CN114209958A

CN114209958A - Embolic protection device

Info

Publication number: CN114209958A
Application number: CN202111437710.7A
Authority: CN
Inventors: 吕斌; 刘镕珲; 王君; 郭方方; 杜志华; 张荣举
Original assignee: First Medical Center of PLA General Hospital
Current assignee: First Medical Center of PLA General Hospital
Priority date: 2021-11-29
Filing date: 2021-11-29
Publication date: 2022-03-22

Abstract

The invention relates to an embolic protection device, which is provided with a pushing guide wire, a catheter and a filter, wherein a pressure sensor is arranged at the far end of a filter screen of the embolic protection device. The filter comprises a filter screen, the push guide wire is connected with the filter, and the filter can be recovered into the guide pipe to form a compression configuration or released out of the guide pipe to form an expansion configuration by controlling the push guide wire and the guide pipe. The embolic protection device can also have at least two pressure sensors disposed at the distal and proximal ends of the filter screen, respectively. The pressure sensor can detect the pressure on two sides of the filter screen in real time in the operation, provides reference for judging whether the embolic protection device is blocked or adheres badly, and is convenient for adjusting the operation strategy in time.

Description

Embolic protection device

Technical Field

The invention relates to a medical instrument, in particular to an embolism protection device.

Background

During intravascular interventional therapy, emboli or plaques may fall off when a guide wire or a catheter passes through a blood vessel or when a stent, a saccule or a rotational abrasion device opens the blood vessel. The dislodged emboli may cause occlusion of the distal supplying blood vessel, possibly causing damage to the corresponding tissue. Especially when the blood vessel is opened to supply brain tissue such as carotid artery, the drop of embolus may cause cerebral apoplexy and damage to nerve function of patient. To prevent emboli that become dislodged from the blood stream embolize into the distal vessel, prior art solutions often prematurely release an embolic protection device distal to the target vessel to be opened. The embolic protection device has a micro-channel with less resistance to blood, but can retain emboli of a certain size in the embolic protection device. The embolic protection device is withdrawn into the catheter and removed from the body at the end of the procedure.

Chinese patent application CN113425374A discloses a typical embolic protection umbrella, which comprises a transportation guide wire, a filter screen bag, and a transportation and recovery sheath. Two ends of the filter screen bag are connected with the transportation guide wire through the first fixing ring and the second fixing ring. The fixed ring can slide along the conveying guide wire and is limited by the fixed sleeve. Chinese patent application CN113081382A discloses another embolic protection device, which comprises a core tube, a filter element, a support frame, a sliding retractor and a recovery system. The filter element opens toward the proximal end of the core tube. The technical solution of the embolic protection umbrella proposed in the above patent is to retain emboli in the filter member, but has the disadvantage that the embolic protection device may be clogged when a large number of detached emboli are captured, or when a large volume of emboli are captured, or when a thrombus is formed on the embolic protection device. It is not easy for the operator to timely find that the embolic protection device is clogged. A large pressure drop may occur across the occluded embolic protection device, possibly resulting in ischemia of the distal tissue. For example, when the distal tissue is brain tissue, damage to the brain tissue and nerve function of the patient may result. In addition, when the embolic packaging device is opened, it may not fit well against the vessel wall, which may not be detected in time due to the restriction of the angle of visualization, possibly resulting in the possibility of emboli escaping through the space between the screen and the vessel wall to the distal vessel.

Disclosure of Invention

In view of the above problems, the present invention is directed to an embolic protection device, which can monitor the pressure at the distal end of the embolic protection device, so that an operator can timely find the blockage of the embolic protection device and timely take necessary measures to avoid the tissue damage of a patient. The embolic protection device provided by the invention can also detect the pressure at the far end and the near end of the filter screen, can also find out the phenomenon of poor adherence, is favorable for timely adjusting the release state of the embolic protection device and avoids embolus from escaping.

