A system for cavity plugging having a helical configuration and a method of delivery

Abstract

The present application relates to the technical field of medical devices, and provides a system with a spiral structure for cavity embolization and a delivery method, the system comprising: an embolization device which is in a spiral structure in a natural state and can be freely stretched and contracted under stress; the embolization device comprises an inner mesh layer and an outer mesh layer which are concentrically arranged, and the sparseness of the outer mesh layer is greater than that of the inner mesh layer; the embolization device is used for sleeving the embolization stent and the inner circle of the spiral structure is tightly attached to the outer wall of the embolization stent. The system, after the release of the embolization device with a spiral structure, can tightly adhere to the periphery of the embolization stent, increase the diameter of the cavity part of the embolization stent, fill the entire cavity or cyst in a physical occupation manner, improve the occlusion effect, avoid the occurrence of internal leakage, and thus avoid secondary surgery. Moreover, since the sparseness of the outer mesh layer is greater than that of the inner mesh layer, the blood flow direction can be better changed, the blood flow speed is reduced, the endothelial material in the blood is quickly deposited in the embolization, the endothelialization is completed, and the tumor cyst is atrophied.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of medical devices, in particular to a system with a spiral structure for cavity embolization and a delivery method. BACKGROUND

[0002] For an aneurysm, whether to intervene is generally determined according to the size of the aneurysm, when the diameter of the aneurysm reaches the diameter that needs to be intervened, surgical operation or intravascular stent intervention can be used for treatment. Surgical operation has large trauma, and with the development of medical devices and surgical procedures, intravascular stent intervention is used more and more. When a stent is used to treat an aneurysm, there is a risk of endoleak, for example, the overall endoleak rate after endovascular abdominal aortic aneurysm repair is as high as 20%-50%. When endoleak occurs, it is generally solved by repositioning the stent or embolization, and the commonly used embolization device is a spring coil. However, in this way, not only a second operation is needed, but also multiple spring coils need to be filled for a larger endoleak, which is high in cost for the patient. SUMMARY

[0003] Therefore, the present application aims to solve the technical problem in the prior art that when an aneurysm is treated, a second operation is needed once endoleak occurs, and multiple spring coils need to be filled for a larger endoleak, which is high in cost for the patient, so as to provide a system with a spiral structure for cavity embolization and a delivery method.

[0004] To solve the above technical problems, the technical scheme of the present application is as follows:

[0005] On the one hand, the present application provides a system with a spiral structure for cavity embolization, comprising: an embolization device made of a shape memory alloy, which is in a spiral structure in a natural state and can be freely stretched and contracted under stress; the embolization device comprises an inner mesh layer and an outer mesh layer arranged concentrically, and the sparseness of the outer mesh layer is greater than that of the inner mesh layer; the embolization device is used to be sleeved outside the embolization stent, and the inner circle of the spiral structure is in close contact with the outer wall of the embolization stent, so as to increase the diameter of the cavity part of the embolization stent.

[0006] Further, the two ends of the inner mesh layer and the outer mesh layer in the axial direction of the embolization device are fixed by a bundle port piece, and the end of the bundle port piece located at the distal end of the embolization device is inwardly recessed.

[0007] Further, a flow resistance film is arranged between the outer mesh layer and the inner mesh layer.

[0008] Further, an oxidation film layer that reduces the precipitation of nickel ions is formed on the surface of the shape memory alloy used to make the embolization device.

[0009] Further, cilia that accelerate the embolization speed are arranged on the outer mesh layer.

[0010] Further, the system for cavity embolization with spiral structure further comprises an embolization stent; the embolization device is sleeved outside the embolization stent, and the inner ring of the spiral structure is close to the outer wall of the embolization stent, so as to increase the diameter of the cavity part of the embolization stent.

[0011] Further, the system for cavity embolization with spiral structure further comprises a delivery device, which comprises an outer sleeve, a middle layer pipe, an inner core pipe, a traction wire, a first limiter, a second limiter, a third limiter and a guide wire; the outer sleeve is sleeved outside the middle layer pipe, and a first gap for accommodating the embolization device is left between the outer sleeve and the middle layer pipe; the first limiter is arranged on the outer wall of the middle layer pipe and located at one side of the distal end of the embolization device, so as to limit the movement of the embolization device in the first gap; the traction wire is arranged in the first gap, one end of the traction wire is connected with the proximal end of the embolization device, and the other end of the traction wire is used for being connected with a device for externally applying traction force; the middle layer pipe is sleeved outside the inner core pipe, and a second gap for accommodating the embolization stent is left between the middle layer pipe and the inner core pipe; the second limiter and the third limiter are both arranged on the outer wall of the inner core pipe and located at two ends of the embolization stent respectively, so as to limit the movement of the embolization stent in the second gap; the inner core pipe is a hollow pipe; and the guide wire is movably inserted into the inner core pipe.

