Medical instrument

Abstract

[Problem] To provide a medical instrument having a sheath member that makes it possible to improve kink resistance and has high followability for curved or meandering portions of a biological lumen. [Solution] Reinforcing members 140 disposed between an outer surface 120a of an inner layer 120 of a sheath member 110 and an inner surface 130b of an outer layer 130 thereof, when in a bent state, move to the first side surface section 131a side of a first region 131A and thereby apply a force to the first region, and deform a second region 132 of the outer layer while contacting the first side surface section of the first region such that a space 150 is formed between a reinforcing member 140 and a second side surface section 131b of the first region.

Description

medical equipment

[0001] The present invention relates to a medical device.

[0002] Conventionally, medical devices including a flexible tubular hollow member (sheath member) have been used when performing various medical procedures within biological organs. Known examples of this type of medical device include guiding catheters used to deliver catheter devices such as balloon catheters to desired positions within a living body, contrast catheters used to inject contrast agents into a living body, microcatheters used for injecting drugs, and sheath introducers used to introduce medical instruments such as guidewires and catheters into biological lumens such as a patient's blood vessels.

[0003] In the above medical devices, in order to provide the sheath member with kink resistance (resistance to bending), a layer structure consisting of an inner layer and an outer layer having desired physical properties may be formed, and a reinforcing member (e.g., a metallic braid wire) may be disposed between the inner and outer layers. For example, Patent Document 1 discloses a sheath introducer having a sheath member including an inner layer, an outer layer, and a reinforcing member disposed between the inner and outer layers.

[0004] Japanese Patent Application Publication No. 7-303703

[0005] According to the sheath member described in Patent Document 1, although the kink resistance of the sheath member can be improved by the reinforcing member, the placement of the reinforcing member reduces the flexibility of the sheath member. Therefore, in a procedure using the sheath member described in Patent Document 1, it becomes difficult to deform the sheath member so as to follow the curves or tortuous portions of a biological lumen. This may hinder smooth procedures using the sheath member.

[0006] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a medical device having a sheath member that has improved kink resistance and high conformability to curved or tortuous portions of a biological lumen.

[0007] The present invention can be achieved by any one of the following means (1) to (6).

[0008] (1) A catheter having a tubular sheath member and a hub member connected to a proximal end of the sheath member, wherein the sheath member comprises: an inner layer having an outer surface and an inner surface; an outer layer having an outer surface and an inner surface; and a reinforcing member located between the outer surface of the inner layer and the inner surface of the outer layer, wherein the outer layer has a first region fixed to the outer surface of the inner layer and a second region not fixed to the outer surface of the inner layer, wherein the second region is arranged spirally along the longitudinal direction of the inner layer at a position adjacent to the first region and forms a gap between the outer surface of the inner layer and the inner surface of the outer layer, and the reinforcing member is arranged spirally in the gap without being fixed to the inner layer and the outer layer, and wherein the second region is configured to be deformable between a natural state having a first width in the longitudinal direction of the inner layer and a bent state having a second width in the longitudinal direction of the inner layer that is larger than the first width, the first region has a first side portion and a second side portion facing the first side portion across the gap portion, and the reinforcing member is configured, when in the bent state, to move toward the first side portion to apply force to the first region, and to deform the second region so as to form a space between the first side portion and the second side portion while contacting the first side portion.

[0009] (2) The medical device according to (1), wherein the reinforcing member is configured to contact the first side surface portion and the second side surface portion in the natural state.

[0010] (3) The medical device according to (1) or (2), wherein the gap portion has a rectangular cross section along the longitudinal direction of the inner layer in the natural state, and the reinforcing member is a metal strip-shaped member having a rectangular cross section.

[0011] (4) The medical device according to any one of (1) to (3), wherein the width of the space along the longitudinal direction of the inner layer is equal to or less than half the width of the cross section of the reinforcing member along the longitudinal direction of the inner layer in the natural state.

[0012] (5) The medical device according to any one of (1) to (4), wherein a width of a cross section of the reinforcing member along the longitudinal direction of the inner layer in the natural state is larger than a width of the first region along the longitudinal direction of the inner layer in the natural state.

[0013] (6) The medical device according to any one of (1) to (5), wherein the gap and the reinforcing member are not disposed at the distal end of the sheath member, and one portion located at the most distal end of the reinforcing member disposed on the proximal side of the distal end of the sheath member and another portion adjacent to the one portion on the proximal side are fixed.

[0014] The sheath member of the medical device of the present invention includes an inner layer, an outer layer, and a reinforcing member disposed between the outer surface of the inner layer and the inner surface of the outer layer. The reinforcing member improves the kink resistance of the sheath member. The outer layer has a first region bonded to the outer surface of the inner layer and a second region not bonded to the outer surface of the inner layer. The second region extends spirally along the longitudinal direction of the inner layer, forming a gap between the outer surface of the inner layer and the inner surface of the outer layer. The reinforcing member is disposed spirally in the gap, and when the sheath member is bent, it contacts the first side surface of the first region and forms a space between the first side surface of the first region and the opposing second side surface. When the sheath member is bent, the reinforcing member in contact with the first side surface deforms the sheath member so that the width of the second region along the longitudinal direction of the inner layer increases. Therefore, the sheath member deforms so that the outer layer located in the second region where the reinforcing member is disposed elongates preferentially along the bending direction, thereby suppressing elongation of the first region where the inner and outer layers are fixed. This reduces peeling between the inner and outer layers when the sheath member is bent, thereby preventing the sheath member from kinking and losing its ability to hold the lumen of the sheath member. Furthermore, when the sheath member is bent, spaces are formed in the gaps in the second region of the outer layer, improving its flexibility and allowing it to exhibit high conformability to curved or tortuous portions of a biological lumen. As described above, the present invention can provide a medical device having a sheath member that has improved kink resistance and high conformability to curved or tortuous portions of a biological lumen.