In order to solve the technical problems, the technical scheme of the invention is to provide an embolic protection device which comprises a pushing guide wire, a catheter and a filter, wherein the filter comprises a filter screen, the pushing guide wire is connected with the filter, the filter can be recovered into the catheter to form a compressed configuration or released out of the catheter to form an expanded configuration by controlling the pushing guide wire and the catheter, and a pressure sensor is arranged at the far end of the filter screen of the embolic protection device. The pressure sensor is used for sensing the pressure change at the far end of the filter screen of the embolic protection device.

Optionally, at least two pressure sensors are mounted on the embolic protection device, respectively at the proximal and distal ends of the filter mesh, for sensing the pressure at the proximal and distal ends of the filter mesh, respectively, at which time the pressure differential of the blood passing through the filter mesh can be further measured.

Optionally, the pressure sensor has a sensor and a protective shell, the protective shell having a slot to allow the sensor to communicate with the outside. The protective shell can protect the sensor from being in contact with the vessel wall or a catheter and the like to generate interference on the pressure signal. The near end of the sensor is connected with a lead wire, the lead wire is used for transmitting pressure signals, and the lead wire extends to an interface at the near end of the delivery guide wire through the inside of the delivery guide wire. The conveying guide wire interface can be connected with a transmitter, and the transmitter can transmit the pressure signal to an external display device in a wired or wireless mode.

Preferably, the pressure sensor is mounted in the delivery guidewire.

Optionally, the two ends of the filter are connected with the pushing guide wire in a sliding mode or in a fixed mode, the filter comprises a sleeve and is installed at the connection position of the filter and the pushing guide wire, and when the sliding connection scheme is adopted, the pushing guide wire is fixedly provided with a limiting device, so that the filter can only move along the pushing guide wire within a certain range. A pressure sensor may also be mounted in the sleeve or the stop.

Preferably, the filter screen is in a shape of a pocket or a cap with a closed proximal end, an open distal end, and is made of a polymer material with micropores or woven by a plurality of thread materials, and the filter, the guide wire, the catheter and the pressure sensor are provided with developing markers made of radiopaque materials.

Optionally, the filter comprises a support ring providing support and good adherence to the screen openings and support links to assist in support of the screen and to assist in recovery of the screen and support ring.

The embolic protection device provided by the invention can monitor the blood pressure change at the far end of the filter screen, and when the pressure at the far end of the filter screen is suddenly reduced to a certain value, the embolic protection device can prompt the blockage of the embolic protection device in time by combining with other blood pressure monitoring results in the operation of a patient. The operator is guided to adopt measures such as replacing a protective umbrella, thrombolysis, controlling operation time, performing blood pressure intervention on the patient and the like in time so as to minimize the tissue damage of the patient. In addition, when the far end and the near end of the filter screen of the embolic protection device are provided with pressure sensors, the pressure difference passing through the filter screen can be measured, on one hand, whether the filter screen is blocked can be judged in time, on the other hand, whether the filter screen has poor adherence can be further indicated, an operator can be guided to adjust the release position and angle of the embolic protection device in time, or the embolic protection device with larger size is replaced, so that the possibility that emboli flows to a far-end blood vessel through the gap between the embolic protection device and the blood vessel wall is reduced.

Drawings

The invention is described in further detail below with reference to the following figures and detailed description:

FIG. 1 is an embolic protection device with a pressure sensor located at the distal end of the filter mesh

FIG. 2 is an embolic protection device with pressure sensors located at the distal and proximal ends of the filter mesh, respectively

FIG. 3 is a view of the rapid exchange catheter and embolic protection device in a compressed state

FIG. 4 is a three-dimensional view of a pressure sensor

FIG. 5 is a pressure sensor with multiple grooves

FIG. 6 is a cross-sectional view of a pressure sensor

FIG. 7 is another form of pressure sensor

FIGS. 8-10 are cross-sectional views of pressure sensor proximal guidewire

FIG. 11 shows an embolic protection device and transmitter, external display device

