Catheter device

Abstract

This catheter device comprises a catheter shaft 30 that includes an inner layer 50 forming a main lumen 40 having a substantially circular cross-sectional shape, and an outer layer 52 provided outside the inner layer 50 and forming a sub-lumen 42. The sub-lumen 42 has a cross-sectional shape curved along the main lumen 40 and having a substantially uniform thickness t in the circumferential direction.

Description

Catheter Device

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

[0002] Conventionally, catheter devices have been known that include a catheter shaft with a multi-lumen structure having a main lumen and sub-lumens. The structures of the main lumen and sub-lumens are primarily determined by their cross-sectional shapes. While the cross-sectional shape of the main lumen is generally generally circular, various cross-sectional shapes have been proposed for the sub-lumens. For example, Patent Document 1 discloses a catheter shaft with a sub-lumen having a rectangular cross-section. Patent Document 2 discloses a catheter shaft with a sub-lumen having a crescent-shaped cross-section. Patent Document 3 discloses a catheter shaft with a sub-lumen having a curved elliptical cross-section.

[0003] International Publication No. 2022 / 085199 JP 2001-508670 A JP 2013-66720 A

[0004] An object of the present invention is to provide a catheter device having a sublumen with a new cross-sectional shape different from that of the conventional sublumens described above.

[0005] In order to solve the above problems, a catheter device according to one aspect of the present invention includes a catheter shaft having an inner layer that forms a main lumen having a substantially circular cross-sectional shape, and an outer layer that is provided outside the inner layer and forms a sub-lumen. The sub-lumen has a cross-sectional shape that is curved along the main lumen and has a substantially uniform thickness in the circumferential direction.

[0006] According to the present invention, a catheter device having a sublumen with a new cross-sectional shape different from conventional sublumens can be provided.

[0007] Fig. 1 is a schematic diagram showing an example of a usage scene of a catheter device according to an embodiment; Fig. 2 is an overall view showing a catheter device according to an embodiment; Fig. 3 is a cross-sectional view perpendicular to the extension direction of a catheter shaft according to an embodiment; Fig. 4 is an enlarged view of a sub-lumen; Fig. 5 is an enlarged view of an end of a sub-lumen; Fig. 6 is a cross-sectional view showing another example of a catheter shaft; Fig. 7 is a view for explaining conditions for defining the circumferential length of a sub-lumen; Fig. 8 is a view for explaining a catheter shaft according to another embodiment.

[0008] Hereinafter, embodiments for carrying out the present invention will be described. The same or equivalent components will be given the same reference numerals, and redundant explanations will be omitted. In each drawing, for the sake of convenience, components will be omitted, enlarged, or reduced as appropriate. The drawings should be viewed in accordance with the orientation of the reference numerals.

[0009] FIG. 1 is a schematic diagram illustrating an example of a usage scenario of a catheter device 10 according to an embodiment. The catheter device 10 is inserted into a target organ 12 of a living body and then used to treat the target organ 12. Here, "treatment" refers to an action related to medical treatment or examination of the living body. Here, an example of such treatment is described in which a medical device is guided to the target organ 12 for treatment or examination of the target organ 12. The target organ 12 is, for example, a circulatory organ, a digestive organ, or the like. The circulatory organ serving as the target organ 12 is, for example, a blood vessel such as the common carotid artery, external carotid artery, internal carotid artery, subclavian artery, brachiocephalic artery, or vertebral artery. The catheter device 10 of this embodiment is used in a transradial neuro-intervention (TRN) technique. In this case, the catheter device 10 is inserted via the radial artery 14 into a cerebral blood vessel (such as the external carotid artery or internal carotid artery) serving as the target organ 12. Here, an example is shown in which the catheter device 10 is inserted through the radial artery 14, the right subclavian artery 16, and the aorta 18 to the left common carotid artery 20, which is the target organ 12.

[0010] 2 is an overall view showing a catheter device 10 according to an embodiment. The catheter device 10 includes a catheter shaft 30 and a handle 32 attached to the proximal end of the catheter shaft 30. The catheter shaft 30 optionally includes a balloon 34 attached to the distal end of the catheter shaft 30.

[0011] The catheter shaft 30 has flexibility that allows it to be bent. The catheter shaft 30 of this embodiment has a bent section 30a provided midway in the axial direction. A tip member 36 is attached to the distal end of the catheter shaft 30. When the target organ 12 is a blood vessel such as a cerebral blood vessel, the outer diameter of the catheter shaft 30 is, for example, 9.5 Fr (3.2 mm) or less.