[0015] Fig. 1 is a diagram showing an introducer circuit according to an embodiment. Fig. 2 is a diagram showing an enlarged view of the vicinity of the distal end portion of a sheath member of a medical device (sheath introducer) according to an embodiment. Fig. 3 is a diagram showing an enlarged view of an axial cross section of a portion of the sheath member in a natural state. Fig. 4 is a diagram showing an enlarged view of an axial cross section of a portion of the sheath member in a bent state. Fig. 5 is a diagram showing an enlarged view of an axial cross section of the distal end portion of a sheath member in a natural state. Fig. 6 is a diagram showing a medical device (catheter) according to a modified example.

[0016] (Embodiment) A medical device 100 according to an embodiment will be described with reference to Figs.

[0017] In this embodiment, an example in which the medical device 100 is applied to a sheath introducer will be described. In addition, when describing the medical device 100, an introducer circuit 10 including the sheath introducer will be described.

[0018] <Introducer Circuit 10 > As shown in FIG. 1 , the introducer circuit 10 includes a medical device 100 and a dilator 200 .

[0019] <Medical Device 100 > The medical device 100 includes a tubular sheath member 110 and a hub member 160 connected to the proximal end portion 113 of the sheath member 110 .

[0020] The medical device 100 can be used to introduce various medical devices into a biological lumen (e.g., a blood vessel) via the lumen 115 of the sheath member 110. Specific methods and procedures for using the medical device 100 are not particularly limited, but for example, the medical device 100 can be used to form an access path for delivering various medical devices (e.g., a stent for placement in the aorta, a device used in artificial valve replacement surgery to treat aortic stenosis, a device for treating pulmonary thrombosis, etc.) from a relatively large-diameter blood vessel running through the lower limb to various parts of the living body, using the blood vessel in the lower limb as the insertion target site.

[0021] In the description of this specification, the direction in which the sheath member 110 extends in the natural state shown in Figures 1, 2, and 3 is referred to as the "axial direction" and is indicated by arrows X1-X2. The direction indicated by arrow X1 is defined as the distal end side of the axial direction, and the direction indicated by arrow X2 is defined as the proximal end side of the axial direction. A virtual line extending along the axial direction of the sheath member 110 in the natural state is indicated by symbol c1.

[0022] In this specification, the term "natural state" refers to a state in which no external force is applied to the sheath member 110 and the sheath member 110 extends in a substantially straight line. Furthermore, the term "bent state" described below refers to a state in which an external force is applied to any location of the sheath member 110 and the sheath member 110 is bent partially or entirely around a predetermined bending center O1 (see FIG. 4 ).

[0023] As will be described later, the second region 132 of the outer layer 130 of the sheath member 110 is configured to be deformable so as to have a first width W21 in a natural state (the state shown in FIG. 3) and a second width W22 when in a bent state (the state shown in FIG. 4).

[0024] <Sheath member 110> Fig. 2 shows an enlarged view of the distal end portion 111 of the sheath member 110 in its natural state and its surrounding area. Fig. 3 shows an axial cross-sectional view of a portion (a portion other than the distal end portion 111) of the sheath member 110 in its natural state. Fig. 4 shows an axial cross-sectional view of a portion (a portion other than the distal end portion 111) of the sheath member 110 in its bent state. Note that Figs. 3 and 4 show only one of the tube wall portions of the sheath member 110 that face each other across the lumen 115 of the sheath member 110 in the axial cross-sectional view.

[0025] 1 and 2 , the sheath member 110 has a distal end portion 111 having a distal end opening 111a formed at the most distal end position, and a proximal end portion 113 disposed inside the hub member 160. Although not shown, the proximal end portion 113 of the sheath member 110 is provided with a proximal end opening that communicates with the interior of the hub member 160.

[0026] The sheath member 110 has an inner lumen 115 that extends continuously from the distal end 111 to the proximal end 113. The distal end 111 of the sheath member 110 can be configured to have a tapered shape in which the outer diameter tapers toward the distal end.

[0027] As shown in FIG. 3 , the sheath member 110 includes an inner layer 120 having an outer surface 120 a and an inner surface 120 b, an outer layer 130 having an outer surface 130 a and an inner surface 130 b, and a reinforcing member 140 located between the outer surface 120 a of the inner layer 120 and the inner surface 130 b of the outer layer 130.

[0028] The inner surface 120b of the inner layer 120 is the inner surface facing the lumen 115. The outer surface 120a of the inner layer 120 is the outer surface located on the outer layer 130 side.

[0029] The inner surface 130b of the outer layer 130 is the inner surface located on the side of the lumen 115. The outer surface 130a of the outer layer 130 is the outer surface that forms the outer surface of the sheath member 110.

[0030] As shown in FIG. 3 , the outer layer 130 has a first region 131 bonded to the outer surface 120 a of the inner layer 120 and a second region 132 not bonded to the outer surface 130 a of the inner layer 120 .

[0031] The first region 131 can be formed by fusing together the resin materials forming the layers 120 and 130 at the portions corresponding to the first region 131 .

[0032] The second region 132 is arranged spirally along the longitudinal direction of the inner layer 120 at a position adjacent to the first region 131, and forms a gap portion 132a between the outer surface 120a of the inner layer 120 and the inner surface 130b of the outer layer 130.

