CN112137755A

CN112137755A - Filter recovery protection device, filter recovery system and method and filter system

Info

Publication number: CN112137755A
Application number: CN201910578980.6A
Authority: CN
Inventors: 朱永锋; 朱清
Original assignee: Shanghai Microport Endovascular Medtech Co Ltd
Current assignee: Shanghai Lanmai Medical Technology Co ltd
Priority date: 2019-06-28
Filing date: 2019-06-28
Publication date: 2020-12-29
Also published as: WO2020258943A1

Abstract

The invention provides a filter recovery protection device, a filter recovery system and method and a filter system. The filter retrieval protector comprises a filter assembly comprising a bag filter layer having opposing first distal and proximal ends and a fixation structure, the first distal end of the bag filter layer having an opening for allowing thrombus within a blood vessel to enter the bag filter layer upon retrieval of the filter; the fixation structure is disposed at the first distal end and is configured to engage an inner wall of a blood vessel. The invention can avoid serious consequences such as pulmonary embolism and the like caused by thrombus entering pulmonary artery when the filter is recovered.

Description

Filter recovery protection device, filter recovery system and method and filter system

Technical Field

The invention relates to the technical field of medical instruments, in particular to a filter recovery protection device, a filter recovery system and method and a filter system.

Background

Venous Thromboembolism (VTE) is a common clinical disease with high morbidity and mortality, including Deep Venous Thrombosis (DVT) Pulmonary Embolism (PE). DVT often occurs in the veins of the lower extremities, while PE is mainly caused by the shedding of the venous system or right-heart thrombus into the pulmonary artery after its formation, and is the main cause of morbidity and mortality in patients. At present, anticoagulation therapy is always the gold standard for VTE therapy, and aims to prevent thrombosis and pulmonary artery embolism and keep vein unobstructed. When a patient has anticoagulation contraindication or is not suitable for anticoagulation treatment when blood complications occur, the falling thrombus can be effectively intercepted by implanting a Vena Cava Filter (VCF), and the occurrence of lethal pulmonary embolism can be prevented.

Clinically, after a patient is implanted into a vena cava filter, the filter needs to be recovered after a certain period of time, but thrombus intercepted in the filter can fall off to cause pulmonary embolism when the filter is recovered, and serious consequences are caused. At present, the recovery of a filter for intercepting large thrombi (generally, the size of the filter is larger than 1cm) is not recommended in a treatment guideline, and for the filter for intercepting large thrombi (generally, the size of the filter is larger than 1cm), a second filter is arranged at the proximal end of an original filter, then a thrombolytic agent is inserted, when the large thrombi are intercepted in the second filter, the filter is treated by adopting the same method, namely, a filter is required to be arranged at the proximal end of the original filter. However, when dealing with plugs in filters, the time window for filter recovery is exceeded, causing the filter to be forced to switch to a permanent filter with long-term complications.

Disclosure of Invention

The invention aims to provide a filter recovery protection device, a filter recovery system and method and a filter system, and aims to solve the problem that thrombus falls off in the filter recovery process.

To achieve the above objects, the present invention provides a filter recovery protection device, comprising a filter assembly including a bag filter layer and a fixation structure, the bag filter layer having opposite first distal and proximal ends, the first distal end of the bag filter layer having an opening for allowing thrombus in a blood vessel to enter the bag filter layer when the filter is recovered; the fixation structure is disposed at the first distal end and is configured to engage an inner wall of a blood vessel.

Optionally, the fixation structure comprises a frame disposed at the first distal end of the bag filter layer and adapted to engage the inner wall of the blood vessel.

Optionally, the fixing structure further comprises a positioning member for keeping the filter assembly fixed relative to the inner wall of the blood vessel.

Optionally, the positioning member comprises at least two barbs disposed on the frame, and at least two barbs are disposed along the circumferential direction of the frame at intervals.

Optionally, the filter element is a compressible element, and in an uncompressed state, the filter element is of a tapered configuration and has a cross-section perpendicular to the axis that decreases from the first distal end to the first proximal end.

Optionally, the filter assembly is a compressible assembly, and in an uncompressed state, the frame is fishmouth shaped; or, the frame is elliptical and not perpendicular to the axis of the filter assembly; or, the frame is a wave-shaped bracket.

