Catheter tip expandable during compression

Abstract

The systems and devices disclosed herein can include a support frame for a blood clot retrieval catheter tip that includes a longitudinal axis, a folded configuration, an expanded deployed configuration, and a plurality of interconnected struts. The plurality of interconnected struts can define an axial series of expansion cells and can join at opposing pairs of x-connectors that are 180 degrees apart about the longitudinal axis. Each opposing pair of x-connectors can be rotated 90 degrees about the longitudinal axis relative to an adjacent opposing pair of x-connectors. The support frame can further include a folded inner diameter in the folded delivery configuration and a larger expanded inner diameter in the expanded deployed configuration when the support frame is placed in a compressed state.

Description

Technical Field

[0001] The present invention generally relates to devices and methods for removing acute occlusions from blood vessels during endovascular medical procedures. More specifically, the present invention relates to a retrieval catheter having an expandable tip capable of retrieving an object or a plurality of objects.

Background Art

[0002] Thrombus retrieval aspiration catheters and devices are often used for mechanical thrombectomy for endovascular intervention when a patient suffers from conditions such as acute ischemic stroke (AIS), myocardial infarction (MI), and pulmonary embolism (PE). In the prior art, access to the neurovascular bed in particular has been difficult because the target vessel is small in diameter, far from the insertion site, and highly tortuous. Conventional devices often either have too large a profile, lack the deliverability and flexibility necessary to navigate particularly tortuous blood vessels, or are not effective at removing thrombi when delivered to the target site.

[0003] Many existing designs for aspiration catheters are often limited to an inner diameter of, for example, 6Fr, i.e., approximately 0.068 - 0.074 inches. For larger sizes, even larger guides or sheaths need to be used, and then a larger femoral access hole needs to be closed. Most physicians prefer to use an 8Fr guide / 6Fr sheath combination, and few physicians would think well of combinations exceeding a 9Fr guide / 7Fr sheath. This means that once the target site is reached, the size of the blood clot may often be larger than the inner diameter of the aspiration catheter, and the blood clot must be immediately compressed in another way to enter the catheter opening. This compression can cause bunching up during recovery, which can then lead to shearing of the blood clot. Blood clots rich in tough fibrin can also clog the tip of the fixed opening of these catheters, making it more difficult to extract them. This clogging can also result in shearing where softer parts of the blood clot are torn from the tough regions of the blood clot.

[0004] Small diameters and fixed tip sizes are also inefficient in inducing the suction required for the removal of blood and thrombus material during the procedure. The fixed tip size may shear or break the blood clot when it enters the tip opening. The suction must be strong enough so that any fragmentation that may occur as a result of the use of a suction or mechanical thrombectomy device keeps the fragments in a static state so that they do not move distally into the blood vessels and cause occlusion. However, when suctioning with a fixed opening catheter, since the diameter of the funnel catheter is smaller than the blood vessel diameter, a significant portion of the suction flow will come from the vascular fluid proximal to the catheter tip where there is no blood clot. This significantly reduces the suction efficiency and the success rate of blood clot removal.

[0005] Any catheter design attempting to overcome these challenges using an expandable distal tip or structure will need to have the strength to extract blood clots and apply stable radial forces in the expanded state. The same structure will also need to be sufficiently flexible and elastic to withstand the severe mechanical strains imparted when navigating tortuous vascular structures in the collapsed state. Summary of the Invention Problems to be Solved by the Invention

[0006] As a result, an improved catheter design that overcomes the above-described design challenges is still needed. The present design aims to provide an improved retrieval catheter having an expandable tip section and a method of using such a catheter with improved performance. Means for Solving the Problems

[0007] It is an object of the present design to provide an apparatus and method that meet the above needs. The present design can be directed to a blood clot retrieval catheter capable of removing blood clots from the cerebral arteries of patients suffering from AIS, from the native coronary or graft vessels of patients suffering from MI, from the pulmonary arteries of patients suffering from PE, and from other peripheral arteries and veins where blood clots are causing obstruction.

[0008] One example of the present disclosure provides a catheter tip. The catheter tip can include a support frame including a longitudinal axis, a folded configuration, an expanded deployment configuration, and a plurality of interconnected struts. The plurality of interconnected struts can define an axial series of expansion cells and can join at opposing pairs of x-connectors spaced 180 degrees apart about the longitudinal axis. Each opposing pair of x-connectors can be rotated 90 degrees about the longitudinal axis relative to an adjacent opposing pair of x-connectors. The support frame can further include a folded inner diameter in the folded delivery configuration and a larger expanded inner diameter in the expanded deployment configuration when the support frame is placed in a compressed state.

[0009] The catheter tip can include an offset mouthpiece strut at the distal end of the support frame, and at least a portion of the offset mouthpiece strut is present within a plane forming an acute angle with the longitudinal axis.

[0010] The support frame can include a proximal collar at the proximal end. The proximal collar can include a ring member circumferentially divided by at least one seam.

[0011] When impacted by an ingested blood clot, the support frame can expand from the folded inner diameter to the expanded inner diameter.

[0012] The support frame can be configured to be heat set to have an expanded inner diameter larger than the folded inner diameter.

[0013] The support frame can include a shape memory alloy having a martensite finish temperature of less than about 30°C.

[0014] The support frame can include a short axial length in the expanded deployment configuration as compared to the folded delivery configuration.

[0015] The support frame can include a maximum outer diameter in an expanded deployment configuration that is less than the inner diameter of the target blood vessel at the treatment site.

[0016] When in the folded delivery configuration, the distal end of the support frame can include a substantially circular cross-section having a center that substantially coincides with the longitudinal axis.

[0017] The interconnected struts of the catheter tip can include a curved profile.

[0018] An axial series of expansion cells can include opposing pairs of cells that are 180 degrees apart about the longitudinal axis, and each opposing pair of cells can be rotated 90 degrees about the longitudinal axis relative to an adjacent pair of opposing cells.

[0019] An axial series of expansion cells can shorten longitudinally when the support frame is placed in a compressed state.

[0020] Another example of the present disclosure provides another catheter tip. The catheter tip can include a support frame that includes a longitudinal axis, a folded delivery configuration, an expanded deployment configuration, and an axial series of hoop ribs that extend in a plane offset from the longitudinal axis. The hoop ribs can include a curved profile, a non-planar cross-section, and a peak that is not distally connected. The support frame can include a mouth having a larger expanded inner diameter when the support frame is placed in a compressed state.

[0021] The support frame can include a larger expanded inner diameter when radially impacted by a blood clot ingested in the expanded deployment configuration and a smaller delivery inner diameter in the folded delivery configuration.

[0022] The support frame can include a shape memory alloy having a martensite finish temperature of less than about 30°C.

[0023] The support frame can be heat set to have an expanded inner diameter that is larger than the inner diameter of the folded delivery configuration.

[0024] The distal end of the support frame in the expanded deployment configuration can have a circular profile that includes a center radially offset from the longitudinal axis.

[0025] The distal end of the support frame in the folded delivery configuration can have a substantially circular cross-section having a center that substantially coincides with the longitudinal axis.

