Dense net support conveying system

Abstract

The invention provides a dense net stent conveying system, and belongs to the technical field of interventional medical instruments. The system comprises a dense mesh stent, a first conveying pipe, a second conveying pipe and a conveying guide wire, wherein the first conveying pipe is used for accommodating and conveying the dense mesh stent; the second conveying pipe is slidably arranged in an inner cavity of the first conveying pipe, and the far end of the second conveying pipe is detachably connected with the near end of the dense net stent; the conveying guide wire is movably arranged in an inner cavity of the second conveying pipe, a control structure is arranged at the far end, and the far end of the dense net support is pressed and held on the control structure. During releasing, the releasing degree is adjusted by controlling the range of the dense net support extending out of the first conveying pipe, before the accurate position is not determined, the position of the dense net support can be adjusted through the second conveying pipe, and complete releasing is achieved after connection is disconnected after the dense net support is in place; according to the system, error correction and position adjustment in the release process can be achieved, and the accuracy, safety and success rate of an interventional operation are greatly improved.

Description

Technical Field

[0001] This invention belongs to the field of interventional medical device technology, specifically relating to a dense mesh stent delivery system. Background Technology

[0002] Intracranial aneurysm is a hemorrhagic stroke, and a common and frequently occurring disease in clinical practice, causing rupture of cerebral blood vessels. It is characterized by high incidence, high disability rate, high mortality rate, and high recurrence rate, making it a leading cause of death and disability among middle-aged and elderly individuals. Furthermore, with the continuous increase in the elderly population and the improvement of living standards, the incidence of cerebrovascular diseases is constantly rising.

[0003] Treatment of intracranial aneurysms has evolved through multiple generations of approaches, from surgical clipping to electrically detached coils, mechanically detached coils, and coil embolization-assisted stents, culminating in flow-directing mesh stents. Among these, the advent of flow-directing mesh stents has transformed the treatment of large saccular or fusiform aneurysms from aneurysm embolization to reconstruction of the parent vessel. Due to its excellent therapeutic effects, it has been widely adopted. Currently, several products are available domestically and internationally, such as Medtronic's Pipeline Flex with Shield, Stryker's Surpass Evolve, and MicroVention's FRED, and their effectiveness in treating large, giant, and fusiform aneurysms has been demonstrated in clinical trials.

[0004] However, existing flow-guided mesh stents still suffer from a technical challenge in clinical application: insufficient controllability and error correction. Specifically, the current structure consists of a delivery system and a stent. During aneurysm surgery, the mesh stent is typically introduced through a delivery sheath into a microcatheter of the appropriate size. Then, a guidewire pushes it through the microcatheter to the target vessel location. After release, the stent expands and supports the vessel wall, covering the aneurysm neck, thus reconstructing the vessel wall and correcting hemodynamic disturbances. This aims to promote blood flow stasis and thrombus formation within the aneurysm, as well as the proliferation of endothelial cells and new intimal tissue within the stent, ultimately repairing the parent artery through intimalization of the aneurysm neck. However, during surgery, the anchoring and release of the stent tip (also known as the "distal end") varies depending on the complexity of the case. When the stent is found to be in an undesirable position or shape after release, the surgeon cannot retrieve and redeploy the stent. Most flow-directing mesh stents on the market currently support 60% release and retrievability. Once the operation exceeds the critical point, the stent is prone to complete detachment from the delivery system due to the expansion force of the released portion, i.e., complete release. At this point, the stent becomes an independent implant in the blood vessel and can no longer be retrieved for repositioning.

[0005] Therefore, there is a need to provide an improved technical solution that addresses the shortcomings of the existing technology. Summary of the Invention

[0006] The purpose of this invention is to provide a dense mesh stent delivery system to solve the technical defects of existing technologies where dense mesh stents cannot be retrieved or have their release position adjusted after being released over a large area within the blood vessel. This system enables the dense mesh stent to be safely retrieved and repositioned after being released over a large area within the blood vessel, greatly improving the accuracy, safety, and success rate of interventional surgery.

