WO2023022202A1

WO2023022202A1 - Medical tape

Info

Publication number: WO2023022202A1
Application number: PCT/JP2022/031245
Authority: WO
Inventors: 明郎萩原; 洋作萩原
Original assignee: 株式会社彩
Priority date: 2021-08-18
Filing date: 2022-08-18
Publication date: 2023-02-23
Also published as: JP2023028168A

Abstract

The present invention is able to provide a medical tape that: is formed of a non-woven fabric having a gradual increase part in which the thickness in the longitudinal direction gradually increases from one-end side toward the other-end side; can be wound around the outer periphery of a tubular organ in a state where the non-woven fabric overlaps itself; when being wound, allows permeation of bodily fluid containing tissue cells of the tubular organ into the non-woven fabric; and is, when treatment of an injured site or the like of a tubular organ is to be conducted, capable of preventing leakage of content for a short term without being invasive to the tubular organ and capable of facilitating long-term healing of the injured site.

Description

medical tape

The present invention relates to a medical tape, and more particularly to a medical tape that is used by being wrapped around the outer circumference of a tubular organ.

Conventionally, circulatory systems such as blood vessels such as arteries and veins, digestive systems such as digestive tracts, bile ducts and hepatic ducts, respiratory systems such as trachea, bronchi and bronchial branches, ureters, urethra, fallopian tubes, vas deferens, etc. For the purpose of treating damage to tubular organs and other organs in the urogenital system, a medical device has been proposed that uses a nonwoven fabric as a base material and combines it with a substance having a desired physiological activity ( Patent Documents 1 and 2).

Patent Document 1 describes a biological tissue reinforcing material kit that can reinforce fragile tissues without using blood products, has high pressure resistance, and has adhesion-preventing ability that does not cause adhesions. Disclosed is a nonwoven fabric and an amount of sodium alginate.

Patent document 2 describes an effective anticoagulant for the purpose of adhering to the vascular wall for a long period of time, covering the aneurysm with connective tissue induced around it, reinforcing the vascular wall, and preventing the aneurysm from increasing, rupturing, and recurring. A coating material for treatment of aneurysms is disclosed which is composed of a fibrinogen component and a thrombin component as components and a nonwoven fabric made of bioabsorbable synthetic fibers as a substrate.

In addition, although not for medical use, Patent Document 3 discloses no-crimp staple fibers and/or low-crimp staples for the purpose of providing a non-woven fabric for coating film waterproofing that does not impair the aesthetic appearance without causing a step in the overlapped portion. In a synthetic fiber nonwoven fabric that uses fiber as the main constituent fiber and can be easily cut by hand, the thickness of portions with a width (V) of 50 to 100 mm from both side ends is gradually reduced toward the ends as an overlap margin. discloses an extremely thin non-woven fabric reinforcement for coating waterproofing and/or corrosion protection.

Japanese Patent No. 5963130 Japanese Patent No. 4398651 JP-A-2001-336055

However,

Patent Documents

1 and 2 do not particularly mention wrapping the nonwoven fabric around the outer periphery of the tubular organ or the thickness of the nonwoven fabric. In the invention described in Patent Document 3, a nonwoven fabric having a portion that gradually decreases toward the end is adopted, but the application is completely different from that of a medical device, and the purpose of adopting the configuration is to reduce the end portion of the nonwoven fabric. To maintain a beautiful appearance without causing a step when superimposed on each other.

By the way, when the tubular organ is, for example, a blood vessel, during surgery, (a) the blood vessel wall is sutured when replacing a part of the own blood vessel (especially artery) with a blood vessel component such as an artificial blood vessel and transplanting it. Bleeding from a needle puncture (needle hole) of a seam of a blood vessel wall or a suture of a blood vessel wall in an operation such as (b) simply repairing blood vessel (e.g., artery) wall damage or bleeding and bleeding. sometimes.

As a countermeasure against such bleeding, permanent hemostasis is performed to permanently stop the bleeding and eliminate the risk of rebleeding. This permanent hemostasis operation is roughly classified into a pressure hemostasis operation and a suture hemostasis operation. Compression hemostasis is a method of artificially compressing the bleeding site to promote the natural hemostatic action of blood, in which blood clots solidify the bleeding site around the bleeding site to stop bleeding. It is an effective hemostasis method for relatively weak bleeding. Suture hemostasis is an operation to stop bleeding by artificially closing the bleeding site by suturing or ligating the bleeding site such as a blood vessel with a surgical needle and thread, and it is also effective for bleeding with strong bleeding. It is an effective hemostasis method.

In permanent hemostasis, first and foremost, complete hemostasis is of utmost importance, and hemostasis that may cause rebleeding from the same site one day after hemostasis is not allowed. Next, it is also important to minimize the risk of thrombus formation and lumen narrowing/occlusion at the site of hemostasis operation after complete hemostasis. From this point of view, the first choice for permanent hemostasis is the pressure hemostasis. The reason is as follows. In the suture hemostasis operation, a new suture wound is formed on the blood vessel wall around the injured site by a needle and thread to invade it. Repair of the damaged area deteriorates by the amount of invasion. As a result, the risk of thrombus formation, stenosis, and occlusion later occurs with suture hemostasis greater than with pressure hemostasis.

Thus, in the hemostasis operation for bleeding from the vascular wall, etc., there is a demand for a treatment that can achieve complete and permanent hemostasis as well as smooth self-repair and healing after hemostasis.

In addition, if the tubular organ is, for example, the ureter, when the torn part of the ureteral wall is joined together and repaired, urine may leak from the joint. The ureter is a tubular organ that delivers urine from the kidneys to the bladder, where the pulsatile intraureteral pressure produced by the peristaltic movement of the muscles that make up the walls of the ureter drives the urine toward the bladder. Since the urine is subject to pulsating internal pressure in this manner, when the ureteral walls are sutured together, there is an unavoidable risk of leakage of urine from the seams of the sutures. To avoid leakage of urine through the sutures in the ureteral wall, it is necessary to apply multiple tight sutures so that the sutures withstand internal pressure. However, it is known that a tightly sewn sutured part causes stenosis of the ureteral lumen and ureteral calculus at an extremely high rate thereafter, and eventually causes renal dysfunction. Therefore, an anastomosis method is selected in which the number of sutures is reduced as much as possible and the sutures are performed sparsely. In this case, urine leaks from the loosely sutured ureteral anastomosis, but a drainage tube is placed from the vicinity of the ureteral anastomosis to the outside of the body through the skin to guide the leaking urine out of the body.・Drainage therapy is used in combination. The drainage tube is removed from the body only when the anastomotic site has healed enough to stop leakage of urine from the ureteral anastomotic site. Until the drainage tube can be removed, the patient spends a long hospital stay connected to the tube outside the body by the drainage tube from the body. Patients can also suffer from retrograde infections (drain infections) through the drainage ducts.

