The present disclosure relates to methods, devices, and systems used in the prevention of limb ischemia, such as that resulting from use of a mechanical circulatory support device.
Limb ischemia is a rapid and sudden decrease in limb perfusion often threatening limb viability. It may occur as a result of blockage of blood due to an indwelling sheath and/or catheter, local occlusion (e.g., atherosclerotic narrowing), and/or continuous occlusion resulting from small vessels and/or large sheaths. It may also occur as a result of a closure issue.
Limb ischemia is associated with mortality, and some literature indicates the rate of limb ischemia may be high. As such, in addition to negatively impacting the patient, it may also negatively impact ongoing clinical trials.
In various aspects, a device may be provided. The device may include a tubular member configured to extend at least partially into a vessel of a patient. The device may include a first anchor coupled to the tubular member and configured to hold a position of the tubular member relative to the vessel. The first anchor may be configured to appose an inner wall of the vessel.
The first anchor may include a delivery configuration and a deployed configuration. In the deployed configuration, the first anchor may have a diameter greater than an opening of the vessel through which the tubular member extends into the vessel. The first anchor may include a plurality of fingers. The first anchor may be attached at or near a distal end of the tubular member. The first anchor may include a footplate. The first anchor may include a nitinol braid and/or polymer configured to flare into a deployed configuration. The first anchor may include an inflatable balloon. The inflatable balloon may be operably coupled to a fluid source. The first anchor may be configured for atraumatic apposition to the inner wall of the vessel. When the first anchor is in a deployed configuration, the first anchor may be configured to be oriented perpendicular to a central axis of the tubular member.
The tubular member may include a cannula or sheath.
The device may include a second tubular member disposed along the tubular member. The second tubular member may be operably coupled to the first anchor to move the first anchor from a delivery configuration to a deployed configuration.
The device may include a second anchor. The second anchor may be configured to placed on an outside surface of the vessel. A first anchor and a second anchor may cooperate to hold the tubular member to the vessel. The second anchor may include a suture pad. The second anchor may include an expandable tip. The second anchor may include nitinol braid or polymer.
The first and second anchors may pinch or sandwich the vessel to hold the tubular member to the vessel. The first and second anchors may include the same features. The first and second anchors may include different features.
In various aspects, a device may be provided. The device may include an anchor configured to hold a position of a tubular member to a vessel. The anchor may be positionable within the vessel. The anchor may include a proximal anchor portion configured to engage with subcutaneous tissue. The anchor may include a distal anchor portion configured to appose an inner wall of the vessel.
The distal anchor portion may include one or more fingers. The distal anchor portion may include a footplate. The distal anchor portion may include one or more barbs. The proximal anchor may include one or more barbs. The one or more barbs of the proximal anchor may be sharper than the one or more barbs of the distal anchor. Each of the distal and proximal anchors may include an atraumatic disk.
In various aspects, a method may be provided. The method may include inserting a tubular member into a vessel of a patient through an access site. The tubular member may extend at least partially into the vessel. The method may include holding a position of the tubular member to the vessel via a first anchor. The first anchor may be configured to appose an inner wall of the vessel.
The method may include inserting a medical device into the patient via the tubular member. The method may include, before the step of holding, inserting the first anchor into the vasculature in a delivery configuration. The method may include, before the step of holding, moving the first anchor to the deployed configuration in which a diameter of the first anchor in the deployed configuration may be greater than a diameter of the opening through which the tubular member is inserted into the vessel.
The method may include returning the first anchor to the delivery configuration and removing the tubular member and first anchor from the patient's vessel.
The step of holding may include holding a position of the tubular member to the vessel via a first anchor and a second anchor. The second anchor may be positioned on an outside of the vessel. The first and second anchors may cooperate with one another to hold the position of the tubular member to the vessel.
