Medical device

Abstract

To provide a medical device equipped with a linear body that can extend along a lengthwise direction of a blood vessel.SOLUTION: A medical device 10 includes a medicine delivery part 30 at the tip of a long shaft 20. In the medicine delivery part 30, a large number of flexible fibrous linear bodies 31 extending from the tip of the shaft 20 are integrated. The linear bodies 31 have medicine on the outer surface or include medicine inside. Alternatively, the linear bodies include a lumen whose tip is opened along the lengthwise direction, and medicine is supplied through the lumen.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a medical device capable of delivering a drug into a biological lumen. [Background technology]

[0002] In coronary microvascular dysfunction (CMD), insufficient blood flow is supplied to the coronary microvessels and subsequent arteries distal to the coronary arteries, resulting in myocardial ischemia. Causes of CMD include peripheral vascular obstruction, perivascular inflammation, and fibrosis. If drugs could be delivered to the lesion using a catheter, a minimally invasive therapeutic effect could be achieved.

[0003] Because the diameter of blood vessels in areas where coronary microvascular dysfunction occurs is small, it is difficult to deliver drugs directly to the lesion. Therefore, it is possible to release drugs upstream of the lesion and deliver them to the lesion via blood flow. However, because blood flow is reduced at the occluded area of ​​the blood vessel, even if drugs are released upstream, they may not be delivered sufficiently to the lesion.

[0004] For this reason, it is conceivable to deliver a small-diameter needle-shaped filamentary body as close as possible to the lesion and release the drug. A medical device equipped with a small-diameter needle-shaped filamentary body for releasing a drug is disclosed, for example, in Patent Document 1. The medical device in Patent Document 1 comes into contact with the surface of biological tissue, and the filamentary body punctures the tissue from that surface. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 5620408 Summary of the Invention [Problem to be solved by the invention]

[0006] In order to deliver a drug to the peripheral side of a blood vessel, it is necessary for the linear body to extend along the length of the blood vessel. The medical device of Patent Document 1 has a short linear body that punctures biological tissue, and it is difficult for the linear body to extend along the length of the blood vessel.

[0007] The present invention has been made to solve the above-mentioned problems, and has an object to provide a medical device having a linear body that can extend along the length of a blood vessel. [Means for solving the problem]

[0008] The medical device (1) of the present invention, which achieves the above-mentioned object, is a medical device having a drug delivery section at the tip of a long shaft, and the drug delivery section is made up of a large number of flexible fibrous linear bodies extending from the tip of the shaft. [Effects of the Invention]

[0009] In the medical device (1) configured as described above, the linear body constituting the drug delivery portion can enter a narrow blood vessel and extend along its length, thereby directly releasing the drug into the narrow blood vessel and efficiently delivering the drug to the target site. In addition, the medical device can also release the drug while pressing the linear body against a lesion in the blood vessel, allowing the drug to be efficiently transferred to the lesion in the blood vessel.

[0010] (2) In the medical device of (1) above, the linear body may have a drug on its outer surface, thereby ensuring that the medical device can transfer the drug to biological tissue with which the linear body comes into contact.

[0011] (3) In the medical device of (1) or (2) above, the linear body may contain a drug therein, thereby preventing the drug from falling off the linear body.

[0012] (4) In the medical device of any one of (1) to (3) above, the linear body may have a lumen along its length that is open at its tip, and a drug may be supplied through the lumen, thereby enabling the medical device to release the drug on the more peripheral side of the blood vessel.

[0013] (5) The medical device of any one of (1) to (4) above may further include a sheath that covers the shaft and the drug delivery portion radially outward, and the sheath may be movable along the length of the shaft to expose the drug delivery portion. This prevents the drug delivery portion from coming into physical contact with the outside when the medical device is inserted into a blood vessel, protecting the drug and maintaining the shape of the drug delivery portion.

[0014] (6) In the medical device of (5) above, at least a part of the linear body forming the drug delivery portion may have a distal end facing radially outward when exposed from the sheath, thereby enabling the medical device to press the linear body against a lesion in a blood vessel wall and effectively deliver a drug to the lesion.

[0015] (7) In the medical device of any one of (1) to (6) above, the drug delivery portion may have an adhesive base in the space between the linear bodies, which allows the medical device to maintain the shape of the drug delivery portion when inserted into a blood vessel.

