Conveying catheter mechanism and stent conveying device

Abstract

The invention belongs to the technical field of medical instruments, and particularly relates to a catheter conveying mechanism and a stent conveying device. The conveying catheter mechanism comprises a sheath core tube and a conical guide tube, the conical guide tube is connected to the far end of the sheath core tube in a sleeving mode and extends out of the far end of the sheath core tube, and the outer diameter of the conical guide tube is gradually reduced in the direction away from the far end of the sheath core tube. A flow guide groove is formed in the outer wall of the conical guide pipe, and the flow guide groove is formed in the near side, opposite to the far-end opening portion of the sheath core pipe, of the conical guide pipe and is spaced from the far-end opening portion of the sheath core pipe. By means of the structure, the sheath core tube is prevented from being exposed outside, and the conveying safety and structural strength of the conveying catheter mechanism in the blood vessel are guaranteed.

Description

Technical Field

[0001] The present invention belongs to the technical field of medical devices, and in particular relates to a delivery catheter mechanism and a stent delivery device. Background Art

[0002] Implanting a stent into the lesion site in the patient's body through a body cavity access is a common interventional procedure, such as implanting intravascular stents in the coronary arteries, peripheral arteries, iliac veins, etc. to treat vascular stenosis, or implanting a covered stent in the aorta to treat arterial dissection. Depending on actual needs, the stent can also be loaded with drugs to achieve better treatment effects.

[0003] The stent needs to be implanted into the patient's body with the help of a delivery catheter. The delivery catheter usually includes a sheath core tube and a guide tube. The guide tube is assembled at the distal end of the sheath core tube. The guide tube has great flexibility. During the process of pushing the guide tube into the human blood vessel, the guide tube can pass through the tortuous blood vessel area to ensure the smooth deployment of the guide tube to the target blood vessel area.

[0004] However, some products have drainage grooves on the guide tube, such as Figure 1 As shown, the drainage groove 41 covers the entire distal area of ​​the sheath core tube 6. The structure of the guide tube 4 at the drainage groove 41 is relatively weak. When passing through a tortuous blood vessel, the distal end of the sheath core tube 6 can easily penetrate the drainage groove 41 and break the guide tube 4, which affects the safety of transportation and also weakens the overall structure of the delivery catheter, which is not conducive to subsequent transportation.

[0005] Moreover, existing products usually use bonding to assemble the guide tube to the sheath core tube. Chinese patent publication number CN215083921U provides an implementation method to make the connection between the two stronger, by assembling an auxiliary tube between the guide tube and the sheath core tube to enhance the connection strength between the guide tube and the sheath core tube.

[0006] Continue to refer to Figure 1 However, due to the addition of the auxiliary tube 5, part of the position that was originally supposed to be the guide tube 4 is occupied, and the drainage groove 41 also covers the entire auxiliary tube 5, making the structure of the guide tube 4 at the drainage groove 41 position weaker and more easily broken due to the displacement of the sheath core tube 6 or the auxiliary tube 5. For example, when producing and processing the catheter, the auxiliary tube 5 is prone to be eccentric relative to the sheath core tube 6 before the glue solidifies. When assembling the guide tube 4, it is easy to break the guide tube 4 from the weak drainage groove 41 position, causing the auxiliary tube 5 to be exposed at that location. Moreover, the auxiliary tube 5 is a metal tube, and the exposed part is in direct contact with the blood, which is prone to infection accidents. In addition, the rupture of the guide tube will also affect the structural strength of the delivery catheter.

[0007] However, the inventors have found that increasing the outer diameter of the guide tube to increase the wall thickness to solve the problem of preventing the auxiliary tube from being exposed will increase the overall size of the guide tube, which is not conducive to guided transportation. Therefore, it is urgent to provide a new design to solve the above problem. Summary of the invention

[0008] The present invention aims to solve the technical problem in the prior art that a sheath core tube and an auxiliary tube easily penetrate a guide tube and are exposed to the outside, and provides a delivery catheter mechanism and a stent delivery device.

[0009] In view of the above technical problems, an embodiment of the present invention provides a delivery catheter mechanism, comprising a sheath core tube and a tapered guide tube, wherein the tapered guide tube is sleeved on the distal end of the sheath core tube and extends beyond the distal end of the sheath core tube, and the outer diameter of the tapered guide tube gradually decreases in a direction away from the distal end of the sheath core tube; The outer wall of the tapered guide tube is provided with a flow guiding groove, which is arranged on the proximal side of the tapered guide tube relative to the distal end of the sheath core tube and is spaced apart from the distal end of the sheath core tube.

