Suction device with sealing structure

Abstract

The present application relates to the technical fields of vascular intervention medical instrument, and discloses a suction device with sealing structure, which comprises a catheter sheath and an extension catheter in nested cooperation, a ring gap is formed between the side wall of the one end of the extension catheter and the head side wall of the catheter sheath, a sealing member in the shape of a cylinder is sleeved on the one end of the extension catheter, and the sealing member is arranged in the ring gap. When the other end of the extension catheter reaches the target position of the middle cerebral artery thrombus and the ring gap needs to be sealed, the one end of the sealing member expands radially and abuts against the head side wall of the catheter sheath, so that the ring gap is sealed, the extension catheter and the catheter sheath are conveniently pushed, the sealing effect between the extension catheter and the catheter sheath is ensured, and the thrombus suction efficiency is guaranteed.

Description

Technical Field

[0001] This invention relates to the field of vascular interventional medical device technology, specifically to a suction device with a sealed structure. Background Technology

[0002] With the rapid development of neurointerventional technology, endovascular mechanical thrombectomy has become a first-line treatment for this type of disease. Among them, thrombectomy is widely used in clinical practice due to its relatively simple operation and high success rate of vascular recanalization. The core of thrombectomy is to establish an effective negative pressure channel through a suction device to mechanically remove the thrombus blocking the blood vessel, thereby restoring blood flow perfusion to the distal brain tissue.

[0003] In neurointerventional aspiration systems, the coordination between the extension catheter and the catheter sheath is a crucial factor in determining the success of the procedure. The extension catheter must be advanced through the lumen of the catheter sheath to the target intracranial vessel. After its distal opening reaches the proximal end of the thrombus, thrombus aspiration is achieved through an external negative pressure source. Due to the slender diameter and tortuous course of intracranial neurovascular anatomy, the instruments must possess sufficient delivery capability while minimizing mechanical stimulation to the vessel wall. This requires that the coordination between the extension catheter and the catheter sheath ensure both sufficient smooth sliding to achieve distal delivery and good sealing during aspiration to guarantee efficient negative pressure transmission.

[0004] However, the design of the fitting between the extension catheter and the catheter sheath has long faced an inherent technical contradiction: if the circumferential gap between them is too small, although it is beneficial for sealing, the sliding friction between the outer wall of the extension catheter and the inner wall of the catheter sheath increases significantly. This leads to a sharp increase in pushing resistance when traversing multiple bends in intracranial and extracranial blood vessels, which not only affects the catheter's ability to reach the distal thrombus target but may also cause frictional damage to the vascular intima during the pushing process. If the gap between them is too large, although it reduces the pushing resistance, air leakage is very likely to occur at the gap under negative pressure aspiration, leading to a decrease in aspiration negative pressure. Blood can also flow back through this gap, which not only weakens the thrombus aspiration efficiency but may also cause the thrombus to fragment and escape to distal blood vessels, triggering new embolic events. Therefore, how to achieve a reliable seal between the catheters while ensuring the smooth placement of the extension catheter is a core problem that urgently needs to be solved in the design of neurointerventional aspiration devices.

[0005] To address the aforementioned inter-catheter sealing problem, several solutions have been proposed in existing technologies, but each has its own insurmountable drawbacks. The first solution involves placing an inflatable balloon outside the extension catheter. Injecting a medium into the balloon causes it to expand radially, thereby sealing the gap between the extension catheter and the catheter sheath. While this solution achieves a controllable seal, the inflation and depressurization of the balloon increases surgical steps and time. Furthermore, improper control of the balloon inflation pressure can easily cause compressive damage to the fragile neurovascular walls. The second solution uses hydrogel as the sealing medium, utilizing its hygroscopic and expanding properties in bodily fluids to achieve gap sealing. Although hydrogels possess good biocompatibility, their expansion rate and final expansion amount are difficult to precisely control due to various factors. Moreover, hydrogels lack mechanical stability under suction negative pressure, making them prone to deformation or even detachment, thus compromising sealing reliability. Additionally, hydrogel degradation products may induce local inflammatory reactions, increasing the risk of postoperative complications. The third solution involves designing the proximal end of the extension catheter as a flared structure, achieving gap sealing through contact between the flared section and the inner wall of the catheter sheath. This solution has a simple structure, but the flared design inherently increases the contact area and pressure between the extended catheter and the catheter sheath, which in turn exacerbates the frictional resistance during the insertion process and adversely affects the catheter's positioning performance. Other solutions attempt to achieve a seal by extending the long overlap area between the catheter and the catheter sheath, but this method requires extremely high dimensional accuracy, and the sealing effect fluctuates with changes in the overlap length and suction pressure, lacking stability.

[0006] In summary, existing aspiration devices, in their design for the sealing of the extension catheter and catheter sheath, either prioritize ensuring proper placement at the expense of sealing effectiveness, or focus on improving sealing performance at the expense of delivery performance. No solution has yet emerged that can simultaneously meet the dual requirements of "low-resistance delivery" and "highly reliable sealing." As the demands for instrument precision, operational safety, and surgical efficiency in neurointerventional surgery continue to increase, developing an aspiration device that can achieve efficient inter-catheter sealing while ensuring smooth catheter placement, and that is easy to operate and safe, has become a pressing technical problem for those skilled in the art. Summary of the Invention

[0007] (a) Technical problems to be solved To address the shortcomings of existing technologies, this invention provides a suction device with a sealing structure, which has the advantages of reasonable structural design, safety and reliability, and good sealing effect. It solves the technical problems of existing technologies that focus on ensuring delivery while sacrificing sealing effect or strive to improve sealing performance while damaging pushing performance.