[0007] To achieve the above objectives, the dense mesh support conveying system of the present invention provides the following technical solution: A dense mesh support conveying system includes: Dense mesh support frame; The first conveying pipe is used to receive and convey the dense mesh support in the contracted state. The second conveying pipe is slidably disposed within the inner cavity of the first conveying pipe. The proximal end of the dense mesh support is detachably connected to the distal end of the second conveying pipe. The connection portion between the dense mesh support and the second conveying pipe accounts for 2%–10% of the overall length. A guide wire is provided, which is movably disposed in the inner cavity of the second delivery tube, and a control structure is provided at the distal end for controlling the release state of the dense mesh support. During the conveying of the dense mesh support, the distal end of the dense mesh support is pressed against the control structure of the conveying guide wire. Before the accurate release position is determined, the second conveying pipe is fixedly connected to the distal end of the dense mesh support. The release position of the dense mesh support is adjusted by driving the proximal end of the dense mesh support relative to the first conveying pipe until the dense mesh support is released into place. Then the connection between the second conveying pipe and the dense mesh support is disconnected, and the dense mesh support is completely released.

[0008] As a further optimized technical solution, a first fixing tube is fixedly sleeved at a position set at a distance from the far end of the conveying guide wire, and a fixing hole for coaxially accommodating the first fixing tube is provided at the far end of the second conveying tube. The far end of the dense mesh bracket is detachably disposed between the first fixing tube and the fixing hole.

[0009] As a further optimized technical solution, a developing tube is fixedly provided at the distal end of the second delivery tube, and the cavity of the developing tube constitutes the aforementioned fixing hole.

[0010] As a further optimized technical solution, the developing tube has a stepped gradient structure, and its diameter gradually increases from the distal end to the proximal end.

[0011] As a further optimized technical solution, the control structure includes an expansion auxiliary component and a fixing component arranged sequentially from the distal end to the proximal end of the guide wire.

[0012] As a further optimized technical solution, the expansion auxiliary component is a massage ball.

[0013] As a further optimized technical solution, the fixing component is a plurality of second fixing tubes arranged at intervals.

[0014] As a further optimized technical solution, a first developing element is provided on the conveying guide wire at a set proportional position corresponding to the dense mesh support, and a second developing element is provided at the far end of the first conveying tube, which is used to determine the release range of the dense mesh support by the relative position of the first developing element and the second developing element.

[0015] As a further optimized technical solution, a continuous spiral groove is provided on the outer wall of the second conveying pipe at a set distance from the far end.

[0016] As a further optimized technical solution, the pitch of the spiral groove gradually increases from the distal end to the proximal end.

[0017] Beneficial effects: Compared with existing technologies, this invention uses a double-layer delivery tube with a detachable connection structure to control the connection length between the proximal end of the dense mesh stent and the distal end of the second delivery tube to 2%-10%. Compared with the limitation of existing technologies that only support the recovery of 60% of the released volume, this system can adjust the position of the proximal end of the dense mesh stent by pushing or pulling back the second delivery tube before the stent is completely released, regardless of the amount released. It can even recover 90%-98% of the released dense mesh stent into the first delivery tube for redeployment, allowing the surgeon to try repeatedly until the most ideal stent release effect is obtained. This avoids the passive situation and risk accumulation caused by a poor release in one attempt, reduces the incidence of complications, and effectively solves the technical problem of not being able to correct errors when the release position or shape of the existing dense mesh stent is not ideal. It significantly reduces the risk of surgical errors and improves the success rate of intracranial aneurysm treatment surgery, especially suitable for complex cases with tortuous blood vessels and special aneurysm locations.

[0018] Furthermore, by setting an expansion auxiliary component and a fixing component at the far end of the conveying guide wire, the shape of the dense mesh support is kept stable during the release and adjustment of its position, thus avoiding problems such as far-end displacement and support deformation.

[0019] Furthermore, by setting a first imaging element on the guidewire and a second imaging element at the distal end of the first delivery catheter, the operator can accurately determine the release ratio of the dense mesh stent in real time, thereby improving the predictability and safety of the operation.

