120 may define the inner surface of the catheter 120.

[0024] In some embodiments, the outer sheath 230 is formed from a plastic material, an elastomeric material, and / or a thermoplastic elastomer (TPE) material. For example, the outer sheath 230 may be formed from a TPE manufactured by Arkema SA (Colombes, France) (e.g., TPE manufactured under the trade name "Pebax"). The inner liner 232 defines the lumen 121 and may be formed from a lubricious material that facilitates movement (e.g., distal advancement, proximal retraction) of various components through the lumen 121, such as agglomeration materials, delivery sheaths, tensioning members, guidewires, interventional devices, other aspiration catheters, etc. In some embodiments, the inner liner 232 is formed from a polymeric material, a fluoropolymer material (e.g., polytetrafluoroethylene (PTFE)), and / or another material with a high degree of lubricity. In some embodiments, the inner liner 232 can have a diameter D (FIG. 2) of about 0.2 to 0.5 inches (e.g., about 0.270 inches), greater than about 10 French, greater than about 16 French, greater than about 20 French, greater than about 24 French, or more. In some embodiments, the diameter D is about 20 French or about 24 French.

[0025] Braid 234 may include wires, filaments, threads, sutures, fibers, etc. (collectively "wires 238") woven together or otherwise bonded, attached, formed, and / or joined at a plurality of interstices 239. Thus, braid 234 may also be referred to as a braided structure, braided filament structure, braided filament mesh structure, mesh structure, mesh filament structure, etc. Wires 238 may be formed from metals, polymers, and / or composite materials. In some embodiments, each of wires 238 is a rolled flat wire having a cross-sectional dimension of about 0.001-0.005 inches (e.g., about 0.002 inches) by about 0.002-0.005 inches (e.g., about 0.0033 inches).

[0026] The coil 236 may include a single wire wound around the braid 234 and the inner liner 232. In other embodiments, the coil 236 includes two or more wires wound around the braid 234 and / or the inner liner 232. For example, the coil 236 may include multiple wires wound on top of each other and / or multiple wires wound to at least partially overlap each other to form a braided or overlapping coil structure on the braid 234 and / or the inner liner 232. The coil 236 may be formed from a metal or other suitably strong material, such as a nickel-titanium alloy (e.g., Nitinol), platinum, cobalt-chromium alloy, stainless steel, tungsten, and / or titanium.

[0027] In some embodiments, the structure of the catheter 120 may be selected / modified to provide desired flexibility, strength, steerability, torque response, pushability, hoop strength, and / or other properties. For example, in some embodiments, the braid 234 and the coil 236 may extend through different regions of the catheter 120 (e.g., the proximal portion 122, the distal portion 124, an intermediate region therebetween, etc.) and / or may only partially overlap. For example, the coil 236 may extend only through the distal region of the catheter 120 to inhibit or prevent kinking or other undesirable movement of the catheter 120 when the lumen 121 is aspirated during a clot removal procedure. Similarly, the hardness, thickness, and / or the like of the outer sheath 230 and the inner liner 232 may vary in different regions of the catheter 120. For example, the outer sheath 230 and / or the inner liner 232 may be (i) relatively stiffer and / or thicker at the proximal portion 122 (FIG. 1) of the catheter 120 to provide good torque response, pushability, and / or maneuverability for the catheter 120, and (ii) relatively softer and / or thinner at the distal portion 124 (FIG. 1) to enable the catheter 120 to be steered and positioned in hard-to-reach areas of the patient's anatomy (e.g., venous anatomy) while still having a relatively large size (e.g., 20 French, 24 French, greater than 24 French).In some embodiments, the catheter 120 may include certain features that are at least generally similar in structure and function, or identical in structure and function, to those of the catheters disclosed in (i) U.S. Patent Application Publication No. 17 / 529,018, filed November 17, 2021, entitled "CATHETERS HAVING SHAPED DISTAL PORTIONS, AND ASSOCIATED SYSTEMS AND METHODS," and / or (ii) U.S. Patent Application Publication No. 17 / 529,064, filed November 17, 2021, entitled "CATHETERS HAVING STEERABLE DISTAL PORTIONS, AND ASSOCIATED SYSTEMS AND METHODS," each of which is incorporated herein by reference in its entirety.

[0028] II. SELECTED EMBODIMENTS OF THE SLUTED ASPIRATION CATHETER In some embodiments, the catheter 120 may include grooves on its inner surface that are configured (e.g., sized and shaped) to improve the efficiency / effectiveness of clot aspiration by the catheter 120 during a clot treatment procedure. Figures 3A and 3B, for example, are close-up isometric and proximal-facing longitudinal views, respectively, of a distal portion 124 (e.g., inlet) of the catheter 120, in accordance with an embodiment of the present technology. Figure 3C is an internal view of the catheter 120 as viewed from within the lumen 121, in accordance with an embodiment of the present technology. And, Figure 3D is a partially see-through isometric view of the catheter 120, in accordance with an embodiment of the present technology.

[0029] 3A-3C together, the catheter 120 includes an inner surface 340 that defines the lumen 121, and a plurality of grooves 342 (which may also be referred to as microchannels, microgrooves, channels, trenches, cuts, gutters, slits, etc.) formed along / in the inner surface 340. In some embodiments, the grooves 342 are formed in the inner liner 232 (FIGS. 2A and 2B). In the illustrated embodiment, the grooves 342 are identical, and the catheter 120 includes 16 grooves 342 equally spaced around the circumference of the inner surface 340, equally spaced circumferentially around the longitudinal axis X of the catheter 120 (FIG. 3D) that extends through the lumen 121. The grooves 342 may each have a rectangular cross-sectional shape, as shown in FIGS. 3A and 3B, or the grooves 342 may each have a curved (e.g., semicircular) shape, as shown in FIG. 3C. In other embodiments, grooves 342 can have other cross-sectional shapes (e.g., rectilinear, polygonal, irregular) and / or different ones of grooves 342 can have different cross-sectional shapes. In some embodiments, grooves 342 have a thickness or depth D (FIG. 3B) of about 0.003-0.100 inches (e.g., about 0.005-0.050 inches, about 0.005-0.0010 inches) and a width W (FIG. 3B) of about 0.005-0.20 inches (e.g., about 0.010-0.015 inches).

