Guide Extension Catheter

Abstract

A guide extension catheter is provided that can provide a low-friction, large-diameter (for a given compatible guide catheter size) passageway proximal to and optionally through a target lesion within the vasculature, thereby reducing micro- and macro-vasculature damage due to the delivery of an interventional device. A guide extension catheter is disclosed that is positionable within a guide catheter and configured to receive an interventional device for insertion into the vascular system. The guide extension catheter includes a push member, a first reinforcing member in contact with the push member, and a radially collapsible tubular membrane in contact with the push member and the first reinforcing member. The tubular membrane is positioned distal to the first reinforcing member and is radially collapsed or wrapped around the push member prior to receiving the interventional device. The push member provides sufficient column strength to prevent longitudinal collapse of the tubular membrane during use.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of priority under 35 U.S.C. § 119(c) to U.S. Provisional Patent Application No. 63 / 479,612, filed January 12, 2023, which is incorporated herein by reference in its entirety.

[0002] The present disclosure relates generally to devices, systems, and methods for interventional procedures, and more particularly to guide extension catheters for assisting in the delivery of interventional devices to a treatment site within a patient. [Background technology]

[0003] Generally, interventional procedures require the delivery of an interventional device through a guide catheter. In many cases, it is necessary to deliver the interventional device beyond the distal end of the guide catheter to a desired location, i.e., a target tissue area, for the device to administer effective therapy. However, delivery of the interventional device beyond the guide catheter may require high delivery forces and may cause micro- and / or macro-damage to the vasculature en route to the target tissue area. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] U.S. Patent Publication No. 2019 / 0247619 [Patent Document 2] U.S. Patent Publication No. 2021 / 0008342 [Patent Document 3] U.S. Patent No. 10,953,197 [Patent Document 4] US Patent Publication No. 2005 / 0234474 [Patent Document 5] U.S. Patent No. 10,751,514 [Patent Document 6] U.S. Patent No. 8,048,032 [Patent Document 7] U.S. Patent No. 10,946,177 [Patent Document 8] U.S. Patent No. 10,159,821 [Patent Document 9] U.S. Patent No. 9,968,763 Summary of the Invention [Problem to be solved by the invention]

[0005] The present inventors have recognized that a need exists for catheter delivery devices, systems, and methods that can be used to deliver interventional devices to desired locations and protect the vasculature from abrasion or damage. [Means for solving the problem]

[0006] According to some embodiments, a guide extension catheter positionable within the guide catheter and configured to receive an interventional device for insertion into the vasculature can include a push member, a first stiffening member in contact with the push member, and a radially collapsible tubular membrane in contact with the push member and the first stiffening member. The tubular membrane is positioned distal to the first stiffening member and can collapse or wrap around the push member prior to receiving the interventional device.

[0007] According to some embodiments, a guide extension catheter for use with a guide catheter can include a radially collapsible tubular membrane defining a lumen including a central axis, and a push member contacting the tubular membrane along its entire length and extending proximally of the tubular membrane for slidably positioning the tubular membrane within and partially beyond the distal end of the guide catheter. The tubular membrane can have no effective radial strength and can be configured to collapse radially inward toward the central axis. The tubular membrane can include sufficient tensile strength to prevent tearing during insertion of an interventional cardiology device.

[0008] According to some embodiments, a method of accessing a coronary artery can include providing a guide catheter, advancing the guide catheter through a blood vessel to a location adjacent an ostium of the coronary artery, and providing a guide extension catheter. The guide extension catheter can include a push member and a radially collapsible tubular membrane wrapped around the push member prior to receiving an interventional device. The method can further include advancing the guide extension catheter through the guide catheter to a location where at least a portion of the tubular membrane extends distally into the coronary artery beyond a distal end of the guide catheter, and advancing the interventional cardiology device through the guide catheter and into a lumen defined by the tubular membrane, including urging the tubular membrane to expand from a collapsed, wrapped configuration to an expanded configuration.

[0009] These and other examples and features of the devices, systems, and methods of the present invention are recited, at least in part, in the Detailed Description below. This Summary is intended to provide non-limiting examples of the inventive subject matter; it is not intended to provide an exclusive or comprehensive description. The Detailed Description below is included to provide further information regarding the devices, systems, and methods of the present invention.

[0010] This written disclosure describes exemplary embodiments that are non-limiting and non-exhaustive. Please refer to the exemplary embodiments depicted in the figures. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 10 is a plan view of a guide catheter advanced through the aorta to an ostium of a coronary vessel according to some embodiments. [Figure 2] FIG. 1 is a plan view of a guide extension catheter when configured in accordance with at least one embodiment for use in conjunction with a guide catheter for delivery of an interventional device into an occluded blood vessel for treatment. [Figure 3] FIG. 1 is an isometric view of a guide catheter and a guide extension catheter with a fixed push member, according to some embodiments. [Figure 4] FIG. 1 is an isometric view of a guide catheter, a guide extension catheter, and a guidewire, in accordance with some embodiments. [Figure 5A] FIG. 1 is an isometric view of a guide extension catheter having a first stiffening member according to some embodiments. [Figure 5B] FIG. 10 is an isometric view of a guide extension catheter having a second stiffening member according to some embodiments. [Figure 6A] 10 is a cross-sectional view of a tubular member with a push member disposed on an outer surface of the tubular member according to some embodiments. [Figure 6B] 10 is a cross-sectional view of a tubular member with a push member disposed on an inner surface of the tubular member according to some embodiments. [Figure 6C] 10A is a cross-sectional view of a tubular member with a push member disposed in the plane of the tubular member according to some embodiments. FIG. [Figure 6D] 10 is a cross-sectional view of a tubular member and a guidewire with a push member disposed in the plane of the tubular member according to some embodiments. [Figure 7A] 10A-10C are cross-sectional views of a radially collapsible tubular membrane in an expanded configuration according to some embodiments. [Figure 7B] 10A-10C are cross-sectional views of radially collapsible tubular membrane folding patterns according to some embodiments. [Figure 7C]10A-10C are cross-sectional views of folding patterns of radially collapsible tubular membranes according to some embodiments. [Figure 7D] 10A-10C are cross-sectional views of folding patterns of radially collapsible tubular membranes according to some embodiments. [Figure 8A] FIG. 10 is a plan view of an interventional device advanced through a guide catheter and a guide extension catheter in accordance with some embodiments. [Figure 8B] FIG. 10 is a plan view of an interventional device advanced through a guide catheter and a guide extension catheter in accordance with some embodiments. [Figure 8C] FIG. 10 is a plan view of an interventional device advanced through a guide catheter and a guide extension catheter in accordance with some embodiments. [Figure 9A] FIG. 1 is an isometric view of a guide catheter and a guide extension catheter having a distal stiffening member, according to some embodiments. [Figure 9B] FIG. 9B is an enlarged isometric view of a distal portion of the guide extension catheter shown in FIG. 9A in accordance with some embodiments. [Figure 9C] FIG. 9B is a side view of an interventional device being retracted proximally toward the distal end of the guide extension catheter configuration shown in FIG. 9A according to some embodiments. [Figure 9D] FIG. 9B is a side view of an interventional device being retracted proximally toward the distal end of another configuration of the guide extension catheter shown in FIG. 9A according to some embodiments. [Figure 10A] FIG. 1 is an isometric view of a guide catheter and a guide extension catheter having a tubular member of variable cross-sectional diameter, according to some embodiments. [Figure 10B] FIG. 10B is a front view of a first configuration of a portion of a tubular member shown in FIG. 10A according to some embodiments. [Figure 10C] FIG. 10B is a front view of a second configuration of the portion of the tubular member shown in FIG. 10A according to some embodiments. [Figure 11] FIG. 1 is an isometric view of a guide catheter and a guide extension catheter having an expandable stiffening member, according to some embodiments. [Figure 12A]1 is a schematic diagram of a column force acting on a tubular member according to some embodiments. FIG. [Figure 12B] 1 is a schematic illustration of a bending force acting on a tubular member according to some embodiments. [Figure 12C] 1 is a schematic illustration of a radial compressive force acting on a tubular member according to some embodiments. FIG. [Figure 12D] 1 is a schematic illustration of a tensile or expansion force acting on a tubular member according to some embodiments. [Figure 13] 1 is a flow chart of a method for accessing and providing treatment to a coronary artery according to some embodiments. DETAILED DESCRIPTION OF THE INVENTION

[0012] In accordance with some embodiments, the present disclosure relates to a guide extension catheter having a push member, a reinforcing portion, and a radially collapsible tubular membrane having an inner lumen. The tubular membrane can have a minimum effective radial compressive strength, a minimum effective column strength, and a minimum effective flexural stiffness. The tubular membrane can have sufficient tensile strength to avoid rupture during insertion and removal of an interventional device into and from a patient. The tubular membrane can have a permanent lubricity on its inner surface to facilitate advancement and withdrawal of an interventional device through its lumen, and can also have a permanent lubricity on its outer surface to improve delivery of the guide extension catheter into a blood vessel.

