Clot retriever cleaning for reinsertion

Abstract

The invention is entitled "Clot retriever cleaning for reinsertion." The invention provides a clot retrieval cleaning instrument that can have bristles, fluid jets, or other technology to release captured clot material from a clot retrieval device so that the clot retrieval device can be reinserted into a patient's vasculature for successive capture attempts. The cleaning instrument can be conveniently integrated into or connected to a hemostatic valve assembly so that the cleaning function can be performed without completely removing the clot retrieval device from the delivery system. Suction can be applied to remove the released thrombus material. The cleaning instrument can be removed from the delivery system to facilitate washing or disposal of the instrument.

Description

TECHNICAL FIELD

[0001] The present invention relates generally to devices and methods that facilitate cleaning of clot retrieval devices and other devices used to remove acute obstructions from blood vessels during endovascular medical treatment. BACKGROUND

[0002] Clot retrieval devices are used in mechanical thrombectomy for endovascular intervention, particularly in cases where a patient is suffering from conditions such as acute ischemic stroke (AIS), myocardial infarction (MI), and pulmonary embolism (PE). Multiple attempts at clot removal are often necessary, particularly in cases where a relatively large clot is formed in a particularly confined space of the vasculature, such as a cerebral passageway.

[0003] In view of the challenges in treating occlusive clots, much attention has been given to specific implementations and practices. The mechanics of a typical mechanical thrombectomy procedure involve slowing or reversing blood flow at the treatment site in the patient to facilitate separation and retrieval of the blood clot or thrombus material. The delivery system can have a source for direct aspiration into an intermediate catheter or into an access catheter, which is typically used in conjunction with a rotating hemostatic valve assembly and clot retrieval device. While this setup facilitates performing the procedure, it also means that the clot retrieval device typically must be completely removed from the delivery system after each capture attempt in order to be cleaned. Cleaning is typically performed manually by the physician using a cloth and / or a saline jet from a syringe.

[0004] The body itself presents additional therapeutic challenges. In addition to the tortuosity of the path associated with contacting the clot, the nearby vasculature can often be fragile. The structural and functional diversity between different blood vessels in a vascular tree results in variations in their associated biomechanical properties. For example, neurovascular vessels are often more fragile than similarly sized vessels in other parts of the body. The small size and fragile nature of these vessels can often impede clot retrieval devices. For example, stent-like clot retrievers (stent retrievers) rely on applying radial tension on the wall as a way of firmly clamping the obstruction in preparation for removal. However, applying too much force on the vessel wall can result in hemorrhage and perforation. Additionally, while strong clamping of the clot can be desirable during the critical initial steps of retrieval, this can also make post-removal cleaning of the device more difficult and time-consuming when the clot is released from its lodgement.

[0005] Clots can have complex morphology and consistency, ranging from simple tubular structures in the shape of the blood vessel to long, chain-like arrangements that can span multiple blood vessels at once. The stage of the clot can also affect its compliance, with clots that are formed earlier tending to be less compressible than fresh clots, and the interaction of blood pressure more able to deform the vessel itself. Experience has also shown that the mechanical properties of the clot can be affected in significant ways depending on the nature of the interaction with the clot retrieval device.

[0006] Because thrombectomy procedures are highly time sensitive, with increasing risk to the patient as the duration increases, there is a continuing need for improved methods, devices, and systems for improving the speed and efficacy of these procedures. For a number of reasons, including some or all of those listed above, physicians often must adjust procedures to address the challenges encountered. One obstacle that can extend procedure time is that current devices and methods for clot removal often require the physician to make multiple attempts at material removal if the embolus is not completely cleared on the initial attempt. Because the goal of the procedure is to remove the occlusive material and reopen the vessel, debris captured by the removal device must be cleared before subsequent attempts can be made.

[0007] Currently, there is no simple way to clean the extractor in situ between capture attempts, which means that the device must be completely removed from the body and delivery system for cleaning after each attempt. Whenever this is done, access to the target site is lost. In addition, this process extends the time of the procedure because it necessitates manipulation of the delivery system's valve gaskets and other accessory devices that may be used in the operation, while increasing exposure to contamination. Existing devices and methods do not adequately or completely address these challenges. The present invention addresses these challenges by placing cleaning instruments in the removal path of the extractor device. As a result, significant time is saved in cleaning the device, thereby increasing the chances of treatment success. Summary of the Invention

[0008] The present invention is directed to systems, devices, and methods that meet the aforementioned needs. Generally, the present invention is directed to a delivery system for a clot retrieval device and a cleaning instrument integrated into or cooperating with the delivery system positioned in a retrieval path of the clot retrieval device. The cleaning instrument has an opening or entryway sized to receive the device in its deployed configuration and is intended to improve the process of preparing the device for reinsertion into a blood vessel, thereby facilitating further material capture attempts and shortening the overall duration of the invasive procedure.

[0009] Delivery systems for clot retrieval devices can include one or more hemostasis valve assemblies, one or more guidewire clamping devices, and one or more controllable suction sources in series with a suction flow path. Rotational hemostasis valve assemblies facilitate the introduction of microcatheters, guidewires, and ancillary devices, typically through an intermediate or guide catheter, while minimizing backflow and blood loss. This is accomplished by utilizing an inlet channel to the lumen that the catheter and other ancillary devices are fed through, then using a rotational adjustable grommet to maintain a hemostatic seal. The grommet, when open, allows for the introduction of devices into the channel. The grommet, when closed and tightened, controls blood loss while also serving as a device lock, exerting a compressive grip on one or more devices to maintain a static position within the vessel or intermediate or guide catheter. Suction sources are typically connected to the side arms or connection ports of the rotational hemostasis valve assemblies to provide and / or regulate vacuum to one or more catheters. Syringes or vacuum pumps can be connected to interact with the distal tip of the catheter through the catheter lumen and apply vacuum / suction as the clot is retrieved. Connection ports can also be used to introduce saline flushes, inject radiopaque contrast or other products and agents.

