CN118524864A - Aspiration catheter having grooved inner surface and associated systems and methods - Google Patents

Abstract

Aspiration catheters having a grooved inner surface for removing clot material from a patient's vasculature and associated systems and methods are disclosed herein. In some embodiments, the aspiration catheter can include a proximal tip, a distal tip, 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. The at least one groove can provide a leakage path around the clot material as it is aspirated through the aspiration catheter to improve uptake of the clot material through the catheter and inhibit clogging.

Description

Aspiration catheter having a grooved inner surface and associated systems and methods

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Patent Application No. 63/304,748, filed on January 31, 2022, entitled “ASPIRATION CATHETERS HAVING GROOVED INNER SURFACES, AND ASSOCIATED SYSTEMS AND METHODS,” and U.S. Provisional Patent Application No. 63/395,586, filed on August 5, 2022, entitled “ASPIRATION CATHETERS HAVING GROOVED INNER SURFACES, AND ASSOCIATED SYSTEMS AND METHODS,” each of which is incorporated herein by reference in its entirety.

Technical Field

The present technology as a whole relates to a clot management system including an aspiration catheter having a grooved or rifled inner surface to promote more clot uptake into the aspiration catheter, reduce clogging of the aspiration catheter, increase/optimize flow rate within the aspiration catheter, and/or enhance clot removal through the aspiration catheter.

Background Art

Thromboembolic events are characterized by vascular obstruction. Thromboembolic diseases such as stroke, pulmonary embolism, heart attack, peripheral thrombosis, atherosclerosis, etc. affect many people. These diseases are the main causes of morbidity and mortality.

When an artery is blocked by a clot, tissue ischemia develops. If the blockage persists, the ischemia will progress to tissue infarction. If blood flow is quickly reestablished, the infarction will not develop or will be greatly limited. Failure to reestablish blood flow may result in limb loss, angina, myocardial infarction, stroke, or even death.

In the venous circulation, obstructive substances can also cause serious harm. Blood clots can form in the large veins of the legs and pelvis, a common condition known as deep vein thrombosis (DVT). DVT most commonly occurs in situations where there is a tendency for blood to clot (e.g., long-distance air travel, inactivity, etc.) and blood to coagulate (e.g., cancer, recent surgery such as plastic surgery). DVT causes harm by (1) blocking the drainage of venous blood from the legs, causing swelling, ulcers, pain, and infection, and (2) acting as a reservoir for blood clots to travel to other parts of the body, including the heart, lungs, brain (stroke), abdominal organs, and/or limbs.

In the pulmonary circulation, unwanted substances can cause damage by blocking a pulmonary artery, a condition known as pulmonary embolism. If the blockage is upstream, in a main trunk or large branch pulmonary artery, it can severely impair total blood flow within the lungs, and therefore the entire body, as well as cause hypotension and shock. If the blockage is downstream, in a large to medium pulmonary artery branch, it can prevent a significant portion of the lungs from participating in the exchange of gases to the blood, leading to low blood oxygen and accumulation of blood carbon dioxide.

There are many existing techniques for reestablishing blood flow through blocked blood vessels. One common surgical technique, embolectomy, involves cutting open the blood vessel and placing a device with a balloon tip, such as a Fogarty catheter, at the site of the blockage. The balloon is then inflated at a point outside the clot and used to translate the blocking material back to the cutting point. The blocking material is then removed by a surgeon. Although such surgical techniques have been useful, exposing the patient to surgery can be traumatic and is best avoided where possible. Additionally, the use of a Fogarty catheter can be problematic because there can be a risk of damaging the inner lining of the blood vessel as the catheter is withdrawn.

Percutaneous methods are also used to reconstruct blood flow. Common percutaneous techniques are referred to as balloon angioplasty, in which a catheter with a balloon head is introduced into a blood vessel (e.g., typically by introducing a catheter). The catheter with a balloon head is then advanced to the point of obstruction and inflated to dilate the stenosis. Balloon angioplasty is suitable for treating vascular stenosis, but it is usually not effective for treating acute thromboembolism because the obstructing material is not removed and the blood vessel can be restenotic after dilation. Another percutaneous technique includes placing a catheter near the clot and injecting streptokinase, urokinase or other thrombolytic agents to dissolve the clot. Unfortunately, thrombolysis usually requires hours to days to be successful. In addition, thrombolytic agents can cause bleeding, and for many patients, the agent cannot be used at all.

Various devices exist for performing thrombectomy or removing other foreign bodies. However, such devices have been found to have highly complex structures, be traumatic to the vessel being treated, or lack adequate retaining structures and therefore may not be properly secured to the vessel to function adequately. In addition, many devices have highly complex structures, which leads to manufacturing and quality control difficulties and delivery issues when passing through tortuous or small diameter catheters. Less complex devices may allow the user to pull through the clot, particularly for inexperienced users, however such devices may not completely capture and/or collect all of the clot material.

BRIEF DESCRIPTION OF THE DRAWINGS

Many aspects of the present technology may be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale. Instead, emphasis is placed on clearly illustrating the principles of the present disclosure.

1 is a partially schematic side view of a clot management system including a catheter in accordance with an embodiment of the present technology.

2A and 2B are enlarged partial cross-sectional side and isometric views, respectively, of a portion of a catheter of the system of FIG. 1 in accordance with an embodiment of the present technology.

Fig. 3A and Fig. 3B are respectively an enlarged isometric view and a proximally facing longitudinal view of a distal portion of the catheter of Fig. 1 according to an embodiment of the present technology. Fig. 3C is an interior view of the catheter as viewed from within the lumen of the catheter according to an embodiment of the present technology. Fig. 3D is a partially transparent isometric view of a catheter according to an embodiment of the present technology.

4 is a partially transparent isometric view of the catheter of FIG. 1 in accordance with additional embodiments of the present technology.

5 is an interior view of the catheter of FIG. 1 as viewed from within the lumen of the catheter in accordance with additional embodiments of the present technology.

6A and 6B are an enlarged isometric view and an enlarged cross-sectional side view, respectively, of a distal portion of the catheter of FIG. 1 in accordance with additional embodiments of the present technology.

7A and 7B are side views of a distal portion of the clot management system of FIG. 1 during a procedure for removing clot material from within a blood vessel of a patient in accordance with an embodiment of the present technology.

8A and 8B are respectively a proximally-facing longitudinal view and an enlarged partially transparent side view of the distal portion of the catheter of FIG. 1 with clot material ingested therein in accordance with an embodiment of the present technology.

Figures 9A and 9B are perspective views of the clot management system of Figure 1 traversing simulated pathways to the right and left pulmonary arteries, respectively, in accordance with embodiments of the present technology. Figures 9C and 9D are distal-facing longitudinal views of the proximal portion of the catheter of Figure 1 in accordance with embodiments of the present technology, illustrating flow patterns during aspiration, respectively, when the catheter is traversed through the simulated pathway to the right pulmonary artery shown in Figure 9A, without any internal grooves and with the arrangement of the grooves shown in Figures 3A to 3D.

