Patent Publication Number: US-2021186541-A1

Title: Devices and methods for treating vascular occlusion

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of U.S. Provisional Patent Application No. 62/949,967, filed Dec. 18, 2019, and titled “DEVICES AND METHODS FOR TREATING VASCULAR OCCLUSION,” which is incorporated herein by reference in its entirety. 
    
    
     TECHNICAL FIELD 
     The present technology generally relates to systems, methods, and devices for extracting thrombi from blood vessels of human patients. In particular, some embodiments of the present technology relate to systems for thrombus extraction from the peripheral vasculature of a human patient. 
     BACKGROUND 
     Thrombosis is the local coagulation or clotting of the blood in a part of the circulatory system, and a thrombus is a blood clot formed in situ within the vascular system. A venous thrombus is a blood clot that forms within a vein. A common type of venous thrombosis is a deep vein thrombosis (DVT), which is the formation of a blood clot within a deep vein (e.g., predominantly in the legs). Nonspecific signs of a thrombosis may include pain, swelling, redness, warmness, and engorged superficial veins. 
     If the thrombus breaks off (embolizes) and flows towards the lungs, it can become a life-threatening pulmonary embolism (PE) (e.g., a blood clot in the lungs). In addition to the loss of life that can arise from PE, DVT can cause significant health issues such as post thrombotic syndrome, which can cause chronic swelling, pressure, pain, and ulcers due to valve and vessel damage. Further, DVT can result in significant health-care costs either directly or indirectly through the treatment of related complications and inability of patients to work. 
     Three processes are believed to result in venous thrombosis. First is a decreased blood flow rate (venous stasis), second is an increased tendency to clot (hypercoagulability), and the third is changes to the blood vessel wall. DVT formation typically begins inside the valves of the calf veins where the blood is relatively oxygen deprived, which activates certain biochemical pathways. Several medical conditions increase the risk for DVT, including diabetes, cancer, trauma, and antiphospholipid syndrome. Other risk factors include older age, surgery, immobilization (as with bed rest, orthopedic casts, and sitting on long flights), combined oral contraceptives, pregnancy, the postnatal period, and genetic factors. The rate of DVT increases dramatically from childhood to old age and, in adulthood, about 1 in 1,000 adults develop DVT annually. 
     Although current devices and methods of prevention and/or treatment of DVT exist, there are a number of shortcomings that have yet to be resolved, such as high incidence of DVT re-occurrence, use of devices not designed to remove large clot volumes, and/or complicated treatments involving multiple treatment devices and/or pharmaceuticals. Accordingly, new devices, systems, and methods of treating thrombus, and particularly DVT are desired. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Many aspects of the present technology can be better understood with reference to the following drawings. The components in the drawings are not necessarily to scale. Instead, emphasis is placed on illustrating clearly the principles of the present disclosure. 
         FIG. 1  is a side view of a thrombectomy system configured in accordance with an embodiment of the present technology. 
         FIGS. 2A and 2B  are side views of a thrombus extraction assembly of the thrombectomy system including a thrombus extraction device in a partially-expanded configuration and a fully-expanded configuration, respectively, configured in accordance with embodiments of the present technology. 
         FIGS. 3A-3D  are an isometric view, a side view, a top view, and a rear view, respectively, of a coring element of the thrombus extraction device configured in accordance with embodiments of the present technology. 
         FIG. 4  is an enlarged side view of the thrombus extraction device coupled to a distal portion of the thrombus extraction assembly and in the fully-expanded configuration in accordance with an embodiment of the present technology. 
         FIGS. 5A and 5B  are side views of a dilator assembly of the thrombectomy system in a first configuration and a second configuration, respectively, configured in accordance with embodiments of the present technology. 
         FIG. 6  is an enlarged cross-sectional side view of a portion of the thrombectomy system including a self-expanding funnel configured in accordance with an embodiment of the present technology. 
         FIGS. 7A-7D  are side views of the dilator assembly positioned within an introducer assembly of the thrombectomy system and illustrating various stages in a process or method for deploying the self-expanding funnel in accordance with embodiments of the present technology. 
         FIGS. 8A, 8C, and 8D  are cross-sectional side views, and  FIG. 8B  is an enlarged cross-sectional isometric view, of a control assembly of the dilator assembly configured in accordance with embodiments of the present technology. 
         FIGS. 9A-9C , are cross-sectional side views of a control assembly configured in accordance with another embodiment of the present technology. 
         FIGS. 10A and 10B  are partially cross-sectional side views of a control assembly configured in accordance with another embodiment of the present technology. 
         FIG. 11  is a schematic view of an introduction technique for accessing a thrombus for treatment with the thrombectomy system in accordance with an embodiment of the present technology. 
         FIGS. 12A-12C  are side views, and  FIGS. 12D-12K  are enlarged side views, of the thrombectomy system positioned within a blood vessel during a thrombectomy procedure in accordance with embodiments of the present technology. 
     
    
    
     DETAILED DESCRIPTION 
     The present technology is generally directed to methods and systems for removing clot material (e.g., a thrombus) from a blood vessel of a human patient. In some embodiments, a system for removing clot material (e.g., a thrombectomy system) includes a thrombus extraction device including (i) a coring element configured to core and separate the clot material from the vessel wall and (ii) a capture element configured to capture the cored and separated clot material. In some embodiments, the coring element comprises a unitary structure having a first region adjacent to a proximal portion of the unitary structure, a second region distal of the first region, a third region distal of the second region, and a fourth region distal of the third region. The first region can include a first mouth configured to core and separate the clot material and the third region can include a second mouth configured to core and separate the clot material. The second and fourth regions can each be generally tubular and can include a plurality of interconnected struts. In one aspect of the present technology, the first and second mouths are radially offset such that at least one of the first and second mouths is positioned and oriented to effectively core and separate the clot material from within the blood vessel during a thrombus extraction procedure using the thrombus extraction device. 
     In some embodiments, the thrombectomy system includes a dilator assembly for deploying an expandable funnel coupled to a distal portion of an introducer sheath. The dilator assembly can include a first shaft defining a lumen, a second shaft slidably positioned within the lumen of the first shaft, and a retention sheath coupled to the second shaft and configured to receive and constrain the funnel therein. A control assembly including an actuator is operably coupled to the first and second shafts. Movement of the actuator to a first position is configured to distally advance the first and second shafts together to deploy the funnel from the retention sheath. Movement of the actuator to a second position is configured to distally advance the first shaft relative to the second shaft such that first shaft and the retention sheath define a generally uniform (e.g., constant diameter) outer surface. In one aspect of the present technology, the generally uniform outer surface of the dilator assembly is unlikely to snag or otherwise damage the funnel or vessel as the dilator assembly is retracted through the introducer sheath. In another aspect of the present technology, the dilator assembly can be coupled to the introducer sheath to inhibit or even prevent unintentional, premature deployment of the funnel. 
     Although many of the embodiments are described below with respect to devices, systems, and methods for treating vascular thrombi (e.g., deep vein thrombosis (DVT)), other applications and other embodiments in addition to those described herein are within the scope of the technology (e.g., intravascular procedures other than the treatment of emboli, intravascular procedures for treating cerebral embolism, intravascular procedures for treating pulmonary embolism). In general, for example, the devices, systems, and methods of the present technology can be used to extract any formation of material in a vessel (e.g., a venous or arterial vessel), such as cancerous growths, vegetation, and the like. Additionally, several other embodiments of the technology can have different configurations, states, components, or procedures than those described herein. Moreover, it will be appreciated that specific elements, substructures, advantages, uses, and/or other features of the embodiments described with reference to  FIGS. 1-12K  can be suitably interchanged, substituted or otherwise configured with one another in accordance with additional embodiments of the present technology. Furthermore, suitable elements of the embodiments described with reference to  FIGS. 1-12K  can be used as standalone and/or self-contained devices. A person of ordinary skill in the art, therefore, will accordingly understand that the technology can have other embodiments with additional elements, or the technology can have other embodiments without several of the features shown and described below with reference to  FIGS. 1-12K . 
     With regard to the terms “distal” and “proximal” within this description, unless otherwise specified, the terms can reference a relative position of the portions of a catheter subsystem with reference to an operator and/or a location in the vasculature. Also, as used herein, the designations “rearward,” “forward,” “upward,” “downward,” and the like are not meant to limit the referenced component to use in a specific orientation. It will be appreciated that such designations refer to the orientation of the referenced component as illustrated in the Figures; the systems of the present technology can be used in any orientation suitable to the user. 
     The headings provided herein are for convenience only and should not be construed as limiting the subject matter disclosed. 
     I. SELECTED EMBODIMENTS OF THROMBECTOMY SYSTEMS 
       FIG. 1  is a side view of a thrombectomy system  100  (which can also be referred to as a thrombus extraction system, clot removal system) configured in accordance with an embodiment of the present technology. In the illustrated embodiment, the thrombectomy system  100  includes an introducer assembly  102 , an obturator or dilator assembly  104  (shown positioned within the introducer assembly  102 ), and a thrombus extraction assembly  106 . In general, the thrombectomy system  100  can be used to (i) access a portion of a blood vessel (e.g., a venous vessel of a human patient) containing a thrombus (e.g., clot material) and (ii) remove all or portions of that thrombus from the blood vessel. More specifically, for example, the introducer assembly  102  and the dilator assembly  104  can be partially advanced into the vasculature of the patient (e.g., a blood vessel or venous vessel of the patient). The dilator assembly  104  can be actuated to deploy a self-expanding funnel (e.g., as shown in  FIGS. 7A-7C ) and then removed from the introducer assembly  102 . Next, the thrombus extraction assembly  106  and an attached thrombus extraction device can be partially inserted through the introducer assembly  102  and deployed at and/or near the location of a thrombus for capturing the thrombus. Finally, the thrombus extraction assembly  106  and/or the introducer assembly  102  can be removed from the patient along with the captured thrombus. In some embodiments, the thrombectomy system  100  and/or methods of operating the thrombectomy system  100  to remove a thrombus from a patient can include some features the same as or similar to the thrombectomy systems described in detail in (i) U.S. Pat. No. 9,700,332, filed Sep. 16, 2016, and titled “INTRAVASCULAR TREATMENT OF VASCULAR OCCLUSION AND ASSOCIATED DEVICES, SYSTEMS, AND METHODS,” and/or (ii) U.S. Pat. No. 10,098,651, filed Apr. 26, 2017, and titled “DEVICES AND METHODS FOR TREATING VASCULAR OCCLUSION,” both of which are incorporated herein by reference in their entirety. 
