Funnel-shaped catheter tip with angled folded hoop

Abstract

The systems and devices disclosed herein are for a clot retrieval catheter that may have a proximal elongate body with a lumen and a distal tip that is expandable to a larger diameter than the outer sheath through which it is delivered. The distal tip may have a flexible metal support frame to provide radial scaffolding and more flexible expansion capabilities when engulfing a clot. The support frame may be designed such that the expansion motion is concentrated to a portion of the circumference through multiple support hoops that may be collapsed for deliverability but expanded for aspiration. This design may be flexible enough to navigate tortuous anatomy but recover to maintain the inner diameter of the lumen if displaced within the vessel.

Description

[Technical field]

[0001] (CROSS REFERENCE TO RELATED APPLICATIONS) This application claims the benefit of and priority to U.S. Provisional Patent Application No. 63 / 341,145, filed May 12, 2022, the entire contents of which are incorporated herein by reference.

[0002] FIELD OF THEINVENTION The present invention relates generally to devices and methods for removing an acute occlusion from a blood vessel during an endovascular medical procedure. More specifically, the present invention relates to a retrieval catheter having an expandable tip capable of retrieving one or more objects. [Background technology]

[0003] Clot retrieval aspiration catheters and devices are often used in mechanical thrombectomy procedures to perform endovascular interventions when patients suffer from diseases such as Acute Ischemic Stroke (AIS), Myocardial Infarction (MI), and Pulmonary Embolism (PE). With conventional techniques, access to neurovascular beds is difficult, especially because the target vessels are small in diameter, distant to the insertion site, and highly tortuous. Conventional devices are often either too large in profile, lack the deliverability and flexibility required to navigate particularly tortuous vessels, or are ineffective to remove clots when delivered to the target site.

[0004] Many existing designs for aspiration retrieval catheters are often limited to an inner diameter of, for example, 6Fr, or approximately 0.068-0.074 inches. Larger sizes require the use of even larger guides or sheaths, which in turn require the closure of larger femoral access holes. Most physicians prefer to use an 8F guide / 6F sheath combination, and few are comfortable with combinations beyond a 9F guide / 7F sheath. This means that once the target site is reached, the size of the clot may often be larger than the inner diameter of the aspiration catheter, and the clot must otherwise be compressed to enter the catheter port. This compression can result in bunching up of the clot during retrieval, which can then lead to shearing of the clot. Tough fibrin-rich clots can also get stuck at the tips of the fixed ports of these catheters, making them more difficult to extract. This clogging can cause the softer parts of the clot to break off from the tough areas of the clot.

[0005] Small diameters and fixed tip sizes are also inefficient in inducing the suction required for removal of blood and thrombus material during the procedure. The suction must be strong enough so that any debris that may result from the use of suction or mechanical thrombus removal devices cannot dislodge and occlude the distal vessel. When aspirating with a fixed port catheter, a significant portion of the aspirate flow will come from the vascular fluid proximal to the tip of the catheter where no clot is present. This significantly reduces the efficiency of aspiration and reduces the success rate of clot removal.

[0006] Thus, intermediate and suction catheters and / or those with expandable tips are desirable because they provide a large lumen and distal port to receive the clot with minimal resistance. However, current designs with fixed braids, frames, or expanded sizes do not allow for any additional expansion of the tip that may complicate interaction with and reception of the clot during uptake. Summary of the Invention [Means for solving the problem]

[0007] It is the object of the present invention to provide a device and method that meets the above needs, which may be for a clot retrieval catheter that can remove clots from the cerebral arteries of patients with AIS, from the native coronary or graft vessels of patients with MI, from the pulmonary arteries of patients with PE, and from other peripheral arteries and veins where a clot is causing an obstruction.

[0008] One embodiment of the present disclosure provides a catheter. The catheter may include an elongate body having a longitudinal axis, an inner diameter, and a distal end. The catheter may include a support frame connected to the distal end of the elongate body. The support frame may have a folded delivery configuration, an expanded deployed configuration, and a framework of struts including a plurality of distal hoop sections. At least a portion of the distal hoop sections may be collapsed distally in the folded delivery configuration such that a folded inner diameter of the support frame is approximately equal to an inner diameter of the elongate body. The support frame may have a maximum outer diameter in the expanded deployed configuration. The maximum outer diameter may be less than an inner diameter of a target vessel at a treatment site.

[0009] A first, more distal, of the plurality of distal hoop sections may have a first diameter when the support frame is in the expanded, deployed configuration, and a second, more proximal, of the plurality of distal hoop sections may form a second diameter when the support frame is in the expanded, deployed configuration. The first diameter may be greater than the second diameter.

[0010] The struts of the distal hoop section may have a curved profile in the collapsed delivery configuration.

[0011] The support frame may have a longitudinal length sized to be less than three times the inner diameter of the elongate body.

[0012] The catheter may include one or more connecting spines connecting the distal hoop section of the support frame to the elongate body.

[0013] The plurality of distal hoop sections may be folded such that the support frame has a folded inner diameter in the folded delivery configuration approximately equal to an inner diameter of the elongate body.

[0014] The plurality of distal hoop sections may include distally unconnected peaks that move distally when the support frame is folded into the collapsed delivery configuration.

[0015] The peaks that are not distally connected may move proximally when the support frame is in the expanded, deployed configuration.

[0016] A first, more distal, of the plurality of distal hoop sections may form a first fold angle with respect to the longitudinal axis when the support frame is in the folded delivery configuration. A second, more proximal, of the plurality of distal hoop sections may form a second fold angle with respect to the longitudinal axis when the support frame is in the folded delivery configuration. The first fold angle may be less than the second fold angle.

