Sheathing and delivery system for collapsible blood pumps

Abstract

A system for inserting a collapsible blood pump into a patient. In some embodiments, the system includes an introducer, the introducer comprising an introducer hub and an introducer sheath extending distally from the introducer hub, the introducer sheath comprising an introducer sheath lumen, the introducer hub comprising a hub connector and a distal hub lumen surrounding a proximal end of the introducer shaft; and a transfer tool comprising a transfer sheath, the transfer sheath comprising a transfer sheath lumen having a diameter substantially equal to a diameter of the introducer sheath lumen and a transfer tool connector adapted to connect to the hub connector, a distal portion of the transfer sheath extending into the distal hub lumen when the transfer tool connector is connected to the hub connector.

Description

SHEATHING AND DELIVERY SYSTEM FOR COLLAPSIBLE BLOOD PUMPSPRIORITY CLAIM

[0001] This patent application claims priority to U.S. provisional patent application no. 63 / 616,349, titled “SHEATHING AND DELIVERY SYSTEM FOR COLLAPSIBLE BLOOD PUMPS,” filed on December 29, 2023, and U.S. provisional patent application no. 63 / 616,172, titled “CATHETER BLOOD PUMPS AND ASSOCIATED METHODS,” filed on December 29, 2023, which are both herein incorporated by reference in their entirety.CROSS REFERENCE TO RELATED APPLICATIONS

[0002] This application is related to International Application No. PCT / US2023 / 060410, filed January 10, 2023, which is herein incorporated by reference in its entirety.INCORPORATION BY REFERENCE

[0003] All publications and patent applications mentioned in this specification are herein incorporated by reference in their entirety to the same extent as if each individual publication or patent application was specifically and individually indicated to be incorporated by reference.BACKGROUND

[0004] Intravascular blood pumps may benefit from being collapsible to facilitate a smaller delivery profile prior to being expanded at the pumping site within the patient’s heart and / or vasculature. Some such pumps are described in WO 2021 / 243263.

[0005] Conventional expandable blood pump systems require both an outer sheath and an introducer. The outer sheath facilitates collapse of the self-expanding pump and expansion to the operational profile. The pump is introduced into a patient by collapsing the pump into the sheath and then inserting the sheath through an introducer. This leads to “stacking” of materials and thus a larger insertion profile, which correlates to higher vascular complication rates. There is a need for a blood pump and delivery system having a lower insertion profile and larger operational configuration. There is a need for a system for quickly introducing an expandable blood pump into a patient.SUMMARY OF THE DISCLOSURE

[0006] A system for inserting a collapsible blood pump into a patient is provided, the system comprising: an introducer, the introducer comprising an introducer hub and an introducer sheath extending distally from the introducer hub, the introducer sheath comprising an introducer sheath lumen, the introducer hub comprising a hub connector and a distal hub lumen surrounding a proximal end of the introducer shaft; a transfer tool comprising a transfer sheath, the transfer sheath comprising a transfer sheath lumen having a diameter substantially equal to a diameter of the introducer sheath lumen and a transfer tool connector adapted to connect to the hub connector, a distal portion of the transfer sheath extending into the hub when the transfer tool connector is connected to the hub connector; and a sheathing tool connectable to the transfer tool, the sheathing tool being configured to collapse the blood pump and place it within the transfer tool.

[0007] In some aspects, the transfer tool comprises a threaded locking ring, the sheathing tool being configured to engage with the threaded locking ring.

[0008] In other aspects, the sheathing tool comprises threads.

[0009] In some aspects, the sheathing tool comprises one or more engagement features configured to engage with the threaded locking ring.

[0010] In other aspects, the sheathing tool comprises one or more detents.

[0011] In one aspect, the hub connector is configured to engage with the threaded locking ring.

[0012] In other aspects, the hub connector comprises threads.

[0013] In some aspects, the sheathing tool comprising a sloped surface configured to engage with the blood pump.

[0014] In additional aspects, the sheathing tool comprising a sloped surface configured to engage with proximal struts of the blood pump.

[0015] In one aspect, the sheathing tool comprises a lumen with a diameter substantially equal to the diameter of the transfer sheath lumen.

[0016] In other aspects, the sheathing tool comprises a lumen with a diameter less than the diameter of the transfer sheath lumen.

[0017] In some aspects, the transfer sheath lumen comprises a flexible distal tip.

[0018] In additional aspects, the flexible distal tip comprises a material that is more flexible than the transfer sheath lumen.

[0019] In some aspects, the sheathing tool comprises a lumen configured to constrain the flexible distal tip.

[0020] In other aspects, the sheathing tool comprises as clamshell design.

[0021] In some aspects, the sheathing tool further comprises a hinge connecting first and second halves of the sheathing tool.

[0022] In some aspects, a locking ring is provided that is configured to constrain a distal end of the sheathing tool when the sheathing tool is connected to the transfer tool.

[0023] In one aspect, a first half of the sheathing tool has a first engagement feature configured to engage with a second engagement feature of the second half of the sheathing tool.

[0024] In another aspect, a first half of the sheathing tool has one or more hooks configured to engage with one or more slots of the second half of the sheathing tool.

[0025] In some aspects, the distal portion of the transfer sheath extends into the distal hub lumen when the transfer tool connector is connected to the hub connector.

[0026] In other aspects, the distal end of the transfer sheath abuts a proximal end of the introducer sheath when the transfer tool connector is connected to the hub connector.

[0027] In some aspects, the introducer hub further comprises a tapered surface extending proximally and radially outwardly from the distal hub lumen.

[0028] In other aspects, the introducer further comprises a one-way valve disposed in the introducer hub proximal to the introducer sheath lumen and configured to seal against vascular pressure.

[0029] In another aspect, the introducer further comprises a seal disposed in the introducer hub proximal to the introducer sheath and configured to seal against vascular pressure around a range of diameters of devices inserted through the seal.

[0030] In one aspect, the introducer further comprising a disc valve disposed in the introducer hub proximal to the introducer sheath and configured to seal against vascular pressure around a range of diameters of devices inserted through the valve.

[0031] In other aspects, the introducer hub further comprises a purge fluid port in fluid communication with the distal hub lumen.

[0032] In additional aspects, the hub connector comprises threads disposed on the introducer hub.

[0033] In some aspects, the hub connector and transfer tool connector are configured to provide an axial force to move the transfer sheath and introducer sheath toward each other.

[0034] In other aspects, the transfer tool further comprises a proximal hub surrounding a proximal portion of the transfer sheath.

[0035] In some aspects, the transfer tool proximal hub comprises a central lumen, the proximal portion of the transfer sheath being disposed in the central lumen, the central lumen having a reduced diameter portion proximal to a proximal end of the transfer sheath.

[0036] In one aspect, the transfer tool proximal hub further comprises a purge fluid port communicating with the central lumen.