FIG10A is a graph of measured flow rate through the catheter of FIG1 versus number of turns of the internal grooves along the length of the catheter for the simulated approach to the right pulmonary artery shown in FIG9A in accordance with embodiments of the present technology. FIG10B is a graph of corresponding measured time for aspiration of an occlusive synthetic clot through the catheter in accordance with embodiments of the present technology.

FIG11A is a graph of measured distance traveled by an occlusive synthetic clot versus number of turns of the internal grooves along the length of the catheter as the clot was aspirated through the catheter of FIG1 for the simulated approach to the right pulmonary artery shown in FIG9A in accordance with embodiments of the present technology. FIG11B is a graph of corresponding measured clot velocity in accordance with embodiments of the present technology.

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 turns of the internal grooves along the length of the catheter as the clot is aspirated through the catheter for the simulated approach to the right pulmonary artery shown in FIG. 9A in accordance with an embodiment of the present technology.

13 is a longitudinal view of a mandrel upon which the catheter of FIG. 1 may be formed in accordance with an embodiment of the present technology.

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 additional embodiments of the present technology.

DETAILED DESCRIPTION

The present technology as a whole relates to an aspiration catheter and associated systems and methods having a grooved inner surface for removing unwanted material from a patient, such as clotted material from the patient's vasculature. In some embodiments, the aspiration catheter can include a proximal end, a distal end, and an inner surface defining an inner cavity. The inner surface includes at least one groove formed therein and extending at least partially between the distal end and the proximal end. When clotted material is aspirated through the aspiration catheter, the at least one groove can provide a leakage path around the clotted material to improve the uptake of the clotted material by the catheter and inhibit blockage.

In some embodiments, the lumen extends around the longitudinal axis, and at least one groove may circumferentially rotate around the longitudinal axis between the proximal end and the distal end. Thus, at least one groove may have a spiral/helical shape along the length of the suction catheter. In some aspects of the present technology, when the clot material is sucked through the suction catheter, the spiral/helical shape of the at least one groove may produce a spiral flow pattern within the lumen. The spiral flow pattern can be used to elongate and/or break up the clot material, and can increase the rate at which the clot material is ingested.

Certain details are set forth in the following description and in FIGS. 1 to 14B to provide a thorough understanding of various embodiments of the present technology. In other cases, known structures, materials, operations, and/or systems that are typically associated with intravascular procedures, clot removal procedures, clot aspiration, catheters, etc. are not shown or described in detail in the following disclosure to avoid unnecessary confusion in 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 set forth herein and/or with other structures, methods, components, etc. In addition, although many devices and systems are described herein in the context of removing and/or treating clotted materials, the present technology may be used to remove and/or treat other unwanted materials in addition to or in place of clotted materials, such as thrombi, emboli, plaques, intimal hyperplasia, post-thrombotic scar tissue, etc. Therefore, the terms "clot" and "clotted material" used herein may refer to any of the aforementioned materials, etc.

The terms used below should be interpreted in their broadest reasonable manner, even though it is used in conjunction with the detailed description of certain examples of the embodiments of the present disclosure. In fact, certain terms may even be emphasized below; however, any term intended to be interpreted in any limited manner will be openly and specifically defined in this detailed description section.

The accompanying drawings depict embodiments of the present technology, and are not intended to limit their scope unless explicitly stated. The sizes of the various depicted elements are not necessarily drawn to scale, and these various elements may be amplified to improve readability. Component details may be separated in the drawings to exclude these details when it is not necessary to fully understand how to make and use the present technology in details such as the position of the components and certain precise connections between such components. Many details, sizes, angles and other features shown in the drawings are only specific embodiments of the present disclosure. Therefore, without departing from the present technology, other embodiments may have other details, sizes, angles and features. In addition, it will be appreciated by those of ordinary skill in the art that other embodiments of the present technology may be implemented without some details described below.

With respect to the terms "distal" and "proximal" in this specification, unless otherwise indicated, these terms may guide the relative position of various parts of the tube system with respect to the operator and/or the position in the vasculature. In addition, as used herein, the designations "rearward," "forward," "upward," "downward," etc. are not intended to limit the referenced components to a particular orientation. It should be understood that such designations refer to the orientation of the referenced components as shown in the accompanying drawings; the system of the present technology may be used in any orientation suitable for the user.

The headings provided herein are for convenience only and should not be construed as limiting the disclosed subject matter.

I. Selected Embodiments of Clot Management Systems

FIG. 1 is a partially schematic side view of a clot handling system 100 according to an embodiment of the present technology. The clot handling 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 handling system and generally described in the context of removing clotted material from a patient's vasculature, the system 100 may be used to handle and/or remove other unwanted material from the patient's vasculature, body vessels, and/or other lumens. For example, the system 100 may be used to handle and/or remove emboli, foreign matter, vegetation, and other material from within the patient's vasculature, gallstones from the gallbladder, and/or other material from other body cavities.

In the illustrated embodiment, the clot handling system 100 includes a tubing assembly 110 fluidly coupled to a catheter 120 via a valve 102. The catheter 120 may be referred to as an aspiration catheter, a guide catheter, an aspiration guide catheter, etc. In general, the clot handling system 100 (i) may include features substantially similar or identical to the features of the clot handling system described in detail in U.S. patent application Ser. No. 16/536,185, filed Aug. 8, 2019, entitled “SYSTEM FOR TREATING EMBOLISM AND ASSOCIATED DEVICES AND METHODS,” which is incorporated herein by reference in its entirety, and/or (ii) may be used to handle/remove clotted material from a patient (e.g., a human patient) using any of the methods described in detail therein.

In the illustrated embodiment, the catheter 120 includes a proximal region or portion 122 and a distal region or portion 124 adjacent to and distal to the proximal portion 122. The catheter 120 also defines a lumen 121 extending completely therethrough from the proximal portion 122 to the distal 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, which is configured to facilitate visualization of the position of the catheter 120 during a medical procedure (e.g., a clot removal procedure) in which the catheter 120 is used. In some embodiments, the catheter 120 may have a length L of between about 20 inches and 50 inches, between about 30 inches and 40 inches, about 35 inches, etc.

The valve 102 is fluidly coupled to the 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 even preventing fluid from flowing through the valve 102 in a proximal direction when various components such as a delivery sheath, a pull member, a guidewire, an interventional device, other aspiration catheters, etc. are inserted through the valve 102 for delivery to a treatment site in a blood vessel through the catheter 120. The valve 102 includes a branch 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 can be a valve of the type disclosed in U.S. patent application Ser. No. 16/117,519, filed on Aug. 30, 2018, and entitled “HEMOSTASIS VALVES AND METHODS OF USE,” which is incorporated herein by reference in its entirety.

