Variable size repositioning sheath

Abstract

To provide a system and a method for inserting a medical device into a blood vessel.SOLUTION: A system may include a sheath assembly including an introducer sheath 120 and a variable size repositioning sheath 110. The variable size repositioning sheath 110 may be configured such that size can be adjusted in a radial direction and so as to be inserted to a blood vessel 142 or an expandable introducer sheath. In some aspects, the system may include an intracardiac device 130 such as a blood pump 137 including an elongated catheter 132.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Provisional Application No. 62 / 836,960, filed April 22, 2019, the entire disclosure of which is incorporated herein by reference. [Background technology]

[0002] background An intracardiac heart pump assembly can be introduced surgically or percutaneously into the heart and used to deliver blood from one location in the heart or circulatory system to another location in the heart or circulatory system. For example, when deployed intracardiac, the intracardiac pump can pump blood from the left ventricle of the heart to the aorta or from the right ventricle to the pulmonary artery. The intracardiac pump can be driven by a motor located outside the patient's body or a motor located inside the patient's body. Some intracardiac blood pump systems can operate in parallel with the native heart to supplement cardiac output and partially or completely relieve the strain on the heart's components. Examples of such systems include the IMPELLA® family of devices (Abiomed, Inc., Danvers, Massachusetts).

[0003] An intracardiac blood pump such as those described above may be inserted by catheterization through the femoral artery, femoral vein, or any other suitable path for delivering the pump to the left or right side of the heart.

[0004] In some cases, an intracardiac blood pump may be inserted using an introducer sheath, such as a rigid, fixed-diameter sheath, e.g., a peel-away introducer sheath, such as the Abiomed Impella CP 14 Fr peel-away sheath. For example, the introducer sheath may be inserted into the femoral artery through an arteriotomy to create an insertion path for the pump assembly. A portion of the pump assembly may then be advanced into the artery through the lumen of the introducer sheath. To accommodate the pump assembly, the inner diameter of the rigid introducer sheath must be large enough to accommodate the largest diameter of the pump assembly, such as the pump head, even if other portions of the pump assembly, such as the catheter, have significantly smaller diameters. In some instances, once the pump assembly is inserted, the introducer sheath may be removed, e.g., a peel-away introducer sheath may be peeled away. In such cases, a repositioning sheath having a smaller diameter than the introducer sheath may then be advanced over the pump assembly into the arteriotomy. Exchanging the introducer sheath in this manner helps close any annular gap that would otherwise exist between the arteriotomy and the medical device, and may reduce limb ischemia and arteriotomy bleeding because the repositioning sheath has a smaller diameter. Additionally, the repositioning sheath may be more easily attached to the patient, for example, by sutures, and thus may cause less discomfort than a larger introducer sheath.

[0005] In other cases, the intracardiac blood pump may be inserted using an expandable introducer sheath. The expandable introducer sheath may also be inserted through the arteriotomy into the femoral artery to create an insertion path for the pump assembly. The pump assembly may then be inserted through the expandable introducer sheath, radially stretching the expandable introducer sheath to a diameter large enough to accommodate the maximum diameter of the pump assembly. The expandable introducer sheath may be configured to radially contract or relax to a smaller resting diameter after the pump assembly is inserted, thereby reducing the time (compared to a rigid sheath, e.g., a peel-away sheath) that the arteriotomy in the patient's vasculature is stretched to a larger diameter that could cause undesirable bleeding. However, in some instances, the expandable introducer sheath assembly may not include a mechanism for fastening the expandable sheath to the catheter at the hub of the expandable introducer sheath. Furthermore, in some instances, after the expandable introducer sheath relaxes to a resting state, it may leave an annular gap between the inner surface of the expandable introducer sheath and the outer surface of the catheter extending therethrough, potentially allowing blood to leak and resulting in thrombosis in the annular gap. In such cases, a repositioning sheath may also be inserted into the expandable introducer sheath to fill such an annular gap. Using a repositioning sheath in this manner may thus help reduce bleeding and regulate blood flow within the expandable sheath and the repositioning sheath. The repositioning sheath may also be configured to be locked in place longitudinally, thereby providing additional stability for long-term support, for example, in an ICU. Summary of the Invention

[0006] overview The present technology relates to systems, devices, and methods for inserting devices (e.g., intravascular medical devices) into a blood vessel using a variable-size repositioning sheath.

[0007] In one aspect, the present disclosure describes a sheath assembly for inserting a medical device into a blood vessel, the sheath assembly including an introducer sheath and a variable-size repositioning sheath configured to be inserted into the blood vessel and radially adjustable in size. In some aspects, the variable-size repositioning sheath is configured to be radially adjustable in size up to 2 Fr less than the radial size of the introducer sheath. In some aspects, the variable-size repositioning sheath further includes a ratcheting inner repositioning sheath component, where the variable-size repositioning sheath is configured to be radially adjustable in size using the ratcheting inner repositioning sheath component. In some aspects, the variable-size repositioning sheath further includes a star-shaped inner repositioning sheath component, where the variable-size repositioning sheath is configured to be radially adjusted in size using the star-shaped inner repositioning sheath component. In some aspects, the variable-size repositioning sheath further includes a cam-type inner repositioning sheath component, where the variable-size repositioning sheath is configured to be radially adjusted in size using the cam-type inner repositioning sheath component. In some aspects, the variable size repositioning sheath further includes a mandrel-type inner repositioning sheath component, wherein the variable size repositioning sheath is configured to be radially sized using the mandrel-type inner repositioning sheath component.

[0008] In another aspect, the present disclosure describes a sheath assembly for inserting a medical device into a blood vessel, the sheath assembly including an expandable introducer sheath and a variable-size repositioning sheath inserted into the expandable introducer sheath and configured to be radially adjustable in size. In some aspects, the variable-size repositioning sheath further includes a ratcheting inner repositioning sheath component, where the variable-size repositioning sheath is configured to be radially adjustable in size using the ratcheting inner repositioning sheath component. In some aspects, the variable-size repositioning sheath further includes a star-shaped inner repositioning sheath component, where the variable-size repositioning sheath is configured to be radially adjusted in size using the star-shaped inner repositioning sheath component. In some aspects, the variable-size repositioning sheath further includes a cam-type inner repositioning sheath component, where the variable-size repositioning sheath is configured to be radially adjusted in size using the cam-type inner repositioning sheath component. In some aspects, the variable size repositioning sheath further includes a mandrel-type inner repositioning sheath component, wherein the variable size repositioning sheath is configured to be radially sized using the mandrel-type inner repositioning sheath component.

[0009] In another aspect, the present disclosure describes a blood pump system including an intracardiac device including a pump and a cannula, the pump having a pump housing, a rotor, and an opening in the pump housing, the cannula having a proximal end that interfaces with the distal end of the pump housing and a distal end with at least one distal opening, the pump configured to be operated by a motor, an elongated catheter whose distal end is coupled to the motor or the pump housing, and a sheath assembly. The sheath assembly includes an introducer sheath configured to introduce the intracardiac device into a blood vessel and a radially adjustable variable-size repositioning sheath configured to reposition the intracardiac device within the blood vessel. In some aspects, the variable-size repositioning sheath is configured to be adjustable in radial size up to 2 Fr smaller than the radial size of the introducer sheath. In some aspects, the variable-size repositioning sheath further includes a ratcheting inner repositioning sheath component, the variable-size repositioning sheath being configured to be radially adjustable in size using the ratcheting inner repositioning sheath component.

[0010] In some aspects, the variable size repositioning sheath further includes a star-shaped inner repositioning sheath component, wherein the variable size repositioning sheath is configured to be radially sized using the star-shaped inner repositioning sheath component. In some aspects, the variable size repositioning sheath further includes a cam-type inner repositioning sheath component, wherein the variable size repositioning sheath is configured to be radially sized using the cam-type inner repositioning sheath component. In some aspects, the variable size repositioning sheath further includes a mandrel-type inner repositioning sheath component, wherein the variable size repositioning sheath is configured to be radially sized using the mandrel-type inner repositioning sheath component.

[0011] In another aspect, the present disclosure describes a sheath assembly for inserting a medical device into a blood vessel, the sheath assembly including a peel-away introducer sheath having a sheath body with a fixed outer diameter and a variable-size repositioning sheath configured to be radially adjustable in size between at least a first state and a second state, where when the variable-size repositioning sheath is in the first state, the outer diameter of the variable-size repositioning sheath is larger than the fixed outer diameter and when the variable-size repositioning sheath is in the second state, the outer diameter of the variable-size repositioning sheath is smaller than the fixed outer diameter. In some aspects, the variable-size repositioning sheath further includes a ratcheting inner repositioning sheath component, where the variable-size repositioning sheath is configured to be radially adjustable in size using the ratcheting inner repositioning sheath component. In some aspects, the variable-size repositioning sheath further includes a star-shaped inner repositioning sheath component, where the variable-size repositioning sheath is configured to be radially adjustable in size using the star-shaped inner repositioning sheath component. In some aspects, the variable size repositioning sheath further includes a cam-type inner repositioning sheath component, wherein the variable size repositioning sheath is configured to be radially sized using the cam-type inner repositioning sheath component. In some aspects, the variable size repositioning sheath further includes a mandrel-type inner repositioning sheath component, wherein the variable size repositioning sheath is configured to be radially sized using the mandrel-type inner repositioning sheath component.

[0012] In some aspects of the present technology, the medical devices described herein can be delivered through an introducer sheath, which can be either a fixed-size introducer sheath, an expandable introducer sheath, or any other type of sheath. A peel-away introducer sheath can be configured to be removed from the insertion path (e.g., an arteriotomy) after a short period of time (e.g., less than one hour) and replaced with a variable-size repositioning sheath to regulate blood flow within the vessel and minimize bleeding. If the introducer sheath is a fixed-size introducer sheath, such as a peel-away introducer sheath, the introducer sheath can be removed before inserting the variable-size repositioning sheath into the arteriotomy. In such cases, the variable-size repositioning sheath can be configured to fill at least a portion of the annular gap between the arteriotomy and the catheter. For example, after a 14 Fr peel-away sheath is removed, the arteriotomy may be approximately 17.9 Fr because the approximate outer diameter of the 14 Fr peel-away sheath (with a 14 Fr inner diameter) is 17.9 Fr. The arteriotomy size may be a function of the diameter of the device being passed therethrough (e.g., a 14 Fr peel-away sheath with an outer diameter of approximately 17.9 Fr), the duration the device is passed therethrough, how gradual the arteriotomy dilation is, how smooth the device transition is, the lubricity of the introducer sheath surface during insertion, and patient factors such as age, vascular health / elasticity, and vascular disease such as plaque or calcium near the access area. In some cases, the catheter of the intravascular medical device may have an outer diameter much smaller than the arteriotomy. For example, the catheter may have an outer diameter of approximately 9 Fr. The variable-size repositioning sheath may be radially sized to fill at least a portion of the annular gap between the arteriotomy and the catheter to minimize unwanted bleeding through the annular gap. If the introducer sheath is an expandable introducer sheath, the introducer sheath may be configured to remain in the insertion path (e.g., arteriotomy) for a relatively long period of time (e.g., more than 1 hour, more than 2 hours, more than 6 hours, or any suitable period of time).If an annular gap is left between the expandable introducer sheath and the catheter, it can result in excessive blood seepage into the annular gap, potentially causing thrombosis in the annular gap. Annular gap thrombus poses a risk to the patient due to potential migration and eventual embolism. If the expandable introducer sheath is unable to seal the arteriotomy (e.g., because it is not rigid enough), a variable-size repositioning sheath can be inserted to provide a more rigid structure and seal the arteriotomy. Additionally, the expandable introducer sheath may occupy a smaller portion of the arteriotomy by itself, and insertion of the variable-size repositioning sheath can expand the sheath to occupy a larger portion of the arteriotomy. This may involve stretching the arteriotomy to a larger diameter. The variable-size repositioning sheath can be sized (e.g., radially expanded) to fit within the arteriotomy after the peel-away introducer sheath is removed. For example, a variable-size repositioning sheath can be sized to have an outer diameter of 16.9 French to fit within a 17.9 French arteriotomy. If the repositioning sheath is to be used in conjunction with a smaller expandable introducer sheath, the variable-size repositioning sheath can be sized to have an outer diameter that fits within a smaller arteriotomy (e.g., 15.9 French). When the variable-size repositioning sheath is radially sized to be slightly smaller than the arteriotomy size, it can be sized based on the allowable amount of recoil at the arteriotomy, i.e., it can be radially sized to have a diameter slightly smaller than the arteriotomy size by an amount equal to or less than the allowable amount of recoil. For example, the allowable recoil can be the amount by which the blood vessel at the arteriotomy can contract. As another example, the variable-size repositioning sheath can be sized (e.g., radially compressed) to fit within an expandable introducer sheath. A variable size repositioning sheath can be configured to be inserted within the expandable introducer sheath to regulate blood flow along the expandable sheath, minimize bleeding, and prevent thrombosis of the annular space.For example, the variable-size repositioning sheath may be sized to fit within an expandable introducer sheath having an inner diameter of 14 French and an outer diameter of 15.2 French. The variable-size repositioning sheath may be configured to be continuously adjustable in size radially over a range of diameters. The variable-size repositioning sheath may be configured to remain adjusted once unless adjusted again. Additionally, the variable-size repositioning sheath may be configured to tighten around the catheter at the hub of the expandable introducer sheath, providing long-term stability and support during extended use of the expandable introducer sheath. For example, the variable-size repositioning sheath may be secured to the catheter using a device such as a Touhy-Borst valve.