Thus, in the operation to repair the rupture of the ureteral wall, the prevention of stenosis of the ureteral anastomosis is of utmost importance. , Although there is a possibility of a drain infection, he is forced to be hospitalized for a long time while connected to a drainage tube. Therefore, in the operation of repairing the rupture of the ureteral wall, there is a demand for a treatment that can prevent ureteral anastomotic stenosis and also prevent urinary leakage.

As described above, treatment strategies differ greatly between blood vessels and ureters. There is a demand for a treatment capable of preventing stenosis and occlusion caused by the invasion, while preventing the vascular wall from becoming invasive and minimizing the invasiveness.

Therefore, an object of the present invention is to prevent short-term leakage of contents without invading the tubular organ when treating a damaged site of the tubular organ, and to prevent long-term leakage of contents. To provide a medical tape capable of promoting repair of a damaged site.

The inventor of the present invention has made intensive studies to solve the above-mentioned problems. As a result, a nonwoven fabric having a gradually increasing portion whose thickness in the longitudinal direction gradually increases from one end to the other end is used, and it is configured so that it can be wrapped around the outer circumference of the tubular organ in layers. found that the above-mentioned problems can be solved. The gist of the present invention is as follows.

(1) It is composed of a nonwoven fabric having a gradually increasing portion whose thickness in the longitudinal direction gradually increases from one end to the other end, and the nonwoven fabric can be overlapped and wrapped around the outer circumference of the tubular organ. 2. A medical tape, wherein, in the wrapped state, body fluids containing tissue cells of said tubular organ are permeable to said nonwoven fabric.
(2) The medical tape according to item (1), wherein the nonwoven fabric is composed of fibers made of a bioabsorbable material.
(3) The medical tape according to item (1) or (2), wherein the gradually increasing portion has a minimum thickness of 40 μm or less and a maximum thickness greater than the minimum thickness and 150 μm or less.
(4) With respect to the entire length of the gradually increasing portion, the weight of the portion from the end of the minimum thickness side to 28 to 35% of the length is 20 g / m ² or less, and 8 from the end of the maximum thickness side. The medical tape according to any one of items (1) to (3), which has a basis weight of 50 g/m ² or less up to 13% of the length.
(5) The medical tape according to any one of items (1) to (4), wherein the median fiber diameter of the fibers constituting the nonwoven fabric is 32 μm or less.
(6) The medical tape according to any one of Items (1) to (5), wherein the nonwoven fabric is a meltblown nonwoven fabric.
(7) The medical tape according to any one of items (1) to (6), which is for hemostasis and can be wrapped around the circumference of a blood vessel.
(8) A treatment kit comprising a combination of the medical tape according to any one of items (1) to (7) and an adhesive.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to prevent short-term contents leakage without invading the tubular organ when treating the damaged site of the tubular organ, and prevent long-term damage to the damaged site. A medical tape can be provided that is capable of promoting repair.

(a) A diagram showing a state in which the artery of the experimental animal was damaged by blocking the blood flow with a blood vessel forceps and crossing the artery halfway around. (b) A diagram showing a state in which a total of three crossed injured sites are loosely sutured to prevent tearing when blood flow is resumed. (c) A diagram showing a state in which the medical tape was wrapped around the crossed injured site and left to stand for 5 minutes. (d) A diagram showing a state of confirming complete hemostasis for 7 minutes after releasing the vascular forceps. (a) A stereomicroscopic image of a common carotid artery excised from an experimental animal including an injured site wrapped with the medical tape of Example 1. FIG. (b) A stereomicroscopic image of the common iliac artery extracted from the experimental animal including the injured site wrapped with the medical tape of Example 1. FIG. (c) A light microscope image of a cross-section of the excised common carotid artery hematoxylin-eosin (HE) stained histological specimen shown in FIG. 2(a). (d) A light microscope image of a cross-section of the isolated common carotid artery HE stained histological specimen shown in FIG. 2(b). FIG. 2 is a diagram showing a state in which the medical tape of Example 1 wrapped around the ureteral anastomosis of an experimental animal is left standing after being sprayed with an adhesive. 1 is a macroscopic photograph of a specimen, such as a ureter, including an anastomosis wound with the medical tape of Example 1, extracted from an experimental animal. FIG. FIG. 5 is a light microscope image of a cross-section of an HE-stained histological specimen of the anastomosis indicated by the arrow in FIG. 4; FIG. 10 is a macroscopic photograph of a specimen such as a ureter including an anastomosis wound with the medical tape of Comparative Example 3, which was excised from an experimental animal. FIG. 7 shows a light microscope image of a cross-section of an HE-stained histological specimen of the anastomosis indicated by the arrow in FIG.

A medical tape according to an embodiment of the present invention is composed of a nonwoven fabric having a gradually increasing portion in which the thickness in the length direction gradually increases from one end to the other end. Then, the nonwoven fabrics can be overlapped and wrapped around the outer periphery of the tubular organ, and body fluid containing tissue cells of the tubular organ can permeate the nonwoven fabric in the wound state. . Here, "gradually increasing" includes cases where the thickness increases from one longitudinal end side to the other longitudinal end side, as well as cases where the thickness is partially the same. Confirmation of the gradual increase can be performed, for example, by measuring the thickness by the method shown in the section of Examples described later. In addition, the "thickness in the length direction" means that the angle at which the imaginary straight line in the length direction of the nonwoven fabric and the imaginary straight line in the direction in which the thickness is constant intersects is a right angle or an acute angle. including.

By having the gradually increasing portion in this way, it is possible to tightly wrap the nonwoven fabrics together without causing slack when the medical tape is wrapped around the tubular organ. In addition, for example, body fluids such as blood may permeate the nonwoven fabric in a wound state, or may adhere to the nonwoven fabric during winding. In such a wet state, the non-woven fabric has increased frictional force between fibers, and can resist shear stress caused by changes in the outer diameter of the tubular organ when the contents pass through the tubular organ. A frictional force can be easily generated between the wound nonwoven fabrics, and a damaged site of a tubular organ can be tightly pressed. In addition, especially in the case of hemostasis of blood vessels, since blood usually flows out from the injured site, the blood that has permeated the wound nonwoven fabric coagulates into a blood clot of a gel-like substance, and the adjacent wound nonwoven fabric It can exhibit the effect|action which adhere|attaches each other. In the case of tubular organs other than blood vessels, as will be described later, it is possible to further improve the adhesion between non-woven fabrics by applying an adhesive to the non-woven fabrics as necessary. As a result, short-term leakage of contents can be prevented.

Moreover, in the long term, simply wrapping the medical tape does not invade the tubular organ, and body fluids such as blood containing tissue cells of the tubular organ permeate the wrapped nonwoven fabric. As a result, it is possible to prevent stenosis/occlusion of various tubular organs and thrombus formation in blood vessels. In addition, it is possible to sufficiently recover the strength of the vascular wall after the completion of natural healing, and to prevent the remaining pathological state of insufficient strength. Furthermore, in the process of tissue repair and healing at the damaged site, the fibers that make up the nonwoven fabric not only have the effect of maintaining the strength of the damaged site, but also serve as an artificial scaffold that promotes the adhesion and proliferation of cells and facilitates the regeneration of blood vessel walls. can work. As a result, it is possible to have tissue regeneration and repair effects that are nearly identical to the own vascular wall.

