Aspiration system with accelerated response

Abstract

To provide a vacuum suction system for sucking a target substance such as an occlusion from a vascular system.SOLUTION: The suction system shows an accelerated decrease of the negative pressure at the distal end of the suction catheter from the opening time of the valve. The system includes a suction pump in communication with the first chamber and a suction catheter configured to be in fluid communication with the first chamber via an elongate suction tube. A second chamber is provided between the suction tube and the catheter, and a valve is provided between the second chamber and the suction catheter. When the valve is opened with the first and second chambers in equilibrium, the resistance to fluid flow between the second chamber and the distal end of the catheter is less than the resistance to fluid flow between the second chamber and the first chamber, thereby causing rapid suction into the second chamber.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority under 35 U.S.C. §119(e) to U.S. Provisional Patent Application No. 63 / 044,511, filed June 26, 2020, the entire contents of which are incorporated herein by reference. This application is a continuation-in-part of U.S. Patent Application No. 17 / 125,723, filed December 17, 2020, and also claims priority under 35 U.S.C. §119(e) to U.S. Provisional Patent Application No. 62 / 950,058, filed December 18, 2019, and U.S. Provisional Patent Application No. 63 / 064,273, filed August 11, 2020, the entire contents of which are incorporated herein by reference. [Background technology]

[0002] Thrombotic lesions and blockages in a patient's blood vessels are serious medical problems, and intervention to remove these lesions and blockages is often required to restore the patient's health. While applicable to a wide range of vascular applications in both the arterial and venous systems, including various small blood vessels, the following background focuses on this issue primarily through the example of a patient suffering from a pulmonary embolism.

[0003] Venous thromboembolism (VTE) is a global crisis. More than 10 million cases of deep vein thrombosis (DVT) and pulmonary embolism (PE) are diagnosed annually worldwide, with over 1 million occurring in the United States and over 700,000 cases annually in France, Italy, Germany, Spain, Sweden, and the United Kingdom. Approximately 60,000 to 100,000 people die from PE each year in the United States. DVT and PE are part of the same spectrum of diseases, with over 95% of emboli originating in the lower extremities. When PE occurs, its severity depends on the embolic burden, the impact on the right ventricle, and underlying cardiopulmonary comorbidities. Death can occur due to a sudden increase in pulmonary artery (PA) pressure with increased right ventricular (RV) afterload and dysfunction.

[0004] Patients with high-risk pulmonary embolism (PE) have primarily been treated with thrombolytic therapy, either delivered systemically or more locally via catheter-directed thrombolysis. These approaches result in multiple catheterization lab visits, prolonged hospital stays, and often lead to bleeding complications. A novel approach to PE treatment involves single-stage thrombectomy procedures without the use of thrombolytic agents. In these procedures, a catheter is inserted into the PA to remove the thrombus by aspiration, and secondary tools may be used to macerate or disrupt the thrombus prior to aspiration. Although thrombectomy results in fewer bleeding complications and shorter hospital stays compared with thrombolytic agents, there remains much room for improvement given the challenges inherent in the procedure, including the ability to capture a wider range of thrombus types and reduce overall procedural blood loss.

[0005] The thrombectomy catheter is introduced through an introducer puncture in a large vein. A flexible guidewire is passed through the introducer and into the vein, and the introducer is removed. The flexible guidewire provides a rail for advancing the flexible guide catheter from the right atrium into the right ventricle and into the pulmonary artery. The flexible guidewire is removed and replaced with a rigid guidewire. A large-diameter thrombectomy catheter with a support dilator is then advanced over the rigid guidewire into the pulmonary artery, and the dilator is removed. If the large-diameter thrombectomy catheter cannot adequately access or aspirate thrombi in more distal portions of the vessel, a smaller-diameter catheter may be inserted through the larger-diameter catheter.

[0006] Additionally, peripheral arterial occlusive (PAO) disease occurs in more than 4% of individuals over the age of 40, with incidence increasing significantly after the age of 70. Acute PAO usually results from peripheral vascular thrombosis and is associated with a serious risk of limb loss. To preserve the limb, treatment of acute PAO focuses on rapidly restoring arterial patency and blood flow, such as by mechanical thrombectomy using procedures similar to those described above.

[0007] Clot aspiration using certain commercially available vacuum-assisted thrombectomy systems may sometimes need to be terminated due to the risk of excessive blood loss by the patient, especially when using large aspiration catheters. During aspiration thrombectomy, when the catheter tip loses contact with a clot or other occlusive material, the tip is exposed to healthy blood, causing the blood within the catheter to completely drain. In this situation, the total blood loss may be excessive, potentially necessitating premature termination of the procedure. For example, when the catheter enters healthy blood during a procedure and full aspiration flow continues, the blood loss rate may be on the order of 30 to 40 cc per second with a 24 French catheter. Given a maximum allowable blood loss of approximately 500 mL, the catheter can only operate in unlimited mode for approximately 10 to 15 seconds. Total blood loss may reach unacceptable levels before sufficient clot removal is achieved. Summary of the Invention

[0008] According to one aspect of the present invention, a first vacuum aspiration system is provided, such as for aspirating targeted material, such as obstructions, from the vasculature. The system includes a housing, a fluid flow path extending through the housing, and a chamber for capturing and storing the removed material. A first catheter is in fluid communication with the flow path, and a connector is configured to allow a source of aspiration (vacuum) to communicate with the flow path. A flow regulator is configured to regulate a fluid flow rate through the flow path. One, two, or more operator-actuated controls are configured to switch the flow regulator between a default low-flow mode and a momentary, operator-initiated high-flow mode in response to operator initiation. The same or a separate control may be provided for switching the aspiration between an off mode and an on mode.

[0009] The system further includes a sidewall containing the flow channel, the sidewall having an optically transparent window, and at least a portion of the sidewall may be in the form of an optically transparent tube.

[0010] The flow regulator may include a variable-sized constriction in the flow path. The flow regulator may include a flexible flow path wall or tubing and an actuator configured to compress the flexible tubing. Alternatively, the flow regulator may include an adjustable opening, such as an iris or valve, or a valve that switches the flow path between a low-flow (e.g., small diameter) path and a high-flow (e.g., large diameter) path. Alternatively, the flow regulator may include tubing having a length and inner diameter selected to provide the desired flow regulation.

[0011] The housing may further include a port in communication with the first catheter for guiding a second, smaller catheter through the housing and into and through the first catheter. A hemostatic valve may be carried by the housing in communication with the port.

[0012] The system may further include a reservoir for receiving the clot and blood retrieved through the first catheter. The reservoir includes a filter for separating the clot from the blood and a window for visually observing clots accumulated on the outer or inner surface of the filter. In one implementation, the filter includes a tubular membrane spaced radially inward from an outer transparent tubular wall to form an annular clot-receiving chamber between the tubular wall and the tubular membrane. Fluid flow during aspiration may be radially inward from the clot-receiving chamber through the membrane. At least a portion of the reservoir may be removably carried by the housing.

[0013] The housing may additionally include an injection port for connecting an injection lumen extending axially through the first catheter to an outlet port located at the distal end of the catheter. The injection lumen may be used to inject a predetermined amount of an active agent, such as a thrombolytic agent, or to introduce a contrast agent to allow visualization of the vasculature. Alternatively, the injection lumen may be used to inject a predetermined amount of saline to facilitate flushing of the catheter and / or dilution of the contrast agent and / or aspirated blood, thereby minimizing total blood loss as a result of the procedure. The lumen may also be utilized to measure blood pressure at the distal end of the catheter.

[0014] The system may additionally include a reinfusion circuit for conducting filtered blood from the reservoir through a reinfusion path through the housing in communication with a reinfusion port configured to communicate with a reinfusion lumen extending axially through a separate reinfusion catheter that may be positioned within a patient's reinfusion site, or to a reinfusion lumen on the access catheter that terminates in an infusion outlet port. The outlet port may be an end port or a side port on the first catheter, spaced proximally from the distal end of the catheter.

[0015] During blood aspiration in the absence of a thrombus, the second, low-flow mode may aspirate fluid at a rate of about 20 cc / sec or less, generally about 10 cc / sec or less, typically in the range of about 1 cc / sec to 5 cc / sec. The third, high-flow mode aspirates fluid at a rate of at least about 10 cc / sec, generally at least about 15 cc / sec, and in one implementation of the invention, about 20 cc / sec. Generally, the aspiration rate in the high-flow mode will be about 40 cc / sec or less when aspiration is unimpeded. The flow rate in the low-flow mode is typically about 10% to about 75% of the aspiration rate in the high-flow mode, and in some implementations, about 20% to 30%.

[0016] A second vacuum suction system may be provided via a Y-connector in the tubing (rather than a separate second pump and canister) for cooperation with the first vacuum suction system, as may be desired depending on the clinical situation. The second vacuum suction system may have all the features and options described in connection with the first vacuum suction system, except that the outer diameter of the second catheter on the second vacuum suction system is smaller than the inner diameter of the fluid passage through the first catheter, and the length of the second catheter is longer than the length of the first catheter.

[0017] If the clot cannot be reached or aspirated by the first vacuum suction system, a second catheter may be advanced distally through the first catheter and beyond the distal end of the first catheter, allowing an additional opportunity to retrieve the clot.

[0018] In one implementation of the invention, the first catheter may be 24 French and may have a length in the range of about 80 cm to about 110 cm. The complementary second catheter may be 16 French and may have a length in the range of about 110 cm to about 130 cm. Typically, the second catheter will have a length that is at least about 10 cm longer than the length of the first catheter, and in some implementations at least about 20 cm longer.

[0019] According to another aspect of the present invention, a vacuum aspiration catheter and control system is provided. The system includes a housing, a fluid flow path extending through the housing, a first catheter in fluid communication with the flow path and a connector configured to connect a suction source to the flow path, and a flow regulator configured to regulate fluid flow through the flow path. At least a first operator-operated control is provided, configured to switch the flow regulator between a default low-flow mode and a momentary, operator-initiated high-flow override mode. The system may additionally include a second operator-operated on-off control for switching between an off mode and the low-flow mode. The first and second controllers may be carried by the housing.

[0020] A second catheter port may be provided on the housing in communication with the first connector for guiding a second catheter through the housing and into and through the first larger diameter catheter. A hemostatic valve may be carried by the housing in communication with the second catheter port.

[0021] The flow path is defined within a tubular sidewall having an inner diameter, and the clinically significant change in the inner diameter in the direction from the first catheter toward the clot collection chamber is an increase. At least a portion of the sidewall may be optically transparent to provide a viewing window for the contents of the flow path. In one implementation, the window is located between the flow control regulator and the first catheter, such as between the housing and the first catheter, or is incorporated within the housing or the first catheter.

[0022] The system may be configured in combination with a reservoir for receiving thrombus and blood retrieved through the first catheter, as described above. A filter may be disposed within the reservoir, and material captured by the filter is visible through a viewing window in a sidewall defining the reservoir. The sidewall may be removably connected to the housing, thereby allowing the reservoir and filter to be removed from the housing.

[0023] The housing may be integrated into the proximal hub of the first catheter. Additional controls may be provided on the housing depending on desired functionality. For example, one, two, or more pull wires may extend axially through the catheter to steer the distal end of the catheter. The proximal ends of the pull wires may be connected to a steering control, such as a lever, slider switch, or rotary control. The pull wires extend distally through the catheter to a steering zone. A single pull wire may be implemented to provide lateral deflection in a single direction within a single plane. Two wires may be implemented to provide lateral deflection in both directions within a single plane, or to provide deflection in two different planes without rotating the catheter or housing.

[0024] According to another aspect of the present invention, a method for removing a vascular occlusion is provided. The method includes transvascularly advancing the distal end of an aspiration catheter into proximity with an obstruction and activating a detection mode that aspirates at a low flow rate through the catheter. In the detection mode, if the actual flow rate is significantly lower than the expected flow rate, indicating the detection of a clot, the method may additionally include operating a momentary control to activate a high-flow bolus aspiration mode, thereby more aggressively drawing the obstruction into the distal end of the catheter. Activating the momentary control may increase the restriction of the flow path between the clot container and the vacuum source. The operator may then deactivate (e.g., release) the override control, and the system will default to a second, low-flow mode. Alternatively, a negative pressure spike at the distal end of the catheter may be achieved using a dual vacuum chamber system, described in more detail below.

[0025] The blood and clots aspirated during the procedure may be directed into a collection chamber and / or through a filter to separate the clots from the blood, and the filtered blood may be returned to the patient.

[0026] Pulling the thrombus proximally through the first catheter may be facilitated by using a second catheter that is driven forward through the first catheter.

[0027] The method may include advancing a distal end of the first catheter or the second catheter to a location near the pulmonary embolism, a location near the deep vein thrombosis, or a location near the peripheral arterial or venous occlusion.

