JP7620276B2 - Medical Clips - Google Patents

Description

The present invention relates to a medical clip.

Conventionally, medical clips have been used by attaching them to endoscopic clip devices as hemostatic clips or as marker clips for identifying the location of affected areas during surgery. For example, clips consisting of a clip body made by bending a metal leaf spring such as stainless steel into an approximate ">" shape and a crimping ring that fits over the clip body to close it (Patent Document 1), and clips made of resin by forming the clip body into a specific shape (Patent Document 2) are known.

In addition, there is a hemostatic clip that is made of an elastic material and has a hook at the tip and a structure that fits onto the hook, so that the clip can be closed without using a crimping ring (Patent Document 3). This hemostatic clip is opened and closed using a forceps-type instrument.

Patent No. 6572229 Patent No. 6675674 Japanese Patent Publication No. 56-3048

Conventional clips using the crimping ring described in Patent Documents 1 and 2 are attached to the clip sheath of an endoscopic clip device and are opened and closed by operating the clip device. For example, as shown in FIG. 16A of the present application, this clip 1X is attached to the inner sheath 41 of the clip sheath 40, and the operating wire 43 is connected by a connecting portion 44. As shown in FIG. 16B, by pulling the operating wire 43 near the affected area, it is pulled into the inner sheath 41, and the crimping ring 2 moves accordingly, narrowing the opening of the clip 1X. When the operating wire 43 is further pulled, the crimping ring 2 moves toward the tip of the clip 1X, and the clip 1X closes and clamps the affected area. However, once the opening of the clip 1X is narrowed by the crimping ring 2, it is not possible to return the clip to its original opening even if one wishes to return it to its original position in order to correct the clamping position of the affected area. That is, even if the inner sheath 41 is pulled back as shown in FIG. 16C, the position of the crimping ring 2 in the clip 1X does not return to its original position, so the opening of the clip 1X remains narrow.

On the other hand, the clip described in Patent Document 3 and the like can be opened and closed again even after it has been closed once, so the position of the affected area clamped by the clip can be corrected. However, opening and closing this clip requires the use of a forceps-type instrument, and this clip cannot be opened and closed with an endoscopic clip device. Also, with this clip, blood vessels etc. are clamped between the tips of a pair of arms (legs) and a hinge part, and this state is maintained by engaging the hooks at the tips, but when the affected area is clamped with the tips, the hooks at the tips cannot be engaged, so the clamped state of the affected area cannot be maintained. For this reason, this clip cannot be used for marking.

In response to this, the present invention aims to provide a medical clip that can be used with an endoscopic clipping device and can be used for both hemostasis and marking, and that allows the clip to be opened and closed again until it is completely closed.

The inventor discovered that, for a leaf spring-like clip with opposing arms, a hook-shaped projection is provided in the longitudinal center of one of the clip's arms, and when the other arm is latched by the hook-shaped projection, the tip of the clip can be used for both hemostasis and marking, and that crimping is no longer necessary. The clip can be repeatedly opened and closed until the hook-shaped projection of one arm completely latches the other arm, and thus came up with the invention.

That is, the present invention provides a leaf spring-like medical clip having a first arm and a second arm opposed to each other, and a continuous portion where one end of the first arm is continuous with one end of the second arm,
the first arm has a pair of hook-shaped projections at a central portion in a longitudinal direction thereof for latching the second arm from both sides;
A medical clip is provided in which, when the first arm and the second arm approach each other to a predetermined distance, a pair of hook-shaped protrusions latch both sides of the second arm, thereby maintaining the first arm and the second arm in a close proximity.

According to the medical clip of the present invention, the tip of the clip is kept completely closed by the latch between the pair of hook-shaped projections at the longitudinal center of the first arm and the second arm. Therefore, the tip of the clip can be used for both hemostasis and marking.

In addition, the first and second arms can be repeatedly opened and closed as long as the hook-shaped protrusion of the first arm does not latch onto the second arm. This makes it easy to adjust the position at which the clip clamps the affected area even after the clip is almost closed.

This medical clip can also be attached to the inner sheath of an endoscopic clip device.

