A retrieval system and method for a vena cava filter

Abstract

The application relates to the technical field of medical devices, and discloses a recovery system and a recovery method for a vena cava filter, the recovery system comprising a vena cava filter and a recovery device, the recovery device comprising a guide device, a snare, a recovery sheath and a guide wire; the guide device comprises a connecting rod and a guide fixing claw, a central cavity capable of accommodating the guide wire is arranged in the connecting rod, a recovery groove is formed in the outer side of one end of the connecting rod, the guide fixing claw is arranged at one end of the connecting rod close to the recovery groove, the guide device is connected with the filter rod of the vena cava filter through the guide fixing claw and is used for adjusting the position of the vena cava filter; the recovery sheath can accommodate the snare, the guide device and the vena cava filter; the guide fixing claw of the guide device can pass through the recovery sheath and enter the blood vessel; the snare is used for capturing the filter recovery hook of the vena cava filter and recovering the vena cava filter into the recovery sheath. The position of the vena cava filter in the blood vessel is adjusted through the guide device, and the recovery is further facilitated.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of medical devices, in particular to a retrieval system and retrieval method of a vena cava filter. BACKGROUND

[0002] Pulmonary embolism (PE) is a common clinical disease with high morbidity and mortality, including deep vein thrombosis (DVT) and pulmonary embolism (PE). DVT often occurs in the lower limb veins, and PE is mainly caused by the embolization of thrombus in the venous system or right heart into the pulmonary artery, which is the main cause of morbidity and mortality. As an implant, the vena cava filter has been proven to be a safe and effective means to prevent pulmonary embolism and can reduce the incidence of pulmonary embolism. With the improvement of interventional medicine, the vena cava filter technology is becoming more and more mature. Currently, the preferred vena cava filter is a temporary filter, which is retrieved within the retrieval time window, so as to achieve the ultimate goal of no implantation.

[0003] Different types of filters have different implantation time windows (retrieval cycle). Umbrella-shaped vena cava filters have a longer retrieval time window and are more concerned. Currently, the umbrella-shaped vena cava filter usually includes a filter retrieval hook and filter struts uniformly distributed along the circumference of the filter retrieval hook. After the vena cava filter is implanted in the blood vessel, it is easy to tilt, and the filter retrieval hook is attached to the blood vessel wall. At this time, it is difficult to directly use a snare to capture the filter retrieval hook, and thus it is difficult to retrieve the vena cava filter.

[0004] Therefore, developing a retrieval system for a vena cava filter can solve the technical problem of retrieval difficulty caused by the adhesion of the vena cava filter or similar mechanical devices, which has become an important topic to be solved at present. SUMMARY

[0005] In order to solve the technical problem that the vena cava filter is easy to tilt in the blood vessel, causing the filter retrieval hook to adhere to the wall and leading to retrieval difficulty, the present application provides a retrieval system and retrieval method for a vena cava filter.

[0006] The present application provides a retrieval system for a vena cava filter, comprising a vena cava filter and a retrieval device, wherein the retrieval device comprises a guide device, a snare, a retrieval sheath and a guide wire.

[0007] The guide device comprises a connecting rod and a guide fixed claw, the connecting rod is provided with a central cavity capable of accommodating a guide wire, the outer side of one end of the connecting rod is provided with a retrieval groove, the guide fixed claw is arranged at one end of the connecting rod close to the retrieval groove, and the guide device is connected with the filter strut of the vena cava filter through the guide fixed claw, so as to adjust the position of the vena cava filter.

[0008] The retrieval sheath can accommodate the snare, the guide device, and the vena cava filter, the guide fixing claw of the guide device can pass through the retrieval sheath into the blood vessel;

[0009] The snare is used for catching the filter retrieval hook of the vena cava filter and retrieving the vena cava filter into the retrieval sheath.