[0020] Furthermore, the present invention provides a helical groove with gradually varying pitch on the outer wall of the second delivery tube, which effectively enhances the flexibility and pushing ability of the delivery tube, making it more adaptable to the tortuous environment of intracranial blood vessels and reducing the difficulty of surgical operation and the risk of vascular damage. Attached Figure Description

[0021] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. Wherein: Figure 1 This is a schematic diagram of the overall structure of an embodiment of the dense mesh support conveying system of the present invention; Figure 2 This is a schematic diagram of the conveyor wire structure of one embodiment of the dense mesh support conveyor system of the present invention; Figure 3 This is a schematic diagram of the second conveying pipe structure of an embodiment of the dense mesh support conveying system of the present invention; Figure 4 This is a schematic diagram of the distal end structure of the second conveying pipe in one embodiment of the dense mesh support conveying system of the present invention; Figure 5 This is a schematic diagram of the release state of an embodiment of the dense mesh support conveying system of the present invention.

[0022] In the diagram: 100, dense mesh support; 200, first conveying tube; 300, second conveying tube; 310, developing tube; 320, spiral groove; 400, conveying guide wire; 410, expansion auxiliary component; 411, developing point; 420, fixing component; 430, first developing element; 440, developing spring; 450, support spring; 500, first fixing tube; 600, conveying sheath. Detailed Implementation

[0023] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention are within the scope of protection of the present invention.

[0024] In the description of this invention, the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," and "bottom," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and do not require the invention to be constructed and operated in a specific orientation; therefore, they should not be construed as limitations on the invention. The terms "connected" and "linked" used in this invention should be interpreted broadly. For example, they can refer to a fixed connection or a detachable connection; they can refer to a direct connection or an indirect connection through intermediate components. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances. Furthermore, the term "proximal end" uniformly refers to the end closer to the operator, while "distal end" refers to the end farther from the operator.

[0025] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described herein can be combined with each other.

[0026] The shapes and sizes of the components in the accompanying drawings do not reflect the actual proportions of the product; they are only intended to illustrate the content of the invention.

[0027] This invention provides a dense mesh support conveying system, primarily addressing the technical problems of poor controllability and low error correction capability in the release of existing dense mesh supports. The system includes a dense mesh support 100, a first conveying pipe 200, a second conveying pipe 300, and a conveying guide wire 400. The first conveying pipe 200 is used to receive and convey the dense mesh support 100 in its contracted state. The second conveying pipe 200 is slidably disposed within the inner cavity of the first conveying pipe 200. The proximal end of the dense mesh support 100 is detachably connected to the distal end of the second conveying pipe 300, with the connection length accounting for 2%–10% of the total length of the dense mesh support 100. The conveying guide wire 400 is movably disposed within the inner cavity of the second conveying pipe 300, and the distal end of the dense mesh support 100 is supported by a control structure on the conveying guide wire 400. When the dense mesh support 100 is released, the release degree is adjusted by controlling the extent to which the dense mesh support 100 extends beyond the first conveying pipe 200. Before determining the accurate position, the position of the dense mesh support 100 can be adjusted through the second conveying pipe 300. Once in position, the connection is disconnected to achieve complete release. The key to this invention lies in the fact that even after the dense mesh stent 100 has been extensively deployed within the blood vessel, if its position or shape is not ideal, the dense mesh stent 100 can be safely retrieved back into the first delivery tube 200 by simultaneously pulling back the second delivery tube 300 and the delivery guidewire 400 or pushing the first delivery tube 200 forward. This achieves position adjustment and re-deployment after extensive (90%-98%) deployment until satisfactory results are achieved, followed by final release. This invention completely solves the technical problem of irreversible one-time deployment of existing dense mesh stents, significantly improving the safety, accuracy, and success rate of interventional treatment for intracranial aneurysms.

[0028] Example 1 like Figure 1 As shown, the dense mesh support conveying system includes a dense mesh support 100, a first conveying pipe 200, a second conveying pipe 300, and a conveying guide wire 400.

[0029] The dense mesh stent 100 is woven from 48-strand and 64-strand cobalt-chromium DFT wires and has self-expanding properties. Its mesh density is adapted to the blood flow guidance treatment requirements of intracranial aneurysms. It can be visualized as a whole under DSA imaging equipment, which makes it easier for the surgeon to observe the position and release status of the dense mesh stent 100 more intuitively during the operation. In addition, the cobalt-chromium material provides good radial support, so that the dense mesh stent 100 does not collapse when implanted at the neck of the aneurysm and can also adhere well to the vessel wall.

