Balloon catheter with porous outer member for air evacuation

Abstract

A balloon catheter (100, 200) with a porous outer member for air evacuation allows for faster preparation and efficient air evacuation. The catheter includes an elongate flexible catheter (102) having a tubular outer member (118) and a tubular inner member (120), each member having a respective lumen (128, 140). The inner member is at least partially disposed within the outer member cavity such that an outer surface of the inner member and an inner surface of the outer member together define an annular expansion cavity (121). The outer member has micropores (122) or microholes (202) configured such that when a contrast agent is injected into the dilation lumen, the micropores or microholes allow air to pass therethrough and then be occluded by the contrast agent. The catheter also has a balloon member (134) with an end secured to and circumferentially surrounding the outer member such that an inner surface of the balloon member and an outer surface of the outer member define an expandable balloon interior (146).

Description

[0001] This application is a divisional application of an application filed on November 6, 2020, with application number 202080077733.9, and invention name “Balloon catheter with a porous external component for air exhaust”. Technical Field

[0002] The presently disclosed invention relates generally to medical devices and methods for performing various procedures within the lumen of a patient's vascular system, and more particularly to balloon catheters for use within the vascular system and methods of using the same that are configured to allow for quick and efficient purging of unwanted air from the balloon catheter. Background Art

[0003] Medical catheters of various designs have been provided previously for performing various medical procedures, including interventional treatments, drug delivery, diagnosis, perfusion, and the like. Typically, medical catheters are used by guiding the catheter through an access site of a patient and into the patient's vascular system (e.g., a vein or artery). By guiding and advancing the catheter through the vascular system, the catheter is advanced from the access site to a target site for performing a therapeutic and / or diagnostic medical procedure.

[0004] An example of one type of intravascular catheter is a balloon catheter comprising an elongated tubular member, wherein the balloon member is fixed to, for example, the distal end portion of the tubular member or other suitable position to form an expandable balloon interior between the inner surface of the balloon member and the outer surface of the tubular member. A common type of balloon catheter is a balloon guide catheter, which is used to guide other instruments to a desired location in a vascular system. The tubular member includes an expansion chamber extending from the proximal end of the tubular member to the expandable balloon interior for injecting fluid to expand the balloon. Various types of balloon catheters have been previously disclosed for performing various medical procedures. For example, a balloon guide catheter used in conjunction with treating a neurological disease (e.g., ischemic stroke) is disclosed in U.S. Patent No. 6,638,245 (the '245 patent), the disclosure of which is fully incorporated herein. Fig.13A and Fig. 13BA prior art balloon guide catheter 250 disclosed in the '245 patent is shown (reference numbers have been changed from the '245 patent). The balloon guide catheter 250 includes an outer tubular member 270 and an inner tubular member 272 located within the outer tubular member 270. The balloon guide catheter 250 has an expandable balloon 260 disposed on the distal end of the outer tubular member 270. The annular space between the outer tubular member 270 and the inner tubular member 272 forms a fluid supply lumen 258 for expanding the balloon 260. The balloon guide catheter 250 is advanced to a target site within the patient's vascular system through an introducer sheath. Once in place, a treatment catheter can be advanced to the target site through the working lumen 252 of the inner tubular member 272. Therefore, existing balloon guide catheters, such as the balloon guide catheter 250, require at least three catheter shaft thicknesses (the combined thickness of the outer tubular member 270, the inner tubular member 272, and the introducer sheath).

[0005] The use of balloon catheters in the neurovascular system presents many challenges to catheter design. First, the blood vessels in the brain are often very small in diameter, as small as a few millimeters or less, which requires the outer diameter of the catheter to be as small as one French (0.33mm) before entering these blood vessels. In addition, the cerebral vascular system is very tortuous, requiring the nerve catheter (especially at the distal end) to be very flexible to pass through and conform to the tortuous path. In addition, the blood vessels in the brain are very fragile, so the nerve catheter must have a smooth, non-traumatic periphery.

[0006] Balloon catheters, including balloon guide catheters, are typically prepared before the balloon catheter is advanced into the patient's vascular system by purging any unwanted air bubbles from the corresponding balloon expansion chamber and the interior of the balloon. As described above, balloon catheters typically have an elongated tube and expansion chamber. In some cases, the balloon catheter may also have multiple tubes (e.g., concentric tubes with an inner tube disposed within an outer tube). Before the balloon catheter is advanced through the patient's vascular system, each of these structures (including one or more tubes, expansion chambers, and balloons) must be purged of air with a fluid (e.g., saline) to prevent air from being introduced into the patient, which may cause embolism or other trauma to the patient.

[0007] However, since the fluid path from the expansion chamber to the balloon is closed at the end, and in many cases, in the working chamber of the balloon catheter, it is difficult and very time-consuming to exhaust all the air from the system. Due to the closed end fluid path, it is also difficult to determine when all the air is exhausted. Therefore, during surgical preparation, it usually takes up to 15 minutes to exhaust the air from the existing balloon catheter, and even then, the exhaust is not always successful. However, since the fluid path from the expansion chamber to the balloon is closed at the end, and in many cases, in one or more tubes of the catheter, it is difficult and very time-consuming to exhaust all the air from the system. Due to the closed end fluid path, it is also difficult to determine when all the air is exhausted from the catheter. Therefore, during surgical preparation, it usually takes up to 15 minutes to exhaust the air from the existing balloon catheter, and even then, the exhaust is not always successful. Summary of the invention

[0008] The disclosed invention is directed to a balloon catheter having an innovative construction that allows for rapid preparation and effective purging of air from within the catheter, including purging air from the balloon dilation lumen and the interior of the balloon. Although the disclosed invention will be described with respect to a balloon guide catheter for inserting and positioning a therapeutic device within a patient's vascular system, it should be understood that the disclosed invention is not limited to balloon guide catheters, but may be used with any suitable balloon catheter.

