Embolization catheter for reflux free delivery of microspheres

Abstract

To provide an embolization microcatheter for delivery of embolization beads to a target area.SOLUTION: An embolization microcatheter includes: a proximal end and a distal end, the distal end terminating in an end opening 180 sized and shaped to allow delivery of a suspension of embolization beads; and a filter section 720 located between in proximity to the distal end opening, the filter section including many openings distributed circumferentially around a wall thereof, the filter section configured to allow outflow of the suspension fluid while preventing outflow of the embolization beads.SELECTED DRAWING: Figure 7

Description

Technical Field

[0001] The present disclosure generally relates to microcatheters for embolization, particularly for performing local embolization of the nutrient blood vessels of a target tissue (e.g., cancerous tissue) while preventing or minimizing off-target embolization. It relates to the field of microcatheters.

Background Art

[0002] Transarterial embolization, tumor embolization, and transcatheter arterial embolization (TAE) involve directly administering an embolizing substance through a microcatheter to a target tissue (e.g., a tumor), thereby blocking or reducing blood flow to cancer cells. It includes reducing blood flow to cancer cells.

[0003] Radioembolization combines embolization and radiotherapy and has been used particularly in the treatment of liver cancer, demonstrating an extension of the survival period of patients with tumors not suitable for surgery and an improvement in their quality of life. In the procedure, tiny glass or resin beads loaded with a radioisotope such as yttrium Y-90 are filled into the tumor nutrient blood vessels, thereby delivering a high dose of radiation to the tumor without affecting normal tissue. It delivers a high dose of radiation to the tumor without affecting normal tissue.

[0004] The main problem associated with embolization is "off-target embolization," which occurs when the embolizing substance flows into vessels other than the intended ones, thereby damaging healthy tissue and causing unpleasant and even dangerous consequences. Possible scenarios include gastric ulcers resulting from hepatic embolization, as well as the embolizing substance flowing retrograde along the microcatheter and reaching the gastric wall, possibly causing ischemia and ulcer formation. Other phenomena that are common, especially in advanced stages of liver cancer, include: is a nontargeted embolization through an arterioportal shunt.

[0005] Furthermore, in order to reach as close as possible to the tumor, the embolization catheter is large-diameter and and / or increasingly narrow catheters that are difficult, if not impossible, to access with rigid catheters In addition, the blood vessels in the body are often maneuverable. When activated, they tend to spasm, thereby preventing effective delivery of embolic material. Therefore, there is an absolute need for flexible, micro-sized catheters. Summary of the Invention [Means for solving the problem]

[0006] The present disclosure provides an embolization microscope for delivering micrometer-sized embolic particles to a target area. Regarding the cross-catheter, the microcatheter is a skeleton and a catheter in and / or out of the skeleton. The present invention relates to a method for delivering a suspension comprising: a polymer layer inserted into a surface; and a suspension comprising a suspending fluid and embolic particles. and a distal end opening of a size and shape that allows the distal end opening to reach the wall of the microcatheter. A predetermined distance from the proximal end opening, for example, 0.5 mm to 10 mm, 1 mm to 8 mm, Multiple side openings formed at 2mm to 5mm, 1mm to 5mm, 2mm to 8mm, or 2mm to 5mm and a filter having an aperture. Each possibility is a separate embodiment.

[0007] A major challenge with transcatheter embolization is the reflux of embolic material, which occurs when embolic material In addition to reaching (and damaging) non-target tissues, Adversely affects the delivery of substances to the target tissue, thus impairing the effectiveness of treatment and leading to a poor clinical outcome. This problem is particularly prominent in radioembolization therapy where microbeads, also called microspheres, with a diameter of one-third of the human hair are used. .

[0008] One aspect of the present disclosure provides a microcatheter configured to deliver a larger quantity of smaller beads in a low-viscosity liquid. The tip of the microcatheter disclosed in the present application includes a fine opening, which is optionally in the form of an axial slit, and a number (typically more than 100) that can generate a fluid barrier sufficient for the outflow of the fluid to prevent the backflow of particles, and each opening is small enough to block the passage of embolic particles. This ensures the delivery of an optimal therapeutic dose through the tip opening of the microcatheter, prevents peripheral embolization, and enables the delivery of embolic particles that are "essentially non-backflowing" at a much higher injection rate than achievable with a standard microcatheter. Therefore, improved treatment outcomes are provided. For example, in the delivery of small beads, such as but not limited to radioactive embolization beads, there are two main challenges: 1) fabricating the fine openings so that they do not close during manufacturing (e.g., during coating), and 2) forming a sufficient number of openings such that the outflow of the suspension fluid reliably prevents backflow (this is particularly difficult when small beads are delivered in a large quantity of low-viscosity liquid) without compromising the structural integrity of the microcatheter. Advantageously, the microcatheter disclosed in the present application addresses these challenges

[0009] ​​​​​​​​​​​​Overcoming both and meeting the requirements of utility (conformity, torque performance, pushability, and radiopacity) In addition, legal regulations (kink resistance and tensile strength) are satisfied, and this will be further described below as follows.

[0010] According to some embodiments, the filter may include one or more filter sections, for example, 2 , 3, 4, or 5 or more filter sections. Each possibility is a separate embodiment .

[0011] According to some embodiments, at least some of the openings of the filter (e.g., the most distal opening) may have a discrete pattern of openings strategically grounded on the filter so as to increase the filter openings .

[0012] According to some embodiments, at least some of the openings of the filter may have an inherent irregular shape . According to some embodiments, the shape of each opening is configured to have at least a first feature that corresponds to a second, mating feature of an adjacent opening, such that when the features are proximate to each other but not in contact, the contours of the features are substantially opposite and complementary. For example, a portion of the outer periphery of a first opening may have a first shape that forms a protruding feature that protrudes or extends outward, and a portion of the outer periphery of an adjacent opening may have a second shape that forms a recessed feature such as a cavity or groove, and the contour of the protruding feature is complementary to the contour of the recessed feature

[0013] . The protruding feature of the first opening is positioned in the vicinity of the recessed feature of the second opening but does not contact it.

[0014] ​In one example, the outer perimeter of the opening shape may include recesses and may also include protrusions.

[0015] The discrete pattern of the openings of the filter may include openings of the same shape. Optionally, this pattern may be configured to have individual openings each having one of two or more different shape options. According to some embodiments, the composite shape of the openings may be irregular.

[0016] In one aspect, the filter pattern includes two types of shapes for the openings. The first opening somewhat resembles the shape of a "dog bone", and the second shape somewhat resembles the shape of a "skewered sphere". Optionally, the shape of the dog bone may somewhat resemble the shape of an hourglass, a dumbbell, or a stretched letter " H". Optionally, the shape of the "skewered sphere" may instead be in the shape of an addition sign ("plus sign") or the letter "t".

[0017] The individual shapes of the openings are configured to obtain several advantages. First, it allows the openings to be closely stacked. In addition, unexpectedly, it has been found that due to the inherent shape of the openings, the beads flowing within the microcatheter "catch" on the openings. This will now cause the inner diameter of the filter section to decrease, and thus the proximal pressure to increase. Advantageously, as a result, the volume of the suspended fluid flowing out of the openings of the proximal filter section from the proximal filter section of the most distal filter section increases, and thus the beads delivered through the distal opening of the microcatheter become more concentrated.

[0018] According to some embodiments, the total opening area of the filter is at least twice, at least three times, or at least four times, at least five times, or at least ten times the area of the distal opening. Each possibility is a separate embodiment. According to some embodiments, this ensures that the suspension fluid flows out of the filter openings sufficiently, prevents backflow, and provides delivery of a high concentration of beads through the end openings.

[0019] To enable a physician to advance the microcatheter to its target location, most of the microcatheter (starting from its proximal end) must be relatively rigid. In contrast, the distal end of the microcatheter, including the filter, must be flexible so that it can twist and bend as needed while being guided through the complex vasculature without kinking and / or damaging the blood vessel wall.

[0020] Furthermore, regardless of its flexibility and the many openings formed in the filter, the microcatheter disclosed in the present application advantageously has a small radius without kinking and a tensile strength exceeding 5 N (Newtons), and thus meets the requirements of ISO 10555.

[0021] According to some aspects, an embolization microcatheter for delivering embolization beads to a target region is provided, the microcatheter including a proximal end and a distal end having an end opening, and a filter positioned proximally adjacent to the distal opening therebetween, the filter including at least 100 openings circumferentially distributed around its wall.

[0022] ​​​​​ According to some embodiments, the proximal end of the microcatheter is sized and shaped such that the suspension can flow through the microcatheter. According to some embodiments , the suspension includes a suspension fluid and plugging beads. According to some embodiments , the filter is configured to block the outflow of the plugging beads while allowing the outflow of the suspension fluid.

[0023] According to some embodiments, the side opening is a secondary side opening. According to some embodiments , the secondary side opening may be formed by a plurality of incisions formed in the polymer layer while leaving the skeleton intact (also referred to herein as "selective cutting"). According to some embodiments , the incisions may have a width of 5 to 15 micrometers or 5 to 10 micrometers and may include 40 to 70 long slits with a length of 5 mm to 15 mm or 5 mm to 10 mm.

[0024] According to some embodiments, at least 100 openings are dispersed in at least five discrete circular patterns. According to some embodiments , each circular pattern includes at least 10 openings.

[0025] According to some embodiments, the length of the filter is defined by the distance between the distal edge of the most distal circular ring and the proximal edge of the most proximal circular ring. According to some embodiments , the total area of the filter refers to the area of the portion of the microcatheter that extends between the distal edge of the most distal circular ring and the proximal edge of the most proximal circular ring.

[0026] According to some embodiments, the filter includes at least 10% opening area, i.e., ​​​​​​​The opening formed in the wall occupies at least 10% of the total filter area. In some embodiments according to, the total opening area of the filter is at least five times larger than the area of the distal end opening. Some embodiments according to, the size of the total opening area of the filter is at least 3.0 mm 2 is .

[0027] In some embodiments, at least 100 openings are such that the plugging beads downstream of the filter flow at a volumetric flow rate such that substantially all particles in the suspension are delivered through the distal end opening, and at the same time are sized and shaped to prevent their backflow.

[0028] In some embodiments, the tensile strength of the microcatheter for embolization is at least 5 N is

[0029] In some embodiments, at least 100 openings are axially dispersed.