FIG. 1A is a perspective view of a clip 1A according to an embodiment in an open state, as viewed from its tip end side. FIG. 1B is a perspective view of the clip 1A of the embodiment in an open state, as viewed from the connecting portion side. FIG. 1C is a top view of the clip 1A of the embodiment in an open state. FIG. 1D is a side view of the clip 1A of the embodiment in an open state. FIG. 2 is a perspective view of the clip 1A of the embodiment in a latched state. FIG. 3A is a cross-sectional view illustrating a method of using the clip 1A of the embodiment. FIG. 3B is a cross-sectional view illustrating a method of using the clip 1A of the embodiment. FIG. 3C is a cross-sectional view illustrating a method of using the clip 1A of the embodiment. FIG. 3D is a cross-sectional view illustrating a method of using the clip 1A of the embodiment. FIG. 3E is a cross-sectional view illustrating a method of using the clip 1A of the embodiment. FIG. 4A is a cross-sectional view illustrating a method of clamping a mucous membrane with the clip 1A of the embodiment. FIG. 4B is a cross-sectional view illustrating a method of clamping a mucous membrane with the clip 1A of the embodiment. FIG. 4C is a cross-sectional view illustrating a method of clamping a mucous membrane with the clip 1A of the embodiment. FIG. 4D is a cross-sectional view illustrating a method of clamping a mucous membrane with the clip 1A of the embodiment. FIG. 5A is a perspective view of a clip 1B according to the embodiment in an open state, as viewed from its tip end side. FIG. 5B is a perspective view of the clip 1B of the embodiment in an open state, as viewed from the connecting portion side. FIG. 6 is a perspective view of the clip 1B of the embodiment in a latched state. FIG. 7A is a cross-sectional view illustrating a method of clamping a mucous membrane with the clip 1B of the embodiment. FIG. 7B is a cross-sectional view illustrating a method of clamping a mucous membrane with the clip 1B of the embodiment. FIG. 8A is a cross-sectional view illustrating a method of using the clip 1C of the embodiment. FIG. 8B is a cross-sectional view illustrating a method of using the clip 1C of the embodiment. FIG. 9 is a side view of a modified embodiment of the clip 1A of the embodiment. FIG. 10 is a side view of a clip 1A according to an embodiment to which a compression piece is attached. FIG. 11 is a top view of a clip 1A according to an embodiment to which a compression piece is attached. FIG. 12 is a cross-sectional view of a state in which a mucous membrane is clamped by a clip 1A of the embodiment to which a compression piece is attached. FIG. 13 is a perspective view of a clip 1D according to the embodiment. FIG. 14A is a perspective view of a clip 1D of the embodiment to which a compression piece is attached, as viewed from the tip end side. FIG. 14B is a perspective view of the clip 1D of the embodiment to which the compression piece is attached, as viewed from the connecting portion side. FIG. 15 is a cross-sectional view of a state in which a mucous membrane is clamped by a clip 1D of the embodiment to which a compression piece is attached. FIG. 16A is a cross-sectional view of a conventional medical clip 1X attached to an inner sheath. FIG. 16B is a cross-sectional view of the conventional medical clip 1X when it is slightly retracted into the inner sheath, resulting in a narrower opening of the clip. FIG. 16C is a cross-sectional view of a conventional medical clip 1X in a state where the inner sheath is pulled back after being slightly pulled into the inner sheath.

The present invention will now be described in detail with reference to the drawings. Note that in each drawing, the same reference numerals represent the same or equivalent components.

<Basic structure of medical clip>
1A and 1B are perspective views of a medical clip 1A according to an embodiment of the present invention in an open state, FIG. 1C is a top view thereof, and FIG. 1D is a side view thereof. Also, FIG. 2 is a perspective view of the medical clip 1A in a latched state.

This clip 1A is made of an elastic material such as a leaf spring, and has a first arm 10 and a second arm 20 facing each other, and a continuous portion 30 where one end of the first arm 10 and one end of the second arm 20 are curved and connected. The other ends of the first arm 10 and the second arm 20 are separated from each other, and the whole is bent in a roughly "<" shape. In the present invention, the continuous portion 30 is not necessarily limited to a curved or bent portion that connects the first arm and the second arm, which is obtained by bending a strip of metal material. For example, as shown in Figures 4 and 7 of Patent No. 6694893, when the first arm and the second arm are formed from two leaf springs whose rear ends are bent in an L shape, the vicinity of their rear ends can be a portion that is connected by a reinforcing member.