[0026] The support frame can include a short axial length in a delivery configuration that is more expanded than the folded delivery configuration.

[0027] The support frame can include a maximum outer diameter of an expanded deployment configuration that is less than the inner diameter of the target blood vessel at the treatment site.

[0028] The peaks not connected distally to each of the hoop ribs can move proximally when the support frame is placed in a compressed state during blood clot extraction.

[0029] At least a portion of each of the hoop ribs can be present in a plane that forms an acute angle with the longitudinal axis.

[0030] The support frame can include one or more connector ribs extending from a ring member connected to the proximal end of the support frame, and the connector ribs branch from the ring member in an offset plane that is substantially perpendicular to the offset plane of the hoop ribs.

[0031] At least one of a series of hoop ribs can be connected proximally to a connector rib, and at least one of a series of hoop ribs can be connected proximally to a ring member.

[0032] The support frame can include one or more support ribs extending from the ring member within a plane that is substantially parallel to the offset plane of the connector rib. The support ribs may have no connection points with either a series of hoop ribs or the connector rib.

[0033] The ring member can be configured to press-fit onto the braided section of the tubular catheter shaft. The support frame can include a proximal collar at the proximal end. The proximal collar can include a ring member circumferentially divided by at least one seam.

[0034] Other aspects of the present disclosure will become apparent by considering the following detailed description in conjunction with the accompanying drawings. Additional features or manufacturing and use processes can 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 will be further considered with reference to the following description in conjunction with the accompanying drawings, in which like numerals in the various drawings indicate like structural elements and features. The drawings are not necessarily to scale, and instead, the main focus is on illustrating the principles of the present invention. The figures depict one or more implementations of the apparatus of the present invention by way of example and not limitation. Those skilled in the art are expected to envision and combine elements from the multiple figures to better suit the user's requirements.

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DETAILED DESCRIPTION OF THE INVENTION

[0036] Here, specific embodiments of the present invention will be described in detail with reference to the drawings, where the same reference numerals indicate functionally similar or identical elements. The embodiments address many of the deficiencies associated with conventional blood clot retrieval suction catheters, such as inadequate or inaccurate deployment to the target site and ineffective blood clot removal.

[0037] The design of this specification, which illustrates various configurations of the catheter tip support frame, can be incorporated into a suction blood clot retrieval catheter with a membrane cover or jacket encapsulation, a proximal shaft, a large bore lumen, and a distal low shear tip (LST) that can expand to a diameter larger than the nominal diameter when interacting with an ingested blood clot or stentriever. The design of this specification can also be pre-expanded and heat set to be incorporated into a collapsible super bore (CSB) catheter with a membrane cover and proximal shaft, crushed for delivery through a guide catheter, expand when exiting the guide catheter, and provide a catheter that can be advanced to the target blood vessel for blood clot suction.

[0038] The design of this specification can have a proximal elongated body for the catheter shaft and a distal tip having an expandable inner frame to impart atraumaticity to the tip. That is, the expandable inner frame can be easily repeatedly folded for delivery and can expand locally under the load from a blood clot (when used in conjunction with an LST catheter) or by being heat set (when used in conjunction with a CSB catheter), thereby enabling the catheter tip to expand beyond its nominal diameter to capture the blood clot. The expandable inner frame can have a proximal ring for attachment to a braided catheter shaft and can have an offset opening that allows for a larger opening for blood clot retrieval and a reduced stiffness for easier expansion. This management of blood clots during capture can significantly reduce blood clot shear. The catheter design can be flexible enough to navigate very tortuous areas of the anatomical structure and to restore and maintain the shape of the lumen inner diameter when displaced within the blood vessel.

[0039] Optionally, this new axis for expanding the tip section using the blood clot itself greatly improves blood clot handling and reduces shear compared to conventional designs. The nominal non-expanded outer diameter maximizes the distal access range, like a standard fixed-port catheter. Then, once the blood clot is captured, by corresponding to the stiff fibrin-rich portion of the blood clot through additional radial expansion, the blood clot can be gradually compressed and blood clot shear can be significantly reduced compared to catheters lacking this ability. Further, due to the tip conformity, the tip can be advanced atraumatically beyond calcified lesions without removing plaque material.

[0040] Accessing various blood vessels within the vascular system involves well-known procedures and the use of numerous conventional commercially available accessory products, regardless of whether they are coronary, pulmonary, or cerebral blood vessels. These products, such as angiographic materials, mechanical thrombus removal devices, microcatheters, and guidewires, are widely used in laboratories and medical procedures. When these products are used in conjunction with the devices and methods of the present invention in the following description, their functions and exact configurations are not described in detail. Also, these descriptions are often related to thrombus removal treatment in intracranial arteries, but the present disclosure can be similarly adapted to other procedures and other body passages.

[0041] Referring to the figures, FIGS. 1A - 1E show an exemplary expandable support frame 210 for use at the distal end of a clot retrieval catheter. When used in conjunction with an LST catheter, the support frame 210 can be manufactured using superelastic nickel titanium or nitinol (NiTi), shape memory NiTi, or stainless steel. Shape memory materials are not required for the LST catheter, but can provide the additional advantage of allowing the support frame 210 to recover its shape if distorted during use or if the support frame 210 is expanded by a clot during a first retrieval pass and needs to be easily recovered to pass back through a guide sheath for a second retrieval pass. When used in conjunction with a CSB catheter, the shape memory material allows the support frame 210 to self-expand as it exits the distal end of the catheter tip and approaches a clot for retrieval. The shape memory alloy used can include a martensite finish temperature of less than about 30°C.

[0042] The support frame 210 can be manufactured by employing raw tubing of the materials as described above, laser cutting the materials, and producing the desired configuration of the support frame 210, as further described below. The raw tubing can have an outer diameter of about 2.00 millimeters, a wall thickness of about 0.05 millimeters, and an inner diameter of about 1.90 millimeters. The support frame 210 can also be manufactured to have a light electropolish or other such finish. The matte finish can provide the advantage of enhancing adhesion to the polymeric catheter jacket.

[0043] The support frame 210 can include a longitudinal axis 111, a folded delivery configuration (Figs. 1A - 1C), an expanded deployment configuration (Figs. 10B - 10C or 11C), and a plurality of interconnected struts 218 that define an axial series of expansion cells 221. The interconnected struts 218 can be joined at opposing pairs of x - connectors 217 that are 180 degrees apart about the longitudinal axis 111. Each opposing pair of x - connectors 217 can be rotated 90 degrees about the longitudinal axis 111 with respect to an adjacent opposing pair of x - connectors 217, as particularly shown in Fig. 1A. Such a rotational configuration can provide enhanced flexibility of the support frame 210 across multiple planes as compared to many conventional support frame designs.