[0009] As explained above, balloon catheters typically require preparation prior to use, including purging air from the system prior to advancing the system in the patient's vascular system. The balloon catheter of the present invention is configured to allow for quick and efficient purging of air from the catheter, particularly from the balloon dilation lumen and balloon, in a single aspiration step, allowing for a simpler and faster preparation procedure than existing balloon catheters.

[0010] In an exemplary embodiment of the invention disclosed herein, a balloon catheter includes an elongated flexible tubular outer member having a proximal portion, a distal portion, and an outer member lumen extending between the proximal portion and the distal portion. The outer member is formed of a microporous material so that the wall of the outer member has micropores. The micropores are constructed (e.g., sized) so that when a contrast agent is injected into the outer member lumen, the micropores allow air to pass through the wall of the outer member. Air passes through the micropores from the outer member lumen to the outside of the outer member. Typically, the contrast agent is mixed with saline to form a contrast agent / saline mixture, and therefore, the term "contrast agent" used herein refers to a contrast agent, a contrast agent / saline mixture, or a contrast agent mixed with any other fluid. In addition, the micropores allow air to pass through and then are blocked by the contrast agent, thereby sealing the micropores and not allowing the contrast agent to pass through the micropores.

[0011] The balloon catheter also includes a flexible, elongated tubular inner member having a proximal portion, a distal portion, and an inner member cavity extending between the proximal portion and the distal portion. The inner member cavity is communicated with the distal opening of the inner member. The inner member is at least partially disposed in the outer member cavity so that the outer surface of the inner member and the inner surface of the outer member together define an annular expansion cavity.

[0012] The balloon member is fixed to the outer member. The balloon member can be fixed to any suitable portion of the outer member, including but not limited to the distal portion. The proximal and distal ends of the balloon are fixed to the outer surface of the outer member and circumferentially surround the outer surface of the outer member, so that the inner surface of the elastomeric member and the outer surface of the outer member define an expandable balloon interior.

[0013] The outer member also has one or more expansion passages through the wall of the outer member, the expansion passages forming a fluid path between the annular expansion lumen and the balloon interior. The expansion passages can be holes through the wall of the outer member, the holes fluidly connecting the annular expansion lumen and the balloon interior.

[0014] In various embodiments, the microporous material has micropores having a nominal pore size diameter in the range of 0.1 μm to 2 μm. This configuration of the microporous material allows air to flow out through the micropores of the outer member when contrast media is injected into the expansion cavity, after which the micropores are blocked and sealed by the contrast media. In addition, the pore size diameter of the micropores is preferably no more than 5 μm, which helps ensure that the micropores can be properly sealed by the contrast media without allowing excess contrast media to leak through the micropores.

[0015] In various embodiments, the microporous material may be any suitable material for making a flexible elongated tube to form an outer member, such as any of the following: TYVEK TM 3345, Woven Polymer, Woven Plastic, Expanded Polytetrafluoroethylene (ePTFE), Sintered Plastic, Sintered Polymer, and GORE-TEX TM Fabric membrane.

[0016] In various embodiments, the micropores can extend from the proximal portion of the outer member to the distal portion. In this way, there are micropores along the entire outer member for venting air trapped in the expansion cavity, which reduces the time required to vent air from the balloon catheter.

[0017] In various embodiments, the microporous material has micropores having a nominal pore area size of 0.079 μm. 2 Up to 12.5μm 2Similar to the pore size diameter, when a contrast agent is injected into the expansion cavity, this feature allows air to flow out through the micropores of the outer member, after which the contrast agent blocks the micropores, thereby sealing the micropores and not allowing the contrast agent to pass through the micropores.

[0018] Another aspect of the present invention relates to a method for purging air from an exemplary embodiment of the above-mentioned balloon catheter, wherein contrast agent is injected into an annular expansion cavity and flows through the corresponding annular expansion cavity, the expansion passage and into the interior of the balloon, thereby purging air from the expansion cavity and the interior of the balloon out of the micropores of the external member. A positive pressure of the contrast agent in the annular expansion cavity is maintained so that after the air is purged from the expansion cavity and the interior of the balloon, the contrast agent seals the micropores of the external member. In order to complete the purge of air from the entire balloon catheter, the internal member cavity can be purged by flushing the internal member cavity with a flushing fluid such as saline until the unwanted air is removed from the internal member cavity. The balloon catheter is now ready ("ready" for use in a surgical procedure). Therefore, when preparing a balloon catheter for performing a surgical procedure, the balloon catheter allows for very rapid and efficient purge of air.

[0019] The preparation method may also include positioning the balloon catheter to elevate the tubular outer member above the balloon such that air trapped in the balloon is forced into the tubular outer member and out of the tubular member through micropores of the outer member.

[0020] Preferably, the contrast medium is injected into the annular expansion cavity with sufficient pressure to expand the balloon member. After the air is purged from the expansion cavity and the balloon member, the balloon member can be deflated by reducing the pressure of the contrast medium.

[0021] The preparation method may further include inspecting the balloon for air bubbles while the balloon is inflated with contrast agent (e.g., a user visually inspecting the balloon), and determining whether any air bubbles in the balloon are exhausted from the balloon. Then, after determining that any air bubbles in the balloon are exhausted from the balloon, deflate the balloon by reducing the pressure of the contrast agent in the inflation lumen and inside the balloon.