In the clip 1A of this embodiment, the tip 11 of the first arm 10 is bent toward the second arm 20, and the tip 21 of the second arm 20 is bent toward the first arm 10, and these tips have a triangular wave shape that fits into each other. Note that in the clip of the present invention, the shape of the tips 11, 21 is not limited to this, and they may be formed into a trapezoid, rectangle, etc., and the tips 11, 21 may not be bent, and may be formed so that these tips 11, 21 overlap each other when the first arm 10 and the second arm 20 are closed.

The clamping portion 15 adjacent to the tip 11 of the first arm 10 and the clamping portion 25 adjacent to the tip 21 of the second arm 20 each have an arm width wider than the continuous portion 30. Both side portions of the clamping portions 15, 25 stand up inward, making it easier for the clamping portions 15, 25 to clamp biological tissue. In the present invention, the shape of the clamping portions 15, 25 can be changed as appropriate depending on the application of the clip.

(Uncus)
The first arm 10 has a pair of hook-shaped projections 12a, 12b at the center in the longitudinal direction, which can latch the second arm 20 from both sides of the second arm 20. More specifically, between the tip 11 of the first arm 10 and the continuous portion 30, the pair of hook-shaped projections 12a, 12b stand in the direction of the second arm portion 20 along both sides of the first arm 10, and the tips of the pair of hook-shaped projections 12a, 12b are bent in the direction facing each other. In the clip 1A of this embodiment, the hook-shaped projections 12a, 12b stand along both sides of the first arm 10, which makes it possible to easily manufacture the clip 1A by bending a metal plate. On the other hand, when the clip 1A is molded from resin, the hook-shaped projections 12a, 12b may stand from the inside of the first arm 10 rather than the side of the arm.

When the first arm 10 and the second arm 20 of this clip 1A are pressed together and brought into close proximity to a predetermined distance, as shown in FIG. 2, the pair of hook-shaped projections 12a, 12b latch the latched portion 22 of the second arm 20. This latched portion 22 is flat, and once the hook-shaped projections 12a, 12b of the first arm 10 latch the latched portion 22 of the second arm 20, the second arm 20 is biased in a direction that increases the opening between the first arm 10 and the second arm 20, because the clip 1A is made of an elastic material, so the latched state is stabilized and the close proximity between the first arm 10 and the second arm 20 is maintained.

(Slope-shaped protrusion)
Meanwhile, a sloped protrusion 23 extending in the longitudinal direction of the second arm 20 is provided on the outer surface 20o of the second arm 20 opposite the first arm 10, closer to the tip 21 than the latched portion 22 of the second arm 20. As shown in Fig. 1D, the height Hs of the sloped protrusion 23 relative to the outer surface 20o of the second arm 20 gradually increases toward the tip 21 of the second arm 20. For this reason, in a side view of the clip 1A, the sloped protrusion 23 has a triangular plate shape.

As described later, when clipping the clip 1A to the affected area using the clip sheath 40, the clip 1A is pulled toward the inner sheath 41, and the inner wall of the inner sheath 41 presses the first arm 10 and the second arm 20 closer to each other. If the sloped projection 23 is inclined as described above, the second arm 20 can be pressed efficiently. In addition, after the hook-shaped projections 12a and 12b of the first arm 10 latch the latched portion 22 of the second arm 20, when the inner sheath 41 is pulled back to place the clip 1A on the affected area, if the sloped projection 23 is inclined as described above, the contact area between the clip 1A and the inner wall of the inner sheath 41 is reduced, and the frictional resistance between them is reduced. This makes it easier to pull back the inner sheath 41 while leaving the clip 1A on the affected area.

It is more preferable that the inclination angle α of the sloped protrusion 23 relative to the outer surface 20o of the second arm 20 gradually increases toward the tip 21 of the second arm 20, that is, that the sloped surface of the sloped protrusion 23 has an R. For the same reason, it is also preferable that the width Ws of the sloped protrusion 23 in the short direction of the second arm 20 is narrow (FIG. 1C), and when the clip 1A is formed by bending a metal plate, it is preferable that the thickness of the sloped protrusion 23 is approximately the same as the thickness of the metal plate.

