JP2003275228A - Medical tubular material and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a medical tubular material having an excellent kink resistance and flexibility and its manufacturing method. <P>SOLUTION: The tubular material includes a two-layer structure of at least an inner layer and an outer layer. The outer layer is constituted of a more rigid material than the inner layer and the outer layer has a groove which reaches the inner layer from the outer layer, but spirally or annularly forms an outer periphery of the tubular material in a depth which does not pass through the inner layer. In this material, a dynamic compliance specified according to an ISO 7198 is 1 %/100 mmHg or more or a crushing drag is 500 gf or less. The outer layer may be porous. The material can quickly deal with a change in a flow rate even when a fluid changing at a flow rate is passed through its interior by assuring the kink resistance and the predetermined dynamic compliance. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a medical tubular body having flexibility, kink resistance, and biocompatibility, an artificial blood vessel, an esophagus, a trachea or a bile duct, and a method for producing the medical tubular body.

[0002]

2. Description of the Related Art A medical tubular body such as an artificial blood vessel, an artificial trachea, an artificial bile duct, or a catheter is used not only in a straight state but also in a bent state. It is necessary that the tubular body is not bent or twisted even in the closed state.

Generally, when a tubular structure is bent, a tensile force is applied to the outside of the bending portion and a compressive force is applied to the inside of the bending portion, and this tensile force or compressive force is the limit of the extensibility or contractility of the tubular structure. If it exceeds, it is difficult to maintain the annular shape of the cross section and a kink occurs. The conventional method of preventing kink in a medical tubular body is roughly classified into (1) a method of making the tubular body stretchable and (2) a method of enhancing the retainability of the annular shape of the cross section.

As a method of imparting elasticity to the tubular structure (1), there is a method of processing the wall surface of the tubular body into a bellows shape. US Pat. No. 5,866,217 describes a silicone / dacron tubular body suitable for arteriovenous graft conduits for dialysis. The innermost layer of the tubular body is a non-porous fusion layer, on which a porous silicon intermediate layer is formed. An uncured silicon bead is wound on the intermediate layer and then cured to form a spiral silicon bead. This spiral silicon bead can provide a structure capable of maintaining an annular cross section even under a compressive force generated by bending with a bending radius of 1 cm or less, and enhances the kink resistance property and anti-crush property when the tubular body is bent. There is. Further, the tubular body is made by right-handed and left-handed winding of PET (polyethylene terephthalate) or Dacron fiber so as to form a continuous spiral on a porous silicon intermediate layer having a spiral silicon bead. The strength against is also secured.

On the other hand, as a method (2) of improving the retaining property of the annular shape, there is a method of reinforcing the outer circumference of a flexible tubular body with a continuous spiral or independent ring-shaped rigid wire. For example, JP-A-2000-197704 discloses a medical tubular body including a lumen formed therein, a soft synthetic resin inner layer, and an outer layer formed of a material harder than the inner layer forming material, A medical tubular body having a groove extending in the lumen direction and not reaching the lumen is disclosed in the outer layer. The tube is used as a catheter, the inner layer and the outer layer are formed by coextrusion, heat fusion, high-frequency fusion, etc., the groove is cut from the outside of the two-layer structure consisting of the inner layer and the outer layer,
It is formed by laser processing. By forming the groove portion in a spiral shape, a spiral outer layer made of a material harder than the inner layer is formed, the annular shape retention property is improved, and the kink resistance property is imparted. Furthermore, since the outermost layer is made of a material that is harder than the inner layer, it is easy to push when inserting the catheter, and the rotation transmitted to the proximal end of the catheter tube is transmitted to the distal end.

[0006]

However, when the tubular structure is processed into a bellows shape in order to impart elasticity, the bellows unevenness is also formed in the innermost layer. When such a tubular body is used as an artificial blood vessel, blood circulating inside is easily trapped by the irregularities and is likely to form a thrombus, which is not preferable.
In addition, when reinforcing the inside or outside of the tubular body with a wire rod, the flexibility of the entire tubular body may be impaired by the wire rod. When this is left in the living body or inserted and used, It is not preferable because it gives excessive stress to the surrounding living tissue in contact.

In particular, various conduits in a living body are inherently provided with a flexibility derived from a living body that can withstand a change in volume. In other words, body fluids that flow in and out of blood vessels, bile ducts, ureters, etc.
Generally, the amount of liquid changes in the living body. Blood vessels transmit pulsation and repeat expansion and contraction, and bile ducts are tubules that introduce bile into the gallbladder when it is excreted from the liver, permitting a change in the amount introduced at any time. This is the same for the ureter, and the change of the introduced amount is allowed according to the excessive amount of urine.

In other words, as medical tubular bodies, there are broadly used catheters, artificial blood vessels, infusion tubes, etc., but the inside of the tubular body is filled with fluid at the time of use, and there is a pressure from the inside of the tubular body toward the outside. There is a case where it is a normal application and a case where such a pressure does not exist, and the strength of the annular shape retention characteristic is different depending on the use situation. Different from balloon catheters for vasodilation and catheters for cerebral blood vessels for injecting embolic substances and coils into aneurysms and arteriovenous malformation tumors in cerebral blood vessels, etc. If the artificial tubular body embedded in the body has a predetermined kink resistance, it is preferable that the artificial tubular body is imparted with affinity to living tissue and appropriate flexibility. However, there is no medical tubular body including an artificial blood vessel or the like that has such kink resistance and flexibility and can tolerate a change in the amount of fluid.

[0009]

Means for Solving the Problems The present inventors have made a detailed study on a medical tubular body that actually has a smaller load on the living body when the medical tubular body is used, and as a result, at least two layers of an inner layer and an outer layer are obtained. A tubular body having a structure, in which the outer layer is made of a harder material than the inner layer and the spiral groove toward the inner layer portion has excellent kink resistance, and the tubular body has a predetermined dynamic compliance. Holding, or having a predetermined crushing resistance to increase biocompatibility,
The present invention has been completed by finding that the biological load is further reduced if the outer layer is porous. That is, the present invention provides the following (1) to (11).

(1) A tubular body including at least a two-layer structure of an inner layer and an outer layer, wherein the outer layer is made of a material harder than the inner layer, and reaches the inner layer from the outer layer but does not penetrate the inner layer. The outer periphery of the tubular body at a depth has a groove forming a spiral shape or an annular shape, and the dynamic compliance defined by ISO7198 is 1% / 100 mmHg or more,
Medical tubular body.

(2) A tubular body including at least a two-layer structure of an inner layer and an outer layer, wherein the outer layer is made of a material harder than the inner layer, and reaches the inner layer from the outer layer but does not penetrate the inner layer. A medical tubular body having a groove forming a spiral or annular shape on the outer periphery of the tubular body at a depth and having a crushing resistance of 500 gf or less.