[0037] In another aspect, the transfer tool proximal hub further comprises a seal adapted to seal around a catheter portion of a blood pump.

[0038] In some aspects, the transfer tool further comprises a handle surrounding the transfer sheath.

[0039] In other aspects, the handle extends proximally from the transfer tool connector.

[0040] In one aspect, the transfer tool further comprises a proximal hub, the handle extending from the transfer tool connector to the proximal hub.

[0041] In another aspect, the transfer tool connector comprises threads disposed at a distal end of the handle, the distal portion of the transfer sheath extending distally beyond the transfer tool connector.

[0042] In some aspects, the transfer tool connector comprises a rotatable ring with internal threads.

[0043] In other aspects, the distal portion of the transfer sheath is radially expandable.

[0044] A system for inserting a collapsible blood pump into a patient is provided, the system comprising: a transfer tool comprising a transfer sheath, the transfer sheath comprising a transfer sheath lumen configured to receive the collapsible blood pump; and an annular support tool disposed proximally of the transfer tool, the annular support tool being configured to provide at least partial circumferential support to a proximal catheter shaft of the blood pump when the blood pump is loaded into the transfer tool.

[0045] In some aspects, the annular support tool is removably attached to the transfer tool.

[0046] In other aspects, the annular support tool comprises a support assembly slideably disposed therein, a distal end of the support assembly being fixed in position relative to the transfer tool.

[0047] In some aspects, the annular support tool supports a first partial circumference of the proximal catheter shaft and the support assembly supports a second partial circumference of the proximal catheter shaft.

[0048] In one aspect, the annular support tool supports up to 50% of the circumference of the proximal catheter shaft and the support assembly supports a remaining circumference of the proximal catheter shaft.

[0049] In other aspects, the system includes a gripping tool configured to engage with the annular support tool, the gripping tool comprising an engagement mechanism configured toengage with the proximal catheter shaft to translate the blood pump axially relative to the transfer tool.

[0050] In some aspects, the engagement mechanism comprises a torsion spring.

[0051] A method of deploying an expandable blood pump in a patient is provided, the blood pump comprising an expandable and compressible pump housing, an impeller disposed in the pump housing, and a catheter extending proximally from the pump housing, the method comprising: moving at least a portion of the pump housing proximally into a sheathing tool to radially compress the pump housing; moving at least a portion of the pump housing proximally from the sheathing tool into a transfer sheath of a transfer tool through a distal opening of the transfer sheath; removing the sheathing tool from the transfer tool; advancing the transfer sheath distally into a hub of an introducer sheath disposed in a blood vessel of the patient; advancing the pump housing out of the transfer sheath into the introducer sheath; and advancing the pump housing out of the introducer sheath and into the blood vessel.

[0052] In some aspects, the transfer sheath advances distally into the hub of the introducer until a distal end of the transfer sheath abuts a proximal end of the introducer sheath.

[0053] In one aspect, the transfer sheath comprises a transfer sheath lumen and the introducer sheath comprises an introducer sheath lumen, the transfer sheath lumen having a diameter substantially equal to a diameter of the introducer sheath lumen.

[0054] In other aspects, the method comprises connecting a connector of the transfer tool to a connector of the introducer hub.

[0055] In some aspects, the connecting step comprises applying an axial force to move the transfer sheath and introducer sheath toward each other.

[0056] In other aspects, the method comprises expanding the distal end of the transfer sheath as the pump housing moves into the transfer sheath.

[0057] In some aspects, the method comprises compressing the distal end of the transfer sheath before the distal end of the transfer sheath abuts the proximal end of the introducer sheath.

[0058] In another aspect, the method includes the step of moving the pump housing proximally into the transfer sheath further comprises moving the pump housing proximally until proximal struts of the pump housing engage a sheathing stop at a proximal end of the transfer sheath.

[0059] In some aspects, the method includes injecting purge fluid into a proximal end of the transfer sheath while the pump housing is disposed in the transfer sheath.

[0060] A catheter blood pump is provided, comprising an expandable shroud forming a blood conduit, the shroud having a stiff distal section, a stiff proximal impeller section, and a flexible central section between the distal section and the proximal impeller section, wherein the central section is configured to span the aortic valve when the proximal impeller section is positioned proximal to the aortic valve; and an elongate catheter shaft coupled to the expandable shroud, the elongate catheter shaft having a section of increased flexibility that is proximal to the expandable shroud, wherein the section of increased flexibility is configured to be positioned across the aortic arch when the central section spans the aortic valve.BRIEF DESCRIPTION OF THE DRAWINGS

[0061] The novel features of the invention are set forth with particularity in the claims that follow. A better understanding of the features and advantages of the present invention will be obtained by reference to the following detailed description that sets forth illustrative embodiments, in which the principles of the invention are utilized, and the accompanying drawings of which:

[0062] FIGS. 1-2 show a collapsible blood pump and a first embodiment of a system for inserting the blood pump into a patient.

[0063] FIGS. 3-4 show the collapsible blood pump of FIG. 1 compressed inside a transfer sheath.

[0064] FIGS. 5-6 show the collapsible blood pump and transfer sheath of FIGS. 1-4 with a sheathing tool removed prior to insertion into an introducer sheath.

[0065] FIGS. 7-13 show embodiments of a sheathing tool.

[0066] FIG. 14 shows an introducer system for a catheter blood pump.

[0067] FIGS. 15-24 show examples of an annular support assembly and gripper tool for advancing and retracting the catheter blood pump.

[0068] FIGS. 25-27 show an alternative embodiment of an annular support assembly.

[0069] FIGS. 28A-28B are side views of an exemplary blood pump that includes an expandable scaffold that supports a blood conduit with an impeller housed therein.

[0070] FIG. 29 is an example of a catheter blood pump disposed within a heart of a subject.DETAILED DESCRIPTION

[0071] FIGS. 1-2 show a proximal portion of a blood pump 10 having a compressible and self-expandable outer housing 12, a rotatable compressible and self-expandable impeller 14 adapted to pump blood from an inlet (in a distal portion of the pump not shown in FIG. 1)through an outlet, and a drive shaft extending proximally from the impeller through a catheter. An optional guide wire extends proximally from the housing 12 along the outside of catheter, or alternatively through catheter. A handle containing a motor (not shown) is connectable to catheter 20 and drive shaft to operate the blood pump 10 by rotating the impeller 14. Housing 12 may also be referred to as a shroud.

[0072] In order to more easily insert blood pump 10 into the vasculature of a patient (e.g., through an opening in a femoral artery) for advancement to a blood pump site (e.g., in the patient’s heart and / or the patient’s aorta), housing 12 and impeller 14 may be compressed to a smaller diameter delivery configuration with a sheathing tool 16 prior to insertion of the blood pump into the patient and optionally during advancement of the blood pump through the patient’s vasculature after insertion.

