A suction catheter system designed to improve suction and to evaluate suction status

Abstract

An aspiration thrombus removal system is described that includes an aspiration catheter having a fitting connected to a conduit and a pump. The aspiration catheter assembly can include a guide catheter and an aspiration catheter. The aspiration catheter can be positioned in the artery such that a distal opening is positioned proximal to the clot. The fitting can include a filter for removing clots from the aspiration flow. The fitting can include a flow meter for measuring flow rate to the pump. The fitting can include a pressure sensor for measuring pressure within the fitting. The aspiration catheter can be manipulated based on the pressure and flow measurements. The fitting can include a docking manifold that docks with a connecting aspiration of the suction extension to allow the suction extension to be removed from the hemostatic isolation portion and clots to be removed from the suction extension without the use of a separate fitting, thereby efficiently reinserting the suction extension with foreign material removed for further use.

Description

[Technical field]

[0001] The present invention relates to an aspiration catheter system designed with fittings designed for efficient and safe operation of aspiration therapy in body vessels having tortuous paths, such as the cerebral arteries. In particular, the present invention relates to an aspiration catheter system including a guide catheter and a suction extension slidably disposed within the guide catheter, and fittings that allow for efficient evaluation of the processing and reuse of the suction extension. [Background technology]

[0002] Treatment of intracerebral blood vessels is becoming a popular approach for ameliorating acute stroke events or other interventions in intracerebral blood vessels. Intracerebral blood vessels may follow particularly complex and tortuous paths, making it more difficult to reach target locations within these blood vessels. The rest of the patient's blood vessels may also follow tortuous paths that make it more difficult to reach target locations.

[0003] Aspiration catheters have been used in connection with the removal of blood clots from blood vessels. Furthermore, a major reason for ischemic injury during percutaneous procedures may be the formation of blood clots, which clog the smaller, more peripheral blood vessels. Aspiration catheters used alone or with embolic protection devices may be effective in capturing blood clots that form during procedures. It remains difficult to deliver effective instruments to the small blood vessels of the brain to remove clots and / or capture clots.

[0004] Ischemic attacks can be caused by blood clots in the cerebral arteries. The clots can block blood flow, which can block brain tissue from its blood supply. The clots can be thrombi that occur locally or emboli that have traveled from another location to the site of the vascular occlusion. Time is a critical factor to reduce the effects of the blockage of blood supply to the tissue. In particular, it is desirable to restore blood flow in as short a time as possible. The cerebral arterial system is also a highly branched vascular system that is connected to the internal carotid artery. The cerebral arteries are highly circuitous. The therapeutic device must be able to navigate along the circuitous path provided by the cerebral arteries in order to be placed in the cerebral arteries. Summary of the Invention [Means for solving the problem]

[0005] In a first aspect, the present invention relates to an aspiration thrombus removal system including an aspiration catheter assembly, a fitting, a pump, and a conduit. The aspiration catheter assembly generally includes an aspiration lumen. The aspiration lumen can extend from a proximal end to a distal opening. The proximal end of the aspiration lumen includes a connector. The fitting generally includes a branch manifold. A first branch of the branch manifold generally includes a hemostasis valve. A second branch of the branch manifold generally includes a connector. The branch manifold can be attached to the connector of the aspiration catheter assembly. The conduit can be connected to the pump and to the connector of the second branch. The conduit generally includes a tube and a filter. The filter can have an inlet and an outlet connected to the tube. The inlet can be connected to the connector of the second branch or within 12 centimeters of it.

[0006] In a further aspect, the invention relates to an aspiration thrombus removal system including an aspiration catheter assembly, a fitting, a pump, a conduit, a pressure sensor, a flow meter, and a controller. The aspiration catheter assembly generally includes an aspiration lumen. The aspiration lumen can extend from a proximal end to a distal opening. The proximal end of the aspiration includes a connector. The fitting generally includes a branch manifold. A first branch of the branch manifold generally includes a hemostasis valve. A second branch of the branch manifold generally includes a connector. The conduit can be connected to the pump and to the connector of the second branch. A pressure sensor can be connected to the fitting to measure pressure within the fitting. A flow meter can be connected to the conduit to measure flow to the pump. The controller generally includes one or more displays configured to display the pressure and flow.

[0007] In a further aspect, the present invention relates to a method of using an aspiration catheter system to remove a blood clot from a patient's vasculature. For carrying out the method, the aspiration catheter system can include an aspiration catheter assembly including an aspiration catheter, a fitting including a branched manifold, a first branch including a hemostasis valve and a second branch including a connector, a pump, a conduit connected to the connector of the pump and the second branch, a pressure sensor connected to the fitting and measuring a pressure in the fitting, a flow meter connected to the fitting and measuring a flow rate to the pump, and a controller including one or more displays configured to display the pressure and flow rate. The method can include positioning the aspiration catheter in an artery such that a distal aspiration opening of the aspiration catheter is positioned proximal to a blood clot, aspirating fluid from the patient's vasculature into the distal opening of the aspiration catheter, monitoring the flow rate and pressure in the fitting, and operating the aspiration catheter based on the pressure and flow measurements. [Brief description of the drawings]

[0008] [Figure 1]FIG. 1 is a side view of an aspiration catheter system including a guide catheter with a suction extension, where the guide catheter is shown transparent to allow visibility of structures within the guide catheter. [Diagram 2] FIG. 1 is a side view of an embodiment of a guide catheter extending from a luer fitting to a distal end. [Diagram 3] 3 is a partial cross-sectional view of the guide catheter of FIG. 2 between points 3-3 of FIG. 2 along a plane passing through the central axis of the catheter. [Figure 4] 4 is a partial cross-sectional view of the guide catheter of FIG. 2 between points 4-4 of FIG. 2 along a plane passing through the central axis of the catheter. [Diagram 5] FIG. 3 is a side view of a branched hemostatic valve suitable for connection to a luer fitting of the guide catheter of FIG. 2. [Figure 6] FIG. 13 is a side view of an embodiment of a suction extension. [Figure 7] FIG. 7 is a top view of the suction extension of FIG. 6 with some hidden structure shown in dashed lines. [Figure 8] 8 is a side cross-sectional view of the suction extension of FIG. 6 taken along line 8-8 of FIG. 7. [Figure 9] FIG. 9 is a partial cross-sectional view taken along line 9-9 of FIG. 6. [Figure 10] FIG. 10 is a partial cross-sectional view taken along line 10-10 of FIG. 6. [Figure 11] 11 is a partial cross-sectional view of the catheter of FIG. 11 taken along the orthographic projection indicated by line 11-11 of FIG. 9. [Figure 12] 12 is a cross-sectional end view of the catheter of FIG. 6 taken along line 12-12 of FIG. 8. [Figure 13] FIG. 13 is a partial cross-sectional view of an alternative embodiment of a suction extension, with an enlarged inset showing attachment of a control wire to a proximal portion with a coiled end of the control wire. [Figure 14] FIG. 14 is a cross-sectional view taken along line 14-14 of FIG. [Figure 15] FIG. 13 is a top view of an alternative embodiment of a suction extension, in which the tubular extension has two tubular sections of different diameters connected by a tapered section. [Figure 16]16 is a cross-sectional view of an alternative embodiment of the suction extension shown in FIG. 15 taken along line 16-16 in FIG. 15. [Figure 17] 11 is an alternative embodiment of the proximal end of the control structure where the handle is attached to the control structure and the end of the control structure is twisted to limit movement of the handle relative to its position on the control device. [Figure 18] FIG. 2 is a partial cross-sectional view of a suction tip having a bent portion. [Figure 19] FIG. 13 is a partial side view of an aspiration tip having a bend and an angled opening. [Figure 20] FIG. 2 is a partial cross-sectional view of an aspiration tip having a gentle curve. [Figure 21] FIG. 13 is an end cross-sectional view of a connecting section of a suction extension contacting an engagement section of a guide catheter having a non-circular cross-section. [Figure 22] FIG. 1 is a schematic diagram of a collection of medical devices that can be used together, or in selected subcombinations, for selected percutaneous procedures in body vessels, including the aspiration system described herein. [Diagram 23] FIG. 13 is a partial side view of the proximal fitting shown with two separate components adjacent to the guide catheter, these two components being a Y-branch manifold and an extended hemostasis fitting. [Figure 24] FIG. 13 is a partial side view of a first alternative embodiment suitable for use with a docking branched manifold in which the proximal hemostasis valve comprises a single, non-branched component adjacent to the guide catheter. [Diagram 25] FIG. 13 is a partial side view of another alternative embodiment of a proximal fitting attached to a guide catheter, comprising a three-branch manifold extending from the guide catheter and an extended hemostasis fitting attached to one branch. [Figure 26] FIG. 13 is a partial side view of a further alternative embodiment of a proximal fitting extending from a guide catheter, the fitting comprising a Y-branch manifold, a T-branch manifold connected to one branch of the Y, an extended hemostasis fitting extending from the straight branch of the T-branch, and a negative pressure device attached along the T-branch conduit. [Figure 27]FIG. 1 is a perspective view of a Y-branch manifold adapted for connection to a pump and attachment to a pressure sensor. [Figure 28] FIG. 1 is a side view of a Y-branch manifold attached to a tubing fitting adapted for a pressure sensor with an electronic connector. [Figure 29] FIG. 13 is a side view of a Y-branch manifold with a terminal pressure sensor along one branch and an electrical connector for connecting to the pressure sensor. [Diagram 30] FIG. 2 is a side view of a first embodiment of a docking branch manifold with branching fluid delivery channels. [Figure 31A] 13 is a side view of an alternative embodiment of a docking branch manifold with docking elements. FIG. [Figure 31B] FIG. 31B is a side view of the docking branch manifold of FIG. 31A with a negative pressure device attached to one of the branches of the branch manifold. [Figure 31C] 31B is a partial cross-sectional view of the docking branch manifold of FIG. 31A showing a distal end of a docking element. [Diagram 32] FIG. 2 is a side view of a guide catheter, a first fitting element comprising a branch manifold forming part of a proximal fitting for an aspiration system, and a docking branch manifold, with hidden docking elements shown in dashed lines. [Diagram 33] FIG. 13 is a side view of a guide catheter, an alternative embodiment of a first fitting element comprising a branch manifold having an additional branch, and a docking branch manifold. [Figure 34A] FIG. 31B is a side view of the fitting components connected to the guide catheter shown in FIG. 31A loaded with a suction extension, with the suction extension control structure shown emerging from the proximal end of the fitting. [Figure 34B] FIG. 34B is a partial cross-sectional view of a portion of the first attachment element and docking branch manifold of FIG. 34A, the cross-section being through a central axis of the lumen, with the suction extension in a docking position engaged with the docking branch manifold. [Figure 34C]34B is a partial cross-sectional view of the first fitting element and a portion of the docking branch manifold of FIG. 34A, except with the suction extension in a separated position. FIG. [Figure 35A] FIG. 2 is a side view of the assembled pin vice handle. [Figure 35B] FIG. 35B is a cross-sectional view of the collet separated from the pin vice of FIG. 35A. [Figure 35C] FIG. 2 is a side view of the pin vise with the head removed. [Figure 35D] FIG. 35B is an exploded view of the pin vice handle of FIG. 35A, with the components separated along the central axis. [Figure 36A] FIG. 2 is an exploded perspective view of a filter having a corrugated filter element. [Figure 36B] FIG. 36B is a side view of the filter of FIG. 36A. [Figure 36C] FIG. 36B is a perspective view showing the flow through the filter element of FIG. 36A. [Figure 37A] FIG. 1 is an exploded perspective view of a filter having a fiber filter element. [Figure 37B] FIG. 1 is an exploded perspective view of a filter having a packing of sheet-like filter material. [Figure 38A] FIG. 2 is an exploded perspective view of a filter having a screen filter element. [Figure 38B] FIG. 38B is a side view of the filter of FIG. 38A. [Figure 39A] FIG. 1 is a side view of a filter having a screen filter element in a compartment secured under a cap. [Figure 39B] FIG. 39B is an exploded side view of the filter of FIG. 39A. [Figure 39C] FIG. 39B is a cross-sectional view of the cap of the filter of FIG. 39A. [Figure 39D] FIG. 39B is a cross-sectional view of the filter of FIG. 39A. [Diagram 40] FIG. [Diagram 41] FIG. [Diagram 42]FIG. 1 is a cross-sectional view of a flow meter having a paddle wheel. [Diagram 43] FIG. 2 is a cross-sectional view of a pressure sensor. [Figure 44A] FIG. 1 is a side view of an embodiment of a proximal fitting for an aspiration system comprising a guide catheter, a branching manifold, a first fitting element with a first branch having a pressure sensor, a flow sensor, a filter, and a negative pressure source. [Figure 44B] FIG. 44B is an alternative embodiment of the aspiration system of FIG. 44A, in which the pressure sensor is on the second branch of the branching manifold. [Diagram 45] FIG. 13 is a partial view of an embodiment of an aspiration system from a location within the neurovasculature towards the proximal attachment. [Figure 46] 1 is a schematic diagram of a human patient and an alternative access approach for guiding a catheter into a cerebral vasculature. [Figure 47] 1 is a view within a branching vessel segment showing delivery of a medical device along a guidewire from a guide catheter to a clot, with the inset showing a close-up of two internal sections of the guide catheter. [Figure 48] 1 is a schematic diagram of an aspiration system in use to remove a blood clot within a compartment of a blood vessel. [Figure 49] 1 is a schematic diagram of a segment of a blood vessel with an aspiration system positioned upstream of a clot and a fiber-based filter deployed downstream of the clot. [Figure 50] FIG. 50 is a schematic diagram of the vascular section of FIG. 49 in which a fiber-based filter has been pulled towards the aspiration tip to draw the clot into the tip to facilitate removal of the clot. [Figure 51] 1 is a schematic diagram of a segment of a blood vessel with an aspiration system positioned upstream of a clot, a fiber-based filter deployed downstream of the clot, and other medical devices positioned at the clot. [Figure 52] 52 is a schematic diagram of the vascular segment of FIG. 51 in conjunction with other medical devices for removal of a blood clot. [Diagram 53]FIG. 1 is a partial view of a treatment system extending from a location within the neurovasculature to a proximal attachment, shown after application of suction to remove blood clots and optional other treatment steps, with an inset showing a cross-sectional view of the tubular extension within the guide catheter. [Figure 54] FIG. 54 is a partial view of the distal portion of the treatment system of FIG. 53 with the tubular extension retracted into the guide catheter, with the inset showing a cross-sectional view of the distal end of the tubular extension within the guide catheter. [Figure 55] FIG. 54 is a partial view of the proximal end of the treatment system of FIG. 53, with the tubular extension fully retracted so that the connecting section of the suction extension is within the proximal fitting on the exterior of the guide catheter, as shown in the cross-sectional view of the inset. [Figure 56] FIG. 54 is a partial view of the proximal end of the treatment system of FIG. 53, in which the tubular extension has been retracted from the guide catheter but remains enclosed within the proximal fitting; the inset on the left shows a cross-sectional view of the distal end of the tubular extension within the Y-branch manifold (and an alternative placement of the distal extension within the extension fitting shown in dashed lines), and the inset on the right shows the connection section of the suction extension within the extension hemostasis fitting, with the control wire extending through the hemostasis valve. [Figure 57] FIG. 54 is a partial view of the proximal end of the treatment system of FIG. 53, where the tubular extension has been pulled out of the guide catheter but remains surrounded by the proximal fitting having a sealed hemostasis valve; the left inset shows a cross-sectional view of the distal end of the tubular extension within the Y-branch manifold (and an alternative placement of the distal extension within the extended hemostasis fitting shown in dashed lines); and the right inset shows the connection section of the suction extension within the extended hemostasis fitting, where the branch manifold is connected to the hemostasis valve and the control wire extends through the hemostasis valve of the branch manifold. [Figure 58] FIG. 54 is a partial view of the proximal end of the treatment system of FIG. 53, showing the tubular extension with at least a portion of a blood clot on its distal end docked to the branch manifold and fully withdrawn from the sealed hemostasis valve of the treatment system. [Figure 59] An integral display is shown, which shows an image of the patient and a window showing pressure and flow. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Further improvements have been made to the aspiration catheter system that provide more reliable control of the aspiration process, particularly suited to the treatment of acute stroke. In particular, a filter is positioned in the proximal fitting of the catheter system to remove clots from the aspiration flow at a location further from the pump, and a robust aspiration pressure is maintained during clot removal. Additionally, the inclusion of a flow meter in the proximal fitting provides valuable information regarding the status of the aspiration process, allowing for better control of the process through understanding the status of clot removal. This improved design of the proximal fitting can be combined with other key designs of the aspiration catheter system to further improve the overall aspiration process from a clinical standpoint.

[0010] The proximal fitting design described herein can generally be used effectively in a variety of aspiration catheter systems. However, the fitting improvements may be particularly advantageous for systems having an aspiration catheter or suction extension designed to be inserted into a guide catheter from its proximal end with its distal end extending beyond the guide catheter. Such an aspiration catheter system forms a single aspiration lumen that extends through the aspiration catheter / suction extension within the guide catheter from the distal end of the aspiration catheter / suction extension to the distal end of the guide catheter. Depending on the perspective, it is reasonable to refer to a component of the aspiration catheter system as either a suction extension in terms of its role of extending the aspiration lumen beyond the distal end of the guide catheter, or as an aspiration catheter because it serves the role of an aspiration catheter even when it is fully inserted into the patient's body during aspiration. Therefore, the terms are used interchangeably.

[0011] Previous improvements in the proximal attachment for the aspiration thrombectomy system have allowed for the effective use of suction with a tether and sealing section, whereby the catheter is delivered into the guide catheter with the distal section extending out from the distal end of the guide catheter and a sealing section within the guide catheter forming an aspiration lumen including a lumen through the aspiration catheter and one section of the guide catheter. Previous improvements have allowed for the entire length of the aspiration catheter to be placed in the proximal attachment separate from the guide catheter but behind the hemostatic valve, as well as allowing the aspiration catheter to be removed from behind the hemostatic valve while maintaining a continuous fluid connection with the aspiration catheter, thereby clearing obstruction from the aspiration catheter and allowing the aspiration catheter to be positioned within the guide catheter and efficiently returned behind the hemostatic valve for the next aspiration to be performed. Additional improvements described herein provide for more efficient aspiration and assessment of the status of the aspiration system.

[0012] While pressure sensors can provide useful information regarding the state of the aspiration process, this information may be incomplete and therefore ambiguous. As described herein, a flow meter is provided in the proximal fitting to provide additional information that can clarify the state of the process. For example, pressure changes may indicate some degree of obstruction, and probing the flow status can provide valuable information regarding the extent of obstruction and the possibility of more impactful changes over time than pressure changes alone. Also, a sudden increase in flow rate may indicate the displacement or dislodging of a clot, which may prompt medical personnel to check for the presence of clots in the filter. Flow meters of various designs can be employed for this purpose, such as commercial ultrasonic flow meters, which can be conveniently clipped onto flow-containing structures such as piping, tubing, and the like.

[0013] Although various negative pressure devices such as syringes or others can be used to draw blood from the suction catheter, the use of a medical pump is desirable to provide a stable and reproducible negative pressure that may be particularly important for acute stroke interventions. Medical pumps are commercially available for use in a variety of pulmonary, surgical, and vascular procedures. To protect the pump, these pumps generally have a large canister for collecting the liquid in the pump housing and a filter to collect any bacteria and debris that escapes the canister. Nevertheless, there is generally a relatively long high pressure compartment, i.e., medical tubing, between the pump and the suction catheter system components. The suction system is sterilized to access the patient's vascular system, and the pump is not specifically sterilized due to various practical constraints. To facilitate the connection of these sterile and non-sterile components, long tubing, generally at least 6 feet in length, is provided to create a practical partition between these different environments.

