Surgical sutures

Abstract

To provide a surgical suture tool capable of suppressing, more than before, unexpected separation of a surgical needle and a suture thread during surgery, and a leakage of body fluid from a penetration hole formed by the surgical needle.SOLUTION: In a surgical suture tool, a metallic needle part and a metallic suture thread part are formed seamlessly into one piece, and the maximum width of the needle part is smaller than the maximum width of the suture thread part.SELECTED DRAWING: None

Description

【Technical Field】 【0001】 The present invention relates to a surgical suture device, and more particularly to a surgical suture device having a needle portion and a suture portion. 【Background Art】 【0002】 Conventionally, this type of surgical suture device has a surgical needle and a suture, and generally the surgical needle and the suture are fixed by separate members by physical means or the like. For example, a surgical suture device in which the surgical needle is made of metal, the suture is made of resin, and the suture is physically fixed to the surgical needle by caulking one end of the suture to the end portion (base portion) on the side opposite to the tip of the surgical needle is known. 【0003】 For example, Patent Document 1 describes an iris needle that is completed by inserting the end of the suture into a stop hole formed in the end face of the base portion of the surgical needle and then caulking the end portion. In this iris needle, the diameter of the periphery of the stop hole can be increased in a stable state, and the chamfered surface from the periphery of the stop hole to the inside can be made smooth. As a result, it is said that the operation of inserting the suture into the stop hole can be performed reliably and easily. 【0004】 Furthermore, Patent Document 2 describes a needle-suture combination that includes (i) a surgical suture needle having a body with two ends and a suture connection position located between the two ends of the body, (ii) a suture, and (iii) a connecting portion in which the first end of the connecting portion is connected to the needle at the suture connection position, and the second end of the connecting portion on the opposite side is connected to the suture. In this embodiment of the needle-suture combination, it is stated that the connection between the connecting portion and the surgical suture needle and suture can be performed by clamping, gluing, melting, welding, etc., and that the maximum needle diameter of the surgical suture needle is 0.1 to 0.6 mm, the diameter of the suture is 0.01 to 0.6 mm, and the diameter of the suture is 0.01 to 0.6 mm, and that the diameter of the connecting portion is smaller than that of the suture. Furthermore, as a specific example, a needle-suture combination in which the diameter of the surgical suture needle is 0.3 mm, the diameter of the connecting portion is 0.05 mm, and the diameter of the suture is 0.15 mm is described. Furthermore, with the above-described configuration, the maximum cross-sectional area of ​​the combined needle and connecting portion, that is, the maximum cross-sectional area pulled through the tissue opening, becomes smaller than the combined cross-sectional area of ​​the suture and needle, which is considered to have a favorable effect in preventing or reducing bleeding through the tissue opening. [Prior art documents] [Patent Documents] 【0005】 [Patent Document 1] Patent No. 5253045 [Patent Document 2] Patent No. 6691104 [Overview of the project] [Problems that the invention aims to solve] 【0006】 For example, in the case of a suturing device that physically fixes a surgical needle and suture using an eyeless needle as described in Patent Document 1, although the two are usually firmly fixed together, the surgical needle and suture may separate during the suturing process. Similarly, as described in Patent Document 2, separation may also occur when the connecting portion is connected to the surgical suture needle and suture using the various methods mentioned above. When such separation occurs, unplanned work is required, which prolongs the surgery time and consequently increases the burden on the patient. In addition, since such separation usually occurs unexpectedly, it forces the surgeon to perform unplanned work, increasing the burden on the surgeon as well. 【0007】 Furthermore, as described in Patent Document 1, when a surgical needle and suture are fixed by physical means such as crimping, the thickness of the base of the surgical needle becomes greater than the thickness of the suture. As a result, the size of the perforation hole created by the penetration with the surgical needle becomes larger than the thickness of the suture, creating a gap between the perforation hole (tissue opening) and the suture. Also, in the invention described in Patent Document 2, the maximum cross-sectional area of ​​the combined needle and connecting portion is smaller than the combined cross-sectional area of ​​the suture and needle, but larger than the cross-sectional area of ​​the surgical suture needle alone, resulting in a gap between the suture and the needle. For example, when suturing very thin membranes such as meninges, the difference in thickness between the needle and thread has a significant effect, and gaps tend to occur easily. If bodily fluids seep out from these gaps, it becomes necessary to wipe away the fluids during the suturing process or to apply tissue adhesive to seal the gaps as much as possible. As a result, the suturing process takes time, placing a burden on both the patient and the surgeon. Furthermore, even if the suturing is deemed successful, bodily fluids may gradually seep from the suture site. In such cases, a drainage tube may need to be left in place for a certain period to remove the fluid, requiring postoperative management and measures to prevent infection in the patient. 