[0013] In some aspects of the present technology, the introducer sheath described herein can be inserted into the femoral artery through an arteriotomy to create an insertion path for the pump assembly. A portion of the pump assembly can then be advanced into the artery through the lumen of the introducer sheath. In some aspects of the present technology, the introducer sheath can be a peel-away introducer sheath, such as any peel-away sheath used with any of the Abiomed Impella devices (e.g., the Abiomed Impella CP 14 Fr peel-away sheath). Other standard sizes of peel-away introducer sheaths can have inner diameters of 14 Fr, 16 Fr, 18 Fr, 20 Fr, etc. In some cases, a 14 Fr peel-away sheath can have an outer diameter of approximately 17.9 Fr and an inner diameter of 14 Fr. Other standard introducer sheaths may include peel-away introducer sheaths with outer diameters of 16.7 Fr, 17.1 Fr, or other sizes between 16.7 Fr and 17.9 Fr. In some cases, the introducer sheath may be an expandable introducer sheath such as that described in U.S. Patent Application No. 16 / 277,378, published as U.S. Patent Application Publication No. 2019 / 0247627, the entire disclosure of which is incorporated herein by reference.

[0014] In some aspects of the present technology, the variable-size repositioning sheaths described herein can be configured to be radially adjusted in size so that they fit for insertion after removal of a peel-away introducer sheath or insertion into an expandable introducer sheath. The variable-size repositioning sheath can have an outer repositioning sheath component and an inner repositioning sheath component. The inner repositioning sheath component and the outer repositioning sheath component can be configured with respective characteristics (e.g., relative size, shape, material, etc.) such that moving one relative to the other can change the outer diameter of the variable-size repositioning sheath (e.g., either radially expand or radially contract). In some cases, the inner repositioning sheath component can be configured to radially expand or contract the outer diameter of the outer repositioning sheath component in response to translational movement of the inner repositioning sheath component. For example, the variable-size repositioning sheath can be configured such that when the inner repositioning component is pushed into the outer repositioning sheath, the outer repositioning sheath moves, causing the outer diameter of the outer repositioning sheath to radially increase in size. Similarly, the variable size repositioning sheath may be configured such that the size of the outer diameter of the repositioning sheath radially decreases as the inner repositioning component is withdrawn from the outer repositioning sheath component. In some aspects of the present technology, the inner repositioning component may have a cross-section shaped to radially expand or contract the size of the outer diameter of the outer repositioning sheath component in response to rotation of the inner repositioning component. In some aspects, a potential advantage of the present technology is that moving the inner and outer repositioning sheath components relative to each other results in a predictable change in size and shape of the variable size repositioning sheath along its entire length, whether the variable size repositioning sheath is in its minimum diameter state, its maximum diameter state, or any state intermediate therebetween.

[0015] In some aspects of the present technology, the variable size repositioning sheath can include a size adjustment device for expanding and contracting the radial size of the variable size repositioning sheath. For example, the device can include a ratchet- or gear-type inner repositioning component, a mandrel-type inner repositioning component, a star-shaped inner repositioning component, a cam-type inner repositioning component, an elliptical inner repositioning component, or any other suitable mechanism. The size adjustment device can be configured to allow an operator (e.g., a physician, medical professional, etc.) to change the radial size of the variable size repositioning sheath by a fixed amount by moving the inner repositioning sheath component (e.g., via translational or rotational motion). For example, the operator can control a handle, knob, lever, push device, or any other device connected to the proximal end of the inner repositioning sheath. In some aspects of the present technology, there is a known relationship between the operator's input and the resulting change in the outer diameter of the variable size repositioning sheath, allowing the operator to precisely determine how far to move the inner repositioning sheath component. For example, a clockwise rotational movement by the operator may increase the outer diameter of the variable-sized repositioning sheath by up to 10 Fr, and a counterclockwise rotational movement by the operator may decrease the outer diameter of the variable-sized repositioning sheath by up to 10 Fr. Alternatively, a counterclockwise rotational movement by the operator may increase the outer diameter of the variable-sized repositioning sheath by up to 10 Fr, and a clockwise rotational movement by the operator may decrease the outer diameter of the variable-sized repositioning sheath by up to 10 Fr. For example, for every 90-degree rotational movement imparted by the operator, the outer diameter of the variable-sized repositioning sheath may increase by 1 Fr. As another example, for every 180-degree rotational movement imparted by the operator, the outer diameter of the variable-sized repositioning sheath may increase by 2 Fr. As another example, for every 90-degree rotational movement imparted by the operator, the outer diameter of the variable-sized repositioning sheath may increase by 0.5 Fr. As another example, for every 90-degree rotational movement imparted by the operator, the outer diameter of the variable-sized repositioning sheath may increase by 0.2 Fr. As another example, for every 90 degree rotational movement imparted by the operator, the outer diameter of the variable-size repositioning sheath may increase by 0.1 Fr.As another example, for each 90-degree rotational movement imparted by the operator, the outer diameter of the variable-size repositioning sheath may decrease by 0.1 Fr. As another example, for each 1 mm translational movement imparted by the operator, the outer diameter of the variable-size repositioning sheath may increase by 1 Fr. As another example, for each 1 mm translational movement imparted by the operator, the outer diameter of the variable-size repositioning sheath may increase by 0.5 Fr. As another example, for each 1 mm translational movement imparted by the operator, the outer diameter of the variable-size repositioning sheath may increase by 0.2 Fr. As another example, for each 1 mm translational movement imparted by the operator, the outer diameter of the variable-size repositioning sheath may increase by 0.1 Fr. As another example, for each 1 mm translational movement imparted by the operator, the outer diameter of the variable-size repositioning sheath may decrease by 0.1 Fr. Thus, the relationship between the degree of movement and the incremental increase or decrease in repositioning sheath diameter is primarily a matter of design choice. The above relationships are exemplary.

[0016] In another example, the relationship between the motion applied by the operator and the resulting change in the outer diameter of the variable size repositioning sheath can be determined by the operator based on the number of clicks heard or felt by the operator when applying the motion. Furthermore, there can be a known correspondence between the length or angle between the clicks heard or felt by the operator and the resulting change in the outer diameter of the variable size repositioning sheath. For example, each click can correspond to a set amount of degree rotation, such as clicks every 30 degrees, 45 degrees, 90 degrees, 180 degrees, etc. Feedback indicating the correspondence can be provided to the operator in any form, including tactile feedback, audio feedback, or any other type of notification that informs the operator of the current size of the variable size repositioning sheath corresponding to the motion applied by the operator. In some examples, there can be gradations along the length of the variable size repositioning sheath, with the gradations occurring at regular distances from each other. For example, the gradations can occur every 1 mm, 0.5 mm, 10 mm, or any other fixed distance. Such an example may advantageously allow the operator to know in real time or near real time how the operator's actions at the proximal end of the variable size repositioning sheath are affecting or will affect the outer diameter of the variable size repositioning sheath.

[0017] In some aspects of the present technology, the outer diameter of the variable size repositioning sheath can be radially expanded from a minimum diameter state or radially contracted from a maximum diameter state to replace the peel-away introducer sheath after the peel-away introducer sheath is removed or to fill an annular gap between the expandable introducer sheath and a catheter extending therethrough. Alternatively, the outer diameter of the variable size repositioning sheath can be radially expanded or contracted from an intermediate state having a first diameter to another intermediate state having a different diameter. The variable size repositioning sheath can be packaged in an expanded state before being inserted into an arteriotomy after removal of the peel-away introducer sheath to avoid problems that can arise from being stored in a compressed state for an extended period of time (e.g., more than one week, more than one month, more than one year, etc.), such as creep of the variable size repositioning sheath when in the compressed state. The variable size repositioning sheath may also be packaged in a contracted state to avoid problems that may arise from being stored in an expanded state for extended periods of time (e.g., more than one week, more than one month, more than one year, etc.), such as, for example, an inability to reduce the size of the sheath, which may prevent the operator from reducing the radial size of the variable size repositioning sheath, or possible plastic deformation of the variable size repositioning sheath.

[0018] As noted above, in some aspects of the present technology, the variable-size repositioning sheath may be radially sized based on the allowable recoil at the arteriotomy, i.e., the amount of diameter the vessel at the arteriotomy can contract. For example, in some cases, the vessel at the arteriotomy may recoil to a smaller diameter by approximately 2 Fr or less. Thus, when using a 14 Fr peel-away introducer sheath with an outer diameter of 17.9 Fr, the variable repositioning sheath may be sized to 15.9 Fr so that the recoil size at the arteriotomy is approximately the same as the outer diameter of the repositioning sheath to allow the vessel to recoil by 2 Fr. In some cases, the variable-size repositioning sheath may also be configured to tolerate additional recoil that may occur after insertion of the variable-size repositioning sheath. For example, after a period of time (e.g., 15 minutes, 1 hour, 1 day, etc.) after insertion of the variable size repositioning sheath, the operator may decrease the radial size of the variable size repositioning sheath (e.g., decrease the radial size by 2 Fr) to allow further recoil of the vessel (e.g., to 13.9 Fr). In some cases, the operator may decrease the radial size of the variable size repositioning sheath in multiple adjustments (e.g., decrease the radial size by 1 Fr every 12 hours for a total radial size reduction of 4 Fr over 48 hours). The variable size repositioning sheath may also be held securely to the elongate catheter by using a mechanism such as a Touhy-Borst valve at the proximal end of the variable size repositioning sheath.

[0019] In some aspects of the present technology, the variable size repositioning sheath can be sized using a size adjustment device, which can include a ratchet or gear inner repositioning sheath, a mandrel inner repositioning sheath, a star inner repositioning sheath, a cam inner repositioning sheath, or an oval inner repositioning sheath. The variable size repositioning sheath can be sized in response to movement by an operator. For example, in response to rotational or translational movement of a handle, level, gear, tab, or any other equivalent device, the size adjustment device can convert the movement into a known expansion or contraction in size of the variable size repositioning sheath. For example, the variable size repositioning sheath can be initially packaged in an expanded state with an outer diameter of 16.7 Fr and configured such that a 360-degree counterclockwise rotation of the handle of the variable size repositioning sheath can convert into a 0.1 Fr radial expansion of the outer diameter of the variable size repositioning sheath. In such an example, the operator may therefore rotate the handle twelve 360-degree counterclockwise rotations to change the outer diameter size of the variable size repositioning sheath from 16.7 Fr to 17.9 Fr, thereby allowing the variable size repositioning sheath to fill the 17.9 Fr arteriotomy remaining after the 14 Fr peel-away sheath is removed.

[0020] In some aspects of the present technology, an expandable introducer sheath described herein can be inserted through an arteriotomy into the femoral artery to form an insertion path for the pump assembly. In some cases, the expandable introducer sheath can have a static outer diameter smaller than the fixed outer diameter of the peel-away introducer sheath body. Using an expandable introducer sheath allows a smaller-sized sheath to be used for insertion, allowing the arteriotomy to be performed with a larger diameter and in a shorter time, even though the sheath is used for a longer duration. Additionally, because the pump assembly only momentarily passes through the arteriotomy, the arteriotomy may be smaller than if a larger, non-expandable sheath were used. Furthermore, because the blood pump only momentarily passes through the blood vessel, friction between the intracardiac device, the expandable introducer sheath, and the vessel wall is minimized, reducing axial load and stress on the blood vessel. That is, the expandable introducer sheath body can be smaller in size and therefore does not push or pull the blood vessel along the axis of the insertion / removal path.

[0021] In some aspects of the present technology, the variable size repositioning sheath can be configured to have an adjustable radial size so that an operator of the sheath assembly can select a size of the variable size repositioning sheath that matches the type and size of the introducer sheath being used, depending on whether the operator uses a peel-away introducer sheath or an expandable introducer sheath. For example, the operator of the sheath assembly can radially adjust the size of the variable size repositioning sheath to make it suitable for use after removal of the peel-away introducer sheath or for use by insertion into an expandable introducer sheath. In some implementations, the variable size repositioning sheath can include a size adjuster for expanding and contracting the radial size of the variable size repositioning sheath. For example, the size adjuster can be a ratchet- or gear-type inner repositioning sheath component, a mandrel-type inner repositioning sheath component, a star-shaped inner repositioning sheath component, a cam-type inner repositioning sheath component, or an elliptical-shaped inner repositioning sheath component.