     In the illustrated embodiment, the introducer assembly  102  includes an elongate sheath  112 , which can also be referred to as a shaft, catheter, and the like. The sheath  112  defines a lumen (obscured in  FIG. 1 ; e.g., identified as lumen  688  in  FIG. 6 ) and includes a proximal portion  113   a  and a distal portion  113   b . The proximal portion  113   a  can terminate at a proximal end, and the distal portion  113   b  can terminate at a distal end. The lumen of the sheath  112  is sized to slidably receive the dilator assembly  104  and the thrombus extraction assembly  106 . For example, the dilator assembly  104  is shown partially positioned within the sheath  112  in  FIG. 1 . The sheath  112  can be elastic and/or flexible and can have any suitable length and diameter. In some embodiments, the sheath  112  can have an outer diameter of at least 10 French, at least 12 French, at least 14 French, at least 18 French, at least 20 French, at least 22 French, at least 26 French, greater than 26 French, between 10 French and 26 French, between 14 French and 24 French, between 15 French and 21 French, between 16 French and 22 French, and/or any other or intermediate size. In some embodiments, the lumen of the sheath  112  can have an internal diameter of at least 2 French, at least 10 French, at least 14 French, at least 18 French, at least 20 French, at least 22 French, between 11 French and 12 French, between 10 French and 22 French, between 14 French and 21 French, between 16 French and 20 French, and/or any other or intermediate size. In some embodiments, the sheath  112  can include a radiopaque marker (not shown) positioned, for example, at the distal portion  113   b  thereof. 
     The introducer assembly  102  further includes a sealable hub  114  coupled to the proximal portion  113   a  of the sheath  112 . The sealable hub  114  is configured to allow access to the lumen of the sheath  112  and can be self-sealing and/or can comprise a self-sealing seal. For example, in the illustrated embodiment the sealable hub  114  is a hemostasis valve that is configured to maintain hemostasis during a thrombus extraction procedure by preventing fluid flow in the proximal direction through the sealable hub  114  as various components—such as portions of the dilator assembly  104  and/or the thrombus extraction assembly  106 —are inserted through the sealable hub  114  to be delivered through the sheath  112  to a treatment site in a blood vessel. More specifically, the sealable hub  114  can be a valve of the type disclosed in U.S. patent application Ser. No. 16/117,519, filed Aug. 30, 2018, and titled “HEMOSTASIS VALVES AND METHODS OF USE,” which is incorporated herein by reference in its entirety. The sealable hub  114  can include one or more buttons or actuators that enable an operator to selectively seal/unseal the sealable hub  114 . 
     The introducer assembly  102  can further include an aspiration port  116  connected to the sealable hub  114  (e.g., to a side port of the sealable hub  114 ) and/or the sheath  112  (e.g., to the proximal portion  113   a  of the sheath  112 ) via, for example, a connecting tube  118 . The aspiration port  116  can be connected to a syringe connector  117  that can be selectively coupled to a syringe or other aspiration device, or the aspiration port  116  can be connected to other suitable elements. In some embodiments, the introducer assembly  102  includes a fluid control device  119  configured to selectively fluidly connect the aspiration port  116  to the lumen of the sheath  112 . In the illustrated embodiment, the fluid control device  119  is a stopcock operably coupled to the connecting tube  118  between the lumen of the sheath  112  and the aspiration port  116 . In other embodiments, the fluid control device  119  can be a clamp or another suitable valve. 
     The dilator assembly  104  can include a control assembly  120  operably coupled to a retention sheath  122  via a first shaft (obscured in  FIG. 1 ; e.g., identified as first shaft  580  in  FIGS. 5A and 5B ). In the illustrated embodiment, the first shaft of the dilator assembly  104  extends through the sealable hub  114  and the sheath  112  such that the retention sheath  122  is positioned distal of the distal portion  113   b  of the sheath  112 . Moreover, the control assembly  120  is releasably coupled to (e.g., mated to, fixed to) the sealable hub  114 . Accordingly, the introducer assembly  102  can carry or hold the dilator assembly  104 . As described in greater detail below with reference to  FIGS. 5A-7D , the dilator assembly  104  (e.g., the retention sheath  122 ) is configured to (i) hold/constrain a self-expanding funnel (obscured in  FIG. 1 ; e.g., identified as funnel  690  in  FIG. 6 ) that is attached to the distal portion  113   b  of the sheath  112 , and (ii) release/deploy the self-expanding funnel. More specifically, for example, the control assembly  120  can include an actuator  124  that is movable (e.g., in the direction of arrow A in  FIG. 1 ) to advance the retention sheath  122  relative to the sheath  112  (and the self-expanding funnel) attached thereto to deploy/release the self-expanding funnel. 
     In some embodiments, the thrombectomy system  100  can further include a loading tool  108  (e.g., a loading funnel) for use in loading the self-expanding funnel into the dilator assembly  104  (e.g., into the retention sheath  122 ). In the illustrated embodiment, the loading tool  108  defines a lumen  127  therethrough and includes a first portion  126  of varying diameter (e.g., a tapered portion such as a funnel portion) and a second portion  128  of generally constant diameter (e.g., a shaft portion). In other embodiments, the second portion  128  can have a partially varying diameter. The first portion  126  is configured (e.g., sized and shaped) to receive the self-expanding funnel and to move the self-expanding funnel to the constrained configuration as the self-expanding funnel is advanced through the first portion  126 . The lumen  127  of the loading tool  108  can be sized to allow the retention sheath  122  to pass completely through the loading tool  108 . 
     In the illustrated embodiment, the thrombus extraction assembly  106  includes a catheter portion  130  and a handle portion  140  (“handle  140 ”) operably coupled to the catheter portion  130 . In operation, the handle  140  is configured to be actuated/manipulated by a user to control (e.g., deploy) one or more components of the catheter portion  130  and/or a thrombus extraction device (not shown in  FIG. 1 ; e.g., identified as thrombus extraction device  250  in  FIGS. 2A and 2B ) coupled to the catheter portion  130 . 
     In the illustrated embodiment the catheter portion  130  includes an outer shaft  132 , an intermediate shaft  133 , and an inner shaft  134  slidably and coaxially aligned relative to one another. For example, each of the shafts  132 - 134  can define a lumen (e.g., a central, axial lumen) and (i) the intermediate shaft  133  can be configured (e.g., sized and shaped) to slidably fit within the lumen of the outer shaft  132  and (ii) the inner shaft  134  can be configured to slidably fit within the lumen of the intermediate shaft  133 . In some embodiments, the outer shaft  132  is configured (e.g., sized) to slidably fit within the sheath  112  of the introducer assembly  102  and can have, for example, a size of at least 8 French, at least 10 French, at least 11 French, at least 12 French, at least 14 French, at least 16 French, between 8 French and 14 French, between 11 French and 12 French, and/or any other or intermediate size. By this arrangement, each of the shafts  132 - 134  can be displaced longitudinally relative to one another and relative to the sheath  112  of the introducer assembly  102 . In some embodiments, each of the shafts  132 - 134  can have the same length while, in other embodiments, one or more of the shafts  132 - 134  can have different lengths. For example, in some embodiments the intermediate shaft  133  can be longer than the outer shaft  132  and the inner shaft  134  can be longer than the intermediate shaft  133 . In other embodiments, the catheter portion  130  can comprise any number of shafts (e.g., catheters, sheaths) that are slidable relative to one another and/or configured to be positioned coaxially relative to one another. For example, in some embodiments the catheter portion can include three intermediate shafts as described in detail in U.S. Pat. No. 10,098,651, filed Apr. 26, 2017, and titled “DEVICES AND METHODS FOR TREATING VASCULAR OCCLUSION,” which is incorporated herein by reference in its entirety. 
     The handle  140  includes a proximal portion  141   a  (e.g., a plunger portion) and a distal portion  141   b  (e.g., a locking portion). In the illustrated embodiment, the intermediate shaft  133  is coupled to and extends distally from the distal portion  141   b  of the handle  140 . The distal portion  141   b  of the handle  140  can include a lock feature  142  such as, for example, a spinlock. The lock feature  142  is configured to selectively engage and/or lockingly engage with a mating feature  135  located near a proximal portion  136   a  of the outer shaft  132 . In some embodiments, the outer shaft  132  can slide proximally over the intermediate shaft  133  until the lock feature  142  engages with the mating feature  135  to thereby secure the position of the outer shaft  132  relative to the intermediate shaft  133 . In some embodiments, the intermediate shaft  133  is relatively longer than the outer shaft  132  such that a portion of the intermediate shaft  133  extends distally from a distal portion  136   b  of the outer shaft  132  when the outer shaft  132  is lockingly engaged with the lock feature  142 . 
     In the illustrated embodiment, the handle  140  further includes a plunger  144  (e.g., an actuator) operably coupled to the inner shaft  134  and movable between a first, non-extended position (e.g., as shown in  FIGS. 1 and 2A ) and a second, extended position (e.g., as shown in  FIG. 2B ). Thus, movement of the plunger  144  relative to the handle  140  displaces the inner shaft  134  relative to the handle  140 , the outer shaft  132 , and/or the intermediate shaft  133 . For example, withdrawing the plunger  144  proximally from the first position to the second position can withdraw the inner shaft  134  through the intermediate shaft  133 . In some embodiments, the inner shaft  134  can have a length such that the inner shaft  134  extends distally past a distal terminus of the intermediate shaft  133  when the plunger  144  is in both the first and second positions. In some embodiments, the plunger  144  can be lockable in the first position and/or the second position to lock the position of the inner shaft  134 . In other embodiments, the plunger  144  can be operably coupled to other components of the catheter portion  130  such as, for example, the intermediate shaft  133  and/or one or more additional shafts (not shown). 
     In the illustrated embodiment, the thrombus extraction assembly  106  further includes a first flush port  138  connected to the outer shaft  132  and a second flush port  148  connected to the handle  140 . The first flush port  138  can be fluidly connected to the lumen of the outer shaft  132  to allow flushing of the lumen of the outer shaft  132 . The second flush port  148  can be fluidly connected to the lumen of the intermediate shaft  133  (e.g., via an internal portion of the handle  140 ) to allow flushing of the lumen of the intermediate shaft  133 . 
     The thrombus extraction assembly  106  can include and/or be coupled to a thrombus extraction device configured to core and capture a thrombus from the patient.  FIGS. 2A and 2B , for example, are side views of the thrombus extraction assembly  106  of  FIG. 1  operably coupled to a thrombus extraction device  250  configured in accordance with embodiments of the present technology. The thrombus extraction device  250  is shown in a deployed and partially-expanded configuration in  FIG. 2A  and a deployed and fully-expanded configuration in  FIG. 2B . The thrombus extraction device  250  can be in an undeployed, constrained (e.g., unexpanded) position when positioned within the outer shaft  132 . 
     Referring to  FIGS. 2A and 2B  together, the thrombus extraction device  250  includes an expandable coring element  252  and an expandable capture element  254  coupled to (e.g., attached to, connected to, integrally formed with) the coring element  252 . The coring element  252  is positioned proximal of the capture element  254 . In the illustrated embodiment, the coring element  252  includes (i) a proximal portion  253   a  coupled to the intermediate shaft  133  (e.g., to a distal portion of the intermediate shaft  133 ) and (ii) a distal portion  253   b  coupled to a proximal portion  255   a  of the capture element  254 . Further, a distal portion  255   b  of the capture element  254  is coupled to the inner shaft  134  (e.g., to a distal portion of the inner shaft  134 ). As shown, the outer shaft  132  is proximally displaced relative to the handle  140  such that the mating feature  135  of the outer shaft  132  contacts/engages the lock feature  142  of the handle  140 . Due to this positioning of the outer shaft  132  relative to the handle  140 , each of the intermediate shaft  133 , the inner shaft  134 , and the thrombus extraction device  250  extend distally beyond the distal portion  136   b  of the outer shaft  132 . 