[0014] The high pressure tube is relatively small in diameter, which is not an issue unless the clot is moving through the tube. Even if the clot is effectively aspirated through the high pressure tube, it will cause a significant drop in negative pressure in the aspiration system as it travels to the large canister for fluid recovery in the pump. Due to the long length of the tube, it will take a significant amount of time for the clot to reach the large canister where it will be captured. In the improved system described herein, a relatively small but effective filter is provided at or near the distal end of the high pressure tube to capture the clot. The filter is typically connected to a fitting on one side and to the high pressure tube on the other side, but in some embodiments, the filter can be attached within 12 centimeters of a fitting connected to a corresponding section of the tube or other flow-containing conduit. In one sense, the end of the fitting can be considered the connection to the filter, and the high pressure tube can be considered the section that separates the sterile environment immediately surrounding the patient from the clean, but not necessarily sterile, environment surrounding the pump. A filter generally has an effectively increased caliber over a limited length and an internal structure or material that traps clots in the blood without significantly restricting flow. The filter may also be beneficial in terms of providing information on the status of the clot, i.e., whether it has been captured and identified as being in a safe location, whether or not the filter is used to avoid clogging the high pressure tubing. The filter may be provided in a sterile condition, and use of the filter may allow for substantial removal of clots from the high pressure tubing. Such a structure may allow for much improved control of the aspiration procedure and / or visualization of the capture of the clot. The use of the filter in a sterile location near the fitting may improve procedures using aspiration catheter designs such as those described in U.S. Patent No. 9,662,129, entitled "Aspiration Catheters for Thrombus Removal" by Galdonik et al., which is incorporated herein by reference, as well as other aspiration catheter designs described herein.

[0015] Aspiration thrombectomy has been performed clinically by applying a relatively steady suction, with suction turned on and off at the desired times. A model study suggests that improved aspiration can be achieved with cyclic aspiration, e.g., 0.5-5 Hertz aspiration pulses. See Good et al., "Hydrodynamics in Acute Ischemic Stroke Catheters Under Static and Cyclic Aspiration Conditions," Cardiovascular Engineering and Technology, Vol. 11(6), December 2020, 689-698, incorporated herein by reference. In clinical practice, forces are important, but the impact on the forces on the clot should be considered. Cyclic aspiration can be applied using the catheter system described herein. Pump technology for achieving cyclic aspiration is described in U.S. Patent No. 10,390,926, by Janardhan et al., entitled "Aspiration Devices and Methods," incorporated herein by reference. To avoid clot fragmentation and embolization under cyclic suction, it may be desirable to utilize a distal filter device, described further below, when applying cyclic suction.

[0016] The suction catheter system can include a guide catheter with a suction extension having a thinner distal tube capable of providing suction at a high flow rate. This two-part system provides the advantage of powerful suction capabilities while at the same time providing some flexibility in efficiently performing the procedure while leaving the guide catheter in place. A fitting design is described that allows the suction extension to be removed to quickly clear debris from the suction extension and reinserted while holding the guide catheter in place. Specifically, the fitting element engages the proximal opening of the suction extension in a docking configuration to allow debris to be cleared from the suction extension. In additional or alternative embodiments, a proximal fitting can be provided to allow the tubular portion of the suction extension (the tubular extension) to be pulled out of the guide catheter without the tubular extension of the suction extension passing through a hemostasis valve. A docking attachment that docks to the end of the suction extension is described that allows contact with the attachment while blowing debris off the suction extension, thereby allowing the suction extension to be reinserted clear of debris through a hemostasis valve and reinserted for additional suction. In many procedures, the suction nozzle can be cleared one or more times to reopen an occluded blood vessel. Efficient cleaning of the suction extension can greatly facilitate the procedure.

[0017] In some embodiments, the suction extension has a connecting section, which has an asymmetric circumference that contacts the inner surface of the guide catheter, providing translation of the suction extension within the guide catheter while contacting at two places to provide an effective fluid seal. In alternative or additional embodiments, the guide catheter can have a distal portion of the tubular element that is of smaller diameter, which effectively limits distal movement of the suction extension. Methods of using the suction catheter system are described that allow a portion of the suction lumen of the suction extension to remain in a sealed configuration with respect to the guide catheter lumen, in some embodiments, for the entire time the guide catheter is within the patient's body. The improved process can be guided using real-time line pressure measurements with a pressure transducer associated with a suitable back-end tool. The suction catheter can be advantageously used to remove thrombus and clots from body vessels, such as arteries. Some vessels may have small diameters and the treatment site may be downstream along a circuitous path, which limits the catheter configurations that can reach the treatment site within the vessel.

[0018] The designs described herein include a slidable suction extension that can be adapted for use with a corresponding guide catheter, which forms a majority of the overall aspiration lumen when the suction extension is deployed from the distal end of the guide catheter. In an improved embodiment of the present application, a fitting located at the proximal end of the catheter system can be designed to improve medical procedures to perform revascularization of occluded blood vessels more efficiently. The increased efficiency can reduce the time the catheter is placed in the patient's vasculature and reduce the time medical personnel spend performing the procedure. Although the aspiration catheter system can be used in any suitable blood vessel in the body, the system may be particularly desirable in cerebral blood vessels, for example, for the treatment of acute stroke. The aspiration catheter system can be effectively used as a stand-alone aspiration catheter for thrombus removal. Additionally, the aspiration catheter system can be effective as a component of a thrombus removal treatment system or other medical system to provide suction using other medical devices, such as a thrombus engagement device for breaking up thrombus and / or a filter structure that can capture clots generated during the procedure, as well as other medical devices used to pull toward the aspiration catheter system. The treatment system can be effectively designed for the treatment of stroke.

[0019] Less invasive procedures, commonly referred to in the art as minimally invasive procedures, often shorten patient recovery times in medical settings and hopefully improve outcomes when appropriate. In particular, minimally invasive procedures are generally performed in the vasculature using catheter-based systems to reach distant locations within selected blood vessels for the implementation of various therapeutic processes. These procedures may also be referred to as percutaneous or transluminal procedures, as opposed to open surgical procedures, to emphasize delivery through the vascular lumen. The discussion herein focuses on the treatment of ischemic stroke, as the device may be effective for treating these clinically significant conditions. However, the device may be used for other procedures in both the vasculature and other body vessels. Patients include humans and may include other animals, including pets and livestock. The terms proximal and distal are used with their conventional meaning in the art, i.e., proximal refers closer to the point of entry into the patient's body along a pathway in the vasculature or other vessel, and distal refers farther from the point of entry along a pathway in the vasculature.

[0020] The slidable suction extension generally includes a connection section that engages the inner wall of the guide catheter to provide a suitable tight fit. The connection section generally connects a control structure, such as a control wire, extending proximally from the connection section, and a tubular extension extending distally from the control structure. The control structure generally extends outside the patient's body to position the suction extension with its distal end near the treatment site within the blood vessel. The tubular extension may have an optional curved tip, allowing it to be nicely tracked over a guidewire to reach hard to reach locations within the blood vessel.

[0021] Since the thrombus may be held at the distal end of the suction extension while applying suction to remove the thrombus from the blood vessel, it may be desirable to retract the tubular extension of the suction extension into the guide catheter by applying suction to reduce the chance of embolization of the thrombus and loss of the thrombus that may migrate upstream in the blood vessel. To further reduce the risk of embolization, it may be desirable to apply suction to completely remove the tubular extension from the guide catheter before removing the guide catheter from the patient. In most procedures, it may be beneficial to remove the foreign body from the suction extension, reinsert the suction extension, and remove another thrombus from the blood vessel. To achieve the best results, it may be effective to repeat the suction process two, three, or perhaps more times.

[0022] A desirable proximal attachment is described on the rear of the catheter system that allows the tubular extension to be removed from the guide catheter without passing the tubular extension of the suction extension through the hemostasis valve. Because the proximal end of the tubular extension is generally open, passing the proximal end of the tubular extension through the hemostasis valve may expose the tubular extension and possibly the lumen of the guide catheter to the surrounding environment, which may or may not be desirable. An additional attachment element allows the suction extension to be removed from the hemostasis valve to remove foreign matter from the catheter while the attachment remains attached to the suction extension at all times, thereby allowing the suction extension to be quickly repositioned. The docking attachment may include a distal docking structure that allows the proximal end of the suction extension to be docked to the docking structure in an effective liquid-tight seal so that it can be removed together from the hemostasis valve. As previously mentioned, such removal of foreign matter from the suction extension may be repeated multiple times.

[0023] The proximal fittings can provide hemostatic isolation of the interior of the device exposed to the interior of the blood vessel. The guide catheter then forms an integral component of an aspiration system, whereby other components can be introduced, including but not limited to a suction extension. The fittings can then provide hemostatic introduction of such components, while being connectable to a negative pressure device, such as a pump or syringe, and possibly a delivery port for introduction of contrast, medication, or other desired fluids. IV contrast dye fluids are well known in the art. Medications can be delivered in suitable liquid form. These fittings then provide relative movement of the aspiration nozzle in and out of the guide catheter, as well as other functions.

[0024] The control structure for the suction extension can be a wire-like element, as described further below. To provide a desirably simple design for the guide and suction catheters, the suction extension can be pushed out of the distal end of the guide catheter, which can make it difficult or impossible to retrieve the suction extension from the patient's body while the guide catheter is in place. Markings on the control structure can prevent attempts to move the control structure in this way, but the user may ignore the marks. To avoid this possibility, a handle or grip can be fixed to the control structure. If appropriate for the handle design, the control structure can be bent, twisted, or otherwise distorted to make it difficult or impossible to remove the handle. The handle can then confine the distal extension of the suction extension within the guide catheter, so that the suction extension cannot extend out of the distal end of the guide catheter.

[0025] In some embodiments, a suitable proximal fitting suitable for withdrawing the tubular extension from the guide catheter but leaving it in hemostatic isolation has a tubular portion of the fitting after the bifurcated structure, the tubular section being long enough to hold the suction extension outside the tubular element of the guide catheter in the isolation area behind the hemostatic valve. Some suitable configurations are described below, and others will be apparent from the description of these embodiments. It can be noted that suction is generally applied from a separate branch of the fitting, and that multiple branches can be provided throughout the manifold, which may or may not be separable components that are assembled for use. This isolation structure can assess the condition of the nozzle before it is withdrawn from hemostatic isolation, and can be used in combination with the fitting to effectively remove foreign material from the suction extension when not in hemostatic isolation, without having to disconnect the suction extension for the appropriate fitting.

[0026] Measuring the pressure in the proximal fitting can provide valuable information regarding the procedure. Possible structures for placement of the pressure sensor are described below. With pressure close to zero in the proximal fitting, flow in the line to the pump is virtually unrestricted. It is observed that the pressure as flow passes through the suction extension creates a measurable pressure drop, but remains at a pressure significantly lower than the pump pressure. If the suction extension becomes clogged with a clot or kinked, the measured pressure may be close to the pump pressure, which generally indicates that flow is essentially blocked in the catheter. Knowledge of the occlusion can be used to significantly improve the procedure in terms of efficiency and safety. For example, if an occlusion occurs early in the procedure, this may be indicative of a kink. An occlusion later in the procedure may indicate that the catheter has been occluded by a lodged clot, which generally signals that contrast or other perfusion fluid should not be delivered from that catheter, as the pressure of delivery may push a clot that has already occluded the catheter further into the vessel. Pressure transducers can be introduced in alternative ways. For example, pressure transducers can be installed along the inside walls of the manifold fittings or in tubing connected to the fittings in a configuration that provides a pressure measurement. The pressure sensor may or may not be sterilized depending on the location.

[0027] For stroke treatment, a treatment device can be advanced through the arteries to the blood vessels of the brain. The blood vessels generally associated with acute stroke treatment are downstream from the internal carotid artery in the bloodstream, and the arteries generally branch and reduce in average diameter as they progress downstream in the arterial vasculature. The body has a right internal carotid artery and a left internal carotid artery. For convenience, the blood vessels downstream from the internal carotid artery are referred to herein as cerebral arteries. The cerebral arteries can be accessed by catheter-based systems, for example, from the femoral artery in the groin, the arteries in the arm, or the carotid artery in the neck, using hemostatic procedures and appropriate fittings, such as those known in the art. Cerebral arteries are known to follow a circuitous path, and tracking devices along the blood vessels can also be complicated due to the small diameter of the vessels as well as dangerous risks from vessel injury that can cause hemorrhagic stroke conditions. Nevertheless, accessing small, tortuous arteries can be desirable for stroke treatment. Although the devices described herein are designed for advantageous use in these small and tortuous cerebral arteries, those skilled in the art will appreciate the utility of these devices in other medical procedures.

[0028] The present aspiration catheter system incorporates a guide catheter with a slidable suction extension suitable for cerebral procedures. In vascular procedures, the use of a guide catheter generally allows for faster and more accurate delivery with less risk to the vessel wall by providing a protected channel to the treatment site in most cases while facilitating delivery of the therapeutic device. In cerebral procedures, the guide catheter can be placed outside the patient's body with the distal end of the guide catheter in the carotid artery or internal carotid artery at the entry point into the vessel. The guide catheter can therefore provide a lumen relatively close to the treatment site. In some embodiments, a conventional guide catheter can be used to assemble the desired aspiration catheter, while in other embodiments, a specific guide catheter design is used to form the aspiration catheter system. The size of the guide catheter sets a limit on the diameter of the therapeutic structure delivered to the treatment site, but this is generally not a major issue since extendable devices can be delivered in a smaller configuration and then deployed in an extended state, and the size of the vessel generally decreases distally from the guide catheter, reducing the need for larger therapeutic devices. The suction devices described herein provide a suction extension that can protrude an adjustable amount from the distal end of the guide catheter by positioning a connecting section of the suction extension in contact with the inner wall of the lumen of the guide catheter. The connecting section can make a sufficiently tight seal with the wall of the guide catheter such that suction within the lumen of the guide catheter is transmitted along the lumen of the suction extension. A desired degree of suction can be obtained through the suction extension using suction applied to the proximal end of the guide catheter.

[0029] The suction extension generally comprises a connecting section, a control structure extending proximally from the connecting section, and a tubular extension extending distally from the connecting section. The suction extension generally contacts the guide catheter and can be designed to be positioned with its tip at a selected location distal to the guide catheter to perform a procedure near a selected location, for example, the location of a thrombus occluding a cerebral vessel. Since the relative location of the treatment site and the distal end of the guide catheter generally varies depending on the specific medical situation, the extent to which the suction extension extends from the guide catheter can be adjusted through relative movement of the suction extension using a control structure such as a control wire. The suction extension should move within the guide catheter lumen without requiring excessive force, which may be facilitated by the use of low friction polymers on one or both adjacent surfaces.

[0030] The connecting section of the suction extension is adapted to contact the inner wall of the guide catheter, thereby preventing little or no flow around the connecting section that does not flow through the lumen of the suction extension, while retaining at least a portion of the connecting section within the guide catheter and allowing the suction extension to slide properly and problem-free with respect to the guide catheter within the patient's vessel. Various embodiments of components that form such contact are discussed in U.S. Patent Application Publication No. 2017 / 0143938 to Ogle et al., entitled "Catheter Systems for Applying Effective Suction in Remote Vessels and Thrombectomy Procedures Facilitated by Catheter Systems" (hereinafter the '938 application), which is incorporated herein by reference. The connecting section, referred to as the proximal portion in the '938 application, can have a non-cylindrical cross-sectional shape. Such a non-cylindrical cross-sectional shape can advantageously be adapted to contact the guide catheter in two locations along its circumference, with a small gap around the remaining section of the circumference of the connecting section. Upon contact with the lumen of the guide catheter, the connecting section exerts some force that partially rounds its circumference. This non-cylindrical shape for the connecting section effectively blocks flow between the guide catheter wall and the connecting section, while not preventing the connecting section from moving longitudinally to position the tip of the suction extension within the vessel. The introduction of a non-cylindrical shape for the connecting section is described in U.S. Patent No. 10,478,535 to Ogle, entitled "Suction Catheter Systems for Applying Effective Aspiration in Remote Vessels, Especially Cerebral Arteries" (hereinafter the '535 patent), which is incorporated herein by reference.

[0031] The non-circular cross-sectional shape of the connecting section of the suction extension may be generally described as an ellipse. The ellipse may be characterized, at least in part, by a major axis along the longer dimension of the ellipse and a minor axis along the shorter dimension of the ellipse that is orthogonal to the longer dimension. The connecting section may then contact or come very close to contacting the inner surface of the engagement section of the guide catheter at two locations associated with points along a circumference associated with the major axis. Correspondingly, the non-circular cross-section may be characterized by an average radius that may provide for an overall very small clearance with the guide catheter while still providing the desired functionality.

[0032] To form a non-circular cross section, ridges can be formed through the connection of the control wire along the surface of the connecting section and additional polymer that provides the desired shape as well as strengthens the connection between the connecting section and the control wire. Further embodiments of the structure of the connecting section having an elliptical cross section are described below. In this manner, the non-circular shape of the connecting section cross section can be designed such that it fits with the overall structure of the suction extension to contact the guide catheter.

[0033] Also, since it may be desirable to prevent the connecting section of the suction extension from extending beyond the distal end of the guide catheter, the suction extension and / or catheter may be designed to limit distal movement of the suction extension. Several different designs of guide catheter and / or suction extension features are described in the '938 application and the '535 patent. To simplify the guide catheter structure and allow the use of conventional guide catheter designs, it may be desirable to use a guide catheter that does not have any particular structural features that limit distal movement of the suction extension. However, the movement of the suction catheter should then be limited through the movement of the control structure. Instructing the user based on marks on the control structure may be prone to user error, which may result in the user extending the connecting section of the suction extension too far beyond the distal end of the guide catheter. Additional elements of the control structure described herein prevent the user from overextending the suction extension.

[0034] Compared to an aspiration catheter delivered through a guide catheter where the suction flow is confined to the aspiration catheter, the present application replaces most of the length of the aspiration catheter with the control element of the aspiration catheter system. This replacement of most of the length of the aspiration catheter with the control element results in a device that allows the tip of the aspiration catheter to be advanced through the patient's blood vessel with less friction because the control wire or other control element can provide less resistance to its movement. The tip of the suction extension can be given a curved tip to make it easier to track the device over the guidewire. In the design described herein, a suction extension for aspiration with a curved tip for tracking the tip over the guidewire can be effectively guided to very hard to reach locations using a control wire or other control element that moves a sliding portion at or near the distal end of the suction extension, and this design provides good aspiration capabilities without sacrificing the ability to reach hard to reach blood vessels such as cerebral blood vessels. The guide catheter portion of the aspiration lumen can be held in place while the suction extension is moved.

[0035] When suction is applied at or near the proximal end of the guide catheter with a suitable negative pressure device, fluid is drawn into the distal opening at the end of the suction extension. It has been found that powerful suction can be transmitted through the suction extension. The suction lumen extends from a negative pressure device attached to a fitting associated with a proximal section, generally at or near the proximal end of the suction system, through the guide catheter lumen to the suction extension, and through the connecting section of the tubular extension of the suction extension and the suction extension to the distal opening. Suitable negative pressure devices include, for example, a syringe, pump, or the like. The guide catheter can provide a large lumen as a significant section of the overall suction lumen. The effective suction lumen can then be viewed as having a large proximal section contributed by the guide catheter and a tapered distal section contributed by the suction extension, which can have one or more tapered sections.

[0036] The tubular extension of the suction extension has a small diameter relative to the guide catheter lumen and a highly flexible lumen that allows its distal end to be placed in smaller blood vessels. However, the lumen of the tubular extension is maintained at a large enough diameter to allow additional treatment devices to be delivered through the lumen to the treatment site. The outer diameter of the suction extension at its tip is generally at least about 1.5 Fr (diameter units are mm=(Fr value) / 3, Fr represents French catheter scale) smaller than the outer diameter of the distal section of the guide catheter. The smaller diameter of the tubular extension allows access to desired blood vessels, such as cerebral vessels.