[0017] The multiple distal hoop sections may form a series of rings concentric with the longitudinal axis when the support frame is in the expanded, deployed configuration.

[0018] At least a portion of each of the plurality of distal hoop sections may form an acute angle with respect to the longitudinal axis when the support frame is in the collapsed delivery configuration.

[0019] Each hoop segment of the plurality of distal hoop segments can have a non-planar cross-section when the support frame is in the collapsed delivery configuration.

[0020] One or more hoops of the plurality of distal hoop sections may include one or more axial curves when the support frame is in the collapsed delivery configuration.

[0021] The support frame may include a plurality of ribs and one or more axial spines, at least one of which may be aligned with a connecting spine of the support frame.

[0022] Another embodiment of the present disclosure provides a catheter. The catheter may have a longitudinal axis. The catheter may include a support frame having a folded delivery configuration, an expanded deployed configuration, and a framework of struts including one or more pairs of opposing C-shaped petals. Each pair of opposing C-shaped petals may include a proximal petal and a distal petal. The proximal and distal petals may be folded into an axially elongated profile in the folded delivery configuration. The support frame may have a maximum outer diameter in the expanded deployed configuration. The maximum outer diameter may be less than an inner diameter of a target vessel at a treatment site.

[0023] The opposing C-shaped petals may be positioned (clocked) at 90 degrees to each other.

[0024] The opposing C-shaped petals may include peaks that are not distally connected.

[0025] At least one of the distally unconnected peaks may include a circumferential undulation.

[0026] At least one of the opposing C-shaped petals may include an intermediate hoop.

[0027] The support frame may further include a proximal ring member connected to the distal end of the elongate body of the catheter.

[0028] The plurality of distal hoop sections may have a flattened cross-section in the expanded, deployed configuration.

[0029] The support frame can have a collapsed length in a collapsed delivery configuration and an expanded length in an expanded deployed configuration, The collapsed length can be greater than the expanded length.

[0030] At least one of the plurality of distal hoop segments can define a plane passing through at least a portion of a circumference of the hoop segment. The plane can form an acute angle with respect to the longitudinal axis when the distal end is in the collapsed delivery configuration.

[0031] The distal end of the support frame in the expanded deployed configuration may have a circular profile with a center that is radially offset from the longitudinal axis of the elongate body.

[0032] In some embodiments, the hoop sections themselves may form the cells of the support frame, and may bend proximally or distally to collapse into a smaller diameter in the folded delivery configuration. In one embodiment, the hoop sections may be a pair or more opposing C-shaped petals that may be heat set or flipped to expand radially outward when the expandable tip is deployed. In another embodiment, the hoop sections form two longitudinally opposed rows connected by one or more axial spines. In a further embodiment, the hoop sections may be in the shape of a wide loop joined by a single axial spine.

[0033] In these examples, when the frame is expanded and the hoops flex radially outward, a first radial size of the more distal hoop or pair of opposing hoops can be larger than a second radial size of the adjacent more proximal hoop or pair of opposing hoops. This can allow the expanded frame to form a substantially funnel shape as the radial size is gradually increased in the more distal hoops. In other examples, at least one of the one or more hoop sections can have a distal peak that does not share a connection with another hoop section, allowing for independent flexion and a greater range of motion.

[0034] Other aspects of the present disclosure will become apparent from the following detailed description considered in conjunction with the accompanying figures. Additional features or manufacturing and use steps may be included as will be recognized and understood by those skilled in the art. [Brief description of the drawings]