Optionally, the bag filter layer is provided with holes for blood to flow through.

Optionally, the shape of the aperture is at least one of circular, oval, diamond, or triangular.

Optionally, the filter retrieval protector further comprises a transport assembly comprising a first sheath, a first sheath dilator, a first guidewire, and an introducer tube set;

the outer diameter of the first sheath dilator is smaller than the inner diameter of the first sheath, and the first sheath dilator is used for penetrating through the first sheath, extending out of the first sheath and guiding the first sheath into a blood vessel under the guidance of the first guide wire;

the introducer tube set is removably disposed within the first sheath and is adapted to receive the filter assembly to deliver the filter assembly to the proximal end of the filter.

Optionally, the transport assembly further comprises a recycling wire connected with the filter assembly for recycling the filter assembly.

Optionally, the introducer tube set comprises a pre-installed tube and a push tube;

the pre-pipe is used for accommodating the filter assembly and is detachably arranged in the first sheath pipe;

the push tube has opposite second distal and proximal ends, the second distal end of the push tube being disposed within the pre-fill tube and adapted to contact the first proximal end of the bag filter to push the filter assembly from the pre-fill tube into the first sheath tube.

Optionally, the first sheath has a third distal end and a third proximal end opposite to each other, and the third distal end of the first sheath is provided with a first developing ring.

Optionally, the first sheath dilator has a lumen extending axially therethrough for passage of the first guidewire.

In order to achieve the above object, the present invention further provides a filter recovery system, comprising a filter recovery device and a filter recovery protection device as described above;

the filter recovery device is used for recovering the filter;

the filter recovery protection device is used for being arranged at the proximal end of the filter and intercepting thrombus falling from the filter.

Optionally, the filter recovery device comprises a second sheath, a capture catheter and a capture device;

the capture catheter is detachably arranged in the second sheath;

the capture device is disposed within the capture conduit and is configured to couple with the filter.

Optionally, the filter retriever further comprises a second sheath dilator and a second guidewire;

the second sheath dilator is detachably connected with the second sheath and is used for penetrating the second guide wire so as to guide the second sheath into the blood vessel.

To achieve the above object, the present invention also provides a filter system comprising a filter and a filter recovery system as described above.

In order to achieve the above object, the present invention also provides a filter recovery method comprising:

providing a filter recovery guard as described above;

delivering the filter assembly into a blood vessel and positioned proximal to the filter;

recovering the filter using a filter recovery device, the filter assembly for intercepting thrombi falling from the filter; and the number of the first and second groups,

withdrawing the filter assembly.

In order to achieve the above object, the present invention also provides another filter recovery method comprising:

providing a filter recovery system as described above;

recovering the filter using the filter recovery device, the filter assembly for intercepting thrombus falling from the filter; and the number of the first and second groups,

withdrawing the filter assembly.

Compared with the prior art, the filter recovery protection device, the filter recovery system and method and the filter system have the following advantages:

the filter recovery protection device comprises a filter assembly and a fixing structure, wherein the filter assembly comprises a bag type filter layer and the fixing structure, the bag type filter layer is arranged at the proximal end of the filter to intercept thrombus falling from the filter when the filter is recovered, and the fixing structure is used for being attached to the inner wall of a blood vessel when the filter is recovered, so that the bag type filter layer can comprehensively intercept thrombus, and the phenomenon that the thrombus with large size enters the vein to cause pulmonary embolism is avoided.

Drawings

FIG. 1 is a schematic view of a filter retrieval protector according to one embodiment of the present invention, with the filter assembly compressed within the transport assembly and with the first sheath and first sheath dilator not shown;

FIG. 2 is a schematic view of a filter retrieval protector according to one embodiment of the present invention with the filter assembly released and the first sheath and first sheath dilator not shown;

FIG. 3 is a schematic diagram of a filter recovery system for recovering a filter and thrombus according to an embodiment of the present invention;

FIG. 4 is a schematic diagram of a filter assembly of a filter recovery and protection device according to an embodiment of the present invention;

FIGS. 5a to 5c are schematic views showing the filter assembly of the filter recovery and protection device of FIG. 4 in a modified configuration;