(3) A tubular body containing at least a two-layer structure of an inner layer and an outer layer, wherein the outer layer is made of a material harder than the inner layer in a porous form and reaches the inner layer from the outer layer. A medical tubular body having a groove that forms a spiral or ring around the outer periphery of the tubular body at a depth that does not penetrate the inner layer.

(4) The space occupancy of the outer layer is 5 to 80%
The medical tubular body according to (3) above.

(5) The medical tubular body according to any one of the above (2) to (4), wherein the dynamic compliance defined by ISO 7198 is 1% / 100 mmHg or more.

(6) The tensile elastic modulus of the inner layer is 0.3 to 2M.
Pa and the tensile elastic modulus of the outer layer material is 30 to 500 MP
The medical tubular body according to any of (1) to (5) above, which is a.

(7) The above (1) to (6) are characterized in that a porous innermost layer is further provided inside the inner layer.
The medical tubular body according to any one of 1.

(8) An artificial blood vessel, esophagus, trachea or bile duct, which comprises the medical tubular body according to any one of (1) to (7) above.

(9) A filament is spirally or annularly placed on the tubular inner layer, and then an outer layer made of a thermoplastic resin harder than the inner layer is provided on the inner layer and the filament. Then, heat treatment is performed, and thereafter, the linear body embedded in the outer layer is taken out by using the cuts provided in the outer layer along both ends of the linear body, and the method for producing a medical tubular body, comprising:

(10) The medical use according to the above (9), characterized in that a porous outer layer portion made of a thermoplastic resin that is harder than the inner layer is provided by melt spraying from the inner layer and the filamentous body. A method for manufacturing a tubular body.

(11) The filament is made of a resin having a glass transition temperature higher than that of the inner layer, and after the outer layer portion is formed, heat treatment is performed at a temperature higher than the glass transition temperature of the inner layer. 9) The method for producing a medical tubular body according to 10).

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION The first aspect of the present invention is a tubular body including at least a two-layer structure of an inner layer and an outer layer, wherein the outer layer is made of a material harder than the inner layer, and the outer layer to the inner layer. ISO 719 having a groove forming a spiral or ring around the outer periphery of the tubular body at a depth reaching the inner layer but not penetrating the inner layer.
Dynamic compliance defined in 8 is 1% / 100m
A medical tubular body having a mHg or more. When a medical tubular body holds a fluid therein such as an artificial blood vessel or an infusion tube, the internal pressure of the fluid tends to maintain the annular shape of the cross section. For this reason, there is a case where a flexible material can be selected as compared with a catheter or the like as compared with a tubular body that does not hold a fluid therein and needs easy invasion into tissue, such as a catheter. Further, in the case of a medical tubular body to be embedded in a living body, flexibility capable of responding to changes in the flow rate is required, and the expandability of the tubular body is prepared in preparation for handling a predetermined amount or more of fluid per unit time. Is preferably secured. The present invention provides a medical tubular body having an excellent balance between kink resistance and flexibility, and as an index of flexibility, the dynamic compliance defined by ISO 7198 is 1% / 100 mmHg or more. did. Hereinafter, the present invention will be described in detail.

FIG. 1 (a) is a sectional view of an embodiment of the medical tubular body of the present invention. The outer shape of the medical tubular body of the present invention is shown in FIG. 1 (b), and the medical tubular body of the present invention is shown. A partially enlarged view of the tubular body is shown in FIG. As shown in FIG. 1 (a), the medical tubular body of the present invention has a two-layer structure including at least an inner layer 30 and an outer layer 40, and a spiral or annular groove 50 reaching the inner layer 30 from the outer layer 40. Are formed. The groove is
There is no penetration through the inner layer 30 and thus through the inner layer from the outer layer of the tubular body. In addition, FIG.
The medical tubular body shown in (b) and (c) has the innermost layer 20 inside the inner layer 30, and the inside of the tubular body is the hollow portion 10. FIG. 2 shows a case where such a medical tubular body is bent.
It is shown in (a), and the groove part extension side of the tubular body cross section at that time is shown in FIG.
FIG. 2C shows the contracted side of the groove in FIG. The circular outer shape is held by the spiral outer layer portion that is harder than the inner layer, and bending stress is dispersed in the groove portion due to expansion and contraction of the groove portion in the bent outer peripheral portion, so that kink can be effectively prevented and the radius of curvature can be reduced.

The inner layer of the medical tubular body of the present invention is preferably made of a flexible and resilient resin material. Such a resin material exhibits rubber-like elasticity near room temperature, does not show a clear yield in the stress-strain relationship during a tensile test, and is capable of allowing a large deformation, and a tensile strain of at least 100%. It is a material that rapidly recovers its original shape and dimensions after unloading even after deformation. The tensile modulus is preferably 0.3 to 2 MPa, more preferably 0.5 to 1 MPa. Examples of such resin materials include general rubber materials, polyalkylene elastomers such as polyethylene elastomer, polypropylene elastomer, and polybutene elastomer; polyolefin resins such as soft vinyl chloride and ethylene-vinyl acetate copolymer, or their resins. Olefin-based elastomers; polyester-based elastomers, polyamide elastomers, urethane-based elastomers, silicone-based elastomers, fluorine-based elastomers, polystyrene-based elastomers, and other thermoplastic elastomers. In the present invention, one of these may be used alone, or two or more thereof may be used in combination. A polymer alloy or polymer blend based on these resins or elastomers can also be used.

Here, as the polyester elastomer, a block copolymer of a saturated polyester such as polyethylene terephthalate or polybutylene terephthalate and a polyether or polyester is typical. In addition to the above, the polyester elastomer includes a polymer alloy of the above polyester elastomer, a softened version of the above saturated polyester with a plasticizer, and a mixture thereof.

Examples of polyamide elastomers include nylon 6, nylon 64, nylon 66, nylon 610, nylon 612, nylon 46, nylon 9, nylon 11, nylon 12, N-alkoxymethyl modified nylon, hexamethylenediamine-isophthalic acid. Block copolymers having various aliphatic or aromatic polyamides such as polycondensation polymers and metaxyloyldiamine-adipic acid polycondensation polymers as hard segments, and polymers such as polyesters and polyethers as soft segments are typical. . In addition to the above, the polyamide elastomer may be a polymer alloy (polymer blend, graft polymer, random polymer, etc.) of the polyamide and a resin having high flexibility, or one obtained by softening the polyamide with a plasticizer or the like. Also includes mixtures of these. As the plasticizer, it is preferable to use one that is difficult to be extracted with a solvent or body fluid such as blood.