[0016] (8) In the medical device of any one of (1) to (7) above, the linear body may extend from the distal end surface and the circumferential surface of the shaft. This allows the linear body to extend radially outward from the shaft, and the linear body can be more reliably brought into contact with the lesion in the blood vessel to release the drug.

[0017] (9) In any one of the medical devices (1) to (8) above, the shaft may be hollow and have a side hole at the tip, which allows the medical device to release the drug radially outward from the shaft and more efficiently deliver the drug to the lesion. [Brief explanation of the drawings]

[0018] [Figure 1] FIG. 2 is a front view of the medical device according to the present embodiment. [Figure 2] FIG. 1 is an enlarged view of the tip of a medical device. [Figure 3] FIG. 1 is an enlarged cross-sectional view of the distal end of a medical device. [Figure 4] 4 is a cross-sectional view taken along the line AA in FIG. 3. [Figure 5] These are cross-sectional views showing the structure for fixing a linear body to a shaft, where (a) shows the case where the linear body is embedded in the tip surface of the shaft, and (b) shows the case where the linear body is fixed to the outer surface of the shaft with a ring body. [Figure 6] FIG. 1 is a cross-sectional view showing a planar view of a branched portion of a blood vessel, illustrating the state in which the distal end of a medical device is placed at the branched portion of the blood vessel. [Figure 7] 1A and 1B are enlarged cross-sectional views of the tip portion of a medical device having a sheath, in which (a) shows the drug delivery portion housed within the sheath, and (b) shows the drug delivery portion exposed at the tip side of the sheath. [Figure 8] FIG. 10 is an enlarged view of the distal end portion of a medical device having a drug delivery section according to a first modified example, showing the state in which the distal end portion is placed on a lesion. [Figure 9] FIG. 10 is an enlarged cross-sectional view of the distal end portion of a medical device having a drug delivery section according to a second modified example, showing the state in which the distal end portion is placed on a lesion. [Figure 10] FIG. 11 is an enlarged cross-sectional view of the distal end portion of a medical device having a drug delivery section according to a third modified example, showing the state in which the distal end portion is placed on a lesion. DETAILED DESCRIPTION OF THE INVENTION

[0019] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Note that the dimensional proportions in the drawings may be exaggerated for convenience of explanation and may differ from the actual proportions. In addition, in this specification, the side of the medical device 10 that is inserted into a living body will be referred to as the "distal end" or "distal side," and the side that is operated by the operator will be referred to as the "proximal end" or "proximal side."

[0020] The medical device 10 of this embodiment is used to deliver a drug to a small blood vessel 110 located on the peripheral side of a blood vessel 100, or to deliver a drug to a lesion 120 of the blood vessel 100. In this embodiment, the drug includes a drug having a therapeutic effect, as well as cells, exosomes, nucleic acid medicines, etc. The drug may be in any of a liquid including a gel, a solid, or a gas. The cells include, for example, somatic stem cells, adult stem cells, mesenchymal stem cells, or cardiomyocytes derived from iPS cells (induced pluripotent stem cells). The somatic stem cells preferably include skeletal myoblasts (myoblast cells).

[0021] 1, the medical device 10 has a drug delivery portion 30 at the distal end of a long shaft 20. A hub 25 is fixed to the proximal end of the shaft 20.

[0022] As shown in FIG. 2, the drug delivery section 30 is formed in a brush-like or pen-like shape by accumulating a large number of flexible fibrous filaments 31 extending from the tip of the shaft 20. The outer surface of the filaments 31 is coated with a drug. The number of filaments 31 per area, i.e., the density, is not particularly limited, but if there are too few, the amount of drug delivered will be insufficient, and if there are too many, the filaments 31 will interfere with each other, making it difficult for them to enter minute blood vessels. For this reason, the density of the filaments 31 should be set to the same density as that of a writing brush or toothbrush, for example, specifically 5 to 100 filaments / mm 2 This allows the drug delivery portion 30 to be formed with a large number of linear bodies 31 accumulated.

[0023] Before insertion into the blood vessel 100, the drug delivery unit 30 has an adhesive base 35 in the spaces between the linear bodies 31. The adhesive base 35 solidifies the drug delivery unit 30 so that the linear bodies 31 do not separate from each other. This prevents the linear bodies 31 from breaking apart and spreading when the drug delivery unit 30 is inserted into the blood vessel 100. If the adhesive base 35 is made of a water-soluble material, the adhesive base 35 dissolves while the drug delivery unit 30 is being inserted to the target site, allowing the linear bodies 31 to spread at the target site. Alternatively, after the drug delivery unit 30 is inserted to the target site, a fluid capable of dissolving the adhesive base 35 may be injected through the lumen 21 of the shaft 20 to dissolve the adhesive base 35.

