Stent for end-to-end anastomosis and method for using same

Abstract

In a stent for end-to-end anastomosis and a method for using same, according to the present invention, the stent for end-to-end anastomosis comprises: a first blood vessel mounting portion which has therein a first hollow structure having a diameter that radially increases toward one end thereof and has a cylindrical outer shape; an anastomosis receiving portion which is integrally formed with the first blood vessel mounting portion, has therein a second hollow structure connected to an end having the minimum diameter of the first hollow structure so as to have the same diameter, and has, in the outer surface thereof, a stepped groove relative to the first blood vessel mounting portion; and a second blood vessel mounting portion which is integrally formed with the anastomosis receiving portion such that the second hollow structure extends continuously, the second blood vessel mounting portion having a cylindrical outer shape and an upper region that has a portion connected to the anastomosis receiving portion and with a thickness that increases toward the anastomosis receiving portion. The stent for end-to-end anastomosis can effectively restrain flexible blood vessels to reduce surgery time, and can prevent blood vessel misalignment to minimize the turbulence of blood flow and reduce blood flow resistance.

Description

Stent for single-stage anastomosis and method of use thereof

[0001] The present invention relates to a vascular anastomosis device, and more particularly, to a stent for end-to-end anastomosis and a method of using the same.

[0002] Blood vessels are the conduits that circulate blood between the heart and each organ and tissue of the body, transporting blood from the heart throughout the body and returning it to the heart. With the aging population, cholesterol deposition occurs on the endothelium of blood vessels. High blood pressure damages these cells, leading to thrombosis, narrowing or blocking blood vessels, and a rapid increase in the number of people suffering from atherosclerosis, a condition that causes blood flow disorders. Representative diseases of atherosclerosis include myocardial infarction, cerebral infarction, and peripheral occlusive vascular disease (PAD).

[0003] In particular, occlusive peripheral vascular disease (PVD) is known to be difficult to cure due to its high recurrence rate. Existing techniques for expanding narrowed blood vessels include percutaneous transluminal balloon angioplasty (PTA), stent placement, and coronary artery bypass grafting (CABG). When performing arterial bypass grafting, autologous or artificial blood vessels are essential. Autologous blood vessels are limited because they can only be accessed through the great venous catheters of both legs, leading to the development and use of artificial blood vessels. Currently, representative commercially available artificial blood vessels include expanded polytetrafluoroethylene (ePTFE) and DACRON (polyester), as described in Prior Art 1 (Korean Patent No. 10-2131101). However, these materials inherently have limited flexibility and elasticity. Furthermore, when performing bypass grafting on areas below the knee and arteries, the vessel diameter is narrow and blood flow is low, significantly reducing the patency rate (the probability that the vessel will not become occluded again) of the artificial blood vessel.

[0004] Furthermore, when operating on small-diameter vessels (those with a diameter of less than 5 mm) or thin vessels such as capillaries, the vessels may become engulfed and form anastomoses. This can result in the vessel not being completely closed after the surgery or may cause leakage, which can lead to surgical failure. This vascular misalignment can cause abnormal blood leakage from the surgical site or blockage of blood flow. Since vascular misalignment can be affected by factors such as surgical precision, suturing technique, and blood flow reestablishment, it tends to depend heavily on the surgeon's experience and surgical technique, which can lead to surgical discomfort.

[0005] Therefore, there is a need to develop a vascular anastomosis device that can prevent vascular misalignment and increase the patency rate of artificial blood vessels during microvascular surgery, such as small-diameter blood vessels or capillaries.

[0006] The first object of the present invention to solve the above-described problem is to provide a stent for end-to-end anastomosis that can mutually suture an autologous blood vessel and an artificial blood vessel.

[0007] In addition, the second object of the present invention is to provide a method of using a stent for single-stage anastomosis to achieve the first object.

[0008] In order to achieve the first object, the present invention provides a stent for end-to-end anastomosis, comprising: a first vascular mounting portion having a first hollow structure having a radially increasing diameter as it goes toward one end thereof, and an outer surface having a cylindrical shape; a second hollow structure having a diameter of the same size as the inner surface, the second hollow structure being formed integrally with the first vascular mounting portion and being connected to an end having a minimum diameter of the first hollow structure, and an anastomosis receiving portion having a groove having a step as compared to the first vascular mounting portion in the outer surface; and a second vascular mounting portion having a cylindrical shape as it is formed integrally with the anastomosis receiving portion so that the second hollow structure is continuous, and a portion of an upper region connected to the anastomosis receiving portion becomes thicker as it goes toward the anastomosis receiving portion.

[0009] The first blood vessel mounting portion includes a first cylindrical portion into which a blood vessel is fitted, a first cylindrical portion that connects the first cylindrical portion and the anastomosis receiving portion and has a diameter smaller than that of the first cylindrical portion, and a first tapered portion that is provided in an upper region of the first cylindrical portion and has a slope that narrows inward.

[0010] The above anastomotic receiving portion includes a second tapered portion having a slope that is narrowed inward and is connected to the first blood vessel mounting portion, and a cylindrical groove portion connected to an end portion having a minimum diameter of the second tapered portion.

[0011] The second blood vessel mounting portion is connected to the anastomosis receiving portion and has a slope that widens outward toward the anastomosis receiving portion, and includes a mismatch prevention portion having a maximum diameter larger than the maximum diameter of the anastomosis receiving portion, a second cylindrical portion connected to an end having a minimum diameter of the mismatch prevention portion and into which a blood vessel is fitted, and a third tapered portion provided in a lower region of the second cylindrical portion and having a slope that narrows inward.

[0012] The above stent has an artificial blood vessel attached to the first blood vessel attachment portion, an autologous blood vessel attached to the second blood vessel attachment portion, and a suture that anastomoses the artificial blood vessel and the autologous blood vessel is placed in the anastomotic receiving portion.

[0013] The above stent comprises one or more titanium alloys selected from the group consisting of Ti-6Al-4V-ELI, Ti-6Al-7Nb, Ti-6Al-4V, Ti-6Al-6V-2Sn and Ti62A.

[0014] The above stent includes an anti-thrombotic layer coated on the exterior and interior.

[0015] The above anti-thrombotic layer is coated after the stent is oxidized and silanized.

[0016] In order to achieve the second object, the present invention provides a method of using a stent for end-to-end anastomosis, the method comprising the steps of preparing a stent including a first vascular attachment portion having a first hollow structure, an anastomosis receiving portion having a second hollow structure formed integrally with the first vascular attachment portion and connected to the first hollow structure, and a second vascular attachment portion connected to the anastomosis receiving portion and in which the second hollow structure is continuous, a step of mounting a first blood vessel on the first vascular attachment portion, a step of mounting a second blood vessel on the second vascular attachment portion, and a step of anastomosis of the first blood vessel and the second blood vessel on the anastomosis receiving portion.

