JP7165011B2 - medical instruments - Google Patents

Description

The present invention relates to medical devices.

BACKGROUND ART In recent years, as a treatment for heart failure and the like, administration of a plurality of types of administration substances such as cells and extracellular matrices to the same site of a living tissue such as the inner wall of the left ventricle of the heart has been studied. In such a case, an elongated medical device is defined by a lumen, which is a hollow portion extending in the axial direction, and the object to be administered is administered into the biological tissue through the lumen by using an elongated medical device whose tip can pierce the biological tissue. can be considered. In order to administer a plurality of types of administered substances, it is preferable that the medical device is divided into a number of lumens corresponding to the number of types of administered substances.

For example, Patent Literature 1 discloses a medical device having a lumen 430 and an auxiliary lumen 440 .

U.S. Patent Application Publication No. 2008/0125745

However, if the medical device has two lumens as disclosed in Patent Document 1, the medical device needs to have an outer diameter that allows two lumens for one needle. As a result, the outer diameter tends to increase, and the puncture resistance tends to increase.

SUMMARY OF THE INVENTION An object of the present invention is to provide a medical device capable of reducing puncture resistance while partitioning a plurality of axially extending lumens.

A medical device as a first aspect of the present invention is an elongated medical device that is pierced into a living tissue from its distal end, and has an inner lumen located radially inward and a lumen radially outward. a cylindrical portion that internally partitions an outer lumen located therein, the side surface of the cylindrical portion includes a tapered surface that decreases in diameter toward the distal end side so as to approach the inner side in the radial direction, and the inner lumen A first distal opening is formed in the distal end surface of the tubular portion, and a second distal opening of the outer lumen is formed in the tapered surface of the tubular portion.

In the medical instrument as one embodiment of the present invention, the distal end surface of the tubular portion is configured by a blade surface that is inclined with respect to the axial direction.

In the medical device according to one embodiment of the present invention, when the tapered surface is a first tapered surface, the side surface of the cylindrical portion is closer to the distal end side than the first tapered surface, and the distal end It has a second tapered surface whose outer diameter gradually decreases toward the side, and the second tapered surface has a smaller angle of inclination with respect to the axial direction than the first tapered surface.

In one embodiment of the medical device of the present invention, the tubular portion divides the outer lumen into a plurality of sections.

In one embodiment of the medical device of the present invention, the cross-sectional area of the inner lumen is greater than the cross-sectional area of the outer lumen.

ADVANTAGE OF THE INVENTION According to this invention, the medical instrument which can reduce puncture resistance can be provided, partitioning the several lumen|lumen extended in an axial direction.

1 illustrates a medical device according to one embodiment of the invention; FIG. FIG. 2 is an external perspective view of the medical instrument shown in FIG. 1; 2 is a front view of the medical device shown in FIG. 1; FIG. 4 is a cross-sectional view taken along line AA of FIG. 3; FIG. 2 is a flow chart showing an example of an administration method performed using the medical device of FIG. 1; FIG. 2 is a schematic diagram showing an example of the state of administration of cells and extracellular matrix administered using the medical device of FIG. 1; It is a figure which shows the modification of the puncture tip part of the medical device shown in FIG.

An embodiment of the present invention will be described below with reference to the drawings. The same reference numerals are given to common components in each figure.

FIG. 1 is a diagram showing a medical device 1 as one embodiment of the present invention. As shown in FIG. 1, the medical device 1 is elongated. FIG. 1 shows the medical device 1 extending from outside the subject's body to the left ventricle LV of the heart lumen through a cylindrical catheter 100 as another medical device. Specifically, the catheter 100 is inserted into the subject's body from the femoral artery FA and extends through the aorta AO and the aortic valve AV into the left ventricle LV. The distal end 8 of the medical device 1 is delivered to the left ventricle LV through the catheter 100 while a part of the proximal end side of the medical device 1 remains outside the subject's body. The catheter 100 may be inserted into the subject's body from, for example, the radial artery of the wrist instead of the femoral artery FA. Hereinafter, the proximal end of the medical device 1 may be simply referred to as the "base end", and the proximal end side may simply be referred to as the "base end side". Further, hereinafter, the distal end 8 of the medical device 1 may be simply referred to as "tip", and the distal end 8 side may simply be referred to as "tip side".

