Device

Abstract

To provide a technology for anastomosis of an artery and a vein.SOLUTION: A device for anastomosing an artery and a vein includes at least a stent. The stent is cylindrical. The stent is configured to expand in a radial direction. The stent forms a net-like peripheral wall in an expansion state. The stent includes a first engagement part, a second engagement part, and a connection part. The first engagement part is configured to engage with a blood vessel wall of the artery from an artery inner lumen side. The second engagement part is configured to engage with a blood vessel wall of the vein from a vein inner lumen side. The connection part connects the first engagement part and the second engagement part. In the expansion state, the connection part has a maximum diameter smaller than the first engagement part and the second engagement part.SELECTED DRAWING: Figure 9

Description

[Technical Field]

[0001] The present disclosure relates to devices for anastomosis between an artery and a vein. [Background technology]

[0002] For example, when a portion of the stomach is removed as a treatment for stomach cancer, the remaining stomach may be anastomosed to the small intestine to ensure a passage for food and digestive fluids. For example, Patent Document 1 describes a stent for anastomosing the stomach and intestinal tract. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-205931 Summary of the Invention [Problem to be solved by the invention]

[0004] Known treatments for abdominal aortic aneurysms include endovascular stent grafting and open aortic aneurysm resection and bypass surgery. However, these surgeries may be difficult to perform depending on the patient's condition or anatomical reasons. In such cases, reducing the pressure of the abdominal aortic aneurysm may be considered to prevent rupture of the aneurysm. The inventor's extensive research has shown that anastomosis between the abdominal aortic aneurysm and the inferior vena cava can reduce the pressure of the abdominal aortic aneurysm. Furthermore, the inventor's extensive research has shown that reducing arterial pressure by anastomosis between the artery and vein can be effective in treating arterial diseases other than abdominal aortic aneurysms.

[0005] One aspect of the present disclosure preferably provides a technique for anastomosis of an artery and a vein. [Means for solving the problem]

[0006] One aspect of the present disclosure is a device for anastomosis between an artery and a vein, comprising at least a stent. The stent is tubular. The stent is configured to be radially expandable. The stent forms a mesh-like circumferential wall in an expanded state. The stent has a first engagement portion, a second engagement portion, and a connecting portion. The first engagement portion is configured to engage with the vascular wall of the artery from the arterial lumen side. The second engagement portion is configured to engage with the vascular wall of the vein from the venous lumen side. The connecting portion connects the first engagement portion and the second engagement portion. In an expanded state, the connecting portion has a smaller maximum diameter than the first engagement portion and the second engagement portion.

[0007] With this configuration, the device can anastomose an artery and a vein.

[0008] In one aspect of the present disclosure, the device is configured to capture a thrombus in the artery at at least one of the first engaging portion and the connecting portion when the stent is in an expanded state. With this configuration, when the device anastomoses the artery and the vein, it is possible to prevent thrombus from flowing from the artery to the vein.

[0009] In one aspect of the present disclosure, the connection portion may have a reduced diameter portion and an expanded diameter portion. The reduced diameter portion reduces in diameter toward the second engagement portion in an expanded state. The expanded diameter portion increases in diameter toward the second engagement portion in an expanded state. The expanded diameter portion is disposed closer to the second engagement portion than the reduced diameter portion. The device may be configured to capture a thrombus at the reduced diameter portion when the stent is in an expanded state.

[0010] With this configuration, for example, even without placing a separate member capable of capturing thrombi within the stent, it is possible to prevent thrombi from flowing from the artery to the vein when the device anastomoses the artery and the vein.

[0011] According to an aspect of the present disclosure, the catheter may further include a filter configured to allow blood to pass through but not allow thrombus to pass through. The filter may be disposed inside at least one of the first engaging portion and the connecting portion.

[0012] With this configuration, when the device anastomoses an artery and a vein, it is possible to capture a thrombus at at least one of the first engagement portion and the connection portion, regardless of the size of the mesh on the peripheral wall of the stent, for example.

[0013] In one aspect of the present disclosure, the filter may be disposed inside at least the first engaging portion of the first engaging portion and the connecting portion. With this configuration, when the device anastomoses the artery and the vein, the amount of thrombus that may flow into the connecting portion can be further reduced.

[0014] According to one aspect of the present disclosure, a cover configured to prevent blood from passing through and covering the outer periphery of the connection portion may be provided, which can prevent blood from leaking around the artery and vein when the device is anastomosing the artery and vein. [Brief explanation of the drawings]

[0015] [Figure 1] Fig. 1A is a front view of the device in an unexpanded state according to the first embodiment, and Fig. 1B is a front view of Fig. 1A with the cover visible. [Figure 2] Fig. 2A is a front view of the device in an expanded state according to the first embodiment, and Fig. 2B is a front view of Fig. 2A with the cover visible. [Figure 3] 1 is a schematic diagram showing an abdominal aortic aneurysm and inferior vena cava to which the device is applied. [Figure 4] FIG. 1 is a schematic diagram showing a state in which a needle penetrates from the inferior vena cava into an abdominal aortic aneurysm during anastomosis. [Figure 5] FIG. 1 is a schematic diagram showing a state in which a catheter is inserted into an abdominal aortic aneurysm during anastomosis. [Figure 6]FIG. 10 is a schematic diagram showing the state in which the outer tube is pulled back into the inferior vena cava during anastomosis. [Figure 7] FIG. 7 is a schematic diagram showing the next state of FIG. 6 during anastomosis. [Figure 8] FIG. 8 is a schematic diagram showing the next state of FIG. 7 during anastomosis. [Figure 9] FIG. 1 is a schematic diagram showing the device anastomosing the abdominal aortic aneurysm and the inferior vena cava. [Figure 10] FIG. 10 is a front view of a device in an unexpanded state according to a second embodiment. [Figure 11] FIG. 10 is a front view of the device in the expanded state according to the second embodiment. [Figure 12] FIG. 10 is a front view of a device in an unexpanded state according to a third embodiment. [Figure 13] FIG. 10 is a front view of the device in the expanded state according to the third embodiment. [Figure 14] FIG. 10 is a front view of a device in an unexpanded state according to a fourth embodiment. [Figure 15] FIG. 10 is a front view of the device in the expanded state according to the fourth embodiment. [Figure 16] FIG. 1 is a schematic diagram showing a dissecting aortic aneurysm and inferior vena cava to which the device is applied. [Figure 17] Figure 17A is a cross-sectional view of the aorta before a tear occurs in the intima, Figure 17B is a cross-sectional view of the aorta when a tear occurs in the intima, and Figure 17C is a cross-sectional view showing the state after Figure 17B. [Figure 18] FIG. 1 is a schematic diagram showing a state in which a device is anastomosing an abdominal aortic aneurysm and an inferior vena cava during anastomosis. [Figure 19] FIG. 10 is a schematic diagram showing an ablation catheter inserted into a stent during anastomosis. [Figure 20] FIG. 10 is a schematic diagram showing a state in which a cauterized area is formed by irradiating high frequency waves during anastomosis. [Figure 21] FIG. 21 is a schematic diagram showing a state after FIG. 20. [Figure 22]Fig. 22A is a cross-sectional view of an aortic aneurysm and inferior vena cava in which an artificial fistula has been formed, and Fig. 22B is a cross-sectional view of the aorta and inferior vena cava in which compression of the true lumen by the false lumen has been eliminated. [Figure 23] Fig. 23A is a perspective view of an ablation catheter used in fistula formation, and Fig. 23B is a partially enlarged view of Fig. 23A. [Figure 24] FIG. 1 is a schematic diagram showing a catheter inserted into a false lumen from the inferior vena cava during fistula formation. [Figure 25] FIG. 1 is a schematic diagram showing the insertion portion of an ablation catheter placed in a false lumen during fistula formation. [Figure 26] FIG. 1 is a schematic diagram showing the state in which the vascular wall of the inferior vena cava and the vascular wall forming the false lumen are clamped by the ablation electrode and the insertion portion during fistula formation. [Figure 27] FIG. 10 is a schematic diagram showing the state in which a cauterized area is formed by irradiating high-frequency waves during fistula formation surgery. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, exemplary embodiments of the present disclosure will be described with reference to the drawings.

