WO2023037861A1 - Recouvrement de vaisseau sanguin - Google Patents

Recouvrement de vaisseau sanguin Download PDF

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Publication number
WO2023037861A1
WO2023037861A1 PCT/JP2022/031606 JP2022031606W WO2023037861A1 WO 2023037861 A1 WO2023037861 A1 WO 2023037861A1 JP 2022031606 W JP2022031606 W JP 2022031606W WO 2023037861 A1 WO2023037861 A1 WO 2023037861A1
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Prior art keywords
cover
elastic index
vein
vascular
blood vessel
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PCT/JP2022/031606
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English (en)
Japanese (ja)
Inventor
明郎 萩原
Original Assignee
明郎 萩原
株式会社カネカ
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Application filed by 明郎 萩原, 株式会社カネカ filed Critical 明郎 萩原
Priority to JP2023546867A priority Critical patent/JPWO2023037861A1/ja
Publication of WO2023037861A1 publication Critical patent/WO2023037861A1/fr

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    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
    • A61F2/00—Filters implantable into blood vessels; Prostheses, i.e. artificial substitutes or replacements for parts of the body; Appliances for connecting them with the body; Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents
    • A61F2/02—Prostheses implantable into the body
    • A61F2/04—Hollow or tubular parts of organs, e.g. bladders, tracheae, bronchi or bile ducts
    • A61F2/06—Blood vessels
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M1/00—Suction or pumping devices for medical purposes; Devices for carrying-off, for treatment of, or for carrying-over, body-liquids; Drainage systems
    • A61M1/36—Other treatment of blood in a by-pass of the natural circulatory system, e.g. temperature adaptation, irradiation ; Extra-corporeal blood circuits

Definitions

  • the present invention relates to a vascular cover used for an anastomosis in which blood vessels are anastomosed together.
  • the present invention relates to a blood vessel cover that can be used by arranging it on the outer peripheral side of the.
  • Dialysis treatment is given regularly.
  • a special needle is inserted into a vein.
  • the artery is anastomosed to the vein because the normal venous blood flow is not sufficient for dialysis.
  • a blood vessel is called a shunt.
  • an incision is made in the skin of the arm to expose the artery and vein, a small incision is made in the artery, the vein is anastomosed, and part of the blood flow from the artery is diverted to the vein.
  • a shunt provided with an artificial blood vessel may be used.
  • this unusual blood flow state is within the range that the body can tolerate, appropriate remodeling due to elastic changes in the venous wall will occur as the body's defense and adaptive response, preventing stenosis and occlusion due to intimal thickening.
  • the shunt blood flow state can be self-adjusted to a state that does not burden the living body.
  • this unusual blood flow condition exceeds the local or systemic conditions of the shunt blood flow (diabetes, hypertension, arteriosclerosis, blood conditions, etc.), appropriate protective/adaptive responses It becomes a pathological biological reaction without causing a local systemic pathology.
  • Non-Patent Document 1 in order to suppress a rapid increase in blood flow immediately after surgery and in the initial stage, the vein wall is reinforced from the outside to prevent excessive blood pressure in the inner vein.
  • vascular banding is performed to prevent hyperextension and blood turbulence caused by this.
  • US Pat. No. 5,300,000 a woven net made by forming a knitted fabric that is seamless, tubular, substantially pileless, is a covering for reinforcing natural veins for use as surgical implants. is disclosed.
  • vascular banding as described above could not sufficiently prevent lesions such as intimal hyperplasia.
  • the reinforced vein wall is altered (arterialized) into an arterial wall-like structure only under certain conditions, but when blood flows from the reinforced site to the unreinforced vein, blood pressure and Since the pulsation is delivered downstream as it is without being buffered, the cause of intimal hyperplasia has not been fundamentally resolved.
  • blood pressure and pulsatility are gradually lowered from the anastomotic site downstream, and the most downstream side of the vein is remodeled to a state in which only low pressure is applied without pulsation, that is, a state of low-pressure buffered blood vessels. There is a need.
  • the present invention has been made in view of the above circumstances, and remodels the vein into a buffer system vessel that can deliver blood to the downstream vein while gradually reducing the blood pressure, pulse pressure, and blood flow rate of the blood flowing through the lumen.
  • An object of the present invention is to provide a vascular cover capable of preventing intimal hyperplasia.
  • a blood vessel cover according to an embodiment of the present invention which can solve the above problems, is as follows.
  • a tubular vascular cover arranged on the outer peripheral side of a vein that is anastomosed with an artery or an artificial blood vessel and continuous over the entire circumference, wherein the inner diameter of the vascular cover is natural over the entire axial direction of the vascular cover.
  • the value E 20 hereafter, 20%
  • the elastic index E20 is 1.3 N or less.
  • E 50 hereinafter referred to as 50% elastic index E 50
  • the value E 100 (hereinafter referred to as 100% elastic index E 100 ) when measured by the following measuring method satisfies the relationship of the following formula (1).
  • [Measuring method] The vascular cover is cut perpendicular to the axial direction along the tangent line in the circumferential direction of the vascular cover to prepare a cylindrical sample having an axial length of 5 mm and continuous over the entire circumference in the axial direction. A first pin and a second pin having a diameter d of 0.75 mm are inserted into the lumen of the tubular sample parallel to the axial direction of the tubular sample.
  • the first pin is fixed, the second pin is pulled radially outward of the cylindrical sample, and when the distance between the first pin and the second pin is L, ⁇ d+2L is 1.1.1 of the circumference of the cylindrical sample in its natural state.
  • the value obtained by this is defined as the 50% elastic index E50 , and the force F100 when ⁇ d+2L is 2.0 times the circumference of the cylindrical sample in its natural state is the strain [(2.0-1.0) /1.0] is taken as the 100% elastic index E100 .