[0044] As shown particularly in FIGS. 1B-1C, the support frame 210 can include a distal strut angle 219 between struts 218 on both sides of the longitudinal axis 111. The distal strut angle 219 can be configured as an obtuse angle so as to provide enhanced flexibility and compressibility during blood clot retrieval, as further described below. The struts 218 can also include a curved profile to assist in the flexibility of the support frame 210. That is, a series of expansion cells 221 can shorten longitudinally when the support frame 210 is placed in a compressed state (FIGS. 10C and 11C). Thus, the support frame 210 can include an axial length 225 (FIG. 1C) that can be shorter in a deployed configuration that is expanded rather than in a folded delivery configuration, as further described below with respect to FIGS. 10A-10C and 11A-11C.

[0045] As shown particularly in FIG. 1B, a series of axial expansion cells 221 can include opposing pairs of cells that are 180 degrees apart about the longitudinal axis 111. Each opposing pair of cells can also be rotated 90 degrees about the longitudinal axis 111 relative to adjacent opposing pairs of cells.

[0046] When in the folded delivery configuration, the distal end 114 of the support frame 210 can include a substantially circular cross-section having a center that substantially coincides with the longitudinal axis, as shown particularly in FIGS. 1A-1B and further described below.

[0047] The support frame 210 can also include a proximal collar 115 at its proximal end 112. The proximal collar 115 can be used to attach the support frame 210 to the braided shaft of the blood clot retrieval catheter. The proximal collar 115 can include a ring member 116 circumferentially divided by at least one seam 117, such as an angled seam, that aids in the assembly of the proximal collar 115 (FIG. 1A). In some embodiments, the ring member 116 may be configured to connect to the braided section of the tubular catheter shaft. For example, the ring member 116 may be configured to be press-fitted onto the braided section or laser welded to the braided section (e.g., fitting under or over the braided section). In other examples, the ring member 116 may be adhesively bonded to the braided section. In some embodiments, rather than the braided section, the ring member 116 may be integrally formed with and / or laser welded to a laser cut proximal catheter support structure.

[0048] As shown in FIGS. 1A-1B, the support frame 210 can include a mouth 213 at its distal end 114, and the mouth 213 has offset mouth struts 220. At least a portion of the offset mouth struts 220 can be in a plane that forms an acute angle 222 with the longitudinal axis 111. As shown, the offset mouth struts 220 can be connected to one or more struts 218 by one or more y-connectors 223. The advantage of the offset mouth struts 220 is that they can allow for a larger space for blood clots to enter the catheter tip. This can provide easier and more efficient blood clot retrieval from the treatment site compared to many conventional support frame designs and can reduce the risk of blood clot shearing or breakage during retrieval. The offset mouth can also allow for an increase in blood clot gripping force due to the larger area of the mouth compared to the circular cross-section of the catheter.

[0049] As shown in FIGS. 1D - 1E, the support frame 210 can include a folded inner diameter 215 (FIG. 1D) in the folded delivery configuration and a larger inner diameter 224 (FIG. 1E) in the expanded deployment configuration when the support frame 210 is placed in a compressed state. The folded inner diameter 215 allows the support frame 210 to fit within the guide sheath 30 (FIG. 10A) when the catheter is being navigated through the blood vessel 12 towards the treatment site. As will be further described below with respect to FIGS. 11A - 11C, when used in conjunction with the LST catheter, the support frame 210 can maintain its folded inner diameter 215 when exiting the distal end 32 of the guide sheath 30, and then expand from the folded inner diameter 215 to the expanded inner diameter 224 when the ingested blood clot 40 collides with it. Alternatively, when used in conjunction with the CSB catheter, as will be further described below with respect to FIGS. 10A - 10C, the support frame 210 can be heat set to have an expanded inner diameter 224 that is larger than the folded inner diameter 215 as soon as the support frame 210 exits the distal end 32 of the guide sheath 30. In some embodiments, when used in conjunction with either the LST catheter or the CSB catheter, for example, when the support frame 210 is in its expanded deployment configuration (FIGS. 10B - 10C and FIG. 11C), its maximum outer diameter can be less than the inner diameter 13 of the target blood vessel 12 at the treatment site, whereby the support frame 210 can advance distally towards the blood clot 40 independently of and without occluding the blood vessel 12. In some embodiments, for example, when used in conjunction with the CSB catheter, the maximum outer diameter of the support frame 210 can be larger than the inner diameter 13 of the target blood vessel 12. In such embodiments, the support frame 210 may be configured to self - collapse so as to provide an occlusion within the blood vessel when advanced distally through a smaller blood vessel.

[0050] Regarding the various support frames disclosed herein, the inner and outer diameters of the support frame in the folded delivery configuration relative to the expanded deployment configuration may depend on the size of the catheter used in conjunction with the support frame.

[0051] For example, when using a support frame in conjunction with a 5Fr low-shear tip, the folded inner diameter may be about 0.054 inches and the folded outer diameter may be about 0.066 inches. A support frame of this size may be used in a target vessel having an inner diameter of about 1.7 millimeters in its folded configuration, while in its expanded configuration, it may be expanded to seal in a target vessel having an inner diameter of about 2.2 millimeters.

[0052] For example, when using a support frame in conjunction with a 6Fr low-shear tip, the folded inner diameter may range from about 0.068 inches to about 0.074 inches, and the folded outer diameter may range from about 0.080 inches to about 0.086 inches. A support frame of this size may be used in a target vessel having an inner diameter of about 2.0 to 2.2 millimeters in its folded configuration, while in its expanded configuration, it may be expanded to seal in a target vessel having an inner diameter of about 3.5 millimeters.

[0053] For example, when using a support frame in conjunction with an 8Fr low-shear tip, the folded inner diameter may range from about 0.082 inches to about 0.095 inches, and the folded outer diameter may range from about 0.094 inches to about 0.115 inches. A support frame of this size may be used within a target vessel having an inner diameter of about 2.4 to 2.9 millimeters, while in its expanded configuration, it may be expanded to seal within a target vessel having an inner diameter of about 5.0 millimeters.

[0054] Figures 2A-2D illustrate another exemplary expandable support frame 310 for use at the distal end of a blood clot retrieval catheter. The support frame 310 can include one or more features that are the same as or similar to those described above with respect to the support frame 210. Further, the manufacture of the support frame 310 can be the same as or similar to the manufacture of the support frame 210 as described above. The support frame 310 can also be manufactured to be electropolished, pickled to roughen the surface of the support frame 310, and / or heat treated to have an oxide layer finish.

[0055] The support frame 310 can include a longitudinal axis 111, a folded delivery configuration (Figs. 2A-2C), an expanded deployment configuration, and a plurality of interconnected struts 318 that define an axial series of expansion cells 321. The interconnected struts 318 can be joined at opposing pairs of x-connectors 317 that are 180 degrees apart about the longitudinal axis 111. Each opposing pair of the x-connectors 317 can be rotated 90 degrees about the longitudinal axis 111 relative to an adjacent opposing pair of the x-connectors 317. Such a rotational configuration can provide enhanced flexibility of the support frame 310 across multiple planes as compared to many conventional support frame designs.