[0013] According to some embodiments, the push member can serve as a support for the tubular membrane. Optionally, the push member can be in the form of a guidewire or gradually tapered push rod that helps steer and support delivery of the guide extension catheter to the target tissue area. A reinforcing portion of the guide extension catheter can be disposed at the proximal end of the tubular membrane and can provide structural support to keep the proximal end of the lumen of the tubular membrane open and accessible. The guide extension catheter can further include a second reinforcing portion disposed at the distal end of the tubular membrane and configured to keep the distal end of the lumen of the tubular membrane open.

[0014] The devices, systems, and methods herein relate generally to the delivery of medical devices through guide extension catheters, and more specifically to devices, systems, and methods for the highly atraumatic delivery of interventional devices into patients undergoing percutaneous interventional procedures (i) to deliver interventional devices that may not be easily delivered using a selected in situ guide catheter alone, and / or (ii) to reduce micro- and macro-arterial trauma resulting from the delivery of non-flexible or non-lubricious interventional devices and existing guide extension catheters. While the description below relates primarily to cardiovascular percutaneous interventional procedures, it should be noted that the devices, systems, and methods described herein may be used in other medical specialties, such as peripheral vascular procedures, urological procedures, respiratory procedures, gastrointestinal procedures, endoscopic diagnostic procedures, and / or any other medical treatment that may benefit from the use of a guide extension catheter.

[0015] FIG. 1 illustrates an exemplary minimally invasive cardiac intervention procedure including a guidewire 112 and a guide catheter 102. The guidewire 112 may include an elongated, small-diameter member designed to pass through a blood vessel to reach a diseased area or vessel segment of interest. Guidewires are available in a variety of configurations, including, for example, a stainless steel or nitinol core wound into a thin wire coil and / or a solid core. The guide catheter 102 may include an elongated, tubular member defining a main lumen 104 along its length. The guide catheter 102 may be formed, for example, from polyurethane and may be shaped along its distal portion to facilitate advancement to and alignment with a coronary artery ostium 106 (or other area of ​​interest within a patient). Guide catheters 102 of various sizes, for example, 6F, 7F, or 8F, where F is an abbreviation for the French catheter scale (unit for measuring catheter diameter (1F = 1 / 3 mm)), can be inserted at the femoral or radial artery and advanced through the aorta 108 to a position adjacent to the ostium 106 of the coronary artery 110.

[0016] The guidewire 112 (or a shorter, larger introducer guidewire) and guide catheter 102 can be advanced through the arc 114 of the aorta 108 to the ostium 106. The guidewire 112 can then be advanced beyond the ostium 106 and into the coronary artery 110. However, the diameter and stiffness of the distal end 116 of the guide catheter may prevent the device from being safely advanced beyond the ostium 106 and into the coronary artery 110.

[0017] Maintaining the position of the guide catheter's distal end 116 at the ostium 106 can facilitate successful access of a guidewire 112 or another interventional device to the affected area (e.g., a stenotic lesion 118). With the guide catheter 102 in place, force can be applied to the guidewire's proximal end to push the guidewire 112 up to and beyond the lesion 118, and a treatment catheter (optionally including a balloon or stent) can be threaded over the guidewire 112 to treat the area. Application of force to the guidewire 112 or treatment catheter can sometimes cause the guide catheter 102 to disengage from the ostium 106 of the coronary artery 110; in such cases, the guidewire or treatment catheter must reach the lesion 118 without being aligned with and supported by the ostium of the guide catheter. This may occur, for example, with a rigid stenotic lesion 118 or convoluted anatomy, where it is often difficult to thread the guidewire 112 or treatment catheter to and beyond the lesion. The inherent unavoidable heartbeat may cause the distal end 116 of the guide catheter to lose position at the ostium or shift elsewhere, thereby displacing the distal end 116 from a position that aligns and supports the guidewire 112 or treatment catheter with the portion of the coronary artery 110 containing the lesion 118.

[0018] As initially shown in FIG. 2 , the guide extension catheter 200 of the present invention can improve access to and provide protection to the coronary artery 210 up to and optionally beyond the stenotic lesion 218. The guide extension catheter 200 can include an elongated tubular member 220 and a push member 222 having a combined length greater than the length of the guide catheter 202 (e.g., 130 cm to 175 cm or longer). The outer diameter of the tubular member 220 can be sized to allow its distal end 224 to be inserted through the guide catheter 202 and into the coronary artery 210 and coronary artery branch containing the lesion 218, thereby providing alignment, support, and a low-friction path for an interventional device (e.g., a treatment catheter) to pass beyond the distal end 216 of the guide catheter 202 to and optionally through the lesion 218. The extension of the tubular member 220 into a smaller-sized artery or branch can also contribute to maintaining the position of the guide catheter 202 at the arterial ostium 206 during the procedure.

[0019] The push member 222 can be in the form of, for example, a guidewire or gradually tapered push rod that assists in steering and supporting the delivery of the guide extension catheter 200 to the lesion 218. The push member 222 can comprise stainless steel, nitinol, or another substantially rigid material and can be configured with sufficient torque stiffness to avoid helical twisting of the guide extension catheter 200 during use. For example, the push member 222 can have a flattened cross section along one or more portions of its length to contribute to resistance to twisting and to reduce the crossing profile of the guide extension catheter 200.

[0020] The tubular member 220 may include a first reinforcement portion (not shown) disposed at its proximal end 226 and a second reinforcement portion disposed at its distal end 224. The tubular member 220 may further include a soft, flexible, radially collapsible tubular membrane 250 positioned distal to the first reinforcement portion and proximal to the second reinforcement portion.

[0021] Delivery of a non-flexible or non-lubricious interventional device without the guide extension catheter 200 through a segment of the coronary artery 210 distal to the guide catheter 202 may result in (i) endothelial damage (microscopic injury), which may contribute to atheroembolism and type 4 peri-procedural myocardial infarction, and / or (ii) more serious macroscopic damage, including plaque rupture and coronary artery dissection, resulting in acute / impending ischemic complications, either of which may contribute to the progression of atherosclerosis and ultimate failure of the target vessel. The soft, flexible, radially collapsible tubular membrane 250 can reduce device-artery interaction by providing a thin-walled structure that lines the artery and provides a lubricious intracoronary delivery pathway.

[0022] In some embodiments, the surgeon can advance the distal end portion 224 of the tubular member 220 over the guidewire 212 and through and beyond the distal end 216 of the guide catheter into the coronary artery 210 by applying a longitudinal force to the push member 222 directly or through a handle member 230, such as the handle member 230 described in U.S. Patent Publication No. 2019 / 0247619, which is owned by the applicant of the present invention and incorporated herein by reference in its entirety. The handle member 230 can include a flexible clip or clamp configured to be attached to an external object when not moving, as described in U.S. Patent Publication No. 2021 / 0008342, which is owned by the applicant of the present invention and incorporated herein by reference in its entirety. The proximal end portion 226 of the tubular member 220 can remain within the guide catheter 202 during the procedure. The surgeon can then thread the treatment catheter over the guidewire 212 through the main lumen 204 of the guide catheter 202 until the working portion of the treatment catheter is positioned beyond the distal end 224 of the tubular member, and then advance the guidewire 212 through the lumen 228 of the tubular member 220. By using the tubular member 220, the surgeon can protect the vasculature from abrasion or injury caused by the advancement of the treatment catheter toward the lesion 218. Additionally, the tubular member 220 can provide additional support for the alignment of the guide catheter 202 relative to the coronary ostium as the treatment catheter is advanced.

[0023] Generally, the lumen 228, and thus the tubular member 220, can be sized and shaped to allow passage of one or more interventional devices therethrough, such as a guidewire and a treatment catheter, when expanded. The cross-sectional shape of the expanded lumen 228 can be similar to the cross-sectional shape of the main lumen 204 of the guide catheter. For example, in some instances, the cross-sectional shape of the expanded lumen 228 can be substantially uniform along the length of the lumen 228. In other instances, the cross-sectional diameter can vary along the length of the tubular member 220. In some such example embodiments, for example, the distal end 224 of the tubular member 220 can be narrower, e.g., tapered, relative to the proximal end 226. In an additional example described below with respect to FIG. 10A , the proximal end of the tubular member can be narrower than the distal end. The lengths of the differently sized portions of the tubular member 220 in such embodiments can also vary, with the distal end 224 of the tubular member being the longest. In examples including proximal and distal ends of different sizes, the difference in diameter between the proximal end 226 and the distal end 224 of the tubular member can be from about 1F to about 4F, or any F value between these F values.

