An embolization microcatheter

Abstract

The present invention relates to an embolization microcatheter, comprising: a delivery section having a delivery cavity; an embolization section, one end near the distal end is recessed towards the embolization cavity of the embolization section and forms a pressure relief portion having a pressure relief hole; one end of the embolization section near the proximal end is sleeved on one end of the delivery section near the distal end, and the embolization cavity is communicated with the delivery cavity; during embolization, an embolization material is continuously injected into the embolization cavity through the delivery cavity, the pressure relief portion bulges outwards in a direction away from the embolization cavity, and then the embolization section gradually expands from the direction of the distal end towards the direction of the proximal end, and promotes the separation of the embolization section from the delivery section to achieve the purpose of embolizing blood vessels. When the embolization cavity is filled with the embolization material, the embolization material will squeeze the wall of the embolization cavity and increase the diameter of the wall of the embolization cavity, thereby promoting the separation of the embolization section from the delivery section to achieve the purpose of embolizing the target blood vessel jointly by the embolization section and the embolization material.

Description

Technical Field

[0001] This invention relates to the field of microcatheter embolization technology, and particularly to an embolization microcatheter. Background Technology

[0002] In the field of neurosurgery, preoperative embolization of the supplying vessels is a common adjunctive treatment for complex lesions such as intracranial arteriovenous malformations (AVMs) or highly vascularized meningiomas at the skull base. This adjunctive treatment effectively reduces intraoperative bleeding by blocking blood flow to the lesion area, thereby lowering surgical risks and creating favorable conditions for subsequent surgical procedures such as tumor resection.

[0003] In clinical practice, endovascular intervention is commonly used, where liquid embolic agents are delivered to the diseased blood vessel via a microcatheter for embolization. However, because the flowability and viscosity of liquid embolic agents are difficult to control precisely within the blood vessel, there is a risk of reflux or misdirection into non-target vessels, potentially leading to serious complications such as cerebral infarction. Furthermore, after embolization, the tip of the microcatheter is prone to adhesion to the solidified embolic agent and the vessel wall, making it difficult to withdraw the catheter from the body, posing a significant clinical challenge.

[0004] To address the aforementioned technical challenges, existing technology (authorization announcement number CN210990516U) includes a microcatheter with a detachable tip. The core of this technology lies in the presence of a truncated portion on the microcatheter. After embolization, a certain mechanical traction force is applied to further separate the tip from the main body of the microcatheter. Even if the tensile strength of the truncated portion is particularly low, this traction force may disturb the fragile intracranial blood vessels, causing changes in the course of the blood vessels or even leading to vascular damage. Summary of the Invention

[0005] To solve, or at least partially solve, the above-mentioned technical problems, the present invention provides an embolization microcatheter.

[0006] The present invention provides an embolization microcatheter, which includes a delivery section and an embolization section. The delivery section has a delivery cavity. The distal end of the embolization section is recessed toward the embolization cavity of the embolization section and forms a pressure relief portion with a pressure relief hole. The proximal end of the embolization section is sleeved on the distal end of the delivery section, and the embolization cavity communicates with the delivery cavity.

[0007] During embolization, embolic material is continuously injected into the embolization cavity through the delivery cavity. The pressure relief section protrudes outward in a direction away from the embolization cavity. Then, the embolic segment gradually expands from the distal end to the proximal end, causing the embolic segment to separate from the delivery segment, thereby achieving the purpose of embolizing the blood vessel.

[0008] Optionally, the delivery section has an expansion channel; the embolization microcatheter further includes an expansion capsule having an expansion cavity communicating with the expansion channel; the expansion capsule is located at one end of the delivery section near the distal end; the embolization section is sleeved on the expansion capsule.

[0009] Optionally, multiple expansion channels are evenly distributed around the axis of the conveying section; multiple expansion bladders are evenly distributed around the axis of the conveying section, and the expansion cavity of each expansion bladder is connected to an expansion channel.

[0010] Optionally, the cross-sectional shape of the side wall of the dilatation bladder that contacts the embolized segment is wavy.

[0011] Optionally, the diameter of the pressure relief hole is 0.1mm to 0.5mm.

[0012] Optionally, the pressure relief part has a pressure relief groove formed by recessing towards the embolization cavity, and the pressure relief hole is located at the bottom of the pressure relief groove.

[0013] Optionally, a groove is formed at one location of the embolization segment, which is recessed inward toward the axis of the embolization segment; the groove divides the embolization cavity into two embolization sub-cavities.

[0014] Optionally, multiple locations of the embolization segment are recessed inward toward the axis of the embolization segment to form multiple grooves; the multiple grooves divide the embolization cavity into multiple embolization sub-cavities.

[0015] Optionally, the groove is provided with multiple reinforcing holes, which are evenly distributed around the axis of the plug section.