[0030] In some embodiments, the microcatheter for embolization comprises a skeleton formed of a mesh wire or a coil wire, and a polymer layer inserted into and / or overlaid on the skeleton. In some embodiments, the thickness of the skeleton is 20 - 60 micrometers or 30 - 50 micrometers. As a non-limiting example, the thickness of the skeleton is about 37 micrometers. In some embodiments, the micro catheter further comprises a hydrophilic coating overlaid on the outer surface of the microcatheter . In some embodiments, at least 100 openings are formed through the outer surface and the hydrophilic coating . In some embodiments, the microcatheter is a microcatheter . In some embodiments, the microcatheter is a microcatheter It further includes an inner layer lined on the inner surface of the tube. According to some embodiments, the inner coating comprises or is made from polytetrafluoroethylene (PTFE). According to several embodiments, the filter does not include an inner layer.

[0031] According to some embodiments, the opening may be conical. According to some embodiments, the opening may have a cross-sectional area on the inner surface of the microcatheter that is smaller than the cross-sectional area on the outer surface of the microcatheter. According to some embodiments, each of at least 100 openings has a width, measured on the inner surface of the microcatheter, in the range of about 5 - 20 micrometers, 5 - 15 micrometers, or 5 - 10 micrometers. Each possibility is a separate embodiment. According to some embodiments, each of at least 100 openings has a length, measured on the inner surface of the microcatheter, in the range of about 30 - 60 micrometers. According to several embodiments, the length of each of the plurality of openings / cuts is, measured on the inner surface of the microcatheter, in the range of about 5 mm - 15 mm or 5 mm - 10 mm. Each possibility is a separate embodiment. According to some embodiments, at least 100 openings may be formed by making a plurality of cuts (also referred to herein as side openings) in the polymer layer while leaving the skeleton intact, whereby the number of resulting side openings (also referred to herein as "secondary side openings") is greater than the number of cuts made in the polymer layer. According to some embodiments, the number of resulting (secondary) side openings is at least twice the number of side openings

[0032] formed in the polymer layer. According to some embodiments, the number of resulting (secondary) side openings is at least twice the number of side openings formed in the polymer layer. According to some embodiments, the number of resulting (secondary) side openings is at least twice the number of side openings formed in the polymer layer. According to some embodiments, the number of resulting (secondary) side openings is at least twice the number of side openings formed in the polymer layer. According to some embodiments, the number of resulting (secondary) side openings is at least twice the number of side openings formed in the polymer layer. According to some embodiments, the number of resulting (secondary) side openings is at least twice the number of side openings formed in the polymer layer. According to some embodiments, the number of resulting (secondary) side The number of the face openings is at least four times the number of the side openings formed in the polymer layer. In some embodiments According to some embodiments, the number of the resulting (secondary) side openings is at least ten times the number of the side openings formed in the polymer layer According to some embodiments, the number of the resulting (secondary) side openings is at least fifty times the number of the side openings formed in the polymer layer According to some embodiments, the number of the resulting (secondary) side openings is at least one hundred times the number of the side openings formed in the polymer layer According to some embodiments, the number of the resulting (secondary) side openings is at least one hundred times the number of the side openings formed in the polymer layer According to some embodiments, the filter includes at least 200 openings. According to some embodiments

[0033] According to some embodiments, the filter includes at least 500 openings. According to some embodiments According to some embodiments, the filter includes at least 1,000 openings. According to some embodiments According to some embodiments, the filter includes at least 2,000 openings. According to some embodiments According to some embodiments, the filter includes at least 4,000 openings. According to some embodiments According to some embodiments, the filter includes at least 5,000 openings. According to some embodiments openings.

[0034] According to some embodiments, at least 100 openings are substantially in the shape of a bone or a skewer sphere.

[0035] According to some embodiments, the microcatheter includes at least two longitudinally spaced filter sections. According to some embodiments, the microcatheter includes a most distal first filter section including at least 500 openings, a central second filter section including at least 2 000 openings, and a most proximal third filter section including at least 1000 openings. According to some embodiments, the first filter section, the central second filter section, and the most proximal third filter section. According to some embodiments, the first The first, second, and third filter sections are spaced 1 to 5 mm apart. In some embodiments according to, the second filter section is longer than the first and third filter sections. According to some embodiments, the length of the opening of the third filter section is longer than the lengths of the openings of the first and second filter sections. According to some embodiments, the shape of the opening of the first filter section is different from the shapes of the openings of the second and third filter sections.

[0036] According to some aspects, an embolization microcatheter for delivering embolization beads to a target region is provided, the microcatheter having a proximal end and a distal end, the distal end including a tip opening, and a filter positioned between them and proximate to the proximal end opening, the filter including a plurality of openings circumferentially / annularly dispersed around its wall, each of the plurality of openings being substantially in the shape of a bone or a skewer sphere, and a filter.

[0037] According to some embodiments, the proximal end is sized and shaped to allow delivery of the suspension flowing through the microcatheter. According to some embodiments, the suspension includes a suspension fluid and embolization beads. According to some embodiments, the filter is configured to allow the suspension fluid to flow out but prevent the embolization beads from flowing out.

[0038] According to some embodiments, the filter includes at least 10% open area, i.e., the openings formed in the wall occupy at least 10% of the total area of the filter. According to some embodiments, the total open area of the filter is at least 5 times larger than the area of the distal end opening. According to some embodiments, the size of the total open area of the filter is at least 3.0 mm ​2 It is.

[0039] According to some embodiments, the microcatheter for embolization has a tensile strength of at least 5 N and has.

[0040] According to some embodiments, the plurality of openings are axially dispersed.

[0041] According to some embodiments, the microcatheter for embolization includes a skeleton formed of a mesh or coiled wire and a polymer layer inserted into and / or overlaid on the skeleton. According to some embodiments, the thickness of the skeleton is 20 to 60 micrometers or 30 to 50 micrometers. As a non-limiting example, the thickness of the skeleton is about 37 micrometers. According to some embodiments, the microcatheter further includes a hydrophilic coating overlaid on the outer surface of the microcatheter. According to some embodiments, at least 100 openings are formed through the surface and the hydrophilic coating. According to some embodiments, at least 100 openings are formed through the surface and the hydrophilic coating. formed.

[0042] According to some embodiments, the microcatheter further includes an inner liner that lines the inner surface of the microcatheter. According to some embodiments, the inner coating includes or is made of polytetrafluoroethylene (PTFE). According to some embodiments the filter does not include an inner liner. According to some embodiments, the portion of the microcatheter extending between the proximal end opening and the distal end opening of the filter does not include an inner liner. According to some embodiments, the portion of the microcatheter extending between the proximal end opening and the distal end opening of the filter does not include an inner liner. no.

[0043] According to some embodiments, the openings may be conical. According to some embodiments, The opening may have a cross-sectional area on the inner surface of the microcatheter that is smaller than the cross-sectional area on the outer surface of the microcatheter. According to some embodiments, the width of each of the plurality of openings, measured on the inner surface of the microcatheter, is in the range of about 5 to 20 micrometers, 5 to 15 micrometers, or 5 to 10 micrometers. Each possibility is a separate embodiment. According to some embodiments, the length of each of the plurality of openings, measured on the inner surface of the microcatheter, is in the range of about 30 to 60 micrometers. According to some embodiments, the length of each of the plurality of openings / cuts, measured on the inner surface of the microcatheter, is in the range of about 5 mm to 15 mm or 5 mm to 10 mm. Each possibility is a separate embodiment. According to some embodiments, the filter includes at least 200 openings. According to some embodiments, the filter includes at least 500 openings. According to some embodiments, the filter includes at least 1,000 openings. According to some embodiments, the microcatheter includes at least two longitudinally spaced filter sections. According to some embodiments, the microcatheter includes a most distal first filter section including at least 500 openings, a central second filter section including at least 2,000 openings, and a most proximal third filter section including at least 1,000 openings. According to some embodiments, the first, second, and third filter sections are spaced 1 to 5 mm apart. According to some embodiments, the second filter section is between the first and third filter sections. According to some embodiments, the opening may have a cross-sectional area on the inner surface of the microcatheter that is smaller than the cross-sectional area on the outer surface of the microcatheter. According to some embodiments, the width of each of the plurality of openings, measured on the inner surface of the microcatheter, is in the range of about 5 to 20 micrometers, 5 to 15 micrometers, or 5 to 10 micrometers. Each possibility is a separate embodiment. According to some embodiments, the length of each of the plurality of openings, measured on the inner surface of the microcatheter, is in the range of about 30 to 60 micrometers. According to some embodiments, the length of each of the plurality of openings / cuts, measured on the inner surface of the microcatheter, is in the range of about 5 mm to 15 mm or 5 mm to 10 mm. Each possibility is a separate embodiment. According to some embodiments, the filter includes at least 200 openings. According to some embodiments, the filter includes at least 500 openings. According to some embodiments, the filter includes at least 1,000 openings.

[0044] According to some embodiments, the microcatheter includes at least two longitudinally spaced filter sections. According to some embodiments, the microcatheter includes a most distal first filter section including at least 500 openings, a central second filter section including at least 2,000 openings, and a most proximal third filter section including at least 1,000 openings. According to some embodiments, the first, second, and third filter sections are spaced 1 to 5 mm apart. According to some embodiments, the second filter section is between the first and third filter sections. According to some embodiments, the opening may have a cross-sectional area on the inner surface of the microcatheter that is smaller than the cross-sectional area on the outer surface of the microcatheter. According to some embodiments, the width of each of the plurality of openings, measured on the inner surface of the microcatheter, is in the range of about 5 to 20 micrometers, 5 to 15 micrometers, or 5 to 10 micrometers. Each possibility is a separate embodiment.

[0045] According to some embodiments, the length of each of the plurality of openings, measured on the inner surface of the microcatheter, is in the range of about 30 to 60 micrometers. According to some embodiments, the length of each of the plurality of openings / cuts, measured on the inner surface of the microcatheter, is in the range of about 5 mm to 15 mm or 5 mm to 10 mm. Each possibility is a separate embodiment. According to some embodiments, the filter includes at least 200 openings. According to some embodiments, the filter includes at least 500 openings. According to some embodiments, the filter includes at least 1,000 openings. According to some embodiments, the microcatheter includes at least two longitudinally spaced filter sections. According to some embodiments, the microcatheter includes a most distal first filter section including at least 500 openings, a central second filter section including at least 2,000 openings, and a most proximal third filter section including at least 1,000 openings. According to some embodiments, the first, second, and third filter sections are spaced 1 to 5 mm apart. According to some embodiments, the second filter section is between the first and third filter sections. According to some embodiments, the opening may have a cross-sectional area on the inner surface of the microcatheter that is smaller than the cross-sectional area on the outer surface of the microcatheter. According to some embodiments, the width of each of the plurality of openings, measured on the inner surface of the microcatheter, is in the range of about 5 to 20 micrometers, 5 to 15 micrometers, or 5 to 10 micrometers. Each possibility is a separate embodiment.