In the illustrated embodiment, the tubing assembly 110 fluidly couples the conduit 120 to a pressure source 106, such as a syringe (e.g., an automatic pressure-locking syringe). The conduit assembly 110 may include (i) one or more conduit segments 112 (each identified as a first conduit segment 112a and a second conduit segment 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 coupling the conduit assembly 110 to the pressure source 106 and/or other suitable components. In some embodiments, the fluid control device 114 is a stopcock that (i) is fluidly coupled to the side port 104 of the valve 102 via the first conduit segment 112a, and (ii) is fluidly coupled to the connector 116 via the second conduit segment 112b. The fluid control device 114 can be externally operated by a user to regulate the flow of fluid through the fluid control device, and specifically regulate the flow of fluid from the lumen 121 of the conduit 120 to the pressure source 106. For example, the fluid control device 114 can be actuated to fluidly connect and fluidly 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 the pressure source 106.

Fig. 2A and Fig. 2B are respectively an enlarged partial cross-sectional side view and an isometric view of a portion of the catheter 120 of Fig. 1 according to an embodiment of the present technology. Referring to Fig. 2A and Fig. 2B together, the catheter 120 includes an outer sheath 230 and an inner liner 232. The outer sheath 230 is positioned on the inner liner 232 (e.g., radially outward). The outer sheath 230 may also be referred to as an outer jacket, an outer shaft or an outer layer, and the inner liner 232 may also be referred to as an inner layer, an inner sheath or an inner shaft. In the illustrated embodiment, the catheter 120 also 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 liner 232 may be omitted, and the outer sheath 230 and/or another component of the catheter 120 may define the inner surface of the catheter 120 .

In some embodiments, the outer sheath 230 is formed of a plastic material, an elastomeric material, and/or a thermoplastic elastomer (TPE) material. For example, the outer sheath 230 may be formed of a TPE manufactured by Arkema S.A. of Colombes, France, such as a TPE manufactured under the trademark "Pebax". The liner 232 defines the inner cavity 121, and the liner may be formed of a lubricating material that facilitates the movement of various components (such as clotted material, delivery sheath, traction member, guidewire, interventional device, other suction catheters, etc.) through the inner cavity 121 (e.g., advance distally, retract proximally). In some embodiments, the liner 232 is formed of a polymer material, a fluoropolymer material (e.g., polytetrafluoroethylene (PTFE)), and/or another material having a high degree of lubricity. In some embodiments, the liner 232 has an inner diameter D ( FIG. 2 ) of between about 0.2 inches and 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 greater. In some embodiments, the diameter D is about 20 French or about 24 French.

Braid 234 can include filaments, filaments, lines, sutures, fibers, etc. (collectively referred to as "filaments 238") that have been braided or otherwise connected, attached, formed, and/or joined together at multiple gaps 239. Therefore, braid 234 can also be referred to as a braided structure, a braided filament structure, a braided filament mesh structure, a mesh structure, a mesh filament structure, etc. Wire 238 can be formed by metal, polymer, and/or composite materials. In some embodiments, each wire in wire 238 is a rolled flat wire having a cross-sectional size between about 0.001 inch to 0.005 inch (e.g., about 0.002 inch) and about 0.002 inch to 0.005 inch (e.g., about 0.0033 inch).

The coil 236 may include a single wire wound around the braid 234 and the liner 232. In other embodiments, the coil 236 includes more than one wire wound around the braid 234 and/or the liner 232. For example, the coil 236 may include multiple wires wound over 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 liner 232. The coil 236 may be formed of a metal or other material of suitable strength, such as a nickel-titanium alloy (e.g., Nitinol), platinum, a cobalt-chromium alloy, stainless steel, tungsten, and/or titanium.

In some embodiments, the configuration of the catheter 120 may be selected/changed 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, the intermediate region between the proximal portion and the distal portion, etc.) and/or only partially overlap. For example, the coil 236 may extend only through the distal region of the catheter 120, and when the lumen 121 is aspirated during a clot removal procedure, the coil may inhibit or even prevent kinking or other unwanted movement of the catheter 120. Similarly, the hardness, thickness, etc. of the outer sheath 230 and the liner 232 may vary in different regions of the catheter 120. For example, the outer sheath 230 and/or inner liner 232 may be (i) relatively stiff and/or thick in the proximal portion 122 ( FIG. 1 ) of the catheter 120 to provide good torque response, pushability, and/or steerability to the catheter 120, and (ii) relatively soft and/or thin in the distal portion 124 ( FIG. 1 ) so that the catheter 120 can be steered into and positioned in difficult-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 features that are at least substantially similar in structure and function or identical in structure and function to those features of the catheter disclosed in (i) U.S. patent application publication No. 17/529,018, filed on November 17, 2021, entitled “CATHETERS HAVING SHAPEDDISTAL PORTIONS, AND ASSOCIATED SYSTEMS AND METHODS” and/or (ii) U.S. patent application publication No. 17/529,064, filed on 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.

II. Selected Embodiments of Grooved Aspiration Catheters

In some embodiments, the catheter 120 may include grooves on its inner surface that are configured (e.g., sized and shaped) to increase the efficiency/effectiveness of aspirating the clot with the catheter 120 during a clot handling procedure. For example, Figures 3A and 3B are an enlarged isometric view and a proximally facing longitudinal view, respectively, of a distal portion 124 (e.g., an inlet) of the catheter 120 according to an embodiment of the present technology. Figure 3C is an interior view of the catheter 120 as viewed from within the lumen 121 according to an embodiment of the present technology. And, Figure 3D is a partially transparent isometric view of the catheter 120 according to an embodiment of the present technology.

Referring to FIGS. 3A to 3C together, the catheter 120 includes an inner surface 340 defining a lumen 121, and a plurality of grooves 342 (which may also be referred to as microchannels, microgrooves, channels, grooves, cuts, slots, slits, etc.) formed along/in the inner surface 340. In some embodiments, the grooves 342 are formed in the liner 232 (FIGS. 2A and 2B). In the illustrated embodiment, the grooves 342 are identical, and the catheter 120 includes sixteen grooves 342 equally spaced around the circumference of the inner surface 340, i.e., equally spaced circumferentially around the longitudinal axis X (FIG. 3D) of the catheter 120 extending 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, the grooves 342 can have other cross-sectional shapes (e.g., linear, polygonal, irregular) and/or different grooves in the grooves 342 can have different cross-sectional shapes. In some embodiments, the grooves 342 have a thickness or depth D ( FIG. 3B ) between about 0.003 inches and 0.100 inches (e.g., between about 0.005 inches and 0.050 inches, between about 0.005 inches and 0.0010 inches) and a width W ( FIG. 3B ) between about 0.005 inches and 0.20 inches (e.g., between about 0.010 inches and 0.015 inches).