[0037] It has been found that good aspiration characteristics are obtained with aspiration catheters that have a reduced diameter at the distal section. Thus, for example, the majority of the length of the aspiration catheter may be of 6 Fr outer diameter, with the distal section having an outer diameter of 5 Fr, which corresponds approximately to a reduced inner diameter. Such catheters can provide vascular access suitable for a 5 Fr catheter, but provide significantly better aspiration than an aspiration catheter with a 5 Fr catheter body along its entire length. Commercially available tapered catheters, such as the Mi-Axus™ catheter (MIVI Neuroscience, Inc.) and the ACE™ 64 catheter (Penumbra, Inc.), have demonstrated good clinical outcomes. Tapered aspiration catheters and their use for thrombectomy in cerebral arteries are described in U.S. Pat. No. 9,532,792 to Galdonik et al., entitled "Aspiration Catheters for Thrombus Removal" (hereinafter the '792 patent), which is incorporated herein by reference. While these catheters provide better suction than catheters with a constant diameter that matches the distal diameter, the present suction catheter system with a sliding suction extension has been found to provide better suction, suggesting that the diameter over most of the length of the aspiration lumen contributes to a significant degree to the suction provided to the distal opening of the aspiration lumen.

[0038] The initial part of the treatment using the devices described herein generally involves accessing the treatment site in the blood vessel. Guidewires are designed to facilitate access to hard-to-reach sites. The term guidewire is used herein broadly to refer to wire structures that may or may not have an internal structure, whether they are made of solid metal or woven metal, such as corewire-overtube integrated structures, coils, or otherwise, which may not have a closed lumen over at least a portion of the length of the device.

[0039] In particular, the devices described herein allow procedures to be performed to provide reperfusion of blood vessels completely or partially occluded by clots. Since clots in cerebral arteries can cause strokes with correspondingly severe consequences, time is of the essence in the treatment of these conditions. The suction extension with the guide catheter can be used to provide suction that can be beneficial for the removal of clots or their debris. Thus, the combination of the suction extension with the guide catheter and the negative pressure device can be used as a standalone device for thrombectomy. However, the suction extension with suction function can be effectively used as part of a treatment system that also includes, for example, a fiber-based filter and / or other components that facilitate the removal of clots or parts thereof. The delivery catheter with the expandable tip is designed for easy access, making it useful as a tool for performing various other procedures.

[0040] In some embodiments of the procedure, a guidewire can be placed at or near the occlusion and a guide catheter with a positionable suction extension can be placed in the blood vessel upstream of the occlusion with the guidewire extending through the inside of the suction extension. If the suction catheter system is used alone, the suction extension can be advanced to an appropriate location near the clot using a control wire on the guidewire. Suction can then be initiated, with or without the guidewire removed, to suck the clot or a portion of it into the distal opening or against the tip of the suction extension. Suction may or may not continue as the suction extension and / or guide catheter are removed from the patient.

[0041] While suction with the suction extension can be effective as a device for clot removal alone, additional therapeutic systems can be combined with other devices for use with the suction catheter system. In particular, the filter device can be used to provide both embolic protection and a tool to facilitate removal of the clot or a portion thereof, which may include directly engaging the clot with the filter device. Fiber-based filter / embolic protection systems have been developed that can be used effectively in small blood vessels of interest. In particular, fiber-based filter systems with appropriate actuation systems can be used to deliver through the occlusion in a low profile state and can be deployed to protect against clot debris if released during the removal process.

[0042] During the process of removing the aspiration catheter system and possibly other components of the treatment system from the patient, aspiration is generally continued until the risk of embolization of thrombus is sufficiently reduced. The suction extension may have thrombus within the lumen and / or trapped at the tip. The proximal end of the tubular section of the suction extension is generally open, whereby the aspiration lumen of the tubular extension may be exposed to the surrounding environment when the proximal end of the tubular extension is removed from the hemostatic valve. Since exposure of the lumen of the tubular extension while still within the patient's body may be undesirable, as described herein, a fitting has been devised that allows the tubular extension to be suspended outside the guide catheter while still within an isolated section of the system outside the patient's body. Aspiration can continue while the tubular extension is removed from the patient and isolated from the environment but outside the guide catheter.

[0043] In some procedures, it may be desirable to remove the tubular extension while it is removed from the patient's body. Once the foreign body is removed, the tubular extension can be reintroduced into the patient's body to retrieve additional thrombus. In such procedures, the docking branch manifold can be configured to facilitate quick removal and cleaning of the tubular extension. It is desirable to return the extension catheter to the blood vessel before the thrombus embolizes with a clot. The docking branch manifold generally has an inlet tubular section and at least one Y-branch with a fitting connected to a flow valve at the end of one branch. The flow valve generally has at least a second port connected to a source of irrigation fluid, although in some embodiments, this or other flow valves can be used to control alternative fluid and / or suction sources. The docking branch manifold generally has a second branch with a hemostatic valve. The docking branch manifold has a tubular inlet at a distal end that includes a docking structure. The docking structure can pass through the hemostasis valve of the first branch manifold, thereby positioning it within the tubular section of the first branch manifold.

[0044] The docking branch manifold can generally be used to irrigate the catheter with fluid from a fluid source, such as a syringe, pressurized container, or pump connected to a reservoir. The docking branch manifold can include multiple fluid sources, such as a contrast fluid source, a therapeutic agent fluid source, and / or an irrigation fluid source, such as buffered saline, and can also be used to irrigate an occluded catheter with contrast. Also, instead of or in addition to suction being configured to be delivered from the first attachment element, suction can be delivered from the docking branch manifold to an aspiration system, which may optionally not include a manifold, for example as shown in the previous figures. If the docking branch manifold is used to deliver any other fluid besides the second fluid and / or suction, the docking branch manifold can include additional branches and / or additional branches along the second branch.

[0045] Generally, the control structure of the proximally extending suction extension can pass through the hemostasis valve, whereupon the valve closes with an appropriate seal around the control structure. Generally, the control structure can pass through both the hemostasis valve of the first branch manifold and the hemostasis valve of the second branch manifold, thereby allowing it to be operated from outside the manifold. The docking structure can slide around the control structure. In this configuration, the proximal end of the tubular extension can be retracted into a docked position with the docking structure. The docking structure can be configured to releasably hold the tubular extension. For example, the docking structure can secure the tubular extension using an interference fit. In an embodiment, the docking structure can include a narrowed portion of the inner wall of the tubular inlet portion. For example, the inner surface of the tubular inlet portion can be inwardly tapered until the inner diameter of the tubular inlet portion is smaller than the outer diameter of the tubular extension. In an alternative or additional embodiment, the docking structure can include a flange on the inner surface of the tubular inlet portion. In embodiments, the docking structure may include a material on the inner surface of the tubular entry section configured to create a friction fit to secure the tubular extension. The docking structure may include structure on the inner surface of the tubular entry section that mates with a corresponding structure on the outer surface of the tubular extension. For example, the docking structure may include pawls on the inner surface of the tubular entry section configured to mate with teeth on the outer surface of the tubular extension.

[0046] With the tubular extension docked to the docking structure, the docking manifold may be disconnected from the first manifold. The docking branch manifold may be separated along with the suction extension by opening the hemostatic valve of the first fitting element, withdrawing the docking branch manifold from the first fitting element, and resealing the first hemostatic valve once the tubular extension is disengaged from the valve. Any thrombus trapped within the tubular extension may be removed from the tubular extension while it is disengaged from the first fitting element. Fluid may be allowed to flow through the tubular extension by opening a fluid source valve attached to the docking branch manifold. The fluid may flush out thrombus and any other debris or material trapped within the tubular extension. The tubular extension, once cleared of foreign material, may be returned to the patient's body. Although it may be desirable to resterilize any components exposed to the environment prior to reintroduction into the patient's body, generally the suction extension is maintained in a sterile state outside the patient's body and may be returned to the vascular system without further sterilization. To reintroduce the tubular extension, the first hemostatic valve of the first fitting element should be opened to allow the tubular extension and docking structure to enter the first fitting element. When the docking structure is in place within the first fitting element, the hemostatic valve can be closed. A control structure can be used to move the tubular extension out of the docking structure, into the guide catheter, and back to the desired location within the patient. In some instances, suction can be maintained with the tubular extension cleared of foreign matter. In other instances, it may be preferable to stop suction when the tubular extension is not positioned within the guide catheter.

[0047] After revascularization of the vessel is completed, the catheter is removed from the patient's body. Depending on the particular fitting used, several alternative procedures can be used for safe removal of the catheter. If the fitting has an isolation section for removing the suction extension in the hemostatic seal, the procedure can be completed once the tubular extension is safely parked outside the guide catheter, which typically includes ending suction and verifying clearing of the occlusion. At the end of the procedure, the guide catheter can be safely removed from the patient. If the fitting does not include an isolation section, the suction extension may or may not be removed through the hemostatic valve before removing the guide catheter. If the suction extension is not removed through the hemostatic valve and isolated from the guide catheter, the distal end of the suction extension will typically be safely positioned within the lumen of the guide catheter when the guide catheter is removed, and suction may continue for at least a portion of the procedure, including removal of the guide catheter.

[0048] In some embodiments, the pressure in the proximal fitting can be monitored throughout the portion of the procedure in which suction is applied. If the pressure in the proximal fitting remains within an expected range, the physician performing the procedure can proceed based on that knowledge. If the pressure increases, the physician can take appropriate action, such as removing the suction extension from the patient, generally without delivering fluid through the tubular extension.

[0049] The devices and corresponding processes described herein provide improved capabilities for performing therapeutic procedures to remove blood clots from blood vessels. As described herein, the devices can be used in various combinations in medical systems for percutaneous procedures. The improved procedures provide practical steps to be performed by medical personnel handling the devices while providing additional safety measures.

[0050] Suction Catheter System with Sliding Suction Extension / Suction Catheter A suction catheter system is described that utilizes the guide catheter lumen as a proximal suction lumen, taking advantage of the better suction provided by the suction lumen with a larger proximal suction and a smaller diameter suction extension. A laterally slidable suction extension or suction catheter extends from a proximal section within the guide lumen, and the suction extension / suction catheter has a smaller distal diameter to provide access to small blood vessels and provide a desired level of suction to remove debris from the vessel as well as to deliver other therapeutic and / or embolic protection structures. As previously mentioned, the terms suction extension and suction catheter are used interchangeably. Control wires or other control structures can be attached to the suction extension to control the sliding and allow the suction extension to be selectively positioned laterally relative to a fixed guide catheter and target treatment site. In some embodiments, the suction extension includes a connecting section that has a non-cylindrical cross section and contacts the guide catheter lumen that contacts in two portions along the circumference. This non-cylindrical contact allows the suction extension to slide relatively easily relative to the guide catheter while blocking flow between the outside of the proximal portion of the suction extension and a proximal location inside the guide catheter. A particular guide catheter design can incorporate various tubing elements along its shaft to provide the desired flexibility, with smaller diameter distal tubing elements being used to hold the proximal section of the suction extension within the guide catheter lumen.

[0051] 1, the aspiration system 100 includes an aspiration guide catheter 102 and a suction extension 104. The aspiration guide catheter 102 includes a proximal section 106 and a tubular shaft 108. The proximal section 106 is generally suitable for use as a handle and may generally include a proximal fitting 120, an aspiration port 122, and an optional control wire port 124, as well as possibly other additional ports and / or fittings that provide desired functionality and access, all of which may be arranged in a bifurcated or other suitable configuration. The proximal fitting 120 may generally include an appropriate hemostatic valve, luer fitting, or the like, for entry of a guidewire and / or structure to be delivered into the guide catheter lumen over the guidewire, such as an alternative therapeutic structure and / or an embolic protection device.

[0052] In an improved embodiment described herein, the proximal fitting 120 may include a segment into which the tubular extension of the suction extension 104 may be placed and does not extend into the tubular shaft 108 of the guide catheter 102 or through a hemostasis valve into the surrounding environment. While desired features of the fixture at the proximal end of the aspiration system 100 may be integrated into the proximal fitting 120, design flexibility may be achieved through embodiments of the proximal fitting 120 that include connectors such as a Tuohy-Borst connector and fitting connections to provide other desired features as mounting components that are attached to the proximal fitting 120 for use, such as a Y-junction, a hemostasis valve, and an extended tubular fitting for storing the tubular extension of the suction extension. Suitable fittings having additional functional features for integration with the proximal fitting 120 are discussed in more detail below in the Treatment System section, with the understanding that the present disclosure below may be considered as integral parts of the proximal fitting 120 rather than as separate components.

[0053] For use with the aspiration system 100, a suitable embolic protection device can be attached to the guidewire and / or other treatment structure can be used. Suitable treatment structures are further described below and can include, for example, a fiber-based filter, a stent, a stent retriever, an atherectomy device, or the like. As shown in FIG. 1, a negative pressure device 126 is shown connected to the aspiration port 122, suitable negative pressure devices include, for example, a syringe, a pump such as a peristaltic pump or other suitable pump, an aspirator / venturi, or the like. Suitable pumps are available from Allied Healthcare Products, Inc., such as Gomco™ brand pumps or the DRE DM-660™ pump.

[0054] In general, the tubular shaft 108 can have a generally constant diameter along its length, or some guide catheters can have sections of different diameters, generally with a smaller diameter section distal to a larger diameter section. In some embodiments described herein, the majority of the length of the tubular shaft has a constant diameter to make the desired contact with the connecting section of the suction extension, which can be referred to as the engagement section of the tubular shaft, and is designed to engage with the suction extension in a configuration suitable for delivering suction to a patient. The portion of the tubular shaft proximal to the engagement section can have a larger inner diameter and generally larger outer profile relative to the engagement section. Conventional guide catheters can be used in some embodiments for the suction catheter system, with specific designs described below. The distal tubular portion of the tubular shaft can have a slightly smaller inner diameter to retain a portion of the suction extension 104 within the tubular shaft 108. The tubular shaft 108 may have one or more radiopaque marker bands to facilitate positioning of the tubular shaft within the patient as well as positioning the connection section of the suction extension within the guide catheter lumen; although Figure 1 shows the marker band 128 near the distal end of the tubular shaft 108, alternative locations may be used as desired. As described below, the tubular shaft 108 may have a coating on its inner and / or outer surface or portions thereof.

[0055] The suction extension 104 generally comprises a connecting section 140, a tubular extension 142, and a control structure 148, such as a control wire. All or a portion of the connecting section 140 can be configured to remain within the lumen of the guide catheter 102. As shown in FIG. 1, the connecting section 140 can include a radiopaque marker band 152, although in some embodiments the connecting section can have no marker band and in other embodiments can include multiple marker bands, and while the tubular extension 142 is shown having a radiopaque marker band 154 near the distal end of the tubular extension 142, again, the tubular extension 142 can include multiple radiopaque marker bands as desired. The control structure 148 can be a control wire or the like that connects with the proximal portion 140 and, in the assembled device, extends outside of the catheter, exiting, for example, through the control wire port 124 or the proximal fitting 120. The control structure 148 can be used to control the positioning of the connection section 140 within the lumen of the shaft 106. The control structure 148 can include a control tool 156, such as a handle, slide, or other such that a control wire or other connection element can be secured to facilitate movement of the control wire. In some embodiments, alternative structures such as multiple wires or a cylindrical wire assembly can connect the proximal portion to the proximal end of the aspiration catheter system to provide a desired level of control over the positioning of the proximal section.

[0056] As previously mentioned, the connecting section of the suction extension engages the lumen of the guide catheter with a suitable interface, allowing the user to translate the suction extension relative to the guide catheter to position the tip of the tubular extension while reducing or eliminating blood flow between the connecting sections of the suction extension. The desired design, in which the connecting section of the suction extension has a non-circular cross section, has been found to specifically meet these criteria. The material selection described herein also allows for a very small average gap between the connecting section of the suction extension and the interior of the guide catheter. When assembled, the lumen of the guide catheter can contact the connecting section of the suction extension in two circumferential locations, which allows the cross section of the connecting section to be partially rounded. This two-point contact configuration allows the user to slide the suction extension with reasonable ease while still providing the desired containment of flow.

[0057] The non-circular cross-section of the connecting section (or a portion thereof) of the suction extension may generally be approximately elliptical in shape. Although not intended to be limiting by this term, in some embodiments, the cross-section may have one axis of symmetry similar to a conventional oval cross-section. As described below, the elliptical shape may be generated by attaching a wire control structure to the proximal section, although other structural features may be used to introduce the elliptical shape, for example providing approximately one axis of symmetry or two axes of symmetry, although the ellipse may also be asymmetric. In general, the cross-section of an ellipse may be characterized in part by its major axis, e.g., the longer dimension along the axis of symmetry, and its minor axis, e.g., the longest line segment connecting the circumference, perpendicular to the major axis. Although the specification of the major and minor axes does not fully specify the ellipse since the specific shape is not specified, the major and minor axes can provide important information regarding the dimensions and relative shape of the ellipse, especially since the shape is not generally far from a circular shape. Additionally, the average clearance may be defined by using the maximum circumference (C) of the cross-section of the ellipse and converting it to a transparent circle to find the appropriate average diameter (D a = C / π).

[0058] An embodiment of a guide catheter is shown in Figures 2-4. Referring to Figure 2, a guide catheter 160 includes a connector attachment hub 162, which may be a Tuohy-Borst connector, a Luer connector, or other part, a shaft 164, and a strain relief support 166. In this embodiment, the proximal end of the shaft 164 passes through the strain relief support 166 to the connector attachment hub 162, and the components may be secured together with an adhesive. Also, a female connector 168 is disposed at the proximal end of the connector attachment hub 162 for connection with a male connector fitting on a proximal fitting, such as a bifurcated connector that may have a rotating hemostasis valve with one or more branches.

[0059] A cross-sectional view of a portion of the shaft 164 near its proximal end is shown in FIG. 3. Referring to the embodiment of FIG. 3, the shaft 164 includes a polymer tube 180 with an embedded stainless steel wire braid 182 and a lubricious liner 184, such as polytetrafluoroethylene (PTFE) or other fluoropolymer. FIG. 4 shows the distal end of the shaft 164. As shown in FIG. 4, a radiopaque marker band 186 is embedded within the polymer tube near the distal end of the shaft 164. A distal section 188 of the tube is also located at the distal end of the shaft 164 and has a slightly reduced inner diameter, as will be further described below. As shown in FIGS. 3 and 4, the metal braid terminates near the marker band 186 (or overlaps and then terminates), and the distal section 188 is free of metal braid in this embodiment. As will be further described below, the composition of the polymer tube included in the shaft can vary along the length of the shaft 164, for example, to increase the flexibility of the shaft toward the distal end of the shaft. In some embodiments, adjacent separate sections of polymer tubing can be bonded together by heating and further supported with metal braids and / or coils that reinforce the majority of the arched upper shaft. In some embodiments, the majority of shaft 164, except for distal section 188, can have a constant inner diameter to allow suction to be applied through a suction extension positioned anywhere proximal to distal section 188 in the guide catheter. However, in alternative embodiments, the proximal section of shaft 164 can have a larger diameter if desired, since the proximal section of the guide catheter may not be used to position the connecting section of the suction extension to apply suction. Appropriate markers on the control wires can be used to ensure that the suction extension is properly positioned to apply suction.

[0060] A lubricious coating, such as a hydrophilic coating, can be disposed on the exterior surface of shaft 164 or a portion thereof. Suitable hydrophilic coatings include, for example, polyvinyl alcohol, heparin-based coatings, or others. Hydrophilic coating solutions are commercially available, for example, LUBRICENT® (Harland Medical Systems, Minnesota, USA) or SERENE™ (Surmodics, Inc., Minnesota, USA). Further description of materials and manufacturing processes is provided below.