[0046] According to some embodiments, the length of each of the plurality of openings, measured on the inner surface of the microcatheter, is in the range of about 30 to 60 micrometers. According to some embodiments, the length of each of the plurality of openings / cuts, measured on the inner surface of the microcatheter, is in the range of about 5 mm to 15 mm or 5 mm to 10 mm. Each possibility is a separate embodiment. According to some embodiments, the filter includes at least 200 openings. According to some embodiments, the filter includes at least 500 openings. According to some embodiments, the filter includes at least 1,000 openings. longer than the three filter sections. According to some embodiments, the length of the opening of the third filter section is longer than the lengths of the openings of the first and second filter sections. According to some embodiments, the shape of the opening of the first filter section is different from the shapes of the openings of the second and third filter sections.

[0047] According to some aspects, an embolization microcatheter for delivering embolization beads to a target region is provided, the microcatheter having a proximal end and a distal end, the distal end including an end opening sized and shaped to permit delivery of a suspension flowing through the microcatheter, and a filter positioned adjacent to the distal end opening therebetween, the filter including a plurality of circumferentially dispersed openings around its wall, each of the plurality of openings having a width in the range of about 5 to 20 micrometers as measured on the inner surface of the microcatheter.

[0048] According to some embodiments, the proximal end is sized and shaped to permit delivery of a suspension flowing through the microcatheter. According to some embodiments, the suspension includes a suspending fluid and embolization beads. According to some embodiments, the filter is configured to permit outflow of the suspending fluid while preventing outflow of the embolization beads.

[0049] According to some embodiments, the filter has an opening area of at least 10%, i.e., the openings formed in the wall occupy at least 10% of the total area of the filter. According to some embodiments, the total opening area of the filter is at least 5 times larger than the area of the distal end opening. According to some embodiments, the size of the total opening area of the filter is at least 3.0 mm 2 .

[0050] According to some embodiments, the tensile strength of the microcatheter for embolization is at least 5 N and is.

[0051] According to some embodiments, the plurality of openings are axially dispersed.

[0052] According to some embodiments, the microcatheter for embolization includes a skeleton formed of a mesh or coiled wire and a polymer layer inserted into and / or overlaid on the skeleton. According to some embodiments, the thickness of the skeleton is 20 to 60 micrometers or 30 to 50 micrometers. As a non-limiting example, the thickness of the skeleton can be about 37 micrometers. According to some embodiments, the microcatheter further includes a hydrophilic coating overlaid on the outer surface of the microcatheter, and at least 100 openings are formed through the hydrophilic coating. According to some embodiments, the microcatheter further includes an inner liner that lines the inner surface of the microcatheter. According to some embodiments, the inner liner includes or is made of polytetra fluoroethylene (PTFE). According to some embodiments, the filter does not include an inner liner. and at least 100 openings are formed through the hydrophilic coating.

[0053] According to some embodiments, the microcatheter further includes an inner liner that lines the inner surface of the microcatheter. According to some embodiments, the inner liner includes or is made of polytetrafluoroethylene (PTFE). According to some embodiments, the filter does not include an inner liner. fluoroethylene (PTFE). According to some embodiments, the filter does not include an inner liner. According to some embodiments, the filter does not include an inner liner.

[0054] According to some embodiments, the filter further includes at least 200 openings. According to some embodiments, the filter includes at least 500 openings. According to some embodiments, the filter includes at least 1,000 openings. According to some embodiments, the filter includes at least 1,000 openings.

[0055] According to some embodiments, the microcatheter has at least two longitudinally spaced filter sections. According to some embodiments, the microcatheter includes a most distal first filter section having at least 500 openings, a central second filter section having at least 2,000 openings, and a most proximal third filter section having at least 1,000 openings. According to some embodiments, the first , second, and third filter sections are spaced 1-5 mm apart. According to some embodiments , the second filter section is longer than the first and third filter sections. According to some embodiments, the length of the openings in the third section is longer than the lengths of the openings in the first and second filter sections. According to some embodiments, the shape of the openings in the first filter section is different from the shapes of the openings in the second and third filter sections.

[0056] According to some aspects, an embolization microcatheter for delivering embolic beads to a target region is provided, the microcatheter having a proximal end and a distal end including a distal end opening sized and shaped to permit delivery of a suspension flowing through the microcatheter , and a filter positioned proximally adjacent to the distal end opening, the filter including a plurality of circumferentially dispersed openings around its wall, the total opening area of the filter being at least five times greater than the area of the distal end opening.

[0057] According to some embodiments, the proximal end is sized and shaped to permit delivery of a suspension flowing through the microcatheter. According to some embodiments, the suspension is a suspension fluid and embolic beads - including beads. According to some embodiments, the filter is configured to prevent the outflow of the plugging beads while allowing the outflow of the suspension fluid , and is configured to prevent the outflow of the plugging beads.

[0058] According to some embodiments, the total opening area of the filter is at least 10 times larger than the area of the distal end opening. According to some embodiments, the size of the total opening area of the filter is at least 3.0 mm 2 is.

[0059] According to some embodiments, the tensile strength of the microcatheter for embolization is at least 5 N is.

[0060] According to some embodiments, the plurality of openings are axial openings.

[0061] According to some embodiments, the microcatheter for embolization includes a skeleton formed of a mesh or coiled wire , and a polymer layer inserted into and / or overlaid on the skeleton. According to some embodiments, the thickness of the skeleton is 20-60 microns rometers or 30-50 micrometers. As a non-limiting example, the thickness of the skeleton can be about 37 micrometers. According to some embodiments, the microcatheter further includes a hydrophilic coating overlaid on the outer surface of the microcatheter, and at least 100 openings are formed through the outer surface and the hydrophilic coating. According to some embodiments, the microcatheter further includes an inner liner that lines the inner surface of the microcatheter. According to some embodiments, the inner liner includes or is made from polytetra

[0062] fluoroethylene (PTFE). According to some embodiments ​​According to [it], the filter does not include an inner liner.

[0063] According to some embodiments, the filter includes at least 200 openings. According to some embodiments, the filter includes at least 500 openings. According to some embodiments, the filter includes at least 1,000 openings.

[0064] According to some embodiments, the microcatheter includes at least two filter sections spaced apart in the longitudinal direction.

[0065] According to some aspects, there is provided an embolization microcatheter for delivering embolization beads to a target region, the microcatheter having a proximal end and a distal end, the distal end including an end opening sized and shaped to permit delivery of a suspension flowing through the microcatheter, and a filter positioned adjacent to the distal end opening, the filter including a plurality of openings formed circumferentially around

[0066] its wall and dispersed irregularly. According to some embodiments, the proximal end is sized and shaped to permit delivery of a suspension flowing through the microcatheter. According to some embodiments, the suspension includes a suspension fluid and embolization beads. According to some

[0067] embodiments, it is configured to block outflow of the embolization beads while permitting outflow of the suspension fluid. According to some embodiments, the total opening area of the filter is at least three At least 10 times larger than the area of the mouth. According to some embodiments, the total opening area of the filter is at least 3.0 mm 2 .

[0068] According to some embodiments, the tensile strength of the microcatheter for embolization is at least 5 N .

[0069] According to some embodiments, the plurality of openings are axial openings

[0070] According to some embodiments, the microcatheter for embolization includes a skeleton formed of a mesh or coiled wire yarn, and a polymer layer inserted into and / or overlaid on the skeleton . According to some embodiments, the thickness of the skeleton is 20 to 60 microns rometers or 30 to 50 micrometers. As a non-limiting example, the thickness of the skeleton can be about 37 micrometers. According to some embodiments, the microcatheter further includes a hydrophilic coating overlaid on the outer surface of the microcatheter, and at least 100 openings are formed through the outer surface and the hydrophilic coating

[0071] According to some embodiments, the microcatheter further includes an inner liner lined on the inner surface of the microcatheter . According to some embodiments, the inner liner includes or is made from polytetra fluoroethylene (PTFE). According to some embodiments , the filter does not include an inner liner

[0072] According to some embodiments, the filter includes at least 200 openings. According to some embodiments , the filter includes at least 500 openings. According to some embodiments The filter includes at least 1,000 apertures.

[0073] According to some embodiments, the microcatheter includes at least two filter sections spaced apart in the longitudinal direction.

[0074] Certain embodiments of the present disclosure may include some, all, or none of the above-described features. One or more technical advantages will be readily apparent to those skilled in the art from the drawings, description, and claims included herein. Further, while certain features are listed above, various embodiments may include all, some, or none of the listed features. In addition to the exemplary aspects and embodiments described above, additional aspects and embodiments will be further elaborated in the drawings and the following detailed description. While certain features are listed above, various embodiments may include all, some, or none of the listed features.

[0075] In addition to the exemplary aspects and embodiments described above, additional aspects and embodiments will be further elaborated in the drawings and the following detailed description.

[0076] Examples of embodiments will be described below with reference to the drawings attached to this application. The same structure, element, or component in multiple drawings is generally labeled with the same number throughout all the drawings in which it appears. Alternatively, an element or component in multiple drawings may be labeled with different numbers in different drawings in which it appears. The dimensions of components and features in the figures are selected for purposes of presentation convenience and clarity and are not necessarily to scale. The drawings are listed below.

Brief Description of the Drawings

[0077]

Figure 1A

Figure 1B

Figure 2

Figure 3A

Figure 3B

Figure 3C

Figure 3D

Figure 4A

Figure 4B

Figure 4C

Figure 5A

Figure 5B

Figure 5C

Figure 6

Figure 7

Figure 8A

Figure 8B

Figure 9

Figure 10

Figure 11

Figure 12

DETAILED DESCRIPTION OF THE INVENTION

[0078] In the following description, various aspects of the present disclosure are described. For the purpose of explanation, specific configurations and details are shown to enable a full understanding of the various aspects of the present disclosure. However it will be apparent to those skilled in the art that the present disclosure may be practiced without the specific details presented herein. Further, well-known features are not shown to avoid obscuring the present disclosure. It may be omitted or simplified to avoid ambiguity.

[0079] Referring now to FIGS. 1A and 1B, there is schematically shown an enlarged view of a microcatheter 100 for embolization and its distal end 112 according to some aspects of the present disclosure. The microcatheter for embolization includes a long body 110 having an outer diameter of 1 mm or less. The long body 110 includes a guiding section 120, a filter 130, and a delivery section 140, and has an end opening 1 80 at its end. According to some embodiments, the polymer layer forming the wall of the filter 130 and / or the delivery section 140 may be more flexible than the polymer layer forming the wall of the guiding section 120.

