JPH09313594A - Catheter and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve durability of low friction, lubricity, and safety of a catheter in inserting to an organ by forming a water lubricant polymer or its cross- linked material on the substrate outer surface of a catheter front part and/or a specific part of the lumen surface by the UV graft polymerization. SOLUTION: A water lubricant polymer or its cross-linked material is formed on the substrate outer surface of the substrate outer surface and/or a specific position of the lumen surface by the UV graft polymerization, for instance, when a catheter for PTCA blood cell dilatation is inserted into a lumen. Thus lubrication and antipeeling performance in a set condition are given to the position to obtain a catheter with lubrication on a inserting front part. The water lubricant polymer to be used be selected by required mechanical strength or functions of an lubricant, from monomers capable of forming a polymer on the substrate surface. For instance, a polymer consisting of acrylic amide, etc., is used.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a medical device such as a medical catheter. More specifically, a medical catheter having excellent lubricity and peeling resistance when wetted by its front portion by a polymer formed on a specific part of the outer surface and / or inner surface of the base material of the material by the UV grafting method. And a manufacturing method thereof.

[0002]

2. Description of the Related Art Medical devices such as catheters that are inserted into the trachea, digestive tract, urethra, blood vessels and other body cavities and tissues, and the base surface of medical devices such as guide wires and stylets that are inserted into these, It is generally known that thrombus, tissue adhesion, foreign body reaction, and the like tend to adhere. Therefore, a lubricious surface is required to reduce damage to the tissue and ensure insertion into the target site, or to minimize inflammation and damage to the mucous membrane during indwelling in the tissue. . In particular, when the catheter front portion can be lubricated when it is inserted into a body cavity such as a blood vessel, trackability (a characteristic of smoothly advancing inside the body cavity such as a blood vessel) is significantly improved.

For this reason, a low friction material is used as a base material, and the surface of the base material is further coated with a lubricant. For example, there is a case where a low friction material such as a fluororesin or a high density polyethylene resin is used as a base material of these medical devices. However, such a method does not have the expected effect as a result of the limited base material. For example, generally, when high density polyethylene which is a low friction material is used for the base material, lubricity is often insufficient. On the other hand, in the case of a catheter tube made of fluororesin, the surface lubricity is excellent, but it is unavoidable that the shaft is slightly stiff and easily kinked. Further, there are cases in which a lubricating liquid such as silicone oil, olive oil, or glycerin is applied on the surface. However, in such a surface coating method, in many cases, permanent lubricity cannot be expected, and further there is a problem in terms of safety such as peeling, elution, and desorption of a substance having lubricity from the substrate surface. there were.
In recent years, dilatation catheters for percutaneous transluminal coronary angioplasty (PTCA), which have been subjected to a water-lubricating treatment on the surface of the base material, have appeared. There were difficulties such as surface peeling when contacting a hard site such as a metastatic lesion.

US Pat. No. 4,100,309 and JP-A-59-19582 disclose that a copolymer of polyvinylpyrrolidone and polyurethane is used as a substance having lubricity. This method is satisfactory in terms of lubricity and durability, but it is essential that at least two kinds of polymer are coated and that an isocyanate group is present as a reactive group. It is difficult to apply because it is impossible to react with a base material having low reactivity with a group and a polymer having lubricity.

In JP-A-59-81341, an unreacted isocyanate group is formed on the surface of a medical device, and this is reacted with a hydrophilic polymer capable of covalently bonding with the isocyanate group to impart lubricity. A method is disclosed. With this method, good lubricity can be obtained, and the lubricity can be expected to be maintained to some extent. However, in this method, when the hydrophilic polymer contains N-vinyl-2-pyrrolidone or the like as a main component, the strength of the polymer is not sufficient, and therefore there is a problem that the lubricity is deteriorated by repeated use. . In addition, when coating a polymer having lubricity after coating an isocyanate group or the like, there are concerns that the coating process may be performed more than once or the presence of an unreacted isocyanate group, and the problem still remains. I have it.