[0028] According to another aspect of the present invention, a flow control device for a large-bore thromboembolic aspiration system is provided. The control device includes a housing defining a central cavity and having a patient port, a manifold port, and a filter port. A movable gate is provided within the housing, the gate having a flow path and configured to selectively communicate the patient port with the filter port and the patient port with the manifold port. The same flow control device, or a separate control device, may also, optionally, communicate the manifold port with the filter port.

[0029] The movable gate may include a cylindrical body having a first port in communication with a second port via a flow passage through the body, and the first port, second port, and solid sidewall may be spaced apart between approximately 120 degrees and 180 degrees around the circumference of the gate.

[0030] Also provided is a system including a catheter and a hemostatic valve. The catheter includes an elongated, flexible tubular body having a proximal end, a distal end, and a central lumen. The hemostatic valve may be disposed within a housing on the proximal end of the catheter. The hemostatic valve includes a collapsible tubular sidewall defining a valve lumen in communication with the central lumen of the catheter. A filament forms a loop around the tubular sidewall, the filament having at least a first tail portion extending away from the loop and connected to a first lever. A first spring is configured to actuate the first lever in a direction to pull the first tail portion away from the tubular sidewall, thereby reducing the diameter of the valve lumen in response to reducing the diameter of the loop.

[0031] The filament may further include a second tail portion extending between the loop and the second lever. The first and second levers may be biased to place the first and second tail portions under sufficient tension to reduce the diameter of the central lumen and provide a seal around a secondary device extending through the valve. The first and second levers may additionally be biased to place the first and second tail portions under sufficient tension to occlude the valve in the absence of a secondary device passing therethrough.

[0032] The inner diameter of the tube may be continuously controlled from the original fully open inner diameter of the collapsible valve lumen to a fully closed state sufficient to clinically eliminate leakage for blood or other fluid flow through the valve, with or without the presence of a dilator, guidewire(s), and / or catheter within the valve lumen. This allows the hemostatic valve to function without air or liquid leakage anywhere between fully closed and fully open, as needed. Two or more devices may extend side-by-side through the hemostatic valve (e.g., a catheter and a guidewire in parallel).

[0033] The hemostatic valve may be shipped with a retention feature, such as a pin or clip, to hold the valve open between manufacture and use. Additionally, in some clinical situations, it may be desirable to hold the valve open for one or more steps, such as to reduce friction with a dilator as it is advanced or retracted through the valve. As may be desired, a retention feature, which may be in the form of a handle, or a clip or control may be provided on the housing to selectively and temporarily lock the valve open during a procedure.

[0034] Also provided is an aspiration catheter deployment system including a catheter with an elongate, flexible tubular body having a proximal end, a distal end, a sidewall defining a central lumen, and a handle on the proximal end, and a dilator advanceable through the central lumen, the dilator having a cannulated elongate body for receiving a guidewire and a split site extending axially along the entire length or a portion of the length of the elongate body and configured to permit partial or total transverse removal of the dilator from the guidewire.

[0035] The handle may have a first engagement surface and the dilator may include a proximal hub having a second engagement surface configured to engage the first engagement surface to releasably secure the dilator within the catheter. The handle may also have a clot reservoir and may further have a hemostatic valve.

[0036] Also provided is a method for placing a catheter, comprising the steps of advancing a catheter and a cannular dilator over a guidewire to an intravascular site and removing the dilator while leaving the catheter and guidewire in place. The removing step includes peeling the dilator laterally off the guidewire as the guidewire is gradually passed through an axially extending split in the sidewall of the dilator. The method may additionally include the step of unlocking the dilator from the catheter prior to the removing step.

[0037] According to a further aspect of the present invention, there is provided an accelerated response aspiration system. The system includes a suction pump in communication with a first aspiration pump chamber. An aspiration catheter may be in fluid communication with the first chamber via an elongated aspiration tube. A second clot collection chamber is located between the aspiration tube and the catheter, and a valve is located between the clot collection chamber and the aspiration catheter. When the valve is open, resistance to fluid flow between the clot collection chamber and the distal end of the catheter is less than resistance to fluid flow between the clot collection chamber and the aspiration pump chamber.

[0038] A proximal handle may be provided on the suction catheter and the second chamber may be carried by the handle. The suction tube may be at least about 50 inches (about 1270 mm), or at least about 75 inches (about 1905 mm), or 100 inches (2540 mm) in length.

[0039] The valve may be provided with a spring-loaded actuation member for momentary valve opening (e.g., by pressing a button or trigger) and for automatic closing, or may be provided with a control device such as a switch, lever, or other mechanism that does not auto-close to allow for a more sustained open state.

[0040] A first control may be provided on the handle to open the valve. The valve may be normally closed and actuation of the control opens the valve. A second control may be provided to actuate the pump.

[0041] The second chamber may be configured to capture blood clots aspirated by the catheter. At least a portion of the second chamber may be removably carried by the handle. The second chamber may include a filter membrane spaced apart from the transparent wall. The aspiration system may additionally include a filter membrane spaced apart from the transparent outer chamber wall. The filter and chamber wall may be tubular.

[0042] The aspiration system may further include an operator-actuated control configured to switch the flow regulator between a default low-flow mode and a momentary, operator-initiated high-flow override mode. The aspiration system may additionally include a hemostasis valve carried by the handle. [Brief explanation of the drawings]

[0043] [Figure 1]FIG. 1 is a schematic diagram illustrating a fluid management system according to the present invention. [Figure 2] FIG. 2 is a schematic view similar to FIG. 1 showing a clot attached to a grasping catheter extending through a large diameter catheter. [Figure 3] FIG. 3 is a schematic diagram similar to FIG. 2, showing the clot being drawn into a clear viewing tube on a large access catheter. [Figure 4] FIG. 4 is a schematic view similar to FIG. 3 showing the clot advancing towards the clot collection chamber. [Figure 5] FIG. 5 is a schematic diagram similar to FIG. 4 showing the clot deposited in a transparent clot collection chamber. [Figure 6] FIG. 6 is a schematic diagram illustrating a thrombus removal system configured to reinfuse filtered and aspirated blood into a patient. [Figure 7A] FIG. 7A is a schematic diagram illustrating an alternative configuration of the fluid management system. [Figure 7B] FIG. 7B is a schematic diagram illustrating an alternative configuration of the fluid management system. [Figure 8] FIG. 8 is a schematic diagram illustrating a grasping catheter configured to apply suction to a blood clot. [Figure 9] FIG. 9 is a schematic diagram illustrating an alternative aspiration system according to the present invention, having a first thrombectomy catheter and a second thrombectomy catheter extending therethrough. [Figure 10-1] 10A is a schematic diagram showing a handpiece for the first thrombectomy catheter of FIG. 9. FIG. [Figure 10-2] 10B and 10C show details of the interface between the filter assembly and the handpiece. [Figure 10-3] 10D and 10E show details of the interface between the filter assembly and the handpiece. [Figure 11A] 11A is a schematic diagram showing a handpiece for the second thrombectomy catheter of FIG. 9. FIG. [Figure 11B] FIG. 11B is a simplified flow diagram showing a dual vacuum chamber suction system. [Figure 11C] FIG. 11C is a qualitative fluid flow diagram at the catheter tip after momentary vacuum control valve opening. [Figure 12] FIG. 12 is a schematic flow diagram for a three-way valve. [Figure 13] 13A-13C show three flow configurations for the three-way valve. [Figure 14-1] 14A to 14C show the operation of the hemostatic valve. [Figure 14-2] FIG. 14D shows an alternative filament configuration for the hemostatic valve. [Figure 15A] FIG. 15A shows a schematic diagram of the components of the proximal handle of the aspiration catheter. [Figure 15B] FIG. 15B shows a schematic diagram of the components of the proximal handle of the aspiration catheter. [Figure 16] 16A and 16B are different implementations of the thrombus engagement tool. [Figure 17] 17A and 17B are side views showing the tip of one thrombus engaging tool. [Figure 18] 18A and 18B are side views showing an alternative thrombus engaging tip. [Figure 19-1] Figure 19A is a side view of a catheter and split dilator system according to the present invention, and Figure 19B shows the system of Figure 19A with the dilator partially retracted and peeled away from the guidewire, allowing the guidewire to gradually escape from the dilator through the axially extending split. [Figure 19-2] Figure 19C shows the dilator fully retracted from the catheter but still positioned on the guidewire, and Figure 19D shows the dilator fully removed from the catheter and guidewire, leaving the catheter and guidewire immobile in their respective positions within the vasculature. [Figure 20-1]FIG. 20A shows the proximal handle for the dilator. [Figure 20-2] 20B and 20C show the proximal handle for the dilator. [Figure 21] FIG. 21 is a partial cross-sectional side view showing a catheter having a cannulated guide rail extending therethrough over a guidewire. [Figure 22] FIG. 22 is a cross-sectional view of a dual dilator system such as that shown in FIG. [Figure 23] FIG. 23 is a side cross-sectional view showing the distal portion of the dual dilator system of the present invention. [Figure 24] FIG. 24 is a cross-sectional view similar to FIG. 23, but with the distal tip formed by a tubular dilator. [Figure 25] FIG. 25 is a side view of a portion of a tubular dilator having a separation line to allow longitudinal tearing of the sidewall upon proximal retraction. DETAILED DESCRIPTION OF THE INVENTION

[0044] Referring to Figure 1, a fluid management system for a large-bore aspiration procedure is illustrated. The system 10 includes a first, large-bore thrombectomy catheter 12 having an elongated tubular body 14 extending between a proximal end 16 and a distal end 18. A central lumen 20 extends between a proximal catheter connector 22 and a distal port 24 at the distal end 18.

[0045] In the illustrated embodiment, the catheter 12 is removably connectable to the flow control module 28 via a complementary modular connector 30. The modular connector 30 provides a removably connection to a complementary catheter connector 22 and may include an opener (not shown) for opening a hemostasis valve in the hub of a large bore catheter (not shown).

[0046] The flow control module 28 includes a fluid flow path 32 extending between the module connector 30 and the flow control module 28. The fluid flow path 32 extends between the flow control module 28 and a reservoir 34, which includes a filter for clot collection and / or evaluation and a chamber for filtered fluid (not shown). In an alternative implementation of the present invention, the flow control module 28 is integrally formed within the hub of the thrombectomy catheter 12, to which the catheter can be permanently attached. Additionally, the flow path between the flow control module 28 and the reservoir 34 may be contained within a continuous, integrated tube, or may be contained within two or more tubing components that are detachably connectable via complementary Luer locks or other connectors.

[0047] Flow control module 28 may include a flow regulator for regulating the flow rate through flow path 32. The flow regulator may be configured to provide a reversible restriction within the flow path, such as by an expandable or contractible iris, a ball valve or other rotating core valve, a leaf valve, a pinch tube, or others known in the art.

[0048] In one implementation, the flow regulator includes a collapsible section of tubular wall defining a flow path, such as a section of polymer tubing. An actuator positioned adjacent to the tubing is movable between a first position, compressing the tubing to restrict flow to a low flow rate, and a second position, moving away from the tubing to allow the tubing to return to its full inner diameter and allow a high flow rate. The actuator may be spring-biased or have other default drivers toward the first (restrictive) position and may be movable to the second position only in the presence of a positive mechanical force or electrical signal that activates a high flow override. When the momentary override command is released, the actuator automatically returns to the first position, creating the low flow mode.

[0049] The actuator may be driven by a mechanical control such as a lever or rotatable knob, or by an electrical drive system such as a solenoid, and may also be operated by any of a variety of buttons, levers, triggers, foot pedals, or other switches known in the art, depending on the desired functionality.

[0050] In another implementation, fluid flow may be selectively directed through a low-flow regulator, such as a small diameter orifice or small diameter tubing, and through a high-flow regulator, such as a large diameter orifice or large diameter tubing. A mechanically or electromechanically actuated valve can momentarily switch flow from the low-flow regulator to the high-flow regulator in response to actuation of a controller.

[0051] Flow control module 28 thus includes one or more controllers for controlling the operation of the system. One controller may be provided to switch the system between a no-flow (off) mode and a low-flow mode. The same controller or a different controller may be provided to momentarily switch the flow regulator between the low-flow mode and a momentary operator-initiated high-flow override mode. Release of the momentary override control returns the regulator to the off mode or to the low-flow mode.