The step of holding may include pinching or sandwiching the vessel between the first and second anchors. The first anchor may include a distal anchor portion and a proximal anchor portion. The distal anchor portion may be configured to appose an internal wall of the vessel. The proximal anchor portion may be configured to engage with subcutaneous tissue.
As is known, limb ischemia is a rapid and sudden decrease in a patient's limb perfusion, which may occur because of a blockage of blood due to an indwelling sheath and/or catheter, a local occlusion (e.g., an atherosclerotic narrowing), and/or a continuous occlusion resulting from small vessels and/or large sheaths. Limb ischemia also may occur as a result of a closure issue. To overcome such instances of limb ischemia, a clinician may need to allow for and/or create a path for flow past and/or around the sheath to deliver oxygenated blood to the distal limb of the patient.
Currently there are not many solutions on the market to address distal limb ischemia, such as when using larger diameter catheters or introducers in arteries. For example, introducer system today typically do not allow for placement of devices and removal from the vasculature without needing significant solutions to solve for bleeding at the arteriotomy site. Such solutions offer a way for the physician to place a larger bore device, such as an IMPELLA® heart pump, through the introducer and then pull the introducer back to allow for blood flow to get to the distal limb while still sealing at the arteriotomy.
Currently the physicians can pull traditional introducer systems back under fluoroscopy until just the tip is through the vessel wall, however, with no anchor in place. there is significant risk of the sheath tip pulling out of the vessel altogether leading to bleeding and possible death. Many patients with IMPELLA® heart pump or other devices may be sent from the Cath Lab to the ICU where they may be on support for long durations. In these settings, the introducers may not be monitored, and their position stability is important.
The inventors have appreciated the benefits of a sheath (e.g., an introducer sheath) that does not block a vessel or can be substantially removed from the vessel while still maintaining a connection, such as via a fixation feature (e.g., an anchor). In some embodiments, the sheath may be configured to allow for flow past and/or around the sheath to deliver oxygenated blood to the distal limb of the patient.
In view of the above, disclosed solutions may offer a means to allow a clinician (e.g., a physician) to locate a distal tip of the sheath relative to the vessel arteriotomy, such as by the anchor. The disclosed solutions also may offer a means to fixate the sheath to the vessel, such as via the anchor. As will be appreciated, the anchor may include a delivery configuration (e.g., for inserting the sheath into the vessel) and a deployed configuration in which the anchor fixates the sheath to the vessel. In some embodiments, the solution may allow the vessel to be fixated in place by pinching it against the artery wall from the inside and outside. In some embodiments, the anchor may include a nitinol braid, a balloon, and/or a footplate that may move between the delivery and deployed configuration.
In still other embodiments, the solutions described herein may offer a way for a clinician to remove the sheath at the end of the procedure without needing a full surgical cut down procedure. For example, the physician may first remove the catheter from the introducer shaft, after which the anchor may be returned to the delivery configuration, allowing the introducer shaft (and anchor from the patient). In on embodiment, the anchor may retract such that the sheath may return to a generally tubular shape. In an illustrative embodiment, the anchor may include a nitinol braid that may revert back down to a tubular shape, a balloon that may deflate back down to the tubular shape, and/or a footplate that may fold inward, allowing the physician to pulls the device from the anatomy.
In some embodiments, the anchor may be disposed at or near a distal tip of an introducer sheath through which a mechanical circulatory support device (“MCS”), such as a percutaneous blood pump, may be inserted. In other embodiments, the anchor may be included on an accessory sheath, such as a repositioning sheath, which may engage with the introducer sheath to fixate the introducer sheath and the repositioning sheath to the vasculature. In such embodiments, the repositioning sheath may be placed inside the introducer sheath. In such embodiments, the repositioning sheath may assist in occluding space between the MCS and the introducer sheath, which may prevent blood stagnation and clot formation in such locations.