[0016] Optionally, the thickness of the embolized segment gradually decreases from the direction of the distal end to the direction of the proximal end.

[0017] Optionally, the end of the conveying cavity near the distal end is a conveying port, and the diameter of the conveying port is half the diameter of the conveying cavity.

[0018] Optionally, the embolization microcatheter further includes an occlusion piece disposed within the embolization cavity and located at one end of the embolization segment near the proximal end; the occlusion piece has an injection hole in its middle portion, the diameter of which is the same as the diameter of the delivery port; the middle portion of the occlusion piece is disposed towards the embolization cavity.

[0019] Compared to existing technologies, in this embodiment, by providing a pressure relief section with a pressure relief hole on the embolization segment, the pressure relief hole allows the microguidewire to pass through during delivery, facilitating the movement of the microcatheter along the microguidewire. When embolizing the target vessel, it is only necessary to withdraw the microguidewire from the vessel to the outside of the body, and then inject the embolic material into the embolization cavity through the delivery chamber. As the embolic material is injected, it compresses the concave pressure relief section, transforming it into an outward convex state. As the embolic material fills the embolization cavity, a portion of the embolic material enters the pressure relief hole. This portion of the embolic material remains within the pressure relief hole, or it passes through the pressure relief hole to the outside. However, the amount of embolic material outside the pressure relief hole is small and does not escape, thus preventing the embolic material from overflowing and embolizing non-target vessels. Therefore, by providing a pressure relief hole on the pressure relief section, the pressure of the embolic material during filling the embolization cavity can be reduced. When the embolization material fills the embolization cavity, it will compress the cavity wall and increase the diameter of the cavity wall, thereby promoting the separation of the embolization segment from the delivery segment, so as to achieve the purpose of embolizing the target blood vessel together through the embolization segment and the embolization material. Attached Figure Description

[0020] To more clearly illustrate the embodiments of the present invention, the relevant accompanying drawings will be briefly described below. It should be understood that the drawings described below are only for illustrating some embodiments of the present invention, and those skilled in the art can obtain many other technical features and connections not mentioned herein based on these drawings.

[0021] Figure 1 This is a schematic cross-sectional view of an embodiment of the embolization microcatheter of the present invention. Figure 1 ;

[0022] Figure 2 This is a cross-sectional structural schematic diagram of the delivery section of an embolization microcatheter according to an embodiment of the present invention;

[0023] Figure 3 This is a schematic cross-sectional view of an embodiment of the embolization segment of an embolization microcatheter according to the present invention. Figure 1 ;

[0024] Figure 4 This is a schematic cross-sectional view of an embodiment of the embolization segment of an embolization microcatheter according to the present invention. Figure 2 ;

[0025] Figure 5 This is a schematic cross-sectional view of an embodiment of the embolization segment of an embolization microcatheter according to the present invention. Figure 3 ;

[0026] Figure 6 This is a schematic cross-sectional view of an embodiment of the embolization microcatheter of the present invention. Figure 2 ;

[0027] Figure 7 This is a partial cross-sectional schematic diagram of the delivery section of an embolization microcatheter according to an embodiment of the present invention;

[0028] Figure 8 This is a schematic cross-sectional view of an embodiment of an embolization microcatheter of the present invention;

[0029] Figure 9 This is a schematic cross-sectional view of an embodiment of the embolization segment of an embolization microcatheter according to the present invention. Figure 4 ;

[0030] Figure 10 This is a schematic cross-sectional view of an embodiment of the embolization segment of an embolization microcatheter according to the present invention. Figure 4 ;

[0031] Figure 11 This is a schematic cross-sectional view of an embodiment of the embolization microcatheter of the present invention. Figure 3 ;

[0032] Figure 12 This is a schematic cross-sectional view of an embodiment of the embolization segment of an embolization microcatheter according to the present invention. Figure 5 .

[0033] Explanation of reference numerals in the attached figures:

[0034] 1. Conveying section; 11. Conveying cavity; 12. Expansion channel; 13. Conveying port; 14. Inner layer; 15. Middle layer; 16. Outer layer; 2. Embolizing section; 21. Embolizing cavity; 211. Embolizing sub-cavity; 22. Pressure relief section; 23. Pressure relief hole; 24. Pressure relief groove; 25. Groove; 26. Reinforcing hole; 27. Imaging wire; 3. Expansion capsule; 31. Expansion capsule cavity; 4. Sealing plate; 41. Injection hole; 5. Microguide wire. Detailed Implementation

[0035] To provide a more detailed understanding of the features and technical content of the embodiments of this disclosure, the implementation of the embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. The accompanying drawings are for illustrative purposes only and are not intended to limit the embodiments of this disclosure. In the following technical description, for ease of explanation, several details are used to provide a full understanding of the disclosed embodiments. However, one or more embodiments may still be implemented without these details. In other cases, well-known structures and devices may be simplified in their depiction to simplify the drawings.