As described above, medical tapes can have fundamental therapeutic effects such as prevention of leakage of the contents of tubular organs and promotion of tissue regeneration and repair at damaged sites. It is possible to treat the so-called severely damaged areas.

The fibers that make up the nonwoven fabric are not particularly limited, and various organic fibers that are acceptable for medical applications can be used. Such fibers may be either fibers made of a bioabsorbable material or fibers made of a non-bioabsorbable material, and can be appropriately selected according to the purpose. As the bioabsorbable material, for example, those described in Patent Document 1 can be used. Specifically, for example, polyglycolide (polyglycolic acid), polylactide (polylactic acid) (D, L, DL form), glycolide (cyclic dimer of glycolic acid)-lactide (cyclic dimer of lactic acid) ( D, L, DL form) copolymer, glycolide-ε-caprolactone copolymer, lactide (D, L, DL form) -ε-caprolactone copolymer, poly(p-dioxanone), glycolide-lactide (D, L, DL form)-ε-caprolactone copolymer, synthetic polymers such as poly-ε-caprolactone, and materials derived from natural products such as collagen, gelatin, chitosan, and chitin. These bioabsorbable materials may be used singly or in combination of two or more, but those derived from natural products are preferably used in combination with synthetic polymers. The copolymer may be a random copolymer or a block copolymer. Among bioabsorbable materials, polyglycolide and lactide (D, L, DL form)-ε-caprolactone copolymer are preferred. The lactide (D, L, DL form)-ε-caprolactone copolymer may be a random copolymer or a block copolymer, but is preferably a block copolymer. Non-bioabsorbable materials include, for example, synthetic polymers such as polyester, polyamide, polyethylene, polypropylene, and polyurethane, and materials derived from natural products such as cotton, silk thread, and spider silk.

The gradually increasing portion gradually increases in thickness in the length direction from one end side to the other end side. The minimum thickness and maximum thickness of the gradually increasing portion can be determined in consideration of the size of the outer diameter of the tubular organ to be wound, the number of windings, and the like. The minimum thickness is preferably 40 μm or less from the viewpoint of more effectively preventing leakage of contents. From the viewpoint of operability, etc., the minimum thickness is preferably 3 μm or more. Moreover, the maximum thickness is preferably 150 μm or less from the viewpoints of adhesiveness between nonwoven fabrics when wound, operability, permeability of body fluids such as blood, and the like. In order to form a tapered structure, the maximum thickness may be greater than the minimum thickness, preferably 50 μm or more. The thickness at the desired position of the gradually increasing portion can be obtained by measuring the thickness at the desired position, for example, by the method described in the Examples section. Moreover, it can be confirmed that the gradual increase is performed at the gradual increase portion based on the measurement result. In this method, the length direction of the nonwoven fabric is equally divided into a plurality of sections, the thickness at the center position is measured to be the representative thickness of the section, and the gradually increasing portion is specified by this representative thickness. . The size (length) of one section in the longitudinal direction is not particularly limited, and can be determined according to the total length of the nonwoven fabric. For example, the length of one section is 8 to 25% of the total length of the nonwoven fabric. is preferred.

The length of the gradually increasing portion can be determined by considering the size of the outer diameter of the tubular organ and the number of turns. For example, the lumen of the tubular organ can be 1.5 to 10 times the length of the empty circumference. When the tubular organ is an artery, for example, 3 to 8 times, when the tubular organ is a vein, for example, 1.5 to 10 times, and when the ureter is, for example, 2.5 to It can be 5 times.

From the viewpoint of dense and uniform winding operation, etc., the weight of the gradually increasing portion, that is, the surface density, is 20 g/m ² or less for the portion from the end of the minimum thickness to 28 to 35% of the length. is preferred. The lower limit of the basis weight of the same part can be, for example, 1 g/m ² or more. Further, from the viewpoint of dense and uniform winding operation, etc., it is preferable that the fabric weight of the portion of 8 to 13% of the length from the end of the maximum thickness is 50 g/m ² or less. The lower limit of the basis weight of the same portion can be, for example, 10 g/m ² or more. The basis weight of the gradually increasing portion can be obtained by measuring, for example, by the method described in the Examples section. In the case of this method, as in the case of thickness measurement, the basis weight of a predetermined section is taken as the representative basis weight of a predetermined position in the length direction. Also, in this case, the end of the minimum thickness is the end opposite to the thick side in the length direction of the section with the minimum thickness, and the end of the maximum thickness is the maximum thickness. The end of the section opposite the thin side in the longitudinal direction.

The fiber diameter of the fibers that make up the nonwoven fabric preferably has a median value of 32 μm or less from the viewpoints of more effectively preventing leakage of contents and promoting the process of repairing and healing damaged areas. In addition, from the viewpoint of more effective permeation of body fluids such as blood, the thickness is preferably 0.6 μm or more. For example, when the nonwoven fabric is obtained by a manufacturing method that provides a generally uniform fiber diameter, the fiber diameter can be measured by the method described in the Examples section below, and the median value can be obtained. When the fiber diameter differs depending on the part of the nonwoven fabric, for example, the fiber diameter can be measured for each part in the same manner as in the case where the fiber diameter is generally uniform, and the median value can be obtained. Here, the median is synonymous with the statistical median.

The nonwoven fabric may have any structure as long as it has the gradually increasing portion described above. Therefore, for example, a part that gradually decreases in the length direction from the end where the thickness of the gradually increasing part is the maximum, or a part that repeats increase and decrease may be continuously provided, but the medical tape is tightly wound and the nonwoven fabrics are tightly attached to each other. From the standpoint of facilitating the expansion, it is preferable that the end where the thickness of the gradually increasing portion is the smallest is not connected to the gradually increasing portion in the length direction. The shape of the nonwoven fabric is not particularly limited, and examples thereof include rectangles, parallelograms, trapezoids, rhombuses, ovals, and the like. Further, as described above, the angle formed by the virtual straight line in the direction of the same thickness and the virtual straight line in the length direction may be a right angle or an acute angle. In addition, a member having a protrusion that can be physically engaged with the wound nonwoven fabric may be provided in a portion extending from the end of the gradually increasing portion of the nonwoven fabric on the side where the thickness in the length direction is greatest. .