[0080] The guiding section 120 is configured to guide the microcatheter. As used herein, the term "guiding section" may refer to the portion of the microcatheter that is necessary to push and / or maneuver the microcatheter into the target area within the vascular structure. The guiding section 120 extends over a majority of the length of the long body 110. The guiding section 120 may be relatively rigid compared to the relatively flexible filter 130 and delivery section 140 of the microcatheter. According to some embodiments, the guiding section 120 allows the microcatheter 1 00 to be efficiently delivered to a target area (not shown), for example, by using a pusher mechanism (not shown) of a handle. The microcatheter 100 further includes a hub 102 molded or otherwise attached to the proximal end of the guiding section 120. The hub is configured to provide access to the lumen of the microcatheter 300 for various functions, such as the injection of fluids or drugs or the introduction of a guidewire. The hub The hub 102 includes a strain relief 104, which is preferably mechanically coupled to the hub 102. . The strain relief 104 may be made of a polymeric material and, as shown in the figure, its distal end may be tapered. The strain relief 104 may be configured to provide structural support to the guide section 120 to prevent its kinking.

[0081] As used herein, the term "filter" refers to a portion of a microcatheter that is configured to block the passage of beads / particles (i.e., , embolic particles) flowing therethrough while allowing lateral outflow of the suspended fluid. The filter is formed at a predetermined distance from the distal outlet (also referred to herein as the "distal end opening"), e.g., from 0.5 mm to 10 mm, 1 mm to 8 mm, 1 mm to 5 mm, 2 mm to 8 mm, or 2 mm to 5 mm from the distal outlet. Each possibility represents a separate embodiment. According to some embodiments, 20-75% of the fluid injected into the catheter exits through the filter. The filter 13 0 is depicted herein as including two filter regions / sections, although other configurations of the filter sections are also possible, e.g., as shown in FIGS. 3A-3D (including three filter sections) and FIGS. 6, 7, and 9 (including one filter section).

[0082] According to some embodiments, the total area of the filter refers to the area of the portion of the microcatheter that extends between the distal edge of the most distal annular ring and the proximal edge of the most proximal annular ring.

[0083] According to some embodiments, the filter 130 is in communication with the delivery section 140 and the guide section 120. It may be integrally formed. According to some embodiments, the portion of the filter including a plurality of openings has a length of 0.3 mm to 20 mm, for example, 1 mm to 10 mm, 1 mm to 5 mm, 1.5 mm to 5 mm, 2 mm to 5 mm, or any other suitable length therebetween and extends therethrough. Each possibility is a separate embodiment.

[0084] As used herein, the term "delivery section" refers to the distal end of the microcatheter that extends between the distal end of the filter 130 and the distal end opening 180. The delivery section 140 is configured to restrict and / or impede the flow of the suspension and / or change the flow to reduce the horizontal velocity of the particles along the longitudinal axis of the microcatheter.

[0085] According to some embodiments, the delivery section 140 may have a tapered inner surface. According to some embodiments, the delivery section may have a tapered inner surface and an outer surface. According to some embodiments, the delivery section may have a substantially untapered inner surface therethrough. Each possibility is a separate embodiment. According to some embodiments, the length of the delivery section is in the range of 2 to 15 mm, 3 to 12 m, 5 to 10 mm, 5 to 8 mm, or any other suitable length within the range of 2 to 20 mm. Each possibility is a separate embodiment. According to some embodiments, the length of the delivery section may be approximately 7 mm. As used herein the term "substantially" with respect to the length of the delivery section may refer to + / −10%, or + / −5%, or + / −2%. Each possibility is a separate embodiment.

[0086] As used herein, the term "distal end opening" refers to the distal end of the microcatheter​​ Refers to the open end leading to the lumen. According to some embodiments, the distal end opening defines the terminus of the micro catheter at its distal end. According to some embodiments, the inner diameter of the distal end opening may be substantially equal to the inner diameter of the lumen of the micro catheter. According to some embodiments, the inner diameter of the distal end opening may be smaller than the inner diameter of the lumen of the micro catheter, whereby the lumen tapers towards its end.

[0087] According to some embodiments, the filter 130 of the microcatheter includes three sections which may be integrally formed as one piece. In such a configuration, advantageously, the microcatheter is easier to manufacture, typically forming a vulnerable connection, and therefore, it can be ensured that the attachment and / or assembly that can cause disassembly / removal of the microcatheter is unnecessary. However, these sections can also be formed as separate elements that are assembled together to form the microcatheter.

[0088] According to some embodiments, the guiding section 120 of the microcatheter may be made of or include a thermoplastic elastomer such as, for example, thermoplastic polyurethane (e.g., Pel lethan™ TPU from The Lubrizol Corporation, OH, USA) or polyether block amide (e.g., Pebax™ TPE from Arkema Group, Colombes, France), nylon, polyimide, silicone, or any combination thereof, but is not limited to these. Each possibility is a separate embodiment.

[0089] According to some embodiments, the walls of the filter and / or delivery section of the microcatheter may be made of a thermoplastic elastomer, such as, for example, thermoplastic polyurethane (e.g., Pelletha n™ TPU) from The Lubrizol Corporation, OH, USA or polyether block amide (e.g., Pebax (TM) TPE) from Arkema Group, Colombes, France, nylon, polyimide, silicone, or any combination thereof, but not limited thereto. Each possibility is a separate embodiment.

[0090] Next, referring to FIG. 2, which schematically shows a cutaway perspective view of the distal end of a microcatheter 200 according to some embodiments. The microcatheter 200 includes an outer polymer layer 222 in which a skeleton 220 is embedded. According to some embodiments, the skeleton 220 may be braided. The microcatheter 200 further includes an inner liner 230. According to some embodiments, the inner liner 230 may comprise or be made from polytetrafluoro ethylene (PTFE).

[0091] According to some embodiments, as shown in FIG. 2, the inner liner 230 extends only along a portion of the microcatheter 200, for example, only along the proximal side of the filter of the microcatheter 200 (here shown with a longitudinal cut 225 formed in the polymer layer but not in the skeleton 220). Advantageously, without providing the liner 230, it would be necessary to penetrate the inner liner 230 when forming the cut 225 of the filter ​​​​​​If it is lost or deposited after its formation, it may no longer be necessary to remove the inner liner material from the incision 225. It may no longer be necessary.

[0092] According to some embodiments, the microcatheter 200 may include a first marker 240 at the proximal end of the filter and a second marker 250 at the distal end of the filter. According to some embodiments, the first marker 240 may be a polymer marker. According to some embodiments the second marker 250 may be a metal marker. According to some embodiments, by dispersing the markers in this way, on the one hand, it is ensured that the microcatheter 200 can withstand a force of at least 5 N, and on the other hand, it is prevented that the meshwork comes loose. As an advantage, due to the difference in radiopacity, the markers may serve to indicate the proximal / distal ends of the filter when moving through a curved vascular structure.

[0093] Next, referring to FIGS. 3A-3D and FIGS. 4A-4C, the deployment views and enlarged views (FIGS. 3B-3D) of a microcatheter 300 including a filter having three filter sections 310a-310c according to some embodiments are schematically shown. Each of the filter sections 3 10a-310c includes a plurality of side openings 312, 314, and 316 respectively disposed in annular rings 322, 324, and 326. The microcatheter 300 is here shown as a microcatheter with a French size of 2.7 mm, but one of ordinary skill in the art will appreciate that the microcatheter may be of other suitable sizes, such as a French size of 2. 4 mm or a French size of 2.8 mm, and is not limited thereto. As can be seen, the microcatheter 300 is small (15 to 60 micrometers) ) suitable for the controlled delivery of embolic beads (also called "microspheres"). 1 In one example, the small embolic beads ranged in size from 15 to 60 micrometers. The microcatheter 300 is not limited to radioembolic beads, but may also be used with larger beads. According to some embodiments, the microcatheter 300 may be utilized to deliver: Arteriovenous malformations, uterine fibroids (UFE), hepatocellular carcinoma, etc. Hypervascular tumors, including but not limited to prostatic arteries (PAEs), embolization of prostatic arteries and symptomatic benign prostatic hyperplasia (BPH) The present invention is suitable for use in the treatment of rostatic hyperplasia.

[0094] The filter section 310a is the most porous of the filter sections 310a to 310c. It is on the proximal side and is approximately L1 mm (L1 is in the range of 10 mm to 30 mm) from the distal end opening 380. In one example, the filter section 310 is positioned proximally. a is positioned approximately 17 mm proximal to the distal end opening 380. The openings included in a (collectively referred to as 312) are also referred to as slits in this specification. The number of such individuals is at least 200, or at least 500, or at least 1,000, Or at least 2,000, or more. For example, FIG. 3D shows a filter cell. Section 310a is shown as having approximately 2,592 apertures (36 rows by 72 columns). Those skilled in the art will appreciate that the number of apertures is not limited to this value. According to an embodiment, the total length L2 of the filter section 310a is 3 mm to 8 mm, and this is good. For example, the length of the filter section 310a may be about 5 mm.

[0095] As can be best seen in FIG. 4A, the opening 312 is relatively long (longer than the openings 314 and 316 of the filter sections 310b and 310c respectively), and its length, measured on the inner surface of the micro catheter, may be, for example, 60 micrometers to 100 micrometers. For example, FIG. 3A shows an opening 312 with a length of 85 micrometers measured on the inner surface of the microcatheter. The opening 312 is narrow, and its width may be 5 micrometers to 15 micrometers. For example, as shown in FIG. 4B, the width of the opening 312 may be 8 micrometers. Each annular ring of the opening is separated from its adjacent ring of the opening by approximately 40 micrometers to 80 micrometers. For example, in FIG. 3D, each annular ring 322 is separated from its adjacent annular ring by approximately 54 micrometers . The size and shape of the opening 312 prevent even the smallest embolization beads from flowing out of the opening 312 even if the microcatheter 300 is bent, while on the other hand, allowing the outflow of the suspension fluid in which the embolization beads are suspended to be relatively unobstructed. According to some embodiments, the slit 312 may be separated from its adjacent slit within the same annular link by approximately 4 to 10 degrees. According to one embodiment, the slit 312 may be separated from its adjacent slit within the same ring by approximately 6 degrees.

[0096] The filter section 310b is positioned between the filter sections 310a and 310c. ​​The central filter section is placed in the distal end opening 380, and L3 (approximately 3 mm to 10 mm) proximally. According to one embodiment, the filter section 310b is located approximately 6 mm proximal to the distal end opening 380. The number of openings included in the section 310b is at least 200, or at least 500, or less. At least 1,000, or at least 2,000, or at least 5,000, or For example, FIG. 3C shows a central filter section 310b having a thickness of about 5.47 mm. 2 apertures (76 rows by 72 columns - collectively referred to as 314). Those skilled in the art will appreciate that the number of openings 314 is not limited to this value. As best seen in FIG. 3B, the opening 314 is relatively short (filter section 310 The approximate length of aperture 314 is , measured on the inner surface of the microcatheter, 30 micrometers to 50 micrometers For example, the length of the opening 314 shown in FIG. 4B is in the range of Measured in plane, it may be approximately 45 micrometers. The opening 314 may be narrow, e.g. Its width, measured on the inner surface of the microcatheter, is between 5 and 15 micrometers. For example, the width of the opening 314 shown in FIG. 3C is 8 micrometers. Each annular ring of apertures is spaced 40 micrometers to 8 micrometers from its adjacent ring of apertures. For example, as shown in FIG. 3C, annular rings 32 Each of the apertures 314 may be spaced apart by approximately 60 micrometers. The shape of the microcatheter 300 is such that even the smallest embolic beads may be bent. is prevented from flowing out through the opening 314, while on the other hand, the suspension in which the plug beads are suspended Although the fluid passing through the opening 312 has a higher degree of flow restriction than the outflow of the fluid through the opening 312, it is possible to ensure this. The fact that the opening 314 is smaller in size than the opening 312 corresponds to the fact that the flow rate downstream of the filter section 310a due to the outflow of the fluid through the opening 312 is less than that.