[0052] The low-flow mode allows the first catheter 12 to closely engage the clot with a relatively small amount of blood aspiration. After engaging the clot, a momentary high-flow control may be activated to generate a high-flow vacuum bolus to draw the clot into the catheter 12. The high flow rate may be at least about 10 cc / sec, preferably at least about 15 cc / sec, but typically no more than about 25 cc / sec. In some configurations, the high flow rate is about 20 cc / sec, with all of the above flow rates providing unimpeded blood aspiration. As used herein, a low flow rate is no more than about 50%, no more than about 35%, or no more than about 25% of the high flow rate. A low flow rate is generally less than about 10 cc / sec or 7 cc / sec, and often in the range of approximately 1 cc / sec to 5 cc / sec.

[0053] The flow control module 28 may be provided with a second catheter port 40 in communication with the central lumen 20 via a hemostatic valve (e.g., a Tuohy Borst valve) (not shown) within the module 28. This allows for the introduction of a second aspiration catheter 42 that extends through the access catheter 12 to the treatment site. The second catheter 42 may be a smaller diameter aspiration catheter, with or without clot agitation or mechanical gripping capabilities, a drug delivery catheter, a mechanical disruptor, or other accessory device that may be useful in the clot retrieval process. In one implementation, the second catheter, including its handpiece and controls, may be identical in materials to the first aspiration catheter, except that the second catheter is of smaller diameter and longer than the first catheter.

[0054] If desired, the second catheter 42 may be connected via a proximal connector 44 to a complementary connector 46 that communicates with the reservoir 34 via a suction line 48. Alternatively, the suction line 48 may be connected to a separate suction collection system (not shown).

[0055] The clot may be removable under vacuum through first catheter 12 without the need for additional assistance. However, if desired, the introduction of second clot grasping catheter 42 may provide additional attachment and / or mechanical disruption of the clot to facilitate removal. Removal may be assisted by application of vacuum to grasping catheter 42 and also to first catheter 12, either sequentially or simultaneously, depending on the desired clinical performance.

[0056] The aspiration pump 50 may include a vacuum pump and may further include a vacuum gauge 51 and an optional pressure regulation control 53. The vacuum gauge 51 is in fluid communication with the vacuum pump and indicates the vacuum pressure generated by the pump. The pressure regulation control 53 allows a user to set a specific vacuum pressure. Any of a variety of controls may be utilized, including switches, buttons, levers, rotatable knobs, and other components as would be apparent to one of ordinary skill in the art in view of the disclosure herein. The aspiration pump 50 may alternatively be a manually operated pump, such as a syringe.

[0057] The reservoir 34 is in fluid communication with the aspiration pump 50 via a vacuum line 35 and acts to transfer vacuum from the air-filled side to the liquid side of the system and also acts to collect aspirated blood and debris. The vacuum line 35 may be used as a flow restrictor. Thus, the reservoir 34 includes a collection canister in fluid communication with the flow path 32 and collects aspirated debris. The collection canister may include a filter to collect blood clots, which may be visually observed or visually accessed through a window to monitor the progress of the procedure and / or used for pathology diagnosis. The vacuum chamber and collection canister may be separate components in fluid communication with each other or may be integrated within a single housing. The flow direction through the system may also be reversed to allow blood to flow through the filter while blood clots collect outside (here downstream) of the filter, for example, between the filter and an outer transparent window or container.

[0058] The flow path 32 extends the entire length of the first catheter 12, through the control module 28, and into the reservoir 34. A transparent window 52 may be provided to allow direct visualization of the contents of the flow path 32. In the illustrated embodiment, the window 52 is in the form of a transparent section of tubing within the sterile field between the proximal end of the access catheter 12 and the flow module 28, allowing the clinician to directly view debris as it exits the proximal end of the access catheter 12 and reaches the reservoir 34, which may be located outside the sterile field. The actual length of the transparent tubing is preferably at least about 2 cm, or 4 cm, or 6 cm, and generally less than about 30 cm or less than 20 cm. In some implementations, the length of the transparent tubing is within the range of about 5 cm to about 15 cm. In alternative implementations, the transparent window may be carried by the proximal hub of the access catheter 12 or may be a proximal portion of the catheter shaft located distal to the hub.

[0059] 2, a second catheter is in the form of a second aspiration catheter 42 that is driven distally and advanced through the access catheter 12 and through the vasculature to a position adjacent to the clot 60. The clot 60 may be grasped by the second catheter 42 in any of a variety of ways, such as by mechanical attachment or aspiration or both.

[0060] 3, the second catheter 42 is partially retracted proximally, drawing the clot 60 into the first catheter 12, making the clot 60 visible through the window 52. This may be facilitated by applying a vacuum through both the grasping catheter 42 and the access catheter 12.

[0061] With continued proximal retraction of the grasping catheter 42, the interface 62 between the grasping catheter 42 and the clot 60 becomes visible through the window 52, ​​providing the clinician with visual confirmation that the clot has been captured.

[0062] 4, further retraction of the grasping catheter 42 in a proximal direction can pull the clot 60 through the flow channel 32 toward the reservoir 34. The clot 60 is then drawn by the vacuum into a collection chamber within the reservoir 34 where it may be captured by a filter and may be viewed through a transparent sidewall or window 37 on the collection chamber.

[0063] Another aspect of fluid management during a thrombectomy procedure is shown in FIG. 6. In this implementation, an aspiration line 64 connects the first catheter 12 to a thrombus filter 66. The thrombus filter 66 is further connected to a pump, such as a syringe aspiration pump 50, via an aspiration line 68. Activating the pump 50, such as by proximal retraction of the plunger, draws thrombi through the access catheter 12 and into the thrombus filter 66, where thrombi and thrombus particles having a size greater than a predetermined threshold are trapped. The thrombus filter 66 may be provided with a transparent window for visual confirmation, as described above.

[0064] Thus, blood drawn into syringe 50 is filtered, leaving debris behind in clot filter 66. Blood in pump 50 or another reservoir downstream from the filter may be reinfused into the patient. In the illustrated configuration, this may be accomplished by reversing the pump (depressing the plunger) and returning the filtered blood to the patient via bypass tubing 70, which joins flow path 32 on the patient side of filter 66. Valve assembly 74 is preferably configured to direct clot-containing blood from the patient into filter 66 and ensure that only filtered blood can communicate through bypass 70 to flow path 32 and be returned to the patient.

[0065] In the illustrated implementation, valve assembly 74 includes a first valve 72 in bypass tubing 70 that allows the flow of filtered blood toward the patient but prevents the flow of unfiltered blood through bypass tubing 70 toward pump 50. A second valve 76 is configured to allow the flow of unfiltered blood toward filter 66 and to prevent the flow of blood from the filter back toward the patient. In one implementation of the invention, first valve 72 and second valve 76 are one-way flap valves that open and close in response to the direction of blood flow.

[0066] Further configurations of the fluid management system are shown schematically in FIG. 7A. An aspiration line 64 connects the first aspiration catheter 12 to a thrombus filter 66. The thrombus filter 66 connects to the aspiration pump 50 via an aspiration line 68. The aspiration line 68 includes a flow control device 76. The flow control device 76 includes an off / on control, such as a switch 78. Actuating the switch 78 to the "on" configuration places the system in a low-flow vacuum mode, as described above. Actuating a momentary full flow control, such as a button 80, changes the system to a high-flow mode.

[0067] In an alternative configuration shown in Figure 7B, the flow control device 76 has been moved from between the aspiration pump 50 and the filter 66 to between the catheter and the filter 66. This allows the negative pressure in the chamber of the filter 66 to reach equilibrium with the canister in the aspiration pump 50 when the valve in the flow control device 76 is closed. Then, when the valve is opened, the relatively short distance between the filter and the patient allows the negative pressure at the distal end of the catheter to be rapidly reduced, as will be described in more detail in connection with Figure 11B. The flow control device 76 may additionally be provided with an optional vent to atmospheric pressure, or to no vacuum, or to a vacuum source with a gentler vacuum pressure than that experienced in the canister of the aspiration pump 50.

[0068] FIG. 8 shows a second, smaller suction catheter 42, such as a 16 French catheter, configured to apply suction to facilitate grasping of the clot. In a typical configuration, the second catheter 42 will extend through the first, larger catheter 12 (not shown), as described above. As with any second catheter disclosed herein, a mechanical agitator 82 may be axially movably disposed within the central lumen of the grasping catheter 42. See also FIGS. 16A-18B. Additional details regarding one suitable mechanical agitator 82 are disclosed in U.S. Pat. No. 10,653,434 to Yang et al., entitled "Devices and Methods for Removing Obstructive Material from an Intravascular Site," the entirety of which is expressly incorporated herein by reference. Additional details regarding the mechanical agitator 82 are disclosed in U.S. patent application Ser. No. 15 / 443,874, filed February 27, 2017, entitled "Telescoping Neurovascular Catheter with Enlargeable Distal Opening," and U.S. patent application Ser. No. 16 / 398,626, filed April 30, 2019, entitled "Devices for Removing Obstructive Material from an Intravascular Site," the entire contents of which are expressly incorporated herein by reference.

[0069] 9 and 10A, a further implementation of an aspiration system 100 is shown. The system includes a first thrombectomy catheter 102, such as a large-bore aspiration catheter, and a second aspiration catheter 104, optionally advanceable through the first thrombectomy catheter 102 as described above, or used alone.

[0070] The thrombectomy catheter 102 includes a proximal handle 106 having an elongated, flexible tubular catheter body 108 extending distally therefrom. A proximal end 110 of the tubular body 108 may be permanently carried by the proximal handle 106, or may be provided with a detachable connector for detachably connecting to a complementary connector on the handle 106.

[0071] In one implementation of the invention, tubular body 108, tubular body 152, or both, are provided with a flexible neck 109 extending between proximal end 110 and transition section 111. Flexible neck 109 has greater flexibility than an adjacent portion of tubular body 108 located distal to transition section 111. Flexible neck 109 may have a length of at least about 2 cm, often at least about 4 cm, but typically may have a length of about 20 cm or less, or 10 cm or less, or less.

[0072] The sidewall of the catheter body 108 at the flexible neck 109 includes a helical coil 113 with adjacent fillers spaced apart to enhance flexibility and allow visualization between adjacent turns of the coil. At least the flexible neck 109 includes a sidewall window, such as a space between adjacent turns of the coil, which may be in the form of an optically transparent outer tubular layer, such as any of a variety of optically transparent shrink tubing polymers. This allows visualization of a clot passing through the sidewall as it passes through the neck 109 before entering the proximal handle. A transparent window on the larger catheter 108 also allows visualization of the distal tip of the inner catheter 152 as it passes through the window. This may be facilitated by placing a visual marker, such as a colored annular band, on the distal end of the inner catheter 152.

[0073] For example, in an implementation having a 24 French tubular body 108, a smaller tubular body 152 (e.g., a 16 French catheter) may be provided with a visual indicator, such as a white tip, on its distal end, which can be visualized through a sidewall window as it passes through the flexible neck 109. The flexible neck 109 may also be provided on the catheter shaft 152.

[0074] The spring coil 113 may extend distally to an end within about 1 or 2 cm of the transition 111, and in one implementation, may extend distally to an end at the transition 111. Distal to the transition, the sidewall of the tubular body 108 may include a tubular braid, which provides greater stiffness and greater pushability compared to the helical coil 113.

[0075] The proximal end of the catheter may be provided with a rotation control, such as a rotation knob 115, which may be rotatably mounted to the catheter and rotatable relative to the handle housing, to facilitate relative rotation between the catheter and the housing for either the large or small bore catheters disclosed herein.

[0076] The central lumen extending through the tubular catheter body 108 communicates with a fluid path extending through the proximal handle 106 to a proximal access port 112. The fluid path between the tubular catheter body 108 and the proximal access port 112 is preferably straight to accommodate axially movable reception of the second catheter 104, which may or may not be utilized in a given procedure. To accommodate the absence of the second catheter 104 and to seal the port 112, the proximal handle 106 is preferably provided with a homeostatic valve 114, such as a Thuohy-Borst valve.

[0077] Manifold switch 116 controls a two-way or three-way manifold valve (shown in FIG. 12) for selectively controlling fluid flow, as described further below. Suction control device 117 is configured to turn suction on and off. Alternatively, manifold switch 116 can be configured to turn suction on and off.

[0078] Filter assembly 120 includes a housing 122 having a sidewall 124, at least a portion of which includes a transparent window 126. Window 126 allows the contents of a filter chamber 128 containing a filter 130 (e.g., aspirated blood clots) to be viewed.

[0079] The filter assembly 120 is configured to position the filter 130 in the flow path between the tubular catheter body 108 and the suction tube 118. Preferably, the filter chamber can be closed to maintain negative pressure delivered from the pump through the suction tube 118, or can be opened to allow insertion or removal of the filter 130. In the illustrated implementation, the filter assembly 120 is removably connected to the handle 106. A connector 134, such as a first thread on the housing 122, is removably engageable with a complementary connector 136, such as a complementary thread on the handle 106. A vent to atmospheric pressure may be provided in communication with the filter chamber to reduce foaming of blood in response to reduced pressure.