[0012] In another aspect, the application provides a delivery method, which comprises the system for cavity embolization with spiral structure, the guide wire is sent to the distal end blood vessel above the aneurysm through the inner core pipe; the delivery device reaches the upper end of the aneurysm along the guide wire; the position of the embolization device is located, and the position of the embolization device is fixed after the embolization device matches the position of the aneurysm sac; the outer sleeve is unlocked, the outer sleeve is withdrawn, the embolization device is released and expanded; the middle layer pipe is unlocked, the middle layer pipe is withdrawn to release the embolization stent, the embolization stent is close to the blood vessel wall after expansion, and the embolization device is wound on the embolization stent.

[0013] Further, when the position of the embolization device is fixed, a certain force is applied to the tail end of the traction wire, so as to prevent the embolization device from being washed away from the predetermined position by blood flow.

[0014] Further, if the release position of the embolization device is not ideal, the traction wire is pulled and the outer sleeve is pushed up, the embolization device is re-released after being retracted into the first gap.

[0015] The technical scheme of the application has the following advantages:

[0016] The application provides a system for cavity embolization with a spiral structure, and the spiral structure of the embolization device can be closely attached to the periphery of the embolization stent after being released, the diameter of the cavity part of the embolization stent is increased, the whole cavity or sac is filled in a physical occupation manner, the blocking effect is improved, internal leakage is avoided, and thus secondary surgery is avoided. Moreover, the sparse degree of the outer net layer is greater than that of the inner net layer, the blood flow direction can be better changed, the blood flow speed is reduced, endothelial substances in the blood are quickly deposited in the embolization, endothelialization is completed, the tumor sac is atrophied, and the treatment effect is improved. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, hereinafter, a brief introduction will be given to the drawings needed to be used in the specific embodiments or prior art description. Obviously, the drawings described hereinafter are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without any creative effort on the basis of these drawings.

[0018] Figure 1 A schematic view of the embolization device (in a natural state) in the system for cavity embolization with a spiral structure in the embodiments of the present application;

[0019] Figure 2 A schematic view of the inner net layer and the outer net layer of the embolization device in the system for cavity embolization with a spiral structure in the embodiments of the present application;

[0020] Figure 3 A schematic view of the position relationship between the embolization device and the embolization stent in the system for cavity embolization with a spiral structure in the embodiments of the present application;

[0021] Figure 4 A schematic view of the cilia of the embolization device in the system for cavity embolization with a spiral structure in the embodiments of the present application;

[0022] Figure 5 A schematic view of the embolization device (with cilia) in the system for cavity embolization with a spiral structure in the embodiments of the present application;

[0023] Figure 6 A schematic view of the delivery device in the system for cavity embolization with a spiral structure in the embodiments of the present application;

[0024] Figure 7 A schematic view of the internal structure of the delivery device in the system for cavity embolization with a spiral structure in the embodiments of the present application;

[0025] Figure 8 A schematic view of the embolization device after being released in the system for cavity embolization with a spiral structure in the embodiments of the present application;

[0026] Figure 9 Figure 6 is a schematic view of the system for cavity embolization with a spiral structure in an embodiment of the present application, showing the embolization stent after being released;

[0027] Figure 10 Figure 7 is a schematic view of the system for cavity embolization with a spiral structure in an embodiment of the present application, showing the delivery device after being withdrawn.

[0028] Explanation of reference signs:

[0029] 1, embolization device; 2, outer mesh layer; 3, inner mesh layer; 4, bundle port; 5, blood vessel; 6, embolization stent; 7, cilia; 8, delivery device; 9, outer sleeve; 10, middle layer tube; 11, inner core tube; 12, pull wire; 13, first gap; 14, second gap. DETAILED DESCRIPTION

[0030] The technical solutions of the present application will be described clearly and completely below in conjunction with the drawings. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative efforts fall within the scope of the present application.

