Balloon catheter with porous outer member for air purging

Abstract

To provide a balloon catheter that enables fast preparation and effective purging of air.SOLUTION: A balloon catheter 100 enables fast preparation and effective purging of air. The catheter includes an elongated, flexible catheter having a tubular outer member and a tubular inner member 120 that each have a lumen 140. The inner member is at least partially disposed in the outer member lumen such that an outer surface of the inner member and an inner surface of the outer member together define an annular inflation lumen. The outer member has micropores 122 or micro-holes configured such that, when a contrast agent is injected into the inflation lumen, the micropores or micro-holes allow air to pass therethrough and thereafter become clogged by the contrast agent.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001]

[0001] The disclosed invention relates generally to medical devices and methods for performing procedures within a lumen of a patient's vascular system, and more particularly to a balloon catheter for use within the vascular system that is configured to allow for rapid and effective purging of unwanted air from the balloon catheter, and a method for using the same. [Background technology]

[0002]

[0002] Medical catheters of various designs have been provided for some time to perform various medical procedures, including interventional therapy, drug delivery, diagnostics, perfusion, etc. Generally, medical catheters are used by introducing the catheter into a patient's vascular system, such as a vein or artery, through an entry site. The catheter is advanced from the entry site by guiding and pushing the catheter through the vascular system to a target site to perform a therapeutic and / or diagnostic medical procedure.

[0003]

[0003] One example of an intravascular catheter is a balloon catheter including an elongated tubular member. The balloon member is attached, for example, to the distal end portion of the tubular member or other suitable location to form an inflatable 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 used to guide other instruments to a desired location within the vascular system. The tubular member includes an inflation lumen extending from the proximal end of the tubular member to the inflatable balloon interior for injecting a fluid to inflate the balloon. Various types of balloon catheters have previously been disclosed for performing a variety of different medical procedures. For example, a balloon guide catheter used in connection with the treatment of neurological disorders such as ischemic stroke is disclosed in U.S. Patent No. 6,638,245 (the '245 patent), the disclosure of which is incorporated herein in its entirety. Figures 13A and 13B show a prior art balloon guide catheter 250 disclosed in the '245 patent (the numerals have been changed from those in the '245 patent). The balloon guide catheter 250 includes an outer tubular member 270 and an inner tubular member 272 within the outer tubular member 270. The balloon guide catheter 250 has an inflatable balloon 260 disposed at 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 inflating the balloon 260. The balloon guide catheter 250 is advanced through an introducer sheath to a target site within a patient's vasculature. Once in place, a treatment catheter can be advanced to the target site through the working lumen 252 of the inner tubular member 272. Thus, conventional balloon guide catheters such as the balloon guide catheter 250 require at least three catheter shaft thicknesses (the combined thicknesses of the outer tubular member 270, the inner tubular member 272, and the introducer sheath).

[0004]

[0004] The use of balloon catheters in the neurovascular system presents many challenges in catheter design. For one thing, blood vessels in the brain are very small, typically measuring a few millimeters or less in diameter, requiring the outer diameter of catheters inserted into these vessels to be approximately 1 French (0.33 mm). Furthermore, the cerebral vasculature is highly tortuous, requiring neurocatheters to be highly flexible, especially at their distal ends, in order to navigate and adapt to the tortuous pathways. Furthermore, because the blood vessels in the brain are very fragile, the outer periphery of neurocatheters must be smooth and atraumatic.

[0005]

[0005] Balloon catheters, including balloon guide catheters, generally require preparation by purging unwanted air bubbles from their respective balloon inflation lumens and the interior of the balloon before advancing the balloon catheter through a patient's vasculature. As described above, balloon catheters typically have an elongated tube and an inflation lumen. In some cases, balloon catheters may also have multiple tubes (e.g., concentric tubes with an inner tube disposed within an outer tube). Each of these structures, including the tubes, inflation lumens, and balloons, requires purging of air with a liquid (e.g., saline) before advancing the balloon catheter through a patient's vasculature to prevent the introduction of air into the patient, which could cause embolism or other trauma to the patient.

[0006]

[0006] However, because the fluid pathways from the inflation lumen to the balloon, and often within the working lumen of the balloon catheter, are closed-ended, purging all air from the system is difficult and time-consuming. Furthermore, because the fluid pathways are closed-ended, it is also difficult to determine when all air has been purged. Therefore, it often takes up to 15 minutes to proactively purge the balloon catheter of air during surgical preparation, and even then, the purge is not always successful. However, because the fluid pathways from the inflation lumen to the balloon, and often within the catheter tubing, are closed-ended, it is also difficult to determine when all air has been purged. Therefore, it often takes up to 15 minutes to proactively purge the balloon catheter of air during surgical preparation, and even then, the purge is not always successful. Summary of the Invention

[0007] The disclosed invention relates to a balloon catheter having an innovative configuration that allows for rapid preparation and effective purging of air within the catheter, including purging air from the balloon inflation lumen and the interior of the balloon. While the description of the disclosed invention relates to a balloon guide catheter used to insert and position a therapeutic device within a patient's vasculature, it is understood that the disclosed invention is not limited to balloon guide catheters and may be used with any suitable balloon catheter.

[0008] As noted above, balloon catheters typically require preparation before use, including purging air from the system before advancing the catheter into a patient's vascular system. The balloon catheter of the disclosed invention is configured to allow air to be quickly and effectively purged from the catheter, particularly from the balloon inflation lumen and balloon, in a single aspiration step, allowing for a simpler and faster preparation procedure than existing balloon catheters.