[0010] Methods and designs for devices commonly used to capture and retrieve clots are disclosed in the prior art. The present disclosure discloses methods for removing occlusive clots by providing steps of a clot retrieval device having a clot engaging portion with a constrained delivery configuration and an expanded deployed configuration. A microcatheter is advanced from a guide or intermediate catheter toward and through an occlusive clot. A device is loaded into the microcatheter and advanced to the obstruction where the device is deployed to capture the clot. The device and captured clot can then be retrieved into a retrieval catheter and withdrawn from the vessel.

[0011] Various designs have been proposed to physically capture clots, and most clot retrieval devices share many common features and geometries. For example, US 2014 / 0371779, which claims priority to US provisional patent application 61 / 785,213, filed March 14, 2013, discloses an elongated member with an inflatable clot engaging element that expands to extend through a clot to be captured. The design stores potential energy in a collapsed delivery configuration and expands to an expanded helical configuration when it exits a delivery microcatheter at a target site adjacent to an occlusive clot. The engaging element can have an inner and outer inflatable member that when expanded can pass through the obstruction forming a flow lumen, while also having embedded struts to provide a strong grip on the clot for the initial step of dislodging the clot from the vessel. To subsequently retrieve the clot, the device and clot can have to be retracted proximally into a guide or intermediate catheter having a larger diameter. The device and clot can then be withdrawn from the patient through the larger catheter, or can be pulled back far enough to retain the more solid clot at the tip or in the larger catheter to be withdrawn one after the other. The control member used by the physician to manipulate such a device is typically a guidewire, flexible shaft, or some other internal elongated member.

[0012] Other designs such as helical devices and constant suction models are also common. One example of the present disclosure involves a guide catheter and an intermediate catheter having a distal mouth and configured so that it can be advanced within the lumen of the guide catheter. The intermediate catheter is advanced within the vessel to a position adjacent to an occlusive clot, at which point suction is applied to the proximal end of the guide catheter. The suction is directed through the distal lumen of the intermediate catheter to draw the clot to the mouth. The catheter and clot can then be removed from the vasculature together.

[0013] Regardless of the device used for capture, it is an object of the present disclosure to provide a system that cleans the device during subsequent withdrawal from the target site. In one example of the present disclosure, a cleaning instrument is positioned along the retrieval path with a rotating hemostatic valve assembly and is ready to receive the clot retrieval device as it is withdrawn. The instrument has an opening or inlet passage sized to receive the device in its expanded configuration. The retrieval path follows the retrieval path of the delivery microcatheter substantially along the longitudinal centerline of the lumen of the hemostatic valve assembly. The retrieval process is accompanied by suction from a source connected to a connection port of the hemostatic valve assembly. The cleaning instrument can have a variety of axial lengths and can or can not be in physical contact with the retrieval device. The cleaning instrument can include a brush, fluid jet, or other mechanism positioned and configured to clean around the circumference of the retrieval device as it is pulled out along the retrieval path. Manipulation of the device along the removal path through the cleaning instrument is performed by exerting a pushing force on the microcatheter and / or device shaft.

[0014] The bristles may extend radially from the sidewall of the cleaning apparatus, forming an opening or inlet that is substantially axisymmetric with respect to the longitudinal axis of the rotary hemostatic valve assembly. The opening or inlet may be more restrictive in the radial direction than the lumen of the hemostatic valve assembly and may extend from the proximal end of the cleaning apparatus to the distal end. The bristles may have various lengths and shapes, and the opening they form may be cylindrical, conical, or other geometric shapes specific to the extraction device used. In some examples, the bristles may be a simple, uniform tubular structure. In other examples, depending on the composition of the clot or the shape of the extraction device used, it may be advantageous to customize the bending characteristics of the bristles by varying the shape and / or material composition. Thus, the bristles may have a composite stiffness that varies three-dimensionally along the axial length of the cleaning apparatus, the radial length of the bristles from the longitudinal axis, or even the radial position around the circumference of the opening.

[0015] The cleaning instrument can also rotate around the longitudinal axis of the lumen of the hemostatic valve assembly. The cleaning instrument arranged in a rotatable hub or collar can be beneficial for removing thrombotic material from all corners around the circumferential area of ​​the device. Cleaning around the circumference can also help break up large clotted materials by changing the direction of the cleaning force applied by the bristles. Smaller pieces of thrombotic material are usually easier to remove from the removal path by suction or filtration to help ensure that they are not reintroduced into the blood vessel. In addition, the rotatable instrument can allow the density of bristles, jet sources or other cleaning elements to be changed. Similar to the previous example, by applying a thrust on the device shaft extending from the distal end of the delivery system in the same manner as the removal device is delivered and removed from the vessel, the device is moved through the cleaning instrument along the removal path. The device can move upstream and downstream through the cleaning instrument by alternating the direction of the force applied.