Also disclosed herein are other manners to create a flow path around a sheath to deliver oxygenated blood to the distal limb of the patient. For example, in conventional systems, the sheath or other tubular member may be configured to have a small window to facilitate placement of the hole such that blood may flow from the tip of the sheath, through the sheath body, and out the hole to the distal artery. As will be appreciated in such an example, if the hole is aligned too far proximal outside the artery, the patient may bleed into subcutaneous tissue. If the hole is aligned too far distally, it will be against the vessel wall and blood will not be able to flow.
Difference in patient anatomy (vessel size, vessel depth) may make it difficult to design an all-in-one solution. The size of the window the hole must be in makes it so the slightest misplacement by the physician or migration of the sheath over time due to patient movement or site maintenance (cleaning, flushing, etc.) could cause one of the failure conditions above.
Turning now to the figures,
As seen in
As appreciated by the inventors, trying to position the sheath tip just perfectly inside the vessel provides a small window for error. If the tip is too far proximal, blood will ooze out of the arteriotomy into the subcutaneous tissue. If it is too far forward, the sheath tip will be against the vessel wall blocking blood flow and potentially causing vascular injury.
As seen in
In view of the above, the inventors have recognized the benefits of a device that can securely and reliably locate the sheath relative to an arteriotomy to promote distal limb perfusion. In some embodiments, the device may include an anchor, which may include one or more features, such as one or more mechanical features to locate the sheath relative to the arteriotomy and hold the position of the sheath relative to the arteriotomy. In some embodiments, the anchor may provide user feedback to allow a user to know the position of the sheath relative to the arteriotomy. In some embodiments, the anchor may include a set of mechanical features, with one of them being positioned in the lumen and a second being positioned outside the lumen. In such embodiments, the features may prevent acute limb ischemia by maintaining distal perfusion to the peripherals.
A first mechanical feature, anchor 108, may be on the sheath body 100 shaft (e.g., at a distal end) and may be configured to locate the arteriotomy by activating it and withdrawing the sheath against the inner wall of the artery (see, e.g.,
In some embodiments, like that shown in
In some embodiments (see, e.g.,
As will be appreciated, the expanded region may have a diameter that exceeds that of the arteriotomy and that is configured to appose the inner wall of the vessel at the arteriotomy. Although not shown, it will be appreciated that when the sheath 102 of
In some embodiments, a laser-cut nitinol stent-like tube may be used in place the above-mentioned braids. As will be appreciated, the nitinol braid and/or laser-cut nitinol stent may have any suitable arrangement.
In
In
In some embodiments, the anchor (e.g., the adjustable feature) may be configured for atraumatic apposition to an inner surface of a blood vessel. In some embodiments, the anchor may be configured to conform to the blood vessel diameter.
In some embodiments, the anchor may be configured to be oriented perpendicular to the central axis of the inner sheath. In some embodiments, the anchor may be configured to be oriented at an angle relative to the central axis of the inner sheath that is 30-60 degrees. In some embodiments, the anchor may be configured to be oriented at an angle relative to the central axis of the inner sheath that is 45 degrees.
In some embodiments, the anchor may be configured to expand to have an outer diameter of 8-10 mm. In some embodiments, the anchor may be configured, when in a compressed state, to have a thickness of no more than 0.4 mm. In some embodiments, the anchor is fully reversible, so as to be compressible to a diameter smaller than the pump sheath inner diameter and configured to be removed through the pump sheath.
In some embodiments, the inner sheath may have a maximum outer diameter of no more than 5.05 mm. In some embodiments, the inner sheath may have an inner diameter of 2.5-3.5 mm, such as 3.0 mm.
In some embodiments, the first mechanical feature, anchor 108, may include a shaped balloon that flares to the desired shape when pressurized with fluid (e.g., to the delivery configuration). In such embodiments, the anchor may be fluidly coupled to a fluid source, and may be positioned at or near a tip of the sheath 100. As will be appreciated, as with the other embodiments disclosed herein, the balloon also may be configured to appose an inner wall of the vasculature and have a diameter that exceeds that of the access opening.