[0030] 3D, in the illustrated embodiment, each of the grooves 342 (i) extends along the entire length L of the catheter 120 between the proximal end 123 and the distal end 125, and (ii) extends circumferentially about the longitudinal axis X along the length L of the catheter 120. That is, the grooves 342 may orbit around the longitudinal axis L to form a spiral or helical pattern. In the illustrated embodiment, each of the grooves 342 orbits around the longitudinal axis X four complete revolutions along the length L of the catheter 120. Thus, in some aspects of the present technology, the grooves 342 form a rib pattern on the inner surface 340 (FIGS. 3A-3C) of the catheter 120. In some embodiments, the length L can be about 36 inches such that the catheter 120 has about 0.14 turns per inch (e.g., 0.1380 turns per inch, about 0.10-0.20 turns per inch, about 0.13-0.16 turns per inch).

[0031] 3A-3D together, in other embodiments, the placement of the grooves 342 may be varied based on, for example, a particular application of the catheter 120 (e.g., a particular clot removal procedure to be performed with the catheter 120) and / or a desired aspiration flow pattern. For example, (i) the number of grooves 342, (ii) the number of turns that the grooves 342 traverse along the length L of the catheter 120, (iii) the cross-sectional shape of the grooves 342, (iv) the width W and / or depth D of the grooves 342, (v) the extent of the grooves 342 along the longitudinal axis X, etc. In some embodiments, the catheter 120 may include 1-20 or more grooves 342, but the grooves 342 may traverse 0-20 turns along the length L of the catheter 120.

[0032] For example, Figure 4 is a partially see-through isometric view of a catheter 120 in accordance with additional embodiments of the present technology. In the illustrated embodiment, the catheter 120 includes eight grooves 342 equally spaced circumferentially about the longitudinal axis X and extending along the entire length L of the catheter 120 between the proximal end 123 and the distal end 125. Further, each of the grooves 342 completes two revolutions around the longitudinal axis X along the length L of the catheter 120. In some embodiments, the length L can be about 36 inches such that the catheter 120 has about 0.053 revolutions per inch (e.g., 0.0526 revolutions per inch, about 0.02-0.09 revolutions per inch, about 0.04-0.07 revolutions per inch).

[0033] For example, Figure 5 is an internal view of catheter 120 as viewed from within lumen 121, in accordance with an additional embodiment of the present technology. In the illustrated embodiment, catheter 120 includes 16 grooves 342 that extend generally parallel to longitudinal axis X (Figure 3D, extending into the page of Figure 5). That is, grooves 342 do not wrap circumferentially around axis X along the length of catheter 120 (e.g., grooves 342 traverse at 0 turns per inch).

[0034] For example, Figures 6A and 6B are enlarged isometric and enlarged cross-sectional side views, respectively, of the distal portion 124 of the catheter 120, according to additional embodiments of the present technology. Referring together to Figures 6A and 6B, in the illustrated embodiment, the catheter 120 includes a single one of the grooves 342 that extends only partially from the distal end 125 toward the proximal end 123 (Figure 1) of the catheter 120. That is, the groove 342 does not extend along the entire length L (Figure 1) of the catheter 120, but extends only partially through the distal portion 124. Furthermore, in the illustrated embodiment, the groove 342 extends circumferentially (e.g., helically) six times around the longitudinal axis X (Figure 6A) before terminating at the proximal end portion. In other embodiments, the groove 342 may make more or fewer revolutions around the longitudinal axis X. In some embodiments, the depth D (FIG. 3B) of groove 342 is about 0.010-0.015 inches and the width W (FIG. 3B) is about 0.120-0.145 inches. As described in more detail below with reference to FIG. 8B, groove 342 can be configured (e.g., shaped and / or sized) to generate a spiral flow pattern within lumen 121 when catheter 120 is aspirated as indicated by arrow H (which spirals / circumnavigates around lumen 121) in FIG. 6A.

[0035] 3A-6B together, in other embodiments, the grooves 342 need not extend from the distal end 124 of the catheter 120, but instead may begin along an intermediate portion of the catheter 120, between the proximal end 123 and the distal end 125. That is, the grooves 342 may be spaced apart from the distal end 125 and need not extend along the entire length L (FIG. 1) of the catheter 120. Additionally, the grooves 342 may be equally spaced apart relative to one another, or may be spaced apart at various distances relative to one another.

[0036] III. SELECTED EMBODIMENTS OF THE CLOMATIC TREATMENT METHOD 7A and 7B are side views of the distal portion 124 of the catheter 120 of the clot treatment system 100 of FIG. 1 during a procedure for removing clot material C (e.g., a pulmonary embolism) from within a blood vessel BV (e.g., a pulmonary vessel) of a patient (e.g., a human patient) in accordance with an embodiment of the present technology. As mentioned above, in some embodiments, the clot removal procedure illustrated in FIG. 7A and 7B may be generally similar or identical to any of the clot removal procedures disclosed in U.S. Patent Application No. 16 / 536,185, entitled "SYSTEM FOR TREATING EMBOLISM AND ASSOCIATED DEVICES AND METHODS," filed on August 8, 2019, which is incorporated herein by reference in its entirety.

[0037] 1 and 7A together, the catheter 120 may be advanced through the patient and adjacent to the blood vessel BV and the clot material C (e.g., advanced to a treatment site within the blood vessel BV). In some embodiments, the catheter 120 may be advanced through the blood vessel BV until a distal end 125 of the catheter 120 is positioned adjacent to a proximal portion of the clot material C. In some embodiments, the location of the distal end 125 may be confirmed or located via visualization of the marker band 126 using fluoroscopy or another imaging procedure (e.g., a radiological procedure). In other embodiments, the distal end 125 may be positioned at least partially within or distal to the clot material C.