     In some embodiments, the thrombus extraction device  250  can further include an atraumatic tip  258 . In some embodiments, the atraumatic tip  258  can include a radiopaque marker to aid in intravascularly positioning the thrombus extraction device  250  within the patient. The thrombus extraction device  250  can additionally or alternatively include one or more radiopaque markers located on, for example, the outer shaft  132  (e.g., the distal portion  136   b  of the outer shaft  132 ) the intermediate shaft  133  (e.g., the distal portion of the intermediate shaft  133 ), and or other components of the thrombus extraction device  250 . In some embodiments, the atraumatic tip  258  can define a channel configured to receive a guidewire therethrough. 
     In the partially-expanded configuration shown in  FIG. 2A , the plunger  144  of the handle  140  is in the first position. In contrast, in the fully-expanded configuration shown in  FIG. 2B , the plunger  144  is in the second position (e.g., proximally retracted away from the handle  140 ) such that the inner shaft  134  is proximally retracted relative to the intermediate shaft  133 . This proximal retraction of the inner shaft  134  relative to the intermediate shaft  133  forces the coring element and capture element  254  to fully expand, as described in greater detail below with reference to  FIG. 4 . 
     The thrombus extraction assembly  106  can comprise one or several features configured to secure the thrombus extraction device  250 , and specifically the coring element  252  and/or the expandable capture element  254  in the fully-expanded position. As used herein, full expansion describes a condition in which the thrombus extraction device  250  is continually biased toward expansion by one or several forces in addition to the self-expanding forces arising from the thrombus extraction device  250 . In some embodiments, full expansion occurs when the thrombus extraction device  250  is deployed and when the plunger  144  is in the second position (e.g., when the inner shaft  134  is proximally retracted relative to the intermediate shaft  133 ). Alternatively or additionally, full-expansion can occur when the thrombus extraction device  250  is deployed and biased towards expansion via a spring connected either directly or indirectly to the thrombus extraction device  250 . Accordingly, when the thrombus extraction device  250  is fully expanded, forces less than a minimal radial compressive force do not change the diameter of the thrombus extraction device  250 . Therefore, when fully-expanded, the thrombus extraction device  250  can maintain at least a desired radial force on a blood vessel when the thrombus extraction device  250  is drawn through that blood vessel. In some embodiments, the dimensions of the thrombus extraction device  250  can be selected such that the thrombus extraction device  250  apposes a wall of the blood vessel and/or applies a desired force to the wall of the blood vessel when fully expanded. 
     In some embodiments, the plunger  144  can be locked in the second position by, for example, rotating the plunger  144  with respect to the handle  140  to thereby engage one or several locking features on the plunger  144  and/or in the handle  140 . Locking the plunger  144  in the second position secures the position of the inner shaft  134  relative to the intermediate shaft  133 , thereby securing the thrombus extraction device  250  in the fully-expanded position. In other embodiments, the inner shaft  134  and the intermediate shaft  133  can be directly locked together via for example, (i) a static coupling in which the position of the inner shaft  134  is fixed relative to the position of the intermediate shaft  133  or (ii) a dynamic coupling in which the position of the inner shaft  134  relative to the intermediate shaft  133  is limited (rather than fixed). For example, the inner shaft  134  can be dynamically locked to the plunger  144  via a compliance spring (e.g., a tension spring, compression spring), which allows limited movement of the inner shaft  134  relative to the intermediate shaft  133  when the plunger  144  is locked in the second position. 
     II. SELECTED EMBODIMENTS OF CORING ELEMENTS 
       FIGS. 3A-3D  are an isometric view, a side view, a top view, and a (proximally-facing) rear view, respectively, of the coring element  252  of the thrombus extraction device  250  of  FIGS. 2A and 2B  configured in accordance with embodiments of the present technology. Referring to  FIGS. 3A-3D  together, the coring element  252  comprises a plurality of struts  360  that together define a plurality of interstices or pores  362 . The struts  360  can have a variety of shapes and sizes and, in some embodiments, the struts  360  can have a thickness and/or diameter between about 0.05-0.15 inch, between about 0.075-0.125 inch, between about 0.09-0.1 inch, about 0.096 inch, and/or other dimensions. In general, the struts  360  can together form a unitary fenestrated structure that is configured to core and separate a portion of a thrombus (e.g., a vascular thrombus) from a blood vessel containing the thrombus. In some embodiments, the coring element  252  can comprise a stent or stent-like device. 
     As best shown in  FIGS. 3B and 3C , the coring element  252  includes a first region  363  including the proximal portion  253   a , a second region  364  distal of the first region  363 , a third region  365  distal of the second region  364 , and a fourth region  366  distal of the third region  365  and including the distal portion  253   b . The second region  364  and the fourth region  366  can be generally tubular. The first region  363  and the third region  365  have relatively fewer of the struts  360  compared to the second region  364  and the fourth region  366 . For example, the first region  363  can include a pair of curved struts  367  (identified individually as first strut  367   a  and second strut  367   a  as best shown in  FIGS. 3A and 3C ) that curve in opposite directions around a central axis L of the coring element  252  and intersect and/or terminate at a pair of first junctions  361  (identified individually as a lower first junction  361   a  and an upper first junction  361   b ) to define a proximal, first mouth  370 . The third region  365  can include (i) a pair of curved lower struts  368  (identified individually as a first lower strut  368   a  and a second lower strut  368   b  shown together in  FIG. 3A ) that extend distally from a lower second junction  371   a  and curve around the central axis L and (ii) a pair of curved upper struts  369  (identified individually as a first upper strut  369   a  and a second upper strut  369   b  shown together in  FIGS. 3A and 3C ) that extend distally from an upper second junction  371   b  and curve around the central axis L. The lower and upper struts  368 ,  369  together define a distal first mouth portion  372   a  and a distal second mouth portion  372   b  (collectively “a second mouth  372 ”). In the illustrated embodiment, the first mouth portion  372   a  is rotationally offset from the second mouth portion  372   b . In other embodiments, the first mouth portion  372   a  can be positioned differently relative to the second mouth portion  372   b  (e.g., in a different rotational and/or longitudinal direction) and/or the second mouth  372  can comprise more than two separate portions (e.g., three, four, or more openings). In general, the first and second mouths  370 ,  372  can be defined by/in regions of the coring element  252  having different porosities. 
     In some embodiments, the coring element  252  is made from a shape memory material such as a shape memory alloy and/or a shape memory polymer. For example, the coring element  252  can comprise nitinol and/or a nitinol alloy. Similarly, the coring element  252  can be made using a variety of techniques including welding, laser welding, cutting, laser cutting, and/or expanding. For example, the coring element  252  can first be laser cut from a piece of nitinol (e.g., a nitinol tube) and then blown up and/or expanded. In general, the size (e.g., the length and diameter) of the coring element  252  can be selected based on the size (e.g., diameter) of the blood vessel from which thrombus is to be extracted. In some embodiments, the coring element  252  can have a length M of between about 0.2-5 inches (e.g., between about 1.5-2.5 inches, between about 1.75-2.25 inches, between about 1.9-2.0 inches, between about 1.5-1.8 inches, about 1.6 inches, about 1.7 inches, about 1.96 inches, about 3.0 inches, about 4.0 inches, smaller than 0.5 inch). In some embodiments, in the fully-expanded position unconstrained within a vessel, the coring element  252  can have a diameter D of between about 2-50 mm (e.g., between about 4-25 mm, between about 6 20 mm, between about 8-16 mm). In some embodiments, the length M of the coring element  252  can be selected based on the fully expanded and unconstrained diameter D of the coring element  252  to prevent undesired tipping and/or rotation of the coring element  252  within the blood vessel during operation. In general, the length M and the unconstrained diameter D of the coring element  252  will vary depending on the size of the vessel the coring element  252  is designed for. For example, the coring element  252  will generally have a smaller length M and diameter D when designed for smaller (e.g., 4 mm) vessels rather than larger (e.g., 25-35 mm) vessels. 
     The coring element  252  is configured to core (e.g., shear, separate) thrombus from within the blood vessel when the coring element is advanced/retracted through the thrombus in the fully-expanded configuration. For example, as described in greater detail below with reference to  FIGS. 12D-12K , the coring element  252  can be withdrawn proximally through the thrombus to core the thrombus. As the coring element  252  is withdrawn through the thrombus the fully-expanded diameter of the coring element  252  will flexibly adapt to match the diameter of the blood vessel. More particularly, the first and second mouths  370 ,  372  are configured (e.g., sized, shaped, and/or positioned) to provide most of the coring function (e.g., coring force) during operation of the coring element  252 . For example, proximally-facing surfaces of the struts  367  can define a first leading edge that cuts through and cores the thrombus. Similarly, proximally-facing surfaces of the lower and upper struts  368 ,  369  can define a second leading edge that can also cut through and core the thrombus. In some embodiments, portions of the struts  367 , the lower struts  368 , and/or the upper struts  369  can be sharpened and/or can include a cutting element (e.g., a knife or knife edge) attached thereto or otherwise integrated with to further facilitate coring of the thrombus. 
     In one aspect of the present technology, the first mouth  370  and the second mouth  372  are longitudinally offset relative to one another. Moreover, the leading edges of the struts  367  and the leading edges of the lower and upper struts  368 ,  369  are oriented differently such that, for example, the first mouth  370  and the second mouth  372  are oriented at different angles when the coring element  252  is within the blood vessel. The arrangement can be more effective at coring thrombus compared to, for example, coring elements including only a single mouth (e.g., including only the first mouth  370 ). It is expected that the coring element  252  provides a greater coring length for engaging the wall of the blood vessel and coring (e.g., adherent) thrombus than coring elements with only a single mouth. Moreover, the coring element  252  can be relatively flexible at the first region  363  and third region  365  which include fewer struts  360  than the second region  364  and fourth region  366 . For example, the coring element  252  can flex/bend at the first junctions  361  and/or the second junctions  371 . In some embodiments, the first and second junctions  361 ,  371  enable the coring element  252  to flex in different directions (e.g., laterally and vertically). In one aspect of the present technology, this ability of the coring element  252  to flex can allow the coring element  252  to maintain a selected orientation—even when moved through tortuous vessels. In another aspect of the present technology, the arrangement of the first and second mouths  370  and  372  ensures that at least one of the first mouth  370 , the first mouth portion  372   a , and the second mouth portion  372   b  is positioned and oriented to effectively core thrombus from within the blood vessel during a thrombus extraction procedure using the coring element  252 . In some embodiments, the first mouth  370  and/or the second mouth  372  can further facilitate the collapse of the coring element  252  to the non-expanded configuration. 