The elastomer may include an alloying agent, a compatibilizing agent, a curing agent, a softening agent, a stabilizer, if necessary.
You may mix | blend various additives, such as a coloring agent. In this case, it is preferable to use an additive component that is difficult to be extracted with a solvent, a drug solution, a body fluid such as blood, or the like. Further, the elastomer is preferably thermoplastic, and if it is thermoplastic, the tubular body can be easily manufactured.

Although the thickness of the inner layer varies depending on the material used, it is generally preferably 100 to 800 μm, more preferably 200 to 600 μm. 10
If the thickness is less than 0 μm, the rigidity of the tubular body may be insufficient and the kink resistance may be impaired. On the other hand, when it exceeds 800 μm, the groove shape of the tubular body has an excessive height with respect to the width, and there is insufficient room for bending, so that kink easily occurs. Also,
The medical tubular body of the present invention has a groove in the outer peripheral portion, and the depth of the groove portion reaches not only the outer layer but also the inner layer. When the groove is formed in such an inner layer, the thickness of the thinnest part of the inner layer of the groove is 10 to 2
It is preferably 00 μm, more preferably 10 to
It is 100 μm. If it is less than 10 μm, pinholes are locally generated, which may cause leakage. On the other hand, 20
If it exceeds 0 μm, the elasticity of the tubular body may be insufficient and the kink resistance may be impaired.

As the outer layer, a material which is easily deformed but poor in elasticity and harder than the inner layer is used. In the present invention, “hard” means that the numerical value evaluated by the tensile elastic modulus is higher than that of the inner layer. Preferably 30-500
It is MPa. The ratio of the tensile modulus of the outer layer to the inner layer is
It is preferably 50 to 500 times, and more preferably
50 to 200 times. For this ratio, when the outer layer is porous, a value obtained by multiplying the tensile elastic modulus of the material by the space occupancy rate is used. Here, the space occupancy means the ratio of the material in the porous structure, which will be described in detail later. Below the lower limit, kink resistance may be impaired. on the other hand,
If the upper limit is exceeded, the dynamic compliance will be 1% / 100
It may be smaller than mmHg, and the crushing drag described below may be larger than 500 gf.

The material used for such an outer layer is not particularly limited as long as it is harder than the inner layer, and it is preferable that it is capable of forming porosity, but more preferably a material having an excellent affinity for living tissues. As the outer layer, a polyolefin resin such as polyethylene, polypropylene, polybutene, vinyl chloride, or ethylene-vinyl acetate copolymer or a polyolefin elastomer thereof; polyester resin or polyester elastomer; polyurethane resin or polyurethane elastomer; polyamide or polyamide elastomer Styrene resin or styrene elastomer; polyester resin such as polyethylene terephthalate and polybutylene terephthalate; resin material such as polyvinyl chloride resin, modified polyphenylene ether, polycarbonate, polyacetal, thermoplastic polyimide, etc. It is not limited to the case of using singly, and two or more kinds may be used in combination. It is also possible to use polymer alloys or polymer blends based on these resins. In addition, various additives such as an alloying agent, a compatibilizing agent, a curing agent, a softening agent, a stabilizer, and a coloring agent may be added to the material of the outer layer, if necessary.

The thickness of the outer layer is preferably 20 to 500 μm, more preferably 100 to 200 μm. If it is less than 20 μm, the rigidity of the tubular body may be insufficient and the kink resistance may be impaired. On the other hand, when it exceeds 500 μm, the groove shape of the tubular body has an excessive height with respect to the width, and there is insufficient room for bending, so that kink easily occurs.

The medical tubular body of the present invention requires a spiral or annular groove provided from the outer layer to the inner layer. The groove is formed so as to reach the inner layer from the outer surface of the outer layer and not to penetrate the inner layer, and to form a spiral or annular groove on the outer periphery of the tubular body. This is because if the hard outer layer remains in the groove, the bending stress is not absorbed by the hardness of the outer layer during bending, and a kink is likely to occur. By providing such a groove, it is possible to provide the tubular body with the ability to retain the annular shape, and at the same time to provide the tubular body with elasticity and flexibility.

When the grooves are formed in a spiral shape, the pitch is preferably 2 to 10 per unit when the outer diameter of the outer layer is one unit. If the pitch is less than 2, the kink may not be prevented because the stress due to the bending and bending of the blood vessel is not sufficiently dispersed. Also,
If it exceeds 10, the rigidity of the entire tubular body is lowered, so that kinks may occur rather on the contrary. The pitch does not have to be a uniform pitch over the entire medical tubular body, and the pitch can be continuously widened or narrowed from the tip to the other end, or different pitches can be arranged throughout. . In FIG. 1A, the unit of the medical tubular body is indicated by p, and the pitch of the medical tubular body is 5.

The width of the groove is 3 to 30 with respect to the inner diameter of the tubular body.
%, More preferably 5 to 20%. If the width of the groove is less than 3% of the inner diameter, the elasticity of the tubular body is insufficient, which may cause kinking. On the other hand, when the width exceeds 30%, the rigidity of the tubular body may be insufficient and the kink resistance may be impaired. The width of the groove does not need to be uniform over the entire area of the medical tubular body, and can be appropriately selected within the above range. In FIG. 1C, the width of the groove of the medical tubular body is indicated by w.

The interval between the grooves is 10 to 60%, more preferably 20 to 50% of the inner diameter of the tubular body. 1
When it is less than 0%, the rigidity of the tubular body may be insufficient and kink resistance may be impaired, while when it exceeds 60%, the elasticity of the tubular body may be insufficient and kink may occur. Further, the ratio of the outer layer to the outer surface of the tubular body should be 50% or more. If it is less than 50%, the rigidity of the tubular body may be insufficient and the kink resistance may be impaired. The distance between the grooves is the distance from the groove center, and the distance does not need to be uniform over the entire area of the medical tubular body, and can be appropriately selected within the above range. In FIG. 1C, the distance between the grooves of the medical tubular body is indicated by d.

The medical tubular body of the present invention is suitable for artificial blood vessels, bile ducts, ureters, esophagus, trachea and the like. Therefore, the total length of the medical tubular body can be appropriately selected depending on the intended use, and a long product can be manufactured and cut into a desired length for use. Similarly, the inner diameter of the medical tubular body can be appropriately selected depending on the application. When used for an artificial blood vessel, an inner diameter of about 5 to 50 mm is suitable, for an artificial bile duct, 3 to 10 mm, for an artificial ureteral tube, 3 to 10 mm, for use in an artificial esophagus, 10 to 30 mm, and an artificial trachea. 10 to 20 mm is suitable for use. The wall thickness of the medical tubular body can be appropriately selected according to the purpose of use, and when used for an artificial blood vessel, it is preferably about 0.5 to 2.0 mm, and for an artificial bile duct, 0.5. ~ 1.0mm, 0.5 ~ 1.0mm for artificial ureter, 1.0 ~ 2.0mm for artificial esophagus, 1.0 ~ for artificial trachea
2.0 mm is suitable.