In still other embodiments, the anchor may include series of nitinol wires that again can be moved between a delivery position and a deployed configuration and again may be configured to appose an inner wall of the patient's vasculature.
In
As will be appreciated, in view of the above, the first mechanical feature, anchor 108, may be located in various positions along the sheath. For example, the anchor may reside at the tip of the sheath so that the sheath lies substantially outside the vessel while maintaining hemostasis and access. As will be appreciated, in some embodiments, this may minimize the amount of sheath that may extend into the vasculature (e.g., possible causing an ischemic event), while still allow a medical device (e.g., a mechanical circulatory support device) to be passed into the patient. In other embodiments, the anchor may reside mid-shaft of the sheath body, in close proximity to a distally adjacent hole (see, e.g., hole 112 in
In some embodiments, the sheath body may include a second mechanical feature, or second lumen, which may be positioned extra-luminal. In some embodiments, the second anchor, may be configured to hold the sheath to the vessel. In some embodiments, the first and second anchors may work in concert to hold the sheath to the vessel at the arteriotomy. In this regard, the first and second anchors may have a press fit, snap fit, or other suitable engagement (e.g., openings and corresponding pins) to allow the first and second anchors to hold to one another. As will be appreciated, the anchor need not include such a second anchor, as described above, and may instead be locked at the arteriotomy via only the first anchor.
In some embodiments, the second mechanical feature may include a component such as ae.g. suture pad that may normally be locked in place and may slide on the sheath body shaft when actively activated (e.g., a button is pressed), and may returns to its normal locked in place configuration. In some embodiments, the component may be secured to a patient (e.g., via sutures).
The second anchor also may include a tube with a soft, expandable tip that when slid towards the first anchor and makes contact with the outer wall of the artery flares/expands open and opposes the soft tip to the outer wall of the vessel.
In still another embodiment, the second anchor may include a nitinol braid and polymer that is a tube when free during insertion and flares to the desired shape when axially compressed after delivered outside the vessel within subcutaneous tissue.
In some embodiments, the second anchor may include a nitinol braid and polymer that is set to the desired shape when free and is held in tension during insertion.
In still other some embodiments, a laser-cut nitinol stent-like tube may be used for the second mechanical feature. A shaped balloon may be used as the second mechanical feature, the balloon being capable of flaring to a desired shape when pressurized with fluid after delivered outside the vessel within subcutaneous tissue. As with the first mechanical feature, the second mechanical feature also may be configured to move between a delivery configuration and a deployed configuration.
As will be appreciated, the second anchor may be positioned in various locations. For example, in some embodiments, the second mechanical feature may be on the sheath body shaft and may have the purpose to secure sheath in place by providing a counter tension with the first mechanical feature. In some embodiments, the second mechanical feature also may be positioned proximally to the first and secures the sheath in place by “pinching” the vessel between the first and second mechanical feature.
In still other embodiments, the second mechanical feature may be positioned proximally to the first and secures the sheath in place by “pinching” the skin/sub-cutaneous tissue/vessel between the first and second mechanical feature.
As will be appreciated, in some embodiments, the first and second mechanical features may have the same features and/or arrangements (e.g., similar to those shown above with respect to the first mechanical feature), although the first and second mechanical features may differ. As will be further appreciated, in some embodiments, the first and second mechanical features also may include first and second anchors (with each including one or more mechanical features).
As seen in
In
In
In
In some embodiments, as shown in
As will be appreciated in view of the figures show in
In
In
As with the above, in the deployed configuration, the distal anchor may appose the vessel wall. In contrast, the proximal barbs may be sharper, and may be configured as a engage (e.g., pierce) the, e.g., subcutaneous tissue. The distal and proximal anchor portions may have any suitable arrangement. In some embodiments, the anchor shown in these views may be used as either the first and/or second anchors disclosed herein.