[0073] FIGS. 1-6 show different views of compressing the blood pump housing 12 with the sheathing tool 16 as it is being inserted into a transfer sheath 18 and then connecting the transfer sheath 18 to an introducer sheath 20 that includes an introducer hub 22. Transfer sheath 18 may have a thin, flexible wall made of, e.g., silicone, high density polyethylene, polytetrafluoroethylene, and low density polyethylene. The hub may include a purge fluid port for injecting purge fluid, such as saline, into the introducer sheath. Purge fluid can be delivered while the blood pump is within the introducer sheath.

[0074] Referring to FIG. 3, the sheathing tool 16 may be attached or coupled to the transfer sheath 18, such as with a threaded locking ring 17. In some aspects, the sheathing tool also comprises threading. In other aspects, described below, the sheathing tool comprises detents or other engagement features configured to engage with the threading of the locking ring. The threaded locking ring may interface with threads or grooves on the transfer sheath. After the pump has been compressed into the transfer sheath 18, the sheathing tool 16 may be removed from the transfer sheath (e.g., by unthreading or unscrewing the sheathing tool from threaded locking ring 17), and the transfer sheath may then be attached or coupled to the hub 22 of the introducer sheath 20 as shown in FIG. 4. In some examples, the threaded locking ring 17 also is configured to interface with threads on the hub 22 (e.g., by threading onto threads or grooves of the hub). Therefore, both the sheathing tool 16 and the hub 22 may include threads configured to engage with or screw into the threaded locking ring 17.

[0075] As shown in FIGS. 3-6, the transfer sheath can include a lumen 24 that has an inner diameter less than the outer diameter of the blood pump housing 12 in its expanded configuration. The lumen 24 can terminate at a tip 28. In some examples, the lumen 24 comprises a metal hypotube and the tip 28 comprises a flexible tip that may be an elastomeror polymer. In some embodiments, the tip 28 comprises a material that is more flexible than the material of the rest of the lumen 24.

[0076] As shown in FIGS. 1-2, to collapse blood pump housing 12 and place it within transfer sheath, the catheter of blood pump 10 is pulled proximally until housing 12 engages a sloped surface 26 of the sheathing tool 16. In some aspects, the sloped surface of the sheathing tool is sized and configured to engage with a top, radially outward-most, or distal portion of the proximal struts of the pump housing to increase or maximize the leverage applied to the struts during compression of the blood pump. The sloped surface has a curvature and an inner diameter defining a lumen that decreases from the distal end of the sheathing tool proximally toward a constant diameter lumen 30 within an outlet section leading to a proximal opening that is sized and configured to receive the lumen 24 of the transfer sheath. Lumen 30 has a diameter equal to or smaller than a diameter of the lumen 24. The constant diameter lumen 30 is configured to constrain tip 28 of the transfer sheath lumen 24 to prevent the tip from tearing, ripping, or breaking when the pump is pulled into the transfer sheath lumen. In some aspects, as shown, lumen 30 can have a larger diameter than the diameter of the sloped surface 26 where the sloped surface abuts the flexible distal tip. This provides a notch or detent to prevent the distal tip from extending into the sloped surface portion of the sheathing tool.

[0077] As blood pump 10 is pulled proximally with respect to sheathing tool 16, sloped surface 26 engages blood pump 10, particularly an upper portion of the proximal struts of the blood pump, to collapse housing 12 and impeller 14 to the collapsed delivery configuration shown in FIGS. 3 and 4. The proximal pulling on catheter ceases when the distal end of blood pump 10 is within the transfer sheath 18. Alternatively, the proximal pulling on catheter may cease when housing 12 has been compressed to the diameter of the transfer sheath lumen, even is the distal end of blood pump 10 is not yet inside of the transfer sheath. The sheathing tool may then be removed, as shown in FIG. 4.

[0078] After the blood pump 10 has been loaded into transfer sheath 18, the transfer sheath 18 may be inserted into or coupled with an introducer sheath 20 that has previously been inserted into the vasculature of the patient through, e.g., an opening in the femoral artery, as shown in FIG. 4. In some embodiments, the shaft 23 of the introducer sheath 20 is 25-33 cm long and therefore extends only a short distance into the patient’s vasculature. The introducer sheath 20 has a shaft 23 defining a lumen. A hemostatic valve or hub 22 may be disposed at the proximal opening of the lumen. The lumen of shaft 23 may have a diameter slightly greater than the outer diameter of transfer sheath 18.

[0079] Referring to FIGS. 5 and 6, transfer sheath 18 is advanced into introducer sheath 20 until a distal end of lumen 24 necks or slots into a corresponding lumen 25 of the hub 22. The transfer sheath lumen 24 as extra travel distance built-in to the design to allow for compression and socketing into the lumen 25 of the hub. The flexible tip 28 facilitates this interaction with the hub lumen. This ensures no gap between the transfer sheath lumen and the hub and accounts for any tolerances between devices in manufacturing.

[0080] After the transfer sheath lumen is engaged with the hub, any further distal movement of the blood pump catheter will advance blood pump 10 out of transfer sheath 18 and the introducer sheath 20 into the patient, thereby permitting the blood pump to selfexpand to its expanded configuration. Blood pump 10 may then be advanced in its expanded configuration from the distal end of introducer sheath 20 through the patient’s vasculature to the pumping site. A guide wire may be managed by a single user as in a standard rapid exchange (Rx) device.

[0081] To remove blood pump 10 from the patient, blood pump 10 is withdrawn from the pumping site (e.g., in the aorta) in its expanded configuration to the distal end of the introducer sheath 20. Further retraction of blood pump 10 compresses it into the introducer sheath for removal from the patient.

[0082] FIG. 7 is another view of the sheathing tool 16. As shown, the sheathing tool can comprise a clamshell design with first and second halves 16a and 16b. The sheathing tool can be constrained on the proximal end with threaded locking ring 17 and on the distal end with compression ring 21. To remove the sheathing tool from the transfer sheath, the compression ring 21 can be removed, and then the sheathing tool can be unthreaded from threaded locking ring 17. The two halves of the clamshell sheathing tool can then be pulled from the lumen of the transfer sheath.

[0083] FIGS. 8-14 show an alternative embodiment of a sheathing tool 16. In this embodiment, the sheathing tool comprises first half 16a and second half 16b which can be connected with a living hinge 32. The sheathing tool can be attached to the transfer sheath and transfer sheath lumen by folding one half of the sheathing tool onto the other half of the sheathing tool (as shown by the arrow) and connecting one or more engagement features 34 and / or 35 of one half to one or more corresponding engagement features 36 and / or 37 of the other half. In the illustrated embodiment, the engagement features can include buttons, snaps, depressions, hooks, slots, or any other form of mechanical engagement.