Referring to FIG. 3D , in the illustrated embodiment, the grooves 342 each (i) extend along the entire length L of the catheter 120 between the proximal end 123 and the distal end 125, and (ii) extend circumferentially along the length L of the catheter 120 around the longitudinal axis X. That is, the grooves 342 can rotate around the longitudinal axis L to form a spiral or helical pattern. In the illustrated embodiment, each of the grooves 342 passes through four full revolutions around the longitudinal axis X along the length L of the catheter 120. Therefore, in some aspects of the present technology, the grooves 342 form a rifling pattern on the inner surface 340 (FIG. 3A to FIG. 3C) of the catheter 120. In some embodiments, the length L can be about 36 inches, so that the catheter 120 has about 0.14 turns/inch (e.g., 0.1380 turns/inch, between about 0.10 and 0.20 turns/inch, between about 0.13 and 0.16 turns/inch).

3A-3D together, in other embodiments, the arrangement of the grooves 342 may vary based on, for example, the specific application of the catheter 120 (e.g., the specific clot removal procedure to be performed with the catheter 120) and/or the 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. may vary. In some embodiments, the catheter 120 may include between 1-20 or more grooves 342, and the grooves 342 may traverse 0-20 turns along the length L of the catheter 120.

For example, FIG4 is a partially transparent isometric view of a catheter 120 according to an additional embodiment of the present technology. In the illustrated embodiment, the catheter 120 includes eight grooves 342 that are equally spaced circumferentially around the longitudinal axis X and extend along the entire length L of the catheter 120 between the proximal end 123 and the distal end 125. In addition, each of the grooves 342 passes through two full turns around the longitudinal axis X along the length L of the catheter 120. In some embodiments, the length L can be about 36 inches, so that the catheter 120 has about 0.053 turns/inch (e.g., 0.0526 turns/inch, between about 0.02 and 0.09 turns/inch, between about 0.04 and 0.07 turns/inch).

For example, FIG5 is an internal view of a catheter 120 viewed from within a lumen 121 according to an additional embodiment of the present technology. In the illustrated embodiment, the catheter 120 includes sixteen grooves 342, and the grooves 342 extend generally parallel to the longitudinal axis X (FIG. 3D; extending into the page of FIG5). That is, the grooves 342 do not circumferentially turn around the axis X along the length of the catheter 120 (e.g., the grooves 342 pass through zero turns per inch).

For example, FIG. 6A and FIG. 6B are enlarged isometric views 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 to FIG. 6A and FIG. 6B together, in the illustrated embodiment, the catheter 120 includes a single groove 342 extending only partially from the distal end 125 toward the proximal end 123 (FIG. 1) of the catheter 120. That is, the groove 342 does not extend along the entire length L (FIG. 1) of the catheter 120, but only partially passes through the distal portion 124. In addition, in the illustrated embodiment, the groove 342 extends circumferentially (e.g., spirally) six times around the longitudinal axis X (FIG. 6A) before terminating at the proximal end portion. In other embodiments, the groove 342 may be more or less circumferential around the longitudinal axis X. In some embodiments, the depth D (FIG. 3B) of the groove 342 is between about 0.010 inches and 0.015 inches, and the width W (FIG. 3B) is between about 0.120 inches and 0.145 inches. As described in more detail below with reference to FIG. 8B, the groove 342 can be configured (e.g., shaped and/or sized) to produce a spiral flow pattern within the lumen 121 when the catheter 120 is aspirated as indicated by arrow H in FIG. 6A (which spirals/revolves around the lumen 121).

3A and 6B together, in other embodiments, the grooves 342 need not extend from the distal tip 124 of the catheter 120, but may begin along the middle portion of the catheter 120 between the proximal tip 123 and the distal tip 125. That is, the grooves 342 may be spaced apart from the distal tip 125 and need not extend along the entire length L ( FIG. 1 ) of the catheter 120. Furthermore, the grooves 342 may be equally spaced relative to one another, or may be spaced apart at varying distances relative to one another.

III. Selected Embodiments of Clot Management Methods

7A and 7B are side views of the distal portion 124 of the catheter 120 of the clot management system 100 of FIG. 1 during a procedure for removing clot material C (e.g., 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 described above, in some embodiments, the clot removal procedure illustrated in FIGS. 7A and 7B may be substantially similar or identical to any clot removal procedure disclosed in U.S. Patent Application No. 16/536,185, filed on August 8, 2019, entitled “SYSTEM FOR TREATING EMBOLISM AND ASSOCIATED DEVICES AND METHODS,” which is incorporated herein by reference in its entirety.

1 and 7A together, the catheter 120 can be advanced through the patient to bring the clot material C into proximity with the blood vessel BV (e.g., to a treatment site within the blood vessel BV). In some embodiments, the catheter 120 can be advanced through the blood vessel BV until the distal tip 125 of the catheter 120 is positioned proximal to the proximal portion of the clot material C. In some embodiments, the position of the distal tip 125 can be confirmed or located via visualization of the marker band 126 using fluoroscopy or another imaging procedure (e.g., a radiographic procedure). In other embodiments, the distal tip 125 can be at least partially positioned within or distal to the clot material C.

Access to the pulmonary vessels can be achieved through the patient's vascular system, for example, via the femoral vein. In some embodiments, the clot handling system 100 may include an introducer (e.g., a Y-shaped connector with a hemostatic valve, not shown); it can be partially inserted into the femoral vein. A guide wire (not shown) can be introduced 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 C, the guide wire can be guided to one or more branches of the right pulmonary artery and/or the left pulmonary artery. In some embodiments, the guide wire may extend completely or partially through the clot material C. In other embodiments, the guide wire may extend to a position just proximal to the clot material C. After positioning the guide wire, the dilator and catheter 120 may be placed on the guide wire and advanced to a position close to the clot material C, as shown in FIG. 7A. The dilator can then be withdrawn proximally through the lumen 121 of the catheter 120. In some embodiments, the guidewire can then be retracted, while in other embodiments, the guidewire can be retained and can be used to guide other catheters (e.g., delivery catheters, additional suction guide catheters), interventional devices, etc. to the treatment site. However, it should be understood that other entry locations into the patient's venous circulatory system are also possible and consistent with the present technology. For example, the user can 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 that are closer to the right atrium of the patient's heart can also be advantageous because it reduces the length of the instrument required to reach the clot material C.

1 and 7B together, the pressure source 106 is configured to generate (e.g., form, create, fill, accumulate) a vacuum (e.g., a negative relative pressure) and store the vacuum for subsequent application to the catheter 120. For example, after positioning the catheter 120 proximate to the clot material C, the user may first close the fluid control device 114 before generating a vacuum in the pressure source 106, such as by withdrawing the plunger of a syringe coupled to the connector 116. In this way, the pressure source 106 is filled with a vacuum (e.g., maintaining a negative pressure) before the pressure source 106 is fluidly connected to the lumen 121 of the catheter 120. In order 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, and thereby apply or release the vacuum stored in the pressure source 106 to the lumen 121 of the catheter 120.