[0008] (II) Technical Solution To achieve the above objectives, the present invention provides the following technical solution: A suction device with a sealed structure includes a nested catheter sheath and an extension catheter. The catheter sheath is made of medical-grade biocompatible material (such as PTFE or polyurethane). An annular gap is formed between the sidewall of one end of the extension catheter and the sidewall of the head of the catheter sheath. The size of the annular gap can be adjusted by selecting different sizes of catheter sheaths 1 according to clinical needs, and the width of the annular gap is greater than 0 and not greater than 2 mm, such as 0.2 mm, 0.35 mm, 0.5 mm, 0.75 mm, 1 mm, 1.35 mm, 1.5 mm, 1.85 mm, and 2 mm. The extension catheter has a hollow tubular structure and is made of a biocompatible and moderately flexible medical material (such as PTFE or nylon), with a total length of 110 cm-130 cm. The extension catheter is inserted... The length of the catheter inserted into the catheter sheath is 8cm-12cm, for example, 8cm, 9cm, 10cm, 11cm, or 12cm, to achieve a nested fit with the catheter sheath; the inner diameter of the other end of the extension catheter is 1mm-2.5mm, for example, 1mm, 1.3mm, 1.5mm, 1.7mm, 2mm, 2.3mm, or 2.5mm; the other end of the extension catheter is used to pass through the catheter sheath to reach the target location of the middle cerebral artery thrombosis; one end of the extension catheter is fitted with a cylindrical sealing element; the sealing element is disposed within the annular gap; when the other end of the extension catheter reaches the target location of the middle cerebral artery thrombosis and it is necessary to seal the annular gap, one end of the sealing element expands radially and abuts against the head sidewall of the catheter sheath, thereby sealing the annular gap.

[0009] Preferably, the sealing element includes a support section fixedly sleeved on the outer periphery of one end of the extension conduit and an expansion section connected to the support section; the expansion section is located on the side of the support section away from the end of the extension conduit; the expansion angle of the expansion section is 30°-85°, for example 30°, 45°, 50°, 60°, 70°, 85°.

[0010] Preferably, the expansion section includes a sealing membrane integrally formed with the support section and having a cylindrical structure, i.e., the material of the support section is the same as the material of the sealing membrane; the circumferential sidewall of the sealing membrane is provided with an elastic skeleton with a wavy annular structure; the sealing membrane is made of medical silicone or polyurethane film, which is tightly wrapped around the outside of the elastic skeleton, which can significantly enhance the sealing effect on the annular gap and avoid problems such as negative pressure leakage; the thickness of the sealing membrane is 0.05mm-0.1mm, for example 0.05mm, 0.06mm, 0.07mm, 0.08mm, 0.09mm, 0.1mm; when the other end of the extension catheter reaches the target location of the middle cerebral artery thrombosis and it is necessary to seal the annular gap, the elastic skeleton expands and unfolds, and the sealing membrane changes from a cylindrical structure to a trumpet-shaped cylindrical structure, and the outer circumferential side of the sealing membrane abuts against the head sidewall of the catheter sheath, thereby achieving the sealing of the annular gap.

[0011] Preferably, the sealing membrane has a sealing lip coaxially arranged at one end away from the support section; when the sealing membrane is transformed into a trumpet-shaped cylindrical structure, the outer circumferential surface of the sealing lip abuts against the head sidewall of the catheter sheath.

[0012] Preferably, a constraint member is provided around the outer periphery of the seal; the constraint member is used to constrain the shape of the seal so that the expansion section cannot expand radially when the other end of the extension catheter has not reached the target location of the thrombus in the middle cerebral artery and the expansion section has not been released from constraint.

[0013] Preferably, the restraining member is made of medical-grade polyester, which is tightly fitted around one end of the extension catheter and covers the sealing member; the restraining member includes a cylindrical restraining section and a fixing section coaxially arranged with the restraining section; the restraining section and the fixing section are integrally formed; the thickness of the restraining section is 0.1mm-0.2mm, for example 0.1mm, 0.12mm, 0.14mm, 0.16mm, 0.18mm, 0.2mm; the fixing section is fixedly fitted around one end of the extension catheter and cannot be torn; the restraining section... The thickness is the same as that of the fixed section; the constraint section is coaxially disposed on the outer periphery of the expansion section; the circumferential sidewall of the constraint section has at least one preset tear line along the axial direction, that is, the length direction of the preset tear line extends along the axial direction of the constraint section; the thickness of the preset tear line is 0.03mm-0.05mm, for example 0.03mm, 0.04mm, 0.05mm; when the other end of the extension catheter reaches the target location of the middle cerebral artery thrombosis and it is necessary to seal the annular gap, the constraint section is torn along the preset tear line, thereby releasing the constraint on the expansion section.

[0014] Preferably, the constraint member is connected to a driving member; the driving member is used to pull the constraint segment so that the constraint segment is torn along a preset tear line, and after the constraint segment is torn, the expansion segment expands radially.