[0084] FIGS. 9 and 10 show a rear view of the sheathing tool 16, including a detent 38 on the proximal end of the sheathing tool. As shown in FIG. 11, the detent is configured to engage with the threaded locking ring 17 of the transfer sheath to constrain the proximal endof the sheathing tool. Referring to FIGS. 12-13, the distal end of the sheathing tool 16 can be constrained by inserting engagement feature 35 (e.g., hooks) from one half of the sheathing tool into corresponding engagement feature 37 (e.g., slots) of the other half of the sheathing tool. When the proximal end of the sheathing tool is constrained within the threaded locking ring, then the hooks and slots will constrain the distal end of the sheathing tool. However, when the proximal end of the sheathing tool is removed from the threaded locking ring, then the living hinge previously described will cause one half to rotate, allowing the hook 35 to release itself from the slot 37 as shown in FIG. 13 for removal of the sheathing tool.

[0085] FIGS. 14-27 show portions of a collapsible blood pump, a transfer tool 16, a transfer sheath 18, an introducer sheath 20, an annular support tool 40, and a gripper tool 42 of an introducer system according to an embodiment of the invention.

[0086] Advancement of the blood pump with respect to the transfer sheath, e.g., by pushing on the catheter extending proximally from the blood pump, will permit the collapsed blood pump to emerge from the distal end of the transfer sheath and expand to its expanded configuration. To aid with the advancement and deployment of the blood pump, the annular support tool and gripper tool are configured to interface with the blood pump catheter at a proximal end of the transfer sheath.

[0087] The annular support tool 40 extends proximally from the transfer sheath and surrounds the catheter to prevent the catheter from kinking while it is being advanced or retracted within the transfer sheath. Referring to FIG. 15, the annular support tool 40 can include a locking mechanism 45 configured to either attach to or engage with the transfer sheath 18, or alternatively, provide circumferential engagement with the catheter shaft. The locking mechanism can comprise, for example, a locking ring that opens to allow the catheter shaft to be placed therein and then can be closed around the shaft. The main body 47 of the annular support tool can include a groove 43 that extends longitudinally along the body. The groove allows for the catheter shaft to be inserted into a central lumen of the main body.

[0088] As shown in FIGS. 15-16, a translatable gripping tool 42 can be attached to the annular support tool via engagement features 44 (e.g., tabs) that slide within open grooves 46 of the annular support tool 40 as shown in FIGS. 15-16. In some embodiments, twisting or rotating the gripping tool / annular support tool when the engagement features are within the open grooves can move the engagement features past detents, providing tactile feedback to the user that the gripping tool is locked or engaged within the annular support tool.

[0089] Referring to FIGS. 17-20, the annular support tool 40 comprises an outer shell 48 that rides along a support assembly 50. The support assembly 50 may be fixed relative to the transfer sheath or to the locking mechanism 45, while the outer shell 48 is configured to slideaxially along the support assembly away from the locking mechanism / transfer sheath. As shown in FIG. 18, the outer shell may include one or more faces 52 along the interior lumen configured to support up to approximately 50% of the circumference of the blood pump catheter shaft, and the support assembly as shown in FIG. 20 also has one or more faces 54 further configured to support the remaining approximately 50% of the circumference of the blood pump catheter shaft. The faces of the main body may be opposed, transverse, or orthogonal to the faces of the support assembly. In some embodiments, the faces of the main body and the faces of the support assembly combine to support 100% of the circumference of the blood pump catheter shaft. The rails 56 of the support assembly 50 are configured to reside and slide within the grooves or openings 58 of the outer shell 48 to facilitate axial translation between the support assembly and the outer shell of the annular support tool. The support assembly 50 may include a tab or protrusion 53 near a proximal end of the support assembly to limit axial translation of the annular support tool, or to prevent the support tool from sliding off the support assembly.

[0090] FIGS. 21-22 show axial translation of the annular support tool with the outer assembly 48 riding along the rails of the support assembly 50.

[0091] FIGS. 23-24 show the same axial translation of the annular support tool, this time controlled by attaching the gripping tool 42 to the annular support tool and depressing button 52 of the gripping tool.

[0092] Advancing gripping tool distally with respect annular support tool while button 52 is depressed, causes a torsion spring to engage with the blood pump catheter to advance the catheter and the blood pump distally with respect to the transfer sheath. In some embodiments, a single advancement of the gripping tool when engaged with the catheter will advance the compressed blood pump completely out of the transfer sheath. In other embodiments, the catheter will have to be advanced and released by the gripping tool two or more times in order to move the blood pump out of the transfer sheath. In still other embodiments, the catheter may be provided with a mark that, e.g., lines up with a handle when the catheter has been advanced far enough to push the blood pump out of the transfer sheath. Tactile feedback to the user will also indicate when the blood pump has completely emerged from the transfer sheath; the frictional forces between the collapsed blood pump and the transfer sheath will disappear, and advancement will become much easier, when the blood pump is out of the transfer sheath.

[0093] FIGS. 25-27 show an alternative design of an annular support tool 40, in which the entire support tool is a clamshell design with two halves 40a and 40b to facilitate loading onto the blood pump catheter shaft. The support assembly 50 is also shown. In this example,the first half 40a of the clamshell support tool 40 can include a face 52 configured to support a first percentage (e.g., up to 25%, up to 35%, etc.) of the blood pump catheter shaft. The second half 40b can include one or more faces 54 configured to support the remaining circumference of the blood pump catheter shaft (e.g., up to 75%, up to 65%, etc.). It should be understood, however, that in any of the embodiments described herein, the faces of the support assembly and annular support tool need not support the full 100% of the circumference of the catheter blood pump shaft to be effective in providing support and preventing kinking.

[0094] The annular support tool may also be used to resheathe the blood pump. As the catheter and blood pump are withdrawn proximally and engage the distal opening of the introducer sheath, the gripping tool can be used to grab and pull the catheter into the introducer sheath.

[0095] In some examples, the depressible portion of the gripping tool can be configured such that when it is depressed the force supplied by the retention elements is released, reduced, dissipated, or otherwise adjusted to allow the gripping tool to move independent of the sheathing catheter and / or to allow the sheathing catheter to move independent of the gripping tool. For example, the depressible portion can be depressed causing the retention elements to release the sheathing catheter allowing the sheathing catheter to slide / advance through the gripping tool.Catheter Blood Pumps

[0096] Minimally-invasive rotary blood pumps are provided that can be inserted into the body in connection with the cardiovascular system to, e.g., pump arterial blood from the left ventricle into the aorta to add to the native blood pumping ability of the left side of the patient’s heart. The blood pumps described herein can be used with any of the systems or devices described above, including the transfer tool and introducer hub. An overall goal for the use of such blood pumps is to reduce the workload on the patient’s heart muscle to stabilize the patient, such as during a medical procedure that may put additional stress on the heart, to stabilize the patient prior to heart transplant, or for continuing support of the patient.

