Funnel catheter tip with angled folding cuffs

Abstract

Disclosed herein are systems and devices for a clot retrieval catheter that may have a proximal elongate body having a lumen and a distal tip that is expandable in diameter to be larger than an outer sheath through which the distal tip is delivered. The distal tip may have a flexible metal support frame to provide radial stent action as well as the ability to further flexibly expand when ingestion of clots. The support frame may be designed such that the expansion motion is concentrated in a portion of the circumference by a plurality of support cuffs that are both collapsible for delivery and expandable for suction. These designs may have sufficient flexibility to traverse tortuous anatomy, but when displaced in the blood vessel, restore to maintain the inner diameter of the lumen.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] 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 these patent applications are incorporated herein by reference. Technical Field

[0003] The present invention generally relates to devices and methods for removing acute blockages from blood vessels during endovascular medical treatment. More specifically, the present invention relates to a retrieval catheter having an expandable tip into which one or more objects may be retrieved. Background Art

[0004] Clot retrieval aspiration catheters and devices are frequently used in mechanical thrombectomy for endovascular intervention in patients with conditions such as acute ischemic stroke (AIS), myocardial infarction (MI), and pulmonary embolism (PE). Accessing neurovascular beds is particularly challenging using conventional techniques because the target vessels are small in diameter, distal relative to the insertion site, and highly tortuous. Conventional devices are often oversized, lack the deliverability and flexibility required to traverse particularly tortuous vessels, or are ineffective in removing clots when delivered to the target site.

[0005] Many existing designs of aspiration retrieval catheters are typically limited to, for example, 6Fr or an inner diameter between approximately 0.068 inches and 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 physicians feel comfortable exceeding a 9F guide / 7F sheath combination. This means that once at the target site, the clot is typically larger in size than the inner diameter of the aspiration catheter and must be compressed in other ways to enter the catheter opening. This compression can cause the clot to clumping and subsequent shearing during retrieval. Fibrin-rich, compacted clots may also aggregate in the fixed open ends of these catheters, making them more difficult to extract. This aggregation can cause the softer portions of the clot to break away from the more compact areas.

[0006] The small diameter and fixed tip size are also less effective at the aspiration required to remove blood and thrombotic material during guided surgery. The aspiration must be strong enough so that any fragmentation that may occur due to aspiration or the use of a mechanical thrombectomy device cannot migrate and occlude the distal vessel. When aspiration is performed with a fixed opening catheter, a significant portion of the aspiration flow ultimately comes from the vascular fluid near the catheter tip, where there is no clot. This significantly reduces the efficiency of aspiration, thereby reducing the success rate of clot removal.

[0007] Therefore, intermediate and aspiration catheters and / or catheters with expandable tips are desirable because they provide a large lumen and distal opening to receive the clot with minimal resistance. However, current designs with fixed braids, frames, or expansion sizes do not allow for any additional expansion of the tip, which can complicate interaction with the clot during uptake and reception of the clot. Summary of the invention

[0008] The present designs are intended to provide devices and methods that meet the above needs. These designs can be used for clot retrieval catheters that can remove clots from the cerebral arteries of patients with AIS, the coronary native or grafted vessels of patients with MI, and the pulmonary arteries of patients with PE, as well as other peripheral arterial and venous vessels where clots have caused obstruction.

[0009] An example of the present disclosure provides a catheter. The catheter includes a slender 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 slender body. The support frame may have a collapsed delivery configuration, an expanded deployment configuration, and a strut framework including a plurality of distal hoop segments. When in the collapsed delivery configuration, at least a portion of the distal hoop segment may be folded distally so that the collapsed inner diameter of the support frame is approximately equal to the inner diameter of the slender body. When in the expanded deployment configuration, the support frame may have a maximum outer diameter. The maximum outer diameter may be less than the inner diameter of the target vessel at the treatment site.

[0010] When the support frame is in the expanded deployed configuration, a first more distal hoop segment of the plurality of distal hoop segments may have a first diameter, and when the support frame is in the expanded deployed configuration, a second more proximal hoop segment of the plurality of distal hoop segments may form a second diameter. The first diameter may be greater than the second diameter.

[0011] When in the collapsed delivery configuration, the struts of the distal hoop segment may have a curved profile.

[0012] The support frame may also have a longitudinal length sized to be one third of the inner diameter of the elongated body.

[0013] The catheter may include one or more connecting ridges connecting the distal hoop segment of the support frame with the elongated body.

[0014] When in the collapsed delivery configuration, the plurality of distal hoop segments can be folded such that the support frame has a collapsed inner diameter that is approximately equal to the inner diameter of the elongated body.

[0015] The plurality of distal hoop segments may include distally disconnected peaks that move distally when the support frame is folded into the collapsed delivery configuration.

[0016] These distally unconnected peaks can move proximally when the support frame is in the expanded deployed configuration.

