JP6372173B2 - Medical equipment - Google Patents

Description

  The present invention relates to a medical device.

  In recent years, catheters that can be inserted into body cavities such as blood vessels have been developed. In general, a catheter is inserted into a body cavity by a technique called over-the-wire using a guide wire. Prior to the desired branch path, the guide wire is placed in a bent state, and the catheter is covered from the proximal end side and pushed along the guide wire. Thereby, a branch path can be selected. In order to select a desired branch path in the branch of the body cavity and to advance in the insertion direction, the catheter is generally formed to be reasonably flexible. For this reason, the catheter is generally long and includes a flexible resin tube. In particular, there has been proposed a catheter provided with a resin tube that can be applied to a thin body cavity with many branches and bends in a complicated manner, such as a blood vessel terminal region, etc., so that the branch can be selected well.

  For example, the catheter described in Patent Document 1 (hereinafter, also referred to as “prior art 1”) has a structure in which the proximal end portion is relatively stiff and gradually has flexibility toward the distal end portion. The resin outer layer is configured to have a low hardness. Specifically, a resin tube that is an outer resin layer is configured by using four types of polyetheresteramide elastomers having different Shore D hardnesses in order of decreasing hardness from the base end portion toward the tip end portion. Patent Document 1 describes that the hardness of the four types of polyetheresteramide elastomer is proportional to the weight ratio of the hard segment of the polyetheresteramide elastomer.

JP 2007-82802 A

  By the way, the catheter advances in the body cavity so as to be pushed in the advance direction along the guide wire in a non-branching region or a branch passage having a relatively large inner diameter and a gentle bending angle. Therefore, it is preferable that the catheter has an appropriate rigidity in addition to the slidability with respect to the guide wire to such an extent that good pushability is exhibited including the distal end portion. That is, the resin tube provided in the catheter is required to have a rigidity that can achieve good pushability.

  On the other hand, when reaching an area where branch selection is not easy, such as a branch path with a narrow inner diameter and a sharp bending angle, the tip of the resin tube is preferably flexible in order to obtain good branch selectivity. . Accordingly, the catheter can be inserted into a desired branch path while the bending state of the guide wire placed in the branch path is maintained in the body cavity. However, if the distal end is stiff, when the catheter is pushed along the guide wire, the distal end portion of the guide wire cannot be placed in a bent state in a desired branch path, and branch selectivity may be poor. is there.

  In this way, it is possible to exhibit good pushability including the distal end, and respond to the complex demands such that the distal end of the catheter in the branching path exhibits flexibility to the extent that it exhibits good branching selectivity. Obtaining catheters have not yet been proposed.

  The present invention has been made in view of the above problems. That is, the present invention provides a medical device including a resin tube with good branch selectivity while maintaining good pushability in a complicatedly bent body cavity or an extremely thin body cavity such as a blood vessel terminal region. And

  The medical device of the present invention is long and flexible, has a medical device body inserted into a body cavity, the medical device body has a long resin tube, A first region composed of a first resin member, and a second region composed of a second resin member that is a resin member different from the first resin member and located closer to the first region. The difference X between the resin hardness of the first resin member measured at room temperature and the resin hardness of the first resin member measured after standing for a predetermined time in a temperature environment of 38 ° C. is measured at room temperature. The difference Y between the resin hardness of the second resin member and the resin hardness of the second resin member measured after being allowed to stand in a temperature environment of 38 ° C. for a predetermined time is greater.

  The present invention includes a resin tube in which a distal end portion is softer than a proximal end portion under a predetermined condition. Thus, the medical device of the present invention has good branch selectivity while maintaining good pushability in a complicatedly bent body cavity or an extremely thin body cavity such as a blood vessel terminal region.

1 is an overall view of a catheter in a first embodiment of the present invention. It is a longitudinal cross-sectional view of the front-end | tip part of the catheter main body which is a 1st embodiment. It is explanatory drawing of the front-end | tip part of the catheter main body which is a 1st embodiment.

Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. In all the drawings, the same components are denoted by the same reference numerals, and redundant description will be appropriately omitted.
The various components of the medical device of the present invention do not have to be individually independent, but a plurality of components are formed as one member, and one component is formed of a plurality of members. A certain constituent element is a part of another constituent element, a part of a certain constituent element and a part of another constituent element are allowed to overlap.

The terms in the present invention or terms used in describing the present invention are defined as follows unless otherwise specified.
In describing the present invention, the terms distal end and proximal end may be used where appropriate. Here, the distal end means a predetermined length region including the end (distal end) on the insertion tip side of the medical device main body in the present invention. Moreover, a proximal end part means the predetermined | prescribed length area | region including the edge part (proximal end) of the base end side of the said medical device main body.
In the present invention, the axis means the central axis in the longitudinal direction of the medical device body.
In the present specification, the longitudinal section of a medical device refers to a cross section of a medical device (a catheter in the embodiment) cut through the axis in parallel to the longitudinal direction.
In the present invention, the resin hardness means a physical property value of the resin member itself. For example, the resin hardness of the first resin member or the second resin member can be measured based on a known test method such as Shore hardness. In addition, regarding the resin hardness, when the first resin member or the second resin member contains an additive other than a resin such as a contrast medium or an optional filler, the first resin member or The resin hardness of the second resin member is measured.

<First embodiment>
The configuration of the catheter 100 according to the first embodiment of the present invention will be described below with reference to FIGS.
FIG. 1 is an overall view of a catheter 100 that is a medical device according to the first embodiment of the present invention. FIG. 2 is a longitudinal sectional view of the distal end portion of the catheter 100. FIG. 3 is an explanatory diagram of the distal end portion of the catheter main body 110 according to the first embodiment. The length of the tip shown in FIG. 3 is shorter than the length of the tip shown in FIG. FIG. 3 is a cross-sectional view of the outer tube 10 and the outer layer 60, and a side view of the inner tube 20, the marker 30, and the metal protective layer 40.