[0033] As shown in FIGS. 2 and 3, the reinforcing member 140 is arranged in a spiral shape in the gap portion 132a without being fixed to the inner layer 120 or the outer layer 130.

[0034] 2 to 4, two adjacent portions of the spirally arranged reinforcing member 140 are denoted by reference numerals 140A and 140B to clearly identify them. The portion denoted by reference numeral 140A is located closer to the distal end of the sheath member 110 than the portion denoted by reference numeral 140B. In addition, in FIGS. 2 and 5, the distal (most extreme) portion of the reinforcing member 140 is denoted by reference numeral 140C, and the portion of the reinforcing member 140 adjacent to the proximal end side of the distal portion 140C is denoted by reference numeral 140D.

[0035] 1 and 2 , the gap 132a is formed continuously at predetermined intervals in the axial direction over a range on the proximal side of the distal end 111 of the sheath member 110, excluding the distal end 111 of the sheath member 110. Therefore, the reinforcing member 140 disposed in the gap 132a is formed continuously at predetermined intervals in the axial direction over a range on the proximal side of the distal end 111 of the sheath member 110, excluding the distal end 111 of the sheath member 110, similar to the gap 132a.

[0036] 2 and 3 , the reinforcing member 140 can extend such that, in the natural state, a predetermined gap is formed between adjacent portions 140A, 140B in the axial direction. That is, in the natural state, the reinforcing members 140 can be arranged so that they do not overlap with each other in the axial direction in the side view of the sheath member 110 as shown in FIG. 2 (a pitch such that an imaginary line H1 extending from the proximal end of any portion 140A of the reinforcing member 140 shown in the side view of FIG. 2 does not overlap with the portion 140B adjacent to the proximal end of any portion 140A). By arranging the reinforcing members 140 so that they do not overlap with each other in the natural state, the flexibility of the sheath member 110 can be increased. In particular, by arranging the reinforcing members 140 of the sheath member 110 so that they do not overlap with each other in the natural state, when the sheath member 110 is bent, the reinforcing members 140 can be prevented from moving toward the first side surface portion 131a and from increasing the area where the reinforcing members 140 overlap with each other in the axial direction. Therefore, by configuring the sheath member 110 in this manner, the flexibility of the sheath member 110 can be increased even when the sheath member 110 is bent.

[0037] The second region 132 is configured to be deformable between a natural state (the state shown in Figure 3) having a first width W21 in the longitudinal direction of the inner layer 120 and a bent state (the state shown in Figure 4) having a second width W22 in the longitudinal direction of the inner layer 120 that is larger than the first width W21.

[0038] In this specification, the "longitudinal direction of the inner layer 120 in its natural state" indicated by reference symbol A1 in Figures 3 and 5 means a direction parallel to the axial direction of the sheath member 110 indicated by reference symbol c1. In other words, the longitudinal direction of the inner layer 120 in its natural state is the same direction as the axial direction. Furthermore, the "longitudinal direction of the inner layer 120 in its bent state" indicated by reference symbol A1' in Figure 4 means a direction along a curved line segment (arc) along the bent inner layer 120.

[0039] As shown in FIG. 3, the first region 131 has a first side surface portion 131a and a second side surface portion 131b facing the first side surface portion 131a with a gap portion 132a therebetween.

[0040] In this specification, a portion of the first region 131 located closer to the proximal end than the distal end 111 of the sheath member 110 is designated by the reference numeral 131A (see FIGS. 3 and 4 ). Also, a portion of the first region 131 located closer to the distal end 111 of the sheath member 110 is designated by the reference numeral 131B (see FIG. 5 ).

[0041] The first side surface portion 131a is a surface located on the first side surface 140c side located on the distal end side of the reinforcing member 140 in the cross section in the natural state shown in Fig. 3. The second side surface portion 131b is a surface located on the second side surface 140d side located on the proximal end side of the reinforcing member 140 in the cross section in the natural state shown in Fig. 3.

[0042] When the reinforcing member 140 is in the bent state shown in Figure 4, it moves toward the first side portion 131a and applies force to the first region 131A, and while contacting the first side portion 131a, it deforms the second region 132 so as to form a space 150 between it and the second side portion 131b.

[0043] Specifically, as shown in FIG. 4, when the sheath member 110 is bent, the reinforcing member 140 (each of the portions 140A and 140B of the reinforcing member 140) moves toward the first side surface portion 131a, bringing the first side surface 140c into contact with the first side surface portion 131a, and widening the width W22 of the second region 132 along the longitudinal direction of the inner layer 120, thereby forming a space 150 between the second side surface 140d and the second side surface portion 131b.

[0044] By forming the space 150 as described above, the sheath member 110 deforms so that the outer layer 130 located in the second region 132 where the reinforcing member 140 is disposed is preferentially stretched along the bending direction, thereby suppressing stretching of the first region 131 where the inner layer 120 and the outer layer 130 are fixed together. This reduces peeling between the inner layer 120 and the outer layer 130 when the sheath member 110 is bent, thereby suppressing kinking of the sheath member 110 and a state in which the lumen 115 of the sheath member 110 cannot be held.

[0045] Furthermore, when the sheath member 110 is bent, a space 150 is formed within the gap portion 132a of the second region 132, thereby improving flexibility and enabling the sheath member 110 to exhibit high conformability to curves and bent portions of the biological lumen.

[0046] As shown in FIG. 3, the reinforcing member 140 is configured to contact the first side surface portion 131a and the second side surface portion 131b in the natural state.

[0047] Specifically, when the sheath member 110 is in its natural state, the first side surface 140c of the reinforcing member 140 contacts the first side surface portion 131a of the first region 131A, and the second side surface 140d of the reinforcing member 140 contacts the second side surface portion 131b of the first region 131A.

