Constraint mechanism for selective deployment and associated methods

Abstract

Various aspects of the present disclosure relate to medical device deployment apparatuses, systems, and methods. The apparatuses, systems, and methods may include at least one constraining fiber configured to form a warp knit fabric around the medical device, wherein a first series of loops forms the warp knit fabric, wherein at least one of the first series of loops includes a first portion forming a knot and a second portion disposed apart from the knot.

Description

Technical Field

[0001] The present disclosure relates to apparatuses, systems, and methods that include constraints for delivery of implantable medical devices. More particularly, the present disclosure relates to apparatuses, systems, and methods that include constraints for expandable devices that are selectively deployed during device delivery. Background Art

[0002] Stents and stent-grafts can be used to radially support a variety of tubular passageways within the body, including arteries, veins, airways, the gastrointestinal tract, and the biliary tract. A preferred method for placing these devices is to use specialized delivery systems that precisely position and deploy the device at the site to be treated. These delivery systems allow practitioners to minimize the trauma and technical difficulty associated with device placement. Attributes of delivery systems include: low profile; ability to pass through introducer sheaths; ability to smoothly and atraumatically navigate tortuous vasculature; protection of constrained devices; and the ability to precisely position and deploy the device.

[0003] The stent or stent graft can be expanded and plastically deformed, such as by elastically recovering from a collapsed or constrained delivery diameter to an expanded and deployed diameter, such as by using an inflatable balloon or self-expansion. Some stents are designed to elastically recover by being made of a material with elastic recovery properties at their functional diameter and then radially compressed for installation on a delivery catheter.

[0004] These stent and stent-graft devices may be retained, compressed, or constrained in a delivery configuration prior to and during delivery to a target location. Summary of the Invention

[0005] According to one example ("Example 1"), a medical device deployment device includes at least one constraining fiber, the at least one constraining fiber being configured to form a warp knit fabric around the medical device, the warp knit fabric being configured to be separated and removed to deploy the medical device; and wherein the at least one constraining fiber includes a first series of loops forming the warp knit fabric, wherein at least one of the first series of loops includes a first portion forming a knot and a second portion arranged apart from the knot.

[0006] According to another example further to the apparatus of Example 1 ("Example 2"), the warp knit fabric includes a second constraining fiber including a second series of loops, and the first series of loops and the second series of loops form a knotted row.

[0007] According to another example ("Example 3") that is further developed from the apparatus of Example 2, the first portion of the series of rings and the second portion of the series of rings are arranged to pass through the second series of rings.

[0008] According to another further example ("Example 4") of the apparatus of Example 3, the second portion of the first series of rings includes a second ring.

[0009] According to yet another further example ("Example 5") of the apparatus of Example 3, the second portion of the first series of loops includes a length of the at least one constraining fiber that extends beyond the length of the at least one constraining fiber that forms the knot.

[0010] According to a further example ("Example 6") of the apparatus of Example 5, the length of at least one constraining fiber is rotated relative to the knot.

[0011] According to another example further to the apparatus of Example 2 ("Example 7"), each knot in the knot row is formed by a first series of loops and a second series of loops, wherein each loop in the first series of loops includes a second portion arranged in addition to the knot.

[0012] According to another example further to the device of Example 1 ("Example 8"), at least one of the first series of loops comprising the first portion forming the knot is arranged at a distal end of the warp knitted fabric.

[0013] According to yet another example ("Example 9") further to the apparatus of Example 1, at least one of the first series of loops comprising the first portion forming the knot is configured to prevent (or block) premature deployment of the medical device.

[0014] According to one example (“Example 10”), a method of releasably restraining a medical device includes: forming a warp knit fabric around the medical device using at least one restraining fiber, the warp knit fabric being configured to be separated and removed to deploy the medical device and including a first series of loops; and forming a knot within the warp knit fabric, wherein at least one loop in the first series of loops includes a first portion and a second portion arranged outside the knot.