[0061] The outer diameter (D) of the guide catheter can be from about 5.5 Fr (1.667 mm diameter) to about 10 Fr (3.333 mm diameter), in further embodiments from about 6 Fr (1.833 mm diameter) to about 9 Fr (3 mm diameter), and in some embodiments from about 6.25 Fr (2 mm diameter) to about 8.5 Fr (2.833 mm diameter). Measurements of the guide catheter generally refer to the outer diameter, with the inner diameter being twice the wall thickness less than the outer diameter. Generally, the inner diameter (d 1 The inner diameter (d) of the distal section 188 can range from about 0.8 mm to about 3.175 mm, in further embodiments from about 0.9 mm to about 2.85 mm, and in further embodiments from about 1.00 mm to about 2.7 mm. 2 ) to the inner diameter (d 1 The amount of reduction for the distal section 188 may be from about 0.00134 inches to about 0.25 mm (0.0098 inches), and in further embodiments from about 0.002 inches to about 0.20 mm (0.0079 inches). The length of the guide catheter shaft may be from about 30 cm to about 150 cm, and in further embodiments from about 35 cm to about 130 cm, and in further embodiments from about 40 cm to about 120 cm, and is generally selected as appropriate for the corresponding procedure. In some embodiments, the length of the distal section 188 (L d) may be from about 1 mm to about 50 mm, in further embodiments from about 1.5 mm to about 25 mm, and in other embodiments from about 2 mm to about 20 mm. A person of ordinary skill in the art will recognize that additional ranges of dimensions within the explicit ranges above are contemplated and are within the present disclosure.

[0062] To use the guide catheter of FIG. 2 to form a proximal attachment similar to that of FIG. 1, a Y-branch hemostatic valve connector 190 can be used, as in the embodiment shown in FIG. 5. The Y-branch hemostatic valve connector 190 comprises a male connector 192, a Y-branch frame 194 with bifurcating flow paths, a rotating hemostatic valve 196, a connector 198, a tube 200 connected to the Y-branch frame 194 at the connector 198, and a suction device 202 connected to the tube 200. The male connector element 192 can be attached to the female connector element 168 of FIG. 2. As shown diagrammatically in FIG. 5, both a control wire 204 and a guide wire 206 are shown exiting the hemostatic valve 196, and the guide wire 206 can be used to guide a treatment device from the guide catheter through the hemostatic valve. Various bifurcated hemostatic valve connectors are available from commercial suppliers, such as Merit Medical, Utah, USA. More generally, various fittings can be attached to the connector mounting hub 162 of the guide catheter 160, and improved embodiments of fittings that include a portion for mounting a tubular extension of the suction extension are described in more detail in the Treatment System section below.

[0063] An embodiment of a suction extension is shown in Figures 6-12. Referring to Figure 6, the suction extension 230 comprises a control wire 232, a connecting section 234, and a tubular extension 236. The connecting section 234 connects the control wire 232 extending proximally from the connecting section and the tubular extension 236 extending distally from the connecting section. In general, the control wire 232 can be a solid wire, coil, or other that transmits pulling and pushing forces to the connecting section 234, which can move correspondingly with the tubular extension 236 relative to the guide catheter in an assembled aspiration catheter system. The control wire 232 can have any reasonable cross-sectional shape, which may be different at various points along the length of the control wire. Additionally, the control wire can be tapered toward the distal end of the control wire to provide a smaller circumference. Typically, the control wire 232 is made of stainless steel, titanium, or other biocompatible metals, although other materials having an appropriate balance of stiffness and flexibility could in principle be used. In some embodiments, the control wire is a round metal wire having an average diameter along its length of about 0.010 inches (0.254 mm) to about 0.040 inches (1.01 mm), and in further embodiments, about 0.0125 inches (0.32 mm) to about 0.030 inches (0.76 mm). The length of the control wire 232 is generally somewhat longer than that of the guide catheter, such that the guidewire extends from the proximal end of the guide catheter, for example, 5 cm or more longer than the guide catheter. A person of ordinary skill in the art will recognize that additional ranges of dimensions within the explicit ranges above are contemplated and are within the scope of the present disclosure.

[0064] The connecting section 234 is generally distinguished by a larger outer diameter than the tubular extension 236, which extends distally from the connecting section 234. In the embodiment of Figures 6-12, the tubular extension 236 has a generally constant outer and inner diameter, with further embodiments described below in which the diameter decreases along the tubular extension. Referring to the cross-sectional view of Figure 10, the tubular extension comprises a polymer tube 240, a metal coil reinforcement 242, and a radiopaque marker band 244. The metal coil reinforcement 242 can include a flat metal wire, which in some embodiments extends from approximately the radiopaque marker band 244 to the radiopaque marker band in the connecting section 234, as described further below, although the metal coil reinforcement can extend above the marker band. The polymer tube 240 can remain the same along the length of the tubular extension 236, or the polymer can change at different locations along the tubular extension 236, for example becoming more flexible in the distal direction. The different sections of polymer can be heated to bond during construction, and the metal coil reinforcement 242, as well as an optional polymer coating layer, can further stabilize the connected sections of polymer tubing. The tip 246 of the tubular extension 236, distal to the radiopaque marker band 244, can comprise a polymer tube 240 without a metal reinforcement. A low friction liner 248, such as PTFE or other fluoropolymer, can extend along the length of the tubular extension 236 and / or the connecting section 234, or a portion thereof.

[0065] The relationship between the connecting section 234 and the control wire 232 and tubular extension 236 is shown in Figures 6-8. Partial cross-sectional views of the connecting section 234 are shown in Figures 9, 11, and 12, showing certain details of the structure. The connecting section 234 can comprise a polymer tube 260 and a radiopaque marker band 262. The polymer tube 260 has a proximal opening 264, which can be angled relative to the longitudinal axis of the polymer tube to facilitate delivery of the device from the suction extension, although a right angle can be used if desired. The angle α is displayed in Figure 8 and can range from 25 degrees to about 85 degrees, in further embodiments from about 30 degrees to about 80 degrees, and in further embodiments from about 33 degrees to about 75 degrees. A person of ordinary skill in the art will recognize that additional ranges of dimensions within the explicit ranges above are contemplated and are within the scope of the present disclosure.

[0066] The contact between the control wire 232 and the connecting section 234 serves both to secure the components together and to help shape the connecting section 234, which can be selected to provide the desired contact with the interior of the guide catheter lumen. In particular, the connection between the connecting section and the control wire can facilitate forming an elliptical cross section of the connecting section. In an alternative embodiment, the control wire 232 can terminate in a flat wire coil that is embedded in a polymer tube to substantially retain the shape of the connecting section, as described in the '938 application and below. In further or alternative embodiments, the elliptical shape of the connecting section can be introduced through polymer molding or other shaping, which may or may not be combined with the bulge from the embedded control wire. Appropriate dimensions of the elliptical cross section and processing to form the connecting section are discussed further below. The low-friction liner 248 may extend through the lumen of the connecting section 234, as shown in Figures 9 and 11, or in some embodiments, a separate low-friction liner may be included in the connecting section 234 as desired.

[0067] 8, 11, and 12, the distal end of the control wire 232 is embedded within a polymer associated with the polymer tube 260. The anchoring of the control wire 232 to the complementary polymer wall changes the cross-sectional shape, resulting in an increase in the length of the longitudinal axis (L 2 ), as can be clearly seen in FIG. M ) is the minor axis (L m ) longer. As previously mentioned, a non-circular cross-section is advantageous for contact between the suction extension and the guide catheter. A cross-section of an alternative embodiment of a non-circular shaped connecting section 280 is shown in FIGS. 13 and 14. In this embodiment, a flat metal coil 282 on the end of a control wire 284 is embedded in a polymer tube 286 of non-circular cross-section. The non-circular cross-section is formed in this embodiment through forming a thicker wall of polymer along one edge of the circumference, as can be seen in the cross-section of FIG. 14. A corresponding circular embodiment is shown in FIGS. 21 and 22 of the '938 application. The connecting section may or may not have a generally constant outer diameter over its entire length, and the outer diameter may taper, e.g., a gradual taper, a step taper, or a combination thereof, to the outer diameter of the adjacent section of the tubular extension over at least a portion of its length.

[0068] In some embodiments, the proximal end of the connecting section is adapted to be docked to a docking element of an attachment element to enable removal of the suction extension from its hemostatic isolation within its associated attachment element. Such an attachment docked with a suction extension can be used to remove a clot from the suction extension in the docked position. Once the clot has been removed, the suction extension can be reintroduced into the patient's body for further use in removing another clot from the patient's blood vessel. Suitable attachments are described in more detail below.

[0069] An alternative embodiment of the suction extension is shown in Figures 15 and 16. The suction extension 300 comprises a control wire 302, a connecting section 304, and a tubular extension 306. The control wire 302 and the connecting section 304 can be the same as the control wire 232 and the connecting section 234, respectively, of the embodiment of Figures 6-12. Referring to Figure 16, the distal end of the control wire 302 is embedded in the connecting section 304 in a polymer to form an expansion section 308 along the surface of the connecting section 304. A proximal opening 310 into the lumen of the connecting section 304 is at an angle α with respect to the axis of the connecting section 304. The connecting section 304 includes a radiopaque marker band 312. The body of the connecting section 304 is a polymer tube 314. A low friction liner 316, for example PTFE or other fluoropolymer, can extend along the lumen of the connecting section 304 and / or the tubular extension 306 or selected portions thereof. A metal reinforcement, such as a flat metal wire coil, can reinforce the polymer tube 314 or a portion thereof. As shown in Figure 16, a flat metal wire coil 318 is embedded throughout the polymer tube 314 distal to the radiopaque marker band 312 and extends to the tubular extension 306. Additionally, the asymmetric cross sections shown in Figures 12 and 14 as well as the control wire attachment schemes of Figures 11 and 13 can also be applied to the embodiments of Figures 15 and 16.

[0070] 15 and 16, the tubular extension 306 includes a first tubular section 330, a tapered section 332, and a second tubular section 334 having a smaller diameter than the first tubular section 330. The tapered section 332 tapers between the diameter of the first tubular section 330 and the diameter of the second tubular section 334. The second tubular section 334 includes a radiopaque marker band 336. A flat metal wire coil 318 extends from the radiopaque marker band 336 to the polymer tube-embedded radiopaque marker band 312 within the connecting section 304. The end of the second tubular section 334 distal to the radiopaque marker band 336 may be free of metal reinforcement. As previously mentioned, the low friction liner 316 may extend along the lumen wall the length of the tubular extension 306 or a selected portion thereof. The bodies of the first tubular section 330, tapered section 332, and second tubular section 334 generally comprise thermoplastic polymer tubing. The polymer tubing sections may be heated to bond together and further supported by embedded flat metal wire coils 318, optionally with a heat shrinkable polymer film covering the metal reinforcement, or otherwise. The composition of the polymer tubing may be varied along its length to select a particular flexibility, generally being more flexible towards the distal end of the device, as desired, and the polymer composition may be varied in and / or within different sections 330, 332, 334.

[0071] 15 and 16, the tapered section 332 provides a linear transition in diameter from the larger diameter of the first tubular section 330 to the smaller diameter of the second tubular section 334. In alternative embodiments, the diameter of the tapered section can be non-linear as desired, although the change is generally monotonic. The tapered section can be formed through extrusion, or by conforming a thermoplastic polymer to a mandrel shape, or by any other suitable process known in the art.

[0072] An important aspect of the suction extension is the small diameter aspiration tip relative to the guide catheter, and the reduced diameter of the second tubular section of the embodiment of Figures 15 and 16 allows for further reach into small neurovasculature. The effective aspiration lumen then extends from the guide catheter into the connecting section of the suction extension and into the tubular extension, which may be of further reduced diameter. The inner diameter of the connecting section may or may not be the same as the inner diameter of the first tubular section. The small diameter of the tubular extension allows for reach into small and tortuous vessels, and the use of a larger diameter proximal aspiration lumen significantly improves aspiration performance without compromising the ability to reach the appropriate site.

[0073] FIG. 17 illustrates an alternative embodiment of a suction extension, where the control structure has a handle at or near its proximal end. With reference to FIG. 17, the control structure / wire 340 has a handle 342 secured near its proximal end. The handle 342 may or may not include a structure for detaching the handle. Certain embodiments of handles are described in more detail below. The control structure / wire 340 has a kink 344 at its distal end to prevent the handle 342 from becoming detached from the control structure 340. The kink 344 may refer to or be replaced by a bend, knot, anchor, or other structure or distortion to prevent or inhibit the handle 342 from becoming detached from the control structure 340.

[0074] To further provide suction strength, the tubular extension itself can have different sections of decreasing diameter, as shown in the embodiment of Figures 15 and 16. Generally, since arteries have a gradually decreasing diameter, a somewhat larger diameter section may be desirable consistent with reaching the suction tip into selected small blood vessels. With respect to the first tubular section, this section generally has a substantially constant diameter (generally, inner or outer diameter, assuming a substantially constant wall thickness), which is generally about 0.95D to about [d+0.1(Dd)], in further embodiments about 0.925D to about [d+0.25(Dd)], and in some embodiments about 0.9D to about [d+0.35(Dd)], where d is the diameter of the second tubular section and D is the average diameter of the connecting section. The length of the first tubular section may be the total length of the tubular extension, e.g., the total length of the first tubular section, the second tubular section, and the optional transition section, or in a corresponding embodiment, the total length of only the single tubular section (L in FIG. 6 ). T 6), about 10% to about 90%, in further embodiments about 20% to about 80%, and in further embodiments about 30% to about 70% of the length of the connecting section (L in FIG. 6). C ) can be from about 4 mm to about 8 cm, and in further embodiments, from about 5 mm to about 6 cm. One of ordinary skill in the art will appreciate that additional ranges of dimensions and relative dimensions within the above explicit ranges are contemplated and are within the scope of the present disclosure. While Figures 15 and 16 show a tubular extension with a single decrease in diameter to a second tubular section, in other embodiments there can be additional tubular sections of constant diameter with further decreases in diameter, which further divide the overall length of the tubular extension as described above. For example, there can be one additional intermediate tubular section, two additional intermediate tubular sections, or three or more additional intermediate tubular sections.

[0075] The tubular extension, or in embodiments having multiple tubular sections of different inner diameters, the distal tubular section of the tubular extension can be about 20 percent to about 90 percent, in further embodiments about 30 percent to about 85 percent, and in further embodiments about 35 percent to about 80 percent of the inner diameter of the engagement section of the guide catheter. For example, the inner diameter of the distal end of the tubular extension can range from about 0.5 mm to about 1.9 mm, in further embodiments about 0.6 mm to about 1.8 mm, and in other embodiments about 0.65 mm to about 1.75 mm. The length of the tubular extension can be about 3 cm to about 60 cm, in some embodiments about 5 cm to about 55 cm, and in further embodiments about 8 cm to about 50 cm. A person of ordinary skill in the art will recognize that additional ranges within the explicit ranges above are contemplated and are within the scope of the present disclosure.

[0076] The distal end of the tubular extension may bend or curve in its natural, unstressed state. Generally, a bent tip catheter can facilitate tracking of the catheter over a guidewire without adversely altering the aspiration capabilities. See, for example, U.S. Patent No. 8,021,351 to Boldenow et al., entitled "Tracking Aspiration Catheter," incorporated herein by reference. Two common forms of bent aspiration tips are shown in FIGS. 18 and 19. With reference to FIG. 18, an aspiration tip 350 includes a straight section 352, a bend 354, and a bent tip section 356 having a flat distal opening 358 that is approximately perpendicular to the axis of the bent tip section 356. With reference to FIG. 19, an aspiration tip 364 includes a straight section 366, a bend 368, and a bent tip section 370 having an oblique distal opening 372 at an angle other than perpendicular to the axis of the bent tip section 370. The bent tip sections 356, 370 may be generally cylindrical and have approximately the same diameter as the corresponding straight sections 352, 366. Although two shapes of openings are shown in Figures 18 and 19, any suitable shape of opening may generally be used.

[0077] A specific embodiment of a bent tip of the suction extension 380 is shown in Figure 20. In this embodiment, the distal end 382 is curved, and although there is no straight section at the distal end of this embodiment, in alternative embodiments there may be a short straight section at the distal end. The distal end 382 extends from a straight section 384 of the suction extension 380. The arc of the curve is approximately circular, although other gentle arcs can be used, in which case the radius of curvature can be the average of the arc.

[0078] In this embodiment, the curvature of the tip is gradual and the distal end may not have a straight section. The angle γ can be defined based on the natural point of the tip taken from the initial curvature point at the center of the distal opening. In some embodiments, the angle γ can be about 5 degrees to about 21 degrees, and in further embodiments, about 7 degrees to about 20 degrees. To achieve a gradual curvature, the radius of curvature is generally relatively large, and in some embodiments, the radius of curvature can be about 21 mm to about 100 mm, and in further embodiments, about 25 mm to about 75 mm. In some embodiments, the length of the straight portion of the tip after the curve can be about 1 cm or less, in other embodiments, about 0.1 mm to about 6 mm, and in further embodiments, about 0.5 mm to about 4 mm. In alternative embodiments, the curve comprises a gradual arc without a large straight section distal thereto, whereby the curve or bend is specified by an angle and a radius of curvature. One of ordinary skill in the art will recognize that additional angle, radius, and length ranges within the above explicit ranges are contemplated and are within the scope of the present disclosure.

[0079] As previously mentioned, the connecting section of the suction extension can have a non-circular elliptical cross section that can then contact the inner surface of the lumen of the guide catheter and contact the inner surface at two circumferential locations. The contact between the connecting section of the suction extension and the mating section of the guide catheter reduces or eliminates flow between these surfaces, thereby directing essentially all of the aspiration flow through the lumen of the suction extension. At the same time, the suction extension can be positioned longitudinally within the mating section, thereby allowing the user to position the suction extension by sliding the control structure. These various conditions can be usefully balanced to provide the desired functionality.

[0080] 21, a cross-sectional view of the connecting section 400 of the suction extension within the engagement portion 402 of the guide catheter is shown. The non-cylindrical character of the cross-section of the connecting section 400 can be easily seen. Due to contact between the elements, the elliptical shape of the connecting section 400 may be distorted relative to its shape when separated from the guide catheter, especially if the undistorted length of the major axis of the connecting section 400 is greater than the inner diameter of the engagement section 402. The connecting section 400 may contact the inner surface of the lumen of the engagement portion 402 at two contact points 404, 406. The size of the contact points 404, 406 generally depends on the dimensions of the elements, the shape of the connecting section 400, and the material properties. Generally, the boundaries of the contact points do not need to be precisely defined.

[0081] As previously mentioned, the non-cylindrical connecting section can be characterized by a major axis, a minor axis, and an average diameter derived from the circumference. Based on these parameters, the critical points of contact between the connecting section 400 and the engagement portion 402 can be identified as the difference between the major axis and the minor axis, the difference between the major axis of the unconstrained connecting section 400 and the inner diameter of the engagement section 402, and the difference between the inner diameter of the engagement section 402 and the average diameter of the connecting section 400. For example, the difference between the major axis and the minor axis can be from about 30 micrometers to about 160 micrometers, and in further embodiments, from about 50 micrometers to about 140 micrometers. In some embodiments, the tolerance, measured as the difference between the diameter of the inner surface of the engagement section 402 and the average diameter of the connecting section, may be, for example, about 4 thou (1 thou=1 / 1000 inch, 4 thou to 102.6 micrometers) or less, in further embodiments about 3 thou (76.2 micrometers) or less, in further embodiments about 1.75 thou (45 micrometers) or less, and in other embodiments about 1 thou (25.4 micrometers) to about 1.75 thou (45 micrometers), and may be about zero in measurement uncertainty. For embodiments in which the long axis of the connecting section separated from the guide catheter is larger than the inner diameter of the guide catheter, the difference between the long axis of the unconstrained (i.e., separated from the guide catheter) connecting section 400 and the inner diameter of the engagement section 402 may be about 0 to about 250 micrometers, in further embodiments about 15 micrometers to about 150 micrometers, and in other embodiments about 20 micrometers to about 100 micrometers. A person of ordinary skill in the art will recognize that additional ranges of deviations within the explicit ranges above are contemplated and are within the present disclosure.