[0015] Preferably, the driving component includes a support rod inserted into the catheter sheath along its length; a drawing wire made of medical-grade 304 stainless steel is slidably inserted into the support rod along its length; one end of the drawing wire is fixed to the circumferential sidewall of the restraint section; the support rod is made of a medical-grade rigid material (such as medical stainless steel or titanium alloy); the support rod has an axially extending channel inside for accommodating the drawing wire and providing precise guidance for its axial movement; by moving the drawing wire, the restraint section is torn along a preset tear line.

[0016] Preferably, the driving component further includes an operating handle fixed to the tail of the catheter sheath; the operating handle has a receiving groove along its length; a slider is slidably connected in the receiving groove; the other end of the wire slides through the operating handle and is inserted into the receiving groove, and is connected to one side of the slider.

[0017] Preferably, a positioning block is installed in the receiving groove; the positioning block is located on the side of the slider away from the catheter sheath; when the slider approaches the positioning block and is locked in position by the positioning block, the constraint segment is torn along the preset tear line.

[0018] (III) Beneficial Effects Compared with the prior art, the present invention provides a suction device with a sealing structure, which has the following advantages: 1. This invention utilizes an expandable seal at one end of the extension catheter. The seal is designed as a combination of an elastic skeleton with shape memory function and a flexible sealing membrane. By taking advantage of the spontaneous expansion characteristics of the elastic skeleton after the constraint is released, the seal remains in a contracted state during the pushing phase, without increasing additional frictional resistance. After reaching the target position, the expansion section expands and seals the annular gap between the catheter sheath and the extension catheter. This achieves a phased working mode of "small gap to reduce resistance during pushing and zero gap to seal during aspiration." This not only ensures the smooth placement of the extension catheter and avoids frictional damage to the vascular endothelium caused by excessive pushing resistance, but also ensures that the seal actively expands to close the annular gap when the target position is reached and sealing of the annular gap is required. This ensures the leak-free transmission of negative pressure during aspiration and effectively prevents the decrease in aspiration efficiency and thrombus fragmentation and escape caused by the attenuation of negative pressure.

[0019] 2. This invention, by encasing a constraint around the seal, transforms the seal's triggering condition from "passive spatial positioning" to "active and controllable tearing." This allows the operator to autonomously decide the timing of the seal's expansion based on imaging confirmation, avoiding issues such as accidental seal expansion during delivery and ensuring the safe positioning of the extension catheter. Simultaneously, the constraint effectively prevents seal displacement and eccentric deformation, further reducing surgical risks. Furthermore, the constraint employs a pre-designed tear line for directional fracture; once the constraint section is torn, the restraint on the seal completely disappears, allowing the elastic skeleton to expand instantly and ensuring rapid seal response. Additionally, no particles are generated after the constraint section is torn; the tear does not produce fragments, and the entire assembly can be withdrawn along with the extension catheter, avoiding the risk of particle residue.

[0020] 3. This invention integrates the driving component with the catheter sheath and utilizes the guiding effect of the support rod to decouple the movement trajectory of the wire pulling from the pushing path of the extension catheter. This allows the sealing triggering operation to be completed entirely outside the body without interfering with the axial movement freedom of the extension catheter, thus achieving effective control over the tearing of the constraint component. At the same time, since the wire pulls through the channel of the support rod, the support rod not only provides guidance and protection for the wire pulling, preventing the wire from becoming entangled or stuck in tortuous blood vessels, but also provides auxiliary support for the pushing of the extension catheter through its own rigidity.

[0021] 4. Unlike existing technologies, this invention does not require additional steps such as balloon inflation, depressurization, or hydrogel stimulation. The restraints can be torn open and the seals unfolded simply by pulling down the slider, ensuring precise and efficient operation. At the same time, the restraint release operation is more convenient. Compared with existing technologies (balloon sealing, hydrogel sealing), the operation process is simplified and the operation time is shortened. It is especially suitable for emergency surgery of acute ischemic stroke, saving valuable treatment time for patients.

[0022] 5. The sealing element of the present invention adopts a "skeleton + membrane" composite design. The sealing membrane can fit tightly against the inner wall of the catheter sheath, and the elastic skeleton can adapt to annular gaps of different widths. The sealing reliability is better than that of existing hydrogel sealing technology. At the same time, it avoids problems such as low mechanical strength and degradation risk of hydrogel materials. It can be adapted to catheter sheaths of different specifications and has strong clinical applicability.

[0023] 6. The overall structure of this invention is reasonably designed, and all components are made of existing medical-grade materials. It does not require complicated processing technology, is easy to mass-produce, has controllable costs, and has good industrialization prospects. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the overall contracted state of a suction device with a sealing structure according to the present invention.

[0025] Figure 2 for Figure 1 The structural diagram at point A in the diagram.

[0026] Figure 3 This is a schematic diagram of the overall unfolded state of a suction device with a sealing structure according to the present invention.

[0027] Figure 4 for Figure 1 The structural diagram at point B in the diagram.

[0028] Figure 5 This is a schematic diagram of the structure of the seal in the contracted state of the present invention.

[0029] Figure 6 This is a schematic diagram of the structure of the seal of the present invention in its unfolded state.

[0030] Figure 7 This is a schematic diagram of the structure of the constraint member in the contracted state of the present invention.

[0031] Figure 8 This is a structural schematic diagram of the constraint member of the present invention in its unfolded state.