[0015] According to another further example ("Example 11") of the method of Example 10, forming the knot includes forming the knot at a distal end of the warp knit fabric.

[0016] According to another further example ("Example 12") of the method of Example 10, forming the knot includes forming a slipknot, wherein a length of the second portion is arranged to exceed the slipknot.

[0017] According to another further example ("Example 13") of the method of Example 10, forming the knot includes forming the second portion in the second loop.

[0018] According to another example ("Example 14") further to the method of Example 10, the knot is configured to prevent premature deployment of the medical device.

[0019] According to another example ("Example 15") further to the method of Example 10, the warp knit fabric includes a second constraining fiber including a second series of loops, and the first series of loops and the second series of loops form a knot row.

[0020] According to one example ("Example 16"), a deployment device includes: an implantable medical device; a restraint configured to releasably restrain the implantable medical device in a constrained structure, the restraint including: a first row of knots, the first row of knots being formed by interweaving a first constraining fiber with a second constraining fiber, which surrounds the medical device in the constrained structure, and a second row of knots, the second row of knots being formed by interweaving a second constraining fiber with a third constraining fiber, which surrounds the medical device in the constrained structure, the first row of knots including a distal knot formed by a first loop of the first constraining fiber and a second loop of the second constraining fiber, wherein the second loop includes a first portion forming the knot and a second portion arranged outside the knot.

[0021] According to another further example ("Example 17") for the device of Example 16, each knot in the second row of knots is formed by a first series of loops and a second series of loops, wherein each loop in the second series of loops includes a first part forming the knot and a second part arranged outside the knot.

[0022] According to another further example ("Example 18") of the apparatus of Example 16, the second portion includes a second ring.

[0023] According to another example further to the apparatus of Example 16 ("Example 19"), the distal structure is configured to prevent premature deployment of the medical device.

[0024] According to yet another example ("Example 20") further to the device of Example 16, the second portion includes a length of fiber that extends beyond a length of a third constraining fiber forming the distal knot.

[0025] The foregoing examples are merely examples and should not be construed as limiting or otherwise narrowing the scope of any inventive concept otherwise provided by this disclosure. Although a number of examples are disclosed, still other examples will become apparent to those skilled in the art from the following detailed description, which shows and describes illustrative examples of the present invention. Accordingly, the drawings and detailed description should be regarded as illustrative in nature and not restrictive in nature. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The accompanying drawings are included to provide a further understanding of the disclosure and are incorporated in and constitute a part of this specification, illustrate embodiments and together with the description serve to explain the principles of the disclosure.

[0027] Figure 1is a top view of a delivery system according to one embodiment, the delivery system including a catheter having a restriction;

[0028] Figure 2 is a side view of an implantable medical device including a restraint according to an embodiment;

[0029] Figure 3 is a diagram of an exemplary deployment device according to an embodiment;

[0030] Figure 4 is a diagram of an exemplary deployment device according to an embodiment;

[0031] Figure 5A is an image of a delivery system in a delivery configuration according to an embodiment; and

[0032] Figure 5B is in a semi-expanded configuration according to one embodiment Figure 5A An image of the delivery system is shown. DETAILED DESCRIPTION

[0033] Definitions and Terminology

[0034] As used herein with respect to ranges of measurements, the terms “about” and “approximately” are used interchangeably to refer to measurements that include the stated measurement and also include any measurement that is reasonably close to the stated measurement but that may differ by a reasonably small amount, as would be understood and readily determined by one of ordinary skill in the relevant art(s) attributable to measurement error, differences in calibration of measurement and / or manufacturing equipment, human error in reading and / or setting measurements, adjustment of optimized performance and / or structural parameters to account for differences in measurements associated with other components, specific implementation scenarios, inaccurate adjustment and / or manipulation of an object by a person or machine, and the like.

[0035] This disclosure is not intended to be read in a limiting manner.For example, the terms used in this application should be read broadly in the context of the meaning that one skilled in the art would ascribe to such terms.