[0010] Through the above technical solution, in the retrieval process of the vena cava filter, the guide fixing claw of the guide device can pass through the retrieval sheath into the blood vessel and reach under the vena cava filter, the guide fixing claw is opened by retracting the retrieval sheath, and is clamped with the filter strut of the vena cava filter, then, by the cooperation of the guide fixing claw and the filter strut, the guide device can further adjust the position of the vena cava filter, ensure that the filter retrieval hook is fully returned into the blood vessel cavity, so as to facilitate the subsequent catching of the filter retrieval hook by the snare, and lay a solid foundation for the subsequent safe and efficient completion of the whole retrieval of the vena cava filter.

[0011] On the other hand, the guide wire guide ensures that the retrieval sheath, the snare and the guide device enter along the same path, and only the upper limb approach is needed to independently complete the operation, thereby reducing the risk of complications at the puncture point.

[0012] Further, the retrieval sheath comprises a retrieval sheath tube and a control valve seat connected with the retrieval sheath tube, and the guide device and the snare pass through the control valve seat into the retrieval sheath tube.

[0013] Through the above technical solution, the control valve seat is connected with the retrieval sheath tube, can serve as a handle to control the operation of the retrieval sheath tube, realizes the advancement and retraction of the retrieval sheath tube, and the guide device and the snare can both pass through the control valve seat into the retrieval sheath tube, thereby ensuring coaxial advancement and reducing the injury caused by the scraping of the blood vessel wall.

[0014] Further, the snare comprises a twist controller, a catheter, a support rod and a catching ring, the catheter is slidingly arranged outside the support rod, one end of the support rod is connected with the twist controller, and the other end is connected with the catching ring, and the twist controller controls the rotation, advancement or retraction of the support rod.

[0015] Through the above technical solution, the snare precisely controls the rotation, advancement or retraction of the support rod through the twist controller, so that the catching ring connected therewith can realize high-precision positioning and angle adjustment in the blood vessel, significantly improves the operation accuracy and success rate of catching the filter, and finally realizes safe, efficient and small-trauma filter retrieval effect.

[0016] Further, the opening angle range of the guide fixing claw is 90-120 degrees, and the guide fixing claw comprises a plurality of guide struts uniformly distributed along the circumference.

[0017] Through the technical scheme, the multiple circumferentially uniformly distributed guide ribs form a ring-shaped clamping structure after being spread, can be self-adaptively clamped with filter rib bars in opposite directions, the force of the contact point between the guide fixing claw and the filter rib bar is uniformly distributed, the position of the vena cava filter can be accurately adjusted, and the filter recovery hook can be returned to the blood vessel cavity.

[0018] Further, the ends of the multiple circumferentially uniformly distributed guide ribs are bent towards the center of the guide fixing claw.

[0019] Through the technical scheme, the design that the ends of the guide ribs are bent towards the center further avoids damage to the blood vessel wall by the guide ribs and improves the efficiency of vena cava filter recovery.

[0020] Further, the snare further comprises a guide sheath capable of accommodating the catheter, the support rod and the catching ring.

[0021] Through the technical scheme, the catheter, the support rod and the catching ring of the snare can pass through the guide sheath, and the guide sheath further assists the snare to enter the recovery sheath, thereby ensuring efficient delivery of the catching ring.

[0022] Further, the guide fixing claw and the catching ring are made of a nickel-titanium alloy material.

[0023] Through the technical scheme, since the nickel-titanium alloy has good flexibility and shape memory function, the guide claw and the catching ring are compressed and deformed in the recovery sheath, and automatically recover to the preset shape after leaving the recovery sheath, thereby facilitating further catching of the vena cava filter.

[0024] Further, the control valve seat is provided with a luer joint for connecting with an external syringe.

[0025] Through the technical scheme, the external syringe is connected with the control valve seat through the luer joint, on one hand, the external syringe can be used to flush the guide wire and the recovery sheath tube before the operation, to prevent thrombosis and improve the safety of the operation; on the other hand, the external syringe can be used to inject contrast agent during the operation, to monitor the position of the vena cava filter in real time by fluorescence, and improve the recovery efficiency of the vena cava filter.

[0026] The application further provides a recovery method of a recovery system based on the vena cava filter.