The medical device (catheter 100) according to the present embodiment is long and flexible, and has a medical device body (catheter body 110) that is inserted into a body cavity. The medical device main body (catheter main body 110) has a long resin tube (outer tube 10). The resin tube (outer tube 10) is composed of a first region 12 composed of the first resin member and a second resin member which is a resin member different from the first resin member, and is proximal to the first region 12. And a second region 14 located in the region.
In the medical device (catheter 100), the difference X between the resin hardness of the first resin member measured at room temperature and the resin hardness of the first resin member measured after being left for a predetermined time in a temperature environment of 38 ° C. is The difference between the resin hardness of the second resin member measured at room temperature and the resin hardness of the second resin member measured after being left standing in a temperature environment of 38 ° C. for a predetermined time is configured to be larger than Y. Yes.

With this configuration, the outer tube 10, including the first region 12, can have sufficient rigidity to exhibit good pushability when inserted into a body cavity. The first region 12 in the outer tube 10 is significantly softened and the distal end portion of the catheter body 110 is softened while being exposed to body temperature (that is, a temperature of about 38 ° C.) for a while in the body cavity. Branch selectivity is improved.
In the operation of the catheter 100, it is very difficult to improve the branch selectivity at a location where a branch selection is difficult and the selection operation takes a long time, or at a body cavity end region (for example, a blood vessel end region) that reaches a predetermined time. It is advantageous.

  Since the first resin member and the second resin member are different resin members, they can exhibit different temperature characteristics as described above. Here, the difference is that the first resin member and the second resin member are each composed of one different kind of resin, one is a composition comprising one resin and the other comprising a plurality of different kinds of resins, Embodiments in which each is a composition comprising a plurality of different resins are included. For example, the first resin member and the second resin member may be the same resin composition in which two or more resin components are contained in each other and may have different component ratios.

  For example, when the catheter 100 enters the blood vessel from a predetermined location and enters a desired living tissue, if a branch selection is difficult to reach, a predetermined time is required for the branch selection operation. . In such a case, the resin hardness of the first resin constituting the first region 12 is significantly lower than the resin hardness in the normal temperature environment during the operation time, and the catheter body 110 is softened. Branch selectivity is improved.

Hereinafter, the medical device according to this embodiment will be described in detail.
A medical device (hereinafter also referred to as a catheter 100) according to the present embodiment includes a medical device main body (hereinafter also referred to as a catheter main body 110). The catheter body 110 is long and flexible and is scheduled to be inserted into a body cavity. The catheter body 110 includes an outer tube 10 that is a long resin tube and an inner tube 20 that is laminated on the inner peripheral side of the outer tube 10. A metal protective layer 40 is provided on the outer periphery of the inner tube 20 by winding the wires 41 at a predetermined interval.

  The catheter 100 is a suitable example that is an intravascular catheter used by being inserted into a blood vessel.

The catheter 100 according to this embodiment is, for example, an inactive catheter. That is, the catheter 100 can be used as an inactive catheter including the catheter body 110 that is inserted into a body cavity by a technique called over-the-wire using a guide wire, and does not have an operation mechanism that bends the distal end portion.
As described above, the catheter 100 has good followability with respect to the guide wire because the first region 12 is more flexible than the second region 14 when a predetermined time has passed in the body cavity.

The outer tube 10 is a long and hollow resin tube. The outer tube 10 includes the first region 12 and the second region 14 as described above.
In the present embodiment, the first region 12 constitutes the distal end portion of the outer tube 10. The second region 14 constitutes the proximal end portion of the outer tube 10. The distal end portion of the outer tube 10 is a predetermined region including the distal end of the outer tube 10 on the distal side of the catheter body 110 or a predetermined region near the distal end not including the distal end. In the present embodiment, the proximal end portion of the outer tube 10 is a region located on the proximal side of the catheter body 110 with respect to the distal end portion, and the proximal end of the outer tube 10 on the proximal side of the catheter body 110. Or a predetermined region near the base end that does not include the base end.
In the present embodiment, specifically, as shown in FIGS. 2 and 3, the first region 12 that is the tip of the outer tube 10 is a predetermined region including the tip of the outer tube 10 on the distal side of the catheter body 110. is there.

That is, in the medical device (catheter 100) according to the present embodiment, the distal end of the first region 12 constitutes the distal end of the resin tube (outer tube 10).
Therefore, when the branch selection operation requires a significant amount of time, the softening of the first region 12 contributes well to the softening of the distal end portion of the catheter body 110.

The first region 12 is composed of a first resin member.
The first resin member includes one or more resins. That is, the first resin member may be composed of only the first resin, or may be a resin composition in which the first resin and one or more other resins are blended.

The second region 14 is composed of a second resin member.
The second resin member includes one or more resins. That is, the second resin member may be composed only of the second resin, or may be a resin composition in which the second resin and one or more other resins are blended.
The first resin and the second resin are different resins.

  In addition, you may make the 1st resin member which comprises the 1st area | region 12, and the 2nd resin member which comprises the 2nd area | region 14 contain arbitrary compounding agents as components other than resin suitably. For example, in order to confirm the position of the catheter body 110, the first region 12 and / or the second region 14 may contain an appropriate amount of contrast agent. Moreover, you may contain the pigment for coloring the 1st area | region 12 and / or the 2nd area | region 14 in a desired color, and the said compounding agent is not limited to these illustrations.