In this embodiment, two sloped protrusions 23 are formed along both the left and right sides of the second arm 20, but the manner in which the sloped protrusions 23 are formed is not limited to this. For example, one sloped protrusion may be formed on the center line A of the width of the second arm 20 in the short side direction.

(Inner sheath stopper)
A protrusion 13 is provided as an inner sheath stopper on the outer surface 10o of the first arm 10 opposite the second arm 20, closer to the tip 11 of the first arm than the pair of hook-shaped projections 12a, 12b. As will be described later, when the clip 1A attached to the clip sheath 40 is pulled toward the inner sheath 41 by the operating wire 43 to bring the first arm 10 and the second arm 20 closer to each other, it is preferable that the inner sheath stopper 13 is provided because the open end face of the inner sheath 41 abuts against the inner sheath stopper 13 and the clip 1A is not unnecessarily pulled into the inner sheath 41.

As shown in FIG. 2, when the hook-shaped projections 12a, 12b of the first arm 10 latch the second arm 20, the position of the continuous part side end 13a of the inner sheath stopper 13 in the clip longitudinal direction is preferably within the range in which the slope-shaped projection 23 is formed in the clip longitudinal direction in the same state. This makes it possible to minimize the length by which the clip 1A is retracted into the inner sheath 41 when the clip 1A attached to the clip sheath 40 is retracted toward the inner sheath 41 to bring the first arm 10 and the second arm 20 closer together.

(Bending portion of first arm and bending portion of second arm)
The first arm 10 has a first arm curved portion 14 curved convexly toward the second arm 20 between the hook-shaped projections 12a, 12b and the continuous portion 30. On the other hand, the second arm 20 has a second arm curved portion 24 curved convexly toward the first arm 10 between the latched portion 22 and the continuous portion 30.

When the clip 1A is retracted into the inner sheath 41 to close it, the first arm curved portion 14 and the second arm curved portion 24 come into contact with each other and become the fulcrum for opening and closing the first arm 10 and the second arm 20. As the retraction amount of the clip 1A in the inner sheath 41 increases and the opening between the first arm 10 and the second arm 20 decreases, the abutment point between the first arm curved portion 14 and the second arm curved portion 24 moves toward the tip 11 of the first arm and the tip 21 of the second arm. This increases the force with which the clamping portions 15 and 25 clamp the biological tissue when the clip 1A is closed, and also disperses the stress applied to the clip 1A when it is closed. Therefore, even if the clip 1A is made of resin, it is possible to prevent the arms 10 and 20 from breaking when the clip 1A is opened and closed.

(Width of the first arm and the second arm)
The width W2 (length in a direction perpendicular to the longitudinal direction of the second arm 20) of the second arm 20 in the top view (FIG. 1C) of the clip 1A is narrowest at the continuous portion 30 and the second arm curved portion 24, and is wider at the latched portion 22 and the portion where the slope-shaped projection 23 is formed. The tip portion 21 and the clamping portion 25 that directly clip the affected area are even wider, and only need to be accommodated in the outer sheath 42 of the clip sheath 40. Similarly, the width W1 of the first arm 10 is wider at the portion where the hook-shaped projections 12a, 12b are formed than the continuous portion 30 and the first arm curved portion 14, and further the tip portion 11 and the clamping portion 15 are formed wider than the portion where the hook-shaped projections 12a, 12b are formed.

(Forming material)
The clip 1A can be easily and inexpensively manufactured by bending a metal plate that will serve as a leaf spring, such as stainless steel.
The clip 1A may be made of a resin such as polycarbonate or ABS that exhibits high rigidity similar to the resin described in Patent Document 2, or a heat-resistant thermoplastic resin such as PEEK (polyether ether ketone) may be used. The material is appropriately selected depending on the application of the clip.

The resin's flexural modulus (JIS K 7171) is preferably 2000 MPa or more, and its flexural strength (JIS K 7171) is preferably 90 MPa or more. Polycarbonate, ABS, etc. are also preferred because of their excellent resistance to acid and alkali against digestive fluids.

When clip 1A is made of resin, it is preferable to increase the amount of resin in continuous portion 30 in order to increase the elasticity of clip 1A in the "<" shape.