Opening the fluid control device 114 instantaneously or nearly instantaneously applies the stored vacuum pressure to the tubing assembly 110 and the catheter 120, thereby generating a suction pulse throughout the catheter 120. In particular, suction is applied at the distal portion 124 of the catheter 120 to aspirate/suction/ingest at least a portion of the clotted material C into the lumen 121 of the catheter 120, as shown in FIG. 7B. In one aspect of the present technology, pre-filling or storing vacuum in the pressure source 106 prior to applying vacuum to the lumen 121 of the catheter 120 is expected to generate greater suction and corresponding fluid flow rates at and/or near the distal tip 125 of the catheter 120 than simply activating the pressure source 106 while the pressure source 106 is fluidly connected to the catheter 120. The vacuum pressure can be used to draw the clotted material C down the entire length of the catheter 120, through the side port 104, through the tubing assembly 110, and into the pressure source 106.

Sometimes, as shown in FIG. 7B , releasing the vacuum stored in the pressure source to aspirate the lumen 121 of the catheter 120 can remove substantially all (e.g., a desired amount) of the clotted material C from the blood vessel BV. That is, a single pulse of aspiration can sufficiently remove the clotted material C from the blood vessel BV. In other embodiments, a portion of the clotted material C may remain in the blood vessel BV. In this case, the user may wish to reapply vacuum pressure (perform another "aspiration pass") to remove all or a portion of the remaining clotted material C in the blood vessel BV. In this case, the pressure source 106 can be disconnected from the tubing assembly 110 and exhausted (e.g., the aspirated clot removal is removed) before the pressure source 106 is reconnected to the tubing assembly 110 and activated again. After the desired amount of clotted material C is removed, the catheter 120 can be withdrawn from the patient.

Sometimes, however, clotted material C may become blocked and stuck within the lumen 121 of the catheter 120 and/or around the distal tip 125 of the catheter 120 (e.g., forming a "lollipop" shape around the distal tip 125). Clearing such a blockage may require (i) performing an additional aspiration pass, (ii) removing the entire catheter 120 from the patient and then reinserting the same or a different catheter 120 for another aspiration pass, (iii) and/or inserting an additional clot removal element through the catheter 120 to mechanically disrupt and remove the blockage. Such techniques for clearing blockages may increase the complexity and time of the clot removal procedure.

In some aspects of the present technology, the grooves 342 (FIGS. 3A and 6B) of the catheter 120 can help improve the uptake/aspiration of clotted material C into and through the catheter 120, thereby inhibiting clotting, compared to, for example, conventional catheters having inner surfaces without grooves. For example, FIGS. 8A and 8B are respectively a proximally facing longitudinal view and an enlarged partially transparent side view of a distal portion 124 (e.g., an inlet) of the catheter 120 according to an embodiment of the present technology, wherein clotted material C is positioned therein. In the illustrated embodiment, the catheter 120 includes the arrangement of grooves 342 shown in FIGS. 3A to 3D.

8A , some or all of the grooves 342 may form fluid paths (e.g., leak paths, microfluidic paths, micro-leak paths) around the clotted material C. These fluid paths may inhibit or prevent the clotted material C from clogging the lumen 121 and causing cavitation within the pressure source 106 by keeping blood flowing generally proximally through the grooves 342 during aspiration. This movement of blood through the grooves 342 may help pull the clotted 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 clotted material C, thereby reducing friction between the clotted material C and the catheter 120, and ultimately reducing the suction force required to move the clotted material C proximally through the entire length of the catheter 120.

8B , the rifling pattern on the grooves 342 (e.g., circumferentially circumferentially around the longitudinal axis of the catheter 120) can form a spiral flow pattern inside the lumen 121 of the catheter 120 during aspiration, as indicated by arrow H. In some aspects of the present technology, the spiral flow pattern can help keep faster moving blood proximally traveling through the lumen 121 near the inner surface 340 while keeping slower moving clot material C toward the center of the lumen 121. The outer "layer" of blood near the inner surface 340 can form a fluid buffer between the clot material C and the inner surface 340 of the catheter 120, which helps the clot material C be more efficiently and reliably transported along the entire length of the catheter 120 and into the pressure source 106 ( FIG. 1 ). More specifically, the spiral flow of blood may (i) apply an axial force to the clot material C, which pulls the clot material C in the proximal direction indicated by arrow P via aspiration of the clot, and (ii) apply a torsional force to the clot material C, as indicated by arrow H. These forces may apply shear and torsional stresses to the clot material C, which serve to deform (e.g., lengthen) and/or break up the clot material C within the lumen 121 in a manner that would not occur with laminar and/or non-spiral flow. This may further 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. The reduction in friction and/or deformation of the clot material C may help the clot material C travel through the lumen 121 without blocking the lumen 121.

IV. Selected Examples of Performance and Associated Optimizations of Embodiments of the Present Technology

Referring to FIGS. 3A-6B together, as described above, the arrangement of the grooves 342 can be varied to provide different aspiration flow patterns, flow rates, etc. In general, for example, it is expected that increasing the number of grooves 342 will improve/enhance the axial flow path around the ingested clot, until the point where the grooves 342 are too small to provide an effective leakage path around the ingested clotted material. Likewise, it is expected that increasing the depth D of the grooves 342 will improve the spiral 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 liner 232 shown in FIGS. 2A and 2B ). For example, it is expected that a significant increase in the depth D requires a corresponding increase in the overall thickness of the liner 232 (e.g., an increase in the thickness of the liner 232 radially outward of the grooves 342 (i.e., on the outside or rear side of the grooves 342)) to maintain the integrity of the liner 232. Increasing the wall thickness of the catheter 120 can reduce the flexibility of the catheter 120. Thus, for example, for applications in which catheter 120 does not need to be made very flexible (e.g., for clot removal procedures in non-tortuous anatomies), groove 342 may be relatively deeper, while for applications in which it is advantageous for catheter 120 to be made very flexible (e.g., for clot removal procedures in tortuous anatomies such as the pulmonary artery), groove 342 may be made shallower.

Similarly, it is expected that increasing the number of turns of the grooves 342 (where the grooves 342 are rifled along the length L of the catheter 120) will (i) improve the spiral flow pattern within the catheter 120, thereby increasing the torsional force used to extend and break up the ingested clotted material, while also (ii) reducing the volumetric flow rate within the catheter 120 by increasing the length that the blood must travel through the catheter 120. However, in the case where the catheter 120 traverses a tortuous path, the linear/laminar flow provided by a catheter without grooves or with linear (e.g., non-revolving) grooves can hinder the flow because the flow must change its trajectory along the length of the catheter. In some aspects of the present technology, the rifling arrangement of the grooves 342 can improve the flow pattern and/or volumetric flow rate of the catheter 120 in tortuous anatomies because the blood flow does not need to change its trajectory through the tortuous path of the catheter 120 as much.

