Medical long body

Abstract

[Problem] To provide a medical long body having a long reach and backup force or kickback resistance. [Solution] The medical long body 1 includes: a first lubrication layer 24 provided on the distal end side; and a second lubrication layer 34 provided on the proximal end side of the first lubrication layer and having lower lubricity than the first lubrication layer.

Description

Long medical body

[0001] The present invention relates to a medical elongate body.

[0002] A guiding catheter (also called a medical elongated catheter), which is one type of catheter, is a catheter used to guide a balloon catheter or the like for treating the heart or lower limb arteries when it is inserted to the target site (see, for example, Patent Document 1 below).

[0003] Catheters and guidewires are often coated with a hydrophilic coating to improve peripheral reach. Devices for treating lower extremities, in particular, require a long hydrophilic coating and excellent sliding properties because the distance from the device insertion point to the treatment site is long.

[0004] International Publication No. 2018 / 092387

[0005] However, if the coating is long and has high sliding properties, problems can arise, such as a decrease in the backup force that keeps the catheter in place, and in the case of a guidewire, the wire will come out on its own when released (kickback).

[0006] The present invention has been made to solve the above-mentioned problems, and has an object to provide a medical elongated body that has high peripheral reachability and backup force or kickback resistance.

[0007] The above object of the present invention can be achieved by the following means.

[0008] (1) A medical elongate body having a first lubricating layer provided on the distal end side, and a second lubricating layer provided on the proximal end side of the first lubricating layer and having lower lubricity than the first lubricating layer.

[0009] (2) The medical elongate body according to (1), wherein when the medical elongate body is moved while being clamped between a pair of abutment members at 500 gf, the difference between the resistance value of the first lubricating layer and the resistance value of the second lubricating layer is 10 gf or more.

[0010] (3) The medical elongate body according to (1) or (2), wherein when the medical elongate body is moved while being clamped by a pair of abutment members at 500 gf, the resistance value of the second lubricating layer is at least twice the resistance value of the first lubricating layer.

[0011] (4) The medical elongate body according to any one of (1) to (3), wherein the first lubricating layer and the second lubricating layer contain a lubricating resin to which a non-lubricating resin has been added.

[0012] (5) The medical elongate body according to any one of (1) to (4), wherein the length of the first lubricating layer along the axial direction is shorter than the length of the second lubricating layer along the axial direction.

[0013] (6) The medical elongate member according to any one of (1) to (5), wherein the lubricating resin of the first lubricating layer and the lubricating resin of the second lubricating layer are the same.

[0014] (7) A medical elongate body described in any one of (1) to (6), wherein the lubricating resins of the first lubricating layer and the second lubricating layer are different, and the lubricating resin of the first lubricating layer has a higher hydrophilic component than the lubricating resin of the second lubricating layer.

[0015] (8) The medical elongate member according to any one of (1) to (7), wherein the thickness of the first lubricating layer is greater than the thickness of the second lubricating layer.

[0016] The medical elongate body configured as described above has a first lubricating layer with high lubricity formed at the tip, providing high peripheral reachability. Furthermore, a second lubricating layer with low lubricity formed on the proximal end side of the first lubricating layer provides backup force or kickback resistance. From the above, a medical elongate body with high peripheral reachability and backup force or kickback resistance can be provided.

[0017] Fig. 1 is an overall view showing a medical elongated body according to an embodiment of the present invention; Fig. 2 is a front cross-sectional view showing a tube of a medical elongated body according to this embodiment; Fig. 3 is a schematic view showing a test device for performing an abrasion test on a medical elongated body according to this embodiment, showing a state in which the medical elongated body is sandwiched between a pair of contact members; Fig. 4 is a schematic view showing a test device for performing an abrasion test on a medical elongated body according to this embodiment, showing a state in which the medical elongated body is separated from the pair of contact members.

[0018] A medical elongated body 1 according to an embodiment of the present invention will be described below with reference to Figures 1 and 2. Figure 1 is an overall view showing a medical elongated body 1 according to an embodiment of the present invention. Figure 2 is a front cross-sectional view showing a tube 10 of the medical elongated body 1 according to this embodiment.

[0019] The medical elongated member 1 according to this embodiment is a guiding catheter for the lower limbs that is used in surgery to diagnose and treat lesions in blood vessels of the lower limbs.