When clip 1A is used as a marker, it is preferable that the resin forming clip 1A contains a fluorescent dye. The fluorescent dye should emit fluorescence in the red or near-infrared wavelength range of 600 to 1400 nm, preferably in the red or near-infrared wavelength range of 700 to 1100 nm. Light in such a wavelength range is highly permeable to human tissues such as skin, fat, and muscle, and can easily reach, for example, the mucous membrane and serosal surface of tubular human tissues such as the rectum.

Fluorescent dyes that emit fluorescence in the above-mentioned wavelength ranges include riboflavin, thiamine, NADH (nicotinamide adenine dinucleotide), indocyanine green (ICG), the azo-boron complex compounds described in JP 2011-162445 A, dyes having a condensed ring structure described in WO 2016/132596 A, dyes having a boron dipyrromethene skeleton described in Japanese Patent No. 5,177,427 A, dyes that chemically bond to silica particles described in JP 2020-74905 A, and phthalocyanine dyes described in JP 2020-105170 A.

The preferred concentration of the fluorescent dye in the resin can be set depending on the type of fluorescent dye and resin, and is usually preferably 0.001 to 1% by mass.

One method for incorporating fluorescent dye into resin is, for example, to knead the fluorescent dye into the resin using a twin-screw kneader. After that, the clip body can be formed by injection molding.

(How to use)
When the clip 1A is used as an endoscopic clip, the clip 1A is attached to a clip sheath 40 of an endoscopic clip device, as shown in Fig. 3A. The clip sheath 40 may be one having an inner sheath 41, an outer sheath 42, and an operating wire 43, as described in Japanese Patent No. 4,388,324, Japanese Patent No. 5,045,484, etc., or a commercially available one. The clip 1A may be attached to the clip sheath 40 by, for example, hooking the connecting portion 44 of the operating wire 43 to the end of the continuous portion 30 of the clip 1A. Alternatively, a connecting hook may be used as described in Japanese Patent No. 5,781,347, etc.

When the endoscopic clipping device is operated to pull clip 1A into outer sheath 42 by operating wire 43, clip 1A closes as shown in Fig. 3B, and when clip 1A is protruded from outer sheath 42, tip 11, 21 of clip 1A opens again as shown in Fig. 3A. When clip 1A is pulled into inner sheath 41 as shown in Fig. 3C, tip 11, 21 of clip 1A gradually closes, and when inner sheath 41 hits continuous part side end 13a of inner sheath stopper 13 and hits the slope of sloped projection 23 as shown in Fig. 3D, hook-shaped projections 12a, 12b of first arm 10 latch second arm 20. Clip 1A cannot be pulled any further into inner sheath 41. Next, by pulling back the inner sheath 41, the clip 1A can be removed from the clip sheath 40 with the first arm 10 and the second arm 20 latched by the hook-shaped protrusions 12a and 12b as shown in FIG. 3E.

To explain the case where clip 1A is used to clamp, for example, an affected area of the mucosa of a hollow organ, clip 1A is attached to operating wire 43, and clip 1A is retracted into outer sheath 42 by operating wire 43 as shown in Figure 3B, and in that state clip sheath 40 is inserted into the inside of the hollow organ. The endoscopic clipping device is operated to protrude clip 1A from outer sheath 42 as shown in Figure 4A, and tips 11, 21 of clip 1A are opened near the affected area of mucosa X. Then, clip 1A is brought into contact with mucosa X as shown in Figure 4B, and clip 1A is retracted into inner sheath 41, closing tips 11, 21 of clip 1A. As shown in FIG. 4B, even if the tips 11, 21 of clip 1A begin to grip mucosa X, if the hook-shaped protrusions 12a, 12b of the first arm 10 have not latched onto the second arm 20, the tips 11, 21 of clip 1A can be opened again by pulling back the inner sheath 41, so the position of the mucosa clipped by the tips 11, 21 of clip 1A can be adjusted as necessary.