FIG. 6a is a schematic view of the connection of the recovery wire and the filter assembly of the filter recovery protection device according to an embodiment of the present invention;

FIG. 6b is a schematic view of the connection of the recovery wire and the filter assembly of the filter recovery protector according to another embodiment of the present invention;

FIG. 7 is a schematic view of a first sheath of a filter recovery and protection device according to an embodiment of the present invention;

FIG. 8 is a schematic view of a first sheath dilator of a filter retrieval protector according to an embodiment of the present invention;

FIG. 9 is a schematic view of the first sheath and first sheath dilator of the filter recovery protection device according to one embodiment of the present invention as assembled;

FIG. 10 is a schematic view of a filter recovery protector according to an embodiment of the present invention recovering a filter assembly;

FIGS. 11a and 11b are schematic views of a filter recovery device of a filter recovery system according to an embodiment of the present invention being deployed into a blood vessel;

fig. 12a and 12b are schematic views illustrating a filter recovery system according to another embodiment of the present invention for recovering a filter and thrombus.

In the figure:

100-filter recovery protection;

1100-a filter assembly;

1110-bag filter, 1111-holes;

1120-a fixed structure;

1121-frame, 1122-spacer;

1200-a transport assembly;

1210-a first sheath;

1211-first tube body, 1212-connecting part, 1213-hemostatic valve, 1214-first developing ring;

1220-a first sheath dilator;

1230-a first guidewire;

1231-soft filament section, 1232-hard filament section;

1240-a catheter set;

1241-pre-loading tube, 1242-pushing tube;

1250-recovering the filaments;

200-a filter;

210-a recovery hook;

300-blood vessels;

400-thrombosis;

500-filter recovery unit;

5100-a second sheath;

5110-second tube, 5120-second connector, 5130-second hemostatic valve, 5111-second developer ring;

5200-capturing the catheter;

5300-a catcher;

5310 connecting rod, 5320 ferrule.

Detailed Description

The core idea of the invention is to provide a filter recovery protection device, comprising a filter assembly, wherein the filter assembly comprises a bag filter layer and a fixed structure, the bag filter layer is provided with a first far end and a first near end which are opposite, the first far end of the bag filter layer is provided with an opening, and the opening is used for allowing thrombus in blood vessels to enter the bag filter layer when the filter is recovered; the fixation structure is disposed at the first distal end and is configured to engage an inner wall of a blood vessel.

The filter recovery protection device is arranged at the proximal end of the filter when the filter is recovered, so that thrombus falling from the filter is intercepted, and large-size thrombus is prevented from entering pulmonary artery to cause pulmonary embolism. And after the filtering component intercepts the thrombus, the thrombus can be recovered along with the filtering component, so that the adverse effect of the thrombus in a human body is thoroughly eliminated.

To make the objects, advantages and features of the present invention more apparent, the filter recovery protecting device, the filter recovery system and method, and the filter system according to the present invention will be described in further detail with reference to the accompanying drawings. It is to be noted that the drawings are in a very simplified form and are not to precise scale, which is merely for convenience and clarity in aiding the description of the invention.

As used in this specification and the appended claims, the singular forms "a", "an", and "the" include plural referents, and the plural referents "include two or more referents unless the content clearly dictates otherwise. As used in this specification and the appended claims, the term "or" is generally employed in its sense including "and/or" unless the content clearly dictates otherwise, and the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either fixedly connected, detachably connected, or integrally connected. Either mechanically or electrically. Either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations. The same or similar reference numbers in the drawings identify the same or similar elements.

As used herein, the terms "distal" and "proximal" refer to the relative orientation, relative position, and orientation of elements or actions relative to one another from the perspective of an operator using the filter retrieval system and filter retrieval system, and although "distal" and "proximal" are not intended to be limiting, the term "distal" generally refers to the end that enters the patient first, and the term "proximal" generally refers to the end of the filter retrieval system and filter retrieval system that is near the operator during normal operation. The terms "proximal" and "distal" refer to the relative positions, relative orientations of the elements relative to each other as viewed from the filter's angle relative to the heart, and as used herein, "proximal" refers to the end of the filter that is proximal to the heart, and "distal" refers to the end of the filter that is distal from the heart.