[0082] The catheter components can be formed from one or more biocompatible materials, including metals such as, for example, stainless steel or alloys, e.g., Nitinol®, or polymers such as polyetheramide block copolymers (PEBAX®), nylon (polyamide), polyolefins, polytetrafluoroethylene, polyester, polyurethane, polycarbonate, polysiloxane (silicone), polycarbonate urethane (e.g., ChronoFlex AR®), mixtures thereof, combinations thereof, or other suitable biocompatible polymers. Radiopacity can be achieved by adding metal markers such as wires or bands, platinum-iridium alloys, tantalum, tungsten, gold, platinum-tungsten alloys, or mixtures thereof, or through radio-pacifiers added to the polymer resin, such as barium sulfate, bismuth trioxide, bismuth subcarbonate, powdered tungsten, powdered tantalum, etc. Medical grade PEBAX with barium sulfate added and various Shore hardness values ​​are commercially available. Additionally, selected sections of the catheter can be formed from materials that impart the desired stiffness / flexibility to that particular section of the catheter.Similarly, the fitting components can be formed from suitable materials, such as one or more metals and / or one or more polymers.

[0083] In some embodiments, the guide catheters, their suction extensions or suitable portions include a thermoplastic polymer with embedded metal elements reinforcing the polymer, such as the polymers described above. The wires can be braided, coiled, or otherwise placed over the polymer tube liner with some tension to keep the wires in place over the tube liner. In some embodiments, a polymer jacket, such as a heat shrink polymer, can be placed over the top and heated to shrink and fuse the covering over the structure, and / or the polymer tube can be thermally softened to allow incorporation of the metal reinforcement. Upon heating to a temperature above the softening and / or heat shrink temperature of the polymer and then cooling, the reinforcing metal is embedded within the polymer. In suitable embodiments, the liner and jacket can be the same or different materials. Suitable wires include, for example, flattened stainless steel wires, and the like. The wire diameter may range from about 0.00025 inches (0.00635 mm) to about 0.004 inches (0.1 mm), and in further embodiments, from about 0.0005 inches (0.013 mm) to about 0.003 inches (0.075 mm). In suitable embodiments, the braid picks per inch may be from about 20 to about 250 picks / inch, and in further embodiments, from about 50 to about 150 picks / inch. In suitable embodiments, the coil may be a single filament or multifilament coil having a pitch of, for example, about 0.005 inches (0.13 mm) to about 0.1 inches (2.54 mm), and in further embodiments, about 0.01 inches (0.26 mm) to about 0.050 inches (1.27 mm). One of ordinary skill in the art will recognize that additional ranges within the ranges explicitly set forth below are contemplated and are within the scope of the present disclosure. The wire adds additional mechanical strength while maintaining an appropriate amount of flexibility. The wire may provide some radiopacity, with the radiopaque band generally providing a darker, more discernible image of the wire, however the image of the wire may provide additional visualization of the catheter during the procedure.

[0084] To reduce the chance of accidental removal of the radiopaque band from the catheter and the chance of the radiopaque band catching on other objects within the vessel, a metal reinforcing wire can be used to cover or encapsulate the radiopaque band, which is then embedded in a polymer. In some embodiments, a polymer jacket can be placed over the metal wire, which correspondingly covers the radiopaque band, and the heat bond also embeds the radiopaque marker band. Placing a marker band under the metal wire can prevent the band from separating from the catheter if the wall is kinked or collapsed. If the catheter wall is kinked or kinked, the braided wire over the surface of the band will fold over the marker band to prevent the marker band from separating from the structure.

[0085] <Treatment System> The aspiration system described herein can be used to effectively remove blood clots from blood vessels, such as blood vessels in the brain, when treating acute stroke conditions. In particular, the fine tip catheter of the '792 patent performed well in human clinical trials to restore blood flow in patients with acute embolic stroke, with good patient outcomes. The devices described herein can be expected to provide even better aspiration while retaining the ability to access difficult to navigate blood vessels. However, in some acute stroke conditions or other embolic events, it may be desirable to use the aspiration catheter system described herein in conjunction with other medical instruments to perform the treatment. Additionally, certain preferred embodiments of the proximal attachment that provide an improved procedure for using the suction extension described herein are described in this section. In particular, the modification of the proximal attachment allows for the removal of the tubular extension of the suction extension from the guide catheter without passing through a hemostasis valve. In some embodiments, the proximal fitting can further include an additional branch fitting that docks with the proximal end of the suction extension to allow convenient removal from the isolated position behind the hemostasis valve and convenient removal and reinsertion of the suction extension from a thrombus occlusion. The thrombus occlusion can be removed with irrigation delivered from a branch of the docking Y connector, while the suction extension remains docked and can be quickly returned to further remove another occluded portion of the patient's vessel. The proximal fitting can also be modified with a pressure sensor that can provide valuable information regarding the status of the aspiration process. The availability of pressure information can be used to improve various aspects of the procedure, increasing efficiency and reducing potential risks to the patient.

[0086] 22, a treatment system 450 is shown that includes a guidewire 452, an embolic protection system 454, an aspiration catheter system 456 with a guide catheter 458 and a suction extension 460 shown separated, a percutaneous medical device 462, a microcatheter 464, a delivery catheter 466, a proximal attachment 468, a negative pressure device, such as a pump or syringe, 470, and a display unit 472. Suitable components of the proximal attachment 468 are described below. Not all medical system embodiments have all of these components, and some medical system embodiments may have multiple components of each type, such as multiple different percutaneous medical devices. A suitable structure covering the preferred embodiment for the proximal attachment 468 is described in the following section.

[0087] Guidewires suitable for use in tortuous body vessels are described in U.S. Patent No. 10,518,066 to Pokorney et al., entitled "Medical Guidewires for Tortuous Vessels," which is incorporated herein by reference. In some embodiments, the embolic protection system 454 can include a guide structure for delivering the device, and these systems may or may not use a separate guidewire. The aspiration catheter system 456 is described in detail herein, and the various embodiments described herein can be adapted for use with the medical system and for use as a stand-alone device. If desired for particularly difficult device delivery, the medical system can include a delivery catheter 466, as described in the '938 application.

[0088] Embolic protection devices have been developed that have small filter longitudinal extents suitable for use in the medical systems described herein and are designed for suitable operation to facilitate delivery within blood vessels.See, for example, U.S. Patent No. 7,879,062 to Galdonik et al., entitled "Fiber Based Embolic Protection Device," and U.S. Patent No. 8,092,483 to Galdonik et al., entitled "Steerable Device Having a Corewire Within a Tube and Combination with a Medical Device," both of which are incorporated herein by reference.Another fiber-based filter device specifically designed for delivery within tortuous blood vessels is described in U.S. Patent No. 8,814,892 to Galdonik et al., entitled "Embolectomy Devices and Method of Treatment of Acute Ischemic Stroke Condition," (hereinafter, the '892 patent), which is incorporated herein by reference.The use of complementary structures is also contemplated in the procedures described herein. The '892 patent describes the use of a filter device as a clot engagement instrument for use with an aspiration catheter. The '892 patent also contemplates the use of complementary structures to facilitate engagement with the clot. The DAISe™ Clot Removal System with a fiber filter is under development by MIVI Neuroscience, Inc. The use of complementary structures is also contemplated in the procedures described herein.

[0089] Microcatheters are designed to access small blood vessels, such as cerebral blood vessels, and cerebral microcatheters are commercially available, for example, Prowler Select™ (Cordis Neurovascular Inc.) and Spinnaker Elite™ (Boston Scientific Co.). Of course, the term microcatheter covers a wide range of devices, and the present description will focus on catheters useful for the procedures described herein. In some embodiments, the microcatheter can include a distal section that is thinner than the proximal section. However, in further embodiments, the microcatheter can have a nearly constant diameter along its length, which makes it easier to deliver other devices over the microcatheter. The small distal diameter allows the catheter to navigate the tortuous blood vessels in the brain. The distal section is very flexible, sufficient to navigate within the blood vessels, but has elasticity to resist kinking. The microcatheter includes at least one lumen. The microcatheter can then be used to deliver other therapeutic devices, suction, therapeutic agents, or other means of treating the condition. The microcatheter can have a selected size, in some embodiments, the distal outer diameter of the microcatheter can be from about 1.0 Fr to about 3.5 Fr, and in further embodiments, from about 1.5 Fr to about 3 Fr, and the length can be from about 30 cm to about 200 cm, and in further embodiments, from about 45 cm to about 150 cm. A person of ordinary skill in the art will recognize that additional ranges of sizes within the explicit ranges above are contemplated and are within the scope of the present disclosure.

[0090] With respect to the percutaneous medical device 762, suitable devices include, for example, clot engagement devices, angioplasty balloons, stent delivery devices, atherectomy devices such as stent retrievers, and the like. Desirable thrombus engagement devices are described in U.S. Patent No. 10,463,386 to Ogle et al., entitled "Thrombectomy Devices and Treatment of Acute Ischemic Stroke With Thrombus Engagement," which is incorporated herein by reference. Stents may be, for example, balloon-expandable, self-expandable, or expandable using any other suitable mechanism. Balloon-expandable stents may also be crimped onto a balloon for delivery to engage a clot in a blood vessel. Some balloon-stent configurations are further described in U.S. Patent No. 6,106,530, entitled "Stent Delivery Device," U.S. Patent No. 6,364,894, entitled "Method of Making an Angioplasty Balloon Catheter," and U.S. Patent No. 6,156,005, entitled "Ballon[sic] Catheter For Stent Implantation," each of which is incorporated herein by reference. Self-expanding stents are further described in U.S. Patent No. 8,764,813, entitled "Gradually Self-Expanding Stem," by Jantzen et al., and U.S. Patent No. 8,419,786, entitled "Self-Expanding Stent," by Cottone, Jr. et al., both of which are incorporated herein by reference.

[0091] After the clot treatment process is completed, it has been found to be advantageous to at least partially detach the tubular extension of the suction extension from the guide catheter before removing the guide catheter from the patient. If a portion of the tubular extension is removed through the hemostatic valve during this removal process, isolation between the blood vessel and the outside of the patient's body may be lost because the proximal end of the tubular extension is not designed to close. Loss of isolation between the outside of the patient's body and the inside of the catheter system may result in an undesirable amount of bleeding as well as complicate the control of trapped clots associated with the nozzle. In some embodiments, the fitting design described herein is intended to address these issues through the inclusion of a tubular storage area distal to the hemostatic valve and connected to access the proximal end of the tubular extension. Some suitable designs are described herein. Blood loss due to this removal of the tubular extension may be reduced or eliminated through the use of a docking branch manifold as described herein. As noted in the following description, the fitting structure may be assembled for commercially available components or may be designed as a specific fitting specifically for the aspiration and / or treatment systems described herein.

[0092] During a procedure using the aspiration system, the tubular extension of the suction extension may be removed from the patient's body to remove the clot and then reinserted to further remove the thrombus. Removing the clot from the tubular extension typically includes removing it from the guide catheter and from the hemostatic valve. After the tubular extension is cleared of obstruction, it is reinserted into the patient's body through the hemostatic valve. Removing the clot typically includes backflowing fluid from the proximal end to the distal end. The fittings described herein allow the connecting section of the suction extension to be docked to a docking element of a docking Y fitting to be removed through the hemostatic valve. Once removed through the hemostatic valve, perfusion fluid can be delivered from one branch of the Y fitting to perfuse the tubular extension without the need for further connection to the suction extension. The other branch of the Y typically includes a hemostatic valve or the like through which a control structure passes and the valve can be closed to direct the perfusion fluid into the suction extension.

[0093] The first fitting element has previously been described in U.S. Patent Application Publication No. 2019 / 0183517 by Ogle, entitled "Supplying Effective Aspiration in Remote Vessels, Especially Cerebral Aerteries," which is incorporated herein by reference. The first fitting element of the present application can essentially be the scope of the proximal fitting, but in a preferred embodiment of the present application, the proximal fitting further includes a docking branch manifold. By using a docking branch manifold, the fitting can include further options regarding the location of the provision of suction and / or delivery of irrigation fluid, such as contrast or therapeutic compounds. Thus, the proximal fitting described above can also apply to the first fitting element for engaging with a docking branch manifold, but the first fitting element can be designed with fewer or different branches, as desired, if a particular function is performed using the docking branch manifold. Thus, some of the embodiments described herein can be correspondingly simplified in some embodiments.

[0094] Three representative embodiments of the first fitting element of the proximal fitting that draws the suction extension into the hemostasis section are shown in Figs. 23-26, in which the tubular extension of the device suction extension is held in a manifold sealed behind one or more hemostasis valves. As shown in Figs. 23-26, the proximal fitting is assembled from multiple fitting components that are designed to allow suction from these first fitting elements. However, if desired, one or more of the components can be manufactured as a unitary structure, eliminating one or more connector groups accordingly, and a particular configuration may include various tradeoffs such as ease of use, cost, packaging, industry standards, design flexibility during use, or otherwise. As shown in Figs. 23 and 24, the components are shown separated, in contrast to Figs. 25 and 26, in which multiple components are shown connected. Of course, in certain applications, additional components of the entire manifold can be incorporated into the final proximal fitting structure. For example, an embodiment that allows for the attachment of a pressure sensor is shown below. Additionally, other components of the manifold allow for docking and undocking of suction extensions associated with the fittings to allow for unblocking of the suction extensions.

[0095] 23, the fitting 500 includes a Y-branch manifold 502 suitable for connection with a guide catheter 504, and an extended hemostatic fitting 506. The guide catheter 504 may be any of the guide catheter embodiments described above. The Y-branch manifold 502 provides multiple connectors for fluid communication with the guide catheter 504. As shown in FIG. 23, the Y-branch manifold 502 includes three connectors 510, 512, 514, which may be Tuohy-Borst connectors, luer connectors, or other suitable connectors. The connector 510 may be selected to connect with the guide catheter 504. The connector 512 may connect to further branch manifolds to provide various connections, such as for a negative pressure source such as a pump or an irrigation fluid source, and generally has at least one connection to a negative pressure device. The connector 514 is configured to connect with the extended hemostatic fitting 506. The extended hemostasis fitting 506 includes a connector 516 for mating connection with the Y-branch manifold 502, a hemostasis valve 518, and a tubular section 520 between the connector 516 and the hemostasis valve fitting 518. The tubular section 520 can have a length suitable for removing the tubular extension of the suction extension from the guide catheter 504 without any portion of the tubular extension or connecting section passing through the hemostasis valve, although the proximal control structure generally passes through the hemostasis valve, which is a possible configuration throughout the procedure. In this embodiment, it may be desirable for the extended hemostasis fitting 506 to be long enough that the distal end of the tubular extension is proximal to one or more branches, such as the branch leading to the connector 512, so that the tubular extension does not get in the way when providing suction or irrigation from or into the guide catheter. FIG. 24 illustrates an alternative embodiment of a first fitting element without a branch, suitable for use with a docking branch manifold configured to deliver suction. The unbranched first fitting element 522 includes a connector 524 , a unbranched tubular element 526 , and a hemostasis valve 528 .

[0096] The length of the tubular section 520 can be selected depending on the length of the tubular extensions, as well as potentially the associated length of the Y-branch manifold 502, as desired, which can be collectively referred to as a tubular section for placing the tubular extensions in hemostatic isolation with the connecting section outside of the guide catheter. It may or may not be desirable to fully retract the tubular extensions into the tubular section 520, allowing the remainder of the manifold to open. In other words, it may be desirable for the tubular section itself to be at least as long as the tubular extensions. With respect to the non-branched tubular element 526 of FIG. 24, this element may or may not have a length suitable for withdrawal of the tubular extensions to be fully isolated within the non-branched tubular element 526. With respect to the range of possible alternative embodiments for the first fitting element of the proximal fitting of FIGS. 23 and 24, the dimensions of the tubular section can be approximately the same in a particular configuration. Generally, the length of the tubular portion 520 of the extended hemostatic fitting 506 can be from about 8 cm to about 55 cm, in further embodiments from about 9 cm to about 50 cm, and in other embodiments from about 10 cm to about 45 cm. A person of ordinary skill in the art will recognize that additional ranges of lengths within the explicit ranges above are contemplated and are within the present disclosure.

[0097] In alternative or additional embodiments, the extended hemostatic fitting 506 can include a tubular element with two connectors on either end and a separate hemostatic valve with a luer or other connector on the opposite end, which are interconnected to form a structure substantially equivalent to that shown in FIG. 23. Similarly, one or more additional fitting components can be connected using appropriate connectors between the extended hemostatic fitting 506 and the Y-branch manifold 502, such as additional branch elements, and similarly, additional fitting components can be connected at connector 512 to provide additional features to the fitting, such as connection of a pressure sensor or other structure. Thus, while providing the ability to retract the tubular extension into the closed fitting, the proximal fitting can be modified with appropriate structure to provide the desired functionality. While this description has focused on assembling multiple fitting components to provide an overall fitting structure, one or more of these components may be formed as an integral part of a corresponding unitary structure, such as integrating the Y-branch manifold 502 and extended hemostatic fitting 506 into a unitary structure by replacing connectors 514 and 516 with a unitary section of tubing, and similar integration may be performed to add additional structures. A unitary structure incorporating the features of the Y-branch manifold 502 and extended hemostatic fitting 506, including a branch manifold with an extended hemostatic valve portion, may be a suitable alternative to the structure of FIG. 24. Thus, various combinations of connection elements, redesigns of unitary components, and the like may be performed to form a desired proximal fitting design.

[0098] Referring to the alternative configuration of the first fitting element in FIG. 25, a three-way manifold 530 is connected to the guide catheter 504, and an extended hemostasis fitting 520 is connected to a connector of one branch of the three-way manifold 530. The three-way manifold 530 includes a first connector 534 connected to a proximal connector 536 of the guide catheter 504, a first branch connector 538, a second branch connector 540, and a hemostasis valve 542. The second branch connector 540 is connected to the extended hemostasis fitting 506, which is described in detail with respect to FIG. 24. The first branch connector 536 can be connected to a negative pressure source directly or through an additional branch manifold. The hemostasis valve 542 can be used for the introduction of a supplemental treatment structure or other desired device. Again, the structure shown in FIG. 25 can be further divided into additional components as desired. For example, the three-way manifold can be formed using, in effect, two consecutive Y-branch connectors. Again, as discussed above with respect to Figure 24, additional fitting components can be connected to the proximal fitting structure of Figure 25 to provide additional features. Similarly, one or more separate components of the proximal fitting can be configured as a unitary structure. Thus, component addition and / or combination / bonding processes can be combined to design a desired proximal fitting configuration.

[0099] 26, a further embodiment of a first fitting element of a proximal fitting using a symmetric Y-branch configuration is shown. As shown in FIG. 26, a symmetric Y-branch manifold 550 includes a first connector 552 connected to a guide catheter 504, a branch hemostatic valve 554, and a branch connector 556. The branch connector 556 is connected to a T-branch fitting 558. The T-branch fitting 558 has a T-connector 560, which is shown connected to a negative pressure device 562, such as a syringe or pump. The T-branch connector 556 is further connected to an extended hemostatic fitting 506, which is described in detail with respect to FIG. 24, including but not limited to the dimensions of its elements. The T-branch connector 556 includes connectors 564, 566 for connecting with mating connectors 556, 516, respectively. The structure shown in Figure 26 can be formed with multiple components used to form the structure, for example a separate component comprising hemostasis valve 554 connected with an appropriate connector to a mating connector on a correspondingly modified symmetric Y-branch manifold 550. Again, additional fitting components can be connected to the proximal fitting structure of Figure 26 to provide the additional features discussed above with respect to Figure 24. Similarly, one or more separate components of the proximal fitting can also be constructed as a unitary structure. Thus, component addition and / or combination / bonding processes can be combined to design a desired proximal fitting configuration.