In Japanese Patent Publication No. 1-55023, a compound having active hydrogen having a main chain of a copolymer composed of two or more kinds of monomers is bonded to the surface of a medical device through a polyisocyanate compound. , A method of imparting biocompatibility is disclosed. However, in this method, the presence of at least one or more of an amino group, an imino group, a carboxyl group, and a mercapto group is indispensable on the surface of the base material constituting the medical device, and the above-mentioned polyolefin, halogenated polyolefin, or the like is used. A medical device having no functional group has a drawback that it cannot be processed.

Further, Japanese Patent Publication No. 1-33181 imparts lubricity by covalently bonding a reactive functional group present on the surface of a base material constituting a medical device and a maleic anhydride polymer. A method is disclosed. But,
Also in this method, the presence of a reactive functional group is indispensable on the surface of the base material constituting the medical device, and there is a drawback that it cannot be directly introduced into a base material having no reactive functional group.
Furthermore, when a substrate having no reactive functional group is used, the substrate is previously treated with a solution of a compound having a reactive functional group so that the reactive functional group is present on the surface of the substrate. Although the method is described in the above publication, there is a problem that a polymer exhibiting lubricity cannot be stably bound unless the compound is stably bound to the surface of the base material.

Further, in WO90 / 01344, a polyurethane surface is coated with an alkali metal alcoholate group, an amino group, an alkali metal amide group,
Disclosed is that at least one of a carboxylic acid group, a sulfonic acid group, a magnesium halide group and a fluorine-boron-based complex group is introduced, and a hydrophilic polymer capable of reacting with these functional groups is immobilized on the surface by a coating operation. Although there are multiple coating operations,
Furthermore, it cannot be applied to olefin materials, and it has been considerably limited as an applicable material.

[0009]

As described above, for the purpose of immobilizing a hydrophilic polymer on a specific portion of the outer surface and / or inner surface of the catheter front portion base material, the durability of the hydrophilic polymer, There has been a long-awaited demand for establishment of a surface treatment having both a sufficient lubricity-imparting effect and safety, but there is still much room for improvement. In particular, when the catheter front portion is made of a plurality of materials, it may be unexpectedly difficult to firmly surface-treat any base material. In the present invention, the catheter front portion refers to a distal end portion when the catheter is inserted into a body vessel such as a blood vessel, and if the outer surface of the catheter can be lubricated, the trackability of the catheter can be improved. Needless to say. On the other hand, in contrast catheters, PTCA dilatation catheters, etc. that have a lumen from the catheter front part to the proximal side, by providing lubricity to the lumen surface, the slidability of the guide wire can be improved. It is possible to improve the trackability of the whole system including the catheter and the catheter.

The object of the present invention is to solve the above-mentioned problems and to maintain a low friction property when it is inserted into an internal organ.
It is to provide a medical device having lubricity and high safety. Further, even when the base material of the medical device is a polyolefin having no reactive group, a polymer having a wet lubricity at its front part, which is particularly effective for trackability, can be easily treated on the base material surface. It is intended to provide a method for manufacturing a medical device such as a catheter. In particular, when the treatment site of the present invention is the front surface including the inner lumen of the catheter, it is expected that the trackability will be improved including the guide wire operability.

[0011]

Such an object is achieved by the invention described below. (1) By forming a water-lubricating polymer or a cross-linked product thereof by an ultraviolet graft method on a specific portion of the outer surface of the base material and / or the inner surface of the front portion when the catheter is inserted into the body cavity, A catheter having a lubricity in the insertion front part, characterized in that the treated part is provided with lubricity when wet and peeling resistance. (2) After forming a liquid film or coating film of a compound having a hydrogen abstraction ability by ultraviolet irradiation on a specific portion of the outer surface of the base material and / or the surface of the inner lumen of the catheter front portion, the liquid film or coating film is irradiated with ultraviolet light and then simultaneously or sequentially. A method for producing a catheter having an insertion front portion having lubricity, wherein the catheter is provided with a water-lubricating polymer graft treatment to impart lubricity when wet and peel resistance. (3) The catheter according to (1) above, wherein the catheter front portion is made of a plurality of different materials and / or materials. (4) The catheter according to (1) or (3) above, wherein the water-lubricating polymer or a cross-linked product thereof is formed at the tip of the inner surface of the catheter into which the guide wire is inserted. (5) In the vicinity of the distal end of the catheter, both the outer diameter of the catheter and the inner diameter of the lumen into which the guide wire is inserted are made thinner than other portions, and the water-lubricating polymer or its crosslinked product is The catheter according to (1) or (3) above, which is formed on the surface of the lumen at the tip of the lumen having a reduced diameter.