[0016] Another example device may include a delivery system having a rotary hemostatic valve assembly and one or more body cavities separated by a branching member disposed therebetween, thereby allowing the body cavities to share a common retrieval path. The branching member may incorporate a seal capable of isolating each body cavity from upstream or downstream fluids and / or pressure differentials. Each body cavity may also have one or more connection ports that share a flow path with the body cavity, wherein the connection ports are sized to receive a fluid injection or suction source. In one example, when the clot retrieval device is withdrawn into the body cavity, heparinized saline or some other fluid may be injected through a first connection port of the body cavity and used in conjunction with a suction source coupled to a second connection port. Such a configuration may allow for flushing and cleaning of the device in one or more body cavities, regardless of other body cavities. Additional cleaning instruments such as a brush or comb may also be incorporated into the body cavity or elsewhere along the retrieval path.

[0017] Cleaning systems that utilize fluid spray or flushing may also be employed, many of which may have the advantage of not involving physical contact of solid objects with the device. The fluid spray may be in gaseous or liquid form, or both, and modulated by a regulator or throttling device to remove clot material from the clot retrieval device and to sterilize the clot retrieval device prior to subsequent reinsertion into the blood vessel. The spray may be delivered, for example, from a nozzle system. The nozzles may be configured to spray simultaneously, or one or more nozzles may operate independently of the other nozzles. For example, the system may include a plurality of nozzles arranged circumferentially in an annular pattern around the retrieval axis. The nozzles may be configured within a housing or shell that may have a Luer fitting, allowing them to be mounted proximal to the hemostatic valve assembly. The shell may have a distal port positioned along the retrieval path, thereby sharing an axis with the longitudinal axis of the hemostatic valve assembly. As the clot retrieval device is pulled out through the port, the nozzle may spray fluid onto the capture portion. Another advantage of such a system is that cleaning is performed around the entire circumference of the retrieval device. The fluid and released material debris may be extracted by a vacuum source, or if it is desired to collect the removed material for further laboratory analysis, the cleaning apparatus may be provided with a filter or reservoir.

[0018] In many cases, it may be desirable to easily remove the cleaning apparatus from the delivery system so that the cleaning apparatus can be cleaned and / or replaced more quickly independently of the system. In one example of the present invention, the cleaning device can be connected in series with the hemostatic valve assembly using a Luer connection or a threaded connection. In other examples of the present invention, the removed cleaning apparatus can be disposable, eliminating the need for sterilization between procedures. In other examples, the material released from the clot removal device can be retained with the cleaning apparatus. Removal of the apparatus allows the material to be collected for further histological laboratory analysis or disposal. Removability also allows the physician to select and use a variety of cleaning apparatus configurations during the same procedure, thereby increasing the chances of successful treatment.

[0019] An exemplary method for cleaning a clot retrieval device in preparation for reinsertion into a patient may include some or all of the following steps and variations thereof. The steps are not listed in any particular order. A delivery system for a clot retrieval device may have a hemostatic valve assembly having a connection port, an inner cavity, a rotary device lock, and a cleaning instrument having an opening sized to receive the clot retrieval device may be provided. A suction source, typically comprising a vacuum pump or a syringe, may be provided and connected to the connection port of the hemostatic valve assembly. A path may be provided through the delivery system and the blood vessel to a location proximate to the occlusive clot, and a cleaning instrument may be positioned in the path. The clot retrieval device with the captured clot may be withdrawn along the path.

[0020] A cleaning device can be used to release clot material from the capture portion of the clot retrieval device while the device remains along a path within the delivery system. The cleaning device can be configured to clean the entire circumference of the capture portion. During the cleaning process, the physician can manipulate the device to allow repeated exposure to the cleaning device, thereby helping to ensure the efficacy of the cleaning process. A suction source can be used to prevent blood backflow and remove released thrombotic material from the path. If desired, the released thrombotic material can be filtered and collected for further laboratory analysis.

[0021] When cleaning is complete, the clot retrieval device can be reinserted into the blood vessel for additional capture attempts. Between capture attempts or at the end of a procedure, the cleaning instrument can also be removed from the system for independent cleaning or disposal.

[0022] Other aspects and features of the present disclosure will become apparent to those of ordinary skill in the art after reviewing the following detailed description in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The above and other aspects of the present invention will be further discussed with reference to the following description of the accompanying drawings, in which like reference numerals indicate like structural elements and features throughout the various figures. The drawings are not necessarily drawn to scale, emphasis instead being placed on illustrating the principles of the invention. The drawings depict one or more specific implementations of the present invention by way of example only and not limitation. It is expected that one skilled in the art will be able to conceive and combine elements from the various drawings to best meet the needs of the user.

[0024] Figure 1 is an illustration of a system for cleaning a clot retrieval device having a delivery system with a cleaning instrument configured within a rotary hemostatic valve assembly according to aspects of the present invention;

[0025] 2a-2b illustrate various views of a removable cleaning instrument having bristles and how the instrument may be integrated into and share a clot retrieval path with a hemostatic valve assembly according to aspects of the present invention;

[0026] 3a-3c illustrate examples of the interaction between a cleaning instrument and a clot retrieval device with a captured clot as the device is pulled along a retrieval path;

[0027] 4a-4b are side and cross-sectional views of a cleaning apparatus disposed along a removal path within a rotatable hub according to aspects of the present invention;

[0028] 5a-5b are illustrations of a system including a cleaning instrument and a hemostatic valve assembly having multiple body lumens and configured to receive fluid injection and aspiration sources;

[0029] Figure 6 A system is shown in which a removable housing has a cleaning instrument integrated with a hemostasis valve assembly to share a removal path;

[0030] Figure 7 yes Figure 6 A side view of a housing having a cleaning apparatus and a collection device according to aspects of the present invention;

[0031] 8a-8c are illustrations of cleaning a nozzle of a clot retrieval device with a captured clot according to aspects of the present invention;

[0032] Figures 9 to 10 are flow charts, each outlining a method for cleaning a clot retrieval device in preparation for reinsertion into a blood vessel according to aspects of the present invention. DETAILED DESCRIPTION

[0033] Specific examples of the present invention will now be described in detail with reference to the accompanying drawings, in which like reference numerals indicate functionally similar or identical elements. However, the present invention is not limited to the examples described, and the construction and details of these examples may vary. The terms "distal" and "proximal" are used throughout the subsequent description and refer to positions and directions relative to the treating physician. Similarly, "distal" or "distalward" refers to a position away from the physician or in a direction away from the physician. Similarly, "proximal" or "proximal" refers to a position close to the physician or in a direction toward the physician.