[0009] In an exemplary embodiment of the disclosed invention, a balloon catheter includes an elongated, flexible, tubular outer member having a proximal portion, a distal portion, and an outer member lumen extending therebetween. The outer member is formed of a microporous material such that the wall of the outer member has micropores. The micropores are configured (e.g., sized) to allow air to pass through the wall of the outer member when contrast agent is injected into the outer member lumen. Air passes from the outer member lumen through the micropores to the exterior of the outer member. Typically, contrast agent is mixed with saline to form a contrast agent / saline mixture; therefore, as used herein, the term "contrast agent" refers to a contrast agent, a contrast agent / saline mixture, or a contrast agent mixed with another fluid. Furthermore, the micropores allow air to pass through but subsequently become clogged with contrast agent, thereby sealing the micropores so that the contrast agent cannot pass through the micropores.

[0010] The balloon catheter further includes a flexible, elongated, tubular inner member having a proximal portion, a distal portion, and an inner member lumen extending therebetween. The inner member lumen communicates with the distal opening of the inner member. The inner member is disposed at least partially within the outer member lumen such that the outer surface of the inner member and the inner surface of the outer member together define an annular inflation lumen.

[0011] The balloon member is secured to the outer member. The balloon member may 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 circumferentially secured to the outer surface of the outer member such that the inner surface of the elastomeric member and the outer surface of the outer member define an inflatable balloon interior.

[0012] The outer member also has one or more inflation passages through its wall that form a fluid path between the annular inflation lumen and the interior of the balloon. The inflation passages may be holes that extend through the wall of the outer member and fluidly connect the annular inflation lumen to the interior of the balloon.

[0013] In various embodiments, the microporous material has pores with a nominal pore size ranging from 0.1 μm to 2 μm. This configuration of the microporous material allows air to pass through the pores in the outer member when contrast agent is injected into the inflation lumen, and the pores are then clogged and sealed by the contrast agent. Furthermore, the pore size is preferably 5 μm or less, which prevents excess contrast agent from leaking through the pores and allows the pores to be adequately sealed by the contrast agent.

[0014]

[0014] In various embodiments, the microporous material can be any suitable material for making a flexible, elongated tube to form the outer member, such as TYVEK™ 3345, woven polymers, woven plastics, ePTFE, sintered plastics, sintered polymers, and GORETEX™ fabric membranes.

[0015] In various embodiments, the micropores can extend from the proximal portion to the distal portion of the outer member, thus providing micropores along the entire outer member for venting air trapped in the inflation lumen, thereby reducing the time required to purge air from the balloon catheter.

[0016] In various embodiments, the microporous material has a pore size of 0.079 μm 2 to 12.5 μm 2 The outer member has pores with a nominal pore area size in the range of 0.01 to 0.05 mm. Similar to the pore size, this feature allows air to pass through the pores in the outer member when contrast media is injected into the inflation lumen, after which the contrast media clogs the pores, thereby sealing them so that the contrast media cannot pass through.

[0017] Another aspect of the disclosed invention relates to a method for purging air from the above-described exemplary embodiment of a balloon catheter, in which contrast medium is injected into the annular inflation lumen and flows through the annular inflation lumen, the inflation passage, and the interior of the balloon, respectively, thereby purging air from the inflation lumen and the interior of the balloon through the micropores of the outer member. A positive contrast medium pressure is maintained within the annular inflation lumen, and after air has been purged from the inflation lumen and the interior of the balloon, the contrast medium occludes the micropores of the outer member. To complete the purging of air from the entire balloon catheter, the inner member can be purged by flushing the inner member lumen with a cleaning fluid, such as saline, until unwanted air is removed from the inner member lumen. The balloon catheter is then ready ("primed" for use in a surgical procedure). Thus, the balloon catheter allows for very rapid and effective purging of air in preparing the balloon catheter for use in performing a surgical procedure.

[0018]

[0018] The preparation method may also include positioning the balloon catheter so that the tubular outer member is elevated above the balloon, allowing air trapped within the balloon to move into the tubular outer member and exit the tubular member through the micropores in the outer member.

[0019] Preferably, the contrast agent is injected into the annular inflation lumen at a pressure sufficient to inflate the balloon member. After air has been purged from the inflation lumen and the balloon member, the balloon member can be deflated by reducing the pressure of the contrast agent.

[0020]

[0020] The preparation method may further include inspecting the balloon for air bubbles (e.g., by a user visually inspecting the balloon) while the balloon is inflated with the contrast agent to determine whether the air bubbles in the balloon have been purged from the balloon. After it has been determined that the air bubbles in the balloon have been purged from the balloon, the balloon is deflated by reducing the pressure of the contrast agent in the inflation lumen and the interior of the balloon.

[0021] In one exemplary use, a primed (air-purged) balloon catheter is inserted into a patient's vascular system. For example, the balloon catheter can be inserted through an entrance incision into an entry vessel, such as the inferior vena cava or femoral artery near the groin. The inner and outer members are then advanced through the vascular system to position the balloon at the treatment site. The inner and outer members can be advanced simultaneously or separately, at the same or different speeds. With the balloon positioned at the treatment site, the balloon member is inflated by injecting contrast agent into the inflation lumen, thereby increasing the pressure of the contrast agent within the inflation lumen and the balloon member. The balloon can be inflated within the vessel so that it seals the vessel. This isolates the vessel downstream from the balloon from blood flow. A therapeutic procedure, such as imaging, embolus removal, endovascular device implantation, etc., can then be performed. For example, an imaging catheter can be inserted through the inner member and advanced beyond the distal end of the inner member to image the vessel and surrounding tissue. When removing an embolus, such as in the treatment of an ischemic stroke, an embolus removal device can be inserted into the inner member and advanced beyond the distal end of the inner member to grasp or capture the embolus and remove it from the blood vessel.