The nonwoven fabric is configured so that body fluids containing tissue cells of the tubular organ can permeate the nonwoven fabric in a state in which the nonwoven fabrics are wrapped around the outer periphery of the tubular organ. With this configuration, when the medical tape is wrapped around the tubular organ, body fluid permeates the nonwoven fabric, increasing the frictional force between the nonwoven fabrics and increasing the diameter of the tubular organ. A resistance to shear stress is obtained. Also, the repair and healing process of the injured site is promoted. Factors that impart such a configuration include the thickness of the nonwoven fabric, basis weight, fiber diameter, fiber material, and the like. Desired permeability can be adjusted by adjusting these in a composite manner. is 30-400 μm, the repair and healing process of the injured site can be promoted more effectively. In addition, as described in the section of Examples, the method for measuring the inter-fiber spacing is changed according to the manufacturing method of the nonwoven fabric. For example, in the case of the melt blow method and the electrospinning method (generally, when the through holes are not clearly formed by the fibers), and in the case of the needle punch method in which a plurality of knitted fabrics are stacked and entangled (generally, the through holes are formed by the fibers). If it is clearly formed), a different measurement method is adopted.

The nonwoven fabric described above can be manufactured using a conventionally known method. Examples thereof include melt blowing, electrospinning, and needle punching. (a) In the melt blowing method, for example, a desired gradual increase portion is obtained by changing the discharge amount of synthetic resin using a general device or adjusting the arrangement of the nozzle holes of a general device. It is possible to obtain a nonwoven fabric having (b) In the electrospinning method, for example, a synthetic resin liquid is spun linearly in an electric field, and the target is shifted left and right when laminating it on the target, thereby obtaining a nonwoven fabric having a desired gradually increasing portion. be able to. Alternatively, the above-described interfiber spacing can be adjusted by forming a nonwoven fabric using water-soluble spacers and then washing the nonwoven fabric with water to remove the spacers. (c) In the needle punch method, for example, when a plurality of knitted fabrics are superimposed and then entangled to form a nonwoven fabric, the method of superimposing the fabrics is adjusted to obtain a nonwoven fabric having a desired gradually increasing portion. be able to. Among these methods, the melt blowing method is preferable because it is easy to obtain the desired nonwoven fabric. That is, a meltblown nonwoven fabric is preferred.

In the medical tape described above, the nonwoven fabric can be permeated by body fluid containing tissue cells of the tubular organ in a state of being wrapped around the tubular organ. However, from the viewpoint of obtaining a better adhesion effect, when the nonwoven fabric is wound, a fixing agent other than the patient's own blood may be applied to the nonwoven fabric. Examples of such an adhesive include fibrin glue, alginic acid, or a mixture of pharmacologically acceptable alginic acid, monovalent cation salts and polyvalent cations (the product after mixing is also referred to as crosslinked alginic acid). , silicone adhesives, anaerobic adhesives, cyanoacrylate adhesives, photocurable adhesives, and the like. Examples of the monovalent cation in the pharmacologically acceptable monovalent cation salt of alginic acid include sodium ion, potassium ion, ammonium ion and the like. Examples of multivalent cations include inorganic multivalent ions such as calcium ions, magnesium ions and iron ions, and multivalent cations such as organic multivalent ions such as polylysine. The polyvalent cation may be in the form of various salts containing such polyvalent cations. Examples of such salts include calcium gluconate, calcium chloride, calcium carbonate, magnesium chloride, ferrous citrate and the like. The fixing agent may be applied to the whole or part of the surface of the nonwoven fabric immediately before winding, may be applied while winding, or may be applied after winding. In this manner, the medical tape and adhesive described above can be combined and used as a treatment kit for treatment of various tubular organs.

The medical tape described above, or a therapeutic kit that combines this with an adhesive, can be used to treat various tubular organs. It is suitable for preventing leakage of urine that can be wrapped around the body, prevention of bile leakage from the biliary tract, prevention of air leakage from the respiratory tract, restoration of reproductive organ walls, prevention of leakage of cerebrospinal fluid from the nervous system, and the like.

Hereinafter, embodiments of the present invention will be described in further detail based on examples.

(Example 1)
<Preparation of nonwoven fabric>
Block copolymer of lactic acid and ε-caprolactam (hereinafter referred to as “LA-CL”) (manufactured by BMG Co., Ltd., content of structural units derived from lactic acid: 73 to 77 mol%, derived from ε-caprolactone Constituent unit content: 23 to 27 mol%, intrinsic viscosity: 1.2 to 1.8 dL/g (Polarimetry Chloroform, 25°C, concentration = 0.1 g/dL), melting range: 104 to 114°C (DSC measurement , 10 ° C./Min)), and by a melt blowing method using a general device in which the arrangement of nozzle holes is adjusted, the fiber diameter is generally uniform throughout the nonwoven fabric, and the thickness is from one end to the other end. A non-woven fabric (meltblown non-woven fabric) was produced with a tapering portion. The obtained nonwoven fabric was cut into a rectangle with a width of 10 mm and a length of 100 mm. . The nonwoven fabric 1 has substantially the same thickness in the direction orthogonal to the length direction.

<Measurement of thickness>
About the obtained nonwoven fabric 1, the thickness of the predetermined position of a length direction was measured and calculated as follows.
Measurement sites were determined at intervals of 10 mm starting from a position 5 mm from the end of the thin side toward the thick side, and the thickness at each site was measured. When measuring, the thickness of the five nonwoven fabrics was measured three times with a dial-type precision thickness measuring instrument (manufactured by Ozaki Seisakusho, G-7C), and the thickness of the five nonwoven fabrics was measured three times. Arithmetic mean value of the thickness of 5 non-woven fabrics. In addition, 1 set of 5 nonwoven fabrics is prepared separately, and the thickness is measured as described above. Calculated. Table 1 shows the results.

<Measurement of basis weight (surface density)>
Regarding the obtained nonwoven fabric 1, the basis weight (area density) at a predetermined position in the length direction was measured and calculated as follows.
In the same way as in the case of measuring the thickness, start from a position 5 mm from the end of the thin side, determine the center position of the measurement site at intervals of 10 mm toward the thick side, cut at the midpoint between adjacent center positions, Ten cut pieces (size: 10 mm×10 mm) with a width of 10 mm in the vertical direction were produced. A set of 10 cut pieces having the same central position was prepared in the same manner. At the time of weighing, the weight of this set of 10 pieces was put together and weighed with a micro balance (PRACTUM124-1S, manufactured by Sartorisu Lab Instruments GmbH & Co. KG). For one set of 10 sheets to be measured at once, 5 sets are prepared separately and weighed as described above, and the arithmetic average of the weighed values of the 5 sets is divided by 10 to obtain the weight of one Calculated. Table 1 shows the results. From the results in Table 1, the gradually increasing portion of nonwoven fabric 1 is regarded as the portion up to 90 mm from the end of the thin side. Then, for example, the basis weight of the portion from the minimum thickness end to 33% (=10 × 3/90 × 100) is 14.4 g / m ² , and the maximum thickness end is 11% (= 10/90×100) with a weight of 31 g/m ² (ie the weight of the cut piece with the center position at a distance of 85 mm from the edge of the thin side).