[0027] Step one: the recovery sheath enters the blood vessel along the guide wire, and one end of the recovery sheath tube reaches under the filter rib bar of the vena cava filter;

[0028] Step two: the guide device passes through the recovery sheath along the guide wire, after the guide fixed jaw reaches under the filter bar of the vena cava filter, the control valve seat releases the guide fixed jaw by retracting the recovery sheath tube, and the guide bar of the guide fixed jaw is opened;

[0029] Step three: after adjusting the position of the guide fixed jaw, the guide device is pulled backward, after the guide fixed jaw is clamped with the filter bar of the vena cava filter, the position of the vena cava filter is adjusted, so that the filter recovery hook of the vena cava filter returns to the blood vessel cavity;

[0030] Step four: the snare passes through the control valve seat into the recovery sheath tube, and the support rod is controlled by the twist controller to introduce the capture ring to the direction of the filter recovery hook, after the capture ring captures the filter recovery hook, the vena cava filter is transported into the recovery sheath tube;

[0031] Step five: keep the recovery sheath still, the guide device, snare and vena cava filter are pulled out of the human body, and then the recovery sheath and guide wire are pulled out of the human body, so that the vena cava filter is recovered.

[0032] Through the above technical solution, the guide fixed jaw of the guide device is clamped with the filter bar of the vena cava filter, so that the position of the vena cava filter is adjusted, the filter recovery hook of the vena cava filter returns to the blood vessel cavity, and then the snare captures the vena cava filter, so that the vena cava filter is recovered, the whole process is orderly, the recovery of the vena cava filter can be efficiently and safely completed, and the technical problem that the vena cava filter is difficult to recover due to being attached to the blood vessel wall is effectively solved.

[0033] Further, if the vena cava filter still cannot be moved through the operation method in step three, that is, the snare still cannot capture the filter recovery hook, after the guide fixed jaw is clamped with the filter bar of the vena cava filter, the capture ring of the snare passes through the recovery sheath tube to reach under the vena cava filter, the capture ring captures the recovery groove, and the snare locks the capture ring on the recovery groove by pushing the catheter, the guide device and the snare move the position of the vena cava filter at the same time, so that the filter recovery hook returns to the blood vessel cavity.

[0034] Through the above technical solution, the guide device and the snare can jointly adjust the position of the vena cava filter in the blood vessel, and can adapt to the situation that the vena cava filter is too inclined or the inside of the blood vessel is relatively complex.

[0035] In summary, the recovery system and recovery method of the vena cava filter provided by the application at least have the following beneficial effects:

[0036] 1. In the recovery process of the vena cava filter, the guide fixing claw of the guide device can pass through the recovery sheath into the blood vessel and reach under the vena cava filter, and the guide fixing claw is expanded and clamped with the filter rod of the vena cava filter by retracting the recovery sheath, then the guide device cooperates with the filter rod through the guide fixing claw to further adjust the position of the vena cava filter, or the guide device cooperates with the snare to make the filter recovery hook which is inclined and attached to the blood vessel wall return to the blood vessel cavity, thereby facilitating the subsequent capture of the filter recovery hook by the snare, laying a solid foundation for the subsequent safe and efficient completion of the whole recovery of the vena cava filter, and solving the technical problem of the difficulty in recovery caused by the attachment of the vena cava filter to the blood vessel wall.

[0037] 1. The guide wire guide can ensure that the recovery sheath, the snare and the guide device enter along the same path, and only the upper limb approach is needed to independently complete the operation, thereby reducing the risk of complications at the puncture point.

[0038] 2. The recovery sheath can accommodate the snare, the guide device and the vena cava filter, thereby providing space and channels for the operation of each component in the blood vessel, achieving smooth recovery of the vena cava filter, and further reducing the damage to the blood vessel wall.