[0022] In one exemplary application, a prepared (air-purged) balloon catheter is inserted into the patient's vascular system. For example, the balloon catheter can be inserted into an entry vessel, such as the inferior vena cava or femoral artery near the groin, through an entry incision. The inner member and outer member are then advanced through the vascular system to position the balloon at the treatment site. The inner member and outer member can advance simultaneously or separately, and at the same rate or at different rates. When the balloon is located at the treatment site, the balloon member is expanded by injecting contrast agent into the expansion chamber, thereby increasing the pressure of the contrast agent in the expansion chamber and the balloon member. The balloon can be expanded in the blood vessel so that the balloon seals the blood vessel. This will isolate the blood flow of the blood vessel downstream of the balloon. Therapeutic procedures such as imaging, thrombus removal, intravascular device implantation or similar procedures can then be performed. For example, an imaging catheter can be inserted through the inner member and advance through the distal end of the inner member to image the blood vessel or surrounding tissue. In the case of removing a thrombus, such as in the treatment of ischemic stroke, a thrombus removal device can be inserted through the inner member and advanced through the distal end of the inner member to grasp or otherwise capture the thrombus and remove it from the vessel.

[0023] In an alternative embodiment of the balloon catheter, the outer member is not formed by a microporous material, but the outer member has an impermeable wall (i.e., impermeable to air, contrast agent and saline), and the impermeable wall has one or more micropores that drill through the wall of the outer member. Therefore, in this alternative embodiment, the balloon catheter includes an elongated tubular outer member, which has a proximal portion, a distal portion and an outer member cavity extending between the proximal portion and the distal portion. The outer member has one or more micropores that drill through the wall of the outer member. The micropores are configured so that when the contrast agent is injected into the outer member cavity (i.e., injected into the expansion cavity), the micropores allow air to pass through it. In other words, air passes through the micropores from the outer member cavity (more specifically, the expansion cavity) to the outside of the outer member. In addition, after allowing air to pass through, the micropores are blocked by the contrast agent, thereby sealing the micropores and not allowing the contrast agent to pass through the micropores.

[0024] An alternative embodiment of the balloon catheter also has a flexible, elongated tubular inner member having a proximal portion, a distal portion, and an inner member cavity extending between the proximal portion and the distal portion. The inner member cavity is in communication with the distal opening of the inner member. The inner member is at least partially disposed within the outer member cavity such that the outer surface of the inner member and the inner surface of the outer member together define an annular expansion cavity.

[0025] As with the exemplary embodiment, the balloon member is secured to the outer member. The balloon member can be secured to any suitable portion of the outer member, including but not limited to the distal portion. The proximal and distal ends of the balloon are secured to the outer surface of the outer member and circumferentially surround the outer surface of the outer member so that the inner surface of the elastomeric member and the outer surface of the outer member define an expandable balloon interior. The outer member also has one or more expansion passages through the wall of the outer member, the expansion passages forming a fluid path between the annular expansion cavity and the interior of the balloon. The expansion passages can be holes through the wall of the outer member that fluidly connect the annular expansion cavity and the interior of the balloon.

[0026] The micropores of this alternative embodiment preferably have a nominal size diameter in the range of 5 μm to 8 μm. Such a configuration of the micropores allows air to flow out through the micropores of the outer member when contrast medium is injected into the expansion cavity, after which the contrast medium blocks the micropores, thereby sealing the micropores. On the other hand, the density of the micropores on the surface area of ​​the outer member is preferably 100 μm per cm 2 The surface area of ​​the external member does not exceed 16 micropores. Optionally, the density of micropores on the surface area of ​​the external member is preferably 16 micropores per cm 2 The surface area of ​​the external component does not exceed 20 micropores, or per cm 2 The surface area of ​​the external component does not exceed 10 micropores, or per cm 2 The surface area of ​​the outer member has no more than 5 micropores. This maximum density of micropores over the surface area of ​​the outer member helps ensure that the contrast agent will seal the micropores and not allow contrast agent (or excess contrast agent) to leak through the micropores.

[0027] As with the exemplary embodiment, the outer member of the alternative embodiment is preferably formed of a material such as polyurethane, PEBAX TM 、VESTAMID TM , thermoplastic elastomers and nylon or other suitable materials that can form a flexible elongated tubular outer member, and micropores can be drilled through the wall of the tubular outer member. The micropores can be drilled using any suitable method, such as laser drilling, mechanical drilling, punching, etc., and are preferably spaced apart and positioned along the outer member from the proximal portion to the distal portion of the outer member. For example, the micropores can be arranged in a spiral pattern along the outer member, or arranged in a rectangular matrix, or other suitable pattern. The micropores preferably have a nominal pore area of ​​1 μm 2 Up to 210μm 2 Similar to the nominal diameter, the nominal pore area allows air to flow out through the micropores of the outer member when the contrast agent is injected into the expansion lumen, and the contrast agent blocks and seals the micropores after the air is expelled.

[0028] Another aspect of the disclosed invention is directed to a method of purging air from an alternative embodiment of a balloon catheter. The air purging method is essentially the same as the method of purging air from the exemplary embodiment, except that the air is purged through micropores and the contrast agent seals the micropores instead of the micropores.

[0029] Thus, the embodiments described herein provide an innovative balloon and method of using the balloon that allows for faster preparation and more efficient purging of air from within the catheter than prior balloon catheters. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The foregoing, as well as other and additional embodiments and aspects of the presently disclosed invention, will now be described in greater detail in the following detailed description, which is to be read with reference to the accompanying drawings, wherein like reference numerals represent like elements, and descriptions of like elements will apply to all relevant embodiments described.