[0036] The terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this disclosure are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of this disclosure described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion.

[0037] In this disclosure, the terms "upper," "lower," "inner," "middle," "outer," "front," and "rear," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are primarily for better description of the embodiments of this disclosure and their implementations, and are not intended to limit the indicated devices, elements, or components to having a specific orientation, or to require them to be constructed and operated in a specific orientation. Furthermore, some of the aforementioned terms may be used to indicate other meanings besides orientation or positional relationship; for example, the term "upper" may in some cases indicate a dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in the embodiments of this disclosure according to the specific circumstances.

[0038] Furthermore, the terms "set up," "connect," and "fix" should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be an internal connection between two devices, components, or parts. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this disclosure according to the specific circumstances.

[0039] Unless otherwise stated, the term "multiple" means two or more, and "multiple groups" means two or more groups.

[0040] It should be noted that, unless otherwise specified, the embodiments and features described in the present disclosure can be combined with each other.

[0041] The inventors discovered that even with existing microcatheters with detachable tips, the mechanical traction applied to the tip can disturb fragile intracranial blood vessels, potentially leading to vascular damage or intracranial complications.

[0042] In view of this, the inventors of the present invention provide an embolization microcatheter to solve the above-mentioned problems. Several specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0043] In this invention, the embolization material can also be referred to as embolization adhesive. For example, the embolization material can be the existing Onyx liquid embolization adhesive. Since the embolization material uses an existing embolization adhesive, further details about the embolization material will not be provided.

[0044] First Embodiment

[0045] The embolization microcatheter mentioned in this embodiment, such as Figure 1 As shown, the embolization microcatheter includes a delivery section 1 and an embolization section 2. The distal end of the delivery section 1 is connected to the proximal end of the embolization section 2. The delivery section 1 has a tubular structure, and the internal space of the delivery section 1 can be regarded as a delivery cavity 11. The delivery cavity 11 allows the microguidewire 5 to be inserted and also allows the embolization material to flow.

[0046] Optional, such as Figure 2 As shown, the conveying section 1 includes an inner layer 14, a middle layer 15, and an outer layer 16. The inner layer 14 is made of PTFE material into a tubular structure, the middle layer 15 is made of woven metal wire into a tubular structure, and the middle layer 15 is fitted inside the inner layer 14. The outer layer 16 is made of polyetheramide material or polyurethane elastic material into a tubular structure, and the outer layer 16 is fitted inside the middle layer 15. This three-layer structure of the conveying section 1 not only ensures the structural strength of the conveying section 1 but also ensures its passability.

[0047] Optionally, the end of the delivery section 1 near the proximal end is connected to the catheter seat. In this technical solution, the structure of the catheter seat and the connection between the catheter seat and the delivery section are existing technologies, and will not be described in detail here.

[0048] In this embodiment, the structure of the embolization segment 2 is as follows:

[0049] Optional, such as Figure 1 , Figure 3As shown, the embolization segment 2 has a tubular structure, and its internal space can be considered as an embolization cavity 21. The distal end of the embolization segment 2 is sealed off. This sealed end can be considered as a pressure relief section 22, which has an arc-shaped or circular cross-section. The pressure relief section 22 has at least one pressure relief hole 23 with a diameter of 0.1 mm to 0.5 mm. When the pressure relief section 22 has only one pressure relief hole 23, this hole is located at the center of the pressure relief section 22 and is coaxial with the embolization segment 2, which facilitates the insertion of the microguidewire. When the pressure relief section 22 has multiple pressure relief holes 23, one pressure relief hole 23 is located at the center of the pressure relief section 22 and is coaxially aligned with the embolization section 2; the remaining pressure relief holes 23 are evenly distributed on the pressure relief section 22. This arrangement not only facilitates the insertion of the microguidewire but also facilitates the cooperation of the pressure relief holes 23 with the embolization material to embolize the blood vessel. The embolization section 2 exists in two states: the delivery state and the embolization state. When the embolization section 2 is in such a state... Figure 1 In the delivery state shown, the pressure relief section 22 is in a concave state, and the concave direction is towards the embolization cavity 21 near the embolization section 2. This arrangement facilitates the insertion of the microguidewire and also makes it easier for the embolization microcatheter to move along the microguidewire. When the embolization section 2 is in such a state... Figure 3 In the embolization state shown, the pressure relief section 22 is in an outward convex state, and the outward convex direction is towards the embolization cavity 21, which is away from the embolization segment 2. The pressure relief section 22 in the delivery state can flexibly switch to the embolization state as the embolization material is injected, which can slowly increase the pressure inside the embolization cavity, avoid the risk of embolization segment rupture, and improve the embolization effect on the target blood vessel.

