STENT RETRIEVER CLEANING DEVICES AND METHODS
20220151730 · 2022-05-19
Inventors
- Dennis J. Rivet, II (Richmond, VA, US)
- Shane Diller (Richmond, VA, US)
- John F. Reavey-Cantwell (Richmond, VA, US)
Cpc classification
B08B2209/032
PERFORMING OPERATIONS; TRANSPORTING
A61B90/70
HUMAN NECESSITIES
A61B17/221
HUMAN NECESSITIES
B08B3/006
PERFORMING OPERATIONS; TRANSPORTING
B08B9/023
PERFORMING OPERATIONS; TRANSPORTING
B08B9/0321
PERFORMING OPERATIONS; TRANSPORTING
International classification
A61B90/70
HUMAN NECESSITIES
B08B11/02
PERFORMING OPERATIONS; TRANSPORTING
B08B9/023
PERFORMING OPERATIONS; TRANSPORTING
Abstract
An exemplary device is indicated for use in physically debriding thrombus fragments from a stent retriever, using hospital-grade saline, or heparinized saline, for example. This device may be used in the sterile field, during a mechanical thrombectomy procedure.
Claims
1. A device for cleaning a stent retriever within a sterile surgical field, comprising a chamber configured to receive and enclose a stent retriever to be cleaned; at least one port configured for connection with a fluid source to enable inflow and/or outflow of a fluid to or from the chamber; one or more support structures configured to support the stent retriever in a fixed position inside the chamber.
2. The device of claim 1, wherein the chamber is configured to permit a tail wire of the stent retriever to extend out of the chamber while enclosing a remainder of the stent retriever.
3. The device of claim 2, wherein the one or more support structures comprises a hole or deformable seal at an edge of the chamber through which the tail wire extends.
4. The device of claim 1, wherein the one or more support structures comprises a support arm projecting from a wall of the chamber.
5. The device of claim 1, wherein the chamber comprises a bottom and a lid attachable with one another to enclose the stent retriever in the chamber and detachable from one another to insert or remove a stent retriever to or from the chamber.
6. The device of claim 5, further comprising a fastener configured to create a positive holding force which holds the bottom and the lid together.
7. The device of claim 6, further comprising one or more levers configured to reduce a user applied force required to overcome the holding force.
8. The device of claim 5, further comprising a snap fit ring configured to seal an interface between the bottom and the lid of the chamber for at least 95% of the interface.
9. The device of claim 1, wherein the chamber is sized to accommodate no more than one stent retriever at a time.
10. The device of claim 1, wherein the chamber has an internal volume of 30 ml or less.
11. The device of claim 1, wherein the device is handheld.
12. The device of claim 1, wherein the at least one port comprises a first port and a second port which permit simultaneous inflow of fluid to the chamber and outflow of fluid from the chamber.
13. A kit for a mechanical thrombectomy procedure, comprising a stent retriever; and a cleaning device for cleaning the stent retriever within a sterile surgical field, the cleaning apparatus comprising a chamber configured to receive and enclose a stent retriever to be cleaned, at least one port configured for connection with a fluid source to enable inflow and/or outflow of a fluid to or from the chamber, and one or more support structures configured to support the stent retriever in a fixed position inside the chamber, wherein the chamber is configured to be used to sufficiently remove debris from the stent retriever to permit reuse of the stent retriever during a single thrombectomy procedure.
14. The kit of claim 13, wherein the chamber is configured to permit a tail wire of the stent retriever to extend out of the chamber while enclosing a remainder of the stent retriever.
15. The device of claim 14, wherein the one or more support structures comprises a hole or deformable sealing surface at an edge of the chamber through which the tail wire extends.
16. The kit of claim 13, wherein the one or more support structures comprises a support arm projecting from a wall of the chamber.
17. The kit of claim 13, wherein the chamber comprises a bottom and a lid attachable with one another to enclose the stent retriever in the chamber and detachable from one another to insert or remove a stent retriever to or from the chamber.