[0031] Figure 1 is a side view of a balloon guide catheter according to a first embodiment of the invention disclosed herein; Figure 2 yes Figure 1 A lateral cross-sectional view of a balloon guide catheter; Figure 3 Depicted Figure 1 The balloon guide catheter is purged of air by injecting contrast agent into the dilation lumen and allowing air to pass through the micropores of the outer member; Figure 4 Depicted Figure 1 The balloon guide catheter is purged of air, wherein the balloon member is expanded and air passes through micropores of the outer member; Figure 5 Depicts the micropores after they have been blocked and sealed with contrast agent and the balloon structure has been deflated. Figure 1 balloon guide catheter; Figure 6 Depicted Figure 1 A balloon guide catheter, wherein the inner member lumen is evacuated of air by injecting saline into the inner member lumen; Figure 7 is a side view of a balloon guide catheter according to a second embodiment of the invention disclosed herein; Figure 8 yes Figure 7 A lateral cross-sectional view of a balloon guide catheter; Fig. 9 Depicted Figure 7 The balloon guide catheter is purged of air by injecting contrast medium into the dilation lumen and allowing air to pass through microscopic holes in the outer member; Fig.10 Depicted Figure 7The balloon guide catheter is deflated, wherein the balloon member is expanded and air passes through microscopic pores of the outer member; Fig.11 Depicts the micropores after they have been plugged and sealed with contrast agent and the balloon structure has been deflated. Figure 7 balloon guide catheter; Fig.12 Depicted Figure 7 A balloon guide catheter, wherein the inner member lumen is evacuated of air by injecting saline into the inner member lumen; Fig.13A and Fig. 13B A prior art balloon guide catheter disclosed in US Pat. No. 6,638,245 is described. DETAILED DESCRIPTION

[0032] Figure 1-Figure 5 A first embodiment of a balloon guide catheter 100 constructed in accordance with a first embodiment of the disclosed invention is illustrated. The balloon guide catheter 100 is generally configured for use in performing procedures within a vascular system, such as for the treatment of ischemic stroke and / or for blocking or restricting blood flow for other therapeutic or diagnostic purposes. Specifically, with respect to the disclosed invention, the balloon guide catheter 100 is particularly configured to allow for rapid preparation of the catheter for performing a surgical procedure, including providing for rapid and effective evacuation of air from the respective dilation lumens 121 and the balloon interior 146, as described in more detail below.

[0033] The balloon guide catheter 100 includes an elongated flexible tubular body 102 having a proximal portion 104, a distal portion 106, and an internal working lumen 108 extending between the proximal portion 104 and the distal portion 106. The working lumen 108 (defined in part by a hub 116 and in part by an inner member lumen 140) is in fluid communication with a distal opening 110 of the tubular body 102 at a distal end 112, and with a proximal opening 114 defined by a hub 116 (described further below) secured to the proximal portion 104 of the tubular body 102.

[0034] The tubular body 102 includes an elongated flexible tubular outer member 118 having a proximal portion 124 and a distal portion 126, and an outer member lumen 128 extending between the proximal portion 124 and the distal portion 126. The tubular body 102 also has an elongated flexible tubular inner member 120 coaxially disposed within the outer member lumen 128 such that an outer surface of the inner member 120 and an inner surface of the outer member 118 together define an annular expansion lumen 121.

[0035] The outer member 118 is formed of a microporous material such that the wall of the outer member 118 has micropores 122 along the entire wall of the outer member 118 extending from the proximal portion 124 to the distal portion 126. The micropores 122 are schematically shown in the figure because the micropores 122 are very small and distributed throughout the wall of the outer member 118. The microporous material has micropores 122, and the micropores 122 are configured to allow air to pass through the wall of the outer member 118 from the expansion cavity 121 to the outside of the outer member 118 when the contrast agent 123 is injected into the outer member cavity 128 (more specifically, into the expansion cavity 121), as shown in FIG. Figure 3 and Figure 4 The configuration of the micropores 122 of the microporous material also provides for the micropores 122 to be blocked by contrast agent 123 after air is purged from the expansion lumen 121 and the balloon member 134. In order to both purge the unwanted air and provide a blocking effect of the contrast agent, the microporous material has micropores 122 having a nominal pore size diameter in the range of 0.1 μm to 2.0 μm. In another way of defining the size of the microporous material, the micropores 122 have a nominal pore area size in the range of 0.079 μm. 2 Up to 12.5μm 2 In addition, the pore size of the micropores 122 should not exceed 5 μm in diameter to ensure that the micropores are properly blocked by the contrast agent after the air is purged. Therefore, the microporous material can be any suitable material with appropriately constructed micropores 122, including but not limited to TYVEK TM 3345, woven polymers, woven plastics, expanded polytetrafluoroethylene, sintered plastics, sintered polymers and GORE-TEX TM Fabric membrane.

[0036] The inner member 120 has a proximal portion 136, a distal portion 138, and an inner member lumen 140 extending between the proximal portion 136 and the distal portion 138. The inner members 120 can each be made of a polymer tube or other suitable material, and can have one or more reinforcing members (not shown) to provide an enhanced and / or reinforced portion. For example, a coil, braid, ribbon, hypotube, or other structural member can be disposed on the inside, outside, and / or embedded in the wall of the inner member 120. Such reinforcing members can be made of any suitable material, such as a superelastic alloy or a shape memory material, to provide a specific shape to the reinforced portion of the tubular body 102 under certain conditions.

[0037] As described above, the balloon guide catheter 100 also includes a hub 116 fixed to the proximal portion 104 of the tubular body 102 (i.e., fixed to each of the inner member 118 and the outer member 120). The hub 116 defines the proximal end opening 114 of the working lumen 108. The hub 116 includes a balloon dilation port 142 in fluid communication with the proximal end of the dilation lumen 121. The balloon dilation port 142 is configured to be connected to an dilation syringe 152 (not drawn to scale) (see FIG. Figure 3-Figure 5 ) or other pressurized inflation fluid source for purging air from balloon guide catheter 100 when preparing catheter 100 for a surgical procedure. For example, balloon inflation port 142 may have a female Lure lock (not shown) for attaching an inflation syringe 152 or other fluid source, with a mating male Lure lock (not shown).

[0038] The expansion lumen 121 extends along the length of the outer member 118 from the balloon expansion port 142 to the expandable balloon interior 146 of the balloon member 134 fixed to the outer member 118 (at Figure 4 146 is best seen in the middle balloon interior). In the first embodiment shown, the outer member 118 and the inner member 120 are connected at the distal portion 126 of the outer member 118, thereby forming the distal end of the expansion cavity 121. The outer member 118 and the inner member 120 can also be connected to each other at one or more other locations (not shown) distal to the hub 116. However, such a connection is not completely circumferential, so as to ensure that the expansion cavity 121 is continuous from the expansion port 142 to the interior of the balloon. As an alternative to an annular expansion cavity 121, the expansion cavity 121 can be one or more channels, ducts, tubes, etc. formed in the wall of the outer member 118. Alternatively, the expansion cavity 121 can be one or more channels, ducts, tubes, etc. formed in the wall of the outer member 118 or attached to the wall of the outer member 118.