[0035] The above and further aspects of the present invention are further discussed with reference to the following description in conjunction with the accompanying drawings, in which like numerals in the various figures indicate like structural elements and features. The drawings are not necessarily to scale, and instead the focus is on illustrating the principles of the present invention. The figures depict one or more implementations of the device of the present invention by way of example only, and not by way of limitation. It is expected that those skilled in the art can conceive and combine elements from multiple figures to better suit the needs of the user. [Figure 1] 1A-1C are diagrams of a clot retrieval catheter having an expandable support frame advanced through the vasculature, according to an aspect of the present invention. [Figure 2A] FIG. 1 is a perspective view of a clot retrieval catheter with an expandable support frame in a collapsed delivery configuration, in accordance with an aspect of the present invention. [Figure 2B] FIG. 2B is a side view of the clot retrieval catheter of FIG. 2A with the expandable support frame in a collapsed delivery configuration, according to an embodiment of the invention. [Figure 2C] FIG. 2C is a top view of the clot retrieval catheter of FIGS. 2A and 2B with the expandable support frame in a collapsed delivery configuration, according to an embodiment of the present invention. [Figure 2D] 2A-2C, showing the expandable support frame in an expanded, deployed configuration, according to an embodiment of the present invention. FIG. [Figure 3A] 1 is a top view of another clot retrieval catheter, the catheter shaft including angled ribs and the expandable support frame in a collapsed delivery configuration, in accordance with an aspect of the invention. [Figure 3B] FIG. 3B is a side view of the clot retrieval catheter of FIG. 3A with the expandable support frame in a collapsed delivery configuration, according to an embodiment of the invention. [Figure 3C] FIG. 3C is a top view of the clot retrieval catheter of FIGS. 3A and 3B, with the expandable support frame in an expanded, deployed configuration, according to an embodiment of the present invention. [Figure 4A]FIG. 1 is a perspective view of a clot retrieval catheter, the shaft of the catheter including interrupted spines and the expandable support frame in a collapsed delivery configuration, in accordance with an aspect of the present invention. [Figure 4B] FIG. 4B is a side view of the clot retrieval catheter of FIG. 4A with the expandable support frame in a collapsed delivery configuration, according to an embodiment of the invention. [Figure 4C] 4C is a top view of the clot retrieval catheter of FIGS. 4A and 4B with the expandable support frame in a collapsed delivery configuration, according to an embodiment of the invention. FIG. [Figure 4D] 4A-4C, with the expandable support frame in an expanded, deployed configuration, according to an embodiment of the present invention. [Figure 5A] 1 is a top view of a clot retrieval catheter, the catheter including a base ring and an expandable support frame in an expanded, deployed configuration, in accordance with an aspect of the present invention. [Figure 5B] FIG. 5B is a top view of the clot retrieval catheter of FIG. 5A with the expandable support frame in a collapsed delivery configuration, according to an embodiment of the invention. [Figure 5C] FIG. 5C is a side view of the clot retrieval catheter of FIGS. 5A and 5B with the expandable support frame in a collapsed delivery configuration, according to an embodiment of the invention. [Figure 5D] FIG. 5C is a perspective view of the clot retrieval catheter of FIGS. 5A-5C with the expandable support frame in a collapsed delivery configuration, according to an embodiment of the invention. [Figure 6A] FIG. 2 is a side perspective view of a clot retrieval catheter, the catheter shaft including a spine connector and the expandable support frame in a collapsed delivery configuration, in accordance with an aspect of the present invention. [Figure 6B] FIG. 6B is a side view of the clot retrieval catheter of FIG. 6A with the expandable support frame in a collapsed delivery configuration, according to an embodiment of the invention. [Figure 6C] FIG. 6C is a top view of the clot retrieval catheter of FIGS. 6A and 6B with the expandable support frame in a collapsed delivery configuration, according to an embodiment of the invention. [Figure 6D]6A-6C, showing an expanded support frame in an expanded, deployed configuration, according to an embodiment of the present invention. FIG. [Figure 7A] FIG. 2 is a side perspective view of a clot retrieval catheter, the catheter shaft including a spine connector and the expandable support frame in a collapsed delivery configuration, in accordance with an aspect of the present invention. [Figure 7B] 7B is a side view of the clot retrieval catheter of FIG. 7A with the expandable support frame in a collapsed delivery configuration, according to an embodiment of the invention. [Figure 7C] 7C is a top view of the clot retrieval catheter of FIGS. 7A and 7B with the expandable support frame in a collapsed delivery configuration, according to an embodiment of the invention. FIG. [Figure 7D] 7A-7C, showing an expanded support frame in an expanded, deployed configuration, according to an embodiment of the present invention. FIG. [Figure 8A] FIG. 2 is a perspective view of a clot retrieval catheter according to an embodiment of the invention, the support frame including C-shaped petals and the expandable support frame in a collapsed delivery configuration. [Figure 8B] 8B is a perspective view of the clot retrieval catheter of FIG. 8A with the expandable support frame in an expanded, deployed configuration, according to an embodiment of the invention. [Figure 9] 1 is a side perspective view of a clot retrieval catheter in which the support frame includes circumferential undulations and the expandable support frame is in a collapsed delivery configuration, in accordance with an aspect of the invention. [Figure 10] FIG. 2 is a perspective view of a clot retrieval catheter with an expandable support frame and jacket in an expanded, deployed configuration, in accordance with an aspect of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0036] Specific embodiments of the present invention will now be described in detail with reference to the Figures, in which like reference numbers indicate functionally similar or identical elements. The embodiments address many of the deficiencies associated with conventional clot retrieval aspiration catheters, such as insufficient or inaccurate deployment at the target site and ineffective clot removal.

[0037] The designs herein may be for a clot retrieval catheter having a lumen and a distal end that, when advanced beyond the distal end, may expand to a diameter greater than the diameter of the guide or sheath through which it is delivered. The designs may have a proximal elongate body for the catheter shaft, an expanding support frame, and a distal tip having a jacket (e.g., a polymer jacket) in some embodiments, providing atraumatic properties for the tip when ingesting a clot and the ability to expand more flexibly in the expanded, deployed configuration. The catheter frame and tip may be sufficiently flexible to navigate highly tortuous areas of the anatomy and to restore and maintain the inner diameter of the lumen if displaced within the vessel.

[0038] Accessing various vessels within the vasculature, whether coronary, pulmonary, or cerebral, involves well-known procedural steps and the use of numerous conventional, commercially available accessory products. These products, such as angiographic materials, mechanical thrombectomy devices, microcatheters, and guidewires, are widely used in laboratories and medical procedures. When these products are used with devices in the following description, their function and exact configuration will not be described in detail. Although these descriptions are often related to thrombectomy treatments in intracranial arteries, the present disclosure may be applied to other procedures and other body passageways as well.

[0039] Turning to the figures, FIG. 1 illustrates a possible sequence for accessing an occlusive clot 40 using a clot retrieval catheter 100 of the design disclosed herein. The clot 40 may be accessed with the catheter 100 folded within a guide sheath 30 or other access catheter. If the vasculature 10 is too narrow and / or tortuous for further distal navigation with the guide sheath 30, the catheter 100 may be deployed for further independent movement distally. The catheter 100 may be highly flexible to be able to navigate the M1 or other tortuous regions of the neurovasculature to reach the occlusive clot, and may have an expanded outer diameter slightly smaller than the outer diameter of the target vessel such that the catheter is capable of independent distal navigation after deployment.

[0040] The clot retrieval catheter 100 may have a flexible elongate body 110 that functions as a shaft with a large inner bore (which may be 0.080 inches or larger in some cases) and a distal tip section with a collapsible support frame 210. They may aid in delivering the catheter to the target site by a variety of methods, including over a guidewire, over a microcatheter, with a dilator / access tool, or by itself.