The medical tubular body of the present invention may have an innermost layer consisting of one or more layers on the cavity side of the inner layer and / or in a manner included in the inner layer. "Included in the inner layer" means, for example, a polyester plain weave tubular body is used for internal reinforcement of the medical tubular body, and the outer periphery of the tubular body is impregnated or applied with an inner layer resin. . In this case, the reinforcing material is included in the inner layer. As a material for such a reinforcing material, polyester,
There are polyimide, cellulose, polytetrafluoroethylene and the like, which can be appropriately selected according to the purpose of use of the medical tubular body.

The material for providing the innermost layer on the cavity side of the inner layer in contact with the inner layer can be appropriately selected depending on the purpose of use of the medical tubular body. The innermost layer is a portion that comes into contact with the fluid flowing in the medical tubular body, depending on the purpose of use, and an optimal material should be selected. For example,
When used as an artificial blood vessel, a silicone resin, a polyethylene terephthalate resin such as polyethylene terephthalate or polybutylene terephthalate, or a fluororesin such as polytetrafluoroethylene is preferable because it has a low thrombus-forming property.

When the medical tubular body of the present invention is used as an artificial blood vessel, the cavity of the tubular body may be formed whether the innermost layer is composed of one layer or two or more layers. It is preferable that the surface in contact with the part is porous. The porous material preferably has a ratio of materials in the porous body, that is, a space occupancy rate of 5 to 80%, preferably 10 to 50%. This range is suitable for engrafting the endovascular tissue when blood is introduced inside. Further, the porous material is not particularly limited as long as it has a knitted shape, a woven material shape, a non-woven material shape, a foamed shape, or any other structure having a large number of spaces inside. The size of the innumerable spaces forming the porous body has an average length of 5 to 1000 μm, more preferably 10 to 100 μm. This is because if it is less than 5 μm, it becomes difficult for cells of the living tissue to invade, whereas if it exceeds 1000 μm, it becomes difficult for cells of the living tissue to invade. The pore length can be determined by image analysis by taking a stereoscopic microscope photograph or a scanning electron microscope photograph of 100 to 1000 times the porous portion.

The medical tubular body of the present invention has an ISO 7
The dynamic compliance defined in 198 is 1% / 10
0 mmHg or more, more preferably 1 to 1.5% / 100
mmHg. When the dynamic compliance is within this range, the characteristics of the blood vessel of the living body can be approximated, the load on the living body can be reduced, the required strength of the material can be obtained, and the kink resistance is excellent. The dynamic compliance in the present application is 50 to 90 mmHg, 80 to 120 m.
In any of mHg, 110-150 mmHg,
It shall belong to the above range.

The method for producing such a medical tubular body is not particularly limited. As a method of fixing the inner layer and the outer layer, for example, a method of molding a resin composition for the inner layer and a resin composition for the outer layer by coextrusion, a method of bonding the inner layer and the outer layer with an adhesive or a solvent, the inner layer And the outer layer are fusion-bonded (for example, heat fusion, high-frequency fusion), the outer layer is swollen with a solvent to insert the inner layer, the outer layer forming material is dipping, applied, or extruded on the outer surface of the inner layer-constituting tube. The method of coating by a method etc. is mentioned. Further, as a method for forming the groove, cutting processing, laser processing, and the like can be mentioned, but laser processing is preferable for performing highly accurate fine processing, and among the laser processing, excimer laser processing suitable for polymer processing is particularly preferable. preferable. However, when performing groove processing by laser processing, it is necessary to select a material having good laser processing property. In the medical tubular body of the present invention, a tube having a two-layer structure of an inner layer and an outer layer formed in advance is formed with grooves from the outside (hard outer layer side), so that the inner layer and the outer layer can be made thin and thin and It can have excellent properties.

A second aspect of the present invention is a tubular body comprising at least a two-layer structure of an inner layer and an outer layer, wherein the outer layer is made of a material harder than the inner layer and reaches the inner layer from the outer layer. The outer circumference of the tubular body has a groove that forms a spiral or an annular shape at a depth that does not penetrate the inner layer, and the crushing resistance is 500 gf.
The following is a medical tubular body. The difference from the first invention is that the crushing resistance is 500 gf or less regardless of the dynamic compliance defined in ISO 7198. Conventionally, there is no medical tubular body having excellent kink resistance and flexibility at the same time. In the present invention, as the flexibility, the crushing resistance is within a predetermined range. The crushing drag is an indicator of the flexibility of the artificial blood vessel as well as the dynamic compliance.If this crushing drag is small, excessive stress is exerted on the surrounding organs and tissues when implanted in the living body. Little to give. In the specification of the application, “crushing resistance” means FD
A Guidance for the Preparation of Research and Mar
keting Applications for Vascular Graft Prostheses
The crush resistance defined by 1. is preferably 500 gf or less, more preferably 100 to 300.
gf. If the crushing resistance is 500 gf or less, when this is used in the living body and connected to other organs,
For living tissue connected to or adjacent to the medical tubular body,
For example, when the medical tubular body is used as an artificial blood vessel, excessive stress is not forced on a living blood vessel, surrounding muscle tissue, nerve tissue, organs, etc., and pressure on surrounding living tissue can be suppressed. If the pressure is 100 gf or less, the tubular body may be collapsed when pressure is applied from surrounding tissues.

In order to manufacture such a medical tubular body having a crush resistance, the inner layer is preferably made of a flexible and resilient resin material. Tensile elastic modulus is 0.3 ~
The pressure is preferably 2 MPa, more preferably 0.5
~ 1 MPa. The outer layer also has a tensile elastic modulus of 30 to 50.
It is preferably 0 MPa, and the ratio of the tensile elastic modulus of the outer layer to the inner layer is preferably 50 to 500 times,
More preferably, it is 50 to 200 times. As such a resin material, those exemplified as the inner layer material of the first medical tubular body can be preferably used. In the present invention, the outer layer material and the inner layer material described in the above first can be used, and the thickness and other conditions of the inner layer and the outer layer, the formation of the groove portion, and the other conditions are the same as in the first invention. However, among these, styrene-based elastomers, silicone-based elastomers,
It is preferable to use a fluorine-based elastomer and a polyolefin-based resin or polyester-based resin as the outer layer material. As a result, a medical tubular body having a crushing resistance within the above range can be obtained.