[0039] The hub 116 also has a working lumen port 143 in fluid communication with the working lumen 108. The working lumen port 143 is configured to be connected to a source of purging fluid (e.g., saline) to purge air from the working lumen 108. During a surgical procedure, a source of flushing fluid (e.g., saline) and / or a source of fluid medication can be connected to the working lumen port 143 with the balloon guide catheter 100 to flush a target site within the vascular system and / or deliver medication to a target site. The working lumen port 143 can have a female Luer lock (not shown) for attaching a syringe 68 or other fluid source (with a mating male Luer lock), such as syringe 155 (see Figure 6 ).

[0040] In the illustrated embodiment, the balloon member 134 is fixed to the distal portion 126 of the outer member 118. However, the balloon member 134 can be fixed to any suitable position on the outer member 118, including proximal to the distal portion 126, or within the middle portion of the outer member 118, etc. The typical balloon member 134 is elastomeric, but can also be non-elastomeric. The balloon member 134 can be transparent or translucent (i.e., translucent) so that the balloon member 134 can be visually inspected for bubbles while the air is purged from the catheter 100, as described herein. The proximal end 148 and the distal end 150 of the balloon member 134 are fixed to the outer surface of the outer member 118 and circumferentially surround the outer surface of the outer member 118. In this way, the inner surface of the balloon member 134 and the outer surface of the outer member 118 form an expandable balloon interior 146. The outer member 118 and the inner member 120 can be combined with each other at one or more locations (not shown) distal to the hub 116. However, such a bond is not completely circumferential in order to ensure that the expansion lumen 121 is continuous from the expansion port 142 to the balloon interior 146 .

[0041] The outer member 118 has one or more balloon dilation passages 156 inside the balloon through the wall of the outer member 118. The dilation passages 156 form a fluid path through the wall of the outer member between the dilation lumen 121 and the expandable balloon interior 146. In the illustrated embodiment, the outer member 118 has four dilation passages 156, wherein the dilation passages 156 are spaced longitudinally along the outer member 118 and spaced circumferentially around the outer member 118 (in the illustrated embodiment, the dilation passages are spaced 180° around the circumference of the outer member 118). The balloon guide catheter 100 can have any suitable number of dilation passages 156, such as between 1 and 10 dilation passages 156.

[0042] Now refer to Figure 1-Figure 6 A method of purging air from a balloon guide catheter 100 is described for the purpose of preparing ("priming") the catheter 100 for use in a medical procedure. Figure 2 As shown, first, a balloon guide catheter 100 is provided without any liquid in the catheter 100, so there is air in the expansion lumen 121 and the working lumen 108. In order to prepare the balloon guide catheter 100 for use in a surgical procedure, air is purged from the catheter 100 (including the expansion lumen 121 and the working lumen 108). The method will be described as first purging the expansion lumen 121 and then purging the working lumen 108, but the method can also be performed in the opposite order, or even purging both at the same time.

[0043] refer to Figure 3, in order to purge air from the expansion lumen 121, a source 152 of contrast agent 123 is attached to the expansion port 142. In the illustrated embodiment, the source of contrast agent 123 is an expansion syringe 152 filled with contrast agent 123. The syringe 152 may have a male Luer lock that mates with a female Luer lock of the expansion port 142. The syringe 152 is used to inject the contrast agent 123 into the expansion port 142, the expansion lumen 121, and the balloon member 134. When the expansion lumen 121 is filled with contrast agent 123, the air in the expansion port 142, the expansion lumen 121, and the balloon member 134 is squeezed out of the outer member 118 through the micropores 122, as shown by arrows 132. The syringe 152 is used to maintain a positive pressure of contrast agent 123 in the expansion port 142, the expansion lumen 121, and the balloon member 134.

[0044] like Figure 4 As shown, after the expansion port 142, the expansion lumen 121, and the balloon member 134 are filled with contrast agent 123, additional contrast agent 123 is injected into the expansion port 142 using the syringe 152, which expands the balloon member 134. The air continues to be purged through the micropores 122. The balloon guide catheter 100 is then manipulated to position the outer member 118 above the balloon member 134 (in other words, the balloon member 134 is positioned below the remainder of the balloon guide catheter 100 proximal to the balloon member 134), so that any air remaining in the balloon member 134 is forced into the outer member 118 and then flows out through the micropores 122 of the outer member 118. Positioning the balloon 134 beneath the outer member 118 may also be implemented at any other time during the evacuation of air from the expansion lumen 121 and balloon member 134, such as prior to initially injecting contrast agent into the expansion port 142, the expansion lumen 121, and the balloon 134, or just prior to expanding the balloon member 134, etc.

[0045] With balloon member 134 expanded, the user preparing balloon guide catheter 100 visually inspects the air in balloon member 134 (e.g., checks for air bubbles). The user determines whether there is any air remaining in balloon member 134. Balloon member 134 may also be visually inspected for any leaks. If balloon member 134 is leaking, balloon guide catheter 100 may be discarded and replaced. If it is determined that balloon member 134 is not leaking, the method of preparing balloon guide catheter 100 may continue.