[0041] In many cases, the design of the tip of the support frame 210 may be configured so that the entire catheter 100 may be delivered through (and retrieved through) a common standard 6F sheath / 8F guide, which typically has an internal lumen of less than 0.090 inches. The tip may self-expand when advanced to an unconstrained position distal to the distal end 32 of the guide sheath 30. The tip support frame 210 is designed to resist collapsing due to suction forces, has excellent lateral flexibility in both the expanded and collapsed states, and has an atraumatic profile to prevent snagging at bifurcations in the blood vessel, so that the catheter may be deployed proximal to a remote occlusion and then independently advanced to the remote occlusion.

[0042] 2A-2D provide illustrations of an exemplary clot retrieval catheter 100 with an expandable support frame 210 in both a collapsed delivery configuration (see FIGS. 2A-2C) and an expanded deployed configuration (see FIG. 2D). The catheter 100 may include an elongated body 110 at a proximal end (i.e., left side of FIG. 2A) having a longitudinal axis 111, an inner diameter 115, and a distal end. The catheter 100 may include a support frame 210 connected to the distal end of the elongated body 110, while a proximal end 212 of the support frame 210 is proximate to the distal end of the elongated body 110. The support frame 210 may have a collapsed delivery configuration, an expanded deployed configuration, and a framework of struts with a plurality of distal hoop sections 213. The distal end of the support frame 210 may open in the expanded deployed configuration at a target site within a blood vessel. The proximal end 212 of the support frame 210 may define a proximal ring 217 that may provide support to the support frame 210 at the junction of the support frame 210 and the elongate body 110 .

[0043] The elongate body 110 structure may define a catheter lumen, which may be used for delivery of auxiliary devices, contrast injection, and direct distal aspiration to the clot surface via the support frame 210. The underlying structure of the elongate body 110 may be, for example, a frame cut from a hypotube of a superelastic material with shape memory properties, such as Nitinol, with an internal low friction liner and one or more outer polymer jackets 180 that may be reflowed into the structure during manufacturing. Alternatively, a more traditional polymer and / or metal braided or coiled support structure, or some combination of these, may be used.

[0044] The exterior surfaces of the elongate body 110 and the support frame 210 may be at least partially covered by one or more jackets 180. FIG. 10 provides an exemplary illustration of the jacket 180, but it will be understood that any exemplary catheter 100 described herein may include the jacket 180. The jacket 180 may block proximal fluids from entering the expanded tip during clot aspiration and retrieval, allowing for more efficient direction of aspiration forces while preventing distal migration of clot fragments or other debris during the procedure. In one embodiment, the jacket 180 may be formed from a highly elastic material such that when in the expanded deployed configuration, the radial force exerted by expanding the expandable tip is sufficient to stretch the membrane into a funnel-shaped profile at the tip. One embodiment may use a ductile elastomer, which has the advantage of being soft and flexible and resistant to tearing and puncture due to high failure strains. Alternatively, the jacket 180 may fit loosely around the catheter 100 and be folded over the edges of the support frame 210, allowing the support frame 210 to move more freely as it expands and collapses.

[0045] As previously mentioned, the elongate body 110 may be sized to be compatible with a relatively low profile guide sheath 30 and catheter, thereby allowing easy and reliable closure of a puncture wound in the patient's groin (in the case of femoral access). For example, the clot retrieval catheter 100 may be required to pass through a lumen of a guide sheath 30 having an inner diameter of less than 0.110 inches, e.g., 0.090 inches, and in some cases, less than 0.087 inches, and preferably less than 0.085 inches. In other embodiments using a 5Fr sheath, the inner diameter may be less than 0.080 inches, and may be as small as 0.070 inches. Thus, the catheter 100 may have an overall delivery profile with an inner diameter 115 of approximately 0.067 to 0.074 inches (0.084 inches or 2 mm outer diameter), and may further expand its distal tip and port in the support frame 210 to a size slightly smaller than the approximate diameter of the blood vessel in which the clot is located, which may be up to 5 mm. It will be appreciated that larger or smaller catheter shafts may be used when paired with larger or smaller guide sheaths 30.

[0046] The support frame 210 may be similarly sized for compatibility. The support frame 210 may have an inner diameter sized for delivery through a selected guide sheath 30 in a collapsed delivery configuration such that radial forces are not excessively high, which may have an inner diameter of, for example, 0.085 inches. When deployed over the distal end 32 of the guide sheath 30, the support frame 210 may be radially larger such that the tip is slightly smaller in diameter than the target vessel. For example, a large size of approximately 3-5 mm for ICA clots, a medium size of approximately 0.090-0.110 inches in diameter for proximal / large M1 clots, and / or a small size of approximately 0.080-0.090 inches in diameter for small / distal M1 clots. In many circumstances, the tip may have a maximum inner diameter 115 in the expanded deployed configuration within the range of approximately 0.080-0.120 inches. The support frame 210 further comprises a longitudinal length 211 sized to be less than three times the inner diameter 115 of the elongate body 110. The support frame 210 can include a collapsed length 221 in a collapsed delivery configuration and an expanded length 222 in an expanded deployed configuration, where the collapsed length is greater than the expanded length.