[0056] The support frame 310 can also include a distal strut angle 319 between struts 318 on both sides of the longitudinal axis 111, particularly as shown in Fig. 2C. The distal strut angle 319 can be configured as an acute angle due to the increased length of the x-connector struts 317. The acute distal strut angle 319 can provide an increase in the expansion of the support frame 310, and the increased length of the x-connector struts 317 can provide less restricted bending as compared to many conventional support frame designs.

[0057] As particularly shown in FIG. 2C, the interconnected struts 318 can also include a curved profile to assist in the flexibility of the support frame 310. That is, a series of expansion cells 321 can shorten longitudinally when the support frame 310 is placed in a compressed state. Thus, as shown in FIG. 2C, the support frame 310 can include an axial length 325 that can be shorter in the deployed configuration that is expanded rather than the folded delivery configuration, as will be further described below with respect to the support frame 210 of FIGS. 10A-10C and FIGS. 11A-11C.

[0058] Also as particularly shown in FIG. 2C, the axial series of expansion cells 321 can include opposing pairs of cells that are 180 degrees apart about the longitudinal axis 111. Each opposing pair of cells can also be rotated 90 degrees about the longitudinal axis 111 relative to adjacent pairs of opposing cells. In some embodiments, the support frame 310 may be modified to have a variable spacing with respect to the expansion cells 321, as particularly shown in FIG. 2D. The variable cell spacing can allow for a progressive expansion during compression of the support frame 310 and can provide laterally enhanced flexibility at the proximal end of the support frame 310, for example near the proximal collar 115, as will be further described below. It should be understood that any of the various support frames disclosed herein can be modified to have a variable cell spacing.

[0059] When in the folded delivery configuration, the distal end 114 of the support frame 310 can include a substantially circular cross-section having a center that substantially coincides with the longitudinal axis, as particularly shown in FIGS. 2A and 2C and as will be further described below.

[0060] The support frame 310 can also include a proximal collar 115 at its proximal end 112. The proximal collar 115 can be used to attach the support frame 310 to the braided shaft of the blood clot retrieval catheter. The proximal collar 115 can include a ring member 116 circumferentially divided by at least one seam 117, such as an angled seam, that aids in the assembly of the proximal collar 115.

[0061] As shown in FIGS. 2A and 2C, the support frame 310 can include a mouth portion 313 at the distal end 114, and the mouth portion 313 has offset mouth struts 320. At least a portion of the offset mouth struts 320 can be in a plane that forms an acute angle 322 with respect to the longitudinal axis 111. The advantage of the offset mouth struts 320 is that it can allow for a larger space for the blood clot to enter the catheter tip. This can provide easier and more efficient blood clot retrieval from the treatment site compared to many conventional support frame designs and can reduce the risk of blood clot shearing or breakage during retrieval.

[0062] Similar to support frame 210, as described above with respect to FIGS. 1D - 1E, support frame 310 can include a folded inner diameter when in a folded delivery configuration and can include a larger inner diameter in an expanded deployment configuration when support frame 310 is placed in a compressed state. In some embodiments, when used in conjunction with either an LST catheter or a CSB catheter, for example, when support frame 310 is in its expanded deployment configuration, its maximum outer diameter can be less than the inner diameter 13 of the target vessel 12 at the treatment site, whereby support frame 310 can advance distally towards the blood clot 40 independently of and without occluding the vessel 12. In some embodiments, for example, when used in conjunction with a CSB catheter, support frame 310 can have an outer diameter larger than the inner diameter of the target vessel 12 and can be configured to self - collapse when advancing distally through the target vessel. For example, the catheter tip including support frame 310 can be configured such that the radial folding force is reduced when support frame 310 is advanced through the vessel 12, and the vessel 12 can be reduced distally with respect to its inner diameter but still maintain a sufficiently high crush resistance such that it remains open to full vacuum when the tip is blocked. This can enable a catheter with support frame 310 to be used in a wide range of vessel sizes.

[0063] FIGS. 3A - 3G show another exemplary expandable support frame 410 for use at the blood clot retrieval catheter tip. Support frame 410 can include one or more features that are the same as or similar to those described with respect to support frames 210 and 310. Further, the manufacture of support frame 410 can be the same as or similar to the manufacture of support frames 210 and 310. Support frame 410 can also be manufactured to be electropolished, pickled to roughen the surface of support frame 410, and / or heat - treated to have an oxide layer finish.

[0064] The support frame 410 can include a longitudinal axis 111, a folded delivery configuration (Figs. 4A - 4C), an extended deployment configuration, and a plurality of interconnected struts 418 that define a series of axial expansion cells 421. The interconnected struts 418 can be joined at opposing pairs of x - connectors 417 that are 180 degrees apart about the longitudinal axis 111. Each opposing pair of x - connectors 417 can be rotated 90 degrees about the longitudinal axis 111 relative to an adjacent opposing pair of x - connectors 417. Such a rotational configuration can also provide enhanced flexibility of the support frame 410 across multiple planes compared to many conventional support frame designs.

[0065] In some embodiments, the interconnected struts 418 can be joined at opposing pairs of u - connectors 417i (as shown in Fig. 3D), s - connectors 417ii (as shown in Fig. 3E), and / or m / w - connectors 417iii (as shown in Fig. 3F). The use of different connector types and / or shapes between the interconnected struts 418 can provide variations in the lateral flexibility of the support frame 410. It should be understood that different connector types and / or shapes may be used in the various support frames disclosed herein.

[0066] The support frame 410 can also include a distal strut angle 419 between struts 418 on both sides of the longitudinal axis 111, particularly as shown in Figs. 3C - 3F. The distal strut angle 419 can be configured as an acute angle due to the increased length of the x - connector struts 417 (Fig. 3A). The acute distal strut angle 419 can provide an increase in the expansion of the support frame 410, and the increase in the length of the x - connector struts 417 can provide more unrestricted flexure compared to many conventional support frame designs.

[0067] The support frame 410 can also include one or more additional v struts 423, as shown in FIGS. 3A-3F. The additional v struts 423 can enable an increase in radial force and crush resistance, particularly in light of the acute distal strut angle 419, compared to many conventional support frame designs.

[0068] As particularly shown in FIG. 3B, the interconnected struts 418 can also include a curved profile to assist with the flexibility of the support frame 410. That is, a series of expansion cells 421 can shorten longitudinally when the support frame 410 is placed in a compressed state. Thus, as shown in FIGS. 3C-3F, the support frame 410 can include an axial length 425 that can be shorter in a deployed configuration that is expanded compared to a folded delivery configuration, as further described below with respect to the support frames 210 of FIGS. 10A-10C and FIGS. 11A-11C.

[0069] Also particularly shown in FIGS. 3C-3F, the axial series of expansion cells 421 can include opposing pairs of cells that are 180 degrees apart about the longitudinal axis 111. Each opposing pair of cells can also be rotated 90 degrees about the longitudinal axis 111 relative to adjacent pairs of opposing cells.

[0070] When in the folded delivery configuration, the distal end 114 of the support frame 410 can include a substantially circular cross-section having a center that substantially coincides with the longitudinal axis, as particularly shown in FIGS. 3A and 3C-3F and further described below.