[0024] As shown in FIG. 3 , the shaft 20 has a lumen 21 along its length. The linear bodies 31 forming the drug delivery unit 30 extend from the distal end surface 22 of the shaft 20 toward the distal end. The linear bodies 31 are formed so as to converge toward the central axis of the shaft 20 toward the distal end, and the distal ends of adjacent linear bodies 31 are in contact with each other. Therefore, the diameter of the drug delivery unit 30 decreases from the proximal end toward the distal end. That is, in the initial state, the drug delivery unit 30 has a tapered shape. The small diameter of the distal end of the drug delivery unit 30 makes it easier to insert the drug delivery unit 30 into a blood vessel 100. In FIG. 3 , all of the linear bodies 31 forming the drug delivery unit 30 have the same length, but the linear bodies 31 at the inner periphery of the drug delivery unit 30 can be shorter than the linear bodies 31 at the outer periphery. This allows the drug delivery unit 30 to have a tapered shape. In addition, in FIG. 3, the tip of the drug delivery unit 30 is closed by multiple filamentous bodies 31 that are in contact with each other, but the filamentous bodies 31 may be arranged so that an opening is formed at the tip of the drug delivery unit 30. This allows a device such as a guidewire to be inserted along the axial direction. The length of the filamentous body 31 can be determined according to the length of the delivery site, but if it is too short, it will not be able to sufficiently reach the target blood vessel, and if it is too long, there is a high risk of the filamentous bodies 31 becoming entangled with body tissue or with each other, so it is set to an appropriate length. Specifically, the length of the filamentous body 31 is preferably in the range of 5 to 50 mm.

[0025] 4, the filamentous bodies 31 are distributed evenly in the circumferential and radial directions on the distal end surface 22 of the shaft 20. The filamentous bodies 31 are densely arranged to form a pen- or brush-like drug delivery portion 30.

[0026] As shown in FIG. 5( a), linear body 31 is embedded and fixed in hole 20a formed in tip surface 22 of shaft 20. Alternatively, as shown in FIG. 5( b), linear body 31 may be arranged along circumferential surface 23 of shaft 20 and fixed from the outer periphery by ring body 28. In this case, circumferential surface 23 of shaft 20 has a notch 20b formed therein with a reduced outer diameter at its tip, and linear body 31 is fixed by ring body 28 at notch 20b. This prevents ring body 28 from being positioned outer periphery of circumferential surface 23 of shaft 20, thereby preventing an increase in the maximum diameter of shaft 20. Furthermore, even without providing notch 20b, ring body 28 can be made of a thin material such as an adhesive film to prevent an increase in the maximum diameter of shaft 20.

[0027] The shaft 20 is preferably made of a material having a certain degree of flexibility, such as polyolefins such as polyethylene, polypropylene, polybutene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ionomer, or a mixture of two or more of these, soft polyvinyl chloride resin, polyamide, polyamide elastomer, polyester, polyester elastomer, polyurethane, fluororesin such as polytetrafluoroethylene, polyimide, PEEK, silicone rubber, and latex rubber.

[0028] The linear body 31 forming the drug delivery portion 30 can be made of a soft and flexible material. For example, the linear body 31 can be made of a resin material such as nylon or polyethylene. The linear body 31 preferably has a microstructure such as a wedge structure or a sea-island structure throughout its interior. This allows the linear body 31 to retain the drug not only on its surface but also inside, preventing the drug from falling off.

[0029] As shown in Figure 6, in order to deliver a drug to a location where multiple small blood vessels 110 with small inner diameters branch off on the peripheral side of a blood vessel 100, the surgeon inserts the tip of the shaft 20 up to the vicinity of the branching point of the blood vessel 100. The drug delivery section 30 is made up of an accumulation of flexible, thin filamentous bodies 31, and as the filamentous bodies 31 expand radially, they enter the small blood vessels 110 and extend longitudinally, allowing the drug coated on the small blood vessels 110 to be directly released. This allows the drug to be delivered directly into the small blood vessels 110, and the drug can be delivered to the target site more efficiently than when the drug is released upstream of the small blood vessels 110.