FIG. 2 is an external perspective view of the medical device 1. FIG. FIG. 3 is a front view of the medical device 1. FIG. 4 is a cross-sectional view taken along line AA of FIG. 3. FIG. Here, in this specification, the surface facing the distal end 8 side of the medical device 1 is defined as the front surface. Hereinafter, the case where the medical device 1 is viewed from the distal end 8 side (see FIG. 3) may be simply referred to as "front view". The medical device 1 has a needle shape on the distal end 8 side.

As shown in FIGS. 2 to 4, the medical device 1 has a tubular portion 30. As shown in FIG. The tubular portion 30 includes a body portion 10 and a puncture tip portion 20 . The puncture tip 20 includes a distal end 8 and can puncture a living tissue such as the inner wall of the left ventricle LV (see FIG. 1) from the distal end 8 . The cylindrical portion 30 extends along a direction along the central axis O (hereinafter also referred to as “axial direction”). The body portion 10 is continuous with the puncture tip portion 20 and is positioned closer to the proximal side than the puncture tip portion 20 . In FIG. 4, the body portion 10 is the portion on the right side of the dashed line L, and the puncture tip portion 20 is the portion on the left side of the dashed line L. As shown in FIG. That is, in FIG. 4 , the base end side of the dashed line L corresponds to the body portion 10 , and the distal end 8 side of the dashed line L corresponds to the puncture tip portion 20 .

The puncture tip 20 has a side surface (outer peripheral surface) with a radius R1 centered on the central axis O in a front view. The main body 10 has a side surface (outer peripheral surface) with a maximum radius R2 around the central axis O in a front view. As shown in FIGS. 3 and 4 , the puncture tip 20 refers to a portion of the medical device 1 on the side of the distal end 8 with a side radius R1 or less in the axial direction. A portion of the side surface having a radius larger than R1 in the axial direction of the medical device 1 belongs to the body portion 10 . With this configuration, the outer diameter of the medical device 1 in the vicinity of the distal end 8 can be reduced, so that the puncture resistance between the medical device 1 and the living tissue is reduced when the medical device 1 is punctured into the living tissue. be able to.

As shown in FIG. 4, in the present embodiment, the side surface 21 of the puncture tip 20 is configured in a cylindrical shape with the same radius R1 around the central axis O from the proximal end side to the distal end 8 side. ing.

The main body part 10 has a tapered surface (first tapered surface) 12 on the side surface 11 that tapers inward in the radial direction from the base end side to the distal end 8 side. That is, the tapered surface 12 reduces the radius of the main body 10 from the maximum radius R2 to R1 from the proximal end side toward the distal end 8 side, and is configured to be continuous with the puncture tip portion 20. there is

The tapered surface 12 is most inclined with respect to the central axis O at an intermediate position 15 between the tapered proximal end position 13 and the coupling position 14 . The tapered base end position 13 is the position closest to the base end (proximal end side) of the tapered surface 12 . That is, the tapered base end position 13 is the position in the body portion 10 where the radius starts to become smaller than R2. The base end side of the tapered base end position 13 of the body portion 10 is configured in a cylindrical shape with a radius of R2. The coupling position 14 is a coupling position with the puncture tip 20 in the main body 10 and is the position closest to the tip side (distal end 8 side) of the tapered surface 12 . For example, the inclination angle of the tapered surface 12 with respect to the central axis O gradually increases from the tapered base end position 13 to the intermediate position 15 , reaches its maximum at the intermediate position 15 , and then gradually decreases toward the coupling position 14 . Specifically, the tapered surface 12 has a convex curvature on the tapered base end position 13 side and a concave curvature on the coupling position 14 side from the intermediate position 15 along the central axis O. .