[0036] Regarding imprecise terms, the terms "about" and "approximately" are used interchangeably to refer to measurements that include the stated measurement, and also include any measurements that are reasonably close to the stated measurement. As understood and readily determined by one of ordinary skill in the relevant art, measurements that are reasonably close to the stated measurement deviate from the stated measurement by a relatively small amount. For example, such deviations may be due to measurement error or minor adjustments made to optimize performance. If it is determined that a person of ordinary skill in the relevant art would not readily determine the value of such a reasonably small difference, the terms "about" and "approximately" may be understood to mean plus or minus 10% of the stated value.

[0037] Certain terms are used herein for convenience only. For example, terms such as "top," "bottom," "up," "down," "left," "right," "horizontal," "vertical," "upward," and "downward" describe only the configuration or orientation of a component in an installed position as shown in a figure. In practice, the referenced components can be oriented in any direction. Similarly, throughout this disclosure, if a process or method is shown or described, the method can be performed in any order or simultaneously unless it is clear from the context that the method depends on certain operations being performed first.

[0038] Description of various embodiments

[0039] Those skilled in the art will readily appreciate that various aspects of the present disclosure may be implemented in any number of ways and devices configured to perform the intended functions. It should also be noted that the drawings referenced herein are not necessarily drawn to scale, but may be exaggerated to illustrate various aspects of the present disclosure, and in this regard, the drawings should not be construed as limiting.

[0040] Various aspects of the present disclosure relate to devices, systems, and methods for forming or manufacturing restraints. The restraint mechanism is configured to hold, compress, or constrain an implantable medical device (e.g., a stent, stent graft, balloon, filter, or any other expandable medical device) in a delivery configuration prior to and during delivery to a target location. In some cases, the restraint can include one or more fibers arranged together. The fibers can be interwoven, stitched, or otherwise interlocked together circumferentially around the device. To remove the restraint, one or more fibers can be untied or disconnected from the other fibers in the restraint.

[0041] A constrained device can store energy by being constrained to a diameter that is smaller than its natural or deployed diameter. Consequently, the device can exhibit radial displacement forces that resist the restraint. During deployment of the constrained device, radial forces can force the restraint to untie without user intervention, causing the restraint to untie itself. However, aspects of the present disclosure eliminate this premature deployment. As discussed in more detail below, the restraint can include a pattern or knot structure that reduces premature deployment.

[0042] Figure 1 is a top plan view of a catheter 100 having a restraint 102 according to some embodiments. Figure 1 As shown, the constraint 102 is configured to constrain an implantable medical device 104 into a delivery configuration. The constraint 102 may include one or more fibers 106 disposed about the implantable medical device 104 to maintain the constraint 102 in the constrained configuration.

[0043] The restraint 102 is disposed along the length of the implantable medical device 104. The restraint 102 is also disposed circumferentially around the implantable medical device 104 and can substantially cover the implantable medical device 104 for delivery. One or more fibers 106 can be disposed within a lumen (not shown) of the catheter 100 and extend toward the proximal end of the catheter 100, which is disposed outside the patient's body, during delivery of the implantable medical device 104. The one or more fibers 106 include a proximal end 108 to which a user can apply tension to release the restraint 102 and deploy the implantable medical device 104.

[0044] In some cases, one or more fibers 106 are released similar to a rip cord, such that interlocked portions (e.g., overlapping fibers or knots) are sequentially released along the length of the implantable medical device 104. As explained in more detail below, the constraint 102 is formed directly on the implantable medical device 104 by interlocking one or more fibers 106 together. The constraints 102 can be braided together and then subsequently placed around the constrained device, or the constraints 102 can be formed directly on the implantable medical device 104. The expandable medical device 104 can be a stent, stent graft, balloon, or similar device.

