Catheters with preset curves

Abstract

The neurovascular catheter may have an elongated flexible tubular body. The tubular body may have a proximal end, a beveled distal end, and a sidewall defining a central lumen. The neurovascular catheter may further have a distal leading tip on a first side of the beveled distal end. The neurovascular catheter may further have a preset curve in a distal zone of the tubular body.

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of priority under 35 U.S.C. § 119(e) of U.S. Provisional Patent Application No. 63 / 310,696, filed February 16, 2022, the entireties of each of which are incorporated herein by reference. [Background technology]

[0002] Stroke is the third leading cause of death and the most disabling neurological disorder in the United States. Nearly 700,000 patients suffer from stroke each year. Stroke is a syndrome characterized by the acute onset of neurological deficits lasting at least 24 hours reflecting focal involvement of the central nervous system and is the result of impaired cerebral circulation. Incidence increases with age. Risk factors for stroke include systolic or diastolic hypertension, hypercholesterolemia, smoking, heavy alcohol consumption, and use of oral contraceptives.

[0003] Hemorrhagic strokes account for 20% of the annual stroke population. Hemorrhagic strokes are often caused by the rupture of an aneurysm or arteriovenous malformation that bleeds into brain tissue, resulting in cerebral infarction. The remaining 80% of the stroke population are ischemic strokes, which occur when a blood vessel is blocked, depriving the brain of oxygen-carrying blood. Ischemic strokes often occur when an embolus or piece of thrombotic tissue breaks off from another body part or from the cerebral vessels themselves and occludes a more distal narrow cerebral artery. When patients present with neurological symptoms and signs that resolve completely within an hour, the term transient ischemic attack (TIA) is used. Etiologically, TIA and stroke share the same pathophysiological mechanisms and therefore represent a continuum based on the persistence of symptoms and the extent of ischemic damage.

[0004] Emboli can form around the valves of the heart and within the left atrial appendage during irregular heart rates and then break off and travel with the bloodstream to distal regions of the body. These emboli can travel to the brain and cause an embolic stroke. As discussed below, many such blockages occur in the middle cerebral artery (MCA), although this is not the only site for emboli to originate.

[0005] When a patient presents with neurological deficits, a diagnostic hypothesis regarding the cause of the stroke can be made based on the patient's medical history, review of stroke risk factors, and neurological examination. If an ischemic event is suspected, the clinician can tentatively evaluate whether the patient has a cardiogenic embolic cause, extracranial or intracranial disease of the large arteries, intraparenchymal disease of the small arteries, or hematologic or other systemic disease. A head CT scan is often performed to determine whether the patient has suffered an ischemic or hemorrhagic injury. Subarachnoid hemorrhage, intracortical hematoma, or intraventricular hemorrhage may result in the presence of blood on the CT scan.

[0006] In the setting of ischemic stroke, a wide variety of thrombectomy devices have been developed to capture and retrieve clots. These include various expandable cages, baskets, snares, catheters or wires that deliver drugs or energy, and aspiration with or without mechanical disruption. Each of these catheters may be required to navigate deep within the vasculature, for example distal to the ophthalmic artery. Navigation challenges may limit the ability of many catheters to successfully reach the occlusion. Proximal retraction of the catheter may also result in tip dislodgement, such as when a marker band engages the occlusion.

[0007] Notwithstanding the above, a need remains for new devices and methods for treating internal vasculature occlusions, including acute ischemic stroke and occlusive cerebrovascular disease, that have improved navigation capabilities through tortuous vasculature to reach remote treatment sites, and / or improved tensile strength to reduce the risk of tip dislodgement. Summary of the Invention [Means for solving the problem]

[0008] In accordance with one aspect of the present invention, a neurovascular catheter is provided having a pre-shaped distal tip that is self-orienting to match the natural curvature of a blood vessel for improved transvascular navigation through tortuous distal vasculature. The catheter includes an elongated flexible tubular body having a proximal end, a beveled distal end, and a sidewall defining a central lumen. A distal leading tip is carried on a first side of the beveled distal end, and a pre-set curve is provided within a distal zone of the tubular body. The distal leading tip is located on the concave side of the curve.

[0009] A tubular radiopaque marker may be embedded in the side wall, the tubular radiopaque marker including a proximal surface and a distal surface, the distal surface of the radiopaque marker being inclined at an angle within the range of about 45 degrees to about 80 degrees relative to the longitudinal axis of the central lumen.

[0010] The central lumen terminates distally in a distal port having an elliptical opening, which may have an area that is at least about 105% or at least about 110%, and generally within the range of about 110% to about 125%, of the cross-sectional area of ​​the central lumen.

[0011] The elliptical opening defines an oblique distal surface that is oblique at an angle within the range of about 55 degrees to about 65 degrees relative to the longitudinal axis of the central lumen.

[0012] The distal surface of the radiopaque marker may also be inclined at an angle within the range of about 55 degrees to about 65 degrees relative to the longitudinal axis of the central lumen. The proximal surface of the radiopaque marker may be approximately perpendicular to the longitudinal axis.

[0013] The distal end of the catheter may be spaced from the distal face of the radiopaque marker to form an advancing section of the tubular body. The advancing section may have an axial length in the range of about 0.1 mm to about 5 mm. The axial length of the advancing section on the leading edge of the tubular body may be greater than the axial length of the advancing section on the trailing edge of the tubular body. The axial length of the advancing section on the leading edge of the tubular body may be at least about 20% greater than the axial length of the advancing section on the trailing edge of the tubular body.

[0014] The radiopaque marker may have at least one axial slit.

[0015] The catheter may further include a support filament to increase tension resistance and / or affect bending properties in the distal zone. The support filament may include an axially extending filament that may be supported between the inner liner and the helical coil and may be disposed on the convex side of the pre-set curve. In one embodiment, the axially extending filament may include Vectran.

[0016] In accordance with another aspect of the present invention, a self-directing catheter is provided. The catheter includes an elongated flexible tubular body having a proximal end, a distal zone, and a sidewall defining a central lumen. A tubular radiopaque marker band may be embedded in the sidewall in the distal zone. The radiopaque marker band may have a first axial length measured along the sidewall at a first circumferential location and a second, longer axial length measured along the sidewall at a second circumferential location offset about 180 degrees around the circumference of the catheter from the first location, and the tubular body may have a preset curve in the distal zone. The preset curve may have a concave side and a convex side, and the second, longer axial length side of the marker may be on the concave side of the curve. The axially extending filament may be disposed on the convex side.

[0017] Also provided is a catheter, such as a neurovascular catheter, having enhanced tensile strength, including an elongated flexible tubular body having a proximal end, a distal end, and a sidewall defining a central lumen; a radiopaque marker adjacent the distal end and extending at least part way around the circumference of the tubular body; and a tensile support extending axially within the sidewall. The tensile support is attached to the marker and anchors the marker to the catheter body to resist dislodging the distal tip during proximal retraction past the obstruction. In one embodiment, the tensile support may extend distally along a first side (e.g., inner) of the radiopaque marker, fold back around a distal edge of the radiopaque marker, and extend along a second side (e.g., outer) of the radiopaque marker.

[0018] The tensile support may include a plurality of fibers, and in one example includes Vectran multifilament liquid crystal polymer fibers. The tensile support may extend circumferentially at least about 180 degrees or 360 degrees or more around the marker. The catheter sidewall may include an inner liner, a tie layer, and a helical coil, and the tensile support extends axially between the helical coil and the inner liner. The sidewall may include an outer jacket including a plurality of tubular sections, a proximal tubular section of the plurality of tubular sections having a durometer of at least about 60D and a distal tubular section of the plurality of tubular sections having a durometer of at most about 35D.

[0019] The radiopaque marker may include a proximal surface and a distal surface, and the distal surface may be angled at an angle in the range of about 45 degrees to about 80 degrees relative to a longitudinal axis of the central lumen. The radiopaque marker may include an annular ring having at least one axial slit.

[0020] The catheter may include an oblique distal face having a distal port with an elliptical opening, the elliptical opening may include an area that is at least about 105% of the cross-sectional area of ​​the central lumen. The area of ​​the elliptical opening may be at least about 110% of the cross-sectional area of ​​the central lumen, and the elliptical opening may lie on a plane that is oblique at an angle within a range of about 55 degrees to about 65 degrees relative to a longitudinal axis of the central lumen.