[0022] In some aspects of the present technology, the blood pump system described herein may include an intracardiac device including a pump and a cannula and may be configured to be at least partially inserted into a patient's heart. For example, the blood pump system may be percutaneously inserted into the heart and operate in parallel with the patient's own heart to supplement cardiac output, such as the IMPELLA® family of devices (Abiomed, Inc., Danvers, Massachusetts). The pump may include a pump housing, a rotor, and an opening in the pump housing. The rotor may be at least partially disposed within the pump housing such that a motor drives the rotor and the rotor pumps blood through the pump housing during system operation. The blood pump system may include a cannula having a proximal end that interfaces with the distal end of the pump housing and a distal end with at least one distal opening. The pump may be configured to be positioned such that the cannula extends across the patient's aortic valve, the distal end is located within the patient's left ventricle, and the proximal end is located within the patient's aorta. Thus, blood can flow through the distal opening of the cannula, through the body of the cannula, and through the pump housing. In some aspects of the present technology, the blood pump can further include a flexible protrusion extending distally from the distal end of the cannula, such as a pigtail-shaped flexible protrusion.

[0023] In some aspects of the present technology, the blood pump system may further include an elongate catheter coupled at its distal end to the motor or pump housing. The catheter may connect the pump to a controller or other operating device. In some cases, such a controller may be configured to operate the blood pump system. For example, the controller may be an Automated Impella Controller (AIC) from Abiomed, Inc. or any other suitable controller. In some aspects of the present technology, the elongate catheter may house electrical connections connecting the pump to the controller. The blood pump system may further include one or more sensors (e.g., differential pressure sensors) configured to communicate with the controller or otherwise provide patient health and pump operation data to a clinician or external device. In some aspects of the present technology, a drive cable may extend through the elongate catheter and be configured to drive operation of the rotor, for example, by controlling the speed at which the rotor rotates.

[0024] In some aspects of the present technology, the variable-size repositioning sheath can be configured to be radially sized using a ratcheting or gear-type inner repositioning sheath component. This can be implemented in any of the aspects described above. For example, the ratcheting or gear-type inner repositioning sheath component can have any type of gear cross-section with teeth. In some aspects of the present technology, the gear can be configured with different sets of teeth that produce a constant change in size of the variable-size repositioning sheath when the inner repositioning sheath component is rotated.

[0025] In some aspects of the present technology, the variable-size repositioning sheath component can be configured to be radially sized using a cam-type inner repositioning sheath. This can be implemented in any of the aspects described above. The cam-type inner repositioning sheath can be of any cam-type shape, such as circular, eccentric, oval, elliptical, hexagonal, star-shaped, etc., such that rotation of the cam-type inner repositioning sheath component corresponds to expansion or contraction of the outer diameter of the variable-size repositioning sheath.

[0026] In some aspects of the present technology, the variable-size repositioning sheath can be configured to be radially sized using a mandrel-driven inner repositioning sheath component. This can be implemented in any of the aspects described above. The mandrel-driven inner repositioning sheath can be configured to a set number of sizes that are achieved by radially expanding or contracting the mandrel component. For example, the mandrel-driven inner repositioning sheath can be configured to expand or contract to five different sizes, where a first of the five sizes corresponds to an outer diameter size of the variable-size repositioning sheath that fits into an arteriotomy left by a standard-sized peel-away introducer sheath (e.g., 17.9 Fr), a second of the five sizes corresponds to an outer diameter size of the variable-size repositioning sheath that fits into an expandable introducer sheath (e.g., 14 Fr), and the other three sizes are intermediate sizes between the first and second sizes.

[0027] These and other objects and advantages will become apparent from the following detailed description considered in conjunction with the accompanying drawings, in which like reference characters refer to like parts throughout. [Brief explanation of the drawings]

[0028] [Figure 1] FIG. 1 illustrates a deployment system according to aspects of the present disclosure, including a peel-away introducer sheath configured to introduce an intracardiac device into a patient's vasculature, and a variable-size repositioning sheath radially sized for insertion into the arteriotomy after removal of the peel-away introducer. [Figure 2] FIG. 1 illustrates a deployment system including an expandable introducer sheath configured to introduce an intracardiac device into a patient's vasculature, and a variable-size repositioning sheath radially sized for insertion into the expandable introducer sheath, according to aspects of the present disclosure. [Figure 3A] 1 is a cross-sectional view illustrating an exemplary sizing device according to aspects of the present disclosure. [Figure 3B]10A-10C illustrate how relative movement between inner and outer components of an exemplary size adjuster device can result in expansion or contraction, according to aspects of the present disclosure. [Figure 3C] 1 is a partial cross-sectional view illustrating an exemplary size adjustment device according to aspects of the present disclosure. [Figure 4A] 1 is a cross-sectional view illustrating an exemplary size adjustment device according to aspects of the present disclosure. [Figure 4B] 1 is a cross-sectional view illustrating an exemplary inner repositioning sheath component according to some aspects of the present disclosure. [Figure 4C] 1 is a cross-sectional view illustrating an exemplary inner repositioning sheath component according to some aspects of the present disclosure. [Figure 4D] 1 is a cross-sectional view illustrating an exemplary inner repositioning sheath component according to some aspects of the present disclosure. [Figure 4E] 1 is a cross-sectional view illustrating an exemplary inner repositioning sheath component according to some aspects of the present disclosure. [Figure 4F] 12A-12C are cross-sectional views illustrating exemplary stepped structures configured to be disposed within a hub of a variable-size repositioning sheath, according to aspects of the present disclosure. [Figure 5] 1A-1C illustrate a deployment system including a variable-size repositioning sheath inserted into an arteriotomy after an intracardiac device has been inserted through an introducer sheath, according to aspects of the present disclosure. [Figure 6] 1A-1C illustrate a deployment system including a variable-size repositioning sheath inserted into an arteriotomy after an intracardiac device has been inserted through an introducer sheath, according to aspects of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0029] Detailed Description To provide a general understanding of the systems, methods, and devices described herein, certain illustrative examples will be described. While the examples and features described herein are particularly described for use in connection with an intracardiac heart pump system, it will be understood that all of the components and other features outlined below can be combined with each other in any suitable manner and adapted for use with other types of medical devices, such as electrophysiology study and catheter ablation devices, angioplasty and stenting devices, angiography catheters, peripherally inserted central catheters, central venous catheters, midline catheters, peripheral catheters, inferior vena cava filters, abdominal aortic aneurysm treatment devices, thrombectomy devices, TAVR delivery systems, cardiac therapy and cardiac assist devices (including balloon pumps), cardiac assist devices implanted using a surgical incision, and any other venous or arterial-based introducer catheters and devices.

[0030] The systems and methods described herein provide a sheath assembly for inserting a medical device (e.g., an intracardiac heart pump) into a blood vessel through a vascular opening. The sheath assembly may include an introducer sheath and a variable-size repositioning sheath. The introducer sheath may include a peel-away introducer sheath or an expandable introducer sheath. The variable-size repositioning sheath may be radially adjustable in size so that its diameter can be adjusted over a certain range. In some aspects, the adjustment range of the variable-size repositioning sheath may include a diameter suitable for enabling insertion of the variable-size repositioning sheath into the introducer sheath.

[0031] The repositioning sheath may be packaged with an intracardiac device that includes a catheter passing through the repositioning sheath, such that the repositioning sheath and catheter share the same central longitudinal axis. The repositioning sheath in existing systems typically has a diameter that cannot be significantly altered. In contrast, a fixed-size repositioning sheath may have a diameter that tapers longitudinally, but the diameter cannot be adjusted before use. Therefore, to use a fixed-size repositioning sheath, the repositioning sheath must be moved longitudinally relative to the catheter into the arteriotomy before being locked into place. Because arteriotomy size can vary significantly depending on the patient or procedure, a repositioning sheath with a fixed size or diameter may not always be effective in sealing the annular gap between the arteriotomy and the catheter to prevent gross leaks and reduce the risk of limb ischemia.

[0032] Advantageously, the radial size adjustability of the variable-size repositioning sheath can be useful for insertion into blood vessels whose sizes may vary depending on patient characteristics (e.g., age, disease) or procedure characteristics (e.g., length, complexity, instruments used). Additionally, because repositioning sheaths are often packaged with intracardiac devices along with catheters that extend through the repositioning sheath, this can prevent an operator from exchanging the packaged repositioning sheath for one of a different size. However, when a variable-size repositioning sheath is included instead of a repositioning sheath having a fixed diameter, the variable-size repositioning sheath can be packaged in a given size and adjusted in size by the operator just before (or simultaneously with) sliding the repositioning sheath into place through the arteriotomy. This adjustment can be made, for example, to allow the repositioning sheath to fill at least a portion of the annular gap between the arteriotomy and the elongated catheter, which may also vary in size depending on patient and / or procedure characteristics.

[0033] The variable-size repositioning sheath with an adjustable diameter can be configured to fit both the peel-away introducer sheath and the expandable-size repositioning sheath. For example, after a 14 Fr peel-away introducer sheath is removed, the diameter of the arteriotomy can be approximately 17.9 Fr because the effective outer diameter of the 14 Fr peel-away introducer sheath is 17.9 Fr. In addition, the elongated catheter can have an outer diameter of approximately 9 Fr. Thus, in some aspects of the present technology, replacing the peel-away introducer sheath with the variable-size repositioning sheath can help fill at least a portion of the annular gap and minimize unwanted bleeding through the annular gap. In addition, in some aspects of the present technology, the variable-size repositioning sheath can be secured to the elongated catheter using a device such as a Touhy-Borst valve.

[0034] In some aspects of the present technology, a peel-away introducer sheath may be inserted into the femoral artery through an arteriotomy to form an insertion path for the pump assembly. In such a case, a portion of the pump assembly may then be advanced through the lumen of the peel-away introducer sheath and into the artery. Once the pump assembly is inserted, the introducer sheath may then be peeled back, and a variable-size repositioning sheath may then be advanced over the pump assembly and into the arteriotomy.

[0035] In some aspects of the present technology, as an alternative to a peel-away introducer sheath, an expandable introducer sheath may be inserted into the femoral artery through an arteriotomy to form an insertion path for the pump assembly. In such cases, a portion of the pump assembly may be advanced into the artery through the lumen of the expandable introducer sheath, and the expandable sheath body may expand and contract between different states to accommodate a medical device. For example, the expandable introducer sheath body may be elongated and have a first, smaller diameter state for inserting the introducer sheath body into the arteriotomy, and then shortened or relaxed to a second, larger diameter state upon reaching the desired location. The second, larger diameter state may be configured to allow a portion of a medical device having a larger cross-sectional area than the cross-sectional area of ​​the lumen in the first, smaller diameter state to pass through the lumen of the introducer sheath. In some aspects of the present technology, the introducer sheath may be further expanded from a resting state when the sheath is in the desired position to a larger diameter state when a medical device is threaded through the introducer sheath.

[0036] 1 illustrates a deployment system 100 according to aspects of the present disclosure, including a peel-away introducer 120 configured to introduce an intracardiac device 130 into a patient's vasculature and a variable-size repositioning sheath 110 that is radially sized for insertion into an arteriotomy 148 after removal of the peel-away introducer 120. The deployment system 100 includes the variable-size repositioning sheath 110, the peel-away introducer sheath 120, and the intracardiac device 130. FIG. 1 illustrates an exemplary deployment of the peel-away introducer 120, where the intracardiac device 130 is inserted through the peel-away introducer sheath 120 and positioned such that the intracardiac device 130 is in the patient's vasculature.

[0037] In the example of FIG. 1 , intracardiac device 130 includes pump 137. Pump 137 includes cannula 136, pump housing 139 having a proximal opening, a rotor (not shown), and distal cage 133 having a distal opening. In all instances herein, the operator (rather than the patient) is used as the reference point, and thus "proximal" refers to a direction pointing toward or closer to the operator, and "distal" refers to a direction away from or farther from the operator. The pump is configured to be operated by a motor within motor housing 131. Elongated catheter 132 is coupled to motor housing 131 at its distal end. Elongated catheter 132 defines a central lumen therein. In some aspects of the present technology, elongated catheter 132 may be coupled to pump housing 139. The proximal end of cannula 136 interfaces with the distal end of pump housing 139. The distal end of the cannula 136 interfaces with a distal cage 133, which defines a distal opening. The cannula 136 defines a lumen therein. In some aspects of the present technology, blood may be pumped proximally through the cannula 136, such that the proximal opening of the pump housing 139 functions as a blood outflow port and the distal opening of the distal cage 133 functions as a blood inflow port. In some aspects of the present technology, blood may be pumped distally through the cannula 136, such that the proximal opening of the pump housing 139 functions as a blood inflow port and the distal opening of the distal cage 133 functions as a blood outflow port. A flexible tip 138 may be attached to the distal end of the distal cage 133. In some aspects of the present technology, the central lumen of the elongate catheter 132 and the lumen of the cannula 136 may together define a lumen through the intracardiac device 130 for use in delivering purge fluid during operation of the device.