[0020] As shown in Figure 1, the medical elongated body 1 has a tube 10, a flexible distal tip 20 provided at the distal end of the tube 10, and a hub (hub tube) 30 provided at the proximal end of the tube 10, and a kink-resistant protector 40 is provided at the distal end of the hub 30.

[0021] The tube 10 is made of a flexible tubular body. A lumen 10H is formed in the tube 10 over the entire length of the tube 10. The lumen 10H opens at the distal end of the distal tip 20.

[0022] As shown in Figure 2, the tube 10 has an inner layer 11 arranged on the inner surface side, an outer layer 12 arranged on the outer periphery of the inner layer 11, a lubricating layer 14 arranged at least on the tip side of the outer periphery of the outer layer 12, and a reinforcing material layer 13 arranged inside the outer layer 12.

[0023] 1, the lubricating layer 14 has a first lubricating layer 24 provided on the distal end side and a second lubricating layer 34 provided on the proximal end side of the first lubricating layer 24. The first lubricating layer 24 is configured to have higher lubricity than the second lubricating layer 34. Methods for making the first lubricating layer 24 more lubricating than the second lubricating layer 34 include the methods described below.

[0024] The first method is to apply solutions containing the same lubricating resin in the first lubricating layer 24 and the second lubricating layer 34, but with different concentrations of the lubricating resin, to the locations where the first lubricating layer 24 and the second lubricating layer 34 are to be formed. Specifically, the lubricity of the first lubricating layer 24 can be increased by applying a solution with a high concentration of the lubricating resin to the location where the first lubricating layer 24 is to be formed.

[0025] The second method is to increase the pull-up speed midway through dip coating of a solution containing the same lubricating resin and having the same concentration of lubricating resin in the first lubricating layer 24 and the second lubricating layer 34. This makes the thickness of the first lubricating layer 24 thicker than the thickness of the second lubricating layer 34, and makes the lubricity of the first lubricating layer 24 higher than that of the second lubricating layer 34.

[0026] A third method is to apply a solution containing the same lubricating resin and having the same concentration of lubricating resin to the locations where the first lubricating layer 24 and the second lubricating layer 34 are to be formed, and then change the amount of heat used for heating and drying for each area. Specifically, by applying a larger amount of heat to the second lubricating layer 34 than to the first lubricating layer 24, cross-linking of the lubricating resin progresses, reducing lubricity.

[0027] A fourth method is to increase the amount of non-lubricating resin (PVC, described below) in the solution applied to the second lubricating layer 34 compared to the amount of non-lubricating resin (PVC, described below) in the solution applied to the first lubricating layer 24. As a result, the greater the amount of non-lubricating resin, the higher the crosslink density of the lubricating resin, and therefore the lower the lubricity.

[0028] A fifth method is to apply solutions containing lubricating resins with different components to the locations where the first lubricating layer 24 and the second lubricating layer 34 are to be formed, respectively, for the first lubricating layer 24 and the second lubricating layer 34. Specifically, the dimethylacrylamide component of the glycidyl methacrylate-dimethylacrylamide copolymer lubricating resin is hydrophilic and provides sliding properties, so a lubricating resin containing a large amount of dimethylacrylamide is used for the first lubricating layer 24.

[0029] A sixth method is to use different solvents for dissolving or dispersing the first non-lubricating resin and the lubricating resin at the locations where the first lubricating layer 24 and the second lubricating layer 34 are formed.

[0030] A seventh method is to make the thickness of the first lubricating layer 24 and the second lubricating layer 34 different from each other.

[0031] By employing an appropriate combination of the seven methods described above, the contrast in lubricity between the first lubricating layer 24 and the second lubricating layer 34 can be made clearer.

[0032] The lubricating resin of the lubricating layer 14 is hydrophilic. For this reason, the lubricating resin is preferably a hydrophilic material. An example of a hydrophilic material is a block copolymer of glycidyl methacrylate (GMA) and dimethylacrylamide (DMAA). Of the glycidyl methacrylate-dimethylacrylamide copolymers, dimethylacrylamide is hydrophilic and exhibits sliding properties. For this reason, it is preferable that the first lubricating layer 24 contains a large amount of dimethylacrylamide.