[0047] 2A-2D, at least a portion of the distal hoop section 213 may be collapsed distally in the collapsed delivery configuration such that the collapsed inner diameter 215 of the support frame is approximately equal to the inner diameter 115 of the elongated body 110. The struts of the distal hoop section 213 may have a curvilinear profile in the collapsed delivery configuration. The support frame 210 may have a maximum outer diameter 224 (e.g., diameter 236) in the expanded deployed configuration (see FIG. 2D) that is smaller than the inner diameter of the target vessel at the treatment site. However, in some embodiments, the support frame 210 may have a maximum outer diameter 224 (e.g., diameter 236) in the expanded deployed configuration that is slightly larger than the target vessel. In such a situation, the flexible distal support frame 210 may size itself to the vessel, allowing it to be advanced to the clot. The elongate body 110 may have an axial spine 116 that extends along the length of the elongate body 110 parallel to the longitudinal axis 111. The spine 116 provides structural support and may define a plane or axis about which the elongate body 110 may bend. The spine 116 may include one or more ribs 118 extending from the spine 116. The ribs 118 may be curved to form a cylindrical shape such that the elongate body 110 is shaped as a lumen for aspirating and capturing / removing clots from a target site.

[0048] The distal hoop section 213 may be folded distally in the folded configuration such that the distal hoop section 213 is angled toward the distal end of the catheter 100. These folds in the support frame 210 may unfold when the catheter 100 is expanded to the expanded configuration. In some embodiments, the distal hoop sections 213 may have distally unconnected peaks 228 that move distally when the support frame 210 is folded into the folded delivery configuration, as shown in FIG. 2B. A first more distal hoop section 229 of the distal hoop sections may have a first fold angle 218 with respect to the longitudinal axis 111 when the support frame 210 is in the folded delivery configuration. When the support frame 210 is in the folded delivery configuration, a second, more proximal hoop section 230 of the plurality of distal hoop sections 213 can have a second fold angle 219 relative to the longitudinal axis 111. The first fold angle 218 can be less (e.g., smaller) than the second fold angle 219. In some examples, when the support frame 210 is in the folded delivery configuration, one or more of the distal-most hoop sections 213 (e.g., the distal-most hoop section 226) can have an acute angle (e.g., angle 218) relative to the longitudinal axis 111. This configuration can allow the distal hoop sections 213 to unfold into a fully shaped expanded configuration shown in FIG. 2D. The plurality of distal hoop sections 213 can form a series of rings concentric with the longitudinal axis 111 when the support frame 210 is in the expanded, deployed configuration.

[0049] In certain embodiments, the support frame 210 can include one or more connecting spines 216 from which the distal hoop sections 213 extend. In some embodiments, the connecting spines 216 can be aligned with the axial spines 116 of the elongate body 110. In some embodiments, the connecting spines 216 can be radially offset from the axial spines 116, as shown in FIG. 2A. A first, more distal hoop section 229 of the plurality of distal hoop sections 213 can have a first diameter 236 when the support frame 210 is in the expanded, deployed configuration, and a second, more proximal hoop section 230 of the plurality of distal hoop sections 213 can have a second diameter 238 when the support frame 210 is in the expanded, deployed configuration. The first diameter 236 can be larger than the second diameter 238 to create a funnel shape in the support frame 210, as shown in FIG. 2D. The plurality of distal hoop sections 213 can have a flat cross-section in the expanded, deployed configuration.

[0050] 3A-3C provide views of an exemplary clot retrieval catheter 100 with the expandable support frame 210 in both a collapsed delivery configuration (see FIGS. 3A and 3B) and an expanded deployed configuration (see FIG. 3C). The exemplary catheter 100 of FIGS. 3A-3C is similar to the embodiment shown in FIGS. 2A-2D, however, the embodiment of FIGS. 3A-3C provides a variation of the elongated body 110. As shown, the elongated body 110 may include interrupted spines 117 positioned along the length of the elongated body 110 (e.g., along the longitudinal axis 111). The interrupted spines 117 may be positioned diametrically opposite the axial spine 116 and may join two or more ribs 118 together to create a more robust elongated body 110. To illustrate using the example shown in FIG. 3B, the interrupted spine 117 includes three ribs 118 connected to each other, and these ribs are separated from the next set of three ribs 118 by an interruption in the interrupted spine 117.

[0051] 4A-4D provide views of an exemplary clot retrieval catheter 100 with the expandable support frame 210 in both a collapsed delivery configuration (see FIGS. 4A-4C) and an expanded deployed configuration (see FIG. 4D). The exemplary catheter 100 of FIGS. 4A-4D is similar to the embodiment shown in FIGS. 3A-3C, however the embodiment of FIGS. 4A-4D provides a variation of the elongated body 110. FIGS. 4A-4D show an embodiment in which the framework of the elongated body 110 has pairs of support ribs 118 that merge into a single spine connector 146 for connection with the axial spines 116. Each set of support ribs 118 can have one, two, three, or more ribs 118. By connecting sets of support ribs 118 with a single connection to one or more spines 116, additional flexibility can be obtained by having longer length spines 116 that are free to bend for a given density of ribs 118. This arrangement may also reduce strain on the connection between the spine connector 146 and the axial spine 116.

[0052] Alternatively, a similar design could see a series of support ribs 118 merging into diametrically opposed spine connectors for connection with biaxial spines 116 spaced 180 degrees apart. Additional spines could also be envisioned, trading some lateral flexibility for better pushability than could be achieved with fewer spines. The additional axial stiffness could also help prevent the elongate body from stretching under tension, such as when the expandable tip is being retracted proximally into the outer sheath with a stiff clot.

[0053] 5A-5D provide views of an exemplary clot retrieval catheter 100 with the expandable support frame 210 in both a collapsed delivery configuration (see FIGS. 5B-5D) and an expanded deployed configuration (see FIG. 5A). The support frame 210 may include a connecting spine 223 that extends collinearly with the axial spine 116 of the elongate body 110. The connecting spine 223 may help position the hoop section 213 of the support frame 210. The support frame 210 may also include a second connecting spine 223 diametrically opposite the first connecting spine 223 to add additional support to the hoop section 213.