[0071] The support frame 410 can include a proximal collar 115 at its proximal end 112. The proximal collar 115 can be used to attach the support frame 410 to the braided shaft of a blood clot retrieval catheter. The proximal collar 115 can include a ring member 116 circumferentially divided by at least one seam 117, such as an angled seam, that assists with the assembly of the proximal collar 115.

[0072] As shown in FIGS. 3A and 3C - 3F, the support frame 410 can include a mouth portion 413 at the distal end 114, and the mouth portion 413 has an offset mouth strut 420. At least a portion of the offset mouth strut 420 can be present in a plane that forms an acute angle 422 with the longitudinal axis 111. The advantage of the offset mouth strut 420 is that it can allow for a larger space for a blood clot to enter the catheter tip. This can provide easier and more efficient blood clot retrieval from the treatment site compared to many conventional support frame designs and can reduce the risk of blood clot shearing or breakage during retrieval. In the case of a firm fibrin - rich blood clot that cannot be fully aspirated through the inner diameter of the catheter, the offset mouth can provide a larger surface area to increase blood clot gripping force, allowing the tip to hold the blood clot and retract it from the blood vessel into a larger guiding catheter positioned more proximally in the vasculature.

[0073] In some embodiments, the mouth portion 413 of the support frame 410 (or the mouth portion of any other support frame disclosed herein) may be provided in two planes, such as the shape of two opposing struts 413a and 413b. The two opposing struts 413a, 413b may be configured to follow the shape of the most distal strut of the support frame 410 such that the surface area of the mouth portion 413 can be provided in two planes. In such embodiments, the mouth portion 413 may have an increased surface area over a shorter length and may allow for aspiration from two opposing sides of the distal tip of the catheter.

[0074] Similar to support frames 210 and 310, support frame 410 can include a folded inner diameter when in a folded delivery configuration and can include a larger inner diameter in an expanded deployment configuration when support frame 410 is placed in a compressed state. In some embodiments, when used in conjunction with either an LST catheter or a CSB catheter, for example, when support frame 410 is in its expanded deployment configuration, its maximum outer diameter can be less than the inner diameter 13 of target vessel 12 at the treatment site, whereby support frame 410 can advance distally toward blood clot 40 independently of and without sealing against vessel 12. In some embodiments, for example, when used in conjunction with a CSB catheter, support frame 410 can have an outer diameter larger than the inner diameter of target vessel 12 and can be configured to self-collapse when advancing distally through the target vessel. For example, the catheter tip including support frame 410 can be configured such that the radial folding force is reduced when support frame 410 is advanced through vessel 12, and vessel 12 can be reduced distally relative to its inner diameter but still maintain a sufficiently high collapse resistance so as to remain open at full vacuum when the tip is blocked. This can enable a catheter with support frame 410 to be used at a wide range of vessel sizes.

[0075] Figures 4A - 4C show another exemplary expandable support frame 510 for use at the blood clot retrieval catheter tip. Support frame 510 can include one or more features that are the same as or similar to those described with respect to support frames 210, 310, and 410. The manufacture of support frame 510 can be the same as or similar to the manufacture of support frames 210, 310, and 410 as described above when used in conjunction with either an LST catheter or a CSB catheter. Support frame 510 can also be manufactured to be electropolished, pickled to roughen the surface of support frame 510, and / or heat treated to have an oxide layer finish.

[0076] The support frame 510 can include a longitudinal axis 111, a folded delivery configuration (Figs. 4A-4C), an expanded deployment configuration, and a series of axial hoop ribs 517 that extend in a plane offset from the longitudinal axis 111. The hoop ribs 517 can include a curved profile, a non-planar cross-section, and peaks 518 that are not distally connected. The support frame 510 can also include a mouth 513 having a larger expanded inner diameter when the support frame 510 is placed in a compressed state (Figs. 10C and 11C).

[0077] Each peak 518 of the hoop rib 517 that is not distally connected can move proximally when the support frame 510 is placed in a compressed state during blood clot retrieval. This feature can enable the blood clot 40 to clog more easily within the support frame 510 during retrieval as compared to many conventional support frame designs.

[0078] As particularly shown in Fig. 4C, at least a portion of each of the hoop ribs 517 can be present in a plane that forms an acute angle 522 with respect to the longitudinal axis 111.

[0079] As shown in Fig. 4A, each of the hoop ribs 517 can also be connected to the proximal collar 115 at a connection point 519. This feature can assist in minimizing the rigidity of the support frame 510. The proximal collar 115 can be used to attach the support frame 510 to the braided shaft of the blood clot retrieval catheter. The proximal collar 115 can include a ring member 116 that is circumferentially segmented by at least one seam 117, such as an angled seam, that assists in the assembly of the proximal collar 115.

[0080] As shown in 4C, the support frame 510 can include an axial length 525 that can be shorter in the expanded deployment configuration than in the folded delivery configuration, as further described below with respect to the support frame 210 of Figs. 10A-10C and 11A-11C.

[0081] Similar to the support frame 210 described above with respect to FIGS. 1D - 1E, the support frame 510 can include a larger expanded inner diameter 224 (FIG. 1E) when radially impacted by the clot 40 taken in the expanded deployment configuration, and a smaller delivery inner diameter 215 (FIG. 1D) in the folded delivery configuration. The folded inner diameter 215 enables the support frame 210 to fit within the guide sheath 30 (FIG. 10A) when the catheter is being navigated through the blood vessel 12 towards the treatment site. As will be further described below with respect to FIGS. 11A - 11C, when used in conjunction with the LST catheter, the support frame 510 can maintain its folded inner diameter 215 when exiting the distal end 32 of the guide sheath 30, and then expand from the folded inner diameter 215 to the expanded inner diameter 224 when impacted by the taken - in clot 40. Alternatively, when used in conjunction with the CSB catheter, as will be further described below with respect to FIGS. 10A - 10C, the support frame 510 can be heat - set to have an expanded inner diameter 224 that is larger than the folded inner diameter 215 as soon as the support frame 510 exits the distal end 32 of the guide sheath 30. When used in conjunction with either the LST catheter or the CSB catheter, when the support frame 510 is in its expanded deployment configuration, its maximum outer diameter can be less than the inner diameter 13 of the target blood vessel 12 at the treatment site, whereby the support frame 510 can advance distally towards the clot 40 independently of and without sealing against the blood vessel 12.

[0082] When in the folded delivery configuration, the distal end 114 of the support frame 510 can include a substantially circular cross - section having a center that substantially coincides with the longitudinal axis 111, as particularly shown in FIGS. 4A and 4C and further described below.

[0083] Figures 5A - 5C show another exemplary expandable support frame 610 for use at the distal end of a blood clot retrieval catheter. The support frame 610 can include one or more features that are the same as or similar to those described with respect to support frames 210, 310, 410, and 510. The manufacture of the support frame 610 can be the same as or similar to the manufacture of support frames 210, 310, 410, and 510 as described above when used in conjunction with either an LST catheter or a CSB catheter. The support frame 610 can also be manufactured to be electropolished, pickled to roughen the surface of the support frame 610, and / or heat treated to have an oxide layer finish.