[0100] The proximal fitting, including the various potential components, can be formed of materials suitable for assembly under sterile conditions, which in some embodiments can include exposing the components to radiation. The components can be formed of either rigid and / or flexible materials, such as the polymers listed herein, and the connectors can be formed of combinations of materials suitable for forming a seal, such as elastomers. The rigid components can be formed, for example, from polycarbonate or other suitable polymers. The tubular portion 520 of the extended hemostatic fitting 506 can be formed of a more flexible polymer, such as one or more of the polymers previously described for the catheter body, such as polyetheramide block copolymers (PEBAX®), nylon (polyamide), polyolefin, polytetrafluoroethylene, polyester, polyurethane, polycarbonate, polysiloxane (silicone), polycarbonate urethane (e.g., ChronoFlex AR®), mixtures thereof, combinations thereof, or other suitable biocompatible polymers. As previously mentioned, the various fixture structures can be assembled from additional components that are in addition to or sub-divided into the various components of the embodiments, and / or the components can be formed as appropriately molded unitary structures. Thus, certain designs can be assembled from existing commercially available components, or all or part of the fixture can be manufactured specifically for these applications.

[0101] The proximal fitting may also include a pressure sensor to help guide the procedure. If a pump is used to provide negative pressure, the pressure set at the pump establishes the differential pressure limit. When fluid flows freely to the pump, the differential pressure in the conduit to the pump may be relatively small. When flow is virtually completely blocked, the gauge pressure in the line may be approximately the pump pressure, which is a negative pressure indicative of suction. Intermediate pressure levels may indicate that flow is restricted by normal catheter or suction extension configurations that may cause some flow resistance, or that flow from various possible sources is less severely blocked. In either case, measuring the line pressure in the proximal fitting can provide valuable information to aid in the procedure, as described further below.

[0102] There are various possible configurations for the pressure sensor associated with the proximal fitting, and three representative embodiments are shown in Figures 27-29. Referring to Figure 27, pump 570 and pressure gauge 572 are connected to a Y-manifold 574 that includes a connector 576 that can be attached to a manifold connector in the fitting that is connected to the guide catheter, as shown in Figures 5 and 24-26. Pump 570 and pressure gauge 572 can be connected to Y-manifold 574 using tubes 578, 580, respectively. The connection of tubes 578, 580 to Y-manifold 574 can be achieved with suitable connectors or they can be formed integrally with the components. In this embodiment, pump 570 and optionally pressure gauge 572 may not be sterile, but it is intended that no flow will reach the patient from these devices. Provided that non-sterile components are properly isolated from the patient's fluids, this configuration may be acceptable even if the device is not sterile. A selected length of division line, for example 6 feet, to provide adequate sterile separation is shown diagrammatically in FIG. 27 by a dashed line annotated with an arrow.

[0103] Commercially available medical suction pumps, some of which are described above as specific pumps, can operate at gauge pressures of about -1 to about -26 inches of mercury (-25 mmHg to -660 mmHg). Medical high pressure tubing is also available, for example, from MIVI Neuroscience, Inc. (HFT 110™) or Penumbra, Inc. The high pressure tubing can have an inner diameter of 0.07 inches to 1.0 inches, in further embodiments about 0.075 inches to 0.5 inches, and in other embodiments 0.08 inches to 0.25 inches, and a length of at least about 4 feet, in further embodiments at least about 6 feet, and in some embodiments 6 feet to about 20 feet. Those skilled in the art will recognize that additional ranges of tubing dimensions within the explicit ranges above are contemplated and are included in the present disclosure. The high pressure tubing is generally reinforced to prevent the tubing from collapsing when subjected to negative pressure. The tubing is generally flexible and can be constructed from polymers of the type described herein for example with respect to the construction of catheters.

[0104] A further embodiment of a fitting modified with a pressure sensor is shown in FIG. 28. The fitting components of FIG. 28 include a Y-branch connector 590 with a distal connector 592, a proximal connector 594, and a branch connector 596, and a pressure sensor component 598 with a first connector 600 and a second connector 602 shown connected to the branch connector 590. The pressure sensor component 598 further includes a pressure sensor 604 attached to a side wall of the pressure sensor component 598. An electrical wire 606 extends from the pressure sensor 604 and terminates in an electrical connector 608, which may be a multi-pin clip or other suitable connector configuration. The electrical connector 608 may be suitable for connection to a suitable monitor or display. Commercial pressure sensor components for use as the pressure sensor component 598 are commercially available, for example from PendoTECH of Princeton, New Jersey, USA. These components may be purchased sterile or they may be sterilized prior to use using any convenient method, such as the use of gamma irradiation. A pump or other negative pressure device can be connected to the second connector 602 or any other suitable part of the final assembled proximal fitting, such as a connector associated with a docking branch manifold.

[0105] Another embodiment of a fitting component modified with a pressure sensor is shown in FIG. 29. In this embodiment, a Y-manifold 620 includes a connector 622 for connecting to other components of the proximal fitting and a connector 624 connected to a tube 626 for connecting to a pump or otherwise. The Y-manifold 620 further includes a branch 628 modified to include a pressure sensor 630 at the end of a conduit. The pressure sensor 630 can be fitted onto a connector cap or it can sealingly mate with the branch 628 or it can be otherwise modified with a sealed attachment. The pressure sensor 630 is operably attached to an electrical cable 632 that terminates in an electrical connector such as a multi-pin clip. Pressure sensor dies or assemblies suitable for medical use are commercially available, for example from Merit Medical Systems, Inc. (Merit Sensors), and can be modified for such connection.

[0106] As mentioned above, the proximal fitting can include a docking branch manifold that facilitates the process of unclog of the tubular extension, and two specific embodiments are described that further elaborate on some possible features, but as with the first fitting element, various component designs may be suitable. A first representative embodiment of a docking branch manifold is shown in FIG. 30. As shown in FIG. 30, the docking branch manifold is shown with a first fluid source, a second fluid source, and a suction source. In alternative embodiments, only the first fluid source can be used, or only the first fluid source and a suction source can be used. Similarly, only the first fluid source and the second fluid source can be used. In further embodiments, a third or more fluid sources can be introduced. The docking branch manifold 561 includes a tubular body 563, a docking inlet tube 565, a side port and channel 567, and a proximal hemostatic valve 569 proximal to the side port and channel 567 along the tubular body 563. Side port and channel 567 are connected to valve 571, access manifold 573, first fluid source 575, second fluid source 577, and suction source 579. Fluid sources 575 and 577 may include reservoirs, delivery systems such as syringes, pumps, and may optionally include valves. Suitable valves may include, for example, stopcocks, flow control switches available from Merit Medical, various mechanical or motorized valves, or the like. The suction source may include a pump or other negative pressure device along with appropriate pressure tubing, and may optionally be associated with another valve.

[0107] A second exemplary embodiment of a docking branch manifold is shown in FIGS. 31-34 of a docking branch manifold 601 that may be used to remove a suction extension, remove clots or other material associated with the suction extension, and return the suction extension to the patient to collect other clots. FIG. 31A shows a side view of the docking branch manifold 601. The docking branch manifold 601 includes an inlet tubular section 603 at a distal end. Proximal to the inlet tubular section 603 is a first branch 612 having a connector 605. In an embodiment, a fluid source valve 607 is connected to the docking branch manifold 601 at the connector 605. The fluid source valve 607 has a second port 623. The fluid source valve 607 may be a two-way valve or a multi-port valve. In some embodiments, the fluid source valve 607 is a stopcock, although other flow control elements may be used and may be desirable, such as some of the valves discussed above. The fluid source valve 607 may be in fluid communication with a fluid source and may be configured such that opening the fluid source valve 607 allows fluid to flow into the docking branch manifold 601 and closing the fluid source valve 607 prevents fluid from flowing to the docking manifold 601. As an example, a positive pressure device, such as a pump or pressurized container, loaded syringe 609, etc. is shown in Figure 31B. One branch of the docking branch manifold 601 generally includes a hemostasis valve 611 that allows passage of a control structure associated with a suction extension.

[0108] The docking branch manifold 201 generally includes a tubular body 613, which may include a tapered connector 614 that connects to the inlet tubular section 603, although the exact configuration of the connecting section is generally not critical. In some embodiments, the tubular body 613 of the docking branch manifold 601 may include a distal section 616 made of a material selected to seal within the hemostasis valve, and a proximal section 618 that includes a different material than the distal section and may further be molded to include a Y-branch. A connector 625 may optionally be used to join the distal section 616 and the proximal section 618, and the connector 625 may be formed of a suitable material. The connector 625 may or may not be visible from the outside, and may or may not vary in outer diameter, inner diameter, or both. If a suitable material is selected, the tubular body 613 may be formed of one material.

[0109] 31C shows a partial cross-sectional view of the docking branch manifold 601, showing that the distal portion of the inlet tubular section 603 includes a docking structure 617. The docking structure 617 may be configured to releasably hold the proximal end of the suction extension, such as any of the previous embodiments. For example, the docking structure 617 may secure the proximal end of the connecting section of the suction extension using an interference fit. In an embodiment, the docking structure 617 may be configured to have an internal taper of the inner wall 619 of the inlet tubular section 603. For example, the inner surface 621 of the inlet tubular section 603 may taper inwardly until the inner diameter of the tubular inlet section is smaller than the outer diameter of the distal end of the suction extension. In additional or alternative embodiments, the docking structure 617 may have a flange on the inner surface 621 of the inlet tubular section 603, which may be considered an infinitely sharp taper. In embodiments, the docking structure 617 may also include structure configured to mate with corresponding structure on the proximal end of the connecting section of the suction extension. For example, the docking structure 617 may include prongs on the inner surface 621 of the tubular inlet section 603 configured to mate with teeth on the outer surface of the tubular extension. In general, however, the docking structure may be any suitable structure, such as, for example, a narrowing tubular structure, that provides a substantially liquid-tight fit of at least the proximal end of the connecting section of the suction extension.

[0110] As shown in the partial view of FIG. 32, the aspiration catheter system generally includes a guide catheter 631, and a Y-manifold 633 is shown as the first attachment element, and any of the previously described guide catheter embodiments and first fitting elements can generally be used for this configuration. As shown in FIG. 32, the docking branch manifold is of the configuration shown in FIG. 31A, and the alternative configurations described with respect to this figure apply equally to the embodiment of FIG. 32. The first fitting element 633 includes a connector 635, a tubular body 637, a branch conduit 639 having a connector 641, and a hemostasis valve 643. Similarly, other embodiments of the first fitting element and the docking branch fitting can be incorporated into the assembled system. The docking branch manifold 601 can be designed to mate with the Y-branch manifold 633 when the proximal section 618 is inserted through the hemostasis valve 643. It should be understood that various manifold configurations are within the scope of the present application. For example, the suction catheter system of the present disclosure is not limited to the two pathways available in the Y-branch manifold 633. For example, a first fitting element without branches as shown in FIG. 24B can be used. As another example, FIG. 33 shows a suction catheter system including a three-branch manifold 651. Manifolds with more branches can also be used. Alternatively, manifolds can be interconnected to create additional pathways. For example, additional manifolds can be attached to the connector 653 or the second connector 655. The three-branch manifold 651 is connected to the guide catheter 631 at the connector 658. At the proximal end of the three-branch manifold 651, the inlet tubular section 603 is inserted through a hemostasis valve 659 to allow docking with a suction extension within the Y-branch manifold 633. Similarly, the first attachment element can include an integral structure or structural component that functions as an extended hemostatic attachment, as shown with respect to Figures 24-26, which allows the tubular extension of the suction extension to be detached from the guide catheter within a hemostatic environment, and the structures of Figures 30-34 can correspondingly be interpreted as including this capability based on adjustment of the dimensions of the structures.

[0111] FIG. 34A shows the assembled system of FIG. 32 with a suction extension disposed through the components, with a control wire 661 shown extending from hemostasis valve 615. FIG. 34B shows a cross-sectional view of a portion of the suction catheter system shown in FIG. 34A. Control wire 661 passes through docking branch manifold 601 and is secured to suction extension 663. As mentioned above, in embodiments in which a docking branch manifold is configured for connection to a negative pressure device, the first fitting element includes a branch manifold, although a non-branched first fitting element can be substituted if desired, although the system can optionally provide suction from a selected connector of a plurality of available connectors, or the manifold connection of the first fitting element can be used to deliver contrast or therapeutic compounds in lieu of a connection to a negative pressure device.

[0112] 34B shows the suction extension 663 docked to the docking structure 617. However, the control wire 661 can be manipulated, for example by pushing it, thereby exerting an axial force in a distal direction to release the suction extension 663 from the docking structure 617 and reintroduce the suction extension 663 into the patient's body. Conversely, when the suction extension 663 is undocked, the control wire 661 can be manipulated to retract the proximal end of the suction extension 663 into the docking structure 617, thereby securing the tubular extension of the suction extension 663. For example, the control wire 661 can be pulled proximally such that the suction extension 663 forms an interference fit with the tapered portion of the inlet tubular section 603. Alternatively, as shown in FIG. 34C, the control wire 661 can extend throughout the docking structure 617 such that the tubular extension of the suction extension 663 is distal to the docking branch manifold 601 .

[0113] Once the suction extension 663 is docked to the docking structure 617, the docking branch manifold 601 can be separated from the Y-branch manifold 633, which allows the suction extension 663 to be retracted proximally through the hemostasis valve 635. Once the structures are separated, the fluid source valve 607 can be opened to allow fluid to flow into the docking branch manifold 601, through the docking structure 617, and then through the suction extension 663. The fluid flow dislodges any thrombus or other material trapped within the tubular extension of the suction extension 663. Examples of fluids include, for example, sterile water, saline, contrast, or other sterile fluids. If the procedure is ongoing, once the suction extension 663 has been cleared of obstruction, it can be reinserted into the Y-branch manifold 633 through the hemostasis valve 635. Once the docking branch manifold 601 is reinserted and secured within the Y branch manifold 633, the control wire 661 can be used to detach the suction extension 663 from the docking structure 617 and reintroduce the tubular extension of the suction extension 663 into the patient's body to collect other coagulated material from the occluded blood vessel.

[0114] The specific embodiment of the docking branch manifold of FIGS. 31-34 is an exemplary embodiment, but other embodiments may have more than two branches using appropriate additional connectors, additional flow control elements, different branch angles, etc. In particular, the features described with respect to FIG. 30 may be adapted to the second exemplary configuration of FIGS. 31-34. For example, the first branch of the docking branch manifold may include a fluid source valve that controls the flow that may be emanated from a fluid source or to a suction source, such as a pump, that draws fluid from the manifold. Rather than using additional branches from the first branch, additional branches may be provided on the manifold to allow access to additional fluid and / or suction sources, similar to the several branches for the first branch manifold of the proximal fitting shown in FIG. 25. Armed with the teachings herein, one of ordinary skill in the art may adjust the design based on functional constraints.

[0115] The docking branch manifold generally has suitable dimensions for convenient handling and manipulation, with internal dimensions suitable for handling the various devices described herein. The components of the docking branch manifold can be made of any rigid and / or flexible material, such as the polymers provided herein, and the connectors can be made of any suitable combination of materials, so long as they are suitable for the intended function of the components. Rigid components can be made of, for example, polycarbonate, polyimide, metal, or other suitable polymers. The portion of the docking branch manifold that is secured to the hemostasis valve of the proximal fitting should have sufficient mechanical strength to avoid being crushed by the hemostasis valve, which can be achieved through appropriate selection of materials and wall thicknesses. In embodiments, the tubular portion can be formed from a more flexible polymer, such as one or more of the polymers previously described for the catheter body, such as polyetheramide block copolymers (PEBAX®), nylon (polyamide), polyolefin, polytetrafluoroethylene, polyester, polyurethane, polycarbonate, polysiloxane (silicone), polycarbonate urethane (e.g., ChronoFlex AR®), mixtures, combinations, or other suitable biocompatible polymers. As previously described, the various fitting structures can be assembled from additional components, added to or separated from the various components of the embodiments, and / or the components can be formed as integral structures that are molded accordingly. Thus, certain designs can be assembled from existing commercially available components, or all or part of the fitting can be manufactured specifically for these applications. In embodiments, some of the components can be translucent or transparent. It can be advantageous for the user to be able to visually inspect the interior of the components. In some procedures, it may be desirable for the user to be able to visually identify when the suction extension has entered the manifold and engaged with the docking structure. Therefore, transparency should be considered especially for fixtures in locations where the docking structure will be placed, and visual inspection along with physical tactile assessment can help to confirm docking.In some procedures, it may be desirable for the user to visually inspect the tubular extension for trapped thrombus or other debris before removing the tubular extension from the hemostatic environment.

[0116] Use of the aspiration system described herein involves manipulating a control structure, such as a control wire, to move the body of the suction extension within the guide catheter. This movement generally involves extending the tubular extension from the distal end of the guide catheter as well as removing the suction extension from the proximal end of the guide catheter. In some embodiments, the guide catheter does not include a stopper or other alignment structure to engage the connecting section of the suction extension to prevent it from moving out of the distal opening of the guide catheter. If the connecting section of the suction extension passes through the distal opening of the guide catheter, it may be difficult to recover the objective of the procedure without removing the guide catheter from the patient's body, resulting in undesirable delays and risks to the patient and increased costs associated with procedure time. The control structure may be provided with markings instructing medical personnel never to insert the control structure, but such a system may involve an undesirable level of risk for user error.

[0117] A handle may be secured to the control structure at or near its proximal end to facilitate gripping of the control structure as well as to prevent the control structure from being inserted too far into the guide catheter. The grip or handle may then have a shape or sufficient thickness perpendicular to the control structure to prevent the handle from being inserted through the hemostasis valve. A variety of configurations may be suitable for the grip or handle, but generally they should be easy for a medical practitioner to grasp with one hand for manipulation during a procedure. The handle may be rigidly attached to the control structure or the grip may be repositionable on the control structure. If the grip is repositionable, the proximal end of the control structure may be bent, knotted, twisted, or otherwise altered to make it difficult or impossible to remove the grip without breaking some component. For use, the handle should be adequately supported if it is not permanently fixed in a particular position. If the handle is repositionable, e.g., for use with different attachments or guide catheter embodiments, the securement of the handle may be provided by screws, clips, snaps, other fasteners, or other suitable structures that may be engaged during manufacture of the product or by the user with appropriate instructions.

[0118] In one exemplary embodiment, the handle is provided by a pin vise. FIGS. 35A-35C show an embodiment of a pin vise 671 having a knurled collet holder 673, a collet 675, and a head 677. In an embodiment, the head 677 may have one or more ribs 679. The ribs 679 may facilitate turning the head 677 to hold or release the control wire 681. Additionally, the ribs 679 may help prevent the pin vise 671 from rolling when placed on, for example, a surgical tray or table. The collet 675 has a through hole 683 configured to receive the control wire. When the control wire is inserted into the through hole 683, rotating the head 677 in a first direction about the threads 685 causes the collet 675 to squeeze the control wire in the vise like a grip, and rotating the head 677 in the opposite direction causes the collet 675 to release the control wire. When the control wires are secured to the collet 675, the collet holder 673 may be manipulated to control the control wires and corresponding suction extensions. For example, twisting the collet holder 673 may apply a torque to the control wires. Pulling the collet holder 673 axially may withdraw the suction extension from the patient and / or dock the suction extension into the docking structure. Similarly, pushing the collet holder 683 axially may release the suction extension from the docking structure and / or reposition the suction extension into the patient's vasculature.