[0021] The proximal surface on the radiopaque marker may be approximately perpendicular to the longitudinal axis. The distal end of the catheter may be spaced from the distal surface of the radiopaque marker to form an advancing section of the tubular body beyond the distal end of the marker. The advancing section may have an axial length in the range of about 0.1 mm to about 5 mm. The axial length of the advancing section on the leading edge of the tubular body may be greater than the axial length of the advancing section on the trailing edge of the tubular body.

[0022] The catheter may be configured to withstand a tension of at least about 1.5 pounds or at least about 3.5 pounds before failure (tip dislodgment), and in some embodiments at least about 5 pounds of tension before failure, or at least about 7 pounds of tension before failure, for catheters having an outer diameter of about 0.10 inches or less, or about 0.080 inches or less.

[0023] In any of the neurovascular catheters described herein, the radiopaque marker may include a tubular sidewall having a proximal end and a distal end, and at least one compression feature that increases compressibility of the proximal end. The compression feature may include at least one compression gap in the sidewall that opens at the proximal end of the sidewall and extends distally. Alternatively, the compression feature may include a plurality of struts joined at their apexes that form a collapsible tubular sidewall that is attached to a coil or other catheter component. [Brief description of the drawings]

[0024] [Figure 1A] FIG. 1A is a side elevational view of the catheter. [Figure 1B] FIG. 1B is a side elevational view of a catheter having a preformed curve. [Figure 1C] FIG. 1C is an enlarged view of the distal section of the catheter of FIG. [Figure 1D] FIG. 1D is another enlarged view of the distal section of the catheter of FIG. [Diagram 2] FIG. 2 illustrates a cross-sectional elevation view of a catheter wall according to another embodiment. [Figure 3A] FIG. 3A illustrates a cross-sectional elevation view of a catheter wall according to another embodiment, showing one or more axially extending tension components. [Figure 3B] FIG. 3B illustrates a side elevational view of the catheter of FIG. 3A. [Figure 3C] FIG. 3C illustrates a cross-sectional view taken along line CC of FIG. 3B, showing one or more axially extending tension components. [Figure 3D] FIG. 3D is a side elevational cross-sectional view through an angled distal catheter or extension tube tip. [Figure 3E] FIG. 3E shows a tip like that of FIG. 3D with a marker band tethered to it. [Figure 4A] 4A-4B are side elevational views of the marker band. [Figure 4B] 4A-4B are side elevational views of the marker band. [Figure 4C] FIG. 4C is a top view of the marker band of FIG. 4B. [Figure 4D] FIG. 4D is a side elevational view of an alternative marker band. [Figure 4E] FIG. 4E is a side elevational view of an alternative marker band with an integral tubular tension component. [Figure 4F] FIG. 4F is a side elevational view of an alternative marker band. [Figure 4G] FIG. 4G is a side perspective view of the alternative marker band of FIG. 4F. [Figure 4H] FIG. 4H is a side elevational view of an alternative marker band. [Figure 4I] FIG. 4I is a side perspective view of the alternative marker band of FIG. [Figure 5A] FIG. 5A is a side elevational view of a progressively strengthened flexible catheter according to an embodiment. [Figure 5B] FIG. 5B is a proximal end view of the enhanced flexible catheter of FIG. 5A. [Figure 6] FIG. 6 is a side elevational view of an embodiment of a catheter. [Figure 7] FIG. 7 is a side elevational view of an embodiment of a catheter within a blood vessel. [Figure 8] FIG. 8 is a side elevational view of an embodiment of a catheter adjacent to an obstruction. [Figure 9] FIG. 9 is a side elevational view of an embodiment of a catheter adjacent to an obstruction. [Figure 10] FIG. 10 is a side elevational view of an embodiment of a catheter adjacent to an obstruction. [Figure 11] FIG. 11 is a side elevational view of an embodiment of a catheter. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] 1A-1C, a catheter 10 is disclosed. Although the catheters of the present embodiments are described primarily in the context of an aspiration catheter having a single central lumen, they can be readily modified to incorporate additional structures, such as a permanent or removable column strength enhancing mandrel, or two or more lumens, such as those allowing for the injection of drugs, contrast agents, or irrigation fluids, or providing inflation media to one or more inflatable balloons supported by the catheter, or combinations of these functions, as will be readily apparent to those of skill in the art in view of the disclosure herein. Additionally, while any device, system, or method provided herein may be described in the context of removing occlusive material from remote vasculature in the brain, it will be understood that they have applicability as an access catheter for delivering or removing any of a variety of diagnostic or therapeutic devices, with or without aspiration.

[0026] The catheters disclosed herein may be easily configured for use anywhere in the body where it may be desirable to advance a low-profile, highly flexible catheter distally into small and / or tortuous vasculature. For example, any of the catheter shafts described herein may be dimensioned for use anywhere in the coronary and peripheral vasculature, gastrointestinal tract, urethra, ureters, fallopian tubes, and other lumens and possible lumens. The catheter shaft configuration may also be used to provide minimally invasive percutaneous tissue access, for example, diagnostic or therapeutic access to solid tissue targets (e.g., breast or liver or brain biopsy or tissue resection), delivery of laparoscopic instruments, or access to bones such as the spine for delivery of screws, bone cement, or other instruments or implants.

[0027] The catheter 10 generally includes an elongated tubular body 16 extending between a proximal end 12 and a distal functional end 14. The catheter 10 may have no preset curve (FIG. 1A) or may have a preset curve (FIGS. 1B-1C). The length of the tubular body 16 depends on the desired application. For example, lengths in the range of about 120 cm to about 140 cm or more are typical for use in percutaneous transluminal coronary applications with femoral access. Intracranial or other applications may require different catheter shaft lengths depending on the vascular access site, as discussed in more detail below.

[0028] Any of the catheters described herein may have a length and diameter suitable for the intended access point and target location. In one example, with reference to Figures 1A-1C, the catheter 10 may have an effective length from the manifold or hub 20 to the distal tip 22 that is generally about 180 cm or less or about 160 cm or less, and typically about 70 cm to about 150 cm, about 90 cm to about 130 cm, or about 105 cm to about 115 cm. The outer diameter of the catheter 10 may be about 0.035 inches to about 0.15 inches, about 0.09 inches to about 0.13 inches, and may be smaller in the distal section than in the proximal section.

[0029] The inner diameter of catheter 10 in single central lumen embodiments may be about 0.1 inch or more, about 0.088 inch or more, or about 0.08 inch or more, or about 0.06 inch or more. The inner diameter of catheter 10 in single central lumen embodiments may be about 0.20 inch or 0.15 inch or less, or about 0.11 inch or less, about 0.1 inch or less, about 0.088 inch or less, or about 0.07 inch or less, and often about 0.095 inch or less.

[0030] 1C illustrates the distal section of tubular body 16. A passive distal steering zone 18 on tubular body 16 includes a preformed curve having a concave side 26 and a convex side 28. Tubular body 16 additionally includes a ramp 31, which will be discussed in more detail in connection with FIG. 3D. Ramped surface 31 creates a leading edge at distal tip 22 and an opposing trailing edge 24. Leading edge 22 is disposed on concave side 26 of the preformed curve.

[0031] In the unconstrained configuration, the preformed curve establishes an angle A between the longitudinal axis of the tubular body 16 proximal to the curve (i.e., on the concave side of the preformed curve) and the longitudinal axis of the distal-most 2 or 3 mm of the tubular body 16. Angle A is generally within the range of about 25° to about 55°, preferably about 50° or less, and in some embodiments within the range of about 30° to about 40°. Angle A is preferably within the range of about 32° to about 38°, and in one example is about 35°. Additionally, in some embodiments, angle A is within the range of about 25° to about 45°, about 20° to about 45°, about 15° to about 55°, or about 15° to about 50°. This angle is small enough that the catheter tip 22, in combination with the low lateral deflection of the preformed curve, will follow the natural vasculature but will not penetrate the sidewall into the extravascular space.

[0032] In some embodiments, as shown in FIG. ID, the preformed curve establishes an angle B between the longitudinal axis of the tubular body 16 proximal to the curve (e.g., at the transition 30, or at the convex side of the preformed curve, or relative to the proximal edge of the marker band) and the distal tip 22. Angle B is generally within the range of about 25° to about 55°, preferably about 50° or less, and in some embodiments within the range of about 25° and about 35°. Angle A is preferably within the range of about 27° to about 33°, and in one example is about 30°. Additionally, in some embodiments, angle B is within the range of about 25° to about 45°, about 20° to about 45°, about 15° to about 55°, or about 15° to about 50°.