Examples of the first resin and the second resin, or other resins blended in the first resin and the second resin are thermoplastic polymers. Examples of the thermoplastic polymer include polyurethane (PU) resin, polyimide (PI) resin, polyamideimide (PAI) resin, polyethylene terephthalate (PET) resin, polyethylene (PE) resin, and polyamide (PA) resin. , Nylon elastomer resin, ethylene-vinyl acetate resin (EVA), polyvinyl chloride (PVC) resin or polypropylene (PP) resin, or a combination thereof.
The thermoplastic polymer includes a thermoplastic elastomer.
In this specification, the thermoplastic elastomer is a polymer alloy (polymer blend, block copolymerization, graft copolymerization, random copolymerization, etc.), a material softened with a plasticizer or the like, and a concept including a mixture thereof. It is. The elastomer includes urethane elastomer, amide elastomer (nylon elastomer), styrene elastomer, olefin elastomer, and vinyl chloride elastomer. The urethane-based elastomer includes a thermoplastic polyurethane elastomer. The amide-based elastomer includes a thermoplastic polyamide elastomer or a thermoplastic polyether block amide copolymer.

  The resin hardness of the first resin member and the second resin member is not particularly limited, but is preferably a resin hardness that can impart good pushability to the outer tube 10 in a room temperature environment. The normal temperature is not a strictly specified temperature, but is, for example, about 23 ° C. ± 2 ° C.

Regarding the catheter 100, the difference between the resin hardness of the first resin member measured in a normal temperature environment and the resin hardness of the first resin member measured after being left for a predetermined time in a temperature environment of 38 ° C. is referred to as a difference X. Further, the difference between the resin hardness of the second resin member measured in a normal temperature environment and the resin hardness of the second resin member measured after being left for a predetermined time in a temperature environment of 38 ° C. is referred to as a difference Y. Difference X is greater than difference Y.
For example, the difference X measures the Shore hardness (hardness A-1) measured in the normal temperature temperature environment according to ISO868 using the 1st test piece which consists of the 1st resin member cut by the appropriate size. Next, the first test piece is dipped in a thermostat kept at 38 ° C. for a predetermined time, and the Shore hardness (hardness A-2) measured according to ISO868 is measured. A value obtained by subtracting (hardness A-2) from (hardness A-1) is difference X.
For the difference Y, a second test piece made of a second resin member cut to the same size as the first test piece is used, and (hardness B-1) is obtained by the same method as (hardness A-1). (Hardness B-2) can be obtained by the same method as for hardness A-2), and (hardness B-2) can be subtracted from (hardness B-1).
In addition, the measuring method of the Shore hardness of the 1st resin member mentioned above and the 2nd resin member is the measurement of the resin hardness of the 1st resin member and the 2nd resin member in a normal temperature environment or a body temperature environment suitably in this embodiment. To be referenced.

  Further, as a different method for obtaining the difference X and the difference Y, a tip bending load test described in an example described later may be performed. In this test method, the resin member to be tested is used as a resin member constituting the outer tube in the distal end region of the catheter, and the load is measured by pressing the distal end of the catheter against the load measuring device from the vertical direction under a predetermined condition. is there. The difference X or difference Y can be obtained from the difference between the load of the test piece measured in the normal temperature environment and the load of the test piece measured using the test piece after being left in the body temperature environment for a predetermined time.

  In the above description, when the resin hardness is measured, the predetermined time for which the resin is left in the temperature environment of 38 ° C. is not particularly limited, and may be adjusted according to the thickness of the test piece. For example, it can be left in a temperature environment of 38 ° C. until the temperature of the test piece itself reaches 38 ° C.

  The relationship between the first resin member and the second resin member is adjusted, for example, such that the ratio of the resin hardness of the first resin at normal temperature to the difference X is larger than the ratio of the resin hardness of the second resin at normal temperature to the difference Y. May be.

In this embodiment, it is preferable that the first resin member includes 50% or more of the first resin, and the second resin member includes 50% or more of the second resin which is a resin different from the first resin.
By configuring so that the physical properties of the first resin member and the second resin member are respectively governed by different resin materials, the above-described magnitude relationship between the difference X and the difference Y can be significantly realized.
The catheter 100 in which the above-described size relationship is remarkably realized has better branch selectivity than when the outer tube 10 is operated by an over-the-tube method using a conventional catheter in which only the second resin member is configured. Something can be felt by the operator.

  As an example of a more preferable aspect, the first resin is a thermoplastic polyurethane resin, and the second resin is a polyamide resin. Such a combination can satisfactorily solve the problems of the present invention and achieve good pushability and good branch selectivity.

Specifically, for example, a thermoplastic polyurethane elastomer can be selected as the first resin, and a polyamide elastomer (nylon elastomer) can be selected as the second resin. These may be blended with other resins to form the first resin member and the second resin member. In particular, the resin material of the first resin member is made of only a thermoplastic polyurethane elastomer, The resin material of the resin member is made of a polyamide-based elastomer.
Specific examples of the thermoplastic polyurethane elastomer as the first resin include “Pellethane” manufactured by Dow Chemical Japan Co., Ltd., “Tecocene” and “Tecoflex” manufactured by Lubrizol. Yes, but not limited to this.
Specific examples of the polyamide-based elastomer that is the second resin include, but are not limited to, “Pebax” provided by Tokyo Materials Co., Ltd., which is a commercial product.

In the catheter 100 according to the present embodiment, the first resin member and the second resin member may be configured as (I) and (II) below.
(I) The resin hardness of the first resin member measured at normal temperature is equal to or higher than the resin hardness of the second resin member.
(II) The resin hardness of the first resin member measured after being left in a temperature environment of 38 ° C. for a predetermined time is less than the resin hardness of the second resin member.

  That is, the first region 12 made of the first resin member is harder than the second region 14 made of the second resin member at the time of intrusion into the body cavity or before a predetermined time has passed since entering the body cavity. Contributes to good pushability at the tip. The first region 12 becomes softer than the second region 14 when the operation time is prolonged in the body cavity and a predetermined time has elapsed. As a result, the catheter 100 can exhibit good branching selectivity at the distal end portion including the first region 12 while maintaining good pushability at the proximal end portion including the second region 14.