[0017] [1. First embodiment] [1-1.Configuration] 1A to 2B is a member for anastomosis between an artery and a vein. The device 1 is biocompatible. The device 1 is also called a covered stent. The device 1 includes a stent 2 and a cover 3.

[0018] The stent 2 is a cylindrical portion configured to be radially expandable. The stent 2 expands radially when a compressive force is released. The stent 2 is a so-called self-expanding type. FIGS. 1A and 1B show the stent 2 in a state where a compressive force is applied and the stent is not expanded (i.e., in a non-expanded state). FIGS. 2A and 2B show the stent 2 in a state where the compressive force is released and the stent is expanded radially (i.e., in an expanded state). The stent 2 has a circular outer shape in a cross section perpendicular to the axial direction in both the non-expanded state and the expanded state.

[0019] The stent 2 forms a peripheral wall 2w that is continuous around its central axis. The peripheral wall 2w is mesh-like at least in the expanded state. The peripheral wall 2w being mesh-like means that a plurality of through-holes that form the mesh are formed in the peripheral wall 2w. In this embodiment, the peripheral wall 2w is mesh-like in both the unexpanded state and the expanded state. As the stent 2 expands radially, the size of the mesh of the peripheral wall 2w increases. Therefore, the size of the mesh of the peripheral wall 2w in the expanded state is larger than the size of the mesh of the peripheral wall 2w in the unexpanded state.

[0020] The stent 2 has a first engagement portion 21, a second engagement portion 22, and a connecting portion 23. The first engagement portion 21 is a tubular portion that includes one end in the axial direction of the stent 2. The second engagement portion 22 is a tubular portion that includes the other end in the axial direction of the stent 2. The connecting portion 23 is a tubular portion that connects the first engagement portion 21 and the second engagement portion 22.

[0021] 1B, the first engaging portion 21 and the second engaging portion 22 each have a terminal portion 211, 221, a continuous portion 212, 222, and an intermediate portion 213, 223. The terminal portions 211, 221 are tubular portions that constitute the end portions in the axial direction of the stent 2. The continuous portions 212, 222 are tubular portions that continue to the connecting portion 23. The intermediate portions 213, 223 are tubular portions that connect the terminal portions 211, 221 and the continuous portions 212, 222.

[0022] In the unexpanded state, the diameters of the terminal portions 211, 221, the continuous portions 212, 222, and the intermediate portions 213, 223 of each of the first engagement portion 21 and the second engagement portion 22 are constant in the axial direction and are the same as each other. That is, the diameters of each of the first engagement portion 21 and the second engagement portion 22 are constant in the axial direction in the unexpanded state.

[0023] 2B, in each of the first engagement portion 21 and the second engagement portion 22, the diameters of the continuous portions 212, 222 decrease toward the connecting portion 23 in the expanded state. In each of the first engagement portion 21 and the second engagement portion 22, the diameters of the intermediate portions 213, 223 increase toward the continuous portions 212, 222 in the expanded state. In each of the first engagement portion 21 and the second engagement portion 22, the diameters of the terminal portions 211, 221 are generally constant in the axial direction even in the expanded state. In the expanded state, the diameters of the first engagement portion 21 and the second engagement portion 22 are largest at the ends of the intermediate portions 213, 223 on the continuous portions 212, 222 side.

[0024] As described above, the connecting portion 23 is a cylindrical portion that connects the first engaging portion 21 and the second engaging portion 22. As shown in FIG. 1B , in the unexpanded state, the diameter of the connecting portion 23 decreases and then increases from the first engaging portion 21 toward the second engaging portion 22. That is, the connecting portion 23 has a reduced diameter portion 231 and an increased diameter portion 232. In the unexpanded state, the reduced diameter portion 231 decreases in diameter toward the second engaging portion 22. In the unexpanded state, the increased diameter portion 232 increases in diameter toward the second engaging portion 22. The increased diameter portion 232 is disposed closer to the second engaging portion 22 than the reduced diameter portion 231.

[0025] 2B, even in the expanded state, the diameter of the connecting portion 23 decreases and increases from the first engaging portion 21 toward the second engaging portion 22. That is, even in the expanded state, the diameter of the reduced diameter portion 231 decreases toward the second engaging portion 22, and the diameter of the increased diameter portion 232 increases toward the second engaging portion 22.

[0026] 2A , in the expanded state, the maximum diameter D3 of the connecting portion 23 is smaller than the maximum diameter D1 of the first engaging portion 21 and the maximum diameter D2 of the second engaging portion 22. Furthermore, in the expanded state, the minimum diameter D4 of the connecting portion 23 may be, for example, 50% or less of the maximum diameter D1 of the first engaging portion 21 and the maximum diameter D2 of the second engaging portion 22, or more specifically, may be 25% to 50% of these maximum diameters D1, D2. Note that in the present embodiment, the maximum diameter D1 of the first engaging portion 21 and the maximum diameter D2 of the second engaging portion 22 are the same, but these maximum diameters D1, D2 may be different from each other, for example.

[0027] 3 to 9 show abdominal aortic aneurysm AAA and inferior vena cava V as examples of arteries and veins, respectively. In arteries and veins, vascular walls 500, 600 form lumens 500a, 600a. The lumens 500a, 600a are channels through which blood flows. The vascular walls 500, 600 are made up of three layers: a tunica intima 501, 601, a tunica media 502, 602, and a tunica adventitia 503, 603. The tunica intima 501, 601, the tunica media 502, 602, and the tunica adventitia 503, 603 are arranged in this order from the lumens 500a, 600a side. In the vascular wall 500, specifically, the tunica intima 501, 601 form the lumens 500a, 600a.

[0028] 8, the first engagement portion 21 is configured to engage with the arterial vascular wall 500 from the arterial lumen 500a side. More specifically, at least the continuous portion 212 of the first engagement portion 21 is configured to engage with the arterial vascular wall 500 from the arterial lumen 500a side. The second engagement portion 22 is configured to engage with the venous vascular wall 600 from the venous lumen 600a side. More specifically, at least the continuous portion 222 of the second engagement portion 22 is configured to engage with the venous vascular wall 600 from the venous lumen 600a side.