[0032] Figure 9 This is a schematic diagram of the structure of the driving component of the present invention.

[0033] Figure 10 This is a schematic diagram of the positioning block of the present invention.

[0034] In the diagram: 1-Catheter sheath, 2-Extension catheter, 3-Seal, 4-Constraint, 5-Driver, 11-Aspiration channel, 21-Iconizing ring, 31-Support section, 32-Expansion section, 41-Constraint section, 42-Preset tear line, 43-Fixing section, 44-Connecting ear, 51-Bearing rod, 52-Pull wire, 53-Operating handle, 54-Accommodation groove, 55-Slider, 56-Positioning block, 57-Groove, 58-Hook, 59-Graduation line, 321-Sealing membrane, 322-Elastic skeleton, 323-Sealing lip. Detailed Implementation

[0035] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0036] In the description of this invention, it should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0037] In addition, a fixed connection refers to a connection in which parts or components are fixed and there is no relative movement; a transmission connection refers to a connection in which mechanical motion or torque is transmitted to other working parts through a transmission component; a sliding connection refers to a connection in which two objects are in contact but not fixed and can slide relative to each other; and a rotational connection refers to a connection in which two objects are in contact but not fixed and can rotate relative to each other.

[0038] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0039] Example 1: This embodiment provides a suction device with a sealing structure, which has the following technical features.

[0040] Please see Figures 1-4As shown, this embodiment provides a suction device with a sealed structure, including a catheter sheath 1 and an extension catheter 2. The catheter sheath 1 is made of medical-grade PTFE, with a length of 100cm and an inner diameter of 2.5mm. The head of the catheter sheath 1 has good flexibility and a length of 5cm, which can effectively reduce stimulation and damage to nerves and blood vessels. The tail end of the catheter sheath 1 is connected to a suction channel 11. The outlet end of the suction channel 11 is connected to a conventional negative pressure suction machine in the art. The extension catheter 2 is made of medical-grade PTFE material and has a length of 120cm. The outer wall of one end of the extension catheter 2 is roughened to enhance the connection strength with subsequent parts. The inner diameter of the other end of the extension catheter 2 is 1.7mm (±0.1mm), and the outer diameter is 1.8mm. The outer wall of the other end of the extension catheter 2 is provided with... The catheter has a polyethylene glycol hydrophilic coating, which can further reduce friction during the delivery process and improve the positioning accuracy. A pair of imaging rings 21 are fixedly sleeved side by side on the outer periphery of the other end of the extension catheter 2, and the imaging rings 21 are conventional platinum-iridium alloy imaging rings in the art. The catheter sheath 1 and the extension catheter 2 are nested together to provide a stable delivery channel and support for the extension catheter 2, and an annular gap with a width of 0.35 mm is formed between the side wall of one end of the extension catheter 2 and the head side wall of the catheter sheath 1. A cylindrical sealing element 3 is sleeved on one end of the extension catheter 2. The sealing element 3 is set in the annular gap. When the other end of the extension catheter 2 reaches the target location of the middle cerebral artery thrombosis and it is necessary to seal the annular gap, one end of the sealing element 3 expands radially and abuts against the head side wall of the catheter sheath 1 to achieve the sealing of the annular gap.

[0041] Specifically, such as Figure 2 and Figures 4-6 As shown, the sealing element 3 includes a support section 31 sleeved on the outer periphery of one end of the extension catheter 2 and an expansion section 32 connected to the support section 31; the support section 31 is connected to the outer wall of one end of the extension catheter 2 via medical cyanoacrylate; the expansion section 32 is located on the side of the support section 31 away from the end of the extension catheter 2; the expansion angle of the expansion section 32 is 50°; the expansion section 32 includes a sealing membrane 321 integrally formed with the support section 31 and having a cylindrical structure, that is, the support section 31 and the sealing membrane 321 are made of the same material; the circumferential sidewall of the sealing membrane 321 is provided with a wavy annular elastic structure. The elastic skeleton 322 is made of nickel-titanium alloy and other materials. Its outer diameter is 3 mm when expanded in its natural state and 1.8 mm when compressed. The sealing membrane 321 is made of medical silicone film with a thickness of 0.08 mm, which is tightly wrapped around the outside of the elastic skeleton 322. When the other end of the extension catheter 2 reaches the target location of the thrombus in the middle cerebral artery, the elastic skeleton 322 expands and unfolds, and the sealing membrane 321 changes from a cylindrical structure to a trumpet-shaped cylindrical structure. The outer circumferential surface of the sealing membrane 321 abuts against the head side wall of the catheter sheath 1, thereby sealing the annular gap.

[0042] Working principle: When the extension catheter 2 is not in place, the sealing element 3 is a compressed cylindrical structure with an outer diameter smaller than the inner diameter of the catheter sheath 1. This ensures that only a very small sliding gap remains between the extension catheter 2 and the catheter sheath 1 during the pushing process, allowing the extension catheter 2 to smoothly pass through the multiple bends of intracranial and extracranial blood vessels with low pushing resistance and successfully reach the target location of the middle cerebral artery thrombosis. When the other end of the extension catheter 2 is confirmed to have reached the target location and needs to seal the annular gap with the assistance of the imaging ring 21, the elastic skeleton 322 recovers due to its own superelasticity. The force causes the sealing membrane 321 to expand and unfold, transforming it from a cylindrical shape to a trumpet-shaped cylindrical structure. The outer circumference of the sealing membrane 321 abuts against the head side wall of the catheter sheath 1, thus sealing the annular gap. Then, the negative pressure suction machine is activated, and the thrombus is extracted through the internal cavity of the extension catheter 2, the internal cavity of the catheter sheath 1, and the suction channel 11. Since the annular gap has been reliably sealed by the sealing element 3, the negative pressure will not leak through the annular gap, and the blood cannot flow back from the annular gap, thereby ensuring the complete transmission of the suction negative pressure and the efficiency of thrombus suction.