Referring to fig. 1 to 3, the filter recovery protecting device 100 of the present embodiment includes a filter assembly 1100, the filter assembly 1100 includes a bag filter 1110 and a fixing structure 1120, the bag filter 1110 has a first distal end and a first proximal end, the first distal end has an opening for allowing thrombus in the blood vessel 300 to enter a lumen formed by the bag filter 1110 when the filter 200 is recovered, and the thrombus can be intercepted by the bag filter 1110; the fixation structure 1120 is disposed at the first distal end and is configured to engage the inner wall of the blood vessel 300 during retrieval of the filter 200. The thrombus 400 in the blood vessel 300 is mainly referred to as thrombus in this embodiment. The following description will be given taking the thrombus 400 as an example.

In detail, the filter assembly 1100 is a compressible assembly having an uncompressed state and a compressed state. The filter assembly 1100 is in a compressed state prior to retrieval of the filter 200 for transport into the blood vessel 300, and the filter assembly 1100 is in the compressed state after retrieval of the filter 200 for withdrawal from the blood vessel 300. Upon retrieval of the filter, the filter assembly 1100 is positioned proximal to the filter 200 and expanded to the uncompressed state with the fixation structure 1120 engaging the inner wall of the vessel 300.

The filter assembly 1100 may be made of a material having elasticity such that it can be compressed to the compressed state when a force is applied thereto and can be automatically expanded to the uncompressed state when the external force is removed. Specific materials that may be used to fabricate filter assembly 1100 include polyethylene terephthalate (PET), Polytetrafluoroethylene (PTFE), and the like. It should be understood that the particular material of the filter assembly 1100 is not limited in this regard and may be compressible and collapsible and may be used for medical purposes.

With continued reference to fig. 1-3, preferably, when the filter assembly 1100 is in the uncompressed state, its cross-section perpendicular to the axial direction gradually increases from the first proximal end to the first distal end of the bag filter 1110 to form a tapered configuration, further facilitating subsequent withdrawal operations.

In addition, the filter assembly 1100 is used to intercept the detached thrombus 400, but it should not obstruct the flow of blood, and thus, a hole 1111 through which blood flows is formed in the bag filter 1110. Generally, when the size of the thrombus 400 is less than 3mm, the possibility of causing pulmonary embolism is low, in other words, when the size of the thrombus 400 entering the blood vessel 300 is 3mm or more, pulmonary embolism is highly likely to be caused, and therefore, the bag filter 1110 should intercept the thrombus 400 having a size of 3mm or more. The holes 1111 may be sized as desired, for example, if the holes 1111 are circular, they may have a diameter of 0.5-3 mm. It should be understood that, in practice, the holes 1111 may also be square, triangular, polygonal or other shapes, and the size of the holes 1111 is only illustrated by taking the circular holes 1111 as an example, which should not be construed as a limitation to the present invention, and when other shapes of holes 1111 are used, the area of the holes 1111 should be determined to intercept the thrombus 400 having a size of 3mm or more.

With continued reference to fig. 3 and with reference to fig. 4, a fixing structure 1120 is disposed at the first distal end of the bag filter 1110 to allow the filter element 1100 to be attached to the inner wall of the blood vessel 300, so that all the fallen thrombus 400 with larger size (more than 3 mm) can be intercepted by the bag filter 1110. It should be understood that the fit herein includes both a void-free fit of the first distal end of bag filter 1110 to the interior wall of vessel 300 and a gap of less than 3mm between the first distal end of bag filter 1110 and the interior wall of said vessel 300.

Specifically, the fixing structure 1120 includes a frame 1121, and the frame 1121 is disposed at a first distal end of the bag filter 1110 and is configured to be attached to the inner wall of the blood vessel 300.