[0097] FIG. 28 A shows an example of an intravascular blood pump 100. The blood pump 100 includes an expandable / collapsible blood conduit 102 that is configured to transition between an expanded state, as shown in FIG. 28A, and a collapsed state (not shown). For example, the conduit 102 may be in the collapsed state when confined within a delivery catheter for delivery to the heart, expanded upon release from the delivery catheter for blood pumping, and collapsed back down within the delivery catheter (or other catheter) for removal from heart. When in the expanded state, the conduit 102 is radially expanded soas to form an inner lumen for passing blood therethrough. When in the expanded state, the inner lumen of the conduit 102 may be configured to accommodate blood pumped by an impeller disposed therein.

[0098] In this example, the blood pump 100 includes an impeller 104 within a proximal portion of the conduit 102. The conduit 102 includes a first (e.g., proximal) end having a first (e.g., proximal) opening 101, and a second (e.g., distal) end having a second (e.g., distal) opening 103. The first opening 101 may be configured as an outlet and the second opening 103 may be configured as an inlet for blood. For example, blood may largely enter the conduit 102 via the second (e.g., distal) opening 103 and exit the conduit 102 via the first (e.g., proximal) opening 101. In such case, the second opening 103 acts as a blood inlet and the first opening 101 acts as a blood outlet. The impeller 104 may be configured to pump blood from the inlet toward the outlet. In an exemplary operating position, the second opening 103 (e.g., inlet) may be distal to the aortic valve, in the left ventricle, and the first opening 101 (e.g., outlet) may be proximal to the aortic valve (e.g., in the ascending aorta).

[0099] The exemplary conduit 102 includes a tubular expandable / collapsible scaffold 106 that provides structural support for a membrane 108 that covers at least a portion of inner surfaces and / or outer surfaces of the scaffold 106. The scaffold 106 defines a supported lumen or blood conduit with radial strength to maintain blood flow during operation of the blood pump. The exemplary conduit is formed to be fluid impermeable by the membrane. The membrane may be attached to the scaffold, cover the scaffold, be sandwiched or molded around the scaffold, or integrated into the scaffold, and other configurations as would be understood by one of skill from the description herein. The exemplary scaffold 106 includes a material having a pattern or plurality of openings with the membrane 108 covering the openings to retain the blood within the lumen of the conduit 102. The scaffold 106 may be unitary and may be made of a single piece of material. For example, the scaffold 106 may be formed by cutting (e.g., laser cutting) a tubular shaped material. Exemplary materials for the scaffold 106 may include one or more of: nickel titanium (nitinol), cobalt alloys, and polymers, although other materials may be used.

[0100] The exemplary scaffold 106 includes proximal struts 112a extending at a proximal end near the first opening 101 (e.g., blood outlet region) and distal struts 112b that extend from the scaffold 106 near the second opening 103 (e.g., blood inlet region). The proximal struts 112a are coupled to first hub 114a of a shaft 110 of a catheter. The distal struts 112b are coupled to second hub 114b. The second or distal hub 114b can be coupled, connected to, or integral with an atraumatic distal tip 116. The distal tip 116 can be extremely flexible and compliant. In some examples, the distal tip can include a distal bend or curvature, just as a J-tip, a pigtail tip, or the like. In this example, the first hub 114a includes a bearing assembly through which a central drive cable extends. The drive cable is operationally coupled to and configured to rotate the impeller 104.

[0101] The conduit 102 has a proximal region 118, a central region 120, and a distal region 122. The central region 120 may be configured to be placed across a valve (e.g., aortic valve) such that the proximal region 118 is configured to be placed at least partially within a first heart region (e.g., ascending aorta) and the distal region 122 is at least partially within a second heart region (e.g., left ventricle). The proximal region 118 may be configured to house an impeller therein. As shown, the blood conduit 102 can have a substantially constant diameter.

[0102] The distal tip 116, conduit 102, and shaft 110 can each include sections of increased flexibility (e.g., less stiffness) relative to other sections of the blood pump. The increased flexibility sections are configured to deflect or bend when a load is applied to the blood pump 100. In some implementations, distal shaft portion 111 of shaft 110, central region 120 of conduit 102, and distal tip section 113 of distal tip 116 are the most flexible regions or sections of the blood pump 100.

[0103] For example, still referring to FIG. 28A, the shaft 110 can include a distal shaft portion 111 that is more flexible than other sections of the shaft 110. The distal shaft portion 111 can achieve increased flexibility by having a reduced braid density, reduced durometer, and / or reduced wall thickness compared to other sections of the shaft 110. The distal shaft portion is typically positioned along the aortic arch when the catheter blood pump is positioned properly in the heart, so the distal shaft portion 111 must be very flexible to bend around the aortic arch and allow the pump to span the aortic valve without kinking or large bends.

[0104] Additionally, the conduit 102 / scaffold 106 can include a central region 120 that is more flexible than the proximal region 118 and distal region 122 of the conduit. The scaffold pattem / design has been optimized to give the central region 120 more flexibility and reduced stiffness relative to the rest of the scaffold. For example, the central region 120 can include a section of helically winding scaffold elements with an optimized pitch and decreased element width to facilitate flexibility and bending in response to the anatomy while resisting kinking or collapse of the conduit.

[0105] Furthermore, the distal tip 116 can include a distal tip section 113 that is also extremely flexible / compliant. The increased flexibility of the distal tip section 113 can be achieved with decreased durometer sections and / or decreased wall thickness. The length of the distal tip 116 is configured to allow the blood pump to “dock” or rest in the ventricle apexto reduce movement of the overall assembly during use. The flexible distal tip section 113 allows for bending and accommodation of heart contraction, pump movement and varying anatomy. Additionally, the distal tip section 113 can include varying wall thickness and durometer to optimize bending and to distribute loads to other sections of the blood pump 100 (e.g., to the central region 120 or the distal shaft portion 111. The distal portion 122 of the scaffold can also include a section 125 of increased element density to increase stiffness around the inlet section. As with the proximal portion, the distal portion can include a plurality of axial elements 127. The section 125 can include elements with an increased width relative to other elements in the scaffold (e.g., the helical elements in central section 120) to provide increased stiffness in section 125. Additionally, the distal struts 112b can have a tapered leg design with a wider base that is optimized for stiffness in the inlet region of the blood pump.

[0106] Also shown in FIG. 28A, the central portion 120 can include a plurality of helical elements 129 with a pitch and width optimized to facilitate bending in the central portion without kinking. The central portion 120 must be sufficiently flexible so that it is softer than the anatomical structures it will be positioned against. Allowing for bending without kinking allows for flow performance to be maintained in a variety of operating conditions. Therefore, accommodating the anatomy does not come at the cost of flow performance.