     In the embodiment illustrated in  FIGS. 3A-3D , a first connection feature  374  and a second connection feature  376  are coupled to the coring element  252 . As described in greater detail below with reference to  FIG. 4 , the intermediate shaft  133  ( FIG. 1 ) can be operably coupled to the first connection feature  374  and the inner shaft  134  can be operably coupled to the second connection feature  376  for controlling operation (e.g., movement and expansion) of the coring element  252 . In the illustrated embodiment, the first connection feature  374  is a ring coupled to the proximal portion  253   a  of the coring element  252  and, more specifically, to the lower first junction  361   a . In other embodiments, the first connection feature  374  can be positioned on a different portion of the coring element  252  (e.g., at the upper first junction  361   b , on one of the struts  367 ). Similarly, the second connection feature  376  can also be a ring and can be coupled to one or more of the struts  360  in the second region  364  or another region of the coring element  252 . As best seen in  FIG. 3D , in some embodiments the first connection feature  374  can have a diameter E 1  that is greater than a diameter E 2  of the second connection feature  376 , and the first and second connection features  374 ,  376  can be axially aligned along an axis extending parallel to the central axis L of the coring element  252 . In other embodiments, the first and second connection features  374 ,  376  can have other shapes and/or configurations and/or can be arranged differently relative to one another. The first and second connection features  374 ,  376  can be the same material as the coring element  252  or can be a different material than the coring element  252 . Likewise, the first and second connection features  374 ,  376  can be integrally formed with the coring element  252  and/or can be attached to the coring element  252  via, for example, one or more of welds, adhesives, mechanical fasteners, and the like. 
       FIG. 4  is an enlarged side view of the thrombus extraction device  250  coupled to a distal portion of the thrombus extraction assembly  106  and in the fully-expanded configuration in accordance with an embodiment of the present technology. In the illustrated embodiment, the coring element  252  is coupled to the intermediate shaft  133  (e.g., to a distal portion of the intermediate shaft  133 ) via the first connection feature  374 . In some embodiments, the coring element  252  is fixedly coupled to the intermediate shaft  133  such that movement of the intermediate shaft  133  also moves the coring element  252 . The proximal portion  255   a  of the capture element  254  is connected to the distal portion  253   b  of the coring element  252 . In some embodiments, the capture element  254  is formed on the distal portion  253   b  of the coring element  252  such that the thrombus extraction device  250  is a unitary/integral structure. For example, the capture element  254  can comprise a mesh (e.g., a braided filament mesh structure) that is woven onto the distal portion  253   b  of the coring element  252 . In some embodiments, the distal portion  255   b  of the capture element  254  is coupled to the to the inner shaft  134  (e.g., to a distal portion of the inner shaft  134 ). 
     In the illustrated embodiment, the inner shaft  134  slidably extends through the second connection feature  376 . That is, the inner shaft  134  can have an outer diameter that is less than the diameter E 2  ( FIG. 4 ) of the second connection feature  376  such that the second connection feature  376  is slidable along the inner shaft  134 . The inner shaft  134  can include a stop feature  478  configured to engage the second connection feature  376  of the coring element  252  to effect expansion of the coring element  252 . In some embodiments, the stop feature  478  can comprise a polymeric member and/or a metallic member that is affixed to a portion of the inner shaft  134  that is distal of the second connection feature  376 . 
     The stop feature  478  is configured (e.g., sized and shaped) to contact and engage the second connection feature  376  when the inner shaft  134  is withdrawn proximally relative to the coring element  252  via, for example, movement of the plunger  144  ( FIGS. 1-3 ) from the first position to the second position. By this arrangement, the coring element  252  is selectively coupled to the inner shaft  134  such that the stop feature  478  can apply a proximally-directed force to the coring element  252  that can expand all or a portion of the coring element  252  to the fully-expanded configuration. For example, movement of the inner shaft  134  can forcibly expand at least the first region  363  ( FIGS. 3B and 3C ) of the coring element which is between the first and second connection features  374 ,  376 . In some embodiments, the second connection feature  376  can be positioned differently with respect to the coring element  252  such that more or less of the coring element  252  is forcibly expanded when the stop feature  478  is pulled against the second connection feature  376 . 
     In some embodiments, the capture element  254  can comprise a braided filament mesh structure, such as a braid of elastic filaments having a generally tubular, elongated portion  477  and a distal tapered portion  479 . In other embodiments, the capture element  254  can be any porous structure and/or can have other suitable shapes, sizes, and configurations. Because the distal portion  255   b  of the capture element  254  is coupled to the inner shaft  134 , axial movement of the inner shaft  134  expands/shortens and collapses/lengthens the capture element  254 . For example, proximal movement of the inner shaft  134  can compress the capture element  254  along its longitudinal axis such that (i) a radius of the capture element  254  increases and (ii) the length of the capture element  254  decreases. Conversely, distal movement of the inner shaft  134  can stretch the capture element  254  along its longitudinal axis such that (i) the radius of the capture element  254  decreases and (ii) the length of the capture element  254  increases. In some embodiments, with reference to  FIGS. 2A, 2B, and 4  together, distal movement of the plunger  144  can move the capture element  252  to a fully-collapsed position before the plunger  144  reaches the fully-depressed first position shown in  FIG. 2A . Thus, continued distal movement of the plunger  144  (e.g., from the second position toward the first position) can pull the coring element  252  to cause the coring element  252  to collapse/longitudinally extend. That is, the plunger  144 , the inner shaft  134 , and the capture element  254  can collectively act to elongate/collapse the coring element  252  as the plunger  144  is distally depressed while the capture element  254  is fully collapsed. In other embodiments, the inner shaft  134  can be selectively decoupled from the capture element  254  such that proximal displacement of the inner shaft  134  expands the coring element  252  without effecting any movement of the capture element  254 . In some embodiments, the capture element  254  can have a length (i) in the collapsed configuration of between about 5-30 inches (e.g., between about 10-20 inches, about 16 inches) and (ii) in the expanded configuration of between about 1-25 inches (e.g., between about 10-20 inches, about 11 inches). 
     In some embodiments, the capture element  254  can be formed by a braiding machine and/or a weaving machine while, in other embodiments, the capture element  254  can be manually braided and/or woven. In some embodiments, the capture element  254  is formed as a tubular braid and is then further shaped using a heat setting process. The braid can be a tubular braid of fine metal wires such as nitinol (nickel-titanium alloy), platinum, cobalt-chrome alloy, stainless steel, tungsten or titanium. In some embodiments, the capture element  254  can be formed at least in part from a cylindrical braid of elastic filaments. Thus, the braid may be radially constrained without plastic deformation such that it can self-expand on release of the radial constraint. Such a braid of elastic filaments can be referred to herein as a “self-expanding braid.” In some embodiments, the thickness of the braid filaments can be less than about 0.15 mm. In some embodiments, the braid may be fabricated from filaments and/or wires with diameters ranging from about 0.05-0.25 mm. In some embodiments, braid filaments of different diameters may be combined to impart different characteristics including: stiffness, elasticity, structure, radial force, pore size, embolic capturing or filtering ability, and so on. In some embodiments the capture element  254  and/or the coring element  252  can be coated to reduce their surface friction/abrasiveness (e.g., for arterial applications). Likewise, the capture element  254  and/or the coring element  252  can be covered with a film (e.g., via dipping or spray coating) to create a non-permeable membrane to contain clot without allowing the clot to become embedded in the interstices of the capture element  254  and/or the coring element  252 , thereby facilitating ease of cleaning. In some embodiments, the number of filaments used to form the capture element  254  can be between about 20-300 (e.g., including 144 filaments, 244 filaments). In some embodiments, the size of the pores formed by the capture element  254  (e.g., in the elongated portion  477 ) can be between about 0.05-4.0 mm (e.g., between about 0.5 mm-2.5 mm, less than 0.4 mm). 
     III. SELECTED EMBODIMENTS OF DILATOR ASSEMBLIES AND ASSOCIATED METHODS 
       FIGS. 5A and 5B  are side views of the dilator assembly  104  of  FIG. 1  in a first configuration and a second configuration, respectively, configured in accordance with embodiments of the present technology. Referring to  FIGS. 5A and 5B  together, the dilator assembly  104  includes a first shaft or sheath  580  extending between and operably coupling the control assembly  120  and the retention sheath  122 . The dilator assembly  104  can further include a second shaft or sheath  582  slidably positioned over the first shaft  580  and operably coupled to the control assembly  120 . Put differently, the second shaft  582  can define a lumen sized to slidably receive the first shaft  580  such that the first and second shafts  580 ,  582  are axially displaceable relative to one another. In the illustrated embodiment, the first shaft  580  is longer than the second shaft  582  such that the retention sheath  122  is positioned distal of a distal portion  583   b  (opposite a proximal portion  583   a ) of the second shaft  582 . The control assembly  120  further includes a housing  595  configured to engage (e.g., mate with) the sealable hub  114  of the introducer assembly  102  ( FIG. 1 ). 
     The retention sheath  122  includes a proximal portion  585   a  and a distal portion  585   b . In the illustrated embodiment, the distal portion  585   a  includes an atraumatic tip  584  and the proximal portion  585   a  includes a first engagement feature  586 . Similarly, the distal portion  583   b  of the second shaft  582  includes a second engagement feature  589 . In some embodiments, the atraumatic tip  584  is radiopaque. 
     When the dilator assembly  104  is in the first configuration shown in  FIG. 5A , the second shaft  582  is proximally positioned (e.g., withdrawn) relative to the first shaft  580  such that the first engagement feature  586  does not engage the second engagement feature  589 . As described in greater detail below with reference to  FIG. 7A , when the dilator assembly  104  is in the first configuration, the first engagement feature  586  is configured to engage (e.g., connect with, mate with) the distal portion  113   b  of the sheath  112  of the introducer assembly  102  ( FIG. 1 ). In some embodiments, the engagement of the first engagement feature  586  with the sheath  112  can form a seal. 
     When the dilator assembly  104  is in the second configuration ( FIG. 5B ), the second engagement feature  589  of the second shaft  582  is configured to engage the first engagement feature  586  of the retention sheath  122 . As shown, the second shaft  582  can have a diameter that is equal to or substantially equal to the outer diameter of the retention sheath  122  such that the dilator assembly  104  has a uniform or substantially uniform (e.g., smooth) outer surface in the second configuration. That is, there is no step or discontinuity in the outer surface between, for example, the first shaft  580  and the retention sheath  122 . In other embodiments, the second shaft  582  and the retention sheath  122  can have different diameters, and the first and second engagement features  586 ,  589  can be configured to provide a smooth transition between the second shaft  582  and the retention sheath  122 . In some embodiments, the engagement of the first engagement feature  586  with the second engagement feature  589  can form a seal. In some embodiments, the operator can move the dilator assembly  104  from the first configuration to the second configuration by actuating the actuator  124  of the control assembly  120  (e.g., by advancing the actuator  124  in the direction of arrows A). More specifically, as described in greater detail below with reference to  FIGS. 7A-7D , actuation of the actuator  124  can distally advance (i) the first and second shafts  580 ,  582  together relative to the sheath  112  and then (ii) the second shaft  582  relative to the first shaft  580 . 
       FIG. 6  is an enlarged cross-sectional side view of a portion of the thrombectomy system  100  shown in  FIG. 1 . More particularly,  FIG. 6  shows a self-expanding funnel  690  coupled to the distal portion  113   b  of the sheath  112  of the introducer assembly  102  and restrained within the retention sheath  122  of the dilator assembly  104  in accordance with an embodiment of the present technology. In the illustrated embodiment, the retention sheath  122  includes a shell portion  692  coupled to the tip  584  and defining a lumen  693 . In some embodiments, the shell portion  692  and the tip  584  are integrally formed together while, in other embodiments, the tip  584  can be a separate component that is coupled to the shell portion  692  by, for example, positioning at least a portion of the tip  584  in the lumen  693  and securing the shell portion  692  to the tip  584  (e.g., via an adhesive, friction fit). 