  The first region 12 in the present embodiment is a tip that is locally provided at the tip of the outer tube 10. For example, the dimension of the first region 12 in the axial direction is not less than 5 mm and not more than 15 mm, more preferably not less than 8 mm and not more than 12 mm. When the dimension of the first region 12 is within the above range, when the first resin member has passed a predetermined time in a temperature environment of 38 ° C. and the resin hardness has decreased, good branching selectivity is imparted to the catheter 100. At the same time, the loss of pushability is sufficiently avoided.

The second region 14 in the present embodiment is configured so that the rigidity continuously increases from the distal side toward the proximal side. Specifically, in the second region 14, the resin member 14a, the resin member 14b, the resin member 14c, the resin member 14d, and the resin member 14e are continuously arranged in this order from the distal side. In FIG. 1, the resin member 14a, the resin member 14b, the resin member 14c, the resin member 14d, and the resin member 14e are located on the inner peripheral side of the outer layer 60, and their boundaries are indicated by broken lines.
As described above, when the second region 14 is configured by arranging a plurality of resin members in the axial direction, the second resin member to be compared with the first resin member is related to various features of the present invention. It is a resin member disposed closest to at least the first resin member among the plurality of resin members constituting the two regions 14.

The magnitude relationship of the resin hardness (Shore hardness) at normal temperature of each resin member constituting the second region 14 is resin member 14a <resin member 14b <resin member 14c <resin member 14d <resin member 14e.
For example, when the resin member 14a, the resin member 14b, the resin member 14c, the resin member 14d, and the resin member 14e are all the same type of resin whose hardness is adjusted (for example, all are polyamide-based elastomers), 38 The resin hardness (Shore hardness) at 0 ° C. is also the same as the tendency of the magnitude relation of the resin hardness at normal temperature described above.

  Although not shown in the drawings, as a modification of the present embodiment, the second region 14 may be formed of a single resin member whose hardness does not change.

  The catheter 100 is provided with a marker 30 for confirming the body cavity intrusion position of the catheter main body 110 with X-rays. The marker 30 has a ring shape including a material that does not transmit radiation such as X-rays. Specifically, the marker 30 is made of a metal material such as platinum. The marker 30 is provided around the inner tube 20, for example.

  The marker 30 in the present embodiment is provided at the distal end portion of the catheter 100 and includes a radiopaque metallic material. The marker 30 is coat | covered with the 1st resin member as FIG. 2, FIG. 3 shows. The dimension in the axial center direction of the first region 12 exceeds the width dimension of the marker 30, and the entire marker 30 attached to the inner tube 20 can be covered from the outer peripheral side. The first region 12 corresponds to a bent region at the distal end of the catheter 100. By providing the marker 30 in the region, the bent state of the distal end of the catheter 100 can be accurately confirmed.

  Next, the inner tube 20 will be described. As shown in FIGS. 2 and 3, the catheter body 110 has an inner tube 20 stacked on the inner periphery of a resin tube (outer tube 10). The inner tube 20 includes a tubular resin material. An inner hole 120 is formed at the center of the inner tube 20 (see FIG. 2). The inner hole 120 is understood as a so-called main lumen and communicates from the proximal end to the distal end of the catheter body 110. In the inner hole 120, a therapeutic instrument or a guide wire can be inserted as appropriate, and liquids such as various drugs and contrast agents injected into the body cavity can be circulated, or liquid such as blood can be sucked from the body.

In the catheter 100, the distal end of the inner tube 20 may be positioned at the same position as the distal end of the first region 12 in the axial direction. Here, the same position means substantially the same position in the axial direction, and includes the extent that it can be visually confirmed that the position is the same even if it is slightly shifted in measurement. For example, the distance between the tip of the inner tube 20 and the tip of the first region 12 is about 0 mm ± 1 mm in the axial direction.
By disposing the inner tube 20 over substantially the entire boundary between the inner hole 120 and the first region 12 (outer tube 10), the following effects are exhibited. That is, even when the viscosity of the peripheral surface of the first region 12 is increased due to a decrease in the resin hardness of the first resin member constituting the first region 12 in the body cavity, the treatment of sliding the inner hole 120 is performed. It is possible to prevent the first region 12 from coming into close contact with the instrument or guide wire. From this viewpoint, it is preferable that the inner tube 20 is made of a material having good sliding properties with respect to a medical instrument such as a fluorine-based thermoplastic polymer material or a guide wire.

Examples of the material of the inner tube 20 include a fluorine-based thermoplastic polymer material. Specifically, the fluorine-based thermoplastic polymer material is, for example, polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), or perfluoroalkoxy fluororesin (PFA).
By configuring the inner tube 20 with such a fluorine-based resin, the delivery property when supplying a contrast agent, a drug solution, or the like to the living tissue through the inner hole 120 is improved.

  The inner tube 20 in the present embodiment is composed of a third resin member that is a resin member different from the first resin member and the second resin member. For example, as the third resin member, one having a resin hardness exceeding the resin hardness of the first resin member and the second resin member in a normal temperature and a temperature environment of 38 ° C. can be selected.

  However, the present invention does not exclude that the outer tube 10 and the inner tube 20 are made of the same type of resin member. For example, the present invention does not exclude that the third resin member constituting the inner tube 20 and either the first resin member or the second resin member are the same type of resin.

  In the catheter 100 according to this embodiment, sub-lumen may be formed inside the outer tube 10 as a modification example not shown. For example, a hollow resin tube having an inner diameter smaller than the inner diameter of the inner hole 120 is embedded in the outer tube 10, and one or more subroutines communicating from the proximal side to the distal side are provided in the outer tube 10. Also good. For example, an operation line for operating the direction of the distal end of the catheter 100 can be inserted into the sub-lumen.