[0012] The handle 32 is held by an operator such as a doctor. The handle 32 includes a main introduction port 32a communicating with the main lumen of the catheter shaft 30 and a sub-introduction port 32b communicating with the sub-lumen of the catheter shaft 30.

[0013] The balloon 34 can be expanded by supplying a fluid therein through a sublumen of the catheter shaft 30. The balloon 34 is used to temporarily block blood flow by expanding it in the blood vessel that is the target organ 23.

[0014] 2, showing a cross section perpendicular to the extension direction (axial direction) of the catheter shaft 30. Hereinafter, when describing the positional relationship and shape of each component of the catheter shaft 30, unless otherwise specified, the positional relationship and shape will be described in the cross section perpendicular to the axial direction of the catheter shaft 30.

[0015] A main lumen 40 and a sub-lumen 42 are formed in the catheter shaft 30. In the cross section of the catheter shaft 30, the cross-sectional area of ​​the main lumen 40 is larger than the cross-sectional area of ​​the sub-lumen 42. In this embodiment, the cross-sectional shape of the main lumen 40 is circular.

[0016] Each of the main lumen 40 and the sub-lumen 42 is used to pass at least one of a medical device and a fluid. The main lumen 40 in this embodiment is used to pass a medical device and guide the medical device to the target organ 12. The sub-lumen 42 in this embodiment is used to pass a fluid for inflating the balloon 34.

[0017] Examples of medical devices to be passed through each lumen 40, 42 include stent grafts, coils, guidewires, wiring members, and various catheters such as electrode catheters, balloon catheters, and microcatheters. Here, the wiring members refer to, for example, flexible wiring substrates that are electrically connected to electrical devices attached to the catheter shaft 30. Examples of electrical devices include ultrasonic transducers used in intracardiac echocardiography (ICE). Examples of fluids to be passed through each lumen 40, 42 include gas for expanding the balloon 34, liquid agents such as contrast agents, and irrigation liquids (e.g., physiological saline).

[0018] An object to be passed through the main lumen 40 is introduced into the main lumen 40 from outside the body through the main inlet port 32a of the handle 32 and discharged into the body through a main outlet port 46 provided on the catheter device 10. The main outlet port 46 is provided, for example, on the tip member 36 (see FIG. 2). An object to be passed through the sub-lumen 42 is introduced into the sub-lumen 42 from outside the body through the sub-inlet port 32b of the handle 32 and discharged into the balloon 34 through a sub-outlet port 48 provided on the catheter device 10. The sub-outlet port 48 is formed, for example, as a side hole opening on the outer circumferential surface of the catheter shaft 30 at the location where the balloon 34 is attached (see FIG. 2).

[0019] The catheter shaft 30 comprises an inner layer 50 that forms the main lumen 40, and an outer layer 52 that is provided outside the inner layer 50 and forms the sub-lumen 42. The catheter shaft 30 according to this embodiment further comprises a reinforcing layer 54 provided between the inner layer 50 and the outer layer 52. That is, the reinforcing layer 54 is provided outside the main lumen 40. The inner layer 50 and the outer layer 52 each comprise at least one resin layer. The inner layer 50, the outer layer 52, and the reinforcing layer 54 may be formed from the proximal end to the distal end of the catheter shaft 30. Alternatively, a shaft having the cross-sectional shape shown in FIG. 3 may be used partway through the catheter shaft 30, and then fused to another tube partway along the length.

[0020] The inner layer 50 may be made of a synthetic resin such as a fluororesin with good slipperiness, such as PTFE (polytetrafluoroethylene) or PFA (perfluoroalkoxyalkane). The resin layer constituting the outer layer 52 may be made of a synthetic resin such as PA, a PA-based elastomer, or TPU.

[0021] The reinforcing layer 54 is formed by braiding multiple wires (not shown) into a tubular shape. Alternatively, the reinforcing layer 54 may be formed by a coil or the like formed by a single or multiple wires (not shown). The reinforcing layer 54 serves to enhance the torque transmission and kink resistance of the catheter shaft 30. Torque transmission here refers to the ability to transmit torque applied to the handle 32 to the distal end of the catheter shaft 30. To achieve this, the reinforcing layer 54 is provided to cover the inner layer 50 of the catheter shaft 30. The wires constituting the reinforcing layer 54 may be made of metals such as stainless steel and Ni-Ti alloys, as well as resins. The wires of this embodiment have a circular cross section perpendicular to their axial direction. The cross-sectional shape of the wires is not particularly limited and may be, for example, flat.