[0080] Implementations of the present invention include an integrated flow control module within the proximal handle 106. Accordingly, an adjustable flow regulator (not shown) may be disposed within the fluid path to controllably switch aspiration between low-flow and high-flow modes. In the illustrated implementation, the optional flow regulator is disposed downstream of the filter 130 and is housed within the housing 122 of the filter assembly 120. A flow regulator controller 132 is provided to control the flow rate. Preferably, as described above, the flow regulator is configured to adjust the fluid flow rate through the fluid path to a default low flow rate. Actuation of the flow controller 132 adjusts the flow rate to a high-flow mode. The flow controller 132 may be a momentary button, slider switch, trigger, knob, or other structure, preferably defaulting to a low-flow mode.

[0081] In any of the catheters disclosed herein, suction performance is enhanced by carrying a filter chamber 128 on the catheter or at least spaced from a remotely located vacuum pump and vacuum canister. Conventional suction pump placement can be far enough from the patient that the length of suction tubing between the pump and catheter must be 50 inches (1270 mm) or 100 inches (2540 mm) or more. The pump typically includes a suction canister for blood collection. When suction is desired, a valve is opened to connect the low-pressure canister to the catheter via the suction tubing, thereby aspirating material from the patient. However, the length of the suction tubing acts as a flow limiting factor, causing a delay between activating the vacuum button and actually applying suction to the clot.

[0082] In accordance with the present invention, the catheter handle 106 or 140 includes a filter chamber 128 that is in communication with a vacuum canister on a pump, for example, via a length of suction tubing 118. An instantaneous suction control 117 is positioned between the filter chamber 128 and the catheter, such that in the default off position, the entire length of the suction tubing 118 and filter chamber 128 can reach the same low pressure as the suction canister on the pump. The flow restriction between the pump canister 129 and the filter chamber 128 is greater than the flow restriction between the filter chamber 128 and the patient.

[0083] In an alternative configuration, 117 may be a vent to atmospheric pressure, allowing the clot canister to be evacuated. Component 142 may alternatively be an injection port, such as a port for injecting contrast, saline, or medication.

[0084] Thus, the only remaining flow restriction between the vacuum source (filter chamber 128) and the patient is the relatively short aspiration path between the valve in the handpiece and the distal end of the catheter. When the instantaneous aspiration control 117 is activated, the flow restriction and containment volume on the patient side of the filter chamber is small compared to the flow restriction and containment volume on the pump side of the filter chamber 128 through the aspiration tube 118.

[0085] This dual chamber configuration creates a sudden spike in the negative pressure experienced at the distal end of the catheter upon activation of the suction control 117. The response time from activation of the suction control 117 to the suction actually experienced at the clot is significantly faster than that achieved in conventional systems having only a single vacuum chamber located at the pump, allowing for significantly greater initial flow rates.

[0086] The negative pressure spike experienced at the distal end of the catheter will subside as pressure equilibrium is reached between the filter chamber and the canister. When the momentary suction control 117 is closed, the vacuum pump will gradually reduce the pressure in the filter chamber 128 to the level in the vacuum canister located at the pump.

[0087] A simplified fluid flow diagram is shown in FIG. 11B, and a qualitative flow diagram is shown in FIG. 11C. The flow restriction between chamber 128 and distal end 107 of catheter 108 is small compared to the flow restriction between vacuum canister 129 and vacuum chamber 128. This allows a near-instantaneous negative pressure peak to be experienced at distal end 107 upon activation of vacuum switch 117. The flow rate of material into catheter 108 quickly peaks and then tapers off as vacuum chamber 128 fills with aspirated material. The vacuum in chamber 128 drops to a minimum and is slowly restored by the large vacuum chamber 129 and associated pump via tubing 118. In use, a clinician may choose to momentarily close vacuum switch 117 at or shortly after the peak flow rate, thereby providing only a short burst or spike of vacuum to facilitate aspirating thrombus into catheter 108.

[0088] Additional details regarding the filter assembly and associated structure are shown in Figures 10B-10E. Referring to Figure 10B, filter assembly 120 includes a tubular sidewall 124 with a transparent window 126. In some implementations, the entire tubular sidewall 124 can be a transparent window. Sidewall 124, as described above, surrounds filter 130. Filter 130 includes a tubular filter sidewall 320 that defines an interior chamber 321 for filtered blood. The filtered blood enters flow path 324 through a first vacuum opening 322, which has a vertical offset 326 within flow path 324, and is pulled toward vacuum line 210. Vertical offset 326 allows blood to be removed from the bottom of the chamber, through the flow path, and out through a second vacuum opening that is more centered relative to the central axis of tubular sidewall 124 and is in communication with vacuum line 210.

[0089] Filter 130 is displaced downward relative to the central longitudinal axis of tubular sidewall 124, leaving filter chamber 128 with a chamber height 129 at least as large as the inner diameter of filter line opening 330, which communicates with filter line 208. This allows unrestricted movement of blood clots from filter line 208 into filter chamber 128, while optimizing the volume of filter chamber 128 atop filter 130 for viewing through window 126.

[0090] Connector 134 may be carried by filter assembly 120, such as in the form of a bayonet attachment or other form of removable attachment to the handpiece housing. A first sealing member 332, such as an annular elastomeric ring, may be provided between tubular sidewall 124 and a complementary surface on the handpiece housing.

[0091] The second vacuum opening 328 is in communication with the first vacuum opening 322 via a flow passage 324. The second vacuum opening 328 may be carried on an axially extending tubular projection 336, which may be removably received within a complementary recess on the handpiece housing.

[0092] A second seal member 340, such as an elastomeric ring, may be provided surrounding the flow passage 324 to provide a seal between the filter assembly and the hand piece. In the illustrated implementation, the second seal member 340 surrounds the tubular projection 336 and is configured to provide a seal against an adjacent complementary surface on the hand piece in the installed orientation.

[0093] 10D, filter assembly 120 further includes a filter base 342 having filter line opening 330 formed therethrough. Flow path 324 additionally extends through filter base 342 and, in the illustrated implementation, leads to a tubular projection 336 carrying second vacuum opening 328.

[0094] A complementary docking platform 350 is carried by the handpiece and has a complementary connector to connector 134 for quick connection and disconnection of filter assembly 120 to and from the handpiece. In the illustrated embodiment, at least a first flange 352 may be received through an opening 354 on filter assembly 120. Rotation of filter assembly 120 drives the first flange into an interference fit against a second flange 356, thereby securing filter assembly 120 to docking platform 350 on the handpiece. Two, three, four, or more similar pairs of flanges and complementary openings may be provided around the periphery of the component. In the illustrated implementation, the circumferential arc length of one of the three pairs of flanges and corresponding openings is greater than the other two pairs to function as a key, thereby allowing the filter assembly to be secured to the docking platform in only a single rotational orientation.

[0095] Docking platform 350 includes a filter line opening 360 for communication with filter line 208 and a vacuum line opening 362 for communication of filter 130 with a vacuum source. Docking platform 350 may be connected to a two-way valve 362 or a three-way valve, as described elsewhere herein, depending on the desired functionality. The valve may carry a rotatable drive gear 304 to rotationally drive an internal rotatable valve gate, as described in further detail below. Alternatively, a lever or other control on the housing may be configured to rotationally drive a shaft directly coupled to the rotatable portion of the valve.

[0096] A valved flow path may also be provided to vent the filter chamber 128 directly to atmospheric pressure. The valve may be opened, such as by depressing a momentary button biased in the closed direction. This can create a sudden pressure change at the distal end of the catheter, facilitating the aspiration of blood clots. This can also be used to vent a vacuum.

[0097] 11A, additional details are disclosed regarding the handle 140 of the second catheter 104. The handle 140 extends between a proximal end and a distal end. An elongate, flexible tubular body 152 extends distally from the distal end of the handle 140 and is configured to be advanced distally through the proximal handle 106 and tubular body 108 of the thrombectomy catheter 102.

[0098] A steering dial 144 may be provided to place one or more steering wires under tension and deflect a deflection zone located near the distal end of the tubular body 152A. A manifold switch 116 may be provided to control fluid flow rate, as described below. The handle additionally includes a suction control 117, such as a slider switch, to turn suction on or off. A maximum button 132 may be provided to deliver a momentary pulse of high suction flow rate, as described above.

[0099] Fluid flow through the thrombectomy system is controlled by a manifold switch 116 (see, e.g., FIG. 9), which may control a two-way or three-way valve. Referring to FIG. 12, a schematic flow diagram for a three-way valve 200 is provided. A patient line 202 may be in fluid communication with the patient via a catheter, such as the large diameter angioctomy catheter 12 or the second catheter 42.

[0100] The patient line 202 may be placed in communication with the manifold line 204 by advancing the three-way valve 200 to a first position, such as to allow delivery of medication, contrast, or saline to the patient.

[0101] Adjusting the three-way valve 200 to a second position isolates the patient line 202 and places the manifold in communication with the filter 206 via the filter line 208. Activating the vacuum pump draws blood from the patient through the filter 206 via the vacuum line 210.

[0102] Further adjustment of the three-way valve 200 to a third position will place the manifold in communication with a vacuum line 210, such as to allow for saline flushing of the filter 206. This third position may be omitted depending on the desired functionality.

[0103] One implementation of a suitable three-way valve 200 is shown in Figures 13A-13C. With reference to Figure 13A, the valve 200 may include a housing 220, such as a cylindrical housing having a central cavity 221. As shown in the exploded view of Figure 13A, a rotatable cylindrical gate 222 may be disposed within the central cavity 221. The rotatable gate 222 includes a flow passage 224 extending between a first end 226 and a second end 228. In the illustrated implementation, the first and second ends 226, 228 of the flow passage are spaced approximately 120 degrees apart around the circumference of the rotatable gate.

[0104] 13A, the first end 226 of the flow path 224 is in communication with the first port 232 and the second end 228 of the flow path 224 is in communication with the second port 234. This corresponds to the first position, described above, in which the patient is in fluid communication with the manifold.

[0105] 13B shows rotatable gate 222 in a second position, with flow path 224 connecting first port 232 to third port 230, thereby connecting filter 206 to the manifold. Rotatable gate 222 may be received within cavity 221 such that rotatable gate 222 seals second port 234, thereby isolating the patient from the flow path in this orientation. Similarly, in each of the other two orientations, two of the ports are in communication with the flow path, while the third port is isolated from the flow path.

[0106] The third position is shown in FIG. 13C, in which the flow path connects the second port 234 to the third port 230, thereby connecting the filter 206 to the patient and isolating the manifold from the flow path.

[0107] This selectivity may be achieved by having three ports spaced approximately 120 degrees around the circumference of the housing to cooperate with end ports of the flow passage 224 that are also spaced approximately 120 degrees around the circumference of the cylindrical gate 222. The gate 222 may be rotationally driven within the housing 220 by a connector 236 extending through the housing 220, such as along an axis of rotation, and may be connected to a control device 116, such as a rotatable knob, lever, or slider switch having a rack and pinion drive assembly.

[0108] Each of the catheters disclosed herein may be provided with a hemostatic valve on its proximal end that allows for selective occlusion or complete occlusion of the central lumen without the need for any penetrating device, such as a guidewire, or a second catheter extending over the guidewire, from a sealing fit around a device of a different diameter. An example of a suitable hemostatic valve is shown schematically in Figures 14A-14C.

[0109] 14A, hemostasis valve 250 includes a frame 252 for supporting a flow path defined within a tubular sidewall 254. Frame 252 may be integrally formed with or attached to a catheter handle or hub.

[0110] The flow channel and tubular sidewall 254 extend between a first end 256 and a second end 258. The first end 256 may be a port 112 (see, e.g., FIG. 9 ) located on the proximal end of any of the catheters disclosed herein. The second end 258 may communicate with the central lumen of a corresponding aspiration catheter, such that a device introduced into the first end 256 and advanced axially through the flow channel can be advanced all the way to and beyond the distal end of the aspiration catheter.

[0111] At least a portion 260 of the sidewall 254 is collapsible in response to external pressure. The portion 260, and optionally the entire length of the tubular sidewall within the valve 250, may comprise a collapsible, resilient tube, such as silicone tubing, that is biased into an open-lumen tubular configuration when unconstrained. A compression member, such as a filament 262, is configured to apply a compressive force against the sidewall 254, thereby reducing the inner diameter of the flow passage and providing a seal against itself (in a total occlusion with no device extending therethrough) or against a device, such as a guidewire or catheter, extending therethrough. In the illustrated implementation, the filament 262 forms a loop 268 around the collapsible portion 260 of the tubular sidewall 254. Moving a first tail portion 270 of the filament 262 away from the sidewall 254 causes the diameter of the loop 268 to contract, thereby collapsing the tubular sidewall portion 260, as shown in FIG. 14A .