  • the vascular cover having the above structure has a portion (A) with a 20% elastic index E20 of 1.3 N or less, it loosely covers the vein when placed on the outer peripheral side of the vein in the shunt-created portion.
  • the pulsatile blood flow with high arterial pressure that flows into the vein of the shunt is gradually buffered by the portion covered with the vascular cover, and finally transitions to the venous blood flow.
  • the vein at the shunt site can be remodeled so that In addition, the vein may gradually grow outward during the process of remodeling into a buffer system blood vessel.
  • the vascular cover of the present invention enables shunt construction that secures a sufficient blood flow while suppressing lesions such as intimal hyperplasia by remodeling veins into buffer-system vessels.
  • the 20% elastic index E20 , the 50% elastic index E50 , and the 100% elastic index E100 have a predetermined relationship in the portion (A).
  • the coating can be loose, and when the blood pressure applied to the blood vessels is high, the coating can be made relatively strong, thereby facilitating the remodeling of the veins into buffer system blood vessels.
  • the contact defect cover is the following [2] to [10].
  • vascular cover according to [1] or [2], wherein the length of the portion (A) in the axial direction is 50% or more of the outer diameter of the anastomosed artery or artificial blood vessel.
  • a portion of the vascular cover that has a 20% elastic index E20 of 1.3 N or less and satisfies a predetermined relationship among the 20% elastic index E20 , the 50% elastic index E50 , and the 100% elastic index E100 .
  • (A) has a predetermined length or longer, it becomes easier to remodel the vein covered with the vessel cover into a buffer system vessel and to secure the blood flow.
  • the vascular cover according to any one of [1] to [3], wherein the entire vascular cover is the portion (A).
  • the 20% elastic index E20 is set to 1.3 N or less throughout the axial direction of the vascular cover, and the 20% elastic index E20 , the 50 % elastic index E50, and the 100% elastic index E100 satisfy a predetermined relationship. Therefore, the vein can be loosely covered over the entire range of the vein covered by the vascular cover, and the vein can be covered loosely when the blood pressure applied to the vein is low and relatively strongly when the blood pressure is high.
  • the remodeling of the vein into a buffer system vessel becomes easier, and it becomes easier to maintain a wide lumen of the vein, which leads to the securing of blood flow.
  • the portion (A) are arranged in parts 1 and 2, and the 20% elastic index E1 20 , 50% elastic index E1 50 and 100% elastic index E1 100 of part (A) in part 1, and the part in part 2 20% elastic index E2 20 , 50% elastic index E2 50 and 100% elastic index E2 100 in (A) satisfy the relationship of the following formula (2):
  • the vascular cover when the first part of the vascular cover is arranged on the upstream side of the vein of the shunt-created part, the upstream side is covered relatively loosely, and when the downstream side of the vascular diameter grows, the vascular cover can be used. This allows a relatively strong covering and facilitates remodeling of the vein into a buffer system vessel.
  • vascular cover according to any one of [1] to [8], wherein the axial length of the vascular cover is 5 mm or more.
  • vascular cover has at least one of knitted fabric, woven fabric, and non-woven fabric as a component constituting a part or a component constituting the whole. Vessel cover as described.
  • the wall structure of the vein is gradually changed downstream from the anastomosis, and the inside of the covered vein is subjected to gradient shear stress, It is possible to change the pressure perpendicular to the blood vessel wall, the blood flow, the blood flow velocity, and the width of change associated with pulsation, thereby suppressing the mismatch of blood vessel wall elasticity, blood turbulence, and excessive high blood flow, Intimal hyperplasia can be prevented.
  • the reasons why the blood vessel cover of the present invention has such effects are considered as follows.
  • arteries and veins consist of the intima, media, and adventitia.
  • the media consists of a smooth muscle layer rich in smooth muscle cells and an elastic fiber layer containing collagen fibers.
  • Arteries have thick smooth muscle layers and elastic fiber layers so that even when the pressure of pulsating luminal blood flow is applied, there is little pulsation change in the vascular wall, and the occurrence of turbulence and fluctuations in frictional stress are minimized. have.
  • Veins on the other hand, have thin blood vessel walls and do not have thick smooth muscle layers and elastic fiber layers like arteries.
  • the vascular cover of the present invention has the above configuration, so that the pulsatile blood flow with high arterial pressure that flows into the vein at the arteriovenous anastomosis of the shunt site or the artificial blood vessel-venous anastomosis is directed downstream.
  • the vein at the shunt site can be remodeled into a buffered vessel that can be gradually buffered and eventually transitioned to venous blood flow. As a result, blood turbulence and pulsating changes in the vein wall are suppressed, and lesions such as intimal hyperplasia can be prevented.
  • the vascular cover of the present invention having the above structure, since the 20% elastic index E20 , the 50% elastic index E50 and the 100% elastic index E100 have a predetermined relationship, the blood pressure applied to the blood vessel is reduced. When the blood pressure is weak, it can be loosely covered, and when the blood pressure applied to the blood vessel is relatively strong, the vein can be easily remodeled into a low-pressure buffer system blood vessel.
  • the vascular cover of the present invention having the above structure does not interfere with the growth of veins, which may gradually grow outward during the process of remodeling into low-pressure buffered vessels, and as a result, the vascular lumen is closed. It can be maintained widely to ensure sufficient blood flow. As a result, it becomes possible to create a shunt that can secure a sufficient blood flow while suppressing lesions such as intimal hyperplasia.