[0038] Access to the pulmonary blood vessels may be achieved through the patient's vascular system, for example, via the femoral vein. In some embodiments, the clot treatment system 100 may include an introducer (e.g., a Y-connector with a hemostatic valve, not shown), which may be partially inserted into the femoral vein. A guidewire (not shown) may be guided through the introducer into the femoral vein 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 C, the guidewire may be guided into one or more of the branches of the right and / or left pulmonary arteries. In some embodiments, the guidewire may extend entirely or partially through the clot material C. In other embodiments, the guidewire may extend to a position just proximal to the clot material C. After positioning the guidewire, a dilator and catheter 120 may be placed over the guidewire and advanced to a position adjacent to the clot material C, as shown in FIG. 7A. The dilator may then be withdrawn proximally through the lumen 121 of the catheter 120. In some embodiments, the guidewire may then be withdrawn, while in other embodiments, the guidewire may remain and be used to guide other catheters (e.g., delivery catheters, additional aspiration guide catheters), interventional devices, etc. to the treatment site. However, it will be understood that other access locations to the patient's venous circulation are possible and consistent with the present technology. For example, the user may gain access through the jugular vein, subclavian vein, brachial vein, or any other vein that connects or ultimately leads to the superior vena cava. Using other blood vessels closer to the right atrium of the patient's heart may also be advantageous as it shortens the length of equipment required to reach the clot material C.

[0039] 1 and 7B, the pressure source 106 is configured to generate (e.g., form, create, fill, accumulate) a vacuum (e.g., a negative relative pressure) and accumulate the vacuum for subsequent application to the catheter 120. For example, after positioning the catheter 120 in proximity to the clot material C, the user may first close the fluid control device 114 before generating a vacuum in the pressure source 106, for example, by pulling back on a plunger of a syringe connected to the connector 116. In this manner, a vacuum is built up (e.g., a negative pressure is maintained) in the pressure source 106 before the pressure source 106 is fluidly connected to the lumen 121 of the catheter 120. To aspirate the lumen 121 of the catheter 120, the user may open the fluid control device 114 to fluidly connect the pressure source 106 to the catheter 120, thereby applying or releasing the vacuum accumulated in the pressure source 106 to the lumen 121 of the catheter 120.

[0040] The release of the fluid control device 114 applies the accumulated vacuum pressure instantaneously or near instantaneously to the tubing assembly 110 and the catheter 120, thereby generating a suction pulse throughout the catheter 120. In particular, suction is applied to the distal portion 124 of the catheter 120 to suck / aspirate / draw at least a portion of the clot material C into the lumen 121 of the catheter 120, as shown in FIG. 7B. In one aspect of the present technology, pre-charging or accumulating vacuum in the pressure source 106 prior to applying vacuum to the lumen 121 of the catheter 120 is expected to generate a greater suction force and corresponding fluid flow rate at and / or near the distal end 125 of the catheter 120, as compared to simply activating the pressure source 106 while fluidly connected to the catheter 120. The vacuum pressure may act to draw the clot material C along the length of the catheter 120, through the side port 104, through the tubing assembly 110, and into the pressure source 106.

[0041] At times, as shown in FIG. 7B, releasing the vacuum stored in the pressure source to aspirate the lumen 121 of the catheter 120 may remove substantially all (e.g., a desired amount) of the clot material C from the blood vessel BV. That is, a single suction pulse may adequately remove the clot material C from the blood vessel BV. In other embodiments, a portion of the clot material C may remain within the blood vessel BV. In such cases, the user may wish to reapply vacuum pressure (performing another "suction pass") to remove all or a portion of the remaining clot material C within the blood vessel BV. In such cases, the pressure source 106 may be disconnected from the tubing assembly 110 and vented (e.g., aspirated clot removal removed) before the pressure source 106 is reconnected to the tubing assembly 110 and activated again. After removing the desired amount of clot material C, the catheter 120 may be retracted from the patient.

[0042] However, sometimes, clot material C may become lodged and stuck within the lumen 121 of the catheter 120 and / or around the distal end 125 of the catheter 120 (e.g., forming a "lollipop" around the distal end 125). Clearing such a clog may require (i) performing additional suction passes, (ii) removing the entire catheter 120 from the patient and then reinserting the same or a different catheter 120 for another suction pass, and / or (iii) inserting additional clot removal elements through the catheter 120 to mechanically break up and remove the clog. Such techniques for clearing clogs may increase the complexity and time of the clot removal technique.

[0043] In some aspects of the present technology, the grooves 342 (FIGS. 3A-6B) of the catheter 120 may facilitate improved uptake / aspiration of clot material C into and through the catheter 120, thereby reducing clogging, as compared to, for example, conventional catheters having non-grooved inner surfaces. FIGs. 8A and 8B, for example, are proximally facing longitudinal and enlarged partially see-through side views, respectively, of a distal portion 124 (e.g., inlet) of a catheter 120 with clot material C disposed therein, in accordance with an embodiment of the present technology. In the illustrated embodiment, the catheter 120 includes an array of grooves 342 as shown in FIGs. 3A-3D.

[0044] 8A , some or all of the grooves 342 may create fluid paths (e.g., leak paths, microfluidic paths, microleak paths) around the clot material C. These fluid paths may inhibit or prevent the clot material C from clogging the lumen 121 and causing cavitation within the pressure source 106 by keeping blood flowing generally proximally through the catheter 120 via the grooves 342 during suction. This movement of blood through the grooves 342 may help draw the clot material C further proximally into and through the lumen 121 of the catheter 120. Similarly, the grooves 342 may also reduce the area of ​​the inner surface 340 that contacts the clot material C, thereby reducing friction between the clot material C and the catheter 120, and ultimately reducing the suction force required to move the clot material C proximally through the entire length of the catheter 120.