Next, the metal protective layer 40 will be described.
The catheter 100 has a metal protective layer 40 provided on the inner peripheral side or inside of the resin tube (outer tube 10). Here, being provided on the inner peripheral side means that the metal protective layer 40 is provided in direct or indirect contact with the inner peripheral surface of the outer tube 10. Moreover, being provided inside means that at least a part of the metal protective layer 40 is provided in a state of being bitten in the thickness direction of the outer tube 10. In FIG. 2, a mode in which the metal protective layer 40 bites in the thickness direction from the inner peripheral surface side of the outer tube 10 is shown. The tip of the metal protective layer 40 of the outer tube 10 is located more proximal than the tip of the first region 12 in the axial direction. For this reason, it is prevented that the front-end | tip of the metal protective layer 40 damages a body cavity. In FIG. 3, the wire 41 is illustrated in a linear shape ignoring the thickness for simplification of illustration.

  The metal protective layer 40 in this embodiment is attached to the inner tube 20 and the outer tube 10, for example. The metal protective layer 40 is configured by winding a wire 41 around the inner tube 20. FIG. 2 illustrates a cross section of the wires 41 arranged from the proximal side to the distal side on the outer periphery of the inner tube 20. FIG. 3 shows that a plurality of (for example, eight) wires 41 are wound around the outer periphery of the inner tube 20 in a right spiral, and a plurality of (for example, eight) wires 41 are wound around the outer periphery in a left spiral, A so-called blade-shaped metal protective layer 40 in which the wires 41 are knitted together is shown. At this time, the pitch of the plurality of wires 41 wound in the same direction is, for example, about 200 μm. Further, the pitch may be changed from the proximal side to the distal side. In the series of metal protective layers 40, the pitch in the region closely contacting the first region 12 and the inner tube 20 may be minimized as compared with other regions. Thereby, the flexibility of the distal end portion of the catheter 100 can be further improved.

  Although illustration is omitted, the metal protective layer 40 can be appropriately changed to a coiled form in which one or more wires 41 are wound in one direction.

  As a material of the wire 41 constituting the metal protective layer 40, for example, a metal is preferably used. However, the material is not limited to this example, and is not limited to this example and is made of a material having higher rigidity and elasticity than the inner tube 20 and the outer tube 10. Other materials (for example, resin) may be used as long as they exist. Specifically, for example, tungsten, stainless steel (SUS), nickel titanium alloy, steel, titanium, or copper alloy can be used as the metal material of the wire 41.

Next, the outer layer 60 will be described.
An outer layer 60 is provided on the outer peripheral side of the outer tube 10. The outer layer 60 in the present embodiment constitutes the outermost layer of the catheter body 110. The outer layer 60 can be made of, for example, a hydrophilic material. In addition, the outer layer 60 may be formed only in the area | region over the partial length of the distal end part 15 of the catheter main body 110, and may be formed over the full length of the catheter 100. FIG.
The outer layer 60 is made hydrophilic by molding it with a hydrophilic resin material such as polyvinyl alcohol (PVA) or polyvinyl pyrrolidone.
Instead of forming the outer layer 60 using an arbitrary material on the outer periphery of the outer tube 10, an arbitrary surface treatment may be performed on the outer peripheral surface of the outer tube 10 to add a desired property. For example, the outer peripheral surface of the outer tube 10 may be subjected to water immersion treatment to add lubricity to the outer surface of the outer tube 10.

Next, the grip part 50 provided on the proximal side of the catheter body 110 will be described. As shown in FIG. 1, a grip 50 is provided adjacent to the proximal end of the catheter body 110. The holding part 50 has a connecting part 530 for inserting an injector (syringe) (not shown) from the rear. A thread groove is formed on the outer periphery of the connecting portion 530 so that the syringe can be fixed. The connecting part 530 is detachable. A hub 500 is provided at the center of the grip portion 50. A hollow penetrating in the axial direction is formed inside the hub 500, and the inner tube 20 and the outer tube 10 extend (not shown). The hub 500 has two wings 510 that extend outward from the outer peripheral surface and face each other via an axis. By rotating the wing 510 around the axis, a torque operation for rotating the entire catheter body 110 is possible, and the direction of the distal end of the catheter body 110 that has entered the body cavity can be adjusted.
A protector 520 is provided on the distal end side of the hub 500 and covers the proximal ends of the inner tube 20 and the outer tube 10 that enter the hub 500.

Next, general dimensions of the catheter body 110 will be described.
The outer diameter of the catheter body 110 is configured as follows, for example. That is, as shown in FIG. 1, the outer diameter 550 of the first region 12 is about 570 μm or more and 770 μm or less (for example, 670 μm), and the outer diameter of the resin member 14 a constituting the tip of the second region 14 is outside the first region 12. The outer diameter 552 of the tip of the resin member 14c is equal to or greater than the diameter, and is approximately 700 μm or more and 900 μm or less (eg, 800 μm), and the outer diameter 554 of the tip of the resin member 14d is approximately 770 μm or more and 970 μm or less (eg, 870 μm). The outer diameter 556 is about 870 μm or more and 1070 μm or less (for example, 970 μm). That is, the maximum outer diameter of the catheter body 110 is around 1 mm in diameter, and preferably 1 mm or less. Thereby, the catheter main body 110 of the present embodiment can be inserted into a blood vessel such as a celiac artery.
In the present embodiment, the outer diameters of the first region 12, the region constituted by the resin member 14a, and the region constituted by the resin member 14e are uniform. On the other hand, the outer diameter of the region constituted by the resin members 14b to 14d has a diameter-expanded portion that is diameter-expanded from the distal end toward the proximal end in the intermediate portion in the axial direction.
In the axial direction, a distance 540 from the distal end of the marker 30 to the distal end of the catheter body 110 is about 0.5 mm to 1 mm, and a distance 560 from the distal end of the marker 30 to the proximal end of the first region 12 is 5 mm to 15 mm. The distance 580 from the distal end to the proximal end of the region constituted by the resin member 14a is about 15 mm to 25 mm (for example, 20 mm) (see FIG. 3).