[0043] It should be emphasized that the core improvement of this embodiment lies in the following: by fitting an expandable sealing element 3 at one end of the extension catheter 2, the sealing element 3 is designed as a combination of an elastic skeleton 322 with shape memory function and a flexible sealing membrane 321. Utilizing the spontaneous expansion characteristics of the elastic skeleton 322 after the constraint is released, the sealing element 3 remains in a contracted state during the pushing phase, without increasing additional frictional resistance. When the target position is reached and the annular gap needs to be sealed, the expansion section 32 expands and seals the annular gap between the catheter sheath 1 and the extension catheter 2, realizing a phased working mode of "small gap to reduce resistance during pushing and zero gap to seal during aspiration". This not only ensures the smooth placement of the extension catheter 2 and avoids frictional damage to the vascular endothelium caused by excessive pushing resistance, but also ensures that the sealing element 3 actively expands and closes the annular gap when the target position is reached and the annular gap needs to be sealed, thus preventing the leakage transmission of aspiration negative pressure and effectively preventing the decrease in aspiration efficiency and thrombus fragmentation and escape caused by negative pressure attenuation.

[0044] In this example, such as Figures 5-6 As shown, to further enhance the sealing effect between the sealing membrane 321 and the head sidewall of the catheter sheath 1, and to prevent leakage due to insufficient contact pressure or local gaps, the sealing membrane 321 has a coaxially arranged sealing lip 323 at one end away from the support section 31. When the sealing membrane 321 is transformed into a trumpet-shaped cylindrical structure, the outer circumferential surface of the sealing lip 323 abuts against the head sidewall of the catheter sheath 1. This further improves the reliability of the seal.

[0045] Example 2: In addition to the technical solutions of the above embodiments, this embodiment also has the following technical features.

[0046] It is understandable that in Embodiment 1, the expansion section 32 of the seal 3 is in a naturally expanded state when not constrained by external force. However, during the entire pushing process of the extension catheter 2, if the seal 3 expands prematurely due to accidental contact with the inner wall of the catheter sheath or blood flow impact before reaching the target position, it will cause additional friction between the seal 3 and the catheter sheath 1, hindering the smooth advancement of the extension catheter 2 and affecting the ability of the extension catheter 2 to reach its destination.

[0047] To solve the above problems, such as Figure 2 and Figure 4 As shown, a constraint member 4 is provided around the outer periphery of the sealing member 3; the constraint member 4 is made of medical polyester material with a thickness of 0.15 mm; the constraint member 4 is used to constrain the shape of the sealing member 3 so that the expansion section 32 cannot expand radially when the other end of the extension catheter 2 does not reach the target location of the thrombus in the middle cerebral artery.

[0048] Specifically, such as Figures 7-8 As shown, the constraint member 4 includes a cylindrical constraint section 41 and a fixed section 43 coaxially arranged with the constraint section 41; the constraint section 41 and the fixed section 43 are integrally formed; the fixed section 43 is sleeved on the outer periphery of one end of the extension catheter 2; the fixed section 43 is bonded to the outer wall of one end of the extension catheter 2 by medical cyanoacrylate; the constraint section 41 is coaxially arranged on the outer periphery of the expansion section 32; a pair of preset tear lines 42 with a thickness of 0.04 mm are opened side by side along the axial direction on the circumferential sidewall of the constraint section 41, and the distance between the two preset tear lines 42 is one-third of the radius of the constraint section 41; when the other end of the extension catheter 2 reaches the target location of the thrombus in the middle cerebral artery and it is necessary to seal the annular gap, the constraint section 41 is torn along the preset tear lines 42, thereby releasing the constraint on the expansion section 32.

[0049] Working principle: By fitting a constraint member 4 around the outer periphery of the sealing member 3, during the pushing phase, the constraint section 41 applies a radial constraint to the expansion section 32, inhibiting the radial expansion of the elastic skeleton 322, preventing the expansion section 32 from expanding radially and keeping it in a compressed state. When the extension catheter 2 is in place and the annular gap needs to be sealed, a preset tension is applied to the constraint section 41, causing the constraint section 41 to be torn along the preset tear line 42, thereby releasing the constraint on the expansion section 32. The elastic skeleton 322 then expands and unfolds, causing the outer circumferential surface of the sealing lip 323 to abut against the head sidewall of the catheter sheath 1, thus sealing the annular gap.