  • FIG. 11 shows a schematic diagram of another example of a shunt-forming portion
  • FIG. 10 is a perspective view showing a vascular cover according to an embodiment of the present invention arranged on the outer peripheral side of the vein in the shunt-created portion
  • 1 depicts a perspective view of a vessel cover according to an embodiment of the present invention
  • FIG. 2 depicts a perspective view of a vessel cover according to another embodiment of the present invention
  • FIG. 10 depicts a perspective view of a vessel cover according to yet another embodiment of the present invention
  • FIG. 3 shows a perspective view showing a method of measuring elastic index.
  • FIG. 8 is a plan view of FIG. 7 viewed from above
  • 4 is a graph showing the relationship between the expansion rate of the inner diameter of the vascular cover and the elastic index.
  • FIG. 1 shows a schematic diagram of a case in which an autologous vein is anastomosed to a small incision of an artery in a shunt-creating part
  • FIG. 10 is a schematic diagram when a vein is anastomosed to the other end of the
  • FIG. 3 shows a perspective view when the blood vessel cover according to one embodiment of the present invention is arranged on the outer peripheral side of the vein in the shunt-created portion.
  • 4-6 depict perspective views of vessel covers according to different embodiments.
  • FIG. 7 represents a perspective view showing a method of measuring the elastic index
  • FIG. 8 represents a plan view when FIG. 7 is viewed from above.
  • the shunt-constructed part 1 can be formed by performing an arteriovenous anastomosis as shown in FIG. 1 or an artificial blood vessel-venous anastomosis as shown in FIG.
  • the shunt-forming part 1 can be formed by anastomosing a vein 4 to a small incision of an artery 3 in an arm 2 to allow the blood flow of the artery 3 to flow into the vein 4 .
  • blood flows from the artery 3 through the anastomosis 6 and the vein 4 in the direction indicated by the arrow B.
  • the shunt-constructing part 1 can be formed by anastomosing one end of an artificial blood vessel 5 to a small incision portion of an artery 3 in an arm 2 and anastomosing a vein 4 to the other end of the artificial blood vessel 5.
  • the blood flows from the artery 3 through the artificial blood vessel 5, the anastomosis 6, and the vein 4 in the direction indicated by the arrow B.
  • the arteriovenous anastomosis shown in FIG. 1 or the artificial vessel-vein anastomosis shown in FIG. It can be arranged on the outer peripheral side, and the vein 4 can be remodeled into a buffer system blood vessel.
  • the vessel cover 10 is preferably arranged from the most upstream part of the vein 4 on the anastomotic part 6 side.
  • the vessel cover 10 has one end 10a and the other end 10b. 10b is preferably arranged.
  • the blood vessel cover 10 covers not only the vein 4 but also a part of the artery 3 and the artificial blood vessel 5 on the anastomosis 6 side. may be arranged to cover the surface.
  • the blood vessel cover 10 is formed in a continuous cylindrical shape over the entire circumference, and has an axial direction x and a radial direction y.
  • the axial direction x of the vessel cover 10 is the direction in which the central axis C of the vessel cover 10 extends. is the direction connecting points on the outer edge of
  • the vascular cover 10 may be a knitted fabric, woven fabric, or net that is continuously constructed all around. Knitted fabrics, woven fabrics, nets, and the like have stitches and textures, but the gaps formed in the stitches and textures are not discontinuous portions of the vascular cover 10, but the above-mentioned "continuous can form a "cylindrical".
  • the blood vessel cover 10 is flexible, and it is preferable that the axial direction x of the blood vessel cover 10 can be curved to follow the extending direction of the veins 4 to be covered.
  • the vessel cover 10 preferably has a lumen with a circular or elliptical shape in cross section in the radial direction y.
  • the outer edge of the cross section in the radial direction y may have fine irregularities.
  • the vessel cover 10 may be in a state in which the lumen is crushed by its own weight in the natural state. Even in such a case, it is possible to define the same cross-sectional shape in the axial direction x, radial direction y, and radial direction y by widening the lumen.
  • a method for widening the lumen collapsed by its own weight for example, a tube whose lumen does not collapse under its own weight and has a central axis parallel to the central axis C of the vessel cover 10 and inscribed in the inner wall of the vessel cover 10 is used. into the lumen of the vessel cover 10, and the like.
  • the blood vessel cover 10 may have a tubular shape, and may have a joint portion, for example, formed by rolling a flat plate member into a tubular shape and joining them by a method such as stitching. In that case, it is preferable that the joint portion such as the suture portion is formed on the outer surface of the vessel cover 10 . This prevents the joint from affecting the vein 4 .
  • a molded member or a knitted fabric a seamless cylindrical member having no joints may be formed.
  • the inner diameter of the vessel cover 10 is the diameter of the lumen in the cross section in the radial direction y, and is the diameter of the circle when the shape of the lumen in the cross section in the radial direction y is circular.
  • the inner diameter of the vessel cover 10 can also be defined as a value obtained by dividing the circumference of the inner wall of the vessel cover 10 by the circular constant ⁇ in a cross section in the radial direction y. According to this, the inner diameter of the vessel cover 10 can be obtained even when the cross section of the vessel cover 10 in the radial direction y is not circular or when the lumen of the vessel cover 10 is crushed by its own weight.
  • the inner diameter of the vessel cover 10 can expand at least 100% in the radial direction y from the natural state over the entire axial direction x. As a result, the gradual outward growth of the blood vessel covered with the vascular cover 10 is not inhibited during the process of remodeling, so that the vascular lumen can be kept wide and a sufficient blood flow can be ensured.
  • the vascular cover 10 has an elastic index E20 (hereinafter referred to as 20% elastic index E20 ) measured by the following measuring method when the inner diameter of the vascular cover 10 is expanded by 20% in the radial direction y from the natural state. ) is 1.3 N or less, and the elastic index when the inner diameter of the vessel cover 10 in the portion (A) is expanded by 50% in the radial direction y from the natural state is measured by the following method.