[0048] As described above, when the sheath member 110 is in its natural state, no space 150 is formed between the reinforcing member 140 and the side surface portions 131 a, 131 b of the first region 131A, thereby improving the adhesion between the reinforcing member 140 and the outer layer 130 located in the first region 131A. This makes it easier for the sheath member 110 to maintain a linear shape in its natural state. This ensures that the medical device 100 has the pushability to transmit a pushing force applied by an operator or the like to the distal end of the sheath member 110 when inserting the sheath member 110 into a biological lumen, and effectively prevents the sheath member 110 from bending or breaking.

[0049] 3, in a natural state, the gap portion 132a has a rectangular cross section along the longitudinal direction of the inner layer 120. The reinforcing member 140 can be formed of a metal strip-shaped member having a rectangular cross section.

[0050] As shown in Figure 3, in its natural state, the reinforcing member 140 has a rectangular cross-sectional shape having an outer surface 140a located on the side of the outer layer 130 located in the second region 132, an inner surface 140b located on the side of the outer surface 120a of the inner layer 120, a first side surface 140c in contact with the first side surface portion 131a of the first region 131A, and a second side surface 140d in contact with the second side surface portion 131b of the first region 131A.

[0051] As shown in FIG. 3, the gap 132a has a rectangular cross-sectional shape that is substantially the same as that of the reinforcing member 140 in its natural state.

[0052] As described above, in the sheath member 110, the gap portion 132a has a rectangular cross section along the longitudinal direction of the inner layer 120, and the reinforcing member 140 is formed as a metal strip-shaped member having a rectangular cross section. This allows for a large contact area between the side surface portions 131a, 131b of the first region 131A and the side surfaces 140c, 140d of the reinforcing member 140 in the natural state. Therefore, when the sheath member 110 deforms from the natural state to the bent state, a force can be efficiently applied from the first side surface 140c of the reinforcing member 140 to the first side surface portion 131a of the first region 131A. This allows the sheath member 110 to more reliably form the space 150 having the desired width W4 (see FIG. 4 ) in the bent state.

[0053] The cross section of the reinforcing member 140 along the longitudinal direction of the inner layer 120 may be circular, elliptical, or the like, instead of rectangular. However, from the viewpoint of more reliably forming the space 150 having the desired width W4 in the bent state as described above, it is preferable that the cross section of the reinforcing member 140 be rectangular.

[0054] The width W4 of the space 150 along the longitudinal direction of the inner layer 120 shown in Figure 4 can be formed to be less than half the cross-sectional width W31 of the reinforcing member 140 along the longitudinal direction of the inner layer 120 in its natural state shown in Figure 3.

[0055] If the width W4 of the space 150 of the sheath member 110 is configured to be excessively large, there is a possibility that the sheath member 110 will bend excessively near the space 150 when it is bent, causing kinking in the sheath member 110. By forming the width W4 of the space 150 in the bent state to be equal to or less than half the cross-sectional width W32 of the reinforcing member 140 as described above, it is possible to prevent the size of the space 150 in the second region 132 from becoming excessively large relative to the reinforcing member 140. This ensures the rigidity of the sheath member 110 in the bent state, and effectively prevents kinking in the sheath member 110.

[0056] The cross-sectional width W31 of the reinforcing member 140 along the longitudinal direction of the inner layer 120 in the natural state shown in Figure 3 can be formed to be larger than the width W11 of the first region 131A along the longitudinal direction of the inner layer 120 in the natural state.

[0057] As described above, the sheath member 110 is formed such that the cross-sectional width W31 of the reinforcing member 140 is larger than the width W11 of the first region 131A in the natural state, and therefore the arrangement ratio of the reinforcing member 140 per unit length in the axial direction of the sheath member 110 increases. Therefore, the reinforcing effect of the reinforcing member 140 can be enhanced, and the sheath member 110 has further improved kink resistance.

[0058] FIG. 5 shows a cross-sectional view of the distal end portion 111 (a portion including a certain range from the most distal end to the proximal end side) of the sheath member 110 in its natural state.

[0059] As shown in FIG. 5, the gap 132 a and the reinforcing member 140 are not disposed at the distal end 111 of the sheath member 110 .

[0060] Furthermore, one portion 140C located at the most distal end of the reinforcing member 140 arranged on the proximal side of the distal end 111 of the sheath member 110 and another portion 140D adjacent to the one portion 140C on the proximal side are fixed.

[0061] One part 140C and the other part 140D of the reinforcing member 140 can be fixed together, for example, by laser welding the second side 140d located on the base end side of the one part 140C to the first side 140c located on the tip end side of the other part 140D.

[0062] As described above, the sheath member 110 has one portion 140C located at the most distal end of the reinforcing member 140 and another portion 140D adjacent to the one portion 140C on the proximal side fixed thereto. Therefore, the width of the reinforcing member 140 along the longitudinal direction of the inner layer 120 in the natural state shown in FIG. 5 (the width of the reinforcing member 140 at the portion where the one portion 140C and the other portion 140D of the reinforcing member 140 are integrated) is longer than the width W31 (see FIG. 3 ) of the other portion of the reinforcing member 140 located proximal to the portions 140C and 140D. Therefore, when the vicinity of the distal end 111 of the sheath member 110 is bent, the one portion 140C located at the most distal end of the reinforcing member 140 is less likely to move toward the distal end in the longitudinal direction of the inner layer 120. This makes it possible to prevent the entire reinforcing member 140 from excessively moving toward the distal end in the longitudinal direction of the inner layer 120 when the vicinity of the distal end 111 of the sheath member 110 is bent.