     The first shaft  580  of the dilator assembly  104  extends through a lumen  688  of the sheath  112  and at least partially through the lumen  693  of the shell portion  692 . In the illustrated embodiment, a portion of the tip  584  snuggly receives a distal portion (e.g., a distal portion) of the first shaft  580  to secure the first shaft  580  to the retention sheath  122 . In other embodiments, the first shaft  580  can be coupled to the retention sheath  122  in other manners. As further shown in  FIG. 6 , the first shaft  580  and the tip  584  can define a continuous lumen  691  for receiving a guidewire (not shown). In some embodiments, the guidewire can have a diameter of about 0.038 inch, 0.035 inch, about 0.018 inch, 0.014 inch, greater than about 0.38 inch, less than about 0.1 inch, or less than about 0.05 inch. 
     In the illustrated embodiment, an inner diameter F 1  of the shell portion  692  is greater than an external diameter F 2  of the first shaft  580  such that an annular retaining/receiving space  694  is formed between the outer surface of the first shaft  580  and the inner surface of the shell portion  692 . The receiving space  694  is configured (e.g., sized and shaped) to receive and/or retain the funnel  690  in a constrained configuration. Accordingly, in some embodiments the funnel  690  can have a diameter substantially matching the inner diameter F 1  of the shell portion  692  when the funnel  690  is in the constrained configuration. In some embodiments, the first engagement feature  586  of the retention sheath  122  can engage (e.g., sealingly engage) the distal portion  113   b  of the sheath  112  when the funnel  690  is retained within the retention sheath  122 . 
       FIGS. 7A-7D  are side views illustrating various stages in a process or method for deploying the funnel  690  in accordance with embodiments of the present technology. Referring first to  FIG. 7A , the dilator assembly  104  is initially positioned within the introducer assembly  102  in the first configuration ( FIG. 5A ) such that (i) the housing  595  of the control assembly  120  is coupled to/engages the sealable hub  114  and (ii) the first engagement feature  586  of the retention sheath  122  sealingly engages the distal portion  113   b  of the sheath  112 . In other embodiments, the first engagement feature  586  need not sealingly engage the sheath  112 . In the initial position shown in  FIG. 7A , the actuator  124  of the control assembly  120  is in a first position (e.g., a fully-retracted position) and the funnel  690  is contained in the constrained configuration within the retention sheath  122 , as shown in  FIG. 6 . 
     In the arrangement shown in  FIG. 7A , the introducer assembly  102  and the dilator assembly  104  (collectively “assemblies  102 ,  104 ”) can be used to percutaneously access a venous vessel of a patient through, for example an access site such as a popliteal access site, a femoral access site, an internal jugular access site, and/or other access site. In some embodiments, the assemblies  102 ,  104  are inserted through another introducer sheath (not shown). In some embodiments, the assemblies  102 ,  104  are advanced within the venous vessel to a treatment position in which the distal portion  113   b  of the sheath  112  is proximate to (e.g., proximal of) a thrombus in the venous vessel. 
     Referring to  FIG. 7B , after positioning the assemblies  102 ,  104 , the funnel  690  (shown as transparent in  FIGS. 7B and 7C  for the sake of clarity) can be deployed by, for example, moving the actuator  124  from the first position ( FIG. 7B ) to a second position (e.g., an intermediate position, a mid-stroke position, a drop-off position) to distally advance the first and second shafts  580 ,  582  together relative to the sheath  112 . The distal advancement of the first shaft  580  causes the retention sheath  122  to move distally over and away from the funnel  690 . The funnel  690  self-expands to an expanded (e.g., unconstrained) configuration when the funnel  690  is no longer constrained by the retention sheath  122 . In other embodiments, the control assembly  120  is configured such that moving the actuator  124  from the first position to the second position distally advances only the first shaft  580  of the dilator assembly  104  rather than both the first and second shafts  580 ,  582  together. 
     The funnel  690  can comprise a variety of shapes and sizes and can be made from a variety of materials. In some embodiments, in the expanded configuration, the funnel  690  can have (i) a maximum diameter greater than and/or equal to the diameter D of the coring element  252  ( FIGS. 3B and 3C ) when the coring element  252  is in the fully-expanded configuration and (ii) a minimum diameter substantially equal to an outer diameter of the sheath  112 . In some embodiments, the funnel  690  can have a length N that is greater than and/or equal to the length M of the coring element  252  ( FIGS. 3A-3D ) such that the coring element  252  can be received and contained within the funnel  690 . In other embodiments, the length N of the funnel  690  can be less than the length M of the coring element  252 . In some embodiments, the funnel  690  can have a conically shaped portion, and specifically, a truncated-conically shaped portion. In some embodiments, the funnel  690  can be formed from at least one of a castellated nitinol braid, a nitinol braided stent, a laser cut nitinol, a laser cut polymer tube, an injection molded polymeric structure, or an inflatable balloon. In some embodiments, the funnel  690  can comprise a mesh having a pore size sufficiently small to prevent the passage of thrombus through the pores of the mesh. In some embodiments, the funnel  690  can be permeable to blood. 
     Referring to  FIG. 7C , after the funnel  690  has been deployed, the dilator assembly  104  can be moved to the second configuration ( FIG. 5B ). For example, the operator can move the actuator  124  of the control assembly  120  from the second position ( FIG. 7B ) to a third position (e.g., a fully-advanced position) to distally advance the second shaft  582  relative to the first shaft  580  until the second engagement feature  589  of the second shaft  582  engages the first engagement feature  586  of the retention sheath  122 . As shown in  FIG. 7D , after moving the dilator assembly  104  to the second configuration, the dilator assembly  104  can be fully retracted and withdrawn from the introducer assembly  102 . For example, the dilator assembly  104  can be proximally retracted through the lumen of the sheath  112  and out of the sealable hub  114  of the introducer assembly  102 . 
     Referring to  FIGS. 7A-7D  together, in one aspect of the present technology, moving the dilator assembly  104  to the second configuration before retracting the dilator assembly  104  from the introducer assembly  102  can inhibit or even prevent the dilator assembly  104  from damaging the funnel  690  or other components of the introducer assembly  102  during retraction of the dilator assembly  104 . More specifically, if the dilator assembly  104  did not include the second shaft  582 , proximal retraction of the retention sheath  122  into the sheath  112  could cause the retention sheath  122  (e.g., the first engagement feature  586 ) to snag or damage the deployed funnel  690 . However, because the second shaft  582  has a diameter that is equal to or substantially equal to the outer diameter of the retention sheath  122 , the dilator assembly  104  has a uniform or substantially uniform (e.g., smooth) outer surface in the second configuration, and is therefore less likely to snag or otherwise damage the funnel  690 , the sealable hub  114 , and/or other components of the introducer assembly  102  during retraction. In other embodiments, the second shaft  582  and the retention sheath  122  can have different diameters, and the first and second engagement features  586 ,  589  can be configured to provide a smooth transition between the second shaft  582  and the retention sheath  122 . 
     In another aspect of the present technology, the movement of the actuator  124  from the first position to the third position both (i) advances the first and second shafts  580 ,  582  together to deploy the funnel  690  (e.g., as the actuator  124  moves from the first position to the second position) and (ii) advances the second shaft  582  relative to the first shaft  580  (e.g., as the actuator  124  moves from the second position to the third position) so that the dilator assembly  104  has a generally uniform outer diameter. This “dual-action” allows the control assembly  120  to be coupled to the sealable hub  114  during both the deployment of the funnel  690  and the advancement of the second shaft  582  toward the first shaft  580 . This can advantageously inhibit or prevent the inadvertent advancement of the retention sheath  122  and therefore the premature deployment of the funnel  690 . For example, the dilator assembly  104  and the introducer assembly  102  must often be fully removed from the patient for reloading of the funnel  690  if the funnel  690  is prematurely deployed—potentially increasing the trauma to the patient and the duration of the thrombectomy procedure. In contrast, some conventional dilator assemblies include a dilator that is “floating” (e.g., not locked to or engaged with an introducer assembly) such that an inadvertent bump or other force on the dilator assembly can cause corresponding movement of the dilator assembly. 
       FIGS. 8A, 8C, and 8D  are cross-sectional side views, and  FIG. 8B  is an enlarged cross-sectional isometric view, of the control assembly  120  configured in accordance with embodiments of the present technology. In  FIGS. 8A and 8B  the actuator  124  is in the first position shown in  FIG. 7A , in  FIG. 8C  the actuator  124  is in the second position shown in  FIG. 7B , and in  FIG. 8D  the actuator  124  is in the third position shown in  FIG. 7C . 
     Referring first to  FIG. 8A , the control assembly  120  includes a proximal portion  801   a  and a distal portion  801   b  and defines a lumen  802  extending therethrough between the proximal and distal portions  801   a, b . In the illustrated embodiment, the control assembly  120  includes a sealable member  804  at or proximate the proximal portion  801   a  and a connection portion  806  at or proximate the distal portion  801   b . The sealable member  804  can be configured to selectively seal the lumen  802  of the control assembly  120  and, in some embodiments, can receive a guidewire (not shown) therethrough. The connection portion  806  is configured to mate/engage with the sealable hub  114  of the introducer assembly  102  to secure the control assembly  120  thereto, as described in detail above with reference to  FIGS. 7A-7C . For example, in some embodiments the connection portion  806  can include a snap feature (e.g., having one or more teeth, flanges), a twist lock (e.g., a bayonet- or luer-type fitting), and/or other feature for engaging and/or locking to the sealable hub  114 . 
     Referring to  FIGS. 8A and 8B  together, in the illustrated embodiment the control assembly  120  further includes a first shaft hub  810  and a second shaft hub  850 . The first shaft hub  810  is configured to be coupled to the first shaft  580  of the dilator assembly  104 , and the second shaft hub  850  is configured to be coupled to the second shaft  582  of the dilator assembly  104 . The first and second shafts  580 ,  582  are not shown in  FIGS. 8A-8D  for the sake of clarity. In the illustrated embodiment, the second shaft hub  850  is connected to (e.g., integrally formed with) the actuator  124 , which extends outside the housing  595  and is configured to be advanced distally and/or retracted proximally by the operator. The first shaft hub  810  includes a first body portion  812  and one or more first engagement or snap features  814  (only one first engagement feature  814  is visible in  FIGS. 8A-8D ) that extend radially and/or axially away from the first body portion  812  and into a corresponding first track  830  formed in the housing  595 . The second shaft hub  850  similarly includes a second body portion  852  and second engagement or snap features  854  (e.g., a pair of similar or identical second engagement features  854 ) that extend radially and/or axially away from the second body portion  852  and into a corresponding second track  840  formed in the housing  595 . 
     In the illustrated embodiment, the first track  830  includes one or more proximal detents  832  (obscured in  FIGS. 8A and 8B ; shown in  FIG. 8C ), one or more distal detents  834 , and a distal terminus  835 . In some embodiments, the first track  830  can include a pair of opposing (e.g., radially opposite) proximal detents  832  and a pair of opposing distal detents  834 . The second track  840  includes a first portion  842  having a first track width or height G 1  ( FIG. 8A ) and a second portion  844  having a second track width or height G 2  ( FIG. 8A ) greater than the first track width G 1 . In some embodiments, the transition (e.g., a slope or step) between the first and second portions  842 ,  844  of the second track  840  is generally aligned over and/or proximate to the distal detents  834  of the first tack  830 . 