18. A method for cleaning a stent retriever of debris to enable immediate reuse of the stent retriever, comprising placing the stent retriever in a chamber with a tail wire of the stent retriever extending out of the chamber; closing the chamber; and introducing a fluid to the chamber via at least one port with a propellant force and fluid agitation sufficient to enable removal of the debris from the stent retriever, wherein the method is performed in a sterile surgical field.
19. The method of claim 18, wherein the fluid is introduced to the chamber via a first port and is removed from the chamber through a second port.
20. The method of claim 18, further comprising the step of recovering the debris removed from the stent for pathological analysis.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
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DETAILED DESCRIPTION
[0041]
[0042] The exemplary device 100 comprises a hinged chamber 101 that has two ports 102 with attachments for connecting the chamber interior to fluid sources such as syringes. The attachments may be, for example, luer tapers (e.g., locking or slipping type luer tapers, e.g., luer locks). The luer tapers may be molded into the chamber wall such that the bottom 101b (or lid as the case may be depending on the port's location) and the luer port are a single item of continuous material. The chamber 101 is created by the combination of a lid 101a and bottom 101b. One or else both the lid 101a and bottom 101b are shaped as a cup or basin, that is to say a structure having walls positioned to hold and retain matter, in particular a liquid. The device 100 may be a single plastic injection molded part with a living hinge 103 and an annular snap fit ring 800 (see the cross-sectional view of
[0043] The two ports 102 may be configured as female luer ports that attach to any standard male syringe part. One or more male luer caps may be used with the device 100 for any user who wishes to block one of the ports and use the device with a fewer number of syringes than there are ports, e.g., a single syringe for a two port device 100. Exemplary washing, discussed below, may be achieved with either one or multiple (e.g., two) syringes attached. The device 100 is recommended to be used with e.g. 15 ml to 20 ml of sterile saline (or more) to remove a thrombus and/or any other debris from a stent retriever enclosed by the chamber 101.
[0044] A support arm 105 projects from a wall of the chamber 101 to support an inserted stent retriever at a fixed position away from the walls of the chamber 101. The support arm 105 may project from either, or both, the lid 101a or bottom 101b. The support arm may be configured to require the stent retriever to clip in, e.g., by way of a cut-out in the arm that is slightly smaller than the size of a stent retriever tail wire. A window, slot, or hole 106 serves as a second support structure of support for the stent retriever as well as a means for a tail wire, which may be 100 cm or more in length, to project out from the interior of the chamber 101. The lid 101a has a window, slot, or hole 109 corresponding in circumferential position with hole 106 of bottom 101b. The lid 101a and bottom 101b have overlapping circumferential lips when the chamber 101 is closed, and in such closed state the holes 106 and 109 also overlap so that a through-hole from the interior of the chamber 101 to the exterior environment remains. The tail wire for which the holes 106/109 are provided is so long due to the incision site for the surgery often being in the wrist or abdomen. The optimal orientation of the tail wire during cleaning is lateral from the operator as this can be laid in the sterile field or held by an assistant. This would decrease the chance of the tail wire being stepped on or falling out of the sterile field.
[0045] In some embodiments, an o-ring or a deformable seal may be provided at or instead of holes 106/109. The deformable seal, e.g. a rubber gasket or the like, may seal the edge of the chamber when no tail wire is present but deform to permit the through passage of the tail wire when the wire is present. According to the exemplary embodiment of device 100, an inserted stent retriever makes contact with the device 100 at only two places, namely the support arm 105 and the hole 106/109. The minimal points of physical contact of an inserted stent retriever with the device 100 reduces the risk of physical damage to the stent retriever, a significant advantage given the typical fragility of stent retrievers.
[0046] The device 100 is intended for ease of use by any physician or medical staff trained to perform or assist with the treatment of ischemic stroke or interventional neuroradiology, or any other procedure requiring removal of blood clots. The device 100 is ergonomic and usable without any supplemental tools besides one or two syringes attachable to the ports 102.