<Measurement of median fiber diameter>
The measurement method was according to Horii's method (Horii T., The effects of fiber diameter and spacing-size of an artificial scaffold on the in vivo cellular response and tissue remodeling, ACS Applied Bio Materials 2021, in press). First, as a preliminary scanning electron microscope (scanning electron microscope) inspection, cut the nonwoven fabric 1 with a sharp cutter, wrap it around a stainless steel hexagonal jig and pull it to open the inside of the stump of the nonwoven fabric 1 and fix it, The fibers inside the nonwoven fabric near the stump were imaged with a scanning electron microscope. From this image, it was confirmed that all the fibers inside the nonwoven fabric were almost circular, and that there were no beaded, club-shaped, or branched fibers. It was found that the shape of the Therefore, fibers with a figure-8 cross-sectional shape or a difference of 1.2 times or more between the maximum and minimum cross-sectional diameters are considered unsuitable for fiber diameter measurement, and will not be used for the next fiber diameter measurement. (selection criteria). Next, the fiber diameter was measured. That is, after freezing and hardening the nonwoven fabric 1 with liquid nitrogen, the freeze-hardened nonwoven fabric 1 was broken by hitting with a small hammer. Next, the cut surface of the nonwoven fabric 1 was photographed with a scanning electron microscope (manufactured by Hitachi, Ltd., product name: S-570). At this time, images were taken at one or more locations in which there were cross-sections that were measurable at least as many times as will be described later in one field of view. From the imaging of one field of view obtained, 50 fiber cross sections were randomly selected from among the fiber cross sections exposed on the cut surface based on the above-described selection criteria based on the preliminary scanning electron microscope inspection. Using distance measurement software (developer: Wayne Rasband (NIH), product name: ImageJ), the sum of the longest diameter and the shortest diameter of the selected fiber cross section was obtained, and the value obtained by dividing this by 2 was taken as the fiber diameter. The median value (which is synonymous with the median value in statistics) of the 50 fiber diameters thus measured was determined. When two or more fields of view are used, the median value is determined for each, and the median value is taken as the median value of the fiber diameters at positions in the longitudinal direction of the photographed cross section. The above measurements are taken at three cut surfaces within 15 mm from both ends and the center in the length direction of the nonwoven fabric. median value. As a result, the median fiber diameter of nonwoven fabric 1 was 15 μm.

<Measurement of fiber spacing>
<<Measurement method a>>
The measurement method was according to Horii's method (Horii T., The effects of fiber diameter and spacing-size of an artificial scaffold on the in vivo cellular response and tissue remodeling, ACS Applied Bio Materials 2021, in press). That is, after freezing and hardening the nonwoven fabric 1 with liquid nitrogen, the freeze-hardened nonwoven fabric 1 was broken by hitting with a small hammer. Next, a cross section of the nonwoven fabric 1 was photographed with a scanning electron microscope (manufactured by Hitachi, Ltd., product name: S-570). Based on the obtained images, one fiber was selected at random from among the fiber cross sections exposed on the cut surface, and a concentric circle was drawn with the center of the selected fiber cross section as the center. The radius of the concentric circle was gradually increased and other fiber stumps falling within this concentric circle were marked. Select 30 fiber stumps marked with this mark in order of distance from the center of the concentric circle, and select the center of the fiber stump selected using distance measurement software (developer Wayne Rasband (NIH), product name ImageJ). The distance between each fiber stump marked with , that is, the distance between the center of the selected fiber stump and the other 30 fiber stumps was measured, and this was measured as the fiber spacing. The median value (synonymous with the median value in statistics) of the 30 measured fiber spacings was determined. Similarly, three locations are randomly selected for the cut surface of one nonwoven fabric 1, and the median values of the three fields of view are obtained. interval. The above measurement of the interfiber spacing is measured at three cut surfaces within 15 mm from both ends and the center in the length direction of the nonwoven fabric, and the median value of the obtained median values is It was taken as the median value of the fiber diameter. As a result, the nonwoven fabric 1 had a fiber spacing of 54 μm.

(Example 2)
Polyglycolic acid (hereinafter referred to as “PGA”) (BMG Co., Ltd., Biodegmar (registered trademark) PGA, average molecular weight 350,000, melting point: 225 to 232 ° C.) was used instead of LA-CL. In the same manner as in Example 1, a nonwoven fabric 2 whose thickness gradually increases from one end to the other end was produced. Further, in the same manner as in Example 1, the thickness in the length direction and basis weight of the nonwoven fabric 2 were measured and calculated. Table 2 shows the results. From the thickness measurement results in Table 2, the entire nonwoven fabric 2 is the gradually increasing portion.

<Measurement of fiber diameter>
The fiber diameter was measured in the same manner as in Example 1, and the median value was obtained. As a result, the median fiber diameter was 4.2 μm.

<Measurement of fiber spacing>
Measurement was performed in the same manner as in Example 1 to determine the inter-fiber spacing. As a result, the fiber spacing was 32 μm.

(Comparative example 1)
Using LA-CA, a nonwoven fabric 1A having a uniform thickness was produced by a melt-blowing method. The thickness was set to be approximately the same as the thickness (15 μm) and basis weight (0.30 mg/cm ² ) of the section containing the thinnest portion of the nonwoven fabric 1 obtained in Example 1. About the obtained nonwoven fabric 1A, the thickness and weight per unit area were measured and calculated in the same manner as in Example 1 at positions where the distance from one end in the length direction was 95 mm and 5 mm. In addition, the median value of the fiber diameter and the fiber spacing were obtained in the same manner as in Example 1. Table 3 shows the results.

(Comparative example 2)
Using LA-CA, a nonwoven fabric 1B having a uniform thickness was produced by a meltblowing method. The thickness of the nonwoven fabric 1 obtained in Example 1 was adjusted to have an intermediate thickness and basis weight. About the obtained nonwoven fabric 1B, the thickness and weight per unit area were measured and calculated in the same manner as in Example 1 at positions where the distance from one end in the length direction was 95 mm and 5 mm. In addition, the median value of the fiber diameter and the fiber spacing were obtained in the same manner as in Example 1. Table 3 shows the results.

(Comparative Example 3)
Using LA-CA, a nonwoven fabric 1C having a uniform thickness was produced by a melt-blowing method. The thickness was set to the same thickness and basis weight as the thickness and basis weight of the section containing the thickest portion of the nonwoven fabric 1 obtained in Example 1. About the obtained nonwoven fabric 1C, the thickness and weight per unit area were measured and calculated in the same manner as in Example 1 at positions where the distance from one end in the length direction was 95 mm and 5 mm. In addition, the median value of the fiber diameter and the fiber spacing were obtained in the same manner as in Example 1. Table 3 shows the results.

(Comparative Example 4)
Using a 15% by weight resin solution obtained by dissolving LA-CA in 1,3-dioxolane, a nonwoven fabric 1D having a uniform thickness was produced by an electrospinning method. The thickness was set to be even smaller than the thickness (15 μm) and basis weight (0.30 mg/cm ² ) of the section containing the thinnest portion of the nonwoven fabric 1 obtained in Example 1. About the obtained nonwoven fabric 1D, the thickness and weight per unit area were measured and calculated in the same manner as in Example 1 at positions where the distance from one end in the length direction was 95 mm and 5 mm. In addition, the median value of the fiber diameter and the fiber spacing were obtained in the same manner as in Example 1. Table 3 shows the results.