More specifically, for example, FIGS. 9A and 9B are perspective views of a clot management system 100 traversing simulated pathways to the right pulmonary artery RPA and the left pulmonary artery LPA, respectively, according to an embodiment of the present technology. Referring to FIGS. 9A and 9B together, the pathway to the right pulmonary artery RPA can 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 of approximately 1.40, which is defined as the amount of curvature of the catheter 120 divided by the length L of the catheter 120 ( FIG. 1 ), while the pathway to the left pulmonary artery LPA has a tortuosity of approximately 1.06.

9C and 9D are distal-facing longitudinal views of a proximal portion 122 (e.g., an outlet) of a catheter 120 according to an embodiment of the present technology, illustrating flow patterns during aspiration without any grooves 342 and with the arrangement of grooves 342 shown in FIGS. 3A to 3D , respectively, as the catheter 120 traverses the simulated pathway shown in FIG. 9A to reach the right pulmonary artery RPA. Referring to FIG. 9C and FIG. 9D together, 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 far 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 passes through the lumen 121 of the catheter more slowly than the more uniform flow pattern shown in FIG. 9D , thereby reducing the volumetric flow rate of the catheter 120 and the efficiency with which the catheter 120 can ingest clot material.

In some aspects of the present technology, the number of turns (and/or turns per unit length) that the grooves 342 traverse along 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 measured flow rate through the catheter 120 versus the number of turns of the grooves 342 along the length of the catheter 120 for a simulated approach to the right pulmonary artery shown in FIG. 9A in accordance with an embodiment of the present technology. The graph illustrates a graph of 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 corresponding measured times for aspiration of an occlusive synthetic clot through the catheter 120 in accordance with an embodiment of the present technology. The graph in FIG. 10B illustrates a graph of a synthetic clot having a spherical shape formed from a silicone 27A mold and having a diameter greater than the diameter of the catheter 120 of 0.28 inches. 10A and 10B together, when the catheter 120 is tested with five turns (e.g., approximately 0.14 turns/inch), the flow rate is maximized and the corresponding aspiration time is minimized, as opposed to having no grooves (e.g., 0 turns/inch) or having grooves with one or ten turns (e.g., approximately 0.03 or 0.28 turns/inch).

Similarly, FIG. 11A is a graph of measured distance traveled by an occlusive synthetic clot through catheter 120 versus the number of turns of grooves 342 along the length of catheter 120 as the clot is aspirated through catheter 120, in accordance with embodiments of the present technology, for the simulated approach to the right pulmonary artery shown in FIG. 9A . The graph illustrates a graph of average clot distance when catheter 120 has a size of 24 French and a length of approximately 36 inches and when the synthetic clot is formed from a silicone 27A mold and has a cylindrical shape having a length of 0.63 inches and a diameter of 0.28 inches. FIG. 11B is a graph of corresponding measured clot velocity in accordance with embodiments of the present technology. FIG. 11B further illustrates a graph of average clot velocity for a synthetic clot having a cylindrical shape having a smaller length of 0.37 inches. 11A and 11B together, when the catheter 120 was tested with five turns, as opposed to having no grooves or grooves with one or ten turns, the distance the clot traveled and the velocity of the clot during aspiration was again maximized.

Similarly, FIG. 12 is a graph of the measured maximum force required to move an occlusive synthetic clot through the catheter 120 versus the number of turns of the groove 342 along the length of the catheter 120 as the clot is aspirated through the catheter 120, in accordance with an embodiment of the present technology, for the simulated approach to the right pulmonary artery shown in FIG. 9A. The graph illustrates a graph of the maximum force when the catheter 120 has a size of 24 French and a length of approximately 36 inches and when the synthetic clot is formed from a silicone 27A mold and has a cylindrical shape with a length of 0.50 inches. As shown, when the catheter 120 is tested with five turns, the maximum force is again minimized as opposed to having no grooves or having grooves with one or ten turns. That is, five turns of the groove 342 minimizes the friction between the clot and the catheter 120 during aspiration.

Thus, in some aspects of the present technology, five or about five revolutions of the groove 342 can maximize the efficiency of clot removal via aspiration through the catheter 120 by (i) increasing the flow rate through the catheter 120, (ii) reducing the clot aspiration time through the catheter 120, (iii) increasing the distance the clot travels through the catheter 120, (iv) increasing the speed at which the clot travels through the catheter 120, (v) reducing friction between the clot and the catheter 120, and/or (vi) reducing the force required to pull the clot through the catheter 120. It is contemplated that the optimal number of revolutions (as well as other parameters) may vary depending on the path the catheter 120 takes through the patient.

In addition, in some aspects of the present technology, it is expected that the optimal number of revolutions depends on the length of the catheter 120. Therefore, the optimal number of revolutions per unit length of the catheter 120 can remain constant for catheters of different lengths. As listed above, for example, the catheter 120 may include between about 0.01 to 0.40 revolutions/inch (e.g., about 0.028 revolutions/inch, about 0.056 revolutions/inch, about 0.139 revolutions/inch, about 0.278 revolutions/inch, between about 0.10 to 0.20 revolutions/inch, between about 0.12 to 0.16 revolutions/inch, etc.). That is, the catheter 120 may include between about 0.005 to 0.15 revolutions/cm (e.g., about 0.011 revolutions/cm, about 0.022 revolutions/cm, about 0.055 revolutions/cm, about 0.109 revolutions/cm, between about 0.03 to 0.08 revolutions/cm, between about 0.04 to 0.07 revolutions/cm, etc.).

V. Selected Embodiments of Apparatus, Systems, and Methods for Making Grooved Aspiration Catheters

Referring to FIGS. 1 to 6B together, in some embodiments, the catheter 120 may be formed around a mandrel, a hypotube, or other elongated member. For example, the liner 232 may first be positioned around the mandrel, and in some embodiments, stretched along the mandrel to a desired thickness. Then, the braid 234 may be formed (e.g., wound, braided) around the mandrel around the liner 232. Next, the coil 236 may be wound around the mandrel around the braid 234 and the liner 232. In some embodiments, the marker band 126 may be positioned around the mandrel in the distal portion 124. Next, the outer sheath 230 may be positioned on the liner 232, the braid 234, and the coil 236, and some or all of these components may then be heat shrunk, melted, laminated, or otherwise fixed together.