[0022]

[0022] In an alternative embodiment of the balloon catheter, instead of the outer member being formed of a microporous material, the outer member has an impermeable wall (i.e., impermeable to air, contrast agent, and saline) with one or more microholes drilled therethrough. Accordingly, in this alternative embodiment, the balloon catheter includes an elongated tubular outer member having a proximal portion, a distal portion, and an outer member lumen extending therebetween. The outer member has one or more microholes drilled therethrough. The microholes are configured to allow air to pass through the microholes when contrast agent is injected into the outer member lumen (i.e., the inflation lumen). That is, air passes from the outer member lumen (more specifically, the inflation lumen) through the microholes to the exterior of the outer member. Furthermore, after the air has passed through, the microholes become clogged with contrast agent, thereby blocking the contrast agent from passing through the microholes.

[0023] An alternative embodiment of the balloon catheter also includes a flexible, elongated, tubular inner member having a proximal portion, a distal portion, and an inner member lumen extending therebetween. The inner member lumen communicates with the distal opening of the inner member. The inner member is at least partially disposed within the outer member lumen such that the outer surface of the inner member and the inner surface of the outer member together define an annular inflation lumen.

[0024] As in 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 circumferentially secured to the outer surface of the outer member such that the inner surface of the elastomeric member and the outer surface of the outer member define an inflatable balloon interior. The outer member also has one or more inflation passages through its wall that form a fluid path between the annular inflation lumen and the balloon interior. The inflation passages can be holes through the wall of the outer member that fluidly connect the annular inflation lumen and the balloon interior.

[0025] The micro-holes in this alternative embodiment preferably have a nominal diameter in the range of 5 μm to 8 μm. This configuration of micro-holes allows air to pass through the micro-holes in the outer member when contrast media is injected into the inflation lumen, after which the contrast media clogs the micro-holes, thereby occluding them. In another aspect, the density of micro-holes across the surface area of ​​the outer member is preferably 1 / 1 cm of the surface area of ​​the outer member. 2 Alternatively, the density of the micro-holes over the surface area of ​​the outer member is preferably 16 or less per square centimeter of the surface area of ​​the outer member. 2 No more than 20 micro-holes per 1cm surface area of ​​the outer member 2 No more than 10 micro-holes per 1cm surface area of ​​the outer member 2 The maximum density of micro-holes across the surface area of ​​the outer member helps ensure that the contrast agent occludes the micro-holes without allowing the contrast agent (or an excessive amount of the contrast agent) to leak out of the micro-holes.

[0026] As with the exemplary embodiment, the outer member of this alternative embodiment is preferably formed from materials such as polyurethane, PEBAX™, VESTAMID™, thermoplastic elastomers, and nylon, or other suitable materials capable of forming a flexible, elongated tubular outer member and of drilling microholes in the wall of the tubular outer member. The microholes may be drilled using any suitable means, such as laser drilling, mechanical drilling, or punching, and are preferably spaced along the outer member from the proximal to the distal portion of the outer member. For example, the microholes may be arranged in a spiral pattern along the outer member, or in a rectangular matrix, or other suitable pattern. The microholes preferably have a diameter of 1 μm or less. 2 to 210 μm 2 Similar to the nominal diameter, this nominal hole area allows air to be expelled through the micro-holes in the outer member when contrast media is injected into the inflation lumen, and the micro-holes are then clogged and blocked by the contrast media after the air has been expelled.

[0027] Another aspect of the disclosed invention relates to a method for purging air from an alternative embodiment of a balloon catheter, which is essentially the same as the method for purging air from the exemplary embodiment, except that the air is purged through micro-holes and the contrast agent seals the micro-holes instead of the micropores.

[0028]

[0028] Thus, the embodiments described herein provide an innovative balloon and method of use that allows for faster preparation and more effective purging of air from within the catheter than conventional balloon catheters. [Brief explanation of the drawings]

[0029]

[0029] The above, together with other and further embodiments and aspects of the disclosed invention, are described in more detail in the following detailed description, which should be read in light of the accompanying drawings, in which like reference numerals refer to like elements and descriptions of similar elements, wherever relevant, are applicable to all embodiments described. [Figure 1]

[0030] FIG. 1 is a side view of a balloon guide catheter according to a first embodiment of the disclosed invention. [Figure 2]

[0031] 2 is a side cross-sectional view of the balloon guide catheter of FIG. 1. FIG. [Figure 3]

[0032] FIG. 3 shows the balloon guide catheter of FIG. 1 being purged of air by injecting contrast medium into the inflation lumen, causing the air to pass through the micropores in the outer member. [Figure 4]

[0033] FIG. 4 shows the balloon guide catheter of FIG. 1 in a state where air is purged from the balloon member in an inflated state, and the air passes through the fine pores of the outer member. [Figure 5]

[0034] FIG. 5 shows the balloon guide catheter of FIG. 1 after the micropores have been filled with contrast medium and sealed, and the balloon member has been deflated. [Figure 6]

[0035] FIG. 6 shows the balloon guide catheter of FIG. 1 in a state where air has been purged from the inner member lumen by injecting saline into the inner member lumen. [Figure 7]

[0036] FIG. 7 is a side view of a balloon guide catheter according to a second embodiment of the disclosed invention. [Figure 8]

[0037] 8 is a side cross-sectional view of the balloon guide catheter of FIG. 7. FIG. [Figure 9]