[0022] In the catheter shaft 30 according to this embodiment, no reinforcing layer is provided on the outside of the outer layer 52. In other words, no reinforcing layer is provided on the outside of the sub-lumen 42. This allows the outer diameter of the catheter shaft 30 to be reduced. Furthermore, the absence of a reinforcing layer on the outside of the sub-lumen 42 is advantageous when collapsing the sub-lumen 42 by, for example, creating a negative internal pressure in the sub-lumen 42 or applying an external force. Collapsing the sub-lumen 42 will be described later.

[0023] As shown in Figure 3, the cross-sectional shapes of the catheter shaft 30 and the main lumen 40 are approximately circular. The center C40 of the main lumen 40 is eccentric in an eccentric direction D1 relative to the center C30 of the catheter shaft 30. The direction directly opposite the eccentric direction D1 relative to the center C30 of the catheter shaft 30 is called the counter-eccentric direction D2. In this case, the sub-lumen 42 is formed in the counter-eccentric direction D2 relative to the main lumen 40. The sub-lumen 42 is not formed in the eccentric direction D1 relative to the center C40 of the main lumen 40. The ratio of the diameter of the main lumen 40 to the diameter of the catheter shaft 30 may be, for example, 80% or more. Furthermore, the ratio of the space occupied by the diameter of the main lumen 40 and the thickness t of the sub-lumen 42 to the diameter of the catheter shaft 30 may be, for example, 85% or more.

[0024] FIG. 4 is an enlarged view of the sub-lumen 42. The sub-lumen 42 is enclosed within the outer layer 52. The sub-lumen 42 has a cross-sectional shape that curves along the main lumen 40 and has a substantially uniform thickness t along the circumferential direction. Here, "substantially uniform thickness t" means that the maximum and minimum values ​​of thickness t are within ±15%, more preferably ±10%, of the average value of thickness t. The average thickness t may be determined, for example, by dividing the sub-lumen 42 into three equal parts in the width direction and averaging the thicknesses t of each part. The thickness t may be measured, for example, with a digital microscope. The thickness t may be substantially uniform from one end of the sub-lumen 42 to the other end. Alternatively, the thickness t may be substantially uniform over 80% of the circumferential length of the sub-lumen 42. The thickness t of the sub-lumen 42 may be, for example, 0.5 mm or less, preferably 0.3 mm or less, and more preferably 0.2 mm or less.

[0025] The sub-lumen 42 is defined by an outer arc-shaped edge 42a located radially outward, an inner arc-shaped edge 42b located radially inward, a first end edge 42c located at one circumferential end, and a second end edge 42d located at the other circumferential end.

[0026] The sub-lumen 42 of this embodiment is formed so that the length of the outer arcuate side 42a and the length of the inner arcuate side 42b are approximately equal. Here, "approximately equal" means that the length of the inner arcuate side 42b is within ±5%, more preferably ±3%, of the length of the outer arcuate side 42a. Furthermore, the sub-lumen 42 of this embodiment is formed so that the outer arcuate side 42a and the inner arcuate side 42b are not concentric. Forming the sub-lumen 42 in this manner achieves a sub-lumen 42 having a cross-sectional shape that is curved along the main lumen 40 and has a substantially uniform thickness t in the circumferential direction. The lengths of the outer arcuate side 42a and the inner arcuate side 42b may be, for example, ¼ or more of the circumference of the catheter shaft 30.

[0027] In this embodiment, the magnitude relationship between the thickness A of the layer located outside the sub-lumen 42 and the thickness B of the layer located inside the sub-lumen 42 remains constant throughout the circumferential direction (extension direction) of the sub-lumen 42. The thickness A of the layer located outside the sub-lumen 42 is the shortest distance from the outer arc-shaped edge 42a to the outer peripheral surface of the outer layer 52. The thickness B of the layer located inside the sub-lumen 42 is the shortest distance from the inner arc-shaped edge 42b to the inner peripheral surface of the inner layer 50. The magnitude relationship between the thickness A and the thickness B may remain constant over 80% of the circumferential length of the sub-lumen 42. Alternatively, the magnitude relationship between the thickness A and the thickness B may remain constant from one circumferential end to the other circumferential end of the sub-lumen 42. The thickness A of the layer located outside the sub-lumen 42 may be, for example, 0.2 mm or less.

[0028] 4 shows thicknesses A1 and B1 at one circumferential end of the sublumen 42, thicknesses A2 and B2 at the center, and thicknesses A3 and B3 at the other end. The magnitude relationship between thicknesses A and B being constant from one end to the other of the sublumen 42 means that when A1 > B1, A2 > B2 and A3 > B3, and conversely, when A1 < B1, A2 < B2 and A3 < B3. There are no combinations with different magnitude relationships, such as A1 > B1, A2 < B2, or A3 > B3.