[0030] The first delivery tube 200 is made of medical polymer material, and its inner diameter matches the outer diameter of the dense mesh stent 100 in the contracted state, which can stably house the dense mesh stent 100 and deliver it to the target position.

[0031] The second delivery tube 300 is slidably disposed within the inner cavity of the first delivery tube 200. It is made of nickel-titanium tubing through a segmented, gradually tapering cutting process. Continuous spiral grooves 320 are provided on the outer wall at a predetermined distance at the distal end to increase its flexibility. Preferably, the pitch of the spiral grooves 320 gradually increases from the distal end to the proximal end. This results in a dense spiral cutting process at the distal end, making it ultra-soft and ultra-elastic, with excellent delivery performance and the ability to reach lesion locations further away. The smooth transition in the middle section and strong support at the proximal end give the delivery spiral tube 3 high delivery accuracy and easy pushing performance. Specifically, as... Figure 3 As shown, a spiral groove 320 is provided within a range of 890mm from the distal end of the second delivery tube 300. The second delivery tube 300 is divided into four sections according to the change in the pitch of the spiral groove 320: the pitch of section L2 is 0.37mm, the pitch of section L3 is a gradient design of 0.37-0.77mm, the pitch of section L4 is 7.07mm, and section L5 has no cutting line. A contrast-enhancing tube 310 is provided at the distal end of the second delivery tube 300. The contrast-enhancing tube 310 is made of platinum-iridium alloy, with a length L1 of 1mm, and has good contrast properties under contrast-enhancing equipment, providing good visual positioning during surgery. The proximal end of the mesh support 100 is detachably connected to the contrast-enhancing tube 310 at the distal end of the second delivery tube 300. Furthermore, the connection between the mesh support 100 and the second conveying pipe 300 accounts for 2%–10% of the overall length. This connection length ensures the stability of the mesh support 100 during adjustment and allows for easy disconnection after the mesh support 100 is released into position. Specifically, during the processing of the second conveying pipe 300, the total length of L1 and L2 is 150mm, with a processing error allowed within ±5mm; the total length of L1, L2, and L3 is 750mm, with a processing error allowed within ±5mm; the total length of L1, L2, L3, and L4 is 890mm, with a processing error allowed within ±5mm; and the total length of L1, L2, L3, L4, and L5 is 900mm, with a processing error allowed within ±5mm.

[0032] like Figure 2As shown, the guide wire 400 is movably disposed within the inner cavity of the second delivery tube 300. A distal imaging spring 440 is provided at the distal end of the guide wire 400. The imaging spring 440 is fixedly mounted on the guide wire 400 via a support spring 450. The imaging spring 440 is made of platinum-tungsten alloy wire, which can be repeatedly molded and has good imaging properties under imaging equipment, providing good navigation during surgery. The support spring 450 is made of stainless steel wire and is fixed to the distal end of the guide wire 400 by welding. When the mesh support 100 is pressed against the guide wire 400, it provides support for the mesh support 100, preventing deformation of the head end of the mesh support 100 during delivery. The distal end of the guide wire 400 is provided with a control structure for controlling the release state of the mesh support 100.

[0033] During delivery of the mesh stent 100, the distal end of the mesh stent 100 is gripped on the control structure of the delivery guidewire 400. The extent of release of the mesh stent 100 is controlled by controlling the range of its extension beyond the distal end of the first delivery tube 200. Before the accurate release position is determined, the second delivery tube 300 is fixedly connected to the distal end of the mesh stent 100. The doctor can adjust the release position of the mesh stent 100 by driving the relative position of the proximal end of the mesh stent 100 with the first delivery tube. For example, if the release position is inaccurate after partial release of the mesh stent 100, the mesh stent 100 can be retracted into the first delivery tube 200 by simultaneously pulling the delivery guidewire 400 and the second delivery tube 300 backward or by pushing the first delivery tube 200 forward until the release position and shape of the mesh stent 100 meet the surgical requirements. Then, the connection between the second delivery tube 300 and the mesh stent 100 is disconnected to achieve complete release of the mesh stent 100.