[0038] FIG. 9 shows the balloon guide catheter of FIG. 7 being purged of air by injecting contrast medium into the inflation lumen, causing the air to pass through the micropores in the outer member. [Figure 10]

[0039] FIG. 10 shows the balloon guide catheter of FIG. 7 in a state where air is purged from the balloon member in an inflated state, and the air passes through the fine pores of the outer member. [Figure 11]

[0040] FIG. 11 shows the balloon guide catheter of FIG. 7 after the micropores have been filled and sealed with contrast medium and the balloon member has been deflated. [Figure 12]

[0041] FIG. 12 shows the balloon guide catheter of FIG. 7 in a state where air has been purged from the inner member lumen by injecting saline into the inner member lumen. [Figure 13]

[0042] 13A and 13B show a prior art balloon guide catheter such as that disclosed in US Pat. No. 6,638,245. DETAILED DESCRIPTION OF THE INVENTION

[0030]

[0043] 1-5 illustrate a first embodiment of a balloon guide catheter 100 constructed in accordance with a first embodiment of the disclosed invention. The balloon guide catheter 100 is generally configured to perform procedures within the vasculature, such as treating ischemic stroke, and / or to occlude or restrict blood flow for other therapeutic or diagnostic purposes. With particular regard to the disclosed invention, the balloon guide catheter 100 is specially configured to enable rapid preparation of the catheter for performing a surgical procedure, including providing rapid and effective purging of air from the respective inflation lumens 121 and balloon interior 146, as described in more detail below.

[0031]

[0044] The balloon guide catheter 100 comprises an elongate, flexible tubular body 102 having a proximal portion 104, a distal portion 106, and an inner working lumen 108 extending therebetween. 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 at a distal end 112 of the tubular body 102 and a proximal opening 114 defined by a hub 116 (described in more detail below) secured to the proximal portion 104 of the tubular body 102.

[0032]

[0045] Tubular body 102 includes an elongated, flexible, tubular outer member 118 having a proximal portion 124, a distal portion 126, and an outer member lumen 128 extending therebetween. Tubular body 102 also includes an elongated, tubular inner member 120 coaxially disposed within outer member lumen 128, the outer surface of inner member 120 and the inner surface of outer member 118 together defining an annular inflation lumen 121.

[0033]

[0046] The outer member 118 is formed of a microporous material such that the wall of the outer member 118 has pores 122 along the entire wall of the outer member 118, extending from the proximal portion 124 to the distal portion 126. The pores 122 are shown schematically in the figures because they are very small and distributed throughout the wall of the outer member 118. The microporous material has pores 122 configured to allow air to pass through the wall of the outer member 118 from the inflation lumen 121 to the exterior of the outer member 118, as shown by arrows 132 in FIGS. 3 and 4, when contrast agent 123 is injected into the outer member lumen 128 (more specifically, the inflation lumen 121). The configuration of the pores 122 in the microporous material also provides for the pores 122 to be blocked by the contrast agent 123 after air has been purged from the inflation lumen 121 and the balloon member 134. To purge unwanted air and provide a contrast agent clogging effect, the microporous material has pores 122 with a nominal pore size ranging from 0.1 μm to 2.0 μm. Another way to define the size of the microporous material is to have pores 122 with a nominal pore size ranging from 0.079 μm to 2.0 μm. 2 to 12.5 μm 2 The microporous material has a nominal pore area size in the range of 1 / 4 μm to 1 / 4 μm. Furthermore, the pore size of the pores 122 should not exceed 5 μm so that the pores are adequately blocked by the contrast agent after the air has been purged. Thus, the microporous material can be any suitable material with appropriately configured pores 122, including, but not limited to, TYVEK™ 3345, woven polymers, woven plastics, ePTFE, sintered plastics, sintered polymers, and GORETEX™ fabric membranes.

[0034]

[0047] Inner member 120 has a proximal portion 136, a distal portion 138, and an inner member lumen 140 extending therebetween. Each inner member 120 may be made of a polymeric tube or other suitable material and may have one or more reinforcing members (not shown) to provide reinforcement and / or rigidity. For example, coils, braids, ribbons, hypotubes, or other structural members may be disposed on the interior, exterior, and / or embedded within the wall of inner member 120. Such reinforcing members may 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 tubular body 102 under specific conditions.

[0035]

[0048] As described above, the balloon guide catheter 100 further includes a hub 116 secured to the proximal portion 104 of the tubular body 102 (i.e., to each of the inner and outer members 118 and 120). The hub 116 defines the proximal end opening 114 of the working lumen 108. The hub 116 includes a balloon inflation port 142 in fluid communication with the proximal end of the inflation lumen 121. The balloon inflation port 142 is configured to be connected to an inflation syringe 152 (not drawn to scale) (see FIGS. 3-5 ) or other source of pressurized inflation fluid for purging air from the balloon guide catheter 100 when preparing the catheter 100 for a surgical procedure. For example, the balloon inflation port 142 may have a female luer lock (not shown) for attaching the inflation syringe 152 or other fluid source having a mating male luer lock (not shown).

[0036]

[0049] Inflation lumen 121 extends from balloon inflation port 142 along the length of outer member 118 to an inflatable balloon interior 146 of balloon member 134 secured to outer member 118 (balloon interior 146 is best seen in FIG. 5 ). In the first illustrated embodiment, outer member 118 and inner member 120 are connected at a distal portion 126 of outer member 118, thereby forming the distal end of inflation lumen 121. Outer member 118 and inner member 120 may also be coupled to one another at one or more other locations (not shown) distal to hub 116. However, such coupling may not be completely circumferential to ensure that inflation lumen 121 is continuous from inflation port 142 to the balloon interior. Instead of an annular inflation lumen 121, inflation lumen 121 may be one or more channels, conduits, tubes, etc. formed in the wall of outer member 118. Alternatively, inflation lumen 121 may be one or more channels, conduits, tubes, etc. formed in or attached to the wall of outer member 118 .