[0047]
[0048] The shape/profile of the exemplary device 100 is curved. For the illustrative embodiment in the figures, the curvature is specifically a bean shape (e.g., kidney-bean shape). The device 100 is preferably configured to be handheld, according to its size, weight, and shape. A curved shape is advantageously more comfortable and secure to hold. At least the largest face of bottom 101b is flat to provide a reliable contact surface with a table or medical tray, and the largest face of lid 101a may also be flat or relatively so to allow a user to set the device down on either of the opposing sides without a risk of the device rolling or moving by accident. The flat side, or sides, prevent the device 100 from rolling off a table and out of the sterile field.
[0049] The bean-shape is exemplary because it accounts for the nature of handheld use and ergonomics. The shape is configured for easy gripping and handling by a single operator. The user's hands will generally be covered by surgical gloves, often wet. Accordingly, the total size of the device is configured to minimize the risk of slippage when being held and handled. An exemplary size range is 3 to 5 inches in length, or 3.5 to 4 inches in length, based on the size of FDA approved stent retrievers and e.g. the grip of the average human adult. An exemplary non-limiting maximum width is 1 to 1.5 inches, in consideration of 6 mm being the widest stent retriever on the market. When closed, the device may be 1-2 inches, e.g. 1.25 in, tall. As further non-limiting but exemplary dimensions, the device 100 may be sized and configured to accommodate stent retrievers from 3-6 mm in diameter, and 24-45 mm in length. The general cavity size within the chamber 101 is such that the device 100 is compatible for use with most if not all stent retriever morphologies commercially available at the time this disclosure was written. Generally a single device 100 will be sized and configured to fit a hold a single stent retriever at a time. The internal volume of the chamber 101 may be e.g. 300 ml or less, or 250 ml or less, 200 ml or less, 190 ml or less, 180 ml or less, 170 ml or less, 160 ml or less, or 150 ml or less.
[0050] The lid 101a and bottom 101b of chamber 101 are connected to one another, preferably permanently in some embodiments. The connection may be made at the time of manufacture, or else the device may be produced as two pieces that are assembled (e.g., snapped together) for use. A tether is one option for a connection. An exemplary option is a hinge, e.g. a living hinge 103. A living hinge reduces assembly time in the Operating Room and enhances human factors in handling of the device with one hand. Exemplary embodiment can be closed with just one hand. The living hinge results in the lid staying attached to the bottom at all times. The hinge 103 is configured for repeated flexure. An exemplary material is polypropylene, which is both capable of repeated flexure and is not prone to warping when producing by a plastic injection molding process.
[0051] Exemplary wash chambers are able to accommodate one or more of the commercially available stent retrievers, presently made by Stryker, Cerenovous, Medtronic and Penumbra. All four companies produce different morphologies of stents, yet some exemplary embodiments are shaped and sized in both chamber and support structures to effectively wash all four or more than four different morphologies.
[0052] As mentioned above, a substantially watertight seal is desirable when the chamber 101 is closed in exemplary embodiments, at least for most if not the entire rim where the lid 101a and bottom 101b meet, with the possible exception of the hole 106/109 provided for the stent tail wire. The hole 106/109 is nevertheless desirable to avoid deformation of the tail wire. A deformed tail wire can cause problems when redeploying the cleaned stent retriever in the narrow blood vessels.