[0050] Optionally, the embolization segment 2 can be made of a polymer material. For example, the embolization segment 2 can be made of polylactic acid or polyurethane.

[0051] Optional, such as Figure 4 , Figure 5 As shown, the pressure relief section 22 has multiple pressure relief grooves 24, which are evenly distributed around the axis of the plug section 2. Each pressure relief groove 24 has an arc-shaped or circular cross-section. Pressure relief holes 23 are located at the bottom of the pressure relief grooves 24. When the plug section 2 is in a position such as... Figure 4 The conveying state is shown, with the pressure relief section 22 in a concave state and the pressure relief groove 24 also in a concave state, and the concave direction of the pressure relief groove 24 is towards the embolization cavity 21 near the embolization section 2. This arrangement is more conducive to the insertion of the microguidewire and also facilitates the movement of the embolization microcatheter along the microguidewire. When the embolization section 2 is in the like... Figure 5The embolization state is shown, with the pressure relief section 22 in a convex state and the pressure relief groove 24 also in a convex state, and the convex direction of the pressure relief groove 24 is towards the embolization cavity 21 away from the embolization segment 2. As the embolic material is injected, the embolic material compresses the pressure relief groove 24, causing the pressure relief groove 24 to switch from a concave state to a convex state. This utilizes the space of multiple pressure relief grooves 24 to further slow down the rate of pressure increase in the embolization cavity 21, avoiding the risk of embolization segment rupture and improving the embolization effect on the blood vessel.

[0052] You can choose any one of the three technical solutions mentioned above. Of course, you can also choose several and combine them.

[0053] The exemplary usage process of the embolization microcatheter disclosed in this embodiment is as follows:

[0054] like Figures 1 to 5 As shown, during the assembly of the embolization microcatheter, the proximal end of the embolization segment 2 is fitted onto the distal end of the delivery segment 1, thus establishing communication between the embolization cavity 21 and the delivery cavity 11. The pressure relief portion 22 of the embolization segment 2 is in a concave state, with the concave direction facing the embolization cavity 21 near the embolization segment 2. This completes the assembly of the embolization microcatheter. In use, the microguidewire 5 is first inserted into the blood vessel and positioned at the designated location. Then, the proximal end of the microguidewire 5 is passed through a pressure relief hole 23 located at the center of the pressure relief portion 22. The embolization microcatheter is then delivered distally, moving along the microguidewire. Once the embolization segment 2 of the embolization microcatheter is in place, the embolization microcatheter stops moving, and the microguidewire 5 is withdrawn from the blood vessel and removed from the body. Embolization material is then injected into the delivery cavity 11 through the proximal end of the delivery segment 1, and the embolization material enters the embolization cavity 21 through the delivery cavity 11. As the embolic material is injected, the embolic cavity 21 gradually expands from the distal end to the proximal end. The embolic material compresses the pressure relief section 22, causing it to bulge outwards. Simultaneously, the embolic material seals the pressure relief orifice 23. Once the embolic cavity 21 is completely filled, with continued injection, the embolic material applies a force of 10g to 30g to the connection between the embolic segment 2 and the delivery segment 1, causing the embolic segment 2 to separate from the delivery segment 1, thereby achieving the purpose of vascular embolization. Preferably, the embolic material applies a force of 10g to 25g to the connection between the embolic segment 2 and the delivery segment 1, causing the embolic segment 2 to separate from the delivery segment 1.

[0055] Compared to existing technologies, in this embodiment, by providing a pressure relief section with a pressure relief hole on the embolization segment, the pressure relief hole allows the microguidewire to pass through during delivery, facilitating the movement of the microcatheter along the microguidewire. When embolizing the target vessel, it is only necessary to withdraw the microguidewire from the vessel to the outside of the body, and then inject the embolic material into the embolization cavity through the delivery chamber. As the embolic material is injected, it compresses the concave pressure relief section, transforming it into an outward convex state. As the embolic material fills the embolization cavity, a portion of the embolic material enters the pressure relief hole. This portion of the embolic material remains within the pressure relief hole, or it passes through the pressure relief hole to the outside. However, the amount of embolic material outside the pressure relief hole is small and does not escape, thus preventing the embolic material from overflowing and embolizing non-target vessels. Therefore, by providing a pressure relief hole on the pressure relief section, the pressure of the embolic material during filling the embolization cavity can be reduced. When the embolization material fills the embolization cavity, it will compress the cavity wall and increase the diameter of the cavity wall, thereby promoting the separation of the embolization segment from the delivery segment, so as to achieve the purpose of embolizing the target blood vessel together through the embolization segment and the embolization material.