[0033] 1, the preformed curve establishes a height H between the longitudinal axis of tubular body 16 proximal to the curve (e.g., at transition 30, or at the convex side of the preformed curve, or relative to the proximal edge of the marker band) and distal tip 22. Height H is generally within the range of about 0.25 cm to about 0.6 cm, and in some embodiments, is within the range of about 0.3 cm to about 0.4 cm, or about 0.35 cm to about 0.45 cm, or about 0.4 cm to about 0.5 cm, or about 0.45 cm to about 0.55 cm.

[0034] The lateral limits of the unconstrained deflection D are generally within the range of about 0.1 and about 0.2 inches, and in one embodiment is about 0.15 inches. In some embodiments, the unconstrained deflection D is generally within the range of about 0.05 to about 0.15 inches, about 0.06 to about 0.13 inches, about 0.07 to about 0.12 inches, about 0.075 to about 0.12 inches, etc. Depending on the diameter of the catheter, the unconstrained deflection D is typically about 0.3 inches or about 0.25 inches or about 0.2 inches or less.

[0035] The tubular body 16 includes a transition section 30 at the proximal limit of the preformed curve. The arc length of the preformed curve measured from the transition section 30 to the distal tip 22 is generally less than about 2 cm, or less than about 1.5 cm, or less than about 1 cm, and often between about 0.5 cm and about 1.5 cm, and in some embodiments, the length is about 1.1 cm to about 1.4 cm. In some embodiments, the arc length is within the range of about 0.75 cm to about 1.75 cm, or about 0.5 cm to about 2 cm, or about 1.25 cm to about 2 cm.

[0036] The tubular body 16 can be sufficiently flexible so that the catheter can easily track for advancement even through narrow and / or tortuous body passages. The catheter can bend in any plane in three-dimensional space as it advances through the curves of the vasculature. Thus, at least the distal preformed curve can spontaneously twist about the longitudinal axis of the catheter during advancement through the body passage as it orients itself to follow the shape of the lowest energy state when passing through the curves of the vessel. The torque transmission through the tubular body 16 is sufficiently low (low torsional stiffness) so that the distal end of the catheter can twist about its axis in both clockwise and counterclockwise directions as desired to self-orient with the vasculature during distal advancement without the need to rotate the proximal end of the catheter. In some embodiments, the distal end of the catheter can twist in either direction at least about 10 degrees, at least about 20 degrees, or in some implementations at least about 45 degrees or 90 degrees or more without rotating the proximal end of the catheter at all. Self-orienting or twisting of the catheter may optimize the angle of interaction between the distal end of the catheter and the clot to enhance or maximize uptake of the clot.

[0037] A preset curve along the distal end portion of the catheter may advantageously allow the catheter tip (e.g., angled distal end) to be oriented along the longitudinal axis of the obstruction, greatly enhancing interaction (e.g., uptake) with obstruction (e.g., blood clot) in the blood vessel. A catheter without a preset curve may be less efficient, for example, when attempting to uptake obstruction through the catheter distal end and into the catheter lumen during aspiration, as a result of poor optimal alignment between the catheter tip and the longitudinal axis of the obstruction. The preset curve may, in some instances, facilitate tracking through tortuous vasculature and / or self-regulation of the catheter distal end to the direction of the vessel curvature.

[0038] 6-10 illustrate various embodiments of catheters, some of which incorporate a catheter distal end having a preset curve. It will be understood that any of the features shown or described in connection with any of the catheters of FIGS. 6-10 can be used with any of the embodiments described and / or contemplated herein. It will also be understood that any of the features described and / or contemplated in connection with any of the embodiments disclosed herein can be utilized with any of the catheters described in connection with FIGS. 6-10. As with all embodiments herein, any of the features, structures, materials, methods, or steps described and / or illustrated in the embodiments of FIGS. 6-10 can be used in conjunction with or in place of any of the features, structures, materials, methods, or steps described and / or illustrated in other embodiments herein.

[0039] The preset curve may have characteristics based on one or more parameters of at least the catheter distal end. FIG. 6 illustrates a catheter 600 incorporating various exemplary parameters of a catheter distal end 610 including a preset curve. The catheter 600 may include a marker 630 proximate a distal end surface 620 of the catheter 600. The marker 630 may be any marker described herein (e.g., radiopaque marker 3040, etc.). At least one of the distal end surface 620 of the catheter 600 or the distal end surface 640 of the marker 630 may be disposed at a non-orthogonal angle relative to the longitudinal axis L1 of the catheter 600. The preset curve of the catheter distal end 610 may be characterized by one or more of a rise R1, a stroke R2, or a radius of curvature R3 that may result in an angle A1 of at least one of the distal end surface 620 of the catheter 600 or the distal end surface 640 of the marker 630 relative to the longitudinal axis L1 of the catheter 600 along the preset curve. In some instances, the distal end surface 640 of the marker 630 may be disposed at a first angle relative to a sidewall at the catheter distal end 610 adjacent the marker 630. The first angle may be different from the angle A1 of the distal end surface 640 of the marker 630 relative to the longitudinal axis L1 of the catheter 600.

[0040] The rise R1 may relate to a dimension indicating the length between the sidewall 602 of the catheter 600 and at least one of the distal end surface 640 of the marker 630 or the distal end surface 620 of the catheter 600. The rise R1 may relate to a dimension indicating the length between the inner sidewall of the blood vessel and at least one of the distal end surface 640 of the marker 630 or the distal end surface 620 of the catheter 600 in some instances. Increasing the rise R1 may result in increased deflection of the catheter distal end 610 from the vessel wall. This increase may advantageously result in smoother tracking being experienced and / or easier advancement of the catheter 600 through tortuous vasculature. The dimension of the rise R1 may be limited in some instances due to the particular size of the vasculature being navigated and / or by the overall size of the catheter 600. For example, a larger catheter may require a smaller rise R1 compared to a smaller catheter placed in the same vessel. In some instances, the rise R1 may be limited to avoid unintended "dragging" and / or "folding" of the catheter distal end 610. For example, if the rise R1 is too large, the distal end 610 may interfere and interact with the vessel sidewall such that frictional forces between the catheter distal end 610 and the vessel sidewall resist movement of the catheter. The frictional forces may further result in the distal end 610 folding back. The rise R1 may range between about 1.5 mm and about 4 mm, or more specifically, between about 2.7 mm and about 3.3 mm. The rise R1 may be about 3.0 mm in some instances.

[0041] As illustrated in FIG. 6, the stroke R2 may relate to a dimension indicating the length between the start of the preset curve of the distal end 610 (e.g., the proximal end point) and at least one of the distal end surface 640 of the marker 630 or the distal end surface 620 of the catheter 600. Increasing the stroke R2 may result in an increase in the ability of the catheter 600 to self-orient when advancing through a tortuous vasculature and when advancing toward an obstruction in a blood vessel. The length of the stroke R2 may be limited because extending the stroke R2 to a significant length may reduce the curvature of the preset curve and cause the catheter 600 to function similarly to a catheter without the preset curve. The stroke R2 may include a sufficient length to limit excessive torqueability that may occur if the stroke R2 is too small. The stroke R2 may range between about 5 mm and about 25 mm, or more specifically, between about 7 mm and about 20 mm. The stroke R2 may be about 7 mm, about 8 mm, about 9 mm, or less than about 10 mm in some instances.

[0042] The angle A1 may relate to a dimension that indicates an angle between the sidewall 602 of the catheter 600 and at least one of the distal end surface 640 of the marker 630 or the distal end surface 620 of the catheter 600. The angle A1 may relate in some instances to an angle between an inner sidewall of a blood vessel and at least one of the distal end surface 640 of the marker 630 or the distal end surface 620 of the catheter 600. As illustrated and discussed in connection with FIGS. 7-10, the extent of the angle A1 may affect the orientation of the longitudinal axis L2, which extends perpendicular to at least one of the marker distal end surface 640 or the catheter distal end surface 620, relative to an obstruction in the blood vessel. This angle A1, and the orientation of the axis L2 relative to the obstruction, may affect the efficacy of removal of the obstruction (e.g., aspiration, etc.). The angle A1 may range between about 70 degrees and about 115 degrees, or more specifically, between about 90 degrees and about 105 degrees. Angle A1 may be approximately 95 degrees in some instances. Angle A1 may be up to approximately 105 degrees.