[0030] Although a portion of the linear body 31 may bend at the branching point of the blood vessel 100 and may not be able to enter the narrow blood vessel 110 completely, the surgeon can insert the linear body 31 evenly into the narrow blood vessel 110 by rotating the shaft 20 and moving it back and forth along the length of the blood vessel 100.

[0031] By directly inserting drug delivery unit 30 into small blood vessel 110, it is also possible to reduce the blood flow rate in small blood vessel 110. This makes it possible to prevent the drug delivered by linear body 31 from being washed away by the blood flow while drug delivery unit 30 is inserted, thereby further increasing the effect of the drug.

[0032] In this embodiment, the outer surface of the linear body 31 of the drug delivery portion 30 is coated with a drug, but if the linear body 31 has a microstructure, the drug may be contained inside the linear body 31. Alternatively, the drug may be injected through the lumen 21 of the shaft 20 and released at the position of the drug delivery portion 30.

[0033] As shown in FIG. 7(a), the medical device 10 may have a tubular sheath 70 that covers the radial outside of the shaft 20 and the drug delivery portion 30. The sheath 70 is movable along the longitudinal direction relative to the shaft 20. Therefore, as shown in FIG. 7(b), moving the sheath 70 toward the proximal end can expose the drug delivery portion 30 to the distal end side of the sheath 70. By providing the sheath 70, when the medical device 10 is inserted into a blood vessel 100, physical contact of the drug delivery portion 30 with the outside can be prevented, the drug can be protected, and the shape of the drug delivery portion 30 can be maintained.

[0034] A drug delivery unit according to a modification will now be described. As shown in FIG. 8, in the drug delivery unit 40 of the first modification, a portion of the linear body 41 extending from the distal end surface 22 of the shaft 20 toward the distal end is exposed from the sheath 70, and the distal end faces radially outward. Therefore, the drug delivery unit 40 as a whole has a shape that spreads radially toward the distal end. The drug delivery unit 40 is housed in the sheath 70 so as not to spread radially when inserted into the blood vessel 100, and is delivered to the position of the lesion 120. By moving the sheath 70 toward the proximal end, the drug delivery unit 40 can spread radially, making it easier to press the linear body 41 against the lesion 120 that has occurred in the blood vessel wall. This allows the drug to be efficiently transferred from the linear body 41 to the lesion 120.

[0035] 9, in the drug delivery unit 50 of the second modification, a portion of the linear body 51 extending from the distal end surface 22 of the shaft 20 toward the distal end faces radially outward, with the distal end facing radially outward, with the linear body 51 being exposed from the sheath 70. The drug delivery unit 50 also has a plurality of side linear bodies 52 extending radially outward from the circumferential surface 23 of the shaft 20. The drug delivery unit 50 can press both the linear body 51 extending from the distal end surface 22 of the shaft 20 and the side linear bodies 52 extending from the circumferential surface 23 of the shaft 20 against a lesion 120 in the blood vessel wall, thereby effectively delivering a drug.

[0036] The shaft 20 has a plurality of side holes 24 that connect the lumen 21 to the outside at the tip where the side linear bodies 52 are arranged on the circumferential surface 23. When a drug is injected into the tip side of the shaft 20 through the lumen 21, the drug is released from the side holes 24 and supplied to the lesion 120 from the base of the side linear bodies 52, allowing the drug to be effectively transferred to the lesion 120.

[0037] As shown in FIG. 10 , the drug delivery unit 60 of the third modification is a hollow fiber in which a linear body 61 has a lumen extending along the length and opening at its tip, and a drug is supplied through the lumen of the linear body 61. To supply a drug to the linear body 61, the shaft 80 has a drug supply lumen 82 extending along the length. A communication section 83 is formed at the tip of the drug supply lumen 82, communicating along the circumferential direction of the shaft 80. The base of each linear body 61 constituting the drug delivery unit 60 is connected to the communication section 83. This allows a drug injected from the base end of the drug supply lumen 82 to be injected into the linear body 61 via the communication section 83 and released from the tip of the linear body 61. Note that the drug may be supplied from the drug supply lumen 82 and released from the tip of the linear body 61, or may be supplied through the lumen 81 of the shaft 80 and released from the tip of the shaft 80.