[0037]

[0050] Hub 116 also has a working lumen port 143 in fluid communication with working lumen 108. Working lumen port 143 is configured to be connected to a source of purge fluid (e.g., saline) for purging air from working lumen 108. A source of fluid (e.g., saline) and / or a source of fluid medication can be connected to working lumen port 143 during a surgical procedure using balloon guide catheter 100 to flush a target site within the vasculature and / or deliver medication to the target site. Working lumen port 143 may have a female luer lock (not shown) for attachment of syringe 68 or other fluid sources with a mating male luer lock, such as syringe 155 (see FIG. 5 ).

[0038]

[0051] In the illustrated embodiment, the balloon member 134 is secured to the distal portion 126 of the outer member 118. However, the balloon member 134 may be secured to any suitable location on the outer member 118, including proximal to the distal portion 126 or at a central portion of the outer member 118, etc. The balloon member 134 is typically elastomeric but may also be non-elastomeric. The balloon member 134 may be transparent or translucent to allow visual inspection for air bubbles while purging air from the catheter 100, as described herein. The proximal and distal ends 148, 150 of the balloon member 134 are secured to and circumferentially secured around the outer surface of the outer member 118. In this manner, the inner surface of the balloon member 134 and the outer surface of the outer member 118 form an inflatable balloon interior 146. The outer member 118 and the inner member 120 may be coupled to one another at one or more locations (not shown) distal to the hub 19. However, such a connection is not perfectly circumferential to ensure that inflation lumen 121 is continuous from inflation port 142 to balloon interior 146 .

[0039]

[0052] The outer member 118 has one or more balloon inflation passages 156 through the wall of the outer member 118 within the balloon interior. The inflation passages 156 form a fluid path through the wall of the outer member between the inflation lumen 121 and the inflatable balloon interior 146. In the illustrated embodiment, the outer member 118 has four inflation passages 156, which are spaced longitudinally along the outer member 118 and circumferentially around the outer member 118 (in the illustrated embodiment, the inflation passages are spaced 180° apart around the circumference of the outer member 118). The balloon guide catheter 100 can have any suitable number of inflation passages 156 (e.g., 1 to 10).

[0040]

[0053] A method for purging air from a balloon guide catheter 100 to prepare ("prep") the catheter 100 for use in a medical procedure will now be described with reference to FIGS. 1-6. As shown in FIG. 2, the balloon guide catheter 100 is initially provided with no liquid within the catheter 100, and therefore air is present in the inflation lumen 121 and the working lumen 108. To prepare the balloon guide catheter 100 for use in a surgical procedure, air is purged from the catheter 100, including the inflation lumen 121 and the working lumen 108. This method is described by purging the inflation lumen 121 first, followed by purging the working lumen 108, although the method can be performed in the reverse order, or both can be purged simultaneously.

[0041]

[0054] 2 , a source 152 of contrast agent 123 is attached to the inflation port 142 to purge air from the inflation lumen 121. In the illustrated embodiment, the source of contrast agent 123 is an inflation syringe 152 filled with contrast agent 123. The syringe 152 may have a male luer lock that mates with a female luer lock on the inflation port 142. The syringe 152 is used to inject the contrast agent 123 into the inflation port 142, the inflation lumen 121, and the balloon member 134. Once the inflation lumen 121 is filled with contrast agent 123, air within the inflation port 142, the inflation lumen 121, and the balloon member 134 is forced out of the outer member 118 through the micropores 122, as indicated by arrow 132. Syringe 152 is used to maintain a positive pressure of contrast agent 123 within inflation port 142 , inflation lumen 121 , and balloon member 134 .

[0042]

[0055] 4, after the inflation port 142, inflation lumen 121, and balloon member 134 are filled with contrast agent 123, additional contrast agent 123 is injected into the inflation port 142 using syringe 152, and the balloon member 134 is inflated. Air continues to be purged through the micropores 122. Next, the balloon guide catheter 100 is manipulated to position the outer member 118 above the balloon member 134 (in other words, position the balloon member 134 below the remainder of the balloon guide catheter 100 proximal to the balloon member 134), causing any air remaining within the balloon member 134 to be forced into the outer member 118 and then out through the micropores 122 of the outer member 118. This placement of the balloon 134 under the outer member 118 can be done at any time while air is being purged from the inflation lumen 121 and balloon member 134, such as before initially injecting contrast agent into the inflation port 142, inflation lumen 121 and balloon 134, or just before inflating the balloon member 134.

[0043]

[0056] With the balloon member 134 inflated, the balloon member 134 is visually inspected for air (e.g., inspected for air bubbles) by the user preparing the balloon guide catheter 100. The user determines whether any air remains in the balloon member 134. The balloon member 134 may also be visually inspected for leaks. If the balloon member 134 is leaking, the balloon guide catheter 100 may be rejected and replaced. If the balloon member 134 is determined to be leak-free, the method of preparing the balloon guide catheter 100 may proceed.