[0046] When air is squeezed out through the micropores 122 of the outer member 118, the contrast agent 123 blocks the micropores 122. Figure 5As shown, the blocked micropores 158 are depicted by lines 158. The blocked micropores 158 are sealed by contrast agent 123, thereby not allowing contrast agent 123 to pass through micropores 122. As described herein, micropores 122 are configured to allow air to be evacuated from expansion lumen 121 through micropores 122, and thereafter, micropores 122 are blocked and sealed by contrast agent 123. In addition, as described herein, Figure 5 As shown, after air is purged from expansion lumen 121 and balloon member 134, balloon member 134 is deflated so that it can be inserted into the vascular system non-expanded. Air is now purged from expansion port 142, expansion lumen 121 and balloon member 134, and balloon member 134 is deflated.

[0047] like Figure 6 As depicted in , preparing the balloon guide catheter 100 may also include purging air from the working chamber 108, which includes the inner member chamber 140 of the inner member 120 and the working chamber port 143. A source of flushing fluid, typically a purging syringe 155 filled with saline 160, is connected to the working chamber port 143. The syringe 155 may have a male Luer lock that mates with a female Luer lock of the working chamber port 143. The syringe 155 is used to inject saline 160 into the working chamber 108, thereby purging air from the working chamber 108 (including the inner member chamber 140 of the inner member 120 and the working chamber port 143). The user can visually check whether the saline 160 leaving the distal opening 110 of the inner member chamber 140 has air bubbles, and when there are no air bubbles, the working chamber 108 is purged of air. The working lumen 108 is still filled with saline 160 in the prepared balloon guide catheter 100 (eg, surface tension holds the saline 160 within the working lumen 108 ).

[0048] The balloon guide catheter 100 is now purged of air and fully prepared for use in a surgical procedure.

[0049] The method of using the prepared balloon guide catheter 100 in a medical procedure may include any appropriate use of the balloon guide catheter 100. In an exemplary method, the balloon guide catheter 100 is inserted into the patient's vascular system. For example, the balloon guide catheter 100 can be inserted into the entry vessel, such as the inferior vena cava or femoral artery near the groin, through an entry incision. The balloon guide catheter 100 including the inner member 120, the outer member 118 and the balloon member 134 advances through the vascular system to position the balloon 134 at the treatment site. The contrast agent 123 allows the user to use a suitable medical imaging device, such as a radiograph, MRI, etc. to track the position of the balloon guide catheter 100. The inner member 120 and the outer member 118 can advance simultaneously or separately, and advance at the same rate or at different rates. In the illustrated embodiment, the inner member 120 and the outer member 118 are connected at the distal portion 126 of the outer member 118, so they advance simultaneously.

[0050] With the balloon member 134 at the treatment site, the contrast agent is injected into the expansion lumen 121 using the expansion syringe 152 (or other suitable expansion fluid source), so that the balloon member 134 is expanded, thereby increasing the pressure of the contrast agent 123 in the expansion lumen 121 and the balloon member 134. The balloon member 134 can be expanded within the blood vessel so that the balloon member 134 seals the blood vessel. This isolates the blood flow downstream of the blood vessel in the balloon member 134. The syringe 155 can also be used to inject saline 160 into the treatment site to flush the treatment site. The syringe 155 of the drug or other therapeutic substance can be used to inject the drug or other substance into the treatment site. Alternatively or additionally, a treatment procedure such as imaging, thrombus removal, intravascular device implantation or the like can be performed. For example, an imaging catheter can be inserted through the working lumen 108 including the inner member lumen 140 and advanced through the distal end of the inner member 120 to image the blood vessel or surrounding tissue. In the case of removing a thrombus, such as in the treatment of ischemic stroke, a thrombus removal device may be inserted through the inner member lumen 140 and advanced through the distal end 112 of the inner member 118 to grasp or otherwise capture the thrombus and remove it from the vessel.

[0051] Steering Figure 7-Figure 12 , a second embodiment of a balloon guide catheter 200 is shown. Balloon guide catheter 200 is also particularly configured to allow for rapid preparation of the catheter for performing a surgical procedure, including providing for rapid and efficient evacuation of air from the respective dilation lumens 121 and balloon interior 146, as described herein. Balloon guide catheter 200 is substantially the same as balloon guide catheter 100, except that outer member 118 is not formed of a microporous material, but rather outer member 118 has an impermeable wall having one or more micropores 202 drilled through the wall of outer member 118.

[0052] Therefore, the outer member 118 has one or more micropores 202 drilled through the wall of the outer member 118. The micropores 202 are configured so that when the contrast agent 123 is injected into the expansion cavity 121 using the syringe 152, the micropores 202 allow air to pass through the micropores 202 to the outside of the outer member 118. In other words, air passes through the micropores from the outer member cavity (more specifically, the expansion cavity) to the outside of the outer member. In addition, after allowing the air to pass through, the micropores are blocked by the contrast agent, thereby sealing the micropores, thereby not allowing the contrast agent to pass through the micropores.

[0053] The outer member 118 may be formed of any suitable material, such as polyurethane, PEBAX TM 、VESTAMID TM , thermoplastic elastomer and nylon, or other suitable materials that can form a flexible elongated tubular outer member, and micro holes can be drilled through the wall of the tubular outer member. The micro holes 202 can be drilled using any suitable method, such as laser drilling, mechanical drilling, punching, etc.

[0054] In order to both exhaust the unwanted air and provide a blocking effect for the contrast agent, the micropores 202 have a nominal size diameter that is in the range of 5 μm to 8 μm. This configuration of the micropores 202 allows air to flow out through the micropores 202 of the outer member 118 when the contrast agent 123 is injected into the expansion cavity 121, after which the contrast agent 123 blocks the micropores 202, thereby sealing the micropores and not allowing the contrast agent 123 to leak out. Alternatively, or in addition, the size of the micropores 202 can be defined based on area. For example, the micropores 202 have a nominal pore area that is in the range of 1 μm to 8 μm. 2 Up to 210μm 2 Similar to the nominal diameter, the nominal pore area allows air to flow out through the micropores 202 of the outer member 118 when the contrast agent is injected into the expansion lumen 121, and the contrast agent 123 blocks and seals the micropores 202 after the air is exhausted.