[0034] In describing the example embodiments, terminology will be employed for the sake of clarity. It is intended that each term assume its broadest meaning as understood by those skilled in the art, and include all technical equivalents that operate in a similar manner to achieve similar purposes. It should also be understood that reference to one or more steps of a method does not preclude the presence of additional method steps or intermediate method steps between those explicitly identified steps. The steps of the method may be performed in an order different from that described herein without departing from the scope of the disclosed technology. Similarly, it should also be understood that reference to one or more components in a device or system does not preclude the presence of additional components or intermediate components between those explicitly identified components.

[0035] As discussed herein, a "patient" or "subject" can be a human or any animal. It should be understood that the animal can be of any suitable type, including but not limited to mammals, veterinary animals, livestock animals, or pet animals. For example, the animal can be a laboratory animal (e.g., rats, dogs, pigs, monkeys, etc.) specifically selected to have certain characteristics similar to those of humans.

[0036] Access to various blood vessels within a blood vessel (whether coronary, pulmonary or cerebral) involves well-known surgical procedures and the use of many conventional commercially available products. These access products, such as catheters, microcatheters, angiographic materials and guidewires, are widely used in laboratories and medical procedures. While these products are used in conjunction with the systems and methods of the present invention described below, their function and exact construction are not described in detail.

[0037] The clot retrieval devices referred to throughout this specification may be any of a number of commercially available products, and most of these products share many common features. Devices that compress the clot upon capture tend to make the clot firmer or "stickier," which can complicate retrieval. Other devices are intended to expand between the clot and the vessel in a manner that minimizes compression while loosening the clot from the vessel wall. Regardless of how the clot characteristics evolve after capture, they affect the level of clamping that the retrieval device can apply and the manner in which the clot is subsequently released from the device during the cleaning process. The advantage of this design is that it allows interaction with the entire circumferential area of ​​the device while providing a high degree of flexibility to the treating physician. The ability of this design to allow for more rapid subsequent retrieval attempts reduces the potential negative effects of clot characteristics and other details that may be beyond the physician's control.

[0038] Figure 1 The clot receiver device 100 of the present invention is shown having a cleaning instrument 120 for removing a clot 40 from a patient's blood vessel 20. A guide catheter can be used to guide the device to the target site. A clot retrieval device 60 can be deployed from the distal end 72 of a delivery microcatheter 70 and can include an elongated proximal shaft 64 having an expanded distal receiver portion 62 for capturing a clot. The delivery system includes a rotary hemostatic valve assembly 101 having a distal end 102, a proximal end 104, and an inner lumen 108, wherein the distal end has an opening sized to accommodate and hemostatically seal the delivery catheter 70. A cleaning instrument 120 has an inlet or channel sized to accommodate the clot retrieval device 60 and can be positioned along and share the clot retrieval path with the hemostatic valve assembly 101. The assembly can have one or more connection ports 110 that can be sized and configured for connection to a suction source, but can also be configured for other functions, such as fluid injection. Typically, a control valve is included to regulate the flow of aspirated blood or other fluid.

[0039] Deployment of the clot retrieval device 60 and positioning of the device during retraction and preparation for cleaning, as well as during cleaning, can be facilitated by applying a radiopaque compound or placing radiopaque markers 68 on the delivery microcatheter 70, guide catheter, and / or clot retrieval device. For example, a radiopaque compound can be incorporated into the receiver portion 62, or one or more radiopaque markers 68 can be added near the distal end of the elongated shaft 66 on both the distal and proximal sides of the receiver portion to mark the end of the device for the physician during the procedure. Suitable practices are frequently used in conjunction with other devices and implants and are well known in the art.

[0040] The rotary hemostasis valve assembly 101 defines a longitudinal axis 114 extending along the lumen 108 from the proximal end 104 to the distal end 102 of the valve assembly. The rotator lock 112 of the hemostasis valve assembly 101 can be articulated by a gasket or seal in closed, partially open, and / or open positions. When the rotator lock 112 is in the partially open position, an accessory (such as the shaft 64 of the clot retrieval device 60) passing through the hemostasis valve assembly 101 can be retracted or delivered through the lumen of the delivery microcatheter 70. Careful positioning of the gasket is crucial. If air leaks through the gasket surrounding the shaft 64, the effectiveness of the applied suction will be reduced. However, if the gasket surrounding the shaft is too tight, it may inhibit the shaft from freely and / or properly engaging during treatment. When in the partially open position, the gasket of the rotator lock 112 provides an adequate seal to prevent air from entering when vacuum is applied to the connection port 110 of the hemostasis valve assembly during suction. In an exemplary thrombectomy procedure, clot retrieval device 60 can capture clot 40 and retract into the guide catheter while the catheter is under vacuum without air leaking through the gasket of the rotary device lock 112 .