FIG. 12 is a schematic view of a pressure sensor on a sleeve

FIG. 13 is a schematic view of a pressure sensor on a limiting device

FIG. 14 is a woven filter screen construction

FIG. 15 is a polymer screen structure with micropores

FIG. 16 is a schematic view of an embolic protection device being occluded

FIG. 17 is a schematic view of the adhesion failure of the embolic protection device

Detailed Description

Fig. 1 shows an embolic protection device comprising a push guidewire 10, a filter 20, and a catheter 30. The illustrated filter 20 is positioned outside of the catheter 30 in an expanded state. The strainer 20 has a screen 21 for blocking emboli. The push guidewire is connected to the filter and has a cannula at the junction, which is divided into a distal cannula 221 and a proximal cannula 222. The sleeve may be fixedly connected to the push guide wire 10, and the fixed connection manner may include one or a combination of welding, crimping, bonding, and the like. The sleeve can also be sleeved on the pushing guide wire and slide along the guide wire. In one embodiment, the push wire has stop means 501 and 502 fixed thereto for limiting the sliding range of the filter within a certain range when the filter is slidably connected to the guide wire. The distal end of catheter 30 has a visualization marker ring 31 to indicate the location of the catheter tip. The embolic protection device features a pressure sensor 40 at the distal end of the filter mesh 21, in this embodiment the pressure sensor 40 is located on the push wire 10. The pressure sensor is used to monitor the pressure change at the distal end of the screen 21.

Figure 2 shows an alternative embodiment of the embolic protection device, differing from the configuration shown in figure 1 in that there are

pressure sensors

401 and 402 at the distal and proximal ends of the screen 21, respectively. In this embodiment, the pressure sensor is mounted on the push guidewire 10. Pressure sensors are used to monitor changes in pressure at the distal and proximal ends of the screen 21, respectively. The limiting device 50 can be only one, is fixed on the push guide wire 10 and is positioned inside the filter.

Figure 3 is a schematic view of the embolic protection device in a compressed state. By controlling the push wire 10 and catheter 30, the embolic protection device can be received into the catheter 30, in a compressed state. The catheter 30 shown in fig. 3 is a rapid exchange catheter having a lateral opening 32, with the proximal end of the push wire 10 extending through the opening 32 to facilitate manipulation of the embolic protection device. While another guidewire 60 may be passed through the embolic protection device on the distal side thereof, the guidewire 60 may be passed through the side opening 32 of the other distal end. The guidewire 60 facilitates providing a path and support for the catheter 30 to enter the distal end of the blood vessel.

One configuration of the pressure sensor 40 is shown in fig. 4 and includes an inductor 41 and a protective shell 42, the inductor being secured within the protective shell. The protective case 42 has a groove 44 so that the inductor 41 can communicate with the outside. The sensor 41 is used for sensing the change of the external pressure signal. The protective shell 42 protects the sensor 41 from interference with the pressure signal caused by the catheter or vessel wall during delivery and operation. A lead 43 is led out from the near end of the inductor 41 for signal transmission. The pressure sensor shown in fig. 4 has a distal guide wire 11 connected to the distal end and a proximal guide wire 13 connected to the proximal end, both belonging to the guide wire 10. When the pressure sensor is positioned at the far end of the filter screen, one embodiment of the far-end guide wire is shown in fig. 4, and the outer layer is wound with a spring to increase the flexibility of the guide wire and also have the function of protecting blood vessels. An alternative embodiment is that there may be more than one slot in the protective shell of the pressure sensor 40, as shown in fig. 5, with two

slots

441 and 442, and the pressure sensor shown in fig. 5 has a guidewire 10 attached to each end. FIG. 6 illustrates a side cross-sectional view of one embodiment of a pressure sensor. In addition to the inductor 41, a core wire 14 is also inserted into the protective case 42. The core wire has a certain strength, and is usually made of nitinol or stainless steel, which can ensure good pushing performance of the guide wire, and the core wire 14 may comprise one or more sections with gradually changed diameters. The core wire 14 and the lead wire 43 are contained within the proximal guidewire 13. Fig. 7 shows another embodiment of a pressure sensor, which has an optical pressure-sensitive element 45. The pressure sensor of the present invention is not limited to the working principle and the specific form of the sensor, and may include a piezoelectric pressure sensor, an optical pressure sensor, etc. The leads 43 are not limited to a specific number, nor to a specific form of transmission signals, such as electric signals, optical signals, and the like.