[0029] As described above, the peripheral wall 2w of the stent 2 is mesh-like at least in the expanded state. The mesh size of the peripheral wall 2w in the expanded state is set appropriately depending on the pressure difference between the artery and vein to which the device 1 is applied. However, at least the portion of the peripheral wall 2w included in the reduced diameter section 231 has a mesh size in the expanded state that is smaller than the thrombus X as shown in FIG. 9. The reduced diameter section 231 is configured to be able to capture the thrombus X. In other words, the device 1 is configured to be able to capture the thrombus X in the reduced diameter section 231 in the expanded state. Note that the thrombus X referred to here is the thrombus X in the artery to which the device 1 is applied. The same applies hereinafter. If the thrombus X flows into a vein, it can become an embolic substance that blocks the vein.

[0030] In this embodiment, the mesh size of the portion of the peripheral wall 2w included in the first engagement portion 21 in the expanded state is also smaller than the thrombus X. In other words, both the reduced diameter portion 231 and the first engagement portion 21 are configured to be able to capture the thrombus X. In yet another way, the device 1 is configured to be able to capture the thrombus X in both the reduced diameter portion 231 and the first engagement portion 21 in the expanded state.

[0031] For example, at least one of the portion of the peripheral wall 2w included in the reduced diameter portion 231 and the portion included in the first engagement portion 21 may have a mesh size smaller than that of a foreign body in the expanded state. In other words, at least one of the reduced diameter portion 231 and the first engagement portion 21 may be configured to be able to capture a foreign body. In other words, at least one of the reduced diameter portion 231 and the first engagement portion 21 may be configured to be able to capture a foreign body in the expanded state, for example. Note that the foreign body referred to here is a substance other than blood and thrombus X in an artery to which the device 1 is applied, and is a substance that can become an embolic substance that embolizes the vein if it flows into the vein. The same applies hereinafter. Specific examples of foreign body include atheroma, hematoma, etc.

[0032] The material of the stent 2 is not particularly limited, but the stent 2 may be made of, for example, a biocompatible metal. Specific examples of biocompatible metals include nickel-titanium alloy (nitinol), cobalt-chromium alloy, and stainless steel. The stent 2 may be manufactured, for example, by braiding wires of a biocompatible metal.

[0033] 1A to 2B, the cover 3 is a cylindrical portion configured to prevent blood from passing through. The cover 3 is disposed so as to cover the outer periphery of the connection portion 23 but not to cover the outer peripheries of the first engaging portion 21 and the second engaging portion 22.

[0034] The cover 3 is elastic. Therefore, when the stent 2 expands radially, the cover 3 also expands radially. As shown in FIG. 1A, the diameter of the cover 3 is constant in the axial direction in the unexpanded state. On the other hand, as shown in FIG. 2A, in the expanded state, the diameter of the cover 3 decreases and then increases from the first engagement portion 21 to the second engagement portion 22. In the expanded state, the maximum diameter D5 of the cover 3 is approximately the same as the maximum diameter D3 of the connecting portion 23. In the expanded state, the minimum diameter D6 of the cover 3 is larger than the minimum diameter D4 of the connecting portion 23. Therefore, in the expanded state, a space is formed between the cover 3 and the connecting portion 23.

[0035] The material of the cover 3 is not particularly limited, but for example, the cover 3 is made of a biocompatible polymer. Specific examples of biocompatible polymers include polytetrafluoroethylene, polyamide, silicone, polyvinyl chloride, polyurethane, polyethylene, polypropylene, and polyglycerin.

[0036] [1-2. Effect] The operation of the device 1 when used in anastomosis of an abdominal aortic aneurysm AAA and the inferior vena cava V shown in FIG. 3 will be described below. An abdominal aortic aneurysm AAA is a bulge formed by a partial bulge of the abdominal aorta A1. The abdominal aorta A1 including the abdominal aortic aneurysm AAA corresponds to an example of an artery. The inferior vena cava V corresponds to an example of a vein. To prevent rupture of an abdominal aortic aneurysm AAA, it is desirable to reduce the pressure of the abdominal aortic aneurysm AAA. According to the present inventors, in order to reduce the pressure of an abdominal aortic aneurysm AAA, it is effective to anastomosing the abdominal aortic aneurysm AAA with the inferior vena cava V, which has a lower pressure than the abdominal aortic aneurysm AAA.

[0037] A known catheter 101 shown in Figure 4 is used for anastomosis. The catheter 101 has a tubular inner tube 102 and an outer tube 103. The outer tube 103 is arranged to cover the outer periphery of the inner tube 102. The outer tube 103 is configured to be displaceable in the axial direction relative to the inner tube 102. The diameters of the inner tube 102 and the outer tube 103 are approximately constant in the axial direction. However, the diameter of the tip portion 102a of the inner tube 102 is larger than the diameter of the other portions of the inner tube 102.

[0038] A well-known needle 104 and guide wire 105 are inserted inside the inner tube 102. The needle 104 and the guide wire 105 are configured to be movable inside the inner tube 102 in the axial direction of the inner tube 102. The tip of the needle 104 is formed with a blade capable of cutting biological tissue.

[0039] The device 1 is disposed between the inner tube 102 and the outer tube 103. The device 1 is disposed in an orientation in which the first engagement portion 21 is located on the distal end portion 102a side of the inner tube 102. When the device 1 is disposed between the inner tube 102 and the outer tube 103, a compressive force is being applied to the device 1. In other words, the device 1 at this time is in a non-expanded state.

[0040] In the anastomosis, first, as shown in Fig. 4, a catheter 101 is inserted into the inferior vena cava V. When the catheter 101 reaches the anastomosis position P, a needle 104 is extended and penetrates from the inferior vena cava V into the abdominal aortic aneurysm AAA. A guide wire 105 is also inserted into the abdominal aortic aneurysm AAA. Thereafter, although not shown, the holes formed in the inferior vena cava V and the abdominal aortic aneurysm AAA by the needle 104 may be widened using, for example, a known balloon.

[0041] 5, the catheter 101 is guided by the guide wire 105 and inserted into the abdominal aortic aneurysm AAA. Specifically, the inner tube 102 and the outer tube 103 are inserted into the abdominal aortic aneurysm AAA with the device 1 disposed therebetween.

[0042] 6 and 7, the outer tube 103 is pulled back into the inferior vena cava V while the inner tube 102 remains inserted into the abdominal aortic aneurysm AAA. This causes the device 1 to become exposed from the first engagement portion 21 side. The exposed portion of the device 1 is released from the compressive force and expands radially.

[0043] As shown in FIG. 8 , the outer tube 103 is pulled back until the device 1 is completely exposed. This places the device 1 in an expanded state, straddling the abdominal aortic aneurysm AAA and the inferior vena cava V. At this time, the first engagement portion 21 is located within the lumen 500a of the abdominal aortic aneurysm AAA. The first engagement portion 21 engages with the vascular wall 500 of the abdominal aortic aneurysm AAA from the lumen 500a side. Specifically, at least the continuous portion 212 of the first engagement portion 21 engages with the intima 501 of the abdominal aortic aneurysm AAA. The second engagement portion 22 is located within the lumen 600a of the inferior vena cava V. The second engagement portion 22 engages with the vascular wall 600 of the inferior vena cava V from the lumen 600a side. Specifically, at least the continuous portion 222 of the second engagement portion 22 engages with the intima 601 of the inferior vena cava V. At least a portion of the connection portion 23 is located inside the vascular wall 500 of the abdominal aortic aneurysm AAA and inside the vascular wall 600 of the inferior vena cava V.