[0034] Furthermore, a first fixing tube 500 is fixedly sleeved on the outer wall of the delivery guide wire 400 at a predetermined distance from the distal end. The cavity of the developing tube 310 forms a fixing hole for coaxially accommodating the first fixing tube 500. The distal end of the mesh support 100 is detachably disposed between the first fixing tube 500 and the fixing hole. This structure enables stable clamping of the distal end of the mesh support, preventing distal displacement during release. In this embodiment, the first fixing tube 500 is made of silicone. During the process of pressing the mesh support 100 with the fixing hole, it not only reduces damage to the mesh support 100 but also generates higher friction with the mesh support 100 during the fixing process.

[0035] Furthermore, the imaging tube 310 has a stepped, gradually increasing diameter from the distal to the proximal end. This gradual increase in diameter enhances imaging properties and makes the tube easier to observe during surgical procedures. In this embodiment, the imaging tube 310 has a two-step structure with a "T"-shaped cross-section along the axial direction.

[0036] In this embodiment, the control structure includes an expansion auxiliary component 410 and a fixing component 420 arranged sequentially from distal to proximal. The expansion auxiliary component 410 is a massage ball, made from nickel-titanium tubing through cutting, heat treatment, and polishing. The massage ball has six branches evenly spaced circumferentially, with three branches each equipped with a contrast point 411, providing visualization under contrast equipment and facilitating observation of instrument positions during surgery. The proximal end of the massage ball is welded to the delivery guidewire 400, and the distal end is slidably fitted onto the delivery guidewire 400. In its compressed state, the massage ball provides support for the compressed mesh stent 100, preventing deformation during delivery. During stent release, the massage ball automatically expands to assist the mesh stent 100's tip in opening better, ensuring adequate contact with the vessel wall.

[0037] The fixing component 420 consists of multiple second fixing tubes arranged at intervals. The second fixing tubes are also made of silicone, thus providing support and friction for the mesh support 100 to facilitate its transport. The number of second fixing tubes can vary depending on the length of the mesh support 100.

[0038] Furthermore, a first imaging element 430 is provided on the guide wire 400 at a position corresponding to 80% of the length of the mesh support 100, and a second imaging element (not shown in the figure) is provided at the distal end of the first delivery tube 200. These elements are used to determine the release range of the mesh support 100 by the relative positions of the first and second imaging elements. Specifically, the first imaging element 430 is made of platinum-tungsten alloy wire wound into a spring, which is welded to the outer wall of the guide wire 400 using a welding process, providing good imaging properties under imaging equipment. Thus, during the release of the mesh support 100, when the position of the first imaging element 430 coincides with the point of the second imaging element at the distal end of the first delivery tube 200, the doctor can determine that the mesh support 100 has been released 80%.

[0039] Specifically, the surgical procedure during the operation is as follows: First, the compressed mesh support 100 is pressed against the distal end of the delivery guide wire 400, with its proximal end connected to the second delivery tube 300, and loaded into the delivery sheath 600. Then, the distal end of the delivery sheath 600 is connected to the proximal end of the first delivery tube 200, and the mesh support 100 is transferred from the delivery sheath 600 to the first delivery tube 200, and moved along the first delivery tube 200 to the target position.

[0040] Then, the first delivery tube 200 is slowly retracted or kept stationary while the delivery guide wire 400 and the second delivery tube 300 are pushed forward, extending the mesh support 100 from the distal end of the first delivery tube 200. The mesh support 100 gradually emerges and unfolds. During this process, the release ratio can be determined by the relative position of the first developing element 430 and the second developing element at the distal end of the first delivery tube 200 (e.g., overlap indicates 80% release). Crucially, the proximal end of the mesh support 100 is always locked within the developing tube 310 by the first fixing tube 500.