When the tip 11, 21 of the clip 1A grasps the mucosa X at the desired position, the hook-shaped protrusions 12a, 12b of the first arm 10 latch the second arm 20, as shown in FIG. 4C, and the tip 11, 21 of the clip 1A clamps the mucosa X. At this time, the inner sheath 41 only contacts the end 13a of the continuous part of the inner sheath stopper 13 and the slope of the slope-shaped protrusion 23, so that the sliding resistance between the inner sheath 41 and the clip 1A is low when the inner sheath 41 is pulled back. Therefore, the inner sheath 41 can be easily pulled back. Therefore, as shown in FIG. 4D, the connecting part 44 of the operating wire 43 is removed from the continuous part 30 of the clip 1A, and the inner sheath 41 and the outer sheath 42 are pulled back, so that the clip 1A clamping the mucosa X can be placed on the mucosa of the tubular organ.

(Modifications)
The medical clip of the present invention can take various forms. For example, in the above-mentioned clip 1A, the inner sheath stopper 13 is formed on the first arm 10 having the hook-shaped projections 12a and 12b, and the slope-shaped projection 23 is formed on the second arm 20 having the latched portion 22. However, the slope-shaped projection 23 may be formed on the first arm 10 having the hook-shaped projections 12a and 12b, and the inner sheath stopper 13 may be formed on the second arm 20 having the latched portion 22.

In addition, in the present invention, the slope-shaped projection 23 and the inner sheath stopper 13 may be omitted. For example, the clip 1B shown in Figs. 5A, 5B, and 6 has the first arm 10 with hook-shaped projections 12a and 12b, which latch the second arm 20 to hold the tip 11 of the first arm 10 and the tip 21 of the second arm 20 in a closed state, which is common to the above-mentioned clip 1A. However, in this clip 1B, the latched portion 22 is recessed toward the first arm 10 in a well-shaped manner. By recessing the latched portion 22 of the second arm 20 toward the first arm 10 in this manner, when the clip 1B is attached to the clip sheath 40 of the endoscopic clip device and the clip 1B is pulled into the inner sheath 41 by the operating wire 43, the hook-shaped projections 12a and 12b of the first arm 10 can be latched to the second arm 20 with a smaller amount of pulling.

In addition, in this clip 1B, the second arm 20 does not have a slope-shaped protrusion, and the first arm 10 does not have an inner sheath stopper 13.

As a result, when clip 1B is attached to clip sheath 40 of an endoscopic clipping device as shown in FIG. 7A and clip 1B is pulled into inner sheath 41 with operating wire 43, convex portion 26 adjacent to the recess on the continuous portion 30 side of the recess of latched portion 22 hits the inner wall of inner sheath 41 as shown in FIG. 7B, thereby closing tip portions 11, 21 of clip 1B.

After the clip 1B is closed in this manner, to remove the clip 1B from the clip sheath 40, the inner sheath 41 is pulled back in the same manner as the clip 1A described above, and the operating wire 43 is removed from the clip 1B.

When the inner sheath 41 of the clip 1B is pulled back, the convex portion 26 of the second arm 20 and the outer surface 10o of the first arm 10 slide against the inner wall of the inner sheath 41. For this reason, it is preferable that the surface of the clip 1B has low sliding resistance.

On the other hand, in order to reduce the area of contact between the clip and the inner wall of the inner sheath 41 and to lower the sliding resistance, for example, as in clip 1C shown in Figures 8A and 8B, hemispherical convex portions 17, 27 may be provided on the portion adjacent to convex portion 26 on the continuous portion 30 side of convex portion 26 of second arm 20 and on the corresponding portion of first arm 10. Since hemispherical convex portions 17, 27 make point contact with the inner wall of inner sheath 41, the sliding resistance between clip 1C and the inner wall of inner sheath 41 can be reduced.

In addition, in each of the above clips, when using a connecting portion 45 of the operating wire 43 whose tip is bent into a hook shape and the hook-shaped portion is hooked onto the continuous portion 30 of the clip, as shown in FIG. 9, a protrusion 31 may be provided on the continuous portion 30 to prevent the tip of the operating wire 43 from moving unnecessarily toward the tip portions 11 and 21 of the clips 1A, 1B, and 1C.

As shown in FIG. 10, for example, a compression piece 50 made of flexible resin and holding a fluorescent dye may be attached to the clamping portion 15, 25 of each of the clips described above, and the compression piece 50 may be protruded from the distal end portion 11, 21 of the arm. FIG. 11 is a top view of a clip 1A having a compression piece 50. FIG. 12 is a cross-sectional view of the state in which the mucosa is clamped by the clip 1A with the compression piece 50.