[0041] FIG2 a shows a cleaning device 120 of the clot retrieval system 100 of the present invention. The cleaning device 120 may have a bristle element 124 extending radially inward from a sidewall 122 of the device and forming an opening 126 coaxial with the longitudinal axis of the hemostatic valve assembly. The opening extends from the proximal end of the cleaning device to the distal end of the cleaning device. An advantage of the bristle configuration is that the clot retrieval device may have less axial stiffness at the distal end, which provides a deliverability advantage because the device can be self-centered in the device during subsequent cleaning.

[0042] As shown in the cross-sectional view in FIG. 2b, the opening 126 defined by the bristles 124 can be more restrictive in the radial direction than the lumen 108 of the hemostatic valve assembly 101. The bristles can have a volumetric opening along the length of the instrument that is a simplified homogenous cylindrical structure as in this configuration, or the bristles can be more complex conical, conic, or other geometric shapes that are more appropriate for the shape of the extraction device being used. In one preferred example, the stiffness and flex characteristics of the bristles are tailored to the expected stability of the clot to be captured, for example when the clot is particularly firm due to high fibrin content. In this way, the cleaning instrument can be tailored to the needs of the respective treatment for improved efficiency.

[0043] The cleaning instrument shown in the figures is used to illustrate one aspect of the present invention. Of course, the present invention can be applied to cleaning instruments of any shape or size and can be made from several parts.

[0044] FIGS. 3a-3c collectively show a side view of an exemplary sequence in which the clot extraction device 60 is pulled out through a cleaning instrument 120 having bristles 124. The instrument can be disposed within the lumen 108 of a hemostatic valve assembly. The bristles can be more restrictive in the radial direction than the lumen and are sized to fit the capture or receiver portion 62 of the clot extraction device 60. The physician uses the shaft 64 of the device to pull the device from downstream along the extraction path. FIG. 3b shows the device as it approaches the cleaning instrument, it moves through the lumen towards the proximal end of the hemostatic valve assembly. The capture or receiver portion 62 shown in this figure includes a plurality of struts and can have a captured clot 40, but can also contain smaller thrombus material 42 or debris from the vasculature at various radial positions around its circumference. The physician can manipulate the device proximally and distally through the bristles as many times as needed until the receiver portion 62 is emptied and the debris 42 is released.

[0045] A vacuum source can have to be used during this extraction procedure to reverse flow in the vasculature to prevent the released clot debris from escaping and passing distally through during cleaning. This negative pressure differential can be maintained or even increased after the material is released from the device to further remove material from the extraction path and lumen. The vacuum can then be further varied or removed when the clot extraction device is reintroduced into the vasculature to complete recanalization of the patient’s blood vessel.

[0046] FIG4 a shows a side view of another example of a system 400. Similar to the previous example, a clot retrieval device is withdrawn along a retrieval path through the lumen 108 of the hemostatic valve assembly 101, from its distal end 102 toward its proximal end 104. A cleaning instrument 120 is disposed within a rotatable hub 460. The hub may have one or more fittings 462 and 464, such as Luer connectors, at its distal and proximal ends to facilitate interaction with the system, thereby allowing it to rotate about the longitudinal axis 114 of the hemostatic valve assembly 101. These fittings also allow for easy removal of the hub from the hemostatic valve assembly. This type of system offers numerous advantages. It allows the hub to mate with any standard hemostatic valve assembly configured with connection fittings at its proximal and / or distal ends. A physician can rotate the hub as much as necessary to remove particularly stubborn clot material around the entire circumference of the device. Removal of clot material from the system 400 can then be accomplished by using a vacuum source (not shown in this figure) connected to the connection port 110 of the hemostatic valve assembly 101. In an advantageous example, the cleaning instrument is positioned proximal to the connection port. Alternatively, the physician may allow debris to remain within the hub, which may be quickly removed from the hemostatic valve assembly by manipulating the distal fitting 462. The hub may then be cleaned or disposed of independently, and, if desired, clotted material collected for further analysis.

[0047] FIG4 b shows a cross-sectional view of the hub 460 showing the cleaning apparatus 120 disposed therein. The optimal dimensions of the cleaning apparatus and bristles 124 depend to a large extent on the size of the clot removal device and the target clot itself. In one example, the bristles 124 are disposed around the entire circumference of the cleaning apparatus sidewall 122. In another example, the bristles may be disposed only at selected timing positions around the circumference of the apparatus sidewall. The bristles may again have a volume opening along the length of the apparatus that is a simplified, uniform tubular structure, or the bristles may be a more complex tapered, conical, or other geometric shape that is more suitable for the shape of the removal apparatus used. As described in the previous examples of the present invention, the stiffness and bending characteristics of the bristles may be customized according to the stability and firmness of the clot to be captured, and, if desired, may even be constructed to have a composite stiffness.

[0048] In this configuration, the physician can even replace the cleaning instrument intraoperatively if the initial cleaning proves to be unsuccessful or inefficient. The first cleaning instrument can be removed by manipulating the distal fitting of the hub, and a second cleaning instrument having different properties or characteristics can then be attached to the hemostatic valve assembly.

[0049] The purpose of the present invention is to eliminate the need for a gripping device or a device removed from a delivery system between removal attempts while also maintaining sterility and a high level of cleanability. Further aggregation and breaking up of clots during cleaning can be beneficial for discharging clots from the system. There are many commonly used methods for clearing cannulas of arterial and venous lines to sterilize and prevent clots and obstructions, which can be used to help remove and separate clots captured in clot removal devices. Flushing is typically used, such as saline or heparinized saline. Breaking up clots can be achieved by introducing fibrinolytic agents such as tissue plasminogen activators (tPA) such as alteplase, reteplase, and tenecteplase.