[0029] Fig. 5 is an enlarged view of the end of the sub-lumen 42. As shown in Fig. 5, a first end edge 42c located at one circumferential end of the sub-lumen 42 has a shape combining an arc 60 and a straight line 62. Similarly, a second end edge 42d located at one circumferential end of the sub-lumen 42 also has a shape combining an arc and a straight line.

[0030] Here, the line obtained by extending the straight line 62 at the first end edge 42c of the sub-lumen 42 is referred to as the first extension line 64, and the line obtained by extending the straight line at the second end edge 42d of the sub-lumen 42 is referred to as the second extension line 66. In this case, in the catheter shaft 30 of this embodiment, as shown in Figure 3, the first extension line 64 and the second extension line 66 do not pass through the center C30 of the catheter shaft 30. Furthermore, in the catheter shaft 30 according to this embodiment, the intersection 68 of the first extension line 64 and the second extension line 66 is located farther from the center C30 of the catheter shaft 30 when viewed from the midpoint C42 of the sub-lumen 42.

[0031] In Fig. 3, the intersection 68 of the first extension line 64 and the second extension line 66 coincides with the center C40 of the main lumen 40, but depending on the orientation of the straight line 62 constituting the first end side 42c and the second end side 42d, the intersection 68 may not coincide with the center C40 of the main lumen 40. Fig. 6 shows an example in which the intersection 68 of the first extension line 64 and the second extension line 66 does not coincide with the center C40 of the main lumen 40. In the embodiment of Fig. 6, the intersection 68 of the first extension line 64 and the second extension line 66 is located farther from the center C30 of the catheter shaft 30 and the center C40 of the main lumen 40 when viewed from the midpoint C42 of the sub-lumen 42.

[0032] FIG. 7 is a diagram illustrating the conditions for defining the circumferential length of the sub-lumen 42. As shown in FIG. 7 , a reference line L tangent to the inner arc-shaped side 42b is drawn at the circumferential midpoint C42 of the sub-lumen 42. At this time, both end portions of the sub-lumen 42 (the first end portion 42c and the second end portion 42d) are located inside the reference line L (below the reference line L in FIG. 7 ). In other words, the sub-lumen 42 is formed so that both end portions are located within the range indicated by the white arrow 70 in FIG. 7 . By determining these conditions, the minimum circumferential length of the sub-lumen 42 can be defined.

[0033] In the catheter device 10, the sub-lumen 42 can be collapsed by controlling the internal pressure of the sub-lumen 42 to a negative pressure. Alternatively, even without creating a negative pressure in the sub-lumen 42, the sub-lumen 42 can be collapsed when a force is applied from the outside of the shaft at the insertion port or inside the body, such as when attempting to insert the sub-lumen 42 into the body. "Collapsing the sub-lumen 42" refers to a state in which the outer layer 52 located outside the sub-lumen 42 deforms radially inward, causing the outer arc-shaped edge 42a and inner arc-shaped edge 42b of the sub-lumen 42 to partially contact each other, thereby reducing the shaft diameter. This contributes to a smaller outer diameter of the catheter shaft 30 and helps realize a catheter device 10 that is minimally invasive during insertion and removal. A certain circumferential length is required to properly collapse the sub-lumen 42. By defining the positions of both ends of the sub-lumen 42 using the reference line L, the circumferential length of the sub-lumen 42 can be ensured, allowing the sub-lumen 42 to be properly collapsed by negative pressure.

[0034] 8 is a diagram illustrating a catheter shaft 30 according to another embodiment. The catheter shaft 30 according to this embodiment can be used when it is desired to maintain the outer shape of the shaft or ensure the permeability of the fluid flowing through the sub-lumen 42.

[0035] As shown in Fig. 8, in the catheter shaft 30 according to this embodiment, the outer layer 52 has ribs 56 that protrude from the outer arcuate side 42a of the sub-lumen 42 toward the inner arcuate side 42b. By forming such ribs 56, it is possible to prevent the sub-lumen 42 from being completely blocked when the internal pressure of the sub-lumen 42 is reduced to a negative pressure, thereby maintaining the outer shape of the shaft and ensuring the permeability of fluid flowing through the sub-lumen 42. The ribs 56 may be formed so as to protrude from the inner arcuate side 42b toward the outer arcuate side 42a. That is, the ribs 56 may be formed so as to protrude from one of the outer arcuate side 42a and the inner arcuate side 42b toward the other.