  • the value E 50 hereinafter referred to as 50% elastic index E 50
  • 50% elastic index E 50 when measured and the elastic index when the inner diameter of the vessel cover 10 in the portion (A) is expanded 100% in the radial direction y from the natural state are shown below.
  • the value E 100 (hereinafter referred to as 100% elastic index E 100 ) when measured by the measuring method satisfies the relationship of the following formula (1). [(E 100 -E 50 )/(100-50)]/[(E 50 -E 20 )/(50-20)] ⁇ 2.5 (1) [Measuring method]
  • the vascular cover 10 is cut perpendicular to the axial direction x along the tangent line in the circumferential direction of the vascular cover 10, and a cylindrical cut is made in the wall with a length of 5 mm in the axial direction x and continuous over the entire circumference in the axial direction x.
  • a sample 100 free of is prepared.
  • a first pin 101 and a second pin 102 having a diameter d of 0.75 mm are inserted through the lumen of the tubular sample 100 in parallel with the axial direction of the tubular sample 100 .
  • the first pin 101 is fixed, the second pin 102 is pulled radially outward of the cylindrical sample 100, and the distance between the first pin 101 and the second pin 102 is L.
  • the force F50 is measured when ⁇ d+2L is 1.5 times the circumferential length of the cylindrical sample 100 in the natural state, and the force F50 is the strain [(1.5-1.
  • the vascular cover 10 has a portion (A) with a 20% elastic index E 20 of 1.3 N or less, pulsatile blood flow with high arterial pressure flowing into the vein 4 of the shunt-constructed portion 1 is prevented.
  • the vein 4 of the shunt-constructed portion 1 can be remodeled so that the portion covered with the vascular cover 10 gradually buffers and eventually becomes a buffer system blood vessel that can transition to venous blood flow.
  • the 20% elastic index E20 , the 50% elastic index E50 , and the 100% elastic index E100 have a predetermined relationship in the portion (A) of the blood vessel cover 10 , when the blood pressure applied to the blood vessel is weak, When the blood pressure applied to the blood vessel is high, the vein 4 can be covered loosely, and the vein 4 can be easily remodeled into a buffer system blood vessel. As a result, blood turbulence and pulsating changes in the vein wall are suppressed, and lesions such as intimal hyperplasia can be prevented.
  • the above formula (1) is a graph in which the horizontal axis represents the expansion rate of the inner diameter of the vessel cover 10 from the natural state and the vertical axis represents the elasticity index. This means that the expansion rate is at least 2.5 times greater than the slope of the elastic index between 20% and 50%. See FIG. 9, which shows a graph in which the 20% elastic index E 20 , 50% elastic index E 50 , and 100% elastic index E 100 obtained in the examples described later are plotted on the vertical axis and the expansion ratio is plotted on the horizontal axis.
  • the vascular cover 10 has a small 20% elastic index E20 of 1.3 N or less, and a slope of the elastic index in which the expansion ratio is in the range of 50% to 100%.
  • the blood vessel cover 10 can cover the blood vessel loosely, and when the blood pressure applied to the vein 4 is high or the outer diameter of the vein 4 grows and becomes large, the blood pressure applied to the vein 4 is increased. A lower or smaller outer diameter of the vein 4 allows a relatively stronger coverage of the vessel. As a result, even if the blood pressure applied to the vein 4 or the outer diameter of the vein 4 fluctuates, the vessel cover 10 can cover the vein 4 with the optimum strength for the fluctuation, and the vein 4 can be routed to the low-pressure buffer system vessel. can be modeled.
  • the slope of the elastic index when the expansion ratio is in the range of 50% to 100% may be 1.7 times or more and 2.0 times or more than the slope of the elastic index when the expansion ratio is in the range of 20% to 50%, It is preferably 3 times or more, more preferably 3.5 times or more, further preferably 4 times or more, and may be 4.2 times or more, or 4.5 times or more.
  • the slope of the elastic index when the expansion ratio is in the range of 50% to 100% is preferably 10 times or less, more preferably 8 times or less, and 6 times the slope of the elastic index when the expansion ratio is in the range of 20% to 50%. More preferred are: If the ratio of the slope of the elastic index when the expansion ratio is in the range of 20% to 50% to the slope of the elastic index when the expansion ratio is in the range of 50% to 100% is within the above range, the above effects can be obtained.
  • the wall of the vein 4 of the shunt-constructed portion 1 has a smooth muscle layer that is thicker than the smooth muscle layer of the normal vein and includes an elastic fiber layer, and an elastic layer that includes collagen fibers that are thicker than the smooth muscle layer on the outside of the smooth muscle layer.
  • Blood vessels are composed of three layers: the intima, the media, and the adventitia. Among them, the intima greatly contributes to anticoagulation, but its mechanical contribution is extremely small.
  • the mechanical elements of the arteries of the extremities which are normal arteries used for artificial dialysis, consist of the media, which contains a small amount of elastic fibers and abundant smooth muscle, and the outer membrane, which consists of elastic fibers and collagen fibers. account for the percentage. Thus, these arteries have a great abundance of smooth muscle and relatively few elastic fibers (“smooth muscle>elastic fiber” configuration).
  • elastic fibers Due to their elasticity, elastic fibers have a cushioning function like a rubber tube that resists and cushions the pulsatile and high blood pressure of arteries.
  • smooth muscle since smooth muscle is a muscle, it also has a more active mechanical function, resisting arterial blood pressure, while on the other hand delivering high pulsatile arterial blood pressure to the periphery without attenuation. It has an active function. Due to the pressure-transmitting function of the abundant smooth muscle of the arteries, the blood pressure of the aorta, which has an inner diameter on the order of a centimeter, and the small artery, which has an inner diameter of only a fraction of a millimeter, hardly changes.