[0038] As described above, the (1) medical device 10 according to this embodiment is a medical device 10 having a drug delivery portion 30 at the distal end of a long shaft 20, and the drug delivery portion 30 is formed by integrating a large number of flexible fibrous filamentous bodies 31 extending from the distal end of the shaft 20. In the (1) medical device 10 configured in this manner, the filamentous bodies 31 constituting the drug delivery portion 30 can enter small blood vessels and extend along their length, thereby directly releasing a drug into the small blood vessels and efficiently delivering the drug to the target site. Furthermore, the medical device 10 can also release the drug by pressing the filamentous bodies 31 against a lesion in the blood vessel, thereby efficiently transferring the drug to the lesion in the blood vessel.

[0039] (2) In the medical device 10 described in (1) above, the linear body 31 may have a drug on the outer surface, thereby enabling the medical device 10 to reliably transfer the drug to the biological tissue with which the linear body 31 comes into contact.

[0040] (3) In the medical device 10 described in (1) or (2) above, the linear body 31 may contain a drug therein. This allows the medical device 10 to prevent the drug from falling off from the linear body 31.

[0041] (4) In the medical device 10 of any one of (1) to (3) above, the linear body 61 may have an inner lumen extending along the length and opening at the tip, through which a drug is supplied. This allows the medical device 10 to release the drug on the more peripheral side of the blood vessel.

[0042] (5) The medical device 10 of any one of (1) to (4) above may have a sheath 70 that covers the radial outside of the shaft 20 and the drug delivery portion 30, and the sheath 70 may be movable along the length of the shaft 20 to expose the drug delivery portion 30. This prevents the drug delivery portion 30 from coming into physical contact with the outside when the medical device 10 is inserted into a blood vessel, protecting the drug and maintaining the shape of the drug delivery portion 30.

[0043] (6) In the medical device 10 described in (5) above, at least a portion of the linear body 41 forming the drug delivery portion 40 may have a tip portion facing radially outward while exposed from the sheath 70. This allows the medical device 10 to press the linear body 41 against a lesion in the blood vessel wall, thereby enabling effective delivery of a drug to the lesion.

[0044] (7) In the medical device 10 of any one of (1) to (6) above, the drug delivery portion 30 may have an adhesive base 35 in the space between the linear bodies 31. This allows the medical device 10 to maintain the shape of the drug delivery portion 30 when inserted into a blood vessel.

[0045] (8) In the medical device 10 of any one of (1) to (7) above, the linear bodies 51, 52 may extend from the distal end surface and the circumferential surface of the shaft 20. This allows the medical device 10 to have the linear bodies 51, 52 extend radially outward from the shaft 20, and allows the linear bodies 51, 52 to more reliably contact the lesion in the blood vessel and release the drug.

[0046] (9) In the medical device 10 of any one of (1) to (8) above, the shaft 20 may be hollow and have a side hole 24 at the tip. This allows the medical device 10 to release the drug radially outward from the shaft 20, thereby enabling the drug to be delivered to the lesion more efficiently.

[0047] The present invention is not limited to the above-described embodiment, and various modifications can be made by those skilled in the art within the technical concept of the present invention. [Explanation of symbols]

[0048] 10 Medical Devices 20 shaft 21 lumens 22 Tip surface 23 Peripheral surface 24 Side hole 25 Hub 30 Drug delivery unit 31 linear body 35 Adhesive base 70 Sheath 80 shaft 100 blood vessels 110 Small blood vessels 120 Lesion

Claims

1. A medical device having a drug delivery portion at the distal end of a long shaft, The drug delivery portion is a medical device in which a large number of flexible fibrous filaments are integrated and extend from the tip of the shaft.

2. The medical device according to claim 1 , wherein the linear body has a drug on its outer surface.

3. The medical device according to claim 1 , wherein the linear body contains a drug therein.

4. The medical device according to claim 1 , wherein the linear body has an inner lumen extending along its length and opening at its tip, and a drug is supplied through the inner lumen.

5. a sheath covering the shaft and the drug delivery portion radially outward; The medical device according to any one of claims 1 to 4, wherein the sheath is movable along the length of the shaft to expose the drug delivery portion.

6. The medical device according to claim 5 , wherein at least a portion of the linear body forming the drug delivery portion has a tip portion facing radially outward when exposed from the sheath.

7. The medical device according to any one of claims 1 to 4, wherein the drug delivery portion has an adhesive base in the space between the linear bodies.

8. The medical device according to any one of claims 1 to 4, wherein the linear body extends from the distal end surface and the circumferential surface of the shaft.

9. The medical device according to any one of claims 1 to 4, wherein the shaft is hollow and has a side hole at the tip.

Images