[0119] The aspiration systems described herein may include a filter near the proximal fitting for manipulating the aspiration catheter with a suction source. Examples of filters are shown in Figures 36A-36C, 37A-37B, 38A-38B, and 39A-39D. The filter components can be constructed of the metals and polymers described above for the fitting components. The filter material can be constructed of the materials described below. The filter, configured to remove clots from the flow from the fitting, is attached and connected to the high pressure tubing upstream, for example, immediately upstream of the high pressure tubing. The high pressure tubing is generally at least 6 feet long and separates the sterile and non-sterile components. The other connectors of the filter can be directly or indirectly connected to the remaining fittings, various configurations and relative positions of the fittings are described herein.

[0120] 36A-36C, filter 800 has a tubular body 801, a forward portion 803, and an end cap 805. In an embodiment, forward portion 803 has a gradual taper. In an embodiment, forward portion 803 is conical. Forward portion 803 generally includes a connector 807, such as a male Luer connector. Removable end cap 805 generally includes a connector 809, such as a female Luer connector. Connections 807, 809 and tubular body 801 are in fluid communication, such that fluid may pass through filter 800. At least one of connections 807, 809 can be easily attached to a high pressure tube of an aspiration system, while the other can be attached to a proximal fitting. In an embodiment, connections 807, 809 are Luer connectors. Tubular body 801 has a larger bore than the relatively small diameter high pressure tube of the aspiration system. Thus, debris such as blood clots that may impede flow in the high pressure tubing of the aspiration system may be collected within the tubular body 801 and not impede flow rate in the high pressure tubing. The end cap 805 may be bonded to the tubular body 801, such as by adhesive or thermal bonding, or in further embodiments may be releasably engaged with the tubular body 801 by friction fit, threaded connection, bayonet engagement, or other convenient engagement.

[0121] In some embodiments, the average bore diameter of the tubular body 801 can range from about 0.4 inches to about 5 inches, in further embodiments from about 0.5 inches to about 3.5 inches, and in further embodiments from about 0.6 inches to about 3 inches. While it may be advantageous for the bore diameter along the tubular body 801 to be approximately constant, this bore diameter can be reasonably varied without altering functionality within the average specifications. The length of the tubular body 801 can range from about 0.5 inches to about 8 inches, in further embodiments from about 0.75 inches to about 7 inches, and in other embodiments from about 1 inch to about 6 inches. One of ordinary skill in the art will recognize that other ranges within the explicit ranges set forth above are contemplated and are within the present disclosure. Generally, the filter 800 can be formed from any suitable polymer, such as polycarbonate, acrylic polymer, polyamide, high density polyethylene, polyester, copolymers thereof, and the like. Luer fittings can include multiple configurations and can be suitably constructed or purchased from suppliers such as Merit Medical.

[0122] The tubular body 801 may include additional structure, such as a filter matrix or other material, configured to trap clots with little effect on the flow rate through the filter 800 and attached tubing. FIGS. 36A-C show exploded views of a filter 800 with a wave filter element 821. The tubular body 801 has a threaded portion 811 that mates with an end cap 805. The wave filter 821 is configured to fit within an interior chamber 813 of the tubular body 801 and is fully contained therein when an end cap 805 with mating threads in the cap is secured to the threaded portion 811. The wave filter 823 has a number of ribs 823 arranged in a pattern that creates a predetermined number of flow paths through the filter 821 when in operation with the tubular body 801. Different configurations of the wave filter 821 may have different numbers of flow paths 825 and optionally different configurations of ribs. When a clot enters wave filter 821, it can travel down one of the channels 825 and become lodged in one of the ribs 823. Even with a clot, fluid continues to flow around ribs 823 such that the flow rate in the attached high pressure tubing is substantially unaffected by a clot lodged in wave filter 821.

[0123] 37A and 37B show filter structures with different filter elements. The filter matrix filter element 827 has a fiber matrix that can trap clots within the fiber elements while allowing fluid to pass generally unimpeded. The fiber matrix filter element 827 can include, for example, cellulose fibers, polyester fibers, or other reasonable fiber elements. The folded matrix element 829 is a folded material that can trap clots within the folds of the material while fluid flows around and / or through the folds. The folded matrix element 829 can include folded filter paper with a pore size suitable to allow blood components to pass through the filter paper. The filter element 821, 827, or 829 is generally sterilized for use due to its proximity to the proximal fitting, and a suitable sterilizing agent can be selected, such as steam or radiation sterilization. It is generally shipped sterile and will be opened from the sterile packaging and assembled under suitable sterile conditions in the treatment room.

[0124] 38A-38B, an embodiment of a filter 800 with a screen-type filter element is shown in exploded form. The filter element 830 includes an open end 835 formed into an engagement ring 845 that engages the end cap 805 in an effective sealed configuration when the end cap 805 is secured to the tubular body 801. The filter element 830 further includes an optional frame 831, a closed end ring 833, a filter screen 837, and struts 839. If the filter screen is sufficiently self-supporting, such as a woven or welded metal screen, the frame 831 may not be used and the rings 833 and 845 may be attached directly to the filter screen. The struts 839 stabilize the filter element 830 within the tubular body 081 in the assembled filter while allowing flow through the ring 833. The interior of the closed end ring 833 may have a filter screen 837 (shown in the circular inset of FIG. 38A) or may be completely closed. This embodiment of filter 800 can be designed to allow filter element 830 to be inserted in either direction into tubular body 801. In principle, filter 800 of the embodiment of Figures 38A-B can operate with flow in either direction, and in some embodiments of this filter it is desirable to have flow enter the interior of filter element 850 through opening 835 and restrict flow containing clots from exiting filter 800 through filter screen 837.

[0125] 39A-39D, filter 850 has an alternative configuration to the filter of FIGS. 36-38, the configuration of FIGS. 39A-39D allowing easy access to the interior of the filter since the connections to the filter are not connected to the filter body. Filter 850 has filter body 851 and end cap 853. End cap 853 includes connections 855, 857 configured to attach to high pressure tubing and proximal fittings. In an embodiment, connections 855, 857 are luer fittings. Filter body 851 mates with a central portion 859 of end cap 853. In an embodiment, filter body 851 and central portion 859 of end cap 853 have corresponding threads 881, 883, respectively, whereby filter body 851 is threaded with central portion 859 to form a seal. If desired, central portion 859 can include a washer or gasket 885 that engages or is threaded to filter body 851. The filter body 851 further has an open upper end 863 opposite a closed lower end 865 and an interior chamber portion 867 therebetween. The end cap 853 has a first channel 875 extending from the first connection 855 to approximately the center of the central portion 859, whereby the channel is in fluid communication with the interior chamber 867 of the filter body 851. The first channel 875 then makes an angled turn, e.g., about 90 degrees, toward the filter body 851 to direct flow. The end cap 853 has a second channel 877 extending from the second connection 857 to approximately the periphery of the central portion 859, whereby the second channel 877 makes an angled turn, e.g., 90 degrees, toward the edge of the filter body 851 outside the area enclosed by the washer / gasket 883, whereby flow outside the screen filter element 861 can flow into the second channel 877.

[0126] The filter 850 may have a filter element 861 or similar filter structure. The screen filter element 861 is configured to fit within the interior chamber portion 867 of the filter body 851 and is fully contained therein when the end cap 853 is secured to the filter body 851. The filter element 861 optionally has a closed end 869 at a lower end opposite an open top end 871 and a mesh screen 873 therebetween. In some embodiments, the closed end 869 engages the lower portion of the filter body 851 to restrict blood clots from exiting the screen filter element 861. The closed end 869 may alternatively have a screen that allows flow through the end. For example, fluid entering the open end 871 of the filter element 861 passes through the screen 873 to exit the filter 850. The filter element 861 should be sized to allow for an appropriate gap between the filter element 861 and the wall of the chamber portion as well as a flow path to the outlet of the interior chamber portion 851. 39D, filter element 861 can have an outer diameter that is smaller than the inner diameter of chamber portion 851. Flow 841 enters filter element 861 through first channel 875. In embodiments, filter element 861 has a height that approximately matches the height of filter body 851, such that filter element 861 is held in place when filter body 851 is secured to end cap 853. In some embodiments, top end 853 can include a washer or the like that engages with the top of filter element 861 when filter body 851 is engaged with end cap 853.

[0127] In an embodiment, the central portion 859 of the end cap 853 may have a lip, protrusion, and / or gasket that engages with the top of the filter element 861. A gap should be maintained between the walls of the chamber portion 851 and the filter element 861, so that the flow 841, upon passing through the screen 837, may continue between the filter element 861 and the walls of the chamber portion 851, and eventually exit the in-line filter 850 through the connection 857. It should be recognized that the flow 841 may be reversible, and the filter 850 may also operate with the flow entering the connection 857 and exiting the connection 855, although the collection of clots is not necessarily equal in the two flow directions. One skilled in the art may adjust these designs to have other configurations that are functionally equivalent based on the teachings of the present application. For example, the inclusion of O-rings, washers, gaskets, etc. may be used as seals to direct the flow 841 without departing from the scope of the present disclosure. In addition, although Figure 39C shows the first channel 875 and second channel 877 connected to the inlet and outlet in a linear fashion, there is no functional requirement for this configuration, and each inlet and outlet can be positioned at any selected angle relative to one another along the circumference, so long as the inlets and outlets do not interfere with one another. The linear configuration of the figure can be advantageous in a variety of situations.

[0128] The mesh screen 837 may be sized to adequately capture clots while allowing fluid flow to remain essentially unimpeded. The pore size of the screen need not be particularly small, since the purpose of the mesh screen is to remove clots that may impede flow through the tubing, and not to purify the blood for the patient. Pore sizes of less than 1 millimeter, and in further embodiments less than 0.5 millimeters, may be appropriate, and generally the pore size should not be too small, e.g., at least greater than about 0.1 mm. Other embodiments may be considered similarly effective filter sizes. For meshes with relatively large pores, fibers may be included in the filter to aid in the capture of clots, and gravity may further assist in the capture of clots, particularly in configurations such as those shown in FIG. 39. The packing of the fibers may be selected to facilitate clot capture without significantly restricting flow or obscuring excessive visibility within the filter. In embodiments, the filter body 851 may be transparent, allowing visual assessment of debris captured within the filter 850. If transparent, being able to identify whether or not a clot has been trapped within the filter can improve safety and help guide medical personnel in performing procedures.

[0129] 40, pressure sensor 900 has a female luer fitting 901, a male luer fitting 903, and a channel 905 therebetween. Pressure sensor 900 may have a display 907 that displays pressure measurements of fluid passing through pressure sensor 900. In embodiments, display 907 may be integral to pressure sensor 900. In embodiments, display 907 may be a separate display unit connected to pressure sensor 900, for example, via an electrical or wireless connection. As described in more detail below, in embodiments, display 907 may be incorporated into a multi-function display that can simultaneously display outputs from multiple sources during a procedure. Female luer fitting 901 and male luer fitting 903 are in fluid communication with the fluid in chamber 905.

[0130] 41, the flow meter 930 has a female luer fitting 931, a male luer fitting 933, and a channel 935 therebetween. The flow meter 930 has a display 937 that displays a measurement of the flow rate of the fluid through the flow meter 930. In an embodiment, the display 937 may be incorporated into the flow meter 930. In an embodiment, the display 937 may be a separate display unit that is connected to the flow meter 930, for example, via an electrical or wireless connection (such as Bluetooth). As described in more detail below, in an embodiment, the display 935 may be incorporated into a multi-function display that can simultaneously display outputs from multiple sources in a procedure. The readings of the flow meter 930 can be displayed on multiple displays simultaneously. The female luer fitting 931 and the male luer fitting 933 are in fluid communication with the fluid flowing through the channel 935.

[0131] 42, in an embodiment, a flow meter 926 has a paddle wheel 909 that is positioned such that one or more paddles 911 extend partway into a channel 905. Fluid flowing through the channel 905 pushes on the one or more paddles 911, causing the paddle wheel 909 to rotate. The flow rate is related to the rotational speed of the paddle wheel 909 as it rotates.

[0132] In an alternative embodiment as shown in FIG. 43, the ultrasonic flowmeter 928 has a first transceiver 939 and a second transceiver 941. The first and second transceivers 939, 941 are in electrical communication with a computing unit 943. The first transceiver 939 emits a first ultrasonic signal 945, which is reflected with modulation from the fluid flow at the inner surface 937 of the channel 935 and received by the second transceiver 941. The second transceiver 941 emits a second ultrasonic signal 947, which is reflected at the inner surface 937 of the channel 935 and received by the first transceiver 939. In an embodiment, the first and second transceivers 939, 941 are ultrasonic transducers and / or ultrasonic sensors. The computing unit 943 receives the output from the first and second transceivers 939, 941. In an embodiment, the computation unit 943 can use the outputs from the first and second transceivers 939, 941 to calculate properties of the fluid flowing through the channel 935. For example, the computation unit 943 can determine the flow rate of the fluid flowing through 935. Ultrasonic flow meters are commercially available adapted for these purposes. For example, a Dynasonics ultrasonic flow meter (e.g., Dynasonics DXN flow meter (Badger Meters, Inc., Wisconsin, USA) for tubing up to 0.5 inch diameter) can be clipped onto the tubing to measure the flow rate based on the Doppler ultrasound effect.

[0133] An example of a proximal fitting configuration including a filter 800, a pressure sensor 900, a flow meter 930, and a negative pressure source 951 attached to the proximal fitting of an aspiration system described herein is shown in FIG. 44A and FIG. 44B. Referring to FIG. 44A, the proximal fitting 468 is shown to have a first branch 932 in fluid communication with the pressure sensor 900, the flow meter 930, the filter 800, and the negative pressure source 470. In such an arrangement, both flow and pressure measurements are made in the first branch of the aspiration system aligned with the negative pressure source 951. In an alternative arrangement, as shown in FIG. 44B, the proximal fitting 468 is shown to have a first branch 934 in fluid communication with the flow meter 930, the filter 800, and the negative pressure source 951. A second branch 936 is shown in fluid communication with the pressure sensor 900. Thus, the pressure in the proximal fitting 468 may be measured independently of the branch attached to the negative pressure source 951. Based on the teachings herein, various other configurations of component arrangements can be realized.

[0134] FIG. 45 shows a partial view of an embodiment of an aspiration system with the catheter elements inserted into a patient. The distal portion of the aspiration system is shown within the neurovasculature 971 illustrating the tubular extension 973 extending from the guide catheter 975. The proximal portion of the aspiration system shows the guide catheter 975 extending proximally from the patient insertion point 977 and the proximal fitting 468 of the aspiration system extending proximally from the guide catheter 975. In an embodiment, the proximal fitting 468 has various branches to provide the desired functionality described in the embodiments presented herein. In an embodiment, the branches 1001, 1003, 1005 can be multiple manifolds in various configurations, such as a three-branch manifold, or two manifolds connected in series. In an embodiment, the first branch 1001 is distal to the second branch 1003. In an embodiment, the second branch 1003 is distal to the third branch 1005. In this particular embodiment, the first branch 1001 may be connected to a fluid source 1007. The second branch 1005 may include a pressure sensor 900, a flow meter 930, a filter 1000, and a negative pressure source 470. The pressure sensor 900 is connected to a pressure sensor display 907, and the flow meter 930 is connected to a flow sensor display 937. In an embodiment, the second branch 1003 includes a Y-branch manifold having a first branch 1011 connected to the pressure sensor and a second branch connected to the filter 1000, the flow meter 930, and the negative pressure source 1009. In an embodiment, the first branch 1011 of the Y-branch manifold is distal to the second branch 1013 of the Y-branch manifold. In an embodiment, the filter 1000 is distal to the flow meter 930.

[0135] The extended hemostatic fitting 1018 is connected to the third branch 1005 at a connector 1017 and terminates in a hemostatic valve 1019. The extended hemostatic fitting 1018 can be coupled to a docking branch manifold at the hemostatic valve 1019, suitable embodiments of which are described above. In an embodiment, the extended hemostatic fitting 1019 can be combined with a docking branch manifold 1021. The docking branch manifold 1021 can have a first branch connected to a fluid source 1023. A control wire 1025 extends from the second branch of the branch manifold 1021 through a hemostatic valve 1027.

[0136] The aspiration catheter system is typically suitably sterilized, such as by e-beam or gas sterilization. The components of the aspiration catheter system may be packaged together or separately in a hermetically sealed package, such as a plastic package, as known in the art. The package is typically appropriately labeled in accordance with regulations of the FDA and other regulatory agencies. The aspiration catheter system may be packaged with other components, such as guidewires, filter devices, and / or other medical devices. The packaged system is typically sold with detailed instructions for use in accordance with legal regulations.

[0137] <Treatment using the treatment system> As mentioned above, the medical system including the aspiration catheter system described herein can be used with the aspiration catheter system as a standalone treatment device, possibly in conjunction with a guidewire and / or other delivery assistance device, or with a supplemental treatment device for the treatment of ischemic vascular occlusion. In particular, in some embodiments, the aspiration system is used with an embolic protection device, and in further embodiments, any form of clot engagement device, stent, balloon, atherectomy device, or the like may also be used. In either case, a guidewire is generally used to provide access to the treatment site. The guide catheter portion of the aspiration catheter system may or may not be positioned prior to introducing the suction extension. The structure of certain components has already been described in detail above and will not be repeated in this section so that the focus can be on the use of the device. The use of alternative embodiments of the various fitting components can be adjusted by those skilled in the art based on the teachings of the present application.

[0138] To treat an acute ischemic stroke condition, with reference to FIG. 46, a patient 700 is shown with three alternative vascular access points, a femoral artery 702, an artery 704 in the arm, or a carotid artery 706 in the neck. Regardless of the access point, a catheter and associated device is guided into the left or right carotid artery to reach a clot 508 in a cerebral artery 710 of the brain. With reference to the schematic diagram of FIG. 47, a clot 708 is shown in the cerebral artery 710 with a guidewire 712 positioned with its distal end past the clot. A guide catheter 714 is positioned over the guidewire in the carotid artery 706. A suction extension 716 is within the guide catheter 714 along with a connecting section 718, and a tubular extension 720 extends from the guide catheter 714 over the guidewire 712. With reference to FIG. 48, the tubular extension 720 can be advanced over the guidewire to a position proximate to the clot 708. Suction can be applied as indicated by the flow arrows in the figure. Guidewire 712 may or may not be removed before suction is applied. The suction catheter has been successful in removing clots causing ischemic strokes without intervention with additional medical devices. However, for more difficult clots, additional treatment devices can be used, as described in more detail below.

[0139] Using an embodiment of the proximal fitting modified with pressure sensing capabilities as shown above, the initiation of suction described with respect to FIG. 48 can be checked for its efficiency. Once negative pressure is applied to the catheter system and adequate flow is established, the pressure in the proximal fitting can be in an appropriate range. The exact range of pressure expected will generally depend on the specific design of the suction extension, and the acceptable pressure range can be adjusted accordingly. In either case, the pressure can be checked in real time during the procedure and compared to the modified specifications for the particular suction catheter component. If the pressure immediately after the initiation of suction is closer to the pump negative pressure than would be expected based on the set acceptable range, the physician can at least partially retract the suction extension from the delivered state, with or without stopping suction. Partial retraction can be utilized when attempting to untwist the suction extension without completely removing it. As will be further described below, if a proximal fitting is used that allows the tubular extension to be removed for the patient without passing through a hemostasis valve, the tubular extension can be checked visually without exposing the tubular extension to the ambient atmosphere. After verifying that the tubular extension is ready for use or after replacing the suction extension, the suction extension can be delivered again.

[0140] At the beginning of the process, the system is generally primed with sterile saline and air is removed from the suction system to the pump. Pressure and flow measurements are then taken of fluid parameters such as blood as saline and / or blood is drawn into the system. When using the suction system to remove actual clots associated with an acute ischemic stroke event, it is common for the tubular extension to become clogged itself before the foreign body in the vessel is completely cleared. It may therefore be desirable to remove the clot from the tubular extension and reintroduce the suction extension into the cerebral vessel to remove other clots. The removal and reintroduction of the foreign body can be repeated as necessary. The fittings described herein can facilitate this process, and the use of these fittings to perform this process is further described below. The desire to remove the clot from the suction extension and the reintroduction of the suction extension can also be performed using additional treatment structures described below.