[0044]

[0057] As air is forced through the pores 122 of the outer member 118, the contrast agent 123 clogs the pores 122. As shown in FIG. 5, the clogged pores 158 are indicated by lines 158. The clogged pores 158 are sealed by the contrast agent 123, preventing the contrast agent 123 from passing through the pores 122. As described herein, the pores 122 are configured to allow air to be purged from the inflation lumen 121 through the pores 122 and then clogged and sealed by the contrast agent 123. Also, as shown in FIG. 5, after air is purged from the inflation lumen 121 and the balloon member 134, the balloon member 134 is deflated, allowing insertion into the vasculature in an uninflated state. At this time, air has been purged from the inflation port 142, the inflation lumen 121, and the balloon member 134, and the balloon member 134 is deflated.

[0045]

[0058] As shown in FIG. 6 , preparing the balloon guide catheter 100 may further include purging air from the working lumen 108, including the inner member lumen 140 and the working lumen port 143 of the inner member 120. A purge syringe 155 filled with a source of flushing fluid, typically saline solution 160, is connected to the working lumen port 143. The syringe 155 may have a male luer lock that mates with the female luer lock of the working lumen port 143. The syringe 155 is used to inject the saline solution 160 into the working lumen 108, thereby purging air from the working lumen 108, including the inner member lumen 140 and the inflation port 142 of the inner member 120. A user may visually inspect the saline solution 160 exiting the distal opening 110 of the inner member lumen 140 for air bubbles; if no air bubbles are present, the working lumen 108 has been purged. In the prepared balloon guide catheter 100, the working lumen 108 remains filled with saline 160 (eg, surface tension holds the saline 160 within the working lumen 108).

[0046]

[0059] The balloon guide catheter 100 is now purged of air and is fully ready for use in a surgical procedure.

[0047]

[0060] Methods of using the prepared balloon guide catheter 100 in a medical procedure include various suitable uses of the balloon guide catheter 100. In one exemplary method, the balloon guide catheter 100 is inserted into a patient's vascular system. For example, the balloon guide catheter 100 may be inserted through an entry incision into an entry vessel, such as the inferior vena cava or femoral artery near the groin. The balloon guide catheter 100, including the inner member 120, outer member 118, and balloon member 134, is advanced through the vascular system until the balloon 134 is positioned at the treatment site. The contrast agent 123 allows a user to track the position of the balloon guide catheter 100 using appropriate medical imaging equipment, such as an X-ray machine or an MRI machine. The inner member 120 and outer member 118 can be advanced simultaneously or separately, at the same or different speeds. In the illustrated embodiment, the inner member 120 and outer member 118 are advanced simultaneously because they are connected at a distal portion 126 of the outer member 118.

[0048]

[0061] With the balloon member 134 positioned at the treatment site, the balloon member 134 is inflated by injecting contrast agent into the inflation lumen 121 using the inflation syringe 152 (or other suitable inflation fluid source), thereby increasing the pressure of the contrast agent 123 within the inflation lumen 121 and the balloon member 134. The balloon member 134 can be inflated within the blood vessel such that the balloon member 134 occludes the blood vessel. This isolates the blood vessel downstream of the balloon member 134 from blood flow. The syringe 152 may also be used to inject saline 160 into the treatment site to flush the treatment site. The syringe 152 of medication or other therapeutic substance can be used to inject medication or other substance into the treatment site. Alternatively or additionally, therapeutic procedures such as imaging, embolus removal, endovascular device implantation, etc. may be performed. For example, an imaging catheter may be inserted through working lumen 108, including inner member lumen 140, and advanced past the distal end of inner member 120 to image the blood vessel or surrounding tissue. When removing emboli, such as in the treatment of ischemic stroke, an embolus removal device may be inserted through inner member lumen 140 and advanced past distal end 112 of inner member 118 to grasp or otherwise capture the emboli and remove them from the blood vessel.

[0049]

[0062] 7-12, a second embodiment of a balloon guide catheter 200 is shown. The balloon guide catheter 200 is also specially configured to allow for rapid preparation of the catheter for performing a surgical procedure, including providing rapid and effective purging of air from the respective inflation lumens 121 and balloon interior 146, as described herein. The balloon guide catheter 200 is substantially similar to the balloon guide catheter 100, except that instead of the outer member 118 being formed from a microporous material, the outer member 118 has an impermeable wall with one or more micro-holes 202 extending therethrough.

[0050]

[0063] Accordingly, outer member 118 has one or more micro-holes 202 drilled through the wall of outer member 118. Micro-holes 202 are configured to allow air to pass through micro-holes 202 to the outside of outer member 118 when contrast agent 123 is injected into inflation lumen 121 using syringe 152. In other words, air passes from the outer member lumen (more specifically, the inflation lumen) through the micro-holes to the outside of the outer member. Furthermore, after allowing the air to pass through, the micro-holes become clogged with the contrast agent, thereby sealing off the contrast agent from passing through the micro-holes.

[0051]

[0064] The outer member 118 can be formed from any suitable material capable of forming a flexible, elongated tubular outer member and capable of drilling micro-holes in the wall of the tubular outer member, such as polyurethane, PEBAX™, VESTAMID™, thermoplastic elastomers, nylon, etc. The micro-holes 202 can be drilled using any suitable means, such as laser drilling, mechanical drilling, punching, etc.

[0052]

[0065] To balance the purging of unwanted air and the clogging effect of the contrast agent, the micro-holes 202 have a nominal size diameter in the range of 5 μm to 8 μm. This configuration of the micro-holes 202 allows air to exit through the micro-holes 202 in the outer member 118 when the contrast agent 123 is injected into the inflation lumen 121, and the contrast agent 123 then clogs the micro-holes 202, sealing them off to prevent the contrast agent 123 from leaking out. Alternatively or additionally, the size of the micro-holes 202 may be defined in terms of area. For example, the micro-holes 202 may be 1 μm or smaller. 2 to 210 μm 2 Similar to the nominal diameter, this nominal hole area allows air to escape through the micro-holes 202 in the outer member 118 when contrast media is injected into the inflation lumen 121, and allows contrast media 123 to fill and seal the micro-holes 202 after the air has been purged.