[0112] In the illustrated implementation, a first tail portion 270 of the filament 262 may be retracted by at least a first lever 264. The lever 264 may be connected to the frame 252 by a first pivot 266 and is attached to the tail portion 270 at an attachment point 272. Advancing the lever in a first direction places the filament under tension, thereby reducing the inner diameter of the valve. Releasing the lever releases the tension, thereby returning the sidewall collapsible portion 260 to an unconstrained, open-lumen configuration.

[0113] In the illustrated implementation, a second lever 274 is attached to the frame 252 at a second pivot 276 and to a second tail portion 278 of the filament 262. Each of the first and second tail portions may include a single filament or may include two, three, or more parallel filaments. In the illustrated two-filament configuration, the filament may be immovably fixed to the lever, or may be a continuous filament looped about a fulcrum 280. The loop 268 may include one, two, three, or more revolutions around the tubular sidewall, depending on the desired performance.

[0114] At least one lever 264 is provided with a spring 282 that biases the lever away from the tubular sidewall, thereby contracting the inner diameter of the collapsible portion 260 to sealingly engage a device extending therethrough or to a fully occluded configuration in the absence of a device. As shown, the second lever 274 may also be biased using the same spring or a second spring.

[0115] As shown in Figure 14C, compressing the levers centrally toward the axis of tubular sidewall 254 releases tension on the filament tail portions, allowing the valve to open and, for example, advance a catheter through the valve. Releasing the levers causes the spring bias to retract the tail portions, thereby reducing the diameter of loop 268 and allowing collapsible portion 260 to collapse into sealing engagement against the exterior surface of a second catheter at an intermediate valve diameter, as seen in Figure 14B.

[0116] Retracting the tail portion 270 of the filament 262 may alternatively be accomplished by winding the tail portion 270 around a rotatable spool, such as a shaft or drum. Rotating a knob or advancing a lever causes the spool to take up the filament and collapse the sidewall.

[0117] An alternative configuration of filament 262 is shown in FIG. 14D. In this implementation, a first tail portion 270 slidably extends about a first fulcrum indicated at 272 and returns to be attached to the housing at attachment point 271. First tail portion 270 extends from the fulcrum and forms a loop 268 around the collapsible tube. Filament 262 may make one, two, or more revolutions around the collapsible tube before advancing about a second fulcrum indicated at 280 to a second attachment point 279 relative to the housing.

[0118] Compressing first lever 264 and second lever 274 relaxes loop 268, allowing the lumen to regain patency. When the levers are released, the spring bias allows first tail portion 270 and second tail portion 278 to slide away from each other about the left and right fulcrums, thereby reducing the diameter of loop 268. Preferably, friction between filament 262 and the fulcrums is minimized, such as by providing a lubricant, such as silicone oil, around fulcrums 280 and 272, and by using a braided Teflon line for filament 262.

[0119] The various components of the aspiration system handle are depicted schematically in connection with FIG. 15A. The proximal handle 140 on the second catheter 104 includes a filter 206, a tubular body 152, and other features as described above. A two-way or three-way valve 200 selectively controls communication between a filter line 208, a patient line 202, and a manifold line 204. In this implementation, the three-way valve control 116 is in the form of a slider switch. The slider switch axially displaces a first linear rack gear 300. The rack gear 300 meshes with a pinion gear 302, which may directly rotationally drive a gate in the valve 200 or, as shown, may drive a third gear 304, which rotationally drives a rotatable gate in the valve 200. An alternative valve control system is shown schematically in FIG. 15B. In this implementation, the slider switch, linear rack gear 300, and pinion gear 302 are omitted. A valve control 116 in the form of a lever 117 is attached directly to the shaft that controls the rotation of the valve gate. The lever may be advanced proximally or distally to adjust the flow of fluid through the valve, as described above.

[0120] A steering mechanism 306 is provided to allow steering of the second catheter 152. A manually rotatable knob 148 allows for manual rotational actuation of the core wire and distal helical tip, as described above. The core wire movably extends axially across the hemostasis valve 146. Alternatively, the core wire and tip (e.g., thrombus engagement tool 400) may be coupled to a motor drive unit at the proximal end of the catheter system.

[0121] In certain implementations of the invention, an aspiration catheter, such as a 16 French catheter, is advanced transluminally over the wire and / or through a larger diameter (e.g., a 24 French aspiration catheter) to the treatment site. If the clot cannot be aspirated into the 16 French catheter by application of vacuum, a long, flexible clot engaging tool may be driven forward through the 16 French aspiration catheter to facilitate clot retrieval.

[0122] 16A and 16B, a clot engagement tool 400 may include an elongate, flexible shaft 402 having a proximal end 404 and a distal end 406. A proximal handpiece, such as a handle 408, may be configured to be rotationally driven by hand. The distal end 406 carries a clot engagement tip 410, which may include one or more radially outwardly extending structures, such as a helical thread 412. The handle 408 may have a rotational indicator, such as a printed or molded arrow 109, indicating the direction in which the handle 408 should be rotationally driven to engage the helical thread 412 with the clot.

[0123] In one implementation, illustrated in FIG. 16B, the clot engagement tool 400 carries a clot engagement tip 410 of the type illustrated in FIGS. 18A and 18B. The proximal end of the tip 410 is bonded to the distal end of a braid-reinforced polyimide tube. The proximal end of the microlumen has a cannulated torque handle 408, and the entire assembly is cannulated so that it can be delivered and operated over a wire 468, such as a 0.035-inch wire. The 0.035-inch wire helps maintain space between the tip and the vessel wall, and the wire can be retracted, if necessary, into the working length of the flexible shaft 402 during rotation and engagement with the clot.

[0124] 17A, the distal tip 410 includes a helical thread 412 extending from the distal end 414 to the proximal end 416 and supported by the flexible shaft 402. The axial length of the distal tip 410, as measured along the flexible shaft 402, is at least about 2 mm, 5 mm, or 10 mm, and in some embodiments, is about 30 mm or less, or 20 mm or less. The helical thread 412 wraps around the axis at least about 1 full turn, or 2 full turns, or 4 full turns, or more, but in some embodiments, about 10 turns or 6 turns or less. In some embodiments, the axial length along the threaded portion of the tip is in the range of about 1 turn to about 8 turns.

[0125] The helical thread 412 in this implementation may have a constant pitch throughout its length. The pitch may be in the range of about 10 to about 20 threads per inch (25.4 mm), or in the range of about 5 to about 10 threads per inch (25.4 mm), depending on the desired performance. Alternatively, the thread may have multiple pitches designed to engage, transport, or grip thrombus within the catheter lumen. The distal pitch may be smaller than the proximal pitch. The pitch may vary continuously along the length of the thread, or may vary in steps from a first constant pitch in the proximal zone of the thread to a second, different pitch in the distal zone of the thread. The thread 412 may include a continuous single helical flange, or may have multiple discontinuities to form multiple teeth or serrations helically arranged around the core wire.

[0126] The lateral height profile or envelope that the distal tip describes as it rotates may have a linear or non-linear tapered shape (e.g., a football shape) on one or both ends that provides a varying diameter along its length from the generally cylindrical ID of the catheter lumen, thus providing clearance.

[0127] The maximum OD of the thread 412 is preferably smaller than the diameter of the sliding fit within the catheter lumen, typically at least about 0.015 inches (0.381 mm), or at least 0.010 inches (0.254 mm) smaller than the catheter lumen ID. In some implementations, the maximum OD of the tip may be significantly smaller than the inner diameter of the catheter lumen to allow more space for the thrombus, yet still provide a significant grip on the thrombus via engagement of the helical thread. In one implementation, the maximum helical thread diameter is about 0.110 inches (2.794 mm) and the catheter lumen ID is about 0.275 inches (6.985 mm) (24F) (there is 0.165 inches (4.191 mm) of clearance between the helical thread and the catheter wall).

[0128] In certain applications, the maximum OD of the tip is about 35% or less, or about 40% or less, or about 60% or less compared to the ID of the catheter to leave a flow path that substantially bypasses the tip. In this implementation, the tip is typically forced toward one side of the aspiration lumen due to the lack of any centering structure on the tip 410 or shaft 402. When a clot becomes lodged between the tip and the opposing catheter wall, the tip can be manually rotated to engage the clot in a worm-gear fashion, either to grasp and retract the clot (e.g., by pinning it against the opposing catheter wall) or to release the clot and aid in its capture into the catheter.

[0129] The profile of the tip 410 as viewed along the axis of rotation may be circular, or may be modified to form a non-circular pattern about the axis of rotation. Thus, when viewed in end view, the tip exhibits a major diameter and a minor diameter. The minor diameter may be about 95% or less, or 90% or less, or 80% or less, or 70% or less of the major diameter, depending on the desired performance.

[0130] 17A and 17B, the illustrated tip 410 includes a distal advancement segment 418 that extends between an atraumatic distal tip at location 420 and a transition to a distal end 416 of the threads 412. The helical threads 412 extend proximally from the transition to a proximal end 414 of the helical threads 412. A trailing segment 422 extends between the proximal end 414 of the threads and a proximal end 424 of the tip.

[0131] The axial length of the advancement segment 418 may be at least about 1 cm or 2 cm, and in some implementations is in the range of about 2 cm to about 4 cm. The axial length of the helical thread 412 along the longitudinal axis is typically in the range of about 1 cm to about 5 cm, and in certain implementations is approximately 2 cm to 3 cm.

[0132] The outer diameter of the advancement segment 418 at the distal tip 420 is typically less than about 0.024 inches (about 0.6096 mm), or less than about 0.020 inches (about 0.508 mm), and in one implementation is about 0.018 inches (about 0.4572 mm). The maximum outer diameter of the advancement segment 418 and helical thread 412 may be in the range of about 0.020 inches to about 0.045 inches (about 0.508 mm to about 1.143 mm), and in one implementation is less than about 0.040 inches (about 1.016 mm), such as about 0.035 inches (about 0.889 mm). The advancement segment, helical thread, and rearward segment of the tip 410 may be molded onto the flexible shaft 402 using any of a variety of polymers known in the catheter art.

[0133] 17B, ​​a first radiopaque marker 430 may be carried on the flexible shaft 402 immediately below the advancing segment 418. A second radiopaque marker 432 may be carried on the flexible shaft 402 within the rearward segment 422. Each radiopaque marker may include a radiopaque tube or coil made of radiopaque wire, such as platinum-iridium alloy wire having a diameter of about 0.002 inches, wound around and soldered to the flexible shaft 402, thereby producing an RO coil having an outer coil diameter of less than about 0.020 inches, such as about 0.012 inches. The radiopaque markers may also act as an axial interference fit between the flexible shaft 402 and the shaped advancement segment 418, rearward segment 422, and can resist pull-out of the core wire from the tip 410.

[0134] In one implementation, the maximum OD of threads 412, compared to the OD of advancement segment 418, exceeds the maximum OD of advancement segment 418 by at least about 15%, or at least 25%, or at least 30%, or more, thereby facilitating the crossing of a clot across advancement segment 418 and engaging the clot with threads 412. The pitch of the threads may be in the range of about 0.75 inches to about 0.30 inches (about 19.05 mm to about 7.62 mm), or in the range of about 0.10 inches to about 0.20 inches (about 2.54 mm to about 5.08 mm), such as about 0.14 inches (about 3.556 mm).

[0135] Preferably, the maximum OD of tip 410 is less than about 60% or less than about 40% compared to the aspiration catheter ID at the distal end of the aspiration catheter, and may be in the range of about 35% to about 55% compared to the catheter ID. In certain implementations, the maximum OD of tip 410 may be in the range of about 0.044 inches to about 0.041 inches (about 1.1176 mm to about 1.0414 mm) in a catheter having a distal tip ID in the range of about 0.068 inches to about 0.073 inches (about 1.7272 mm to about 1.8542 mm).

[0136] Depending on the clinical application, it may be desirable to control the extent to which the distal tip 410 extends beyond the distal end of the catheter, if at all. For example, the distal extension of the spiral tip's distal end beyond the distal end of the catheter may be limited in some implementations to about 5 mm or less, or 3 mm or less, or 1.5 mm or less, or 1.0 mm or less, or less. In other clinical environments, the distal tip 420 may be allowed to extend beyond the catheter by at least about 2 cm or 3 cm, and preferably between 4 cm and 8 cm, depending on the desired performance, but will typically be limited to extend no more than a preset distance beyond the catheter, such as 12 cm, 8 cm, or 5 cm. In one implementation, the distal advancement of the tip 410 is limited so that the distal tip is no more than 2 cm, no more than 1 cm, or no more than 0.5 cm, either distally or proximally, from the distal end of the aspiration catheter.