The flexible resin from which the compression piece 50 is made is preferably one that will not denature even if left in the digestive tract for a long period of time and has acid resistance to stomach acid. Examples of such flexible resins include resins used in medical devices, such as soft polyvinyl chloride, thermoplastic polyurethane, silicone, and ethylene-vinyl acetate copolymer.

In addition, it is preferable that the compression piece 50 has a suitable hardness and elasticity so that the protruding portion 51 can effectively compress the biological tissue by bending the compression piece 50 when the clip 1A is clamping the biological tissue.

The hardness of the compression piece 50 is preferably in the range of A10 to A90 as Shore A (JIS K 6253) or D40 to D70 as Shore D (JIS K 6253) measured with a durometer. The hardness of the compression piece 50 is preferably selected appropriately depending on the shape, size, etc. of the compression piece 50.

The elasticity of the compression piece 50 is preferably a flexural modulus (ASTM D 790) of 4 to 200 MPa, more preferably 10 to 100 MPa.

The fluorescent dye held in the compression piece 50 is preferably one that emits fluorescence in the red or near-infrared wavelength range of 600 to 1400 nm, preferably in the red or near-infrared wavelength range of 700 to 1100 nm, and the above-mentioned dyes can be used.

Specific examples of how the fluorescent dye can be retained in the compression piece 50 include incorporating the fluorescent dye into the flexible resin that forms the compression piece 50, or forming a coating film that contains the fluorescent dye on the surface of a compression piece formed from a flexible resin. When incorporating the fluorescent dye into the flexible resin that forms the compression piece 50, the preferred concentration of the fluorescent dye can be set according to the type of fluorescent dye and resin, and is usually preferably 0.001 to 1% by mass.

The compression piece 50 is generally rectangular in shape, and in each of the first arm 10 and the second arm 20, the compression piece 50 protrudes from the clamping portion 15, 25 in the longitudinal direction of the arm. The compression piece 50 can be provided with constrictions 52, 53 on the inside and outside of the longitudinal direction of the arm near the tip 11, 21 of each arm. This makes it easier for the protruding portion 51 of the compression piece 50 to bend, as shown by the dashed line in FIG. 10. Depending on the size, shape, and presence or absence of the constrictions 52, 53, the force with which the compression piece 50 presses against the biological tissue when the biological tissue is clamped by the clip 1A with the compression piece 50 can be adjusted.

As shown in FIG. 12, when the biological tissue X is clamped with the clip 1A with the compression piece 50, the compression piece 50 bends, and the bent part strongly presses the biological tissue X in the thickness direction of the biological tissue, and blood in the vascular network Y of the submucosa is expelled. In this state, when the compression piece 50 is irradiated with excitation light in the red to near-infrared wavelength range from the serosal membrane side, the excitation light is absorbed by the fluorescent dye held by the compression piece 50 without being absorbed and inhibited by hemoglobin, and the fluorescent dye emits fluorescence in the red to near-infrared wavelength range. This fluorescence is emitted to the outside of the tubular organ without being absorbed and inhibited by hemoglobin. Therefore, this fluorescence can be observed well from the outside of the tubular organ, and the position of the biological compression clip clamped inside the tubular organ can be determined, and the position of the affected area can be identified.

When providing a compression piece 50 to a clip, the area from the tip 11, 21 of each arm 10, 20 to the clamping portion 15, 25 may be comb-shaped, as in clip 1D shown in Figure 13. Figures 14A and 14B are perspective views of clip 1D in which compression pieces 50 are provided by insert molding in the clamping portions 15, 25.

That is, in this clip 1D, two comb teeth 11t, 21t are arranged in parallel from the tip 11, 21 of each arm 10, 20 to the clamping portion 15, 25, and there is a comb tooth space 11s, 21s between the two comb teeth. In addition, in the clamping portion 15, 25 of each arm 10, 20, holes 18, 28 are provided as necessary in the portion closer to the continuous portion 30 than the comb teeth 11t, 21t to ensure the fixation of the compression piece 50. In the clip 1D of this embodiment, two comb teeth 11t, 21t are provided on each arm 10, 20, but in the present invention, the number of comb teeth on each arm 10, 20 is not limited to this and can be two or more, and is preferably two to three.