[0043] The radius of curvature R3 may relate to a dimension that indicates the location and curvature of the preset curve along the catheter distal end 610. As illustrated and discussed in connection with FIGS. 9 and 10, the radius of curvature R3 may affect the orientation of the longitudinal axis L2, which extends perpendicular to at least one of the marker distal end face 640 or the catheter distal end face 620, relative to an obstruction in a blood vessel. This radius of curvature R3 and the orientation of the axis L2 relative to the obstruction may affect the efficacy of removal of the obstruction (e.g., by aspiration, etc.). In some instances, it is advantageous to place the radius of curvature as close as possible to the distal end face 620. For example, as the length between the radius of curvature R3 and the distal end face 620 increases, the stiffness of the catheter distal end 610 may increase and approach the stiffness of a catheter that does not include the preset curve. The radius of curvature R3 may be up to about 15 mm or about 12 mm. The radius of curvature R3 may be in the range of between about 5 mm and about 15 mm, or, more specifically, between about 6 mm and about 12 mm. In some instances, the radius of curvature R3 may be about 12 mm or about 9 mm.

[0044] FIG. 7 illustrates an example of a catheter that does not include a preset curve along its distal end. The longitudinal axis L2 represents a longitudinal axis that extends perpendicular to at least one of the distal end surface of the radiopaque marker or the distal end surface of the catheter distal end. As illustrated, the orientation of the axis L2 is angled with respect to the central axis L3 of the vascular occlusion. This angular difference results in a misalignment between the catheter distal end surface and the occlusion, thereby reducing the efficacy of occlusion removal (e.g., by aspiration). In contrast, FIG. 8 illustrates a catheter that includes a preset curve having a longitudinal axis L2 that is generally parallel to, aligned with, or oriented along the central axis L3 of the occlusion. The preset curve may be configured to minimize any resulting angle between the longitudinal axis L2 and at least one of the longitudinal axis of the blood vessel or the longitudinal axis L3 of the occlusion to facilitate removal of the occlusion from the blood vessel through the catheter. 9 and 10 illustrate the resulting angle A3 between the longitudinal axis L2 and the longitudinal axis L3 of the occlusion. In some instances, the resulting angle between the longitudinal axis L2 and at least one of the longitudinal axis of the vessel or the longitudinal axis L3 of the occlusion may be at most about 30 degrees, at most about 20 degrees, at most about 15 degrees, or at most about 10 degrees. In some instances, the resulting angle may be between 0 degrees and about 15 degrees.

[0045] FIG. 11 illustrates an embodiment of a catheter incorporating a catheter distal end having a preset curve. It will be understood that any of the features shown or described in connection with the catheter of FIG. 11 can be used with any of the embodiments described and / or contemplated herein. It will also be understood that any of the features described and / or contemplated in connection with any of the embodiments disclosed herein can be utilized with the catheter described in connection with FIG. 11. For example, unless otherwise noted, the reference symbols in FIG. 11 refer to components that are identical or generally similar to components in the remaining figures discussed herein (e.g., these reference symbols may refer to components having the same or similar last two digits as presented in the remaining figures). As with all embodiments herein, any of the features, structures, materials, methods, or steps described and / or illustrated in the embodiment of FIG. 11 can be used with or in place of any of the features, structures, materials, methods, or steps described and / or illustrated in any other embodiment herein.

[0046] The preset curve may have characteristics based on one or more parameters of at least the catheter distal end. FIG. 11 illustrates a catheter 700 incorporating various exemplary parameters of the catheter distal end 710 including a preset curve. At least one of the distal end surface 720 of the catheter 700 or the distal end surface 740 of the marker 730 may be disposed at a non-orthogonal angle A1 with respect to the longitudinal axis L1 of the catheter 700. The preset curve of the catheter distal end 710 may be characterized by at least one of a rise R1, a stroke R2, or one or more radii of curvature R3, R4 that may result in an angle A1 of at least one of the distal end surface 720 of the catheter 700 or the distal end surface 740 of the marker 730 with respect to the longitudinal axis L1 of the catheter 700 along the preset curve.

[0047] The rise R1 may relate to a dimension indicating the length between the sidewall 702 of the catheter 700 and at least one of the distal end surface 740 of the marker 730 or the distal end surface 720 of the catheter 700. In some instances, the rise R1 may relate to the length between the inner sidewall of the blood vessel and at least one of the distal end surface 740 of the marker 730 or the distal end surface 720 of the catheter 700. Increasing the rise R1 may result in increased deflection of the catheter distal end 710 from the blood vessel wall. This increase may advantageously result in smoother tracking and / or easier advancement of the catheter 700 through tortuous vasculature. The rise R1 may range between about 1.5 mm and about 4 mm, or more specifically, between about 2.5 mm and about 3.5 mm. In some instances, the rise R1 may be about 3.0 mm.

[0048] As illustrated in FIG. 11, the stroke R2 may relate to a dimension indicating the length between the beginning of the preset curved portion of the distal end 710 (e.g., the proximal end point) and at least one of the distal end surface 740 of the marker 730 or the distal end surface 720 of the catheter 700. Increasing the stroke R2 may result in an increased ability of the catheter 700 to self-direct when advancing through a tortuous vasculature and when advancing toward an obstruction in a blood vessel. The stroke R2 may range between about 5 mm and about 25 mm, or more specifically, between about 7 mm and about 20 mm. The stroke R2 may be about 7 mm, about 8 mm, about 9 mm, or less than about 10 mm in some instances.

[0049] The angle A1 may relate to a dimension indicating an angle between the sidewall 702 of the catheter 700 and at least one of the distal end surface 740 of the marker 730 or the distal end surface 720 of the catheter 700. The angle A1 may relate in some instances to an angle between at least one of the inner sidewall of the blood vessel or the longitudinal axis L1 of the catheter 700 and at least one of the distal end surface 740 of the marker 730 or the distal end surface 720 of the catheter 700. The extent of the angle A1 may affect the orientation of the longitudinal axis L2, which extends perpendicular to at least one of the marker distal end surface 740 or the catheter distal end surface 720, relative to an obstruction in the blood vessel. This angle A1, and the orientation of the axis L2 relative to the obstruction, may affect the efficacy of removal of the obstruction (e.g., aspiration, etc.). The angle A1 may range between about 70 degrees and about 125 degrees, or more specifically, between about 90 degrees and about 115 degrees. Angle A1 may, in some instances, be about 100 degrees, about 105 degrees, about 106 degrees, or about 107 degrees. Angle A1 may be up to about 110 degrees.

[0050] The catheter 700 may include one or more segments along the catheter distal end 710 that, in some instances, include one or more values ​​of radius of curvature R3, R4, respectively. The radius of curvature may relate to a dimension that indicates the curvature of a preset curve along the catheter distal end 710. For example, a smaller value of radius of curvature along a portion of the catheter corresponds to a greater degree of curvature along that segment compared to another segment having a larger value of radius of curvature. In some instances, the radius of curvature may be equal to one divided by the derivative of the curvature taken along the length.

[0051] Each of the radii of curvature R3, R4 may affect the orientation of the longitudinal axis L2, which extends perpendicular to at least one of the marker distal end surface 740 or the catheter distal end surface 720, relative to the occlusion in the blood vessel and / or the longitudinal axis L1 of the catheter 700. In some instances, each of the radii of curvature R3, R4 may be optimized to further facilitate passage of the catheter 700 through tortuous vasculature. These radii of curvature R3, R4 and the orientation of the axis L2 relative to the occlusion may affect the efficacy of removal of the occlusion (e.g., by aspiration, etc.). In some instances, it is advantageous to place one or more radii of curvature as close as possible to the distal end surface 720.

[0052] In some embodiments, the catheter distal end 710 may include a first curved section 750 including a first radius of curvature R3 and a second curved section 760 including a second radius of curvature R4. The first curved section 750 may be located proximally along the catheter distal end 710 relative to the first and second curved sections 750. For example, the first curved section 750 may be proximally adjacent to or spaced apart from the second curved section 760. The second curved section 760 may include and / or be adjacent to a section of the catheter distal end 710 that includes the marker 730 and / or the catheter distal end face 720 in some instances.

[0053] The first radius of curvature R3 may be greater than the second radius of curvature R4 in some instances. In this manner, the first curved section 750 may have a smaller degree of curvature relative to the second curved section 760. Alternatively, in certain embodiments, the first radius of curvature R3 may be smaller than the second radius of curvature R4, and thus have a larger degree of curvature.

[0054] The first radius of curvature R3 may be at most about 25 mm or about 20 mm. The first radius of curvature R3 may be at least about 10 mm or about 13 mm. The first radius of curvature R3 may be in a range between about 10 mm and about 25 mm, or more specifically, between about 13 mm and about 21 mm. The first radius of curvature R3 may be about 16 mm, about 17 mm, or about 18 mm in some instances.