[0024] The outer diameter of the expanded tubular member 220 can have the largest cross-sectional dimension that allows the tubular member 220 to slide coaxially relative to the guide catheter 202. In other embodiments, the outer cross-sectional dimension of the expanded tubular member 220 can be smaller than the maximum allowable value. In various embodiments, the diameter of the lumen 228 of the expanded tubular member 220 is not significantly smaller than the lumen 204 of the guide catheter 202 by more than about 1 French. In one embodiment, the guide extension catheter 200 can be manufactured in at least three sizes corresponding to the internal volumes of 8F, 7F, and 6F guide catheters commonly used in interventional cardiology procedures. The size difference between the outer diameter of the expanded tubular member 220 and the inner diameter of the guide catheter 202 can vary. For example, the cross-sectional diameter gap between the inner diameter of the guide catheter and the outer diameter of the expanded tubular member 220 can be any distance less than, about, or between 0.001 inch, 0.001 inch, 0.002 inch, 0.003 inch, 0.004 inch, or 0.005 inch. In certain embodiments, the cross-sectional diameter gap can range from about 0.002 inch to 0.003 inch, or from about 0.002 inch to 0.0035 inch. For example, if the guide catheter has an inner diameter of 0.070 inch and the guide extension catheter has an expanded outer diameter of 0.068 inch, the gap would be 0.002 inch. The diameter gap between the outer diameter of the tubular member 220 when expanded and the lumen 204 of the guide catheter 202 can be substantially continuous along the length or most of the length of the tubular member 220 in some embodiments, or the diameter gap can increase along one or more distal portions of the tubular member 220.

[0025] The length of the tubular member 220 can be substantially shorter than the length of the guide catheter 202, but the tubular member 220 can be designed to have any length, such as from about 6 cm to about 45 cm, from about 10 cm to about 35 cm, from about 14 cm to about 25 cm, or from about 18 cm to about 20 cm, depending on the desired application.

[0026] 3 illustrates an isometric view of a guide extension catheter 300 extending from a distal end 304 of a guide catheter 302. The guide extension catheter 300 includes a tubular member 320 having a proximal end 326 and a distal end 324. FIG. 3 illustrates what is referred to herein as a "fixed wire" embodiment in which a push member 322 is fixed to and extends distally from the tubular member 320. The push member 322 includes a distal tip 328.

[0027] The proximal end 326 of the tubular member 320 can include a first stiffening member 306, which can include an elongated tube or a concave track configured to provide additional pushing strength during insertion of the guide extension catheter 300 into a blood vessel and / or to maintain the first lumen 308 of the guide extension catheter 300. In other embodiments, the first stiffening member 306 can include a non-elongated tube, for example, a tube or ring having an inner diameter greater than its length. The first stiffening member 306 can be, for example, a full or partial ring formed of a polymer or metal suitable for maintaining an expanded state of the entry / exit points and allowing free advancement and withdrawal of the guide extension catheter 300. In one embodiment, the first stiffening member 306 can include a polyether block amide having a durometer hardness of 72, for example, PEBAX 7233 available from Arkema. PEBAX 7233 has a Shore D hardness of 61, a tensile strength at yield of 3,770 psi, a tensile modulus of 74.0 ksi, and an elongation at yield of 18%. A lubricating layer of polytetrafluoroethylene (PTFE) can be coated on the inner surface of PEBAX 7233.

[0028] The tubular member 320 further includes a radially collapsible tubular membrane 310 positioned distally of the first reinforcing member 306. The proximal end 312 of the tubular membrane 310 can be secured to the distal end 307 of the first reinforcing member 306, where the first reinforcing member 306 is configured to maintain patency of the lumen 314 of the tubular membrane 310. In one embodiment, the tubular membrane 310 can include a lubricious layer, a non-crosslinkable layer, and a crosslinked heat shrinkable layer. The lubricious layer can include PTFE. The non-crosslinkable layer can include a polyether block amide having a durometer hardness of 35, such as PEBAX 3533 available from Arkema. PEBAX 3533 has a Shore D hardness of 25, a tensile strength at yield of 5,660 psi, and a tensile modulus of 2.61-2.76 ksi. The crosslinked heat shrink layer can comprise a polyether block amide having a durometer hardness of 55, such as PEBAX 5533 available from Arkema. PEBAX 5533 has a Shore D hardness of 50, a tensile strength at yield of 1,740 psi, and a tensile modulus of 23.9 to 24.7 ksi.

[0029] In various embodiments, the tubular membrane 310 can have a column strength, radial strength, and bending stiffness that is significantly lower than that of the first reinforcement member 306 .

[0030] The column strength, radial strength, and bending stiffness of the tubular membrane 310 may be ineffective, i.e., the radially collapsible tubular membrane 310 is considered to have no effective column strength, effective radial strength, and effective bending stiffness. In other words, any radial, column, or bending force can deflect, collapse, and / or bend the tubular membrane 310, and the tubular membrane 310 does not provide effective resistance to the radial, column, or bending force.

[0031] The tubular membrane 310 can have sufficient tensile strength to prevent tearing of the wall of the tubular membrane 310 during advancement and withdrawal of the interventional device. For example, during advancement of an interventional device through the tubular membrane 310, the interventional device may exert a force that urges the wall of the tubular membrane 310 radially outward. The tubular membrane 310 can have sufficient tensile strength to withstand the radially outward force of the interventional device without the interventional device tearing or otherwise damaging the wall of the tubular membrane 310.

[0032] The tubular membrane 310 can be permanently lubricious via a hydrophobic silicone or polymer coating on one or both of its inner and outer surfaces. The lubricious inner surface of the tubular membrane 310 can be configured to reduce friction between the tubular membrane 310 and an interventional device during insertion and / or withdrawal of the device. The lubricious outer surface of the tubular membrane 310 can be configured to reduce friction between the tubular membrane 310 and the guide catheter 302 during insertion and / or withdrawal of the guide extension catheter 300 from the guide catheter 302.

[0033] FIG. 3 illustrates the lumen 314 of the tubular membrane 310 in a fully expanded / open state. In the fully expanded state, the lumen 314 of the tubular membrane 310 has a first inner diameter, a first outer diameter, and a first cross-sectional area. The tubular membrane 310 includes a wall thickness of 0.00075 to 0.004 inches and an outer diameter to wall thickness ratio ranging from 10:1 to 200:1, or optionally 10:1 to 50:1, e.g., 18:1, 24:1, 30:1, 36:1, 42:1, and ratios therebetween. The thin-walled nature of the tubular membrane 310 for a given compatible guide catheter size, and the resulting larger cross-sectional area, allows interventionalists in today's complex interventional medical field to perform a wider variety of challenging procedures via traditional femoral artery access or the newer radial artery access.

[0034] In some embodiments, the lumen 314 of the tubular membrane 310 can be freely collapsible, i.e., the tubular membrane 310 cannot maintain the first cross-sectional area without external support (e.g., a reinforcing member 306 that maintains the patency of the lumen 314) or internal support (e.g., an interventional device inserted through the tubular membrane forces the lumen open from the inside). Thus, when the tubular membrane 314 is not supported by auxiliary components or features, the lumen 314 will "collapse," i.e., the cross-sectional area of ​​the lumen 314 will be smaller than the first cross-sectional area (i.e., the cross-sectional area in the fully open state shown in FIG. 3).

[0035] In the collapsed state, the tubular membrane 310 may not exhibit significant tensile strength, i.e., the tubular membrane 310 will not provide significant resistance to pulling forces when the cross-sectional area of ​​the lumen 314 is smaller than its cross-sectional area in the fully opened state. However, in the fully opened state, the tubular membrane 310 may provide sufficient tensile strength to prevent tearing of the wall of the tubular membrane 310 during insertion of an interventional device and to prevent micro- and / or macro-damage to the vessel wall. In other words, when the cross-sectional area of ​​the tubular membrane 310 is expanded to the fully opened state, the tubular membrane 310 will provide resistance to any radially outward pulling force. In various embodiments, the tensile strength of the tubular membrane may be greater than about 2.25 lbs.

[0036] In the embodiment shown in FIG. 3 , the push member 322 extends distally from the distal end 324 of the tubular member 320. The push member 322 can include a stainless steel or nitinol core wound into a thin wire coil and / or a solid core. The distal tip 328 of the push member 322 can include an atraumatic guidewire-like distal tip. In some embodiments, the atraumatic guidewire-like distal tip includes a tapered core surrounded by a coil, and in some embodiments, a steerable tip. The push member 322 can serve as a support for the tubular membrane 310, i.e., the push member 322 can provide column strength and / or bending stiffness to facilitate advancement and withdrawal of the guide extension catheter 300. In some embodiments, the proximal portion of the push member 322 can include or be surrounded by a removable support member, as described in U.S. Pat. No. 10,953,197, which is commonly owned and incorporated herein by reference in its entirety.

[0037] 4 illustrates an isometric view of a guide extension catheter 300' and a guidewire 450, according to some embodiments. The guide extension catheter 300' is referred to herein as a "rapid-exchange" embodiment, in which the push member 322' terminates at or before the distal end 324 of the tubular member 320, and the guidewire 450 guides the guide extension catheter 300' and / or interventional device distally beyond the distal end 324. The guidewire 450 may be slidable relative to the tubular member 320, or alternatively, may be slid over the guidewire 450 and advanced into a position adjacent the target area.