[0033] In particular, the lubricating resin of the lubricating layer 14 is preferably an acrylic resin. The acrylic resin preferably contains a structural unit derived from a reactive monomer. By introducing such a structural unit derived from a reactive monomer, polymers are crosslinked or polymerized via the epoxy group, which is a reactive monomer, to form a network structure. This allows the medical elongated body to maintain surface lubricity even when subjected to friction; in other words, the resistance value due to friction is low or does not decrease, and the amount of fine particles generated can be reduced.

[0034] The reactive monomer is preferably a (meth)acrylic acid ester having an epoxy group, and among these, because it is easy to control the crosslinking or polymerization of the polymer, it is preferable to include at least one selected from the group consisting of glycidyl acrylate, glycidyl methacrylate (GMA), 3,4-epoxycyclohexylmethyl acrylate, 3,4-epoxycyclohexylmethyl methacrylate, and β-methylglycidyl methacrylate, with glycidyl (meth)acrylate being more preferred, and glycidyl methacrylate (GMA) being even more preferred. Note that, in this specification, "(meth)acrylate" includes both acrylate and methacrylate. The above reactive monomers may be used alone or in combination of two or more.

[0035] Furthermore, the acrylic resin preferably has a structural unit (A) derived from a reactive monomer having an epoxy group and a structural unit (B) derived from a hydrophilic monomer, and more preferably consists of a structural unit (A) derived from a reactive monomer having an epoxy group and a structural unit (B) derived from a hydrophilic monomer.

[0036] Examples of the hydrophilic monomer include acrylamide and its derivatives, vinylpyrrolidone, acrylic acid, methacrylic acid and their derivatives, polyethylene glycol acrylate and its derivatives, monomers having sugars or phospholipids in the side chain, and water-soluble monomers such as maleic anhydride, but the hydrophilic monomer is preferably N,N-dimethylacrylamide (DMAA).The hydrophilic monomers may be used alone or in combination of two or more.

[0037] The method for producing the acrylic resin is not particularly limited, and a block copolymer having a hydrophilic site and a reactive site can be produced by the method described in, for example, Japanese Patent Application Laid-Open No. 9-131396.

[0038] The first non-lubricating resin of the lubricating layer 14 is preferably vinyl chloride resin (PVC). In block copolymers containing epoxy groups, the ring-opening of the epoxy groups promotes crosslinking (bonding) between the block copolymers, thereby increasing the film strength of the surface lubricating layer. Therefore, by adding a small amount of vinyl chloride resin to the block copolymer, the chlorine contained in the vinyl chloride resin is released (dechlorinated) from the vinyl chloride resin, promoting the ring-opening of the epoxy groups in the block copolymer. This allows for faster ring-opening and crosslinking of the epoxy groups compared to when the vinyl chloride resin is not present, resulting in a lower thermal load on the substrate and coating resin, such as shorter heating time and lower heating temperature. The shorter heating time reduces working time and energy consumption, reducing costs while also increasing the film strength of the block copolymer. In the present invention, the lubricating layer does not necessarily contain the first non-lubricating resin; it may be included in either the first lubricating layer or the second lubricating layer, or both.

[0039] Furthermore, the first non-lubricating resin of the lubricating layer 14 is preferably water-insoluble. This configuration improves durability. "Water-insoluble" refers to a substance that is insoluble (or poorly soluble) in water at room temperature (23°C) and normal pressure (1 atmosphere). For example, this refers to a substance that dissolves less than 1 g in 100 ml of water at room temperature and normal pressure, but is not limited to this.

[0040] The mass ratio of the amount of the first non-lubricating resin added to the lubricating resin is preferably 1 / 1000 to 1 / 1.

[0041] The outer layer 12 is made of a second non-lubricating resin. The second non-lubricating resin of the outer layer 12 may be made of a polyamide elastomer and / or polyamide resin, or may be made of polyester, polyester elastomer, polyurethane elastomer, or polyurethane resin, which has kink resistance, favorable pushability, and conformability.

[0042] The reinforcing material layer 13 has a plurality of reinforcing wires that reinforce the tube 10. Examples of the reinforcing wires include spiral and braided reinforcing wires. The reinforcing wires are made of metal such as stainless steel. Specific examples include a structure in which stainless steel wires are flattened into a plate shape and then a plurality of approximately 8 to 32 of these wires are used to form a spiral or braided structure (braided body) so that the radial thickness of the tube 10 is thin. The number of reinforcing wires is preferably a multiple of 8 to achieve balanced reinforcement in the tubular shape, but the tube may not have any reinforcing wires.