[0097] According to some embodiments, the total length L4 of the filter section 310b may be 5 mm to 15 m m or 5 mm to 12 mm. For example, the length of the filter section 310b may be about 8 mm.

[0098] According to some embodiments, the slits 314 may be spaced apart from their adjacent slits in the same annular ring by approximately 4 to 10 degrees According to one embodiment, the slit 31 4 may be spaced apart from its adjacent slit in the same annular ring by approximately 6 degrees.

[0099] The filter section 310c is the most distal one among the filter sections 310a to 310c and is positioned at L5 (about 1 to 3 mm) from the distal end opening 380 of the microcatheter 300. According to one embodiment, the filter section 310c is positioned proximally about 2 mm from the distal end opening 380. The number of openings included in the filter section 310c may be at least 100, or at least 200, or at least 5 00, or at least 1,000 openings, or more. For example, FIG. 3B shows that the openings are circumferentially distributed around the wall of the microcatheter 300 and are collectively referred to as 316 and are positioned proximally about 2 mm from the distal end opening 380. The number of openings included in the filter section 310c may be at least 100, or at least 200, or at least 500, or at least 1,000 openings, or more. For example, FIG. 3B shows that the openings are circumferentially distributed around the wall of the microcatheter 300 and are collectively referred to as 316 and may be at least 100, or at least 200, or at least 500, or at least 1,000 openings, or more. For example, FIG. 3B shows that the openings are circumferentially distributed around the wall of the microcatheter 300 and are collectively referred to as 316 and are circumferentially distributed around the wall of the microcatheter 300 and are collectively referred to as 316 and are circumferentially distributed around the wall of the microcatheter 300 and are collectively referred to as 316 shows a filter section 310c having approximately 1,200 apertures (20 rows × 60). One skilled in the art will understand that the number of apertures 316 is not limited to this value. The apertures 316 are configured to prevent the outflow of the plugging beads while allowing the outflow of the suspension fluid in which the plugging beads are suspended.

[0100] According to some embodiments, the overall length L6 of the filter section 310c may be 1 mm to 5 mm or 1.5 mm to 2.5 mm. For example, the length of the filter section 310b may be approximately 2 mm.

[0101] Each annular ring of the apertures is spaced 40 micrometers to 80 micrometers from its adjacent ring of the apertures. For example, as shown in FIG. 3B, each of the annular rings 326 may be spaced approximately 50 micrometers apart.

[0102] According to some embodiments, the slits 316 may be separated by approximately 3 to 10 degrees from its adjacent slit in the same column. According to one embodiment, the slits 316 may be separated by approximately 5 degrees from its adjacent slit in the same column.

[0103] According to some embodiments, the apertures 316 may be of an irregular shape. For example, as shown in FIG. 4C the aperture 116 may be either in the shape of a "dog bone" 316a or a "skewered sphere" 316, which is best seen in FIG. 4C. Due to the irregular shape of the apertures 316, the beads flowing through the microcatheter 300 are caught by the apertures 316 which in turn reduces the inner diameter of the filter section 310c and thus the proximal pressure is ​​​​rises. As an advantage, as a result, the volume of the suspension fluid injected through the openings 312 and 314 of the filter sections 310a and 310b proximal to the filter section 310a increases, and the concentration of the beads delivered through the end opening 380 becomes higher. As shown in FIG. 3B, the openings 316 are preferably arranged such that openings having different but complementary shapes are adjacent to each opening. This arrangement ensures an optimal stacking of the openings and allows many openings to be formed in each circumferential row, regardless of their irregular shape. Other "irregularly shaped openings" such as the opening 505 shown in FIG. 5A may also be envisioned. According to some embodiments, the opening includes a protruding feature that protrudes or extends outward, and a portion of the outer periphery of an adjacent opening may include a recessed feature, such as a cavity or groove, having a second shape, and the contour of the protruding feature is complementary to the contour of the recessed feature. For example, the protruding feature of the first opening 505a is positioned adjacent to, but not in contact with, the recessed feature of the second opening 505b. It is also to be understood that the distribution of the openings may be irregular, as shown, for example, by the distribution of the openings 510 in FIG. 5B. In other aspects, the pattern of the openings on the filter includes at least two types of shapes, as shown in FIG. 5C. In this example, the shape 512 includes two concave features, which are complementary to the convex features of the shape 514. Those skilled in the art will appreciate that other shapes, including irregular shapes, may also be utilized for the shape of the openings. This arrangement ensures an optimal stacking of the openings and allows many openings to be formed in each circumferential row, regardless of their irregular shape. regardless of their irregular shape. .

[0104] Other "irregularly shaped openings" such as the opening 505 shown in FIG. 5A may also be envisioned. According to some embodiments, the opening includes a protruding feature that protrudes or extends outward, and a portion of the outer periphery of an adjacent opening may include a recessed feature, such as a cavity or groove, having a second shape, and the contour of the protruding feature is complementary to the contour of the recessed feature. For example, the protruding feature of the first opening 505a is positioned adjacent to, but not in contact with, the recessed feature of the second opening 505b. .

[0105] It is also to be understood that the distribution of the openings may be irregular, as shown by the distribution of the openings 510 in FIG. 5B.

[0106] In other aspects, the pattern of the openings on the filter includes at least two types of shapes, as shown in FIG. 5C. In this example, the shape 512 includes two concave features, which are complementary to the convex features of the shape 514. Those skilled in the art will appreciate that other shapes, including irregular shapes, may also be utilized for the shape of the openings.

[0107] According to some embodiments, the cross-sectional area at the inner surface of the microcatheters of the openings 505, 510, 512, and 512 is smaller than the cross-sectional area at the outer surface of the microcatheter. That's okay.

[0108] According to some embodiments, at least 5% of each of the filter sections has an opening area. Optionally, the opening area may be at least 10%, or at least 15%, or at least 20% of each of the filter sections 310a-310c. Each possibility is a separate embodiment. According to some embodiments, the total opening area of each of the filter sections 310a- 310c is at least twice, at least three times, at least five times, at least eight times, or at least ten times the area of the distal end opening 380. This ensures that the suspension fluid from the openings 312, 314, and 316 prevents backflow from the end opening 380 and flows out sufficiently to provide delivery of a high concentration of beads therefrom. Each possibility is a separate embodiment. According to some embodiments, the size of the total opening area of the filter sections 310 a-310c is at least 1.5 mm a-310c is at least 2.0 mm 2 2 2 2 2 That's okay. Each possibility is a separate embodiment.

[0109] According to some embodiments, the opening area of each opening of the filter section 310a is about 0. 0004-0.001 mm 2 or about 0.0006-0.0007 mm 2 For example, the opening area of each opening of the filter section 310a (which is most clearly shown in FIG. 4A) is 8 μm * to 85 μm, which is 0.00068 mm 2 in size. Those skilled in the art will understand that the opening area of each opening of the filter section 310a is not limited to this specific value.

[0110] According to some embodiments, the total opening area of the filter section 310a may be about 0.7 to 2 .5 mm 2 , about 1.0 to 2.0 mm 2 , or about 1.5 to 1.8 mm 2 . For example, the total opening area of the filter section 310a is 2592 (the number of openings in the filter section 310a) × 0.00068 mm (the opening area of each opening of the filter section 310a 2 ), which is 1.76 mm . Those skilled in the art will understand that the total opening area of the filter section 310a is not limited to this specific value. 2

[0111] According to some embodiments, the opening area of each opening of the filter section 310b may be about 0 .0001 to 0.0005 mm 2 or about 0.0002 to 0.0004 mm 2 . For example, the opening area of each opening of the filter section 310b (which is most clearly shown in FIG. 4B) is 8 μm × 45 μm, which is 0.00036 mm . Those skilled in the art 2 will understand that the total opening area of each opening of the filter section 310b is not limited to this specific value.

[0112] According to some embodiments, the total opening area of the filter section 310b is about 1.5 to 3 .0 mm 2 , about 1.5 to 2.5 mm 2 , or about 1.7 to 2.0 mm 2 and may be. For example , the total opening area of the filter section 310b is 5472 (the number of openings of the filter section 310b ) × 0.00036 mm 2 (the opening area of each opening of the filter section 310b ), which is 1.97 mm 2 . Those skilled in the art will understand that the total opening area of the filter section 310b is not limited to this specific value.

[0113] According to some embodiments, the opening area of each of the "dog bone" shaped openings 3 16a of the filter section 310c is about 0.0003 to 0.0008 mm 2 or about 0.0005 to 0.0007 mm 2 and may be. For example, the opening area of each of the "dog bone" shaped openings of the filter section 310c (most clearly shown in FIG. 4C) is 0.00059 mm 2 . Those skilled in the art will understand that the opening area of each of the "dog bone" shaped openings of the filter section 310c is not limited to this specific value.

[0114] According to some embodiments, the opening area of each of the "skewered sphere" shaped openings 316b of the filter section 310c is about 0.0003 to 0.0008 mm or about 0.00 2 05 to 0.0007 mm and may be. For example, the opening area of each of the "skewered 2 sphere" shaped openings of the filter section 310c (most clearly shown in FIG. 4C) is 0.00 and the like. 050 mm 2 That is, those skilled in the art will understand that the opening area of each opening of the "dog bone" shape of the filter section 310c is not limited to this specific value.

[0115] According to some embodiments, the total opening area of the openings 316a of the "dog bone" shape of the filter section 310c is about 0.1 - 1.0 mm 2 about 0.2 - 0.7 mm 2 or about 0. 3 - 0.5 mm 2 may be. For example, the total opening area of the openings 316a of the "dog bone" shape of the filter section is 600 (the number of openings of the "dog bone" shape of the filter section 310c) × 0.00059 mm (the opening area of each opening of the filter section 310c), which is 2 0.35 mm That is, those skilled in the art will understand that the total opening area of the openings 316a of the "dog bone" shape of the filter section 310c is not limited to this specific value. 2 will be.