[0010] Optionally, an auxiliary tube is also included, which is sleeved on the distal end of the sheath core tube and is sleeved by the conical guide tube. The auxiliary tube is located on the distal side of the guide groove. The auxiliary tube includes a coaxially arranged proximal section and a distal section, and at least part of the guide groove is arranged on the outer wall of the conical guide tube sleeved on the proximal section.

[0011] Optionally, the tapered guide tube comprises a first tapered tube section and a straight tube section which are coaxially arranged, and the outer diameter of the first tapered tube section gradually decreases from an end close to the straight tube section toward an end away from the straight tube section, the straight tube section is sleeved on the sheath core tube, and the first tapered tube section is sleeved on the auxiliary tube; The guide groove includes a first groove, and the first groove is arranged on the outer wall of the first cone tube section.

[0012] Optionally, the guide groove further includes a second groove communicated with the first groove, and the second groove is arranged on the outer wall of the straight tube section sleeved on the sheath core tube.

[0013] Optionally, the bottom wall of the first groove is an inclined wall, and the distance between the inclined wall and the axis of the tapered guide tube gradually increases from an end close to the second groove toward an end away from the second groove.

[0014] Optionally, the outer diameter of the proximal section gradually decreases from an end close to the distal section toward an end away from the distal section.

[0015] Optionally, a plurality of spaced-apart bevel teeth are provided on the outer wall of the distal section, and the distance between the bevel teeth and the axis of the auxiliary tube gradually decreases from an end close to the proximal section toward an end away from the proximal section.

[0016] Optionally, the conical guide tube has an inner hole, which includes a coaxially connected conical hole section and a straight hole section, the proximal section is installed in the conical hole section, and the outer wall of the proximal section abuts against the inner wall of the conical hole section; the distal section is installed in the straight hole section, and the outer wall of the distal section abuts against the inner wall of the straight hole section.

[0017] Optionally, the length of the first groove is less than two-thirds of the length of the proximal segment.

[0018] Optionally, the width of the guide groove gradually increases from an end close to the axis of the tapered guide tube toward an end away from the axis of the tapered guide tube.

[0019] Another embodiment of the present invention further provides a stent delivery device, comprising an outer sheath tube and the above-mentioned delivery catheter mechanism; the outer sheath tube is sleeved on the sheath core tube and the tapered guide tube.

[0020] In the present invention, the guide groove on the tapered guide tube is arranged on the proximal side of the tapered guide tube relative to the distal end of the sheath core tube, and is spaced from the distal end of the sheath core tube. By shortening the guide groove on the tapered guide tube, the guide groove is located on the proximal side of the tapered guide tube and is staggered from the distal end of the sheath core tube, thereby preventing the distal side of the tapered guide tube with a smaller outer diameter from being broken through the guide groove by the sheath core tube, thereby preventing the sheath core tube from being exposed to the outside, thereby ensuring the safety of the delivery catheter mechanism in the blood vessel. In addition, because the distal side of the tapered guide tube has a sufficient wall thickness, the overall strength of the delivery catheter mechanism is ensured. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0022] Figure 1 It is the catheter related technical drawings mentioned in the background technology of the present invention; Figure 2 is a structural schematic diagram of a delivery catheter mechanism provided by an embodiment of the present invention; Figure 3 is a front view of a delivery catheter mechanism provided by an embodiment of the present invention; Figure 4 It is an axial cross-sectional view of a delivery catheter mechanism provided in one embodiment of the present invention.

[0023] The reference numerals in the specification are as follows: 1. Sheath core tube; 2. Conical guide tube; 21. Guide groove; 211. First groove; 212. Second groove; 22. First cone tube section; 23. Straight tube section; 24. Second cone tube section; 25. Conical hole section; 26. Straight hole section; 3. Auxiliary tube; 31. Proximal section; 32. Distal section; 321. Bevel teeth. DETAILED DESCRIPTION

[0024] In order to make the technical problems, technical solutions and beneficial effects solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0025] It should be understood that the directions or positional relationships indicated by terms such as "upper", "lower", "left", "right", "front", "back", and "middle" are based on the directions or positional relationships shown in the accompanying drawings and are only for the convenience of describing the present invention and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation of the present invention.