[0038] In some aspects of the present technology, the motor of the pump 137 may be "on-board," as shown in FIG. 1 , and may be located inside the patient's body during operation and may include electrical leads that send power to the motor to drive the pump 137. In some aspects of the present technology, the motor of the pump 137 may be located outside the patient's body and may actuate the rotor via a drive shaft, drive cable, or drive line. For example, the motor of the pump 137 may be located within the handle (not shown) of the intracardiac device 130. In some aspects of the present technology, the drive cable may extend through the elongate catheter body 132 to a rotor located near the proximal end of the cannula 136.

[0039] The peel-away introducer sheath 120 includes a hub 124 and a peel-away introducer sheath body 122. The peel-away introducer sheath body 122 is defined by a distal end 128, a proximal end 126, and a lumen extending through the sheath body 122 between the proximal and distal ends. At the proximal end 126, the hub 124 is attached to the peel-away introducer sheath body 122. Within the hub 124 is a hemostatic valve (not shown) that allows insertion of components through the hub 124 and into the sheath body 122 while preventing fluid (e.g., blood) within the sheath body 122 from leaking through the hub 124.

[0040] The peel-away introducer sheath body 122 has a fixed, predetermined outer diameter 123 and a predetermined inner diameter 125. Both the inner and outer diameters are fixed along the entire length of the introducer sheath body 122. The distal end 128 of the introducer sheath body 122 has a tip. In some aspects of the present technology, the tip of the distal end 128 is tapered and has an inner diameter and an outer diameter. In some aspects, the taper can be linear for both the inner and outer diameters. If the peel-away introducer sheath 122 is not radially expandable, the inner diameter 125 must be large enough to accommodate the largest diameter of the intracardiac device 130 (e.g., pump head, etc.), even if other portions of the pump assembly (e.g., catheter) have significantly smaller diameters. 1 , once the intracardiac device 130 is positioned within the patient's vasculature, the peel-away introducer 120 may be peeled away (e.g., by peeling the peel-away introducer 120 along axial cuts or lines thereon that allow the sheath to tear axially) and removed from the patient. In some aspects of the present technology, the peel-away introducer sheath 120 may have a sheath body with an inner diameter of 14 Fr and an outer diameter of 17.9 Fr, leaving an approximately 17.9 Fr opening at the arteriotomy 148 in the blood vessel 142 and / or at the insertion site 146 in the skin 140 after the peel-away introducer sheath 120 is removed.

[0041] The variable size repositioning sheath 110 includes a hub 114 and a variable size repositioning sheath body 112. The variable size repositioning sheath body 112 is defined by a distal end 118, a proximal end 116, and a lumen 119 extending through the sheath body 112 between the proximal and distal ends. The distal end of the hub 114 is attached to the proximal end 116 of the variable size repositioning sheath body 112. The hub 114 includes a size adjustment device 115 configured to adjust an outer diameter 117 of the variable size repositioning sheath body 112. In some aspects of the present technology, an operator may adjust the outer diameter 117 by moving (e.g., pushing, toggling, twisting, etc.) the proximal end of the size adjustment device 115. For example, a translational or rotational movement may cause a radial expansion or contraction of the outer diameter 117 of the variable size repositioning sheath body 112. Various possible configurations of size adjuster 115 are described in detail with reference to examples in Figures 3A-3C and 4A-4F. While Figure 1 shows outer diameter 117 of variable-size repositioning sheath body 112 as being larger than outer diameter 123 of peel-away introducer sheath body 122, the illustration in Figure 1 is not intended to indicate relative dimensions, and outer diameter 117 may be smaller than, equal to, or larger than outer diameter 123.

[0042] In some aspects of the present technology, the variable size repositioning sheath hub 114 may be configured to lock to the introducer sheath hub 124 using any suitable type of locking mechanism. For example, the variable size repositioning sheath hub 114 may lock to the introducer sheath hub 124 using a locking pin, a clamp, a twist lock, a pop lock, a snap fit, etc. In some aspects of the present technology, the locking mechanism may be further configured to rotate the variable size repositioning sheath hub 114 relative to the introducer sheath hub 124 when the two are locked together.

[0043] In some aspects of the present technology, the variable size repositioning sheath 110 can be part of a larger assembly, such as a repositioning unit or a guidewire repositioning unit.

[0044] In some aspects of the present technology, intracardiac device 130 may be inserted into the femoral artery through an arteriotomy to form an insertion path for the pump assembly. A portion of the pump assembly may then be advanced into the artery (e.g., blood vessel 142) through the lumen of peel-away introducer sheath 120. Once pump assembly 137 is inserted, introducer sheath 120 may be peeled back. After removing peel-away introducer sheath 120, variable size repositioning sheath 110 may then be advanced, for example, into the arteriotomy to replace the removed peel-away introducer sheath 120. By replacing peel-away introducer sheath 120 with a variable size repositioning sheath 110 having an outer diameter smaller than the outer diameter of peel-away introducer sheath 120, limb ischemia and arteriotomy bleeding may be reduced. After removal of the peel-away repositioning sheath 120, an annular gap may exist between the arteriotomy 148 and the outer surface of the elongate catheter 132, which can lead to bleeding at the arteriotomy 148 and possibly at the insertion site 146. Insertion of the variable size repositioning sheath 110 may be used to fill the annular gap and prevent bleeding while still allowing the arteriotomy 148 to undergo an acceptable amount of recoil (e.g., about 0 Fr to about 2 Fr). Additionally, in some aspects of the present technology, the variable size repositioning sheath 110 may also be configured to be secured to the patient using, for example, sutures, to prevent movement of the variable size repositioning sheath 110 relative to the elongate catheter 132 and potential patient discomfort. To allow some recoil of arteriotomy 148 in blood vessel 142 while still avoiding an annular gap that could allow bleeding, outer diameter 117 of variable size repositioning sheath body 112 can be adjusted so that it is within a range of about 0 Fr to about 2 Fr of outer diameter 123 of peel away introducer sheath body 122. For example, if peel away introducer sheath body 122 creates a 17.9 Fr arteriotomy 148, outer diameter 117 of variable size repositioning sheath body 112 can be set using size adjustment device 115 to be no less than 15.9 Fr and no greater than 17.9 Fr.In some aspects of the present technology, this adjustment of outer diameter 117 of variable size repositioning sheath body 112 may occur before or simultaneously with the distal end 118 of variable size repositioning sheath 110 being advanced into arteriotomy 148. In some aspects, outer diameter 117 of variable size repositioning sheath body 112 may be adjusted (or readjusted) after distal end 118 of variable size repositioning sheath 110 has been inserted into arteriotomy 148.

[0045] In some aspects of the present technology, variable size repositioning sheath 110 may be packaged in an expanded state to avoid problems that may arise from being stored in a compressed state, such as creep of variable size repositioning sheath 110 when in the compressed state. For example, variable size repositioning sheath 110 may deform if held in a compressed state for an extended period of time (e.g., more than about one week, more than about one month, more than about one year, etc.). However, variable size repositioning sheath 110 may also be packaged in a compressed or neutral state if creep is not an issue and / or if it is preferable to do so due to other considerations.

[0046] In some aspects of the present technology, variable size repositioning sheath 110 may be packaged in a state that reduces the likelihood that adjustment of outer diameter 117 will be necessary before advancing into arteriotomy 148 after removal of peel away introducer sheath 120. For example, if variable size repositioning sheath 110 is packaged with, or is expected to be used with, a peel away introducer sheath 120 having an outer diameter 123 of 17.9 Fr, variable size repositioning sheath 110 may be packaged in an expanded state such that its outer diameter 117 is preset using size adjustment device 115 to a value between 15.9 Fr and 17.9 Fr (or some other range if recoil of arteriotomy 148 is expected to be greater or less than 0 Fr to 2 Fr). However, in some aspects, variable size repositioning sheath 110 may be packaged in a state that requires it to be expanded or contracted using size adjustment device 115 to be the appropriate size for insertion into arteriotomy 148.

[0047] The size of the variable size repositioning sheath 110 may be adjusted for each patient because the inner diameter of the blood vessel 142, the distance 144 between the skin 140 and the blood vessel 142, the size of the arteriotomy 148, and the amount of recoil at the arteriotomy 148 may all vary from patient to patient. Thus, a size adjustment device 115 may be used to adjust the outer diameter 117 of the variable size repositioning sheath body 112 smaller or larger depending on these patient-specific characteristics.

[0048] Additionally, an operator using a sheath assembly to place a pump within a patient may choose to use either a peel-away introducer sheath, such as that shown in FIG. 1 and described above, or an expandable introducer sheath, such as that shown in FIG. 2 and described below. The operator's choice of which type of introducer sheath to use may be based, in part, on the operator's experience or knowledge of each type of introducer sheath, the type of procedure, and / or the patient's anatomy. As further described below, the variable-size repositioning sheaths disclosed herein may also be used in conjunction with expandable introducer sheaths.

[0049] 2 illustrates a deployment system 200 according to aspects of the present disclosure, including an expandable introducer 220 configured to introduce an intracardiac device 230 into a patient's vasculature and a variable-size repositioning sheath 210 that is radially sized for insertion into the expandable introducer sheath 220. The variable-size repositioning sheath 210 is of the same type as the variable-size repositioning sheath 110 illustrated and described in FIG. 1. The deployment system 200 includes the variable-size repositioning sheath 210, the expandable introducer sheath 220, and an intracardiac device 230. FIG. 2 illustrates an exemplary deployment of the expandable introducer 220, with the intracardiac device 230 inserted through the expandable introducer sheath 220 and positioned such that the intracardiac device 230 enters the patient's vasculature.

[0050] In the example of FIG. 2, intracardiac device 230 includes pump 237. Pump 237 includes cannula 236, pump housing 239 having a proximal opening, a rotor (not shown), and distal cage 233 having a distal opening. The pump is configured to be operated by a motor within motor housing 231. Elongated catheter 232 is coupled at its distal end to motor housing 231. Elongated catheter 232 defines a central lumen therein. In some aspects of the present technology, elongated catheter 232 may be coupled to pump housing 239. A proximal end of cannula 236 interfaces with a distal end of pump housing 239. A distal end of cannula 236 interfaces with distal cage 233, which defines a distal opening. Cannula 236 defines a lumen therein. In some aspects of the present technology, blood may be pumped proximally through cannula 236, such that a proximal opening of pump housing 239 functions as a blood outflow port and a distal opening of distal cage 233 functions as a blood inflow port. In some aspects of the present technology, blood may be pumped distally through cannula 236, such that a proximal opening of pump housing 239 functions as a blood inflow port and a distal opening of distal cage 233 functions as a blood outflow port. A flexible tip 238 may be attached to the distal end of distal cage 233. In some aspects of the present technology, the central lumen of elongate catheter 232 and the lumen of cannula 236 may together define a lumen through intracardiac device 230 for use in delivering purge fluid during operation of the device.

[0051] In some aspects of the present technology, the motor of the pump 237 may be "on-board," as shown in FIG. 2, and may be located inside the patient's body during operation and may include electrical leads that send power to the motor to drive the pump 237. In some aspects of the present technology, the motor of the pump 237 may be located outside the patient's body and may actuate the rotor via a drive shaft, drive cable, or drive line. For example, the motor of the pump 237 may be located in the handle (not shown) of the intracardiac device 130. In some aspects of the present technology, the drive cable may extend through the elongate catheter body 232 to a rotor located near the proximal end of the cannula 236.

[0052] The expandable introducer sheath 220 includes a hub 224 and an expandable introducer sheath body 222. The expandable introducer sheath body 222 is defined by a distal end 228, a proximal end 226, and a lumen extending through the sheath body 222 between the proximal and distal ends. At the proximal end 222, the hub 224 is attached to the expandable introducer sheath body 222. Proximal to the hub 224 is a hemostasis valve (not shown) within the hub 224. Such a hemostasis valve within the hub 224 can allow insertion of components through the hub 224 and into the sheath body 222 while preventing fluid (e.g., blood) within the sheath body 222 from leaking through the hub 224. The distal end 228 of the expandable introducer sheath body 222 may also be configured to be atraumatic to prevent or minimize the risk of damaging the blood vessel wall or any other anatomical structure during insertion and / or while the expandable introducer sheath body 222 remains within the patient.