(Comparative Example 5)
Using PGA, a nonwoven fabric 2A having a uniform thickness was produced by a meltblowing method. The thickness was set to be approximately the same as the thickness (40 μm) and basis weight (0.50 mg/cm ² ) of the section containing the thinnest portion of the nonwoven fabric 2 obtained in Example 2. About the obtained nonwoven fabric 2A, the thickness and weight per unit area were measured and calculated in the same manner as in Example 1 at positions where the distance from one end in the length direction was 95 mm and 5 mm. In addition, the median value of the fiber diameter and the fiber spacing were obtained in the same manner as in Example 1. Table 3 shows the results.

(Comparative Example 6)
Using a commercially available non-woven fabric (Gunze Co., Ltd., Neovel Nano (registered trademark) D5, material: PGA fiber, manufacturing method: meltblown method, thickness: uniform), it is cut to a width of 10 mm and a length of 100 mm. A nonwoven fabric 2C having a uniform thickness in the direction was produced. Regarding the nonwoven fabric 2C, the thickness and weight per unit area were measured and calculated in the same manner as in Example 1 at positions at distances of 95 mm and 5 mm from one end in the length direction. In addition, the median value of the fiber diameter and the fiber spacing were obtained in the same manner as in Example 1. Table 3 shows the results.

(Comparative Example 7)
Commercially available nonwoven fabric (Gunze Co., Ltd., Neoveil (registered trademark) sheet 015G, material: PGA fiber, manufacturing method: 10 to 12 monofilaments with an average fiber diameter of 16 μm are bundled, and a plurality of multifilament knitted fabrics are piled up and needle punched. (thickness: uniform) was cut into a width of 10 mm and a length of 100 mm to produce a nonwoven fabric 2B having a uniform thickness in the longitudinal direction. Regarding the nonwoven fabric 2B, the thickness and weight per unit area of the nonwoven fabric 2B were measured and calculated in the same manner as in Example 1 at positions where the distance from one end in the length direction was 95 mm and 5 mm. Also, the median value of the fiber diameter was obtained in the same manner as in Example 1. The fiber spacing was obtained as follows. Table 3 shows the results.

<Measurement of fiber spacing>
<<Measurement method b>>
The surface of the nonwoven fabric is photographed with a stereoscopic microscope (manufactured by Carl Zeiss, product name: Stemi 2000-C, light source: KL1500 LCD, magnification of 10 times or less, light source irradiation from both the front and back sides), and the obtained images are computer images. Based on the image captured by the system (Carl Zeiss, AxioVision), distance measurement software (developer: Wayne Rasband (NIH), product name: ImageJ, capable of measuring up to 0.01 μm) is used to measure the fiber spacing. asked for Calculation of the interfiber spacing is performed by randomly selecting 30 holes formed by one loop formed by the filament yarn in the knitted fabric. The pore diameter was obtained by dividing the sum of the longest diagonal line of the shape or polygon and the longest pore transverse line perpendicular to it divided by two. The median value (synonymous with the median value in statistics) of the 30 values obtained as the diameter was taken as the fiber spacing.

(Comparative Example 8)
Using a 15% by weight resin solution obtained by dissolving PGA (the same as in Example 2) in 1,3-dioxolane, a nonwoven fabric 2D having a uniform thickness was produced by an electrospinning method. The thickness was set to be even smaller than the thickness (40 μm) and basis weight (0.50 mg/cm ² ) of the section containing the thinnest portion of the nonwoven fabric 2 obtained in Example 2. About the obtained nonwoven fabric 2D, the thickness and weight per unit area were measured and calculated in the same manner as in Example 1 at positions where the distance from one end in the length direction was 95 mm and 5 mm. In addition, the median value of the fiber diameter and the fiber spacing were obtained in the same manner as in Example 1. Table 3 shows the results.

(Evaluation 1)
The nonwoven fabrics of Examples 1 and 2 and Comparative Examples 1 to 8 were used as medical tapes (also hemostatic tapes; the same applies hereinafter in Evaluation 1), and hemostasis and promotion of repair of damaged blood vessels in experimental animals were evaluated. . The experimental method and results are as follows.

<Experimental method>
Beagle dogs weighing around 12 kg were used as experimental animals. In this experiment, assuming use during cardiovascular surgery where hemostasis is difficult, an experiment was conducted by creating a blood anticoagulant state with heparin. Under general anesthesia, the dog's abdominal aorta, carotid artery, and common iliac artery were exposed. A blood vessel forceps was used to interrupt the blood flow of the artery, and the arterial wall was crossed radially through the wall to half its diameter to create an arterial wall injury site (see FIG. 1(a)). The stumps of the crossed arterial wall were placed between the crossed arterial wall stumps in order to prevent spontaneous tearing between the intimal and medial layers due to the load of arterial pressure when blood flow resumed. One stitch was made at each of three locations on both sides, and a total of three stitches were loosely sutured with 6-0 vascular suture (see FIG. 1(b)).

At this time, the nonwoven fabrics used as medical tapes were 10 mm wide and 60 mm long for the common carotid artery, 10 mm wide and 80 mm long for the common iliac artery, and 10 mm wide and 80 mm long for the common iliac artery. The aorta was 10 mm wide and 100 mm long. Of these, when creating a 10 mm wide and 60 mm long one for the common carotid artery and a 10 mm wide and 80 mm long one for the common iliac artery, in this embodiment, the thicker side is excised and discarded. A portion of the nonwoven fabric with a length of 60 mm or 80 mm including the thin side of the remaining thickness was used as a medical tape with a length of 60 mm for the common carotid artery or a medical tape with a length of 80 mm for the common iliac artery. . In the comparative example, since there is no difference in the thickness of the nonwoven fabric in the longitudinal direction, a portion of 20 mm or 40 mm in length at one end was excised and discarded, and the remaining portion of 60 mm or 80 mm in length was used for the common carotid artery. It was used as a 60 mm long medical tape or an 80 mm long medical tape for the common iliac artery.

Each medical tape was wrapped around the entire circumference of the artery around the damaged site of the arterial wall that had been damaged across the arterial wall as described above, so that the nonwoven fabrics overlapped with each other to stop bleeding. In the example, there is a gradual increase in thickness, so that the winding is performed from the thinnest end first (i.e., as the innermost layer in the winding), and then the nonwoven is wrapped over this. The medical tape was wrapped in layers so that the thickest end was wrapped last (ie, the outermost layer). At the time of this winding, the medical tape was wound while lightly pulling the medical tape, taking care that the first artery wall and the nonwoven fabrics constituting the medical tape to be wound were in close contact with each other without slack. In the comparative example, since the thickness of the nonwoven fabric was uniform, it did not matter which end was wound first, but the medical tape was wound in the same manner as in the example.