BEST MODE FOR CARRYING OUT THE INVENTION

The present invention will be described in detail below. In the present invention, by a UV grafting method, by forming a cross-linked product or a polymer compound of a water-soluble or water-swellable polymer on a specific portion of the outer surface of the base material and / or the inner surface of the catheter front portion, The surface lubrication layer having excellent peel resistance can be formed by imparting lubricity when wet to the surface of the base material subjected to the treatment.

The catheter to which the present invention can be applied can improve operability and reduce damage to tissue mucous membranes by imparting lubricity to the surface in an aqueous liquid such as body fluid or physiological saline. . Specifically, a catheter or the like including a guide wire used in a blood vessel can be exemplified. (1) Microcatheter for blood vessels such as PTCA vasodilator catheter, microcatheter for cerebral blood vessel or abdominal blood vessel, microcatheter with tip guide wire, etc. (2) 4Fr (4 French: such as angiographic catheter, dilator or introducer indwelling needle, IVH catheter, thermodilution catheter)
Catheter that is inserted or left in a normal blood vessel of 1.3 mm or more. Alternatively, guide wires, stylets, etc. for these catheters. (3) Catheter such as gastric tube catheter, feeding catheter and tube feeding tube, which are orally or nasally inserted or left in the digestive organs. (4) Oxygen catheter, oxygen canula, endotracheal tube tube or cuff, tracheostomy tube tube or cuff,
Catheter such as intratracheal suction catheter that is orally or nasally inserted or placed in the respiratory tract or trachea. (5) Catheter such as urethral catheter, urinary catheter, balloon catheter or balloon, which is inserted or left in the urethra or ureter. (6) Catheter to be inserted or left in various body cavities, organs, tissues such as suction catheter, drainage catheter, and rectal catheter. Of the above catheters, the present invention is preferably applied to a microcatheter which is required to reach in a peripheral blood vessel, and an angiographic catheter having a relatively small diameter, and most preferably applied. , PTC whose catheter front part is composed of multiple materials
A dilatation catheters, micro catheters for brain and abdomen.

The front portion of the present invention refers to the trackability by contacting with the inner wall of the body tube or the narrowed portion in the process of inserting the catheter alone or integrally with the guide wire into the body tube such as a blood vessel. Refers to the site in the catheter that has a large effect. For example, in the case of a microcatheter for the brain and abdomen, it is several tens of centimeters from the leading edge,
Further, in the PTCA dilatation catheter, it is from the most distal end to the straight part of the balloon (a substantially cylindrical part that is in contact with the body tube for expansion), or even a part closer to the proximal side by about several tens of cm. The preferred front area for applying the lubricity treatment of the present invention is described further below.

Typical polymers applicable as a specific base material constituting the catheter front portion are, for example, polyolefin, modified polyolefin, halogenated polyolefin, polyvinyl chloride, polystyrene, various poly (meth) acrylates and poly. Various engineering polymers such as acrylate, polyacrylonitrile, polyether, polyurethane, polyamide (polyamide elastomer), polyester (polyester elastomer), polycarbonate, polyimide, phenol resin, amino-epoxy resin, cellulose derivative, silicone, or various rubber materials The polymers usually used as the material of the catheter can be mentioned. Furthermore, these block or graft polymers, polymer alloys and multi-layered tubes, and combinations thereof, and compounds containing fillers and pigments such as contrast agents, if necessary, may also be included in the material of the present invention. I can. The present invention is preferably applicable even when the catheter front portion is made of a plurality of materials and / or materials. Therefore, a wider range of material options can be created compared to the conventional surface lubricity treatment method that can be applied to certain materials and materials that make up the front part, but is easily peeled off to other materials and materials. .