[0045] Figure 2 is a side view of a device 104 including a restraint 102 according to one embodiment. As shown, the device 104 includes a delivery diameter D1 and a deployment diameter D2 (not shown) that is larger than the delivery diameter D1. The removable restraint 102 is attached to the device 104 at its delivery diameter D1. As shown, the restraint 102 includes at least two restraining fibers in the form of a warp knit (fabric). For example, the restraint 102 may include a first restraining fiber 110 and a second restraining fiber 112. The first restraining fiber 110 and / or the second restraining fiber 112 may operate, for example, as a deployment line 120 that is configured to release the restraint 102 and transition the device 104 from the delivery diameter D1 to the deployment diameter D2 in response to a force applied to the deployment line 120 (which may be coupled to one or more knot rows 114, as discussed in more detail below).

[0046] The device 104 can have a desired deployed diameter D2 of, for example, about 5 mm to 15 mm, or 6 mm to 9 mm, or 6 mm to 12 mm, 10 mm to 20 mm, 15 mm to 30 mm, or 25 mm to 45 mm, and a delivery diameter D1 that is less than the deployed diameter D2. For example, in some cases, the ratio of the delivery diameter D1 of the device 104 to the deployed diameter D2 of the device 104 (not shown) is less than about 0.3, less than about 0.29, less than about 0.28, less than about 0.27, or less than about 0.26. For reference, the term "diameter" is not meant to require a circular cross-section, but is broadly understood to refer to the largest dimension of the device 104 across a cross-section.

[0047] Figure 3 is an illustration of an exemplary deployment device according to an embodiment. Figure 3 Aspects of a deployment device including at least one constraining fiber 110 are shown. In some cases, the at least one constraining fiber 110 forms a loop on itself to form a braided row 114. In other cases, the at least one constraining fiber 110 includes a first constraining fiber 110 and a second constraining fiber 112. For ease of illustration, Figure 3 The description will refer to the first constraining fiber 110 and the second constraining fiber 112.

[0048] In some cases, at least one constraining fiber 100 is arranged to form a warp knit fabric around a medical device. The warp knit fabric is configured to be separated and removed to deploy the medical device. In addition, at least one constraining fiber 100 may include a first series of loops forming the warp knit fabric, wherein at least one of the first series of loops 318 (one is highlighted for ease of illustration) includes a first portion 320 forming a knot 326 and a second portion 322 arranged in addition to the knot 326.

[0049] In some cases, the first and second constraining fibers 110, 112 can form the constraint 102. At the distal end of the constraint 102 (e.g., at the distal end of the knot row 114), a distal knot 326 can be formed by a loop of at least one constraining fiber 110 (or the first and second constraining fibers 110, 112). In some cases, the second constraining fiber 112 includes a second series of multiple loops 324 (one is highlighted for ease of illustration), and the first series of loops 318 and the second series of loops 324 form the knot row 114.

[0050] like Figure 3As shown, first portion 320 of series of loops 318 and second portion 322 of series of loops 318 are arranged to pass through second series of multiple loops 324. First portion 320 and second series of multiple loops 324 may form a knot in knot row 114. In some cases, distal knot 326 may include first portion 320 of series of loops 318 and second portion 322 of series of loops 318, while the remaining knots in knot row 114 do not include excess length of second portion 322 of series of loops 318. For example, first portion 320 of series of loops 318 may have a length such that it forms a knot with second series of multiple loops 324. The additional length provided by second portion 322 of series of loops 318 (beyond the length used to form the knot) requires additional displacement of the constraining fiber material to untie knot 326. The additional displacement facilitates and prevents premature deployment of constraint 102. In response to tension applied to the deployment thread or at least one constraining fiber 110, the warp knit fabric unravels. The additional length provided by second portion 322 of series of loops 318 increases the friction required to untie knot 326 (or multiple knots in knot row 114 having the additional length provided by second portion 322 of series of loops 318), which may prevent premature unwinding.