[0137] Distal advancement of the tip 420 may be limited by providing a mechanical interference member at a desired distal travel limit. In one implementation, a distal stop surface 440 on the handle 408 interferes with a complementary proximal surface carried by an aspiration catheter through which the thrombus engagement tool 400 is advanced. Alternatively, a distal engagement surface can be carried anywhere along the length of the thrombus engagement tool 400 for sliding engagement with a complementary proximal opposing stop surface carried by the catheter. Additional details are provided in U.S. Patent Application Serial No. 17 / 036,258, filed September 29, 2020, entitled "Embolic Retrieval Catheter," the entire contents of which are expressly incorporated herein by reference.

[0138] The limiting member for distal advancement of the helical tip may include a first configuration that limits distal advancement to a first position proximal to the distal end of the drainage catheter to prevent damage to the vessel wall. Upon user-initiated adjustment, the helical tip may advance to a second position distal to the distal end of the catheter, such as for inspection and cleaning purposes. This adjustment of the limiting mechanism may be locked out after cleaning or inspection to limit distal movement to the first position to prevent undesirable exposure of the helical tip member while the system is within the patient's vasculature. Any of various movable interference levers on the pin may be engaged to limit movement to the first position or disengaged to allow movement to the second position.

[0139] 18A and 18B, tip 410 includes a tubular sidewall 440 defining a hub with a connector, such as a cavity 442, for coaxially receiving the distal end of a support shaft, such as a braid-reinforced polyamide tube. The inner diameter of cavity 442 decreases by a step 444 at the distal end of the hub to a smaller diameter lumen 446 that communicates with a distal opening 448. This provides a continuous lumen throughout the length of the microluminal shaft and tip 410 so that a thrombus engagement tool can be introduced over the wire.

[0140] Generally, the pitch of threads 412 may range from about 0.07 to about 0.11, and in one embodiment, is about 0.09. The width of threads 412, as measured along an axis perpendicular to the plane of the threads, may range from about 0.009 to about 0.04, and in one embodiment, is about 0.02. The maximum major diameter of threads 412 may be at least about 10%, or at least about 15%, or at least about 20% larger than the diameter of the proximal hub end of tip 410 surrounding cavity 442. In one implementation, the outer diameter of the proximal hub is about 0.090 inches (about 2.286 mm), and the outer diameter of threads 412 is about 0.110 inches (about 2.794 mm). The actual length of the tip 410, including the proximal hub, may be in the range of about 0.2 inches to about 0.8 inches (about 5.08 mm to about 20.32 mm), and in some implementations may be in the range of about 0.4 inches to about 0.6 inches (about 10.16 mm to about 15.24 mm).

[0141] The tip 410 may be manufactured according to any of a variety of techniques known in the art, such as machining, etching, additive processes, and / or subtractive processes. In one implementation, the tip 410 may be molded from a polymer such as PEBAX, which may have a hardness of 55D. The PEBAX may include a radiopaque agent, such as bismuth subcarbonate, which is present in a range of about 50% to about 70% by weight.

[0142] The dimensions and configurations of any tip disclosed herein may be interchanged with any of the dimensions, configurations, drive shafts, and related structures of other tips depending on the desired clinical performance.

[0143] 19A-19D, there is shown a split dilator system 450 that may be utilized with any of the catheters disclosed herein. The system includes a catheter 452 having an elongated tubular body 454 extending between a proximal end 456 and a distal end 458. The proximal end 456 includes a proximal hub or manifold 457, as described above in connection with the other catheters disclosed herein.

[0144] The elongated flexible dilator 460 has a length sufficient to extend the entire length of the catheter 452. The dilator 460 extends between a proximal end 462 and a distal end 464 having a tapered distal tip 466. The dilator 460 has a central lumen (not shown) so that it can be advanced over a guidewire 468. The proximal end 462 of the dilator has a proximal hub 470.

[0145] The split 472 extends along the length of the hub 470 and along the sidewall of the tubular dilator 460. The split may be in the form of a slot, perforation line, groove, or other weakening that extends through the entire wall thickness of the dilator, allowing for the formation of a slit through the dilator sidewall, thereby permitting the guidewire 468 to be removed laterally through the split, as described below. The longitudinal split 472 may extend the entire length of the dilator 460, or may extend distally from the proximal end to an end point 473 located within a range of at least about 2 cm or 5 cm to about 40 cm or less or 30 cm or less from the tapered tip 466.

[0146] Preferably, a first locking member carried by hub 470 is releasably engageable with a complementary second locking member carried by hub 457 .

[0147] 19B, after transvascular advancement of the catheter and dilator assembly to the desired intravascular location, the dilator 460 may be proximally removed, leaving the catheter 452 in place. Desirably, the guidewire 468 may remain stationary at the target vascular site upon removal of the dilator 460, preferably without requiring proximal extension of the guidewire. To this end, the guidewire 460 may be gradually removed laterally from the dilator at a separation point 473 that advances axially along the split 472 as the dilator 460 is withdrawn proximally from the catheter 452 and from the guidewire 468.

[0148] After the tapered tip 466 is retracted proximally from the catheter, the guidewire 468 may be grasped between the dilator 460 and the catheter 462, and the dilator 460 may be removed proximally from the catheter 452 and from the guidewire 468. This allows the dilator to be removed without disturbing the position of the catheter or guidewire, which can then be utilized for a subsequent intravascular procedure.

[0149] 20A and 20B, a proximal dilator handle 480 is illustrated. The handle 480 includes a body 482 having a proximal end 484, a distal end 486, and a longitudinal axis. At least a first proximal gripping surface 488 is carried by the body. In the illustrated implementation, the first gripping surface 488 is provided on at least one side of a paddle-shaped grip 490 configured to be held between the thumb and index finger. A second gripping surface 492 may be provided on the opposite side of the handle. Both gripping surfaces may be provided with friction-enhancing surface structures, such as a plurality of ridges oriented transversely to the longitudinal axis of the dilator handle 480.

[0150] The proximal exit port 494, which is in communication with the dilator guidewire lumen, is oriented along the longitudinal axis of the dilator handle 480 so that the guidewire extending from the exit port 494 lies along the first gripping surface 488. This allows a clinician to use a finger, such as the thumb, to position the guidewire against the gripping surface 488, thereby allowing the dilator and guidewire to be moved as a unit using one hand.

[0151] The dilator may be removably secured to the catheter, such as by a retaining clip 496 carried by the proximal end of the handle. A release member, such as a button or a deformable interference snap fit, may be provided to unlock the dilator handle from the housing, allowing the dilator to be proximally retracted from the catheter. In the illustrated implementation, a retaining surface, such as the proximal surface of a retaining ring 497 carried by the proximal end 486 of the body 482, provides an interference fit with the retaining clip 496, combining the dilator and handle / catheter into a single system. The paddle may be released from the retaining clip, and the paddle may be withdrawn proximally, by depressing at least a first button 506 and also a second button 508 carried on the top and bottom surfaces of the retaining clip housing as shown.

[0152] 16A and 16B. The distal limit safety feature of the thrombus engagement tool 400 fits within the retaining clip 496 and ensures that the distal tip of the tool 400 cannot be advanced forwardly beyond the distal tip of the catheter without both aligning a protrusion on the tool 400 with the rotation key 502 and intentionally advancing the tool 400 through the retaining clip while depressing at least a first button 506 or other unlocking control.

[0153] After the distal restraint is released, the tip 410 may be advanced distally beyond the distal end of the catheter by no more than about 4 cm, typically about 1 cm to 2 cm, intended to allow for visual inspection of the tip 410 after the thrombus engagement tool is withdrawn from the patient.

[0154] The engagement tool 400 may also be retracted proximally into the catheter, typically less than about 3 cm or less than about 2 cm, and the engagement tool 400 may be spring biased to return to approximate axial alignment between the distal end of the tip 410 and the distal end of the catheter.

[0155] A hemostatic clamp 500 may be provided to hold the hemostatic valve open, such as during shipping or when advancing or retracting the device therethrough. The hemostatic valve is opened by depressing at least a first control button, which in the illustrated implementation is a first control button and a second control button located on opposite sides of the handle. The hemostatic clamp includes a generally U-shaped body 502 having a first arm 504 configured to depress the first button and an opposing second arm (not shown) configured to depress a second button located on the opposite side of the handle. The hemostatic clamp 500 may be removably retained on the handle by a friction fit or an interference fit between the handle and body, which can be overcome by plastic deformation when the body is pulled away from the handle to release the hemostatic control button.

[0156] Referring to FIG. 21, a long, flexible cannulated rail or dilator 561 is shown extending over the guidewire 570 and occupying the space between the guidewire 570 and the larger inner diameter of the central lumen 558 of the large diameter catheter 560, thereby supporting the catheter and / or atraumatic tip during delivery.

[0157] This catheter-cannulated rail-guidewire assembly is intended to track anatomical targets more easily than a catheter, where the catheter-rail-guidewire assembly serves as the first stage of a catheter delivery system, allowing a large diameter catheter or large diameter catheter system to be inserted onto this first stage and independently advanced percutaneously over a guidewire within a vessel (e.g., the femoral vein) and advanced to a remote target site of interest through a potentially tortuous vasculature without requiring advanced technique or causing catheter kinking.

[0158] The cannulated rail 561 may comprise a soft, flexible cylindrical body having a guidewire lumen with a diameter of about 0.040 inches (about 1.016 mm) or less and a smaller outer diameter than the inner diameter of the larger diameter catheter, such as about 0.025 inches (about 0.635 mm) or more, or about 0.010 inches (about 0.254 mm) or more. Thus, the wall thickness of the cannulated rail 561 is typically smaller than the radius of the larger diameter catheter by at least about 0.010 inches (about 0.254 mm), and in some implementations by at least about 0.120 inches (about 3.048 mm) or more, depending on the size of the annular space between the inner diameter of the catheter and the outer diameter of the guidewire.

[0159] The cannulated rail 561 may have an elongated, tapered distal tip 562 that may protrude beyond the distal end 554 of the catheter 560. The thickened sidewall of the cannulated rail 561 may comprise one or more flexible polymers and may have one or more embedded column strength enhancing features, such as axially extending wires, metallic or polymeric woven or braided sleeves, or metal tubing, depending on the desired pushability and trackability along the length of the dilator.

[0160] Optionally, the proximal segment of the rail or dilator that is not intended to extend from the distal end of the catheter may be a structure that is not coaxial with the guidewire, but may be a control wire that runs parallel to the guidewire within the catheter, allowing the control wire to retract or extend the distal tubular telescoping segment of the rail or dilator without putting the entire length of the rail structure in an over-the-wire configuration (similar to a rapid-exchange catheter). This allows removal or insertion of the rail or dilator over a shorter guidewire due to the short coaxial segment tracking over the guidewire.

[0161] The catheter 560 may be provided with a proximal hub 520 having a port for axially movably receiving the rail 561 therethrough. The hub 520 may be provided with an engagement structure, such as a first connector 522, for releasably engaging with a second complementary connector 524 located on the hub 526 at the proximal end of the rail 561. The first connector 522 may include an interference structure, such as at least one radially movable protrusion 530, for releasably engaging with a complementary engagement structure, such as a recess 532 (e.g., an annular ridge or annular groove), on the hub 526. By driving the rail 561 distally forward into the catheter 560, the protrusion 530 snaps into the recess 532, axially locking the catheter 560 and the rail 561 together, which may then be manipulated as a unit.

[0162] The dilator is inserted through the hemostatic valve in the hub 520 of a large-bore (e.g., 24F) catheter 560 and driven forward through the catheter until the retaining clip on the dilator hub 526 or the catheter hub 520 snaps into a complementary recess on the other hub. In this engaged configuration, the advancement segment along the flexible distal end of the 24F rail dilator 561 extends beyond the distal end 554 of the 24F catheter 560 by at least about 5 cm or at least 10 cm, and in some implementations, at least about 15 cm or at least 20 cm. The rail dilator and 24F catheter system are then driven forward distally over the previously placed guidewire and into the introducer sheath.

[0163] The dilator-catheter combination of the present invention is distinguished from prior art systems by both the flexibility of the dilator's distal zone and the longer length of the dilator than the corresponding catheter. Typically, the dilator has a consistent stiffness and length consistent with the catheter, with only a short, atraumatic tip of the dilator extending beyond the distal end of the catheter. The dilator of the present invention has a supportive proximal end and a flexible distal end, and the total length of the dilator is much longer than that of the catheter 60, allowing, by way of example, the following procedure:

[0164] In use, a guidewire 570, such as a 0.035 inch (0.889 mm) guidewire, is advanced into a selected blood vessel under fluoroscopic guidance using conventional techniques. A cannulated rail 561, optionally with a catheter 560 mounted thereon, is loaded onto the proximal end of the guidewire 570 and advanced distally over the wire until the distal end of the rail is located at the target site.

