Patent Application
20230346582
Embodiments of the present invention relate generally to medical devices and more particularly to methods and apparatus for deploying stents in a lumen of a subject.
Stents are typically deployed within a lumen of a body of a subject for various reasons. In some cases, a stent is deployed within a lumen in order to widen a narrowed section of the lumen. In one example, insertion of a stent into a bile duct is used to treat obstructions and strictures that occur in the bile duct. A stent is typically a tube-like structure that can be used to support a narrowed part of a lumen and inhibit the reformation of the stricture. A tube or catheter is often used to deploy stents, and a guidewire is often used to aid in guiding the stent to its targeted deployment location within the lumen. Locking mechanisms are used to control movement of the stent relative to the tube or catheter during deployment, but available devices require additional steps to release or disengage the locking mechanisms.
According to embodiments disclosed herein, a stent-deployment assembly for use with a guidewire comprises: (a) an elongated stent-conveyance tube comprising a guidewire-retaining segment, the guidewire-retaining segment (i) including a lengthways laterally-breachable portion and (ii) being configured for having the guidewire traverse longitudinally therethrough; (b) a stent arranged to surround a stent-conveyance tube segment that is proximally displaced from the guidewire-retaining segment; (c) a pushing tube surrounding the stent-conveyance tube segment and proximally displaced from the stent; and (d) a proximally-withdrawable locking mechanism, proximally engaging the stent with the pushing tube so as to constrain distal movement of the stent relative to the pushing tube, wherein, when movement of the stent is externally constrained, a proximal-direction withdrawal of the stent-conveyance tube is effective to (i) cause the guidewire to breach the laterally-breachable portion of the guidewire-retaining segment so as to decouple the guidewire from the tube without manipulation of the guidewire, and (ii) disengage the proximally-withdrawable locking mechanism.
In some embodiments, it can be that a proximal-direction withdrawal of the stent-conveyance tube effective to cause the guidewire to breach the laterally-breachable portion of the guidewire-retaining segment can be effected by applying a proximal-withdrawal force of at least 100 grams and no more than 20 kg.
In some embodiments, the stent-deployment assembly can additionally comprise the guidewire.
In some embodiments, the proximally-withdrawable locking mechanism can include a first locking member proximally engaged with the elongated stent-conveyance tube. In some embodiments, the first locking member can be integrally formed with the elongated stent-conveyance tube. In some embodiments, the first locking member can be fixedly attached to the elongated stent-conveyance tube. In some embodiments, the first locking member can be detachably attached to the elongated stent-conveyance tube.
In some embodiments, the proximally-withdrawable locking mechanism can include a second locking member comprising a loop portion. In some embodiments, the second locking member can transversely traverse the pushing tube. In some embodiments, a portion of the second locking member can be constrained within an interior volume of the stent by the presence of the first locking member.
In some embodiments, the disengaging of the proximally-withdrawable locking mechanism can include proximally withdrawing the first locking member so as to no longer constrain the portion of the second locking member.
A method is disclosed, according to embodiments, for assembling a stent-deployment apparatus. The method comprises: (a) providing a stent-conveyance tube comprising a distal guidewire-retaining segment, the stent-conveyance tube having a first locking member of a proximally-withdrawable locking mechanism engaged with the stent-conveyance tube; (b) arranging a pushing tube around a first stent-conveyance tube segment; (c) arranging a stent around a second stent-conveyance tube segment that is proximally displaced from the guidewire-retaining segment and distally displaced from the first stent-conveyance tube segment; and (d) installing a second locking member, wherein the installing includes (i) engaging the second locking member with the pushing tube and (ii) constraining a loop portion of the second locking member within an interior volume of the stent to be constrained therein by the presence of the first locking mechanism.
In some embodiments, the method can additionally comprise: passing the guidewire longitudinally through the distal guidewire-retaining segment of the stent-conveyance tube.
In some embodiments, it can be that the passing through of the guidewire is not factory-performed and all other steps are factory-performed.
In some embodiments, the first locking member can be integrally formed with the stent-conveyance tube. In some embodiments, the first locking member can be fixedly attached to the stent-conveyance tube. In some embodiments, the first locking member cam be detachably attached to the stent-conveyance tube.