[0084] The support frame 610 can include a longitudinal axis 111, a folded delivery configuration (Figs. 5A - 5C), an expanded deployment configuration, and an axial series of hoop ribs 617 that extend in a plane offset from the longitudinal axis 111. The hoop ribs 617 can include a curved profile, a non - planar cross - section, and peaks 618 that are not distally connected. The support frame 610 can also include a mouth 613 that has a larger expanded inner diameter when the support frame 610 is placed in a compressed state (Figs. 10C and 11C).

[0085] Each peak 618 that is not distally connected of the hoop ribs 617 can move proximally when the support frame 610 is placed in a compressed state during blood clot aspiration. This feature can enable the blood clot 40 to be more easily clogged within the support frame 610 during retrieval compared to many conventional support frame designs.

[0086] As particularly shown in Fig. 5C, at least a portion of each of the hoop ribs 617 can be present in a plane that forms an acute angle 622 with respect to the longitudinal axis 111.

[0087] As shown particularly in FIG. 5A, at least one hoop rib 617 can be directly connected to the proximal collar 115 at connection point 619. One or more other hoop ribs 617 can instead be connected to one or more connector ribs 620 at one or more connection points 619. The connector ribs 620 can extend from a ring member 116 connected to the proximal end 112 of the support frame 610. The connector ribs 620 can branch from the ring member 116 in an offset plane that is substantially perpendicular to the offset plane of the hoop rib 617, as shown particularly in FIG. 5C. The connector ribs 620 can assist in increasing the flexibility of the support frame 610 during tacking and can allow for a more symmetric expansion during blood clot retrieval compared to many conventional support frame designs.

[0088] As shown particularly in FIG. 5C, one or more of the hoop ribs 617 can also include a first curved portion 623 and a second curved portion 624 to assist in flexing the support frame 610 during expansion and blood clot retrieval.

[0089] Similar to the other support frames discussed herein, the support frame 610 can also include an axial length that can be shorter in an expanded deployment configuration than in a folded delivery configuration, as further discussed below with respect to FIGS. 10A-10C and FIGS. 11A-11C.

[0090] Similar to the support frame 210 described above with respect to FIGS. 1D-1E, the support frame 610 can include a larger expanded inner diameter 224 (FIG. 1E) when radially impacted by a blood clot 40 taken in the expanded deployment configuration and a smaller delivery inner diameter 215 (FIG. 1D) of the folded delivery configuration. The support frame 610 can include one or more of the same or similar features as the support frame 510 when used in conjunction with an LST catheter or a CSB catheter, as described above.

[0091] When in the folded delivery configuration, the distal end 114 of the support frame 610 can include a substantially circular cross-section having a center that substantially coincides with the longitudinal axis 111, as particularly shown in FIGS. 5A and 5C and further described below.

[0092] FIGS. 6A - 6C show another exemplary expandable support frame 710 for use at the distal end of a blood clot retrieval catheter. The support frame 710 can include one or more features that are the same as or similar to those described with respect to the support frames 210, 310, 410, 510, and 610. The manufacture of the support frame 710 can be the same as or similar to the manufacture of the support frames 210, 310, 410, 510, and 610 when used in conjunction with either an LST catheter or a CSB catheter. The support frame 710 can also be manufactured to be electropolished, pickled to roughen the surface of the support frame 710, and / or heat treated to have an oxide layer finish.

[0093] The support frame 710 can include a longitudinal axis 111, a folded delivery configuration (FIGS. 6A - 6C), an expanded deployment configuration, and an axial series of hoop ribs 717 that extend in a plane offset from the longitudinal axis 111. The hoop ribs 717 can include a curved profile, a non-planar cross-section, and peaks 718 that are not distally connected. The support frame 710 can also include a mouth 713 having a larger expanded inner diameter when the support frame 710 is placed in a compressed state (FIGS. 10C and 11C).

[0094] Each peak 718 that is not distally connected of the hoop ribs 717 can move proximally when the support frame 710 is placed in a compressed state during blood clot retrieval. This feature can enable the blood clot 40 to be more easily clogged within the support frame 710 during retrieval as compared to many conventional support frame designs.

[0095] As shown particularly in FIG. 6C, at least a portion of each of the hoop ribs 717 can be located within an offset plane 721 that forms an acute angle 722 with the longitudinal axis 111.

[0096] As shown particularly in FIG. 6A, at least one hoop rib 717 can be directly connected to the proximal collar 115 at the connection point 719. One or more other hoop ribs 717 can instead be connected to one or more connector ribs 720 at one or more connection points 719. The connector ribs 720 can extend from a ring member 116 connected to the proximal end 112 of the support frame 710. The connector ribs 720 can branch from the ring member 116 in an offset plane 727 that is substantially perpendicular to the offset plane 721 of the hoop rib 717, as shown particularly in FIG. 6C. The connector ribs 720 can assist in increasing the flexibility of the support frame 710 during tacking and can allow for a more symmetric expansion during blood clot retrieval compared to many conventional support frame designs.

[0097] The support frame 710 can also include one or more support ribs 726 that extend from the ring member 116 in a plane that is substantially parallel to the offset plane 727 of the connector ribs 720. The support ribs 726 can be without connection points to either a series of hoop ribs 717 or connector ribs 720, which can allow for a greater degree of expansion and a more symmetric expansion compared to many conventional support frame designs.

[0098] As shown particularly in FIG. 6C, one or more of the hoop ribs 717 can also include a first curved portion 623 and a second curved portion 624 to assist in the flexibility of the support frame 710 during expansion and blood clot retrieval.

[0099] FIGS. 7 and 8 show examples of catheter shaft profiles 110 when the support frame(s) described herein are in an expanded deployment configuration and are used in conjunction with either a CSB catheter or an LST catheter.

[0100] FIG. 7 shows an example of the catheter shaft profile 110. The shaft profile 110 can include a circular profile that is symmetric about the longitudinal axis 111. That is, the shaft 110 can include a tip section 810 that includes a proximal end 812, a distal end 814, and a funnel profile 816 disposed between the proximal end 812 and the distal end 814. The funnel profile 816, as well as the distal and proximal sections of the funnel profile 816, can be symmetric about the longitudinal axis 111. The symmetry of the shaft profile 110 can be based on the heat setting of the support frame such that when exiting the distal end 32 of the guide sheath 30 (FIG. 10B), the support frame can expand to the expanded inner diameter 224.

[0101] FIG. 8 shows another example of the catheter shaft profile 110. The funnel profile 816 can include a center 818 that is radially offset from the longitudinal axis 111. That is, the center 818 can be centered with respect to the offset axis 811, thereby configuring the funnel profile 816 to be offset with respect to the longitudinal axis 111.