The diameter 558 of the inner hole 120 at the distal end of the catheter body 110 is about 400 μm or more and 600 μm or less (for example, 500 μm) in a range smaller than the outer diameter of the first region 12. For example, a guide wire having a diameter of about 460 μm can be inserted into the inner hole 120. The diameter of the inner hole 120 may be uniform from the distal end to the proximal end, or the φ may be increased in proportion to the expansion of the outer diameter of the outer tube 10.
The overall length of the catheter body 110 is 1250 mm, for example.
At the distal end of the catheter 100, the inner tube 20 can have a thickness of about 10 μm to 50 μm, and the outer tube 10 can have a thickness of about 30 μm to 160 μm. Particularly in the first region 12, the thickness of the inner tube 20 and the thickness of the outer tube 10 in the above ranges are suitable, and it is a preferred embodiment that the thickness of the outer tube 10 is larger than the thickness of the inner tube 20.

Next, an example of a general manufacturing method of the catheter 100 will be described.
First, a core material having a peripheral surface matching the shape of the inner hole 120 of the catheter body 110 is prepared, and the inner tube 20 is formed along the outer periphery of the core material. Thereafter, the wire 41 is wound around the outer peripheral surface of the inner tube 20 to form the metal protective layer 40. The wire 41 may be wound at a constant pitch with a commercially available device or the like. Of course, the pitch may be changed midway.
Next, a metal ring made of a radiopaque material is fitted to the tip of the metal protective layer 40 and caulking is performed to form the marker 30.
Next, the outer tube 10 is formed so as to cover the metal protective layer 40. Specifically, a plurality of hollow resin tubes (specifically, from the first region 12 and the region of the resin member 14a to the region of the resin member 14e) molded with a resin member suitable for each region of the outer tube 10 6) are prepared. These resin tubes are sequentially fitted to the inner tube 20 provided with the metal protective layer 40, and the heat-shrinkable member is covered from the outer periphery of the resin tube while the adjacent resin tubes are in contact with each other or slightly overlapped. To do. As a result, each resin tube is softened, partly melted and the ends of the adjacent resin tubes are fused and joined together, and the outer tube 10 attached to the metal protective layer 40 can be formed. After peeling the heat-shrinkable member crimped to the outer periphery of the outer tube 10, the core material is extracted, and then the outer layer 60 is formed on the outer periphery of the outer tube 10 using a hydrophilic material. Or you may surface-treat so that the outer peripheral surface of the outer tube | pipe 10 may become hydrophilic. Finally, by attaching the grasping part 50, the manufacture of the catheter 100 is completed. Note that the above is an example of a method for manufacturing the catheter 100 and does not limit the present invention.

Next, how to use the catheter 100 will be briefly described by taking the over-the-wire method as an example.
First, a guide wire is inserted through the body cavity (not shown). At this time, a sheath (not shown) may be installed in the body cavity as appropriate.
Next, the guide wire inserted into the body cavity is inserted to an appropriate position in the body cavity. For example, the distal end of the guide wire is made to reach an arbitrary place through one or more branches. Subsequently, the catheter body 110 is caused to enter the body cavity along the guide wire. When the catheter body 110 reaches the vicinity of the distal end of the guide wire, the guide wire is further penetrated into the deep part of the body cavity as necessary, and then the catheter body 110 is advanced. In this way, the distal end of the catheter 100 is reached to a desired living tissue. When the distal end of the catheter body 110 reaches a desired living tissue, a medical solution or a contrast medium is injected to perform treatment or examination. Further, in order to confirm the distal end of the catheter 100 while the catheter main body 110 is invading into the body cavity, the guide wire is once pulled out, and a contrast medium is injected into the inner hole 120 via the connecting portion 530 to distant the catheter 100. The position may be confirmed by X-rays discharged from the distal end to the body cavity.
Note that, as described above, the first region 12 of the catheter body 110 is significantly softened when a predetermined time elapses in a temperature environment of 38 ° C. (that is, an environment inside the body cavity). Therefore, in a branch that is difficult to select, the first region 12 naturally softens while the catheter body 110 is bent along the guide wire and a predetermined time is required for the branch selection, and the proximal end of the catheter body 110 is softened. Since the flexibility of the part increases, the branching selectivity of the catheter 100 is improved.
When the first region 12 once softened in the body cavity is to be hardened again to improve the pushability of the distal end of the catheter body 110, the first region 12 is circulated through a liquid of less than 38 ° C. (for example, about room temperature) through the inner hole 120. One region 12 may be cooled. Alternatively, with the guide wire left in the body cavity, the catheter body 110 may be pulled out and the tip including the first region 12 may be exposed to room temperature.

  In this specification, the term “body cavity” includes any hole that is a narrow hole in the body. For example, the body cavity can be applied to a blood vessel or a “tube” in a living body such as a ureter or a digestive tract other than the blood vessel.

The first embodiment of the present invention has been described above. The present invention is not limited to the above-described embodiment, and includes various modifications and improvements as long as the object of the present invention is achieved.
For example, the medical device of the present invention can also be used as an active catheter with a built-in operation line (not shown). In addition, the medical device of the present invention can be used as the catheter 100, and can also be used for other medical devices used for similar procedures and treatments.