In order to form the groove 342, the mandrel may be formed with a corresponding feature that shapes the liner 232. For example, FIG. 13 is a longitudinal view of a mandrel 1350 according to an embodiment of the present technology, on which the catheter 120 may be formed. In the illustrated embodiment, the mandrel 1350 includes a body 1352 (e.g., a cylindrical body) and a convex feature 1354 (e.g., an extrusion, a ridge, a protrusion) that protrudes radially outward from the body 1352 and is separated by a groove or groove 1356. Referring to FIGS. 1 to 6B and 13 together, the convex feature 1354 may correspond to the desired pattern of the groove 342. For example, the feature 1354 may have a size corresponding to the desired depth D and width W of the groove 342, and may be rotated around the body 1352 for any number of turns to provide the desired rifling pattern of the groove 342. The number of features 1354, the spacing between features 1354, the size of features 1354 (e.g., height, width), the pitch or spiral pattern of features 1354, and/or other parameters of features 1354 can be selected to produce 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 produce grooves 342 having a rectangular cross-sectional shape, while in other embodiments, features 1354 can have other cross-sectional shapes (e.g., circular, polygonal, irregular, etc.) to produce grooves 342 of corresponding shapes. As another example, in FIG. 13, mandrel 1350 includes 16 features 1354, so that catheter 120 has corresponding 16 grooves 342. Mandrel 1350 can have any number of features 1354.

When the catheter 120 is formed (e.g., laminated) on the mandrel 1350, the catheter 120 may be radially contracted around the mandrel 1350 and against/between the features 1354 to form the grooves 342. Specifically, the liner 232 may be melted and flow into the grooves 1356 between the features 1354 before being cured to form the grooves 342 (e.g., when the liner 232 includes a Pebax material). Alternatively or additionally, the liner 232 may be pressed and/or formed into the grooves 1356 without melting (e.g., when the liner 232 includes a PTFE material). In some embodiments, to facilitate removal of the catheter 120 from the mandrel 1350 after manufacturing, a lubricant (e.g., a silicone spray lubricant) may be applied to the mandrel 1350 before manufacturing the catheter 120 (e.g., during a demolding process). Similarly, the mandrel 1350 may include a more durable thin layer of PTFE coating on its outer surface to facilitate removal and release of the catheter 120. In some embodiments, the manufacturing process may include a destructive process step that stretches and necks the mandrel 1350 down to a smaller outer diameter to facilitate removal and release of the catheter 120.

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 rifling pattern of the grooves 342. For example, the mandrel 1350 may be rotated a desired number of times during manufacturing (e.g., with the liner 232 in a molten state) so that the grooves 342 pass through a corresponding number of revolutions along the length L of the catheter 120. In some embodiments, the features 1354 may at least partially revolve around the body 1352, and the mandrel 1350 may be rotated during manufacturing of the catheter 120 to introduce further rotation into the grooves 342.

The features 1354 of the mandrel 1350 can be formed by machining a body 1352 (e.g., a hypotube or solid tube) to cut or etch the grooves 1356. In some embodiments, the machining is performed by a multi-axis machine that can rotate the mandrel 1350 during machining so that the grooves 1356 (and corresponding features 1354) revolve around the body 1352. In other embodiments, the mandrel 1350 can be formed by extruding the body 1352 to form the male features 1354 and the grooves 1356.

14A and 14B are respectively a cross-sectional longitudinal view and an enlarged isometric view of a mandrel 1450 according to an additional embodiment of the present technology, on which the catheter 120 can be formed. Referring to FIG. 14A and FIG. 14B together, in the illustrated embodiment, the mandrel 1450 includes a body 1452 and a filament or thread 1454 (e.g., a convex feature) positioned around the body 1452 corresponding to the desired pattern of the groove 342 (FIGS. 1 to 6B). The thread 1454 can be welded to the body 1452, tightly wrapped around the body 1452 (e.g., and fixed at both ends of the thread 1454), or otherwise fixed around/to the body 1452. 1 to 6B, 14A, and 14B together, when the catheter 120 is formed around the mandrel 1450, the liner 232 may melt and flow into the spaces between the wires 1454 before solidification to form the grooves 342, and/or may be pressed and/or 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 spiral 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 each other to form a more uniform pattern of grooves 1454. Likewise, in FIGS. 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 from one another will produce a pattern with a greater depth D and width W of the grooves. 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 manufacturing to produce a gyratory (e.g., spiral) pattern of grooves 342.

VI. Additional Embodiments

Several aspects of the present technology are illustrated in the following examples:

1. A suction catheter, comprising:

proximal end;

distal tip; and

An inner surface defines an inner lumen, wherein the inner surface includes 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 tip to the proximal tip.

3. An aspiration catheter according to Example 1 or Example 2, wherein the inner cavity extends along a longitudinal axis, and wherein the at least one groove rotates circumferentially 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 rotates about the longitudinal axis between the proximal tip and the distal tip approximately 0.05 times or more per inch.

5. The aspiration catheter of Example 3, wherein the at least one groove makes about 0.13 to 0.15 revolutions per inch about the longitudinal axis between the proximal tip and the distal tip.

6. The aspiration catheter of Example 3, wherein the at least one groove makes more than about 0.13 revolutions per inch about the longitudinal axis between the proximal tip and the distal tip.

7. The aspiration catheter of any one of embodiments 1 to 6, wherein the at least one groove has a spiral shape.

8. The aspiration catheter of any one of embodiments 1 to 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. The aspiration catheter of Example 8 or Example 9, wherein the inner cavity extends along a longitudinal axis, and wherein the plurality of grooves rotate circumferentially around the longitudinal axis between the proximal end and the distal end.

11. The aspiration catheter of Example 10, wherein the plurality of grooves rotate about the longitudinal axis between the proximal tip and the distal tip approximately 0.05 times or more per inch.

12. The aspiration catheter of Example 10, wherein the plurality of grooves rotate about the longitudinal axis between the proximal tip and the distal tip approximately 0.13 to 0.15 times per inch.

13. The aspiration catheter of Example 10, wherein the plurality of grooves rotate about the longitudinal axis between the proximal tip and the distal tip more than about 0.13 times per inch.

14. The aspiration catheter of any one of embodiments 1 to 13, wherein the catheter further comprises:

a liner having the inner surface, wherein the at least one groove is formed in the liner;

a braided silk thread fabric, the braided silk thread fabric being located on the inner lining;

a wire coiled on the liner; and

An outer sheath is positioned over the braid, the wires, and the liner.

15. A suction catheter comprising:

proximal end;

distal tip; and

An inner surface defining an inner cavity extending along a longitudinal axis, wherein the inner surface includes a plurality of grooves formed therein, wherein the grooves extend at least partially between the distal end and the proximal end, and wherein the grooves rotate circumferentially about the longitudinal axis between the distal end and the proximal end.

16. The aspiration catheter of Example 15, wherein the groove is disposed at the proximal end and

The distal tips rotate about the longitudinal axis about 0.13 to 0.15 times per inch.

17. The aspiration catheter of Example 15 or Example 16, wherein the grooves are equally 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 tip.

19. The aspiration catheter of any one of Examples 15 to 18, wherein the groove extends completely between the distal tip and the proximal tip.