According to embodiments of the invention, a stent-deployment assembly comprises: (a) an elongated stent-conveyance tube comprising a hollow longitudinal lumen configured to have a guidewire traverse longitudinally therethrough; (b) a stent arranged to surround a first stent-conveyance tube segment; (c) a pushing tube surrounding a second stent-conveyance tube segment that is proximally displaced from the first stent-conveyance tube segment; (d) a first locking member engaged with the elongated stent-conveyance tube; and (e) a second locking member comprising a first portion arranged to transversely traverse the pushing tube and a second portion constrained within an interior volume of the stent by the presence of the first locking member.
In some embodiments, the first and second locking members can be effective in combination to constrain distal movement of the stent relative to the pushing tube.
In some embodiments, when movement of the stent is externally constrained, a proximal-direction withdrawal of the stent-conveyance tube can be effective to cause the second locking member to no longer be constrained by the first locking member.
In some embodiments, the first locking member can be integrally formed with the stent-conveyance tube. In some embodiments, the first locking member can be fixedly attached to the stent-conveyance tube. In some embodiments, the first locking member cam be detachably attached to the stent-conveyance tube.
The invention will now be described further, by way of example, with reference to the accompanying drawings, in which the dimensions of components and features shown in the figures are chosen for convenience and clarity of presentation and not necessarily to scale. In the drawings:
The invention is herein described, by way of example only, with reference to the accompanying drawings. With specific reference now to the drawings in detail, it is stressed that the particulars shown are by way of example and for purposes of illustrative discussion of the preferred embodiments of the present invention only, and are presented in the cause of providing what is believed to be the most useful and readily understood description of the principles and conceptual aspects of the invention. In this regard, no attempt is made to show structural details of the invention in more detail than is necessary for a fundamental understanding of the invention, the description taken with the drawings making apparent to those skilled in the art how the several forms of the invention may be embodied in practice. Throughout the drawings, like-referenced characters are generally used to designate like elements.
According to embodiments, a stent assembly includes a stent mounted on a catheter tube adapted, e.g., for conveying the stent to a target deployment location within a lumen of a human subject.
The scope of the present invention includes stent assemblies intended for use in any suitable lumen in the human body. For example, techniques and apparatus described herein may be used in connection with stents for use in a urethra, and/or in a ureter, and/or in a pancreatic duct, and/or in an esophagus, and/or in a trachea of a subject. Additionally, or alternatively, techniques and apparatus described herein may be used in connection with prostatic stents. Additionally, or alternatively, techniques and apparatus described herein may be used in connection with biliary stents, i.e., stents used to to maintain flow viability of a bile duct.
The assembly is configured for advancement along a guidewire which is typically inserted into the subject's body in advance of deploying the stent. A distal end of the guidewire is disposed within the target lumen, and the proximal end remains outside the body. In the case of employing short-wire systems, the guidewire can be externally locked. The terms ‘distal’ and ‘proximal’ are used throughout this disclosure and the appended claims as follows: ‘distal’ means further into the body (along an insertion path) from a point of entry into the body, while ‘proximal’ means closer to the point of entry into the body. Where the terms are used in reference to apparatus outside of a patient's body, a distal portion or distal end is that portion or end of the apparatus configured to be inserted into the body first, while a proximal end or proximal portion is either inserted last or may never be inserted (as in the case of a guidewire, for example). Additionally, when used relatively, e.g. ‘distally displaced from’ or ‘proximal of’, the meaning is, respectively, closer to the distal end than’ or ‘closer to the proximal end than’.
As will be further described hereinbelow and in the accompanying figures, a catheter tube (which can be alternatively called, equivalently, ‘guide tube,’ ‘stent-conveyance tube,’ or, simply, ‘tube’) for conveyance of the stent is disclosed as having, at or near a distal tip, arrangements for engaging a guidewire. Apertures are provided on either end of a longitudinal guidewire-engaging or guidewire-retaining segment of the tube, and the guidewire can be threaded through these apertures so as to traverse the interior of the guidewire-retaining segment of the tube. The guidewire does not interiorly traverse the tube segment proximal to the guidewire-retaining segment, and thus ‘departs’ the interior of the tube, at least temporarily, at the proximal aperture. The distal aperture can be at the distal tip of the tube, or it can be displaced proximally from the tip. It is preferable that the distal aperture faces distally, i.e., faces in a direction in which the distal tip is facing, within 15° of that direction, or within 30° of that direction, or within 45° of that direction. The proximal aperture preferably faces proximally, i.e., faces in a direction opposite to the direction in which the distal tip is facing, or within 15° of that ‘opposite’ direction, or within 30° or within 45° of that ‘opposite’ direction. Thus, when the guidewire exits the proximal aperture, it is directed to continue alongside the tube (and alongside the stent that surrounds the tube) proximal to the proximal aperture.
