Aneurysm occlusion device
Technical Field
The invention relates to the technical field of aneurysm treatment, in particular to an aneurysm occlusion device.
Background
Intracranial aneurysm refers to localized bulging and dilatation of the vessel wall of an artery due to the action of acquired pathological factors or congenital malformations. Intracranial aneurysm has a very high incidence rate of about 5%, and its course is often more secret, rupture bleeding is often more sudden, and the fatality rate or disability rate is also high. The lethality rate of the first rupture bleeding is 8% -45%, the lethality rate in one year is higher than 60%, and the lethality rate in 2 years is more than 85%. Therefore, it is globally emphasized that early diagnosis and treatment of intracranial aneurysms is of great clinical importance to improve patient survival and quality of life.
At present, two standard treatment methods are available for cerebral aneurysm rupture bleeding, namely craniotomy clamping and endovascular interventional embolization. For a long time, the treatment of cerebral aneurysms has been dominated by craniotomy clamping procedures, which have the significant disadvantage that the surgeon has to sever the various tissues to reach the aneurysm, and to secure metal clips around the base of the aneurysm, so that the patient experiences a great deal of trauma in the area of the aneurysm. The recovery time after surgery is long and there is a possibility of epilepsy development after surgery. In recent years, with the progress of medical imaging and the continuous progress of interventional embolization technology, the application of interventional embolization is increasing, and about 85% of aneurysms in some european centers are currently treated with interventional embolization. The method is safe and effective for treating intracranial aneurysm by using an intravascular interventional therapy method for a specific patient, and the interventional embolization has the advantages of small pain, small wound, no need of vexation, short operation recovery period and complete intravascular operation, so that the quality of life of the patient can be improved, the death rate can be reduced, and the aim of healing can be fulfilled.
The common interventional therapy product in the market is provided with a spring ring, a liquid embolic agent, an auxiliary embolism, a blood flow guiding device, a covered stent and a tumor cavity internal blood flow device, wherein the spring ring, the liquid embolic agent and the tumor cavity internal blood flow device are all placed in the tumor cavity to fill the tumor cavity and interfere the tumor internal blood flow to form an embolism in the tumor so as to achieve the purpose of blocking the tumor cavity. The blood flow guiding device and the tectorial membrane bracket are both arranged in a blood vessel and interfere with blood flow entering the tumor or seal the tumor cavity to form embolism to seal the tumor cavity. However, occlusion of an aneurysm at a vessel bifurcation has been a troublesome problem, and embolization requires occlusion of the aneurysm without affecting parent blood flow. At present, a spring ring is commonly used for aneurysm at a bifurcation, but the spring ring has the defects of multiple packing, troublesome operation, difficult control of packing density, possibility of over-full or under-full packing, and difficulty in measuring the over-full state of the aneurysm; thus, there may be overfilling that causes the coil to burst into the parent artery, affecting blood flow and increasing the likelihood of arterial thrombosis. For wide-neck aneurysms, the spring ring may need to be placed and blocked with the assistance of a stent, so that the spring ring is prevented from falling off, and the operation cost and the placing operation difficulty are increased. The liquid embolic agent has high embolism rate, but extravasation and the occlusion of a perforator are serious complications of the liquid embolic agent, and the liquid embolic agent is rarely used as an intracavitary embolic agent for filling and treating intracranial aneurysm at present. The clinical application of the covered stent and the blood flow guiding device provides a new method for treating intracranial aneurysm, and becomes another innovation in the treatment history of intracranial aneurysm. The applicability is limited, and the aneurysm at the bifurcation position is not applicable. Intratumoral blood flow devices, which are spring ring extension products, such as Woven Endoluminal Bridge (WEB) devices, are designed for wide-neck and bifurcated aneurysm treatment and can interfere with intratumoral blood flow from the cervical level of the aneurysm to achieve the purpose of long-term occlusion.
According to the investigation, most of the existing blood flow devices in the tumor cavity are formed by weaving nickel-titanium alloy wires, are shaped into a spherical shape or a hemispherical shape, and support the neck or the inside of the tumor by utilizing the elasticity of a woven mesh, so that the device stays in the tumor and simultaneously blocks the neck of the tumor. However, these intratumoral blood flow devices still have many problems in clinical applications, including whether the sealing of the tumor neck is good, whether slippage occurs, whether the parent artery is occupied, whether visualization is available, whether porosity is adequate, whether delivery is feasible, etc.