[0044] The anastomosis is then completed using a known procedure. In this manner, as shown in Fig. 9, the device 1 is placed in the living body with the abdominal aortic aneurysm AAA and the inferior vena cava V anastomosed. A shunt is formed between the abdominal aortic aneurysm AAA and the inferior vena cava V by the device 1.

[0045] An example of blood flow is shown by arrows in Figure 9. When the device 1 anastomoses the abdominal aortic aneurysm AAA and the inferior vena cava V, the pressure difference between the abdominal aortic aneurysm AAA and the inferior vena cava V causes blood to flow from the abdominal aortic aneurysm AAA to the inferior vena cava V via the device 1. This reduces the pressure in the abdominal aortic aneurysm AAA.

[0046] Here, in many cases, a thrombus X is present within the lumen 500a of the abdominal aortic aneurysm AAA. When the abdominal aortic aneurysm AAA and the inferior vena cava V are anastomosed by the device 1, it is conceivable that the thrombus X within the lumen 500a will flow into the inferior vena cava V along with the blood flow from the abdominal aortic aneurysm AAA to the inferior vena cava V.

[0047] However, the device 1 is configured to be able to capture the thrombus X at the first engagement portion 21 and the reduced diameter portion 231 in the expanded state. Specifically, the mesh size of the portion of the peripheral wall 2w of the stent 2 that is included in the first engagement portion 21 and the reduced diameter portion 231 in the expanded state is smaller than the thrombus X. Therefore, as shown by arrow a, when blood passes through the peripheral wall of the first engagement portion 21 and flows into the stent 2, even if the thrombus X rides this blood flow and reaches the first engagement portion 21, the thrombus X does not pass through the peripheral wall of the first engagement portion 21. In other words, the thrombus X is captured at the first engagement portion 21. Furthermore, even if the thrombus X flows into the stent 2 from an opening formed by the end portion 211 of the first engagement portion 21, the thrombus X will be caught by the first engagement portion 21 or the reduced diameter portion 231 from the inner circumferential side, as shown by arrows b and c. That is, the thrombus X is captured by the first engaging portion 21 or the reduced diameter portion 231.

[0048] In this manner, the inflow of thrombus X from abdominal aortic aneurysm AAA into inferior vena cava V is inhibited.

[0049] [1-3.Effects] According to the first embodiment described above in detail, the following effects can be obtained.

[0050] (1a) The device 1 includes a first engagement portion 21, a second engagement portion 22, and a connecting portion 23. With this configuration, the first engagement portion 21 engages with the vascular wall 500 of the artery from the side of the arterial lumen 500a, and the second engagement portion 22 engages with the vascular wall 600 of the vein from the side of the venous lumen 600a, thereby enabling anastomosis of the artery and the vein. At this time, since the connecting portion 23 has a smaller maximum diameter in the expanded state than the first engagement portion 21 and the second engagement portion 22, it is possible to more easily prevent the position of the device 1 relative to the artery and the vein from shifting in the axial direction of the device 1. Therefore, the device 1 can more easily anastomose the artery and the vein.

[0051] (1b) The first engaging portion 21 and the second engaging portion 22 each have a continuous portion 212, 222. The continuous portions 212, 222 are continuous with the connecting portion 23, and their diameters decrease toward the connecting portion 23 in the expanded state.

[0052] When an artery and a vein are anastomosed by the device 1, the continuous portions 212, 222 are particularly likely to come into contact with the vascular walls 500, 600. According to the configuration described above, the diameter of the continuous portions 212, 222 is reduced toward the connection portion 23 in the expanded state, which makes it easier for the continuous portions 212, 222 to fit along the vascular walls 500, 600. Therefore, the device 1 can more easily anastomosed the artery and the vein.

[0053] (1c) The first engagement portion 21 has an intermediate portion 213 in addition to the continuous portion 212. In the expanded state, the diameter of the intermediate portion 213 expands toward the continuous portion 212. That is, in the expanded state, the diameter of the intermediate portion 213 decreases toward the opposite side (the distal end portion 211 side in this embodiment) from the continuous portion 212. With this configuration, the size of the opening in the first engagement portion 21 opposite the connecting portion 23 can be reduced. Therefore, even if a thrombus X is present in an artery and the device 1 anastomoses the artery and the vein, and the thrombus X in the artery reaches the device 1, the thrombus X can be prevented from flowing into the stent 2 through the opening in the first engagement portion 21. Therefore, the thrombus X can be prevented from flowing from the artery to the vein.

[0054] (1d) In the expanded state, the device 1 is configured to be able to capture the thrombus X at at least the connecting portion 23 out of the connecting portion 23 and the first engaging portion 21. Specifically, in the peripheral wall 2w of the stent 2, at least the portion included in the connecting portion 23 has a mesh size larger than the thrombus X in the expanded state.

[0055] According to this configuration, when the device 1 anastomoses the artery and the vein, even if a thrombus X in the artery reaches the device 1, the thrombus X can be captured at least at the connection part 23. Therefore, it is possible to prevent the thrombus X from flowing from the artery into the vein.

[0056] (1e) In this embodiment, the device 1 is configured to be able to capture the thrombus X in the expanded state at both the connecting portions 23 and the first engaging portions 21. Specifically, the mesh size of the portions of the peripheral wall 2w of the stent 2 that are included in the connecting portions 23 and the first engaging portions 21 is larger than the thrombus X in the expanded state.

[0057] According to this configuration, when the device 1 anastomoses the artery and the vein, the thrombus X can be captured not only at the connection portion 23 but also at the first engagement portion 21. Therefore, the flow of the thrombus X from the artery to the vein can be further suppressed.

[0058] (1f) The connecting portion 23 has a reduced diameter portion 231 and an increased diameter portion 232. The device 1 is configured to be able to capture a thrombus X at the reduced diameter portion 231 in the expanded state. Specifically, the mesh size of at least the portion of the peripheral wall 2w of the stent 2 included in the reduced diameter portion 231 is larger than the thrombus X in the expanded state.

[0059] Because the diameter of the reduced diameter portion 231 decreases toward the second engagement portion 22, when the device 1 anastomoses the artery and the vein, the flow of blood that has flowed from the artery into the stent 2 is more likely to hit the reduced diameter portion 231. Therefore, with the above-described configuration, if a thrombus X flows into the stent 2 along with this blood flow, the thrombus X can be more easily caught by the reduced diameter portion 231. Therefore, for example, the thrombus X can be captured in the reduced diameter portion 231 without the need to dispose a separate member capable of capturing the thrombus X inside the stent 2.

[0060] (1g) The device 1 has a cover 3. The cover 3 covers the outer periphery of the connection part 23. With this configuration, when the device 1 anastomoses the artery and the vein, it is possible to prevent blood from leaking around the artery and the vein.

[0061] [2. Second Embodiment] [2-1.Configuration] The second embodiment has the same basic configuration as the first embodiment, so differences will be described below. Note that the same reference numerals as those in the first embodiment indicate the same configuration, and reference is made to the preceding description.

[0062] A device 1A of the second embodiment shown in FIGS. 10 and 11 includes a stent 2A, a cover 3, and a filter 4.

[0063] The stent 2A has substantially the same configuration as the stent 2 of the first embodiment. However, the stent 2A differs from the stent 2 of the first embodiment in that the stent 2A has a connecting portion 23A instead of the connecting portion 23.