【0008】 Therefore, the object of the present invention is to provide a surgical suturing device in which unexpected separation of the surgical needle and suture during surgery is suppressed more than in conventional devices, and leakage of bodily fluids from the perforation hole formed by the surgical needle is suppressed more than in conventional devices. [Means for solving the problem] 【0009】 The inventors of this invention conducted diligent research to solve the aforementioned problems. As a result, they found that the aforementioned problems can be solved by forming the surgical needle and suture thread together seamlessly, and by making the maximum width of the portion that becomes the surgical needle less than or equal to the maximum width of the portion that becomes the suture thread. The gist of the present invention is as follows. 【0010】 (1) A surgical suture device in which a metal needle portion and a metal suture portion are formed integrally without seams, and the maximum width of the needle portion is less than or equal to the maximum width of the suture portion. (2) The surgical suture device according to item (1), wherein the tensile strength of the needle portion is equal to or greater than the tensile strength of the suture portion, and the tensile strength of the suture portion is 100 MPa or more. (3) The surgical suture device according to item (1) or (2), wherein the maximum width of the suture portion is 0.001 to 1.299 mm. [Effects of the Invention] 【0011】 According to the present invention, it is possible to provide a surgical suturing device in which unexpected separation of the surgical needle and suture during surgery is suppressed more than in the conventional method, and leakage of bodily fluids from the perforation hole formed by the surgical needle is suppressed more than in the conventional method. [Modes for carrying out the invention] 【0012】 In an embodiment of the present invention, the surgical suture device has a metal needle portion and a metal suture portion formed integrally without any seams. Furthermore, the maximum width of the needle portion is less than or equal to the maximum width of the suture portion. 【0013】 Because the metal needle and suture parts are formed seamlessly as a single unit, the separation of the two parts can be reduced compared to conventional methods. Furthermore, since the thickness of the needle part is less than or equal to the thickness of the suture part, and the thickness of the suture part is greater than or equal to the size of the puncture hole formed by the needle part, the occurrence of gaps between the puncture hole and the suture part is suppressed, making it possible to suppress the leakage of bodily fluids more than conventional methods. Here, "seamless" means that there are no visible joined parts, and "integrated" means that the whole is one, or that it is a single unit that cannot be separated. 【0014】 The needle and suture parts are made of metal. The type of metal is not particularly limited and includes, for example, steel such as piano wire, stainless steel, tungsten and its alloys, magnesium and its alloys, titanium and its alloys, cobalt and its alloys, platinum and its alloys, etc. These may be one type or a combination of two or more types. The metal materials of the needle and suture parts may be the same or different, as long as they can be formed integrally without seams, but it is preferable that they be the same from the viewpoint of seamless formation of the needle and suture parts, and from the viewpoint of tensile strength, etc. Also, for the same reason, it is preferable that there is only one type of metal. 【0015】 The tensile strength of the needle and suture portion should be appropriate to their respective functions, but it is preferable that the tensile strength of the needle portion be greater than or equal to that of the suture portion. Specifically, for example, it is preferable that the tensile strength of the suture portion be 100 MPa or more. The needle portion should be selected to have a tensile strength equal to or greater than that of the suture portion. The tensile strength can be adjusted depending on the type of metal material used. For example, it can be 610 to 2200 MPa for stainless steel and 2000 to 3000 MPa for tungsten. The tensile strength can be measured, for example, in accordance with JIS Z 2241, the tensile testing method for metallic materials. 【0016】 Although the needle portion and the suture portion are formed integrally without seams, it is preferable that a transition portion be formed in the suture portion adjacent to the needle portion in order to suppress extreme changes in tensile strength in the adjacent portion between the needle portion and the suture portion. That is, it is preferable that the suture portion has a transition portion and a main body portion adjacent to the transition portion and extending in the direction opposite to the needle portion. Furthermore, it is preferable that the transition portion has the same tensile strength or hardness (tensile strength, etc.) as the needle portion and the main body portion, and it is more preferable that it gradually decreases from the portion adjacent to the needle portion to the portion adjacent to the main body portion, from the tensile strength, etc. of the needle portion to the tensile strength, etc. of the main body portion. Here, hardness can be a value measured by, for example, a micro-Vickers hardness tester. Such a transition portion can be provided by the method described later. 