[0017] The first blood vessel is an autologous blood vessel or an artificial blood vessel, and the second blood vessel is an autologous blood vessel.

[0018] In the step of preparing the above stent, a process of forming an anti-thrombotic layer on the exterior and interior of the stent is further included.

[0019] The process for forming the above-mentioned anti-thrombotic layer includes a process for forming a titanium oxide layer by immersing the stent in a sodium hydroxide solution, a process for silanizing the stent on which the titanium oxide layer has been formed by immersing the stent in a 3-aminopropyltriethoxysilane (APTES) solution, and a process for forming the anti-thrombotic layer by immersing the silanized stent in an anti-thrombotic drug solution.

[0020] The above antithrombotic drug solution contains heparin, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC), and N-hydroxysuccinimide (NHS).

[0021] The process of immersing the above stent in a sodium hydroxide solution is performed at a temperature of 80 to 90°C for 24 to 30 hours.

[0022] The process of immersing the stent having the titanium oxide layer formed thereon in a 3-aminopropyltriethoxysilane solution is performed for 10 to 12 hours with a 2 to 4% v / v 3-aminopropyltriethoxysilane solution.

[0023] The process of immersing the above-mentioned silanized stent in an antithrombotic drug solution is performed at room temperature for 24 to 30 hours.

[0024] According to the present invention described above, an artificial blood vessel and an autologous blood vessel can be easily sutured, thereby preventing the occurrence of thrombosis.

[0025] In addition, the single-stage anastomosis stent of the present invention has high bio-affinity based on a titanium alloy (Ti alloy) material, and can prevent vascular misalignment, which is a phenomenon in which blood vessels are rolled up by suturing during microsurgery.

[0026] In addition, the stent for single-stage anastomosis of the present invention has biocompatibility that does not cause an immune rejection reaction, and can also be used to replace human blood vessels.

[0027] In addition, the single-stage anastomosis stent of the present invention supports flexible blood vessels, thereby reducing surgical time and shortening the patient's recovery time.

[0028] The technical effects of the present invention are not limited to those mentioned above, and other technical effects not mentioned will be clearly understood by those skilled in the art from the description below.

[0029] Figure 1 is a front view of a stent for single-stage anastomosis according to one embodiment of the present invention.

[0030] Figure 2 is a cross-sectional view of a stent for single-stage anastomosis according to one embodiment of the present invention.

[0031] FIG. 3 is an image of stents for single-stage anastomosis having various diameters according to one embodiment of the present invention.

[0032] Figure 4 is a schematic diagram showing a method of inserting a stent for single-stage anastomosis into an artificial blood vessel and an autologous blood vessel according to one embodiment of the present invention.

[0033] FIG. 5(a) and FIG. 5(b) are a schematic diagram and an actual image showing a stent for single-stage anastomosis according to one embodiment of the present invention inserted into an artificial blood vessel or an autologous blood vessel.

[0034] Figure 6 is an image showing a stent for single-stage anastomosis according to one embodiment of the present invention inserted into both ends of an artificial blood vessel.

[0035] Figure 7 is a schematic diagram showing a step of forming an anti-thrombotic layer according to one embodiment of the present invention.

[0036] Figure 8 is an image showing an artificial blood vessel transplanted into a pig's carotid artery with or without a stent according to one embodiment of the present invention.

[0037] Figure 9 is an image showing the graft site 3 days after the artificial blood vessel was grafted using a stent into the carotid artery of the pig in Figure 9.

[0038] Figure 10 shows the results of ultrasound blood flow evaluation performed before vascular grafting in the carotid artery of a pig according to one embodiment of the present invention.

[0039] Figure 11 shows the results of an ultrasound blood flow evaluation performed after a small-diameter artificial blood vessel was transplanted by end-to-end anastomosis using a stent in the carotid artery of a pig according to one embodiment of the present invention.

[0040] Figure 12 is an image showing a cross-section of a sample taken 7 days after transplantation of a small-diameter artificial blood vessel using a stent into the carotid artery of a pig by end-to-end anastomosis according to one embodiment of the present invention.

[0041] Figure 13 is an image showing a blood vessel sutured using a conventional blood vessel suture method.

[0042] Hereinafter, an embodiment of the present invention will be described in detail with reference to the attached drawings.

[0043] While the present invention is susceptible to numerous modifications and variations, specific embodiments thereof are illustrated in the drawings and will be described in detail below. However, the invention is not intended to be limited to the particular forms disclosed; rather, the invention includes all modifications, equivalents, and alternatives consistent with the spirit of the invention as defined by the claims.

[0044] When an element such as a layer, region or substrate is referred to as existing "on" another element, it will be understood that this may be directly on the other element, or that there may be intermediate elements in between.

[0045] Although the terms first, second, etc. may be used to describe various elements, components, regions, layers and / or regions, it will be understood that these elements, components, regions, layers and / or regions should not be limited by these terms.

[0046]

[0047] Example

[0048] FIG. 1 is a front view of a stent for single-sided anastomosis according to one embodiment of the present invention, and FIG. 2 is a cross-sectional view of a stent for single-sided anastomosis according to one embodiment of the present invention.

[0049] Referring to FIGS. 1 and 2, the single-stage anastomosis stent of the present invention may include a first vascular attachment portion (100) having a first hollow structure (420), an anastomosis receiving portion (200) having a second hollow structure (440) integrally formed with the first vascular attachment portion (100) and connected to the first hollow structure (420), and a second vascular attachment portion (300) connected to the anastomosis receiving portion (200) and in which the second hollow structure (440) is continuous.

[0050] The first blood vessel mounting portion (100) may have a first hollow structure (420) formed inside that radially increases in diameter toward one end, and may have a cylindrical shape on the outside. The anastomosis receiving portion (200) may be formed integrally with the first blood vessel mounting portion (100) and connected to an end having a minimum diameter of the first hollow structure (420), and may have a second hollow structure (440) formed inside that has the same diameter, and may have a groove having a step with respect to the first blood vessel mounting portion (100) on the outside. The second blood vessel mounting portion (300) may be formed integrally with the anastomosis receiving portion (200), such that the second hollow structure (440) is continuous, and may have a cylindrical shape on the outside, but a portion of an upper region connected to the anastomosis receiving portion (200) may become thicker toward the anastomosis receiving portion (200). The stent of the present invention can be used to anastomose (or suture) the blood vessels by inserting each end of the stent into the end of an autologous blood vessel and / or an artificial blood vessel. The end-to-end anastomosis refers to anastomosing the end of one blood vessel with the end of another blood vessel, and may also be referred to as an end-to-end anastomosis.