In addition, it is preferable that the claws 11a, 21a standing inward at the tips of the comb teeth 11t, 21t are formed so that the claws 11a, 21a are spaced apart from the central axis L of the clip 1D when the clip 1D is closed. Here, in the present invention, the central axis L of the clip is an axis that bisects the width W of the arm in the top view of the clip (FIG. 11) and is equidistant from the pair of arms 10, 20 in the side view of the clip (FIG. 12). When the clip 1D is closed, the claws 11a, 21a of the tips 11, 21 are spaced apart from the central axis L, so that when the clip 1D clamps the mucous membrane of the living tissue as shown in the cross-sectional view of FIG. 15, the fluorescence emitted not only by the protruding part 51 and outer part 54 of the compression piece 50 but also by the inner part 55 and the part between the comb teeth 56 is emitted toward the serosal membrane without being blocked by the metal plates and claws 11a, 21a that constitute each arm 10, 20. This makes it possible to significantly increase the fluorescence intensity in the observation direction.

In addition, the clip 1D having the compression piece 50 can be easily manufactured by insert molding, and even when a separately molded compression piece is attached to the clamping portions 15, 25 of the arms 10, 20 with adhesive, the compression piece 50 can be easily and firmly attached by fitting the compression piece into the inter-tooth spaces 11s, 21s.
The various modifications described above can be combined as appropriate.

1A, 1B, 1C, 1D Clip 1X Clip 2 Crimping ring 10 First arm 10o Outer surface of first arm 11 Tip 11a Claw 11t Comb teeth 11s Space between comb teeth 12a, 12b Hook-shaped protrusion (latch portion)
Reference Signs List 13 Inner sheath stopper, protruding portion 13a Continuous portion side end portion of inner sheath stopper 14 First arm curved portion 15 Clamping portion 16 Operation convex portion 17 Hemispherical convex portion 18 Hole portion 20 Second arm 20o Outer surface of second arm 21 Tip portion 21a Claw 21t Comb teeth 21s Space between comb teeth 22 Latched portion 23 Slope-shaped protrusion 24 Second arm curved portion 25 Clamping portion 26 Convex portion 27 Hemispherical convex portion 28 Hole portion 30 Continuous portion 31 Protruding portion 40 Clip sheath 41 Inner sheath 42 Outer sheath 43 Operation wire 44 Connecting portion 45 Connecting portion 50 Compression piece 51 Protruding portion 52 Narrowed portion 53 Narrowed portion 54 Outer portion 55 Inner portion 56 Portion between comb teeth 57 Reinforcement portion A Center line Hs of width in the short direction of second arm Height L of slope-shaped protrusion Central axis W, W1, W2 of clip Width of arm, width of first arm, width of second arm Ws Width of slope-shaped protrusion X Mucous membrane, biological tissue Y Vascular network α Inclination angle of slope-shaped protrusion

Claims (3)

A leaf spring-like medical clip having a first arm and a second arm opposed to each other, and a continuous portion between one end of the first arm and one end of the second arm,
The first arm has a pair of hook-shaped projections at the longitudinal center thereof for latching both sides of the second arm, the first arm has a first arm curved portion between the hook-shaped projections and the continuous portion, the first arm curved portion being curved in an arc from the flat portion of the first arm toward the second arm, and the second arm has a second arm curved portion between the latched portion and the continuous portion, the second arm curved portion being curved in an arc from the flat portion of the second arm toward the first arm,
When the clip is in an open state, the end portion of the first arm curved portion on the side of the continuous portion comes into contact with the end portion of the second arm curved portion on the side of the continuous portion, and the contact point serves as a fulcrum for opening and closing the first arm and the second arm, and as the opening between the first arm and the second arm becomes smaller, the contact point moves toward the tip end of the first arm and the second arm,
A medical clip in which when the first arm and the second arm approach each other to a predetermined distance, a pair of hook-shaped protrusions latch onto both sides of the second arm, thereby maintaining the first arm and the second arm in a close proximity. The medical clip according to claim 1, which is made of resin. The medical clip according to claim 1, which is made of metal.

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