[0043] By making the reinforcing wire flat, it receives external stress evenly compared to an ellipse, resulting in consistent physical properties.

[0044] The inner layer 11 is preferably made of a material that provides low friction at least in the portion that comes into contact with a device such as a treatment catheter or a guidewire when the device is inserted into the lumen 10H. This configuration allows the device inserted into the tube 10 to move longitudinally with less sliding resistance, improving operability. Specifically, the inner layer 11 can be made of a fluorine-based resin material such as polytetrafluoroethylene (PTFE), but the inner layer may not be provided.

[0045] The number of layers constituting the tube 10 and the material of each layer may vary along the longitudinal direction of the tube 10. For example, in order to make the distal end portion of the tube 10 more flexible, the number of layers may be reduced, a more flexible material may be used, or a reinforcing material may not be provided in that portion.

[0046] Since the insertion of the medical elongated body 1 into the body is performed while checking its position under X-ray fluoroscopy, it is preferable that an X-ray opaque material (X-ray contrast agent) be blended into the constituent material of the outer layer 12. Examples of the X-ray opaque material that can be used include barium sulfate, bismuth oxide, and tungsten.

[0047] Furthermore, such radiopaque material need not necessarily be present over the entire length of the tube 10, but may be present only in a portion of the tube 10, for example, only in the distal end or only in the distal tip 20.

[0048] The distal end of the tube 10 is curved into a desired shape suitable for the site where the distal end of the tube 10 is to be inserted, such as the left coronary artery, the right coronary artery, etc. In particular, the distal end is shaped to facilitate the operation of engaging the distal end with the coronary artery ostium (engagement operation), or to more reliably maintain the state of engagement with the coronary artery ostium (engagement), but the distal end does not need to have a shape if it is to be used in the arteries of the lower limbs.

[0049] A distal tip 20 is connected to the distal end of the tube 10. This distal tip 20 is made of a highly flexible material, and its distal end is preferably rounded. By providing such a distal tip 20, the tube can be smoothly and safely navigated even in curved, bent, or branched blood vessels. Examples of materials that can be used to construct the distal tip 20 include various rubber materials such as natural rubber, isoprene rubber, butadiene rubber, chloroprene rubber, silicone rubber, fluororubber, and styrene-butadiene rubber, as well as various thermoplastic elastomers such as styrene-based, polyolefin-based, polyurethane-based, polyester-based, polyamide-based, polybutadiene-based, trans-polyisoprene-based, fluororubber-based, and chlorinated polyethylene-based materials, with polyamide elastomer being preferred.

[0050] Furthermore, the constituent material of the distal tip 20 may contain an X-ray opaque material (X-ray contrast agent) as described above.

[0051] The length of the distal tip 20 is not particularly limited, but is usually preferably about 0.5 to 3 mm, and more preferably about 1 to 2 mm.

[0052] A hub 30 is attached (fixed) to the proximal end of the tube 10. An inner cavity that communicates with the lumen 10H is formed in this hub 30. This inner cavity has an inner diameter that is approximately equal to the inner diameter of the lumen 10H, and is continuous with the inner surface of the proximal end of the lumen 10H without creating any steps or the like.

[0053] For example, long objects (linear objects) such as guide wires, catheters (e.g., balloon catheters, stent delivery catheters), endoscopes, ultrasound probes, and temperature sensors can be inserted or removed through the hub 30, and various liquids such as contrast agents (X-ray contrast agents), medicinal solutions, and physiological saline can be injected through the hub 30. The hub 30 can also be connected to other devices, such as a Y-shaped branch connector.

[0054] Next, a method for manufacturing the medical elongated body 1 according to this embodiment will be described.

[0055] First, a medical elongate body having an outer layer 12 containing a second non-lubricating resin is prepared.

[0056] Next, a coating liquid containing a first non-lubricating resin and a lubricating resin is prepared.