[0051] The above first blood vessel mounting portion (100) is configured to mount an end of a blood vessel to be anastomosed, and can perform a function of effectively supporting the mounted end of the blood vessel even during the suturing process.

[0052] FIG. 3 is an image of stents for single-stage anastomosis having various diameters according to one embodiment of the present invention.

[0053] As shown in Fig. 3, the diameter of the first blood vessel attachment part (100) can be configured in various ways, and a diameter suitable for the diameter (or inner diameter) of the blood vessel to be anastomosed can be used.

[0054] The first blood vessel mounting portion (100) may include an exterior having a specific shape and a hollow interior structure, as described below. Since the blood vessel end must be fitted onto the first blood vessel mounting portion (100), the exterior of the first blood vessel mounting portion (100) may be formed in a structure that facilitates the fitting of the blood vessel end.

[0055] Specifically, the first blood vessel mounting portion (100) may include a first-first cylindrical portion (110) into which a blood vessel is fitted, a first-second cylindrical portion (130) that connects the first-first cylindrical portion (110) and the anastomosis receiving portion (200) and has a diameter smaller than that of the first-first cylindrical portion (110), and a first tapered portion (150) that is provided in an upper region of the first-first cylindrical portion (110) and has a slope that narrows inward.

[0056] The above 1-1 cylindrical portion (110) may be provided in a hollow cylindrical shape similar to the shape of a blood vessel, since a blood vessel is fitted and mounted on the 1-1 cylindrical portion (110). Accordingly, the blood vessel mounted on the 1-1 cylindrical portion (110) can be effectively supported.

[0057] The above 1-2 cylindrical portion (130) may be configured to integrally connect the 1-1 cylindrical portion (110) with the anastomosis receiving portion (200). Since the 1-2 cylindrical portion (130) is provided in a cylindrical shape having a diameter smaller than that of the 1-1 cylindrical portion (110), a step may be provided between the 1-1 cylindrical portion (110) and the 1-2 cylindrical portion (130). By virtue of this step, the user can easily mount the blood vessel to be anastomosis onto the 1-1 cylindrical portion (110) by holding or supporting the 1-2 cylindrical portion (130) when mounting the blood vessel onto the 1-1 cylindrical portion (110).

[0058] The first tapered portion (150) is arranged in the upper region of the first-first cylindrical portion (110) and may be formed integrally with the first-first cylindrical portion (110). As shown in Fig. 1, the first tapered portion (150) may have a slope that narrows inwardly toward the uppermost portion from the first-first cylindrical portion (110) having a diameter of a certain size. Through this, the first tapered portion (150) may help facilitate the insertion of the first-first cylindrical portion (110) into the blood vessel when mounting the blood vessel on the first-first cylindrical portion (110).

[0059] The interior of the first blood vessel mounting portion (100) may include a first hollow structure (420), as shown in FIG. 2. The first hollow structure (420) may be provided in a shape in which the diameter (diameter of the hollow structure) increases radially from the first-second cylindrical portion (130), which is the lower portion of the first blood vessel mounting portion (100), to the first tapered portion (150), which is the upper portion of the first blood vessel mounting portion (100). Accordingly, smooth movement of blood flow within the blood vessel mounted on the first blood vessel mounting portion (100) can be induced.

[0060] The anastomosis receiving portion (200) may be provided between the first blood vessel mounting portion (100) and the second blood vessel mounting portion (300), on which two blood vessels to be anastomoseed are mounted, to connect them. In addition, the anastomosis receiving portion (200) may provide a space in which anastomosis is performed between the blood vessel mounted on the first blood vessel mounting portion (100) and the blood vessel mounted on the second blood vessel mounting portion (300). To this end, the anastomosis receiving portion (200) may include an outer surface having a specific shape described below and a hollow inner structure. The outer surface of the anastomosis receiving portion (200) may be provided so that the first blood vessel mounting portion (100) and the second blood vessel mounting portion (300) may be connected as one body while performing their own functions, while also providing a space for performing anastomosis of two blood vessels and preventing misalignment of the anastomosis portion.

[0061] Specifically, the anastomosis receiving portion (200) may include a second tapered portion (210) having a slope that is narrowed inward and is connected to the first blood vessel mounting portion (100), and a cylindrical groove portion (230) connected to an end portion of the second tapered portion (210) having a minimum diameter.

[0062] The second tapered portion (210) may be positioned at the lower portion of the first blood vessel mounting portion (100), that is, at the lower portion of the first-second cylindrical portion (130), and may be integrally connected with the first blood vessel mounting portion (100). The second tapered portion (210) may have a slope that starts from the lower portion of the first blood vessel mounting portion (100) and narrows inward. By the second tapered portion (210), the groove portion (230) described below may be formed to have a diameter smaller than the diameter of the first blood vessel mounting portion (100), and may form an exterior that is flexibly integrally connected with the first blood vessel mounting portion (100).

[0063] The above-mentioned groove (230) is arranged in a cylindrical shape at the lower portion of the second tapered portion (210) and can be integrally connected with the second tapered portion (210). Since the groove (230) is arranged at the lower portion of the second tapered portion (210) having an inwardly narrowing slope, it can be connected to an end portion of the second tapered portion (210) having a minimum diameter. Accordingly, since the groove (230) has a smaller diameter than the upper diameters of the first blood vessel mounting portion (100) and the second blood vessel mounting portion (300) described below, it can be arranged with a step from the first blood vessel mounting portion (100) and the second blood vessel mounting portion (300). That is, the groove (230) can form a sunken space (groove) due to a relatively low step difference compared to the lower region of the first blood vessel mounting portion (100) and the upper region of the second blood vessel mounting portion (200). This space can be used as a place where the blood vessel mounted on the first blood vessel mounting portion (100) and the blood vessel mounted on the second blood vessel mounting portion (200) can be anastomosed and the anastomosed suture can be placed.

[0064] The interior of the above-described anastomosis receiving portion (200) may include a second hollow structure (440), as shown in FIG. 2. The second hollow structure (440) may be connected to an end having a minimum diameter of the first hollow structure (420) so as to have a diameter the same size as the minimum diameter of the first hollow structure (420). In addition, the first hollow structure (420) and the second hollow structure (440) may be provided to penetrate each other.

[0065] The second blood vessel mounting portion (300) is configured to mount an end of a blood vessel to be anastomosed, and can support the mounted end of the blood vessel. As shown in FIG. 3, the diameter of the second blood vessel mounting portion (300) can be configured in various ways, and a portion having a diameter suitable for the diameter of the blood vessel to be anastomosed can be used. The second blood vessel mounting portion (300) can include an outer surface having a specific shape described below and a hollow inner structure. Since the end of the blood vessel must be fitted onto the second blood vessel mounting portion (300), the outer surface of the second blood vessel mounting portion (300) can be provided with a structure that makes it easy to fit the end of the blood vessel.