[0041] During the release of the mesh stent 100, if the surgeon, under multi-angle angiography, observes stent misalignment, poor wall adhesion, or undesirable shape, the retrieval procedure can be initiated immediately: Keeping the delivery guidewire 400 and the second delivery tube 300 essentially stationary, push the first delivery tube 200 forward, or keeping the first delivery tube 200 stationary, pull the delivery guidewire 400 and the second delivery tube 300 backward, gradually retrieving the mesh stent 100 into the first delivery tube 200. Then, readjust the position of the mesh stent 100 until a satisfactory result is achieved. Release the mesh stent 100 again. Finally, by keeping the delivery guidewire 400 stationary and pulling the second delivery tube 300 backward, the first fixing tube 500 on the delivery guidewire 400, carrying the mesh stent 100, is removed from the lumen of the contrast tube 310, thus disconnecting the mesh stent 100 from the second delivery tube 300 and completely releasing the mesh stent 100. Figure 5 As shown.

[0042] In summary, the dense mesh stent delivery system provided by this invention, through the design of a double-layer delivery tube and a controllable release structure, achieves precise control and position adjustment during the release process of the dense mesh stent, solving the problem of low error correction capability in stent release in existing technologies, and improving the success rate and safety of intracranial aneurysm blood flow diversion therapy. It is understood that the above description is merely exemplary and the embodiments of this application do not limit the scope of the application.

[0043] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention are within the protection scope of the present invention.

Claims

1. A dense mesh support conveying system, characterized in that, include: Dense mesh support (100); The first conveying pipe (200) is used to receive and convey the dense mesh support (100) in the contracted state. The second delivery pipe (300) is slidably disposed in the inner cavity of the first delivery pipe (200). The proximal end of the mesh support (100) is detachably connected to the distal end of the second delivery pipe (300). The connection portion between the mesh support (100) and the second delivery pipe (300) accounts for 2% to 10% of the overall length. A delivery guide wire (400) is movably disposed in the inner cavity of the second delivery tube (300), and a control structure is provided at the distal end for controlling the release state of the dense mesh support (100); When the mesh support (100) is being conveyed, the distal end of the mesh support (100) is pressed against the control structure of the conveying guide wire (400). Before the accurate release position is determined, the second conveying tube (300) is fixedly connected to the distal end of the mesh support (100). The release position of the mesh support (100) is adjusted by driving the relative position of the proximal end of the mesh support (100) and the first conveying tube (200) until the mesh support (100) is released into place. Then the connection between the second conveying tube (300) and the mesh support (100) is disconnected, and the mesh support (100) is completely released.

2. The dense mesh support conveying system according to claim 1, characterized in that, A first fixing tube (500) is fixedly sleeved at a position set at a distance from the far end of the conveying guide wire (400). The far end of the second conveying tube (300) is provided with a fixing hole for coaxially accommodating the first fixing tube (500). The far end of the dense mesh support (100) is detachably disposed between the first fixing tube (500) and the fixing hole.

3. The dense mesh support conveying system according to claim 2, characterized in that, The distal end of the second delivery tube (300) is fixedly provided with a developing tube (310), and the cavity of the developing tube (310) forms the fixing hole.

4. The dense mesh support conveying system according to claim 3, characterized in that, The developing tube (310) has a stepped gradient structure, and its diameter gradually increases from the distal end to the proximal end.

5. The dense mesh support conveying system according to claim 1, characterized in that, The control structure includes an expansion auxiliary component (410) and a fixing component (420) arranged sequentially from the distal end to the proximal end of the delivery guide wire (400).

6. The dense mesh support conveying system according to claim 5, characterized in that, The expansion auxiliary component (410) is a massage ball.

7. The dense mesh support conveying system according to claim 5, characterized in that, The fixing component (420) consists of multiple second fixing tubes arranged at intervals.

8. The dense mesh support conveying system according to any one of claims 1-7, characterized in that, A first developing element (430) is provided on the conveying guide wire (400) at a predetermined position corresponding to the mesh support (100), and a second developing element is provided at the far end of the first conveying tube (200) to determine the release range of the mesh support (100) by the relative position of the first developing element (430) and the second developing element.

9. The dense mesh support conveying system according to any one of claims 1-7, characterized in that, A continuous spiral groove (320) is provided on the outer wall of the second conveying pipe (300) at a set distance from the far end.

10. The dense mesh support conveying system according to claim 9, characterized in that, The pitch of the spiral groove (320) gradually increases from the distal end to the proximal end.

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