[0055] The second radius of curvature R4 may be at most about 15 mm or about 10 mm. The second radius of curvature R4 may be at least about 2 mm or about 5 mm. The second radius of curvature R4 may be in a range between about 2 mm and about 10 mm, or more specifically, between about 5 mm and about 8 mm, or between about 5 mm and about 6 mm. The second radius of curvature R4 may be about 5 mm, about 5.5 mm, or about 6 mm in some instances.

[0056] The first radius of curvature R3 and the second radius of curvature R4 may be determined as a percentage or ratio to each other. The ratio of the value of the first radius of curvature R3 divided by the value of the second radius of curvature R4 may be at most about 4.5 or about 4.2. The ratio may be at least about 1.5 or about 1.6. The ratio may range between about 2 and about 3, or more specifically, between about 2.5 and about 2.75. The ratio may be about 2.8 in some instances.

[0057] 2 illustrates a cross section through the sidewall of a distal section of a single lumen catheter that may be formed with or without a preset curve. Adjacent loops or filler of the coil 3024 may have a constant pitch throughout the length of the coil, or may be tightly wound in the proximal zone and have more loose spacing between adjacent loops in the distal section. In embodiments having coil sections 3024 with axial lengths between at least about 20% and about 30% of the total catheter length (e.g., a 28 cm coil length in a 110 cm catheter shaft 16), at least the distal about 1 cm, or about 2 cm, or about 3 cm, or about 4 cm of the coil will have a spacing of at least about 130% of the spacing of the proximal coil sections, and in some embodiments at least about 150% or more. For a 110 cm catheter shaft 3000 with nitinol coils, the spacing in the proximal coils may be about 0.004 inches and in the distal section may be at least about 0.006 inches or about 0.007 inches or more.

[0058] The distal end of the coil 3024 can be spaced proximally from the distal end of the inner liner 3014 to provide room for, for example, an annular radiopaque marker 3040. The coil 3024 can be set back proximally from the distal end by approximately 1 cm, 2 cm, or 3 cm or less in some embodiments. In one embodiment, the distal end of the catheter 10 includes an inclined distal surface 3006 that lies on a plane having an angle of at least about 10 degrees or about 20 degrees, and in one embodiment about 30 degrees, relative to the longitudinal axis of the catheter 10. The radiopaque marker 3040 can be located in a plane transverse to the longitudinal axis. Alternatively, at least the distally facing edge of the annular radiopaque marker 3040 can be an ellipse that lies on a plane that is inclined relative to the longitudinal axis to be complementary to the oblique angle of the distal surface 3006. Additional details are described in connection with accompanying FIG. 3D.

[0059] After application of the proximal braid 3010 over the tie layer 3012, the distal coil 3024 and RO marker 3040 are provided with an outer jacket 3020, such as a shrink-wrap tube, that surrounds the catheter body 16. The outer shrink-wrap sleeve 3020 may comprise any of a variety of materials, such as polyethylene, polyurethane, polyether block amide (e.g., PEBAX™), nylon, or others known in the art. Sufficient heat is applied to cause a polymer to flow into and embed the proximal braid and distal coil.

[0060] In one embodiment, the outer shrink-wrap jacket 3020 is formed by sequentially advancing a number of short tubular sections 3022, 3026, 3028, 3030, 3032, 3034, 3036, 3038 concentrically over the catheter shaft subassembly and shrinking the sections onto the catheter 10 by application of heat to provide a smooth, continuous outer tubular body. The aforementioned segmented structure may extend along at least the most distal 10 cm of the catheter body 10, and preferably at least the most distal 20 cm, about 25 cm, about 30 cm, about 35 cm, about 40 cm, or greater than about 40 cm. The entire length of the outer shrink-wrap jacket 3020 may be formed from tubular sections, and the length of the distal tubular sections (e.g., 3022, 3026, 3028, 3030, 3032, 3034, 3036, 3038) may be shorter than one or more of the tubular sections forming the proximal portion of the outer shrink-wrap jacket 3020 to provide proximal backup support and a sharper transition in flexibility toward the distal end of the catheter 10.

[0061] The durometer of the outer wall sections may decrease distally. For example, the proximal sections, such as 3022 and 3026, may have a durometer of at least about 60D or about 70D, with the durometer of the subsequent sections gradually decreasing distally to durometers of about 35D or less, or less than about 25D. The 25 cm section may have at least about three or about five or about seven or more sections, and the entire catheter 10 may have at least about six or about eight or about ten or more distinct flexibility zones. The distal one or two or four or more sections 3036, 3038 may have a smaller contracted OD than the more proximal sections 3022-3034, thereby forming a tapered OD in the finished catheter body 16. The length of the smaller OD section 3004 may be in the range of about 3 cm to about 15 cm, and in some embodiments is in the range of about 5 cm to about 10 cm, e.g., about 7 cm or about 8 cm, and may be completed by providing distal sections 3036, 3038 having a smaller wall thickness.

[0062] In another embodiment, the most distal portion of the catheter 10 may include a durometer less than approximately 35D (e.g., 25D) to form a highly flexible distal portion of the catheter and may have a length between approximately 25 cm and approximately 35 cm. The distal portion may include one or more tubular sections (e.g., section 3038) of the same durometer. A series of proximally adjacent tubular sections may form a transition region between the proximal stiffer portion of the catheter 3000 and the distal highly flexible portion. The series of tubular sections forming the transition region may have the same or substantially similar lengths, for example, approximately 1 cm.

[0063] The length of each of the series of tubular sections may be relatively short to provide a steep drop in durometer across the transition region. For example, the transition region may have a proximal tubular section 3036 (adjacent the distal portion) having a durometer of approximately 35D. The adjacent proximal section 3034 may have a durometer of approximately 55D. The adjacent proximal section 3032 may have a durometer of approximately 63D. The adjacent proximal section 3030 may have a durometer of approximately 72D.

[0064] The more proximal section may include a durometer greater than approximately 72D and may extend to the proximal end of the catheter or extension catheter section. Illustratively, the extension catheter section may include a proximal portion greater than approximately 72D between about 1 cm and about 3 cm. In some embodiments, the proximal portion may be about 2 cm long. In some embodiments, the most distal section (e.g., 3038-3030) may include PEBAX™ and the more proximal sections may include a generally harder material, such as Vestamid®.

[0065] The inner diameter of the catheter 10 may be between approximately 0.06 and 0.08 inches, between approximately 0.065 and 0.075 inches, or between approximately 0.068 and 0.073 inches. In some embodiments, the inner diameter is approximately 0.071 inches.

[0066] In some embodiments, the distal-most portion may taper to a reduced inner diameter, as described elsewhere herein. The taper may occur approximately between the distal highly flexible portion and the transition region (e.g., over the most proximal portion of the distal highly flexible portion). The taper may be relatively gradual (e.g., occurring over approximately 10 cm or more) or relatively abrupt (e.g., occurring over approximately less than 5 cm). The inner diameter may taper to an inner diameter of between about 0.03 and about 0.06 inches. For example, the inner diameter may be about 0.035 inches, about 0.045 inches, or about 0.055 inches at the distal end of the catheter 3000. In some embodiments, the inner diameter may remain constant at least over the catheter extension section.

[0067] In some embodiments, the coil 3024 may extend proximally from the distal end of the catheter 10 along a highly flexible distal section that terminates at the distal end of the transition region. In other embodiments, the coil 3024 may extend proximally from the distal end of the catheter to the proximal end of the transition region, to a point along the transition region, or beyond the transition region. In other embodiments, the coil 3024 may extend the entire length of the catheter 10 or catheter extension section, as described elsewhere herein. The braid 3010, if present, may extend from the proximal end of the coil 3024 to the proximal end of the catheter 10.

[0068] 3A-3D, the catheter may further include an axial tension component or support, such as a ribbon or one or more filaments or fibers, to increase tension resistance and / or affect bending properties in the distal zone. The tension support may include one or more monostrand or multistrand filaments 3042 extending axially. The tension component or components 3042 may be axially disposed within the catheter wall near the distal end of the catheter. The filaments may be disposed on the convex side of the catheter with a preset curve. The tension component or components 3042 may act as a tension support to resist stretching of the catheter wall under tension (e.g., when the catheter is retracted proximally through a tortuous or narrow vasculature).

[0069] At least one of the one or more tension components 3042 may extend proximally along the length of the catheter wall from within about 1.0 cm of the distal end of the catheter, to less than about 10 cm from the distal end of the catheter, to less than about 20 cm from the distal end of the catheter, to less than about 30 cm from the distal end of the catheter, to less than about 40 cm from the distal end of the catheter, or to less than about 50 cm from the distal end of the catheter.