  • the venous wall changes like a normal artery, it is arterialization (remodeling into an artery) and not into a buffer system vessel. If the arterialization gradually weakens and naturally transitions downstream to a completely normal vein, it means that it gradually thins and transitions to the vein with its "smooth muscle > elastic fiber" configuration. , high pulsatile blood pressure acts on the venous wall and causes pathological changes in the downstream veins. This point is a clear functional difference between the case where the buffer system blood vessel gradually thins and shifts to a normal vein, and the case where a normal artery-like blood vessel gradually thins and shifts to a normal vein.
  • the vessel cover 10 according to the embodiment of the present invention having the above configuration can loosely cover the vein 4 of the shunt-constructed portion 1, the wall structure of the vein 4 can be changed as described above to form a buffer system vessel. Can be remodeled.
  • the vascular cover 10 according to the embodiment of the present invention, it is possible to form the shunt-constructed portion 1 that can ensure a sufficient blood flow while suppressing lesions such as intimal hyperplasia.
  • the 20% elastic index E20 of the portion (A) is preferably 1.2N or less, more preferably 1.1N or less, still more preferably 1N or less, 0.9N or less, 0.8N or less, 0.6N or less, 0 .4N or less.
  • the 20% elastic index E 20 of the portion (A) is preferably 0.1 mN or more, more preferably 0.5 mN or more, and even more preferably 1 mN or more. Since the 20% elastic index E 20 of the portion (A) is a predetermined value or more, the blood vessel can be covered with a force of a predetermined value or more even when the blood pressure applied to the blood vessel is low.
  • the 50% elastic index E50 of the portion (A) is preferably 3.2N or less, more preferably 3N or less, still more preferably 2.5N or less, 2N or less, 1.8N or less, 1.5N or less, 1.2N. Below, it may be 1.1N or less, 1N or less, 0.8N or less, or 0.7N or less.
  • the 50% elastic index E 50 of the portion (A) is preferably 0.1 mN or more, more preferably 0.5 mN or more, and even more preferably 1 mN or more. Since the portion (A) has a 50% elastic index E 50 within the above range, the blood vessel can be loosely covered even when the blood pressure applied to the blood vessel is relatively high, and the above effects can be achieved.
  • the 100% elastic index E 100 of the portion (A) is preferably 7N or less, more preferably 6N or less, still more preferably 5N or less, 4N or less, 3.5N or less, 3N or less, 2.8N or less, 2.5N or less. , 2N or less, or 1.5N or less.
  • the 100% elastic index E 100 of the portion (A) is preferably 0.1 mN or more, more preferably 0.5 mN or more, and even more preferably 1 mN or more. Since the portion (A) has a 100% elastic index E 100 within the above range, the blood vessel can be covered with a predetermined force or less even when the blood pressure applied to the blood vessel is high, and the above effect can be achieved. .
  • FIG. 1 A cylindrical sample 100 is prepared by cutting the vessel cover 10 perpendicularly to the axial direction x along a circumferential tangent line of the vessel cover 10 . At this time, by cutting out the entire circumference along a cut plane perpendicular to the axial direction x, that is, along a cutting line in the circumferential direction, a cylindrical shape having a length of 5 mm in the axial direction x and continuous over the entire circumference in the axial direction x is obtained. Cut the vessel cover 10 so as to obtain a tubular sample 100 with an unbroken wall. Next, as shown in FIG.
  • a first pin 101 and a second pin 102 each having a diameter d of 0.75 mm are inserted into the lumen of the cylindrical sample 100 in parallel with the axial direction of the cylindrical sample 100 .
  • the lengths of the first pin 101 and the second pin 102 are not particularly limited, they are preferably longer than the length of the cylindrical sample 100 in the axial direction x.
  • the distance L between the first pin 101 and the second pin 102 is the distance from the center of the first pin 101 and the second pin 102 as shown in FIG.
  • the inner diameter of the cylindrical sample 100 is 1/2 of the circumference ⁇ d of the first pin 101, 1/2 of the circumference ⁇ d of the second pin 102, and 2 of the distance L between the first pin 101 and the second pin 102. equal to the sum of doubles, ie ⁇ d+2L.
  • the force F 20 that pulls the second pin 102 is The 20% elastic modulus E 20 can be obtained by dividing by the strain [(1.2-1.0)/1.0].
  • the method for measuring the 50% elastic index E50 and the 100% elastic index E100 is the method for measuring the 20% elastic index E20 described above, where ⁇ d+2L is 1.5 times and 2 times the circumference of the tubular sample 100 in its natural state.
  • the method for measuring the 20% elastic modulus E20 is the same, except that the forces F50 and F100 at 0.0 are measured.
  • the cylindrical sample 100 having a length of 5 mm in the axial direction x and continuous over the entire circumference in the axial direction x is a knitted fabric, a woven fabric, or a net that is continuously formed over the entire circumference.
  • Knitted fabrics, woven fabrics, nets, and other stitches and gaps formed by weaves are not included in the "breaks" of the above "unbroken sample”.
  • the portions (A) may be provided continuously in the axial direction x or may be provided at intervals.
  • the portion other than the portion (A) is preferably 75% or less, more preferably 50% or less, even more preferably 30% or less, and particularly preferably 10% or less of the total length of the vessel cover 10 in the axial direction x of the vessel cover 10. 0% is most preferred.
  • 4 to 6 schematically show the part where the part (A) is arranged, but the part where the vascular cover 10 has the part (A) is limited to these figures. Instead, any portion may have the portion (A) as long as it satisfies each of the above requirements.