[0038] The slidable nature of the guidewire 450 relative to the guide extension catheter 300′ allows for rapid exchange of interventional devices. For example, an interventional device, such as a balloon dilator (not shown), can be slidably advanced over the guidewire 450. The balloon dilator can be advanced through the guide catheter 302 and the guide extension catheter 300′ and further distally from the distal end 324 of the tubular member 320 to the target tissue. Treatment can be provided to the target tissue (e.g., the balloon dilator can be inflated to open a vascular lesion), and the balloon dilator can be slidably retracted over the guidewire 450 from the target tissue through the guide extension catheter 300′ and the guide catheter 302. The balloon dilator can be withdrawn from the patient and detached from the guidewire 450. A second interventional device, such as a stent, can then be slidably received over the guidewire 450 and advanced through the guide catheter 302 and the guide extension catheter 300′ to the target tissue located distal to the distal end 324 of the tubular member 320. A second treatment can be provided to the target tissue (e.g., a stent can be deployed), i.e., guidewire 450 can allow for rapid exchange of interventional devices.

[0039] In some embodiments, the push member 322' can terminate in a second stiffening member 334 of the guide extension catheter 300'. The push member 322' can be secured directly to the second stiffening member 334, where the push member 322' is configured to provide additional pushing strength during insertion of the guide extension catheter 300 into the blood vessel and the second stiffening member 334 is configured to maintain the lumen 314 of the tubular membrane 310. The second stiffening member 334 can have sufficient flexibility and yieldability along the axis of the guide extension catheter 300' to adapt its shape to generate a reduced crossing profile when the guide extension catheter 300' encounters resistance to advancement. The second stiffening member 334 can be housed in the guide catheter and deployed externally. For example, a hollow guidewire or push member 322' can allow for the second stiffening member 334 to be in the form of a retractable distal stiffening ring.

[0040] 5A illustrates an isometric view of the guide extension catheter 300 showing the first stiffening member 306. The proximal end 330 of the first stiffening member 306 can include a concave opening 332 leading into the first lumen 308. The concave opening 332 can be configured to facilitate insertion of a guidewire (not shown) or an interventional device (not shown) into the first lumen 308 of the first stiffening member 306. For example, the concave opening 332 can provide a larger area for receiving an interventional device within the tubular member than an area associated with an opening oriented perpendicular to the longitudinal axis of the tubular member. In some embodiments, the first stiffening member 306 can include an extended concave track defining a half-pipe feature configured to assist in guiding an interventional device into the first lumen 308 of the first stiffening member 306. Exemplary embodiments of the half-pipe concave track and other first reinforcing members and features are described in commonly owned U.S. Patent Publication No. 2019 / 0247619, the entire contents of which are incorporated herein by reference.

[0041] The first reinforcing member 306 can have a length l defined between the proximal end 330 and the distal end 307. The first reinforcing member 306 can have an inner diameter d i (also called the first bore diameter) and the outer diameter d o In some embodiments, the length l of the first reinforcing member may be d i It can be reduced to about 10.

[0042] In some embodiments, the first reinforcing member 306 can be formed from an inner polymer layer, an outer polymer layer, and / or a reinforcing layer (e.g., braid or coil) disposed between or adjacent to the polymer layers. In such examples, the inner polymer layer can be constructed of or coated with silicone, PTFE, or another lubricious material to provide a slippery surface for an interventional device to receive. The outer polymer layer can include one or more materials having a decreasing durometer along the length of the tubular member, such as polyurethane, polyethylene, polyolefin, or polyether block amide, and can be coated with a friction-reducing material (e.g., a hydrophilic material) to facilitate ease of insertion and trackability through the vasculature and guide catheter. In embodiments featuring a braid or coil, the reinforcing braid or coil can be formed of, for example, stainless steel or platinum alloy and can extend between the polymer layers along at least a portion of the length of the tubular member.

[0043] In some embodiments, the push member 322 can include one or more depth markers that can be positioned at predetermined lengths relative to the distal end of the tubular member 320. One or more radiopaque marker bands can be positioned on the tubular member 320. The marker bands can be composed of tungsten, platinum, or alloys thereof and can have a metal band structure. Alternatively, for space-saving reasons, the marker bands can be formed by impregnating portions of the tubular member 320 with a radiopaque filler material such as barium sulfate, bismuth trioxide, bismuth carbonate, tungsten powder, tantalum powder, or the like.

[0044] 5B illustrates a tubular member 320 including a second reinforcing member 334 disposed at the distal end 324 of the tubular member 320. The second reinforcing member 334 can be configured to maintain patency of the lumen 314 at the distal end 324 of the tubular membrane 310 so that an interventional device can be pulled back into the lumen 314 of the guide extension catheter 300 from the diseased area. In some embodiments, the second reinforcing member 334 can be configured to selectively open or close the distal end 324 of the tubular membrane 310.

[0045] In some embodiments, the second reinforcing member may comprise a small diameter snare-like device emerging from the hollow push member 322, such as the snare device described in U.S. Patent Publication No. 2005 / 0234474, which is owned by the assignee of the present invention and is incorporated herein by reference in its entirety.

[0046] As shown in FIGS. 5A-5B, the push member 322 can be secured to the inner surface of the tubular member 320 (see also FIG. 6B). In other embodiments, e.g., FIGS. 6A and 6C-6D, the push member 322 can be secured to the outer surface of the tubular member 320 (see, e.g., FIG. 6A) or can be integrated into the wall of the tubular member 320, e.g., sandwiched between inner and outer polymer layers (see, e.g., FIGS. 6C-6D). The location of the push member 322 can be configured to maximize the first lumen area, i.e., maximize the cross-sectional area within the lumen of the first stiffening member 306, to enable delivery of larger interventional devices through the guide catheter. In other embodiments, the location of the push member 322 can be configured to minimize the outer diameter, i.e., enable delivery of the guide extension catheter 300 through the guide catheter 302. In yet another embodiment, the location of the push member 322 can be configured to control the flexibility, steerability, and / or deflection of the guide extension catheter 300.

[0047] As shown in FIGS. 6A-6D , the push member 322 can define a circular cross-section along a portion of its length. However, the cross-sectional shape and dimensions of the push member 322 can vary. For example, the push member 322 can include a circular or flat sheet-like cross-sectional shape, with rectangular, irregular, oval, and oblong cross-sectional shapes also falling within the scope of the present disclosure. Exemplary embodiments of push members are described in commonly owned U.S. Pat. No. 10,751,514, the entire contents of which are incorporated herein by reference. The hardness of the push member 322 can be uniform or substantially uniform along its length, or can define regions of variable hardness along its length. For example, the push member 322 can have greater flexibility near its distal end than its proximal end. The push member 322 can include sufficient rigidity to avoid helical twisting of the guide extension catheter 300 during use.

[0048] 6D illustrates a cross-sectional view of a tubular member 320 having a push member 322 integrated into its wall and a guidewire 450 extending therethrough. The guidewire 450 may be slidable relative to the tubular member 320, i.e., the guidewire 450 may slide longitudinally relative to the longitudinal axis of the tubular member 320. In some embodiments, the guidewire 450 may be able to advance laterally and vertically within the tubular member (e.g., the guidewire 450 may move around the inner circumference of the tubular member 320 or near a center point).

[0049] As discussed above, the tubular membrane 310 may be freely collapsible and / or may not exhibit significant column strength, radial strength, or bending stiffness. Accordingly, the tubular membrane 310 may be loosely wrapped around the push members 322, 322′ and / or guidewire 450 prior to insertion into a patient. In some embodiments, the tubular membrane 310 may be folded around the push members 322, 322′ to reduce cross-sectional area and / or friction during insertion. FIGS. 7A-7D illustrate cross-sectional views of exemplary folds of the tubular membrane 310 of the guide extension catheter 300. While the push member 322 is positioned near the center of the tubular membrane, in other embodiments, the push member 322 may be anchored to the inner wall, outer wall, or integral to the tubular membrane 310 away from the center.

[0050] In the embodiment shown in FIGS. 7A-7D , the tubular membrane 310 is shaped to include one or more folding flaps 740, in this case four. The one or more folding flaps 740 are rotated about the push member 322 to reduce the cross-sectional profile of the guide extension catheter 300. In some embodiments, the one or more folding flaps 740 can include a variety of different folding geometries and sizes. The folding flaps 740 can be configured to open or unfold when an interventional device is inserted through the tubular membrane 310. For example, when an interventional device is inserted through the folded tubular membrane 310, it can exert a radially outward force on the tubular membrane 310, urging the walls radially outward, thereby urging the folding flaps 740 outward and unfolding. An embodiment of unfolding and / or unfolding the tubular membrane is illustrated in FIGS. 8A-8C .

[0051] 8A-8C illustrate an exemplary progression of insertion of an interventional device 850 through the guide extension catheter 300. In some embodiments, a guidewire 450 can be positioned within the patient before the guide extension catheter 300 and interventional device 850 are inserted and can be configured to guide the guide extension catheter 300 to the proper position. In this manner, the guide extension catheter 300 can slide over the guidewire 450 and follow the guidewire 450 to a position adjacent the target tissue area. The guide extension catheter 300 can be guided or steered into position through the guide catheter 302 (not illustrated in FIGS. 8A-8C ). The guide extension catheter 300 can be slidably advanced toward the target tissue area by applying a force to the push member 322. In some embodiments, a delivery assist device (e.g., a device described in U.S. Pat. No. 8,048,032, owned by the assignee of the present invention and incorporated herein by reference in its entirety) can be used to help open the lumen 314 of the tubular membrane 310.