[0026] like Figures 1 to 3 As shown, a delivery catheter mechanism provided by one embodiment of the present invention includes a sheath core tube 1 and a tapered guide tube 2. The tapered guide tube 2 is sleeved on the distal end of the sheath core tube 1 and extends beyond the distal end of the sheath core tube 1. The outer diameter of the tapered guide tube 2 gradually decreases in the direction away from the distal end of the sheath core tube 1, which plays a guiding role in pushing the sheath core tube 1 in the blood vessel. The inner cavity of the sheath core tube 1 is connected to the distal opening of the tapered guide tube 2, so that the guide wire can pass through the inner cavity of the sheath core tube 1 and pass through the distal end of the tapered guide tube 2.

[0027] The outer wall of the conical guide tube 2 is provided with a flow guide groove 21 for guiding out the physiological saline for cleaning the sheath core tube 1. The flow guide groove 21 is arranged on the proximal side of the conical guide tube 2 relative to the distal end of the sheath core tube 1 and is spaced from the distal end of the sheath core tube 1. By shortening the flow guide groove 21 on the conical guide tube 2 so that it is located on the proximal side of the conical guide tube 2 and staggered from the distal end of the sheath core tube 1, it is avoided that the distal side of the conical guide tube 2 with a smaller outer diameter is broken through the flow guide groove 21 by the sheath core tube 1, thereby avoiding the sheath core tube 1 from being exposed to the outside, thereby ensuring the safety of the delivery catheter mechanism in the blood vessel; in addition, because the distal side of the conical guide tube 2 has a sufficient wall thickness, the overall strength of the delivery catheter mechanism is ensured.

[0028] In one embodiment, the delivery catheter mechanism also includes an auxiliary tube 3, which is sleeved on the distal end of the sheath core tube 1 and is sleeved by the tapered guide tube 2. The sheath core tube 1 and the tapered guide tube 2 are made of a tube made of a polymer material, and the auxiliary tube 3 can be made of a metal tube. The two opposite surfaces of the auxiliary tube 3 are respectively connected to the sheath core tube 1 and the tapered guide tube 2, so that the tapered guide tube 2 and the sheath core tube 1 do not slide axially and radially relative to each other and form a combined integral structure. In addition, the addition of the auxiliary tube 3 plays a role of transition connection, which significantly enhances the connection strength and connection reliability between the two plastic components, so that a stable fixed connection is formed between the sheath core tube 1 and the tapered guide tube 2, which helps to form a force transmission and also reduces the risk of the tapered guide tube 2 falling off.

[0029] In one embodiment, the inner diameter of the auxiliary tube 3 can be increased while ensuring the wall thickness of the auxiliary tube 3, so that there is more glue filling space between the inner wall of the auxiliary tube 3 and the outer wall of the sheath core tube 1 to increase the bonding strength of the auxiliary tube 3.

[0030] Specifically, in the present embodiment, the auxiliary tube 3 is located at the distal side of the flow guiding groove 21, and the auxiliary tube 3 includes a coaxially arranged proximal section 31 and a distal section 32, and at least part of the flow guiding groove 21 is arranged on the outer wall of the tapered guide tube 2 sleeved on the proximal section 31. It can be understood that, as projected on the sheath core tube 1, at least part of the flow guiding groove 21 overlaps with the projection of the proximal section 21, that is, the flow guiding groove 21 does not completely cover the entire auxiliary tube 3, but is staggered with the auxiliary tube 3 to a certain extent, thereby ensuring the structural strength of the tapered guide tube 2 at the distal end, and is not easily penetrated by the distal end of the auxiliary tube 3.

[0031] In one embodiment, if Figures 1 to 3 As shown, the tapered guide tube 2 includes a first tapered tube section 22 and a straight tube section 23 that are coaxially arranged; the outer diameter of the first tapered tube section 22 gradually decreases from one end close to the straight tube section 23 toward the end away from the straight tube section 23; it can be understood that the connection surface between the first tapered tube section 22 and the straight tube section 23 is a step surface, and the first tapered tube section 22 has a larger outer diameter than the straight tube section 23 at the step, and the first tapered tube section 22 and the straight tube section 23 are transitionally connected through the step. The formation of the step facilitates the subsequent sleeve installation of the outer sheath tube, and the step can abut the outer sheath tube to form a limit to the outer sheath tube.