[0053] The expandable introducer sheath body 222 has an expandable outer diameter 223 and an inner diameter 225. The expandable outer diameter 223 of the expandable introducer sheath body 222 may be smaller than the fixed outer diameter 123 of the peel-away introducer sheath body 122 when in a relaxed state. The use of an expandable introducer sheath allows the sheath body to be reduced in size during insertion and after a medical device has been passed through the sheath into the blood vessel. As a result, the expandable introducer sheath may allow the blood vessel and arteriotomy to spend less time at a larger diameter than a fixed-sized peel-away sheath, even if the expandable introducer sheath remains in the patient for a longer period of time than a peel-away sheath. This may allow the expandable introducer sheath to cause less trauma to the blood vessel and tissue than a fixed-diameter introducer sheath, such as a peel-away introducer sheath. In that regard, the outer diameter 223 of the expandable introducer sheath body 222 may be smaller than the largest outer diameter of the intracardiac device 230 at rest and may expand to a larger diameter as the intracardiac device passes through the expandable introducer sheath body 222. Similarly, the expandable introducer sheath body 222 may be configured to relax or recoil so that its outer diameter 223 returns to a smaller, resting state after the largest portion(s) of the intracardiac device 230 have passed through the expandable introducer sheath body 222. This also allows the blood vessel 242, arteriotomy 248, and insertion site 246 to recoil to a smaller, more natural diameter after the largest portion(s) of the intracardiac device 230 have passed through the expandable introducer sheath body 222. Furthermore, the intracardiac device 230 may recoil to a smaller size than would be the case with a fixed diameter sheath because it only momentarily passes through the vessel wall at the arteriotomy 248. Additionally, because the intracardiac device 230 only momentarily passes through the blood vessel 242, friction between the intracardiac device 230, the expandable introducer sheath body 222, and the blood vessel wall may be reduced, again reducing axial loads and stress on the blood vessel 242 (compared to a fixed diameter introducer sheath).That is, in a relaxed or resting state with no applied force, the expandable introducer sheath body 222 may have a smaller diameter than a fixed diameter introducer sheath body (e.g., peel-away introducer sheath body 122) and therefore does not push or pull on the blood vessel 242 and / or arteriotomy 248. Additionally, when the intracardiac device 230 passes through the expandable introducer sheath body 222, the blood vessel 242 and arteriotomy 248 are simply expanded radially outward.

[0054] The expandable introducer sheath body 222 may have any suitable configuration. In some aspects of the present technology, the expandable introducer sheath body 222 may have a structure comprised of a frame and one or more coatings, or other configurations such as those described in U.S. Patent Application No. 16 / 277,378, published as U.S. Patent Application Publication No. 2019 / 0247627, which is incorporated herein by reference. For example, the frame may include multiple strands extending longitudinally between the proximal and distal ends of the frame. The frame may also include a smooth coating around the outer surface and protrusions extending into the lumen along the inner surface. In some aspects of the present technology, the frame may be comprised of at least one of the following materials: nitinol round wire, nitinol flat wire, stainless steel round wire, stainless steel flat wire, liquid crystal polymer, polyamide, polyetheretherketone (PEEK), polyethylene, or polytetrafluoroethylene (PTFE). In some aspects, the frame may have a braided configuration. In some aspects, the frame may be encapsulated by at least one of the following polymers: silicone, thermoplastic polyurethane, styrenic block copolymer (SBC), elastomers including thermoplastic elastomers (TPE), fluorinated ethylene propylene (FEP), or cyclic olefin copolymer (COC). Such a frame and encapsulation material combination may allow the sheath body 222 to expand and contract while maintaining an open lumen and retaining sufficient rigidity to withstand axial forces when a medical device is inserted or withdrawn, and may further promote smooth blood flow along the outer surface of the sheath to reduce the risk of thrombus (blood clot) formation.

[0055] The variable size repositioning sheath 210 includes a hub 214 and a variable size repositioning sheath body 212. The variable size repositioning sheath body 212 is defined by a distal end 218, a proximal end 216, and a lumen 219 extending through the sheath body 212 between the proximal and distal ends. The distal end of the hub 214 is attached to the proximal end 216 of the variable size repositioning sheath body 212. The hub 214 includes a size adjustment device 215 configured to adjust an outer diameter 217 of the variable size repositioning sheath body 212. In some aspects of the present technology, an operator may adjust the outer diameter 217 by moving (e.g., pushing, toggling, twisting, etc.) the proximal end of the size adjustment device 215. For example, a translational or rotational movement may cause a radial expansion or contraction of the outer diameter 217 of the variable size repositioning sheath body 212. Various possible configurations of size adjuster 215 are described in detail with reference to the examples in Figures 3A-3C and 4A-4F. While Figure 2 shows outer diameter 217 of variable-size repositioning sheath body 212 as being larger than outer diameter 223 of expandable introducer sheath body 222, the illustration in Figure 2 is not intended to depict relative dimensions, and outer diameter 217 may be smaller than, equal to, or larger than outer diameter 223.

[0056] In some aspects of the present technology, a variable size repositioning sheath body 210 may be inserted into an expandable introducer sheath 220. For example, the variable size repositioning sheath body 212 may be routed over an elongate catheter 232, through the hub 224 of the expandable introducer 220, and into the expandable introducer sheath body 222. The variable size repositioning sheath body 212 may then be advanced through the expandable introducer sheath body 222 until the distal end 218 of the variable size repositioning sheath body 212 passes through the arteriotomy 228. Inserting the variable size repositioning sheath 210 into the expandable introducer sheath 220 in this manner may allow the variable size repositioning sheath 220 to be used to partially or completely fill any annular gap that may exist between the inner surface of the expandable introducer sheath body 222 and the outer surface of the elongate catheter 232, as well as any annular gap that may exist between the arteriotomy 248 and the outer surface of the expandable introducer sheath body 222. Inserting the variable size repositioning sheath 210 into the expandable introducer sheath 220 may also provide stability and prevent kinking within the expandable introducer sheath body 222.

[0057] Depending on the needs of the operator, before or simultaneously with inserting the variable size repositioning sheath 210 into the expandable introducer 220, the outer diameter 217 of the variable size repositioning sheath body 212 can be adjusted using the size adjustment device 215 to be less than, the same as, or greater than the relaxed inner diameter 225 of the expandable introducer sheath body 222. For example, in some aspects of the present technology, the expandable introducer sheath body 222 can have an outer diameter 223 of about 15.9 Fr and an inner diameter 225 of about 14.7 Fr, and the outer diameter 217 of the variable size repositioning sheath body 212 can be adjusted to be less than 14.7 Fr. Similarly, in some aspects of the present technology, the outer diameter 217 of the variable size repositioning sheath body 212 may be adjusted to be the same as or larger than the largest portion of the intracardiac device 230 (e.g., 5.05 mm to 5.25 mm if the intracardiac device 230 is one of the Abiomed Impella devices, such as an Impella CP pump). Additionally, in some aspects of the present technology, the outer diameter 217 of the variable size repositioning sheath body 212 may be adjusted (or readjusted) after the variable size repositioning sheath 210 is inserted into the expandable introducer 220.

[0058] In some aspects of the present technology, variable size repositioning sheath 210 may be further configured to be clamped or fastened onto elongate catheter 232 to prevent or limit relative movement therebetween in the longitudinal direction. For example, variable size repositioning sheath 210 may be secured to elongate catheter 232 using a device such as a Touhy-Borst valve, which may be located within or adjacent to hub 214. In some aspects of the present technology, variable size repositioning sheath 210 may be configured to be attached to the patient, for example, by sutures, and thus prevent or limit relative movement between variable size repositioning sheath 210 and the patient, and, when clamped, between elongate catheter 232 and the patient.

[0059] In some aspects of the present technology, variable size repositioning sheath 210 may be packaged in an expanded state to avoid problems that may arise from being stored in a compressed state, such as creep of variable size repositioning sheath 210 when in the compressed state. For example, variable size repositioning sheath 210 may deform if held in the compressed state for an extended period of time (e.g., more than about one week, more than about one month, more than about one year, etc.). However, variable size repositioning sheath 210 may also be packaged in a compressed or neutral state if creep is not an issue and / or if it is preferable to do so due to other considerations.

[0060] In some aspects of the present technology, variable size repositioning sheath 210 may be packaged such that it is less likely to require adjustment when used in conjunction with expandable introducer sheath 220. For example, if variable size repositioning sheath 210 is packaged with, or is expected to be used in conjunction with, an expandable introducer sheath 220 that has an inner diameter 225 of 14.7 Fr at rest, variable size repositioning sheath 210 may be packaged such that its outer diameter 217 is preset to a value of 14.7 Fr or less using size adjustment device 215. However, in some aspects, variable size repositioning sheath 210 may be packaged such that it needs to be expanded or contracted using size adjustment device 215 to be sized appropriately for insertion into expandable introducer sheath 220. For example, in some aspects of the present technology, variable size repositioning sheath 210 may be packaged in a manner that reduces the likelihood that adjustment of outer diameter 217 will be necessary when used in conjunction with a standard peel-away introducer sheath, as described above in connection with FIG. 1. In such a case, an operator can simply actuate size adjustment device 215 of variable size repositioning sheath 210 to configure the size of variable size repositioning sheath body 212 to their particular needs, even if variable size repositioning sheath 210 is ultimately used in combination with an expandable introducer sheath such as that shown in FIG.

[0061] The size of the variable size repositioning sheath 210 may be adjusted for each patient because the inner diameter of the blood vessel 242, the distance 244 between the skin 240 and the blood vessel 242, the size of the arteriotomy 248, the amount of recoil at the arteriotomy 248, and the annular gap between the outer surface of the elongate catheter 232 and the inner surface of the expandable introducer sheath body 222 may all vary from patient to patient. Thus, a size adjustment device 215 may be used to adjust the outer diameter 217 of the variable size repositioning sheath 210 smaller or larger depending on these patient-specific characteristics.

[0062] 3A illustrates an exemplary size adjustment device configured to expand or contract the size of a variable-size repositioning sheath in accordance with aspects of the present technology. In that regard, size adjustment device 300 includes a variable-size repositioning sheath 310, which includes an outer repositioning sheath component 312 with a hub 314, an inner repositioning sheath component 320, and a handle 317. Outer repositioning sheath component 312 includes a distal end 318, a proximal end 316, and a tapered cavity or lumen extending therethrough between the proximal and distal ends. Inner repositioning sheath component 320 is disposed within the tapered cavity or lumen of outer repositioning sheath component 312. The outer surface of the portion of inner repositioning sheath component 320 disposed within outer repositioning sheath component 312 is also linearly tapered. The inner repositioning sheath 320 includes a distal end 328, a proximal end 326, and a lumen 319 extending therethrough between the proximal and distal ends such that an elongated catheter 332 can be inserted through the lumen 319. A handle 317 is disposed at the proximal end 326 of the inner repositioning sheath component 320. In some aspects of the present technology, the handle 317 can be replaced with a level, tab, gear, or any other device suitable for moving the inner repositioning sheath component 320.

[0063] In some aspects of the present technology, the inner repositioning sheath component 320 can be more rigid than the outer repositioning sheath component 312. In some aspects of the present technology, the inner repositioning sheath component 320 can be reinforced with a sleeve of a different material. For example, the inner repositioning sheath component 320 can be polymeric and reinforced with a metal sleeve. In some aspects of the present technology, the inner repositioning sheath component 320 can be made of a material that has higher strength than the outer repositioning sheath component 312. In some aspects of the present technology, the inner repositioning sheath component 320 can include a metal frame. Making the inner repositioning sheath component 320 more rigid than the outer variable-size repositioning sheath component 312 can help prevent or limit deformation of the inner repositioning sheath component 320 when it acts on the outer repositioning sheath component 312 to expand or contract the outer diameter of the variable-size repositioning sheath 310.

[0064] The size adjustment devices described herein (e.g., size adjustment device 300, size adjustment device 400) can be configured so that the inner repositioning component acts on the outer repositioning sheath component to expand or contract the variable size repositioning sheath continuously or in discrete increments. In some aspects of the present technology, the size adjustment devices described herein can be configured to allow the operator to determine how much the variable size repositioning sheath will be expanded or contracted with each adjustment. For example, in some aspects of the present technology, the size adjustment device can have graduated graduations that indicate what the outer diameter of the variable size repositioning sheath will be based on the position or orientation of the inner repositioning component. In some aspects of the present technology, the size adjustment device can have detents spaced at regular intervals so that the operator gets tactile feedback via handle 317 for each increment (e.g., every 0.1 Fr, every 0.5 Fr, etc.) by which the outer diameter of the variable size repositioning sheath is adjusted. In such cases, the detents can be further configured to provide some resistance or friction to the size adjustment device being moved so that the size adjustment device attempts to maintain its setting. In some aspects of the present technology, the size adjustment device may include circuitry configured to provide audio, visual, and / or tactile feedback (or provide signals to one or more additional components configured to generate audio, visual, and / or tactile output based thereon). In such cases, the audio, visual, and / or tactile feedback may be delivered in real time or substantially in real time.