[0066] Specifically, the second blood vessel mounting portion (300) may include a mismatch prevention portion (310) that is connected to the anastomosis receiving portion (200) and has a slope that widens outward toward the anastomosis receiving portion (200) and has a maximum diameter that is larger than the maximum diameter of the anastomosis receiving portion (200), a second cylindrical portion (330) that is connected to an end portion of the mismatch prevention portion (310) that has a minimum diameter and on which a blood vessel is fitted, and a third tapered portion (350) that is provided in a lower region of the second cylindrical portion (330) and has a slope that narrows inward.

[0067] The above misalignment prevention unit (310) may be connected to the anastomosis receiving unit (200) and may be provided as an integral part with the anastomosis receiving unit (200). The misalignment prevention unit (310) may be provided in a shape having a slope that widens outward toward the anastomosis receiving unit (200). Accordingly, the maximum diameter of the misalignment prevention unit (310) may be larger than the maximum diameter of the anastomosis receiving unit (200). That is, since the misalignment prevention unit (310) is provided with a larger diameter in the area where the misalignment prevention unit (310) and the anastomosis receiving unit (200) are connected, the misalignment phenomenon in which the blood vessel of the anastomosis site disposed in the anastomosis receiving unit (200) is rolled up and sutured can be prevented, and the state during anastomosis can be maintained as much as possible.

[0068] The second cylindrical portion (330) may be connected to the misalignment prevention portion (310) and may be formed integrally with the misalignment prevention portion (300). Since the blood vessel to be anastomosed is fitted into the second cylindrical portion (330), the second cylindrical portion may be formed in a hollow cylindrical shape similar to the shape of the blood vessel. Accordingly, the blood vessel mounted on the second cylindrical portion (330) can be effectively supported.

[0069] The third tapered portion (350) is positioned in the lower region of the second cylindrical portion (330) and may be formed integrally with the second cylindrical portion (330). As shown in Fig. 1, the third tapered portion (350) may have a slope that narrows inwardly toward the lowermost end from the second cylindrical portion (330) having a predetermined diameter. Through this, the third tapered portion (350) may help facilitate the insertion of the second cylindrical portion (330) into the blood vessel when the blood vessel is mounted on the second cylindrical portion (330).

[0070] The interior of the second blood vessel mounting portion (300) may be provided such that the second hollow structure (440) of the anastomosis receiving portion (200) is continuous, as shown in FIG. 2. The second hollow structure (440) may be continuous from the interior of the anastomosis receiving portion (200) to the interior of the second blood vessel mounting portion (300) while maintaining the same diameter. Accordingly, the first hollow structure (420) and the second hollow structure (440) may have a trumpet shape.

[0071] FIG. 4 is a schematic diagram showing a method of inserting a stent for end-to-end anastomosis according to one embodiment of the present invention into an artificial blood vessel and an autologous blood vessel, FIG. 5 is a cross-sectional view showing a form in which a stent for end-to-end anastomosis according to one embodiment of the present invention is inserted into an artificial blood vessel and an autologous blood vessel, and FIG. 6 is an image showing a form in which a stent for end-to-end anastomosis according to one embodiment of the present invention is inserted into both ends of an artificial blood vessel.

[0072] As shown in FIGS. 4 to 6, the single-stage anastomosis stent (1) of the present invention can be applied as a docking site for transplanting an artificial blood vessel, thereby effectively transplanting the first blood vessel (10) between second blood vessels (20). In one embodiment, the first blood vessel (10) may be an artificial blood vessel, and the second blood vessel (20) may be an autologous blood vessel. That is, the stent (1) may be configured such that an artificial blood vessel is coupled to the first blood vessel mounting portion (100), an autologous blood vessel is coupled to the second blood vessel mounting portion (300), and a suture (not shown) for anastomosing the artificial blood vessel and the autologous blood vessel may be placed in the anastomosis receiving portion (200).

[0073] Specifically, as shown in FIG. 5(a) and FIG. 5(b), the suture point (P) where the first blood vessel (10) and the second blood vessel (20) are joined may mean an area where the first blood vessel (10) and the second blood vessel (20) come into contact.

[0074] The above stent may include one or more titanium alloys selected from the group consisting of Ti-6Al-4V-ELI, Ti-6Al-7Nb, Ti-6Al-4V, Ti-6Al-6V-2Sn, and Ti62A. Since the above-described titanium alloys are biocompatible and do not cause immune rejection, they can be applied as materials for the end-to-end anastomosis stent of the present invention to improve the biocompatibility and biocompatibility of the stent within the blood vessel during end-to-end anastomosis.

[0075] The stent may further include an anti-thrombotic layer coated on the exterior and interior of the stent. That is, the stent for end-to-end anastomosis of the present invention may be coated with an anti-thrombotic layer on the exterior surface and the entire interior having the first hollow structure (420) and the second hollow structure (440). The anti-thrombotic layer may help prevent thrombosis at the contact site with the inserted stent or the anastomosis site when blood flow within the blood vessels that are end-to-end anastomosis is moved by inserting the stent. The anti-thrombotic layer may include a substance that prevents thrombosis. Specifically, the anti-thrombotic layer may include an anti-thrombotic drug solution including heparin, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC), and N-hydroxysuccinimide (NHS).

[0076] The above anti-thrombotic layer can be coated after the stent is oxidized and silanized. That is, by performing a pretreatment of oxidizing and silanizing the stent before coating the anti-thrombotic layer on the exterior and interior of the stent, the anti-thrombotic layer can be coated more effectively. Specifically, by oxidizing the titanium alloy material constituting the stent, titanium oxide can be formed on the surface, and when the formed titanium oxide is silanized, a silane group is introduced into the titanium oxide, and as the anti-thrombotic material is attached to the introduced silane group, a strong bond can be formed, so that the coating strength can be increased compared to when coating directly on a titanium alloy material having a smooth surface.

[0077] As described above, the stent for end-to-end anastomosis of the present invention not only prevents vascular misalignment and improves blood flow disturbance after anastomosis through its structural features, but also provides an anti-thrombotic layer coated over the entire surface of the stent, thereby preventing thrombosis after end-to-end anastomosis surgery, thereby enabling faster recovery of the patient.

[0078]

[0079] Another aspect of the present invention provides a method of using the stent for end-to-end anastomosis described above. The method of using the stent for end-to-end anastomosis may include the steps of preparing a stent including a first vascular attachment portion having a first hollow structure, an anastomosis receiving portion having a second hollow structure formed integrally with the first vascular attachment portion and connected to the first hollow structure, and a second vascular attachment portion connected to the anastomosis receiving portion and in which the second hollow structure is continuous, a step of mounting a first blood vessel on the first vascular attachment portion, a step of mounting a second blood vessel on the second vascular attachment portion, and a step of anastomosis of the first blood vessel and the second blood vessel on the anastomosis receiving portion.