With the guidewire passing through the interior of the guidewire-retaining segment, the tube can be advanced along the length of the guidewire with little resistance from the guidewire, for example pushed forward by an additional stent engaged with the guidewire or by a ‘pusher’ catheter (also called a ‘pushing tube’) engaged with the guidewire. The stent can be mounted on the tube before or after the tube is engaged with the guidewire, so as to surround a segment of the tube that is proximal to the guidewire-retaining segment. There can be a gap between the guidewire-retaining segment and the stent-carrying segment.
The configuration in which the stent is mounted on the tube so as to surround a segment that is proximal to the guidewire-retaining segment, and in which the tube is engaged with the guidewire in that the guidewire passes through the interior of the guidewire-retaining segment, is referred to herein as the ‘stent-advancement configuration’ of the stent assembly.
The guidewire-retaining segment is configured to retain the guidewire therewithin during the advancement of the stent into the body lumen in the stent-advancement configuration. In some embodiments, the relative longitudinal stability of the position of the stent relative to the tube is accomplished using a locking stent as will be discussed hereinbelow. The guidewire-retaining segment has a lengthways, laterally breachable portion, making the guidewire-retaining segment laterally breachable by the guidewire. The guidewire-retaining segment of the tube is designed to be laterally breached by the guidewire when a shearing force is applied, beginning at the proximal aperture when the tube is proximally withdrawn once the stent is deployed and anchored in the lumen (and any locking system is ‘unlocked’). The laterally-breachable portion can be a weakened or pre-breached sidewall of the guidewire-retaining portion, as will be discussed in greater detail hereinbelow with respect to
Once the stent has been advanced to a target stent-deployment location in the lumen of the patient's body, e.g., the bile duct, the stent-conveyance tube can be withdrawn proximally so as to leave the stent deployed in the lumen. The stent is preferably self-anchoring with one or more anchor flaps maintaining the position of the stent against the force used to withdraw the tube, such that the stent slides off the distal end of the tube when the tube is withdrawn. Once the proximal aperture of the guidewire-retaining reaches the edge of the stent, the guidewire exiting the proximal aperture is trapped against the proximal aperture by the unmoving stent, and the resulting shearing force causes the guidewire to breach the laterally-breachable portion of the guidewire-retaining segment. Continued application of the force causes the guidewire to laterally exit the breached guidewire-retaining segment and thus be disengaged or decoupled therefrom. The force necessary to breach the laterally-breachable portion of the guidewire-retaining segment can be at least 100 grams and no more than 20 kg. In various embodiments, the necessary force can be at least 500 grams and no more than 10 kg, or at least 1 kg and no more than 5 kg, or at least 1.5 kg and no more than 2.5 kg. Once the guidewire-retaining portion is completely breached, the force necessary to withdraw the tube from the anchored stent can be less than the force required to breach the guidewire-retaining portion.
We now refer to the figures, and in particular to
As shown in
It can be seen in
Referring now to
The differences between the examples of
With respect to the cross-section of segment 232, in the example shown in
With respect to the design of the laterally breachable portion 278 of the guidewire-retaining segment 232, the first of the two cross-sectional detail boxes labeled A1 in
Design of the laterally breachable portion 278 is not limited to the specific designs illustrated in the non-limiting examples of
One or more anchor flaps 522 are formed on the external surface of the stent 52, as shown in
Referring now to
Step S01 passing an end, e.g., a proximal end, of the guidewire 12 through the guidewire-retaining segment 222 of the stent-conveyance tube 220 via respective distal and proximal apertures 320, 262; and
Step S02 arranging the stent 52 on the stent-conveyance tube 220, proximal to the guidewire-retaining segment 222. As mentioned earlier, there can be an additional segment 232 intermediating between the guidewire-retaining segment 222 and the tube segment on which stent 52 is mounted.
As shown in the flowchart, Steps S01 and S02 can be carried out in either order, i.e., first Step S01 and then Step S02, or first Step S02 and then Step S01. As an example, it may be desirable to have the tube 220 engaged with the guidewire 12 before mounting the stent 52 on the tube 220. As another example, it may be desirable to have the stent 52 in place on the tube 220 before engaging the tube 220 with the guidewire 12.