20. A system for removing material from an internal cavity of a human patient, the system comprising:

an aspiration catheter configured to be positioned proximate a treatment site of the substance within the lumen, wherein the aspiration catheter comprises:

proximal end;

distal tip; and

an inner surface defining an inner lumen, wherein the inner surface includes at least one groove formed therein and extending at least partially from the distal end toward the proximal end;

a tubing assembly fluidly coupled to the conduit and comprising a fluid control device; and

A pressure source fluidly coupled to the conduit assembly and configured to generate negative pressure, wherein the fluid control device is movable between (a) a first position in which the pressure source is fluidly coupled to the suction conduit via the conduit assembly and (b) a second position in which the pressure source is fluidly disconnected from the suction conduit.

21. A system according to embodiment 20, wherein the inner cavity extends along a longitudinal axis, wherein the at least one groove includes a plurality of grooves, wherein the grooves are equally spaced around the circumference of the inner surface, wherein the grooves extend at least partially from the distal end to the proximal end, and wherein the grooves rotate circumferentially around the longitudinal axis between the proximal end and the distal end.

22. A method for removing material from an internal cavity of a human patient, the method comprising:

positioning a distal portion of an aspiration catheter proximate the substance within the lumen, wherein the aspiration catheter includes an inner surface having at least one groove formed therein, and wherein the at least one groove extends 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 conduit via a fluid control device, wherein (a) opening of the fluid control device fluidly connects the pressure source to the aspiration conduit, and (b) closing of the fluid control device fluidly disconnects the pressure source from the aspiration conduit;

activating the pressure source to generate a vacuum when the fluid control device is closed; and

The fluid control device is opened to apply the vacuum to the aspiration conduit, thereby aspirating at least a portion of the substance into the aspiration conduit.

23. The method of embodiment 22, wherein the at least one groove defines a leakage path around the clotted material when the clotted material is aspirated into the aspiration catheter.

24. The method of Example 22 or Example 23, wherein the at least one groove creates a spiral flow pattern in the inner cavity when the clot material is aspirated into the aspiration catheter.

25. A mandrel for forming a catheter, comprising:

a cylindrical body; and

A plurality of features extend radially outward from the body, wherein the conduit is configured to be formed on the body and the features such that the conduit has a plurality of grooves corresponding to the arrangement of the features.

26. The mandrel of embodiment 25, wherein the feature is formed integrally with the body.

27. The mandrel of embodiment 25, wherein the feature is a wire.

28. The mandrel of any one of embodiments 25 to 27, wherein the feature extends helically around the body.

29. A method of forming a catheter, the method comprising:

positioning a liner of the catheter about a mandrel, wherein the mandrel includes a cylindrical body and a plurality of features extending radially outward from the body;

positioning an outer liner of the catheter onto the inner liner around the mandrel; and

The inner liner and the outer liner are heated such that the inner liner includes a plurality of grooves corresponding to the features of the mandrel.

30. The method of embodiment 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 embodiment 29 or embodiment 30, wherein the method further comprises rotating the mandrel after heating the inner liner and the outer liner to rotate the feature and the corresponding groove in the inner liner.

32. The method of any one of embodiments 29 to 31, wherein the feature is formed integrally with the body.

33. The method of any one of embodiments 29 to 31, wherein the feature is a wire.

34. The method of any one of embodiments 29 to 33, wherein the feature extends helically around the body.

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, those skilled in the relevant art will recognize that various equivalent modifications may be made within the scope of the present technology. For example, although the steps are given in a given order, alternative embodiments may perform the steps in a different order. The various embodiments described herein may also be combined to provide other embodiments.

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

In addition, unless the word "or" is expressly limited to mean only a single item in a list involving two or more items that excludes other items, the use of "or" in such a list should be interpreted as including (a) any single item in the list, (b) all items in the list, or (c) any combination of items in the list. In addition, the term "comprising" refers to at least including the mentioned features from beginning to end, so that any greater number of the same features and/or other types of features are not excluded. It should also be understood that specific embodiments have been described here for illustrative purposes, but various modifications can be made without departing from the present technology. In addition, although the advantages associated with certain embodiments of the present technology have been described in the context of these embodiments, other embodiments may also exhibit such advantages, and not all embodiments must exhibit such advantages to belong to the scope of the present technology. Therefore, the present disclosure and related technologies may include other embodiments not explicitly shown or described herein.

Claims (24)

1. A suction catheter, comprising:

A proximal end;

A distal tip; and

An inner surface defining a lumen, wherein the inner surface includes 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 tip to the proximal tip.

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

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

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

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

7. The aspiration catheter of claim 1, wherein the at least one groove has a serpentine 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 about the circumference of the inner surface.

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

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

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

13. The aspiration catheter of claim 10, wherein the plurality of grooves revolve more than about 0.13 times per inch about the longitudinal axis between the proximal and distal ends.

14. The aspiration catheter of claim 1, wherein the catheter further comprises:

A liner having the inner surface, wherein the at least one groove is formed in the liner;

A wire braid located on the liner;

a wire coiled around the liner; and

An outer sheath over the braid, the filaments, and the liner.

15. A suction catheter, comprising:

A proximal end;

A distal tip; and

An inner surface defining a lumen extending along a longitudinal axis, wherein the inner surface includes a plurality of grooves formed therein, wherein the grooves extend at least partially between the distal and proximal ends, and wherein the grooves revolve circumferentially about the longitudinal axis between the distal and proximal ends.

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

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

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

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

20. A system for removing material from within a lumen of a human patient, the system comprising:

A suction catheter configured to be positioned proximate to a treatment site of the substance within the lumen, wherein the suction catheter comprises:

A proximal end;

A distal tip; and

An inner surface defining a lumen, wherein the inner surface includes at least one groove formed therein and extending from the distal end at least partially toward the proximal end;

a conduit assembly fluidly coupled to the conduit and including a fluid control device; and

A pressure source fluidly coupled to the conduit 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 conduit via the conduit assembly, and (b) a second position in which the pressure source is fluidly disconnected from the suction conduit.

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

22. A method for removing material from within a lumen of a human patient, the method comprising:

Positioning a distal portion of a suction catheter proximate to the substance within the lumen, wherein the suction catheter comprises an inner surface having at least one groove formed therein, and wherein the at least one groove extends from a distal tip of the suction catheter at least partially toward a proximal tip of the suction catheter;

coupling a pressure source to the suction catheter via a fluid control device, wherein (a) opening of the fluid control device fluidly connects the pressure source to the suction catheter, and (b) closing of the fluid control device fluidly disconnects the pressure source from the suction catheter;

Activating the pressure source to create a vacuum when the fluid control device is closed; and

Opening the fluid control device to apply the vacuum to the aspiration conduit to aspirate at least a portion of the substance into the aspiration conduit.

23. The method of claim 22, wherein the at least one groove defines a leakage path that bypasses the clot material as it is aspirated into the aspiration catheter.

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