[0053]

[0066] The density of the micro-holes 202 over the surface area of ​​the outer member 118 may have a maximum density that ensures that the contrast agent 123 seals the micro-holes 202 without allowing the contrast agent 118 (or an excessive amount of the contrast agent) to leak out of the micro-holes 202. The density of the micro-holes 202 over the surface area of ​​the outer member 118 is preferably 1 cm per 1 cm of the surface area of ​​the outer member 118. 2 Alternatively, the density of the micro-holes 202 over the surface area of ​​the outer member 118 is 16 or less per cm of the surface area of ​​the outer member 118. 2 No more than 20 micro-holes per square centimeter or surface area of ​​the outer member 118 2 No more than 10 micro-holes per square centimeter or surface area of ​​the outer member 118 2 There are five or fewer micro-holes 202 per hole.

[0054]

[0067] The microperforations 202 are spaced along the outer member 118 from the proximal portion 124 to the distal portion 126 of the outer member 118. The microperforations 202 may be arranged in a pattern along the outer member 118, such as in one or more spiral patterns along the outer member 118, or in a rectangular matrix, or other suitable pattern.

[0055]

[0068] As shown in Figures 7-12, the method for preparing the balloon guide catheter 200 for use in a surgical procedure is substantially the same as the method for preparing the balloon guide catheter 100. As shown in Figure 8, the balloon guide catheter 200 is initially provided with no liquid within the catheter 200, and therefore air is present in the inflation lumen 121 and the working lumen 108. To prepare the balloon guide catheter 200 for use in a surgical procedure, it is necessary to purge the air from the catheter 200, including the inflation lumen 121 and the working lumen 108. As with the catheter 100, the method is illustrated by purging the inflation lumen 121 first, followed by purging the working lumen 108, although this method can be reversed or both purged simultaneously.

[0056]

[0069] 9 , a source 152 of contrast agent 123 is attached to inflation port 142 to purge air from inflation lumen 121. Again, the source of contrast agent 123 is inflation syringe 152 filled with contrast agent 123. Syringe 152 may have a male luer lock that mates with the female luer lock of inflation port 142. Syringe 152 is used to inject contrast agent 123 into inflation port 142, inflation lumen 121, and balloon member 134. Once inflation lumen 121 is filled with contrast agent 123, air within inflation port 142, inflation lumen 121, and balloon member 134 is forced out of outer member 118 through micro-holes 202, as indicated by arrow 132. Syringe 152 is used to maintain a positive pressure of contrast agent 123 within inflation port 142 , inflation lumen 121 , and balloon member 134 .

[0057]

[0070] 10 , after the inflation port 142, inflation lumen 121, and balloon member 134 are filled with contrast agent 123, additional contrast agent 123 is injected into the inflation port 142 using syringe 152, and the balloon member 134 is inflated. Air continues to be purged through the micro-holes 202. Next, the balloon guide catheter 200 is manipulated to position the outer member 118 above the balloon member 134 (in other words, position the balloon member 134 below the remaining portion of the balloon guide catheter 200 proximal to the balloon member 134), causing any air remaining within the balloon member 134 to migrate into the outer member 118 and then exit through the micro-holes 202 in the outer member 118. Placing the balloon 134 under the outer member 118 can be done at any time while purging air from the inflation lumen 121 and balloon member 134, such as before initially injecting contrast agent into the inflation port 142, inflation lumen 121 and balloon 134, or just before inflating the balloon member 134.

[0058]

[0071] With the balloon member 134 inflated, the balloon member 134 is visually inspected for air (e.g., inspected for air bubbles) by the user preparing the balloon guide catheter 200. The user determines whether any air remains in the balloon member 134. The balloon member 134 may also be visually inspected for leaks. If the balloon member 134 is leaking, the balloon guide catheter 200 may be rejected and replaced. If the balloon member 134 is determined to be leak-free, the method of preparing the balloon guide catheter 200 may proceed.

[0059]

[0072] As air is forced through the micro-holes 202 in the outer member 118, the contrast agent 123 clogs the micro-holes 202. As shown in FIG. 11 , the micro-holes 202 are sealed by plugs 204 formed by the contrast agent 123. The clogged micro-holes 202 are then sealed by the contrast agent 123 so that the contrast agent 123 cannot pass through the micro-holes 202. As described herein, the micro-holes 202 are configured so that air is purged from the inflation lumen 121 through the micro-holes 202 and then clogged and sealed by the contrast agent 123. Also, as shown in FIG. 11 , after air is purged from the inflation lumen 121 and the balloon member 134, the balloon member 134 is deflated, allowing insertion into the vasculature in an uninflated state. At this time, air has been purged from the inflation port 142, the inflation lumen 121, and the balloon member 134, and the balloon member 134 is deflated.

[0060]

[0073] Preparing the balloon guide catheter 200 may further include purging air from the working lumen 108, including the inner member lumen 140 and the working lumen port 143 of the inner member 120. A purge syringe 155 filled with saline 160 is connected to the working lumen port 143. The syringe 155 may have a male luer lock that mates with the female luer lock of the working lumen port 143. The syringe 155 is used to inject the saline 160 into the working lumen 108, thereby purging air from the working lumen 108, including the inner member lumen 140 and the inflation port 142 of the inner member 120. A user may visually inspect the saline 160 exiting the distal opening 110 of the inner member lumen 140 for air bubbles; if no air bubbles are present, air has been purged from the working lumen 108. In the prepared balloon guide catheter 200, the working lumen 108 remains filled with saline 160 (eg, surface tension holds the saline 160 within the working lumen 108).