[0057] The solvent for dissolving or dispersing the first non-lubricating resin and the lubricating resin according to the present invention is not particularly limited as long as it can dissolve the first non-lubricating resin and the lubricating resin according to the present invention. The molecular extent of the block copolymer varies depending on the solvent used, which in turn affects the solution viscosity. In addition, since volatility and other characteristics vary depending on the type of solvent, it is best to select the solvent appropriately based on the application location (the location where the first lubricating layer 24 and the second lubricating layer 34 are formed) and the desired sliding properties. Mixed solvents containing two or more solvents may also be used. Specific examples include, but are not limited to, alcohols such as methanol, ethanol, isopropanol, and ethylene glycol; ketones such as acetone, methyl ethyl ketone, and cyclohexanone; esters such as ethyl acetate; halides such as chloroform; olefins such as hexane; ethers such as tetrahydrofuran (THF) and butyl ether; aromatics such as benzene and toluene; amides such as N,N-dimethylformamide (DMF); and sulfoxides such as dimethyl sulfoxide (DMSO). These may be used alone or in combination of two or more, and N,N-dimethylformamide (DMF), THF or a mixed solvent of both are preferred.

[0058] Then, the outer layer 12 containing the second non-lubricating resin is coated or immersed in a solution for the second lubricating layer 34 obtained by adding the first non-lubricating resin to the lubricating resin, and then dried at room temperature for 30 minutes.

[0059] Next, the outer layer 12 having the second lubricant layer 34 formed on its outer periphery is coated or immersed in a solution for the first lubricant layer 24 obtained by adding the first non-lubricant resin to the lubricant resin.

[0060] The mixture is then heated at 130°C or below for 6 hours or less (preferably 1 hour or less) to form a lubricating layer 14 on the outer periphery of the outer layer 12 containing the second non-lubricating resin. The heating temperature is preferably 90 to 150°C, and more preferably 100 to 140°C. In particular, by setting the temperature to 100 to 130°C, the heat treatment can be carried out in a short time, crosslinking can be performed without applying excessive thermal load to the substrate layer, and lubricity can be more easily imparted and controlled even to substrates with relatively low heat resistance. The above temperature may be changed during the heat treatment process.

[0061] The medical elongated body 1 according to this embodiment can be manufactured by the above steps. Here, the second lubricating layer 34 is formed on the inner circumferential side of the first lubricating layer 24.

[0062] The drying or heat treatment time is not particularly limited, but is preferably 30 minutes to 30 hours, more preferably 1 to 25 hours, and particularly preferably 1 to 6 hours. By setting the drying or heat treatment time in this manner, polymerization is effectively promoted, resulting in the formation of a strong outer layer. Therefore, high lubricity (surface lubricity) can be maintained for a longer period of time. Furthermore, by setting the drying or heat treatment time in this manner, excessive crosslinking or polymerization can be prevented. Therefore, a decrease in swelling due to excessive hardness of the lubricating layer can be prevented, and as a result, good lubricity (surface lubricity) can be maintained.

[0063] In this step, from the viewpoint of particularly effectively (efficiently) promoting crosslinking or polymerization, it is preferable to further perform a heat treatment after the drying treatment. In this way, by undergoing the drying and heat treatment, the further heat treatment is performed in a state in which the solvent has been distilled off, and therefore the effect of promoting crosslinking or polymerization of the polymer is further improved. Therefore, since the heat treatment can be shortened, even a polymer material that is easily deformed or plasticized by heat can be used as the base layer.

[0064] Next, a test device 90 for performing an abrasion test on the medical elongated body 1 according to this embodiment will be described with reference to Figures 3 and 4. Figure 3 is a schematic diagram showing the test device 90 for performing an abrasion test on the medical elongated body 1 according to this embodiment, illustrating a state in which the medical elongated body 1 is sandwiched between a pair of contact members 91, 92. Figure 4 is a schematic diagram showing the test device 90 for performing an abrasion test on the medical elongated body 1 according to this embodiment, illustrating a state in which the medical elongated body 1 is sandwiched and separated between the pair of contact members 91, 92.

[0065] 3 and 4, the testing device 90 has a pair of contact members 91, 92. The pair of contact members 91, 92 are configured to be able to move toward and away from each other, and when the pair of contact members 91, 92 are in a close proximity to each other, the medical elongated body 1 can be clamped with a predetermined force with the core bar inserted. As the testing device 90, a DL1000 manufactured by OAKRIVER TECHNOLOGY can be used.

[0066] Next, a method for measuring the resistance value using the test device 90 will be described.