[0050] It should be emphasized that the core improvement of this embodiment lies in the following: by attaching a constraint member 4 around the outer periphery of the seal member 3, the triggering condition of the seal member 3 is upgraded from "passive spatial positioning" to "active and controllable tearing". This allows the operator to make a decision on the timing of the expansion of the seal member 3 based on imaging confirmation, avoiding problems such as accidental expansion of the seal member 3 during the push and ensuring the safety of the extension catheter 2 in place. At the same time, the constraint member 4 can effectively prevent the seal member 3 from shifting or deforming eccentrically, further reducing surgical risks. Moreover, the constraint member 4 adopts a directional fracture design with a preset tear line 42. After the constraint section 41 is torn open, the restraint on the seal member 3 is completely eliminated, and the elastic skeleton 322 can expand instantly, ensuring the rapid response of the seal member 3. In addition, after the constraint section 41 is torn open, no particles are generated, and no fragments are produced when torn open. The whole can be withdrawn together with the extension catheter, avoiding the risk of particle residue.

[0051] It should be noted that, in order to further reduce the frictional resistance between the restraint segment 41 and the inner wall of the catheter sheath 1 during the pushing process and reduce the impact on pushing performance, the outer wall of the restraint segment 41 is provided with a conventional low-friction coating in the art. The low-friction coating forms a lubrication interface between the restraint segment 41 and the inner wall of the catheter sheath 1, which significantly reduces the coefficient of friction between the restraint segment 41 and the catheter sheath 1 as the extension catheter 2 slides along the inner lumen of the catheter sheath 1, further reducing the pushing resistance and thus improving the passage performance of the extension catheter 2 in tortuous blood vessels.

[0052] Example 3: In addition to the technical solutions of the above embodiments, this embodiment also has the following technical features.

[0053] It is understandable that, in Embodiment 2, although the preset tear line 42 of the constraint member 4 is designed with a weakened area, how to apply the required tensile force for tearing accurately and effortlessly from a distance outside the catheter sheath 1, while avoiding accidental contact or premature tearing during the pushing process, is a problem that needs to be solved.

[0054] To solve the above problems, such as Figures 1-4 As shown, the constraint member 4 is connected to the driving member 5; the driving member 5 is used to pull the constraint segment 41 so that the constraint segment 41 is torn along the preset tear line 42, and after the constraint segment 41 is torn, the expansion segment 32 expands radially.

[0055] Specifically, such as Figure 2 , Figure 4 and Figure 9As shown, the circumferential sidewall of the constraint section 41 is integrally formed with a connecting ear 44; the connecting ear 44 is disposed between two preset tear lines 42, and the distance between the connecting ear 44 and any one of the preset tear lines 42 is less than the distance between the two preset tear lines 42; the driving component 5 includes a support rod 51 inserted into the catheter sheath 1 along the length direction of the catheter sheath 1 and an operating handle 53 fixed to the tail of the catheter sheath 1; a drawing wire 52 made of medical-grade 304 stainless steel fine wire is slidably inserted into the support rod 51 along the length direction; one end of the drawing wire 52 is bonded to the connecting ear 44; the support rod 51 is made of medical stainless steel; The inner side of the support rod 51 has a through channel along the axial direction to accommodate the wire 52 and provide precise guidance for its axial movement, and the gap between the wire 52 and the channel is 0.05mm; the operating handle 53 has a receiving groove 54 along the length direction; a slider 55 is slidably connected in the receiving groove 54, and one end of the slider 55 extends out of the receiving groove 54 and is located outside the operating handle 53; the other end of the wire 52 slides through the operating handle 53 and is inserted into the receiving groove 54, and is connected to one side of the slider 55; by moving the slider 55, the wire 52 is pulled, so that the constraint section 41 is torn along the preset tear line 42.

[0056] Working principle: When the other end of the extension catheter 2 is confirmed to have reached the target location of the thrombus in the middle cerebral artery with the assistance of the imaging ring 21 and the annular gap needs to be sealed, the operator manually moves the slider 55. The slider 55 drives the pull wire 52 connected to it to move synchronously. The pull wire 52 slides in the channel of the support rod 51, transmitting the tension at its distal end to the end fixed to the connecting ear 44 of the constraint section 41. This tension causes the part of the constraint section 41 located between the two preset tear lines 42 to be subjected to tensile force, causing the preset tear lines 42 to be torn axially. The constraint section 41 splits into two halves, releasing the radial constraint on the expansion section 32. The elastic skeleton 322 of the expansion section 32 immediately expands radially after losing its constraint, causing the sealing membrane 321 to change from a cylindrical structure to a trumpet-shaped cylindrical structure. The outer circumferential surface of the sealing lip 323 abuts against the head side wall of the catheter sheath 1, completing the sealing of the annular gap.

[0057] It should be emphasized that the core improvement of this embodiment lies in the following: by integrating the drive component 5 with the catheter sheath 1, the movement trajectory of the pull wire 52 is decoupled from the pushing path of the extension catheter 2 by utilizing the guiding effect of the support rod 51. This allows the sealing triggering operation to be completed entirely outside the body without interfering with the axial movement freedom of the extension catheter 2, thus achieving effective control over the tearing of the constraint component 4. At the same time, since the pull wire 52 passes through the channel of the support rod 51, the support rod 51 not only provides guidance and protection for the pull wire 52, preventing the pull wire 52 from getting tangled or stuck in tortuous blood vessels, but also provides auxiliary support for the pushing of the extension catheter 2 through its own rigidity.