Moreover, the medical device (for example, the catheter 100) of the present invention includes the first region and the second region described above, so that the flexibility of the distal local region of the medical device including the first region is good in the body. . That is, the medical device of the present invention includes a first region and a tip local region having a length region substantially equal to the first region in the axial direction, and is disposed adjacent to the proximal side of the tip local region. And a proximal adjacent region having a region having a length substantially equal to that of the second region in the axial direction.
For example, the tip local region and the proximal adjacent region in the present invention can have the following properties by reflecting the characteristics of the first region and the second region described above. That is, the difference XI between the bending strength of the tip local region measured at room temperature and the bending strength of the tip local region measured after standing for a predetermined time in a temperature environment of 38 ° C. was measured at room temperature. It is larger than the difference YI between the bending strength of the proximal adjacent region and the bending strength of the proximal adjacent region measured after standing for a predetermined time in a temperature environment of 38 ° C.

  Here, the bending strength of the tip local region and the proximal adjacent region can be evaluated by a so-called three-point bending test for evaluating bending characteristics. More specifically, for example, the distal end local region is taken out by cutting the catheter 100 perpendicular to the axial direction at the position of the distal end and the proximal end of the first region. Then, the extracted local region of the tip is cut from the outer periphery to the vicinity of the axial center in parallel with the axial direction and developed in the circumferential direction to create a test piece, and a three-point bending test is performed using the test piece. . In the three-point bending test, a fulcrum is applied to the distal end side and the proximal end side of the distal end local region, and a load is applied to the middle. The bending strength of the proximal adjacent region can be similarly tested. However, in order to align the preparation conditions of the tip local region and the specimen to be compared, the test piece in the proximal adjacent region is the tip of the proximal adjacent region (ie, the boundary position between the tip local region and the proximal adjacent region). It is preferable to cut a portion corresponding to the axial length of the first region from the first region, make a cut to the vicinity of the axial center, and develop the test piece in the circumferential direction.

  Moreover, the following method can be mentioned as a different test which compares the said difference XI and the difference YI. That is, a catheter test body having a configuration similar to that of the distal end local region and a catheter test body having a configuration similar to that of the proximal adjacent region to the catheter main body are prepared, and these will be described later. Tested in the same manner as the tip bending load test shown in. As a result, it is possible to estimate the rate of decrease in the bending strength of the tip local region and the rate of decrease in the bending strength of the proximal adjacent region in the normal temperature environment and the body temperature environment.

Example 1
A catheter was created with the same configuration as the catheter 100 illustrated in the first embodiment. Specifically, the diameter 558 of the inner hole 120 at the distal end of the catheter body 110 was 500 μm, and the outer diameter 550 was 670 μm (see FIG. 1). The thickness of the outer tube 10 in the first region 12 was 140 μm. Pelecene 80AE (manufactured by Dow Chemical Japan Co., Ltd.) was used as the first resin member constituting the first region 12. The catheter produced as described above was taken as Example 1.

(Comparative Example 1)
As a first resin member constituting the first region 12, a Pebax 2533 (provided by Tokyo Materials Co., Ltd.) was used, and a catheter configured in the same manner as in Example 1 was prepared except that 40% by mass of barium sulfate was contained therein. This was designated as Comparative Example 1.

(Tip bending load test)
Using Example 1 and Comparative Example 1, a tip bending load test was performed as follows.
First, a guide pipe having both ends opened and having a hole with an inner diameter of 0.8 mm extending in the linear direction and a length of 3 cm was prepared.
An electronic balance was placed so that the measurement surface was horizontal. The guide pipe is fixed so that the extending direction of the hole is perpendicular to the measurement surface and the distance from the lower end of the guide pipe (lower end opening of the hole) to the measurement surface of the electronic balance is 5 mm. did.

In a temperature environment of normal temperature (23 ° C.), the tip of Example 1 was entered from the upper end of the hole in the guide pipe and exposed from the lower end of the hole. The tip of Example 1 was pressed against the measurement surface of the electronic balance until the exposed length from the lower end was 7 mm. Thereby, the load displayed on the electronic balance was measured as “room temperature environmental load”. The measurement was performed 5 times.
In Comparative Example 1, the room temperature environmental load was measured in the same manner as in Example 1.

  Next, from the tip of Example 1 to about 80 cm, it was immersed for 10 minutes in the thermostat adjusted to 38 degreeC. Except for using the catheter immediately after removal from the thermostat, the load was measured in the same manner as the room temperature environmental load measurement method, and this was designated as “body temperature environmental load”. The body temperature environmental load was similarly measured for Comparative Example 1.

About Example 1, the average value of the measured value (N = 3) which remove | excluded the highest value and the lowest value from the normal temperature environmental load (N = 5) measured as mentioned above was calculated | required. Similarly, the average value was calculated | required also about the body temperature environmental load. As a result, the average value of the normal temperature environmental load of Example 1 is 1.048 (gf), the average value of the body temperature environmental load is 0.730 (gf), and the difference A between the normal temperature environmental load and the body temperature environmental load is A. Was 0.318.
Similarly, average values of normal temperature environmental load and body temperature environmental load of Comparative Example 1 were also obtained. As a result, the average value of the normal temperature environmental load is 1.212 (gf), the average value of the body temperature environmental load is 1.105 (gf), and the difference B between the normal temperature environmental load and the body temperature environmental load is 0. 107.

  From the above results, it was confirmed that the difference A in Example 1 was larger than the difference B in Comparative Example 1. That is, Example 1 had a greater degree of softening in the tip region after heating to 38 ° C. than Comparative Example 1. Since Example 1 and Comparative Example 1 are configured similarly except that the resin member constituting the first region 12 of the outer tube 10 is different, the difference between the difference A and the difference B is exclusively used. It was understood that it originated in the property of the obtained resin member.