[0052] The interventional device 850 can be slidably secured to the guidewire 450 so that it moves longitudinally along the length of the guidewire 450. As shown in FIG. 8A , the interventional device enters the first reinforcing member 306 of the tubular member 320. The first reinforcing member can be configured to maintain patency of the first lumen 308 of the tubular member 320 so that the interventional device 850 can be easily inserted into the tubular member 320. The first reinforcing member 306 can be configured to maintain patency of the lumen 314 of the tubular membrane 310 at the proximal end 312 of the tubular membrane 310. In some embodiments, the tubular membrane 310 can be folded along a significant portion of its length prior to insertion of the interventional device 850 (see, e.g., FIGS. 7A-7D ). In some embodiments, the tubular membrane 310 can be freely collapsed, i.e., the cross-sectional area of ​​the lumen 314 is smaller than the cross-sectional area in a fully open state (see, e.g., FIG. 3 ).

[0053] As shown in FIG. 8B , the interventional device 850 can be advanced distally of the first reinforcement portion 306 and enter the tubular membrane 310. The lumen 314 of the tubular membrane 310 can open when the interventional device 850 is advanced through the tubular membrane 310. For example, in embodiments in which the tubular membrane 310 is folded along a significant portion of its length (see, e.g., FIGS. 7A-7D ), advancement of the interventional device 850 can unfold the tubular membrane 310 and press the wall of the tubular membrane 310 radially outward, increasing the cross-sectional area of ​​the lumen 314. In embodiments in which the tubular membrane 310 is freely collapsed prior to insertion of the interventional device, advancing the interventional device 850 through the tubular membrane 310 can urge the lumen 314 of the tubular membrane 310 open.

[0054] As shown in FIG. 8C , an interventional device can be advanced distal to the distal end 324 of the tubular member 320 to deliver therapy to or near the location of the target tissue. In some embodiments, the tubular member 320 can include a second reinforcing member 334 disposed at its distal end 324. The second reinforcing member 334 (not shown in FIGS. 8A-8C ) can be configured to maintain the lumen 314 of the tubular membrane 310 at the distal end 324 to prevent unhindered retraction of the interventional device 850 from the target tissue area and into the tubular member 320. For example, if the distal end 324 of the tubular member 320 is collapsed or folded, the lumen 314 may be smaller than the cross-sectional size of the interventional device 850, resulting in kinking, twisting, or folding of the wall of the tubular membrane 310 upon retraction of the interventional device 850. The second reinforcing member 334 may comprise a tube or ring having a column strength, radial strength, and / or bending stiffness greater than the column strength, radial strength, and / or bending stiffness, respectively, of the tubular membrane 310 .

[0055] 9A provides an isometric view of a guide extension catheter featuring a distal stiffening member configured to pivot, deflect, tilt, or otherwise undergo a change in angular position upon contact with a proximally retracting interventional device in a manner that opens a passageway for the device defined by the lumen of the tubular member. The guide extension catheter 500, shown extending from the distal end 504 of the guide catheter 502, includes a tubular member 520 having a distal end 524, a proximal end 526, and a radially collapsible tubular membrane 510 having a push member 522 secured thereto. A guidewire 528 passes through the lumen 514 of the tubular membrane 510, shown in a fully opened / fully expanded state, and extends through the tubular member 520 to a location distal to its distal end 524. The tubular membrane 510 can be freely collapsible and / or foldable in accordance with the tubular membrane embodiments described herein.

[0056] The proximal end 526 of the tubular member 520 can include a first reinforcing member 506, which can include a substantially circular component, such as a ring or a coil. Embodiments of the reinforcing member 506 can include or include similar or identical features to the reinforcing member 306, such as an elongated tube, a concave track, a non-elongated tube (e.g., a partial or complete ring or coil), or a combination thereof. Embodiments of the first reinforcing member 506 can include a variety of materials, non-limiting examples of which can include one or more metals, plastics, or a combination thereof.

[0057] As further shown in FIG. 9A , the distal end 524 of the tubular member 520 can include a second distal reinforcing member 534 comprising a resilient support ring or supporting coil member (hereinafter referred to as “coil member 534”) attached to the distal end of the tubular membrane 510 and configured to facilitate the advancement of one or more interventional devices, e.g., a treatment catheter, into the tubular member 520 during proximal retraction of such devices from a target site within the subject's vasculature. The coil member 534 can comprise a flexible, deformable, shape-memory material and / or a recovery configuration that is biased toward a static, unconstrained configuration that is substantially perpendicular to the longitudinal axis of the push member 522, as shown in FIG. 9A , or otherwise orthogonal thereto. The unconstrained configuration of the coil member 534 can establish, expand, and / or maintain patency of at least a distal portion of the lumen 514 of the tubular membrane 510. In a resting state, not positioned within a guide catheter or confined within a working space within a subject's vasculature, coil member 534 can define a distal opening into tubular member 520 that is oriented and sized to accommodate the unobstructed entry and passage of one or more interventional devices therethrough.

[0058] When trapped within a blood vessel during an interventional procedure, the coil member 534 can tilt, bend, or otherwise warp in a proximal or distal direction, as represented by the dashed outline of the coil member 534 shown in FIG. 9B. In this configuration, when no interventional device is positioned within the tubular membrane 510, the membrane 510 may be in a collapsed state, loosely wrapped or folded over the push member 522, which may hinder retrograde advancement of the interventional device, particularly beyond the distal end of the tubular membrane 510, in some instances due to the potential risk of the membrane interfering with the path of the interventional device. To facilitate the advancement of an interventional device 538 being retracted proximally (in the direction of the horizontal arrow shown in FIGS. 9C and 9D ) toward the distal end 524 of the tubular member 520, contact between the interventional device 538 and the leading edge or distal-most portion 535 a, 535 b of the deflected coil member 534 results in the coil member 534 pivoting or rotating toward an unconstrained configuration substantially perpendicular or orthogonal to the longitudinal axis of the push member 522, thereby transitioning the distal end of the lumen 514 of the tubular membrane 510 to an expanded, uncollapsed state and opening an unobstructed passageway through the opening defined by the coil member 534 into the tubular member 520 for proximal retraction of the interventional device therethrough. Thus, the angle of the coil member 534 relative to the longitudinal axis of the push member 522 can be varied in response to force applied by the interventional device. Due to the material composition and configuration of the coil member 534, the angled portion and / or cross-sectional configuration of the coil member 534 can also change in response to changes within the subject's vasculature, for example, the widening and narrowing of tortuous blood vessels.

[0059] In embodiments featuring a coil member 534 that deflects proximally when confined within the guide catheter 502 and / or blood vessel (see dashed coil member 534 in FIG. 9C ), contact between the distal-most portion 535 a of the coil member 534 and a proximally retracted interventional device 538 can cause the opposite “free” end 536 a of the coil member 534 to pivot or pivot in the direction of the curved arrow shown in FIG. 9C toward an unconstrained, resting configuration, leaving the distal end of the tubular membrane 510 and end 536 a attached. When deflected distally when confined within the guide catheter 502 and / or blood vessel (see dashed coil member 534 in FIG. 9D ), contact between the distal-most portion 535 b of the coil member 534 (which in this configuration constitutes the “free” end) and the proximally retracting interventional device 538 can cause the distal-most portion 535 b of the coil member 534 to pivot or pivot in the direction of the curved arrow shown in FIG. 9D toward an unconstrained, resting configuration, again with the end 535 b attached to the distal end of the tubular membrane 510. Thus, as a result of proximal retraction of the interventional device, the coil member 534 can return to or near its resting, unconstrained state, where the cross-sectional area of ​​the lumen 514 of at least the distal portion of the tubular membrane 510 is increased or maximized, reducing interference with the proximally retracting interventional device along with the potential for damage to the associated tubular membrane 510. The angled portion of the coil member 534 can thus respond directly to the position and movement of the interventional device 538 and the size and curvature of the surrounding vessel wall.

[0060] Embodiments of coil member 534 can be integrally formed with push member 522, such that coil member 534 can be continuous with push member 522 and, in some embodiments, coil member 534 can define the distal end of push member 522. According to such embodiments, push member 522 can include an elongated push rod or body having a longitudinal axis that is substantially aligned with the longitudinal axes of tubular member 520 and guide catheter 502, and a distal portion that coils, curls, or otherwise curves away therefrom. In other embodiments, coil member 534 can include a separate component, part, or segment that is secured, coupled, or otherwise attached, for example, by welding, to the distal end of push member 522.