After carrying out Steps S01 and S02, the stent assembly 101 can be seen to be in a ‘stent-advancement configuration’ in which the guidewire 12 passes through the distal and proximal apertures 320, 262 so as to interiorly traverse the guidewire-retaining segment 222, and the stent 52 is arranged to surround a stent-conveyance tube segment that is proximally displaced from the guidewire-retaining segment 222, for advancement of the stent 52 together with the stent-conveyance tube 220 along the guidewire 12 into a body lumen of a human subject.
The method additionally comprises:
Step S03 advancing the stent-conveyance tube 220 along the guidewire 12 together with the stent 12, i.e., with guidewire-retaining segment 222 engaged with the guidewire 12, to deliver the stent 52 to a target location in a lumen, e.g., a bile duct, of a patient; and
Step S04 proximally withdrawing the stent-conveyance tube 220 to deploy the stent in the lumen, without manipulating the guidewire. The term ‘without manipulating the guidewire’ describes a situation wherein the stent 52 is anchored in the lumen by one or more anchor flaps 522 and is substantially immobilized (e.g., won't move longitudinally more than 1 mm, or more than 2 mm, or more than 3 mm, or more than 5 mm, or more than 10 mm) so as to resist longitudinal forces associated with withdrawing the stent-conveyance tube 220.
Steps of the instant method for deploying a stent in a lumen of a human body using a stent assembly 101, according to embodiments of the present invention, will be explained in greater detail in connection with
In the particular example of the stent assembly 101 illustrated in
Unlike the illustrations of
We now refer to
We now refer to
The locking mechanism is effective to maintain a position of a stent 52 relative to the stent-conveyance tube 220 when the stent-deployment assembly is advanced along the guidewire 12. The locking mechanism is also effective to maintain a position of a stent 52 relative to the pushing tube 60.
A stent 52 is arranged to surround a first portion of a stent-conveyance tube 220. (shown in
A second locking member 820 enters the pushing tube 60 through a hole 66, traverses a portion of the pushing tube 60 transversely, and exits through a second hole 66 (not visible in
The skilled artisan will understand that if the stent-deployment assembly 100 employs a stent-conveyance tube 220 having a guidewire-retaining segment 222 that includes a lengthways laterally-breachable portion 278 as illustrated, e.g., in
Referring now to
Step S11: providing a stent-conveyance tube 220 having a first locking member 810 of a proximally-withdrawable locking mechanism engaged with the stent-conveyance tube 220. In some embodiments, the stent-conveyance tube 220 comprises a distal guidewire-retaining segment 222.
Step S12: arranging a pushing tube 60 around a first stent-conveyance tube segment.
Step S13: arranging a stent 52 around a second stent-conveyance tube segment that is proximally displaced from the guidewire-retaining segment 222, and distally displaced from the first stent-conveyance tube segment.
Step S14: installing a second locking member 820, wherein the installing includes (i) engaging the second locking member 820 with the pushing tube 60 and (ii) constraining a loop portion of the second locking member 820 within an interior volume of the stent 52 to be constrained therein.
In some embodiments, the method additionally comprises, as shown in the flowchart of
Step S15: passing a guidewire 12 longitudinally through the distal guidewire-retaining segment 222 of the stent-conveyance tube 220.
In some embodiments, Steps S11 through S14 are performed at a factory or assembly facility, while Step S15 is not performed at the factory or assembly facility.
According to embodiments, the method steps can be carried out in any order deemed practical for assembling the stent-deployment apparatus 100. In some embodiments, not all of the steps need be carried out.
It will be appreciated by persons skilled in the art that the present invention is not limited to what has been particularly shown and described hereinabove. Rather, the scope of the present invention includes both combinations and sub-combinations of the various features described hereinabove, as well as variations and modifications thereof that are not in the prior art, which would occur to persons skilled in the art upon reading the foregoing description.
This patent application claims the benefit of U.S. Provisional Patent Application No. 63/046,746 filed on Sep. 15, 2021, which is incorporated herein by reference in its entirety. This patent application is a continuation of U.S. patent application Ser. No. 17/140,001 filed on Jan. 1, 2021, which is incorporated herein by reference in its entirety. U.S. patent application Ser. No. 17/140,001 claims the benefit of U.S. Provisional Patent Application No. 62/956,294 filed on Jan. 1, 2021, which is incorporated herein by reference in its entirety.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/IB2021/058386 | 9/14/2021 | WO |
| Number | Date | Country | |
|---|---|---|---|
| 63078539 | Sep 2020 | US | |
| 63078539 | Sep 2020 | US | |
| 62956294 | Jan 2020 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 17140001 | Jan 2021 | US |
| Child | 18025623 | US |