In the present invention, the UV grafting method is applied to form a water-swellable polymer or the like capable of imparting lubricity on a specific portion of the outer surface of the base material and / or the inner surface of the lumen of the front portion of the catheter. In order to impart excellent surface lubricity, a combination of a base material and a lubricity imparting polymer,
Reaction conditions, reaction devices, etc. can be preferably selected. It is preferable that the front portion of the catheter is washed with an organic solvent such as water or alcohol before the UV graft treatment. The UV grafting method applied to the present invention comprises a reaction step of drawing out hydrogen atoms from a base material and a reaction step of reacting a water-lubricating monomer / polymer with the base material. Therefore, there are a one-step method in which each reaction step is performed at one time and a two-step method in which the reaction steps are allowed to proceed substantially sequentially, both of which can be applied to the present invention. From the viewpoint of the durability of the water-lubricated layer subjected to the graft treatment, the two-step method is often superior to the one-step method. It is obvious to those skilled in the art that the ultraviolet grafting method in the present invention is carried out in a deoxygenated atmosphere / state in both the one-step method and the two-step method.

The one-step UV grafting is performed by using a substrate, a water-lubricating monomer (oligomer) and a hydrogen-abstraction photoinitiator (photo-initiato) in a solvent suitable for UV grafting such as benzene, chlorobenzene, and acetonitrile.
A method of reacting r) under irradiation of ultraviolet rays to introduce a water-lubricating monomer described below to a specific portion of the outer surface of the base material and / or the inner surface of the front portion of the catheter to form a graft polymer layer. Is. It is important to select a reaction solvent that is less likely to cause hydrogen abstraction than the substrate. These solvents can be selected from various ones known to those skilled in the art in the UV grafting technique.

The photoinitiator used in the UV grafting method can be selected from conventionally known compounds suitable for the purpose. Representative compounds are benzophenone and its derivatives. The development of photoinitiator
It has been progressing in recent years, for example, USP 5,414,07.
Japanese Patent Publication No. 5 discloses an example of a molecularly designed photoinitiator. With such a photoinitiator having a high molecular weight, the UV graft reaction can be carried out in the absence of a solvent, which is one of the preferred embodiments.

On the other hand, in the present invention, the water-soluble or water-swellable polymer having lubricity when wet is selected from various conventionally known monomers suitable for the purpose depending on the required mechanical strength and lubricity function. However, it can be selected from those which can be formed as a polymer layer on the surface of the substrate by the UV grafting method. Typical examples of the lubricity imparting polymer applicable to the present invention are given below (the monomer or oligomer is supplied to the reaction system at the start of the UV grafting, but since it is generated as a polymer or the like at the catheter front site, (Listed): Acrylamide, polymer composed of acrylamide derivative (including quaternary amine substitution product), polyvinylpyrrolidone, various polymers substituted with sulfonic acid, polyvinyl alcohol, polymer having polyethylene glycol chain, N, N
Mention may be made of dimethylaminoethyl acrylate. Further, a sugar such as chito acid, a cellulose derivative, a glycogen derivative, a polymer having a monomer having a phospholipid in a side chain as a constituent component, or a maleic anhydride-based polymer can be used. The maleic anhydride-based polymer is not limited to water solubility, and may be insolubilized as long as it contains a maleic anhydride-based polymer as a main component as long as it exhibits lubricity when wet. . Further, considering that the polymer is dissolved in the solvent for swelling the base material for coating, a polymer soluble in an organic solvent, that is, an amphipathic polymer can also be used in the present invention.

On the other hand, in the two-stage method UV graft, the base material surface is activated by irradiating the base material with UV light in the presence of a hydrogen-abstraction photoinitiator in a solvent suitable for the above-mentioned UV graft. Then, after introducing the water-lubricating monomer / oligomer, UV irradiation is performed again to graft the water-lubricating polymer, and the water-lubricating polymer is grafted onto the specific part of the outer surface of the base material and / or the inner surface of the catheter front part. It is a method of forming a graft layer of a lubricious polymer.