Disclosure of Invention
The invention aims to provide an aneurysm occlusion device, so as to solve the problem that a bifurcation type aneurysm is difficult to be stably occluded by an occlusion device.
In order to solve the technical problems, the invention adopts the following technical scheme:
the aneurysm occlusion device is formed by an elastic net body, the near end of the elastic net body is radially inwards folded and connected with a near end mark part, the far end of the elastic net body is radially inwards folded and connected with a far end mark part and reversely folded, so that the far end of the elastic net body where the far end mark part is located extends into the elastic net body, a double-layer net structure formed by the reverse folding forms the elastic net body of an expansion part, a single-layer net structure which is not reversely folded forms the elastic net body of a neck part, and in a self-expansion state, the radial size of the elastic net body of the expansion part is gradually increased from the near end to the far end or is increased and then reduced.
It should be understood that "self-expanding state" herein refers to the state that the device assumes without any external force being applied by man.
According to the aneurysm occlusion device provided by the invention, the neck elastic net body and the expansion part elastic net body can respectively and tightly adhere to the neck and the wall of the aneurysm in a self-expansion state, so that the aneurysm can be effectively occluded.
Furthermore, the device can be divided into a short neck occlusion device and a long neck occlusion device in different embodiments for adapting to different types of aneurysms, and the devices are distinguished according to different size ratios of the expansion part elastic net body and the neck part elastic net body. Wherein the short neck occluding device is more suitable for a narrow neck aneurysm and the long neck occluding device is more suitable for a wide neck aneurysm.
According to a preferred aspect of the present invention, there is provided a short neck occlusion device, more suitable for use in narrow neck aneurysms, primarily for better conformity to the neck of the aneurysm, characterized by a narrow neck, a shorter neck length, a bulbous shape, a cylindrical dome shape, etc. within the aneurysm cavity, the diameter of the aneurysm cavity being greater than the diameter of the aneurysm neck. The short-neck occlusion device designed aiming at the narrow-neck aneurysm has the characteristics that the elastic reticular body at the neck part is shorter, the near end is flat, and the elastic reticular body at the expansion part is longer.
In the case of the short neck occlusion device, the shape of the expanded portion elastic mesh body extending distally may be curved, linear, wavy, irregularly curved, or the like. The diameter of the elastic reticular body of the expansion part relative to the elastic reticular body of the neck part can be gradually increased or increased and then decreased. Preferably curved or straight.
For the short neck blocking device, the neck elastic net body can be attached to the neck of the aneurysm, the diameter of the neck elastic net body is larger than or equal to that of the neck of the aneurysm in a free state, the net body is a single-layer net body, and the section perimeter of the neck elastic net body is further larger than or equal to that of the neck of the aneurysm.
Preferably, the diameter of the neck elastic reticular body is more than or equal to 0.5 mm; the perimeter of the cross section is more than or equal to 1.5 mm. The length of the neck elastic reticular body is more than or equal to the height of the tumor neck, and is preferably more than 0.5 mm.
The shorter neck elastic net body can ensure the radial force and simultaneously be parallel and level or slightly convex on the parent artery, thereby improving the probability of completely sealing the neck opening at the later stage and simultaneously reducing the probability of forming thrombus in the parent artery. The elastic reticular body of the longer expansion part is in a spherical or columnar dome shape, is tightly attached to the tumor cavity and has micro-tension. The tension at the top of the tumor can be further reduced by increasing the radial tension at the middle position of the expansion part while providing the radial micro-tension. The diameter of the maximum position of the elastic reticular body of the expansion part is more than or equal to the maximum position of the tumor cavity, and the preferred diameter is more than or equal to 0.5 mm; the perimeter is more than or equal to 1.5 mm.
Because the position of the tumor top is weakest and easy to crack, according to a preferred scheme of the invention, when the far-end marking part is arranged inwards, the risk of cracking of the tumor top is reduced, and the application requirement is met.