【0017】 The overall shape of the needle portion can be the same as that of a typical surgical needle, and examples include straight shapes, curved shapes such as quarter circles, half circles, three-eighth circles, and four-fifth circles. In shapes that include curved shapes, a straight shape may be included in the portion continuous with the suture. In the case of a straight shape, the needle portion may be formed only from a tapered portion that narrows towards the tip, or it may be configured to include a straight portion (non-tapered portion) of a constant width and a tapered portion. The cross-sectional shape of the needle portion can also be the same as that of a typical surgical needle, and examples include polygons and circles. 【0018】 The suture portion may be a single wire, a twisted wire, or a braided thread, but a single wire is preferred from the viewpoint of forming the needle portion and the suture portion as a single unit without joints, and from the viewpoint of tensile strength. The cross-sectional shape of the suture portion is not particularly limited, and examples include circular, oval, elliptical, semi-elliptical, key-shaped, rectangular, crescent, square, convex ribbon, concave ribbon, star shape, invariant equilateral, and octagon, as well as shapes having a contour line consisting of at least one type selected from circular arcs and elliptical arcs and two or more consecutive arcs. Note that the shape having a contour line consisting of at least one type selected from circular arcs and elliptical arcs and two or more consecutive arcs is shown as the cross-sectional contour line in the case of a twisted wire. 【0019】 The maximum width of the suture can be the same as the diameter of a typical medical suture, preferably between 0.001 and 1.299 mm. Furthermore, the maximum width can be appropriately determined depending on the application site. For example, when suturing the meninges in cranial or spinal surgery, a maximum width of 0.001 to 0.199 mm is preferable from the viewpoint of suppressing cerebrospinal fluid leakage. According to the standards of the Pharmaceuticals and Medical Devices Act (Act on Securing Quality, Efficacy and Safety of Pharmaceuticals, Medical Devices, etc.), Ministry of Health and Welfare Notification No. 393 of March 3, 1999 (hereinafter sometimes referred to as "Pharmaceuticals and Medical Devices Act Standards"), the minimum diameter of a suture corresponding to 12-0 is 0.001 mm, and the maximum diameter of a suture corresponding to 10 of the same number is 1.299 mm. Therefore, sutures from 10 to 12-0 of the same number can be used. Furthermore, since the maximum diameter of suture thread corresponding to size 4-0 is 0.199 mm, when suturing the meninges, suture threads ranging from size 4-0 to 12-0 are preferable. Note that the maximum width of the needle portion is less than or equal to the maximum width of the suture portion, and can therefore be determined according to the maximum width of the suture portion. 【0020】 The aforementioned surgical sutures can be manufactured, for example, as follows: First, a raw wire rod of a metal material with a predetermined maximum width is prepared. Preferably, the raw wire rod is a single wire rod, more preferably a single strand of raw wire rod. Then, the maximum width of the raw wire rod is reduced by continuous wire drawing to produce a wire rod A having a desired maximum width. The cross-sectional shape of wire rod A can be made into a desired shape by forming processes such as drawing with a wire drawing die or rolling. Wire rod A that has been plastically deformed by continuous wire drawing has a desired tensile strength. Furthermore, the tensile strength can be adjusted by heat treatment. By applying heat treatment, the crystal grains of the metal structure can be coarsened and the tensile strength can be reduced. The conditions for continuous wire drawing and heat treatment can be appropriately determined considering the type of material of the raw wire rod, the maximum width of the raw wire rod, the maximum width of wire rod A, etc. 【0021】 Next, using a heat treatment apparatus, heat treatment is performed on a predetermined range in the length direction of the wire A. The heated portion after the heat treatment becomes the suture thread portion, and the unheated portion becomes the needle portion. Here, among the portions not directly heated by the heat treatment apparatus, the portions adjacent to the directly heated portion are also heated to some extent by radiant heat or the like. And, the heating temperature decreases as the distance from the heat treatment apparatus increases. As a result, in a predetermined range extending in a direction away from the directly heated portion with respect to the heat treatment apparatus, there are portions where the coarsening of the crystal grains of the metal structure has progressed to some extent and portions where it has not progressed much, which are formed according to the applied temperature. This portion becomes the aforementioned transition portion. Also, the directly heated portion becomes the aforementioned main body portion. The heat treatment apparatus is not particularly limited, and examples include a walking heat treatment furnace (pipe annealing furnace), a direct current heating apparatus, etc. The heat treatment method may be a batch type or a continuous type such as current annealing using a direct current heating apparatus. The length of the transition portion can be adjusted according to the heat treatment apparatus and the heat treatment method, depending on the degree of cooling of the unheated portion, the heating time, the take-out speed from the heat treatment apparatus, etc. 