[0050] In another embodiment, shown in Figures 5a and 5b, a system 500 may include a rotary hemostasis valve assembly 501 comprising a proximal end 104, a distal end 102 sized for a delivery microcatheter, a swivel lock 112, a longitudinal centerline 114, and at least two internal body lumens separated by one or more central branches 516. The central branches may have a closeable mechanical seal or gasket 518 disposed therein. In one example, the hemostasis valve assembly may have a first body lumen 515 and a second body lumen 517 located proximal to the first body lumen and sharing a retrieval path with a clot retrieval device. When the seal 518 is open, the first and second body lumens share a common flow path. When the seal is closed, the common flow path is divided into a first flow path in the first body lumen, which is isolated from a second flow path in the second body lumen. The first body lumen may have at least one connection port 510 that shares a flow path with the first body lumen and is sized to receive a suction source, such as a vacuum pump or syringe. The second body cavity may have at least a first connection port 509 and a second connection port 511, each of the first connection point and the second connection point sharing a flow path with the second body cavity. The first connection port 509 of the second body cavity may be sized to receive fluid infusion, such as water, heparinized saline and / or tPA, and configured to flush the second body cavity when the clot retrieval device is withdrawn therefrom. The second connection port 511 of the second body cavity is sized to receive a suction source for draining the contents of the second body cavity. The suction source may be the same as the suction source connected to the connection port 510 of the first body cavity, or it may be a second source, thereby allowing the vacuum pressure drawn in the second body cavity to be different from the vacuum pressure drawn in the first body cavity. The seal 518 prevents the contents of the second body cavity from migrating downstream. If desired, additional connection ports may be constructed into the side of the hemostatic valve assembly 501 to provide the physician with greater procedural flexibility.

[0051] In this example, a bristled cleaning instrument 520 may be further integrated with the hemostatic valve assembly 501. Alternatively, the cleaning instrument may be disposed within a rotatable hub as previously seen in the system 400 and connected to the system 500. The cleaning instrument may be used in conjunction with fluid irrigation to aid in the removal of clotted material from the retrieval device.

[0052] In another example, Figure 6 The illustrated system 600 includes a housing or shell 680 integrated with the hemostasis valve assembly 101. The shell is configured to be mounted upstream and proximal to the proximal end 104 of the hemostasis valve assembly. The shell can have a distal fitting 682 and a proximal fitting 684, such as a Luer connection, for coupling and disconnecting with the hemostasis valve assembly 101 or other devices in the delivery system. As in the previous examples, the hemostasis valve assembly has a connection port 110 for attaching a suction source. The hemostasis valve assembly can also have a distal end 102 and an inner lumen 108, wherein the distal end is sized to fit within a delivery catheter and the inner lumen has a longitudinal axis 114 that is along a retrieval path of a clot retrieval device.

[0053] A view of the interior of the housing 680 of the system 600 is shown in FIG. Figure 7 . The housing may have a distal mouth 794 with a circumferential opening 730 that shares an axis with the longitudinal axis 114 of the hemostatic valve assembly and the removal path. Proximal to the mouth, the cleaning device 720 may include a plurality of nozzles 726 that are arranged in an annular pattern around the axis 114 and are configured to spray 798 fluid onto a circumferential area of ​​the clot retrieval device as the clot retrieval device 60 is withdrawn along the removal path. This allows the cleaning process to be performed without physical contact other than the fluid and without exposing the device to contaminants external to the system. As in the previous example, the engagement of the clot retrieval device with the shaft 64 allows repeated exposure to the spray of the cleaning device, or allows the device to remain in the spray if a fibrinolytic agent such as tPA is used in the system.

[0054] The nozzles 726 can be configured to spray 798 simultaneously in a balanced manner, or one or more nozzles can operate independently of the other nozzles. The angle of incidence of the spray on the capture portion 62 of the retrieval device can vary from nozzle to nozzle, ranging from almost perpendicular to the retrieval path (as shown in Figure 8a) to a substantially more oblique angle. Such an arrangement also provides the following advantages: more surface area of ​​the clot 40 is exposed to the spray 798, while changing the direction of the force acting on the clot from the spray. The spray can be in the form of a gas or liquid or both, and the volume flow rate can be varied by throttling modulation. The spray can be configured to remove clot material from the capture portion 62 and sterilize the clot retrieval device before subsequent reinsertion into the blood vessel.

[0055] Figure 6 and Figure 7The housing shown is used to illustrate an example according to various aspects of the present invention. Of course, the present invention is applicable to housings of any shape or size, and may be made of several parts and made of materials that allow the user to see the interior. The housing may or may not be symmetrical, as long as it is located on the removal path.

[0056] The fluid and released material debris 42 may be removed by a vacuum source, or if it is desired to collect the removed clot material for further laboratory analysis, the housing 680 may also include a collection device 792 having a filter 788 and a collection reservoir or basin 790. The collection device 792 may have threads or some other means of attachment to the housing, allowing it to be removed at any point during the mechanical thrombectomy procedure.

[0057] Laboratory analysis may include clot analysis, such as some or all of a series of steps, but not limited to: blood tests, non-contrast computed tomography (CT) scans, including quantitative methods of analyzing stroke severity, such as the Alberta Stroke Program Early CT Score (e.g., ASPECTS), and automated assessment of ASPECTS using software (e-ASPECTS) taking into account patient history, stroke severity, such as the National Institute of Health Stroke Severity Scale (NIHSS) clinical examination and / or neurological examination.