[0032] The straight tube section 23 is sleeved on the sheath core tube 1 , and the first tapered tube section 22 is sleeved on the auxiliary tube 3 ; further, the first tapered tube section 22 is sleeved on the distal section 32 and the proximal section 31 .

[0033] The flow guide groove 21 includes a first groove 211 , and the first groove 211 is arranged on the outer wall of the first cone tube section 22 sleeved on the proximal section 31 .

[0034] The flow guide groove 21 also includes a second groove 212 connected to the first groove 211. The second groove 212 is arranged on the outer wall of the straight tube section 23 and is staggered from the proximal region of the auxiliary tube 3. In this embodiment, the outer portion of the sheath core tube 1 is directly the straight tube section 23 without the auxiliary tube 3, so the straight tube section 23 has a sufficient wall thickness and is less likely to be penetrated than the position where the auxiliary tube 3 is provided.

[0035] In one embodiment, if Figure 1 and Figure 2 As shown, the second groove 212 is axially straightly opened on the outer wall of the straight pipe section 23, and the bottom wall of the first groove 211 is an inclined wall; from the end close to the second groove 212 toward the end away from the second groove 212, the distance between the inclined wall and the axis of the tapered guide tube 2 gradually increases, so as to form a scheme in which the guide groove 21 extends outwardly corresponding to the position of the auxiliary pipe 3, so that the tapered guide tube 2 is thicker at the position of the auxiliary pipe 3 and has a higher structural strength.

[0036] In one embodiment, the depth of the first groove 211 is deeper at one end close to the second groove 212, and is shallower at one end away from the second groove 212. In addition, the second groove 212 is axially straightly opened on the outer wall of the straight tube section 23, and the first groove 211 is inclined and expanded outward, so that physiological saline can flush the sheath core tube and flow smoothly toward the distal first groove 211.

[0037] Specifically, the first groove 211 has a first end connected to the second groove 212, and a second end relatively far away from the second groove 212. The flow guide groove 21 gradually tilts outwards in the direction extending from the first end to the second end of the first groove 211, forming an outwardly expanded groove. Wherein, the guide grooves 21 are respectively provided on the opposite sides of the tapered guide tube 2. It can be understood that the distance between the second ends of the first grooves 211 on the opposite sides is greater than the distance between the first ends.

[0038] In one embodiment, if Figures 1 to 3 As shown, the tapered guide tube 2 is sleeved on the proximal section 31 and the distal section 32; the outer diameter of the proximal section 31 gradually decreases from the end close to the distal section 32 toward the end away from the distal section 32. It can be understood that the proximal section 31 is a tapered tubular structure, and the distal section 32 is a straight tubular structure.

[0039] Due to the design of the guide groove 21, the wall thickness of the conical guide tube 2 at this position is very limited and the structural strength is relatively weak. Therefore, in order to prevent the conical guide tube 2 from being damaged, the auxiliary tube 3 with a thinner wall thickness located in the conical guide tube 2 is designed to be conical, and the thickness of the auxiliary tube 3 is thinned to increase the wall thickness of the conical guide tube 2 at this position.

[0040] In the present invention, the design of the tapered guide tube 2 not only guides the sheath core tube 1 in the blood vessel, but also increases the wall thickness of the tapered guide tube 2 outside the auxiliary tube 3 without increasing the size of the tapered guide tube 2 by reducing the outer diameter of the auxiliary tube 3, so that when the guide groove 21 is opened on the tapered guide tube 2, the guide groove 21 is not easy to penetrate the tapered guide tube 2, so that the sheath core tube 1 and the auxiliary tube 3 are not easy to be exposed outside, ensuring the safety of the delivery catheter mechanism in the blood vessel. In addition, the tapered guide tube 2 outside the auxiliary tube 3 has a sufficient wall thickness to ensure the strength of the tapered guide tube 2.

[0041] In other embodiments, a straight-cylindrical auxiliary pipe may be used, and only the conical guide pipe 2 with the outward-expanding guide groove 21 may be used to increase the material thickness between the conical guide pipe 2 and the auxiliary pipe 3.