[0021] In the above-mentioned US Pat. No. 5,414,075, an example of a sheet-like coupon (test piece) is introduced (although there is no description of the site specification of the catheter to which water lubricity is given). In the present invention, unlike the case of the test piece, it is intended to surface-graft on a site having a unique three-dimensional shape and / or lumen structure called a catheter front site. In this way, by imparting water lubricity only to a specific portion, the insertability of the catheter into a body cavity such as a blood vessel is significantly improved. Regardless of the one-step method or the two-step method, in order to achieve accurate grafting to a three-dimensional shape, in place of a low-viscosity liquid phase, a relatively high-viscosity liquid, an aqueous gel, or in a film, A method for carrying out the UV graft can be preferably selected. Of course, a high-viscosity liquid that serves as a medium,
The aqueous gel-like material or film has sufficient UV transparency to allow the UV graft to proceed on the surface of the base material, and when the graft treatment is also performed on the catheter lumen surface, it is also applied to the inside of the distal end of the lumen. Need to penetrate. The catheter with the front part grafted,
It is important to be able to completely remove it by washing with an appropriate solvent in the subsequent step, and further to select one that does not interfere with the hydrogen abstraction reaction from the substrate. When the ultraviolet transparency of the above-mentioned various media is not sufficient or when the processing speed is desired to be increased, a photosensitizer may be used in combination to accelerate the reaction.

Water-lubricating polymer is obtained by irradiation of ultraviolet rays,
After the formation at the target site on the catheter front, the photoinitiator, unreacted monomers and polymers not bound to the base material are removed by washing with an appropriate solvent such as water or alcohol. Washing conditions such as temperature and time can be optimized according to the materials used and the processing chemicals.

The tip portion of the catheter to which water lubricity is to be applied is generally the front portion which is inserted into and enters the body canal such as a blood vessel and its peripheral portion. Of course, depending on the catheter shape, size, purpose of use, etc., the optimum range of the optimum site is finally determined while evaluating the trackability when inserting the blood vessel. Taking a microcatheter to which the present invention is preferably applied as an example, the tip is often selected from several cm to several tens of cm. In the PTCA dilatation catheter which requires particularly high trackability, the lubrication treatment of the balloon tip joint portion, balloon taper portion and balloon straight portion is extremely effective from the leading edge. Further, in the case of a catheter using a relatively hard shaft material, a catheter subjected to a treatment from a distal end portion to a shaft portion passing through a highly curved blood vessel often exhibits good trackability. Also, when applied to an angiography catheter, a suitable site can be selected according to the same judgment criteria as the PTCA dilatation catheter. In each case, a proper blood vessel model or body tube model is prepared in advance, various samples with different positions and lengths of the treated parts, sliding levels of water lubricity, etc. are prepared and compared with each other. It is also possible to determine a suitable treatment site.

Further, by applying a lubricity treatment to the distal end portion of the surface of the lumen of the catheter into which the guide wire is inserted, the slidability of the guide wire is improved and the operability of the guide wire becomes extremely good. The water-lubricating polymer formed by the UV graft treatment of the present invention or a crosslinked product thereof has extremely excellent peeling resistance, can withstand frequent sliding of the guide wire, and is used in a catheter into which the guide wire is inserted. It is suitable as a polymer for lubricity treatment of cavity surfaces. Further, in particular, in the case of a microcatheter, the tip end portion of the catheter is pulled down or the like so that the vicinity of the catheter tip can be made more flexible to prevent damage to the tissue and the catheter can be inserted into more peripheral body cavity tissue. It is preferable to make the inner diameter and the outer diameter smaller than those of other portions. When this processing is performed, the inner diameter of the distal end portion of the lumen into which the guide wire is inserted also narrows, and the slidability with respect to the guide wire tends to decrease at this distal end portion. However, according to the method of the present invention, it is possible to suitably perform lubricity treatment even on such a distal end portion of the lumen, and to obtain a catheter excellent in both flexibility near the catheter tip and guide wire operability. To be In this case, adjustment of the length of the site where lubricity (sliding property) is developed is performed, for example, by inserting a core metal leaving the tip of the lumen for which lubricity is desired to be provided and masking the part other than the tip. It can be carried out by performing an ultraviolet graft treatment in the above state.