[0053] To create a tight seal that is at least semi-watertight, substantially equal pressure is exerted about all sides of the device 100 when closed. The curved shape/profile of the chamber 101 provides not only an ergonomic benefit, as discussed already, but a better seal than a shape having any square corners. Said differently, some exemplary embodiments preferably have a shape without any corners, especially sharp corners such as ninety degree corners, to provide improved sealing along the edges where the lid 101a and bottom 101b meet. The snap fit ring may be configured to seal an interface between the bottom and the lid of the chamber for at least 95%, or at least 98%, or at least 99%, of the interface. In addition, it is generally desirable that the device comprise one or more fasteners that create a positive holding which holds the bottom and the lid together. Accordingly a positive user applied force is required to separate the top from the bottom after closure to overcome the holding force created by the fastener. The holding force is desirably relatively high, making it difficult to separate the bottom and lid by accident. Physical lips/levers 107 are provided on each of the lid 101a and bottom 101b to provide leverage points for a user to manually overcome the forces holding the chamber 101 shut after closure. The levers 107 create a simple lever that results in the user needing to apply less than the holding force to overcome the holding force. The provision of levers 107 at only specific regions about the chamber 101 and not at any other regions reduces the likelihood of accidental opening of the chamber 101. The levers 107 may be thumbcatches, e.g. physical grooves or tabs, that can be used to create enough force to pull the tooth upward out of the groove.
[0054] The holding force required to keep the lid 101a and bottom 101b tight to one another absent user force applied to levers 107 may be provided by one or more of different types of fasteners.
[0055] The exemplary embodiment depicted by
[0056] Once the projection 801 is past the gap between projection 802 and wall 805, the projection 802 elastically returns to its original position, effectively trapping the projection 801 in the groove 803 in the absence of external forces providing for another deflection of projection 802 away from wall 805. In sum, the arrangement of projections 801 and 802 creates a “snap” fit of the rings 800a and 800b. The arrangement depicted by
[0057] In addition to providing a holding force in the closed state of the chamber, the annular snap fit ring provides a physical barrier to water escaping the chamber without the need for a rubber o-ring or gasket. This advantage both reduces the number of parts and simplifies manufacturability and production costs.
[0058] It should be appreciated that the arrangement of the projections 801 and 802 may be inverted in alternative embodiments. As depicted in
[0059] The number of snap projections, the depth of each projection, the leading angles, and receding angles all affect the force required to close and open the device and may be configured to meet acceptable and desired force thresholds. Because the snap-fit projections 802 of the lid 101a are meant to interfere and deflect with the projections 801 on the bottom 101b of the device 100, the projections 802 may be made into a cantilevered beam to reduce the likelihood of shearing of the snap-fit projections.
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[0063] As an exemplary use case, a stent retriever is placed in the bottom 101b of device 100 balanced on the support of hole 106 and support arm 105. The lid 101a is closed with sufficient force to engage the snap fit ring (again, see
[0064] The device 100 reduces the time required to clean the stent retriever before re-insertion to under 15 seconds. In addition, the device may be used by a single operator without leaving the sterile operating field. With the possible exception of negligible leakage through hole 106/109, the device seals its contents during use such that neither the stent, wash fluid, or debris removed from the stent escape the chamber 101 while it remains closed. Once opened, the cleaned stent is ready for re-use, and any removed thrombus debris may be collected from the basin of bottom 101b.
[0065] The time required to open a sterile embodiment from its packaging, insert a stent, wash the stent, and remove the stent is generally less than or equal to ten seconds. Of course longer wash cycles may be performed, but exemplary embodiments require no more than 10 seconds of use to effectively clean a stent and have the stent ready for immediate reuse after the elapsed wash time.