  • the length of the portion (A) is preferably 50% or more of the outer diameter of the anastomosed artery 3 or artificial blood vessel 5.
  • the length of the portion (A) in the axial direction x is more preferably 60% or more, more preferably 80% or more, and may be 100% or more of the outer diameter of the anastomosed artery 3 or artificial blood vessel 5 .
  • the upper limit of the length of the portion (A) in the axial direction x is not particularly limited, it may be 2000% or less, 1750% or less, or 1500% or less of the outer diameter of the anastomosed artery 3 or artificial blood vessel 5.
  • the portion (A) of the vascular cover 10 having a 20% elastic index of 1.2 N or less has a length greater than or equal to a predetermined length, so that remodeling of the vein 4 covered with the vascular cover 10 into a buffer system blood vessel and blood flow reduction. It becomes easier to secure the flow rate.
  • the inner diameter of the blood vessel cover 10 can be set to an appropriate value depending on the diameter of the blood vessel to be applied.
  • the inner diameter of the blood vessel cover 10 is preferably 10 mm or less, more preferably 9 mm or less, and even more preferably 8 mm or less.
  • the vessel cover 10 may have different inner diameters depending on the axial direction x.
  • the vessel cover 10 may have a straight shape with a similar inner diameter from one end 10a to the other end 10b, or may have a tapered shape with an inner diameter that gradually increases from one end 10a to the other end 10b. .
  • the blood vessel cover 10 may have a bellows shape in which the inner diameter changes periodically in the axial direction x.
  • the entire blood vessel cover 10 is the portion (A).
  • the vessel cover 10 as a whole satisfies the requirements of the portion (A), so that the remodeling of the vein 4 into a buffer system vessel is further facilitated, and it is easier to maintain the lumen of the vein 4 wide, thereby preventing blood flow. It leads to securing of flow.
  • the portion from the midpoint 10c of the one end 10a and the other end 10b of the vessel cover 10 to the one end 10a is referred to as the first portion 11, and the portion from the midpoint 10c to the other end 10b is referred to as the second portion 12.
  • the 20% elastic index E2 20 of the second portion 12 is preferably smaller than the 20% elastic index E1 20 of the first portion 11 .
  • the portion from the midpoint 10c of the one end 10a and the other end 10b of the vessel cover 10 to the one end 10a is referred to as the first portion 11, and the portion from the midpoint 10c to the other end 10b is referred to as the second portion 12.
  • the 50% elastic index E2 50 in the second portion 12 is preferably smaller than the 50% elastic index E1 50 in the first portion 11 .
  • the portion from the midpoint 10c of the one end 10a and the other end 10b of the vessel cover 10 to the one end 10a is referred to as the first portion 11, and the portion from the midpoint 10c to the other end 10b is referred to as the second portion 12.
  • the 100% elastic index E2 100 in the second portion 12 is preferably less than the 100% elastic index E1 100 in the first portion 11 .
  • the portion from the midpoint 10c of the one end 10a and the other end 10b of the vessel cover 10 to the one end 10a is referred to as the first portion 11, and the portion from the midpoint 10c to the other end 10b is referred to as the second portion 12.
  • the part (A) is arranged in the first part 11 and the second part 12, and the 20% elastic index E1 20 and 50% elastic index E1 50 of the part (A) in the first part 11 and 100% elastic
  • the index E1 100 and the 20% elastic index E2 20 , 50% elastic index E2 50 and 100% elastic index E2 100 of the portion (A) in the second part 12 preferably satisfy the relationship of the following formula (2).
  • the vascular cover 10 when the first portion 11 of the vascular cover 10 is arranged on the upstream side of the vein 4 of the shunt-created portion 1, the vascular cover can prevent the vascular diameter from growing on the downstream side rather than on the upstream side. It becomes possible to exhibit a relatively strong covering effect, and the remodeling of the vein 4 into a buffer system vessel becomes easier.
  • the length of the blood vessel cover 10 in the axial direction x is preferably 5 mm or more.
  • the length of the blood vessel cover 10 in the axial direction x is preferably 10 mm or longer, more preferably 20 mm or longer, particularly preferably 30 mm or longer, and may be 40 mm or longer.
  • the length of the blood vessel cover 10 in the axial direction x is preferably 120 mm or less, more preferably 100 mm or less, and even more preferably 90 mm or less. If the length of the vascular cover 10 in the axial direction x is within the above range, the vein 4 of the shunt-constructed portion 1 can be covered with the vascular cover 10 having a length greater than or equal to the predetermined length, and the vein 4 can be reconnected to the buffer system blood vessel. Easier to model.
  • the vascular cover 10 preferably has at least one of a knitted fabric, a woven fabric, and a nonwoven fabric as a component that partially configures it or as a component that configures the whole. With these materials, it is easy to form the elastically deformable blood vessel cover 10 .
  • the type of knitted fabric is not particularly limited, and may be warp knitted or weft knitted. Knitting structures of warp knitting include half knitting, back half knitting, queens coat knitting, and satin knitting. Weft knitting includes circular knitting and flat knitting, and knitting structures of weft knitting include plain knitting, rubber knitting, double-sided knitting, milanese rib knitting, and jacquard knitting.
  • the knitted fabric is preferably composed of weft knitting from the viewpoint of excellent stretchability.
  • the type of woven fabric is not particularly limited, and may be plain weave, twill weave, satin weave, or the like.
  • the vascular cover 10 may be composed of a nonwoven fabric produced by any method such as meltblowing, needle punching, spunlacing, electrospinning, or the like.