[0045] 8B, the ribbing pattern on the grooves 342 (e.g., circumferentially around the longitudinal axis of the catheter 120) may create a spiral flow pattern inside the lumen 121 of the catheter 120 during aspiration, as shown by arrow H. In some aspects of the present technology, the spiral flow pattern may help to keep the faster moving blood through the lumen 121 moving proximally near the inner surface 340 while maintaining the slower moving clot material C toward the center of the lumen 121. The outer "layer" of blood near the inner surface 340 may create a fluid buffer between the clot material C and the inner surface 340 of the catheter 120 that facilitates more efficient and reliable transport of the clot material C down the entire length of the catheter 120 and into the pressure source 106 (FIG. 1). More specifically, the helical flow of blood may (i) apply an axial force to the clot material C that draws the clot material C in a proximal direction, as indicated by arrow P, via suction on the clot, and (ii) apply a twisting force to the clot material C, as indicated by arrow H. These forces may apply shear and twisting stresses to the clot material C that act to deform (e.g., stretch) and / or break up the clot material C within the lumen 121 in a manner such that laminar and / or non-helical flow does not occur. This may further reduce the area of ​​the inner surface 340 in contact with the clot material C, thereby reducing friction between the clot material C and the catheter 120. The reduced friction and / or deformation of the clot material C may aid in the movement of the clot material C through the lumen 121 without clogging the lumen 121.

[0046] IV. SELECTED EXAMPLES OF PERFORMANCE AND RELATED OPTIMIZATIONS OF EMBODIMENTS OF THE PRESENT TECHNOLOGY 3A-6B together, as discussed above, the placement of the grooves 342 may be varied to provide different aspiration flow patterns, flow rates, etc. It is generally expected that, for example, increasing the number of grooves 342 will improve / enhance the axial flow path through the entrapped clot to the point that the grooves 342 are too small to provide an efficient leakage path through the entrapped clot material. Similarly, increasing the depth D of the grooves 342 will improve the helical flow pattern at the expense of increasing the wall thickness of the catheter 120 in which the grooves 342 are formed (e.g., the thickness of the inner liner 232 shown in FIGS. 2A and 2B). For example, it is expected that a significant increase in the depth D will require a corresponding increase in the overall thickness of the inner liner 232 (e.g., an increase in the thickness of the inner liner 232 radially outward of the grooves 342, i.e., outside or behind the grooves 342) to maintain the integrity of the inner liner 232. Increasing the wall thickness of the catheter 120 may decrease the flexibility of the catheter 120. Thus, for example, grooves 342 may be relatively deeper for applications in which catheter 120 does not need to be very flexible (e.g., a clot removal procedure in a non-tortuous anatomical structure), while grooves 342 may be relatively shallower for applications in which it is advantageous for catheter 120 to be very flexible (e.g., a clot removal procedure in a tortuous anatomical structure such as the pulmonary artery).

[0047] Similarly, it is also expected that increasing the number of turns of the grooves 342 (if the grooves 342 are raftered along the length L of the catheter 120) will (i) improve the helical flow pattern within the catheter 120, thereby increasing the twisting forces that act to lengthen and break up entrapped clot material, while (ii) decreasing the volumetric flow rate within the catheter 120 by increasing the length that blood must travel through the catheter 120. However, when the catheter 120 traverses a tortuous path, the linear / laminar flow provided by a catheter without grooves or with straight (e.g., non-raftered) grooves may impede flow as the flow must change its trajectory along the length of the catheter. In some aspects of the present technology, the raftered arrangement of the grooves 342 may improve the flow pattern and / or volumetric flow rate of the catheter 120 in tortuous anatomy, as the blood flow does not have to change its trajectory as much through the tortuous path of the catheter 120.

[0048] More specifically, for example, Figures 9A and 9B are perspective views of the clot treatment system 100 traversing simulated pathways to the right pulmonary artery RPA and the left pulmonary artery LPA, respectively, in accordance with an embodiment of the present technology. With joint reference to Figures 9A and 9B, the pathway to the right pulmonary artery RPA may be more tortuous than the pathway to the left pulmonary artery LPA. More specifically, in the illustrated embodiment, the pathway to the right pulmonary artery RPA has a tortuosity defined as the amount of curvature of the catheter 120 divided by the length L of the catheter 120 (Figure 1) of about 1.40, and the pathway to the left pulmonary artery LPA has a tortuosity of about 1.06.

[0049] 9C and 9D are longitudinal views facing distally of the proximal portion 122 (e.g., outlet) of the catheter 120 showing flow patterns during aspiration without any of the grooves 342 and with the arrangement of grooves 342 shown in FIGS. 3A-3D, respectively, as the catheter 120 traverses a simulated path to the right pulmonary artery RPA shown in FIG. 9A, in accordance with an embodiment of the present technology. Referring together to FIGS. 9C and 9D, in both embodiments, the fastest flow is toward the center of the lumen 121. However, the flow pattern produced by the catheter 120 without the grooves 342 is much less uniform than the flow pattern produced by the catheter 120 with the grooves 342. In some aspects of the present technology, the non-uniform flow pattern shown in FIG. 9C traverses the catheter lumen 121 even more slowly than the more uniform flow pattern shown in FIG. 9D, reducing the volumetric flow rate of the catheter 120 and the efficiency with which the catheter 120 can pick up clot material.