As shown in fig. 4, when the filter assembly 1100 is in the open state, the frame 1121 may have an oval shape that intersects with but is not perpendicular to the axis of the filter assembly 1100. When the elliptical frame 1121 is projected onto a plane perpendicular to the axis of the filter assembly 1100, the diameter of the projected circle obtained should be not less than the diameter of the blood vessel 300. The frame 1121 typically has an aperture of 15-22mm according to the diameter of the actual blood vessel 300. In other embodiments, the frame 1121 may also be fish-mouth shaped as shown in FIG. 5 a; alternatively, the frame 1121 is a wavy stent structure as shown in fig. 5 b; alternatively, the frame 1121 may also be a spring structure as shown in fig. 5 c. In summary, the embodiment of the present invention does not limit the specific form of the frame 1121, as long as it can make the first distal end of the bag filter 1110 adhere to the inner wall of the blood vessel 300, so that the gap between the inner wall of the blood vessel 300 and the first distal end of the bag filter 1110 is less than 3mm or no gap exists, and thus all the dropped thrombi 400 with the size of more than 3mm can be intercepted.

Further, the fixing structure 1120 further includes a positioning element 1122, and referring to fig. 3 and 4, the positioning element 1122 is, for example, a barb disposed on the frame 1121, and the barb may pierce the inner wall of the blood vessel 300, so that the filtering assembly 1100 is fixed on the blood vessel 300, and is prevented from being displaced due to the influence of the flow force of the blood flow, and further, the thrombus 400 cannot be intercepted. Specifically, the barbs may be hook-shaped structures, and the number of the barbs may be multiple and be uniformly arranged along the circumferential direction of the frame 1121. The positioning member 1121 and the frame 1121 may be connected by welding, mechanical clamping, or the like, or may be integrally formed.

In a further refinement, the filter recovery and protection device 100 further comprises a transport assembly 1200. Prior to retrieval of the filter 200, the filter assembly 1100 may be compressed to the collapsed condition and housed within the transport assembly 1200 for transport by the transport assembly 1200 into the vessel 300; and, after recovery of the filter 200, the filter assembly 1100 may be compressed and housed in the transport assembly 1200 for transport by the transport assembly 1200 out of the vessel 300.

That is, in this embodiment, the filter assembly 1100 needs to be transported to the proximal end of the filter 200 by the transport assembly 1200 before the filter 200 is recovered, and the filter assembly 1100 can also be recovered by the transport assembly 1200 after the thrombus 400 is intercepted.

In detail, referring to fig. 1 and 2 in conjunction with fig. 7-9, the delivery assembly 1200 can include a first sheath 1210, a first sheath dilator 1220, a first guidewire 1230, an introducer tube set 1240, and a retrieval wire 1250.

Referring to fig. 7, the first sheath 1210 includes a first tube 1211, the first tube 1211 is hollow and has a first inner cavity extending axially through the first tube 1211, the first tube 1211 has a third distal end and a third proximal end opposite to the third distal end, the third distal end of the first tube 1211 is provided with a first connection portion 1212 having a sealing member (not shown), and the first connection portion 1212 is provided with a first hemostatic valve 1213. Typically, the first tube 1211 has an outer diameter of 10-16F and a length corresponding to the distance from the jugular vein to the proximal end of the filter 200, for example, between 40-60 cm. In addition, a first developing ring 1214 is disposed at the third distal end of the first tube 1211.

The first sheath dilator 1220 may directly use a conventional first sheath dilator. In size, the length of the first sheath dilator 1220 is 10-50mm longer than that of the first sheath 1210, the first sheath dilator 1220 is also a hollow structure and has a second inner cavity extending through in the axial direction, and the first sheath dilator 1220 is used for being detachably connected with the first sheath 1210, so that the first guide wire 1230 can be arranged after the second inner cavity of the first sheath dilator 1220 is communicated with the first inner cavity of the first sheath 1210.

The first guidewire 1230 can be implemented as a conventional medical guidewire, and the first guidewire 1230 can be removably disposed within the first sheath dilator 1220 and used to subsequently guide the filter assembly 1100 into the blood vessel 300. Specifically, the first guide wire 1230 includes a soft wire section 1231 and a hard wire section 1232, and the soft wire section 1231 and the hard wire section 1232 are connected to each other, wherein the soft wire section 1231 is adapted to the structure of the blood vessel 300 during the process of advancing the blood vessel 300, so as to avoid damage to the blood vessel 300, and the hard wire section 1232 provides sufficient supporting force for subsequently guiding other members into the blood vessel 300. It should be understood that reference herein to "soft segments" means less stiff than "hard segments", and similarly, "hard segments" means more stiff than "soft segments".