As will be appreciated, the anchor may bet attached at different portions along the sheath, such as at or near a distal tip and/or at a portion of the sheath near an opening through which blood may flow.
In an illustrated example (see
In another illustrated example, the device may include an introducer sheath. The device may be configured to have a first state, which may be used for, e.g., insertion of sheath with corresponding dilator and used to deliver a pump (e.g., an Impella® blood pump) through calcification, tortuosity, or other patient anatomy that could not otherwise pass the pump.
The first Mechanical feature may be a Nitinol braid, located concentrically around and at the distal tip of the inner sheath body. At the distal most portion may be fixed to the inner sheath body. The proximal end of the mechanical feature may be fixed to an outer sheath shaft that may slide along the inner sheath shaft. The Inner sheath shaft may have a liner (e.g., a PTFE liner), that may be coil reinforced, and may have an outer jacket. It may be attached on its proximal end to a sheath hub comprising a hemostatic valve and side-arm for flushing. The Outer sheath shaft may be attached on its proximal end to a molded hub that may be locked in two positions. In the first state, it may be located in a proximal position adjacent distally to the sheath hub of the inner shaft.
The second mechanical feature may be a catheter lock including a housing, button with spring, locking tube, and suture pad. It may be located concentrically on the outer shaft between its proximal end and distal end. In the first state, the button is not depressed so the spring creates a compressive force on the locking tube, fixing the second mechanical feature to the outer sheath shaft. The second mechanical feature may be in a proximal position adjacent distally to the molded hub of the outer sheath shaft. The introducer sheath may take up significant or complete luminal cross-sectional area with little to no flow getting past the sheath.
The device may be configured to have a second state, which may be used to, e.g., place the pump and initiate therapy. The sheath may be retracted partially out of the artery with the distal tip still within the arterial lumen. The first mechanical feature may be activated, and the sheath may be pulled in tension, so the mechanical feature opposes to the vessel wall without pulling out. The second mechanical feature may be activated, slide down to press with a force against the skin, and un-activated to fix in place on the shaft to provide a counter force to the first mechanical feature to secure the sheath in place. The molded hub of the outer shaft may be moved in a forward direction to a second position where it locks in place. The length of the first feature may reduce and the diameter may increase. The introducer sheath takes up limited luminal cross-sectional area with sufficient distal perfusion pas the sheath.
The device may be configured to have a third state, which may be used, e.g., when therapy is complete, and the user removes the pump from the sheath. A wire to maintain access may be inserted into the sheath. The first mechanical feature may be returned to an un-expanded state and the sheath may be removed. The arteriotomy is closed with common technique (manual pressure, vascular closure device, etc.). The hub of the outer shaft may be moved in a distal direction to the first position where it locks in place. The length of the first feature may increase back to its original length and the diameter substantially returns to its original diameter.
Although embodiments are shown and described in which the anchor(s) and or first and second mechanical features may be include on the introducer (e.g., introducer sheath for inserting the medical device), in some embodiments, the anchor may instead be formed on another accessory, such as a repositioning sheath, which is configured to engage with the introducer sheath.
In some embodiments, as shown in
During deployment, as shown in
The anchor can be undeployed by retracting the repositioning sheath.
Embodiments of the present disclosure are described in detail with reference to the figures wherein like reference numerals identify similar or identical elements. It is to be understood that the disclosed embodiments are merely examples of the disclosure, which may be embodied in various forms. Well known functions or constructions are not described in detail to avoid obscuring the present disclosure in unnecessary detail. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present disclosure in virtually any appropriately detailed structure.
The present application claims priority to U.S. Provisional Application Nos. 63/340,352, filed May 10, 2023, and 63/444,529, filed Feb. 9, 2023, the contents of which are each incorporated by reference herein in its entirety.
Number | Date | Country | |
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63340352 | May 2022 | US | |
63444529 | Feb 2023 | US |