[0039] 3. The external injector is connected with the control valve seat through a luer joint, on the one hand, the external injector can be used to flush the guide wire and the recovery sheath tube before the operation to prevent thrombosis and improve the safety of the operation, and on the other hand, the external injector can be used to inject contrast medium during the operation to monitor the position of the vena cava filter in real time and improve the recovery efficiency of the vena cava filter. BRIEF DESCRIPTION OF DRAWINGS

[0040] Figure 1 is a working schematic diagram of the recovery system of the vena cava filter provided by the application in the blood vessel;

[0041] Figure 2 is a structural schematic diagram of the existing vena cava filter;

[0042] Figure 3 is a structural schematic diagram of the guide device of the recovery system of the vena cava filter provided by the application;

[0043] Figure 4 is an enlarged view of the guide fixing claw of the recovery system of the vena cava filter provided by the application;

[0044] Figure 5 is a structural schematic diagram of the recovery sheath of the recovery system of the vena cava filter provided by the application;

[0045] Figure 6 is a working schematic diagram of the guide device of the recovery system of the vena cava filter provided by the application;

[0046] Figure 7Structure diagram of snare of the retrieval system of vena cava filter provided by the present application; Figure 8 Working diagram of snare of the retrieval system of vena cava filter provided by the present application;

[0047] Figure 9 Working diagram of the cooperation of guide device and snare of the retrieval system of vena cava filter provided by the present application.

[0048] Explanation of reference signs:

[0049] 1. Vena cava filter; 11, filter retrieval hook; 12, filter strut;

[0050] 20, guide device; 21, guide fixed claw; 22, rod body; 23, rod seat; 24, retrieval groove; 211, guide strut;

[0051] 30, retrieval sheath; 31, retrieval sheath tube; 32, control valve seat; 321, three-way valve; 3211, first luer joint; 3212, second luer joint; 3213, control knob;

[0052] 40, snare; 41, capture ring; 42, support rod; 43, knob control; 44, catheter; 45, guide sheath;

[0053] 50, guide wire. DETAILED DESCRIPTION

[0054] The following will be described in combination with the accompanying Figures 1-9 The present application is explained.

[0055] Example 1

[0056] Referring to Figures 1-2 The present application provides a retrieval system of vena cava filter, which comprises a vena cava filter 10 and a retrieval device, the retrieval device comprises a guide device 20, a retrieval sheath 30, a snare 40 and a guide wire 50, wherein the vena cava filter 10 has an umbrella structure, comprising a filter retrieval hook 11 and filter struts 12 which are evenly distributed around the circumference, the vena cava filter 10 is tilted after being implanted in the blood vessel, the filter retrieval hook 11 is attached to the blood vessel wall (such as Figure 1 ).

[0057] Referring to Figures 3-4The guiding device 20 comprises a connecting rod and a guiding fixed claw 21, the connecting rod is provided with a central cavity allowing the guide wire to pass through, the connecting rod comprises a rod body 22 and a rod base 23 fixedly connected with the rod body 22, a recovery groove 24 is formed at one end of the rod body 22 away from the rod base 23, the guiding fixed claw 21 is arranged at one end of the rod body 22 close to the recovery groove 24, the guiding fixed claw 21 comprises a plurality of guiding ribs 211 which are uniformly distributed along the circumference and smooth, the plurality of guiding ribs 211 are curved towards the center of the guiding fixed claw 21, and the direction of the guiding rib 211 is towards the rod base 23.

[0058] Further, the guiding fixed claw 21 is made of nickel-titanium alloy material, and the opening angle of the guiding fixed claw 21 ranges from 90 to 120 degrees.

[0059] Referring to Figure 5 The recovery sheath 30 can accommodate the vena cava filter 10, the guiding device 20 and the snare 40, and comprises a recovery sheath tube 31 and a control valve seat 32 connected with the recovery sheath tube 31, one end of the control valve seat 32 is connected with a three-way valve 321, the three-way valve 321 is provided with a first luer joint 3211 and a second luer joint 3212 at two ends connected with the outside, and the three-way valve 321 is further provided with a control knob 3213, which is used for controlling the opening and closure of the port of the three-way valve 321.

[0060] Further, the external syringe can be connected through the first luer joint 3211 or the second luer joint 3212 for preoperative flushing of the recovery sheath and the guide wire or for injection of the required liquid during the operation, thereby improving the recovery efficiency of the vena cava filter.