Further, in the present invention, the medical tubular body has a crushing resistance of 500 gf or less, and at the same time, the dynamic compliance defined by ISO 7198, which is a feature of the first invention, is 1% / 100 mmHg or more. More preferable. This is because when the medical tubular body is embedded in a living body, it is possible to cope with flexibility that can cope with changes in the flow rate, and it is possible to suppress pressure on a living tissue that is connected to or adjacent to when it is embedded.

The medical tubular body of the present invention may further have an innermost layer consisting of one or more layers inside the inner layer.
The material of such innermost layer can be appropriately selected depending on the purpose of use of the medical tubular body, and the same material as the innermost layer of the first medical tubular body can be used. The use and size of the medical tubular body of the present invention are the same as in the first invention.

A third aspect of the present invention is a tubular body containing at least a two-layer structure of an inner layer and an outer layer, wherein the outer layer is made of a material harder than the inner layer in a porous form, and the outer layer to the inner layer. A medical tubular body having a groove that spirals or forms an outer periphery of the tubular body at a depth that reaches a point that does not penetrate the inner layer. The difference from the first medical tubular body is ISO71
There are no restrictions on dynamic compliance defined in 98, and the outer layer is porous. Since the outer layer is porous, it has excellent biocompatibility, and when it is embedded in a living body such as an artificial blood vessel or a bile duct, stress on the living body is small. Hereinafter, the present invention will be described in detail.

The inner layer of the third medical tubular body of the present invention is preferably made of a flexible and resilient resin material. The tensile modulus is preferably 0.3 to 2 MPa, more preferably 0.5 to 1 MPa. As such a resin material, those exemplified as the inner layer material of the first medical tubular body can be preferably used.

Although the thickness of the inner layer varies depending on the material used, it is generally preferably 100 to 800 μm, more preferably 200 to 600 μm. 10
If the thickness is less than 0 μm, the rigidity of the tubular body may be insufficient and the kink resistance may be impaired. On the other hand, when it exceeds 800 μm, the groove shape of the tubular body has an excessive height with respect to the width, and there is insufficient room for bending, so that kink easily occurs. Also,
The medical tubular body of the present invention has a groove in the outer peripheral portion, and the depth of the groove portion reaches not only the outer layer but also the inner layer. When the groove is formed in such an inner layer, the thickness of the thinnest portion of the inner layer of the groove is the above-mentioned first,
Similarly to the second invention, the thickness is preferably 10 to 200 μm, more preferably 10 to 100 μm. 10
If it is less than μm, pinholes are locally generated, which may cause leakage. On the other hand, when it exceeds 200 μm, the elasticity of the tubular body is insufficient and the kink resistance may be impaired.

As the outer layer, a material which is easily deformed but poor in elasticity and harder than the inner layer is used. In the present invention, “hard” means that the numerical value evaluated by the tensile elastic modulus is higher than that of the inner layer. Preferably 30-500
It is MPa. The ratio of the tensile modulus of the outer layer to the inner layer is
It is preferably 50 to 500 times, and more preferably
50 to 200 times. For this ratio, when the outer layer is porous, a value obtained by multiplying the tensile elastic modulus of the material by a space occupancy rate described later is used. Below the lower limit, kink resistance may be impaired. On the other hand, if the upper limit is exceeded, the dynamic compliance may be less than 1% / 100 mmHg, and the crushing resistance may be greater than 500 gf.

On the other hand, in the outer layer, the ratio of the material in the porous body, that is, the space occupancy rate is 5 to 80%, preferably 1.
It is preferably 0 to 50%. In the present application, the "space occupancy rate" is based on the following measuring method. First,
The porous portion of the outer layer is cut out from the tubular body with a sharp blade. Next, the size of the cut-out portion is measured with a magnifying glass to determine the volume of the space occupied by the cut-out porous portion. Next, the mass of the porous portion is measured, and the mass is divided by the density of the outer layer material to calculate the volume of the space occupied by the outer layer material. Finally, the volume percentage of the volume of the space occupied by the outer layer material with respect to the volume of the space occupied by the porous portion is determined as the space occupancy rate. This is because if the space occupancy rate is in this range, even if the space is buried in the living body, the living tissue can easily enter the buried portion. Further, the porous material is not particularly limited as long as it has a knitted shape, a woven material shape, a non-woven material shape, a foamed shape, or any other structure having a large number of spaces inside. The size of the innumerable spaces forming the pores has an average length of 5 to 1000 μm, more preferably 10 to 100.
μm. If it is less than 5 μm, it becomes difficult for cells to invade the living tissue, while if it exceeds 1000 μm, the density of cell invasion may be reduced.

The material used for such an outer layer is not particularly limited as long as it is harder than the inner layer and can form porosity, but more preferably it is a material having an excellent affinity for living tissues. As the outer layer, a polyolefin resin such as polyethylene, polypropylene, polybutene, vinyl chloride, ethylene-vinyl acetate copolymer or a polyolefin elastomer thereof; a polyester resin or a polyester elastomer; a polyurethane resin or a polyurethane elastomer; a polyamide or a polyamide elastomer Elastomer: Styrene-based resin or styrene-based elastomer; Polyester-based resin such as polyethylene terephthalate and polybutylene terephthalate; Resin materials such as polyvinyl chloride resin, modified polyphenylene ether, polycarbonate, polyacetal, thermoplastic polyimide, and the like. The species are not limited to being used alone, and two or more species may be used in combination. It is also possible to use polymer alloys or polymer blends based on these resins.

The thickness of the outer layer is preferably 20 to 500 μm, more preferably 100 to 200 μm. If it is less than 20 μm, the rigidity of the tubular body may be insufficient and the kink resistance may be impaired. On the other hand, when it exceeds 500 μm, the groove shape of the tubular body has an excessive height with respect to the width, and there is insufficient room for bending, so that kink easily occurs.

The medical tubular body of the present invention requires a spiral or annular groove provided from the outer layer to the inner layer, and the groove pitch, width, and groove-to-groove spacing are the same as those in the first medical treatment. It is similar to the tubular body.

The medical tubular body of the present invention is suitable for artificial blood vessels, bile ducts, ureters, esophagus, trachea and the like. Therefore, the total length of the medical tubular body can be appropriately selected depending on the intended use, and a long product can be manufactured and cut into a desired length for use. Similarly, the inner diameter of the medical tubular body can be appropriately selected depending on the application, and its length is the same as that described in the first invention. The wall thickness of the medical tubular body can be appropriately selected according to the purpose of use, and the wall thickness is also the same as that described in the first invention.

The medical tubular body of the present invention may have an innermost layer consisting of one or more layers inside the inner layer. The material of such innermost layer can be appropriately selected depending on the purpose of use of the medical tubular body, and the same material as the innermost layer of the first medical tubular body can be used.