【0022】 By adjusting the various conditions of continuous wire drawing and heat treatment as described above, it is possible to form a wire A having portions that can become a needle portion and a suture thread portion with a desired tensile strength. In the case where the raw material wire is a long continuous wire, it can be cut to a desired length after the heat treatment, if necessary. 【0023】 Thereafter, a needle tip is formed on the tip portion of the unheated portion (non-heated portion) of the wire A during the heat treatment. When the raw material wire is a single wire, the needle tip can be formed by, for example, the method described in Patent Document 1. First, the tip portion of the non-heated portion that will become the needle portion is ground by a conventional method such as grinding or polishing so as to become thinner generally toward the tip side. Thereafter, by performing electrolytic polishing, chemical polishing, etc., a tapered portion having a sharp tip that gradually becomes thinner toward the tip side can be formed. The cross-sectional shape of the tapered portion can be given a conventional shape such as a polygon or a circle by appropriately selecting the processing conditions. When the overall shape of the needle portion includes a curved shape, it can be formed by press working, bending, etc. using a mold. Also, the taper angle, length, etc. of the tapered portion can be adjusted by appropriately selecting the processing conditions. A non-tapered portion with a constant width where the tapered portion is not formed can also be provided in a portion close to the suture portion. 【0024】 By forming a tapered portion having a tip on the non-heated portion as described above, a surgical suture in which a predetermined suture portion and a needle portion are integrally formed without a seam is obtained. In this surgical suture, separation between the needle portion and the suture portion is suppressed, and since the maximum width of the needle portion is also less than or equal to the maximum width of the suture portion, leakage of body fluid from the puncture hole is suppressed. Also, when using a conventional surgical suture, the puncture hole made by the surgical needle becomes larger than the suture. As a result, when trying to suture strongly, stress due to tightening of the suture concentrates on a part of the side wall of the puncture hole, cutting the tissue and expanding the puncture hole, and there is a high possibility of worsening of body fluid leakage. However, in the surgical suture tool described above, since the thickness of the suture portion is equivalent to the puncture hole, concentration of stress is suppressed, and it is considered that it is possible to suppress cutting of the tissue and worsening of body fluid leakage due to it compared to the case of a conventional surgical suture. 【Example】 【0025】 Hereinafter, based on examples, embodiments of the surgical suture of the present invention will be described in more detail. 【0026】 (Example 1) A single wire rod made of stainless steel (SUS304W1) with a diameter of 0.4 mm was prepared, and a wire rod with a diameter of 0.05 mm (corresponding to the 7-0 standard of the Pharmaceuticals and Medical Devices Act) was produced by continuous wire drawing. The tensile strength of the obtained wire rod was measured using a VE905D tensile testing machine manufactured by Toyo Seiki Seisakusho Co., Ltd. in accordance with JIS Z 2241 Tensile Testing Method for Metallic Materials, and was found to be 2600 MPa. Next, a heat treatment was performed on a predetermined range in the longitudinal direction of the obtained wire rod using a running heat treatment furnace (pipe annealing furnace). The temperature was set to 800°C, and after holding the wire rod in the furnace for 15 seconds, it was removed from the furnace and cooled. The tensile strength of the portion directly heated in the furnace was measured in the same manner as above in accordance with JIS Z 2241 Tensile Testing Method for Metallic Materials, and was found to be 970 MPa. As described above, a single metal wire was formed with a portion that would become the needle, having a tensile strength of 2600 MPa, and a portion that would become the suture, including a portion with a tensile strength of 970 MPa (the main body). In addition, a transitional region was formed in the suture region, which was heated to some extent in close proximity to the outside of the intermittent heat treatment furnace. When the structure of each part was examined with a scanning electron microscope (JEOL Ltd., Analytical Scanning Electron Microscope JSM-6510LA), the following points were observed: (a) The structure of the needle portion had been plastically deformed by wire drawing, resulting in refined crystal grains; (b) The main body of the suture had coarser crystal grains due to heat treatment; (c) The transitional region of the suture had crystal grains that were intermediate between the structure of the needle portion and the main body due to radiant heat from the heating furnace and heat conduction from the heated wire. From these results, it is inferred that the tensile strength of the transitional region is between the values ​​of the needle portion and the main body, i.e., 970 to 2600 MPa. Furthermore, the tensile strength values ​​of the needle and suture portions of the heat-treated wire indicate that the strength of each part meets the standards of the Pharmaceuticals and Medical Devices Act. 