[0080] First, a stent having the shape and internal structure described above can be prepared. Any conventional method can be used for the step of preparing the stent. Specifically, for example, lathe processing or 3D printing can be used.

[0081] In the step of preparing the above stent, as shown in FIGS. 1 and 2, the description of the appearance and internal structure of the first blood vessel attachment portion (100), the anastomosis receiving portion (200), and the second blood vessel attachment portion (300) can be based on the description of the structure of the stent for single-end anastomosis described above.

[0082] The above stent may include one or more titanium alloys selected from the group consisting of Ti-6Al-4V-ELI, Ti-6Al-7Nb, Ti-6Al-4V, Ti-6Al-6V-2Sn, and Ti62A. Since the above-described titanium alloys are biocompatible and do not cause immune rejection, they can be applied as materials for the end-to-end anastomosis stent of the present invention to improve the biocompatibility and biocompatibility of the stent within the blood vessel during end-to-end anastomosis.

[0083] Then, as shown in FIGS. 4 to 6, the first blood vessel (10) can be mounted on the first blood vessel mounting portion (100) of the stent (1). The first blood vessel (10) can be fitted onto the first blood vessel mounting portion (100) so that the internal structure of the first blood vessel mounting portion (100) and the interior of the first blood vessel (10) can be connected.

[0084] After this, the second blood vessel (20) can be mounted on the second blood vessel mounting portion (200) of the stent (1). The second blood vessel (20) can be fitted onto the second blood vessel mounting portion (200) so that the internal structure of the second blood vessel mounting portion (200) and the interior of the second blood vessel (20) can be connected.

[0085] Then, the first blood vessel (10) and the second blood vessel (20) can be anastomosed. Accordingly, a suture (not shown) that anastomoses the first blood vessel (10) and the second blood vessel (20) can be placed on the anastomotic receiving portion (200) of the stent (1).

[0086] The first blood vessel (10) may be an autologous blood vessel or an artificial blood vessel (20), and the second blood vessel (20) may be an autologous blood vessel. FIGS. 4 to 6 illustrate examples of the stent of the present invention used in end-to-end anastomoses between an autologous blood vessel and an artificial blood vessel. Depending on the embodiment, the stent may also be used in end-to-end anastomoses between an autologous blood vessel and an autologous blood vessel. In this case, the diameters of the first blood vessel attachment portion (100) and the second blood vessel attachment portion (300) of the stent may be provided to be the same size.

[0087] As described above, the method of using the end-to-end anastomosis stent of the present invention can effectively prevent misalignment when inserting blood vessels into the stent and performing anastomosis. Generally, when suturing small-diameter blood vessels with a diameter of less than 3 mm or capillaries with a diameter of less than 1 mm, the blood vessels can be twisted, resulting in a misalignment of 0.5 to 1.0 mm, which can result in a 16 to 50% vascular occlusion. The present invention can prevent such misalignment through the stent having the above-described characteristics and the method of using the same. In addition, by preventing misalignment, turbulence in blood flow can be minimized, thereby reducing the occurrence of fibrosis or thrombosis. This minimization of blood flow turbulence can reduce blood flow resistance, thereby improving blood compatibility. In addition, the stent for single-stage anastomosis of the present invention can support a flexible blood vessel for easy suturing, thereby shortening the time required for anastomosis during anastomosis surgery.

[0088] The step of preparing the stent may further include a step of forming an anti-thrombotic layer on the exterior and interior of the stent. After the step of preparing the stent, an anti-thrombotic layer may be formed on the entire surface of the stent, including the exterior and interior. The anti-thrombotic layer may help prevent thrombosis at the contact site with the inserted stent or the anastomosis site when blood flow moves within the blood vessels that are anastomosed by inserting the stent. The anti-thrombotic layer may include a substance that prevents thrombosis.

[0089] Specifically, the antithrombotic layer can be formed using an antithrombotic drug solution. The antithrombotic drug solution can include heparin, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC), and N-hydroxysuccinimide (NHS). The heparin, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC), and N-hydroxysuccinimide (NHS) can be mixed and used in a ratio suitable for preventing thrombosis. In one embodiment, to perform covalent binding of heparin within the antithrombotic drug solution, heparin, EDC and NHS may be dissolved in a 0.1 M MES buffer (2-[N-morpholino]ethanesulfonic acid, 2-(N-morpholino)ethanesulfonic acid) solution at pH 5.5.

[0090] The above heparin is a type of sugar that can selectively interact with various proteins in plasma through the negative charge of the sulfate group and the three-dimensional structure formed by the sugar chain, and can be a substance that exhibits an anticoagulant effect on blood.

[0091] The above 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC) and N-hydroxysuccinimide (NHS) may be added together with the heparin to activate the -COOH group of the heparin.

[0092] Figure 7 is a schematic diagram showing a process for forming an anti-thrombotic layer according to one embodiment of the present invention.

[0093] Referring to FIG. 7, the process of forming the anti-thrombotic layer may include a process of forming a titanium oxide layer by immersing the stent in a sodium hydroxide solution, a process of silanizing the stent on which the titanium oxide layer has been formed by immersing the stent in a 3-aminopropyltriethoxysilane (APTES) solution, and a process of forming the anti-thrombotic layer by immersing the silanized stent in an anti-thrombotic drug solution.

[0094] Specifically, in order to oxidize the stent, a stent made of a titanium alloy material (including Ti-6Al-4V in one embodiment) may be immersed in a sodium hydroxide solution to form a titanium oxide layer (or AlOH may also be formed) on the surface of the stent. Accordingly, as shown in Fig. 7, a plurality of OH groups are arranged on the surface of the stent, and the surface may be changed into a hydrophilic surface.

[0095] The process of immersing the stent in the sodium hydroxide solution may be performed at a temperature of 80 to 90°C for 24 to 30 hours. If the temperature of the stent in the sodium hydroxide solution is lower than 80°C or the immersion time is less than 24 hours, titanium oxide may not be sufficiently formed on the surface of the stent through the sodium hydroxide, making effective pretreatment difficult. Furthermore, if the temperature of the stent in the sodium hydroxide solution exceeds 90°C or the immersion time exceeds 30 hours, side reactions that degrade the coating performance may occur or the coating time may increase.

[0096] Then, the stent having the titanium oxide layer formed thereon can be immersed in a 3-aminopropyltriethoxysilane (APTES) solution to perform a silanization process. As a result, as shown in FIG. 7, the -OH group disposed on the surface of the stent is silanized, NH2 is disposed at the terminal, and an amino group is formed, so that the surface of the stent can be pretreated and changed into a hydrophobic surface.