[0050] In some aspects of the present technology, the number of turns (and / or number of turns per unit length) that the groove 342 traverses the length L of the catheter 120 can affect the flow rate and efficiency of clot aspiration through the catheter 120. For example, FIG. 10A is a graph of the measured flow rate through the catheter 120 versus the number of turns of the groove 342 along the length of the catheter 120 for a simulated path to the right pulmonary artery shown in FIG. 9A in accordance with an embodiment of the present technology. The graph shows a plot for the average flow rate when the catheter 120 has a size of 24 French and a length of approximately 36 inches. FIG. 10B is a graph of the corresponding measured time to aspirate an obstructing synthetic clot through the catheter 120 in accordance with an embodiment of the present technology. The graph in FIG. 10B shows a plot of a synthetic clot formed of silicone type 27A and having a spherical shape with a diameter larger than the diameter of the catheter 120 at 0.28 inches. 10A and 10B together, when the catheter 120 was tested with 5 turns (e.g., about 0.14 turns / inch), flow rate was maximized and corresponding suction time was minimized as opposed to having no grooves (e.g., 0 turns / inch) or grooves with 1 or 10 turns (e.g., about 0.03 or 0.28 turns / inch).

[0051] Similarly, Figure 11A is a graph of the measured distance traveled by an occlusive synthetic clot through the catheter 120 versus the number of revolutions of the groove 342 along the length of the catheter 120 as the clot is aspirated through the catheter 120 for a simulated path to the right pulmonary artery shown in Figure 9A in accordance with an embodiment of the present technology. The graph shows a plot for the average clot distance when the catheter 120 has a 24 French size and a length of approximately 36 inches, and when the synthetic clot is formed of silicone type 27A and has a cylindrical shape with a length of 0.63 inches and a diameter of 0.28 inches. Figure 11B is a graph of the corresponding measured clot velocity in accordance with an embodiment of the present technology. Figure 11B further shows a plot of the average clot velocity for a synthetic clot having a cylindrical shape with a shorter length of 0.37 inches. Referring again to both Figures 11A and 11B, the distance traveled by the clot during aspiration and the velocity of the clot were greatest when the catheter 120 was tested with five revolutions, as opposed to no grooves or one or ten revolutions of the grooves.

[0052] Similarly, Figure 12 is a graph of the measured maximum force required to move an obstructing synthetic clot through the catheter 120 versus the number of revolutions of the grooves 342 along the length of the catheter 120 as the clot is aspirated through the catheter 120 for a simulated pathway to the right pulmonary artery shown in Figure 9A in accordance with an embodiment of the present technology. The graph shows a plot of the maximum force when the catheter 120 has a 24 French size and a length of approximately 36 inches, and when the synthetic clot is formed of silicone type 27A and has a cylindrical shape with a length of 0.50 inches. As shown, the maximum force was again minimized when the catheter 120 was tested with 5 revolutions as opposed to without the grooves or with 1 or 10 revolutions of the grooves. That is, 5 revolutions of the grooves 342 minimized friction between the clot and the catheter 120 during aspiration.

[0053] Thus, in some aspects of the present technology, 5 or about 5 revolutions of grooves 342 may maximize the efficiency of clot removal via suction through catheter 120 by (i) increasing the flow rate through catheter 120, (ii) decreasing clot aspiration time through catheter 120, (iii) increasing the distance the clot travels through catheter 120, (iv) increasing the rate at which the clot travels through catheter 120, (v) decreasing friction between the clot and catheter 120, and / or (vi) decreasing the force required to pull the clot through catheter 120. It is expected that the optimal number of revolutions (among other parameters) may vary depending on the path that catheter 120 travels through the patient.

[0054] Further, in some aspects of the present technology, it is expected that the optimal number of turns will depend on the length of the catheter 120. Thus, the optimal number of turns per unit length of the catheter 120 may remain constant for catheters of different lengths. As discussed above, for example, the catheter 120 may include about 0.01 to 0.40 turns per inch (e.g., about 0.028 turns per inch, about 0.056 turns per inch, about 0.139 turns per inch, about 0.278 turns per inch, about 0.10 to 0.20 turns per inch, about 0.12 to 0.16 turns per inch, etc.). That is, the catheter 120 may include approximately 0.005 to 0.15 turns per centimeter (e.g., approximately 0.011 turns per centimeter, approximately 0.022 turns per centimeter, approximately 0.055 turns per centimeter, approximately 0.109 turns per centimeter, approximately 0.03 to 0.08 turns per centimeter, approximately 0.04 to 0.07 turns per centimeter, etc.).

[0055] V. SELECTED EMBODIMENTS OF DEVICES, SYSTEMS, AND METHODS FOR MANUFACTURING SLUTTING ASPIRATION CATHETERS 1-6B together, in some embodiments, the catheter 120 may be formed about a mandrel, hypotube, or other elongated member. For example, the inner liner 232 may first be positioned around the mandrel and, in some embodiments, stretched along the mandrel to a desired thickness. The braid 234 may then be formed (e.g., wrapped or braided) around the inner liner 232 around the mandrel. The coil 236 may then be wrapped around the mandrel, around the braid 234 and the inner liner 232. In some embodiments, the marker band 126 may be positioned around the mandrel at the distal portion 124. The outer sheath 230 may then be positioned over the inner liner 232, braid 234, and coil 236, and some or all of these components may then be heat shrunk, fused, laminated, or otherwise secured together.

[0056] To form the grooves 342, the mandrel can be formed with corresponding features that shape the inner liner 232. FIG. 13 is a longitudinal view of a mandrel 1350 from which, for example, a catheter 120 can be formed in accordance with an embodiment of the present technology. In the illustrated embodiment, the mandrel 1350 includes a body 1352 (e.g., a cylindrical body) and convex features 1354 (e.g., protrusions, ridges, protuberances) that protrude radially outward from the body 1352 and are separated by grooves or trenches 1356. With reference to FIGS. 1-6B and 13 together, the convex features 1354 can correspond to the desired pattern of the grooves 342. For example, the features 1354 can have dimensions that correspond to the desired depth D and width W of the grooves 342 and can spiral any number of times around the body 1352 to provide the desired lumen pattern of the grooves 342. The number of features 1354, the spacing between features 1354, the size (e.g., height, width) of features 1354, the pitch or spiral pattern of features 1354, and / or other parameters of features 1354 may be selected to generate a pattern of grooves 342 having a desired number, depth D, and width W. For example, features 1354 have a rectangular cross-sectional shape in FIG. 13 to generate grooves 342 having a rectangular cross-sectional shape, while in other embodiments features 1354 may have other cross-sectional shapes (e.g., circular, polygonal, irregular, etc.) to generate grooves 342 of a corresponding shape. As a further example, in FIG. 13 mandrel 1350 includes 16 features 1354 such that catheter 120 has a corresponding 16 grooves 342. Mandrel 1350 may have any number of features 1354.