[0056] Second Embodiment

[0057] The inventors discovered that if the embolization section is simply expanded using embolization material to separate it from the delivery section, the embolization section and the delivery section may still have some connection, thus reducing the separation effect.

[0058] In view of this, this embodiment also proposes an embolization microcatheter. The second embodiment is a further improvement based on the first embodiment, mainly in the structure of the delivery section, as detailed below:

[0059] Optional, such as Figure 6 As shown, an expansion channel 12 is provided within the wall of the delivery section 1. Specifically, an expansion channel 12 is provided within the wall of the outer layer 16. The expansion channel 12 is not connected to the delivery cavity 11. The embolization microcatheter also includes an expansion capsule 3, which is located at the distal end of the delivery section 1. The expansion capsule 3 is arranged along the outer wall of the delivery section 1 and encircles the axis of the delivery section 1. The expansion capsule 3 has an expansion cavity 31 within it, and the distal end of the expansion channel 12 is connected to the expansion cavity 31.

[0060] The exemplary usage process of the embolization microcatheter disclosed in the above technical solution is as follows:

[0061] like Figure 1 , Figure 6As shown, during the assembly of the embolization microcatheter, the proximal end of the embolization segment 2 is fitted onto the dilation balloon 3, at which point the dilation balloon 3 is in a compressed state. This establishes communication between the embolization cavity 21 of the embolization segment 2 and the delivery cavity 11 of the delivery segment 1. The pressure relief portion 22 of the embolization segment 2 is then placed in a concave state, with the concave direction pointing towards the embolization cavity 21 near the embolization segment 2, thus completing the assembly of the embolization microcatheter. In use, the microguidewire 5 is first inserted into the blood vessel and positioned to the designated location. Then, the proximal end of the microguidewire 5 is passed through a pressure relief hole 23 located at the center of the pressure relief portion 22. The embolization microcatheter is then delivered distally, moving along the microguidewire. Once the embolization segment 2 of the embolization microcatheter is in place, the embolization microcatheter stops moving, and the microguidewire 5 is withdrawn from the blood vessel and removed from the body. Then, embolic material is injected into the delivery chamber 11 through the proximal end of the delivery section 1, and the embolic material enters the embolization chamber 21 through the delivery chamber 11. As the embolic material is injected, the embolization chamber 21 gradually expands from the distal end to the proximal end, and the embolic material squeezes the pressure relief part 22 to switch to an outward convex state. At the same time, the embolic material seals the pressure relief hole 23. When the embolic material fills the embolization chamber 21, as the embolic material continues to be injected, the embolic material applies a force of 10g to 30g at the connection between the embolization section 2 and the delivery section 1, causing the embolization section 2 to separate from the delivery section 1.

[0062] If the embolic segment 2 and the delivery segment 1 are not completely separated, contrast agent is injected into the dilation channel 12 near its proximal end. The contrast agent is then injected into the dilation cavity 31 through the dilation channel 12. As the contrast agent is injected into the dilation cavity 31, the dilation cavity 3 gradually expands. The expanded dilation cavity 3 dilates the proximal end of the embolic segment 2, increasing the diameter of the proximal end of the embolization cavity 21. When the outer wall of the proximal end of the embolic segment 2 touches the inner wall of the blood vessel, the injection of contrast agent is stopped, and the contrast agent in the dilation cavity 31 is withdrawn. This causes the dilation cavity 3 to gradually deflate until it returns to its original state. At this point, the outer wall of the proximal end of the embolic segment 2 still touches the inner wall of the blood vessel, thus separating the embolic segment 2 from the delivery segment 1. Then, while moving the delivery segment 1 proximally, continue injecting embolic material into the embolization cavity 21 of the embolization segment 2 through the delivery cavity 11, ensuring that the embolic material completely fills the embolization cavity 21. Finally, stop injecting the embolic material and move the delivery segment 1 proximally until it is withdrawn from the body. This completes the embolization of the blood vessel.

[0063] Optional, such as Figure 6 , Figure 7As shown, based on the above-mentioned optional technical solutions, the cross-sectional shape of the side wall of the dilatation capsule 3 away from the delivery section 1 is wavy. When the proximal end of the embolization section 2 is fitted onto the dilatation capsule 3, the wavy side wall contacts the embolization section 2. The wavy side wall makes linear contact with the wall of the embolization cavity 21. After the dilatation capsule 3 dilates the proximal end of the embolization section 2, the contrast agent located in the dilatation capsule cavity 31 is subsequently extracted. The wavy side wall facilitates the separation of the dilatation capsule 3 from the embolization section 2.

[0064] Either of the two optional technical solutions mentioned above can be chosen.

[0065] In the existing technology, when there is still a partial connection between the embolization section and the delivery section, if the embolization material is continued to be injected, it will not only fail to separate the embolization section from the delivery section, but may also cause the embolization material to escape to the proximal end.