[0055] The density of the micropores 202 on the surface area of ​​the outer member 118 may have a maximum density to ensure that the contrast agent 123 will seal the micropores 202 and not allow the contrast agent 118 (or excess contrast agent) to leak through the micropores 202. The density of the micropores 202 on the surface area of ​​the outer member 118 is preferably 100 micropores per cm 2 The surface area of ​​the outer member 118 does not exceed 16 micropores. Optionally, the density of the micropores 202 on the surface area of ​​the outer member 118 is 16 micropores per cm 2 The surface area of ​​the outer member 118 does not exceed 20 micropores, or per cm 2The surface area of ​​the outer member 118 does not exceed 10 micropores, or per cm 2 The surface area of ​​the outer member 118 does not exceed 5 micro-holes 202 .

[0056] The micropores 202 are spaced apart along the outer member 118 from the proximal portion 124 to the distal portion 126 of the outer member 118. The micropores 202 can be arranged in a pattern along the outer member 118, such as in one or more spiral patterns, or in a rectangular matrix, or other suitable pattern.

[0057] like Figure 7-Figure 12 As shown, the method of preparing the balloon guide catheter 200 for use in a surgical procedure is substantially the same as the method of preparing the balloon guide catheter 100. Figure 8 As shown, first, a balloon guide catheter 200 is provided without any liquid in the catheter 200, so there is air in the expansion lumen 121 and the working lumen 108. In order to prepare the balloon guide catheter 200 for use in a surgical procedure, it is necessary to evacuate the air from the catheter 200 (including the expansion lumen 121 and the working lumen 108). As with the catheter 100, the method will be described as evacuating the expansion lumen 121 first and then the working lumen 108, but the method can also be performed in the opposite order, or even evacuate both at the same time.

[0058] Steering Fig. 9 , in order to purge air from the expansion lumen 121, a source 152 of contrast agent 123 is attached to the expansion port 142. Again, the source of contrast agent 123 is an expansion syringe 152 filled with contrast agent 123. The syringe 152 may have a male Luer lock that mates with the female Luer lock of the expansion port 142. The syringe 152 is used to inject the contrast agent 123 into the expansion port 142, the expansion lumen 121, and the balloon member 134. When the expansion lumen 121 is filled with contrast agent 123, the air in the expansion port 142, the expansion lumen 121, and the balloon member 134 is squeezed out of the outer member 118 through the micro-holes 202, as shown by arrows 132. The syringe 152 is used to maintain a positive pressure of contrast agent 123 in the expansion port 142, the expansion lumen 121, and the balloon member 134.

[0059] like Fig.10As shown, after the expansion port 142, the expansion lumen 121, and the balloon member 134 are filled with contrast agent 123, additional contrast agent 123 is injected into the expansion port 142 using the syringe 152, which expands the balloon member 134. The air continues to be expelled through the micropores 202. The balloon guide catheter 200 is then manipulated to position the outer member 118 above the balloon member 134 (in other words, the balloon member 134 is positioned below the rest of the balloon guide catheter 200 proximal to the balloon member 134), so that any air remaining in the balloon member 134 is forced into the outer member 118 and then flows out through the micropores 202 of the outer member 118. Positioning balloon 134 beneath outer member 118 may also be performed at any other time during purging of air from expansion lumen 121 and balloon member 134, such as prior to initially injecting contrast agent into expansion port 142, expansion lumen 121, and balloon 134, or just prior to expanding balloon member 134.

[0060] With balloon member 134 expanded, the user preparing balloon guide catheter 200 visually inspects the air in balloon member 134 (e.g., checks for air bubbles). The user determines whether there is any air remaining in balloon member 134. Balloon member 134 may also be visually inspected for any leaks. If balloon member 134 is leaking, balloon guide catheter 200 may be discarded and replaced. If it is determined that balloon member 134 is not leaking, the method of preparing balloon guide catheter 200 may continue.

[0061] When air is squeezed out through the micropores 202 of the outer member 118, the contrast agent 123 blocks the micropores 202. Fig.11 As shown, the micropores 202 are sealed by plugs 204 formed by contrast agent 123. The blocked micropores 202 are sealed by contrast agent 123, thereby not allowing contrast agent 123 to pass through the micropores 202. As described herein, the micropores 202 are configured to allow air to pass through the micropores 202 and be exhausted from the expansion lumen 121, and thereafter, the micropores 202 are blocked and sealed by contrast agent 123. In addition, as described herein, Fig.11 As shown, after the air is purged from the expansion lumen 121 and balloon member 134, the balloon member 134 is deflated so that it can be inserted into the vascular system non-expanded. The air is now purged from the expansion port 142, the expansion lumen 121 and the balloon member 134, and the balloon member 134 is deflated.

[0062] Preparing the balloon guide catheter 200 may also include purging air from the working chamber 108, which includes the inner member chamber 140 of the inner member 120 and the working chamber port 143. A purging syringe 155 filled with saline 160 is connected to the working chamber port 143. The syringe 155 may have a male Luer lock that mates with the female Luer lock of the working chamber port 143. The syringe 155 is used to inject saline 160 into the working chamber 108, thereby purging air from the working chamber 108 (including the inner member chamber 140 of the inner member 120 and the working chamber port 143). The user can visually check whether the saline 160 leaving the distal opening 110 of the inner member chamber 140 has air bubbles, and when there are no air bubbles, the working chamber 108 is purged of air. The working chamber 108 is still full of saline 160 in the prepared balloon guide catheter 200 (e.g., surface tension retains the saline 160 in the working chamber 108).

[0063] The balloon guide catheter 200 is now purged of air and fully ready for use in a surgical procedure.

[0064] The method of using the prepared balloon guide catheter 200 in a medical procedure is substantially the same as the method described herein for the prepared balloon guide catheter 100 .