  • the blood vessel cover 10 may be composed of a combination of two or more different materials, for example, one part is composed of a knitted fabric and the other part is composed of another material such as a non-woven fabric.
  • yarns forming knitted fabrics, woven fabrics, and non-woven fabrics are also made of resin materials with superior plastic deformation, such as polyolefin resins such as polyethylene and polypropylene; polyamide resins such as nylon; polyethylene terephthalate. polyimide resins; fluorine resins such as PTFE, PFA and ETFE; synthetic resins such as polyvinyl chloride resins.
  • resin materials with superior plastic deformation such as polyolefin resins such as polyethylene and polypropylene; polyamide resins such as nylon; polyethylene terephthalate.
  • polyimide resins fluorine resins such as PTFE, PFA and ETFE
  • synthetic resins such as polyvinyl chloride resins.
  • the yarn forming the knitted fabric or woven fabric can also be made of a resin material (e.g., polyester, PTFE) used for artificial blood vessels, and specifically, ePTFE obtained by stretching PTFE and polyester fiber from DuPont. Dacron (registered trademark) and the like can be mentioned.
  • the vessel cover 10 may be made of a biodegradable material such as aliphatic polyester such as polylactic acid, polyglycolic acid, and polyhydroxyalkanoic acid; aliphatic polyether.
  • the yarn forming the knitted or woven fabric may be composed of natural fibers such as silk or cotton, or may be composed of a combination of resin materials, biodegradable materials, and natural fibers.
  • the evaluation of whether or not the vein 4 is remodeled into the low-pressure buffer system blood vessel needs to be confirmed by both the morphological confirmation method described below and the confirmation method by measuring the buffer action.
  • a morphological method it can be performed by confirming whether a two-layer structure consisting of a smooth muscle layer containing elastic fibers and elastic fibers containing collagen fibers thicker than the smooth muscle layer is formed. can.
  • the vein 4 of the shunt-forming portion 1 is cut out, subjected to special staining such as hematoxylin-eosin (HE) staining and elastica-fungieson (EvG) staining, and the cross section of the vein wall is observed with a microscope.
  • HE hematoxylin-eosin
  • EvG elastica-fungieson
  • smooth muscle is stained turbid yellow, elastic fibers are dark purple, and collagen fibers are stained dark red, so the smooth muscle layer containing elastic fibers and the elastic fiber layer containing collagen fibers are observed, This can be done by confirming "thickness of smooth muscle layer containing elastic fibers ⁇ thickness of elastic fiber layer containing collagen fibers".
  • a vascular cover was cut perpendicular to the axial direction along the circumferential tangent line of the vascular cover, and a cylindrical shape having an axial length of 5 mm and continuous over the entire circumference in the axial direction was attached to the wall.
  • a continuous sample was prepared.
  • a first pin and a second pin each having a diameter of 0.75 mm were inserted through the lumen of the tubular sample parallel to the axial direction of the tubular sample. The first pin is fixed, the second pin is pulled outward in the radial direction of the cylindrical sample, and the sum of twice the distance between the first pin and the second pin and ( ⁇ ⁇ 0.75 mm) is the cylindrical sample.
  • the 20% elastic index was obtained by dividing the force at 1.2 times the circumference in the natural state by the strain [(1.2-1.0)/1.0].
  • a vascular cover was cut perpendicular to the axial direction along the circumferential tangent line of the vascular cover, and a cylindrical shape having an axial length of 5 mm and continuous over the entire circumference in the axial direction was attached to the wall.
  • a continuous sample was prepared.
  • a first pin and a second pin each having a diameter of 0.75 mm were inserted through the lumen of the tubular sample parallel to the axial direction of the tubular sample. The first pin is fixed, the second pin is pulled outward in the radial direction of the cylindrical sample, and the sum of twice the distance between the first pin and the second pin and ( ⁇ ⁇ 0.75 mm) is the cylindrical sample.
  • the 50% elastic index was obtained by dividing the force at 1.5 times the circumference in the natural state by the strain [(1.5-1.0)/1.0].
  • a vascular cover was cut perpendicular to the axial direction along the tangent line in the circumferential direction of the vascular cover.
  • a continuous sample was prepared.
  • a first pin and a second pin each having a diameter of 0.75 mm were inserted through the lumen of the tubular sample parallel to the axial direction of the tubular sample.
  • the first pin is fixed, the second pin is pulled outward in the radial direction of the cylindrical sample, and the sum of twice the distance between the first pin and the second pin and ( ⁇ ⁇ 0.75 mm) is the cylindrical sample.
  • the 100% elastic index was obtained by dividing the force at 2.0 times the circumference in the natural state by the strain [(2.0-1.0)/1.0].
  • Macroscopic findings at autopsy include patency of the vascular lumen, smooth vascular walls with no varicose veins or unnatural irregularities, and intima as a pathological finding that affects blood flow. No thickening, stenosis or thrombus formation.
  • B In the observation of (5) above, it has a smooth muscle layer containing elastic fibers that is clearly thicker than the smooth muscle layer on the inside, and an elastic fiber layer containing collagen fibers that is thicker than the smooth muscle layer on the outside. A bilayer structure should be observed, and there should be no intimal thickening or thrombus formation.
  • the outer elastic fiber layer containing collagen fibers is thicker than the inner smooth muscle layer.
  • Production example 1 A seamless tubular vascular cover with an axial length of 55 mm and an inner diameter of 6 mm was fabricated by the braiding technique using 48 strands per turn of nylon woolly textured monofilaments. A 25 mm axial length in the central portion of the manufactured vascular cover was shortened to 5 mm in a bellows shape, and 20% elastic index, 50% elastic index, and 100% elastic index were measured. The results are shown in Table 1 and FIG.