[0070] One or more tension components 3042 may have a length of about 40 cm or more, about 30 cm or more, about 20 cm or more, about 10 cm or more, or about 5 cm or more.

[0071] At least one of the one or more tension components 3042 may extend to at least about the most distal 50 cm of the length of the catheter, at least about the most distal 40 cm of the length of the catheter, at least about the most distal 30 cm or about 20 cm or about 10 cm of the length of the catheter.

[0072] In some embodiments, the tension component extends proximally from the distal end of the catheter along the length of the coil 24, terminating proximally within about 5 cm or about 2 cm or less on either side of the transition 3011 between the coil 3024 and the braid 3010. The tension component may terminate at the transition 3011 without overlapping the braid 3010.

[0073] One or more tension components 3042 may be disposed near or radially outward of the tie layer 3012 or inner liner 3014. One or more tension components 3042 may be disposed near or radially inward of the braid 3010 and / or coil 3024. One or more tension components 3042 may be carried between the inner liner 3014 and the helical coil 3024 and may be secured by an adhesive to the inner liner or other substrate surface prior to adding the next outer adjacent layer, such as a coil.

[0074] When one or more tension components 3042 or filament bundles are circumferentially spaced within the catheter wall, the tension components 3042 may be arranged in a radially symmetrical manner. For example, the angle between two tension components 3042 relative to the radial center of the catheter may be about 180 degrees. Alternatively, depending on the desired clinical performance (e.g., flexibility, trackability), the tension components 3042 may be arranged in a radially asymmetrical manner. The angle between any two tension components 3042 relative to the radial center of the catheter may be less than about 180 degrees, about 165 degrees or less, about 135 degrees or less, about 120 degrees or less, about 90 degrees or less, about 45 degrees or less, or about 15 degrees or less.

[0075] The tension component(s) 3042 may comprise materials such as Vectran, Kevlar, polyester, Meta-Para-Aramide, or any combination thereof. At least one of the tension component(s) 3042 may comprise a single fiber or a bundle of multiple fibers, and the fiber or bundle may have a circular or rectangular (e.g., ribbon) cross-section. The term fiber or filament does not denote composition, but may comprise any of a variety of high tensile polymers, metals, or alloys, depending on design considerations such as desired tensile fracture limits and wall thickness. The cross-sectional dimension of the tension component(s) 3042 may be less than or equal to about 2%, 5%, 8%, 15%, or 20% of the cross-sectional dimension of the catheter 10, measured radially.

[0076] The cross-sectional dimension of one or more tension components 3042, measured radially, may be about 0.001 inches or less, about 0.002 inches or less, about 0.004 inches or less, about 0.006 inches or less, about 0.008 inches or less, or about 0.015 inches or less.

[0077] The one or more tensioning components 3042 may increase the tensile strength of the distal zone of the catheter prior to breaking under tension to at least about 1 pound, at least about 2 pounds, at least about 3 pounds, at least about 4 pounds, at least about 5 pounds, at least about 6 pounds, at least about 7 pounds, at least about 8 pounds, or at least about 10 pounds or more.

[0078] Any of the catheters disclosed herein may be equipped with an angled distal tip, with or without an axial tension component. Referring to Figure 3D, a distal catheter tip 3110 includes a tubular body 3112 including an advancement section 3114, a marker band 3116, and a proximal section 3118. An inner tubular liner 3120 may extend the entire length of the distal catheter tip 3110 and may include dip-applied PTFE.

[0079] A reinforcing element 3122 , such as a braid or spring coil, is embedded in an outer jacket 3124 that may extend the entire length of the distal catheter tip 3110 .

[0080] The advancing section 3114 terminates distally in an angled surface 3126 to provide a leading sidewall portion 3128 having a length measured between the distal end 3130 of the marker band 3116 and the distal tip 3132. The trailing sidewall portion 3134 of the advancing section 3114 has an axial length approximately equal to the axial length of the leading sidewall portion 3128, measured approximately 180 degrees around the catheter from the leading sidewall portion 3128, in the illustrated embodiment. The leading sidewall portion 3128 may have an axial length within the range of about 0.1 mm to about 5 mm, generally within the range of about 1 to about 3 mm. The trailing sidewall portion 3134 may be at least about 0.1 or 0.5 or 1 mm or 2 mm or more shorter than the axial length of the leading sidewall portion 3128, depending on the desired performance.

[0081] The angled surface 3126 is inclined at an angle in the range of about 45 degrees to about 80 degrees from the longitudinal axis of the catheter. In certain embodiments, the angle is in the range of about 55 degrees to about 65 degrees, or in the range of about 55 degrees to about 65 degrees from the longitudinal axis of the catheter. In one embodiment, angle A is about 60 degrees. One consequence of angle A being less than 90 degrees is that the long axis of the region of the distal port is elongated, which may increase the surface area of ​​the port and enhance clot aspiration or retention. Compared to the surface area of ​​a circular port (angle A is 90 degrees), the area of ​​the angled port is generally at least about 105% and not more than about 130%, in some embodiments in the range of about 110% and about 125%, and in one example about 115%.

[0082] In the illustrated embodiment, the axial length of the advancing section is substantially constant around the circumference of the catheter such that the angled surface 3126 is generally parallel to the distal surface 3136 of the marker band 3116. The marker band 3116 has a proximal surface that is generally transverse to the longitudinal axis of the catheter, producing the marker band 3116 with a trapezoidal configuration in side elevation. The short sidewall 3138 is in rotational alignment with the trailing sidewall portion 3134 and has an axial length within a range of about 0.2 mm to about 4 mm, typically about 0.5 mm to about 2 mm. The opposing long sidewall 3140 is in rotational alignment with the leading sidewall portion 3128. The long sidewall 3140 of the marker band 3116 is generally at least about 10% or 20% longer than the short sidewall 3138, and may be at least about 50% or 70% or 90% or more longer than the short sidewall 3138 depending on the desired performance. Generally, the long sidewall 3140 has a length of at least about 0.5 mm or 1 mm, and less than about 5 mm or about 4 mm.

[0083] Any of the marker bands described herein may be a continuous annular structure or may optionally have at least one, and optionally two or more, axially extending slits 3117 throughout its length. The slits may be located on the short sidewall 3138, or on the long sidewall 3140, or in between, depending on the bending characteristics desired. Any of the marker bands described herein may comprise any of a variety of radiopaque materials, such as a platinum / iridium alloy, and have a wall thickness preferably less than about 0.003 inches, and in one embodiment about 0.001 inches. In one embodiment, at least one axial slit is aligned with the convex side of the preset curve, and the filament extends distally beyond the proximal face of the marker into the axial slit.

[0084] The marker band zone of the assembled catheter may have a relatively high bending stiffness and high crush strength, for example at least about 50% or at least about 100% less than the proximal section 3118, but generally no more than about 200% less than the proximal section 3118. The high crush strength may provide radial support to the adjacent advancing section 3114, particularly to the leading sidewall portion 3128, to facilitate functioning of the distal tip 3132 as an atraumatic shock absorber during transluminal advancement, as well as resist contraction under vacuum. The proximal section 3118 preferably has a lower bending stiffness than the marker band zone, and the advancing section 3114 preferably has a lower bending stiffness and crush strength than the proximal section 3118.

[0085] The advancing section 3114 may include an outer jacket 3124 and optionally a distal extension of the inner liner 3120 without other internal support structure distal to the marker band 3116. The outer jacket may include extruded Tecothane. The advancing section 3114 may have a bending stiffness and radial crush stiffness that is about 50% or less than the corresponding values ​​of the proximal section 3118, and in some embodiments about 25% or about 15% or about 5% or less.

[0086] A tension component 3142, having dimensions and materials as discussed elsewhere herein, extends through at least a distal portion of the length of the proximal section 3118. As illustrated, the tension component 3142 may terminate distally at a proximal surface of the marker band 3116 and may extend radially outward of the tubular liner 3120 and radially inward from the support coil 3122. Alternatively, the marker band may include at least one or two axially extending slits 3117, and the fibers may extend into the slits, thus overlapping the marker band axially. The tension component 3142 may extend substantially parallel to the longitudinal axis, or may be angled into a gentle spiral that completes no more than 10, 7, 3, or 1 full revolution around the catheter along its length. The fibers may comprise high tensile strength materials such as multifilament yarns spun from liquid crystal polymers, such as Vectran multifilament LCP fibers.