[0107] In some aspects, the scaffold 106 shown in FIG. 28 A and 1 can generally be divided into five distinct sections: 1) central portion 122, 2) section 125, 3) section 119, 4) distal strut section 112b, 5) proximal strut section 112a. As described above, the scaffold can include central portion 122 which can include flexible helical elements that are designed to bend without kinking or collapsing, allowing flow performance to be maintained in a variety of operating conditions. Accommodating the anatomy does not come at the cost of flow performance. The central section must be sufficiently flexible so that it’s softer than anatomical structures and gives way when the blood pump contacts the anatomy. The scaffold further includes stiffer sections 119 (around the impeller 104) and 125 (towards the inlet section). Furthermore, the sections around the proximal and distal struts (the inflow and outflow sections) are also relatively stiff. In combination with sections 119 and 125, the sections on the proximal and distal ends of the scaffold function as a relatively stiff beam, especially compared to the flexible central portion. Thus, the central portion will always give or bend first when a side load is applied to the scaffold (e.g., contact with the anatomy).

[0108] FIG. 28B is a close-up view of a blood conduit 102 of the blood pump 100, including scaffold 106, membrane 108, proximal struts 112a, first opening (outlet) 101, distal struts 112b, and second opening (inlet) 103. The blood conduit and / or scaffold of the bloodpump can include features or design elements configured to maintain tip gap between the impeller and scaffold / membrane during use. As previously described, the conduit 102 can include a proximal region 118, a central region 120, and a distal region 122. The blood conduit 102 of the pump is designed with specific features configured to maintain tip gap between the impeller and the scaffold / membrane in varying anatomy. This includes design elements that allow specified sections or portions of the blood conduit to be flexible while other specified portions or sections of the blood conduit are stiff. In some embodiments, the helical elements 129 have a width that is less than a width of elements in section 119 of the proximal portion 118 and section 125 of the distal portion 122.

[0109] For example, the proximal region 118 of the scaffold can include a section 119 of increased element density to increase stiffness around the impeller and the outlet section. The section 119 of increased element density can include a plurality of axial elements 121 connected to a plurality of radial elements 123. In some embodiments, the radial elements can be arranged in a chevron pattern or arrangement of diagonal elements. In the illustrated embodiment, the axial elements 121 are positioned between two sections or rows of radial elements 123a and 123b. In some embodiments, the radial and axial elements within the section 119 can have increased width relative to other elements in the scaffold (e.g., the helical elements in central section 120) to provide increased stiffness in section 119. Additionally, the proximal struts 112a can have a tapered leg design with a wider base that is optimized for stiffness in the outlet region of the blood pump.

[0110] Additionally, the section 125 of increased element density can include a plurality of axial elements 121b connected to a plurality of radial elements 123c and 123d. In some embodiments, each set of radial elements can be arranged in a chevron pattern or arrangement of diagonal elements. In the illustrated embodiment, the axial elements 121b are positioned between a first section or row of radial elements 123 c and a second section or row of radial elements 123 d. In some embodiments, the radial and axial elements within the section 125 can have increased width relative to other elements in the scaffold (e.g., the helical elements 129 in central section 120) to provide increased stiffness in section 125. Additionally, the distal struts 112b can have a tapered leg design with a wider base that is optimized for stiffness in the outlet region of the blood pump.[OHl] The overall length of the blood conduit 102 can be approximately 60-80mm. In some examples, the length of the proximal section 118 is determined by the length of the impeller. While flexibility is desirable in the central section 120, structural rigidity can be advantageous in the distal section 122 to maintain the structure of the inlet and also allow for pushability of the blood pump / conduit, such as during pump positioning. Therefore, in oneembodiment, adjustments in the overall length of the blood conduit can be implemented by increasing a length of the axial elements 121b between the rows of radial elements 123c and 123d. For example, a 60mm long pump conduit may include identically dimensioned proximal and central sections to a 70mm or 80mm long pump conduit. However, the longer pump conduits may have increased length in the distal section 122 relative to the shorter pump versions. This increased length may be implemented by increasing the length of axial elements 121b.

[0112] FIGS. 28 A and 28B show the sections of the blood pump with increased flexibility and the sections of the pump with increased stiffness. Collectively, these sections of stiffness and flexibility are designed and arranged to provide for stiffness in sections that promote concentricity of the impeller within the scaffold while allowing for flexibility in sections that contact the tissue or must bend around the anatomy. Generally, the inlet and outlet sections of the blood pump are relatively stiff compared to the central section of the scaffold, the distal tip, and the catheter shaft which are relatively flexible. This allows for a load applied to the distal tip (e.g., contacting the heart wall with the distal tip) to be transferred from the distal tip to the center of the scaffold (central region 120) to prevent bending at the hub or inlet section of the pump. Thus, the central region is designed and configured to always give in first when a side load is applied to the blood pump or scaffold (e.g., contacting the anatomy). In the inlet and outlet sections, the struts can have increased width near attachment to the hubs (e.g., hubs 114a and 114b) to stiffen the scaffold in those sections. The outlet section includes stiff radial and axial elements and rigid support in the impeller bearing assembly for the cantilevered impeller and impeller shaft design to promote concentricity of impeller and scaffold and maintain appropriate tip gap. Similarly, the inlet section can include an increase in width for distal elements to maintain the inlet and prevent collapse. Rigidity in the distal inlet section allows any potential force from distal tip to be translated to central portion of the scaffold (and not to the inlet section). The central section accommodates compound bending and pump movement while minimizing deflection to the outlet section on the proximal portion of the scaffold.

[0113] FIG. 29 illustrates an example of a blood pump including the central region 120 of the blood conduit 102 in positioned across the aortic valve, with the distal region 122 distal to the aortic valve and the proximal region 118 proximal to the aortic valve. In this example, the flexible shaft portion 111 bends around the share radius of curvature of the aortic arch, allowing for proper positioning of the pump across the aortic valve without bending or kinking, which can increase flow through the pump and help hemolysis when the pump is in this bent configuration within the anatomy. As described above, shaft portion 111 and thecentral region 120 (positioned across the valve) are relatively flexible compared to the proximal and distal regions (outlet and inlet respectively). The flexibility of the shaft portion 111 allows for navigation around the aortic arch, and the flexible central region 120 allows for flexibility across the valve to prevent damage to the valve and surrounding anatomy. The relative stiffness of the inlet and outlet allow for blood to enter and exit the pump which can increase flow through the pump and reduce or eliminate hemolysis and / or clotting.

[0114] When a feature or element is herein referred to as being “on” another feature or element, it can be directly on the other feature or element or intervening features and / or elements may also be present. In contrast, when a feature or element is referred to as being “directly on” another feature or element, there are no intervening features or elements present. It will also be understood that, when a feature or element is referred to as being “connected”, “attached” or “coupled” to another feature or element, it can be directly connected, attached or coupled to the other feature or element or intervening features or elements may be present. In contrast, when a feature or element is referred to as being “directly connected”, “directly attached” or “directly coupled” to another feature or element, there are no intervening features or elements present. Although described or shown with respect to one embodiment, the features and elements so described or shown can apply to other embodiments. It will also be appreciated by those of skill in the art that references to a structure or feature that is disposed “adjacent” another feature may have portions that overlap or underlie the adjacent feature.

