Microcatheter capable of preventing backflow

Abstract

The utility model discloses a microcatheter capable of preventing backflow, which at least comprises a main body tube, the main body tube is of a multi-layer structure, and one layer of structure of the main body tube forms a closable structure at a far-end port of the main body tube; the main body tube is of a three-layer structure, namely the inner layer, the middle layer and the outer layer, the main body tube is provided with the tube cavity capable of containing embolism agents and pushing the guide wire, the outlet at the far end of the tube cavity is of a closable structure, the problem of backflow of embolism materials, contrast agents or medicine solutions in an operation can be effectively solved through the structure, and the injection efficiency can be improved. The main body tube is of a reducing structure, and the super-selectivity of the micro-catheter can be improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of medical apparatus and instruments, in particular to a microcatheter capable of preventing reflux. BACKGROUND

[0002] In recent years, with the development of interventional surgery, embolization has developed rapidly, and transarterial chemoembolization (TACE) is a surgical procedure for blocking blood flow in target blood vessels by delivering drugs through a catheter, which is globally recognized as the preferred treatment for non-surgical resection of liver cancer. Taking hepatic arterial chemoembolization as an example, the femoral artery is usually punctured percutaneously to access the arterial blood vessels, and a microcatheter is used to super-selectively enter the target blood vessels of liver tumors, and embolization or therapeutic substances are injected through the catheter. During embolization, due to the pressure during injection, reflux of embolization or therapeutic substances is a common phenomenon and an important factor for complications. Currently, a blocking balloon catheter is commonly used on the market to block blood flow in target blood vessels to prevent reflux. However, this method may damage the inner wall of the blood vessel during balloon inflation, causing unnecessary complications, and the microcatheter with a balloon installed at the distal end is difficult to achieve superselectivity in the blood vessel. For the above situation, there is an urgent need in the market for a microcatheter with superselectivity and effective prevention of reflux. SUMMARY

[0003] The utility model provides a kind of microcatheter capable of preventing reflux, which can solve the problems identified in the background art.

[0004] A microcatheter capable of preventing reflux includes at least a main body tube, which has a multi-layer structure. One layer of the main body tube forms a closable structure at the distal end port of the main body tube.

[0005] Preferably, the microcatheter further includes a catheter seat, a stress relief tube, and a radiopaque ring.

[0006] Preferably, the distal end of the main body tube has a variable diameter structure to form a variable diameter channel in the lumen.

[0007] Preferably, the length of the variable diameter structure is 3-15 cm.

[0008] Preferably, the multi-layer structure includes at least a polymer layer, a woven layer, and a PTFE layer.

[0009] Preferably, the polymer layer is the outer layer, the woven layer is the intermediate layer, and the PTFE is the inner layer.

[0010] Preferably, the woven layer is a metal woven layer or a fiber woven layer.

[0011] Preferably, the closable structure is a four-corner opening structure.

[0012] Preferably, the closable structure is a three-corner opening structure.

[0013] Preferably, the closable structure is a microporous structure.

[0014] Compared with existing technologies, the beneficial effects of this invention are as follows: The main tube of this invention has a three-layer structure, namely an inner layer, a middle layer, and an outer layer, and has a lumen that can accommodate embolic agents and guidewires. The distal outlet of the lumen has a closable structure, which can effectively improve the problem of reflux of embolic materials, contrast agents, or drug solutions during surgery and improve injection efficiency. The main tube has a variable diameter structure, which can improve the superselectivity of the microcatheter. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of a microcatheter;

[0016] Figure 2 This is a magnified view of the distal end of the microcatheter.

[0017] Figure 3 This is a diagram of the first type of closable structure.

[0018] Figure 4 This is a diagram of the second type of structure that can be closed.

[0019] Figure 5 This is a diagram of the third type of structure that can be closed.

[0020] Figure 6 This is a diagram illustrating the usage process of this utility model.