[0066] Unlike existing technologies, this embodiment uses an expansion bladder located at the distal end of the delivery section, connected to the embolization section. When a partial connection remains between the embolization and delivery sections, the expansion bladder can be inflated and then returned to its original state to separate the embolization and delivery sections. Alternatively, if separation is not achieved in one attempt, the expansion bladder can be repeatedly inflated to facilitate separation.

[0067] Third Embodiment

[0068] In the second embodiment, the inventors discovered that if the expansion and contraction of the cyst is relied upon repeatedly, there may still be a situation where the embolization segment and the delivery segment are still partially connected.

[0069] In view of this, this embodiment also proposes an embolization microcatheter. The third embodiment is a further improvement based on the second embodiment, the main improvement being:

[0070] like Figure 6 , Figure 8 As shown, multiple expansion channels 12 are provided inside the pipe wall of the conveying section 1. Specifically, expansion channels 12 are provided inside the pipe wall of the outer layer 16. None of the expansion channels 12 are connected to the conveying cavity 11, and the expansion channels 12 are not interconnected. The expansion channels 12 are evenly distributed around the axis of the conveying section 1. The number of expansion bladders 3 is the same as the number of expansion channels 12. Multiple expansion bladders 3 are evenly distributed around the axis of the conveying section 1, and the expansion cavities 31 of the multiple expansion bladders 3 are not interconnected. The expansion cavity 31 of each expansion bladder 3 is connected to one expansion channel 12.

[0071] In this embodiment, we take the case where a quarter of the area of ​​the embolization segment 2 and the delivery segment 1 is not completely separated as an example, and the number of expansion bladders 3 is four. When a quarter of the area of ​​the embolization segment 2 and the delivery segment 1 is not completely separated, we first identify one expansion bladder 3 that is not separated from the embolization segment 2. This expansion bladder 3 is called expansion bladder 3 number one. Then, we identify two expansion bladders 3 close to expansion bladder 3 number one and expansion bladder 3 number three, respectively. Expansion bladders 3 number two and expansion bladder 3 number three are located on both sides of the delivery segment 1 and are symmetrically arranged. Figure 8 See, dilatation balloons 2 and 3 are aligned in a straight line. First, dilatation balloons 2 and 3 are expanded through the dilation channels 12 corresponding to them, bringing them into an inflated state. These inflated balloons work together to expand the embolic segment 2, fixing it within the blood vessel and preventing any movement. Next, dilatation balloon 1 is expanded through the dilation channel 12 corresponding to it, bringing it into an inflated state. Then, the contrast agent is withdrawn, causing dilatation balloon 1 to quickly deflate back to its original state. This process is repeated, switching dilatation balloon 1 between its inflated and original states, thereby promoting separation of dilatation balloon 1 from the embolic segment 2. After the first dilatation balloon 3 separates from the embolization segment 2, the contrast agent in the second and third dilatation balloons 3 is withdrawn, and the second and third dilatation balloons 3 are restored to their original state. Then, while moving the delivery segment 1 proximally, embolic material is continuously injected into the embolization cavity 21 of the embolization segment 2 through the delivery lumen 11, until the embolic material completely fills the embolization cavity 21. Finally, the injection of embolic material is stopped, and the delivery segment 1 is moved proximally until it is withdrawn from the body. This completes the embolization of the blood vessel.

[0072] In the second embodiment, if there is a partial connection between the embolization segment and the delivery segment, the entire expansion bladder needs to be inflated. This method is not targeted and may result in the embolization segment and the delivery segment still being partially connected.

[0073] Compared to the second embodiment, this embodiment uses multiple expansion bladders, which are designed in sections. When there is a partial connection between the embolization segment and the delivery segment, it is only necessary to find one expansion bladder that has not separated from the embolization segment and its two adjacent expansion bladders. First, the two adjacent expansion bladders are expanded so that they support the embolization segment. Then, only the expansion bladder connected to the embolization segment needs to be expanded, and then the expansion bladder is returned to its original state to separate the partial connection between the embolization segment and the delivery segment. If the partial connection between the embolization segment and the delivery segment cannot be separated in one operation, it is only necessary to repeatedly expand a single expansion bladder to induce separation at the partial connection between the embolization segment and the delivery segment.