The body portion 10 of the medical device 1 defines a plurality of axially extending lumens. In this embodiment, as shown in FIGS. 3 and 4, the multiple lumens are divided into one inner lumen 31 and four outer lumens 32a, 32b, 32c and 32d. In this specification, when the four outer lumens 32a, 32b, 32c and 32d are not distinguished from each other, they are collectively referred to as "outer lumen 32".

The inner lumen 31 is positioned radially inward in the body portion 10 . Specifically, the inner lumen 31 is formed in a region having a radius less than R1 from the central axis O. The outer lumen 32 is positioned radially outward in the body portion 10 . Specifically, the outer lumen 32 is formed in a region having a radius of R1 or more and less than R2 from the central axis O. As shown in FIG. The outer lumen 32 may, for example, be axially parallel. Therefore, as shown in FIG. 3, for example, when the medical device 1 is viewed from the front, an inner lumen 31 is formed in the central portion including the central axis O, and a plurality of outer lumens 32 are formed radially outward of the inner lumen 31. is formed. That is, the body portion 10 partitions a plurality of outer lumens 32 . In this embodiment, four outer lumens 32 are described, but the number of outer lumens 32 is not limited to this. Any number of one or more outer lumens 32 may be formed in the main body 10 . The inner lumen 31 and the outer lumen 32 may be formed to have circular cross sections as shown in FIG.

The puncture tip 20 of the medical device 1 defines an inner lumen 31 therein. On the other hand, puncture tip 20 does not define outer lumen 32 . That is, as described above, since the inner lumen 31 is formed in the region having a radius less than R1 from the central axis O, the inner lumen 31 is also formed in the puncture tip 20 . On the other hand, the outer lumen 32 is formed in a region having a radius equal to or greater than R1 and less than R2 from the central axis O. Since the maximum radius of the puncture tip 20 is R1, the outer lumen 32 is formed in the puncture tip 20. not.

The inner lumen 31 has an opening (hereinafter also referred to as “first tip opening”) 33 on the distal end 8 side of the puncture tip 20 and communicates with the outside at the first tip opening 33 . A first tip opening 33 is formed in the tip surface 22 of the puncture tip 20 . The tip surface 22 may be configured by a blade surface that is inclined with respect to the axial direction, as shown in FIGS. 2 and 4, for example. As a result, the puncture resistance between the medical device 1 and the living tissue at the distal end 8 of the puncture tip portion 20 can be reduced when the medical device 1 punctures the living tissue.

The outer lumen 32 has an opening (hereinafter also referred to as a “second tip opening”) 34 in the tapered surface 12 of the main body 10 and communicates with the outside at the second tip opening 34 . Thus, the outer lumen 32 has a second distal opening 34 in the tapered surface 12, so that when different fluids are supplied from the inner lumen 31 and the outer lumen 32 as will be described later, these different fluids can be directed axially. can be fed to different locations in the

The inner lumen 31 and the outer lumen 32 communicate with the outside on the proximal side of the medical device 1 . The inner lumen 31 and the outer lumen 32 can be supplied with a fluid as a substance to be administered from the proximal side to the living tissue. The fluid supplied to the inner lumen 31 and the outer lumen 32 includes, for example, cells, an extracellular matrix having a function of adhering the cells to living tissue, growth factors such as fibroblast growth factor (bFGF) preparations, contrast agents, and one or more of biocompatible materials.