[0058] It should be noted that, in order to ensure that the constraint segment 41 can be reliably torn open when subjected to the pulling force of the driving member 5, and will not be torn open due to accidental force during normal pushing and bending, the fracture strength of the constraint segment 41 is preset to 5N-7N, which is greater than the expansion tension of the seal 3 (3N-4N) and less than the pulling force of the driving member 5 on the constraint member 4 (8N-10N). Since the fracture strength (5N-7N) is greater than the expansion tension (3N-4N), the expansion force of the elastic skeleton 322 is insufficient to cause the constraint segment 41 to tear on its own when not pulled by the wire 52, thus ensuring the reliability of the constraint segment 41 during the pushing process. At the same time, since the fracture strength (5N-7N) is less than the pulling force of the driving member 5 (8N-10N), when the operator pulls the slider 55, the pulling force applied by the wire 52 to the connecting ear 44 is sufficient to overcome the fracture strength of the constraint segment 41, ensuring that the preset tear line 42 can be reliably torn open, providing a quantitative guarantee for the reliable constraint and controllable unfolding of the seal 3.

[0059] It should be noted that the support rod 51 adopts a segmented structural design, namely a rigid body and a flexible transition section, which gives it both rigidity and flexibility. The rigid body is connected to the operating handle 53, which can ensure the accurate transmission of pushing force during pushing and avoid bending deformation. The flexible transition section is located near one end of the extension catheter 2 and is processed with a spiral or grid-like hollow structure using laser cutting technology, which can achieve 0-90° bending, accurately adapt to the tortuous direction of nerves and blood vessels, and avoid damage to the blood vessel wall.

[0060] In this embodiment, as Figure 9 As shown, in order to lock the slider 55 in place after it is pulled to prevent the wire 52 from springing back, a positioning block 56 is installed in the receiving groove 54, and one end of the positioning block 56 extends out of the receiving groove 54 and is located outside the operating handle 53; the positioning block 56 is located on the side of the slider 55 away from the catheter sheath 1; when the slider 55 approaches the positioning block 56 and is locked in place by the positioning block 56, the constraint section 41 is torn along the preset tear line 42. Due to the locking effect of the positioning block 56 on the slider 55, the wire 52 is held in the position after being pulled, the constraint section 41 remains in the torn state, and the seal 3 remains in the expanded state, so that the sealing effect can be maintained without the operator applying continuous force, thus improving reliability.

[0061] Specifically, such as Figures 9-10As shown, in order to achieve unlockable locking of the positioning block 56 onto the slider 55, facilitating postoperative unlocking and removal, a groove 57 is provided on the end face of the other end of the slider 55; a hook 58 corresponding to the groove 57 is integrally formed on the surface of the positioning block 56 near the slider 55; when the slider 55 and the opposite side of the positioning block 56 are in contact, the hook 58 engages in the groove 57, thereby locking the slider 55 in position; in addition, an elastic part with a frame-like structure is integrally formed on the end face of the other end of the positioning block 56; a through hole is provided on one edge of the elastic part away from the slider 55; a protrusion is integrally formed on the surface of the receiving groove 54 near the elastic part; the protrusion is fitted into the through hole with a clearance, and a limiting head is integrally formed on one end of the protrusion located inside the elastic part; the limiting head is used to constrain the position of the elastic part to prevent the protrusion from disengaging from the through hole. When unlocking is required after surgery, the operator presses the positioning block 56 to disengage the hook 58 from the groove 57, allowing the slider 55 to slide freely back to its original position. This ensures reliable maintenance of the sealed unfolded state and facilitates postoperative removal. After the hook 58 disengages from the groove 57, it resets under the elastic force of the elastic part, ensuring the effectiveness of the positioning block 56.

[0062] In this embodiment, as Figure 9 As shown, to provide the operator with a visual reference for the movement distance of the slider 55 and to facilitate the determination of whether the constraint section 41 has been completely torn apart, a scale line 59 is provided along the length direction on the outer surface of the operating handle 53; the accuracy of the scale line 59 is 0.5mm, used to indicate the movement distance of the slider 55. During the pushing of the slider 55, the operator can observe the position of the slider 55 relative to the scale line 59 to determine whether the pulling distance of the wire pull 52 has reached the preset value, thereby assisting in determining whether the constraint section 41 has been completely torn apart. This avoids the constraint section 41 not being completely torn apart due to insufficient pulling distance, which would affect the reliability of the seal 3 unfolding.