In accordance with another preferred aspect of the present invention, a long neck occlusion device is provided that is more suitable for use with wide-neck aneurysms. Clinical carotid aneurysms mostly appear as dome-shaped columns or hemispheres, and the diameter of a tumor neck is usually the maximum outer diameter of a tumor cavity, namely, wide-necked aneurysm. The treatment of such aneurysms has been a very delicate problem in the industry, and conventionally requires a stent to be treated with a coil, but this increases the difficulty and expense of the operation. To this end, the invention provides, inter alia, such a long neck occlusion device specifically for wide neck aneurysms. Different from the short-neck blocking device, the elastic net body for the neck of the long-neck blocking device is composed of a longer single-layer net body, so that more contact areas in the tumor cavity can be provided, and the tension of an opening section in the tumor cavity can be provided.
For the long-neck blocking device, the diameter of the elastic net-shaped body at the neck part is more than or equal to the diameter of the neck part of the tumor cavity, and the preferred diameter is more than or equal to 0.5 mm; the perimeter is more than or equal to 1.5 mm. The length of the neck elastic reticular body is more than or equal to 10 percent of the total tumor height, preferably more than or equal to 50 percent of the total tumor height.
Preferably, the cross-sectional perimeter of the expandable section elastic mesh body at the distal end of the long neck occlusion device is smaller, and the length of the expandable section elastic mesh body is less than or equal to 50% of the total tumor height, preferably less than or equal to 30% of the total tumor height.
The diameter of the maximum position of the elastic reticular body of the expansion part is more than or equal to the maximum size in the tumor cavity, and the preferred diameter is more than or equal to 0.5 mm; the perimeter is more than or equal to 1.5 mm. The diameter grow of distal end expansion portion elasticity dictyosome, the similar rabbit ear of outside expansion in cross-section for the elasticity of expansion portion is bigger, more is favorable to the support to stay in the straight tumour chamber of wide neck, and the holding power of distal end is less, reduces the cracked risk of tumour top.
In accordance with a preferred embodiment of the present invention, the aneurysm occlusion device further comprises a connecting wire for connecting the proximal marker portion and the distal marker portion, wherein the proximal and distal ends of the aneurysm occlusion device are better shaped and relatively more supportive when the connecting wire is present, and wherein the proximal end of the elongated body is in the form of a single-layer mesh and the distal end of the elongated body is compressed when the aneurysm occlusion device is stretched into a pre-delivery configuration with the elongated body.
In accordance with another preferred embodiment of the present invention, the proximal and distal markers are not connected by a connecting wire, the proximal and distal ends of the occluding device are relatively free, the holding force is relatively low, and the entire aneurysm occluding device is compressed in a single-layered mesh when stretched into an elongated body for pre-delivery.
According to the aneurysm occlusion device provided by the invention, the neck elastic reticular body and the expansion part elastic reticular body can be obtained by weaving a plurality of wires or weaving a single wire, or cutting in a tubular shape, or molding by a sheet material. The elastic net-shaped body is composed of a plurality of diamonds, parallelograms or polygons which can be compressed. The reticular body material is elastic memory metal or polyester material or degradable material, such as degradable polyurethane, degradable polyester, poly (L-lactide-co-D-lactide), poly (L-lactide-co-D, L-lactide), poly (D-lactide-co-D, L-lactide), poly (lactide-co-glycolide), poly (lactide-co-epsilon-caprolactone) and poly (glycolide-co-epsilon-caprolactone).
Furthermore, according to the present invention, after the elastic mesh body is formed, a drug may be attached to the surface, and the drug may be an anti-rejection drug, an anti-platelet drug, an anticoagulant drug, an antithrombotic drug, an anti-inflammatory drug. The medicine can be coated on the surface of the reticular body by adopting the processes of spraying, dip coating, electrostatic adsorption and the like.
According to a preferred embodiment of the present invention, the proximal end of the elastic net-shaped body of the neck of the aneurysm occlusion device is gathered radially inward to form a net-shaped body gathering portion in advance, and the proximal marker portion is fixedly connected to the net-shaped body gathering portion at the proximal end of the elastic net-shaped body. The proximal marker may be shaped as a cylinder, or as a cylinder housing closed at one end, or as a wire. The proximal marker portions may be disposed one each outside or inside the collection of mesh bodies, or both. The fixed connection can be a press riveting mode, an adhesion mode, a welding mode, hot melting and the like. The proximal marker is made of a radiopaque material.