[0017] When the support frame is in the collapsed delivery configuration, a first more distal hoop segment of the plurality of distal hoop segments may form a first folding angle relative to the longitudinal axis. When the support frame is in the collapsed delivery configuration, a second more proximal hoop segment of the plurality of distal hoop segments may form a second folding angle relative to the longitudinal axis. The first folding angle may be less than the second folding angle.

[0018] When the support frame is in the expanded deployed configuration, the plurality of distal hoop segments can form a series of rings concentric with the longitudinal axis.

[0019] When the support frame is in the collapsed delivery configuration, at least a portion of each of the plurality of distal hoop segments can form an acute angle relative to the longitudinal axis.

[0020] When the support frame is in the collapsed delivery configuration, each of the plurality of distal hoop segments may have a non-planar cross-section.

[0021] When the support frame is in the collapsed delivery configuration, one or more hoop segments of the plurality of distal hoop segments may include one or more axial bends.

[0022] The support frame may include a plurality of ribs and one or more axial ridges. At least one axial ridge of the one or more axial ridges may be aligned with a connecting ridge of the support frame.

[0023] Another example of the present disclosure provides a catheter. The catheter may have a longitudinal axis. The catheter may include a support frame having a collapsed delivery configuration, an expanded deployment configuration, and a strut framework including one or more pairs of opposing C-shaped petals. Each pair of opposing C-shaped petals may include proximal petals and distal petals. When in the collapsed delivery configuration, the proximal petals and the distal petals may be folded into an axially elongated profile. When in the expanded deployment configuration, the support frame may have a maximum outer diameter. The maximum outer diameter may be less than the inner diameter of the target vessel at the treatment site.

[0024] The opposing C-shaped petals may be at 90 degrees to each other (synchronized).

[0025] The opposing C-shaped petals may include distally disconnected peaks to one another.

[0026] At least one of the distal non-connected peaks may include a circumferential undulation.

[0027] At least one of the opposing C-shaped petals may include an intermediate hoop.

[0028] The support frame may also include a proximal ring member connected to the distal end of the elongated body of the catheter.

[0029] The plurality of distal hoop segments may have a planar cross-section when in the expanded deployed configuration.

[0030] The support frame may have a collapsed length when in the collapsed delivery configuration and an expanded length when in the expanded deployment configuration. The collapsed length may be greater than the expanded length.

[0031] At least one of the plurality of distal hoop segments may define a plane passing through at least a portion of the circumference of the hoop segment. The plane may form an acute angle relative to the longitudinal axis when the distal end is in the collapsed delivery configuration.

[0032] In the expanded deployed configuration, the distal end of the support frame can have a circular profile including a center radially offset from the longitudinal axis of the elongated body.

[0033] In some examples, the hoop segments themselves can form units of the support frame when in the collapsed delivery configuration and can be bent proximally or distally to fold into a smaller diameter. In one example, the hoop segments can be one or more pairs of opposing C-shaped petals that can be heat set or sprung to expand radially outward when the expandable tip is deployed. In another example, the hoop segments form two longitudinally opposing rows connected by one or more axial ridges. In another example, the hoop segments can be in the shape of a wide hoop joined by a single axial ridge.

[0034] In these examples, as the framework expands and the hoops bend radially outward, a more distal hoop or a pair of opposing hoops may have a first radial dimension greater than a second radial dimension of an adjacent more proximal hoop or a set of opposing hoops. This may allow the expanded framework to form a substantially funnel shape as the radial dimensions gradually increase in the more distal hoops. In other examples, at least one of the one or more hoop segments may have a distal peak that does not share a connection with another hoop segment, thereby allowing independent bending and a greater range of motion.

[0035] Other aspects of the present disclosure will become apparent after viewing the following detailed description in conjunction with the accompanying drawings. Additional features or manufacturing steps and use steps may be included as will be understood and appreciated by those of ordinary skill in the art. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The above aspects and other aspects of the present invention will be further discussed with reference to the following description and in conjunction with the accompanying drawings, in which similar numbers indicate similar structural elements and features in various figures. The accompanying drawings are not necessarily drawn to scale, but instead, the focus is on illustrating the principles of the present invention. The accompanying drawings depict one or more specific implementations of the device of the present invention only by way of example and not by way of limitation. It is expected that those skilled in the art will be able to conceive and combine elements from multiple drawings to better meet the needs of the user.