[0031] In the description of the present application, it should be noted that the orientations or positional relationships indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second", "third" are only for the purpose of description, and cannot be understood as indicating or implying relative importance.

[0032] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connecting" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integrally connected; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, or the internal communication of two elements. For those skilled in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances.

[0033] In addition, the technical features involved in different embodiments of the present application described below can be combined with each other as long as there is no conflict between them.

[0034] In the present application, the end connected with the delivery device 8 is defined as the proximal end, and the other end is defined as the distal end. It can also be understood that the end closer to the operator is the proximal end, and the other end is the distal end.

[0035] As shown in Figure 1 , Figure 2 , Figure 3 The embodiment provides a system for cavity embolization with a spiral structure, which comprises an embolization device 1 made of a shape memory alloy, which is in a spiral structure in a natural state and can be freely stretched and contracted under stress. For example, the embolization device 1 can be made of a nickel-titanium alloy material by weaving and shaping. In the natural state, the number of spiral turns N is greater than or equal to 1. The embolization device 1 comprises an inner mesh layer 3 and an outer mesh layer 2 arranged concentrically, and the sparseness of the outer mesh layer 2 is greater than that of the inner mesh layer 3. The embolization device 1 is used to be sleeved outside the embolization stent 6, and the inner circle of the spiral structure is in close contact with the outer wall of the embolization stent 6, so as to increase the diameter of the cavity part of the embolization stent 6.

[0036] The system for cavity embolization with a spiral structure provided by the embodiment can tightly fit around the embolization stent 6 after the release of the embolization device 1 with a spiral structure, thereby increasing the diameter of the cavity part of the embolization stent 6, filling the entire cavity or sac in a physical occupation manner, improving the occlusion effect, avoiding internal leakage, and thus avoiding secondary surgery. Moreover, since the sparseness of the outer mesh layer 2 is greater than that of the inner mesh layer 3, the blood flow direction can be better changed, the blood flow speed can be reduced, the endothelial material in the blood can be quickly deposited in the embolization, the endothelialization can be completed, the tumor sac can be atrophied, and the treatment effect can be improved.

[0037] In the axial direction of the embolization device 1, the two ends of the inner mesh layer 3 and the outer mesh layer 2 are fixed by a bundle port member 4, and the end of the bundle port member 4 located at the distal end of the embolization device 1 is inwardly recessed. For example, the bundle port member 4 can be a stainless steel alloy. The inner mesh layer 3 and the outer mesh layer 2 are wrapped by the bundle port member 4. For the proximal end, the entire embolization device 1 can be more easily pulled by the bundle port member 4. For the distal end, the inwardly recessed bundle port member 4 can prevent the stainless steel bundle port member 4 from protruding to form a sharp end to cause harm to the human body.

[0038] In the axial direction of the embolization device 1, the two ends of the inner mesh layer 3 and the outer mesh layer 2 are fixed by a bundle port member 4, and the end of the bundle port member 4 located at the distal end of the embolization device 1 is inwardly recessed. For example, the bundle port member 4 can be a stainless steel alloy. The inner mesh layer 3 and the outer mesh layer 2 are wrapped by the bundle port member 4. For the proximal end, the entire embolization device 1 can be more easily pulled by the bundle port member 4. For the distal end, the inwardly recessed bundle port member 4 can prevent the stainless steel bundle port member 4 from protruding to form a sharp end to cause harm to the human body.

[0039] The surface of the shape memory alloy used to make the embolization device 1 is formed with an oxide film layer that reduces the release of nickel ions. For example, the surface of the nickel-titanium alloy used to make the embolization device 1 can be treated, including heat treatment to form an oxide film layer, surface coating strengthening by physical or chemical methods, surface cleaning treatment to form a dense oxide layer, such as polishing treatment, plasma treatment, or one or more of these methods. In this way, the release of nickel ions can be reduced, and the corrosion resistance of the material can be improved.

[0040] As shown in Figure 4 , Figure 5 , the outer mesh layer 2 is provided with cilia 7 that accelerate the formation of emboli. For example, PET or nylon cilia 7 can be fixed to the outer mesh layer 2 of the embolization device 1 in a sewing manner to form the embolization device 1 with cilia 7. In this way, the formation speed of the embolization device 1 can be improved.