[0065] In some aspects of the present technology, the inner repositioning sheath component 320 can be made from a material with a low coefficient of friction. For example, the inner repositioning sheath component 320 can be coated with at least one of the following low-friction materials: a hydrophilic coating, a lubricious silicone coating, a non-hydrophilic lubricious silicone coating, an MDX coating, or a PTFE coating. Additionally, the inner repositioning sheath component 320 can be formed from a polymeric material containing a lubricious additive (e.g., polymers with Mobilize additives from Compounding Solutions, LLC, or polymer products such as ProPell Low Friction Compound from Foster Corporation). In some aspects, vapor deposition can be used to add a low-friction coating, such as fluorinated ethylene propylene (FEP), cyclic olefin copolymer (COC), or thermoplastic polyurethane (TPU), to the inner repositioning sheath component 320. The use of a low-friction material or coating on the inner repositioning sheath component 320 can help prevent abrasion between the inner repositioning sheath component 320 and the outer repositioning sheath component 312, and / or between the lumen 319 of the inner repositioning sheath component 320 and the portion of the medical device passing therethrough (e.g., the elongated catheter 332).

[0066] As shown in the example of FIG. 3A and described further below with respect to FIG. 3B, the inner repositioning sheath component can be linearly tapered. In that regard, in the example of FIG. 3A, the inner repositioning sheath component 320 uniformly tapers at a constant angle along the length of the inner repositioning sheath, and the outer repositioning sheath component 312 has a complementary taper. Additionally, as shown in the example of FIG. 4A and described further below with respect to FIGS. 4A-4F, the cross-section of the inner repositioning sheath component can also be uniform in the longitudinal direction. In that regard, in the example of FIG. 4A, the portion of the inner repositioning sheath component 420 that interacts with the outer repositioning sheath component is not tapered in diameter.

[0067] The handle 317 may be formed on or attached to the proximal end 326 of the inner repositioning sheath component 320. For example, the handle 317 and the remainder of the inner repositioning sheath component 320 may be formed from a single piece of material or may be separate pieces joined together. When the handle 317 is configured to be attached to the distal end 326 of the inner repositioning sheath component 320, a snap fit, press fit, or any other suitable connection may be used. In some aspects of the present technology, the handle 317 may further be configured to be detachable from the remainder of the inner repositioning sheath component 320. In the example of FIG. 3A , the lumen 319 passes through the handle 317. However, in some aspects of the present technology, the handle 317 may be configured to be attached to the proximal end 326 of the inner repositioning sheath component 320 such that the lumen 319 does not need to pass through the handle 317.

[0068] 3A , the outer surface of inner repositioning sheath component 320 and the inner surface of outer repositioning sheath component 312 have complementary tapers. As a result of these complementary tapers, moving inner repositioning sheath component 320 distally relative to outer repositioning sheath component 312 causes variable size repositioning sheath 310 to expand the outer diameter of variable size repositioning sheath 310. Additionally, variable size repositioning sheath 310 can be configured such that moving inner repositioning sheath component 320 proximally relative to outer repositioning sheath component 312 causes variable size repositioning sheath 310 to contract or be allowed to contract the outer diameter of variable size repositioning sheath 310. In some aspects of the present technology, this relative longitudinal movement between the inner repositioning sheath component 320 and the outer repositioning sheath component 312 can be caused by the operator rotating the inner repositioning sheath component 320 (e.g., by the operator rotating the inner repositioning sheath component 320 using the handle 317). For example, in some aspects of the present technology, the inner repositioning sheath component 320 and the outer repositioning sheath component 312 (or portions thereof) can be threaded such that rotation of the inner repositioning sheath component 320 is translated into relative longitudinal movement between the inner repositioning sheath component 320 and the outer repositioning sheath component 312. In some aspects of the present technology, this relative movement between the inner repositioning sheath component 320 and the outer repositioning sheath component 312 can be caused by the operator translating the inner repositioning sheath component 320 in a proximal or distal direction (e.g., by the operator sliding the inner repositioning sheath component 320 proximally or distally using the handle 317).

[0069] In some aspects of the present technology, both the outer surface of inner repositioning sheath component 320 and the inner surface of outer repositioning sheath component 312 may taper in the opposite direction to that shown in FIG. 3A such that both the outer diameter of inner repositioning sheath component 320 and the inner diameter of outer repositioning sheath component 312 decrease toward their proximal ends. In such a case, moving inner repositioning sheath component 320 proximally relative to outer repositioning sheath component 312 causes variable size repositioning sheath 310 to expand the outer diameter of variable size repositioning sheath 310, and moving inner repositioning sheath component 320 distally relative to outer repositioning sheath component 312 causes or allows variable size repositioning sheath 310 to contract the outer diameter of variable size repositioning sheath 310.

[0070] For example, in some aspects of the present technology, the variable size repositioning sheath 310 can be configured such that clockwise rotation of the inner repositioning sheath component 320 corresponds to a uniform radial contraction of the outer diameter of the outer repositioning sheath component 312, and counterclockwise rotation of the inner repositioning sheath component 320 corresponds to a uniform expansion of the outer diameter of the outer repositioning sheath component 312. Similarly, in some aspects of the present technology, the variable size repositioning sheath 310 can be configured such that counterclockwise rotation of the inner repositioning sheath component 320 corresponds to a uniform contraction of the outer diameter of the outer repositioning sheath component 312, and clockwise rotation of the inner repositioning sheath component 320 corresponds to a uniform expansion of the outer diameter of the outer repositioning sheath component 312.

[0071] In some aspects of the present technology, the variable size repositioning sheath 310 can be configured such that each degree of clockwise rotation of the inner repositioning sheath component 320 corresponds to a certain amount of radial contraction of the outer diameter of the outer repositioning sheath component 312, and each degree of counterclockwise rotation of the inner repositioning sheath component 320 corresponds to a certain amount of expansion of the outer diameter of the outer repositioning sheath component 312. Similarly, in some aspects of the present technology, the variable size repositioning sheath 310 can also be configured such that each degree of counterclockwise rotation of the inner repositioning sheath component 320 corresponds to a certain amount of radial contraction of the outer diameter of the outer repositioning sheath component 312, and each degree of clockwise rotation of the inner repositioning sheath component 320 corresponds to a certain amount of expansion of the outer diameter of the outer repositioning sheath component 312. For example, the variable-size repositioning sheath 310 can be configured such that a 180-degree rotation (e.g., one-half rotation of the handle 317) can correspond to a radial expansion or contraction of the outer diameter of the outer repositioning sheath component 312 by a certain amount (e.g., 0.5 Fr). As another example, a 360-degree rotation (e.g., one rotation of the handle 317) can correspond to a radial expansion or contraction of the outer diameter of the outer repositioning sheath component 312 by a certain amount (e.g., 1 Fr).

[0072] As noted above, in some aspects of the present technology, variable size repositioning sheath 310 may be configured such that handle 317 provides feedback to the operator corresponding to known changes in the outer radial diameter of variable size repositioning sheath 310. For example, at certain changes in radial size (e.g., every 0.1 Fr, every 0.5 Fr, etc.), handle 317 may provide feedback to the operator in the form of a "click" of a notch in the handle, vibration of the handle, or tactile feedback, audio feedback, or any other type of notification so that the operator can determine the current size of variable size repositioning sheath 310.

[0073] In some aspects of the present technology, the variable size repositioning sheath 310 can be configured such that an operator can impart translational motion to the inner repositioning sheath component 320 to radially expand or contract the size of the variable size repositioning sheath 310. For example, the variable size repositioning sheath 310 can be configured such that by pushing or pulling the inner repositioning sheath component 320 (e.g., via handle 317) a certain amount (e.g., 1 cm), the outer diameter of the variable size repositioning sheath 310 can expand or contract by a set amount (e.g., 1 Fr). In some aspects of the present technology, the size adjustment device 300 can further include a “stepped” or “click” connector, as further described in FIG. 4F , in which a certain amount of translational motion in the proximal or distal direction corresponds to a “step” or “click,” with each “step” or “click” in the connector corresponding to a known change in the radial size of the variable size repositioning sheath 310.

[0074] 3B illustrates how distal movement of the inner repositioning sheath component 320 relative to the outer repositioning sheath component 312 (whether caused by the operator rotating or translating the inner repositioning sheath component 320) corresponds to a uniform radial expansion of the outer diameter of the outer repositioning sheath component 312. In particular, FIG. 3B illustrates how the angle 322 of the taper of the inner repositioning sheath component 320 determines the change in radial size of the variable-size repositioning sheath 312. In that regard, as the inner repositioning sheath component 320 moves in the x-direction from position 320A to 320B, its outer surface exerts a normal force against the complementary tapered inner surface of the outer repositioning sheath 312, resulting in the outer surface of the outer repositioning sheath 312 being pushed radially outward from position 312A to position 312B. The tangent of the taper angle 322 of the inner repositioning sheath component 320 (which is the same taper angle of the outer repositioning sheath component 312) determines how much radial expansion occurs with a given movement in the x-direction. Thus, if angle 322 is 60 degrees and the operator translates handle 317 a distance of 1 cm (or rotates handle 317 the amount necessary to translate variable-size repositioning sheath 320 by 1 cm), the outer surface of the outer repositioning sheath component 312 will expand in the full radial direction by [(1 cm) × tan(60°)], and the diameter of the outer repositioning sheath component 312 will therefore expand by twice that amount (i.e., [2 × (1 cm) × tan(60°)]). Taper angle 322 can thus be selected to obtain a desired rate of diameter change between incremental handle translation and the resulting radial expansion of the repositioning sheath.

[0075] 3C is a cross-sectional view of an additional exemplary size adjustment device configured to expand or contract the size of a variable-size repositioning sheath in accordance with aspects of the present technology. In the example of FIG. 3C, rather than the entire outer surface of the inner repositioning sheath component 320 tapering linearly between the proximal and distal ends as shown in FIG. 3A, the outer surface of the inner repositioning sheath component 320 (or one or more portions thereof) may instead have serrated features. Similarly, rather than the entire inner surface of the outer repositioning sheath component 312 tapering linearly between the proximal and distal ends as shown in FIG. 3A, the inner surface of the outer repositioning sheath component 312 (or one or more portions thereof) may instead have serrated features complementary to the serrated features of the inner repositioning sheath 320. For clarity, the illustration in FIG. 3C shows an exaggerated gap between the complementary serrations of the inner repositioning sheath component 320 and the outer repositioning sheath component 312; however, there may be little or no gap between these surfaces at rest, and the surfaces contact during use (as described below). In that regard, in the example of FIG. 3C , as the inner repositioning sheath component 320 translates proximally or distally, the serrations of the inner repositioning sheath component 320 move into contact with the complementary serrations of the outer repositioning sheath component 312, causing it to radially expand or contract (or allow contraction). For example, when an operator of the sizing device in FIG. 3C translates the inner repositioning sheath component 320 a distance 315, the surfaces of each serration of the inner repositioning sheath component 320 slide over the complementary surfaces of each serration of the outer repositioning sheath component 312, until, for example, peak 321 reaches peak 323. This relative motion causes the outer repositioning sheath component 312 to expand, according to the same principles as described above with respect to Figure 3B. Similarly, if the inner repositioning sheath component 320 is then moved in the opposite direction such that peak 321 begins to move away from peak 323, the outer repositioning sheath component 312 will (or can) contract.

[0076] In some aspects of the present technology, the use of serration features, as shown in FIG. 3C , can help the outer repositioning sheath component 312 expand and contract more uniformly along its entire length, thereby reducing bending and deformation. In some aspects of the present technology, the operator can impart translational motion to the inner repositioning sheath component 320 by pushing or pulling the inner repositioning sheath component 320 or a handle attached thereto, as described above. In some aspects of the present technology, the operator can impart translational motion to the inner repositioning sheath component 320 by rotating the inner repositioning sheath component 320 or a handle attached thereto, as described above. In such a case, the serrations on the inner repositioning sheath component 320 and the outer repositioning sheath component 312 are not threads, but there may be threaded connections in other portions of the interface between the inner repositioning sheath component 320 and the outer repositioning sheath component 312 such that rotating the inner repositioning sheath component 320 may cause the inner repositioning sheath component 320 to translate relative to the outer repositioning sheath component 312.

[0077] FIG. 4A illustrates an exemplary size adjustment device configured to expand or contract the size of a variable-size repositioning sheath in accordance with aspects of the present technology. In that regard, the size adjustment device 400 includes a variable-size repositioning sheath 410, including an outer repositioning sheath component 412 with a hub 414, an inner repositioning sheath component 420, and a handle 417. The outer repositioning sheath component 412 includes a distal end 418, a proximal end 416, and a cylindrical or generally cylindrical cavity or lumen extending therethrough between the proximal and distal ends. The inner repositioning sheath component 420 is disposed within the cavity or lumen of the outer repositioning sheath component 412. The portion of the inner repositioning sheath 320 disposed within the cavity or lumen of the outer repositioning sheath component 412 is also cylindrical or generally cylindrical and may be configured as further described below with respect to the exemplary cross-section of FIG. 4A shown in FIGS. 4B-4F. The inner repositioning sheath 420 includes a distal end 428, a proximal end 426, and a lumen 419 extending therethrough such that an elongated catheter 432 can be inserted through the lumen 419. A handle 417 is disposed at the proximal end 426 of the inner repositioning sheath component 420. In some aspects of the present technology, the handle 417 can be replaced with a level, tab, gear, or any other device suitable for moving the inner repositioning sheath component 420. Except as described below, the sizing device 400 can have the same functions and components as the sizing device 300, as described above with reference to FIGS. 3A-3C.