The introducer tube set 1240 is used to house the filter assembly 1100 prior to recovery of the filter 200 and to deliver the filter assembly 1100 into the blood vessel 300 to the proximal end of the filter 200. In detail, as shown in fig. 1 and 2, the introducer tube set 1240 includes a pre-installed tube 1241 and a push tube 1242, the pre-installed tube 1241 is a hollow tube, and the filter assembly 1100 is compressible within the pre-installed tube 1241. The pre-assembly tube 1241 is adapted to be removably disposed within the first sheath 1210. The push tube 1242 may be a hollow cylindrical tube and has a second distal end and a second proximal end opposite to the first distal end, the second distal end being disposed in the pre-assembly tube 1241 and contacting the first proximal end of the bag filter 1110 to push the filter assembly 1100 into the first sheath 1210.

The number of the recovery wire 1250 may be one, or two or more, and the recovery wire 1250 is connected to the filter assembly 1100, and is used to recover the filter assembly 1100 after the filter assembly 1100 intercepts the thrombus 400. The recycling filaments 1250 may be attached to the filter assembly 1100 in a variety of ways, for example, the recycling filaments 1250 may be attached to the bag filter layer 1110 by stitching or adhesive bonding. The front end of the recycling wire 1250 may be bent into a circle to be connected to the frame 1121 as shown in fig. 6 a. Alternatively, the recycling wire 1250 and the frame 1121 may be fabricated as an integral structure to achieve the connection between the filter assembly 1100 and the recycling wire 1250, as shown in fig. 6 b. The recovery filament 1250 is shown removably disposed within the first sheath dilator 1220 and the recovery filament 1250 remains within the first sheath 1210 after the first sheath dilator 1220 is withdrawn from the first sheath 1210.

Next, the method of using the filter recovery protection device will be described with reference to fig. 1 to 12 b.

(1) The first sheath 1210 is introduced into the blood vessel 300.

First, as shown in fig. 9, a first sheath 1210, a first sheath dilator 1220 and a first guide wire 1230 are assembled, wherein the first sheath dilator 1220 is locked by the first connecting portion 1212;

then, the first tube 1211 is filled with the saline from the first hemostatic valve 1213 to evacuate the air in the first tube 1211.

Thereafter, the first sheath 1210 is introduced by conventional means via the jugular vein along the first guidewire 1230 by puncture, and the front end of the first sheath 1210 is positioned at the proximal end of the filter 200 according to the position of the first imaging ring 1214;

finally, the first sheath dilator 1220 is withdrawn from the body.

(2) The filter assembly 1100 is introduced into a blood vessel 300.

As shown in fig. 1, the filter assembly 1000 with the attached recovery wires 1250 is first compressed to a collapsed state and loaded into the pre-assembly tube 1241;

the pre-loaded tube 1241 is then inserted over the first guide wire 1230 into the first connector 1212 of the first sheath 1210, and the second distal end of the pusher tube 1242 is inserted into the first sheath 1210 from the third proximal end of the first sheath 1210;

thereafter, pushing the push tube 1242 such that the second distal end of the push tube 1242 contacts the first proximal end of the bag filter 1110 contained in the pre-fill tube 1241, and continuing to push the push tube 1242 until the first distal end of the bag filter 1110 reaches the first developer ring 1214;

subsequently, the push tube 1242 is secured and the first sheath 1210 is withdrawn, releasing and expanding the filter assembly 1100 from the first sheath 1210 to an open position, in which the filter recovery protector is in the position shown in fig. 2 and 3;

finally, the pre-fill tube 1241 and the push tube 1242 are retracted.

Recovery of filter 200 can begin after expansion of filter assembly 1100 is complete. During the process of recycling the filter 200, part of the thrombus 400 is cut by the filter 200 and falls out of the filter 200, and then flows into the filter assembly 1100 along with the blood flow, wherein the thrombus 400 with a larger size (more than 3 mm) can be intercepted by the bag filter 1110, thereby avoiding serious consequences such as pulmonary embolism.

(3) The filter assembly 1100 is recovered.