[0063] The width W5 of the first region 131B along the longitudinal direction of the inner layer 120 in the natural state shown in Figure 5 is preferably longer than, for example, the width W11 of the first region 131A in the natural state (see Figure 3), for the following reason.

[0064] When the sheath member 110 is bent, the one portion 140C located at the most distal end of the reinforcing member 140 comes into contact with the first side surface portion 131a of the first region 131B, which has a width W5 larger than the width W11 of the first region 131 located proximal to the distal end portion 111 of the sheath member 110. By having the width W5 as described above, the first region 131B located at the distal end portion 111 of the sheath member 110 has a stronger fixing strength (fusion strength) between the inner layer 120 and the outer layer 130 than the first region 131A having the width W11. Therefore, when the one portion 140C located at the most distal end of the reinforcing member 140 comes into contact with the first side surface portion 131a of the first region 131B located at the distal end portion 111 of the sheath member 110, excessive movement of the one portion 140C toward the distal end side can be effectively prevented. Furthermore, since the sheath member 110 can prevent the one portion 140C from moving excessively toward the distal end as described above, a gap is less likely to occur between the second side surface 140d of the other portion 140D of the reinforcing member 140 and the second side surface portion 131b of the first region 131 located on the proximal side thereof. Therefore, it is possible to prevent the pitch distance between the portions 140A, 140B of the reinforcing member 140 located on the proximal side of the distal end portion 111 from becoming excessively wide.

[0065] On the other hand, when an external force is applied to the distal end portion 111 of the sheath member 110 and the second region 132 in which the portions 140C and 140D of the reinforcing member 140 are arranged is bent, with the portions 140C and 140D of the reinforcing member 140 integrated, the first side surface 140c of the one portion 140C of the reinforcing member 140 comes into contact with the first side surface portion 131a of the first region 131B located on the distal end side thereof, thereby applying a force to the first region 131A. Therefore, while the first side surface 140c of the one portion 140C of the reinforcing member 140 comes into contact with the first side surface portion 131a of the first region 131B as described above, a certain amount of space 150 (see FIG. 4 ) is formed between the second side surface 140d of the other portion 140D of the reinforcing member 140 and the second side surface portion 131b of the first region 131 located on the proximal end side thereof. Therefore, even when the vicinity of the distal end 111 of the sheath member 110 is bent, the sheath member 110 can be prevented from kinking, and can exhibit the ability to follow the bends and curved portions of the biological lumen.

[0066] The positions at which the reinforcing member 140 and the second region 132 are provided in the sheath member 110 are not particularly limited. However, in consideration of the load that the sheath member 110 receives when inserted into a biological lumen, it is preferable that the reinforcing member 140 and the second region 132 be provided in a certain range that includes at least the distal end side of the sheath member 110. Furthermore, from the viewpoint of suppressing excessive movement of the reinforcing member 140 toward the distal end side as described above, it is preferable that the reinforcing member 140 and the second region 132 not be provided in a certain range that includes the distal end portion 111 of the sheath member 110.

[0067] The dimensions of each part of the sheath member 110 can be determined as follows, for example.

[0068] The width W11 of the first region 131A (the portion located closer to the base end than the distal end 111) along the longitudinal direction of the inner layer 120 in the natural state shown in Fig. 3 can be formed to be, for example, 0.2 mm or more and 0.6 mm or less. Furthermore, the width W12 of the first region 131A (the portion located closer to the base end than the distal end 111) along the longitudinal direction of the inner layer 120 in the bent state shown in Fig. 4 can be formed to be, for example, 0.3 mm or more and 0.7 mm or less.

[0069] The first width W21 of the second region 132 along the longitudinal direction of the inner layer 120 in the natural state shown in Fig. 3 can be formed to be, for example, 0.3 mm or more and 0.7 mm or less. Furthermore, the second width W22 of the second region 132 along the longitudinal direction of the inner layer 120 in the bent state shown in Fig. 4 can be formed to be larger than the first width W21, and can be formed to be, for example, 0.5 mm or more and 1.0 mm or less.

[0070] The width W31 of the reinforcing member 140 along the longitudinal direction of the inner layer 120 in the natural state shown in Figure 3 can be made larger than the width W11 of the first region 131A along the longitudinal direction of the inner layer 120 in the natural state, and can be made, for example, to be 0.3 mm or more and 0.7 mm or less.

[0071] When the reinforcing member 140 is made of a metal material with a relatively high hardness, the width W31 of the reinforcing member 140 along the longitudinal direction of the inner layer 120 in the natural state shown in Fig. 3 and the width W32 of the reinforcing member 140 along the longitudinal direction of the inner layer 120 in the bent state shown in Fig. 4 are substantially the same size. In this embodiment, as shown in Fig. 4, the reinforcing member 140 is illustrated as having a curved shape along the longitudinal direction of the inner layer 120 in the bent state. For example, when the cross-sectional shape of the reinforcing member 140 is deformed to bend in the bent state as in this embodiment, the width W32 of the reinforcing member 140 can be defined as the distance between the first side surface 140c and the second side surface 140d along a curve with the same curvature as the curve A1 along the longitudinal direction of the bent (curved) inner layer 120 as shown in Fig. 4.

[0072] The width W4 of the space 150 along the longitudinal direction of the inner layer 120 in the bent state shown in Figure 4 can be formed to be less than half the width W31 of the reinforcing member 140 along the longitudinal direction of the inner layer 120 in its natural state, and can be formed to be, for example, 0.15 mm or more and 0.35 mm or less.