Cells to be administered include, for example, adherent cells (adherent cells). Adherent cells include, for example, adherent somatic cells (e.g., cardiomyocytes, fibroblasts, epithelial cells, endothelial cells, hepatocytes, pancreatic cells, kidney cells, adrenal cells, periodontal ligament cells, gingival cells, periosteal cells, skin cells, synovial cells, chondrocytes, etc.) and stem cells (e.g., myoblasts, tissue stem cells such as cardiac stem cells, embryonic stem cells, pluripotent stem cells such as iPS (induced pluripotent stem) cells, mesenchymal stem cells, etc.) etc. Somatic cells may be differentiated from stem cells, particularly iPS cells. Non-limiting examples of cells to be administered include myoblasts (e.g., skeletal myoblasts), mesenchymal stem cells (e.g., bone marrow, adipose tissue, peripheral blood, skin, hair roots, muscle tissue, endometrium, placenta, those derived from umbilical cord blood, etc.), cardiomyocytes, fibroblasts, cardiac stem cells, embryonic stem cells, iPS cells, synovial cells, chondrocytes, epithelial cells (e.g., oral mucosal epithelial cells, retinal pigment epithelial cells, nasal mucosa epithelial cells, etc.), endothelial cells (e.g., vascular endothelial cells, etc.), hepatocytes (e.g., liver parenchymal cells, etc.), pancreatic cells (e.g., pancreatic islet cells, etc.), renal cells, adrenal cells, periodontal ligament cells, gingival cells, periosteal cells, skin cells, and the like.

Extracellular matrices as administered substances include, for example, non-cellular constituents present in various tissues and organs such as myocardium, kidney, bladder, and cartilage. The extracellular matrix can be extracted by, for example, homogenizing organs such as myocardium and cartilage. The composition of the extracellular matrix is mainly composed of fibrous proteins, structural proteins, glycosaminoglycans, etc., and includes all types of collagen: fibrils (types I, II, III, V facit (types IX, XII, XIV); short chains (types VIII, X), basement membrane (type IV), and others (types VI, VII, XIII), Elastin, fibronectin, fibrinogen, fibulin, cadherin, laminin, agrin, entactin, tenascin, link protein, proteoglycan, aggrecan, perlecan, versican, neurocan, brevican, decorin, biglycan, serglycin, syndecan, glypican, lumican, keratocan, chondroitin Contains sulfated proteoglycans, hyaluronic acid, chitin, and the like. Also, the proportions of the individual components of the extracellular matrix depend on the proportions of the components that make up the tissue.

Examples of biocompatible materials for administration include polyacrylamide gel, polyvinylpyrrolidone gel, gelatin gel, β-glucan gel, agarose gel, carboxymethylcellulose gel, ethylene vinyl alcohol, zirconium, hydroxyapatite, polydimethylsiloxane, and dextranomer. , silicones, glycols, mixtures thereof, and particles, porous particles, fibers, porous fibers, sheets, porous sheets, and combinations thereof.

In this embodiment, as an example, a case of supplying cells from the inner lumen 31 and supplying an extracellular matrix from the outer lumen 32 will be described below.

The cross-sectional area of the inner lumen 31 may be greater than the cross-sectional area of the outer lumen 32, eg, as shown in FIG. Here, the cross-sectional area refers to the cross-sectional area of the inner lumen and the cross-sectional area of the outer lumen in any one cross section perpendicular to the axial direction. With this configuration, highly viscous fluids, such as cells, are delivered through the inner lumen 31, which has a larger cross-sectional area, while less viscous fluids, such as extracellular matrix, are delivered through the outer lumen 32, which has a smaller cross-sectional area. When supplying through the lumen, the difference in the velocity of the fluid flowing through both lumens (that is, the flow velocity) can be reduced, and the difference in the injection resistance, which is the tube frictional resistance of the fluid, can be reduced.