[0025]

EXAMPLES The present invention will be specifically described below with reference to examples. (Example 1) A PTCA dilatation catheter (the shaft material of the tip is nylon elastomer for both inner and outer tubes, and the balloon material is nylon elastomer) was subjected to masking against ultraviolet rays from the tip to the half of the balloon straight portion. A partially masked dilatation catheter was placed in a glass UV irradiation device, and deoxygenated acetonitrile was used as a solvent to add benzophenone
High-pressure mercury lamp (UM45 made by USHIO INC.)
2: 450 W) for 20 minutes. After removing the acetonitrile solution under an argon stream, deoxygenate the dimethylacrylamide / benzophenone / acetonitrile solution (weight ratio = 80/5/15) that had been previously deoxygenated, and inject it into the UV irradiation device under an argon stream and again pressurize. The mercury lamp was irradiated for 20 minutes. P processed at the tip
The outer surface of the TCA dilatation catheter and the lumen of the inner tube were first cleaned with alcohol and then immersed in saline or water and showed excellent lubricity. Further, it was confirmed that even if it was washed all day and night in running water, it had the lubricity before washing and was excellent in durability.

Comparative Example 1 In exactly the same manner as in Example 1,
The catheter coated with the homopolymer solution of polydimethylacrylamide once exhibited excellent lubricity when immersed in physiological saline or water. However, it was confirmed that after overnight cleaning with running water, it had little lubricity and low durability. A decrease in lubricity was also observed with time even in a catheter coated with lubricious silicone.

(Embodiment 2) In exactly the same manner as in Embodiment 1,
Similarly, the PTCA dilatation catheter (the shaft material of the tip is nylon for both the inner and outer tubes, and the surface material of the balloon is polyester elastomer) was masked while leaving the entire balloon straight portion from the leading end. Hereafter, the tip portion of the catheter which had been subjected to the same UV graft treatment and washing as in Example 1 was shown to have excellent lubricity when immersed in physiological saline or water. Further, it was confirmed that even if it was washed all day and night in running water, it had the lubricity before washing and was excellent in durability.

Example 3 Using the dilatation catheters obtained in Examples 1 and 2 and Comparative Example 1 and untreated dilatation catheters, using a cardiovascular model made of a vinyl chloride tube, A model evaluation of peripheral accessibility of each catheter was performed. Example 1 Catheter Tracker Good Good Comparative Example 1 Tracker Badness Example 2 Tracker Good Good Untreated Tracker Badness

(Example 4) In the same manner as in Example 1, single-step method UV grafting was carried out. That is, a deoxygenated dimethylacrylamide / benzophenone / acetonitrile solution (weight ratio = 30/5/65) was injected into the ultraviolet irradiation device under an argon stream, and the high pressure mercury lamp was irradiated again for 30 minutes. The solution during irradiation became increasingly viscous. It was confirmed that even if the graft-treated catheter was washed in running water all day and night, it had the lubricity before washing and was excellent in durability.

Reference Example 1 In the same procedure as in Example 1, an ultraviolet treatment of the inner surface of the tube was tried. First, a nylon elastomer tube (inner diameter 2.6 mm, thickness 50 μm, length 1 m) was filled with a deoxygenated dimethylacrylamide / benzophenone / acetonitrile solution (weight ratio = 30/5/65) in advance. Then, a high-pressure mercury lamp was irradiated for 20 minutes using an optical fiber ultraviolet irradiation device. The liquid in the tube, the lumen of which was graft-treated, was drained and then washed in running water for 24 hours. It was confirmed that the product has sufficient lubricity even after cleaning and has excellent durability.