     In operation, the first and second shaft hubs  810 ,  850  are configured to slide within the lumen  802  along the first and second tracks  830 ,  840 , respectively. In some embodiments, the first engagement features  814  and/or the second engagement features  854  are flexible such that they can flex/bend as the first and second shaft hubs  810 ,  850  move along the first and second tracks  830 ,  840 . The configuration/arrangement of the first and second shaft hubs  810 ,  850  and the first and second tracks  830 ,  840 —for example, the arrangement of the proximal and distal detents  832 ,  834 , the first portion  842 , and/or the second portion  844 —can facilitate the movement of the dilator assembly  104  from the first configuration ( FIG. 5A ) to the second configuration ( FIG. 5B ). 
     More specifically, in the first position shown in  FIGS. 8A and 8B , the actuator  124  is positioned at a most proximal position along the housing  595 . For example, the first shaft hub  810  can abut a proximal wall portion  807  of the housing  595 . In the first position, the first portion  842  of the second track  840  compresses (e.g., presses, constrains) the second engagement features  854  of the second shaft hub  850  radially inward toward and into engagement with the first shaft hub  810  (e.g., with the first body portion  812 ). Put differently, a distance (e.g., diameter) of the second shaft hub  850  between the second engagement features  854  can be greater than the first diameter G 1  when the second shaft hub  850  is in a relaxed state, unconstrained by the first portion  842  of the second track  840 . By this arrangement, the second shaft hub  850  is secured to the first shaft hub  810  such that movement of the actuator  124  along the first portion  842  of the second track  840  moves both the first and second shaft hubs  810 ,  850 . In some embodiments, the first body portion  812  of the first shaft hub  810  can include various features (e.g., grooves, channels, teeth) for mating with the second engagement features  854  of the second shaft hub  850  to thereby secure the first and second shaft hubs  810 ,  850  together. 
     Moreover, in the first position, at least a portion of the first engagement features  814  of the first shaft hub  810  can be positioned proximal of the proximal detents  832  ( FIGS. 8C and 8D ). The proximal detents  832  can thus retain the first shaft hub  810 —and the second shaft hub  850  and the actuator  124  secured thereto—in the first position until a predetermined force is applied to the actuator  124  in the distal direction. In one aspect of the present technology, this arrangement can inhibit the unintended distal advancement of the first shaft  580 —and thus the premature deployment of the funnel  690  ( FIGS. 7A-7C ). In some embodiments, when the predetermined force is applied to the actuator  124 , the first engagement features  814  flex inwardly such that first shaft hub  810  can slide distally thereby. 
     Accordingly, referring to  FIGS. 8A-8C  together, the actuator  124  can be advanced distally from the first position to the second position shown in  8 C after the first engagement features  814  disengage the proximal detents  832 . As the actuator  124  is moved distally, the first and second shaft hubs  810 ,  850  move distally together—thereby advancing the first and second shafts  580 ,  582  together as shown in  FIG. 7B —until the first shaft hub  810  reaches the distal terminus  835  of the first track  830  and/or the second shaft hub  840  reaches the second portion  844  of the second track  840 . More specifically, the distal terminus  835  and/or the distal detents  834  of the first track  830  can engage the first engagement features  814  to prevent the first shaft hub  810  (and thus the first shaft  580 ) from moving farther distally. At the same time, the greater-diameter second portion  844  of the second track  840  allows the second engagement features  854  to move radially outward (e.g., flex radially outward toward the relaxed state) and out of engagement with first shaft hub  810 . That is, the control assembly  120  is configured such that the second engagement features  854  of the second shaft hub  850  reach the transition point between the first and second portions  842 ,  844  of the first track  840  at substantially the same time as the first engagement features  814  of the first shaft hub  810  reach/engage the distal detents  834  of the first track  830 . 
     Accordingly, as shown in  FIG. 8D , the second shaft hub  850  can leave the first shaft hub  810  behind and advance further distally to the third position. As the second shaft hub  850  moves distally while the first shaft hub  810  remains stationary, the second shaft  582  is advanced distally toward the retention sheath  122  as shown in  FIG. 7C . In some embodiments, the second shaft hub  850  can abut a distal wall portion  809  of the housing  595  in the third position. 
     Referring to  FIGS. 5A-8D  together, in one aspect of the present technology, the control assembly  120  facilitates the movement of the dilator assembly  104  from the first configuration to the second configuration with only as a single movement of the actuator  124  from the first to third positions. As described above, this advantageously allows the control assembly  120  to be coupled to the sealable hub  114  at all times during deployment of the funnel  690 , which controls deployment of the funnel  690  and prevents the funnel  690  from inadvertently being deployed. This is expected to reduce the potential for the other components of the system, such as the retention sheath  122 , from catching on the funnel  690  as the dilator is retracted through the sheath  112 . Moreover, deployment of the funnel  690  and advancement of the second shaft  582  are achieved by a single stroke and are thus greatly simplified. 
     In some embodiments, the actuator  124  can be moved proximally (e.g., from the third position toward the first position) to facilitate loading of the funnel  690 . For example, the dilator assembly  104  can be inserted into the sheath  112  when the control assembly  120  is in the third position such that the retention sheath  122  extends from the distal portion  113   b  of the sheath  112  and distally beyond the funnel  690 . The operator can then move the actuator  124  to the second position, thereby forcing the second shaft hub  850  into engagement with the first shaft hub  810  via the narrowing of the second track  840  from the second portion  844  to the first portion  842 . The loading tool  108  ( FIG. 1 ) can then be slid proximally over the retention sheath  122  and the funnel  690  until the funnel  690  is fully encapsulated by the loading tool  108  and/or until the funnel  690  is in the constrained configuration. The operator can then move the actuator  124  from the second position to the first position to retract the retention sheath  122  over the funnel  690  to thereby load/capture the funnel  690  within the receiving space  694  of the retention sheath  122 . Finally, the loading tool  108  can be removed. 
     In other embodiments, control assemblies in accordance with the present technology can include other components and/or configurations for facilitating the dual-action of (i) advancing the first and second shafts  580 ,  582  to deploy the funnel  690  and (ii) advancing the second shaft  582  relative to the first shaft  580  to provide a uniform outer surface that facilitates retraction of the dilator assembly  104 .  FIGS. 9A-9C , for example, are cross-sectional side views of a control assembly  920  including the actuator  124  in the first position, the second position, and the third position ( FIGS. 7A-7C ) configured in accordance with another embodiment of the present technology. 
     The control assembly  920  can include some features generally similar to the control assembly  120  described in detail above with reference to  FIGS. 8A-8D . For example, referring to  FIGS. 9A-9C  together, the control assembly  920  includes a first shaft hub  910  coupled to the first shaft  580  of the dilator assembly  104 , and a second shaft hub  950  coupled to the second shaft  582  of the dilator assembly  104 . In the illustrated embodiment, the second shaft hub  950  is connected to (e.g., integrally formed with) the actuator  124 , which extends outside a housing  995  of the control assembly  920  and is configured to be advanced distally and/or retracted proximally by the operator. The first and second shaft hubs  910 ,  950  are configured to slide at least partially through a lumen  902  extending through the housing  995 . 
     In the illustrated embodiment, the control assembly  920  further includes an elongate member  960  (shown as transparent in  FIGS. 9A-9C  for the sake of clarity) having (i) a proximal portion  961   a  positioned proximal of the first shaft hub  910  and (ii) a distal portion  961   b  positioned distal of the first shaft hub  910  and coupled to the second shaft hub  950 . The first shaft hub  910  can be slidably positioned within the elongate member  960 . A biasing member  964 , such as a compression spring, extends between the proximal portion  961   a  of the elongate member  960  and the first shaft hub  910 . In some embodiments, a proximal portion  965   a  of the biasing member  964  is connected to the proximal portion  961   a  of the elongate member  960  and a distal portion  965   b  of the biasing member  964  is connected to the first shaft hub  910 . 
     The control assembly  920  can further include a stop member  970  coupled to the first shaft  580  (e.g., to a proximal portion of the first shaft  580 ). The stop member  970  is configured to slide at least partially through the lumen  902  of the housing during operation of the control assembly  920  and can be fully contained within the housing  995  (e.g., as shown in  FIGS. 9B and 9C ) and/or can extend fully or partially outside of the housing  995  (e.g., as shown in  FIG. 9A ). As shown in  FIG. 9B , the stop member  970  has a dimension (e.g., diameter) H 1  that is greater than a dimension H 2  of a stop portion  972  of the housing  995 . By this arrangement, the stop member  970  is configured to contact the stop portion  972  of the housing  995  to thereby prevent the first shaft  580  (and the retention sheath  122  attached thereto) from advancing farther distally. 
     Referring to  FIG. 9A , in the first position, the first shaft hub  910  engages (e.g., mates with) the second shaft hub  950  such that distal advancement of the actuator  124  moves both the first and second shaft hubs  910 ,  950 . Moreover, the biasing member  964  is at equilibrium and thus does not exert any force on, for example, the first shaft hub  910 . In some embodiments, the actuator  124  and/or the second shaft hub  950  can include first engagement features  954  (e.g., bumps, projections) that can engage (e.g., mate with) corresponding first detents  957  in the housing  995  to releasably secure the actuator  124  in the first position until a predetermined force is applied to the actuator in the distal direction. In some embodiments, when the predetermined force is applied to the actuator  124 , the first engagement features  954  can flex outwardly and out of the first detents  957  to permit the first and second shaft hubs  910 ,  950  to move distally. 
     Accordingly, referring to  FIGS. 9A and 9B  together, the actuator  124  can be advanced distally from the first position to the second position after the first engagement features  954  disengage the first detents  957 . As the actuator  124  is moved distally, the first and second shaft hubs  910 ,  950  move distally together—thereby advancing the first and second shafts  580 ,  582  together as shown in  FIG. 7B —until the stop member  970  reaches and contacts the stop portion  972  of the housing  995 . More specifically, the biasing member  964  can exert a force against the first shaft hub  910  to move the first shaft hub  910  together with the second shaft hub  950 . When the stop member  970  contacts the stop portion  972 , the first shaft hub  910  is stopped from advancing farther distally. 
     Accordingly, referring to  FIGS. 9B and 9C  together, the second shaft hub  950  can leave the first shaft hub  910  behind as the actuator  124  is moved farther distally to the third position. As the second shaft hub  950  moves distally while the first shaft hub  910  remains stationary, the second shaft  582  is advanced distally toward the retention sheath  122  as shown in  FIG. 7C . In some embodiments, the second shaft hub  950  can abut a distal wall portion  909  of the housing  995  in the third position, which prevents the second shaft hub  950  from advancing farther. As further shown in  FIG. 9C , advancing the second shaft hub  950  to the third position compresses the biasing member  964  between the first shaft hub  910 , which remains stationary, and the proximal portion  961   a  of the elongate member  960  which continues to move with the second shaft hub  950 . In some embodiments, the bias force exerted by the biasing member  964  can facilitate the subsequent movement of the actuator  124  from the third position to the second position. In some embodiments, the actuator  124  can include second engagement features  958  (e.g., bumps, projections) that can engage (e.g., mate with) corresponding second detents  959  in the housing  995  to releasably secure the actuator  124  in the third position until a predetermined force is applied to the actuator in the proximal direction. In some embodiments, this force can be less than that required to disengage the first engagement features  954  from the first detents  957  due to the biasing force of the biasing member  964 . In other embodiments, the detents  959  can comprise a track (e.g., an L-shaped track), and the second shaft hub  950  can be rotated to rotate the second engagement features  958  into the track to releasably secure the actuator  124  in the third position. 