[0165] The 24F catheter 560 is then unlocked from the rail 561 and, supported by the combination of the rail 561 and guidewire 570, driven forward on the rail 561 to the desired site. Because the uncovered advancement section of the rail has already traversed the difficult bends through the heart, the catheter 561 can now easily pass to the final target site by simply sliding over the advancement section of the rail. The supportive proximal zone and flexible distal advancement section of the rail allow for ease of delivery through the most difficult anatomy, such as in a PE procedure from the vena cava through the tricuspid and pulmonary valves of the heart into the central pulmonary artery, without fear of damaging the tissue (atraumatic flexible tip) or the dilator (high kink resistance due to the flexible, thick-walled "solid" dilator structure).

[0166] Cannulated rail 561, or alternatively, the combination of cannula 561 and guidewire 570, may then be withdrawn proximally, leaving large-bore catheter 560 in position to guide a treatment catheter, such as any of the aspiration catheters disclosed elsewhere herein, to the target site.

[0167] 22 , the large diameter (LD) catheter 560 may, in some circumstances, have a small diameter (SD) catheter through its central lumen for the purpose of introducing additional functionality (e.g., a clot-grasping catheter 562, an imaging catheter 10, or a mechanical thrombectomy tool 66) and / or for the purpose of telescoping the small diameter (SD) catheter to a more distal location within the anatomy. To enable the LD catheter 560 and SD catheter to be delivered as a single system, the SD catheter may have a core dilator 568 for support, and the gap between the outer diameter of the SD catheter and the inner diameter of the LD catheter 560 may be maintained or supported by a second tubular dilator 571. The tubular dilator 571 may have a shaped distal tip 572 for a smooth, tapered transition from the SD catheter 541 to the LD catheter 540. The distal end 534 of the core dilator may be provided with a tapered shape complementary to the distal taper of the thin-walled SD dilator (FIG. 23), or alternatively, the distal end 534 of the core dilator may terminate at the distal end of the LD catheter (FIG. 24).

[0168] The core dilator 568 inside the SD catheter 541 and the tubular dilator 570 located between the two catheters may have interlocking features to form a single (SD+LD) catheter+(core+tubular) dilator system. For example, complementary connectors may be provided on a hub located on the proximal end of the system components.

[0169] 24, the tip of tubular dilator 570 may be configured to taper relative to guidewire lumen 576 so that it extends distally over and beyond small diameter catheter 541 when small diameter catheter 541 is in place. The tip of tubular dilator 570 may be provided with one or more longitudinally extending slits 578 cut or perforated therein, allowing the tip to be split longitudinally and retracted into the space between the LD and SD catheters, fully exposing the distal end of small diameter catheter 541. See FIG. 25.

[0170] The single (SD+LD) catheter + (core + tubular) dilator system may be preassembled and removably interlocked at the proximal hub. Additional tubular dilators with a range of outer diameters and wall thicknesses may be provided so that an SD catheter can be used in combination with an LD catheter of different diameters. An LD catheter may be used with different SD catheters by providing tubular dilators with the same OD but a range of different inner diameters. The core + tubular dilator may be withdrawn as a single system by simply pulling proximally, or the tubular dilator may have a tab or handle at its proximal end and may have slits, notches, perforations, or other mechanisms to split, peel, or tear along its longitudinal axis upon withdrawal, allowing the tubular dilator to peel away from the SD catheter as it slides proximally through the gap between the LD and SD catheters (Figure 25).

[0171] Illustrative Embodiments

[0172] 1. An accelerated response aspiration system comprising:

[0173] a suction pump in communication with the first chamber;

[0174] a suction catheter configured to be in fluid communication with the first chamber via a suction tube;

[0175] a second chamber located between the suction tube and the catheter;

[0176] a valve located between the second chamber and the suction catheter; and

[0177] When the valve is opened by negative pressure in the first and second chambers, the resistance to fluid flow between the second chamber and the distal end of the catheter is less than the resistance to fluid flow between the second chamber and the first chamber, thereby causing rapid suction into the second chamber.

[0178] The suction system of any embodiment herein, further comprising a handle on the suction catheter, wherein the second chamber is carried by the handle.

[0179] The suction system of any embodiment herein, further comprising a first control on the handle for opening the valve.

[0180] The aspiration system of any embodiment herein, wherein the valve is normally closed and actuated by the controller to momentarily open the valve.

[0181] The suction system of any embodiment herein, further comprising a second controller for driving the pump.

[0182] The aspiration system described in any embodiment herein, further comprising a hemostasis valve carried by the handle.

[0183] An aspiration system as described in any embodiment herein, wherein the hemostatic valve includes a collapsible tubular side wall defining a valve lumen, and a filament configured to form a loop around the tubular side wall and collapse the valve lumen.

[0184] The suction system of any embodiment herein, wherein the hemostatic valve further includes a frame and a lever, and the filament has at least a first tail portion extending around a first fulcrum on the lever in a direction away from the loop and is fixed against axial movement relative to the frame.

[0185] The suction system of any embodiment herein, wherein the first tail portion is connected to the frame.

[0186] The suction system of any embodiment herein, further comprising a second lever, wherein the filament further comprises a second tail portion extending from the loop around a second fulcrum on the second lever and connected to the frame.

[0187] The suction system of any embodiment herein, wherein the suction tube is at least about 50 inches (1270 mm) in length.

[0188] The aspiration system of any embodiment herein, wherein the second chamber is configured to capture blood clots aspirated by the catheter.

[0189] The suction system of any embodiment herein, wherein at least a portion of the second chamber is removably carried by the handle.

[0190] The suction system of any embodiment herein, wherein the second chamber includes a filter membrane spaced apart from the transparent wall.

[0191] The aspiration system of any embodiment herein, comprising a tubular filter membrane spaced radially inward from a transparent outer tubular wall.

[0192] The suction system of any embodiment herein, further comprising an operator-driven control device configured to switch the flow regulator between a default low-flow mode and a momentary, operator-initiated high-flow override mode.

[0193] 10. The suction system of any embodiment herein, wherein the second chamber is configured for placement inside a sterile field and the first chamber is configured for placement outside the sterile field.

[0194] The suction system described in any embodiment herein, further comprising a handle on the suction catheter and a tube between the handle and the second chamber, the tube being about 20 inches (about 508 mm) in length or less.

[0195] 1. A split dilator aspiration system comprising:

[0196] a catheter having an elongated, flexible tubular body with a proximal end, a distal end, a sidewall defining a central lumen, and a handle on the proximal end;

[0197] a dilator that can be advanced through the central lumen, the dilator having a cannulated elongate body for receiving a guidewire and a split site extending axially along at least a portion of the elongate body and configured to allow for laterally removing a portion of the dilator from the guidewire; A split dilator aspiration system comprising one or more of:

[0198] A split dilator aspiration system as described in any embodiment herein, wherein the handle includes a first engagement surface and the dilator includes a proximal hub having a second engagement surface configured to engage with the first engagement surface to releasably secure the dilator within the catheter.

[0199] The split dilator aspiration system described in any embodiment herein, including a retaining clip carried by the proximal end of the catheter handle.

[0200] The split dilator aspiration system of any embodiment herein, further comprising a holding surface carried by the gripping body.

[0201] The split dilator aspiration system of any embodiment herein, wherein the retention surface is located on a retention ring configured to engage with the retention clip.

[0202] The split dilator aspiration system of any embodiment herein, further comprising a release control for disengaging the gripping body from the catheter handle.

[0203] The split dilator aspiration system as described in any embodiment herein, wherein the release control device includes at least one push button.

[0204] The split dilator aspiration system of any embodiment herein, further comprising a clot container on the handle.

[0205] The split dilator aspiration system of any embodiment herein, further comprising a hemostasis valve on the handle.

[0206] A split-type dilator aspiration system as described in any embodiment herein, wherein the split includes a weakened portion of the wall to allow for the gradual formation of a slit through the wall to allow the guidewire to escape laterally.

[0207] The split dilator aspiration system of any embodiment herein, wherein the split comprises a pre-formed slit completely through the wall.

[0208] The split dilator aspiration system of any embodiment herein, wherein the split extends from the distal end of the catheter to a distal termination point spaced proximally.

[0209] The split dilator aspiration system of any embodiment herein, wherein the distal end is spaced proximally from the distal end of the catheter within a range of about 5 cm to about 40 cm.

[0210] The split dilator aspiration system described in any embodiment herein, further comprising a proximal handle on the dilator.

[0211] A split dilator aspiration system as described in any embodiment herein, wherein the handle includes a gripping body having a first gripping surface and a guidewire outlet port configured to guide a guidewire along the first gripping surface.

[0212] A split dilator aspiration system as described in any embodiment herein, wherein the body is configured as a paddle shape having a first gripping surface on a first side and is configured to be held between the thumb and index finger so that a guidewire can be placed between the thumb and the first gripping surface.

[0213] The split dilator aspiration system of any embodiment herein, further comprising a friction-enhancing surface structure on the first gripping surface.

[0214] The split dilator suction system of any embodiment herein, wherein the friction-enhancing surface structure comprises a plurality of ridges.

[0215] A hemostatic valve,

[0216] A support;

[0217] at least a first lever pivotally supported relative to the support;

[0218] a collapsible tubular sidewall defining a valve lumen and carried by a support;

[0219] a filament forming a loop around the tubular sidewall, the filament having at least a first tail portion spaced from the loop and extending to a first lever;

[0220] a first spring configured to move the first lever in a direction to pull the first tail portion away from the tubular sidewall, thereby reducing the diameter of the valve lumen in response to reducing the diameter of the loop; and A hemostatic valve comprising one or more of:

[0221] A hemostatic valve as described in any embodiment herein, further comprising a second lever pivotally supported relative to the support.

[0222] The hemostatic valve described in any embodiment herein, further comprising a second tail portion extending away from the loop to a second lever.

[0223] The hemostatic valve described in any embodiment herein, wherein the first tail portion, the second tail portion, and the loop are one continuous filament.

[0224] The hemostatic valve of any embodiment herein, further comprising a lubricious coating on the filaments.

[0225] The hemostatic valve of any embodiment herein, wherein the lubricious coating comprises silicone oil.

[0226] A hemostatic valve as described in any embodiment herein, wherein the first and second levers are biased in an orientation that places the first and second tail portions under sufficient tension to reduce the diameter of the valve lumen and provide a seal around a device extending through the valve.

[0227] A hemostatic valve as described in any embodiment herein, wherein the first lever and the second lever are biased in a direction that places the first tail portion and the second tail portion under sufficient tension to close the valve.

[0228] A hemostatic valve as described in any embodiment herein, wherein the first tail portion is attached to the first lever.

[0229] A hemostasis valve as described in any embodiment herein, wherein the first tail portion slidably extends around a first fulcrum on the first lever and is attached to the frame.

[0230] A hemostasis valve as described in any embodiment herein, wherein the second tail portion slidably extends around a second fulcrum on the second lever and is attached to the frame.

[0231] A hemostatic valve as described in any embodiment herein, wherein the first fulcrum and the second fulcrum comprise pins.

[0232] The hemostatic valve described in any embodiment herein, mounted on the proximal end of the catheter.

[0233] A hemostasis valve as described in any embodiment herein, further comprising a connector in communication with the valve lumen and configured to be connected to a vacuum source.

[0234] 1. A vacuum suction system comprising:

[0235] Housing and

[0236] a fluid flow path extending through the housing;

[0237] a first catheter in fluid communication with a fluid path and a connector configured to place a suction source in communication with the fluid path;

[0238] a clot container carried by the housing;

[0239] a hemostatic valve located within the housing and configured to receive the second catheter and to guide the second catheter through the first catheter; a vacuum suction system.

[0240] The vacuum suction system of any embodiment herein, further comprising a flow regulator configured to regulate a fluid flow rate through the flow path.

[0241] The vacuum suction system of any embodiment herein, wherein at least a portion of the clot container is removably carried by the housing.

[0242] The vacuum suction system of any embodiment herein, wherein the clot container comprises a filter membrane spaced apart from the transparent wall.

[0243] The vacuum suction system of any embodiment herein, comprising a tubular filter membrane spaced radially inward from the transparent outer tubular wall.

[0244] The vacuum suction system of any embodiment herein, further comprising an operator-actuated control device configured to switch the flow regulator between a default low-flow mode and a momentary, operator-initiated high-flow override mode.

[0245] The vacuum suction system of any embodiment herein, wherein the operator-activated control includes a momentary control that places the system in high flow override mode only when activated by the operator.

[0246] The vacuum suction system of any embodiment herein, further comprising an on-off control device for switching between an off mode and a low-flow mode.