[0061] Continuing Figure 6 In combination Figure 1 When the medical staff operates, the recovery sheath 30 enters the blood vessel along the guide wire 50, and after one end of the recovery sheath tube 31 reaches the bottom of the filter rib rod 12, the guiding device 20 enters the blood vessel along the guide wire through the recovery sheath 30, so that the guiding fixed claw 21 reaches the bottom of the filter rib rod 12, the control valve seat 32 releases the guiding fixed claw 21 by withdrawing the recovery sheath tube 31, the guiding rib 211 of the guiding fixed claw 21 is opened, the guiding device 20 adjusts the position of the guiding fixed claw 21 by moving, then the guiding device 20 is pulled backward, because the direction of the guiding rib 211 is opposite to that of the filter rib rod 12, the guiding fixed claw 21 is clamped with the filter rib rod 12, the guiding device 20 adjusts the position of the vena cava filter 10 through the interaction between the guiding fixed claw 21 and the filter rib rod 12, so that the filter recovery hook 11 returns to the blood vessel cavity, and the snare 40 is ready to capture the filter recovery hook 11.

[0062] Referring to Figure 7The snare 40 comprises a catching ring 41, a supporting rod 42, a twist controller 43 and a catheter 44, one end of the supporting rod 42 is connected with the catching ring 41, the other end is connected with the twist controller 43, the catheter 44 is sleeved outside the supporting rod 42 and is in sliding connection with the supporting rod 42, the twist controller 43 can further control the rotation, pushing and withdrawing of the supporting rod 42, so as to realize the rotation, pushing and withdrawing of the catching ring 41, and the filter hook 11 can be caught accurately.

[0063] Further, the catching ring 41 is made of nickel-titanium alloy material.

[0064] Referring to Figure 8 After the filter hook 11 returns to the blood vessel cavity, the snare 40 enters the recovery sheath 31 through the control valve seat 32, and the supporting rod 42 is controlled by the twist controller 43 to introduce the catching ring 41 to the direction of the filter hook 11, after the catching ring 41 catches the filter hook 11, the catching ring 41 is locked with the filter hook 11 by pushing the catheter 44, so that the snare 40 is withdrawn to the recovery sheath 30, and the vena cava filter 10 is transported into the recovery sheath 30, and the recovery of the vena cava filter is further realized.

[0065] In the embodiment, the snare 40 is further provided with a guide sheath 45, when the snare 40 enters the recovery sheath 30, the initial state of the catching ring 41 is accommodated in the inside of the guide sheath 45, the catching ring 41 is out of the guide sheath 45 and enters the recovery sheath 30 by moving the supporting rod 42 and the catheter 44 in the guide sheath 45, and then the supporting rod 42 and the catheter 44 of the snare 40 also pass through the guide sheath 45 and enter the recovery sheath 30, and the rotation or pushing of the supporting rod 42 is controlled by the twist controller 43, so that the catching ring 41 accurately catches the vena cava filter 10.

[0066] Embodiment 2

[0067] Based on the above-mentioned vena cava filter recovery system, the application further provides a vena cava filter recovery method, comprising the following steps:

[0068] Step one: the recovery sheath 30 enters the blood vessel along the guide wire 50, and one end of the recovery sheath tube 31 reaches under the filter strut 12 of the vena cava filter 10;

[0069] Step two: the guide device 20 passes through the recovery sheath 30 along the guide wire 50, after the guide fixed jaw 21 reaches under the filter strut 12 of the vena cava filter 10, the control valve seat 32 releases the guide fixed jaw 21 by withdrawing the recovery sheath tube 31, and the guide strut 211 of the guide fixed jaw 21 is opened;

[0070] Step three: adjust the position of the guiding fixed claw 21, then pull the guiding device 20 backward, after the guiding fixed claw 21 is connected with the filter strut 12 of the vena cava filter 10, adjust the position of the vena cava filter 10, so that the filter retrieval hook 11 of the vena cava filter 10 is back to the blood vessel cavity;

[0071] Step four: the snare 40 passes through the control valve seat 32 to enter the retrieval sheath 31, and the support rod 42 is controlled by the twist controller 43 to introduce the capture ring 41 to the direction of the filter retrieval hook 11, after the capture ring 41 captures the filter retrieval hook 11, the vena cava filter 10 is transported into the retrieval sheath 31;

[0072] Step five: keep the retrieval sheath 30 still, pull out the guiding device 20, the snare 40 and the vena cava filter 10 from the human body, then pull out the retrieval sheath 30 and the guide wire 50 from the human body, so as to realize the retrieval of the vena cava filter 10.