(Embodiment 5) PTCA dilatation catheter (shaft central portion 3.2 Fr. (1.1 mm), tip portion 2.
8 Fr. (0.93 mm)) was used, and the ultraviolet irradiation was performed after the solution was suctioned using a nispoid immediately before the ultraviolet irradiation and the solution was drawn into the catheter inner tube for more than 10 cm, and then the ultraviolet irradiation was performed. The ultraviolet rays of the first step were irradiated in exactly the same manner. Then, the solution in the lumen of the inner tube was replaced with a deoxygenated dimethylacrylamide / benzophenone / acetonitrile solution using a mini-spid under an argon stream, and then a second stage of ultraviolet irradiation was performed. On the other hand, in another catheter of the same type, the core metal was inserted into the inner tube, and the same grafting treatment was performed in a state of protruding several centimeters from the tip. When a guide wire of 0.014 inch (0.3556 mm) was used to evaluate the slidability of both guide wires, the catheter grafted to the distal end of the inner tube was superior.

[0032]

As described above, the catheter having the insertion front portion having lubricity according to the present invention exhibits excellent trackability when inserted into a body vessel such as a blood vessel. In particular, when it is inserted into a body cavity having a high degree of flexion and marked stenosis, the insertion resistance at the tip is remarkably reduced, so that the effect is remarkable. In this sense, it goes without saying that the catheter to which the present invention is preferably applied is a so-called microcatheter. That is, in a microcatheter, the shaft itself is generally thinned, and the trackability of the catheter as a whole is also lowered due to the lowered pushability of the catheter. Further, according to the method for manufacturing a catheter having an insertion front portion having lubricity, by imparting water lubricity to the catheter front portion, the reachability to end-use is significantly increased even in a micro catheter having a small diameter. Improve to. Further, for example, the peeling resistance of the slidability-treated layer, which has occurred during the conventional procedure using silicon oil, glycerin, or the like, is significantly improved. That is, unlike the conventional method, in the present invention, since it is immobilized on the surface of the substrate, it is possible to obtain a medical device having high durability and safety without peeling or elution. Further, since the polymer that is the treated layer exhibits lubricity when wet, the peeling resistance is remarkably improved in combination with the effect of reducing the resistance when the polymer is inserted into the body. As described above, the catheter of the present invention has effects of improving operability, reducing damage to tissue mucosa, and reducing patient pain, and is extremely useful. In addition, when the water-lubricating polymer or a cross-linked product thereof is formed at the tip of the catheter lumen surface into which the guide wire is inserted, the guide wire operability of the catheter can be improved. Also,
In the vicinity of the tip of the catheter, both the outer diameter of the catheter and the inner diameter of the lumen into which the guide wire is inserted are thinner than other portions, and the water-lubricating polymer or its crosslinked product is thinner. When it is formed on the surface of the inner lumen at the distal end of the inner lumen, it is possible to obtain a catheter that is less likely to damage the tissue, can be inserted into a more peripheral body cavity tissue, and has excellent guide wire operability of the catheter. it can.

Claims (5)

[Claims] 1. A UV-grafting method is used to form a water-lubricating polymer or a cross-linked product thereof on a specific portion of the outer surface of the base material and / or the inner surface of the front portion when inserting a catheter into a body cavity. A catheter having an insertion front portion having lubricity, wherein the treated portion is provided with wet lubricity and peel resistance. 2. A liquid film or coating film of a compound having a hydrogen abstraction ability is formed on a specific portion of the outer surface of the base material and / or the inner surface of the lumen of the catheter front portion by ultraviolet irradiation, and then the film is simultaneously irradiated with ultraviolet rays. Alternatively, a method for producing a catheter having an insertion front portion having lubricity is characterized by imparting lubricity when wet and peeling resistance by sequentially performing a graft treatment with a water-lubricating polymer. 3. The catheter according to claim 1, wherein the catheter front portion is made of a plurality of different materials and / or materials. 4. The catheter according to claim 1 or 3, wherein the water-lubricating polymer or a crosslinked product thereof is formed at the tip of the inner surface of the catheter into which the guide wire is inserted. 5. The water-lubricating polymer or its cross-linking structure, wherein both the outer diameter of the catheter and the inner diameter of the lumen into which the guide wire is inserted are made smaller in diameter near the distal end of the catheter than other portions. The catheter according to claim 1 or 3, wherein an object is formed on the surface of the lumen at the tip of the lumen having a reduced diameter.