[0247] The vacuum suction system of any embodiment herein, further comprising a sidewall comprising the flow channel, and an optically transparent window within the sidewall.

[0248] The vacuum suction system of any embodiment herein, wherein the flow regulator comprises a variable constriction portion in the flow path.

[0249] The vacuum suction system of any embodiment herein, wherein the flow regulator comprises a flexible channel sidewall and an actuator configured to compress the flexible sidewall.

[0250] 10. The vacuum suction system of any embodiment herein, comprising: a flexible filament surrounding the sidewall; and at least one lever configured to place the filament under tension and close the valve by reducing the diameter of the sidewall.

[0251] The vacuum suction system of any embodiment herein, further comprising at least one spring biasing the lever in a direction to close the valve.

[0252] The vacuum suction system of any embodiment herein, wherein the flow regulator comprises a tube having an inner diameter and length to provide the desired flow rate.

[0253] A vacuum suction system as described in any embodiment herein, wherein the low flow mode aspirates fluid at a rate of about 10 cc / sec or less, and the high flow mode aspirates fluid at a rate of at least about 15 cc / sec if suction is not obstructed.

[0254] 1. A vacuum suction system comprising:

[0255] Housing and

[0256] a fluid flow path extending through the housing;

[0257] a first catheter in fluid communication with a fluid path and a connector configured to place a suction source in communication with the fluid path;

[0258] a flow regulator configured to regulate a fluid flow rate through the flow path;

[0259] a first operator-actuated controller configured to switch the flow regulator between a default low-flow mode and a momentary, operator-initiated high-flow override mode;

[0260] a second operator-actuated control configured to turn off fluid flow; a vacuum suction system.

[0261] The vacuum suction system of any embodiment herein, further comprising a port on the housing that communicates with the first connector and is configured to guide a second catheter through the housing and into and through the first catheter.

[0262] The vacuum suction system described in any embodiment herein, further comprising a hemostasis valve in communication with the port and carried by the housing.

[0263] The vacuum suction system of any embodiment herein, further comprising a reservoir carried by the housing for receiving thrombus and blood retrieved through the first catheter.

[0264] The vacuum suction system of any embodiment herein, wherein the reservoir comprises a transparent tubular wall removably carried by the housing.

Claims

1. 1. An accelerated response aspiration system comprising: a suction pump in communication with the first chamber; a suction catheter configured to be in fluid communication with the first chamber via a suction tube; a second chamber located between the suction tube and the catheter; a valve located between the second chamber and the suction catheter; When the valve is opened by negative pressure in the first and second chambers, the resistance to fluid flow between the second chamber and the distal end of the catheter is less than the resistance to fluid flow between the second chamber and the first chamber, thereby causing rapid suction into the second chamber.

2. The aspiration system of claim 1 , further comprising a handle on the aspiration catheter, the second chamber being carried by the handle.

3. The aspiration system of claim 2 further comprising a first control on the handle for opening the valve.

4. 4. The suction system of claim 3, wherein the valve is normally closed and the control device activates the valve to momentarily open.

5. The aspiration system of claim 3 further comprising a second controller for driving the pump.

6. The aspiration system of claim 2 further comprising a hemostasis valve carried by the handle.

7. 7. The aspiration system of claim 6, wherein the hemostatic valve includes a collapsible tubular sidewall defining a valve lumen, and a filament configured to form a loop around the tubular sidewall and collapse the valve lumen.

8. 8. The aspiration system of claim 7, wherein the hemostatic valve further includes a frame and a lever, the filament having at least a first tail portion extending around a first fulcrum on the lever in a direction away from the loop and fixed against axial movement relative to the frame.

9. The aspiration system of claim 8 , wherein the first tail portion is connected to the frame.

10. 9. The suction system of claim 8, further comprising a second lever, the filament further comprising a second tail portion extending from the loop around a second fulcrum on the second lever and connected to the frame.

11. 10. The suction system of claim 1, wherein the suction tube is at least about 50 inches (1270 mm) long.

12. The aspiration system of claim 1 , wherein the second chamber is configured to capture blood clots aspirated by the catheter.

13. The aspiration system of claim 12 , wherein at least a portion of the second chamber is removably carried by the handle.

14. 14. The aspiration system of claim 13, wherein the second chamber includes a filter membrane spaced apart from a transparent wall.

15. 15. The aspiration system of claim 14, including a tubular filter membrane spaced radially inward from a transparent outer tubular wall.

16. 10. The aspiration system of claim 1, further comprising an operator-actuated control configured to switch the flow regulator between a default low-flow mode and a momentary, operator-initiated high-flow override mode.

17. 10. The aspiration system of claim 1, wherein the second chamber is configured for placement inside a sterile field and the first chamber is configured for placement outside the sterile field.

18. 10. The suction system of claim 1, further comprising a handle on the suction catheter and a tube between the handle and the second chamber, the tube having a length of about 20 inches (about 508 mm) or less.

19. 1. A split dilator aspiration system comprising: a catheter having an elongated, flexible tubular body with a proximal end, a distal end, a sidewall defining a central lumen, and a handle on the proximal end; a split dilator aspiration system including: a dilator that can be driven forward through the central lumen, the dilator having a cannulated elongate body for receiving a guidewire, and a split extending axially along at least a portion of the elongate body and configured to allow for laterally removing a portion of the dilator from the guidewire.

20. 20. The split dilator aspiration system of claim 19, wherein the handle includes a first engagement surface and the dilator includes a proximal hub having a second engagement surface configured to engage the first engagement surface to releasably secure the dilator within the catheter.

21. 21. The split dilator aspiration system of claim 20, including a retaining clip carried by the proximal end of the catheter handle.

22. 22. The split dilator aspiration system of claim 21, further comprising a holding surface carried by the gripping body.

23. 23. The split dilator aspiration system of claim 22, wherein the retention surface is located on a retention ring configured to engage the retention clip.

24. 23. The split dilator aspiration system of claim 22, further comprising a release control for disengaging the grip body from the catheter handle.

25. 25. The split dilator aspiration system of claim 24, wherein the release control comprises at least one push button.

26. 20. The split dilator aspiration system of claim 19, further comprising a clot container on the handle.

27. 20. The split dilator aspiration system of claim 19, further comprising a hemostasis valve on the handle.

28. 20. The split dilator aspiration system of claim 19, wherein the split includes a weakened portion of the wall to allow for the gradual formation of a slit through the wall to allow for lateral escape of the guidewire.

29. 20. The split dilator aspiration system of claim 19, wherein the split comprises a preformed slit completely through the wall.

30. 20. The split dilator aspiration system of claim 19, wherein the split extends to a distal termination spaced proximally from the distal end of the catheter.

31. 31. The split dilator aspiration system of claim 30, wherein the distal termination point is spaced proximally from the distal end of the catheter within a range of about 5 cm to about 40 cm.

32. 20. The split dilator aspiration system of claim 19, further comprising a proximal handle on the dilator.

33. 33. The split dilator aspiration system of claim 32, wherein the handle includes a gripping body having a first gripping surface and a guidewire exit port configured to guide a guidewire along the first gripping surface.

34. 34. The split dilator aspiration system of claim 33, wherein the body includes a paddle shape having the first gripping surface on a first side and is configured to be held between the thumb and index finger such that a guidewire can be positioned between the thumb and the first gripping surface.

35. 35. The split dilator aspiration system of claim 34, further comprising a friction-enhancing surface structure on the first gripping surface.

36. 36. The split dilator aspiration system of claim 35, wherein the friction-enhancing surface structure comprises a plurality of ridges.

37. A hemostatic valve, A support; at least a first lever pivotally supported relative to said support; a collapsible tubular sidewall defining a valve lumen and carried by said support; a filament forming a loop around the tubular sidewall, the filament having at least a first tail portion spaced from the loop and extending toward the first lever; a first spring configured to move the first lever in a direction to pull the first tail portion away from the tubular side wall, thereby reducing the diameter of the valve lumen in response to reducing the diameter of the loop.

38. 38. A hemostasis valve according to claim 37, further comprising a second lever pivotally supported relative to the support.

39. 39. A hemostatic valve according to claim 38, further comprising a second tail portion extending away from the loop to the second lever.

40. 40. The hemostatic valve of claim 39, wherein the first tail portion, the second tail portion, and the loop are one continuous filament.

41. 41. The hemostatic valve of claim 40, further comprising a lubricious coating on the filaments.

42. 42. The hemostasis valve of claim 41, wherein the lubricious coating comprises silicone oil.

43. 40. The hemostatic valve of claim 39, wherein the first and second levers are biased in a direction that places the first and second tail portions under sufficient tension to reduce the diameter of the valve lumen and provide a seal around a device extending through the valve.

44. 40. The hemostasis valve of claim 39, wherein the first and second levers are biased in a direction that places the first and second tail portions under sufficient tension to close the valve.

45. 38. A hemostasis valve according to claim 37, wherein the first tail portion is attached to the first lever.

46. 38. The hemostasis valve of claim 37, wherein the first tail portion slidably extends about a first fulcrum on the first lever and is attached to the frame.

47. 47. The hemostasis valve of claim 46, wherein the second tail portion slidably extends about a second fulcrum on the second lever and is attached to the frame.

48. 48. The hemostatic valve of claim 47, wherein the first fulcrum and the second fulcrum comprise pins.

49. 38. The hemostatic valve of claim 37 mounted on the proximal end of the catheter.

50. 38. The hemostasis valve of claim 37, further comprising a connector in communication with the valve lumen and configured to be connected to a vacuum source.

51. 1. A vacuum suction system comprising: Housing and a flow passage extending through the housing; an on-off control device provided in the flow path; a first catheter in fluid communication with the fluid path and a connector configured to place a suction source in communication with the fluid path; a clot container carried by the housing; a hemostasis valve located within the housing and configured to receive a second catheter and guide the second catheter through the first catheter.

52. 52. The vacuum aspiration system of claim 51, further comprising a flow regulator configured to regulate fluid flow through the flow path.

53. 53. The vacuum aspiration system of claim 52, wherein at least a portion of the clot container is removably carried by the housing.

54. 53. The vacuum aspiration system of claim 52, wherein the clot container includes a filter membrane spaced apart from a transparent wall.

55. 55. The vacuum aspiration system of claim 54, including a tubular filter membrane spaced radially inward from the transparent outer tubular wall.

56. 52. The vacuum aspiration system of claim 51, further comprising an operator-actuated control configured to switch the flow regulator between a default low-flow mode and a momentary, operator-initiated high-flow override mode.

57. 57. The vacuum aspiration system of claim 56, wherein the operator-actuated control includes a momentary control that places the system in the high flow override mode only when actuated by the operator.

58. 58. The vacuum suction system of claim 57, further comprising an on-off control for switching between an off mode and said low-flow mode.

59. 52. The vacuum suction system of claim 51, further comprising a sidewall containing the flow channel, and an optically transparent window within the sidewall.

60. 52. The vacuum aspiration system of claim 51, wherein the flow regulator comprises a variable constriction within the flow path.

61. 61. The vacuum aspiration system of claim 60, wherein the flow regulator includes a flexible channel sidewall and an actuator configured to compress the flexible sidewall.

62. 62. The vacuum suction system of claim 61, comprising a flexible filament surrounding the side wall, and at least one lever configured to place the filament under tension and close the valve by reducing the diameter of the side wall.

63. 63. The vacuum suction system of claim 62, further comprising at least one spring biasing the lever in a direction to close the valve.

64. 61. The vacuum aspiration system of claim 60, wherein the flow regulator comprises a tube having an inner diameter and length to provide a desired flow rate.

65. 52. The vacuum suction system of claim 51, wherein the low flow mode aspirates fluid at a rate of about 10 cc / sec or less, and the high flow mode aspirates fluid at a rate of at least about 15 cc / sec when suction is unimpeded.

66. 1. A vacuum suction system comprising: Housing and a fluid flow path extending through the housing; a first catheter in fluid communication with the fluid path and a connector configured to place a suction source in communication with the fluid path; a flow regulator configured to regulate a fluid flow rate through the flow path; a first operator-actuated control configured to regulate fluid flow; a second operator-actuated control configured to turn off the fluid flow.

67. 67. The vacuum aspiration system of claim 66, further comprising a port on the housing that communicates with the first connector and is configured to guide a second catheter through the housing and into and through the first catheter.

68. 68. The vacuum aspiration system of claim 67, further comprising a hemostasis valve in communication with the port and carried by the housing.

69. 67. The vacuum aspiration system of claim 66, further comprising a reservoir carried by the housing for receiving thrombus and blood retrieved through the first catheter.

70. 70. The vacuum suction system of claim 69, wherein the reservoir includes a transparent tubular wall removably carried by the housing.

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