[0087] In the embodiment illustrated in FIG. 3E, the tension component 3142 extends axially distally along the outside (or inside) of the coil toward an anchor, which may be in the form of a continuous or slit-like annular ring, such as the marker band 3116, which may have a slanted distal surface as discussed. The tension component 3142 is preferably secured to the anchor to increase the tensile force threshold before breaking due to tip dislodging. This may allow the catheter to be pulled proximally through constraints, such as vascular constraints or kinks in the guide catheter, where the marker band may contract but not dislodge. The increased tensile strength also provides the physician with tactile feedback when encountering a constraint that may shear the marker band. In an embodiment having a slit 3117, the axis of the tension component 3142 may be circumferentially offset from the slit 3117 to avoid pulling the fiber through the slit.

[0088] The tension component 3142 may be securely secured to the anchor in any of a variety of ways depending on the structure and materials involved, including adhesives, welding, or a mechanical interference fit. In the illustrated embodiment, the tension component 3142 is wrapped around at least the distally facing edge of the marker band 3116, such as the distal edge of the marker band or the proximal edge of the opening through the marker band 3116. In one embodiment, the tension component 3142 extends axially along and beyond the first surface of the marker band, around the distal edge of the marker band, and folded back onto the second surface of the marker band and is securely secured to the tubular body (e.g., to the marker band or to the tension component itself).

[0089] In the illustrated embodiment, a first section 3150 of the tension component 3142 extends axially along the catheter body, over or preferably under the coil, under the marker band 3116, and distally along the inner surface of the marker band to the distal edge 3156 of the marker band. The tension component folds back over the distal edge 3156, extends proximally on the outer surface of the marker band along the angled section 3152, and is wrapped circumferentially around the tubular body, such as over the marker band 3116 and / or adjacent catheter sidewall, to the end 3154. The tension component may be wrapped circumferentially through an angle of at least about 180 degrees, and preferably at least about 270 degrees or about 360 degrees, or at least about 450 degrees or more. The tension component may be attached over the marker band or adjacent catheter shaft with an adhesive such as Loctite prior to application of the outer polymer jacket.

[0090] Alternatively, the tension component may be folded back around the marker band and back proximally over itself, with an adhesive zone running proximally for at least about 1 or about 2 or about 5 cm or more and adhered along that adhesive zone to itself before being covered with the outer jacket.

[0091] In the illustrated embodiment, the tension component intersects the marker band at a circumferential offset range of approximately 20 degrees to approximately 40 degrees from the center of the slit 3117. Alternatively, the tension component may intersect the marker band at a circumferential offset range of approximately 80 degrees to approximately 100 degrees from the slit, or at a circumferential offset range of approximately 170 degrees to approximately 190 degrees from the slit. In embodiments where the slit is not located at the shortest axial dimension of the marker band, the aforementioned offsets may be measured from the shortest axial dimension.

[0092] The radial compressibility of the marker band may desirably increase proximally from the distal end of the marker band to the proximal end of the marker band, forming a continuous or stepped compressibility. This may facilitate radial compressibility at the proximal end of the marker band, such as in the event that the marker band encounters an obstruction (e.g., an obstruction on a vessel or a kink in the guide catheter) during proximal retraction of the catheter. Further proximal retraction may allow the sidewall of the marker band to be pulled up to the diameter of the distal end of the marker band, displacing the obstruction laterally and / or progressively contracting the marker band to push the marker band past the obstruction. This, in combination with an attached tensioning component, optimizes the likelihood of avoiding dislodging the marker band.

[0093] The basic geometry of the marker band 3116 previously described is illustrated in Figure 4A. The marker band 3116 extends between a proximal cross surface 3150 and a distal angled surface 3136. A long side wall 3140 terminates distally in a distal tip 3130. An opposing short side wall 3138 may contain an axial slit as discussed.

[0094] 4B, the marker band 3116 includes a compression feature that increases the radial compressibility of the proximal end of the marker band. In the illustrated embodiment, the compression feature includes at least a first compression gap 3152 and may include at least a second compression gap in the form of a proximally-facing recess 3154. The first compression gap 3152 extends distally from the proximal surface 3150 at least about 25% of the length of the elongate sidewall 3140, and in some embodiments at least about 50% or about 70% or more.

[0095] The second compression gap may be rotated approximately 90 degrees in a first circumferential direction from the first compression gap 3152 and extend distally from the proximal face 3150. At least a third compression gap may be provided rotated approximately 90 degrees in a second circumferential direction from the first compression gap 3152.

[0096] The aforementioned structure provides an arcuate base 3156 in the form of a proximal edge of the marker band 3116 that lies in the plane of the proximal face 3150 and is for contacting the distal end of a coil or other sidewall reinforcement within the catheter body. A first foot 3158 and a second foot 3160 are also formed that also lie generally in a plane corresponding to the proximal face 3150 and are for supporting the marker band 3116 back to back with the distal end of the spring coil or other catheter body reinforcement. This allows radial compression of the proximal end of the marker band 3116 while simultaneously supporting the marker band 3116 against a tilt relative to the distal face of the coil.

[0097] In the embodiment shown in FIG. 4D, a marker band 3116 having the characteristics of the marker band of FIG. 4A is modified by providing at least a first compression gap 3152 to promote radial compression. A second compression gap 3162 and optionally a third compression gap 3164, or more, may be provided depending on the desired performance. The proximal openings of the compression gaps may be located on a transverse plane, such as on the proximal face 3150 of the marker band 3116. Each compression gap preferably has a width measured circumferentially at its proximal end that exceeds the width of the compression gap near its distal end. The axial depths of the compression gaps may be approximately equal, such that the distal ends of the compression gaps are all aligned in a transverse plane approximately parallel to the proximal face 3150. Alternatively, as illustrated in FIG. 4D, the distal ends of the compression gaps may be progressively aligned such that they are located on an inclined plane that may be approximately parallel to the inclined distal face 3136.

[0098] Alternatively, as shown in the marker bands of Figures 4F-4I, one or more compression gaps may extend between the proximal cross-plane 3150 and the distal angled surface 3136, but may not intersect the proximal cross-plane 3150 (e.g., in contrast to the marker bands of Figure 4E). As noted above, each compression gap 3176, 3178, 3180 may have a width measured circumferentially at its proximal end that exceeds the width of the compression gap near its distal end, as shown in Figures 4H-4I. Alternatively, each compression gap 3170, 3172, 3174 may have a width measured circumferentially at its proximal end that is substantially equal to or substantially similar to the width of the compression gap near its distal end, as shown in Figures 4F-4G. The angle and / or shape of the distal ends 3170a, 3174a, 3176a, 3180a of the compression gaps 3170, 3174, 3176, 3180, respectively, may be substantially equal to or similar to the angle of the distal surface 3136, as described above and shown in Figures 4F-4I. The circumferentially continuous proximal cross-section 3150 of each of the embodiments of Figures 4F-4I is such as to allow for secure fixation to a coil, as described elsewhere herein and below.

[0099] In addition to or in lieu of a tensioning component, any of the marker bands disclosed herein may be securely secured to the coil, such as by adhesive, welding, or a mechanical interference fit. In one embodiment of a mechanical interference fit, a helical slot may be formed in the proximal sidewall of the marker band and extend circumferentially at least about 45 degrees, and in some embodiments at least about 180 degrees or up to about 360 degrees or more. This allows the distal end of the helical coil to be threaded into the helical slot in the marker band sidewall while simultaneously retaining the ID of the lumen and OD of the catheter across the junction.

[0100] As a further alternative, the marker band and the long, proximally extending axial or helical strut tension element may be laser cut from a single tube of material such that one or more tension components are formed integrally with the marker band.

[0101] The tension component may take the form of at least one, and optionally at least two or four or ten or more struts, which may extend proximally in a straight, spiral, or intersecting, e.g., diamond, pattern.

[0102] For example, the marker band of FIG. 4E (with optional compression gap omitted for simplicity) includes a tension component in the form of multiple intersecting struts 3166 defining a tubular body with multiple sidewall openings 3168, which may be progressively more or less compressible in a proximal direction. The marker band and associated tension component struts 3166 may be slidably fitted onto the tie layer with the coil wound around at least a portion of the length of the tension component, with or without application of adhesive prior to winding the coil. Alternatively, multiple proximal apices may be aligned and formed on a transverse plane or other geometry complementary to the geometry of the distal end of the support structure (e.g., coil) within the catheter shaft, and welded end to end to provide a tightly secured joint. Additionally, any of the embodiments of FIGS. 4A-4I may or may not include axially extending slits, as described elsewhere herein.