[0037] Figure 1 is an illustration of a clot retrieval catheter having an expandable support frame advanced through vasculature in accordance with aspects of the present invention;

[0038] Figure 2A is a perspective view of a clot retrieval catheter in a collapsed delivery configuration and having an expandable support frame according to aspects of the present invention;

[0039] Figure 2B According to various aspects of the present invention Figure 2A a side view of a clot retrieval catheter in a collapsed delivery configuration and having an expandable support frame;

[0040] Figure 2C According to various aspects of the present invention Figure 2A and Figure 2B a top view of a clot retrieval catheter in a collapsed delivery configuration and having an expandable support frame;

[0041] Figure 2D According to various aspects of the present invention FIG. 2A to FIG. 2C a side view of a clot retrieval catheter in an expanded deployed configuration and having an expandable support frame;

[0042] Figure 3A is a top view of another clot retrieval catheter having an expandable support frame in a collapsed delivery configuration according to aspects of the present invention, wherein the shaft of the catheter includes angled ribs;

[0043] Figure 3B According to various aspects of the present invention Figure 3A a side view of a clot retrieval catheter in a collapsed delivery configuration and having an expandable support frame;

[0044] Figure 3C According to various aspects of the present invention Figure 3A and Figure 3B a top view of a clot retrieval catheter in an expanded deployed configuration and having an expandable support frame;

[0045] Figure 4A is a perspective view of a clot retrieval catheter having an expandable support frame in a collapsed delivery configuration, wherein a shaft of the catheter includes interrupted ridges according to aspects of the present invention;

[0046] Figure 4B According to various aspects of the present invention Figure 4A a side view of a clot retrieval catheter in a collapsed delivery configuration and having an expandable support frame;

[0047] Figure 4C According to various aspects of the present invention Figure 4A and Figure 4Ba top view of a clot retrieval catheter in a collapsed delivery configuration and having an expandable support frame;

[0048] Figure 4D According to various aspects of the present invention FIG. 4A to FIG. 4C a top view of a clot retrieval catheter in an expanded deployed configuration and having an expandable support frame;

[0049] Figure 5A is a top view of a clot retrieval catheter having an expandable support frame in an expanded deployed configuration according to aspects of the present invention, wherein the catheter includes a base ring;

[0050] Figure 5B According to various aspects of the present invention Figure 5A a top view of a clot retrieval catheter in a collapsed delivery configuration and having an expandable support frame;

[0051] Figure 5C According to various aspects of the present invention Figure 5A and Figure 5B a side view of a clot retrieval catheter in a collapsed delivery configuration and having an expandable support frame;

[0052] Figure 5D According to various aspects of the present invention FIG. 5A to FIG. 5C a perspective view of a clot retrieval catheter in a collapsed delivery configuration and having an expandable support frame;

[0053] Fig. 6A is a side perspective view of a clot retrieval catheter having an expandable support frame in a collapsed delivery configuration according to aspects of the present invention, wherein a shaft of the catheter includes a spine connector;

[0054] Figure 6B According to various aspects of the present invention Fig. 6A a side view of a clot retrieval catheter in a collapsed delivery configuration and having an expandable support frame;

[0055] Figure 6C According to various aspects of the present invention Fig. 6A and Figure 6B a top view of a clot retrieval catheter in a collapsed delivery configuration and having an expandable support frame;

[0056] Fig.6D According to various aspects of the present invention FIG. 6A to FIG. 6C a side perspective view of a clot retrieval catheter in an expanded deployed configuration and having an expandable support frame;

[0057] Fig. 7A is a side perspective view of a clot retrieval catheter having an expandable support frame in a collapsed delivery configuration according to aspects of the present invention, wherein a shaft of the catheter includes a spine connector;

[0058] Figure 7B According to various aspects of the present invention Fig. 7A a side view of a clot retrieval catheter in a collapsed delivery configuration and having an expandable support frame;

[0059] Figure 7C According to various aspects of the present invention Fig. 7A and Figure 7B a top view of a clot retrieval catheter in a collapsed delivery configuration and having an expandable support frame;

[0060] Fig.7D According to various aspects of the present invention 7A to 7C a side perspective view of a clot retrieval catheter in an expanded deployed configuration and having an expandable support frame;

[0061] Fig. 8A is a perspective view of a clot retrieval catheter in a collapsed delivery configuration and having an expandable support frame, wherein the support frame includes C-shaped petals, according to aspects of the present invention;

[0062] Figure 8B According to various aspects of the present invention Fig. 8A a perspective view of a clot retrieval catheter in an expanded deployed configuration and having an expandable support frame;

[0063] Fig. 9 is a side perspective view of a clot retrieval catheter in a collapsed delivery configuration and having an expandable support frame including circumferential undulations according to aspects of the present invention; and

[0064] Fig.10 is a perspective view of a clot retrieval catheter in an expanded deployed configuration having an expandable support frame and a jacket according to aspects of the present invention. DETAILED DESCRIPTION

[0065] Specific examples of the present invention are now described in detail with reference to the drawings, wherein like reference numerals indicate functionally similar or identical elements. These examples address many of the deficiencies associated with conventional clot retrieval aspiration catheters, such as the inability to properly or accurately deploy to the target site and ineffective clot removal.

[0066] The designs herein can be used for clot retrieval catheters having a lumen and a distal tip that, when advanced beyond the distal end, can expand in diameter to a greater diameter than the guide or sheath through which the distal tip is delivered. These designs can have a proximal elongated body for the shaft of the catheter, and a distal tip with an expanded support frame and (in some examples) a jacket (e.g., a polymer jacket) to provide the tip with atraumatic properties and the ability to further flexibly expand in an expanded deployed configuration when a clot is ingested. The catheter frame and tip can be sufficiently flexible to traverse highly tortuous regions of the anatomical structure and to restore and maintain the inner diameter of the lumen when displaced in a vessel.