[0074] Fourth embodiment

[0075] This embodiment also proposes an embolization microcatheter. The fourth embodiment is a further improvement based on any one of the first to third embodiments, with the main improvement being the structure of the embolization segment, as detailed below:

[0076] Optional, such as Figure 8 As shown, the middle part of the embolization segment 2 is recessed towards the axis of the embolization segment 2, forming a groove 25. The groove 25 divides the embolization cavity 21 into two interconnected embolization sub-cavities 211. The cross-sectional shape of the groove 25 is arc-shaped. The bottom of the groove 25 has multiple reinforcing holes 26, which are evenly distributed around the axis of the embolization segment 2. When embolizing the target blood vessel, embolic material is injected into the delivery cavity 11 through the proximal end of the delivery segment 1. The embolic material enters the distal embolization sub-cavity 211 through the delivery cavity 11, causing the distal part of the embolization segment 2 to expand first. As the embolic material is injected, the embolic material in the distal embolization sub-cavity 211 will squeeze the pressure relief part 22 to switch to an outward convex state. At the same time, the embolic material will block the pressure relief hole 23. After the embolic material fills the distal embolic lumen 211, as the embolic material continues to be injected, it quickly fills the connection between the two embolic lumen 211s. Then, it continues to fill the proximal embolic lumen 211, expanding a portion of the proximal embolic segment 2. Both parts of the embolic segment 2 are in an expanded state and abut against the vessel wall. A space is formed between the groove 25 and the vessel wall. While the embolic material fills the proximal embolic lumen 211, embolic material located at the connection between the two embolic lumen 211s enters the space between the groove 25 and the vessel wall through the reinforcement hole 26, filling the space between the groove 25 and the vessel wall. This allows the embolic segment 2 to adhere to the vessel wall, thereby increasing the stability of the embolic segment 2 within the vessel.

[0077] Optionally, not shown in the figure, based on the above optional technical solutions, the wall thickness of the embolization section 2 is further improved. Using groove 25 as the dividing line, the wall thickness of the portion of the embolization section 2 near the distal end is greater than the wall thickness of the portion near the proximal end. Preferably, the wall thickness of the portion of the embolization section 2 near the distal end is 1.5 to 2 times that of the portion near the proximal end. In this technical solution, the thicker wall thickness of the portion of the embolization section 2 near the distal end increases the pressure-bearing capacity of this portion and reduces the risk of rupture. Conversely, the thinner wall thickness of the portion near the proximal end facilitates the separation of the embolization section 2 from the delivery section 1.

[0078] Optional, such as Figure 10 As shown, based on the first optional technical solution in this embodiment, multiple locations of the embolization segment 2 are recessed towards the axis of the embolization segment 2 to form multiple grooves 25. These grooves 25 are evenly spaced and arranged sequentially along the axis of the embolization segment 2. The multiple grooves 25 divide the embolization cavity 21 into multiple interconnected embolization sub-cavities 211. Since the structure of each groove 25 is identical, the structure of one groove 25 is described as an example. The bottom of the groove 25 has multiple reinforcing holes 26, which are evenly distributed around the axis of the embolization segment 2. Providing multiple grooves 25 on the embolization segment 2 not only increases the flexibility of the embolization segment but also further increases the stability of the embolization segment 2 within the blood vessel.

[0079] Optional, such as Figure 3 As shown, the wall thickness of the embolization section 2 gradually decreases from the distal end to the proximal end. In this technical solution, by improving the wall thickness of the embolization section 2, the wall thickness of the portion of the embolization section 2 near the distal end is increased, which enhances the pressure-bearing capacity of this portion and reduces the risk of rupture. Conversely, the wall thickness of the portion of the embolization section 2 near the proximal end is thinner, which facilitates the separation of the embolization section 2 from the delivery section 1.

[0080] Optionally, in this embodiment, the fourth optional technical solution can also be combined with the first or third optional technical solution.

[0081] You may choose any one of the five optional technical solutions mentioned above.

[0082] Optional, such as Figure 9As shown, the embolization segment 2 also includes multiple radiopaque wires 27, all of which are disposed within the groove 25 and are evenly distributed around the axis of the embolization segment 2. Since the multiple radiopaque wires 27 have the same structure, only one radiopaque wire 27 is described as an example. The radiopaque wire 27 can be made of radiopaque material, for example, a nickel-titanium alloy. The radiopaque wire 27 has a wavy or spiral structure, which increases the compliance and passage of the embolization segment 2 within tortuous blood vessels. By placing the radiopaque wires 27 within the groove 25, the operator can easily determine the location of the embolization segment 2 by observing the position of the radiopaque wires 27 when the embolization microcatheter is implanted into the blood vessel. Furthermore, during embolization, when the embolic material enters the space between the groove 25 and the inner wall of the blood vessel, the radiopaque wires 27 located within the embolic material provide structural reinforcement.

[0083] Fifth embodiment

[0084] This embodiment also proposes an embolization microcatheter. The fifth embodiment is a further improvement based on any one of the first to fourth embodiments, with the main improvement being:

[0085] like Figure 11 As shown, the end of the conveying cavity 11 near the distal end is the conveying port 13, and the diameter of the conveying port 13 is half the diameter of the conveying cavity 11. From the direction of the proximal end to the direction of the distal end, the diameter of the conveying cavity 11 gradually decreases to the diameter of the conveying port 13.