As shown in fig. 10, after filter 200 is recovered, pulling recovery filaments 1250, said recovery filaments 1250 pulling filter assembly 1100 into said first sheath 1210 and withdrawing said filter assembly 1100 out of the body along first sheath 1210; finally, the first sheath 1210 is removed from the body.

When the filter assembly 1100 is retracted, the filter assembly 1100 is compressed by the force of the inner wall of the first sheath 1210 when it is pulled into the first sheath 1210. Meanwhile, if the filter element 1100 intercepts the large-sized thrombus 400, the large-sized thrombus 400 is wrapped in the bag filter 1110 and is recovered along with the filter element 1100 as the filter element 1100 is compressed into a strip shape.

By this time, the entire recovery process of filter 200 is complete.

Based on the filter recovery protection device, the invention also provides a filter recovery system, as shown in fig. 3, the filter recovery system comprises: a filter recovery device 500 for recovering the filter 200; and a filter retrieval protector 100 as previously described for being disposed at a proximal end of the filter 200 and intercepting thrombus 400 falling from the filter 200.

The filter recovery device 500 may be any one of the existing filter recovery devices, and the method of recovering the filter 200 may be the prior art. Specifically, as shown in fig. 11a and 11b, the filter recovery device 500 includes a second sheath 5100, a catching catheter 5200 and a catching device 5300. The second sheath 5100 has a similar structure to the first sheath 1210, and includes a second tube 5110, the second tube 5110 has a fourth distal end and a fourth proximal end, the fourth distal end of the second tube 5110 is preferably provided with a second developer ring 5111, the fourth proximal end of the second tube 5110 is provided with a second connecting portion 5120 having a sealing member (not shown), and the second connecting portion 5120 is provided with a second hemostatic valve 5130. The catching conduit 5200 is detachably disposed in the second sheath 5100, and the catching device 5300 includes a link 5310 and a collar 5320, wherein the link 5310 is disposed in the catching conduit 5200, and the collar 5320 is disposed at a front end of the link 5310 and outside the catching conduit 5200.

As shown in fig. 3, 11a and 11b, when the recovery hook 210 is disposed at the proximal end of the filter 200, the filter recovery device 500 recovers the filter 200 as follows:

the bag filter 1110 first proximal end is provided as an opening and the first sheath 1210 communicates with the first distal end of the bag filter 1110. Inserting the second sheath 5100 along the first guidewire 1230 into the first sheath 1210 and out the first distal end of the filter assembly 1100; then withdrawing the first guide wire 1230, and introducing the capturing catheter 5200 and the capturing device 5300 into the second sheath 1210 until the loop 5300 is hooked by the retracting hook 210; then pulling the rod 5310 and thereby the ferrule 5320 to move allows the filter 200 to be received in the capturing catheter 5200 and to be removed from the body along the second sheath 5100; finally, the second sheath 5100 is withdrawn from the body to complete the recovery of the filter 200. Here, the diameter of the second sheath 5100 should be smaller than the first sheath 1210 and smaller than the minimum diameter of the bag-type filter layer 1110.

In another embodiment, as shown in fig. 12a and 12b, when the retrieval hook 210 is disposed at the distal end of the filter 200, the filter retrieval device 500 further comprises a second sheath dilator (not shown) and a second guidewire (not shown). The second sheath dilator is detachably disposed in the second sheath 5100 and is used for passing through the second guide wire. The recovery process of the filter 200 in this example is as follows:

first, the second sheath 5100, the second sheath dilator, and the second guidewire are assembled;

then, a second sheath 5100 is introduced through the femoral vein along a second guide wire puncture, and the fourth distal end of the second sheath 5100 is determined to reach the distal end of the filter 200 according to the position of the second developing ring 5111;

next, the second guide wire is withdrawn and the capture catheter 5200 and the capture device 5300 are introduced along the second sheath 5100 until the loop is hooked by the retrieval hook 210;

then, the filter 200 is recovered by pulling the rod 5310;

finally, the second sheath 5100 is withdrawn from the body to complete recovery of the filter 200.

In addition, the present invention also provides a filtration system comprising the filter 200 and the aforementioned filter recovery system.