[0067] Access to various intravascular vessels (whether coronary, pulmonary or cerebral) involves well-known surgical procedures and the use of many 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 in conjunction with the devices described below, their functions and exact constructions are not described in detail. Although this specification is in the context of thrombectomy treatment of intracranial arteries in many cases, the disclosure may also be applicable to other surgeries and other body passages.

[0068] Turning to the attached figure, Figure 1 A possible sequence of approaching an obstructive clot 40 using a clot retrieval catheter 100 having a design disclosed herein is shown. As the catheter 100 is collapsed within the introducer sheath 30 or other access catheter, the clot 40 can be approached. When the vasculature 10 becomes too narrow and / or tortuous to be traversed further distally with the introducer sheath 30, the catheter 100 can be deployed to advance further distally independently. The catheter 100 can be highly flexible so that it can traverse the M1 or other tortuous areas of the neurovasculature in order to reach the obstructive clot, and can have an expanded outer diameter slightly smaller than the target vessel so that the catheter can be traversed distally alone after deployment.

[0069] The clot retrieval catheter 100 may have a flexible elongated body 110 that serves as a shaft with a large inner diameter (in some cases, may be 0.080 inches or more) and a distal tip section with a collapsible support frame 210. They may facilitate delivery of the catheter to a target site by a variety of methods, including over a guidewire, over a microcatheter, with a dilator / access tool, or by itself.

[0070] In many cases, the design of the end of the support frame 210 can be configured so that the entire catheter 100 can be delivered (and retrieved) through a common standard 6F sheath / 8F guide, which typically has a lumen of less than 0.090 inches. The end is capable of self-expanding once it is advanced to an unconstrained position distal to the distal end 32 of the guide sheath 30. Because the catheter can be deployed proximal to the distal obstruction and then advanced to the distal obstruction alone, the support frame 210 at the end is designed to resist collapse caused by suction forces, has excellent lateral flexibility in both expanded and collapsed states, and has an atraumatic profile that prevents obstruction of the vessel bifurcation.

[0071] FIG. 2A to FIG. 2D Provided in a collapsed delivery configuration (see FIG. 2A to FIG. 2C ) and the expanded configuration (see Figure 2D ) and having an expandable support frame 210. The catheter 100 may include a proximal end (i.e., at the Figure 2A The catheter 100 may include a slender body 110 at the left side of the catheter 100, the slender body 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 slender body 110, and the proximal end 212 of the support frame 210 is close to the distal end of the slender body 110. The support frame 210 may have a collapsed delivery configuration, an expanded deployment configuration, and a strut framework including a plurality of distal hoop segments 213. The distal end of the support frame 210 can be opened in an expanded deployment configuration at a target site in a blood vessel. The proximal end 212 of the support frame 210 may define a proximal ring 217, which can provide support to the support frame 210 at the junction of the support frame 210 and the slender body 110.

[0072] The structure of the elongated body 110 may define a catheter lumen that may be used to deliver auxiliary devices, contrast injections, and direct distal aspiration to the clot surface through the support frame 210. The underlying structure of the elongated body 110 may be, for example, a frame cut from a hypotube of a superelastic material having shape memory properties, such as Nitinol with an internal low friction lining, and one or more outer polymer jackets 180 that may be reflowed into the structure during manufacturing. Alternatively, a more conventional polymer and / or metal braid or coil support structure, or some combination of these, may be used.

[0073] The outer surfaces of the elongated body 110 and the support frame 210 may be at least partially covered by one or more jackets 180 . Fig.10An exemplary view of a jacket 180 is provided, but it should be understood that any exemplary catheter 100 described herein may include a jacket 180. During aspiration and retrieval of clots, the jacket 180 can prevent proximal fluid from entering the expanded end, thereby allowing a more effective guidance of the aspiration force while preventing clot fragments or other debris from migrating distally during surgery. In one example, the jacket 180 can be formed of a highly elastic material so that the radial force applied by expanding the expandable end is sufficient to stretch the membrane into a funnel-shaped profile of the end when in the expanded deployment configuration. An example can be the use of a ductile elastomer, which has the following advantages: soft and flexible to resist tearing and perforation due to high failure strains. Alternatively, the jacket 180 can be loosely assembled with the catheter 100 and folded over the edge of the support frame 210 so that the support frame 210 can move more freely when expanded and collapsed.