Claims

1. A balloon catheter, comprising: an elongated tubular outer member having a proximal portion, a distal portion, and an outer member lumen extending between the proximal portion and the distal portion, the tubular outer member being formed of a microporous material such that a wall of the tubular outer member has micropores along the entire wall extending from the proximal portion to the distal portion, the micropores being configured such that when contrast media is injected into the outer member lumen, the micropores allow air to pass through the micropores, and then the micropores are blocked by the contrast media, thereby sealing the micropores and not allowing contrast media or air to pass through the micropores; a balloon member having respective proximal and distal ends secured to and circumferentially surrounding an outer surface of the distal portion of the tubular outer member such that an inner surface of the balloon member and the outer surface of the tubular outer member together define an expandable balloon interior; and An expansion lumen extends from an expansion port at a proximal portion of the tubular outer member to the interior of the expandable balloon.

2. The balloon catheter according to claim 1, wherein: The micropores of the microporous material have a nominal pore size diameter in the range of 0.1 μm to 2 μm.

3. The balloon catheter according to claim 1, wherein: The micropores of the microporous material have a nominal pore area, and the nominal pore area is 0.079 μm 2 Up to 12.5μm 2 within the range.

4. The balloon catheter according to claim 1, wherein: The micropores have a nominal pore size diameter of no more than 5 μm.

5. The balloon catheter according to any one of claims 1 to 4, wherein: The microporous material is a woven polymer.

6. The balloon catheter according to any one of claims 1 to 4, wherein: The microporous material is a woven plastic or a sintered plastic.

7. The balloon catheter according to any one of claims 1 to 4, wherein: The microporous material is expanded polytetrafluoroethylene.

8. The balloon catheter according to claim 1, wherein: The expansion lumen includes one or more channels, ducts or tubes formed in or attached to the wall of the tubular outer member.

9. A balloon catheter, comprising: an elongated tubular outer member having a proximal portion, a distal portion, and an outer member lumen extending between the proximal portion and the distal portion, the tubular outer member having a plurality of micropores bored through a wall of the tubular outer member, the plurality of micropores being configured such that when contrast media is injected into the outer member lumen, the micropores allow air to pass through the micropores, and then the micropores are blocked by the contrast media, thereby sealing the plurality of micropores and not allowing contrast media or air to pass through the micropores; a balloon member having respective proximal and distal ends secured to and circumferentially surrounding an outer surface of the distal portion of the tubular outer member such that an inner surface of the balloon member and the outer surface of the tubular outer member together define an expandable balloon interior; and An expansion lumen extends from an expansion port at a proximal portion of the tubular outer member to the interior of the expandable balloon.

10. The balloon catheter according to claim 9, wherein: The micro-voids have a nominal size diameter ranging from 5 μm to 8 μm.

11. The balloon catheter according to claim 9, wherein: The micropores have a nominal pore area, and the nominal pore area is 1 μm 2 Up to 210μm 2 within the range.

12. The balloon catheter according to any one of claims 9 to 11, wherein: The tubular outer member is formed of polyurethane or nylon.

13. The balloon catheter according to claim 12, wherein: The micro-holes extend from the proximal portion of the tubular outer member to the distal portion of the tubular outer member.

14. The balloon catheter according to any one of claims 9 to 11, wherein: The micro-holes extend from the proximal portion of the tubular outer member to the distal portion of the tubular outer member.

15. The balloon catheter according to any one of claims 9 to 11, wherein: The tubular outer member is formed from a thermoplastic elastomer.

16. The balloon catheter according to claim 9, wherein: The expansion lumen includes one or more channels, ducts or tubes formed in or attached to the wall of the tubular outer member.

17. A method of purging air from a balloon catheter according to any one of claims 1 to 8, comprising: injecting a contrast agent such that the contrast agent passes through the expansion lumen and into the balloon member, thereby purging air from the expansion lumen and the balloon interior through the micropores of the tubular outer member; and Maintaining a positive pressure of contrast medium in the expansion lumen causes the contrast medium to seal the micropores, not allowing contrast medium or air to pass through the micropores.

18. The method according to claim 17, wherein: The contrast agent is injected into the expansion lumen at a sufficient pressure to expand the balloon member, and wherein the method further comprises: The balloon catheter is positioned such that the proximal portion of the tubular outer member is elevated above the balloon member such that air trapped in the balloon member is forced into the tubular outer member and out of the tubular outer member through the micropores of the tubular outer member.

19. The method according to claim 18, further comprising: When the balloon member is expanded with contrast agent, checking whether the balloon member has air bubbles; ensuring that any air bubbles in the balloon member are purged from the balloon member; as well as After determining that any air bubbles in the balloon member are exhausted from the balloon member, the balloon member is deflated by reducing the pressure of the contrast medium in the dilation lumen and the interior of the balloon.

20. A method of purging air from a balloon catheter according to any one of claims 9 to 16, comprising: injecting a contrast agent so that the contrast agent passes through the expansion lumen and enters the balloon member, thereby purging air from the expansion lumen and the interior of the balloon through the micropores of the tubular outer member; and A positive pressure of contrast medium is maintained in the expansion lumen such that the contrast medium seals the micropores of the tubular outer member, not allowing contrast medium or air to pass through the micropores.

21. The method according to claim 20, wherein: The contrast agent is injected into the expansion lumen at a sufficient pressure to expand the balloon member, and wherein the method further comprises: The balloon catheter is positioned so that the proximal portion of the tubular outer member is elevated above the balloon member such that air trapped in the balloon member is forced into the tubular outer member and out of the tubular outer member through the micropores of the tubular outer member.

22. The method according to claim 21, further comprising: When the balloon member is expanded with contrast agent, checking whether the balloon member has air bubbles; ensuring that any air bubbles in the balloon member are purged from the balloon member; as well as After determining that any air bubbles in the balloon member are exhausted from the balloon member, the balloon member is deflated by reducing the pressure of the contrast medium in the dilation lumen and the interior of the balloon.

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