The material for forming the body portion 10 and the puncture tip portion 20 of the medical device 1 preferably has a certain degree of flexibility, and for example, metal or resin can be used. Examples of metals include pseudoelastic alloys (including superelastic alloys) such as Ni—Ti alloys, stainless steels (e.g., SUS304, SUS303, SUS316, SUS316L, SUS316J1, SUS316J1L, SUS405, SUS430, SUS434, SUS444, SUS429, SUS430F, SUS302, etc., all kinds of SUS), cobalt-based alloys, gold, precious metals such as platinum, tungsten-based alloys, carbon-based materials (including piano wire), and the like. Examples of resins include polyolefins (e.g., polyethylene, polypropylene, polybutene, ethylene-propylene copolymers, ethylene-vinyl acetate copolymers, ionomers, or mixtures of two or more thereof), polyvinyl chloride, polyamides, and polyamides. Polymeric materials such as elastomers, polyesters, polyester elastomers, polyurethanes, polyurethane elastomers, polyimides, fluororesins, or mixtures thereof, or two or more of the above polymeric materials can be used. Furthermore, engineering plastics typified by polyetheretherketone can be mentioned as resins. Moreover, the body part 10 and the puncture tip part 20 can also be configured by a multi-layer tube or the like made of a composite material formed of these metals or resins.

FIG. 5 is a flow chart showing an example of an administration method performed using the medical device 1. As shown in FIG. As shown in FIG. 5, the administration method performed using the medical device 1 includes a puncture step S1, a first administration step S2, and a second administration step S3.

In the puncture step S1, the distal end 8 of the puncture tip 20, which defines an inner lumen 31 as a hollow portion that communicates with the outside at the distal end 8, is punctured into the living tissue. Specifically, for example, as shown in FIG. 1, the distal end 8 of the puncture tip 20 of the medical device 1 delivered to the left ventricle LV through the catheter 100 is protruded from the catheter 100 to form living tissue. puncture the inner wall of the left ventricle LV. The medical device 1 can be operated by an operator such as a medical professional by manipulating a part of the base end side (proximal end side) of the medical device 1 located outside the subject's body.

In the first administration step S<b>2 , the cells are administered to the living tissue through the inner lumen 31 as the hollow portion of the medical device 1 . Specifically, for example, cells are supplied from the base end side of the medical device 1 through the inner lumen 31 . Cells are then administered to the living tissue through the inner lumen 31 .

In the second administration step S3, after the first administration step S2, the extracellular matrix is administered to the biological tissue through the outer lumen 32 as the hollow portion of the medical device 1. Specifically, for example, the extracellular matrix is supplied through the outer lumen 32 from the proximal end side of the medical device 1 . The extracellular matrix is then administered to the living tissue through the outer lumen 32 .

In this way, after the cells are administered to the biological tissue in the first administration step S2, the extracellular matrix is administered to the biological tissue in the second administration step S3, so that the composition can be in a fluid state during catheter administration. After that, the viscosity of the composition increases due to the in vivo environment of the administration target, thereby preventing leakage of the administered cells or biologically active substance. Therefore, after the medical device 1 is removed from the living body, it is possible to prevent the previously administered cells from leaking due to heartbeat or the like.

FIG. 6 is a schematic diagram showing an example of the state of administration of cells and extracellular matrix administered using the medical device 1. As shown in FIG. FIG. 6 is a diagram schematically showing the arrangement of cells and extracellular matrix in a living tissue when the distal end 8 is punctured from top to bottom. When cells are supplied from the inner lumen 31 and extracellular matrix is supplied from the outer lumen 32 in a state in which the distal end 8 is punctured into the living tissue, the extracellular matrix is formed near the inner wall as shown in FIG. The cells are administered to the back side of the living tissue. With the distal end 8 punctured into the living tissue, the second tip opening 34 of the outer lumen 32 is arranged near the inner wall, and the first tip opening 33 of the inner lumen 31 is arranged on the far side of the living tissue. This is because By administering the cells and the extracellular matrix in this way, it becomes easier for the cells to engraft into the living tissue.

As described above, the medical device 1 according to the present embodiment includes the tubular portion 30 that partitions the inner lumen 31 positioned radially inward and the outer lumen 32 positioned radially outward. The tubular portion 30 has a tapered surface 12 on the side surface, the first distal opening 33 of the inner lumen 31 is formed in the distal surface 22 of the tubular portion 30, and the second distal opening 34 of the outer lumen 32 is formed in the tapered surface 12. formed. With this configuration, the medical device 1 can reduce the puncture resistance between the medical device 1 and the living tissue. That is, according to the medical device 1, it is possible to reduce the puncture resistance by reducing the outer diameter near the distal end 8 while partitioning a plurality of lumens extending in the axial direction.