[0074] As described above, the elongated body 110 can be sized to be compatible with a relatively low profile guide sheath 30 and catheter so that a puncture wound in the patient's groin (in the case of proximity to the femoral artery) can be easily and reliably closed. For example, a clot retrieval catheter 100 may be required to pass through the lumen of a guide sheath 30 having an inner diameter of less than 0.110 inches, such as 0.090 inches, or in some cases less than 0.087 inches, and preferably less than 0.085 inches. In other examples with 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 inches-0.074 inches (0.084 inches or 2 mm outer diameter), and may also be capable of expanding its distal end and the opening at the support frame 210 to a size just smaller than the diameter of the vessel near where the clot is located, which may be as large as 5 mm. It should be understood that a larger or smaller catheter shaft may be used if paired with a larger or smaller introducer sheath 30 .

[0075] The size of the support frame 210 can be similarly designed for compatibility. When in the collapsed delivery configuration, the support frame 210 can have an inner diameter that is sized so that the radial force is not too high for delivery through a selected guide sheath 30, which can, for example, have an inner diameter of 0.085 inches. Once deployed beyond the distal end 32 of the guide sheath 30, the support frame 210 can grow radially so that the diameter of the end is just less than the diameter of the target vessel. For example, for clots in the ICA, a large size of approximately 3mm-5mm; for proximal / large M1 clots, a medium size of approximately 0.090 inches-0.110 inches in diameter; and / or for small / distal M1 clots, a small size of approximately 0.080 inches-0.090 inches in diameter. In many cases, when in the expanded deployment configuration, the end has a maximum inner diameter 115 in the range of approximately 0.080 inches-0.120 inches. Support frame 210 also includes a longitudinal length 211 sized to be one-third of the inner diameter 115 of elongated body 110. Support frame 210 may include a collapsed length 221 in the collapsed delivery configuration and an expanded length 222 in the expanded deployment configuration that is greater than the expanded length.

[0076] Refer again FIG. 2A to FIG. 2D In the collapsed delivery configuration, at least a portion of the distal hoop segment 213 can be folded distally so that the collapsed inner diameter 215 of the support frame is approximately equal to the inner diameter 115 of the elongated body 110. In the collapsed delivery configuration, the struts of the distal hoop segment 213 can have a curved profile. In the expanded deployment configuration (see Figure 2D ), the support frame 210 may have a maximum outer diameter 224 (e.g., diameter 236) that is smaller than the inner diameter of the target vessel at the treatment site. However, in some examples, when in the expanded deployed configuration, the support frame 210 may have a maximum outer diameter 224 (e.g., diameter 236) that is slightly larger than the target vessel. In such cases, the adaptive distal support frame 210 can adjust its size according to the vessel size, thereby allowing it to be advanced to the clot. The elongated body 110 may have an axial ridge 116 extending parallel to the longitudinal axis 111 along the length of the elongated body 110. The ridge 116 may provide structural support and define a plane or axis about which the elongated body 110 can bend. The ridge 116 may include one or more ribs 118 extending from the ridge 116. The rib 118 may be bent to form a cylindrical shape so that the elongated body 110 is formed into a lumen to aspirate and capture / remove a clot from the target site.

[0077] When in the collapsed configuration, the distal hoop segment 213 can be folded distally so that the distal hoop segment 213 is angled toward the distal end of the catheter 100. When the catheter 100 is expanded into the expanded configuration, these folds in the support frame 210 can unfold. Figure 2B As shown, the plurality of distal hoop segments 213 may have distally unconnected peaks 228 that move distally when the support frame 210 is folded into the collapsed delivery configuration. When the support frame 210 is in the collapsed delivery configuration, the first more distal hoop segment 229 of the plurality of distal hoop segments may have a first folding angle 218 relative to the longitudinal axis 111; when the support frame 210 is in the collapsed delivery configuration, the second more proximal hoop segment 230 of the plurality of distal hoop segments 213 may have a second folding angle 219 relative to the longitudinal axis 111. The first folding angle 218 may be smaller than the second folding angle 219. In some examples, when the support frame is in the collapsed delivery configuration, one or more of the distal most hoop segments 213 (e.g., the distal most hoop segment 226) may have an acute angle (e.g., angle 218) relative to the longitudinal axis 111. This configuration enables the distal hoop segments 213 to be deployed into Figure 2D The fully shaped expanded configuration is shown. When the support frame 210 is in the expanded deployed configuration, the plurality of distal hoop segments 213 can form a series of rings concentric with the longitudinal axis 111 .

[0078] In some examples, the support frame 210 may include one or more connecting ridges 216 from which the distal hoop segments 213 extend. In some examples, the connecting ridges 216 may be aligned with the axial ridges 116 of the elongated body 110; in some examples, the connecting ridges 216 may be radially offset from the axial ridges 116, such as Figure 2A When the support frame 210 is in the expanded deployed configuration, the first more distal hoop segment 213 of the plurality of distal hoop segments 229 may have a first diameter 236, and when the support frame 210 is in the expanded deployed configuration, the second more proximal hoop segment 230 of the plurality of distal hoop segments 213 may have a second diameter 238. The first diameter 236 may be greater than the second diameter 238 to create a funnel shape for the support frame 210, such as Figure 2D When in the expanded deployed configuration, the plurality of distal hoop segments 213 may have a planar cross-section.