[0051] In some cases, second portion 322 of series of loops 318 comprises a second loop, wherein first portion 318 is a first loop. In some cases, second portion 322 of series of loops 318 (or the length excluding knot 326) is rotated or twisted relative to knot 326. Additionally, first series of loops 318 includes first portion 320 forming knot 326, which can be configured to prevent premature deployment of the medical device.

[0052] Figure 4 is an illustration of an exemplary deployment device according to one embodiment. The constraint 102 is shown as a sheet of interwoven fibers, however, the constraint 102 can be arranged circumferentially around the implantable medical device. The constraint 102 can include a sheet formed as described above with reference to Figure 3 The first constraining fiber 110 and the second constraining fiber 112. For example and as Figure 4 As shown, the restraining member 102 includes a first restraining fiber 110, a second restraining fiber 112, a third restraining fiber 438, and a fourth restraining fiber 440. The restraining fibers 110, 112, 438, 440 can be arranged together to form a plurality of knotted rows 114, 442, 444, 446. In some cases, the number of restraining fibers 110, 112, 438, 440 can be equal to the number of knotted rows 114, 442, 444, 446. In addition, the restraining fibers 110, 112, 438, 440 can be interwoven or interlocked with each other to form the knotted rows 114, 442, 444, 446.

[0053] In some cases, the first row of knots 114 of the restraining member 102 can be formed by interweaving the first restraining fibers 110 with the second restraining fibers 112. As shown, the first restraining fibers 110 are interwoven with the second restraining fibers 112 to form the row of knots 114 in the warp knit fabric.

[0054] Furthermore, a second row of knots 442 may be formed by interweaving the second constraining fibers 112 with the third constraining fibers 438. The second constraining fibers 112 may be interwoven with the third constraining fibers 438 to form the row of knots 442. Furthermore, a third row of knots 444 may be formed by interweaving the third constraining fibers 438 with the fourth constraining fibers 440, and a fourth row of knots 446 may be formed by interweaving the fourth constraining fibers 440 with the first constraining fibers 110.

[0055] In some cases, when the restraint 102 is in a constrained configuration around a medical device, each of the rows of knots 114, 442, 444, 446 can be a warp knit fabric. Figure 3 As described above, the constraint 102 can be formed from one or more constraining fibers 110. To deploy the constraint 102 from the constrained configuration, tension can be applied to one of the constraining fibers 110. In some cases, a knot 326 can be formed within the warp knit fabric, wherein at least one of the first series of loops 318 includes a second portion 322 and a first portion 320 arranged in addition to the knot 326. In some cases, the knot 326 can be at the distal end of the constraint 102 or the row of knots 114. The knot 326 and all of the knots in the row of knots 114 can be formed from loops 324 (one highlighted for ease of illustration) formed from the second constraining fiber 112.

[0056] In some cases, the second series of loops 324 of the second constraining fiber 112 may also include a first portion 448 and a second portion 450 disposed in addition to the knot 326. Each of the second portions 322, 450 may include a length of the constraining fiber 110, 112 that extends beyond a length of the constraining fiber (e.g., the first portion 320, 448) that forms the knot 326. In some cases, the second series of loops 324 may be a single loop, such as Figure 3 In addition, each knot in the knot row 114 may include an additional length of the second portion 322, 450. In other cases, only the first constraining fiber 110 or the second constraining fiber may include an additional length of the second portion 322, 450.

[0057] In some cases, knot 326 can be a slipknot. In addition, knot 326 or multiple knots can be configured to prevent the medical device from prematurely deploying. In addition, except for the knots of knot rows 442,444,446, other knot rows 442,444,446 can be similarly configured to include excess length.

[0058] Figure 4The warp-knitted pattern of the restraint 102 shown in FIG (which may include a single knot 326, multiple knots in a single knot row 114, a single distal knot 326 in multiple knot rows 114, 442, 444, 446, or multiple knots in multiple knot rows 114, 442, 444, 446 having a second portion or excess length) reduces premature deployment or mis-deployment when the restraint 102 is untied. For example, the excess length or longer loops require additional displacement to untie them. The longer loops are created by doubling the loops around the loops of the previously created knots in the knot rows 114, 442, 444, 446. Once the loop is untied from the double loop, it may become a twisted loop that can also be untied. To untie the twisted loop, the loop must be pulled farther than a loop made with a single loop. The additional length required to pull out the double loop may require additional circumferential displacement to self-untie the structure and thereby reduce the possibility of premature deployment (e.g., self-untie or accelerated deployment).