[0066] A more specific exemplary sequence of steps of use is as follows. First, the packaging is opened and the device placed in the sterile field. Next, the chamber is opened using e.g. the thumb catches, unless the device is packaged in the open state, in which case no opening step is required. Next, the soiled stent retriever is placed in the main compartment (the chamber) by guiding the tail-wire across the notched post of the support arm and into the notch/hole in the lid. The stent retriever should be facing one or more of the luer connectors. Next the lid is closed, while ensuring that the tail-wire stays in the notch that permits it to extend out of the chamber. The snap fit ring is pressed closed until it snaps. At this point or before any step prior, two syringes are filled with e.g. 10 mL of saline each. Next, each syringe is attached to a luer connector port. Grasping one syringe in each hand, the plungers are alternatively depressed, similar to creating an agitated bubble chamber, for e.g. 5-15 seconds. The wash chamber may be angled with respect to gravity during use so that the saline in the chamber flows back into the syringes in order to create maximum turbulence. Next, the user may visually inspect the enclosed stent retriever through the clear lid of the chamber. If the blood clot or thrombus has not been removed from the stent retriever, further cycles of actuating the syringes may be performed. The user may gently shake the device if desired, knowing the support structure inside the chamber will generally keep hold of the stent retriever and prevent it from making contacts with the chamber walls. Once visual inspection through the wall of the chamber shows satisfactory cleanliness of the stent retriever, the thumb catches are used to open the chamber. The stent retriever is removed, and a final visual inspection of cleanliness may be conducted. The stent retriever is then ready for immediate reuse. If required or desired, the chamber with the dirty wash fluid may be tilted and the fluids extracted into one of the attached syringes to collect the thrombus and saline for composition analysis. Alternatively, the chamber can be attached to an external suction pump via one of the ports, and the saline or other liquid in the chamber may be aspirated out mechanically by the suction pump.
[0067] An exemplary wash device may be made in part or entirely from a plastic injection molded plastic, e.g. medical grade polypropylene. After manufacture, the device may be sealed in a sterile peel pouch (e.g., a Tyvek® peel pouch) until it is needed.
[0068] Generally, exemplary devices are well-suited for provision as sterile, single use devices. The most common methods for sterilizing medical devices are Ethylene Oxide (EtO), Gamma Irradiation, and wet or dry steam autoclaving. The materials may be polymers suitable for such sterilization procedures.
[0069] While not required of all embodiments, optically transparent materials are desirable for part of or else the entirety of the wash chamber. A window or else transparent walls allow the operator to visually inspect the results of the washing cycle without opening the device. Thermoplastics such as polycarbonate and polypropylene are suitable for this purpose. While polypropylene is not as optically transparent as polycarbonate, both would still allow visual monitoring of the cleaning.
[0070] While an exemplary device need not necessarily satisfy a specific Ingress Protection (IP) rating, some embodiment may be configured to satisfy such a rating, e.g. IP 65, 66, 67, or 68. An IP65 rated chamber, known as “dust tight” and protected against moderate jets of water, from any angle, may be used for example. In some embodiments, a deliberate opening such as the hole for the tail wire may be desirable to permit air to leave the chamber as its displaced by fluid being added to the chamber from the syringe or other fluid source.
[0071] Exemplary embodiments discussed above suggest the use of syringes as a fluid source. Syringes are advantageously an inexpensive and easily obtained medical supply. The wash device thus requires no power besides that of the human hand. However, exemplary wash devices may be connected (e.g., configured for connection with) fluid sources other than syringes. For example, a battery or wall powered device with motors may be connected. Pulsed lavage or other equipment for the creation of water jets or water propulsion may also be used. Though more expensive, such alternatives may be used when more forceful waterjets are desired in the wash chamber than may be possible with syringes. Such alternatives also may reduce the need for human actuation, which may be desirable by some users.
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[0073] The position of the ports on the device may vary among embodiments.
[0074] Various attachments or nozzles may be made part of or attachable to the ports where fluid is admitted to the chamber, or else nozzles may be attached to syringes or other fluid sources prior to their attachment to the ports. Nozzles may be used to provide specific fluid stream characteristics, e.g., a nozzle with a smaller diameter hole than the port of the chamber may be used to increase pressure and flow rate of fluid being admitted to the device's chamber. Another example nozzle may be a spray head with micromachined holes, or holes produced by other means, to create a multiple streams at a single port, much like a shower head, turning one stream into multiple smaller streams with a higher pressure.
[0075] While exemplary embodiments of the present invention have been disclosed herein, one skilled in the art will recognize that various changes and modifications may be made without departing from the scope of the invention as defined by the following claims.