[0064] In the first embodiment, the diameter of the connecting portion 23 decreases and increases from the first engagement portion 21 to the second engagement portion 22 in both the unexpanded state and the expanded state. In contrast, in the second embodiment, as shown in FIG. 10, the diameter of the connecting portion 23A is constant in the axial direction in the unexpanded state. Also, as shown in FIG. 11, the diameter of the connecting portion 23A is constant in the axial direction except for both ends in the axial direction in the expanded state. The end of the connecting portion 23A on the first engagement portion 21 side decreases in diameter toward the second engagement portion 22 in the expanded state. The end of the connecting portion 23A on the second engagement portion 22 side increases in diameter toward the second engagement portion 22 in the expanded state.

[0065] As in the first embodiment, the mesh size of the peripheral wall 2w of the stent 2A in the expanded state is set appropriately depending on the pressure difference between the artery and vein to which the device 1A is applied. In this embodiment, the mesh size of at least the portions of the peripheral wall 2w included in the first engaging portions 21 and the connecting portions 23A in the expanded state is smaller than the thrombus X. In other words, the device 1A is configured to be able to capture the thrombus X at the first engaging portions 21 and the connecting portions 23A in the expanded state.

[0066] The filter 4 is a member configured to allow blood to pass through but prevent thrombus X from passing through. The filter 4 is plate-shaped. When viewed in the thickness direction, the filter 4 has a circular shape. The filter 4 has a plurality of pores that communicate with each other in the thickness direction. The size of the pores is larger than the substances that make up the blood but smaller than the thrombus X.

[0067] The filter 4 is disposed inside the connecting portion 23 A. The thickness direction of the filter 4 is parallel to the axial direction of the connecting portion 23 A. The outer peripheral surface of the filter 4 is joined to the connecting portion 23 A along the entire periphery.

[0068] The filter 4 is elastic. Therefore, when the stent 2A expands radially, the filter 4 also expands radially. The filter 4 blocks the inside of the connection portion 23A in both the unexpanded state and the expanded state. The size of the multiple pores in the filter 4 is designed to be larger than the substances that make up blood but smaller than the thrombus X, even when the filter 4 is expanded radially. Therefore, if a thrombus X enters the stent 2A, the thrombus X will be captured by the filter 4. The fact that the device 1A is configured to be able to capture the thrombus X at the connection portion 23A, as described above, is also achieved by disposing the filter 4 inside the connection portion 23A.

[0069] The material of the filter 4 is not particularly limited, but for example, the filter 4 is made of a biocompatible polymer. Specific examples of the biocompatible polymer are as given in the first embodiment.

[0070] [2-2. Effect] The device 1A of the second embodiment is placed in a living body with an artery and a vein anastomosed, similar to the device 1 of the first embodiment. At this time, the device 1A is in an expanded state. In the expanded state, the device 1A is configured to be able to capture a thrombus X at the first engagement portion 21 and the connection portion 23A.

[0071] Specifically, the mesh size of the portions of the peripheral wall 2w of the stent 2A included in the first engagement portions 21 and the connecting portions 23A in the expanded state is smaller than that of the thrombus X. Therefore, when blood passes through the peripheral wall of the first engagement portions 21 and flows into the stent 2A, even if the thrombus X rides this blood flow and reaches the first engagement portions 21, the thrombus X does not pass through the peripheral wall of the first engagement portions 21. In other words, the thrombus X is captured by the first engagement portions 21. Furthermore, even if the thrombus X flows into the stent 2A from an opening formed by the end portions 211 of the first engagement portions 21, the thrombus X is caught by the first engagement portions 21 or the connecting portions 23A from the inner peripheral side. In other words, the thrombus X is captured by the first engagement portions 21 or the connecting portions 23A.

[0072] Furthermore, a filter 4 is disposed inside the connecting portion 23A. The filter 4 is configured to allow blood to pass through but not allow thrombus X to pass through. Therefore, even if thrombus X flows into the stent 2A from the opening formed by the end portion 211 of the first engaging portion 21, the thrombus X will not pass through the filter 4. In other words, the thrombus X is captured by the filter 4. In other words, the thrombus X is captured at the connecting portion 23A.

[0073] In this way, the inflow of thrombus X from the artery into the vein is suppressed. Meanwhile, blood passes through the filter 4 and flows into the vein.

[0074] [2-3. Effects] According to the second embodiment described above in detail, the same effects as those (1a) to (1e) and (1g) above can be obtained, and the following additional effects can be obtained.

[0075] In the device 1A, a filter 4 is disposed at the connection portion 23A. The filter 4 is configured to allow blood to pass through but not allow thrombus X to pass through.

[0076] With this configuration, for example, the filter 4 can capture the thrombus X at the connection portion 23A regardless of the size of the mesh of the peripheral wall 2w of the stent 2A. Therefore, it is possible to more easily obtain the device 1A capable of capturing the thrombus X. Also, for example, by using a plurality of filters 4 with different pore sizes, it is possible to adjust the pressure difference between the artery and the vein.

[0077] 3. Third Embodiment [3-1.Configuration] The third embodiment has the same basic configuration as the second embodiment, and therefore differences will be described below. Note that the same reference numerals as those in the second embodiment indicate the same configuration, and reference is made to the preceding description.

[0078] As shown in FIGS. 12 and 13 , the device 1B of the third embodiment includes a stent 2A, a cover 3, and a filter 4, similar to the device 1A of the second embodiment. However, in the third embodiment, the filter 4 is disposed inside the first engagement portion 21, not inside the connection portion 23A. For example, the filter 4 is disposed so as to overlap the portion of the first engagement portion 21 that has the largest diameter in the expanded state in the radial direction of the first engagement portion 21. The thickness direction of the filter 4 is parallel to the axial direction of the first engagement portion 21. The outer peripheral surface of the filter 4 is bonded to the first engagement portion 21 along the entire circumference. The filter 4 blocks the interior of the first engagement portion 21 in both the unexpanded state and the expanded state. This allows the device 1B to capture a thrombus X at the first engagement portion 21.

[0079] As described in the second embodiment, the portion of the peripheral wall 2w of the stent 2A included in the first engagement portion 21 has a mesh size in the expanded state that is smaller than the thrombus X. This also makes it possible for the device 1B to be configured to be able to capture the thrombus X at the first engagement portion 21.

[0080] [3-2. Effect] The device 1B of the third embodiment is placed in a living body with an artery and a vein anastomosed, similar to the device 1A of the second embodiment. At this time, the device 1B is in an expanded state. In the expanded state, the device 1B is configured to be able to capture a thrombus X at the first engagement portion 21 and the connection portion 23A.

[0081] Specifically, the mesh size of the portion of the peripheral wall 2w of the stent 2A included in the first engagement portion 21 in the expanded state is smaller than that of the thrombus X. Therefore, as described in the second embodiment, when blood passes through the peripheral wall of the first engagement portion 21 and flows into the stent 2A, even if the thrombus X rides this blood flow and reaches the first engagement portion 21, the thrombus X will not pass through the peripheral wall of the first engagement portion 21. Furthermore, even if the thrombus X flows into the stent 2A from an opening formed by the end portion 211 of the first engagement portion 21, the thrombus X will be caught by the first engagement portion 21 from the inner peripheral side. In other words, the thrombus X is captured by the first engagement portion 21.