[0021] Explanation of reference numerals in the attached figures:

[0022] 1-Main tube, 2-Internal stress relief tube, 3-External stress relief tube, 4-Catheter seat, 5-Iconizing ring, 6-Lumen, 7-Braided layer, 8-Polymer layer, 9-PTFE layer, 10-Tumor-supplying artery, 11-Microcatheter, 12-Embossing material, 13-Tumor. Detailed Implementation

[0023] The following describes a specific embodiment of the present invention in detail with reference to the accompanying drawings. However, it should be understood that the scope of protection of the present invention is not limited to the specific embodiment.

[0024] like Figures 1 to 6 As shown in the figure, the present invention provides a microcatheter for preventing backflow. The microcatheter includes a main tube 1, a stress-relieving tube, a catheter seat 4, and a radiopaque ring 5. The stress-relieving tube includes an inner stress-relieving tube 2 and an outer stress-relieving tube 3.

[0025] The main tube 1 is connected to the catheter seat 4, the inner stress relief tube 2, and the outer stress relief tube 3 to form the microcatheter body. The main tube 1 has a lumen 6, and the imaging ring 5 is usually installed at the distal end of the microcatheter.

[0026] The distal end of the main tube 1 has a variable diameter structure so that the lumen 6 forms a variable diameter channel;

[0027] The main tube typically consists of three layers: an outer polymer layer (8), a middle metal or fiber braided layer (7), and an inner PTFE layer (9). The distal end of the main tube features a variable diameter structure, typically 3-15 cm in length. The smaller outer diameter at the distal end allows it to reach peripheral blood vessels, achieving superselectivity, while the larger outer diameter at the proximal end allows for close contact with the blood vessel, effectively blocking backflow. Simultaneously, the variable inner diameter, according to kinetics, allows the average flow velocity μ to be equal to the fluid's volumetric flow rate Q. V The ratio to the cross-sectional area A of the lumen, i.e.:

[0028]

[0029] With a smaller inner diameter, the flow rate at the embolization injection outlet increases, which helps the embolic or therapeutic substance flow into the target location.

[0030] In this design, the polymer layer encapsulates the distal outlet, forming a closable structure, which can be a structure with four corner openings (such as...). Figure 3 As shown), triangular opening structure (such as...) Figure 4 (as shown) or microporous structures (such as) Figure 5 As shown in the diagram, the distal closure structure remains closed under a certain external force. When the fluid pressure inside the lumen reaches a certain value, the distal lumen outlet is opened. During embolization injection, this structure opens the distal lumen outlet due to the injection pressure, and closes the outlet at the end of the injection, effectively preventing backflow.

[0031] Usage method (e.g.) Figure 6 (As shown): 13 is the tumor, 10 is the tumor's feeding artery, 11 is the microcatheter, and 12 is the embolic material. After the microcatheter is in place, embolic injection is performed. The thicker segment fits the blood vessel closely, blocking reflux. After the injection, the distal opening of the lumen closes, preventing reflux. The microcatheter is then withdrawn from the lumen, and the embolic material effectively blocks the tumor and its feeding artery.

[0032] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit and essential characteristics of this invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0033] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A reflux-preventing microcatheter, characterized by, At least comprising a main tube, the main tube is a multi-layer structure, one layer of the main tube forms a closable structure at the distal port of the main tube; Further comprising a catheter seat, a stress relief tube and a developing ring; The distal end of the main tube is a variable diameter structure to form a variable diameter channel in the lumen; The multi-layer structure at least comprises a polymer layer, a braided layer and a PTFE layer.

2. A reflux-preventing microcatheter as claimed in claim 1, wherein The length of the variable diameter structure is 3cm-15cm.

3. A reflux-preventing microcatheter as in claim 1, wherein The polymer layer is an outer layer, the braided layer is an intermediate layer and the PTFE is an inner layer.

4. A reflux-preventing microcatheter according to claim 1 or 3, wherein The braided layer is a metal braided layer or a fiber braided layer.

5. A reflux-preventing microcatheter as in claim 1, wherein, The closable structure is a quadrangular opening structure.

6. A reflux-preventing microcatheter as in claim 1, wherein, The closable structure is a triangular opening structure.

7. A reflux-preventing microcatheter as in claim 1, wherein, The closable structure is a microporous structure.

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