[0116] According to some embodiments, the total opening area of the openings 316b of the "skewered sphere" shape of the filter section 310c is about 0.1 - 1.0 mm 2 about 0.2 - 0.7 mm 2 or about 0.3 - 0.5 mm 2 may be. For example, the total opening area of the openings 316b of the "dog bone" shape of the filter section is 600 (the number of openings of the "skewered sphere" shape of the filter section 310c) × 0.00050 mm (the opening area of each opening of the filter section 310c), which is 2 0.30 mm That is, those skilled in the art will understand that the total opening area of the openings 316b of the "skewered sphere" shape of the filter section 2 310c is not limited to this specific value. The total opening area of the opening 316b in the shape of a "skewered sphere" of 310c is not limited to this specific value. It will be understood that it is not.

[0117] According to some embodiments, the tensile strength of the microcatheter 300 is at least at least 3 N, at least 4 N, or at least 5 N. Each possibility is a separate embodiment is.

[0118] According to some embodiments, the openings 312, 314, and / or 316 are axially dispersed are.

[0119] According to some embodiments, the wall of the microcatheter 300 includes a skeleton (not shown) formed of a mesh or coiled wire and a polymer layer (not shown) inserted into and / or overlaid on the skeleton. According to some embodiments the openings 312, 314, and / or 316 are formed such that the mesh / coil remains intact (not severed). As an advantage, this ensures the structural integrity of the microcatheter 300 (tensile strength of at least 5 N, kink resistance, flexibility and torque performance). and torque performance). is ensured.

[0120] According to some embodiments, the polymer layer may include or be made from a thermoplastic elastomer, which may be, for example, a thermoplastic polyurethane (e.g., Pellethane (trademark) TPU from The Lubrizo l Corporation, OH, USA) or a polyether block amide (e.g., Pebax (trademark) TPE from Arkema Group, Colombes , France), nylon, polyimide, silicone, or , France), nylon, polyimide, silicone, or is any combination of these, but is not limited to these. Each possibility is a separate embodiment form.

[0121] According to some embodiments, the thickness of the skeleton is 20 to 60 micrometers or 30 to 50 micrometers. By way of non-limiting example, the thickness of the skeleton may be about 37 mic rometers. According to some embodiments, the skeleton may be a tungsten mesh work. According to some embodiments, the meshwork / coil may be made of nickel titanium (nitino ol). According to some embodiments, the meshwork / coil may be made of, or include, stainless st eel, cobalt chromium, platinum iridium, nylon, or any combination of these Each possibility is a separate embodiment. Advantageously, such a relatively thick wire allows the polymer of the wall of the microcatheter to be (e.g., using a femtosecond laser equipped with a galvanoscan head and a supplementary optical system to be selectively cut while minimizing the impact / damage to the meshwork at the same time can be).

[0122] According to some embodiments, the wall of the microcatheter 300 further includes a hydrophilic liner (not shown) that is overlaid on the polymer layer of the microcatheter 3 00. According to some embodiments the filter sections 310a, 310b, and / or 310c may not include a liner This can help maintain the integrity of the meshwork during laser cutting and increase the kink resistance of the microcatheter, which can be advantageous Alternatively, the openings 312 314, and / or 316 are formed through the polymer layer and the hydrophilic liner

[0123] ​​ According to some embodiments, the polymer layer of the microcatheter 300 may be made of different polymer materials along its length. According to some embodiments, among the microcatheters 3 00, the Shore hardness of the polymer layer of the proximal portion of the filter section 310a is higher than that of the proximal portion of the microcatheter 3 00 that is closer to the filter section 310a. According to some embodiments, the Shore hardness of the polymer layer of the proximal portion of the filter section 310c of the microcatheter 300 is higher than that of the distal portion of the microcatheter 300 that is closer to the filter section 310c. According to some embodiments, the microcatheter 300 further includes an inner layer (also referred to herein as an inner liner) that lines the inner surface of the wall of the microcatheter 300. According to some embodiments, the layer may include or be made from polytetrafluoroethylene (PTFE). According to some embodiments, the openings 312, 314, and / or

[0124] 316 are formed through the inner layer. According to some embodiments, the inner layer extends only along the proximal portion of the filter section 310a of the microcatheter 300, so that when forming the openings, it is not necessary to penetrate the inner layer, or when deposited, after the openings 312, 3 14, and / or 316 are formed, it is not necessary to remove the material of the inner layer from the openings. According to some embodiments, the microcatheter 300 is shown here as having three filter sections, but any number (e.g., 1, 2, 4, 5, or more) of filter sections may be contemplated and are therefore included within the scope of the present disclosure. Each possibility represents a separate embodiment. 316 are formed through the inner layer. According to some embodiments, the inner layer extends only along the proximal portion of the filter section 310a of the microcatheter 300, so that when forming the openings, it is not necessary to penetrate the inner layer, or when deposited, after the openings 312, 3 316 are formed, it is not necessary to remove the material of the inner layer from the openings. The microcatheter 300 is shown here as having three filter sections, but any number (e.g., 1, 2, 4, 5, or more) of filter sections may be contemplated and are therefore included within the scope of the present disclosure. Each possibility represents a separate embodiment. 14, and / or 316 are formed, it is not necessary to remove the material of the inner layer from the openings. 14, and / or 316 are formed, it is not necessary to remove the material of the inner layer from the openings. There is no need to remove the inner layer material from the openings.

[0125] Although the microcatheter 300 is shown here as having three filter sections, any number (e.g., 1, 2, 4, 5, or more) of filter sections may be contemplated and are therefore included within the scope of the present disclosure. Each possibility represents a separate embodiment. Although the microcatheter 300 is shown here as having three filter sections, any number (e.g., 1, 2, 4, 5, or more) of filter sections may be contemplated and are therefore included within the scope of the present disclosure. Each possibility represents a separate embodiment. of filter sections may be contemplated and are therefore included within the scope of the present disclosure. Each possibility represents a separate embodiment. is in a state. According to some embodiments, the filter sections are spaced apart by 2 to 5 mm well, where the filter section 310a is about 3 mm spaced from the filter section 310b, and the filter section 310b is about 2 mm spaced from the filter section 310c is.

[0126] According to some embodiments, the length of the filter section may be 4 to 10 mm. According to some embodiments, the filter sections may be of the same length or different lengths . Here, the length of the filter section 310a is about 5 mm, and the filter section 3 10b has a length of about 8 mm, and the filter section 310c has a length of about 2 mm.

[0127] According to some embodiments, the microcatheter 300 may further include one or more radiopaque transient markers (not shown). According to some embodiments, the micro catheter 300 may include a proximal marker positioned at least proximal to the filter section 310c and a distal marker positioned near the distal side of the filter section 310c of the filter section 310c . According to some embodiments, the proximal marker may be made of a polymeric material configured to retain the tensile strength of the microcatheter 300 . According to some embodiments, the distal marker may be a metal marker well, which prevents the skeleton mesh / coil from unraveling. Advantageously, due to the difference in radiopacity, the marker may serve as an indication of the proximal / distal ends of the filter section when moving through a curved vascular structure.

[0128] The microcatheter 300 further includes a hub (not shown) molded at or otherwise attached to the proximal end of the microcatheter 300. The hub is configured to provide access to the lumen of the microcatheter 300 for various functions, such as injection of fluid or drug or introduction of a guide wire. Referring now to FIG. 6, this schematically shows an alternative configuration of a filter 600 of an embolization microcatheter such as the microcatheter 200 of FIG. 2. According to some embodiments, the filter 600 preferably includes one filter section 620, which includes a plurality of circumferential / annular rings (collectively referred to as 616), such as 50-200 or 75-125 rings (e.g., 116 rings), each ring including a plurality of side openings, collectively referred to as 625, which are, for example, 40-100, or 40-80, or 50-70 slits (e.g., 60 side openings as shown herein). According to some embodiments, the filter 620 may have a length L7, which ranges from 15 mm to 25 mm, such as about 19 mm. For injection of fluid or drug or introduction of a guide wire, etc. To enable access to the lumen of the microcatheter 300.

[0129] Referring now to FIG. 6, this schematically shows an alternative configuration of a filter 600 of an embolization microcatheter such as the microcatheter 200 of FIG. 2. According to some embodiments, the filter 600 preferably includes one filter section 620, which includes a plurality of circumferential / annular rings (collectively referred to as 616), such as 50-200 or 75-125 rings (e.g., 116 rings), each ring including a plurality of side openings, collectively referred to as 625, which are, for example, 40-100, or 40-80, or 50-70 slits (e.g., 60 side openings as shown herein). According to some embodiments, the filter 620 may have a length L7, which ranges from 15 mm to 25 mm, such as about 19 mm. According to some embodiments, the filter 600 preferably includes one filter section 620, which includes a plurality of circumferential / annular rings (collectively referred to as 616), such as 50-200 or 75-125 rings (e.g., 116 rings), each ring including a plurality of side openings, collectively referred to as 625, which are, for example, 40-100, or 40-80, or 50-70 slits (e.g., 60 side openings as shown herein). According to some embodiments, the filter 620 may have a length L7, which ranges from 15 mm to 25 mm, such as about 19 mm. Preferably includes one filter section 620, which includes a plurality of circumferential / annular rings (collectively referred to as 616), such as 50-200 or 75-125 rings (e.g., 116 rings), each ring including a plurality of side openings, collectively referred to as 625, which are, for example, 40-100, or 40-80, or 50-70 slits (e.g., 60 side openings as shown herein). According to some embodiments, the filter 620 may have a length L7, which ranges from 15 mm to 25 mm, such as about 19 mm. Including a plurality of circumferential / annular rings (collectively referred to as 616), such as 50-200 or 75-125 rings (e.g., 116 rings), each ring including a plurality of side openings, collectively referred to as 625, which are, for example, 40-100, or 40-80, or 50-70 slits (e.g., 60 side openings as shown herein). According to some embodiments, the filter 620 may have a length L7, which ranges from 15 mm to 25 mm, such as about 19 mm. Collectively referred to as 625, which are, for example, 40-100, or 40-80, or 50-70 slits (e.g., 60 side openings as shown herein). According to some embodiments, the filter 620 may have a length L7, which ranges from 15 mm to 25 mm, such as about 19 mm. For example, 40-100, or 40-80, or 50-70 slits (e.g., 60 side openings as shown herein). According to some embodiments, the filter 620 may have a length L7, which ranges from 15 mm to 25 mm, such as about 19 mm. According to some embodiments, the filter 620 may have a length L7, which ranges from 15 mm to 25 mm, such as about 19 mm. Range, such as about 19 mm.