[0079] FIG. 3A to FIG. 3C Provided in a collapsed delivery configuration (see Figure 3A and Figure 3B ) and the expanded configuration (see Figure 3C ) and a view of an exemplary clot retrieval catheter 100 having an expandable support frame 210. FIG. 3A to FIG. 3C The exemplary catheter 100 in FIG. 1 is similar to the catheter 100 for FIG. 2A to FIG. 2D The example shown, however FIG. 3A to FIG. 3CThe example in provides a variation of the elongated body 110. As shown, the elongated body 110 may include an interrupted ridge 117 positioned along the length of the elongated body 110 (e.g., along the longitudinal axis 111). The interrupted ridge 117 may be positioned diametrically opposite the axial ridge 116, and two or more ribs 118 may be joined together to form a stronger elongated body 110. In order to use Figure 3B The example shown illustrates that the interrupted ridge 117 includes three ribs 118 connected to each other, which are separated from the next group of three ribs 118 by the interruption of the interrupted ridge 117 .

[0080] 4A to 4D Provided in a collapsed delivery configuration (see FIG. 4A to FIG. 4C ) and the expanded configuration (see Figure 4D ) and a view of an exemplary clot retrieval catheter 100 having an expandable support frame 210. 4A to 4D The exemplary catheter 100 in FIG. 1 is similar to the catheter 100 for FIG. 3A to FIG. 3C The example shown, however 4A to 4D The examples in provide variations of the elongated body 110 . 4A to 4D An example of an elongated body 110 framework having pairs of support ribs 118 that merge into a single spine connector 146 for connection with an axial spine 116 is shown. Each group of support ribs 118 may have one, two, three, or more ribs 118. By connecting the support ribs 118 into groups with a single connection to one or more spines 116, additional flexibility may be achieved by extending the length of the spine 116, which may bend freely for a given density of ribs 118. This arrangement may also reduce strain at the connection between the spine connector 146 and the axial spine 116.

[0081] Alternatively, a similar design may see a series of support ribs 118 that merge into diametrically opposed ridge connectors for connection with dual ridges 116 spaced 180 degrees apart. Additional ridges are also contemplated, trading some lateral flexibility for the better pushability that can be achieved with fewer ridges. Additional axial stiffness may also help prevent the elongated body from stretching under tension, such as when the expandable tip is pulled proximally into an outer sheath with a firm clot.

[0082] FIG. 5A to FIG. 5D Provided in a collapsed delivery configuration (see FIG. 5B to FIG. 5D ) and the expanded configuration (see Figure 5A) and an exemplary clot retrieval catheter 100 having an expandable support frame 210. The support frame 210 may include a connecting ridge 223 extending colinearly with respect to the axial ridge 116 of the elongated body 110. The connecting ridge 223 may help position the hoop segment 213 of the support frame 210. The support frame 210 may also include a second connecting ridge 223 diametrically opposite the first connecting ridge 223 to add additional support to the hoop segment 213.

[0083] The catheter 100 may include a support ring 234 positioned between the elongated body 110 and the support frame 210. One end of the support ring 234 may be connected to one or more axial ridges 116 of the elongated body (e.g., after the most distal rib 227), and the other end of the support ring 234 may be connected to one or more connecting ridges 223 of the support frame 210. The support ring 234 may increase the structural support of the joint between the elongated body 110 and the support frame 210. The support ring 234 may also provide an indication of the position of the support frame 210 within the target vessel, such as when the target site is observed under fluoroscopy. In some examples, the support ring 234 may include a radiopaque marker 235 embedded therein or otherwise attached thereto. The radiopaque marker 235 may include a denser material than the rest of the catheter 100 so as to alert the user to the position of the support frame 210. For example, the catheter 100 may include a flexible material such as nitinol, and the radiopaque marker 235 may include a high-density material such as gold or platinum.

[0084] In some examples, the support frame 210 may include one or more floating ridges 220. The floating ridges 220 may be positioned around the circumference of the hoop segments 213 at, for example, 90 degrees, and may provide support to the hoop segments 213 as they are deployed to the expanded deployed configuration. For example, the floating ridges 220 may ensure that the hoop segments 213 are deployed into a substantially circular shape. Unlike the connecting ridges 223, the floating ridges 220 may be disconnected from the support ring 234.