The medical tubular body of the present invention further comprises an IS.
Dynamic compliance defined by O 7198 is 1%
/ 100 mmHg or more may be sufficient. More preferably, it is 1.1 to 1.5% / 100 mmHg. This is because, by having a dynamic compliance of 1% / 100 mmHg or more, it is excellent in biocompatibility and can easily cope with a change in the amount of fluid in the tube.

Further, it is preferable that the "crushing resistance" which is a feature of the second invention is 500 gf or less. This is because if the crushing resistance is in this range, it is possible to suppress pressure on surrounding living tissues.

The outer layers of the first to third medical tubular bodies of the present invention may be further coated with an antithrombotic material. Examples of the antithrombotic material include heparin, polyalkyl sulfone, ethyl cellulose, acrylic acid ester-based polymer, methacrylic acid ester-based polymer (for example, poly HEMA [polyhydroxyethylmethacrylate]), hydrophobic segment and hydrophilic segment. Block or graft copolymer having both of (for example, HEMA-styrene-HE
MA block copolymer, HEMA-MMA [methyl methacrylate] block copolymer, HEMA-LM
A block copolymer of A [lauryl methacrylate],
PVP [polyvinylpyrrolidone] -MMA block copolymer, HEMA-MMA / AA [acrylic acid] block copolymer), and a blended polymer obtained by mixing these block copolymers with a polymer having an amino group,
And fluorine-containing resins can be used. Preferably H
EMA-styrene-HEMA block copolymer, HE
MA-MMA block copolymer, HEMA-MMA /
Examples thereof include AA block copolymers. Then, it is preferable to coat the blood contact surface with a hydrophilic resin other than heparin described above, and then further fix heparin thereon. In this case, in order to fix heparin to the surface of this hydrophilic resin, the hydrophilic resin has a hydroxyl group, amino group, carboxyl group, epoxy group, isocyanate group, thiocyanate group, acid chloride group, aldehyde group and carbon-carbon. It is preferable to have any of the double bonds or a group that can be easily converted into these groups. It is particularly preferable to use a blended polymer in which a polymer having an amino group is mixed with the hydrophilic resin,
As the polymer having an amino group, polyamine, particularly PEI (polyethyleneimine) is preferable.

Heparin is fixed by coating the above-mentioned hydrophilic resin on the blood contact surface of a medical tubular body, contacting the surface with an aqueous solution of heparin, and then aldehydes such as glutaraldehyde, terephthalaldehyde, formaldehyde, and the like. Diphenylmethane diisocyanate, 2,4-tolylene diisocyanate, carbodiimide-modified diphenylmethane diisocyanate, epichlorohydrin, 1,4
-By contacting with an immobilizing agent such as butanediol diglycidyl ether or polyethylene glycol diglycidyl ether, the hydrophilic resin can be covalently bonded and immobilized. The wall thickness of the coating layer of such an antithrombotic material is preferably minimized to the extent that it does not substantially affect the flexibility or outer diameter of the tube.

In a fourth aspect of the present invention, a filament is spirally or annularly placed on a tubular inner layer, and then an outer layer made of a thermoplastic resin which is harder than the inner layer and the filament on the inner layer. A tubular body for medical treatment, characterized in that the filamentous body embedded in the outer layer is taken out by using a cut provided in the outer layer along both ends of the filamentous body, and then performing heat treatment. Is a manufacturing method. The outer layer portion can be formed into a porous shape by melt spraying. Further, the filamentous body is made of a resin having a glass transition temperature higher than that of the resin forming the inner layer, and it is preferable to perform heat treatment at a temperature higher than the glass transition temperature of the inner layer after forming the outer layer portion. As a method of forming a spiral groove on the outer surface of a medical tubular body by a conventional method, cutting / grinding with a tool such as a blade or laser processing is generally used, but foreign matter is generated in the cutting / grinding process. However, there are drawbacks such as the need for expensive and large processing equipment. According to the present invention, a medical tubular body having a spiral outer layer can be easily manufactured. The manufacturing method is preferable as the manufacturing method for the first to third medical tubular bodies, but is not limited to these.

In the present invention, the filament is spirally or annularly placed on the tubular inner layer. However, in order to ensure workability, the tubular inner layer has a diameter equal to the inner diameter of the medical tubular body in advance. Is preferably provided so as to cover a tubular body such as a stainless steel rod having. Generally, a resin for the inner layer is applied to the stainless rod by coating or impregnation, and a heat-shrinkable film is coated on the rod, and a temperature of 5 °
The inner layer is formed by heating to 0 to 200 ° C. Alternatively, the stainless rod may be coated with an inner layer prepared in a tubular shape in advance. As the resin for the inner layer, the resin used in the first medical tubular body can be preferably used, but the resin is not limited thereto. Also, the thickness of the inner layer is not particularly limited. Generally, the glass transition temperature of the inner layer resin is 35 ° C. or lower. Examples of such resins include general rubber materials, polyalkylene elastomers such as polyethylene elastomer, polypropylene elastomer, and polybutene elastomer; polyolefin resins such as soft vinyl chloride and ethylene-vinyl acetate copolymer, and olefins thereof. -Based elastomers: polyester-based elastomers, urethane-based elastomers, silicone-based elastomers, fluorine-based elastomers, polystyrene-based elastomers, and other thermoplastic elastomers, all of which can be preferably used.

In the present invention, the filament is mounted on this inner layer in a spiral or annular shape. In order to mount the linear member in a spiral shape, it is convenient to mount the linear member while rotating the stainless steel rod. At this time, the linear body is to be removed later to form a groove, and when the first or second medical tubular body is manufactured by this manufacturing method, it is optimal in each of the above ranges. A filament having an inner diameter may be used. Further, when manufacturing a tubular body outside the above range, a filament body having an inner diameter capable of forming an optimum groove portion may be used. The depth of the groove can be controlled by the diameter of the filament to be wound, the tension of the filament during winding, and the heating temperature and time.

The material of the filament is stainless steel, copper wire, N
It may be a metal such as an i-Ti alloy or a resin filament. The shape may be a single linear filament or a metal particle filament in which metal particles or resin particles are connected to the filament. Metal is preferable because it is easy to reuse,
In particular, the metal particle filaments can be used without depending on the spiral deformation formed during the previous use. Further, in the case of a resin filament, since it is a material that is flexible enough to be wound around the inner layer and withstands the temperature at the time of heating, it has a glass transition temperature higher than that of the resin for the inner layer. Is preferred. When the glass transition temperature is lower than that of the resin for the inner layer during heat treatment after the formation of the outer layer, the inner layer may be partially depressed, fused, fixed, and difficult to take out.