[0067] First, the medical elongated body 1 is placed in the test device 90 in water, the temperature of which is room temperature.

[0068] Next, the pair of contact members 91, 92 are brought close to each other to sandwich the medical elongate body 1 with a pad height of 12.35 mm and a pad width of 31.75 mm, made of silicone with a Shore A60 at 500 gf.

[0069] Next, the resistance value is measured while the elongated medical body 1 is pulled up at a predetermined speed. The speed at which the elongated medical body 1 is pulled up is, for example, 8.3 mm / s, and the pulling distance is, for example, 25 mm.

[0070] Next, the pair of contact members 91, 92 are moved away from each other to release the sandwiched state, and the medical elongate body 1 is returned to its initial position.

[0071] The above steps are repeated a predetermined number of times to measure the resistance value a predetermined number of times, for example, 50 times.

[0072] The present invention will be described in more detail below with reference to examples, although the technical scope of the present invention is not limited to the following examples.

[0073] Synthesis Example 1: Synthesis of Block Copolymer (1) Block copolymer (1) was produced by the following reaction.

[0074]

[0075] [Formation of Surface Lubrication Layer] 1. Preparation of Block Copolymer (Synthesis Example 1) 29.7 g of triethylene glycol was added dropwise to 72.3 g of adipic acid dichloride at 50 ° C., and the mixture was then heated at 50 ° C. for 3 hours. The hydrochloric acid was then removed under reduced pressure to obtain 22.5 g of oligoester. 4.5 g of methyl ethyl ketone was then added dropwise to a solution consisting of 5 g of sodium hydroxide, 6.93 g of 31% hydrogen peroxide, 0.44 g of surfactant dioctyl phosphate, and 120 g of water, and the mixture was allowed to react at -5 ° C. for 20 minutes. The resulting product was repeatedly washed with water and methanol, and then dried to obtain a polyperoxide (PPO) having multiple peroxide groups in the molecule. Subsequently, 0.5 g of this PPO was used as a polymerization initiator, and 9.5 g of glycidyl methacrylate (GMA) as a hydrophobic monomer was added to benzene as a solvent and polymerized at 65 ° C. for 2 hours while stirring under reduced pressure. The reaction product was reprecipitated with diethyl ether to obtain polyGMA having peroxide groups in the molecule (PPO-GMA).

[0076] Subsequently, 1.35 g of the obtained PPO-GMA (corresponding to 9.5 mmol of GMA) was dissolved in chlorobenzene as a polymerization initiator together with 11.2 g (113 mmol) of N,N-dimethylacrylamide (DMAA) as a hydrophilic monomer, and the solution was polymerized by heating to 80°C for 7 hours under a nitrogen atmosphere. The reaction product was recovered by reprecipitation with cyclohexane, producing block copolymer 1 having DMAA moieties as hydrophilic moieties and GMA moieties as hydrophobic moieties. The GMA:DMAA ratio of the produced block copolymer 1 was measured by 1H-NMR, and the GMA:DMAA ratio (i.e., the molar ratio of hydrophilic moieties to hydrophobic moieties in the block copolymer) was found to be 1:12 (molar ratio). Furthermore, the viscosity of a 1 wt % chloroform solution of the obtained block copolymer 1 was measured in a 30° C. environment using a B-type rotational viscometer (manufactured by Brooksfield, device name: DV-I Prime) and was found to be 6.0 mPa·s.

[0077] Synthesis Example 2 Block Copolymer 2 0.60 g (corresponding to 4.2 mmol of GMA) of PPO-GMA obtained in the same manner as in Block Copolymer 1 was dissolved in chlorobenzene together with 10.1 g (102 mmol) of DMAA as a polymerization initiator, and the solution was heated to 75° C. for 7 hours in a nitrogen atmosphere to polymerize, thereby obtaining Block Copolymer 3.

[0078] The GMA:DMAA ratio (molar ratio) of block copolymer 2 prepared by the same method as block copolymer 1 was measured and found to be 1:29 (molar ratio). The solution viscosity of block copolymer 3, measured by the same method as block copolymer 1, was 14.0 mPa s.