[0103] 5A-5B, an example of an outer jacket section layering pattern for a progressively flexible catheter of the type discussed in connection with FIG. 2 is shown. The distal section 3038 may have a length in the range of about 1-3 cm and a durometer of about 35D or less than about 30D. The adjacent proximal section 3036 may have a length in the range of about 4-6 cm and a durometer of about 35D or less than 30D. The adjacent proximal section 3034 may have a length in the range of about 4-6 cm and a durometer of about 35D or less. The adjacent proximal section 3032 may have a length in the range of about 1-3 cm and a durometer in the range of about 35D to about 45D (e.g., 40D). The adjacent proximal section 3030 may have a length in the range of about 1-3 cm and a durometer in the range of about 50D to about 60D (e.g., about 55D). The adjacent proximal segment 3028 may have a length in the range of about 1-3 cm and a durometer in the range of about 35D to about 50D to about 60D (e.g., about 55D). The adjacent proximal segment 3026 may have a length in the range of about 1-3 cm and a durometer of at least about 60D, typically less than about 75D. The more proximal segments may have a durometer of at least about 65D or 70D. The most distal two or three segments may comprise a material such as Tecothane, and the more proximal segments may comprise PEBAX, or other catheter jacket materials known in the art. At least three or five or seven or nine or more individual segments may be utilized, where the change in durometer between the highest and lowest along the length of the catheter shaft is at least about 10D, preferably at least about 20D, and in some embodiments at least about 30D or 40D or more.

[0104] Exemplary embodiments

[0105] below: 1. An elongate flexible tubular body including a sidewall defining a central lumen and a distal end surface, the distal end portion of the sidewall comprising: a first curved section including a first radius of curvature; a second curved section located distal to the first curved section and including a second radius of curvature; A flexible tubular body comprising: A catheter comprising one or more of: A catheter, wherein the first radius of curvature is different from the second radius of curvature.

[0106] The catheter of any of the embodiments herein, wherein a distal end surface of the side wall is disposed at a non-orthogonal angle relative to the side wall at the distal end of the tubular body.

[0107] The catheter of any of the embodiments herein, further comprising a radiopaque marker at a distal end portion of the sidewall.

[0108] A catheter as described in any embodiment herein, wherein the radiopaque marker comprises a distal end surface at a distal end portion of the tubular body and disposed at a non-orthogonal angle relative to the sidewall.

[0109] The catheter of any of the embodiments herein, wherein the radiopaque marker comprises a proximal end face disposed at a generally perpendicular angle to the sidewall at the distal end portion of the tubular body.

[0110] The catheter of any of the embodiments herein, wherein a radiopaque marker is located along the second curved section.

[0111] The catheter of any of the embodiments herein, wherein the radiopaque marker is located distal to the second curved section.

[0112] The catheter of any of the embodiments herein, wherein the first curved section is adjacent to the second curved section.

[0113] The catheter of any of the embodiments herein, wherein the distal end portion comprises a rise of between about 1.5 mm and about 4 mm.

[0114] The catheter of any of the embodiments herein, wherein the rise is between about 2.5 mm and about 3.5 mm.

[0115] The catheter of any of the embodiments herein, wherein the distal end portion comprises a stroke of between about 5 mm and about 25 mm.

[0116] The catheter of any of the embodiments herein, wherein the distal end portion comprises a stroke of between about 7 mm and about 20 mm.

[0117] The catheter of any of the embodiments herein, wherein the first radius of curvature is between about 10 mm and about 25 mm.

[0118] The catheter of any of the embodiments herein, wherein the first radius of curvature is between about 15 mm and about 20 mm.

[0119] The catheter of any of the embodiments herein, wherein the second radius of curvature is between about 5 mm and about 8 mm.

[0120] The catheter of any of the embodiments herein, wherein the second radius of curvature is between about 5 mm and about 6 mm.

[0121] The catheter of any of the embodiments herein, wherein the second radius of curvature is smaller than the first radius of curvature.

[0122] The catheter of any of the embodiments herein, wherein a ratio of the first radius of curvature to the second radius of curvature is between about 1.5 and about 4.5.

[0123] The catheter of any of the embodiments herein, wherein a ratio of the first radius of curvature to the second radius of curvature is between about 2 and about 3.

[0124] The catheter of any of the embodiments herein, wherein the distal end face of the tubular body is disposed at a non-orthogonal angle relative to the longitudinal axis of the tubular body.

[0125] The catheter of any of the embodiments herein, wherein the non-orthogonal angle is between about 90 degrees and about 115 degrees.

[0126] The catheter of any of the embodiments herein, wherein the non-orthogonal angle is up to about 110 degrees.

[0127] below: an elongate flexible tubular body including a sidewall defining a central lumen and a distal end surface; a radiopaque marker in the sidewall at the distal end of the tubular body, the radiopaque marker including a distal end face disposed at a first angle relative to the sidewall at the distal end of the tubular body; a preset curve at the distal end of the tubular body such that a distal end surface of the radiopaque marker is oriented at a second angle relative to a longitudinal axis of the tubular body, the second angle being different from the first angle; A catheter comprising one or more of:

[0128] The catheter of any one of the embodiments herein, wherein the first angle is not orthogonal.

[0129] The catheter of any of the embodiments herein, wherein the second angle is orthogonal.

[0130] The catheter of any of the embodiments herein, wherein the second angle is between about 90 degrees and 105 degrees.

[0131] The catheter of any of the embodiments herein, wherein the preset curve comprises a rise of between about 1.5 mm and about 3.0 mm.

[0132] The catheter of any of the embodiments herein, wherein the rise is about 3.0 mm.

[0133] The catheter of any of the embodiments herein, wherein the pre-set curve comprises a travel of between about 7 mm and about 20 mm.

[0134] The catheter of any of the embodiments herein, having a stroke of about 9 mm.

Claims

1. an elongated flexible tubular body including a sidewall defining a central lumen and a distal end surface; the distal end portion of the sidewall includes a first curved section including a first radius of curvature and a second curved section located distal to the first curved section and including a second radius of curvature; A catheter wherein the first radius of curvature is different from the second radius of curvature.

2. The catheter of claim 1 , wherein a distal end surface of the sidewall is disposed at a non-orthogonal angle relative to the sidewall at the distal end of the tubular body.

3. The catheter of claim 1 , further comprising a radiopaque marker at a distal end portion of the sidewall.

4. The catheter of claim 3 , wherein the radiopaque marker comprises a distal end surface at a distal end portion of the tubular body that is disposed at a non-orthogonal angle relative to the sidewall.

5. The catheter of claim 3 , wherein the radiopaque marker comprises a proximal end face disposed at a generally perpendicular angle to the sidewall at the distal end portion of the tubular body.

6. The catheter of claim 3 , wherein the radiopaque marker is located along the second curved section.

7. The catheter of claim 3 , wherein the radiopaque marker is located distal to the second curved section.

8. The catheter of claim 1 , wherein the first curved section is adjacent to the second curved section.

9. The catheter of claim 1 , wherein the distal end portion includes a rise of between about 1.5 mm and about 4 mm.

10. 10. The catheter of claim 9, wherein the rise is between about 2.5 mm and about 3.5 mm.

11. The catheter of claim 9 , wherein the distal end portion comprises a stroke of between about 5 mm and about 25 mm.

12. The catheter of claim 1 , wherein the distal end portion comprises a stroke of between about 7 mm and about 20 mm.

13. The catheter of claim 1 , wherein the first radius of curvature is between about 10 mm and about 25 mm.

14. 14. The catheter of claim 13, wherein the first radius of curvature is between about 15 mm and about 20 mm.

15. The catheter of claim 1 , wherein the second radius of curvature is between about 5 mm and about 8 mm.

16. 16. The catheter of claim 15, wherein the second radius of curvature is between about 5 mm and about 6 mm.

17. The catheter of claim 1 , wherein the second radius of curvature is smaller than the first radius of curvature.

18. The catheter of claim 1 , wherein a ratio of the first radius of curvature to the second radius of curvature is between about 1.5 and about 4.

5.

19. 20. The catheter of claim 18, wherein a ratio of the first radius of curvature to the second radius of curvature is between about 2 and about 3.

20. The catheter of claim 1 , wherein the distal end face of the tubular body is disposed at a non-orthogonal angle relative to the longitudinal axis of the tubular body.

21. 21. The catheter of claim 20, wherein the non-orthogonal angle is between about 90 degrees and about 115 degrees.

22. 22. The catheter of claim 21, wherein the non-orthogonal angle is at most about 110 degrees.

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