[0141] The use of a flow meter provides an important additional parameter to guide the procedure. Although pressure changes may provide some overlapping information, additional flow measurements can provide additional guidance. If the flow rate drops, this may indicate that a clot is lodged somewhere or that the suction extension has kinked. Depending on the stage of the procedure, the suction extension / aspiration catheter may be removed from the guide catheter to remove any clots present. This then allows the guide catheter to be checked to ensure that the blockage has been removed. A sudden increase in flow rate may indicate that the clot has been removed. If the clot is in the filter, this may indicate that the procedure has progressed, but if no clot is noted in the filter, the medical practitioner may carefully check for other locations where a clot may be present and proceed with caution to prevent the clot from being unintentionally redirected back into the patient's body.

[0142] 49 and 50, the use of a fiber-based filter device is shown in use with an aspiration catheter system. As shown in FIG. 49, a clot 708 is shown in a cerebral artery 710, and a deployed fiber-based filter 734 supported on a guidewire 736 is positioned with the filter deployed past the clot. The fiber-based filter 734 can have fiber elements that extend essentially to the wall of the blood vessel, i.e., the cerebral artery 710. A tubular extension 736 can be positioned with its distal end just proximal to the clot, with the remainder of the aspiration catheter system not shown in this view. With reference to FIG. 50, the fiber-based filter 734 can be pulled toward the tubular extension 736 while suction is applied to facilitate removal of the clot 730. The clot 708 can be broken up and removed by suction, and / or all or a portion of the clot 708 can be drawn into the tubular extension 736, optionally along with all or a portion of the fiber-based filter, and / or all or a portion of the clot 708 can be held up to the opening of the tubular extension 736, with the fiber-based filter retaining the clot. In either case, once the clot has been properly stabilized, the device and any clot still within the vessel or catheter can be removed from the patient. Removal of the device is discussed further below.

[0143] Further use of additional medical devices to facilitate clot removal is shown in Figs. 51 and 52. As shown in Fig. 51, a clot 708 is shown in a cerebral artery 710, a treatment device 754 is positioned at the clot, and a deployed fiber-based filter 756 supported on a guidewire 758 is positioned with the filter deployed past the clot. Suitable treatment devices for engaging the clot are described above. The selected treatment device is deployed, generally with protection from the deployed fiber-based filter, and optionally with suction. Once the treatment device has engaged the clot, the collection of the remaining portion of the clot and the treatment device can be removed, as shown in Fig. 52, similar to the process shown in Fig. 51. Notably, the treatment device can be removed, but portions such as a stent may be left in place, and removal can proceed or be performed in conjunction with removal of the remaining debris of the filter and / or clot in the vessel. All or a portion of the clot 708, if not already broken up and removed by suction, can be drawn into the tubular extension 736, optionally along with all or a portion of the fiber-based filter, and / or all or a portion of the clot 708 can be retained to the distal opening of the tubular extension 736, with the fiber-based filter retaining the clot. Again, once the clot has been adequately stabilized, the device and any clot still within the vessel or catheter can be removed from the patient. The use of multiple additional therapeutic devices can be accomplished by extending the procedure outlined above and repeating the steps involving the additional medical devices.

[0144] Also, in the embodiment of Figures 47-52, a pressure sensor connected to the proximal fitting can be used to guide the procedure. If the pressure in the proximal fitting rises to a pressure outside the target range when negative pressure is initiated, corrective care can be taken to remove any kinks, replace / eliminate the suction extension, or other appropriate precautions. Additionally, once suction is applied and the clot appears to be addressed, the pressure in the proximal fitting can be checked to assess the condition of the clot and catheter, e.g., whether the clot is lodged in the distal end of the suction extension, etc. Appropriate action can be taken based on the pressure in the proximal fitting.

[0145] FIG. 53 shows the suction treatment system after treating a clot in a cerebral artery 750. A tubular extension 752 is positioned with its distal end in the cerebral artery 750, with a thrombus 754 that may or may not be at the orifice. A guide catheter 756 is positioned with its distal end in the carotid artery 758. A section of the interior of the guide catheter 756 is shown in the balloon inset of FIG. 53. A connecting section 760 of the suction extension 752 is within the guide catheter 756 with a control wire 762 extending proximally. A patient's leg 764 is shown with an introducer sheath 766 with a hemostasis valve 768 extending from the leg. The guide catheter 756 extends from the hemostasis valve 768. A Y-branch manifold 770 is connected to the distal end of the guide catheter 756 at a connector 772. The extended hemostasis fitting 774 is connected to a Y-branch manifold 770 at a connector 776, which terminates at a hemostasis valve 778. The control wires 762 extend from the hemostasis valve 778. The Y-branch manifold 770 has a connector 780 which is connectable to a further Y-branch manifold 782 having a connector 784 for connecting to the connector 780. The Y-branch manifold can be connected to a negative pressure line 786 which can be connected to a pump or other negative pressure device, and a pressure sensor line 788 which can be connected to a suitable pressure sensor as shown in Figures 27-29. The fitting of Figure 53 can be combined with a docking branch manifold at the hemostasis valve 778, suitable embodiments of which are described above. The combination of the Y-branch manifold 770 and the extended hemostasis fitting 774 can be considered components of a first fitting element.

[0146] At the stage of the procedure shown in FIG. 48 (assuming the clot has been removed as desired) and at the stage of the procedure shown in FIG. 53, the step of the procedure can begin in which the device is gradually removed from the patient. FIGS. 54-56 show the removal process using an extended fitting to completely remove the suction extension from the guide catheter behind the hemostatic valve. FIGS. 57 and 58 show the use of a docking Y fitting for efficient removal and reintroduction of the suction extension. It may be advantageous to hold the guide catheter in place while other components are removed and the success of the procedure is confirmed. Generally, it is desirable to hold the guide catheter in place until the procedure is completely completed, since the placement of the guide catheter is labor intensive. As previously mentioned, the suction extension may be removed, clot removed, and reintroduced as well as for additional clot removal before the entire procedure is completed. This removal and reintroduction of the suction extension can be performed while the guide catheter remains fixed in place. While pressure readings at the proximal fitting can provide useful information regarding conditions under which flow to the suction extension 752 may be obstructed, other, more qualitative assessments can be made, such as the termination of fluid flow to the pump.

[0147] Referring to FIG. 54, the guide catheter 756 is still in place in the carotid artery 758, and the cerebral artery 750 is free of devices and clots. Referring to the balloon inset associated with FIG. 54, a further enlarged cross-sectional view shows the distal end of the suction extension 752 within the interior of the guide catheter 756. A thrombus (thrombus 790) may or may not be associated with the distal end of the guide catheter 756, which may have accumulated in situ as the suction extension 752 is retracted into the guide catheter 756 and / or at the distal end of the suction extension 752 (thrombus 754). Again, pressure measurements at the proximal fitting can provide useful information regarding the possibility of a thrombus blocking flow from the catheter system to a negative pressure device such as a pump.

[0148] 55, the balloon inset shows a further enlarged cross-sectional view of the connecting section 760 of the suction extension 752 in the T-junction manifold 770 as the suction extension 752 is further withdrawn from the patient. Continuing to apply negative pressure in this state will cause fluid to be drawn out of the guide catheter 756 rather than through the suction extension 752. Whether the suction extension 752 is clogged or not, this state can provide the ability to further remove the clot 790 at the end of the guide catheter 756, and the suction can further stabilize the clot 790, if any, for the subsequent portion of the procedure. At this stage of the procedure, the pressure in the proximal fitting can provide information regarding the flow of fluid into the guide catheter 756.

[0149] The suction extension 752 is shown completely removed from the guide catheter 756 in FIG. 56. The distal balloon inset in FIG. 56 shows a further close-up view of the distal end of the suction extension 752 in the T-branch manifold 770, but the distal end of the suction extension 752 can be fully retracted into the extended hemostasis fitting 774, as indicated by the dashed line connected to the balloon inset. The proximal balloon inset in FIG. 56 shows a further close-up cross-sectional view of the connecting section 760 in the extended hemostasis fitting 774 in a position distal to the hemostasis valve 778. Again, the pressure within the proximal fitting can be useful to provide information during this portion of the procedure.

[0150] Although the guide catheter 756 can be removed from the patient after treatment of the clot, it may be desirable to at least partially remove the suction extension 752 with the guide catheter in place relative to its deployed position to reduce the risk of embolization of thrombus that may have become trapped associated with the aspiration system components but not fully removed from the patient. Figures 44-46 show three stages of suction extension removal, at which point the guide catheter 756 may be selected to be removed from the patient, generally through the hemostatic valve 768 of the introducer 766. As shown in Figure 54, with the distal end of the suction extension 752 in the guide catheter 756, any thrombus associated with the suction extension 752 will be within the guide catheter 756, thereby reducing the likelihood of embolization. 55, as previously described, with the connecting section 760 in the Y-branch manifold 770, suction is applied directly to the lumen of the guide catheter 756 whether the suction extension 752 is clogged or not, and thus applying suction directly to the guide catheter 756 provides additional safety in terms of reducing the possibility of embolization. Furthermore, as shown in FIG. 56, the suction extension 752 can be completely removed from the guide catheter 756, providing additional safety against embolization of thrombus associated with the suction extension 752. As shown in FIG. 56, the suction extension 752 remains isolated behind the hemostatic valve 778, which allows for desirable control of pressure within the guide catheter 756, further reducing the risk of embolization as well as contamination.

[0151] FIG. 57 illustrates a docking branch manifold 601 having a distal end that is inserted through a hemostasis valve 778 and a control wire 762 extending proximally. As previously described, the use of the docking branch manifold 601 allows for efficient removal and reintroduction of the suction extension. As shown in FIG. 57, the suction extension 752 is removed from the guide catheter 756 but remains in isolation behind the hemostasis valve 778. If the suction extension 752 becomes clogged, the illustrated configuration provides increased safety against embolization of thrombus. However, to safely reintroduce the suction extension 752 into the patient, any clots should first be removed from the suction extension 752. As previously described, the control wire 762 may be used to dock the suction extension 752 within the docking branch manifold 601.

[0152] FIG. 58 shows both the docking branch manifold 601 and the suction extension 752 fully withdrawn from the isolation section behind the hemostasis valve 778. In this configuration, the proximal end of the suction extension 752 is docked within the inlet tubular section 603. Additionally, at least a portion of the clot 708 is shown lodged in the distal end of the suction extension 752. It may be unsafe to reintroduce the suction extension 752 into the patient's body while the clot 708 remains lodged in a portion of the suction extension 752. Thus, with the suction extension 752 fully removed from the hemostasis valve 778, the valve 607 may be opened and a positive pressure device such as a syringe 609 may dispense fluid to flush the clot 708 from the suction extension 752. Once the suction extension 752 is cleared of any foreign material, the suction extension 752 may be reinserted through the hemostasis valve 778. Sterilization procedures can be used to maintain the suction extension 752 in a sterile condition for reintroduction into the patient. In some procedures, the cleaned suction extension 752 may be completely reintroduced into the patient to retrieve additional emboli. As previously mentioned, the docking manifold can be configured to deliver suction, contrast, or other fluids to facilitate performance of the procedure. For these additional or alternative embodiments, the procedure can be easily modified.

[0153] 59 shows a video monitor 680 displaying a real-time x-ray image 682 of the patient at the thrombectomy site along with pressure values ​​684 and flow rates 686. Through having all of these images visible simultaneously, medical personnel have access to all the information to make decisions regarding the next steps in the procedure.

[0154] Bench tests and calculations were performed to evaluate the general aspiration performance of using a suction extension in contact with a guide catheter or on other commercially available aspiration catheters. These results are described in the '938 application and are incorporated herein by reference.

[0155] The above embodiments are intended to be illustrative and not limiting. Further embodiments are within the scope of the claims. Moreover, although the present invention has been described with respect to specific embodiments, those skilled in the art will understand that changes in form and detail may be made without departing from the spirit and scope of the present invention. Any incorporation by reference of the above-mentioned documents is limited to not incorporation of any subject matter contrary to the explicit disclosure herein. Unless otherwise expressly indicated, and as suggested in the discussion, to the extent that a given structure, configuration and / or process is described with components, elements, ingredients or other parts, the disclosure of the present specification should be understood to encompass embodiments that comprise a given embodiment, a given component, element, ingredient, other part, or combination thereof, as well as embodiments that essentially consist of such a given component, ingredient or other part, or combination thereof, which may include additional features that do not change the basic nature of the subject matter.

Claims

1. an aspiration catheter assembly including an aspiration lumen extending from a proximal end having a connector to a distal opening; a fitting including a branch manifold having a first branch including a hemostasis valve and a second branch including a connector, the branch manifold being attached to the connector of the aspiration catheter assembly; A pump and a conduit connected to the pump and the connector of the second branch, the conduit comprising tubing having a lumen configured to be in fluid communication with the aspiration lumen through the second branch of the branch manifold; a filter having an inlet and an outlet connected to the tubing, the inlet connected to the connector of the second branch or within 12 centimeters of the connector of the second branch; Equipped with Suction thrombectomy system.

2. the tube is flexible, the inner diameter of the tube is about 0.25 inches or less, and the tube has a length of at least about 4 feet; The aspiration thrombus removal system of claim 1 .

3. The suction catheter assembly includes: a guide catheter having an inner diameter along a lumen and an outer diameter, the inner diameter and the outer diameter depending on a position along the length of the guide catheter; an aspiration catheter including a tubular extension having a distal end, a connection section, and a control element extending proximally from the connection section, the connection section engaging the guide catheter with a fit that restricts or eliminates flow along its lumen between the connection section and the guide catheter at an appropriate location, the aspiration catheter having an outer diameter having a value for permitting the aspiration catheter to move within the lumen of the guide catheter such that the distal end of the tubular extension of the aspiration catheter extends from a distal opening of the guide catheter; Including, The suction thrombus removal system according to claim 1 or 2.

4. the fitting includes a tubular segment between the hemostatic valve and the proximal end of the guide catheter, the tubular segment providing a length at least equal to the length of the tubular extension of the aspiration catheter; The aspiration thrombus removal system of claim 3 .

5. the fitting includes a first tubular section extending from a connector to the hemostasis valve, the first tubular section having at least the same length as the tubular extension of the aspiration catheter; and a docking branch manifold including an inlet tubular section connected to at least one Y-branch having a valve and terminating in a connector and a second branch having a hemostasis valve; the inlet tubular section includes a docking structure that engages with the proximal end of the connecting section of the aspiration catheter at a location distal to the Y-junction to form a continuous fluid channel from a central lumen to the docking branch manifold; at least a portion of the inlet tubular section is configured to be inserted through and secured within the hemostasis valve; The aspiration thrombus removal system of claim 3 .

6. the filter includes a filter body defining an interior chamber along a flow path between the inlet and the outlet, and a filter element configured to fit within the interior chamber such that aspirant flow between the inlet and the outlet flows through the filter element; the inlet is associated with a first connector and the outlet is associated with a second connector; The aspiration thrombus removal system of claim 1 .

7. the filter element includes a mesh screen configured to separate flow between the inlet and the outlet within the interior chamber, whereby flow from the inlet to the outlet passes through the mesh screen. The aspiration thrombus removal system of claim 6.

8. the inlet and outlet are positioned at selected locations around the circumference of the cap; the cap includes a first channel extending from the inlet to a central portion of the cap and a second channel extending from the outlet to an interior of the filter body, wherein fluid flowing through the inlet passes through a filter element before exiting through the second channel; The suction thrombus removal system according to claim 6 or 7.

9. the second branch is distal to the first branch; The aspiration thrombus removal system of claim 1 .

10. the fitting includes a third branch connected to a fluid source; The aspiration thrombus removal system of claim 1 .

11. the hemostatic valve of the first branch is connected to a proximal manifold; the proximal manifold having a first branch connected to a fluid source and a control element extending proximally from a second branch through a hemostasis valve; The aspiration thrombus removal system of claim 1 .

12. an aspiration catheter assembly including an aspiration lumen extending from a proximal end having a connector to a distal opening; a fitting including a branch manifold with a first branch including a hemostasis valve and a second branch including a connector; A pump and a conduit connected to the pump and the connector of the second branch, the conduit comprising tubing having a lumen configured to be in fluid communication with the aspiration lumen through the second branch of the branch manifold; a pressure sensor connected to the fixture to measure pressure within the fixture; a flow meter connected to the conduit to measure the flow rate of aspirant from the aspiration lumen through the conduit, the flow meter comprising a flow passage disposed relative to the lumen of the tubing for receiving aspirant from the aspiration lumen, the flow passage having an inner diameter greater than the inner diameter of the lumen of the tubing; a controller including one or more displays configured to display the pressure and the flow rate; Equipped with Suction thrombectomy system.

13. The suction catheter assembly includes: a guide catheter having an inner diameter along a lumen and an outer diameter, the inner diameter and the outer diameter depending on a position along the length of the guide catheter; an aspiration catheter including a tubular extension having a distal end, a connecting section, and a control element extending proximally from the connecting section, the connecting section engaging the guide catheter with a fit that restricts or eliminates flow along its lumen between the connecting section and the guide catheter at an appropriate location, the connecting section having an outer diameter having a value for allowing the aspiration catheter to move within the lumen of the guide catheter such that the distal end of the tubular extension of the aspiration catheter extends from a distal opening of the guide catheter; Including, The aspiration thrombus removal system of claim 12.

14. the fitting includes a first tubular section extending from a connector to the hemostasis valve, the first tubular section having at least the same length as the aspiration catheter, and a docking branch manifold including an inlet tubular section connected to at least one Y-branch having a valve and terminating in a connector and a second branch having a hemostasis valve; the inlet tubular section includes a docking structure that engages with the proximal end of the connecting section of the aspiration catheter at a location distal to the Y-junction to form a continuous fluid channel from a central lumen to the docking branch manifold; at least a portion of the inlet tubular section is configured to be inserted through and secured within the hemostasis valve; The aspiration thrombus removal system of claim 13.

15. a filter connected to the conduit between the pump and the connector of the second branch; the filter is configured to retain clots flowing through the conduit; the filter is adjacent to the fixture; The aspiration thrombus removal system of claim 12.

16. a second branch manifold attached to the connector of the second branch of the branch manifold, the second branch manifold having a first branch connected to the pressure sensor and a second branch connected to the flow meter; the flow meter is separated from the filter by at least about 6 feet of the tubing; 16. The aspiration thrombus removal system of claim 15.

17. the flow meter includes a paddle wheel or an ultrasonic transducer; The aspiration thrombus removal system of claim 12.

18. the controller is configured to simultaneously display a real-time x-ray image of the patient, the pressure in the fitting, and the flow rate to the pump on a single display; The aspiration thrombus removal system of claim 12.

19. 1. A system for using an aspiration catheter system to remove a thrombus from a patient's vasculature, comprising: the suction catheter system comprises: an aspiration catheter assembly including an aspiration catheter; a fitting including a branch manifold having a first branch including a hemostasis valve and a second branch including a connector; a pump; a conduit connected to the pump and the connector of the second branch; a pressure sensor connected to the fitting and measuring a pressure within the fitting; a flow meter connected to the fitting and measuring a flow rate to the pump; and a controller including one or more displays configured to display the pressure and the flow rate; How to use: positioning the aspiration catheter within the artery such that a distal aspiration opening of the aspiration catheter is located proximal to the clot; Aspirating fluid from the patient's vascular system into a distal opening of the aspiration catheter; monitoring flow and pressure within the fitting; operating the aspiration catheter based on pressure and flow measurements; Including, system.

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