[0042] Furthermore, in one embodiment, the structure includes both an outward-expanding guide groove and a tapered auxiliary tube, and the guide groove 21 is set as an outward-expanding groove. When the auxiliary tube 3 is designed to be tapered to reserve sufficient wall thickness for the tapered guide tube, the outward-expanding groove further increases the wall thickness space of the tapered guide tube 2 at the groove. In this embodiment, since the tapered guide tube 2 outside the proximal section 31 has sufficient wall thickness, the first groove 211 is set on the outer wall of the tapered guide tube 2 outside the proximal section 31, which further ensures that the first groove 211 is not easy to penetrate the tapered guide tube 2, so that the auxiliary tube 3 is not easy to be exposed, thereby further ensuring the safety of the delivery catheter mechanism in the intravascular delivery.

[0043] The first groove 211 is arranged relative to the proximal section 31, and the first groove 211 extends outward. It can be understood that the wall thickness of the proximal section 31 of the auxiliary tube 3 gradually decreases from the end close to the distal section 32 toward the end away from the distal section 32. Compared with the straight-cylindrical auxiliary tube in the prior art that is easy to penetrate the conical guide tube, the conical auxiliary tube 3 of the present application reserves enough injection volume of the conical guide tube 2 in the conical area, that is, the bottom of the guide groove 21 can separate the auxiliary tube 3 from a greater distance, and there is a certain wall thickness of the conical guide tube 2 between the two, which can effectively prevent the auxiliary tube 3 from piercing the conical guide tube 2 at the position of the guide groove 21, thereby avoiding the risk of the auxiliary tube 3 being exposed and contacting the blood.

[0044] Since the straight tube section 23 outside the proximal section 31 has a sufficient wall thickness, the second groove 212 is arranged on the outer wall of the first tapered tube section 22 outside the proximal section 31, which further ensures that the first groove 211 is not easy to penetrate the tapered guide tube 2. In addition, the design of the straight tube section 23 ensures the stability of the tapered guide tube 2 sleeved on the sheath core tube 1. In addition, after the catheter assembly is assembled, an outer sheath tube is sleeved on the outside of the sheath core tube 1. Before the implantation operation, it is necessary to perfuse physiological saline to disinfect the inside of the catheter assembly. The design of the first groove 211 and the second groove 212 makes it easy for the physiological saline at the outer end of the conveying catheter mechanism to flow out through the second groove 212 and the first groove 211, thereby improving the convenience of cleaning the conveying guide mechanism.

[0045] In one embodiment, if Figure 1 and Figure 3 As shown, a plurality of spaced-apart oblique teeth 321 are provided on the outer wall of the distal section 32; from the end close to the proximal section 31 toward the end away from the proximal section 31, the distance between the oblique teeth 321 and the axis of the auxiliary tube 3 gradually decreases, that is, the inclination direction of the oblique teeth 321 is arranged from the distal end toward the proximal end. It can be understood that there is an oblique groove between two adjacent oblique teeth 321, and more tapered guide tube 2 material can be injected into the oblique groove, ensuring the stability of the tapered guide tube 2 sleeved on the auxiliary tube 3. In addition, the oblique teeth 321 are inclined toward the proximal end of the auxiliary tube 3, so that the tapered guide tube 2 is not easy to be pulled out from the auxiliary tube 3, further ensuring the stability of the tapered guide tube 2 sleeved on the auxiliary tube 3.

[0046] In addition, the segmented design of the tapered proximal section 31 and the straight distal section 32 of the auxiliary tube 3 also helps to distinguish the assembly direction of the auxiliary tube 3 during the assembly of the catheter mechanism. The proximal section 31 is assembled on the inner side of the sheath core tube 1 so that the tip of the bevel tooth 321 can face the proximal side of the tapered guide tube 2, effectively strengthening the connection strength between the tapered guide tube 2 and the auxiliary tube 3 and preventing the tapered guide tube 2 from escaping from the distal end.

[0047] In one embodiment, if Figures 1 to 3 As shown, the length of the first groove 211 is less than two-thirds of the length of the proximal section 31. In this embodiment, the length of the first groove 211 is relatively small, only one-half of the length of the proximal section 31, so that the proximal section 31 where the first groove 211 is located has a thicker wall thickness, further ensuring that the first groove 211 is not easy to penetrate the tapered guide tube 2.