[0079] Example 1 The block copolymer obtained in Synthesis Example 1 and polyvinyl chloride resin (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) were dissolved in tetrahydrofuran (THF) at a mass ratio (first non-lubricating resin / second non-lubricating resin) of 1 / 25, and the first non-lubricating resin was present at 0.1 mass % in the coating solution, to prepare coating solution A. Polyamide elastomer (second non-lubricating resin, Shore hardness 60D, (Vestamid A tube (effective length 120 cm) with an outer diameter of 2.37 mm molded from a 100% polyester resin (E62, manufactured by EVONIK) was immersed for 120 cm in the above coating solution A and dried at room temperature (25°C) for 30 minutes to form a coating film (Tube A). Next, the block copolymer obtained in Synthesis Example 1 and polyvinyl chloride resin were dissolved in N,N-dimethylformamide (D) at a mass % (first non-lubricating resin / first lubricating resin) of 1 / 50, and the first non-lubricating resin in the coating solution was 0.1 mass %. MF) to prepare coating solution B. Tube A was immersed in coating solution B up to 30 cm from the tip and dried at room temperature (25°C) for 1 hour to form a coating film. Tube A was then heat-treated in an oven at 130°C for 1 hour to form the coating film, and then cooled to room temperature. In this way, a medical elongated body 1 was produced in which the GMA:DMAA ratio of the lubricating resin, in other words the ratio of the hydrophilic components, was the same, and a lubricating layer was formed in which the resistance value was lower at the tip than at the base.

[0080] Example 2 The block copolymer obtained in Synthesis Example 1 and polyvinyl chloride resin (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) were dissolved in tetrahydrofuran (THF) at a mass ratio (first non-lubricating resin / second lubricating resin) of 2 / 35, and the first non-lubricating resin was present at 0.2 mass% in the coating solution, to prepare coating solution C. Polyamide elastomer (second non-lubricating resin, Shore hardness 46D, (Vestamid A tube with an outer diameter of 2.80 mm (effective length 45 cm) molded from a 100% polyester resin (E47-S1, manufactured by EVONIK) was immersed 40 cm into the above coating solution C and dried at room temperature (25°C) for 30 minutes to form a coating film (Tube B). Next, N,N-dimethylformamide (DMF) and tetrahydrofuran (THF) were mixed to prepare a solvent A with a mass % of 1:1. The block copolymer and polyvinyl chloride resin obtained in Synthesis Example 2 were dissolved in solvent A with a mass % (first non-lubricating resin / first lubricating resin) of 1 / 50, and the first non-lubricating resin in the coating solution was 0.1 mass %. Coating solution D was prepared. Tube B was immersed in coating solution D up to 5 cm from the tip and dried at room temperature (25°C) for 1 hour to form a coating film. Tube B was then heat-treated in an oven for 2 hours to form the coating film. The oven temperature was initially 100°C and gradually increased to a final temperature of 130°C. Finally, tube B was removed from the oven and cooled to room temperature. In this way, a medical elongated body 2 was produced, which had a lubricating layer with a different GMA:DMAA ratio in the lubricating resin, in other words, a higher ratio of hydrophilic components at the tip and a lower resistance value at the tip than at the base.

[0081] [Results] In the medical elongate body 1 fabricated in Example 1, the first lubricating layer 24 had a sliding resistance value of 8.0 gf, and the difference obtained by subtracting the resistance value at the 5th cycle from the resistance value at the 50th cycle was 0 gf. In the medical elongate body 1 fabricated in Example 1, the second lubricating layer 34 had a resistance value of 20.3 gf, and the difference obtained by subtracting the resistance value at the 5th cycle from the resistance value at the 50th cycle was 0 gf. These results demonstrate that lubricating layers with different lubricity were formed in the first lubricating layer 24 and the second lubricating layer 34. Furthermore, the difference obtained by subtracting the resistance value at the 5th cycle from the resistance value at the 50th cycle was 0 gf for both the first lubricating layer 24 and the second lubricating layer 34, demonstrating excellent durability. With the medical elongate body 1 configured in this manner, the highly lubricating first lubricating layer 24 is formed at the distal end, thereby providing high peripheral reachability. Furthermore, the less lubricating second lubricating layer 34 is formed proximal to the first lubricating layer 24, providing backup force or kickback resistance. From the above, it is possible to provide a medical elongated body 1 that has high peripheral reachability and backup force or kickback resistance.