[0058] The patient's clinical history may include factors such as whether the patient is between 18 and 85 years of age; an mRS score of 0 or 1; angiographically confirmed internal carotid artery (ICA) occlusion (including T or L occlusion), M1 or M2 MCA, VA, or BA occlusion with an mTICI flow of 0 to 1; MRI criteria: a visually assessed diffusion-restricted volume ≤ 50 mL; CT criteria including an ASPECTS score of 6 to 10 on baseline CT or CTA source images, or a significantly decreased CBV ≤ 50 mL; a life expectancy of less than 6 months; a pregnant or breastfeeding woman; a history of severe allergic reaction to contrast media; a known nickel allergy at the time of treatment; known current cocaine use at the time of treatment; a stroke in the past 3 months; or a NIHSS score of <8 or > 25, or in a clinically relevant, uninterrupted coma as assessed by a physician; using warfarin or any new anticoagulant with an international normalized ratio (INR) > 3.0; platelet count < 50,000 / μL; glucose < 50 mg / dL; any known bleeding or coagulation deficiency; unstable renal failure with serum creatinine > 3.0 or glomerular filtration rate (GFR) < 30; patients receiving direct thrombin inhibitors within the past 48 hours; prothrombin time (PTT) less than 1.5 times normal; patients with severe hypertension (SBP > 220 mmHg) Hg and / or DBP >120 mm Hg); cerebral vasculitis; improvement in neurologic status; clinical symptoms suggestive of bilateral stroke or stroke in multiple territories; ongoing seizures due to stroke; evidence of active systemic infection; metastatic disease; evidence of recent bleeding on CT or MRI; a mass or intracranial tumor (excluding meningioma) on baseline CT or MRI; suspected aortic dissection with presumed septic embolism or suspected bacterial endocarditis; stenosis or any obstruction in a proximal vessel requiring treatment or blocking access to the site of obstruction; evidence of extracranial or intracranial arterial dissection; and / or obstruction of multiple vascular territories (e.g., bilateral anterior circulation or anterior / posterior circulation).

[0059] The laboratory analysis may also include a CT scan, whereby one normal X-ray and a second, less powerful X-ray are used simultaneously to make an image. The two X-rays will produce different spectra using different tube potentials. One method of using a CT scan is described in U.S. patent application Ser. No. 16 / 001,427, which is incorporated herein by reference in its entirety as if set forth verbatim herein. In conjunction with the laboratory analysis herein, it is also contemplated to use MRI and / or advanced MR images of the patient's brain to assess the clot. Advanced MR images may include precision magnetic resonance imaging techniques that assess the freedom of water molecule movement in a selected area, microvascular integrity and hemodynamic properties, and the chemical composition of the clot. Advanced MR may include perfusion imaging, diffusion-weighted imaging, and MR spectroscopy, as well as magnetic resonance angiography and / or magnetic resonance photography.

[0060] Laboratory analysis may also include carotid ultrasound, cerebral angiography, echocardiography, intravascular ultrasound (IVUS), and / or optical coherence tomography (OCT).

[0061] Laboratory analysis may also include one or more blood tests and non-contrast and / or contrast CT scans of the patient, including areas of the brain to view the brain's structure and evaluate for clots, especially since no preparation is required for the patient.

[0062] With respect to analyzing the material fragments 42 released from the fluid reservoir 790 or trapped in the filter 788, the analysis may also include spectroscopic techniques, such as near infrared spectroscopy (NIR) and / or Raman spectroscopy, to generate spectra related to the chemical composition and physical characteristics of the corresponding obstruction. In this regard, the information contained in the spectral bands can be interpreted to provide an almost instantaneous analysis of the properties of the material being tested. In certain embodiments, instrumentation associated with NIR and / or Raman spectroscopy can be included in a microcatheter associated with the clot retrieval system.

[0063] Laboratory analysis can also include scanning the fluid and released material debris using a catheter with a fiber optic bundle core connected to a NIR or Raman spectrophotometer 42. A spectrum of the transmitted light can be generated, and this information can be used to predict the composition of the material from which the light was reflected. For example, chemical information corresponding to the bulk composition of the clot can be deciphered from light absorption in the near-infrared portion of the electromagnetic spectrum and can be used to measure the relative composition of RBCs, water, fibrin, etc. within the clot. Physical information that can be detected in this embodiment can relate to the compactness and organization of the clot caused by the scattering and diffusion of light.

[0064] Laboratory analysis can also include determining criteria associated with the fluid and released material debris 42. For example, red blood cell counts, white blood cell counts, serum levels, fibrin levels, etc. can be established to classify the clot. A sample of the clot can then be visually or tactilely analyzed to help select an appropriate device for further procedures. An indication of clot composition can be provided that advantageously allows the clot to be classified as follows in both qualitative and quantitative terms, including excluding the presence of hemorrhagic stroke. Such information can include cellular components, extracellular components, morphology, organization and distribution of components, permeability, adhesion, water content, resistance to degradation, fibrin crosslink density, fiber diameter, modulus, strain, deformation (e.g., elasticity, plasticity, viscoelasticity), compressibility and / or fracture behavior. An example table of such indications is provided herein without limitation, and other qualitative and / or quantitative indications are contemplated for use with the embodiments disclosed herein:

[0065] The housing 680 of system 600 can also include an entry port 686 for entering the interior of the housing without removing it from the hemostatic valve assembly. The entry port can be any of a variety of shapes and can have a cover that can be hinged or slid to seal the port when not in use. The entry port can allow a physician to perform a target function without removing the clot removal device from system 600. For example, a method for further promoting fibrinolysis can be utilized to target stubborn clots. In addition, as shown in Figure 8b, a manually hinged nozzle 896 can be introduced to enhance the spray 798 pattern of the cleaning apparatus 720. For example, a thrombus fragment 42 is retained in a more isolated fragment of the capture portion 62 of the clot removal device 60 to be selectively targeted. Figure 8c also shows that the entry port can also allow selective application of heat or alternate sterilization methods, such as steam, ultraviolet radiation or gas vapor sterilants (e.g., ethylene oxide, ozone).