[0061] 10A provides an isometric view of a guide extension catheter configured to accept a proximally retracted interventional device via a tubular member having a cross-sectional area that varies along its length. As shown, the guide extension catheter 600 includes a tubular member 620 having a distal end 624, a proximal end 626, and a radially collapsible tubular membrane 610 having a push member 622 secured thereto. A guidewire can pass through the lumen 614 of the tubular membrane 610, shown in the fully opened / fully expanded state, and extend through the tubular member 620 to a location distal to its distal end 624. In the illustrated example, the radially collapsible tubular membrane 610 is tapered such that the cross-sectional area of ​​the distal end 624 of the tubular member 620 is greater than the cross-sectional area of ​​the proximal end 626 of the tubular member 620 in the expanded state. The proximal end 626 of the tubular member 620 can include a first reinforcing member 606, which can be similar to or substantially identical to reinforcing members 306 and / or 506.

[0062] The distal portion 624 of the tubular member 620 can include or be defined by a distal stiffening member 634 attached to the distal end of the tubular membrane 610. The distal stiffening member 634 can include a flexible shape memory material and / or recovery configuration configured to bend radially outward to an expanded state when advanced distally beyond the distal end 604 of the guide catheter 602. An embodiment of the distal stiffening member 634 can include a resilient circular element, such as a coil member 534, that can be configured to deform and undergo angular adjustment relative to the longitudinal axis of the push member 622. In the expanded configuration, the tubular member 620 can assume a conical or funnel shape with its diameter, and therefore cross-sectional area, greatest at the distal end 624. When the distal reinforcing member 634 is released from the guide catheter 602, radial expansion or bending of the distal reinforcing member 634 and therefore widening of at least the distal portion of the lumen 614 of the tubular membrane 610 attached to the associated distal reinforcing member 634 occurs automatically in a spring-like manner, which can open or expand the cross-sectional space available for the entry and smooth passage of an interventional device into and through the distal end 624, for example, during an interventional procedure or during proximal retraction of such device upon completion.

[0063] This distal expansion of tubular member 620, along with the self-expandable, flexible configuration of distal reinforcing member 634, may be enabled by the narrow cross-sectional wall thickness and small cross-sectional space occupied by radially collapsible tubular membrane 610 in the collapsed state. The compactness of tubular membrane 610 in the collapsed configuration may configure tubular member 620 for advancement through guide catheter 602 having an inner diameter smaller relative to at least a portion of the inner and / or outer diameter of tubular member 620 in the expanded state. Thus, the cross-sectional diameter of tubular member 620 along at least a distal portion in the expanded state may not be limited by the inner diameter of guide catheter 602. As a result, guide extension catheter 600 may be able to accommodate a wider variety of interventional devices than existing guide extension devices and may accommodate the simultaneous passage of more than one interventional device during a given procedure, thereby enhancing the ease with which a wide range of interventional procedures may be performed.

[0064] The cross-sectional dimension of the tubular member 620 along its length in the expanded state can vary. In some examples, after advancing beyond the distal end 604 of the guide catheter 602, at least a distal portion of the tubular member 620, having a diameter B, can expand until its outer circumference abuts the inner surface of the surrounding blood vessel wall. In such embodiments, at least a portion of the tubular member 620 in the expanded state can have an outer diameter approximately equal to or greater than the inner diameter of the guide catheter 602. Various sizes of guide catheters 602 can be used, e.g., 6F, 7F, or 8F guide catheters, and the difference in diameter between the proximal end 626 and the distal end 624 of the tubular member 620 can vary by about 1F to about 4F, or any F value between these F values. The cross-sectional size gap between the inner diameter of the guide catheter 602 and the outer diameter of the tubular member 620 at or along at least a portion of the length of the tubular member 620 in the expanded state can also vary. For example, the gap between the inner diameter of the guide catheter 602 and the larger outer diameter of at least a portion of the tubular member 620 when extended beyond the distal end 604 of the guide catheter 602 can be less than, greater than, and / or about, or any number of inches between 0.001 inch, 0.002 inch, 0.003 inch, 0.004 inch, 0.005 inch, 0.006 inch, 0.007 inch, 0.008 inch, 0.009 inch, 0.010 inch, 0.011 inch, 0.012 inch, 0.013 inch, 0.014 inch, 0.015 inch.

[0065] The cross-sectional diameter, and therefore the cross-sectional area, of the tubular member 620 extending beyond the distal end 604 of the guide catheter 602 can increase in a smooth gradient such that the resulting conical configuration defines a constant or substantially constant slope. In other embodiments, the dilation tubular member 620 can define one or more discrete segments or steps that define different slopes. Thus, the cross-sectional area of ​​the dilation tubular member 620 can increase smoothly or in steps in the distal direction.

[0066] The proximal end 626 of the tubular member 620, which remains within the guide catheter 602, can have a maximum cross-sectional dimension that allows the tubular member 620 to slide coaxially relative to the guide catheter 602. In other embodiments, the outer diameter of at least the proximal portion of the tubular member 620 can be smaller than the maximum allowable value. In various embodiments, the diameter of the first lumen 608 of the tubular member 620 positioned within the guide catheter 602, e.g., diameter A, can be no more than about one French size smaller than the inner diameter of the lumen of the guide catheter 602. In one embodiment, the guide extension catheter 600 can be manufactured in at least three sizes corresponding to the internal volumes of 8F, 7F, and 6F guide catheters commonly used in interventional cardiology procedures. The size difference between the outer diameter of at least the proximal portion 626 of the tubular member 620 and the inner diameter of the guide catheter 602 can vary. For example, the cross-sectional diameter gap between the inner diameter of guide catheter 602 and the maximum outer diameter of at least the proximal portion 626 of tubing member 620, e.g., at proximal stiffening member 606, can be a number of inches less than, about, or any number of inches between 0.001 inch, 0.002 inch, 0.003 inch, 0.004 inch, or 0.005 inch. In certain embodiments, the cross-sectional diameter gap can range from 0.002 to 0.003 inch or from about 0.002 to 0.0035 inch. The diameter gap between the maximum outer diameter of at least the proximal portion of tubing member 620 and the lumen of guide catheter 602 can, in some embodiments, be substantially continuous along a significant portion or a majority of the length of tubing member 620, or may increase along one or more portions of tubing member 620.

[0067] FIGS. 10B and 10C provide front views of the distal reinforcing member 634 in different configurations, illustrating the flexibility, resilience, and deformability characteristics of the distal reinforcing member 634. FIG. 10B illustrates the distal reinforcing member 634 in a substantially circular configuration, which can be a static, unconstrained configuration unconstrained by a small blood vessel or guide catheter. This configuration can bend to a more oblong configuration, as shown in FIG. 10C, in response to anatomical changes, including externally applied compression, a constriction within the guide catheter, and / or vessel convolutedness and / or narrowing. The shape and configuration of the reinforcing member 634 can be substantially conformal to the inner surface of any surrounding structure, allowing for versatility in various environments. The embodiments of the coil member 534 shown in FIGS. 9A-9D can be configured similarly or identically in whole or in part, allowing the distal reinforcing member 634 and the coil member 534 to have flexibility in cross-sectional configuration as well as in their angled portions relative to the longitudinal axis of the push member. These deformability, bendability, and / or flexibility characteristics can significantly enhance the versatility of the guide extension catheter 600 (and, e.g., the guide extension catheter 500). For example, the distal reinforcing member 634 (and, e.g., the coil member 534) can be thinned by an ellipsoidal deformation to pass through a relatively stenosed arterial segment. The ellipsoidal deformation of the distal reinforcing member 634 can aid in passing the tubular member 620 through a guide catheter having a smaller cross-sectional area. Thus, the radial expansion of the distal reinforcing member 634 can, in whole or in part, be related to or coincide with the change in cross-sectional configuration that occurs when the distal reinforcing member 634 exits the distal end 604 of the guide catheter 602, such that the cross-sectional area of ​​the distal reinforcing member 634 increases even though the circumference of the distal reinforcing member 634 remains the same. Within the guide catheter 602, the distal reinforcing member 634 can be deformed into a variety of cross-sectional configurations, including, for example, the oblong configuration shown in FIG. 10C. Upon exiting the guide catheter 602, the distal stiffening member 634 can assume a more ring-like, circular cross-sectional configuration as shown in FIG. 10B.Thereafter, the cross-sectional configuration of the distal reinforcing member 634 can continue to adjust in response to anatomical changes encountered during advancement through the subject's vasculature, such as temporarily returning to a generally oblong or irregular cross-sectional shape when passing through tight bends or small blood vessels.

[0068] 11 illustrates a guide extension catheter featuring a tubular member including a radially collapsible tubular membrane flanked by two inflatable reinforcing members configured to enable selective, controlled expansion of the tubular member. Specifically, guide extension catheter 700 includes tubular member 720 having a distal end 724, a proximal end 726, and a radially collapsible tubular membrane 710 secured to a hollow push member 722. The proximal end 726 of tubular member 720 includes a first reinforcing member 706 including one or more inflatable helical coils, and the distal end 724 of tubular member 720 includes a second reinforcing member 734 including one or more inflatable helical coils. The lumen of each coil structure, which may be arranged in a helical configuration and include a flexible, inflatable balloon, may be continuous with the lumen of hollow push member 722 such that the reinforcing members can be inflated, when desired, by injection of an inflation fluid into the proximal end of hollow push member 722. Expansion of the reinforcing members 706, 734 transitions the tubular membrane 710, and thus the tubular member 720, generally from a collapsed configuration to an expanded configuration shown in FIG. 11 to accommodate the entry and passage of one or more interventional devices through the tubular member 720.