[0054] The catheter 100 may include a support ring 234 positioned between the elongate body 110 and the support frame 210. One end of the support ring 234 may connect to one or more axial spines 116 of the elongate body (e.g., after the distal-most rib 227) and the other end of the support ring 234 may connect to one or more connecting spines 223 of the support frame 210. The support ring 234 may add structural support to the junction between the elongate body 110 and the support frame 210. The support ring 234 may also provide an indication of the location of the support frame 210 within the target vessel, for example, when viewing the target site under fluoroscopy. In some embodiments, the support ring 234 may include a radiopaque marker 235 embedded therein or otherwise attached thereto. The radiopaque marker 235 may include a material that is denser than the remainder of the catheter 100 to alert the user to the location of the support frame 210. For example, the catheter 100 may comprise a flexible material, such as Nitinol, while the radiopaque markers 235 may comprise a dense material, such as gold or platinum.

[0055] In some embodiments, support frame 210 may include one or more mobile spines 220. Mobile spines 220 may be positioned, for example at 90 degrees, around the circumference of hoop sections 213 and may provide support to hoop sections 213 when hoop sections 213 are deployed to an expanded deployed configuration. For example, mobile spines 220 may ensure that hoop sections 213 deploy in a substantially circular shape. Unlike connecting spines 223, mobile spines 220 may be decoupled from support ring 234.

[0056] 6A-6D provide views of an exemplary clot retrieval catheter 100 with an expandable support frame 310 in both a folded delivery configuration (see FIGS. 6A-6C) and an expanded deployed configuration (see FIG. 6D). The exemplary catheter 100 of FIGS. 6A-6D is similar to the embodiment shown in FIGS. 2A-2D, however the embodiment of FIGS. 6A-6D provides a variation of the support frame 310, or in particular, the hoop section (referred to above as hoop section 213). As shown, at least one hoop section 326 of the plurality of distal hoop sections 313 can define a plane 318 that passes through at least a portion of the circumference of the at least one hoop section 326. The plane 318 can form an acute angle 319 with respect to the longitudinal axis 111 when the distal end 114 of the elongate body 110 is in the folded delivery configuration. The distally unconnected peaks 328 of the distal hoop segments 313 may be spaced progressively farther apart from one another as the distal hoop segments 313 become more distal from the elongate body 110. To this end, when in the folded delivery configuration, the more proximal ones of the distal hoop segments 313 may have a hoop fold angle 321 closer to 90 degrees relative to the longitudinal axis 111 than the more distal hoop segments (e.g., the hoop segments 326 at the distal end 314 of the support frame 310). This configuration may accommodate the distal-most hoop segment 313 having a first radial size 336 that is greater than the second radial size 338 of the most proximal hoop segment 326 (e.g., the hoop segment proximate the elongate body 110). When the support frame 310 is deployed in the deployed configuration (e.g., FIG. 6D ), the planes 318 of the multiple distal hoop sections 313 can all be approximately 90 degrees relative to the longitudinal axis 111. The axial spine 316 shown in FIGS. 6A-6D can be similar to the axial spine 116 described herein.

[0057] 7A-7D provide views of an exemplary clot retrieval catheter 100 with the expandable support frame 310 in both a folded delivery configuration (see FIGS. 7A-7C) and an expanded deployed configuration (see FIG. 7D). One or more of the hoops of the plurality of distal hoop sections 313 may include one or more axial curves (e.g., a first axial curve 331 and a second axial curve 332) when the support frame 310 is in the folded delivery configuration. These axial curves 331, 332 may provide height to the circular distal hoop sections 313 such that when they are deployed to the expanded deployed configuration, the distal hoop sections 313 have a circular profile with a center 330 that is radially offset from the longitudinal axis 111 of the elongate body 110. It should be noted that each hoop section of the plurality of distal hoop sections 213 may have a non-planar cross section when the support frame 310 is in the folded delivery configuration.

[0058] In some embodiments, the elongate body 110 may include seams 148 between particular ribs 118 of the elongate body 110 and the axial spine 116. The seams 148 may serve to somewhat decouple the ribs 118 from the axial spine 116 to allow radial expansion of the elongate body 110 and provide the body with a greater degree of flexibility. The seams 148 may be created by forming the ribs 118 in a serpentine shape such that only every other, every third, every fourth, etc. rib 118 is attached to the axial spine 116 via the spine connectors 146.

[0059] 8A and 8B are perspective views of a clot retrieval catheter 100 having an expandable support frame 410, which includes C-shaped petals 413, according to an embodiment of the present invention. FIG. 8A shows an exemplary catheter 100 in a folded configuration, and FIG. 8B shows an exemplary catheter 100 in an expanded, deployed configuration, according to an embodiment of the present invention. Each pair of opposing C-shaped petals 413 can include a proximal petal 420 and a distal petal 421. The proximal petal 420 can be connected to a rib 118 (e.g., the distal-most rib 227) via a connecting spine 416. The distal petal 421 can be connected to the proximal petal 420 via one or more connecting struts 417. The proximal and distal petals 420 and 421 can be folded axially into an elongated profile in the folded delivery configuration (see FIG. 8A). The support frame 410 can have a maximum outer diameter 224 in the expanded, deployed configuration that is less than the inner diameter of the target vessel at the treatment site.