Fig. 8-10 illustrate several arrangements of the lead wire 43 and core wire 14 within the pushwire 10. The push guidewire 10 further comprises an outer sleeve 15, and the outer sleeve 15 may be a hypotube formed by laser cutting a metal material such as stainless steel or nickel-titanium alloy, or may be a polymer material. In the embodiment shown in fig. 8, both the lead wire 43 and the core wire 14 are located in a cavity inside the outer sheath 15. In the embodiment shown in fig. 9, the lead is embedded in an outer sheath 15, in which case a polymer material is more suitably used for the outer sheath, and the core wire 14 is located in the lumen of the outer sheath. In the embodiment shown in fig. 10, the lead 43 is located in a lumen inside the core wire, the core wire 14 now being tubular. The core wire 14 is located within the lumen of the outer sheath 15.

Fig. 11 shows one way of connecting the embolic protection device to the transmitter 70 and the display device 80. The proximal end of the embolic protection device guidewire 10 has an interface 12 that can be connected to a transmitter 70 and transmit signals. An alternative embodiment is that the interface 12 has an electrode ring 121 connected to a lead 43, and the electrode rings are insulated from each other. The electrode ring may transmit the pressure signal to a transmitter. The transmitter 70 has a switch 71 for turning on or off the pressure transmission to the display 80 and an indicator light 72 for indicating whether the current pressure signal is being transmitted. The display 80 can receive and display pressure signals, when the embolic protection device has a plurality of pressure sensors, the display can display a plurality of signals in parallel and perform signal processing and operation, and alarm information can be generated when the signals are abnormal. The display 80 may be connected to the transmitter 70 via a transmission line 90, or may be connected in a wireless communication manner.

In addition to being located on the push guidewire 10, the pressure sensor may also be located on the cannula of the filter or on a stop device on the guidewire.

Pressure sensors

401 and 402 are shown in fig. 12 on the distal 221 and proximal 222 cannulas of the filter, respectively. This arrangement allows the pressure sensor to be located closer to the screen 21 and more accurately measure pressure information. The connection of the

sleeves

221 and 222 to the guide wire 10 can be a fixed connection or a sliding connection, wherein a fixed connection is more convenient to implement. The slide coupling method requires the lead wire 43 to be provided in an extendable or contractible configuration depending on the slide distance. The pressure sensor may also be located on the limiting means. As shown in fig. 13, the

pressure sensors

401 and 402 are located on the distal stop 501 and the proximal stop 502, respectively, and the stops are fixedly attached to the push guidewire 10.

The screen of the embolic protection device is typically in the form of a bag or cap with a proximal opening and a distal closure. In the embodiment shown in fig. 14, the mesh is woven from a plurality of filamentary materials, through which blood flow can pass and emboli of a larger volume cannot pass and be intercepted by the mesh. The filiform material may be nickel-titanium alloy wire or stainless steel wire.

Sleeves

221 and 222 are connected to both ends of the braided wire, respectively. In the embodiment shown in fig. 15, the screen 212 is made of a polymer material having micro-holes, and blood flows through the screen through the micro-holes 27 of the screen, so that emboli with larger volume cannot pass through the screen and are intercepted. The proximal end of the screen is provided with a support ring 25 for additional support at the opening, to which support links 26 are attached to assist in supporting and facilitating retrieval and release of the filter 20. Without limiting the number of support rods, the support rods 26 may also extend along the screen wall into the screen interior and may even be attached to the screen distal end. In the embodiment of fig. 15, the distal end of the screen is secured to the push wire 10 by adhesive 24. The two filter screen structures can be coated with an antithrombotic functional coating or a hydrophilic coating.