     In other embodiments, the stop member  970  is not configured to stop distal advancement of the first shaft  580 . Rather, the stop member  970  can instead be a luer flush port  970  (or another component) that simply moves together with the first shaft  580 , or can be omitted altogether. In such embodiments, the first shaft hub  910  can move along a track (not shown) formed in the housing  995  in a similar manner as the first shaft hub  810  described in detail with reference to  FIGS. 8A-8D . For example, the first shaft hub  910  can include first engagement or snap features  914  (only one first engagement feature  914  is visible in  FIGS. 9A-9C ) that extend (i) radially and/or axially away from a body portion of the first shaft hub  910 , (ii) out of the elongate member  960 , and (iii) into the track in the housing  995 . The track can include a detent or other feature (not shown) configured (e.g., positioned and shaped) to stop the first shaft hub  910  from moving farther distally when the first shaft hub  910  reaches the second position shown in  FIG. 9B . 
       FIGS. 10A and 10B  are partially cross-sectional side views of a control assembly  1020  configured in accordance with another embodiment of the present technology. In general, the control assembly is movable between (i) the first position (shown in  FIG. 10A ) in which the second shaft  582  is retracted proximally relative to the first shaft  580  as shown in  FIGS. 5A and 7A  and (ii) the third position (shown in  FIG. 10B ) in which the second shaft  582  is advanced distally relative to the first shaft  580  to form a generally uniform outer surface of the dilator assembly  104  as shown in  FIGS. 5B and 7C . In one aspect of the present technology, the control assembly  1020  does not include the intermediate second position ( FIG. 7B ), but instead fluidly moves between the first and third positions. 
     The control assembly  1020  can include some features generally similar to the control assembly  120  and/or the control assembly  920  described in detail above with reference to  FIGS. 8A-9C . For example, referring to  FIGS. 10A and 10B  together, the control assembly  1020  includes an actuator  1024  (e.g., a plunger  1024 ) that is movable relative to/through a lumen  1002  of a housing  1095 . The plunger  1024  is coupled to (i) a first shaft hub  1010  that is coupled to the first shaft  580  of the dilator assembly  104  and (ii) a second shaft hub  1050  that is coupled to the second shaft  582  of the dilator assembly  104 . The first and second shafts  580 ,  582  are not shown in  FIGS. 10A and 10B  for the sake of clarity. 
     In the illustrated embodiment, the second shaft hub  1050  includes engagement features  1054  that are configured (e.g., sized and shaped) to engage with a corresponding stop portion  1056  formed in the housing  1095  when the plunger  1024  is in the first position shown in  FIG. 10A . The first shaft hub  1010  is configured to slide along a track  1080  formed in/along a portion of the plunger  1024 . In some embodiments, the track  1080  includes at least one detent  1084  at a distal portion thereof and configured to stop/block distal advancement of the first shaft hub  1010 . In other embodiments, the housing  1095  can include a flange or other component configured to stop distal advancement of the first shaft hub  1010 . 
     A first biasing member  1064  (e.g., a compression spring) extends between and operably couples (e.g., connects) the first shaft hub  1010  and a proximal portion  1096  of the housing  1095 . A second biasing member  1066  (e.g., a compression spring) extends between and operably couples (e.g., connects) the first and second shaft hubs  1010 ,  1050 . In the first position shown in  FIG. 10A , both of the first and second biasing members  1064 ,  1066  are compressed and under load and therefore urge the first and second shaft hubs  1010 ,  1050 , respectively, distally. In some embodiments, the first biasing member  1064  has a larger compression force than the second biasing member  1066 . 
     In the first position shown in  FIG. 10A , the plunger  1024  is locked in a proximally retracted position by the engagement of the engagement features  1054  with the stop portion  1056  of the housing  1095 . To move the control assembly  1020  to the third position shown in  FIG. 10B , the operator can rotate the plunger  1024  (e.g., as indicated by arrow I in  FIG. 10A ) to unlock the second shaft hub  1050  and the plunger  1024 . When the plunger  1024  is unlocked, the first biasing member  1064  is configured to drive the first shaft hub  1010  distally until the first shaft hub  1010  is stopped by/within the detent  1084 . In one aspect of the present technology, because the first biasing member  1064  is stronger than the second biasing member  1066 , the second biasing member  1066  remains substantially compressed until the first shaft hub  1010  engages the detent  1084 . Therefore, both the first and second shaft hubs  1010 ,  1050 —and thus both the first and second shafts  580 ,  582 —move together until the first shaft hub  1010  reaches the detent  1084 . Then, the second biasing member  1066  is configured to drive the second shaft hub  1050  distally relative to the first shaft hub  1010  (e.g., away from the first shaft hub  1010 ). In the third position shown in  FIG. 10B , the first and second biasing members  1064 ,  1066  can bias the first and second shaft hubs  1010 ,  1050  distally to maintain the control assembly  1020  in the third position. By this arrangement, the first and second shafts  580 ,  582  are automatically moved from the first configuration ( FIG. 5A ) to the second configuration ( FIG. 5B )—deploying the funnel and readying the dilator assembly  104  for retraction as shown in  FIGS. 7A-7D . 
     In other embodiments, the first and second biasing members  1064 ,  1066  can be arranged in an opposite configuration. For example, the first biasing member  1064  can extend between and operably couple the first and second shaft hubs  1010 ,  1050 , and the second biasing member  1066  can extend between and operably couple the second shaft hub  1050  and a distal portion  1098  of the housing  1096 . Likewise, the second biasing member  1066  can have a larger compression force than the first biasing member  1064 . Thus, the first and second biasing members  1064 ,  1066  can bias the control assembly  1020  to the first position. To move the control assembly  1020  to the third position, the user can advance the plunger  1024  against the compression forces of the first and second biasing members  1064 ,  1066  until the second shaft hub  1050  reaches the third position. In some embodiments, the user can then rotate the plunger  1024  to lock the control assembly  1020  in the third position. 
     IV. SELECTED EMBODIMENTS OF THROMBECTOMY METHODS 
       FIG. 11  is a schematic view of an introduction technique for accessing a thrombus  1190  for treatment with the thrombectomy system  100  in accordance with an embodiment of the present technology. The thrombus  1190  (e.g., clot material) can be located in a blood vessel  1196  and accessed through an access site  1192  such as the popliteal access site, or other venous or arterial access sites. The introducer assembly  102  can extend from the popliteal access site  1192 , or other venous or arterial access sites, to a deployment position  1194  at which the self-expanding funnel  690  can be deployed and which can be proximate to the thrombus  1190 . As described in greater detail below with reference to  FIGS. 12A-12K , the thrombus extraction device  250  can be passed through the thrombus  1190  in the direction of blood flow and then retracted through the thrombus  1190  in a direction with blood flow. During retraction, the coring element  252  can core/separate the thrombus  1190  and the capture element  254  can capture all or a portion of the thrombus  1190 . In some embodiments, some or all of the thrombus extraction device  250  can extend into one of the iliac veins and/or the inferior vena cava. 
     More particularly,  FIGS. 12A-12C  are side views, and  FIGS. 12D-12M  are enlarged side views, of the thrombectomy system  100  positioned within the blood vessel  1196  during a thrombectomy procedure to treat (e.g., remove) the thrombus  1190  in accordance with embodiments of the present technology. 
       FIG. 12A  illustrates the thrombectomy system  100  intravascularly positioned within the blood vessel  1196  after (i) deploying the self-expanding funnel  690  (e.g., as described in detail with reference to  FIGS. 5A-10B ), (ii) removing the dilator assembly  104  from the introducer assembly  102 , and (iii) advancing the outer shaft  132  of the thrombus extraction assembly  106  through the sheath  112  and the thrombus  1190 . The distal advance of the outer shaft  132  through the thrombus  1190  can be either with or against the direction of blood flow. 
       FIG. 12B  illustrates the thrombectomy system  100  after advancing the thrombus extraction device  250  through the outer shaft  132  to a deployed position distal of the thrombus  1190 . In some embodiments, the thrombus extraction device  250  can be constrained within the outer shaft  132  and inserted, together with the outer shaft  132 , into the lumen of the sheath  112  via the sealable hub  114 . In some embodiments, the thrombus extraction device  250  can be deployed by advancing the thrombus extraction device  250  beyond the distal portion  136   b  of the sheath  112  and/or by retracting the outer shaft  132  relative to the thrombus extraction device  250  until the thrombus extraction device  250  is beyond the distal portion  136   b  of the outer shaft  132 . 
       FIG. 12C  illustrates the thrombectomy system  100  after fully-expanding the thrombus extraction device  250 . In some embodiments, at least a portion of the coring element  252  and/or the capture element  254  contact a wall  1297  of the blood vessel  1196  in the fully-expanded position. As described in detail above with reference to  FIGS. 2A and 2B , in some embodiments the thrombus extraction device  250  can be fully expanded by moving the plunger  144  from the first position to the second position and securing the plunger  144  in the second position to thereby fix the relative position of the inner shaft  134  with respect to the intermediate shaft  133 . 
     In general,  FIGS. 12D-12K  illustrate the proximal retraction of the thrombus extraction device  250  through the thrombus  1190  to capture at least a portion of the thrombus  1190 , and the subsequent joint retraction of the thrombus extraction device  250  and the captured thrombus  1190  into the funnel  690  and the sheath  112 . 
     Referring first to  FIG. 12D , proximal retraction of the thrombus extraction device  250  causes the coring element  252  to separate and/or core a distal portion  1298   b  of the thrombus  1190  from the wall  1297  of the blood vessel  1196 . As shown in  FIG. 12E , continued proximal retraction of the thrombus extraction device  250  through the thrombus  1190  causes the capture element  254  to capture the distal portion  1298   b  of the thrombus  1190  therein.  FIGS. 12F-12H  illustrate further proximal retraction of the thrombus extraction device  250  which causes further separation, coring, and/or capture of the thrombus  1190 . As seen in  FIG. 12H , a proximal portion  1298   a  of the thrombus  1190  is cored and captured as the thrombus extraction device  250  is proximally retracted toward the funnel  690  and the sheath  112 . 
     As described in detail above with reference to  FIGS. 3A-4 , the coring element  252  can include both the first mouth  370  and the second mouth  372  (identified in  FIG. 12D ). Thus, the first mouth  370 , the first mouth portion  372   a , and/or the second mouth portion  372   b  can facilitate the coring/separating of the thrombus  1190  during proximal retraction of the thrombus extraction device  250 . In one aspect of the present technology, the first mouth  370  and the second mouth  372  are radially offset relative to one another which can increase the coring effectiveness—even when the blood vessel  1196  is very tortuous and/or the thrombus  1190  is strongly adhered to the wall  1297  of the blood vessel  1196 —by ensuring that at least one of the first mouth  370  and the second mouth  372  is positioned and oriented to effectively core the thrombus  1190 . 