In the case of a resin filament, the filament may have a melting point higher than the melting point of the outer layer material, preferably 200 ° C. or higher, more preferably 250 ° C. or higher.
As the resin having such a melting point, polyester,
Polyamide and polysulfone are available.

In the present invention, a thermoplastic resin that is harder than the inner layer is then applied, coated, and coated on the inner layer and the filament.
The outer layer portion is formed by a method such as impregnation or melt spraying. The outer layer resin preferably has a lower softening point and a higher melting point than the thinning processing temperature. It may be difficult to satisfactorily bond the inner layer and the outer layer during the thinning processing. On the other hand, if the melting point is lower than the thin forming processing temperature, the outer layer may melt during the thin forming processing heat treatment, and the structure such as the porosity of the outer layer may collapse.

Such a resin for the outer layer can be appropriately selected according to the purpose of use of the medical tubular body, and polyethylene,
Polypropylene, polybutene, vinyl chloride, ethylene-
Polyolefin resins such as vinyl acetate copolymers or their polyolefin elastomers; polyester resins or polyester elastomers; polyurethane resins or polyurethane elastomers; polyamide or polyamide elastomers; styrene resins or styrene elastomers; polyethylene terephthalate, polybutylene Polyester resins such as terephthalate; resin materials such as polyvinyl chloride resin, modified polyphenylene ether, polycarbonate, polyacetal, thermoplastic polyimide, and the like, which are not limited to the case where one of these is used alone. You may use together.

When the outer layer portion is formed by a melt-spraying method in which the outer layer resin is melted and linearly supplied, the outer layer constituent resin is sprayed onto the inner layer and the filamentous body in a mist or fibrous form by blowing air. A non-woven porous body is formed. As such a porous material, the space occupancy rate, the average length of the space portion, and the like can be selected according to the purpose of use of the medical tubular body. Generally, the porous body of the outer layer has a space occupancy rate of 5 to 80%, preferably 10 to 50%, and the innumerable space portions forming the pores have an average length of 5 to 1000 μm. , And more preferably 10
It is 100 μm. To form such a porosity,
Depending on the type of outer layer resin used, the outer layer material melted at a temperature higher than the melting point of the outer layer resin by 50 ° C. or more is 0.02 min. The outer layer is blown at a rate of 2.0 g, and air heated to a temperature higher than the melting point of the outer layer material is blown from the outer tube of the double tube at a rate of 10 to 80 liters per minute, while the outer layer is blown to form a porous layer. You can

In the present invention, heat treatment is performed after forming the outer layer portion. The heat treatment includes, for example, a method in which a heat-shrinkable film is coated on the outer layer portion and heated to a temperature higher than the glass transition temperature of the inner layer and lower than the melting point of the outer layer member. When the temperature of the heat treatment is lower than the glass transition temperature of the inner layer, the inner layer does not change and the groove structure is not formed. On the other hand, when heat treatment is performed at a temperature higher than the melting point of the outer layer, the filament and the outer layer are fused,
It becomes impossible to remove the filaments after heat treatment.

Then, after cooling to room temperature, the filaments embedded in the outer layer are taken out by using the cuts provided in the outer layer along both ends of the filaments. How to make a break is cutting,
Any method such as laser processing may be used.

According to the manufacturing method of the present invention, since the groove is formed by using the filamentous body, there is no corner. The rounded shape of the bottom surface of the groove makes it possible to moderately change the physical properties at both ends of the groove, as compared to a rectangular shape, and the curvature is good, especially A medical tubular body having excellent biocompatibility can be obtained.

According to the method for producing a medical tubular body of the present invention, it is possible to produce various medical tubular bodies which prevent kinking of artificial blood vessels, esophagus, bile ducts, trachea, infusion tubes, catheters and the like.

[0071]

EXAMPLES The present invention will be specifically described below with reference to examples.

Example 1 A stainless steel rod having a diameter of 6 mm was covered with a polyester knitted tubular body. Inner diameter of 6 as a member corresponding to the inner layer.
5 mm, 0.4 mm thick styrene elastomer (glass transition temperature about -50 ° C, tensile elastic modulus 0.85 MPa)
Was coated and heat-treated at 100 ° C. for 15 minutes to be fused. On this tubular body, a polyester monofilament having a diameter of 0.85 mm (glass transition temperature 70 ° C., melting point about 27)
(0 ° C) is wound at an interval of about 2.2 mm, and a linear low-density polyethylene resin (glass transition temperature of about -20 ° C, softening point of 90 ° C, melting point of 126 ° C, tensile elastic modulus of 300 MPa) corresponding to the outer layer is wound thereon. About 100μ by melt blown
It was sprayed at a thickness of m and heat-treated at 120 ° C. for 19 minutes. After cooling to room temperature, the outer layer was cut off only at the portion laminated on the polyester monofilament.

By the above method, about 0.08 m at the groove
m, the inner layer having a thickness of about 0.4 mm in other parts,
A medical tubular body having an outer layer having a thickness of about 0.15 mm was obtained. The kink property and flexibility of the tubular body were measured.

When this medical tubular body was bent, the groove portion expanded on the outer side of the curved portion as shown in FIG. 2 (b) and contracted on the inner side of the curved portion as shown in FIG. 2 (c). On the other hand, the portion other than the groove maintained the annular shape of the cross-section of the tubular body without expanding or contracting.

With respect to the medical tubular body, dynamic compliance and kink resistance were evaluated by the following methods. The results are shown in Table 1.

Evaluation method (1) The dynamic compliance is ISO 7198 (Card) which is an international standard in the evaluation test method of medical tubular bodies.
iovascular implants-Tubular vascular prostheses 8.
10 Determination of dynamic compliance).

Specifically, the specimen was attached to a pulsation test device capable of loading a sinusoidal internal pressure change in a constant temperature water bath at 37 ° C. and a test speed of 1 Hz was 50 to 90 mm.
Hg and 80 to 120 mmHg, 110 to 150
A change in outer diameter when a pulsatile pressure was applied in each pressure range of mmHg was measured with a laser measuring instrument.

The inner radius R _p in the pressurized state is calculated from the outer diameter D _p and the wall thickness t when the pressure is measured by a laser outer diameter measuring device.

[0079]

[Equation 1]

And the minimum pressure is p ₁ (mmHg)
And from the maximum pressure p ₂ (mmHg),

[0081]

[Equation 2]

According to the dynamic compliance C _d (% /
100 mmHg) was calculated.

(2) Kink resistance was evaluated according to ISO 71
98 (Cardiovascular implants-Tubular vascular pros
theses 8.9 Determination of kink diameter / radius)
It was carried out according to.