[0063] The entire working process of a suction device with a sealing structure specifically includes: 1) Preoperative preparation: First, select a suitable catheter sheath 1, and then put the sealing element 3 on the outer periphery of one end of the extension catheter 2; second, use medical cyanoacrylate to bond the support section 31 to the outer periphery of one end of the extension catheter 2, then compress the expansion section 32, and put the restraint element 4 on the outer periphery of one end of the extension catheter 2 so that the restraint section 41 covers the expansion section 32, and then bond the fixing section 43 to the outer wall of one end of the extension catheter 2 using medical cyanoacrylate; third, bond one end of the pull wire 52 to the connecting ear 44, and insert the pull wire 52 into the support rod 51; then, nest the extension catheter 2 in the catheter sheath 1, and fix the other end of the pull wire 52 to the slider 55; finally, connect the suction channel 11 to the negative pressure suction machine and check the sealing performance; 2) Pushing to the target location: Push the other end of the extension catheter 2 through the catheter sheath 1 to the target location of the thrombus in the middle cerebral artery, and observe the position of the imaging ring 21 by DSA imaging. Stop pushing after confirming that it is in place; 3) Sealing and unfolding: When it is necessary to seal the annular gap, manually move the slider 55 to drive the wire 52 to pull the connecting ear 44. The slider 55 moves closer to the positioning block 56 and is locked in position by the positioning block 56. The constraint section 41 is torn along the preset tear line 42, and the expansion section 32 expands radially. The outer circumferential surface of the sealing lip 323 abuts against the head side wall of the catheter sheath 1 to complete the sealing of the annular gap. 4) Thrombus aspiration: Start the negative pressure aspiration machine and set the aspiration negative pressure to -20kPa. The thrombus is drawn out through the inside of the extension catheter 2, the inner lumen of the catheter sheath 1, and the aspiration channel 11. Because the sealing element 3 reliably seals the annular gap between the catheter sheath 1 and the extension catheter 2, there is no leakage of negative pressure, and the aspiration efficiency is greatly improved, which can quickly and thoroughly remove the thrombus. At the same time, during the thrombus aspiration process, the sealing element 3 can adaptively adjust the fit according to the changes in negative pressure to ensure the reliability of the seal. 5) Postoperative withdrawal: After thrombus aspiration is completed, press the positioning block 56 to unlock the slider 55, and gently push the slider 55 back to pull the wire 52 back. Then, withdraw the extension catheter 2 and catheter sheath 1 from the blood vessel to complete the operation.

[0064] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0065] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A suction device with a sealing structure, characterized in that, Including a nested catheter sheath (1) and an extension catheter (2); An annular gap is formed between the side wall of one end of the extension catheter (2) and the head side wall of the catheter sheath (1); a cylindrical sealing element (3) is sleeved on one end of the extension catheter (2); the sealing element (3) is disposed in the annular gap; when it is necessary to seal the annular gap, one end of the sealing element (3) expands radially and abuts against the head side wall of the catheter sheath (1) to seal the annular gap.

2. The suction device with a sealing structure according to claim 1, characterized in that, The sealing element (3) includes a support section (31) fixedly sleeved on the outer periphery of one end of the extension conduit (2) and an expansion section (32) connected to the support section (31); the expansion section (32) is located on the side of the support section (31) away from the end of the extension conduit (2).

3. A suction device with a sealing structure according to claim 2, characterized in that, The expansion section (32) includes a sealing membrane (321) that is coaxially connected to the support section (31) and has a cylindrical structure; the circumferential sidewall of the sealing membrane (321) is provided with an elastic skeleton (322) with a wave-shaped annular structure; when it is necessary to seal the annular gap, the elastic skeleton (322) expands and unfolds, and the sealing membrane (321) changes from a cylindrical structure to a trumpet-shaped cylindrical structure, and the outer circumferential side of the sealing membrane (321) abuts against the head sidewall of the catheter sheath (1), thereby sealing the annular gap.

4. A suction device with a sealing structure according to claim 3, characterized in that, The sealing membrane (321) has a sealing lip (323) coaxially arranged at one end away from the support section (31); when the sealing membrane (321) is transformed into a trumpet-shaped cylindrical structure, the outer circumferential surface of the sealing lip (323) abuts against the head side wall of the catheter sheath (1).

5. A suction device with a sealing structure according to claim 2, characterized in that, The outer periphery of the seal (3) is fitted with a constraint member (4); the constraint member (4) is used to constrain the shape of the seal (3) so that the expansion section (32) cannot expand radially when the constraint is not released.

6. A suction device with a sealing structure according to claim 5, characterized in that, The constraint member (4) includes a constraint section (41) with a cylindrical structure; the constraint section (41) is coaxially disposed on the outer periphery of the expansion section (32); the circumferential sidewall of the constraint section (41) has at least one preset tear line (42) along the axial direction; when it is necessary to seal the annular gap, the constraint section (41) is torn along the preset tear line (42) to release the constraint on the expansion section (32).

7. A suction device with a sealing structure according to claim 6, characterized in that, The constraint member (4) is connected to a drive member (5); the drive member (5) is used to pull the constraint segment (41) so that the constraint segment (41) is torn along a preset tear line (42), and after the constraint segment (41) is torn, the expansion segment (32) expands radially.

8. A suction device with a sealing structure according to claim 7, characterized in that, The driving component (5) includes a support rod (51) inserted into the catheter sheath (1) along the length direction of the catheter sheath (1); a pull wire (52) is slidably inserted into the support rod (51) along the length direction; one end of the pull wire (52) is fixed to the circumferential side wall of the constraint section (41); by moving the pull wire (52), the constraint section (41) is torn along the preset tear line (42).

9. A suction device with a sealing structure according to claim 8, characterized in that, The drive unit (5) also includes an operating handle (53) fixed to the tail of the catheter sheath (1); a receiving groove (54) is provided on the operating handle (53) along the length direction; a slider (55) is slidably connected in the receiving groove (54); the other end of the wire (52) slides through the operating handle (53) and is inserted into the receiving groove (54), and is connected to one side of the slider (55).

10. A suction device with a sealing structure according to claim 9, characterized in that, The receiving groove (54) is equipped with a positioning block (56); the positioning block (56) is located on the side of the slider (55) away from the catheter sheath (1); when the slider (55) approaches the positioning block (56) and is locked in position by the positioning block (56), the constraint segment (41) is torn along the preset tear line (42).

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