[0060] The C-shaped petals 413 may be clocked at 90 degrees relative to one another to improve flexibility and enhance the ability of the support frame 410 to regain and maintain its shape and inner diameter if displaced laterally within a vessel. Note that the clocked offset between the connecting spines 416 of the support frame 410 and the axial spines 116 of the elongated body 110 may have a hinge effect that allows the structure to easily deflect away from the vessel wall. As shown, the opposing C-shaped petals 413 may include a peak 428 at the distal end 414 of the support frame 410 that is not connected distally.

[0061] FIG. 9 is a side perspective view of a clot retrieval catheter 100 with an expandable support frame 410 in a collapsed delivery configuration, according to an embodiment of the present invention, the support frame 410 including circumferential undulations 418. The catheter 100 shown in FIG. 9 is similar to the embodiment shown in FIGS. 8A and 8B, but with a modification to the support frame 410. One or more circumferential undulations 418 on the support frame 410 may expand with a large bend radius for atraumatic contact with the vessel wall. The support frame 410 may further include one or more intermediate hoops 429 extending from the C-shaped petals 413. The intermediate hoops 429 may provide additional scaffolding for a membrane (e.g., jacket 180 shown in FIG. 10) attached to the catheter 100 and direct fluid and / or clots into the elongate body 110. Extending from the proximal ring member 434 may be a base ring support hoop 435, which may be separate from the proximal petal 420 and provide additional scaffolding for a membrane (e.g., the jacket 180 shown in FIG. 10).

[0062] 10 is a perspective view of the clot retrieval catheter 100 with the expandable support frame 410 and jacket 180 in an expanded, deployed configuration. The jacket 180 may be a polymer jacket extrusion that may be reflowed or laminated in place. Applied heat may allow the outer polymer to fill the interstitial areas between the ribs 118 of the elongate body 110. Suitable jacket 180 materials may include a resilient polyurethane such as Chronoprene, a silicone elastomer, or similar material that may have a Shore hardness of 40A or less.

[0063] The jacket 180 may also be applied in a combination of other methods. Depending on the axial location on the elongate body 110 and / or support frame (e.g., support frame 210, 310, 410), the jacket 180 may be dip coated, sprayed, electrospun, and / or plasma deposited onto the support frame. In other embodiments, the jacket 180 may be a straight extrusion or may be extruded and post-formed onto the dilator tip and catheter body.

[0064] To allow for smooth delivery of the clot retrieval catheter 100 through the outer catheter, the outer surface of the jacket 180 may be coated with a low friction or lubricious material, such as PTFE, or a commercially available lubricious coating.

[0065] The present invention is not necessarily limited to the described embodiments, which may vary in configuration and details. The terms "distal" and "proximal" are used throughout the foregoing description and are intended to refer to a location and direction relative to the treating physician. Thus, "distal" or "distally" refers to a location away from or a direction away from the physician. Similarly, "proximal" or "proximally" refers to a location closer to or a direction toward the physician. Additionally, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise.

[0066] As used herein, the term "about" or "approximately" in relation to any numerical value or numerical range indicates a suitable dimensional tolerance that enables a portion of a component or a collection of components to function for its intended purpose as described herein. More specifically, "about" or "approximately" may refer to a range of values ​​of ±20% of the recited value, for example, "about 90%" may refer to a range of values ​​of 71% to 99%.

[0067] In describing the exemplary embodiments, technical terms are utilized for clarity. As a result, not all possible combinations are listed, and such variations will often be apparent to those skilled in the art and are intended to be within the scope of the following claims. Each term is intended to be construed as having its broadest meaning as understood by those skilled in the art and to include all technical equivalents that operate in a similar manner to achieve a similar purpose without departing from the scope and spirit of the present invention. It should also be understood that a reference to one or more steps of a method does not preclude the presence of additional method steps or intervening method steps between those steps that are explicitly identified. Similarly, some steps of the method may be performed in a different order than described herein without departing from the scope of the disclosed technology.

[0068] [Embodiment] (1) an elongate body including a longitudinal axis, an inner diameter, and a distal end; a support frame connected to the distal end of the elongate body, the support frame including a collapsed delivery configuration, an expanded deployed configuration, and a framework of struts including a plurality of distal hoop sections; A catheter, wherein at least a portion of the distal hoop section is collapsed distally in the collapsed delivery configuration such that a collapsed inner diameter of the support frame approximately equals the inner diameter of the elongate body. (2) The catheter of embodiment 1, wherein a first more distal hoop section of the plurality of distal hoop sections has a first diameter when the support frame is in the expanded deployed configuration, and a second more proximal hoop section of the plurality of distal hoop sections forms a second diameter when the support frame is in the expanded deployed configuration, the first diameter being greater than the second diameter. (3) A catheter as described in embodiment 1, wherein the struts of the distal hoop section have a curved profile in the folded delivery configuration. (4) The catheter of embodiment 1, wherein the support frame further comprises a longitudinal length sized to be less than three times the inner diameter of the elongate body. (5) The catheter of embodiment 1, further comprising one or more connecting spines connecting the distal hoop section of the support frame to the elongate body.

[0069] (6) The catheter of embodiment 1, wherein the plurality of distal hoop sections are folded such that the support frame has a folded inner diameter in the folded delivery configuration approximately equal to the inner diameter of the elongate body. (7) The catheter of embodiment 1, wherein the plurality of distal hoop sections include distally unconnected peaks that move distally when the support frame is folded into the folded delivery configuration. (8) The catheter of embodiment 7, wherein the distally unconnected peaks move proximally when the support frame is in the expanded deployed configuration. (9) a first more distal hoop section of the plurality of distal hoop sections forms a first fold angle with respect to the longitudinal axis when the support frame is in the folded delivery configuration; a second, more proximal hoop section of the plurality of distal hoop sections forms a second folded angle with respect to the longitudinal axis when the support frame is in the folded delivery configuration; 2. The catheter of claim 1, wherein the first fold angle is smaller than the second fold angle. (10) The catheter of embodiment 1, wherein the plurality of distal hoop sections form a series of rings concentric with the longitudinal axis when the support frame is in the expanded, deployed configuration.