[0082] Furthermore, a filter 4 is disposed inside the first engagement portion 21. Therefore, even if a thrombus X flows into the stent 2A from an opening formed by the end portion 211 of the first engagement portion 21, the thrombus X does not pass through the filter 4. That is, the thrombus X is captured by the filter 4. In other words, the thrombus X is captured in the first engagement portion 21.

[0083] In addition, the mesh size of the portion of the peripheral wall 2w of the stent 2A included in the connection portion 23A in the expanded state is smaller than that of the thrombus X. Therefore, even if the thrombus X reaches the connection portion 23A, the thrombus X will be caught by the connection portion 23A. That is, the thrombus X will also be captured at the connection portion 23A.

[0084] In this way, the thrombus X is prevented from flowing into the vein. Meanwhile, blood passes through the filter 4 and flows into the vein.

[0085] [3-3. Effects] According to the third embodiment described above in detail, the same effects as those (1a) to (1c) and (1g) above can be obtained, and the following effect can also be obtained.

[0086] (3a) In the expanded state, the device 1B is configured so that at least the first engagement portion 21 of the first engagement portion 21 and the connection portion 23A can capture the thrombus X. With this configuration, when the device 1B anastomoses an artery and a vein, even if the thrombus X in the artery reaches the device 1B, the thrombus X can be captured at least by the first engagement portion 21. Therefore, similar to (1d) above, it is possible to prevent the thrombus X from flowing from the artery to the vein.

[0087] (3b) In this embodiment, the device 1B is configured so that, in the expanded state, it can capture the thrombus X at both the first engaging portion 21 and the connecting portion 23A. Therefore, it is possible to obtain the same effect as in (1e) above.

[0088] (3c) In the device 1B, a filter 4 is disposed in the first engagement portion 21. The filter 4 is configured to allow blood to pass through but not allow thrombus X to pass through.

[0089] According to this configuration, a larger amount of thrombus X can be captured by the first engaging portion 21. Therefore, the amount of thrombus X flowing into the connecting portion 23A can be further reduced. As a result, the connecting portion 23A can be further prevented from being blocked by the thrombus X.

[0090] [4. Fourth Embodiment] [4-1.Configuration] The fourth embodiment has the same basic configuration as the second embodiment, and therefore the differences will be described below. Note that the same reference numerals as those in the second embodiment indicate the same configuration, and reference is made to the preceding description.

[0091] As shown in FIGS. 14 and 15 , the device 1C of the fourth embodiment includes a stent 2C and a cover 3C. The stent 2C and the cover 3C have substantially the same configuration as the stent 2A and the cover 3 of the second embodiment. However, the stent 2C and the cover 3C are made of a material that generates heat when high-frequency current, such as radio waves, is applied. Specific examples of the material for the stent 2C include alloys containing elements such as nickel and chromium. Specific examples of the material for the cover 3C include polymers to which inorganic fillers containing elements such as nickel and chromium are added. The cover 3C is configured so as not to adhere to the vascular walls 500, 600 of the artery and vein even when heated.

[0092] In the second embodiment, the mesh size of at least the portions of the peripheral wall 2w of the stent 2A that are included in the first engaging portion 21 and the connecting portion 23A in the expanded state is smaller than the thrombus X. In contrast, in the fourth embodiment, the mesh size of the peripheral wall 2w of the stent 2C in the expanded state does not necessarily have to be smaller than the thrombus X. In other words, the device 1C does not necessarily have to be configured to be able to capture the thrombus X in the expanded state.

[0093] [4-2. Effect] The operation of the device 1C when used in anastomosis surgery for anastomosis of a dissecting aortic aneurysm DAA and the inferior vena cava V shown in FIG. 16 will be described below. A dissecting aortic aneurysm DAA is a bulge in the vascular wall 500 of the aorta A0, where tears T1 to T3 occur in the vascular wall 500, causing blood to flow into the vascular wall 500, resulting in a partial swelling of the vascular wall 500. The device 1C is used in anastomosis surgery for dissecting aortic aneurysms DAA, particularly Stanford type B dissecting aortic aneurysms DAA. The aorta A0 including the dissecting aortic aneurysm DAA corresponds to an example of an artery. The abdominal aorta A1 described above is a part of the aorta A0.

[0094] As shown in Figures 17A and 17B, a tear T1 specifically occurs in the tunica intima 501 of a blood vessel wall 500. Then, as blood flows into the tunica media 502 through the tear T1, the tunica media 502 peels into two layers as shown in Figure 17B, or the tunica media 502 and the tunica adventitia 503 separate. As a result, as shown in Figure 17C, a lumen 500b into which blood can flow is formed in the blood vessel wall 500. Hereinafter, in order to distinguish between the lumen 500a originally formed in the aorta A0 and the lumen 500b newly formed by the flow of blood into the tunica media 502, these will also be referred to as the true lumen 500a and the false lumen 500b, respectively.

[0095] In the tunica intima 501, for example, only one tear T1 may occur, or multiple tears T1 to T3 may occur as shown in Fig. 16. The most upstream tear T1 is also referred to as Primary Entry. The second and subsequent tears from the upstream side, T2 and T3, are also referred to as Re-entry.

[0096] Regardless of the number of fissures T1 to T3, the false lumen 500b has a higher diastolic blood pressure than the true lumen 500a. For example, if the true lumen 500a has a systolic blood pressure of 120 mmHg and a diastolic blood pressure of 70 mmHg, the false lumen 500b may have a systolic blood pressure of 120 mmHg and a diastolic blood pressure of 110 mmHg. Because the false lumen 500b has a higher diastolic blood pressure than the true lumen 500a, the false lumen 500b may compress the true lumen 500a, resulting in insufficient blood flow, as shown in FIGS. 16 and 17C. Therefore, it is desirable to reduce the pressure in the false lumen 500b. According to the present inventors, anastomosis of the false lumen 500b with the inferior vena cava V, which has a lower blood pressure, is effective in reducing the pressure in the false lumen 500b. The blood pressure in the inferior vena cava V is, for example, 4 to 8 mmHg.

[0097] In an anastomosis procedure, the device 1C is placed in an expanded state across the false lumen 500b and the inferior vena cava V as shown in FIG. 18 by a procedure similar to that exemplified in the first embodiment. At this time, the first engagement portion 21 is located inside the dissecting aortic aneurysm DAA and engages with the vascular wall 500 of the dissecting aortic aneurysm DAA. Specifically, the first engagement portion 21 is located within the false lumen 500b. At least the continuous portion 212 of the first engagement portion 21 engages with at least one of the tunica media 502 and the tunica adventitia 503 that form the false lumen 500b from the false lumen 500b side. The second engagement portion 22 is located inside the inferior vena cava V and engages with the vascular wall 600 of the inferior vena cava V. Specifically, at least the continuous portion 222 of the second engagement portion 22 engages with the tunica intima 601 of the inferior vena cava V from the lumen 600a side.

[0098] Next, a known ablation catheter 106 shown in FIG. 19 is used. The ablation catheter 106 is a hollow member with an electrode attached to its tip. An electric wire runs through the inside of the ablation catheter 106. This electric wire electrically connects the electrode of the ablation catheter 106 to an ablation device placed outside the patient's body. When a voltage is applied to the electrode of the ablation catheter 106 by the ablation device, the ablation catheter 106 is capable of passing a high-frequency current from the electrode to the target. A specific example of high-frequency current is radio waves.