[0097] The process of immersing the stent having the titanium oxide layer formed thereon in a 3-aminopropyltriethoxysilane solution can be performed for 10 to 12 hours with a 2 to 4% v / v 3-aminopropyltriethoxysilane solution. If the concentration of the 3-aminopropyltriethoxysilane solution (APTES) is less than 2% v / v or the immersion time is less than 10 hours, the silanization treatment is not performed well, making it difficult to achieve the target coating strength. In addition, if the concentration of the 3-aminopropyltriethoxysilane solution (APTES) exceeds 4% v / v or the immersion time exceeds 12 hours, the 3-aminopropyltriethoxysilane solution (APTES) may form a multilayer on the titanium oxide layer, which may affect the properties of the antithrombotic layer and the stent.

[0098] Thereafter, a process of forming an anti-thrombotic layer by immersing the silanized stent in an anti-thrombotic drug solution can be performed. Accordingly, as shown in Fig. 7, heparin is bound to -NH2, and the heparin, which has the function of preventing thrombosis, has a strong coating power on the stent including the titanium alloy material, and can be effectively coated on the entire exterior and interior of the stent.

[0099] The process of immersing the silanized stent in the antithrombotic drug solution can be performed at room temperature for 24 to 30 hours. Room temperature can mean laboratory temperature or room temperature, and can generally be 25°C. If the time for immersing the silanized stent in the antithrombotic drug solution is less than 24 hours, the reaction between the pretreated stent and the antithrombotic drug solution may not sufficiently occur, resulting in a decrease in the antithrombotic efficacy. In addition, if the time for immersing the silanized stent in the antithrombotic drug solution exceeds 30 hours, uncoated residues may remain on the surface of the stent, which may increase the time required to clean them or cause the coating to be formed unevenly.

[0100] As described above, the method of using the stent for single-stage anastomosis of the present invention prepares a stent having the above-described structure and provides an anti-thrombotic layer to the prepared stent, thereby preventing misalignment, improving blood flow disturbance, and preventing thrombosis, thereby further enhancing the biocompatibility and suitability of the stent, and can be effective in the surgical outcome and patient recovery.

[0101] Hereinafter, preferred manufacturing examples and experimental examples are presented to aid in understanding the present invention. However, the following manufacturing examples and experimental examples are provided solely to aid in understanding the present invention, and the present invention is not limited to the following manufacturing examples.

[0102] <Manufacturing Example 1>

[0103] A stent for end-to-end anastomosis was manufactured, including a first hollow structure having an internal portion having a radially increasing diameter toward one end and a first vascular attachment portion having a cylindrical exterior, a second hollow structure having the same diameter as the internal portion and an anastomosis receiving portion having a groove having a step with the first vascular attachment portion and an end portion having a minimum diameter of the first hollow structure, and a second vascular attachment portion having a cylindrical exterior portion having an upper portion connected to the anastomosis receiving portion so that the second hollow structure is continuous, and a second vascular attachment portion having a cylindrical exterior portion, and a portion of an upper region connected to the anastomosis receiving portion becomes thicker toward the anastomosis receiving portion. The stent was composed of Ti-6Al-4V-ELI and was manufactured using a bio metal 3D printer.

[0104] The above stent was ultrasonically cleaned with acetone, isopropyl alcohol (IPA), ethanol, and distilled water (DI water) for 10 minutes each. The cleaned stent sample was immersed in a 2N sodium hydroxide (NaOH) solution and reacted at 80°C for 6 hours to form titanium oxide on the surface of the stent sample, and then thoroughly washed with distilled water. The stent sample on which the titanium oxide was formed was immersed in a 3% v / v 3-aminopropyltriethoxysilane (APTES) solution to silaneize. The silanized stent was immersed in an antithrombotic drug solution containing 5 mg / ml heparin, 200 mM 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC), and 100 mM N-hydroxysuccinimide (NHS) for 12 hours at laboratory temperature (25°C) to form an antithrombotic layer on the surface of the stent.

[0105] <Experimental Example 1>

[0106] Using the stent and small-diameter artificial blood vessel manufactured in the above Manufacturing Example 1, the autologous blood vessel and the artificial blood vessel were transplanted into the porcine carotid artery by end-to-end anastomosis, and then performance evaluation was conducted. The inside of the small-diameter artificial blood vessel was also coated with the above antithrombotic drug solution.

[0107] The average weight of pigs used for surgery was 40 to 45 kg. To prevent thrombosis during surgery, 10,000 to 30,000 IU of heparin was dissolved in 1 L of Ringer's solution and injected at a rate of 30 drops per minute. As an antibiotic (dose: 20 to 40 mg / kg), 1 g of cefazol diluted in 2 to 3 mL of lidocaine solution was administered intramuscularly twice a day every 8 to 12 hours during the surgery. If symptoms were severe, 2 to 3 g of cefazol was administered, and cefazol was administered for at least 5 to 7 days after surgery. As an analgesic (dose: 1 to 4 mg / kg), tramadol (product name: 50 mg / mL Hanol tramadol hydrochloride injection) was administered intramuscularly at a dose of 50 to 100 mg every 6 to 8 hours. However, the daily dose was not to exceed 400 mg. Tramadol was administered for at least 3 to 5 days after surgery.

[0108] After surgery, the incision site was covered with a skin bond, and 250 mg or 500 mg of amoxicillin was administered orally three times a day as an antibiotic, and 500 mg of aspirin was administered orally once a day as an anticoagulant and analgesic.

[0109] The schedule of surgery and medication during the surgery for the experiment is shown in Table 1 below.

[0110] ScheduleDay 0Day 1Day 2Day 3Day 4Day 5Day 6Day 79:00Surgery preparation, heparin administrationAmoxicillin, aspirin 1 tabletAmoxicillin, aspirin 1 tabletAmoxicillin, aspirin 1 tabletAmoxicillin, aspirin 1 tabletAmoxicillin, aspirin 1 tabletAmoxicillin, aspirin 1 tabletAmoxicillin, aspirin 1 tabletTest18:00Artificial blood vessel transplantation (1.5 vials of tramadol each, 1g of cefazol each)Amoxicillin, aspirin 1 tabletAmoxicillin, aspirin 1 tabletAmoxicillin, aspirin 1 tabletAmoxicillin, aspirin 1 tabletAmoxicillin, aspirin 1 tablet

[0111] <Experimental Example 2>

[0112] As a control group, all conditions and methods were identical to those in Experimental Example 1 except that a stent was used. Then, autologous and artificial blood vessels were transplanted into the carotid artery of a pig using end-to-end anastomosis, and then performance evaluation was conducted. For the average value, the transplantation was performed identically in two pigs.