[0057] When the catheter 120 is formed (e.g., laminated) on the mandrel 1350, the catheter 120 may radially shrink around the mandrel 1350 against / between the features 1354 to form the grooves 342. Specifically, the inner liner 232 may melt and flow into the trenches 1356 between the features 1354 (e.g., if the inner liner 232 comprises a Pebax material) before solidifying to form the grooves 342. Alternatively or additionally, the inner liner 232 may be pressed and / or formed into the trenches 1356 without melting (e.g., if the inner liner 232 comprises a PTFE material). In some embodiments, a lubricant (e.g., a silicone spray lubricant) may be applied to the mandrel 1350 prior to manufacture of the catheter 120 (e.g., during a demolding process) to facilitate removal of the catheter 120 from the mandrel 1350 after manufacture. Similarly, the mandrel 1350 may include a more permanent thin layer of PTFE (polytetrafluoroethylene) coating on its outer surface to facilitate removal and release of the catheter 120. In some embodiments, the manufacturing process may include a fracturing process step that stretches and necks down the mandrel 1350 to a smaller outer diameter to facilitate removal and release of the catheter 120.

[0058] In some embodiments, the features 1354 may extend linearly along the length of the body 1352, and the mandrel 1350 may be fixed at one end and then rotated to provide the lumen pattern of the grooves 342. For example, the mandrel 1350 may be rotated a desired number of times during manufacture (e.g., while the inner liner 232 is in a molten state) such that the grooves 342 traverse a corresponding number of turns along the length L of the catheter 120. In some embodiments, the features 1354 may at least partially wrap around the body 1352, and the mandrel 1350 may be rotated during manufacture of the catheter 120 to introduce additional turns into the grooves 342.

[0059] The features 1354 of the mandrel 1350 may be formed by machining the body 1352 (e.g., a hypotube or solid tube) to cut or etch the trenches 1356. In some embodiments, the machining is performed by a multi-axis machine that may rotate the mandrel 1350 during machining such that the trenches 1356 (and corresponding features 1354) orbit the body 1352. In other embodiments, the mandrel 1350 may be formed by extruding the body 1352 to form the convex features 1354 and trenches 1356.

[0060] 14A and 14B are cross-sectional longitudinal and enlarged isometric views, respectively, of a mandrel 1450 upon which a catheter 120 may be formed, in accordance with an additional embodiment of the present technology. Referring together to FIGS. 14A and 14B, in the illustrated embodiment, the mandrel 1450 includes a body 1452 and a filament or wire 1454 (e.g., raised features) positioned about the body 1452 corresponding to the desired pattern of grooves 342 (FIGS. 1-6B). The wire 1454 may be welded to the body 1452, tightly wound around the body 1452 (e.g., secured at both ends of the wire 1454), or otherwise secured about / to the body 1452. 1-6B, 14A, and 14B together, when the catheter 120 is formed around the mandrel 1450, the inner liner 232 may melt and flow into the spaces between the wires 1454 before solidifying to form the grooves 342, and / or may be pressed / formed into the spaces between the wires 1454 to form the grooves 342. The number of wires 1454, the spacing between the wires 1454, the size (e.g., diameter) of the wires 1454, the pitch or helical pattern of the wires 1454, and / or other parameters of the wires 1454 may be selected to produce a pattern of grooves 342 having a desired number, depth D, and width W. For example, in the illustrated embodiment, the wires 1454 are evenly spaced circumferentially around the body 1452 and contact one another to form a more uniform pattern of grooves 1454. 14A and 14B, the mandrel 1450 includes 24 wires 1454 such that the catheter 120 has a corresponding 24 grooves 342. For example, reducing the number of wires 1454 will produce a pattern with fewer grooves 342, and spacing the wires 1454 apart will produce a pattern with a greater groove depth D and width W. Similar to the convex feature 1354 of FIG. 13, the wires 1454 may be wound helically around the body 1452 to correspond to the desired number of turns of the grooves 342, or the wires 1454 may extend linearly (or at least partially helically) along the body 1452 and the mandrel 1450 may be rotated during manufacture to produce a circumferential (e.g., helical) pattern of grooves 342.