[0073] Embodiment 3

[0074] The difference between embodiment 3 and embodiment 2 is step three, please refer to Figure 9 and Figure 1 If the vena cava filter 10 is too inclined or the blood vessel is complex, the guiding device 20 cannot return the filter retrieval hook 11 to the blood vessel cavity, after the guiding fixed claw 21 is connected with the filter strut 12 of the vena cava filter 10, the capture ring 41 of the snare 40 passes through the retrieval sheath 30 to reach the bottom of the filter strut 12, the capture ring 41 captures the retrieval groove 24 of the guiding device 20, the snare 40 locks the capture ring 41 on the retrieval groove 24 by pushing the catheter 44, a bridge structure is formed between the guiding device 20 and the snare 40, which can jointly act and move the position of the vena cava filter 10 so that the filter retrieval hook 11 is back to the blood vessel cavity.

[0075] It can be understood that when the capture ring 41 of the snare 40 passes through the retrieval sheath 30 to reach the bottom of the filter strut 12, the position where it reaches corresponds to the filter strut 12 which is spaced apart from the filter strut 12 connected with the guiding fixed claw 21 by two or more filter struts 12, or is located at the opposite filter strut 12.

[0076] The above are preferred embodiments of the present application, which do not limit the protection scope of the present application, therefore: any equivalent changes made on the structure, shape and principle of the present application shall be covered within the protection scope of the present application.

Claims

1. A venous vena cava filter recovery system, comprising a venous vena cava filter and a recovery device, characterized in that: The recovery device includes a guiding device, a snare, a recovery sheath, and a guide wire; The guiding device includes a connecting rod and a guiding fixing claw. The connecting rod has a central cavity that can accommodate the guide wire. A retrieval groove is opened on the outer side of one end of the connecting rod. The guiding fixing claw is located at the end of the connecting rod near the retrieval groove. The guiding fixing claw includes multiple guide ribs evenly distributed along the circumference. The guiding device is engaged with the filter ribs of the vena cava filter through the guiding fixing claw, and is used to adjust the position of the vena cava filter. The retrieval sheath can accommodate the snare, the guide device, and the vena cava filter, and the guide fixing claw of the guide device can pass through the retrieval sheath into the blood vessel; The snare is used to capture the filter retrieval hook of the vena cava filter and retrieve the vena cava filter into the retrieval sheath.

2. The venous filter recovery system according to claim 1, characterized in that: The recovery sheath includes a recovery sheath tube and a control valve seat connected to the recovery sheath tube, and the guide device and the snare pass through the control valve seat into the recovery sheath tube.

3. The venous filter recovery system according to claim 2, characterized in that: The snare includes a torque controller, a guide tube, a support rod, and a capture ring. The guide tube is slidably disposed outside the support rod. One end of the support rod is connected to the torque controller, and the other end is connected to the capture ring. The torque controller controls the rotation, advancement, or retraction of the support rod.

4. The venous filter recovery system according to claim 3, characterized in that: The opening angle range of the guide fixing claw is 90-120 degrees.

5. A venous filter recovery system according to claim 4, characterized in that: The ends of the multiple guide ribs, which are evenly distributed along the circumference, bend toward the center of the guide fixing claw.

6. A venous filter recovery system according to claim 3, characterized in that: The snare also includes a guide sheath that can accommodate the conduit, support rod, and capture ring.

7. A venous filter recovery system according to claim 3, characterized in that: The guide claw and the capture ring are made of nickel-titanium alloy.

8. A venous filter recovery system according to claim 3, characterized in that: The control valve seat is provided with a Luer connector for connecting to an external syringe.

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