The crush resistance was measured using the medical tubular body obtained in Example 1. The measurement method is FDA
Guidance for the Preparation of Research and Marke
tingApplications for Vascular Graft Prostheses 12.
6 Conducted in accordance with Determination of crush resistance. That is, two stainless steel flat plates with a width of 50 mm are attached to the upper and lower sample grips of the tensile / compression test device so that the surfaces are parallel to each other, and the upper and lower flat plate spacing is 10 m.
Adjusted to m. A medical tubular body sample (length 100 mm) produced as an artificial blood vessel of Example 1 and Comparative Example 2 was allowed to stand between the flat plates, and was compressed and displaced by 6 mm at a speed of 100 mm / min. The displacement was recorded. Starting from the point where the flat plate contacts the sample in each sample, 1.
The load value when displaced to 5 mm was crushed and used as the drag force. The results are shown in Table 1.

Comparative Example 1 Using the same resin for the inner layer and the outer layer as in Example 1, a tubular body in which the inner layer and the outer layer were adhered to each other was manufactured, and a polyester having a diameter of 0.35 mm was formed on the outer layer. The body was helically coated to produce a medical tubular body with external reinforcement. The medical tubular body does not have a groove that forms a spiral or ring around the outer periphery of the tubular body at a depth that reaches the inner layer from the outer layer but does not penetrate the inner layer.

The crushing drag of the tubular body was measured.
As a result, the crushing resistance was 1848.6 gf.

[0087]

[Table 1]

Example 2 The same medical tubular body as in Example 1 was prepared by the melt blown method using the outer layer resin of Example 1 except that the space occupancy rate was 67.8%. The kink resistance, crushing resistance and dynamic compliance of the medical tubular body were measured. The results are shown in Table 2.

[0089]

[Table 2]

Example 3 A polyolefin resin porous material having a space occupancy of 90%, 64%, 32% and 31% was prepared by the melt blown method using the outer layer resin of Example 1. The porosity was embedded subcutaneously in the dorsal part of the rabbit and the tissue penetration was examined. The evaluation of tissue penetration was performed as follows. Two to four samples were implanted subcutaneously in the back of 16 normal Japanese White Rabbits (body weight 2.4 to 3.2 kg), and extracted one month and three months later. The obtained sample was fixed with 10% neutral formalin and then embedded in paraffin by a conventional method to prepare a thin section. HE staining and Azan staining were applied to this section,
It was subjected to a histopathological search.

Extraction was carried out 1 month and 3 months after implantation,
As a result of the evaluation, the space occupancy rate is 64%, 32% and 31.
% Non-woven fabric showed better mesenchymal cell invasion and collagen production than the non-woven fabric having 90% space occupancy.

[0092]

Industrial Applicability The medical tubular body of the present invention comprises at least an inner layer and an outer layer harder than the inner layer, and the outer layer has a spiral or annular groove reaching the inner layer. When such a tubular structure is bent, the groove portion extends outside the bending portion and the groove portion contracts inside the bending portion to relieve the bending stress and effectively prevent kink. Moreover, since the inner layer and the outer layer are each made of a flexible and resilient resin material,
It ensures a given dynamic compliance and excels in operability when handling varying fluid volumes. Further, by forming the spiral groove by winding the filament on the inner layer and heating it, it is possible to easily and inexpensively form the groove without generation of foreign matter.

[Brief description of drawings]

FIG. 1 is a front view (a), a side view and a sectional view (b) in a non-curved state, and an enlarged sectional view (c) in a non-curved state in an embodiment of the present invention.

FIG. 2 is a side view (a) of a medical tubular body of the present invention when curved, an enlarged outer cross-sectional view (b) when curved, and an enlarged inner cross-sectional view (c) of when curved.

[Explanation of symbols]

10 ... cavity, 20 ... innermost layer, 30 ... inner layer, 40 ... outer layer, 50 ... groove.

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 4C081 AB12 AB13 AB15 BB07 BB09                       CA03 CB011 CB05 DA03                       DB03 DC01                 4C097 AA14 AA15 AA17 BB01 CC02                 4C167 AA01 AA06 BB13 BB47 CC08                       CC10 CC12 GG02 GG03 GG04                       GG05 GG06 GG07 GG08 GG09                       GG10 GG22 GG24 GG36 GG42                       GG46 HH04 HH18

Claims (11)

[Claims] 1. A tubular body including at least a two-layer structure of an inner layer and an outer layer, the outer layer being made of a material harder than the inner layer, and a depth reaching from the outer layer to the inner layer but not penetrating the inner layer. The medical tubular body having a groove forming a spiral shape or an annular shape on the outer circumference of the tubular body and having a dynamic compliance defined by ISO 7198 of 1% / 100 mmHg or more. 2. A tubular body including at least a two-layer structure of an inner layer and an outer layer, the outer layer being made of a material harder than the inner layer, and a depth reaching from the outer layer to the inner layer but not penetrating the inner layer. A medical tubular body having a groove forming a spiral or an annular shape on the outer periphery of the tubular body and having a crushing resistance of 500 gf or less. 3. A tubular body including at least a two-layer structure of an inner layer and an outer layer, wherein the outer layer is made of a material harder than the inner layer and is porous, and the inner layer extends from the outer layer to the inner layer. A medical tubular body having a groove that forms a spiral or an annular shape on the outer periphery of the tubular body at a depth that does not penetrate the tubular body. 4. The medical tubular body according to claim 3, wherein the space occupancy of the outer layer is 5 to 80%. 5. The medical tubular body according to any one of claims 2 to 4, wherein the dynamic compliance defined by ISO 7198 is 1% / 100 mmHg or more. 6. The medical tubular body according to claim 1, wherein the inner layer has a tensile elastic modulus of 0.3 to 2 MPa, and the outer layer material has a tensile elastic modulus of 30 to 500 MPa. 7. The medical tubular body according to any one of claims 1 to 6, further comprising a porous innermost layer inside the inner layer. 8. An artificial blood vessel, esophagus, trachea or bile duct, which comprises the medical tubular body according to any one of claims 1 to 7. 9. A filamentous body is placed spirally or annularly on a tubular inner layer, and then an outer layer portion made of a thermoplastic resin harder than the inner layer is provided from the inner layer and the filamentous body, and then. A method for producing a medical tubular body, characterized by performing a heat treatment, and thereafter taking out the filamentous body embedded in the outer layer by using cuts provided in the outer layer along both ends of the filamentous body. 10. The medical tubular body according to claim 9, wherein a porous outer layer portion made of a thermoplastic resin that is harder than the inner layer is provided by melt spraying from the inner layer and the filamentous body. Manufacturing method. 11. The filamentous material is made of a resin having a glass transition temperature higher than that of the inner layer, and is heat-treated at a temperature higher than the glass transition temperature of the inner layer after forming the outer layer portion. Or the method for producing a medical tubular body according to 10.