  • Production example 2 Using a WHOLEGARMENT flat knitting machine, a knitted fabric was formed from woolly polyester textured yarn (multifilament) to produce a seamless vascular cover having a tapered shape with an axial length of 60 mm. The inner diameter of one end of the vessel cover was 3 mm, and the inner diameter of the other end was 10 mm. Cylindrical samples were cut out from portions having an inner diameter of 9 mm near one end and the other end of the manufactured vascular cover, and 20% elastic index, 50% elastic index, and 100% elastic index were measured for each of the cylindrical samples. rice field. The results are shown in Table 1 and FIG.
  • Production example 3 Using a commercially available artificial blood vessel made of foamed polyurethane (Solatec artificial blood vessel, sold by Goodman Co., Ltd.), the softest part of the reinforcement at the end was cut out to form a seamless straight blood vessel with an axial length of 55 mm and an inner diameter of 6 mm. A cover was made. A cylindrical sample was cut out from the central portion of the manufactured vascular cover, and the 20% elastic index and 50% elastic index were measured. The results are shown in Table 1 and FIG.
  • Example 1 An artery and a vein are anastomosed to form a shunt in the neck of a beagle dog, and the vascular cover is placed on the outer peripheral side of the vein so that one end of the vascular cover obtained in Production Example 1 is placed at the anastomosis. and followed up for 16 weeks. Veins were then evaluated in Doppler blood flow measurements and color Doppler ultrasound diagnostic imaging. Beagle dogs were euthanized and the vein at the site of the shunt was excised. Observation and thickness measurement of the smooth muscle layer and elastic fiber layer containing collagen fibers of the isolated vein were performed, and the remodeling evaluation to the buffer system blood vessel was performed. The result of evaluation based on the above criteria (a) to (e) was ⁇ . Table 2 shows the results.
  • Comparative example 1 An artery and a vein are anastomosed to construct a shunt in the neck of a beagle dog, and the vascular cover is placed on the outer peripheral side of the vein so that one end of the vascular cover obtained in Production Example 3 is placed at the anastomosis. and followed up for 16 weeks. Veins were then evaluated in Doppler blood flow measurements and color Doppler ultrasound diagnostic imaging. Beagle dogs were euthanized and the vein at the site of the shunt was excised. Observation and thickness measurement of the smooth muscle layer and elastic fiber layer containing collagen fibers of the isolated vein were performed, and the remodeling evaluation to the buffer system blood vessel was performed. The result of evaluation based on the above criteria (a) to (e) was x. Table 2 shows the results.
  • shunt-forming part 2 arm 3: artery 4: vein 5: artificial blood vessel 6: anastomotic part 10: vessel cover 10a: one end 10b of vessel cover: the other end 10c of vessel cover: middle point 11 of vessel cover: First part 12: Second part 100: Cylindrical sample 101: First pin 102: Second pin x: Axial direction y: Radial direction

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  • Health & Medical Sciences (AREA)
  • Heart & Thoracic Surgery (AREA)
  • Vascular Medicine (AREA)
  • General Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Veterinary Medicine (AREA)
  • Engineering & Computer Science (AREA)
  • Biomedical Technology (AREA)
  • Cardiology (AREA)
  • Public Health (AREA)
  • Animal Behavior & Ethology (AREA)
  • Oral & Maxillofacial Surgery (AREA)
  • Gastroenterology & Hepatology (AREA)
  • Pulmonology (AREA)
  • Transplantation (AREA)
  • Anesthesiology (AREA)
  • Hematology (AREA)
  • Prostheses (AREA)

Abstract

L'invention concerne un recouvrement de vaisseau sanguin permettant de prévenir l'épaississement intimal en remodelant une veine en un vaisseau sanguin à système tampon.　Un recouvrement tubulaire de vaisseau sanguin (10) est disposé sur le côté périphérique externe d'une veine (4) anastomosée avec une artère (3) ou un vaisseau sanguin artificiel, et la circonférence entière du recouvrement est continue. Le diamètre interne du recouvrement de vaisseau sanguin (10) est au moins 100% extensible à partir d'un état naturel dans la direction radiale y, et un indice d'élasticité de 20% E20, un indice d'élasticité de 50% E50, et un indice d'élasticité de 100% E100 satisfont la relation de la formule (1).　Formule (1) : [(E100 - E50)/(100-50)]/[(E50 - E20)/(50-20)] ≥ 2,5
PCT/JP2022/031606 2021-09-08 2022-08-22 Recouvrement de vaisseau sanguin WO2023037861A1 (fr)

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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008522735A (ja) * 2004-12-08 2008-07-03 パーバシス セラピューティクス， インコーポレイテッド 血管アクセスを強化するための方法および組成物
US20150119908A1 (en) * 2013-10-25 2015-04-30 Abbott Cardiovascular Systems Inc. Extravascular devices supporting an arteriovenous fistula
WO2021161884A1 (fr) * 2020-02-14 2021-08-19 明郎 萩原 Couvercle de protection pour site d'anastomose vasculaire
WO2021177273A1 (fr) * 2020-03-03 2021-09-10 明郎 萩原 Enveloppe de veine

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008522735A (ja) * 2004-12-08 2008-07-03 パーバシス セラピューティクス， インコーポレイテッド 血管アクセスを強化するための方法および組成物
US20150119908A1 (en) * 2013-10-25 2015-04-30 Abbott Cardiovascular Systems Inc. Extravascular devices supporting an arteriovenous fistula
WO2021161884A1 (fr) * 2020-02-14 2021-08-19 明郎 萩原 Couvercle de protection pour site d'anastomose vasculaire
WO2021177273A1 (fr) * 2020-03-03 2021-09-10 明郎 萩原 Enveloppe de veine

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