[0130] According to some embodiments, the side openings 625 may be in the form of slits. According to some embodiments, the width of each of the side openings 625, measured on the inner surface of the microcatheter, may be 5 micrometers to 15 micrometers or 5 micrometers to 10 micrometers (e.g., 8 micrometers). According to some embodiments, the length of the side openings 625, measured on the inner surface of the microcatheter, is 70-150 micrometers. According to some embodiments, the side openings 625 may be in the form of slits. According to some embodiments, the width of each of the side openings 625, measured on the inner surface of the microcatheter, may be 5 micrometers to 15 micrometers or 5 micrometers to 10 micrometers (e.g., 8 micrometers). According to some embodiments, the length of the side openings 625, measured on the inner surface of the microcatheter, is 70-150 micrometers. Measured on the inner surface of the microcatheter, may be 5 micrometers to 15 micrometers or 5 micrometers to 10 micrometers (e.g., 8 micrometers). According to some embodiments, the length of the side openings 625, measured on the inner surface of the microcatheter, is 70-150 micrometers. For example, 8 micrometers). According to some embodiments, the length of the side openings 625, measured on the inner surface of the microcatheter, is 70-150 micrometers. According to some embodiments, the length of the side openings 625, measured on the inner surface of the microcatheter, is 70-150 micrometers. It may be toru or 80 to 100 micrometers (for example, 95 micrometers). According to some embodiments, the outermost one of the rings of the filter may be positioned L8 mm from the distal end opening, where L8 ranges from about 1 to 10 mm or 2 to 8 mm, and for example is about 3 mm, but is not limited thereto. According to some embodiments, each ring may be spaced apart from an adjacent ring by a length L9, where L9 ranges from 50 to 100 micrometers or 60 to 80 micrometers, for example 70 micrometers.

[0131] According to some embodiments, the side opening 625 may be formed by a selective cut (for example, a selective laser cut), that is, without cutting the wire forming the skeleton 220. According to some embodiments, the polymer layer positioned between the wires of the mesh skeleton 220 is penetrated during slit formation. Advantageously, by selective cutting of the polymer layer (leaving the mesh skeleton 220 substantially intact), at least some of the side openings may be subdivided into two or more secondary side openings that are separated by the mesh and not by the polymer outer layer.

[0132] Referring now to FIG. 7, this schematically shows another alternative structure of the filter 700 of the embolization microcatheter such as the microcatheter 200 of FIG. 2. According to some embodiments, the filter 700 may include one filter section 720 which includes a plurality of side openings, collectively referred to as side openings 725. According to some embodiments the openings may be in the form of axial slits. According to some embodiments the openings may be in the form of axial slits. According to some embodiments ​​​, the slits may be distributed annularly (i.e., circumferentially distributed around the wall of the microcatheter). According to some embodiments, the filter section 720 includes 40 - 100 or 40 - 80 or 50 - 70 slits (e.g., 60 side openings). According to some embodiments, the width of each of the side openings 725, measured on the inner surface of the microcatheter, may be 5 micrometers - 15 micrometers or 5 micrometers - 10 micrometers (e.g., 8 micrometers). According to some embodiments, the length of each of the side openings 725, measured on the inner surface of the microcatheter, may be 6 mm - 15 mm (e.g., 7 mm). According to some embodiments, the filter section 720 includes 40 - 100 or 40 - 80 or 50 - 70 slits (e.g., 60 side openings). According to some embodiments, the width of each of the side openings 725, measured on the inner surface of the microcatheter, may be 5 micrometers - 15 micrometers or 5 micrometers - 10 micrometers (e.g., 8 micrometers). According to some embodiments, the width of each of the side openings 725, measured on the inner surface of the microcatheter, may be 5 micrometers - 15 micrometers or 5 micrometers - 10 micrometers (e.g., 8 micrometers). According to some embodiments, the length of each of the side openings 725, measured on the inner surface of the microcatheter, may be 6 mm - 15 mm (e.g., 7 mm). According to some embodiments, the length of each of the side openings 725, measured on the inner surface of the microcatheter, may be 6 mm - 15 mm (e.g., 7 mm). According to some embodiments, the side openings 725 may be in the form of slits. According to some embodiments, the width of each of the side openings 725, measured on the inner surface of the microcatheter, may be 5 micrometers - 15 micrometers or 5 micrometers - 10 micrometers (e.g., 8 micrometers). According to some embodiments, the length of each of the side openings 725, measured on the inner surface of the microcatheter, may be 0.75 mm - 25 mm, 1 - 20 mm, or 0.75 - 10 mm (e.g., 19 mm).

[0133] According to some embodiments, the side openings 725 may be in the form of slits. According to some embodiments, the width of each of the side openings 725, measured on the inner surface of the microcatheter, may be 5 micrometers - 15 micrometers or 5 micrometers - 10 micrometers (e.g., 8 micrometers). According to some embodiments, the width of each of the side openings 725, measured on the inner surface of the microcatheter, may be 5 micrometers - 15 micrometers or 5 micrometers - 10 micrometers (e.g., 8 micrometers). According to some embodiments, the length of each of the side openings 725, measured on the inner surface of the microcatheter, may be 0.75 mm - 25 mm, 1 - 20 mm, or 0.75 - 10 mm (e.g., 19 mm). According to some embodiments, the length of each of the side openings 725, measured on the inner surface of the microcatheter, may be 0.75 mm - 25 mm, 1 - 20 mm, or 0.75 - 10 mm (e.g., 19 mm). According to some embodiments, the filter 700 may be positioned at a position that is about 1 - 10 mm or 2 - 8 mm, for example, about 3 mm, but not limited thereto, from the distal end opening. According to some embodiments, the filter 700 may be positioned at a position that is about 1 - 10 mm or 2 - 8 mm, for example, about 3 mm, but not limited thereto, from the distal end opening. According to some embodiments, the side openings 725 may be formed by selective cutting (e.g., selective laser cutting), i.e., without cutting the wire forming the skeleton 220. According to some embodiments, the side openings 725 may be formed by selective cutting (e.g., selective laser cutting), i.e., without cutting the wire forming the skeleton 220.

[0134] According to some embodiments, the side openings 725 may be formed by selective cutting (e.g., selective laser cutting), i.e., without cutting the wire forming the skeleton 220. According to some embodiments, the side openings 725 may be formed by selective cutting (e.g., selective laser cutting), i.e., without cutting the wire forming the skeleton 220. Yes. According to some embodiments, the polymer layer positioned between the wires of the mesh skeleton 220 is penetrated during slit formation. Advantageously, by selectively cutting the polymer layer (leaving the mesh 200 substantially intact), at least some of the side openings are subdivided into a plurality of secondary side openings 727 that are separated by the skeleton 220 but not by the polymer outer layer. For example, as shown in FIG. 7B, by forming approximately 60 side openings 725 in the polymer layer, more than 2500, and even more than 3000 secondary side openings may be obtained. According to some embodiments, the number of resulting secondary side openings is greater than the number of side openings formed in the polymer layer. According to some embodiments, the number of resulting secondary side openings is at least twice the number of side openings formed in the polymer layer. According to some embodiments, the number of resulting secondary side openings is at least four times the number of side openings formed in the polymer layer. As shown in FIGS. 8A and 8B, which show the front and side details of a filter 800 that may be substantially similar to any of the filters (e.g., filters 600, 700, and 900) disclosed herein. As shown in FIG. 8A, the side openings 825 may be substantially in the shape of a trapeze, whereby the cross-section of each side opening on the inner surface of the filter is smaller than the cross-section of the opening on the outer surface of the filter. According to some embodiments, the side openings may be formed by selective cutting (e.g., selective laser cutting), i.e., without cutting the wires forming the mesh 890, as shown in FIG. 8B. According to some embodiments, the laser

[0135] According to some embodiments, the number of resulting secondary side openings is greater than the number of side openings formed in the polymer layer. According to some embodiments, the number of resulting secondary side openings is at least twice the number of side openings formed in the polymer layer. According to some embodiments, the number of resulting secondary side openings is at least four times the number of side openings formed in the polymer layer. According to some embodiments, the number of resulting secondary side openings is greater than the number of side openings formed in the polymer layer. According to some embodiments, the number of resulting secondary side openings is at least twice the number of side openings formed in the polymer layer. According to some embodiments, the number of resulting secondary side openings is at least four times the number of side openings formed in the polymer layer. According to some embodiments, the number of resulting secondary side openings is at least twice the number of side openings formed in the polymer layer. According to some embodiments, the number of resulting secondary side openings is at least four times the number of side openings formed in the polymer layer. According to some embodiments, the number of resulting secondary side openings is at least twice the number of side openings formed in the polymer layer. According to some embodiments, the number of resulting secondary side openings is at least four times the number of side openings formed in the polymer layer.

[0136] A filter 800 that may be substantially similar to any of the filters (e.g., filters 600, 700, and 900) disclosed in this application is shown in FIGS. 8A and 8B, showing the front and side details. As shown in FIG. 8A, the side openings 825 may be substantially in the shape of a trapeze, whereby the cross-section of each side opening on the inner surface of the filter is smaller than the cross-section of the opening on the outer surface of the filter. According to some embodiments, the side openings may be formed by selective cutting (e.g., selective laser cutting), i.e., without cutting the wires forming the mesh 890, as shown in FIG. 8B. According to some embodiments, the laser ​​​​​​​​​​​Among them, the part under the wire remains intact. According to some embodiments, the poly mer layer and the inner liner positioned between the wires of the mesh 890 are both penetrated during slitting . According to some embodiments, the number of resulting secondary openings is greater than the number of side openings formed in the poly mer layer. According to some embodiments, the number of resulting secondary side openings is at least twice the number of side openings formed in the polymer layer. According to some embodiments, the number of resulting secondary side openings is at least four times the number of side openings formed in the polymer layer. According to some embodiments, the number of resulting secondary side openings is at least four times the number of side openings formed in the polymer layer. Next, referring to FIG. 9, this schematically shows another optional structure of the filter 900 of the embolization microcatheter such as the microcatheter 200 of FIG. 2. According to some

[0137] embodiments, the filter 900 may include one filter section 920, which includes a plurality of side openings, collectively referred to as side openings 925. According to some embodiments, the filter section 920 includes 20 - 80 or 25 - 65 or 40 - 50 side openings (e.g., 45 side openings). According to some embodiments, the slits are axial slits. According to some embodiments, the slits are dispersed in an annular ring. According to some embodiments, the width of each of the side openings 925, measured on the inner surface of the microcatheter, may be 5 micrometers - 15 micrometers or 5 micrometers - 1 0 micrometers (e.g., 8 micrometers), and its length L10, measured on the inner surface of the microcatheter, may be 1 - 15 mm, 1 - 10 mm, or 5 - 10 mm . According to some embodiments, the length L10, measured on the inner surface of the microcatheter, may be 1 - 15 mm, 1 - 10 mm, or 5 - 10 mm (e.g., 9 mm). According to some embodiments, the length L10, measured on the inner surface of the microcatheter, may be 1 - 15 mm, 1 - 10 mm, or 5 - 10 mm (e.g., 9 mm). (e.g., 9 mm).