[0099] As shown in Fig. 19, the ablation catheter 106 is inserted into the stent 2C from the second engagement portion 22 side so that the electrode at the tip is located within the connection portion 23A. Note that in Fig. 19, the device 1C is indicated by a two-dot chain line, but the connection portion 23A is located in the area surrounded by the cover 3C. The same is true in Fig. 20.

[0100] With the electrode of the ablation catheter 106 positioned within the connection portion 23A, a high-frequency current is applied from the electrode to the connection portion 23A and the cover 3C. This heats the connection portion 23A and the cover 3C, forming the cauterized portion R as shown in FIG. 20 . The cauterized portion R is a portion of the vascular walls 500, 600 of the dissecting aortic aneurysm DAA and the inferior vena cava V where protein denaturation has occurred due to heat transfer from the cover 3C (i.e., the portion cauterized by high frequency). The cauterized portion R surrounds the cover 3C. The cauterized portion R forms an artificial fistula connecting the false lumen 500b and the inferior vena cava V by fusing the vascular walls 500, 600 of the dissecting aortic aneurysm DAA and the inferior vena cava V together.

[0101] The magnitude of the high-frequency current and the time for which the current is passed are determined according to the size of the target artificial fistula. For example, if high-frequency current is passed for a predetermined time or longer, as shown in Fig. 21, the portion of the vascular wall 500, 600 in contact with the cover 3C or the stent 2C is burned off, and the portion surrounding that portion becomes the cauterized portion R. Therefore, the size of the fistula formed by the cauterized portion R may be larger than the outer diameter of the cover 3C.

[0102] Furthermore, the amount of heat generated by the cover 3C or stent 2C when a high-frequency current is passed through it may be adjusted by, for example, the material of the cover 3C or stent 2C or the size of the mesh of the stent 2C. The amount of heat generated by the cover 3C or stent 2C can affect the size of the fistula that is formed, the time required to form the fistula, and the like.

[0103] When the radiofrequency ablation is completed, the ablation catheter 106 is withdrawn from the body. Furthermore, if necessary, the device 1C is also removed from the body using known procedures. That is, the device 1C may be left in the body with the false lumen 500b and the inferior vena cava V anastomosed, for example, or may be placed in the body only during surgery and removed from the body after an artificial fistula has been formed. The anastomosis is then completed using known procedures.

[0104] As shown in Figure 22A, the false lumen 500b and the inferior vena cava V are connected by a fistula formed by the cauterized area R, allowing blood to flow from the false lumen 500b to the inferior vena cava V. By reducing the pressure in the false lumen 500b, the true lumen 500a is no longer compressed by the false lumen 500b, as shown in Figure 22B. As a result, circulatory failure is resolved. Furthermore, the reduction in pressure in the false lumen 500b reduces the risk of future aneurysm formation in the aorta A0.

[0105] Such anastomosis can be performed simultaneously with endovascular stent graft insertion (TEVAR) to occlude the primary entry, eliminating the need for post-TEVAR treatment such as the PETTICOAT technique.

[0106] [4-3. Effects] According to the fourth embodiment described above in detail, at least the same effects as (1a), (1b) and (1g) above can be obtained.

[0107] 5. Other Embodiments Although the embodiments of the present disclosure have been described above, it goes without saying that the present disclosure is not limited to the above-described embodiments and can take on various forms.

[0108] (5a) In the first to third embodiments described above, the devices 1, 1A, and 1B are configured to be able to capture thrombus X in the artery at both the first engagement portion 21 and the connection portion 23 and 23A in the expanded state. However, the devices may be configured to be able to capture thrombus X in the artery at only one of the first engagement portion and the connection portion in the expanded state.

[0109] Furthermore, for example, like device 1C of the fourth embodiment, a device does not necessarily have to be configured to be able to capture thrombus X. For example, because treatment for dissecting aortic aneurysm DAA as described in the fourth embodiment is highly urgent, anastomosis for anastomosis of dissecting aortic aneurysm DAA with inferior vena cava V is often performed at a stage when thrombus X has not yet formed in the dissecting aortic aneurysm DAA. In this way, when it is recognized that there is a low possibility that thrombus X has formed in the artery to which the device is applied, the device does not necessarily have to be configured to be able to capture thrombus X.

[0110] (5b) In the first embodiment, the connecting portion 23 has a reduced diameter portion 231 and an expanded diameter portion 232. The reduced diameter portion 231 has a diameter that decreases toward the second engaging portion 22 in both the non-expanded state and the expanded state. The expanded diameter portion 232 has a diameter that increases toward the second engaging portion 22 in both the non-expanded state and the expanded state.

[0111] However, when the connecting portion has a reduced diameter portion and an expanded diameter portion as in the first embodiment, the reduced diameter portion does not necessarily have to have a diameter that decreases toward the second engaging portion in the unexpanded state. For example, the reduced diameter portion may have a constant diameter in the axial direction in the unexpanded state. Furthermore, the reduced diameter portion may have a shape that decreases in diameter toward the second engaging portion as it expands radially (i.e., as it changes to the expanded state).

[0112] Similarly, the diameter of the enlarged diameter portion does not necessarily have to increase toward the second engagement portion in the unexpanded state. For example, the diameter of the enlarged diameter portion may be constant in the axial direction in the unexpanded state. Furthermore, the enlarged diameter portion may have a shape in which the diameter increases toward the second engagement portion as it expands radially, for example.

[0113] (5c) In the first to fourth embodiments, the first engagement portion 21 and the second engagement portion 22 each have a terminal portion 211, 221, a continuous portion 212, 222, and an intermediate portion 213, 223. However, the shapes of the first engagement portion and the second engagement portion are not particularly limited. For example, the first engagement portion and the second engagement portion may not have an intermediate portion, and the terminal portion may be directly connected to the continuous portion. Also, for example, the first engagement portion and the second engagement portion may have only a continuous portion, and the continuous portion may constitute the end portion of the stent. The fact that the first engagement portion and the second engagement portion have only a continuous portion means that the first engagement portion and the second engagement portion have a shape in which the diameter increases as they move away from the connection portion in the expanded state.

[0114] However, when the device is applied to an artery in which a thrombus X has formed, it is preferable that the first and second engagement parts have a portion whose diameter expands and contracts from the connecting part in the expanded state. In other words, it is preferable that the first and second engagement parts have at least a continuous part and an intermediate part. The reason for this is that the same effect as in (1c) above can be obtained.

[0115] (5d) In the above embodiments, the devices 1, 1A to 1C are provided with the covers 3, 3C. However, the devices do not necessarily have to be provided with covers.

[0116] (5e) In the second and third embodiments, the devices 1A and 1B each include one filter 4. However, the number of filters included in the device is not particularly limited, and may be a single filter as in the second and third embodiments, or multiple filters.

[0117] (5f) The function of one component in the above embodiments may be distributed among multiple components, or the functions of multiple components may be integrated into one component. Also, part of the configuration of the above embodiments may be omitted. Furthermore, at least part of the configuration of the above embodiments may be added to or substituted for the configuration of another of the above embodiments.

[0118] [6.Reference information] As described in the fourth embodiment, in order to reduce the pressure in the false lumen 500b of the dissecting aortic aneurysm DAA, it is conceivable to form an artificial fistula connecting the false lumen 500b and the inferior vena cava V. According to the inventor's intensive studies, when forming an artificial fistula, for example, the above-mentioned devices 1, 1A to 1C may be used, or such devices may not be used. For reference, a fistula formation technique for forming an artificial fistula connecting the false lumen 500b and the inferior vena cava V without using a device will be described below.