[0041] The system for cavity embolization with a spiral structure further includes an embolic stent 6; the embolization device 1 is sleeved outside the embolic stent 6, and the inner circle of the spiral structure is in close contact with the outer wall of the embolic stent 6 to increase the diameter of the cavity part of the embolic stent 6. For example, the embolic stent 6 can be a covered stent. For example, the embolic stent 6 can also be a bare stent.

[0042] As shown in Figure 6 , Figure 7 , the system for cavity embolization with a spiral structure further includes a delivery device 8, which includes an outer sleeve 9, a middle layer tube 10, an inner core tube 11, a traction wire 12, a first limiter, a second limiter, a third limiter, and a guide wire; the outer sleeve 9 is sleeved outside the middle layer tube 10, and a first gap 13 for accommodating the embolization device 1 is left between the outer sleeve 9 and the middle layer tube 10; the first limiter is arranged on the outer wall of the middle layer tube 10 and located on one side of the distal end of the embolization device 1 to limit the movement of the embolization device 1 in the first gap 13; the traction wire 12 is arranged in the first gap 13, one end of the traction wire 12 is connected to the proximal end of the embolization device 1, and the other end of the traction wire 12 extends out of the first gap 13 and is used to be connected to an external device for applying traction; the middle layer tube 10 is sleeved outside the inner core tube 11, and a second gap 14 for accommodating the embolic stent 6 is left between the middle layer tube 10 and the inner core tube 11; the second limiter and the third limiter are both arranged on the outer wall of the inner core tube 11 and located at the two ends of the embolic stent 6, respectively, to limit the movement of the embolic stent 6 in the second gap 14; the inner core tube 11 is a hollow tube; and the guide wire is movably inserted into the inner core tube 11.

[0043] Specifically, the delivery device 8 is composed of 3 layers of sheath nested together, from outside to inside, the outer sleeve 9, the middle layer tube 10 and the inner core tube 11, the first gap 13 between the outer sleeve 9 and the middle layer tube 10 is about 1mm, the embolization device 1 is preloaded between the outer sleeve 9 and the middle layer tube 10. The first limiter can be located on the upper side wall of the outer surface of the middle layer tube 10, which is set to prevent the embolization device 1 from moving in the first gap 13. There is a traction wire 12 between the outer sleeve 9 and the middle layer tube 10, one end of the traction wire 12 extends from the proximal end of the first gap 13, and the other end is connected with the proximal end of the embolization device 1. The embolization stent 6 is preloaded in the second gap 14 formed between the inner core tube 11 and the middle layer tube 10, and the second limiter and the third limiter are arranged on the outer surface of the inner core tube 11 according to the length of the embolization stent 6 to prevent the embolization stent 6 from moving in the second gap 14. Among them, the inner core tube 11 is in a hollow state, and its size should be able to allow the smooth passage of guide wires, such as super-hard guide wires, loach guide wires, etc.

[0044] Another embodiment provides a delivery method, including the above-mentioned system for cavity embolization with a spiral structure, sending a guide wire through the inner core tube 11 to the distal blood vessel 5 above the aneurysm; the delivery device 8 reaches the upper end of the aneurysm along the guide wire; positioning the position of the embolization device 1, fixing the position of the embolization device 1 after the embolization device 1 matches the position of the aneurysm sac; unlocking the outer sleeve 9, withdrawing the outer sleeve 9 to release the embolization device 1 and expand it; unlock the middle layer tube 10, withdraw the middle layer tube 10 to release the embolization stent 6, and the embolization stent 6 expands to tightly adhere to the wall of the blood vessel 5, and the embolization device 1 is wrapped around the embolization stent 6.

[0045] Among them, when fixing the position of the embolization device 1, a certain force is applied to the tail end of the traction wire 12 to prevent the embolization device 1 from being washed away from the predetermined position by the blood flow.

[0046] Among them, if the release position of the embolization device 1 is not ideal, pull the traction wire 12 and push the outer sleeve 9 upwards, put the embolization device 1 into the first gap 13 and release it again.