[0115] Terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. For example, as used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and / or “comprising,” when used in this specification, specify the presence of stated features, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or groups thereof. As used herein, the term “and / or” includes any and all combinations of one or more of the associated listed items and may be abbreviated as “ / ”.

[0116] Spatially relative terms, such as “under”, “below”, “lower”, “over”, “upper” and the like, may be used herein for ease of description to describe one element or feature’s relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if a device in the figures is inverted, elements described as “under” or “beneath”other elements or features would then be oriented “over” the other elements or features.Thus, the exemplary term “under” can encompass both an orientation of over and under. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly. Similarly, the terms “upwardly”, “downwardly”, “vertical”, “horizontal” and the like are used herein for the purpose of explanation only unless specifically indicated otherwise.

[0117] Although the terms “first” and “second” may be used herein to describe various features / elements (including steps), these features / elements should not be limited by these terms, unless the context indicates otherwise. These terms may be used to distinguish one feature / element from another feature / element. Thus, a first feature / element discussed below could be termed a second feature / element, and similarly, a second feature / element discussed below could be termed a first feature / element without departing from the teachings of the present invention.

[0118] Throughout this specification and the claims which follow, unless the context requires otherwise, the word “comprise”, and variations such as “comprises” and “comprising” means various components can be co-jointly employed in the methods and articles (e.g., compositions and apparatuses including device and methods). For example, the term “comprising” will be understood to imply the inclusion of any stated elements or steps but not the exclusion of any other elements or steps.

[0119] As used herein in the specification and claims, including as used in the examples and unless otherwise expressly specified, all numbers may be read as if prefaced by the word “about” or “approximately,” even if the term does not expressly appear. The terms “about,” “substantially,” or “approximately” may be used when describing magnitude and / or position to indicate that the value and / or position described is within a reasonable expected range of values and / or positions. For example, a numeric value may have a value that is + / - 0.1% of the stated value (or range of values), + / - 1% of the stated value (or range of values), + / - 2% of the stated value (or range of values), + / - 5% of the stated value (or range of values), + / - 10% of the stated value (or range of values), etc. Any numerical values given herein should also be understood to include about or approximately that value, unless the context indicates otherwise. For example, if the value “10” is disclosed, then “about 10” is also disclosed.Any numerical range recited herein is intended to include all sub-ranges subsumed therein. It is also understood that when a value is disclosed that “less than or equal to” the value, “greater than or equal to the value” and possible ranges between values are also disclosed, as appropriately understood by the skilled artisan. For example, if the value “X” is disclosed the “less than or equal to X” as well as “greater than or equal to X” (e.g., where X is a numericalvalue) is also disclosed. It is also understood that the throughout the application, data is provided in a number of different formats, and that this data, represents endpoints and starting points, and ranges for any combination of the data points. For example, if a particular data point “10” and a particular data point “15” are disclosed, it is understood that greater than, greater than or equal to, less than, less than or equal to, and equal to 10 and 15 are considered disclosed as well as between 10 and 15. It is also understood that each unit between two particular units are also disclosed. For example, if 10 and 15 are disclosed, then 11, 12, 13, and 14 are also disclosed.

[0120] Although various illustrative embodiments are described above, any of a number of changes may be made to various embodiments without departing from the scope of the invention as described by the claims. For example, the order in which various described method steps are performed may often be changed in alternative embodiments, and in other alternative embodiments one or more method steps may be skipped altogether. Optional features of various device and system embodiments may be included in some embodiments and not in others. Therefore, the foregoing description is provided primarily for exemplary purposes and should not be interpreted to limit the scope of the invention as it is set forth in the claims.

[0121] The examples and illustrations included herein show, by way of illustration and not of limitation, specific embodiments in which the subject matter may be practiced. As mentioned, other embodiments may be utilized and derived there from, such that structural and logical substitutions and changes may be made without departing from the scope of this disclosure. Such embodiments of the inventive subject matter may be referred to herein individually or collectively by the term “invention” merely for convenience and without intending to voluntarily limit the scope of this application to any single invention or inventive concept, if more than one is, in fact, disclosed. Thus, although specific embodiments have been illustrated and described herein, any arrangement calculated to achieve the same purpose may be substituted for the specific embodiments shown. This disclosure is intended to cover any and all adaptations or variations of various embodiments. Combinations of the above embodiments, and other embodiments not specifically described herein, will be apparent to those of skill in the art upon reviewing the above description.

Claims

CLAIMSWhat is claimed is:

1. A system for inserting a collapsible blood pump into a patient, the system comprising: an introducer, the introducer comprising an introducer hub and an introducer sheath extending distally from the introducer hub, the introducer sheath comprising an introducer sheath lumen, the introducer hub comprising a hub connector and a distal hub lumen surrounding a proximal end of the introducer shaft; a transfer tool comprising a transfer sheath, the transfer sheath comprising a transfer sheath lumen having a diameter substantially equal to a diameter of the introducer sheath lumen and a transfer tool connector adapted to connect to the hub connector, a distal portion of the transfer sheath extending into the hub when the transfer tool connector is connected to the hub connector; and a sheathing tool connectable to the transfer tool, the sheathing tool being configured to collapse the blood pump and place it within the transfer tool.

2. The system of claim 1, wherein the transfer tool comprises a threaded locking ring, the sheathing tool being configured to engage with the threaded locking ring.

3. The system of claim 2, wherein the sheathing tool comprises threads.

4. The system of claim 2, wherein the sheathing tool comprises one or more engagement features configured to engage with the threaded locking ring.

5. The system of claim 2, wherein the sheathing tool comprises one or more detents.

6. The system of claim 2, wherein the hub connector is configured to engage with the threaded locking ring.

7. The system of claim 6, wherein the hub connector comprises threads.

8. The system of claim 1, the sheathing tool comprising a sloped surface configured to engage with the blood pump.

9. The system of claim 1, the sheathing tool comprising a sloped surface configured to engage with proximal struts of the blood pump.

10. The system of claim 1, wherein the sheathing tool comprises a lumen with a diameter substantially equal to the diameter of the transfer sheath lumen.

11. The system of claim 1, wherein the sheathing tool comprises a lumen with a diameter less than the diameter of the transfer sheath lumen.

12. The system of claim 1, wherein the transfer sheath lumen comprises a flexible distal tip.

13. The system of claim 12, wherein the flexible distal tip comprises a material that is more flexible than the transfer sheath lumen.

14. The system of claim 12, wherein the sheathing tool comprises a lumen configured to constrain the flexible distal tip.

15. The system of claim 1, wherein the sheathing tool comprises as clamshell design.

16. The system of claim 1, further comprising a hinge connecting first and second halves of the sheathing tool.

17. The system of claim 1, further comprising a locking ring configured to constrain a distal end of the sheathing tool when the sheathing tool is connected to the transfer tool.