In addition, the invention also provides a filter recovery method, which comprises the following steps:

providing the filter recovery protection device;

recovering the filter using a filter recovery device, the filter assembly for intercepting emboli falling from the filter; and the number of the first and second groups,

withdrawing the filter assembly.

In detail, the filter may be delivered into the blood vessel by conventional methods. The filter assembly is first compressed and then received in a transport assembly and transported by the transport assembly into the blood vessel. After the filter is recovered, the filter assembly is compressed to the folded state and is contained in the transportation assembly so as to be withdrawn out of the body.

Here, the filter assembly may include a retrieval string disposed inside the first sheath and connected with the filter assembly, and when the retrieval string is drawn, the filter assembly is compressed by the first sheath, and at the same time, the filter assembly enters the first sheath and may be withdrawn from the body along the first sheath.

providing a filter recovery system as described above;

withdrawing the filter assembly.

Although the present invention is disclosed above, it is not limited thereto. Various modifications and alterations of this invention may be made by those skilled in the art without departing from the spirit and scope of this invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims and their equivalents, the present invention is intended to include such modifications and variations.

Claims

1. A filter retrieval protector comprising a filter assembly including a bag filter layer and a fixation structure, the bag filter layer having opposing first distal and proximal ends, the first distal end of the bag filter layer having an opening for allowing thrombus within a blood vessel to enter the bag filter layer upon retrieval of the filter; the fixation structure is disposed at the first distal end and is configured to engage an inner wall of a blood vessel.

2. The filter retrieval protector of claim 1, wherein the securing structure comprises a frame disposed at the first distal end of the bag filter and adapted to engage the inner wall of the blood vessel.

3. The filter retrieval protector of claim 2, wherein the securing structure further comprises a securing member for holding the filter assembly in fixed relation to the inner wall of the blood vessel.

4. The filter reclamation protection apparatus of claim 3, wherein the positioning member comprises at least two barbs disposed on the frame, at least two of the barbs being spaced circumferentially of the frame.

5. The filter retrieval protector of claim 1, wherein the filter assembly is a compressible assembly, wherein in an uncompressed state the filter assembly is of a tapered configuration and wherein its cross-section perpendicular to the axis decreases from the first distal end to the first proximal end.

6. A filter recovery protection device according to any of claims 1-5, wherein the filter element is a compressible element, the frame being in the shape of a fish mouth in an uncompressed state; or, the frame is elliptical and not perpendicular to the axis of the filter assembly; or, the frame is a wave-shaped bracket.

7. A filter reclamation protection as recited in any of claims 1 to 5, wherein the bag filter has apertures therethrough for the passage of blood therethrough.

8. The filter reclamation protection device of claim 7, wherein the apertures are at least one of circular, oval, diamond, or triangular in shape.

9. The filter retrieval protector of any one of claims 1-5, further comprising a transport assembly, the transport assembly comprising a first sheath, a first sheath dilator, a first guidewire, and an introducer tube set;

10. The filter retrieval protector of claim 9, wherein the transport assembly further comprises a retrieval string coupled to the filter assembly for retrieving the filter assembly.

11. The filter retrieval protector of claim 9, wherein the set of inlet tubes comprises a pre-installed tube and a push tube;

12. The filter retrieval protector of claim 9, wherein the first sheath has third and third proximal opposite ends, the third distal end of the first sheath being provided with the first developer ring.

13. The filter retrieval protector of claim 9, wherein the first sheath dilator has a lumen extending axially therethrough for passage of the first guidewire.

14. A filter recovery system comprising a filter recovery device and a filter recovery protection device according to any one of claims 1 to 13;

the filter recovery device is used for recovering the filter;

15. The filter recovery system of claim 12, wherein the filter recovery device comprises a second sheath, a capture catheter, and a capture device;

the capture catheter is detachably arranged in the second sheath;

16. The filter retrieval system of claim 14, wherein the filter retrieval device further comprises a second sheath dilator and a second guidewire;

17. A filtration system comprising a filter and a filter recovery system according to any of claims 13 to 16.

18. A filter recovery method, comprising:

providing a filter retrieval protection device of any one of claims 1-13;

withdrawing the filter assembly.

19. A filter recovery method, comprising:

providing a filter recovery system according to any one of claims 14 to 16;

withdrawing the filter assembly.