[0085] FIG. 6A to FIG. 6D Provided in a collapsed delivery configuration (see FIG. 6A to FIG. 6C ) and the expanded configuration (see Fig.6D ) and a view of an exemplary clot retrieval catheter 100 having an expandable support frame 310. FIG. 6A to FIG. 6D The exemplary catheter 100 in FIG. 1 is similar to the catheter 100 for FIG. 2A to FIG. 2D The example shown, however FIG. 6A to FIG. 6DThe example in provides a variation of the support frame 310, or specifically, the hoop segment (which is referred to as the hoop segment 213 above). As shown, at least one hoop segment 326 of the plurality of distal hoop segments 313 may define a plane 318 that passes through at least a portion of the circumference of the at least one hoop segment 326. When the distal end 114 of the elongated body 110 is in the collapsed delivery configuration, the plane 318 may form an acute angle 319 relative to the longitudinal axis 111. The farther the distal hoop segment 313 is from the elongated body 110, the further the distal unconnected peaks 328 of the distal hoop segment 313 may be spaced apart from each other. To this end, when in the collapsed delivery configuration, the more proximal hoop segment in the distal hoop segment 313 may have a hoop fold angle 321 that is closer to 90 degrees relative to the longitudinal axis 111 compared to the more distal hoop segment (e.g., the hoop segment 326 at the distal end 314 of the support frame 310). This configuration can accommodate distal-most hoop segments 326 having first radial dimensions 336 that are greater than second radial dimensions 338 of proximal-most hoop segments 313 (e.g., those hoop segments proximal to elongated body 110). Fig.6D ), the planes 318 of the plurality of distal hoop segments 313 may all be approximately 90 degrees relative to the longitudinal axis 111. FIG. 6A to FIG. 6D The illustrated axial ridges 316 may be similar to the axial ridges 116 described herein.

[0086] 7A to 7D Provided in a collapsed delivery configuration (see 7A to 7C ) and the expanded configuration (see Fig.7D ) and an exemplary clot retrieval catheter 100 having an expandable support frame 310. When the support frame 310 is in the collapsed delivery configuration, one or more of the plurality of distal hoop segments 313 may include one or more axial bends (e.g., a first axial bend 331 and a second axial bend 332). These axial bends 331, 332 may provide height to the circular distal hoop segments 313 so that when they are deployed into the expanded deployed configuration, the distal hoop segments 313 have a circular profile including a center 330 radially offset from the longitudinal axis 111 of the elongated body 110. Additionally, when the support frame 310 is in the collapsed delivery configuration, each of the plurality of distal hoop segments 213 may have a non-planar cross-section.

[0087] In some examples, the elongated body 110 may include seams 148 between certain ribs 118 of the elongated body 110 and the axial ridges 116. The seams 148 may help disconnect the ribs 118 from the axial ridges 116 at an angle to allow the elongated body 110 to expand radially and provide a greater degree of flexibility to the body. The seams 148 may be created by forming the ribs 118 into a serpentine shape, such that only each second rib, third rib, fourth rib, etc. rib 118 is attached to the axial ridge 116 via the ridge connector 146.

[0088] Fig. 8A and Figure 8B is a perspective view of a clot retrieval catheter 100 having an expandable support frame 410 including C-shaped petals 413 according to aspects of the present invention. Fig. 8A An exemplary catheter 100 is shown in a collapsed configuration according to aspects of the present invention, and Figure 8B An exemplary catheter 100 is shown in an expanded deployment configuration according to aspects of the present invention. Each pair of opposing C-shaped petals 413 may include a proximal petal 420 and a distal petal 421. The proximal petal 420 may be connected to the rib 118 (e.g., the distal-most rib 227) via a connecting ridge 416. The distal petal 421 may be connected to the proximal petal 420 via one or more connecting struts 417. When in a collapsed delivery configuration (see Fig. 8A ), the proximal petal-shaped member 420 and the distal petal-shaped member 421 can be folded into an axially elongated profile. In the expanded deployment configuration, the support frame 410 can have a maximum outer diameter 224 that is smaller than the inner diameter of the target blood vessel at the treatment site.

[0089] The C-shaped petals 413 may be synchronized at 90 degrees to each other to improve flexibility and enhance the ability to recover and maintain the shape and inner diameter of the support frame 410 when displaced laterally in a vessel. In addition, the synchronized offset between the connecting ridges 416 of the support frame 410 and the axial ridges 116 of the elongated body 110 may have a hinge effect, allowing the structure to easily deflect away from the vessel wall. As shown, the opposing C-shaped petals 413 may include distal unconnected peaks 428 at the distal end 414 of the support frame 410.

[0090] Fig. 9 is a side perspective view of a clot retrieval catheter 100 in a collapsed delivery configuration and having an expandable support frame 410 including circumferential undulations 418 in accordance with aspects of the present invention. Fig. 9 The catheter 100 shown is similar to Fig. 8A and Figure 8BThe embodiment shown in FIG. 1 , but the support frame 410 is varied. One or more circumferential undulations 418 on the support frame 410 may be flared with a large bend radius to provide atraumatic contact with the vessel wall. The support frame 410 may also include one or more intermediate hoops 429 extending from the C-shaped petals 413. The intermediate hoops 429 may be a membrane (e.g., Fig.10 The jacket 180 shown in FIG. 18A provides additional scaffolding to direct fluid and / or clots into the elongated body 110. Extending from the proximal ring member 434 may be a base ring support hoop 435 that is separable from the proximal petals 420 and is a membrane (e.g., Fig.10 The jacket 180 shown provides additional support.