18. The system of claim 15, wherein a first half of the sheathing tool has a first engagement feature configured to engage with a second engagement feature of the second half of the sheathing tool.

19. The system of claim 15, wherein a first half of the sheathing tool has one or more hooks configured to engage with one or more slots of the second half of the sheathing tool.

20. The system of claim 1, wherein the distal portion of the transfer sheath extends into the distal hub lumen when the transfer tool connector is connected to the hub connector.

21. The system of claim 1, wherein the distal end of the transfer sheath abuts a proximal end of the introducer sheath when the transfer tool connector is connected to the hub connector.

22. The system of any of the previous claims, wherein the introducer hub further comprises a tapered surface extending proximally and radially outwardly from the distal hub lumen.

23. The system of any of the previous claims, wherein the introducer further comprises a one-way valve disposed in the introducer hub proximal to the introducer sheath lumen and configured to seal against vascular pressure.

24. The system of any of the previous claims, wherein the introducer further comprises a seal disposed in the introducer hub proximal to the introducer sheath and configured to seal against vascular pressure around a range of diameters of devices inserted through the seal.

25. The system of any of the previous claims, wherein the introducer further comprising a disc valve disposed in the introducer hub proximal to the introducer sheath and configured to seal against vascular pressure around a range of diameters of devices inserted through the valve.

26. The system of any of the previous claims, wherein the introducer hub further comprises a purge fluid port in fluid communication with the distal hub lumen.

27. The system of any of the previous claims, wherein the hub connector comprises threads disposed on the introducer hub.

28. The system of any of the previous claims, wherein the hub connector and transfer tool connector are configured to provide an axial force to move the transfer sheath and introducer sheath toward each other.

29. The system of any of the previous claims, wherein the transfer tool further comprises a proximal hub surrounding a proximal portion of the transfer sheath.

30. The system of claim 29, wherein the transfer tool proximal hub comprises a central lumen, the proximal portion of the transfer sheath being disposed in the central lumen, the central lumen having a reduced diameter portion proximal to a proximal end of the transfer sheath.

31. The system of claim 29, wherein the transfer tool proximal hub further comprises a purge fluid port communicating with the central lumen.

32. The system of claim 29, wherein the transfer tool proximal hub further comprises a seal adapted to seal around a catheter portion of a blood pump.

33. The system of any of the previous claims, wherein the transfer tool further comprises a handle surrounding the transfer sheath.

34. The system of claim 33, wherein the handle extends proximally from the transfer tool connector.

35. The system of claim 34, wherein the transfer tool further comprises a proximal hub, the handle extending from the transfer tool connector to the proximal hub.

36. The system of any of claims 33-35, wherein the transfer tool connector comprises threads disposed at a distal end of the handle, the distal portion of the transfer sheath extending distally beyond the transfer tool connector.

37. The system of claim 36, wherein the transfer tool connector comprises a rotatable ring with internal threads.

38. The system of any of the previous claims, wherein the distal portion of the transfer sheath is radially expandable.

39. A system for inserting a collapsible blood pump into a patient, the system comprising: a transfer tool comprising a transfer sheath, the transfer sheath comprising a transfer sheath lumen configured to receive the collapsible blood pump; andan annular support tool disposed proximally of the transfer tool, the annular support tool being configured to provide at least partial circumferential support to a proximal catheter shaft of the blood pump when the blood pump is loaded into the transfer tool.

40. The system of claim 39, wherein the annular support tool is removably attached to the transfer tool.

41. The system of claim 39, wherein the annular support tool comprises a support assembly slideably disposed therein, a distal end of the support assembly being fixed in position relative to the transfer tool.

42. The system of claim 41, wherein the annular support tool supports a first partial circumference of the proximal catheter shaft and the support assembly supports a second partial circumference of the proximal catheter shaft.

43. The system of claim 42, wherein the annular support tool supports up to 50% of the circumference of the proximal catheter shaft and the support assembly supports a remaining circumference of the proximal catheter shaft.

44. The system of claim 39, further comprising a gripping tool configured to engage with the annular support tool, the gripping tool comprising an engagement mechanism configured to engage with the proximal catheter shaft to translate the blood pump axially relative to the transfer tool.

45. The system of claim 44, wherein the engagement mechanism comprises a torsion springA46. A method of deploying an expandable blood pump in a patient, the blood pump comprising an expandable and compressible pump housing, an impeller disposed in the pump housing, and a catheter extending proximally from the pump housing, the method comprising: moving at least a portion of the pump housing proximally into a sheathing tool to radially compress the pump housing; moving at least a portion of the pump housing proximally from the sheathing tool into a transfer sheath of a transfer tool through a distal opening of the transfer sheath;removing the sheathing tool from the transfer tool; advancing the transfer sheath distally into a hub of an introducer sheath disposed in a blood vessel of the patient; advancing the pump housing out of the transfer sheath into the introducer sheath; and advancing the pump housing out of the introducer sheath and into the blood vessel.

47. The method of claim 46, wherein the transfer sheath advances distally into the hub of the introducer until a distal end of the transfer sheath abuts a proximal end of the introducer sheath.

48. The method of claim 46 or claim 47, wherein the transfer sheath comprises a transfer sheath lumen and the introducer sheath comprises an introducer sheath lumen, the transfer sheath lumen having a diameter substantially equal to a diameter of the introducer sheath lumen.

49. The method any of claims 46-48, further comprising connecting a connector of the transfer tool to a connector of the introducer hub.

50. The method of claim 49, wherein the connecting step comprises applying an axial force to move the transfer sheath and introducer sheath toward each other.

51. The method of any of claims 46-50, further comprising expanding the distal end of the transfer sheath as the pump housing moves into the transfer sheath.

52. The method of any of claims 46-51, further comprising compressing the distal end of the transfer sheath before the distal end of the transfer sheath abuts the proximal end of the introducer sheath.

53. The method of any of claims 46-52, wherein the step of moving the pump housing proximally into the transfer sheath further comprises moving the pump housing proximally until proximal struts of the pump housing engage a sheathing stop at a proximal end of the transfer sheath.

54. The method of any of claims 46-53, further comprising injecting purge fluid into a proximal end of the transfer sheath while the pump housing is disposed in the transfer sheath.

55. A catheter blood pump comprising an expandable shroud forming a blood conduit, the shroud having a stiff distal section, a stiff proximal impeller section, and a flexible central section between the distal section and the proximal impeller section, wherein the central section is configured to span the aortic valve when the proximal impeller section is positioned proximal to the aortic valve; and an elongate catheter shaft coupled to the expandable shroud, the elongate catheter shaft having a section of increased flexibility that is proximal to the expandable shroud, wherein the section of increased flexibility is configured to be positioned across the aortic arch when the central section spans the aortic valve.

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