[0073] The width W5 of the first region 131B along the longitudinal direction of the inner layer 120 shown in Figure 5 can be made larger than the width W11 (see Figure 3) of the first region 131A in the part other than the tip portion 111 when it is bent, and can be made, for example, to be 3 mm or more and 15 mm or less.

[0074] Each part of the sheath member 110 can be made of, for example, the following materials.

[0075] Examples of materials that can be used to form the inner layer 120 include fluorine-based resin materials such as polytetrafluoroethylene (PTFE) and tetrafluoroethylene-perfluoroalkoxyethylene copolymer (PFA); resin materials such as polystyrene, polyolefin, polyurethane, polyester, and polyamide; various thermoplastic elastomer materials such as styrene-based, polyolefin-based, polyurethane-based, polyester-based, polyamide-based, polybutadiene-based, transpolyisoprene-based, fluororubber-based, and chlorinated polyethylene-based materials; and combinations of two or more of these materials (polymer alloys, polymer blends, laminates, etc.).

[0076] Examples of materials that can be used to form the outer layer 130 include resin materials such as polystyrene, polyolefin, polyurethane, polyester, and polyamide, various thermoplastic elastomer materials such as styrene-based, polyolefin-based, polyurethane-based, polyester-based, polyamide-based, polybutadiene-based, trans-polyisoprene-based, fluororubber-based, and chlorinated polyethylene-based materials, and combinations of two or more of these materials (polymer alloys, polymer blends, laminates, etc.). Note that the sheath member 110 may be formed using the same material for the inner layer 120 as for the outer layer 130.

[0077] The reinforcing member 140 can be made of, for example, a material harder than the resin material that makes up the inner layer 120 and the resin material that makes up the outer layer 130. When each layer 120, 130 is made of the resin material exemplified above, the material that can be used to make the reinforcing member 140 can be, for example, stainless steel such as SUS304, SUS316, precipitation hardened stainless steel (PH stainless steel), tungsten, aluminum, Ni-Ti alloy, or other metal material.

[0078] 1, a valve body 161 is disposed inside the hub member 160. The valve body 161 is configured to allow the insertion of the dilator tube 210 or various medical devices to be inserted into a biological lumen.

[0079] The valve body 161 prevents gaps from forming between the dilator tube 210 or the medical device when the dilator tube 210 or the medical device is inserted, and prevents liquids such as blood or saline injected into the inside of the hub member 160 from flowing back toward the base end of the hub member 160.

[0080] The hub member 160 has a first port portion 165 and a second port portion 167 that communicate with the interior of the hub member 160 .

[0081] A tube 171 connected to a three-way stopcock 173 for supplying a liquid such as saline to the inside of the hub member 160 can be connected to the first port portion 165 .

[0082] A suction device can be connected to the second port 167 via a predetermined tube. The suction device can be used when performing a procedure to suction a blood clot or the like in a vein. Note that the installation of the second port 167 can be omitted as appropriate depending on the intended use of the medical device 100, etc.

[0083] The medical device 100 has a cap member 180 connected to the proximal side of the hub member 160. The cap member 180 has an opening that communicates with the inside of the hub member 160. The surgeon or the like can insert the dilator tube 210 into the inside of the hub member 160 and the lumen 115 of the sheath member 110 by pushing the dilator tube 210 into the proximal side of the cap member 180.

[0084] <Dilator 200> As shown in FIG. 1, the dilator 200 includes a dilator tube 210 and a dilator hub 220.

[0085] The dilator 200 can detachably fix the dilator hub 220 to the cap member 180 in a state in which the dilator tube 210 is inserted through the inside of the hub member 160 of the medical device 100 and the inner cavity 115 of the sheath member 110 .

[0086] With the dilator 200 assembled to the medical device 100, the surgeon inserts the sheath member 110 into a perforation formed in the living body that connects the living body lumen into which the sheath member 110 is to be inserted and the outside of the living body, and pushes open the perforation. The dilator 200 prevents the sheath member 110 from being bent or otherwise damaged when the sheath member 110 is inserted into the living body lumen through the perforation as described above.

[0087] Prior to inserting the dilator 200 and the sheath member 110 into the biological lumen as described above, the surgeon passes a guide wire, which is disposed between the biological lumen and the outside of the living body, through the dilator tube 210 via a perforation formed in the living body, and inserts the dilator 200 and the sheath member 110 along the guide wire into the biological lumen. After inserting the distal end of the dilator 200 to a desired position in the biological lumen, the surgeon removes the dilator tube 210 from the sheath member 110. The surgeon can use the lumen 115 of the sheath member 110, from which the dilator tube 210 has been removed, as an access route to deliver various medical devices to desired positions in the biological lumen.

[0088] As described above, the medical device 100 according to this embodiment includes a tubular sheath member 110 and a hub member 160 connected to the proximal end 113 of the sheath member 110. The sheath member 110 includes an inner layer 120 having an outer surface 120a and an inner surface 120b, an outer layer 130 having an outer surface 130a and an inner surface 130b, and a supporting member 160 positioned between the outer surface 120a of the inner layer 120 and the inner surface 130b of the outer layer 130. The outer layer 130 has a first region 131A bonded to the outer surface 120a of the inner layer 120 and a second region 132 not bonded to the outer surface 120a of the inner layer 120, the second region 132 being arranged spirally along the longitudinal direction of the inner layer 120 at a position adjacent to the first region 131A, and a gap being formed between the outer surface 120a of the inner layer 120 and the inner surface 130b of the outer layer 130. The reinforcing member 140 is arranged spirally in the gap 132a without being fixed to the inner layer 120 and the outer layer 130, and the second region 132 is configured to be deformable between a natural state having a first width W21 in the longitudinal direction of the inner layer 120 and a bent state having a second width W22 in the longitudinal direction of the inner layer 120 that is larger than the first width W21, and the first region 131A has a first side surface portion 131a and a second side surface portion 131b facing the first side surface portion 131a across the gap 132a, and the reinforcing member 140 is configured to move toward the first side surface portion 131a when in the bent state to apply a force to the first region 131A, and to deform the second region 132 so as to form a space 150 between the first side surface portion 131a and the second side surface portion 131b while coming into contact with the first side surface portion 131a.