[0113] Fig. 8 is an image showing an artificial blood vessel transplanted into a pig carotid artery with or without a stent according to one embodiment of the present invention. In Fig. 8, SVG stands for small vascular graft. Specifically, the image on the left of Fig. 8 is a control group in which an artificial blood vessel was transplanted without using the stent of the present invention in Experimental Example 2, and the image on the right is an image in which an artificial blood vessel was transplanted using the stent of the present invention in Experimental Example 1.

[0114] As shown in the left image of Figure 8, Experimental Example 1, which used a stent and artificial vessel together, demonstrated smoother pulsation than the case where only an artificial vessel was used without a stent. Furthermore, bleeding at the docking site was reduced when a stent was used to transplant an artificial vessel. Furthermore, the surgical time for transplanting an artificial vessel using a stent was reduced by half compared to conventional surgery.

[0115] After performing all conditions and methods identically, autologous and artificial blood vessels were transplanted into the porcine carotid arteries via end-to-end anastomosis, and performance was evaluated. For average values, the transplants were performed identically in two pigs.

[0116] Figure 9 is an image showing the graft site 3 days after the artificial blood vessel was grafted using a stent into the carotid artery of the pig in Figure 9.

[0117] That is, Fig. 9 shows the results of observing the transplant site 3 days after transplanting an artificial blood vessel using a stent in Experimental Example 1, and pulsation was observed in the carotid artery of the pig. On the other hand, when the artificial blood vessel was transplanted without using a stent in Experimental Example 2, pulsation was not felt 3 days later. This can be seen as a result of the stent for end-to-end anastomosis of the present invention being inserted into the autologous blood vessel and the artificial blood vessel, as in Experimental Example 1, preventing misalignment of the anastomosis and minimizing turbulence of blood flow or problems resulting therefrom, thereby showing a good outcome during transplantation and after transplantation.

[0118] Fig. 10 shows the results of ultrasound blood flow evaluation performed before blood vessel transplantation in the carotid artery of a pig according to one embodiment of the present invention, and Fig. 11 shows the results of ultrasound blood flow evaluation performed after transplantation of a small-diameter artificial blood vessel using a stent into the carotid artery of a pig by end-to-end anastomosis according to one embodiment of the present invention (Experimental Example 1). Table 2 below shows the results of ultrasound blood flow evaluation of five pigs before transplantation surgery, and Table 3 shows the results of ultrasound blood flow evaluation after transplantation of an artificial blood vessel with or without a stent.

[0119] surgery Pig 1 Pig 2 Pig 3 Pig 4 Pig 5 Average PS [cm / s] 25.38 25.25 26.9 4.6 25.76 29.58 ED [cm / s] 4.4 4.6 9 3.9 17.8 5 3.17 4.79 TAMAX [cm / s] 9.5 5 9.5 18.67 15.63 9.88 10.65 TAMEAN [cm / s] 1.9 4.3 5 1.63 5.25 3.0 13.04 PI 2.19 2.16 2.66 2.35 2.29 2.33 RI 0.8 20.8 10.8 6 0.8 20.8 8 0.84 S / D 5.7 15.38 7.0 75.68 8.12 6.39 HR [bpm] 108 107 99 9 4 129 107.4

[0120] Postoperative Experimental Example 2-1 Experimental Example 2-2 Experimental Example 1 PS [cm / s] 19.92 13.83 33.5 ED [cm / s] 2.4 16.34 14.21 TAMAX [cm / s] 5.06 5.27 21.46 TAMEAN [cm / s] 1.10.96 6.47 PI 3.46 1.42 0.9 RI 0.88 0.54 0.58 S / D 8.26 2.18 2.36 HR [bpm] 949 882

[0121] In Tables 2 and 3 above, PS is peak systolic velocity, ED is end-diastolic velocity, TAMAX is time-averaged maximum velocity, TAMEAN is time-averaged mean velocity, PI is pulsatility index, RI is vascular resistance index, S / D is systolic / diastolic ratio, and HR is heart rate. Referring to Figures 10, 11, Tables 2 and 3, PS (peak systolic velocity) was measured to be a similar value from 33.03 cm / s before transplantation to 33.5 cm / s after transplantation, and ED (end-diastolic velocity) was measured to be a larger value from 9.5 cm / s before transplantation to 14.21 cm / s after transplantation. This is thought to be the result of the use of stents and the faster rate of vascular contraction as small-diameter artificial blood vessels are transplanted larger than autologous blood vessels.

[0122] Pre-transplant PI (pulse index, PI=(V max - V min ) / (V mean )) was 1.5, and the PI after transplantation was measured to be 0.9. In addition, the RI (vascular resistance index, which increases when vascular occlusion occurs) before transplantation was 0.71, and the RI after transplantation was measured to be 0.58. It is judged that the pulsation index was measured low because the difference between the systolic and diastolic blood flow velocities after small-diameter artificial blood vessels and stent transplantation was small, and it can be seen that the blood flow resistance was lowered after transplantation. As described above, the stent for end-to-end anastomosis of the present invention can improve the blood flow velocity and vascular resistance in blood vessels due to end-to-end anastomosis.

[0123] Figure 12 is an image showing a cross-section of a sample taken 7 days after transplantation of a small-diameter artificial blood vessel using a stent into the carotid artery of a pig according to one embodiment of the present invention (Experimental Example 1).

[0124] As shown in Fig. 12, a cross-sectional examination of a sample taken 7 days after transplantation confirmed that no cells or other tissues adhered to the end-to-end anastomosis stent and the artificial blood vessel of the present invention. No cells or other tissues adhered to the end-to-end anastomosis stent and the artificial blood vessel. This indicates that the end-to-end anastomosis stent of the present invention can prevent cell proliferation within the blood vessel, thereby reducing blood flow disturbances.

[0125] Figure 13 is an image showing a blood vessel sutured using a conventional blood vessel suture method.

[0126] As shown in the circular symbol in Fig. 13, when sutured using a conventional vascular suture method, the blood vessel may become rolled inward and be sutured. Such rolled-in blood vessels impede blood flow, increase blood flow resistance, and provide sites for neointimal hyperplasia or fibrosis to attach. In addition, the narrowed blood vessel increases pressure, which eventually causes the blood vessel to stretch like an atherosclerosis and may lead to thrombosis and occlusion. Furthermore, when the blood vessel is thin (less than 3 mm), the surgical time may be prolonged because a microscopic suture surgery is performed. As described above, when performing an end-to-end anastomosis using the stent for end-to-end anastomosis of the present invention, it is possible to prevent vascular misalignment caused by rolling in the blood vessel, thereby effectively improving the conventional anastomosis method.