A time limit was set for the wrapping so that it could be wrapped completely within 3 minutes each time. The reason is that the operability of the tape is also evaluated. Regarding the operability, each operator individually, for each medical tape of each example and comparative example (i) medical tape that is considered to have good overall operability in practical use The operator was asked to write a comment (within 100 characters) about the evaluation of medical tapes that were considered to have problems in operability with an "x" mark, and (ii) the feeling of use in operation felt by the operator.

After the wrapping is completed, autologous blood, alginic acid and calcium ions, or fibrin glue is sufficiently permeated into the nonwoven fabric of the medical tape as a fixing agent, and left to stand for 5 minutes (see FIG. 1(c)). , then the vascular forceps were removed. For 7 minutes after removal of the vascular forceps, the presence or absence of bleeding from the damaged site of each arterial wall was observed. Complete hemostasis was defined as complete hemostasis and no bleeding from the damaged site wrapped with medical tape. It was determined (see FIG. 1(d)). If even a slight sign of bleeding was observed during these 7 minutes, it was determined as bleeding.

The surgical technique, including hemostasis, was performed independently by two surgeons in exactly the same manner. The homonymous artery hemostasis experiment was performed once per animal. A single surgeon used one type of medical tape to stop bleeding at a total of 6 sites: 2 abdominal aortas, 2 common iliac arteries, and 2 common carotid arteries. 12 hemostasis operations were performed by two surgeons.

<Experimental results>
<<Short-term hemostatic effect>>
(1) Example 1 and Comparative Examples 1-4
In the hemostasis operation of the medical tapes composed of the nonwoven fabrics of Example 1 and Comparative Examples 1 to 4, the wrapping of the medical tapes around blood vessels was completed within 3 minutes. Complete hemostasis was achieved in all 12 hemostasis operations when the medical tape composed of 1 nonwoven fabric 1 was used. On the other hand, when the medical tapes of nonwoven fabrics 1A to 1D of Comparative Examples 1 to 4 were used, there were cases where complete hemostasis could not be achieved. With regard to operability, both of the two surgeons evaluated the operability of Example 1 as good (○), but all of Comparative Examples 1 to 4 had better operability than those of the Examples. It was evaluated as being inferior and having issues. Moreover, the content of the task was almost the same between the two surgeons.

(2) Example 2 and Comparative Examples 5-8
Even in the hemostasis operation of the medical tape composed of the nonwoven fabrics of Example 2 and Comparative Examples 5 to 8, the wrapping of the medical tape around the blood vessel was completed within 3 minutes. 2, complete hemostasis was achieved in all 12 hemostasis operations. On the other hand, when the medical tapes of nonwoven fabrics 2A to 2D of Comparative Examples 5 to 8 were used, there were cases where complete hemostasis could not be achieved. With regard to operability, both of the two surgeons rated the operability of Example 2 as good (○), but all of Comparative Examples 5 to 8 had better operability than those of the Examples. It was evaluated as being inferior and having issues. Moreover, the content of the task was almost the same between the two surgeons.

<< long-term repair promotion effect >>
After an observation period of 2 months, 4 months or 6 months, the experimental animals subjected to hemostasis as described above were euthanized and dissected. Healing status was assessed pathologically below. After that, they were fixed in formalin and prepared as hematoxylin-eosin (HE)-stained histological specimens with a thickness of 4 μm according to the usual method, and the healing state was evaluated under an optical microscope.

All experimental animals that underwent hemostasis operations using the medical tapes of Examples 1 and 2 as described above survived well during the observation period described above. Then, as described above, after the lapse of the observation period from the hemostatic operation, the state of restoration of all the arterial walls subjected to the hemostatic operation was pathologically examined. Among the results of experimental animals using the medical tapes of Examples 1 and 2, the results of the common carotid artery and common iliac artery are shown in FIG. FIG. 2(a) is a stereomicroscopic image of the common carotid artery extracted from the experimental animal including the injured site wrapped with the medical tape of Example 1, and FIG. Fig. 2(c) is a stereomicroscopic image of the iliac artery, Fig. 2(c) is an optical microscopic image of a cross section of the HE-stained histological specimen of the excised common carotid artery shown in Fig. 2(a). FIG. 2(d) is a light microscope image of a cross-section of the HE stained histological specimen of the common iliac artery shown in FIG. 2(b). Similar images were obtained when other arteries and the medical tape of Example 2 were used.

As shown in Fig. 2, etc., no findings indicating rebleeding occurred at all sites. In addition, complete healing was achieved through a smooth healing process in the state of repair of the arterial wall. Pathological findings such as aneurysm formation, cicatricial arterial stenosis, cicatricial arterial occlusion, thrombotic arterial stenosis, thrombotic arterial occlusion, dissecting changes, and infectious changes in the arterial wall, which are findings indicating abnormal progress in I didn't approve.

In the experimental animals using the medical tapes of Comparative Examples 1-8, several died due to bleeding from the abdominal aorta within four months. Examination was carried out in the same manner as in Examples 1 and 2, and it was found that, macroscopically or histopathologically, aneurysm formation or There was evidence of hematoma formation or hematoma scar healing indicative of bleeding.

From the above results, the medical tapes of Examples 1 and 2 are not only capable of complete hemostasis with early hemostatic effect, but also help regenerate and repair excellent vascular wall in repairing long-term vascular injury sites. It was thought that the effect could be expected.

(Evaluation 2)
Each of the nonwoven fabrics of Example 1 and Comparative Examples 1 to 3 was used as a medical tape (also a ureter tape; the same applies hereinafter in Evaluation 2) to prevent urine leakage and repair ureters that underwent repair and reconstruction surgery in experimental animals. evaluated for facilitation. The experimental method and results are as follows.

<Experimental method>
Beagle dogs weighing around 12 kg were used as experimental animals. This experiment was carried out assuming the use at the time of surgery in which the ureter is partially cut and the ureter of the cut part stump is anastomosed end-to-end for repair and reconstruction. The dog's ureter was exposed under general anesthesia. A canine experimental ureteral catheter (manufactured by Create Medic Co., Ltd., small diameter Foley catheter for animals 4.5 French size) was retrogradely advanced from the bladder to the renal pelvis and placed there. The ureter was then cut centrally and excised over a 2 cm length. The kidney-side and bladder-side ureteral stumps remaining after this ureterectomy were anastomosed to the ends by the following operation. That is, both stumps of the ureter were brought together while the catheter was passed through, and both stumps were ligated loosely with a full-thickness single nodule using a 7-0 vascular suture. Single knot suture ligations were made at even intervals and were kept to 3 stitches. In this state, the tip of the catheter in the ureter was moved to 10 mm from the ureteral anastomosis on the kidney side. Next, a syringe containing colored saline and a water pressure gauge were connected in parallel to the bladder-side tube port of the catheter. It was confirmed that the colored saline smoothly leaked into the abdominal cavity from the sutured portion of the ureteral anastomosis.