[0089] As described above, the sheath member 110 included in the medical device 100 includes the inner layer 120, the outer layer 130, and the reinforcing member 140 disposed between the outer surface 120a of the inner layer 120 and the inner surface 130b of the outer layer 130. The reinforcing member 140 improves the kink resistance of the sheath member 110. The outer layer 130 also includes a first region 131A bonded to the outer surface 120a of the inner layer 120 and a second region 132 not bonded to the outer surface 120a of the inner layer 120. The second region 132 extends spirally along the longitudinal direction of the inner layer 120, forming a gap 132a between the outer surface 120a of the inner layer 120 and the inner surface 120b of the outer layer 130. The reinforcing member 140 is arranged spirally in the gap 132a, and when the sheath member 110 is in a bent state, the reinforcing member 140 comes into contact with the first side surface portion 131a of the first region 131A, forming a space 150 between the first region 131A and the second side surface portion 131b of the first region 131A. When the sheath member 110 is in a bent state, the reinforcing member 140 in contact with the first side surface portion 131a deforms the sheath member 110 so that the width of the second region 132 along the longitudinal direction of the inner layer 120 increases. Therefore, the sheath member 110 deforms so that the outer layer 130 located in the second region 132 where the reinforcing member 140 is arranged preferentially stretches along the bending direction, thereby suppressing stretching of the first region 131 where the inner layer 120 and the outer layer 130 are fixed to each other. As a result, when the sheath member 110 is bent, peeling between the inner layer 120 and the outer layer 130 is reduced, thereby preventing the sheath member 110 from kinking and becoming unable to hold the inner lumen 115 of the sheath member 110. Furthermore, when the sheath member 110 is bent, the flexibility of the sheath member 110 is improved by the formation of spaces 150 in the gaps 132a of the second region 132 of the outer layer 130, allowing the sheath member 110 to exhibit high conformability to curved or tortuous portions of a biological lumen. As described above, according to the present embodiment, it is possible to provide a medical device 100 having a sheath member 110 that has improved kink resistance and high conformability to curved or tortuous portions of a biological lumen.

[0090] Furthermore, the reinforcing member 140 is configured to come into contact with the first side surface portion 131a and the second side surface portion 131b in the natural state.

[0091] As described above, the sheath member 110 is configured such that the reinforcing member 140 and the side surface portions 131a, 131b of the first region 131A are in contact with each other in the natural state, so that no gaps are formed between the reinforcing member 140 and the side surface portions 131a, 131b. This enhances the adhesion between the reinforcing member 140 and the outer layer 130 located in the first region 131A. This facilitates maintaining the sheath member 110 in a linear shape in the natural state. Therefore, when inserting the sheath member 110 into a biological lumen, the sheath member 110 can ensure pushability, which transmits a pushing force applied by an operator to the distal end of the sheath member 110, and can effectively prevent the sheath member 110 from bending or breaking.

[0092] In addition, when in its natural state, the gap portion 132a has a rectangular cross section along the longitudinal direction of the inner layer 120, and the reinforcing member 140 is made of a metal strip-shaped member having a rectangular cross section.

[0093] As described above, in the sheath member 110, in the natural state, the gap portion 132a has a rectangular cross section along the longitudinal direction of the inner layer 120, and the reinforcing member 140 is formed of a metal strip-shaped member having a rectangular cross section, thereby increasing the contact area between the side surface portions 131a, 131b of the first region 131A and the reinforcing member 140. Therefore, when the sheath member 110 deforms from the natural state to the bent state, the reinforcing member 140 can efficiently apply force to the first side surface portion 131a of the first region 131A. This allows the sheath member 110 to more reliably form a space 150 having a desired width W4 between the reinforcing member 140 and the second side surface portion 131b in the bent state.

[0094] Furthermore, the width W5 of the space 150 along the longitudinal direction of the inner layer 120 is less than half the width W31 of the cross section of the reinforcing member 140 along the longitudinal direction of the inner layer 120.

[0095] As described above, in the sheath member 110, the width W5 of the space 150 along the longitudinal direction of the inner layer 120 is equal to or less than half the width W31 of the cross section of the reinforcing member 140 along the longitudinal direction of the inner layer 120, and therefore, the space 150 can be prevented from being formed excessively large with respect to the reinforcing member 140 in the second region 132. This ensures the rigidity of the sheath member 110 in a bent state, and effectively prevents the sheath member 110 from kinking even in a bent state in which the space 150 is formed.

[0096] Furthermore, the width W31 of the cross section of the reinforcing member 140 along the longitudinal direction of the inner layer 120 in the natural state is larger than the width W11 of the first region 131A along the longitudinal direction of the inner layer 120 in the natural state.

[0097] As described above, the sheath member 110 is formed such that the cross-sectional width W31 of the reinforcing member 140 in the natural state is larger than the width W11 of the first region 131A in the natural state, and therefore the arrangement ratio of the reinforcing member 140 per unit length in the axial direction of the sheath member 110 is increased. Therefore, the reinforcing effect of the reinforcing member 140 can be enhanced in the sheath member 110, and the kink resistance of the sheath member 110 is further effectively improved.