In addition, the administration method executed using the medical device 1 is not limited to the method described above. For example, a second administration step of administering extracellular matrix may be performed before the first administration step of administering cells. In this case, it is possible to prepare in advance an environment in which the cells are likely to engraft in the living tissue.

In the above embodiment, the case where the side surface 21 of the puncture tip 20 has a cylindrical shape with a constant diameter has been described. However, as shown in FIG. 7, the side surface 21 of the puncture tip 20 may be configured to have a tapered surface (second tapered surface) whose outer diameter gradually decreases toward the distal end 8 side. As a result, the puncture resistance between the medical device 1 and the living tissue when the medical device 1 is punctured into the living tissue can be further reduced. The second tapered surface may have a smaller angle of inclination with respect to the axial direction than the first tapered surface.

In the above embodiment, the outer lumen 32 is formed parallel to the axial direction, but the outer lumen 32 does not necessarily have to be formed parallel to the axial direction. The outer lumen 32 may be formed in a region having a radius of R1 or more and less than R2 from the central axis O so as to extend in the axial direction. Therefore, for example, the outer lumen 32 may be formed in a spiral shape in a region having a radius of R1 or more and less than R2 from the central axis O.

In the above embodiment, the inner lumen 31 and the outer lumen 32 have circular cross sections, but the inner lumen 31 and the outer lumen 32 may not necessarily have circular cross sections. For example, the cross-sections of the inner lumen 31 and the outer lumen 32 may be elliptical, polygonal including rectangular, or the like. Moreover, the cross section of the inner lumen 31 and the outer lumen 32 may be formed in an arc shape along the circumferential direction. Moreover, the cross section of the outer lumen 32 may be formed in an annular shape centering on the central axis O in a cross-sectional view. In this case, a connecting portion may be provided that connects the wall surface defining the inner lumen 31 and the wall surface defining the outer lumen 32 . The connecting portion may be provided at any position in the axial direction and at any position in the circumferential direction.

The present invention is not limited to the configurations specified in the respective embodiments described above, and various modifications are possible without departing from the scope of the claims.

The present disclosure relates to medical devices.

Reference Signs List 1 medical device 8 distal end 10 main body 11 side 12 tapered surface 13 tapered proximal position 14 coupling position 15 intermediate position 20 puncture tip 21 side 22 distal surface 30 barrel 31 inner lumen 32 outer lumen 33 first distal opening 34 second tip opening 100 catheter

Claims (4)

An elongated medical device that is pierced into living tissue from its distal end,
a cylindrical portion that internally partitions an inner lumen positioned radially inward and an outer lumen positioned radially outward;
The cylindrical portion is
a piercing tip including the distal end;
a main body portion formed integrally with and continuous with the puncture tip portion and positioned closer to the proximal end than the puncture tip portion;
a side surface of the main body portion has a tapered surface whose diameter decreases toward the inner side in the radial direction toward the distal end side;
The first tip opening of the inner lumen is formed on the tip surface of the puncture tip ,
a second tip opening of the outer lumen is formed on the tapered surface of the main body ,
A medical instrument according to claim 1, wherein the distal end surface of the puncture distal end portion is configured by a blade surface inclined with respect to the axial direction . When the tapered surface is a first tapered surface, the side surface of the puncture tip portion is a second tapered surface whose outer diameter gradually decreases toward the distal end side of the first tapered surface toward the distal end side. Equipped with a tapered surface,
2. The medical instrument according to claim 1 , wherein said second tapered surface has a smaller angle of inclination with respect to the axial direction than said first tapered surface. The medical instrument according to claim 1 or 2 , wherein the tubular portion divides the outer lumen into a plurality of sections. 4. The medical device of any one of claims 1-3 , wherein the cross-sectional area of the inner lumen is greater than the cross-sectional area of the outer lumen.

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