According to a preferred embodiment of the present invention, the distal end of the elastic mesh body of the expandable portion of the aneurysm occlusion device is radially inwardly gathered to form another mesh body gathering portion in advance, and the distal marker portion is fixedly connected to the mesh body gathering portion at the distal end of the elastic mesh body. The distal marker may be shaped as a cylinder, or as a cylinder housing closed at one end, or as a wire. The distal marker portions may be provided one each outside or inside the mesh-like body assembly portion, or both. The fixed connection can adopt a press riveting mode, a bonding mode, a welding mode, hot melting and the like. The proximal marker is made of a radiopaque material.
According to a preferred embodiment of the present invention, when the proximal marker portion and the distal marker portion are connected by the connecting wire, the elastic mesh body can be axially stretched into an elongated body in a self-expanding state, and the elongated body can be delivered or withdrawn along the micro-catheter; the near end of the slender body is of a single-layer net structure, and the far end of the slender body is of a double-layer net structure.
According to another preferred embodiment of the present invention, the jointless string connecting the proximal marker portion and the distal marker portion, wherein the relatively self-expandable configuration allows the elastic mesh body to be axially stretched into an elongated body that can be delivered or withdrawn along the inside of the microcatheter; the whole body of the slender body is of a single-layer net structure.
According to the invention, the intracavity blood flow device for treating intracranial aneurysm can better support and seal wide carotid aneurysm and narrow carotid aneurysm, particularly provides effective support at the neck of aneurysm, has the function similar to a plug, occupies a small space in parent artery, reduces the possibility of arterial thrombosis, has reasonable tension in the aneurysm cavity, and reduces or avoids the risk of weak and easy-to-break top of aneurysm.
In conclusion, the invention provides an occlusion device capable of effectively treating aneurysm, solves the problems of poor occlusion effect, higher operation cost and higher operation difficulty in the prior art, can reduce the possibility of arterial thrombosis, and also reduces or even avoids the risk of weak and easily broken top of aneurysm. Clinical research results show that the aneurysm occlusion device provided by the invention can quickly isolate intracranial aneurysms from circulation, has a better embolization rate than a stent auxiliary spring ring for wide-neck aneurysms and bifurcation aneurysms, and provides an effective clinical basis for treating the wide-neck aneurysms and the bifurcation aneurysms by a blood flow device in a tumor cavity.
Drawings
FIG. 1 is a schematic structural view of a short neck occlusion device provided in accordance with a preferred embodiment of the present invention;
FIG. 2 is a schematic structural view of a short neck occlusion device provided in accordance with another preferred embodiment of the present invention;
FIG. 3 is a schematic structural view of a short neck occlusion device provided in accordance with yet another preferred embodiment of the present invention;
FIG. 4 is a schematic structural view of a long neck occluding device provided in accordance with another preferred embodiment of the present invention;
FIG. 5 is a schematic view of the long neck occluding device shown in FIG. 4 in a distal expanded state;
FIG. 6 is a schematic view of the short neck occlusion device of FIG. 2 in use;
fig. 7 is a schematic view of the long neck occlusion device of fig. 4 in use.
Detailed Description
The present invention will be further described with reference to the following specific examples. It should be understood that the following examples are illustrative only and are not intended to limit the scope of the present invention.
In order to solve the problem that the bifurcation type aneurysm is difficult to be stably blocked by the blocking device, the invention provides the aneurysm blocking device which can provide effective support at the neck of the aneurysm, has the effect similar to a plug, occupies small space in the parent artery, reduces the possibility of arterial thrombosis, has reasonable tension in the aneurysm cavity and reduces the risk of weak and easy-to-break aneurysm top.
In order to better realize the stable occlusion of the narrow-neck aneurysm and the wide-neck aneurysm respectively, the invention provides two aneurysm occlusion devices which are divided into a short-neck occlusion device and a long-neck occlusion device according to different size ratios of an expansion part elastic net body and a neck elastic net body, wherein the short-neck occlusion device is more suitable for the narrow-neck aneurysm, and the long-neck occlusion device is more suitable for the wide-neck aneurysm.