[0061] VI. Additional Examples Several aspects of the present technology are described in the following examples. 1. A suction catheter comprising: a proximal end portion; and a distal end portion; and an inner surface defining an inner lumen, the inner surface including at least one groove formed therein and extending from the distal end at least partially toward the proximal end. 2. The aspiration catheter of example 1, wherein the at least one groove extends from the distal end to the proximal end. 3. The aspiration catheter of example 1 or 2, wherein the inner lumen extends along a longitudinal axis and the at least one groove circumferentially circles around the longitudinal axis between the proximal end and the distal end. 4. The aspiration catheter of example 3, wherein the at least one groove wraps around the longitudinal axis between the proximal end and the distal end at about 0.05 turns per inch or more. 5. The aspiration catheter of example 3, wherein the at least one groove rotates about 0.13 to 0.15 turns per inch around the longitudinal axis between the proximal end and the distal end. 6. The aspiration catheter of example 3, wherein the at least one groove wraps around the longitudinal axis between the proximal end and the distal end at more than about 0.13 turns per inch. 7. The aspiration catheter of any one of Examples 1-6, wherein the at least one groove has a helical shape. 8. The aspiration catheter of any one of Examples 1-7, wherein the at least one groove comprises a plurality of grooves. 9. The aspiration catheter of example 8, wherein the plurality of grooves are equally spaced around the circumference of the inner surface. 10. An aspiration catheter as described in Example 8 or 9, wherein the inner lumen extends along a longitudinal axis and the plurality of grooves circumferentially surround the longitudinal axis between the proximal end and the distal end. 11. The aspiration catheter of example 10, wherein the plurality of grooves circumnavigate the longitudinal axis at about 0.05 turns per inch or more between the proximal end and the distal end. 12. The aspiration catheter of example 10, wherein the plurality of grooves rotate about 0.13 to 0.15 turns per inch around the longitudinal axis between the proximal end and the distal end. 13. The aspiration catheter of example 10, wherein the plurality of grooves wrap around the longitudinal axis between the proximal end and the distal end at more than about 0.13 turns per inch. 14. The catheter is an inner liner having an inner surface, the at least one groove being formed in the inner liner; a braid of wires on the inner liner; a coiled wire on the inner liner; The aspiration catheter of any one of Examples 1 to 13, further comprising an outer sheath over the braid, the wire, and the inner liner. 15. A suction catheter comprising: a proximal end portion; and a distal end portion; and 1. An aspiration catheter comprising: an inner surface defining a lumen extending along a longitudinal axis, the inner surface including a plurality of grooves formed therein, the grooves extending at least partially between the distal end and the proximal end, the grooves circumferentially circumferentially around the longitudinal axis between the distal end and the proximal end. 16. The aspiration catheter of example 15, wherein the groove rotates about 0.13 to 0.15 turns per inch around the longitudinal axis between the proximal and distal ends. 17. The aspiration catheter of example 15 or 16, wherein the grooves are evenly spaced around the circumference of the inner surface. 18. The aspiration catheter of any one of Examples 15 to 17, wherein the groove extends to the distal end. 19. The aspiration catheter of any one of Examples 15-18, wherein the groove extends completely between the distal end and the proximal end. 20. A system for removing material from a lumen of a human patient, the system comprising: a suction catheter configured to be positioned at a treatment site proximate the material within the lumen, the suction catheter comprising: a proximal end portion; and a distal end portion; and an aspiration catheter comprising: an inner surface defining an inner lumen, the inner surface including at least one groove formed therein and extending from the distal end at least partially toward the proximal end; a tubing assembly fluidly connected to the catheter and including a fluid control device; a pressure source fluidly connected to the tubing assembly and configured to generate a negative pressure, wherein the fluid control device is movable between (a) a first position in which the pressure source is fluidly connected to the suction catheter via the tubing assembly, and (b) a second position in which the pressure source is fluidly disconnected from the suction catheter. 21. The system of example 20, wherein the lumen extends along a longitudinal axis, the at least one groove comprises a plurality of grooves, the grooves being equally spaced around the circumference of the inner surface, the grooves extending at least partially from the distal end to the proximal end, and the grooves circumferentially circumferentially around the longitudinal axis between the proximal end and the distal end. 22. A method for removing material from a lumen of a human patient, the method comprising: positioning a distal portion of an aspiration catheter adjacent the material within the lumen, the aspiration catheter including an inner surface having at least one groove formed therein, the at least one groove extending from a distal end of the aspiration catheter at least partially toward a proximal end of the aspiration catheter; coupling a pressure source to the suction catheter via a fluid control device, (a) fluidly connecting the pressure source to the suction catheter by opening the fluid control device, and (b) fluidly disconnecting the pressure source from the suction catheter by closing the fluid control device; activating the pressure source to generate a vacuum while the fluid control device is closed; opening the fluid control device to apply the vacuum to the suction catheter, thereby aspirating at least a portion of the material into the suction catheter. 23. The method of example 22, wherein the at least one groove defines a leakage path for passing the clot material when the clot material is aspirated into the aspiration catheter. 24. The method of example 22 or 23, wherein the at least one groove creates a helical flow pattern within the lumen when the clot material is aspirated into the aspiration catheter. 25. A mandrel for use in forming a catheter, comprising: A cylindrical body; and a plurality of features extending radially outward from the body, the catheter being configured to be formed over the body and the features such that the catheter has a plurality of grooves corresponding to the arrangement of the features. 26. The mandrel of example 25, wherein the feature is integrally formed with the body. 27. The mandrel of example 25, wherein the feature is a wire. 28. The mandrel of any one of examples 25-27, wherein the feature extends helically around the body. 29. A method of forming a catheter, the method comprising: positioning an inner liner of the catheter about a mandrel, the mandrel including a cylindrical body and a plurality of features extending radially outward from the body; Positioning an outer liner of the catheter over the inner liner and around the mandrel; and heating the inner liner and the outer liner such that the inner liner includes a plurality of grooves corresponding to the features of the mandrel. 30. The method of example 29, further comprising cooling the inner liner and the outer liner such that the outer liner fuses to the inner liner. 31. The method of example 29 or 30, further comprising rotating the mandrel after heating the inner liner and the outer liner to orbit the feature and the corresponding groove in the inner liner. 32. The method of any one of examples 29-31, wherein the feature is integrally formed with the body. 33. The method of any one of examples 29-31, wherein the feature is a wire. 34. The method of any one of examples 29-33, wherein the feature extends helically around the body.

[0062] VII. Conclusion The above detailed description of the embodiments of the present technology is not intended to be exhaustive or to limit the present technology to the precise form disclosed above. Although specific embodiments and examples of the present technology are described above for illustrative purposes, various equivalent modifications are possible within the scope of the present technology, as those skilled in the art will recognize. For example, while steps are presented in a given order, alternative embodiments may perform steps in a different order. Various embodiments described herein may also be combined to provide further embodiments.

[0063] From the above, it will be understood that, although specific embodiments of the present technology are described herein for illustrative purposes, well-known structures and functions have not been shown or described in detail in order to avoid unnecessarily obscuring the description of the embodiments of the present technology. Where the context permits, singular or plural terms may also include the plural or singular terms, respectively.