[0102] FIG. 9 illustrates a possible sequence for approaching an occlusive clot 40 using a large bore clot retrieval catheter 100 used in conjunction with the support frame design disclosed herein. The clot 40 can be approached with the catheter 100 collapsed within the guide sheath 30 or other access catheter. The catheter 100 can be deployed to move more distally independently when the vasculature 10 is too narrow and / or tortuous for further distal navigation using the guide sheath 30. The catheter 100 can be very flexible so as to be able to navigate the M1 or other tortuous regions of the neurovascular system to reach the occlusive clot. As described herein, the catheter 100 may have an expanded outer diameter that is slightly smaller than the outer diameter of the target vessel so that the catheter can perform independent distal navigation after deployment, or may be sized larger than the target vessel and configured to be radially compressed so as to be used to treat smaller sized vessels.

[0103] The clot retrieval catheter 100 can have a flexible elongate body 110 of a design disclosed herein, such as a support frame 210, that functions as a shaft having a large internal bore (which in some cases can be 0.080 inches or greater), and a distal tip section having a support frame that can be folded. The large bore serves to deliver the catheter to the target site in various ways. These can include over a microcatheter, over a guidewire, using a dilator / access tool, or by itself.

[0104] In many cases, the tip design can be configured such that the entire catheter 100 can be delivered (and retrieved) through a common standard 6F sheath / 8F guide having an internal lumen typically less than 0.090 inches. The tip can self-expand when advanced to an unconstrained position distal to the distal end 32 of the guide sheath 30. The support frame of the tip is designed to resist folding from the suction force and has excellent lateral flexibility in both the expanded and collapsed states, and has a non-traumatic profile to prevent snagging on bifurcations within the blood vessel, so that the catheter can be deployed proximally and then advanced independently to distal occlusion.

[0105] Figures 10A - 10C illustrate exemplary treatment steps for using the expandable support frame of the blood clot retrieval catheter of the design disclosed herein, in conjunction with the CSB catheter as described above. Figures 10A - 10C show the use of the support frame 210, although other support frames described herein (e.g., 310, 410, 510, 610, 710) may be used in the same or similar series of treatment steps. Figure 10A shows the support frame 210 inside the catheter shaft 110 and inside the distal end 32 of the guide sheath 30 when the catheter tip is moving through the target blood vessel 12 towards the blood clot 40 (Figure 10B). As shown, when inside the guide sheath 30 in the collapsed delivery configuration, the support frame 210 includes a collapsed inner diameter 215.

[0106] Figure 10B shows the support frame 210 transitioning to its expanded deployment configuration as it exits the distal end 32 of the guide sheath 30. As described above, when used in conjunction with the CSB catheter, the support frame 210 can be heat set such that when it exits the distal end 32 of the guide sheath 30, the support frame 210 can expand to an expanded inner diameter 224 that is larger than the folded inner diameter 215. The funnel profile 816 of the support frame 210 may be symmetric about the longitudinal axis 111, as described above with respect to FIG. 7. However, even when in its expanded deployment configuration, the maximum outer diameter of the support frame 210 can be less than the inner diameter 13 of the target vessel 12, whereby the support frame 210 can advance distally towards the blood clot 40 independently of and without sealing against the vessel 12.

[0107] Figure 10C shows the mouth 213 of the support frame 210 that encloses the proximal portion of the blood clot 40. As described above, the support frame 210 can be longitudinally shortened when placed in a compressed state against and / or around the blood clot 40.

[0108] Figures 11A - 11C show exemplary treatment steps for using the expandable support frame of the blood clot retrieval catheter of the design disclosed herein in conjunction with the LST catheter, as described above. Figures 11A - 11C show the use of the support frame 210, although other support frames described herein (e.g., 310, 410, 510, 610, 710) may be used in the same or similar series of treatment steps. Figure 11A shows the support frame 210 inside the catheter shaft 110 and inside the distal end 32 of the guide sheath 30 as the catheter tip moves through the target vessel 12 towards the blood clot 40 (Figure 11B). As shown, when inside the guide sheath 30 in the folded delivery configuration, the support frame 210 includes a folded inner diameter 215.

[0109] FIG. 11B shows the support frame 210 emerging from the distal end 32 of the guide sheath 30. As described above, when used in conjunction with the LST catheter, the support frame 210 can maintain its folded inner diameter 215 when emerging from the distal end 32 of the guide sheath 30. As shown, the distal tip section 810 of the support frame 210 begins to align with the inclined mouth plane 821.

[0110] FIG. 11C shows the mouth 213 of the support frame 210 enclosing the proximal portion of the blood clot 40. As described above, the support frame 210 can shorten longitudinally when placed in a compressed state against and / or around the blood clot 40. Additionally, the funnel profile 816 can be radially offset from the longitudinal axis 111 as described above with respect to FIG. 8. Also, similar to when the support frame 210 is used in conjunction with the CSB catheter (FIGS. 10A - 10C), the maximum outer diameter of the support frame 210 can be made less than the inner diameter 13 of the target vessel 12 even when in its expanded deployment configuration, such that the support frame 210 can advance distally towards the blood clot 40 independently of and without sealing the vessel 12.

[0111] The present invention is not necessarily limited to the described examples and can vary in its configuration and details. The terms "distal" and "proximal" are used throughout the foregoing description and are intended to refer to the position and direction with respect to the treating physician. Thus, "distal" or "distally" refers to a position away from or a direction away from the physician. Similarly, "proximal" or "proximally" refers to a position close to or a direction towards the physician. Further, unless the context clearly dictates otherwise, the singular forms "a", "an", and "the" include plural referents.

[0112] As used herein, the term "about" or "substantially" with respect to any numerical value or range of numerical values indicates a suitable dimensional tolerance that allows a component or collection of components to function for its intended purpose as described herein. More specifically, "about" or "substantially" may refer to a range of values of ±20% of the recited value; for example, "about 90%" may refer to a range of values from 71% to 99%.

[0113] In describing exemplary embodiments, technical terms are used for clarity. As a result, not all possible combinations are enumerated, and such variations are often apparent to those skilled in the art and are intended to be within the scope of the following claims. Each term is intended to have its broadest meaning as understood by those skilled in the art and is intended to include all technical equivalents that act 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 reference to one or more steps of a method does not exclude the presence of additional method steps or method steps intervening between those explicitly identified. Similarly, some steps of a method can be performed in an order different from that described herein without departing from the scope of the disclosed technology.

[0114] 〔Embodiment〕 (1) A catheter tip portion, a. A support frame comprising a longitudinal axis, a folded delivery configuration, an expanded deployment configuration, and a plurality of interconnected struts defining a series of axially extending cells, wherein the interconnected struts are joined at opposing pairs of x-connectors spaced 180 degrees about the longitudinal axis, b. Each opposing pair of x-connectors is rotated 90 degrees about the longitudinal axis relative to an adjacent opposing pair of x-connectors, c. The catheter tip further comprises an inner diameter that is folded in the folded delivery configuration and a larger expanded inner diameter in the expanded deployment configuration when the support frame is in a compressed state. (2) The catheter tip according to embodiment 1, wherein the support frame further comprises a proximal collar at the proximal end of the support frame. (3) The catheter tip according to embodiment 1, wherein the interconnected struts comprise a curved profile. (4) The catheter tip according to embodiment 1, wherein the support frame further comprises a shape memory alloy having a martensite finish temperature of less than about 30°C. (5) The catheter tip according to embodiment 1, wherein the support frame expands from the folded inner diameter to the expanded inner diameter when impacted by an ingested blood clot.