A nonwoven fabric with a width of 10 mm and a length of 60 mm was used as a medical tape. In the production thereof, in Example 1, 40 mm from the end of the thin side was cut and discarded, and the remaining 60 mm long portion of the nonwoven fabric including the thick side was used as a medical tape. In the comparative example, since there was no difference in thickness in the longitudinal direction of the nonwoven fabric, a 40 mm long portion was cut off from one end and discarded, and the remaining 60 mm long portion was used as a medical tape.

Each medical tape composed of the nonwoven fabric described above was tightly wrapped around the ureteral anastomosis of each experimental animal within 3 minutes from the thin end to the end of the winding. 1 ml of a 20 mg/ml sodium alginate aqueous solution (manufactured by Fuji Kagaku Kogyo Co., Ltd., Snow Algin SSL) and a 10% calcium gluconate aqueous solution were sprayed on top of this state in two batches, and then on the nonwoven fabric. It was allowed to stand for 5 minutes for sufficient permeation (see Figure 3). Thereafter, while pressurizing the syringe connected to the bladder side of the catheter, the colored saline solution was gradually injected into the catheter, and whether or not the colored saline solution leaked from the anastomosis was visually observed. Judgment was made when the alginic acid around the anastomotic site turned blue, even if only _{a little} , as the colored saline solution. was set as a pass (complete leakage prevention). In addition, the operability was determined by (i) and (ii) in the same manner as in Evaluation 1. Table 6 shows the results.

A series of surgical techniques for repairing and reconstructing the ureter were performed by two surgeons independently.

<Experimental results>
<<Short-term urinary leakage prevention effect>>
In the operation of winding the medical tapes composed of the nonwoven fabrics of Example 1 and Comparative Examples 1 to 4, the winding of the medical tapes around blood vessels was completed within 3 minutes. When the medical tape composed of 1 nonwoven fabric 1 was used, complete urine leakage prevention was achieved in all 6 winding operations. On the other hand, when the medical tapes composed of the nonwoven fabrics 1A to 1D of Comparative Examples 1 to 4 were used, none of them could completely prevent urine leakage in some cases. With regard to operability, both of the two surgeons evaluated the operability of Example 1 as good (○), but the operability of Comparative Examples 1 to 4 was inferior to that of Examples. Evaluated as having issues. Moreover, the content of the task was almost the same between the two surgeons.

<< long-term repair promotion effect >>
Each experimental animal that underwent a series of ureter repair and reconstruction operations as described above was euthanized after an observation period of 3 months. Healing status was assessed pathologically. After that, they were fixed in formalin and prepared as hematoxylin-eosin (HE)-stained histological specimens with a thickness of 4 μm according to the usual method, and the healing state was evaluated under an optical microscope.

The experimental animals that underwent surgical procedures as described above using the medical tape of Example 1 survived well during the observation period. Then, the state of restoration of the ureteral wall of the ureter at the anastomotic site excised as described above was pathologically examined. The results of experimental animals using the medical tape of Example 1 are shown in FIGS. FIG. 4 is a macroscopic photograph of a specimen such as a ureter including an excised anastomosis. The portion indicated by the arrow is the ureteral anastomosis. As shown in FIG. 4, the ureter was smooth as a whole, and the ureter including the anastomosis was in a healthy state. FIG. 5 is a light microscope image of a cross-section of an HE-stained histological specimen of the anastomosis indicated by the arrow in FIG. As shown in FIG. 5, it can be seen that no space due to leakage of urine is observed between the ureter (symbol A) and its surrounding loose connective tissue (symbol B). A small amount of nonwoven fabric remains in the surrounding tissue, indicated by the dotted line, indicating good healing of the anastomosis.

　Figures 6 and 7 show the results of experimental animals that underwent surgical procedures as described above using the medical tape of Comparative Example 3. Of the experimental animals using the medical tapes of Comparative Examples 1 to 3, 10 animals for which complete leakage prevention could not be achieved were excluded from the experimental subjects from the viewpoint of animal welfare. The remaining 8 individuals that were completely prevented from leaking were observed in March in the same manner as in Examples, and survived well during the observation period. FIG. 6 is a macroscopic photograph of a specimen such as a ureter including an anastomosis excised after three months of observation. The portion indicated by the arrow is the ureteral anastomosis. As shown in FIG. 6, the ureter is edematous as a whole, suggesting the continuation of chronic inflammation throughout the ureter. FIG. 7 shows a light microscope image of a cross-section of an HE-stained histological specimen of the anastomosis indicated by the arrow in FIG. As shown in FIG. 7, between the ureter (symbol A) and the surrounding loose connective tissue (symbol B), a large space (symbol C) formed by leakage of urine is recognized. In addition, a large amount of non-woven fabric remains in the surrounding tissue, as indicated by the dotted line, indicating that the anastomosis is not well healed.

As described above, when the medical tape of Example 1 was used, no findings indicating ureteral stenosis or urine leakage were observed, and the ureteral epithelium was continuously regenerated smoothly. Turns out I was going through a healing process. On the other hand, for example, in the case of the medical tape of Comparative Example 3, at the time of surgery, urine leakage occurred even in individuals who were considered to have completely prevented urine leakage at the time of surgery, and the anastomosis was not complete. . Therefore, the medical tape of Example 1 not only enables complete prevention of urinary leakage due to its early urinary leakage prevention effect, but also helps regenerate and repair the ureter wall excellently in long-term anastomosis repair. It was thought that the effect could be expected.

A Ureter B Loose connective tissue around the ureter C Space formed by urinary leakage

Claims

It is composed of a nonwoven fabric having a gradually increasing portion whose thickness in the length direction gradually increases from one end to the other end. A medical tape, wherein the nonwoven fabric is permeable to body fluids containing tissue cells of the tubular organ in a relaxed state.
The medical tape according to claim 1, wherein the nonwoven fabric is composed of fibers made of a bioabsorbable material.
The medical tape according to claim 1 or 2, wherein the gradually increasing portion has a minimum thickness of 40 µm or less and a maximum thickness of 150 µm or less, which is larger than the minimum thickness.
For the total length of the increment,
The weight of the portion from the end of the minimum thickness to 28 to 35% of the length is 20 g / m 2 or less,
The basis weight of the part from the end of the maximum thickness to 8 to 13% of the length is 50 g / m 2 or less,
The medical tape according to any one of claims 1 to 3.
The medical tape according to any one of claims 1 to 4, wherein the median fiber diameter of the fibers constituting the nonwoven fabric is 32 μm or less.
The medical tape according to any one of claims 1 to 5, wherein the nonwoven fabric is a meltblown nonwoven fabric.
The medical tape according to any one of claims 1 to 6, which is for hemostasis and can be wrapped around the circumference of a blood vessel.
A treatment kit comprising a combination of the medical tape according to any one of claims 1 to 7 and an adhesive.