[0048] The auxiliary tube 3 is arranged between the step of the tapered guide tube and the distal end of the sheath core tube 1. Specifically, the proximal section 31 of the auxiliary tube 3 has a relative starting end and a stopping end, the starting end is the proximal end of the auxiliary tube 3, and the stopping end is an end connected to the distal section 32. The first groove 211 has a first end and a second end. In this embodiment, the tapered guide tube 2 is sleeved on the auxiliary tube 3, and the step of the tapered guide tube 2 is correspondingly arranged at the periphery of the starting end, that is, the installation position of the auxiliary tube 3 is arranged at the maximum cross-section of the tapered guide tube 2, which ensures the structural reliability of the tapered guide tube 2 having the maximum wall thickness. The second groove 212 partially extends to the periphery of the proximal section 31, the first groove 211 connects to the second groove 212 and extends outwardly at an angle corresponding to the periphery of the proximal section 31, and the second end is stopped at half the length of the proximal section 31, and the wall thickness of the tapered guide tube 2 at the auxiliary tube 3 is retained as much as possible.

[0049] The first groove 211 can be tilted outwardly by 20° to 60° relative to the axial direction of the sheath core tube 1 . In order to facilitate the extraction of physiological saline, an inclination angle of 30° to 45° is preferred.

[0050] The wall thickness of the conical guide tube at the first end of the guide groove is about 0.3mm±0.1mm, and the wall thickness at the second end is 0.5mm±0.1mm. The thickest wall thickness in the middle can reach 0.6mm±0.1mm, which is equivalent to the distance between the bottom of the guide groove and the proximal section.

[0051] In one embodiment, if Figures 1 to 3 As shown, the tapered guide tube 2 further includes a second tapered tube section 24 connected to the straight tube section 23 and away from the first tapered tube section 22; the outer diameter of the second tapered tube section 24 gradually decreases from the end close to the straight tube section 23 toward the end away from the straight tube section 23. In this embodiment, the design of the second tapered tube section 24 can play a guiding role when the delivery catheter mechanism exits the blood vessel.

[0052] In one embodiment, if Figure 1 and Figure 3 As shown, the tapered guide tube 2 has an inner hole, and the inner hole includes a coaxially connected tapered hole section 25 and a straight hole section 26. The proximal section 31 is installed in the tapered hole section 25, and the outer wall of the proximal section 31 abuts against the inner wall of the tapered hole section 25; the distal section 32 is installed in the straight hole section 26, and the outer wall of the distal section 32 abuts against the inner wall of the straight hole section 26. In the process of manufacturing the sheath tube, the auxiliary tube 3 is first bonded to the head of the sheath core tube 1, and then the bonded auxiliary tube 3 and the sheath core tube 1 are placed in an injection mold, so that the injection material fills the injection mold to form the structure of the tapered guide tube 2 of the present application, so that the tapered guide tube 2 can be more tightly connected with the sheath core tube 1 and the auxiliary tube 3.

[0053] It can be understood that the first tapered tube section 22 is sleeved on the proximal section 31 through the tapered hole section 25, and is sleeved on the distal section 32 through the straight hole section 26. In this embodiment, the second groove 212 is provided on the outer wall of the first tapered tube section 22 corresponding to the tapered hole section 25, so that the design of the tapered hole section 25 further ensures that the first tapered tube section 22 where the second groove 212 is located has a sufficient wall thickness, so that the second groove 212 is not easy to penetrate the tapered guide tube 2.

[0054] In one embodiment, if Figure 1 and Figure 2 As shown, the width of the guide groove 21 gradually increases from the end close to the axis of the tapered guide tube 2 toward the end away from the axis of the tapered guide tube 2. It can be understood that the cross section of the guide groove 21 presents an outward eight-character shape, that is, the width of the bottom of the guide groove 21 is smaller than the width of the top opening, so that the physiological saline inside the catheter assembly can be discharged more easily and quickly through the guide groove 21.

[0055] Another embodiment of the present invention further provides a stent delivery device, comprising an outer sheath tube (not shown) and the above-mentioned delivery catheter mechanism; the outer sheath tube is sleeved on the sheath core tube 1 and the tapered guide tube 2.

[0056] It can be understood that the maximum cross-section (step) of the tapered guide tube 2 abuts against the inner wall of the outer sheath tube to form a limit to the outer sheath tube. During the cleaning process of the delivery guide mechanism in the outer sheath tube, the saline at the outer end of the delivery guide mechanism can flow to the distal end and be discharged through the guide groove 21, and the oblique design of the first groove 211 allows the flow of the saline to be discharged obliquely outward along the axial direction of the sheath core tube, which speeds up the extraction speed of the saline to a certain extent. The delivery catheter mechanism of this embodiment can be used alone in interventional surgery, for example, it can be deployed in a complex and tortuous blood vessel segment that is difficult for a general catheter or guide wire to pass through to establish an interventional channel, and it can also be coordinated with other catheter components, for example, combined with an outer sheath tube to form a stent delivery catheter component for the delivery and release of the stent.