[0078] In some aspects of the present technology, the inner repositioning sheath component 420 can be more rigid than the outer repositioning sheath component 412. In some aspects of the present technology, the inner repositioning sheath component 420 can be reinforced with a sleeve of a different material. For example, the inner repositioning sheath component 420 can be polymeric and reinforced with a metal sleeve. In some aspects of the present technology, the inner repositioning sheath component 420 can be made of a material that has higher strength than the outer repositioning sheath component 412. In some aspects of the present technology, the inner repositioning sheath component 420 can include a metal frame. Making the inner repositioning sheath component 420 more rigid than the outer variable-size repositioning sheath component 412 can help prevent or limit deformation of the inner repositioning sheath component 420 when it acts on the outer repositioning sheath component 412 to expand or contract the outer diameter of the variable-size repositioning sheath 410.

[0079] In some aspects of the present technology, the inner repositioning sheath component 420 can be configured as a hollow mandrel such that an elongated catheter 432 can be inserted through the lumen of the mandrel. In some aspects of the present technology, the inner repositioning sheath component 420 can have different cross-sectional areas that determine the expansion or contraction of the size of the variable-size repositioning sheath body 412, as will be described in detail with reference to FIGS. 4B-4E.

[0080] In some aspects of the present technology, the variable size repositioning sheath 410 can be configured such that by moving the inner repositioning sheath component 420, the inner repositioning sheath component 420 acts on the outer repositioning sheath component 412 to radially expand or contract the size of the variable size repositioning sheath 410. For example, rotational movement of the inner repositioning sheath component 420 (e.g., an operator rotating the inner repositioning sheath component 420 using the handle 417) can correspond to a radial expansion or contraction of the outer diameter of the outer repositioning sheath component 412. In that regard, in some aspects of the present technology, the variable size repositioning sheath 410 can be configured such that clockwise rotation of the inner repositioning sheath component 420 corresponds to a uniform radial contraction of the outer diameter of the outer repositioning sheath component 412, and counterclockwise rotation of the inner repositioning sheath component 420 corresponds to a uniform expansion of the outer diameter of the outer repositioning sheath component 412. Similarly, in some aspects of the present technology, the variable-size repositioning sheath 410 can be configured such that counterclockwise rotation of the inner repositioning sheath component 420 corresponds to a uniform radial contraction of the outer diameter of the outer repositioning sheath component 412, and clockwise rotation of the inner repositioning sheath component 420 corresponds to a uniform radial expansion of the outer diameter of the outer repositioning sheath component 412.

[0081] In some aspects of the present technology, the variable size repositioning sheath 410 can be configured such that each degree of rotation of the inner repositioning sheath component 420 corresponds to a set amount of expansion or contraction of the outer diameter of the outer repositioning sheath component 412. For example, the variable size repositioning sheath 410 can be configured such that a 180 degree rotation (e.g., one half rotation of the handle 317) can correspond to a fixed amount (e.g., 0.5 Fr) of radial expansion or contraction of the outer diameter of the outer repositioning sheath component 412. As another example, a 360 degree rotation (e.g., one rotation of the handle 317) can correspond to a fixed amount (e.g., 1 Fr) of radial expansion or contraction of the outer diameter of the outer repositioning sheath component 412.

[0082] 4B shows a cross-sectional area of ​​an exemplary inner repositioning sheath component 420 in accordance with aspects of the present technology. In the example of FIG. 4B, the inner repositioning sheath component 420 has a ratchet or gear-type mechanism made up of an outer ratchet component 440 and an inner ratchet component 441. The inner ratchet component 441 has a series of alternating long teeth 442 and short teeth 444, and the outer ratchet component 440 has a corresponding pattern of long and short gaps into which each of these teeth may fit. The inner ratchet component 441 is rotated relative to the outer ratchet component 440, causing each long tooth 442 to move into the short gaps of the outer ratchet component 440 (and each short tooth 444 to move into the long gaps of the outer ratchet component 440), thereby causing the outer ratchet component 440 to radially expand. The expansion of the outer ratchet component 440 acts on the outer repositioning sheath component 412, expanding the size of the variable size repositioning sheath 410, as described above. Further rotation in the same direction causes the long teeth 442 to return into the long gaps of the outer ratchet component 440 and the short teeth 444 to return into the short gaps of the outer ratchet component 440, thereby allowing the outer ratchet component 440 to radially contract again (thus allowing the variable size repositioning sheath 410 to contract, as described above). In some aspects of the present technology, the inner ratchet component 441 can be made of a stronger material than the outer ratchet component 440. In some aspects of the present technology, the outer ratchet component 440 can be made of a flexible material, such as one of the polymers described above. In some aspects of the present technology, the inner ratchet component 441 can be made of a rigid material, such as a metal. The inner ratchet component 441 has a hole 446 that can form a portion of the lumen 419.

[0083] 4B shows four long teeth 442 and four short teeth 444, any suitable number of teeth may be used. Similarly, while the teeth 442 and 444 in FIG. 4B have straight edges, teeth of any suitable shape and contour may be used. In some aspects of the present technology, the size of the long teeth 442 and short teeth 444 (and thus the corresponding sizes of the long and short gaps of the outer ratchet component 440) may be selected to provide a particular amount of expansion and contraction. For example, the size of the long teeth 442 and short teeth 444 (and the corresponding sizes of the long and short gaps of the outer ratchet component 440) may be configured so that the variable-size repositioning sheath 410, when in the expanded state, fits into an arteriotomy left by a standard-sized peel-away introducer sheath (e.g., a 17.9 Fr arteriotomy) and, when in the contracted state, fits into a smaller expandable introducer sheath (e.g., having an inner diameter of 14 Fr).

[0084] 4C shows a cross-sectional area of ​​an exemplary inner repositioning sheath component 420 in accordance with aspects of the present technology. In the example of FIG. 4C, the inner repositioning sheath component 420 has a cam-type mechanism made up of an outer cam component 450 and an inner cam component 451. The inner cam component 451 has a series of alternating valleys 452 and peaks 444, and the outer cam component 450 has corresponding contoured gaps made up of thicker and thinner portions 456 and 458 into which the valleys 452 and peaks 454 can mate. The inner cam component 451 is rotated relative to the outer cam component 450, causing the peaks 454 to move into the thicker portions 456 of the outer cam component 450 and the valleys 452 to move into the thinner portions 458 of the outer cam component 450, thereby causing the outer cam component 450 to radially expand. The expansion of the outer cam component 450 acts on the outer repositioning sheath component 412, as described above, to expand the size of the variable size repositioning sheath 410. Further rotation in either direction causes the peaks 454 to return to the thinner portions 458 of the outer cam component 450 and the valleys 452 to return to the thicker portions 456 of the outer cam component 450, thereby allowing the outer cam component 450 to radially contract again (thus allowing the variable size repositioning sheath 410 to contract, as described above). In some aspects of the present technology, the inner cam component 451 can be made of a stronger material than the outer cam component 450. In some aspects of the present technology, the outer cam component 450 can be made of a flexible material, such as one of the polymers described above. In some aspects of the present technology, the inner cam component 451 can be made of a rigid material, such as a metal. The inner cam component 451 has a hole 456 that can form a portion of the lumen 419.

[0085] 4C shows six valleys 452 and six peaks 454, any suitable number of peaks and valleys may be used. Similarly, peaks and valleys of any suitable shape and contour may be used, such as circular, eccentric, oval, elliptical, hexagonal, star-shaped, etc. In some aspects of the present technology, the size of the valleys 452 and peaks 454 (and thus the corresponding sizes of the thicker and thinner portions 456 and 458 of the outer cam component 450) may be selected to provide a particular amount of expansion and contraction. For example, the size of the valleys 452 and peaks 454 (and the corresponding sizes of the thicker and thinner portions 456 and 458) may be configured so that the variable-size repositioning sheath 410, when in the expanded state, fits into an arteriotomy left by a standard-sized peel-away introducer sheath (e.g., a 17.9 Fr arteriotomy) and, when in the contracted state, fits into a smaller expandable introducer sheath (e.g., having an inner diameter of 14 Fr).

[0086] FIG. 4D illustrates a cross-sectional area of ​​an exemplary inner repositioning sheath component 420 in accordance with aspects of the present technology. In the example of FIG. 4D, the inner repositioning sheath component 420 has a mandrel-type mechanism. In that regard, FIG. 4D illustrates the mandrel-type inner repositioning sheath component 460, including a hole 466 (which may form a portion of the lumen 419) and mandrel components 460A-460C. The mandrel-type inner repositioning sheath component 460 is attached to a hub (not shown) configured to actuate the mandrel components 460A-460C, such as a hub with a stepped connector as described below with respect to FIG. 4F. When the mandrel-type inner repositioning sheath component 460 is rotated relative to the hub, the hub applies a force to the mandrel components 460A, 460B, and 460C, causing them to expand radially outward, which further expands the inner repositioning sheath component 420 and the variable-size repositioning sheath 410 as described above. Similarly, in some aspects of the present technology, when the mandrel-type inner repositioning sheath component 460 is rotated relative to its hub, the hub forces (or unforces) the mandrel components 460A, 460B, and 460C to contract radially outward, which contraction further contracts or allows the inner repositioning sheath component 420 and the variable-size repositioning sheath 410 as described above. In some aspects of the present technology, the mandrel-type inner repositioning sheath component 460 can be configured to contract radially inward in response to a clockwise rotation and expand radially outward in response to a counterclockwise rotation. In some aspects of the present technology, the mandrel-type inner repositioning sheath component 460 can be configured to contract radially inward in response to a counterclockwise rotation and expand radially outward in response to a clockwise rotation.

[0087] In some aspects of the present technology, as further described with reference to FIG. 4F , the mandrel-driven inner repositioning sheath component 460 and its hub may be configured in a set number of sizes that allow the mandrel components 460A-460C to radially expand or contract. For example, the mandrel-driven inner repositioning sheath component 460 and its hub may be configured in five different sizes. For example, one of the five sizes may be preset to adjust the diameter of the variable-size repositioning sheath 410 to fit an arteriotomy left by a standard-size peel-away introducer sheath (e.g., a 17.9 Fr arteriotomy), a second of the five sizes may be preset to produce a diameter of the variable-size repositioning sheath 410 that fits a smaller expandable introducer sheath (e.g., having a 14 Fr inner diameter), and the other three sizes may be preset to produce diameters between the first and second sizes to accommodate patient-specific and procedure-specific criteria.

[0088] FIG. 4E illustrates a cross-sectional area of ​​an exemplary inner repositioning sheath component 420 in accordance with aspects of the present technology. In the example of FIG. 4E, the inner repositioning sheath component 420 has a set of conduits 472 through which a set of elliptical slotted rods 474 pass. The slotted rods 474 are connected to a hub (not shown) configured to rotate each rod 474 within its respective conduit 472. In the example of FIG. 4E, the inner repositioning sheath component 420 comprises a material that is sufficiently elastic to allow the conduits 472 to deform when the slotted rods 474 are rotated. In doing so, when the elliptical slotted rods 474 are rotated 90 degrees in a radial direction from the tangential orientation illustrated in FIG. 4E (i.e., the major axis of each ellipse is tangential to the center point of the inner repositioning sheath component 420), the conduits 472 deform radially, thereby expanding the outer diameter of the inner repositioning sheath component 420 (and thus the variable-size repositioning sheath 410, as described above). Similarly, when the elliptical gap rod 474 is rotated another 90 degrees from the radial orientation to the original tangential orientation shown in FIG. 4E , the conduit 472 relaxes radially and deforms tangentially, thereby contracting the outer diameter of the inner repositioning sheath component 420 (and thus, as described above, the variable-size repositioning sheath 410). In some aspects of the present technology, the inner repositioning sheath component 420 may further include a rigid inner sleeve (not shown) configured to prevent deformation resulting from rotation of the gap rod 474 from increasing or decreasing the size of the hole 476. As described above, the hole 476 may form a portion of the lumen 419. While the example of FIG. 4E shows an elliptical gap rod 474 and a circular conduit 472, the gap rod and conduit may be of any shape suitable for causing deformation when the gap rod 472 is rotated within the conduit 474.