[0036] 8, the ribs 56 are provided in three locations, at the center and near both ends of the sub-lumen 42, but the number and location of the ribs 56 are not particularly limited. The height h of the ribs 56 is set to a size that does not contact the opposing surface, and may be 30% to 80%, preferably 40% to 60%, for example 50%, of the thickness t of the sub-lumen 42. Note that, while it has been described above that the sub-lumen 42 has a cross-sectional shape with a substantially uniform thickness t along the circumferential direction, this does not necessarily apply to the portions where the ribs 56 are formed.

[0037] The above has described in detail the configuration of the sub-lumen 42 in the catheter device 10 according to this embodiment. The sub-lumen 42 of this embodiment has a new cross-sectional shape that differs from sub-lumens in conventional catheter devices.

[0038] As described above, the sub-lumen 42 of this embodiment has a cross-sectional shape that is curved along the main lumen 40 and has a substantially uniform thickness t in the circumferential direction. For example, in the sub-lumen with a crescent-shaped cross section disclosed in the aforementioned Patent Document 2, the lumen thickness decreases toward the end, resulting in increased fluid resistance. By making the thickness t of the sub-lumen 42 of this embodiment substantially uniform in the circumferential direction, the fluid resistance of the sub-lumen 42 can be made uniform in the circumferential direction. This is advantageous for allowing fluid to flow smoothly through the sub-lumen 42.

[0039] Furthermore, for example, in the case of the sub-lumen having a rectangular cross section disclosed in the above-mentioned Patent Document 1, in order to ensure the required cross-sectional area of ​​the sub-lumen, the thickness of the sub-lumen must be increased, which may result in an increase in the outer diameter of the catheter shaft. The sub-lumen 42 of this embodiment has a cross-sectional shape that is curved along the main lumen 40 and has a substantially uniform thickness t in the circumferential direction, thereby ensuring the required cross-sectional area of ​​the sub-lumen without increasing the outer diameter of the catheter shaft 30.

[0040] The above-described embodiments and variations are merely examples. The abstract technical concepts should not be interpreted as being limited to the contents of the embodiments and variations. Many design changes are possible in the contents of the embodiments and variations, such as changes, additions, and deletions of components. In the above-described embodiments, the term "embodiment" is used to emphasize the contents in which such design changes are possible. However, design changes are also permitted even in contents without such notation. Hatching on cross sections in the drawings does not limit the materials of the hatched objects. The structures and numerical values ​​referred to in the embodiments and variations naturally include those that can be considered identical when manufacturing errors, etc. are taken into account.

[0041] The present invention can be used in a catheter device.

[0042] 10 catheter device, 30 catheter shaft, 32 handle, 34 balloon, 36 tip member, 40 main lumen, 42 sub-lumen, 46 main outlet port, 48 sub-outlet port, 50 inner layer, 52 outer layer, 54 reinforcing layer, 56 rib.

Claims

1. A catheter device comprising: a catheter shaft having an inner layer that forms a main lumen having a substantially circular cross-sectional shape; and an outer layer that is provided on the outside of the inner layer and forms a sub-lumen, the sub-lumen having a cross-sectional shape that is curved along the main lumen and has a substantially uniform thickness in the circumferential direction.

2. A catheter device as described in claim 1, characterized in that the relationship in thickness between the layer located outside the sublumen and the layer located inside the sublumen is invariable in the circumferential direction of the sublumen.

3. The catheter device according to claim 1, wherein the outer arcuate edge of said sub-lumen and the inner arcuate edge of said sub-lumen are not concentric.

4. The catheter device according to claim 1, wherein the length of the outer arcuate side of said sublumen is approximately equal to the length of the inner arcuate side of said sublumen.

5. The catheter device according to claim 1, wherein the end of the sub-lumen includes a shape that combines an arc and a straight line.

6. The catheter device according to claim 5, wherein an extension of the straight line at the end of the sub-lumen does not pass through the axis of the catheter shaft.

7. A catheter device as described in claim 5 or 6, characterized in that the intersection of an extension of the straight line at one end of the sublumen and an extension of the straight line at the other end of the sublumen is located farther from the center of the catheter shaft when viewed from the midpoint of the sublumen.

8. A catheter device as described in claim 1, characterized in that, when a reference line is drawn tangent to the inner arc-shaped side at the circumferential midpoint of the sublumen, both ends of the sublumen are located inside the reference line.

9. The catheter device according to claim 1, wherein a reinforcing layer is provided on the outside of said main lumen, and no reinforcing layer is provided on the outside of said sub-lumen.

10. The catheter device according to claim 1, wherein said outer layer has a rib protruding from one of the outer arcuate edge and the inner arcuate edge of said sublumen toward the other.

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