  From the behavior of Example 1 and Comparative Example 1, a thermoplastic urethane elastomer is used as the first resin member constituting the first region 12, and the amide elastomer is used as the second resin member constituting the second region 14. It was estimated that the difference X in the first region 12 is larger than the difference Y in the second region 14. That is, it was inferred that exposure to a temperature environment of 38 ° C. for a predetermined time increased the degree of softening of the first region 12 compared to the second region 14 and improved the branching selectivity of the catheter.

The above embodiment includes the following technical idea.
(1) It is long and flexible, and has a medical device body that is inserted into a body cavity.
The medical device body has a long resin tube,
The resin tube includes a first region formed of a first resin member and a second resin member that is a resin member different from the first resin member, and is positioned closer to the proximal side than the first region. Two regions,
The difference X between the resin hardness of the first resin member measured at room temperature and the resin hardness of the first resin member measured after standing for a predetermined time in a temperature environment of 38 ° C. was measured at room temperature. A medical device characterized in that a difference Y between the resin hardness of the second resin member and the resin hardness of the second resin member measured after being left standing in a temperature environment of 38 ° C. for a predetermined time is greater.
(2) The medical device according to (1), wherein the first resin member includes 50% or more of the first resin, and the second resin member includes 50% or more of a second resin that is a resin different from the first resin. machine.
(3) The medical device according to any one of (1) and (2), wherein the first resin is a thermoplastic polyurethane resin, and the second resin is a polyamide resin.
(4) The first resin member and the second resin member are
(I) The resin hardness of the first resin member measured at normal temperature is not less than the resin hardness of the second resin member,
(II) The resin hardness of the first resin member measured after being left in a temperature environment of 38 ° C. for a predetermined time is less than the resin hardness of the second resin member.
The medical device according to any one of (1) to (3) above.
(5) having an inner tube laminated on the inner periphery of the resin tube;
The medical instrument according to any one of (1) to (4), wherein a distal end of the inner tube is located at the same position as a distal end of the first region in an axial direction.
(6) The medical device according to any one of (1) to (5), wherein a distal end of the first region constitutes a distal end of the resin tube.
(7) The medical device according to any one of (1) to (6), wherein a marker including a radiopaque metal material provided at a distal end is covered with the first resin member.
(8) having a metal protective layer provided on the inner peripheral side or inside of the resin pipe,
The medical device according to any one of (1) to (7), wherein a distal end of the metal protective layer is positioned more proximally than a distal end of the first region in the axial direction.
(9) The medical device according to any one of (1) to (8), wherein the dimension of the first region in the axial direction is not less than 5 mm and not more than 15 mm.
(10) The medical device according to any one of (1) to (9), wherein the medical device is an inactive catheter.

DESCRIPTION OF SYMBOLS 10 ... Outer tube 12 ... 1st area | region 14 ... 2nd area | region 14a ... Resin member 14b ... Resin member 14c ... Resin member 14d ... Resin member 14e ... Resin member 15 ... Distal end 20 ... Inner tube 30 ... Marker 40 ... Metal protective layer 41 ... Wire 50 ... Grip part 60 ... Outer layer 100 ... Catheter 110 ... Catheter body 120 ... inner hole 500 ... hub 510 ... wing 520 ... protector 530 ... connecting part 540 ... distance 550 ... outer diameter 552 ... outer diameter 554 .... Outer diameter 556 ... Outer diameter 558 ... Diameter 560 ... Distance 580 ... Distance

Claims (10)

Long and flexible, having a medical device body inserted into a body cavity,
The medical device body has a long resin tube,
The resin tube includes a first region formed of a first resin member and a second resin member that is a resin member different from the first resin member, and is positioned closer to the proximal side than the first region. Two regions,
The difference X between the resin hardness of the first resin member measured at room temperature and the resin hardness of the first resin member measured after standing for a predetermined time in a temperature environment of 38 ° C. was measured at room temperature. and the resin hardness of the second resin member, much larger than the difference Y between the resin hardness of said measured second resin member after being left for a predetermined time at 38 ° C. temperature environment,
The first resin member and the second resin member are
(I) The resin hardness of the first resin member measured at normal temperature is not less than the resin hardness of the second resin member,
(II) the resin hardness of the first resin member measured after being left in a temperature environment of 38 ° C. for a predetermined time is less than the resin hardness of the second resin member;
The first region has a uniform outer diameter;
The second region is a medical device having a first resin portion that is connected to a proximal end side of the first region and has a uniform outer diameter that is equal to the first region .   The second region has a second resin part connected to the base end side of the first resin part, and is connected to the base end side of the second resin part, and has a resin hardness higher than that of the second resin part. A high third resin part,
  2. The medical device according to claim 1, wherein the second resin portion includes a diameter-expanded portion having an outer diameter that increases from the distal end toward the proximal end in an intermediate portion in the axial direction of the second resin portion. Wherein the first resin member comprises a first resin 50% or more, the second resin member is a medical device according to claim 1 or 2 including a second resin and the first resin is a resin different from more than 50%. The medical device according to claim 3, wherein the first resin is a thermoplastic polyurethane resin, and the second resin is a polyamide resin. Having an inner tube laminated on the inner periphery of the resin tube;
The medical device according to any one of claims 1 to 4, wherein a distal end of the inner tube is located at the same position as a distal end of the first region in the axial direction. The tip of the first region, medical device according to claim 1, any one of 5 constituting the front end of the resin tube.   The medical device according to any one of claims 1 to 6, wherein a marker including a radiopaque metallic material provided at a distal end portion is covered with the first resin member. It has a metal protective layer provided on the inner peripheral side or inside of the resin tube,
The medical device according to any one of claims 1 to 7, wherein a distal end of the metal protective layer is positioned more proximally than a distal end of the first region in the axial direction.   The medical device according to any one of claims 1 to 8, wherein a dimension of the first region in the axial direction is not less than 5 mm and not more than 15 mm.   The medical device according to any one of claims 1 to 9, which is an inactive catheter.

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