[0082] Furthermore, in the medical elongate body 2 produced in Example 2, the first lubricating layer 24 had a sliding resistance value of 3.3 gf, and the difference obtained by subtracting the resistance value at the 5th cycle from the resistance value at the 50th cycle was 0.3 gf. In the medical elongate body 2 produced in Example 2, the second lubricating layer 34 had a resistance value of 22.8 gf, and the difference obtained by subtracting the resistance value at the 5th cycle from the resistance value at the 50th cycle was 0 gf. These results demonstrate that lubricating layers with different lubricity could be formed in the first lubricating layer 24 and the second lubricating layer 34. Furthermore, the difference obtained by subtracting the resistance value at the 5th cycle from the resistance value at the 50th cycle was low for the first lubricating layer 24 and the second lubricating layer 34, indicating excellent durability. With the medical elongate body 2 configured in this manner, the first lubricating layer 24 with high lubricity is formed at the distal end, thereby providing high peripheral reachability. Furthermore, the second lubricating layer 34 with low lubricity is formed on the proximal end side of the first lubricating layer 24, providing backup force or kickback resistance. From the above, it is possible to provide a medical elongated body 2 that has high peripheral reachability and backup force or kickback resistance.

[0083] The above describes the medical elongated body 1 according to the present invention through an embodiment, but the present invention is not limited to the configuration described in the embodiment, and can be modified as appropriate based on the description of the claims.

[0084] For example, in the above-described embodiment, the medical elongated body 1 was used as a guiding catheter for the lower limbs, but it may also be used as an angiography catheter, a microcatheter, a guidewire support catheter, a balloon catheter, a stent delivery catheter, an imaging diagnostic catheter, an atherectomy catheter, an introducer sheath, a dilator, etc., or as a guidewire.

[0085] For example, in the above-described embodiment, the outer layer is made of the second non-lubricating resin, but the metal inner core may be coated with a lubricating layer containing a lubricating resin to which the first non-lubricating resin has been added. The metal inner core may be made of a metal member such as SUS or Ni-Ti. For example, various metal materials can be used, such as Ni-Ti alloys, stainless steels such as SUS302, SUS304, SUS303, SUS316, SUS316L, SUS316J1, SUS316J1L, SUS405, SUS430, SUS434, SUS444, SUS429, and SUS430F, piano wire, cobalt-based alloys, and superelastic alloys.

[0086] In the above-described embodiment, the first lubricating layer 24 and the second lubricating layer 34 are formed along the axial direction of the medical elongated body 1. However, an uncoated layer may be provided on the base end side of the second lubricating layer 34.

[0087] This application is based on Japanese Patent Application No. 2024-33999, filed on March 6, 2024, the disclosure of which is incorporated herein by reference in its entirety.

[0088] 1, 2 Medical elongated body, 10 Tube, 14 Lubricating layer, 24 First lubricating layer, 34 Second lubricating layer.

Claims

1. A medical elongated body having a first lubricating layer provided on the tip side and a second lubricating layer provided on the base end side of the first lubricating layer and having lower lubricity than the first lubricating layer.

2. A medical elongate body according to claim 1, wherein when the medical elongate body is moved while being clamped between a pair of abutment members at 500 gf, the difference between the resistance value of the first lubricating layer and the resistance value of the second lubricating layer is 10 gf or more.

3. A medical elongated body according to claim 1 or 2, wherein when the medical elongated body is moved while being clamped by a pair of abutment members at 500 gf, the resistance value of the second lubricating layer is at least twice the resistance value of the first lubricating layer.

4. A medical elongate member according to claim 1 or 2, wherein the first lubricating layer and the second lubricating layer contain a lubricating resin to which a non-lubricating resin has been added.

5. A medical elongate body according to claim 1 or 2, wherein the length along the axial direction of the first lubricating layer is shorter than the length along the axial direction of the second lubricating layer.

6. The medical elongate member according to claim 1 or 2, wherein the lubricating resin of the first lubricating layer and the lubricating resin of the second lubricating layer are the same.

7. A medical elongated body as described in claim 1 or 2, wherein the lubricating resins of the first lubricating layer and the second lubricating layer are different, and the lubricating resin of the first lubricating layer has a higher hydrophilic component than the lubricating resin of the second lubricating layer.

8. A medical elongate body according to claim 1 or 2, wherein the thickness of the first lubricating layer is greater than the thickness of the second lubricating layer.

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