[0089] FIG. 4F shows a cross-sectional view of an exemplary stepped structure configured to be disposed within a variable-size repositioning sheath hub, in accordance with aspects of the present technology. The stepped structure 484 is configured to be disposed within the variable-size repositioning sheath hub, which may be further lockingly connected within an introducer sheath hub (e.g., introducer sheath hub 124), as described above. In some aspects of the present technology, the stepped structure 484 may be an integral part of the variable-size repositioning sheath hub. In the example of FIG. 4F, the stepped structure 484 has a set of locking stages 484A-484E of different lengths. When the variable-size repositioning sheath hub with the stepped structure 484 is rotated relative to a component of the inner repositioning sheath component 412 (e.g., mandrel-type inner repositioning sheath component 460), a single one of the locking stages 484A-484E may be configured to engage with a component of the inner repositioning sheath component 412 at a time. 4D , the variable size repositioning sheath hub can be configured such that, when rotated one relative to the other (e.g., by rotating handle 417), locking stages 484A-484E sequentially engage mandrel components 460A-460C, thereby changing the outer diameter of inner repositioning sheath component 420 by an amount determined by the size of each locking stage. In some aspects of the present technology, locking stages 484A-484E can be selected to change the diameter of variable size repositioning sheath 410 by a fixed amount of French or to produce a size corresponding to the expected use (e.g., for use with a standard size peel-away introducer sheath (e.g., a 17.9 Fr arteriotomy), a smaller expandable introducer sheath (e.g., having a 14 Fr inner diameter), etc.). 4F includes five locking stages 484A-484E, any number of stages may be used. For example, when sizing a variable-size repositioning sheath, more locking stages (e.g., anywhere from 10 to 100) may be used for greater refinement and accuracy (e.g., 5 stages with a 0.5 Fr step size vs. 50 stages with a 0.05 Fr step size).

[0090] 5 illustrates an exemplary deployment system including a variable-size repositioning sheath inserted into an arteriotomy after an intracardiac device 518 has been inserted into a patient's vasculature through an introducer sheath according to some aspects of the present disclosure. The deployment system 500 includes a handle 502, a sterile sleeve 504, a Touhy-Borst adapter 508, a hemostatic stylet 510, an elongate catheter 506, a variable-size repositioning sheath 514 having a hub 512 attached to its proximal end, an insertion site 516, and the intracardiac device 518. The handle 502 is proximal to the sterile sleeve 504. The sterile sleeve 504 is distal to the handle 502 and proximal to the Touhy-Borst adapter 508. The hemostatic stylet 510 is connected at its proximal end to the distal end of the Touhy-Borst adapter 508. An elongated catheter 506 is inserted through the lumen of the sterile sleeve 504 , the lumen of the Touhy-Borst 508 adapter, the lumen of the hemostatic stylet 510 , and the lumen of the variable-size repositioning sheath 514 .

[0091] In some aspects of the present technology, the elongated catheter 506 can be a 9 Fr catheter. In some aspects of the present technology, the hub 512 of the variable size repositioning sheath 514 can be configured to clamp or fasten the elongated catheter 506 to stabilize the elongated catheter 506 and prevent it from moving longitudinally relative to the variable size repositioning sheath 514.

[0092] In some aspects of the present technology, the gap 507 between the hemostatic stylet 510 and the hub 512 may form a sterile barrier for the elongated catheter 506. For example, the hub 512 may be clamped or tightened around the elongated catheter 506 to ensure that the gap 507 is maintained between the distal end of the hemostatic stylet 510 and the hub 512.

[0093] 6 illustrates an exemplary deployment system including a variable-size repositioning sheath inserted into an arteriotomy after an intracardiac device 618 has been inserted into a patient's vasculature through an introducer sheath, according to some aspects of the present disclosure. The deployment system 600 includes a handle 602, a sterile sleeve 604, a Touhy-Borst adapter 608, a hemostatic stylet 610, an elongate catheter 606, a hub 612, the variable-size repositioning sheath 614, an insertion site 616, and the intracardiac device 618. The handle 602 is proximal to the sterile sleeve 604. The sterile sleeve 604 is distal to the handle 602 and proximal to the Touhy-Borst adapter 608. The hemostatic stylet 610 is connected at its proximal end to the distal end of the Touhy-Borst adapter 608. The hemostatic stylet 610 is inserted into the lumen of the variable size repositioning sheath 614 at the proximal end of the variable size repositioning sheath 614. The elongate catheter 606 is inserted through the lumen of the sterile sleeve 604, the lumen of the Touhy-Borst 608 adapter, the lumen of the hemostatic stylet 610, and the lumen of the variable size repositioning sheath 614. Because the hemostatic stylet 610 is inserted into the variable size repositioning sheath 614, there is no gap between the hemostatic stylet 610 and the variable size repositioning sheath 614.

[0094] In some aspects of the present technology, the elongated catheter 606 can be a 9 Fr catheter. In some aspects of the present technology, the hub 612 of the variable size repositioning sheath 614 can be configured to clamp or tighten the elongated catheter 606 to stabilize the elongated catheter 606 and prevent it from moving longitudinally relative to the variable size repositioning sheath 614.

[0095] 6, the portion of the elongate catheter 606 proximal to the hub 612 is covered by a sterile sleeve 604. In some aspects of the present technology, the sterile sleeve 604 may be composed of polyolefin, polyethylene, low density polyethylene (LDPE), linear low density polyethylene (LLDPE), medium density polyethylene (MDPE), or high density polyethylene (HDPE).

[0096] In some aspects of the present technology, the hemostatic stylet 610 may be configured to lock to the hub 612 of the variable size repositioning sheath 614. In that regard, the hemostatic stylet 610 may be configured to lock to the hub 612 using any suitable locking mechanism, such as a twist lock, a pop lock, a locking pin, or any other equivalent locking mechanism. In some aspects of the present technology, in addition to the hemostatic stylet 610 configured to lock to the hub 612, the hub 612 may also be configured to secure the elongated catheter 606 in place (e.g., using a clamp or fastening means). Locking the hemostatic stylet 610 to the hub 612 and locking the hub 612 around the elongated catheter 606 may regulate hemostasis between the variable size repositioning sheath 614 and the opening of the blood vessel, which may further regulate blood flow along the variable size repositioning sheath and help reduce the likelihood of ischemia.

[0097] In addition to the benefits discussed above, the variable size repositioning sheath assembly herein may be advantageous over existing expandable sheath assemblies because it maintains guidewire access throughout the entire procedure by always allowing the operator to remove the pump with the repositioning sheath in place.

[0098] The foregoing description merely illustrates the principles of the present technology. Thus, the devices and methods described herein can be implemented in other than the described implementations, which are presented for purposes of illustration and not limitation. While the systems, devices, and methods disclosed herein are described with respect to use in percutaneous insertion of a blood pump, it should be understood that they may be applied in any situation in which a device is inserted into a patient and hemostasis is required. Additionally, the disclosed features may be implemented in any combination or subcombination (including multiple subcombinations and subcombinations) with one or more other features described herein. The various features described or illustrated above, including any components thereof, may be combined or integrated into other systems. Finally, certain features may be omitted or not implemented without departing from the spirit of the present technology.

Claims

1. an introducer sheath; a variable-size repositioning sheath configured to be inserted into a blood vessel and to be radially adjustable in size; A sheath assembly for inserting a medical device into a blood vessel, comprising:

2. The sheath assembly of claim 1 , wherein the variable-size repositioning sheath is configured to be adjustable to a radial size up to 2 Fr smaller than the radial size of the introducer sheath.

3. the variable-size repositioning sheath an outer repositioning sheath component; an inner repositioning sheath component at least partially disposed within the outer repositioning sheath component; Including, the variable-size repositioning sheath is further configured to change radial size based on translational or rotational movement of the inner repositioning sheath component relative to the outer repositioning sheath component.

10. The sheath assembly of claim 1.

4. 10. The sheath assembly of claim 1, wherein the variable size repositioning sheath further comprises a ratcheting inner repositioning sheath component, the variable size repositioning sheath configured to be radially adjustable in size using the ratcheting inner repositioning sheath component.

5. 10. The sheath assembly of claim 1, wherein the variable size repositioning sheath further comprises a cam-type inner repositioning sheath component, the variable size repositioning sheath configured to be radially sized using the cam-type inner repositioning sheath component.

6. 10. The sheath assembly of claim 1, wherein the variable size repositioning sheath further comprises a mandrel-type inner repositioning sheath component, the variable size repositioning sheath configured to be radially sized using the mandrel-type inner repositioning sheath component.

7. an expandable introducer sheath; a variable-size repositioning sheath configured to be inserted within the expandable introducer sheath and to be radially adjustable in size; A sheath assembly for inserting a medical device into a blood vessel, comprising:

8. the variable-size repositioning sheath an outer repositioning sheath component; an inner repositioning sheath component at least partially disposed within the outer repositioning sheath component; Including, the variable-size repositioning sheath is further configured to change radial size based on translational or rotational movement of the inner repositioning sheath component relative to the outer repositioning sheath component.

8. The sheath assembly of claim 7.

9. the variable size repositioning sheath further includes a ratcheting inner repositioning sheath component, the variable size repositioning sheath configured to be radially adjustable in size using the ratcheting inner repositioning sheath component.

8. The sheath assembly of claim 7.

10. 8. The sheath assembly of claim 7, wherein the variable size repositioning sheath further comprises a cam-type inner repositioning sheath component, the variable size repositioning sheath configured to be radially sized using the cam-type inner repositioning sheath component.

11. 8. The sheath assembly of claim 7, wherein the variable size repositioning sheath further comprises a mandrel-type inner repositioning sheath component, the variable size repositioning sheath configured to be radially sized using the mandrel-type inner repositioning sheath component.

12. an intracardiac device including a pump and a cannula, the pump having a pump housing, a rotor, and an opening in the pump housing, the cannula having a proximal end that interfaces with the distal end of the pump housing and a distal end with at least one distal opening, the pump configured to be operated by a motor; an elongate catheter coupled at a distal end to the motor or the pump housing; and an introducer sheath configured to introduce the intracardiac device into a blood vessel; a radially adjustable variable-size repositioning sheath configured to reposition the intracardiac device within the blood vessel; including a sheath assembly A blood pump system comprising:

13. 13. The blood pump system of claim 12, wherein the variable-size repositioning sheath is configured to be adjustable to a radial size up to 2 Fr smaller than the radial size of the introducer sheath.

14. the repositioning sheath: an outer repositioning sheath component; an inner repositioning sheath component at least partially disposed within the outer repositioning sheath component; Including, the variable-size repositioning sheath is further configured to change radial size based on translational or rotational movement of the inner repositioning sheath component relative to the outer repositioning sheath component.

13. The blood pump system of claim 12.

15. 13. The blood pump system of claim 12, wherein the variable size repositioning sheath further comprises a ratcheting inner repositioning sheath component, and the variable size repositioning sheath is configured to be radially adjustable in size using the ratcheting inner repositioning sheath component.

16. 13. The blood pump system of claim 12, wherein the variable size repositioning sheath further comprises a cam-type inner repositioning sheath component, and the variable size repositioning sheath is configured to be radially sized using the cam-type inner repositioning sheath component.

17. 13. The blood pump system of claim 12, wherein the variable size repositioning sheath further comprises a mandrel-type inner repositioning sheath component, and the variable size repositioning sheath is configured to be radially sized using the mandrel-type inner repositioning sheath component.

18. a peel-away introducer sheath having a sheath body with a fixed outer diameter; a variable-size repositioning sheath configured to be radially adjustable in size between at least a first state and a second state; Including, an outer diameter of the variable-size repositioning sheath greater than the fixed outer diameter when the variable-size repositioning sheath is in the first state; the outer diameter of the variable size repositioning sheath is smaller than the fixed outer diameter when the variable size repositioning sheath is in the second state; A sheath assembly for inserting a medical device into a blood vessel.

19. the variable-size repositioning sheath an outer repositioning sheath component; an inner repositioning sheath component at least partially disposed within the outer repositioning sheath component; Including, the variable-size repositioning sheath is further configured to change radial size based on translational or rotational movement of the inner repositioning sheath component relative to the outer repositioning sheath component.

20. The sheath assembly of claim 18.

20. 20. The sheath assembly of claim 18, wherein the variable size repositioning sheath further comprises a ratcheting inner repositioning sheath component, the variable size repositioning sheath configured to be radially adjustable in size using the ratcheting inner repositioning sheath component.

21. 20. The sheath assembly of claim 18, wherein the variable size repositioning sheath further comprises a cam-type inner repositioning sheath component, the variable size repositioning sheath configured to be radially sized using the cam-type inner repositioning sheath component.

22. 20. The sheath assembly of claim 18, wherein the variable size repositioning sheath further comprises a mandrel-driven inner repositioning sheath component, the variable size repositioning sheath configured to be radially sized using the mandrel-driven inner repositioning sheath component.

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