[0057] In summary, the delivery catheter mechanism of the present invention shortens the guide groove 21 on the tapered guide tube 2 so that it is located on the proximal side of the tapered guide tube 2 and staggered with the distal end of the sheath core tube 1, thereby preventing the distal side of the tapered guide tube 2 with a smaller outer diameter from being broken through by the sheath core tube 1 and penetrating the guide groove 21. In addition, by reducing the outer diameter of the auxiliary tube 3, the wall thickness of the tapered guide tube 2 outside the auxiliary tube 3 is increased without increasing the size of the tapered guide tube 2, so that when the guide groove 21 is opened on the tapered guide tube 2, the guide groove 21 is not easy to penetrate the tapered guide tube 2, so that the sheath core tube 1 is not easy to be exposed outside, thereby ensuring the safety of the delivery catheter mechanism in intravascular delivery. In addition, the tapered guide tube 2 outside the auxiliary tube 3 has a sufficient wall thickness to ensure the strength of the tapered guide tube 2.

[0058] The above are merely embodiments of the delivery catheter mechanism and stent delivery device of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A delivery catheter mechanism, characterized in that: It comprises a sheath core tube and a tapered guide tube, wherein the tapered guide tube is sleeved on the distal end of the sheath core tube and extends beyond the distal end of the sheath core tube, and the outer diameter of the tapered guide tube gradually decreases in a direction away from the distal end of the sheath core tube; The outer wall of the tapered guide tube is provided with a flow guiding groove, which is arranged on the proximal side of the tapered guide tube relative to the distal end of the sheath core tube and is spaced apart from the distal end of the sheath core tube.

2. The delivery catheter mechanism according to claim 1, characterized in that: It also includes an auxiliary tube, which is sleeved on the distal end of the sheath core tube and is sleeved by the tapered guide tube. The auxiliary tube is located on the distal side of the guide groove. The auxiliary tube includes a coaxially arranged proximal section and a distal section. At least part of the guide groove is arranged on the outer wall of the tapered guide tube sleeved on the proximal section.

3. The delivery catheter mechanism according to claim 2, characterized in that: The conical guide tube comprises a first conical tube section and a straight tube section which are coaxially arranged, and the outer diameter of the first conical tube section gradually decreases from an end close to the straight tube section toward an end away from the straight tube section, the straight tube section is sleeved on the sheath core tube, and the first conical tube section is sleeved on the auxiliary tube; The guide groove includes a first groove, and the first groove is arranged on the outer wall of the first cone tube section.

4. The delivery catheter mechanism according to claim 3, characterized in that: The guide groove also includes a second groove communicated with the first groove, and the second groove is arranged on the outer wall of the straight tube section sleeved on the sheath core tube.

5. The delivery catheter mechanism according to claim 4, characterized in that: The bottom wall of the first groove is an inclined wall, and the distance between the inclined wall and the axis of the tapered guide tube gradually increases from an end close to the second groove toward an end away from the second groove.

6. The delivery catheter mechanism according to claim 2, characterized in that: The outer diameter of the proximal section gradually decreases from an end close to the distal section toward an end away from the distal section.

7. The delivery catheter mechanism according to claim 2, characterized in that: A plurality of spaced-apart oblique teeth are disposed on the outer wall of the distal section, and the distance between the oblique teeth and the axis of the auxiliary tube gradually decreases from an end close to the proximal section toward an end away from the proximal section.

8. The delivery catheter mechanism according to claim 2, characterized in that: The conical guide tube has an inner hole, which includes a conical hole section and a straight hole section that are coaxially connected. The proximal section is installed in the conical hole section, and the outer wall of the proximal section abuts against the inner wall of the conical hole section; the distal section is installed in the straight hole section, and the outer wall of the distal section abuts against the inner wall of the straight hole section.

9. The delivery catheter mechanism according to claim 3, characterized in that: The length of the first groove is less than two thirds of the length of the proximal section.

10. A stent delivery device, characterized in that: It comprises an outer sheath tube and a delivery catheter mechanism as described in any one of claims 1 to 9, wherein the outer sheath tube is sleeved on the sheath core tube and the tapered guide tube.

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