Referring to fig. 1, a short neck occlusion device 10 is provided in accordance with a preferred embodiment of the present invention. The device is formed by an elastic net body which is approximately cylindrical in an initial state and comprises: a proximal marker part 1, a neck elastic reticular body 2, an expansion part elastic reticular body 3, a distal marker part 4 and a connecting line 5. The neck elastic reticular body 2 is connected with the near-end marking part 1 by radially inwards folding at the near end, the neck elastic reticular body 2 extends to the far end along the axial direction and is connected with the far-end marking part 4 by radially inwards folding, the neck elastic reticular body 2 is of a double-layer reticular structure formed by reverse folding operation, and the neck elastic reticular body 2 is of a single-layer reticular structure which is not reversely folded. The short neck blocking device 10 is characterized in that the elastic net-shaped body 2 of the neck part is short and flat at the proximal end, and the elastic net-shaped body 3 of the expansion part is long.
In the short neck occlusion device 10, the elastic neck net 2 can be attached to the neck of an aneurysm, and the elastic neck net 2 has a diameter equal to or larger than the diameter of the aneurysm neck in a free state, and is a single-layer net, and further, the cross-sectional perimeter of the elastic neck net 2 is equal to or larger than the perimeter of the aneurysm neck.
Preferably, the diameter of the neck elastic reticular body 2 is more than or equal to 0.5 mm; the perimeter of the cross section is more than or equal to 1.5 mm. The length of the neck elastic reticular body 2 is more than or equal to the height of the tumor neck, and is preferably more than 0.5 mm.
The shorter neck elastic net-shaped body 2 can ensure the radial force and simultaneously is parallel and level or slightly convex on the parent artery, thereby improving the probability of completely sealing the neck opening at the later stage and simultaneously reducing the probability of forming thrombus in the parent artery. The elastic reticular body 3 of the longer expansion part is in a spherical or columnar dome shape, is tightly attached to the tumor cavity and has micro-tension.
The diameter of the maximum radial dimension position of the elastic reticular body 3 of the expansion part is more than or equal to the maximum radial dimension position of the tumor cavity, and the preferred diameter is more than or equal to 0.5 mm; the perimeter is more than or equal to 1.5 mm.
As shown in figure 1, the proximal marker portion 1 and the distal marker portion 4 are further connected by a connecting wire 5, and in a relatively self-expanding configuration, the elastic mesh body can be axially stretched into an elongated body to achieve delivery or withdrawal of the elongated body along the microcatheter, wherein the proximal end of the elongated body is a single-layer mesh structure, and the distal end of the elongated body is a double-layer mesh structure. When the connection between the proximal marker 1 and the distal marker 4 is achieved using the connecting wire 5, the proximal and distal shapes of the occluding device are better maintained and the support is relatively large.
According to another preferred embodiment of the present invention, as shown in fig. 2, the proximal marker portion 1 and the distal marker portion 4 are not connected by a connecting wire, and the elastic mesh body can be axially stretched into an elongated body to achieve delivery or withdrawal of the elongated body along the micro-catheter in a relatively self-expanding configuration, wherein the elongated body has an overall single-layer mesh structure. When the connecting wire 5 is not connected, the proximal end and the distal end of the occlusion device are relatively free, the supporting force is relatively small, and the whole occlusion device is compressed in a single-layer net shape.
As shown in fig. 2, the proximal marker 1 is attached to the neck portion beyond the end of the elastic mesh body 2. The proximal marker 1 is cylindrical or a cylindrical housing closed at one end or wire-like. The proximal marker 1 and the end portion assembly of the neck elastic mesh body 2 may be fixedly connected by any one of a press-riveting method, an adhesive method, a welding method, a hot-melting method, and the like. The proximal marker 1 is made of a radiopaque material.
As shown in fig. 2, the distal marker 4 is connected to the gathering portion where the end of the elastic mesh body 3 of the expansion portion is gathered inward, and the distal marker 4 is cylindrical or has a cylindrical shell with one end closed or has a wire shape. The distal marker 4 and the end portion of the expanded portion elastic mesh body 3 may be fixedly connected by any one of a press-riveting method, an adhesive method, a welding method, a hot-melting method, and the like. The distal marker 4 is also made of a radiopaque material.
According to another preferred embodiment of the present invention, as shown in fig. 3, the proximal marker 1 may be further connected to the inside of the end of the elastic net body 2 of the neck portion by reverse inward bending.