[0115] (6) The catheter tip according to embodiment 4, wherein the support frame is heat set to have the expanded inner diameter that is larger than the folded inner diameter. (7) The catheter tip according to embodiment 1, wherein the support frame further comprises an axial length, and the axial length is shorter in the expanded deployment configuration than in the folded delivery configuration. (8) The catheter tip according to embodiment 1, wherein the series of expansion cells shorten longitudinally when the support frame is in a compressed state. (9) The series of axial expansion cells comprises opposing pairs of cells spaced 180 degrees about the longitudinal axis, Each opposing pair of cells is rotated 90 degrees about the longitudinal axis relative to an adjacent pair of opposing cells. The catheter tip according to embodiment 1. (10) The catheter tip according to embodiment 1, further comprising an offset mouthpiece strut at the distal end of the support frame, and at least a portion of the offset mouthpiece strut is present in a plane forming an acute angle with the longitudinal axis.

[0116] (11) The catheter tip according to embodiment 1, further comprising a maximum outer diameter in the expanded deployment configuration that is less than or greater than the inner diameter of the target blood vessel at the treatment site. (12) The catheter tip according to embodiment 1, wherein in the folded delivery configuration, the distal end of the support frame further comprises a substantially circular cross-section having a center that substantially coincides with the longitudinal axis. (13) A catheter tip, comprising a support frame having a longitudinal axis, a folded delivery configuration, an expanded deployment configuration, and an axial series of hoop ribs extending in a plane offset from the longitudinal axis, wherein the hoop ribs comprise a curved profile, a non-planar cross-section, and a peak that is not distally connected, The catheter tip, wherein the mouth of the support frame has a larger expanded inner diameter when the support frame is placed in a compressed state. (14) The catheter tip according to embodiment 13, wherein the support frame further comprises a shape memory alloy having a martensite finish temperature of less than about 30°C. (15) The catheter tip according to embodiment 13, wherein each non-distally connected peak of the hoop ribs moves proximally when the support frame is compressed during blood clot extraction.

[0117] (16) The catheter tip according to embodiment 13, wherein at least a portion of each of the hoop ribs is present in a plane that forms an acute angle with the longitudinal axis. (17) The catheter tip according to embodiment 13, further comprising a larger expanded inner diameter when the support frame is radially impacted by a blood clot ingested in the expanded deployment configuration and a smaller delivery inner diameter in the folded delivery configuration. (18) The catheter tip according to embodiment 14, wherein the support frame is heat set to have an expanded inner diameter that is larger than the inner diameter of the folded delivery configuration. The distal end of the support frame in the expanded deployment configuration has a circular profile with a center radially offset from the longitudinal axis, the catheter tip according to embodiment 13. (20) The support frame further comprises one or more connector ribs extending from a ring member connected to the proximal end of the support frame, the connector ribs branching from the ring member at an angle to the offset plane of the hoop rib in an offset plane, the catheter tip according to embodiment 13.

Claims

1. A catheter tip, comprising: a. A support frame including a longitudinal axis, a folded delivery configuration, an expanded deployment configuration, and a plurality of interconnected struts defining a series of expansion cells in the axial direction, wherein the interconnected struts are joined in opposing pairs of x-connectors spaced 180 degrees apart about the longitudinal axis; b. Each opposing pair of x-connectors is rotated 90 degrees about the longitudinal axis relative to an adjacent opposing pair of x-connectors; c. The support frame further includes a folded inner diameter in the folded delivery configuration and a larger expanded inner diameter in the expanded deployment configuration when the support frame is in a compressed state.

2. The catheter tip according to claim 1, wherein the support frame further includes a proximal collar at the proximal end of the support frame.

3. The catheter tip according to claim 1, wherein the interconnected struts have a curved profile.

4. The catheter tip according to claim 1, wherein the support frame further includes a shape memory alloy having a martensite finish temperature of less than about 30°C.

5. The catheter tip according to claim 1, wherein the support frame expands from the folded inner diameter to the expanded inner diameter when impacted by an ingested blood clot.

6. The catheter tip according to claim 4, wherein the support frame is heat set to have the expanded inner diameter that is larger than the folded inner diameter.

7. The catheter tip according to claim 1, wherein the support frame further includes an axial length, and the axial length is shorter in the expanded deployment configuration than in the folded delivery configuration.

8. The catheter tip according to claim 1, wherein the series of expansion cells shorten longitudinally when the support frame is in a compressed state.

9. The series of axial expansion cells includes opposing pairs of cells spaced 180 degrees apart about the longitudinal axis. Each opposing pair of cells is rotated 90 degrees about the longitudinal axis relative to an adjacent opposing pair of cells.

10. The catheter tip according to claim 1, further comprising an offset mouth strut at the distal end of the support frame, at least a portion of the offset mouth strut being in a plane that forms an acute angle with the longitudinal axis.

11. The catheter tip according to claim 1, wherein the support frame further comprises a maximum outer diameter in the expanded deployment configuration that is less than or greater than the inner diameter of the target blood vessel at the treatment site.

12. The catheter tip according to claim 1, wherein in the folded delivery configuration, the distal end of the support frame further comprises a substantially circular cross-section having a center that substantially coincides with the longitudinal axis.

13. A catheter tip, comprising a support frame having a longitudinal axis, a folded delivery configuration, an expanded deployment configuration, and an axial series of hoop ribs extending in a plane offset from the longitudinal axis, wherein the hoop ribs comprise a curved profile, a non-planar cross-section, and peaks that are not distally connected, wherein the mouth of the support frame has a larger expanded inner diameter when the support frame is placed in a compressed state, the catheter tip.

14. The catheter tip according to claim 13, wherein the support frame further comprises a shape memory alloy having a martensite finish temperature of less than about 30°C.

15. The catheter tip according to claim 13, wherein each of the non-distally connected peaks of the hoop ribs moves proximally when the support frame is compressed during blood clot retrieval.

16. The catheter tip according to claim 13, wherein at least a portion of each of the hoop ribs is in a plane that forms an acute angle with the longitudinal axis.

17. The catheter tip according to claim 13, wherein the support frame further comprises a larger expanded inner diameter when radially impacted by a blood clot ingested in the expanded deployment configuration and a smaller delivery inner diameter in the folded delivery configuration.

18. The catheter tip according to claim 14, wherein the support frame is heat set to have an expanded inner diameter that is larger than the inner diameter of the folded delivery configuration.

19. The distal end of the support frame in the extended deployment configuration has a circular profile with a center radially offset from the longitudinal axis, the catheter tip according to claim 13.

20. The support frame further comprises one or more connector ribs extending from a ring member connected to the proximal end of the support frame, the connector ribs branching from the ring member at an angle to the offset plane of the hoop rib in the offset plane, the catheter tip according to claim 13.

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