[0059] Figure 5A is an image of the delivery system 10 in a delivery configuration, according to one embodiment. Figure 5B is an image of the delivery system 10 in a semi-deployed configuration according to an embodiment. As shown, breaking one of the binding fibers (e.g., the second binding fiber 112) causes at least a portion of the binding member 102 to begin unwinding, as shown in FIG. Figure 5B shown.

[0060] The inventive concepts of the present application have been described above generally and with reference to specific embodiments. It will be apparent to those skilled in the art that various modifications and variations may be made to the embodiments without departing from the scope of the present disclosure. It is therefore intended that the embodiments cover modifications and variations of the inventive concepts as come within the scope of the appended claims and their equivalents.

Claims

1. A medical device deployment device, comprising: at least one constraining fiber configured to form a warp knit fabric around a medical device, the warp knit fabric configured to separate at knots and be removed to deploy the medical device; and wherein at least one constraining fiber comprises a first series of loops and a second series of loops forming the warp knitted fabric, wherein the first series of loops and the second series of loops are interwoven to form the row of knots, and wherein at least one of the first series of loops comprises a first portion forming a knot and a second portion arranged apart from the knot, and wherein the warp knitted fabric comprises a distal knot formed at a distal end of the warp knitted fabric, the distal knot comprising a first portion and a second portion of the first series of loops, wherein the warp knitted fabric comprises a first constraining fiber and a second constraining fiber, the first constraining fiber comprising a first series of loops, the second constraining fiber comprising a second series of loops, and wherein the first portion of the series of loops and the second portion of the series of loops are arranged to pass through the second series of loops, wherein said second portion of said first series of rings comprises a second ring, wherein the second portion of the first series of loops includes a length of the at least one constraining fiber that extends beyond a length of the at least one constraining fiber forming the knot.

2. The device according to claim 1, characterized in that The length of at least one constraining fiber is rotated relative to the knot.

3. The device according to claim 1, characterized in that Each knot in the row of knots is formed by the first series of loops and the second series of loops, wherein each loop in the first series of loops comprises a second portion arranged apart from the knot.

4. The device according to claim 1, characterized in that At least one of the first series of loops, including the first portion forming the knot, is disposed at a distal end of the warp knit fabric.

5. The device according to claim 1, characterized in that At least one loop of the first series of loops, including the first portion forming the knot, is configured to prevent premature deployment of the medical device.

6. A deployment device, comprising: implantable medical devices; a restraint configured to releasably restrain the implantable medical device in a constrained configuration, the restraint comprising: a first row of knots formed by interweaving first constraining fibers with second constraining fibers, the first row of knots surrounding the medical device in the constrained configuration, and A second row of knots, the second row of knots being formed by interweaving the second constraining fiber with a third constraining fiber, the second row of knots surrounding the medical device in the constrained configuration, the first row of knots comprising a distal knot formed by a first loop of the first constraining fiber and a second loop of the second constraining fiber, wherein the second loop comprises a first portion forming the knot and a second portion arranged in addition to the knot, and wherein the distal knot comprises the first portion and the second portion, wherein each knot in the second row of knots is formed by a first series of loops and a second series of loops, each loop in the second series of loops comprising a first portion forming the knot and a second portion arranged in addition to the knot, and wherein the second portion comprises a second loop.

7. The device according to claim 6, characterized in that The structure acts to prevent premature deployment of the medical device.

8. The device according to claim 6, characterized in that The second portion includes a length of fiber that extends beyond a length of the third constraining fiber that forms the distal knot.

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