As previously mentioned, in accordance with another preferred embodiment of the present invention, a long neck occlusion device 20 is also provided, as shown in Figs. 4-5. The long neck occluding device 20 differs from the short neck occluding device 10 in that the long neck occluding device 20 has a longer elastic mesh 2 of the neck, thereby providing more intra-tumor contact area and providing intra-tumor open segment tension. The diameter of expansion portion elasticity dictyosome 3 from the near-end to the distal end is grow gradually, and the similar outside rabbit ear that expands in cross-section for the elasticity of expansion portion is bigger, more is favorable to the support to stay in the tumour intracavity that the broad neck is straight, and the holding power of distal end is less, reduces tumour top rupture risk.
For the long-neck blocking device 20, the diameter of the neck elastic reticular body 2 is more than or equal to the diameter of the neck of the tumor cavity, and the preferred diameter is more than or equal to 0.5 mm; the perimeter is more than or equal to 1.5 mm. The length of the neck elastic reticular body 2 is more than or equal to 10 percent of the total height of the tumor, preferably more than or equal to 50 percent of the total height of the tumor. It should be understood that "total tumor height" herein refers to the size of the tumor body from the tumor top 104 to the tumor neck opening 102 as shown in fig. 6.
Preferably, the cross-sectional perimeter of the expandable section elastic mesh body 3 at the distal end of the long neck occlusion device 20 is smaller, and the length of the expandable section elastic mesh body 3 is less than or equal to 50% of the total height of the tumor, preferably less than or equal to 30% of the total height of the tumor.
Preferably, the maximum diameter of the elastic reticular body 3 of the expansion part is more than or equal to the maximum size in the tumor cavity, and the preferred diameter is more than or equal to 0.5 mm; the perimeter is more than or equal to 1.5 mm.
While the long neck occlusive device 20 shown in fig. 4-5 does not show a connecting wire 5, it should be understood that the connecting wire 5 may be added accordingly as needed to better maintain the proximal and distal shapes when stretched.
Referring to fig. 6 and 7, there are shown schematic views of the short neck occlusion device 10 and the long neck occlusion device 20 provided according to the preferred embodiment described above, after they have been implanted in an aneurysm. In clinical applications, the conventional electrolytic desorption delivery system (such as CN208130024U, etc.) or mechanical delivery system on the market can be used for matching delivery, and the delivery system is only briefly described herein because the delivery system is not the innovation point of the invention.
In the pre-delivery state, the proximal marker portion 1 is connected to the delivery system and the occluding device is stretched into an elongated body for placement within a sheath of the delivery system.
In operation, the elongated body is delivered into the tumor cavity 103 through the tumor neck 101 along the inside of the micro-catheter, and the occlusion device is slowly pushed at a proper position in the tumor cavity 103, so that the occlusion device is expanded in the tumor cavity 103. After the device is unfolded, the neck elastic net body 2 is attached to the inner wall of the tumor neck 101, the expansion part elastic net body 3 is attached to the inner wall of the tumor cavity 103, and whether the position or other marking silk threads are proper is confirmed through the near-end marking part 1 and the far-end marking part 4 of the occlusion device, so that the near-end marking part 1 is flush with the outer end of the tumor neck opening 102, and the far-end marking part 4 is not contacted with the tumor top 104. If the neck elastic reticular body 2 does not tightly clamp the neck opening 102, the blocking device can be further pushed and pulled by the conveying system, the position is adjusted to achieve the blocking effect, after the blocking is finished, the conveying system is separated from the blocking device, and the conveying system is withdrawn, so that the implantation of the blocking device is finished.
The aneurysm occlusion device provided by the invention can provide effective support at the neck of a aneurysm, has the function similar to a plug, occupies a small space in the parent artery, reduces the possibility of arterial thrombosis, has reasonable tension in the aneurysm cavity, can reduce the risk of weak and easy-to-break top of the aneurysm, can better support and block wide carotid aneurysm and bifurcation aneurysm, and has a satisfactory treatment effect.
The above embodiments are merely preferred embodiments of the present invention, which are not intended to limit the scope of the present invention, and various changes may be made in the above embodiments of the present invention. All simple and equivalent changes and modifications made according to the claims and the content of the specification of the present application fall within the scope of the claims of the present patent application. The invention has not been described in detail in order to avoid obscuring the invention.