[0061]

[0074] The balloon guide catheter 200 is now purged of air and is fully ready for use in a surgical procedure.

[0062]

[0075] The method of using this prepared balloon guide catheter 200 in a medical procedure is substantially the same as for the prepared balloon guide catheter 100, as described herein.

Claims

1. In the balloon catheter, an elongate tubular outer member having a proximal portion, a distal portion, and an outer member lumen extending therebetween, the outer member being formed from a microporous material such that a wall of the outer member has pores configured such that, when contrast agent is injected into the outer member lumen, the pores allow air to pass therethrough and are subsequently clogged by the contrast agent, thereby sealing the pores so that neither the contrast agent nor the air can pass therethrough; a balloon member having proximal and distal ends secured to an outer surface of the distal portion of the outer member and circumferentially secured thereto, the inner surface of the balloon member and the outer surface of the outer member together defining an inflatable balloon interior; an inflation lumen extending from an inflation port in the proximal portion of the tubular outer member to an interior of the inflatable balloon; The micropores extend from the proximal portion to the distal portion of the outer member, thereby allowing air to be purged from the outer member from the proximal portion to the distal portion of the outer member.

2. 2. The balloon catheter of claim 1, wherein the microporous material has micropores, the micropores having a nominal pore size in the range of 0.1 μm to 2 μm.

3. The balloon catheter of claim 1 , wherein the micropores have a nominal pore size of 5 μm or less.

4. The balloon catheter of claim 1 , wherein the microporous material is selected from the group consisting of woven polymers, woven plastics, ePTFE, sintered plastics, and sintered polymers.

5. 2. The balloon catheter of claim 1, wherein the microporous material has micropores, the micropores having a nominal pore area in the range of 0.079 μm to 12.5 μm.

6. The balloon catheter of claim 1 , wherein the inflation lumen comprises one or more channels, conduits, or tubes formed in or attached to the wall of the outer member.

7. In the balloon catheter, an elongate tubular outer member having a proximal portion, a distal portion, and an outer member lumen extending therebetween, the tubular outer member having a plurality of micro-holes drilled through a wall of the outer member, the micro-holes configured such that when contrast medium is injected into the outer member lumen, the micro-holes allow air to pass therethrough and subsequently become clogged with contrast medium, thereby sealing the micro-holes so that neither the contrast medium nor air can pass through the micro-holes; a balloon member having proximal and distal ends secured to an outer surface of the distal portion of the outer member and circumferentially secured thereto, the inner surface of the balloon member and the outer surface of the outer member together defining an inflatable balloon interior; an inflation lumen extending from an inflation port in the proximal portion of the tubular outer member to an interior of the inflatable balloon; The microholes are configured to extend from the proximal portion to the distal portion of the outer member, thereby allowing air to be purged from the outside of the outer member from the proximal portion to the distal portion of the outer member.

8. The balloon catheter of claim 7, wherein the microholes have a nominal diameter in the range of 5 μm to 8 μm.

9. The balloon catheter of claim 7 , wherein the outer member is formed from a material selected from the group consisting of polyurethane, thermoplastic elastomer, and nylon.

10. 8. The balloon catheter of claim 7, wherein the microholes have a nominal hole area in the range of 1 μm to 210 μm.

11. The balloon catheter of claim 7 , wherein the inflation lumen comprises one or more channels, conduits, or tubes formed in or attached to the wall of the outer member.

12. 10. A method for purging air from a balloon catheter according to claim 1, comprising: Injecting a contrast agent into the balloon member through the inflation lumen to purge air from the inflation lumen and the interior of the balloon through the small holes in the outer member; and maintaining a positive contrast pressure within the inflation lumen such that the contrast seals the pores in the outer member to prevent contrast and air from passing through the pores.

13. The contrast agent is injected into the inflation lumen at a pressure sufficient to inflate the balloon member, and the method further comprises:

13. The method of claim 12, including positioning the balloon catheter such that a proximal portion of the tubular outer member is above the balloon member such that air trapped within the balloon member moves into the outer member and out through micropores in the outer member.

14. inspecting the balloon member for air bubbles while the balloon member is inflated with contrast; determining whether all air bubbles within the balloon member have been purged from the balloon member; and after determining that all air bubbles have been purged from the balloon member, deflating the balloon member by reducing the pressure of the contrast agent within the inflation lumen and the interior of the balloon.

15. 8. A method for purging air from a balloon catheter according to claim 7, comprising: Injecting a contrast agent into the balloon member through the inflation lumen to purge air from the inflation lumen and the interior of the balloon through the small holes in the outer member; and maintaining a positive contrast pressure within the inflation lumen such that the contrast seals the micropores in the outer member to prevent contrast and air from passing through the micropores.

16. The contrast agent is injected into the annular inflation lumen at a pressure sufficient to inflate the balloon, and the method further comprises:

16. The method of claim 15, comprising positioning the balloon catheter such that a proximal portion of the tubular outer member is above the balloon member such that air trapped within the balloon migrates into the tubular outer member and exits the tubular member through micro-holes in the outer member.

17. inspecting the balloon for air bubbles while it is inflated with contrast; determining whether the balloon has been purged of all air bubbles therein; and after determining that the balloon has been purged of all air bubbles therein, deflating the balloon by reducing the pressure of the contrast agent within the inflation lumen and the interior of the balloon.

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