[0069] While the illustrated example includes two expandable reinforcing members 706, 734, additional embodiments may feature only one, for example, located at the distal or proximal end of tubular member 720. Embodiments having only one expandable reinforcing member may include an additional non-expandable reinforcing member, for example, including one or more of the features described above with respect to reinforcing members 306, 334, 506, 534, 606, and / or 634. For example, a guide extension catheter may include a proximal reinforcing member including one or more expandable coils and a distal reinforcing member including a resilient ring or coil, such as coil member 534 or distal reinforcing member 634.

[0070] Upon actuation, one or both stiffening members 706, 734 of the guide extension catheter 700 can be inflated to establish and / or maintain patency of the lumen 714 of the radially collapsible tubular membrane 710, thereby facilitating the entry and passage of one or more interventional devices distally or proximally through the lumen 714. One or more cycles of stiffening member inflation and subsequent deflation can be performed to accommodate the exchange of various interventional devices during a given procedure.

[0071] The number of complete helical coils included in each reinforcing member 706, 734 can vary. Embodiments can feature one or more helical coils, such as about two coils, three coils, four coils, five coils, or six or more coils. In embodiments featuring two reinforcing members, the number of expandable coils included in each reinforcing member can be the same or different. For example, the proximal reinforcing member can feature two expandable coils, while the distal reinforcing member can include only one expandable coil.

[0072] The coils of the reinforcing members 706, 734 may be formed according to a variety of methods, one of which may involve helically winding an inflatable tube around a central axis into a series of windings that are then stacked and bonded together, as described, for example, in U.S. Pat. Nos. 10,946,177, 10,159,821, and 9,968,763, the entire contents of which are incorporated herein by reference.

[0073] FIGS. 12A-12D show examples of column strength, bending stiffness, radial strength, and tensile strength, respectively. FIG. 12A illustrates a schematic top view of a tubular member 820 with arrows 825 indicating a column force. In this case, the term "column strength" refers to structural resistance to column force 825. FIG. 12B illustrates a schematic top view of a tubular member 820 with arrows 835 indicating a bending force. In this case, the term "bending stiffness" (or bending strength) refers to structural resistance to bending force 835. FIG. 12C illustrates a schematic cross-sectional view of a tubular member 820 with arrows 845 indicating a radial compressive force. In this case, the term "radial strength" refers to structural resistance to radial compressive force 845. FIG. 12D illustrates a schematic cross-sectional view of a tubular member 820 with arrows 855 indicating a tensile or expansive force. In this case, the term "tensile strength" refers to structural resistance to tensile force 855.

[0074] 13 illustrates a method of accessing a coronary artery, protecting it from abrasion or injury, and providing therapy thereto. Method 1300 can include step 1302 of providing a guide catheter, which can include providing a guide catheter formed of polyurethane, for example, and capable of being shaped along a distal portion to facilitate advancement to the coronary artery ostium (or other area of ​​interest within a patient). Any size guide catheter can be provided, for example, a 6F, 7F, or 8F guide catheter, where F is an abbreviation for the French catheter scale (a unit for measuring catheter diameter, 1F=1 / 3 mm).

[0075] The method 1300 includes step 1304 of advancing a guide catheter, the step 1304 including advancing the guide catheter through a blood vessel to a location adjacent an ostium of a coronary artery. In some embodiments, the guide catheter can be inserted into the femoral or radial artery and advanced through the aorta to a location adjacent an ostium of a coronary artery. In some embodiments, the guide catheter can be guided by a guidewire, optionally including a steerable and / or deflectable guidewire tip. The guide catheter can include a radiopaque marker to communicate the location of the guide catheter as it is advanced through the patient.

[0076] The method 1300 includes step 1306 of providing a guide extension catheter including a push member and a tubular membrane wrapped therearound. In some embodiments, the guide extension catheter includes a first reinforcement portion configured to maintain patency of the lumen. The tubular membrane is considered to have no effective column strength, effective radial strength, or effective bending stiffness. In other words, any radial, column, or bending force would cause the tubular membrane to flex, collapse, and / or bend, and the tubular membrane would not provide effective resistance to the radial, column, or bending forces (see, e.g., FIGS. 7A-7D ). The tubular membrane can provide sufficient tensile strength to prevent tearing of the wall of the tubular membrane and to prevent micro- and / or macro-damage to the vessel wall during advancement of the interventional cardiology device.

[0077] The method 1300 includes advancing 1308 a guide extension catheter through the guide catheter to a position where at least a portion of the tubular membrane extends distally beyond the distal end of the guide catheter and into the coronary artery. In some embodiments, the guide extension catheter is advanced by providing a forward force to a push member.

[0078] The method 1300 includes step 1310 of advancing an interventional cardiology device, which step 1310 includes advancing the interventional cardiology device through a guide catheter and into a lumen defined by a tubular membrane and urging the tubular membrane to expand from a collapsed, wrapped configuration to an expanded configuration. In some embodiments, advancing the interventional cardiology device into and through the lumen defined by the tubular membrane includes protecting from damage an endothelial layer of a coronary artery between the distal end of the guide catheter and the target tissue treatment area.

[0079] The devices, systems, and methods of the present invention provide or utilize delivery tools that reduce (i) arterial injury caused by abrasion of the coronary endothelium during delivery of an interventional device or (ii) coronary trauma / dissection caused by high delivery forces, guide catheter retraction during operation, or relatively stiff guide extension catheters. In contrast to existing stiffer guide extension catheters, the devices of the present invention are configured to (1) protect the coronary vessels and (2) optimize lubricity throughout the intracoronary delivery pathway.

[0080] The foregoing Detailed Description includes reference to the accompanying drawings, which form a part hereof. This Detailed Description should be read with reference to the drawings. The drawings show, by way of example, specific embodiments in which the devices, systems, and methods of the present invention may be practiced. These embodiments are also referred to herein as "Examples."

[0081] The Detailed Description is intended to be illustrative, not limiting. For example, the above-described examples (or one or more features or components thereof) can be used in combination with each other. One or more features of guide extension catheters 300, 300′, 500, 600, and / or 700 can be, for example, interchangeable. For example, guide extension catheters 300 and / or 310′ can include a distal reinforcing member, including coil member 534 and / or distal reinforcing member 634. Certain elements that are numbered differently in multiple separate figures can be the same or substantially the same in size, shape, material composition, and / or configuration. For example, radially collapsible tubular membrane 310 can be similar to, identical to, or easily interchangeable with radially collapsible tubular membranes 510 and / or 710. Similarly, push member 322 can be similar to, identical to, or easily interchangeable with push members 522 and / or 622. Upon reviewing the Detailed Description and accompanying drawings, one skilled in the art may utilize other embodiments. Similarly, various features or components have been or can be grouped together to streamline the disclosure of the invention. This should not be construed as intending that unclaimed features of the disclosure are essential to any claim. Instead, inventive subject matter may lie in less than all features of the disclosed embodiments of the invention. That is, the following claims are hereby incorporated into the Detailed Description, with each example standing on its own as a separate embodiment.

[0082] In Example 1, a guide extension catheter positionable within a guide catheter and configured to receive an interventional device for insertion into the vasculature can include a push member, a first stiffening member in contact with the push member, and a radially collapsible tubular membrane in contact with the push member and the first stiffening member. The tubular membrane is positioned distal to the first stiffening member and is collapsed or wrapped around the push member prior to receiving the interventional device.

[0083] In Example 2, the guide extension catheter of Example 1 is optionally configured such that the tubular membrane has no effective column strength, no effective radial strength, no independent bending stiffness, and has sufficient tensile strength to prevent tearing during insertion of the interventional device.

[0084] In Example 3, the guide extension catheter of Example 1 or Example 2 is optionally configured such that the distal end of the push member extends distally relative to the distal end of the tubular membrane.

[0085] In Example 4, the guide extension catheter of Example 3 is optionally configured such that the distal end of the push member includes an atraumatic guidewire-like distal tip.

[0086] In Example 5, the guide extension catheter of Example 4 is optionally configured such that the atraumatic guidewire-like distal end includes a tapered core surrounded by a coil.

[0087] In Example 6, the guide extension catheter of Example 5 is optionally configured such that the atraumatic guidewire-like distal end accepts and maintains a user-induced curvature.

[0088] In Example 7, the guide extension catheter of any one of Examples 1 or 2 is optionally configured such that a distal end of the push member terminates at or adjacent to a distal end of the tubular membrane.

[0089] In Example 8, the guide extension catheter of any one or any combination of Examples 1 to 7 is optionally configured such that the push member is tapered in one or more dimensions along a portion of its length.

[0090] In Example 9, the guide extension catheter of any one or any combination of Examples 1 to 8 is optionally configured such that the first stiffening member includes a deployable loop.