[0070] (11) The catheter of embodiment 1, wherein at least a portion of each of the plurality of distal hoop sections forms an acute angle with respect to the longitudinal axis when the support frame is in the folded delivery configuration. (12) The catheter of embodiment 1, wherein each hoop section of the plurality of distal hoop sections includes a non-planar cross-section when the support frame is in the folded delivery configuration. (13) The catheter of embodiment 1, wherein one or more of the distal hoop sections further include one or more axial curves when the support frame is in the folded delivery configuration. (14) The catheter of embodiment 5, wherein the elongated body comprises a plurality of ribs and one or more axial spines, at least one of the one or more axial spines being aligned with a connecting spine of the support frame. (15) a longitudinal axis; a support frame including a folded delivery configuration, an expanded deployed configuration, and a framework of struts including one or more pairs of opposed C-shaped petals; A catheter, wherein each pair of opposing C-shaped petals includes a proximal petal and a distal petal, the proximal and distal petals being folded into an axially elongated profile in the folded delivery configuration.

[0071] (16) The catheter of embodiment 15, wherein the opposing C-shaped petals are clocked at 90 degrees to each other. (17) The catheter of embodiment 15, wherein the opposing C-shaped petals have peaks that are not connected distally. (18) The catheter of embodiment 17, wherein at least one of the distally unconnected peaks includes a circumferential undulation. (19) The catheter of embodiment 15, wherein at least one of the opposing C-shaped petals further comprises an intermediate hoop. (20) The catheter of embodiment 15, wherein the support frame further comprises a proximal ring member connected to a distal end of the elongate body of the catheter.

Claims

1. an elongate body including a longitudinal axis, an inner diameter, and a distal end; a support frame connected to the distal end of the elongate body, the support frame including a collapsed delivery configuration, an expanded deployed configuration, and a framework of struts including a plurality of distal hoop sections; A catheter, wherein at least a portion of the distal hoop section is collapsed distally in the collapsed delivery configuration such that a collapsed inner diameter of the support frame is approximately equal to the inner diameter of the elongate body.

2. 2. The catheter of claim 1, wherein a first, more distal hoop section of the plurality of distal hoop sections comprises a first diameter when the support frame is in the expanded, deployed configuration and a second, more proximal hoop section of the plurality of distal hoop sections forms a second diameter when the support frame is in the expanded, deployed configuration, the first diameter being greater than the second diameter.

3. The catheter of claim 1 , wherein the struts of the distal hoop section comprise a curved profile in the collapsed delivery configuration.

4. The catheter of claim 1 , wherein the support frame further comprises a longitudinal length sized to be less than three times the inner diameter of the elongate body.

5. The catheter of claim 1 , further comprising one or more connecting spines connecting the distal hoop section of the support frame to the elongate body.

6. The catheter of claim 1 , wherein the plurality of distal hoop sections are folded such that the support frame comprises a folded inner diameter in the folded delivery configuration approximately equal to the inner diameter of the elongate body.

7. The catheter of claim 1 , wherein the plurality of distal hoop sections include distally unconnected peaks that move distally when the support frame is folded into the folded delivery configuration.

8. The catheter of claim 7 , wherein the distally unconnected peaks move proximally when the support frame is in the expanded deployed configuration.

9. a first more distal hoop section of the plurality of distal hoop sections forms a first folded angle with respect to the longitudinal axis when the support frame is in the folded delivery configuration; a second, more proximal hoop section of the plurality of distal hoop sections forms a second folded angle with respect to the longitudinal axis when the support frame is in the folded delivery configuration; The catheter of claim 1 , wherein the first fold angle is less than the second fold angle.

10. The catheter of claim 1 , wherein the plurality of distal hoop sections form a series of rings concentric with the longitudinal axis when the support frame is in the expanded, deployed configuration.

11. The catheter of claim 1 , wherein at least a portion of each of the plurality of distal hoop sections forms an acute angle with respect to the longitudinal axis when the support frame is in the collapsed delivery configuration.

12. The catheter of claim 1 , wherein each hoop section of the plurality of distal hoop sections includes a non-planar cross-section when the support frame is in the folded delivery configuration.

13. The catheter of claim 1 , wherein one or more hoops of the plurality of distal hoop sections further include one or more axial curves when the support frame is in the collapsed delivery configuration.

14. The catheter of claim 5 , wherein the elongate body comprises a plurality of ribs and one or more axial spines, at least one of the one or more axial spines being aligned with a connecting spine of the support frame.

15. A longitudinal axis; a support frame including a folded delivery configuration, an expanded deployed configuration, and a framework of struts including one or more pairs of opposed C-shaped petals; A catheter, wherein each pair of opposing C-shaped petals includes a proximal petal and a distal petal, the proximal and distal petals being folded into an axially elongated profile in the folded delivery configuration.

16. The catheter of claim 15 , wherein the opposing C-shaped petals are disposed at 90 degrees from each other.

17. The catheter of claim 15 , wherein the opposing C-shaped petals include peaks that are not connected distally.

18. The catheter of claim 17 , wherein at least one of the distally unconnected peaks includes a circumferential undulation.

19. The catheter of claim 15 , wherein at least one of the opposing C-shaped petals further comprises an intermediate hoop.

20. The catheter of claim 15 , wherein the support frame further comprises a proximal ring member connected to a distal end of the elongate body of the catheter.

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