     In some embodiments, as shown in  FIGS. 121 and 12G , the thrombus extraction device  250  can be proximally retracted until the proximal portion  253   a  of the coring element  252  is contained (e.g., positioned) within the funnel  690 . More specifically, the thrombus extraction device  250  can be proximally retracted until all or a portion of the first mouth  370  and/or the second mouth  372  of the coring element  252  are contained within the funnel  690 . In some embodiments, when one or both of the first and second mouths  370 ,  372  are positioned within the funnel  690 , the thrombus extraction device  250  can be moved or transformed from the expanded deployed state to the compressed state to compress and secure the thrombus  1190  captured by the thrombus extraction device  250 . In some embodiments, for example, the intermediate shaft  133  ( FIG. 12H ) can be unlocked and/or decoupled from the inner shaft  134  (e.g., via user actuation of the plunger  144  shown in  FIGS. 1-2B ) such that the inner shaft  134  can be advanced distally relative to the intermediate shaft  133  to collapse or compress the thrombus extraction device  250 . 
     After the thrombus extraction device  250  has been collapsed, the thrombus extraction device  250  can be proximally retracted through the funnel  690  and into the sheath  112  as depicted in  FIG. 12K . The thrombus extraction device  250  can continue to be proximally retracted until the thrombus extraction device  250  and the captured thrombus  1190  are fully contained within the sheath  112 . In some embodiments, the thrombus extraction device  250  and the captured thrombus  1190  can then be withdrawn through the sheath  112  and the sealable hub  114  ( FIG. 12B ). 
     In some embodiments, a vacuum (e.g., a pre-charged vacuum) can be applied to the sheath  112  at any point during retraction of the thrombus extraction device  250 . In some embodiments, application of the vacuum can generate instantaneous or nearly instantaneous suction at the distal portion of the sheath  112  that can aspirate any remaining portions of the thrombus  1190  into and/or through the sheath  112 . For example, the generated suction can aspirate any of the thrombus  1190  that captured or extruded by the funnel  690 . Moreover, in some embodiments, application of a vacuum can facilitate smooth retraction of the captured thrombus  1190  through the sheath  112 . For example, a burst of suction generated by application of the vacuum can help inhibit clogging of the sheath  112 , and/or help resolve (e.g., break apart) a clog formed in the sheath  112  during retraction. 
     V. EXAMPLES 
     Several aspects of the present technology are set forth in the following examples: 
     1. A coring element for coring a vascular thrombus within a blood vessel of a patient, the coring element comprising:
         a unitary structure having—
           a first region adjacent to a proximal portion of the unitary structure, wherein the first region includes a first mouth configured to core the vascular thrombus;   a second region distal of the first region, wherein the second region is generally tubular and includes a first plurality of interconnected struts;   a third region distal of the second region, wherein the third region includes a second mouth configured to core the vascular thrombus; and   a fourth region distal of the third region, wherein the fourth region is generally tubular and includes a second plurality of interconnected struts.   
               

     2. The coring element of example 1 wherein the first mouth is radially offset from the second mouth. 
     3. The coring element of example 1 or example 2 wherein the unitary structure extends along a longitudinal axis, and wherein the first region includes a pair of first curved struts that curve in opposite directions around the longitudinal axis and intersect at a pair of first junctions to define the first mouth. 
     4. The coring element of any one of examples 1-3 wherein the unitary structure extends along a longitudinal axis, wherein the third region includes (a) a pair of upper curved struts that curve around the longitudinal axis and intersect each other at an upper junction and (b) a pair of lower curved struts that curve around the longitudinal axis and intersect each other at a lower junction, and wherein the lower and upper curved struts define the second mouth. 
     5. The coring element of example 4 wherein the lower and upper curved struts define (a) a first mouth portion opening in a first direction generally orthogonal to the longitudinal axis and (b) a second mouth portion opening in a second direction generally orthogonal to the longitudinal axis, and wherein the first and second mouth portions define the second mouth. 
     6. The coring element of example 5 wherein the first direction is generally opposite to the second direction. 
     7. The coring element of any one of examples 1-6 wherein the coring element is expandable from a compressed delivery configuration to an expanded deployed configuration. 
     8. The coring element of example 7 wherein the coring element is configured to self-expand. 
     9. The coring element of example 8 wherein the coring element is made from a shape memory material. 
     10. The coring element of any one of examples 1-9 wherein the fourth region of the unitary structure is configured to be connected to a braided filament mesh structure. 
     11. A dilator assembly for deploying an expandable funnel coupled to a distal portion of an introducer sheath, the dilator assembly comprising:
         a first shaft defining a lumen;   a second shaft slidably positioned within the lumen of the first shaft;   a retention sheath coupled to the second shaft and configured to receive and constrain the funnel therein; and   a control assembly including an actuator operably coupled to the first and second shafts, wherein movement of the actuator from a first position to a second position advances the first and second shafts together to deploy the funnel from the retention sheath, and wherein movement of the actuator from the second position to a third position advances the first shaft relative to the second shaft.       

     12. The dilator assembly of example 11 wherein the retention sheath has substantially a same outer diameter as the first shaft. 
     13. The dilator assembly of example 11 or example 13 wherein movement of the actuator from the second position to the third position brings a distal portion of the first shaft into contact with a proximal portion of the retention sheath. 
     14. The dilator assembly of any one of examples 11-13 wherein the control assembly includes—
         a housing;   a first shaft hub slidably positioned within the housing and coupled to the first shaft; and   a second shaft hub slidably positioned within the housing and coupled to the second shaft.       

     15. The dilator assembly of example 14 wherein the first shaft hub is configured to engage the second shaft hub when the actuator is moved from the first position to the second position such that the first and second shafts advance together. 
     16. The dilator assembly of example 14 or example 15 wherein the first shaft hub is configured to disengage the second shaft hub when the actuator is moved from the second position to the third position such that first shaft advances relative to the second shaft. 
     17. The dilator assembly of any one of examples 14-16 wherein the first shaft hub is configured to engage the second shaft hub when the actuator is moved from the first position to the second position such that the first and second shafts advance together, and wherein the first shaft hub is configured to disengage the second shaft hub when the actuator is moved from the second position to the third position such that first shaft advances relative to the second shaft. 
     18. The dilator of assembly of any one of examples 14-17 wherein the second shaft hub includes a first engagement feature, wherein the housing includes a second engagement feature, and wherein the first engagement feature is configured to engage the second engagement feature at the second position to prevent movement of the second shaft hub when the actuator is moved from the second position to the third position. 
     19. The dilator assembly of example 18 wherein the first engagement feature is a snap feature, and wherein the second engagement feature is a detent formed in the housing. 
     20. The dilator assembly of any one of examples 14-19, further comprising a biasing member operably coupled to the first shaft hub, wherein the biasing member is configured to bias the first shaft hub from the third position toward the second position. 
     21. The dilator assembly of any one of examples 11-20 wherein the control assembly further includes a housing, wherein the actuator is movable relative to the housing, wherein the movement of the actuator from the first position to the second position is distal movement of the actuator relative to the housing, and wherein the movement of the actuator from the second position to the third position is further distal movement of the actuator relative to the housing. 
     22. The dilator assembly of any one of examples 11-21, further comprising the introducer sheath and the funnel. 
     23. A system for capturing a vascular thrombus within a blood vessel of a patient, the system comprising:
         an introducer sheath having a distal portion;   an expandable funnel coupled to the distal portion of the introducer sheath;   a dilator assembly configured to be inserted through the introducer sheath and to deploy the expandable funnel, wherein the dilator assembly includes—
           a first shaft defining a lumen;   a second shaft slidably positioned within the lumen of the first shaft;   a retention sheath coupled to the second shaft and configured to receive and constrain the funnel therein; and   a control assembly including an actuator operably coupled to the first and second shafts, wherein movement of the actuator from a first position to a second position distally advances the first and second shafts together to deploy the funnel from the retention sheath, and wherein movement of the actuator from the second position to a third position advances the first shaft relative to the second shaft; and   
           a clot removal device configured to be inserted through the introducer sheath to capture at least a portion of the vascular thrombus.       

     24. The system of example 23 wherein the clot removal device includes an expandable coring element coupled to an expandable capture element, wherein the coring element is configured to separate at least a portion of the vascular thrombus from a wall of the blood vessel, and wherein the capture element is configured to capture and retain the portion of the vascular thrombus separated from the wall of the blood vessel. 
     25. The system of example 23 or example 24 wherein the funnel has a first length when deployed from the retention sheath, and wherein the coring element has a second length when expanded that is less than the first length. 
     26. A system for capturing a vascular thrombus within a blood vessel of a patient, the system comprising:
         an introducer sheath having a distal portion;   an expandable funnel coupled to the distal portion of the introducer sheath;   a dilator assembly configured to be inserted through the introducer sheath and to deploy the expandable funnel; and   a clot removal device configured to be inserted through the introducer sheath, wherein the clot removal device includes an expandable coring element coupled to an expandable capture element, wherein the coring element includes a first region including a first mouth and a second region including a second mouth, wherein the first and second mouths are configured to separate at least a portion of the vascular thrombus from a wall of the blood vessel, and wherein the capture element is configured to capture and retain the portion of the vascular thrombus separated from the wall of the blood vessel.       

     27. The system of example 26 wherein the first mouth is radially offset from the second mouth. 
     28. The system of example 27 wherein the coring element is formed from a unitary structure including a plurality of struts, wherein the struts define the first and second mouths, wherein the struts further define a plurality of interstices, and wherein the first and second mouths are larger than each of the interstices. 
     VI. CONCLUSION 
     The above detailed descriptions of embodiments of the technology are not intended to be exhaustive or to limit the technology to the precise form disclosed above. Although specific embodiments of, and examples for, the technology are described above for illustrative purposes, various equivalent modifications are possible within the scope of the technology as those skilled in the relevant art will recognize. For example, although steps are presented in a given order, alternative embodiments may perform steps in a different order. The various embodiments described herein may also be combined to provide further embodiments. 
     From the foregoing, it will be appreciated that specific embodiments of the technology have been described herein for purposes of illustration, but well-known structures and functions have not been shown or described in detail to avoid unnecessarily obscuring the description of the embodiments of the technology. Where the context permits, singular or plural terms may also include the plural or singular term, respectively. 
     Moreover, unless the word “or” is expressly limited to mean only a single item exclusive from the other items in reference to a list of two or more items, then the use of “or” in such a list is to be interpreted as including (a) any single item in the list, (b) all of the items in the list, or (c) any combination of the items in the list. Additionally, the term “comprising” is used throughout to mean including at least the recited feature(s) such that any greater number of the same feature and/or additional types of other features are not precluded. It will also be appreciated that specific embodiments have been described herein for purposes of illustration, but that various modifications may be made without deviating from the technology. Further, while advantages associated with some embodiments of the technology have been described in the context of those embodiments, other embodiments may also exhibit such advantages, and not all embodiments need necessarily exhibit such advantages to fall within the scope of the technology. Accordingly, the disclosure and associated technology can encompass other embodiments not expressly shown or described herein.