[0119] 23A, a known ablation catheter 107 is used for fistula formation. The ablation catheter 107 has a hollow portion 1071, a shaft portion 1072, an insertion portion 1073, and an electrode 1074.

[0120] 23B, hollow portion 1071 and shaft portion 1072 are cylindrical portions. The outer diameter of shaft portion 1072 is smaller than the inner diameter of hollow portion 1071. Shaft portion 1072 is inserted into hollow portion 1071. The tip of shaft portion 1072 is exposed from the tip of hollow portion 1071.

[0121] An electrode 1074 is disposed inside the tip of the hollow portion 1071 so as to surround the shaft portion 1072. The electrode 1074 is fixed to the hollow portion 1071 but is not fixed to the shaft portion 1072. The electrode 1074 is electrically connected to an ablation device (not shown). By applying a voltage from the ablation device to the electrode 1074, it is possible to pass a high-frequency current from the electrode 1074 to the target object.

[0122] The insertion portion 1073 is a portion provided on the outer periphery of the tip of the shaft portion 1072. The outer diameter of the insertion portion 1073 expands toward the hollow portion 1071. The end of the insertion portion 1073 on the hollow portion 1071 side is made of a material (for example, a metal such as aluminum) that can generate heat when high-frequency current is applied.

[0123] In the fistula formation procedure, for example, the needle 104 described in the first embodiment is extended from inside the inferior vena cava V toward the dissecting aortic aneurysm DAA side and penetrates into the false lumen 500b. Then, as shown in Fig. 24, a tubular catheter 108 is inserted from the inferior vena cava V side into the hole formed by the needle 104.

[0124] Next, the ablation catheter 107 is inserted into the catheter 108 with the hollow portion 1071 and the insertion portion 1073 separated as shown in Figure 23B. The ablation catheter 107 is advanced through the catheter 108 until the insertion portion 1073 reaches the inside of the false lumen 500b as shown in Figure 25. At this time, the hollow portion 1071 is positioned within the lumen 600a of the inferior vena cava V. Note that Figure 25 shows a state in which the catheter 108 has been pulled back into the lumen 600a of the inferior vena cava V after the ablation catheter 107 has been inserted.

[0125] 26, with the position of the shaft portion 1072 fixed, the hollow portion 1071 is displaced so as to approach the insertion portion 1073. The hollow portion 1071 is displaced to a position where the electrode 1074 and the insertion portion 1073 clamp the vascular wall 600 of the inferior vena cava V and at least one of the tunica media 502 and the tunica adventitia 503 that form the false lumen 500b.

[0126] Then, a voltage is applied to the electrode 1074, and a high-frequency current is passed through it. As a result, as shown in Fig. 27, the portions of the vascular walls 500, 600 of the dissecting aortic aneurysm DAA and the inferior vena cava V that are clamped by the electrode 1074 and the insertion section 1073 are burned away. Protein denaturation occurs in the portion surrounding the portions, and a cauterized portion R is formed. The cauterized portion R forms an artificial fistula connecting the false lumen 500b and the inferior vena cava V.

[0127] As described above, it is possible to form an artificial fistula connecting the false lumen 500b and the inferior vena cava V by using the ablation catheter 107 as well.

[0128] [Technical idea disclosed in this specification] [Item 1] A device for anastomosis between an artery and a vein, comprising: The present invention provides a method for treating a vascular endovascular disease, comprising: providing a tubular stent configured to be radially expandable, the stent forming a mesh-like peripheral wall in an expanded state; The stent is a first engagement portion configured to engage with a vascular wall of the artery from the lumen side of the artery; a second engagement portion configured to engage with the vascular wall of the vein from the lumen side of the vein; a connecting portion that connects the first engaging portion and the second engaging portion, the connecting portion having a smaller maximum diameter than the first engaging portion and the second engaging portion in an expanded state; A device having:

[0129] [Item 2] Item 1, the device according to The device is configured to capture a thrombus in the artery at at least one of the first engagement portion and the connection portion when the stent is in an expanded state.

[0130] [Item 3] Item 2: The device according to item 2, The connection portion is a reduced diameter portion whose diameter decreases toward the second engagement portion in an expanded state; an enlarged diameter portion that expands in diameter toward the second engagement portion in an expanded state, the enlarged diameter portion being disposed closer to the second engagement portion than the reduced diameter portion; and The device is configured to capture the thrombus at the reduced diameter portion when the stent is in an expanded state.

[0131] [Item 4] The device according to item 2 or 3, a filter configured to allow blood to pass through while preventing the passage of the thrombus; The device, wherein the filter is disposed inside at least one of the first engagement portion and the connection portion.

[0132] [Item 5] Item 4: The device according to item 4, A device, wherein the filter is disposed inside at least the first engagement portion of the first engagement portion and the connection portion.

[0133] [Item 6] The device according to any one of items 1 to 5, The device further comprises a cover configured to impermeably block the passage of blood, the cover covering an outer periphery of the connection portion. [Explanation of symbols]

[0134] 1, 1A, 1B, 1C...device, 2, 2A, 2C...stent, 2w...circumferential wall, 21...first engaging portion, 22...second engaging portion, 23, 23A...connecting portion, 231...reduced diameter portion, 232...expanded diameter portion, 3, 3C...cover, 4...filter, 500, 600...vascular wall, 500a, 500b, 600a...lumen, A0...aorta, A1...abdominal aorta, AAA...abdominal aortic aneurysm, DAA...dissecting aortic aneurysm, P...anastomosis position, R...cauterized portion, V...inferior vena cava, X...thrombus.

Claims

1. A device for anastomosis between an artery and a vein, comprising: The present invention provides a method for treating a vascular endovascular disease, comprising: providing a tubular stent configured to be radially expandable, the stent forming a mesh-like peripheral wall in an expanded state; The stent is a first engagement portion configured to engage with a vascular wall of the artery from the lumen side of the artery; a second engagement portion configured to engage with a blood vessel wall of the vein from the lumen side of the vein; a connecting portion that connects the first engaging portion and the second engaging portion, the connecting portion having a smaller maximum diameter than the first engaging portion and the second engaging portion in an expanded state; A device having:

2. 10. The device of claim 1, The device is configured to capture a thrombus in the artery at at least one of the first engagement portion and the connection portion when the stent is in an expanded state.

3. 3. The device of claim 2, The connection portion is a reduced diameter portion whose diameter decreases toward the second engagement portion in an expanded state; an enlarged diameter portion that expands in diameter toward the second engaging portion in an expanded state, the enlarged diameter portion being disposed closer to the second engaging portion than the reduced diameter portion; and The device is configured to capture the thrombus at the reduced diameter portion when the stent is in an expanded state.

4. 4. The device of claim 2 or claim 3, a filter configured to allow blood to pass through while preventing the passage of the thrombus; The device, wherein the filter is disposed inside at least one of the first engagement portion and the connection portion.

5. 5. The device of claim 4, A device, wherein the filter is disposed inside at least the first engagement portion of the first engagement portion and the connection portion.

6. 3. A device according to claim 1 or claim 2, The device further comprises a cover configured to impermeably block the passage of blood, the cover covering an outer periphery of the connection portion.

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