[0138] According to some embodiments, the filter 900 is positioned at a position that is L9 mm, i.e., about 1 to 10 mm or 2 to 8 mm, for example about 3 mm, but not limited thereto, from the distal end opening. It may be positioned.

[0139] According to some embodiments, the side opening 925 is formed by a selective cut (e.g., a selective laser cut), i.e., without cutting the wire forming the skeleton 220. According to some embodiments, the polymer layer positioned between the wires of the skeleton 220 is penetrated during slit formation. Advantageously, by a selective cut of the polymer layer (basically leaving the mesh 2 00 intact), at least some of the side openings are subdivided into two or more secondary side openings that are separated by the mesh but not by the polymer outer layer, thereby providing, in effect, more than 100 side openings, more than 500 side openings, or more than 1000 side openings. It may be subdivided. Accordingly, more than 500 side openings, or more than 1000 side openings are provided.

[0140] The terms used herein are for the purpose of describing particular embodiments only and are not intended to be limiting. As used herein, the singular articles "a", "an", and "the" are intended to include the plural as well, unless the context clearly dictates otherwise. Further, the term "comprises" or "comprising", as used herein, specifies the presence of the stated feature, integer, step, operation, element, or component, but does not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or groups thereof. rises) or "comprising" is used herein, as used herein, specifies the presence of the stated feature, integer, step, operation, element, or component, but does not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or groups thereof. ​​It should be understood that the presence or addition of an ingredient, or a set thereof, is not excluded or precluded. . According to some embodiments, the term "comprising" may be replaced with "consisting essentially of", or "consisting of".

[0141] The term "about" refers to a reasonable variation from the recited amount that maintains the ability to achieve substantially the same one or more of the recited functional effects. This term also in this specification, plus or minus 10% of the recited value, or plus or minus 5%, or plus or minus 1%, or plus or minus 0.5% , or plus or minus 0.1%, or any percentage value between them may refer to.

[0142] Above, a number of exemplary aspects and embodiments have been discussed, but those skilled in the art will envision certain specific improvements, additions, and partial combinations. Accordingly, the following appended claims and claims to be introduced hereafter are intended to include all such improvements, additions, and partial combinations as well, as being within the actual spirit and scope thereof.

Example

[0143] Example 1 - Delivery of Sirtex Y90 Radioembolization Beads (Sir-Sphere® ) The backflow of beads using the microcatheter disclosed in FIGS. 3A - 3D was compared under the same test conditions as the backflow using a standard microcatheter.

[0144] Each microcatheter was connected at its distal end to a filter composed of a coarse mesh for collecting the injected beads and inserted into a tube connected to a flow regulator that maintained a constant flow rate of 5 cc / min within the tube. Sirtex Y90 (25 micrometer) beads (Sir-Sphere (registered trademark)) were injected at a constant flow rate of 5 - 10 cc / min using a syringe pump, the injection was recorded, and the backflow of the beads was monitored. When using a standard microcatheter, backflow started at an injection flow rate just exceeding 5 cc / min, whereas when using the microcatheter disclosed in the present application, no backflow was observed even at an injection flow rate as high as 9 cc / min. Figure 10 shows representative images taken at various time points during the monitoring of the backflow of Sirtex Y90 beads using the microcatheter for embolization disclosed in the present application (MC - lower panel disclosed in the present application) and a standard microcatheter (standard MC - upper panel). It can be clearly seen that backflow is considerably prevented when using the microcatheter disclosed in the present application as compared to the standard microcatheter (the backflowed beads are indicated by arrow 1000). Further, as can be seen from Figure 11, when using the microcatheter disclosed in the present application, backflow of Sirtex Y90 beads (Sir - Sphere (registered trademark)) occurs for the first time at an injection volume 1.8 times higher than that in the case of a standard microcatheter (about 9 ml / min versus about 5 ml / min). (Sir - Sphere(registered trademark)) was injected at a constant flow rate of 5 - 10 cc / min using a syringe pump, the injection was recorded, and the backflow of the beads was monitored. When using a standard microcatheter, backflow started at an injection flow rate just exceeding 5 cc / min, whereas when using the microcatheter disclosed in the present application, no backflow was observed even at an injection flow rate as high as 9 cc / min.

[0145] When using a standard microcatheter, backflow started at an injection flow rate just exceeding 5 cc / min, whereas when using the microcatheter disclosed in the present application, no backflow was observed even at an injection flow rate as high as 9 cc / min. When using a standard microcatheter, backflow started at an injection flow rate just exceeding 5 cc / min, whereas when using the microcatheter disclosed in the present application, no backflow was observed even at an injection flow rate as high as 9 cc / min. When using a standard microcatheter, backflow started at an injection flow rate just exceeding 5 cc / min, whereas when using the microcatheter disclosed in the present application, no backflow was observed even at an injection flow rate as high as 9 cc / min.

[0146] Figure 10 shows representative images taken at various time points during the monitoring of the backflow of Sirtex Y90 beads using the microcatheter for embolization disclosed in the present application (MC - lower panel disclosed in the present application) and a standard microcatheter (standard MC - upper panel). It can be clearly seen that backflow is considerably prevented when using the microcatheter disclosed in the present application as compared to the standard microcatheter (the backflowed beads are indicated by arrow 1000). Further, as can be seen from Figure 11, when using the microcatheter disclosed in the present application, backflow of Sirtex Y90 beads (Sir - Sphere(registered trademark)) occurs for the first time at an injection volume 1.8 times higher than that in the case of a standard microcatheter (about 9 ml / min versus about 5 ml / min). (Sir - Sphere(registered trademark)) was injected at a constant flow rate of 5 - 10 cc / min using a syringe pump, the injection was recorded, and the backflow of the beads was monitored. When using a standard microcatheter, backflow started at an injection flow rate just exceeding 5 cc / min, whereas when using the microcatheter disclosed in the present application, no backflow was observed even at an injection flow rate as high as 9 cc / min. When using a standard microcatheter, backflow started at an injection flow rate just exceeding 5 cc / min, whereas when using the microcatheter disclosed in the present application, no backflow was observed even at an injection flow rate as high as 9 cc / min. When using a standard microcatheter, backflow started at an injection flow rate just exceeding 5 cc / min, whereas when using the microcatheter disclosed in the present application, no backflow was observed even at an injection flow rate as high as 9 cc / min. Figure 10 shows representative images taken at various time points during the monitoring of the backflow of Sirtex Y90 beads using the microcatheter for embolization disclosed in the present application (MC - lower panel disclosed in the present application) and a standard microcatheter (standard MC - upper panel). It can be clearly seen that backflow is considerably prevented when using the microcatheter disclosed in the present application as compared to the standard microcatheter (the backflowed beads are indicated by arrow 1000). Further, as can be seen from Figure 11, when using the microcatheter disclosed in the present application, backflow of Sirtex Y90 beads (Sir - Sphere(registered trademark)) occurs for the first time at an injection volume 1.8 times higher than that in the case of a standard microcatheter (about 9 ml / min versus about 5 ml / min). When using a standard microcatheter, backflow started at an injection flow rate just exceeding 5 cc / min, whereas when using the microcatheter disclosed in the present application, no backflow was observed even at an injection flow rate as high as 9 cc / min. When using a standard microcatheter, backflow started at an injection flow rate just exceeding 5 cc / min, whereas when using the microcatheter disclosed in the present application, no backflow was observed even at an injection flow rate as high as 9 cc / min. When using a standard microcatheter, backflow started at an injection flow rate just exceeding 5 cc / min, whereas when using the microcatheter disclosed in the present application, no backflow was observed even at an injection flow rate as high as 9 cc / min.

[0147] Example 2 - Delivery of Celonova Embozene(registered trademark) 40 - micrometer beads When using a standard microcatheter, backflow started at an injection flow rate just exceeding 5 cc / min, whereas when using the microcatheter disclosed in the present application, no backflow was observed even at an injection flow rate as high as 9 cc / min. The backflow of beads using the microcatheter disclosed in FIGS. 3A to 3D was compared under the same test conditions as the backflow using a standard microcatheter.

[0148] Each microcatheter was connected at its distal end to a filter composed of a coarse mesh for recovering the injected beads and inserted into a tube connected to a flow regulator that maintains a constant flow rate of 5 cc / min in the tube. Embozene® 40 micrometer beads were injected at a constant flow rate of 5 - 10 cc / min using a syringe pump, the injection was recorded, and the backflow of the beads was monitored.

[0149] When using a standard microcatheter, the backflow started at an injection flow rate just above 5 cc / min, whereas when using the microcatheter disclosed in the present application, no backflow was observed up to an injection flow rate of 9 cc / min.

[0150] FIG. 11 shows representative images taken at various times during the monitoring of the backflow of Embozene® 40 micrometer beads using the embolization microcatheter (lower panel) disclosed in the present application and a standard microcatheter (upper panel). It can be clearly seen that the backflow is significantly prevented when using the microcatheter disclosed in the present application compared to the standard microcatheter (the backflowed beads are indicated by arrow 1100). Furthermore, as can be seen from FIG. 12, when using the microcatheter disclosed in the present application in FIG. 3A (white bar), Sir-Sphere® (shown as bead type 1 in FIG. 12), TheraSphere® beads (in FIG. 12 shown as bead type 2), and Embozene® beads (Figure 12 where it is shown as bead type 3) backflow occurs only at an injection rate 1.8 times higher than that using a standard microcatheter case (black bar), starting at an injection rate about 1.8 times higher (about 9 ml / min vs. about 5 ml / min). l / min).

Claims

[Claim 1] 1. An embolization microcatheter for delivering embolic beads to a target area, comprising: a proximal end and a distal end, the distal end including an end opening; a skeleton formed of braided or coiled wire; a polymer layer inserted into and / or overlying said skeleton; a filter disposed proximal to the distal end opening, the filter including at least 100 openings circumferentially distributed around a wall of the filter, the at least 100 openings being essentially bone-shaped or skewered sphere-shaped, the total open area of ​​the filter being at least three times greater than the area of ​​the distal end opening; an inner layer lining the inner surface of the microcatheter; Including, the proximal end is sized and shaped to permit delivery of a suspension flowing through the microcatheter, the suspension including a suspending fluid and the embolic beads, and the filter is configured to permit the exit of the suspending fluid while preventing the exit of the embolic beads; The outer diameter of the microcatheter is 1 mm or less, and the tensile force of the microcatheter is greater than 5 N (Newtons); A microcatheter for embolization, wherein the filter does not include the inner layer.

Images