[0086] like Figure 11 As shown, the embolization microcatheter also includes a sealing plate 4, which has a circular structure and an injection hole 41 located in the middle of the sealing plate 4. The sealing plate 4 is disposed within the embolization cavity 21 of the embolization segment 2, and is located at the proximal end of the embolization segment 2. The diameter of the injection hole 41 is the same as the diameter of the delivery port 13. When assembling the embolization microcatheter, the proximal end of the embolization segment 2 is fitted onto the distal end of the delivery segment 1, and the delivery port 13 is aligned with the injection hole 41, which facilitates the entry of embolic material into the embolization cavity 21. After the embolic material fills the embolization cavity 21 and the embolization segment 2 separates from the delivery segment 1, the sealing plate 4 acts as a limiter for the embolic material in the embolization cavity 21, preventing the embolic material in the embolization cavity 21 from flowing proximally.

[0087] Optional, such as Figure 12 As shown, based on the above scheme, the structure of the occlusion piece is further improved, with the middle part of the occlusion piece 4 positioned towards the embolization cavity 21. The cross-sectional area of ​​the occlusion piece 4 gradually increases from the distal end towards the proximal end. This arrangement facilitates the entry of embolization material into the embolization cavity.

[0088] Finally, it should be noted that those skilled in the art will understand that many technical details have been presented in the embodiments of the present invention to facilitate a better understanding of the invention. However, even without these technical details and various variations and modifications based on the above embodiments, the technical solutions claimed in the claims of the present invention can be substantially achieved. Therefore, in practical applications, various changes in form and detail can be made to the above embodiments without departing from the spirit and scope of the present invention.

Claims

1. An embolization microcatheter, characterized in that, include: The conveying section has a conveying cavity; The embolization section has one end near the distal end recessed into the embolization cavity of the embolization section, forming a pressure relief section with a pressure relief hole; The proximal end of the embolization section is sleeved on the distal end of the delivery section, and the embolization cavity is in communication with the delivery cavity; During embolization, embolic material is continuously injected into the embolization cavity through the delivery cavity. The pressure relief section protrudes outward in a direction away from the embolization cavity. Then, the embolic segment gradually expands from the distal end to the proximal end, causing the embolic segment to separate from the delivery segment, thereby achieving the purpose of embolizing the blood vessel.

2. The embolization microcatheter according to claim 1, characterized in that, The conveying section has an expansion channel; The embolization microcatheter also includes: The dilatation sac has a dilatation cavity communicating with the dilatation channel; the dilatation sac is located at the distal end of the delivery section; the embolization section is sleeved on the dilatation sac.

3. The embolization microcatheter according to claim 2, characterized in that, Multiple expansion channels are evenly distributed around the axis of the conveying section; Multiple expansion bladders are evenly arranged around the axis of the transport section, and the expansion cavity of each expansion bladder is connected to an expansion channel.

4. The embolization microcatheter according to claim 2, characterized in that, The cross-sectional shape of the side wall of the dilatation bladder that contacts the embolized segment is wavy.

5. The embolization microcatheter according to claim 1, characterized in that, The diameter of the pressure relief hole is 0.1mm~0.5mm.

6. The embolization microcatheter according to claim 5, characterized in that, The pressure relief section has a pressure relief groove formed by being recessed towards the embolization cavity, and the pressure relief hole is located at the bottom of the pressure relief groove.

7. The embolization microcatheter according to claim 1, characterized in that, A groove is formed at one location of the embolization segment, which is recessed inward toward the axis of the embolization segment; the groove divides the embolization cavity into two embolization sub-cavities.

8. The embolization microcatheter according to claim 1, characterized in that, Multiple grooves are formed at various locations of the embolization segment, which are recessed inward toward the axis of the embolization segment; the multiple grooves divide the embolization cavity into multiple embolization sub-cavities.

9. The embolization microcatheter according to any one of claims 7 or 8, characterized in that, The groove is provided with multiple reinforcing holes, which are evenly distributed around the axis of the plug section.

10. The embolization microcatheter according to claim 1, characterized in that, The thickness of the embolized segment gradually decreases from the distal end to the proximal end.

11. The embolization microcatheter according to claim 1, characterized in that, The end of the conveying cavity closest to the distal end is the conveying port, and the diameter of the conveying port is half the diameter of the conveying cavity.

12. The embolization microcatheter according to claim 11, characterized in that, Also includes: An occlusion piece is disposed within the embolization cavity and located at the proximal end of the embolization segment; The sealing plate has an injection hole in the middle, and the diameter of the injection hole is the same as the diameter of the conveying port; The middle part of the occlusion piece is positioned towards the embolization cavity.

Images