[0066] The system 600 can be designed according to the examples and principles disclosed herein and need not be specifically designed or shaped as shown in the figures.

[0067] Figure 9 and Figure 10 The present invention provides a flow chart, each of which includes method steps for cleaning a clot retrieval device in preparation for reinsertion into a patient's blood vessel for subsequent capture attempts. The method steps can be implemented by any of the exemplary systems, devices, and / or apparatus described herein or by means known to one of ordinary skill in the art.

[0068] refer to Figure 9 The method 900 shown, step 910 describes providing a delivery system for a clot retrieval device, the delivery system including a hemostatic valve assembly with one or more connection ports, an inner cavity, a rotator lock, and a cleaning instrument having an opening sized to receive the clot retrieval device. In step 920, the cleaning instrument can be removed from the delivery system. In step 930, the delivery system has a common housing for integrating a suction source, the cleaning instrument, the rotator lock, and the hemostatic valve assembly. In step 940, a suction source (typically a vacuum pump or a syringe) is attached to the connection port of the hemostatic valve assembly.

[0069] In step 950, a path is defined through the delivery system and the patient's blood vessels to a location proximate to the occlusive clot. A clot retrieval device is used to capture the clot, and the clot retrieval device is removed using conventionally known techniques. In step 960, the clot retrieval device is withdrawn along the path along with the captured clot. While the device is along the path and within the delivery system, in step 970, a cleaning instrument is used to release the captured clot material from the capture portion of the clot retrieval device.

[0070] See also Figure 10In step 1010, a physician manipulates a shaft or control member of a clot retrieval device to repeatedly expose the capture portion of the device to a cleaning instrument. In step 1020, a suction source is used to prevent backflow of blood while also removing released thrombotic material from the retrieval path. In step 1030, a filter element is provided within the system to collect clot material and debris for further laboratory analysis. In step 1040, the cleaned clot retrieval device is reinserted into the blood vessel for subsequent capture attempts of additional thrombotic material. In step 1050, the cleaning instrument is removed from the system for cleaning and / or disposal.

[0071] "Comprising" or "containing" or "including" means that at least the named compound, element, particle or method step is present in the composition or article or method, but does not exclude the presence of other compounds, materials, particles, method steps, even if other such compounds, materials, particles, method steps have the same function as those named.

[0072] It should also be noted that, as used in this specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Ranges may be expressed herein as "about" or "approximately" one particular value and / or "about" or "approximately" another particular value. When such a range is expressed, other exemplary embodiments include from the one particular value and / or to the other particular value.

[0073] Some references, which may include various patents, patent applications, and publications, are cited in the reference list and discussed in the disclosure provided herein. Citation and / or discussion of such references are provided solely to illustrate the description of the present invention and are not an admission that any such reference is "prior art" for any aspect of the disclosure described herein. In terms of notation, "[n]" corresponds to the nth reference in the list. All references cited and discussed in this specification are incorporated herein by reference in their entirety to the same extent as if each reference were individually incorporated by reference.

[0074] The descriptions contained herein are examples of embodiments of the present invention and are not intended to limit the scope of the present invention in any way. Although specific examples of the present invention have been described, various modifications may be made to the apparatus and method without departing from the scope and spirit of the present invention. For example, although the examples described herein relate to specific components, the present invention includes other examples of implementing the functions using various combinations of components, implementing the functions using alternative materials, combining components of various examples, combining components of various examples with known components, etc. The present invention contemplates replacing the component parts shown herein with other well-known and commercially available products. For those of ordinary skill in the art to which the present invention relates, these modifications are generally apparent and are intended to fall within the scope of the following claims.

Claims

1. A system for cleaning a clot retrieval device, comprising: A hemostatic valve assembly, comprising: distal end; an inlet at the distal end, the inlet sized to receive a delivery catheter; proximal end; a hollow lumen having a longitudinal axis disposed between the proximal end and the distal end; and a swivel lock at said proximal end; and A cleaning instrument is sized to receive a clot retrieval device and share a retrieval path of the clot retrieval device with the hemostatic valve assembly.

2. The system of claim 1, wherein the cleaning apparatus comprises a plurality of bristles extending radially from a sidewall of the cleaning apparatus.

3. The system of claim 2, wherein the bristles form a substantially axisymmetric opening coaxial with a longitudinal axis of the hemostatic valve assembly.

4. The system of claim 3, wherein the opening formed by the bristles of the cleaning instrument is sized to be radially more restrictive than the lumen of the hemostatic valve assembly.

5. The system of claim 1, wherein the cleaning instrument is disposed within a removable hub rotatable about a longitudinal axis of the hemostatic valve assembly.

6. The system of claim 1, further comprising a connection port sized to receive a suction source.

7. The system of claim 1, wherein the cleaning instrument is removable from the hemostatic valve assembly.

8. The system of claim 1 , wherein the hemostatic valve assembly further comprises: a central branch disposed between a first body cavity and a second body cavity proximal to the first body cavity; a seal disposed within the length of the central branch; a connection port that shares a flow path with the first body cavity, the connection port being sized to receive a suction source; as well as A first connection port and a second connection port, wherein the first connection port shares a flow path with the second body cavity, the first connection port is sized to receive fluid injection, and the second connection port shares a flow path with the second body cavity, the second connection port is sized to receive a suction source.

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