[0127] 1: Stent for single-stage anastomosis

[0128] 10: First blood vessel

[0129] 20: Secondary blood vessel

[0130] 100: First vascular attachment site

[0131] 110: 1-1 Cylinder Section

[0132] 130: 1-2nd cylindrical section

[0133] 150: First taper section

[0134] 200: Anastomotic receptacle

[0135] 210: Second taper section

[0136] 230: Home

[0137] 300: Second blood vessel attachment part

[0138] 310: Mismatch Prevention Department

[0139] 330: Second cylinder

[0140] 350: Third taper section

[0141] 420: First hollow structure

[0142] 440: Second hollow structure

Claims

1. A first blood vessel mounting portion having a first hollow structure inside that radially increases in diameter as it goes toward the first end and having a cylindrical exterior; An anastomosis receiving portion formed integrally with the first blood vessel mounting portion and having a second hollow structure having the same diameter as the first hollow structure and connected to an end having the minimum diameter of the first hollow structure, and having an exterior having a groove having a step with the first blood vessel mounting portion; and A stent for single-stage anastomosis, comprising a second vascular attachment portion formed integrally with the anastomosis receiving portion, wherein the second hollow structure is continuous, has a cylindrical appearance, and a portion of the upper region connected to the anastomosis receiving portion becomes thicker as it goes toward the anastomosis receiving portion.

2. In paragraph 1, The above first blood vessel attachment part is, The 1-1 cylindrical part into which the blood vessel is fitted, A 1-2 cylindrical portion connecting the 1-1 cylindrical portion and the anastomosis receiving portion and having a smaller diameter than the 1-1 cylindrical portion, A stent for single-stage anastomosis, comprising a first tapered portion having a slope that narrows inward and is provided in the upper region of the first-first cylindrical portion.

3. In paragraph 1, The above anastomotic receiving portion is, A second tapered portion connected to the first blood vessel attachment portion and having a slope that narrows inward, A stent for single-stage anastomosis comprising a cylindrical groove portion connected to an end portion having a minimum diameter of the second tapered portion.

4. In paragraph 1, The above second blood vessel attachment part is, A misalignment prevention section connected to the anastomosis receiving section and having a slope that widens outward toward the anastomosis receiving section and has a maximum diameter larger than the maximum diameter of the anastomosis receiving section; A second cylindrical portion connected to the end portion having the minimum diameter of the above misalignment prevention portion and having a blood vessel fitted therein; A stent for single-stage anastomosis, comprising a third tapered portion having a slope that narrows inward and is provided in the lower region of the second cylindrical portion.

5. In paragraph 1, The above stent, An artificial blood vessel is attached to the first blood vessel attachment portion, A magnetic blood vessel is attached to the second blood vessel attachment portion, The above anastomotic receiving portion is a stent for end-to-end anastomotic connection in which a suture that connects the artificial blood vessel and the autologous blood vessel is placed.

6. In paragraph 1, The above stent, A stent for single-stage anastomosis comprising at least one titanium alloy selected from the group consisting of Ti-6Al-4V-ELI, Ti-6Al-7Nb, Ti-6Al-4V, Ti-6Al-6V-2Sn and Ti62A.

7. In paragraph 1, A stent for single-stage anastomosis further comprising an anti-thrombotic layer coated on the exterior and interior of the stent.

8. In paragraph 7, The above anti-thrombotic layer is, A stent for single-stage anastomosis in which the coating is performed after the above stent is oxidized and silanized.

9. A step of preparing a stent including a first vascular attachment portion having a first hollow structure, an anastomotic receiving portion having a second hollow structure formed integrally with the first vascular attachment portion and connected to the first hollow structure, and a second vascular attachment portion connected to the anastomotic receiving portion and in which the second hollow structure is continuous; A step of mounting a first blood vessel on the first blood vessel mounting portion; A step of mounting a second blood vessel on the second blood vessel mounting portion; and A method of using a stent for single-stage anastomosis, comprising: a step of anastomosis of the first blood vessel and the second blood vessel on the anastomosis receiving portion.

10. In paragraph 9, The above first blood vessel attachment part is, The 1-1 cylindrical part into which the blood vessel is fitted, A 1-2 cylindrical portion connecting the 1-1 cylindrical portion and the anastomosis receiving portion and having a smaller diameter than the 1-1 cylindrical portion, A method of using a stent for single-stage anastomosis, comprising a first tapered portion having a slope that narrows inward and is provided in the upper region of the first-first cylindrical portion.

11. In paragraph 9, The above anastomotic receiving portion is, A second tapered portion connected to the first blood vessel attachment portion and having a slope that narrows inward, A method of using a stent for single-stage anastomosis, the stent including a cylindrical groove portion connected to an end portion having a minimum diameter of the second tapered portion.

12. In paragraph 9, The above second blood vessel attachment part is, A misalignment prevention section connected to the anastomosis receiving section and having a slope that widens outward toward the anastomosis receiving section and has a maximum diameter larger than the maximum diameter of the anastomosis receiving section; A second cylindrical portion connected to the end portion having the minimum diameter of the above misalignment prevention portion and having a blood vessel fitted therein; A method of using a stent for single-stage anastomosis, comprising a third tapered portion having a slope that narrows inward and is provided in the lower region of the second cylindrical portion.

13. In paragraph 9, The above first blood vessel is an autologous blood vessel or an artificial blood vessel, The above second blood vessel is a method of using a stent for single-stage anastomosis that is an autologous blood vessel.

14. In paragraph 9, In the step of preparing the above stent, A method of using a stent for single-stage anastomosis, further comprising a process of forming an anti-thrombotic layer on the exterior and interior of the stent.

15. In paragraph 14, The process of forming the above anti-thrombotic layer is as follows: A process of forming a titanium oxide layer by immersing the above stent in a sodium hydroxide solution, A process of silanizing a stent having the titanium oxide layer formed thereon by immersing it in a 3-aminopropyltriethoxysilane (APTES) solution, A method of using a stent for single-stage anastomosis, comprising a process of forming an anti-thrombotic layer by immersing the above-mentioned silanized stent in an anti-thrombotic drug solution.

16. In paragraph 15, The above antithrombotic drug solution is, Method of using a stent for end-to-end anastomosis containing heparin, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC), and N-hydroxysuccinimide (NHS).

17. In paragraph 15, The process of immersing the above stent in a sodium hydroxide solution is as follows: A method of using a stent for single-stage anastomosis performed at a temperature of 80 to 90°C for 24 to 30 hours.

18. In paragraph 15, The process of immersing the stent having the titanium oxide layer formed thereon in a 3-aminopropyltriethoxysilane solution is as follows: A method of using a stent for end-to-end anastomosis performed for 10 to 12 hours with a 2 to 4% v / v 3-aminopropyltriethoxysilane solution.

19. In paragraph 15, The process of immersing the above-mentioned silanized stent in an antithrombotic drug solution comprises: Method of using a stent for single-stage anastomosis performed at room temperature for 24 to 30 hours.

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