【0027】 Furthermore, using a raw wire with a diameter of 0.4 mm, heat treatment was performed on a predetermined range in the longitudinal direction of the raw wire in the same manner as described above. The raw wire after heat treatment also had a needle portion, a main body portion, and a transition portion formed in the same way, and the Vickers hardness of each portion was measured using a micro-Vickers hardness tester (Mitutoyo Corporation, Vickers hardness tester HM-221) in accordance with the JIS Z 2244 Vickers hardness test, and the average value was calculated. As a result, (i) the portion that becomes the needle portion had an average hardness of 550 Hv, (ii) the portion that becomes the main body portion of the suture had an average hardness of 315 Hv, and (iii) the portion that becomes the transition portion of the suture had an average hardness of 450 Hv. The reason for using a raw wire with a diameter of 0.4 mm in the Vickers hardness measurement was that it was difficult to measure in accordance with JIS Z 2244 with a wire with a diameter of 0.05 mm. However, it is self-evident that the results for raw wire with a diameter of 0.4 mm will show a generally similar trend for wire with a diameter of 0.05 mm. 【0028】 Next, a tapered section with a circular cross-section and a gradually decreasing diameter towards the tip was formed at the tip of the needle portion. First, a predetermined range from the tip of the needle portion was ground to create a shape that generally tapers towards the tip. Then, electropolishing was performed to form the tapered section and obtain a surgical suture. The characteristics of the obtained surgical suture are shown in Table 1. The diameter of each part was measured using a micrometer (Mitutoyo Corporation, MDC-25MX), and the length was measured using a digital microscope (Keyence Corporation, Digital Microscope VHX-7000) and a metal ruler (Shinwa Measuring Instruments Co., Ltd., JIS Class 1, 30cm). 【0029】 [Table 1] 【0030】 (evaluation) <Penetration Test> A piece of meat was prepared by cutting commercially available ham to a thickness of 1 mm. A cut approximately 5 cm long was made in the meat piece, and the cut was sutured using the surgical suture obtained in Example 1. The suturing procedure involved repeatedly piercing from one side (front) to the cut, crossing the cut, and then piercing from the other side (back) to the front, until the 5 cm cut was sutured. The meat piece was pierced twice in this single suturing operation. The dimensions of the tapered portion of the needle were measured after each suturing operation. The suturing operation was performed four times consecutively, and the dimensional change of the needle and whether or not a gap was formed between the piercing hole of the needle and the suture were checked. The results are shown in Table 2. 【0031】 [Table 2] 【0032】 The surgical suture of Example 1 is formed from a single wire of the same metal material, and therefore the needle portion and the suture portion are formed integrally without any joints. As a result, no separation of the needle portion and the suture portion was observed even when multiple suturing procedures were performed consecutively. Furthermore, since the diameter of the needle portion is less than or equal to the diameter of the suture portion, no gap was observed between the puncture hole and the suture portion, and it is expected that leakage of bodily fluids from the sutured area can be suppressed more effectively than with conventional methods. The tensile strength of the needle portion is greater than or equal to that of the suture portion, greater than that of the main body portion of the suture portion, and greater than that of the transition portion. As a result, there is no extreme difference in strength in the continuous portion between the needle portion and the suture portion, and as a result, separation of the needle portion and the suture portion is further suppressed, and it is thought that repeated suturing operations were possible in combination with having the predetermined tensile strength.

Claims

[Claim 1] A surgical suture in which a metal needle portion and a metal suture portion are formed integrally without seams, the maximum width of the needle portion is less than or equal to the maximum width of the suture portion, the maximum width of the suture portion is 0.001 to 0.199 mm, and the formation of a gap between the puncture hole of the needle portion and the suture portion, and the enlargement of the puncture hole due to the suture portion cutting tissue are suppressed, thereby suppressing leakage of bodily fluids from the puncture hole. [Claim 2] The surgical suture device according to claim 1, wherein the tensile strength of the needle portion is equal to or greater than the tensile strength of the suture portion, and the tensile strength of the suture portion is 100 MPa or more.

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