[0064] Furthermore, unless the term "or" is expressly limited in relation to a list of two or more items to mean only a single item exclusively from the other items, the use of "or" in such a list should be interpreted as including (a) any single item in the list, (b) all of the items in the list, or (c) any combination of the items in the list. It should be noted that the term "comprising" is used throughout to mean the inclusion of at least the recited features, without excluding any more of the same features and / or other features of additional types. It will also be understood that, although particular embodiments have been described herein for purposes of illustration, various modifications may be made without departing from the technology. Furthermore, although advantages associated with some embodiments of the technology have been described in the context of these embodiments, other embodiments may also exhibit such advantages, and not all embodiments necessarily exhibit such advantages to fall within the scope of the technology. Thus, the present disclosure and related technology may encompass other embodiments not expressly shown or described herein.

Claims

1. 1. A suction catheter comprising: a proximal end portion; and a distal end portion; and an inner surface defining an inner lumen, the inner surface including at least one groove formed therein and extending from the distal end at least partially toward the proximal end.

2. The aspiration catheter of claim 1 , wherein the at least one groove extends from the distal end to the proximal end.

3. The aspiration catheter of claim 1 , wherein the lumen extends along a longitudinal axis and the at least one groove circumferentially surrounds the longitudinal axis between the proximal and distal ends.

4. 4. The aspiration catheter of claim 3, wherein the at least one groove wraps around the longitudinal axis between the proximal and distal ends at about 0.05 turns per inch or more.

5. 4. The aspiration catheter of claim 3, wherein the at least one groove rotates about the longitudinal axis between the proximal and distal ends at about 0.13 to 0.15 turns per inch.

6. 4. The aspiration catheter of claim 3, wherein the at least one groove wraps around the longitudinal axis between the proximal and distal ends at greater than about 0.13 turns per inch.

7. The aspiration catheter of claim 1 , wherein the at least one groove has a helical shape.

8. The aspiration catheter of claim 1 , wherein the at least one groove comprises a plurality of grooves.

9. The aspiration catheter of claim 8 , wherein the plurality of grooves are equally spaced around a circumference of the inner surface.

10. The aspiration catheter of claim 8 , wherein the lumen extends along a longitudinal axis and the plurality of grooves circumferentially circumferentially around the longitudinal axis between the proximal and distal ends.

11. The aspiration catheter of claim 10, wherein the plurality of grooves circumnavigate the longitudinal axis at about 0.05 turns per inch or more between the proximal and distal ends.

12. The aspiration catheter of claim 10, wherein the plurality of grooves rotate about the longitudinal axis between the proximal and distal ends at about 0.13 to 0.15 turns per inch.

13. The aspiration catheter of claim 10, wherein the plurality of grooves circumnavigate the longitudinal axis at greater than about 0.13 turns per inch between the proximal and distal ends.

14. The catheter, an inner liner having an inner surface, the at least one groove being formed in the inner liner; a braid of wires on the inner liner; a coiled wire on the inner liner; The aspiration catheter of claim 1 , further comprising an outer sheath over the braid, the wire, and the inner liner.

15. 1. A suction catheter comprising: a proximal end portion; and a distal end portion; and 1. An aspiration catheter comprising: an inner surface defining a lumen extending along a longitudinal axis, the inner surface including a plurality of grooves formed therein, the grooves extending at least partially between the distal end and the proximal end, the grooves circumferentially circumferentially around the longitudinal axis between the distal end and the proximal end.

16. 16. The aspiration catheter of claim 15, wherein the grooves rotate about the longitudinal axis between the proximal and distal ends at about 0.13 to 0.15 turns per inch.

17. The aspiration catheter of claim 15, wherein the grooves are equally spaced around the circumference of the inner surface.

18. The aspiration catheter of claim 15 , wherein the groove extends to the distal end.

19. The aspiration catheter of claim 15, wherein the groove extends completely between the distal end and the proximal end.

20. 1. A system for removing material from a lumen of a human patient, the system comprising: an aspiration catheter configured to be positioned at a treatment site proximate the material within the lumen, the aspiration catheter comprising: a proximal end portion; and a distal end portion; and an aspiration catheter comprising: an inner surface defining a lumen, the inner surface including at least one groove formed therein and extending from the distal end at least partially toward the proximal end; a tubing assembly fluidly connected to the catheter and including a fluid control device; a pressure source fluidly coupled to the tubing assembly and configured to generate a negative pressure, the fluid control device being movable between (a) a first position in which the pressure source is fluidly connected to the suction catheter via the tubing assembly, and (b) a second position in which the pressure source is fluidly disconnected from the suction catheter.

21. 21. The system of claim 20, wherein the lumen extends along a longitudinal axis, the at least one groove comprises a plurality of grooves, the grooves being equally spaced around a circumference of the inner surface, the grooves extending at least partially from the distal end to the proximal end, and the grooves circumferentially circumferentially around the longitudinal axis between the proximal end and the distal end.

22. 1. A method for removing material from a lumen of a human patient, the method comprising: positioning a distal portion of an aspiration catheter adjacent the material within the lumen, the aspiration catheter including an inner surface having at least one groove formed therein, the at least one groove extending from a distal end of the aspiration catheter at least partially toward a proximal end of the aspiration catheter; coupling a pressure source to the aspiration catheter via a fluid control device, (a) fluidly connecting the pressure source to the aspiration catheter by opening the fluid control device, and (b) fluidly disconnecting the pressure source from the aspiration catheter by closing the fluid control device; activating the pressure source to generate a vacuum while the fluid control device is closed; and opening the fluid control device to apply the vacuum to the suction catheter, thereby aspirating at least a portion of the material into the suction catheter.

23. 23. The method of claim 22, wherein the at least one groove defines a leakage path for passing the clot material when the clot material is aspirated into the aspiration catheter.

24. 23. The method of claim 22, wherein the at least one groove creates a helical flow pattern within the lumen when the clot material is aspirated into the aspiration catheter.

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