To facilitate positioning of the embolic protection device under angiography, a contrast material is typically affixed to portions of the embolic protection device, or certain components of the embolic protection device themselves are made of radiopaque contrast material such as gold, platinum-tungsten alloy, platinum-iridium alloy, and the like. The specific positions can be the positions of a support ring of the filter, a support connecting rod, a filter screen braided wire, a sleeve, a limiting device, a pressure sensor protective shell, a far-end guide wire spring, certain areas on the guide wire, a developing ring on the guide pipe and the like.

The function of the pressure sensor in the event of occlusion and malapposition of the embolic protection device is described below with reference to the accompanying drawings. In fig. 16, 81 is a blood vessel and 82 is a stenotic lesion, such as an atherosclerotic plaque, within the blood vessel to be treated. The embolic protection device is released distal to the lesion and in an expanded state. In the situation of fig. 16, there are already more emboli 83 and the embolic protection device is occluded. If intervention is not timely performed, remote tissue ischemia can occur, and the safety of the patient is endangered. When the embolic protection device is clogged, the distal pressure sensor 401 may sense a decrease in the distal pressure of the filter screen in time, which may indicate that the filter screen is clogged. Whether the embolic protection device is clogged can be more accurately determined when the proximal and distal ends of the filter screen are provided with pressure sensors. When the screen is open, the pressure measured by screen proximal pressure sensor 402 is typically greater than the pressure sensed by distal sensor 401, but the differential pressure across the screen is not great, so the differential pressure measured by the two pressure sensors is not great. When the filter screen is blocked, the pressure difference across the filter screen becomes large, the pressure difference obtained by subtracting the pressure of the pressure sensor 401 from the pressure of the pressure sensor 402 also becomes large, the filter screen is prompted to be blocked, and an operator can replace the embolic protection device in time or perform other intervention means in time.

In the situation shown in fig. 17, the embolic protection device is not fully adherent. The pressure difference obtained by subtracting the pressure 401 from the pressure of the pressure sensor 402 is smaller than the pressure difference across the filter screen in the normal adherence complete state, so that the adherence insufficiency of the filter screen can be prompted, an operator can adjust the position and the release state of the embolic protection device in time, or the embolic protection device with larger size can be replaced in time, and the possibility of embolus omission is reduced.

Claims

1. An embolic protection device having a push guidewire, a catheter, a filter, the filter comprising a screen, the push guidewire being connected to the filter, the filter being retractable into the catheter to form a compressed configuration or releasable from the catheter to form an expanded configuration by controlling the push guidewire and the catheter, characterized in that a pressure sensor is mounted at a distal end of the screen of the embolic protection device.

2. An embolic protection device as in claim 1, wherein there are at least two pressure sensors, one at the distal end and one at the proximal end of the screen.

3. An embolic protection device as in claim 1, wherein the pressure sensor comprises a sensor and a protective housing, the protective housing having a channel to allow the sensor to communicate with the outside, the sensor having a proximal end connected to a lead wire, the lead wire extending through an interface inside the delivery guidewire to the proximal end of the delivery guidewire and being connectable to a transmitter through the interface, the transmitter being adapted to transmit the pressure signal to an external display device.

4. An embolic protection device as in claim 1, wherein the pressure sensor is mounted in a push guidewire.

5. An embolic protection device as in claim 1, wherein the filter end is slidably or fixedly connected to the push guidewire, the filter comprises a sleeve mounted at the connection to the push guidewire, and a stop means is fixed to the push guidewire during slidable connection.

6. An embolic protection device as in claim 5, wherein the pressure sensor is located on the sleeve or the stopper.

7. An embolic protection device as in claim 1, wherein the screen is in the form of a pocket or cap with a proximal opening and a distal closure, and the screen is made of a microporous polymeric material or is woven from a plurality of filamentary materials.

8. An embolic protection device as in claim 1, wherein the filter comprises a support ring and a support link.

9. An embolic protection device as in claim 1, wherein the filter, guidewire, catheter and pressure sensor are provided with visualization markers of radiopaque material.