[0047] As Figure 8 , Figure 9 and Figure 10As shown, when the embolization stent 6 is delivered with the embolization device 1, first, the guide wire is sent to the distal blood vessel 5 above the aneurysm through the inner core tube 11, the delivery system reaches the upper end of the aneurysm along the guide wire, and the position of the embolization device 1 is positioned under ultrasound or DSA, so that the embolization device 1 can match the position of the aneurysm sac, and then the fixed position of the embolization device 1 is determined. The outer sleeve 9 of the delivery device 8 is unlocked, the outer sleeve 9 is withdrawn, the embolization device 1 is released and expanded, at this time the embolization device 1 will be washed by the blood flow, in order to prevent the embolization device 1 from being washed away from the predetermined position by the blood flow, a certain force can be applied to the tail end of the traction wire 12; at the same time, if the release position is not ideal, the traction wire 12 can be pulled and the outer sleeve 9 can be pushed up, the occluder can be re-released into the delivery device 8 to achieve the ideal release effect. Then, the middle layer tube 10 of the delivery device 8 is unlocked, the middle layer tube 10 is withdrawn to release the embolization stent 6, the embolization stent 6 is expanded and tightly attached to the inner wall of the blood vessel 5, and the embolization device 1 is wrapped around the embolization stent 6, and the effect is as shown in Figure 9 . Finally, the traction wire 12 is twisted to unlock the connection between the traction wire 12 and the embolization device 1, the traction wire 12 is withdrawn, and the inner core tube 11 is withdrawn from the position below the embolization stent 6, as shown in Figure 10 , the delivery device 8 exits the blood vessel 5 to complete the release.

[0048] Obviously, the above embodiments are only examples for clear illustration, and are not limitations on the embodiments. Based on the above description, other different forms of changes or variations can be made by those of ordinary skill in the art. Here, all the embodiments need not and cannot be exhausted. The obvious changes or variations derived therefrom are still within the protection scope of the present application.

Claims

1. A system for cavity plugging having a helical structure, characterized in that, The system for cavity embolization with spiral structure comprises an embolization device (1) made of shape memory alloy, which is in a spiral structure in a natural state and can be freely stretched and contracted under force; the embolization device (1) comprises an inner mesh layer (3) and an outer mesh layer (2) arranged concentrically, and the sparseness of the outer mesh layer (2) is greater than that of the inner mesh layer (3); the embolization device (1) is used for sleeving outside an embolization stent (6) and closely abutting the inner circle of the spiral structure with the outer wall of the embolization stent (6) to increase the diameter of the cavity part of the embolization stent (6).

2. The system for cavity embolization with spiral structure according to claim 1, wherein the two ends of the inner mesh layer (3) and the outer mesh layer (2) are fixed by a bundle port member (4) in the axial direction of the embolization device (1), and the end of the bundle port member (4) at the distal end of the embolization device (1) is inwardly recessed.

3. The system for cavity embolization with spiral structure according to claim 1, wherein a flow resistance film is arranged between the outer mesh layer (2) and the inner mesh layer (3).

4. The system for cavity embolization with spiral structure according to claim 1, wherein an oxidation film layer reducing the precipitation of nickel ions is formed on the surface of the shape memory alloy used to make the embolization device (1).

5. The system for cavity embolization with spiral structure according to claim 1, wherein cilia (7) for accelerating the embolization speed are arranged on the outer mesh layer (2).

6. The system for cavity embolization with spiral structure according to claim 1, further comprising an embolization stent (6).

7. The system for cavity embolization with spiral structure according to claim 6, further comprising a delivery device (8), wherein the delivery device (8) comprises an outer sleeve (9), a middle layer tube (10), an inner core tube (11), a traction wire (12), a first limiter, a second limiter, a third limiter and a guide wire; the outer sleeve (9) is sleeved outside the middle layer tube (10), and a first gap (13) for accommodating the embolization device (1) is left between the outer sleeve (9) and the middle layer tube (10); the first limiter is arranged on the outer wall of the middle layer tube (10) and located on one side of the distal end of the embolization device (1) to limit the movement of the embolization device (1) in the first gap (13); the traction wire (12) is arranged in the first gap (13), one end of which is connected with the bundle port member (4) at the proximal end of the embolization device (1), and the other end of which extends out of the first gap (13) and is used for being connected with a device for externally applying traction force; the middle layer tube (10) is sleeved outside the inner core tube (11), and a second gap (14) for accommodating the embolization stent (6) is left between the middle layer tube (10) and the inner core tube (11). ​ ​ ​ ​ ​ ​ ​ ​ The second position limiter and the third position limiter are arranged on the outer wall of the inner core pipe (11) and are respectively located at the two ends of the embolism stent (6) to limit the movement of the embolism stent (6) in the second gap (14); The inner core pipe (11) is a hollow pipe; The guide wire is movably inserted into the inner core pipe (11).

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