[0098] Furthermore, the gap 132a and the reinforcing member 140 are not disposed at the distal end portion 111 of the sheath member 110, and one portion 140C located at the most distal end of the reinforcing member 140 disposed closer to the proximal end than the distal end portion 111 of the sheath member 110 and another portion 140D adjacent to the one portion 140C on the proximal end side are fixed.

[0099] As described above, in the sheath member 110, one portion 140C located at the most distal end of the reinforcing member 140 and another portion 140D adjacent to the one portion 140C on the proximal side are fixed. Therefore, the width of the reinforcing member 140 along the longitudinal direction of the inner layer 120 in its natural state (the width of the portion of the reinforcing member 140 where the one portion 140C and the other portion 140D of the reinforcing member 140 are integrated) is longer than the width W31 of the reinforcing member 140 located proximal to the portions 140C and 140D. Therefore, when the vicinity of the distal end 111 of the sheath member 110 is bent, the one portion 140C located at the most distal end of the reinforcing member 140 is less likely to move toward the distal end in the longitudinal direction of the inner layer 120. This makes it possible to suppress excessive movement of the entire reinforcing member 140 toward the distal end in the longitudinal direction of the inner layer 120 when the vicinity of the distal end 111 of the sheath member 110 is bent.

[0100] (Modification) In the above-described embodiment, an example was described in which the medical device 100 was applied to a sheath introducer. However, the application of the medical device according to the present invention is not limited to sheath introducers, and it can also be applied to, for example, catheters known in the medical field (e.g., guiding catheters, microcatheters, contrast catheters, etc.).

[0101] As an example, as in the modified example shown in FIG. 6 , it is possible to configure a medical device 300 as a catheter including a sheath member 110 having an inner layer and an outer layer in which a reinforcing member 140 and a gap portion 132 a are arranged, a distal tip 380 arranged at the distal end of the sheath member 110, a kink-resistant protector 390 arranged so as to cover a part of the proximal end side of the sheath member 110, and a hub member 360 arranged at the proximal end of the sheath member 110.

[0102] The medical device according to the present invention has been described above through embodiments and modifications, but the present invention is not limited to the contents described in this specification and can be modified as appropriate based on the claims.

[0103] The structure of each part and the arrangement of components described in the specification may be changed as appropriate, and the use of additional components described in the drawings may be omitted or other additional components may be used as appropriate.

[0104] This application is based on Japanese Patent Application No. 2024-86076, filed on May 28, 2024, the disclosure of which is incorporated herein by reference in its entirety.

[0105] 10 Introducer circuit 100 Medical device 110 Sheath member 111 Distal end portion of sheath member 115 Lumen of sheath member 120 Inner layer 120a Outer surface of inner layer 120b Inner surface of inner layer 130 Outer layer 130a Outer surface of outer layer 130b Inner surface of outer layer 131 First region 131A First region 131B First region 131a First side portion 131b Second side portion 132 Second region 132a Gap portion 140 Reinforcing member 140A Reinforcing member 140B Reinforcing member 140C One portion of reinforcing member 140D Another portion of reinforcing member 150 Space 160 Hub member 200 Dilator 300 Medical device W11 Width of first region in natural state W12 W21: Width of the first region in the bent state; W22: Second width of the second region; W31: Width of the reinforcing member in the natural state; W32: Width of the reinforcing member in the bent state; W4: Width of the space.

Claims

1. A catheter having a tubular sheath member and a hub member connected to a proximal end of the sheath member, wherein the sheath member comprises: an inner layer having an outer surface and an inner surface; an outer layer having an outer surface and an inner surface; and a reinforcing member located between the outer surface of the inner layer and the inner surface of the outer layer, wherein the outer layer has a first region fixed to the outer surface of the inner layer and a second region not fixed to the outer surface of the inner layer, wherein the second region is arranged spirally along the longitudinal direction of the inner layer at a position adjacent to the first region and forms a gap between the outer surface of the inner layer and the inner surface of the outer layer, and the reinforcing member is arranged spirally in the gap without being fixed to the inner layer or the outer layer, and the second region is configured to be deformable between a natural state having a first width in the longitudinal direction of the inner layer and a bent state having a second width in the longitudinal direction of the inner layer that is larger than the first width, the first region has a first side portion and a second side portion facing the first side portion across the gap portion, and the reinforcing member is configured, when in the bent state, to move toward the first side portion to apply force to the first region, and to deform the second region so as to form a space between the first side portion and the second side portion while contacting the first side portion.

2. The medical device according to claim 1, wherein the reinforcing member is configured to contact the first side portion and the second side portion when in the natural state.

3. The medical device according to claim 1, wherein the gap portion has a rectangular cross section along the longitudinal direction of the inner layer in the natural state, and the reinforcing member is a metal strip-shaped member having a rectangular cross section.

4. The medical device according to claim 1, wherein the width of the space along the longitudinal direction of the inner layer is equal to or less than half the width of the cross section of the reinforcing member along the longitudinal direction of the inner layer in the natural state.

5. The medical device according to claim 1, wherein the width of the cross section of the reinforcing member along the longitudinal direction of the inner layer in the natural state is greater than the width of the first region along the longitudinal direction of the inner layer in the natural state.

6. The medical device according to claim 1, wherein the gap and the reinforcing member are not disposed at the distal end of the sheath member, and one portion located at the most distal end of the reinforcing member disposed proximal to the distal end of the sheath member and another portion adjacent to the one portion on the proximal side are fixed.

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