[0091] Fig.10 1 is a perspective view of a clot retrieval catheter 100 in an expanded deployed configuration and having an expandable support frame 410 and a jacket 180. The jacket 180 may be a polymer jacket extrusion that may be reflowed or laminated in place. The applied heat may allow the outer polymer to fill the interstitial areas between the ribs 118 of the elongated body 110. Suitable jacket 180 materials may include a resilient polyurethane such as neoprene, a silicone elastomer, or the like that may have a Shore hardness of 40A or less.

[0092] Alternatively, the jacket 180 may also be applied in other combinations. Depending on their axial position on the elongated body 110 and / or the support frame (e.g., support frame 210, 310, 410), the jacket 180 may be dip-coated, spray-coated, electrospun, and / or plasma deposited onto the support frame. In other examples, the jacket 180 may be a vertical extrusion, or may be extruded and post-formed onto the expanded tip and catheter body.

[0093] 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 lubricating material, such as PTFE, or a commercially available lubricating coating.

[0094] The present invention is not necessarily limited to the examples described, the configurations and details of which may vary. The terms "distal" and "proximal" are used throughout the foregoing description and refer to positions and directions relative to the treating physician. Similarly, "distal" or "toward the distal side" refers to a position away from the physician or in a direction away from the physician. Similarly, "proximal" or "toward the proximal side" refers to a position close to the physician or in a direction toward the physician. In addition, unless the context clearly indicates otherwise, the singular forms "a", "an", and "the / said" include plural references.

[0095] As used herein, the term "about" or "approximately" for any numerical value or range indicates a suitable dimensional tolerance that allows a collection of parts or components to achieve its intended purpose as described herein. More specifically, "about" or "approximately" can refer to a value range of ±20% of the recited value, for example, "about 90%" can refer to a value range of 71% to 99%.

[0096] In describing the example embodiments, terminology has been employed for the sake of clarity. Therefore, not all possible combinations are listed, and such variations are generally obvious to those skilled in the art and are intended to fall within the scope of the following claims. Without departing from the scope and spirit of the present invention, it is intended that each term contemplates its broadest meaning as understood by those skilled in the art, and includes all technical equivalents that operate in a similar manner to achieve similar purposes. It should also be understood that reference to one or more steps of a method does not exclude the presence of additional method steps or intermediate method steps between those explicitly identified steps. Similarly, some steps of the method may be performed in an order different from that described herein without departing from the scope of the disclosed technology.

Claims

1. A catheter, comprising: an elongated body comprising a longitudinal axis, an inner diameter, and a distal end; and a support frame connected to the distal end of the elongated body, the support frame comprising a collapsed delivery configuration, an expanded deployed configuration, and a strut framework including a plurality of distal hoop segments; and In the collapsed delivery configuration, at least a portion of the distal hoop segment is folded distally such that a collapsed inner diameter of the support frame is approximately equal to the inner diameter of the elongated body.

2. According to the catheter according to claim 1, when the support frame is in the expanded and deployed configuration, the first more distal hoop segment among the multiple distal hoop segments includes a first diameter, and when the support frame is in the expanded and deployed configuration, the second more proximal hoop segment among the multiple distal hoop segments forms a second diameter, and the first diameter is larger than the second diameter.

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

4. The catheter of claim 1, the support frame further comprising a longitudinal length sized to be one-third of the inner diameter of the elongated body.

5. The catheter of claim 1, further comprising one or more connecting ridges connecting the distal hoop segment of the support frame to the elongated body.

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

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

8. The catheter of claim 7, wherein the distal non-connected peaks are moved proximally when the support frame is in the expanded deployed configuration.

9. The catheter of claim 1, wherein when the support frame is in the collapsed delivery configuration, a first more distal hoop segment of the plurality of distal hoop segments forms a first fold angle relative to the longitudinal axis, When the support frame is in the collapsed delivery configuration, a second, more proximal hoop segment of the plurality of distal hoop segments forms a second fold angle relative to the longitudinal axis, and The first folding angle is smaller than the second folding angle.

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

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

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

13. The catheter of claim 1, wherein one or more of the plurality of distal hoop segments further comprises one or more axial bends when the support frame is in the collapsed delivery configuration.

14. The catheter of claim 5, the elongated body comprising a plurality of ribs and one or more axial ridges, and at least one of the one or more axial ridges is aligned with a connecting ridge of the support frame.

15. A catheter, comprising: longitudinal axis; a support frame comprising a collapsed delivery configuration, an expanded deployment configuration, and a strut framework comprising one or more pairs of opposing C-shaped petals; and Each pair of opposing C-shaped petals includes proximal and distal petals that are folded into an axially elongated profile when in the collapsed delivery configuration.

16. The catheter of claim 15, said opposing C-shaped petals being synchronized at 90 degrees to each other.

17. The catheter of claim 15, the opposing C-shaped petals comprising distally disconnected peaks.

18. The catheter of claim 17, at least one of the distal non-connected peaks comprising a circumferential undulation.

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

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

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