[0091] In Example 10, the guide extension catheter of any one or any combination of Examples 1 to 8 is optionally configured such that the first reinforcing member defines a concave trajectory leading into the tubular membrane and has higher column strength and radial strength than that of the tubular membrane.

[0092] In Example 11, the guide extension catheter of any one or any combination of Examples 1 to 10 is optionally configured such that the push member contacts the inner surface of the tubular membrane.

[0093] In Example 12, the guide extension catheter of any one or any combination of Examples 1 to 10 is optionally configured such that the push member contacts the exterior surface of the tubular membrane.

[0094] In Example 13, the guide extension catheter of any one or any combination of Examples 1 to 10 is optionally configured such that the push member is secured along a plane of the outer wall of the tubular membrane.

[0095] In Example 14, the guide extension catheter of any one or any combination of Examples 1 to 13 is optionally configured such that the tubular membrane is folded around the push member prior to receiving the interventional device.

[0096] In Example 15, the guide extension catheter of any one or any combination of Examples 1 to 14 is optionally configured such that the first reinforcing member is secured to the push member and maintains patency of the lumen leading into the proximal end of the tubular membrane.

[0097] In Example 16, the guide extension catheter of any one or any combination of Examples 1 to 15 optionally further includes a second reinforcing member disposed at a distal end of the tubular membrane, the second reinforcing member configured to maintain patency of the lumen at the distal end of the tubular membrane.

[0098] In Example 17, the guide extension catheter of Example 16 is optionally configured such that the second stiffening member selectively opens or closes the distal end of the tubular membrane.

[0099] In Example 18, the guide extension catheter of any one or any combination of Examples 1 to 17 is optionally configured such that the tubular membrane comprises a wall thickness and an outer diameter, and the ratio of the outer diameter to the wall thickness is in the range of 10:1 to 50:1, inclusive.

[0100] In Example 19, the guide extension catheter of any one or any combination of Examples 1 through 18 is optionally configured such that the tubular membrane is lubricious on one or both of the inner or outer surfaces.

[0101] In Example 20, the guide extension catheter of any one or any combination of Examples 1 to 19 is optionally configured such that the tubular membrane is composed of a lubricious layer, a non-crosslinked polymer layer, and a crosslinked polymer layer.

[0102] In Example 21, a guide extension catheter for use with a guide catheter can include a radially collapsible tubular membrane, the tubular membrane defining a lumen including a central axis when urged to an open position, and a push member extending proximally of the tubular membrane for contacting the tubular membrane along its entire length and slidably positioning the tubular membrane within and partially beyond the distal end of the guide catheter. The tubular membrane has no effective radial strength and is configured to collapse toward the central axis when subjected to a radially inward urging force. The tubular membrane has sufficient tensile strength to prevent rupture during insertion of an interventional cardiac device.

[0103] In Example 22, a method of accessing a coronary artery includes providing a guide catheter, advancing the guide catheter through a blood vessel to a position adjacent an ostium of the coronary artery, providing a guide extension catheter including a push member and a radially collapsible tubular membrane wrapped around the push member prior to receiving an interventional device, advancing the guide extension catheter through the guide catheter to a position where at least a portion of the tubular membrane extends distally into the coronary artery beyond a distal end of the guide catheter, and advancing an interventional cardiac device through the guide catheter into a lumen defined by the tubular membrane, the advancing step including urging the tubular membrane to expand from a collapsed configuration to an expanded configuration.

[0104] In Example 23, the method of Example 22 is optionally configured such that the step of advancing the interventional cardiology device into and through the lumen defined by the tubular membrane includes protecting from damage the endothelial layer of the coronary artery between the distal end of the guide catheter and the target tissue treatment area.

[0105] Certain terms are used throughout this patent document to refer to features or components. Different people may refer to the same feature or component by different names. This patent document does not intend to distinguish between these components or features that differ in name but not function.

[0106] The scope of the devices, systems, and methods of the present invention should be determined with reference to the claims, along with the full scope of equivalents to which they are entitled. In the appended claims, the terms "including" and "in which" are used as the plain-English equivalents of the terms "comprising" and "wherein." Also in the following claims, the terms "including" and "comprising" are open-ended, i.e., devices, systems, or methods that include features or components other than those recited after such terms in a claim are still deemed to fall within the scope of that claim. Further, in the following claims, the terms "first," "second," "third," etc. are used merely as labels and are not intended to impose numerical requirements on their objects.

[0107] The Abstract is provided to allow the reader to quickly ascertain the nature of the technical disclosure of the present invention. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. [Explanation of symbols]

[0108] 300 Guide Extension Catheter 302 Guide catheter 310 Tubular membrane 320 Tube member 322 Push member 328 Distal tip of push member

Claims

1. a guide extension catheter positionable within the guide catheter and configured to receive an interventional device for insertion into the vascular system, the guide extension catheter comprising: A push member; a first reinforcing member in contact with the push member; a radially collapsible tubular membrane in contact with the push member and the first reinforcing member, the radially collapsible tubular membrane being positioned distally to the first reinforcing member and being collapsed or wrapped around the push member prior to receiving the interventional device; a guide extension catheter.

2. 10. The guide extension catheter of claim 1, wherein the tubular membrane has no effective column strength, no effective radial strength, no independent bending stiffness, and has sufficient tensile strength to prevent tearing during insertion of the interventional device.

3. The guide extension catheter of claim 1 , wherein the distal end of the push member extends distally of the distal end of the tubular membrane.

4. The guide extension catheter of claim 3 , wherein the distal end of the push member comprises an atraumatic guidewire-like distal tip.

5. The guide extension catheter of claim 4 , wherein the atraumatic guidewire-like distal tip includes a tapered core surrounded by a coil.

6. The guide extension catheter of claim 5 , wherein the atraumatic guidewire-like distal tip is configured to accept and maintain a user-induced curvature.

7. The guide extension catheter of claim 1 , wherein the distal end of the push member terminates at or adjacent the distal end of the tubular membrane.

8. The guide extension catheter of claim 1 , wherein the push member is tapered in one or more dimensions along a portion of its length.

9. The guide extension catheter of claim 1 , wherein the first stiffening member comprises a deployable loop.

10. The guide extension catheter of claim 1 , wherein the first reinforcing member defines a concave track leading into the tubular membrane and has greater column and radial strength than that of the tubular membrane.

11. The guide extension catheter of claim 1 , wherein the push member contacts an inner surface of the tubular membrane.

12. The guide extension catheter of claim 1 , wherein the push member contacts an outer surface of the tubular membrane.

13. The guide extension catheter of claim 1 , wherein the push member is fixed along the plane of the outer wall of the tubular membrane.

14. The guide extension catheter of claim 1 , wherein the tubular membrane is configured to be folded around the push member prior to receiving the interventional device.

15. The guide extension catheter of claim 1 , wherein the first stiffening member is secured to the push member and is configured to maintain patency of a lumen leading into the proximal end of the tubular membrane.

16. 16. The guide extension catheter of claim 15, further comprising a second stiffening member disposed at a distal end of the tubular membrane and configured to maintain patency of the lumen at the distal end of the tubular membrane.

17. 17. The guide extension catheter of claim 16, wherein the second stiffening member is configured to selectively open or close the distal end of the tubular membrane.

18. the tubular membrane includes a wall thickness and an outer diameter; the ratio of the outer diameter to the wall thickness ranges from 10:1 to 50:1, inclusive; The guide extension catheter of claim 1 .

19. The guide extension catheter of claim 1 , wherein the tubular membrane is lubricious on one or both of its inner and outer surfaces.

20. The guide extension catheter of claim 1 , wherein the tubular membrane is comprised of a lubricious layer, a non-crosslinked polymer layer, and a crosslinked polymer layer.

21. 1. A guide extension catheter for use with a guide catheter, comprising: a radially collapsible tubular membrane defining a lumen including a central axis when biased to an open position; a push member extending proximally of the tubular membrane for contacting the tubular membrane along its entire length and for slidably positioning the tubular membrane within and partially beyond the distal end of the guide catheter; Including, the tubular membrane has no effective radial strength and is configured to collapse toward the central axis when subjected to an inward radial biasing force, the tubular membrane comprising sufficient tensile strength to prevent tearing during insertion of an interventional cardiology device. Guide extension catheter.

22. 1. A method of accessing a coronary artery, comprising: providing a guide catheter; advancing the guide catheter through a blood vessel to a position adjacent an ostium of the coronary artery; a push member, and a radially collapsible tubular membrane wrapped around the push member prior to receiving an interventional device; providing a guide extension catheter comprising: advancing the guide extension catheter through the guide catheter to a position where at least a portion of the tubular membrane extends distally beyond the distal end of the guide catheter into the coronary artery; advancing an interventional cardiology device through the guide catheter and into a lumen defined by the tubular membrane, the interventional cardiology device including urging the tubular membrane to expand from a collapsed configuration to an expanded configuration; A method comprising:

23. 23. The method of claim 22, wherein advancing the interventional cardiology device into and through the lumen defined by the tubular membrane includes protecting an endothelial layer of the coronary artery from damage between the distal end of the guide catheter and a target tissue treatment area.

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