Bile duct stents and delivery devices

Abstract

A device, system, and method for deploying a biliary stent. The biliary stent has lobes and folds for expanding between a condensed position and an expanded position. The stent is delivered to the bile duct in the condensed position, loaded onto the shaft of a delivery device. As the shaft is retracted through the stent, wings on the shaft push the stent outward to a larger expanded position. In the expanded position, the folds form drainage channels to reduce obstruction over the lifetime of the stent.

Description

Technical Field

[0001] The present disclosure generally relates to medical devices, and more specifically to expandable bile duct stents.

Background Art

[0002] Partial or total occlusion of one or more bile ducts can be treated by the use of a bile duct stent. Conventional bile duct stents are generally tubes made of plastic or metal having a circular or oval cross-section. With the advent of endoscopic surgery for stent placement, the maximum radius of each stent is limited by the maximum diameter within the endoscopic device channel used to deliver the stent. Expandable bile duct stents are known, but the smooth cylindrical shape of the stent can result in the stent filling the bile duct and rapidly clogging. There is a need for a reliable method for delivering and deploying an expandable stent with an external channel for easy mechanical dilation and drainage.

[0003] The present disclosure provides medical devices and methods of using them that avoid the aforementioned drawbacks of existing devices.

Summary of the Invention

[0004] The present disclosure provides designs, materials, manufacturing methods, and use alternatives for medical devices and medical systems. In a first embodiment, a bile duct stent comprises a plurality of folds and a plurality of lobes arranged alternately in the radial direction, each of the plurality of lobes having a first contracted position biased inwardly from the plurality of folds such that the bile duct stent has a first cross-sectional diameter, and each of the plurality of lobes having a second expanded position biased outwardly from the plurality of folds such that the bile duct stent has a second cross-sectional diameter greater than the first cross-sectional diameter.

[0005] Alternatively or additionally to any one of the above examples, the plurality of lobes are of the same length such that the stent is symmetric. In addition to or as an alternative to any of the above examples, the stent is made of biocompatible plastic.

[0006] Alternatively or in addition to any one of the above examples, each lobe forms a convex curve with adjacent folds when in the second expansion position, thereby allowing adjacent lobes to form the sidewalls of the channel outside the stent during expansion of the bile duct stent.

[0007] Alternatively or in addition to any one of the above examples, the stent in the first contraction position has a cross-sectional diameter of 1 mm to 5 mm. In addition to or as an alternative to any one of the above examples, the stent in the second expansion position has a cross-sectional diameter of 2 mm to 10 mm.

[0008] Alternatively or in addition to any one of the above examples, the stent has an axial length of 2 mm to 20 mm. In another embodiment, the biliary stent delivery device comprises a shaft sized to be inserted into the patient's bile duct and one or more wings at the distal end of the shaft, each wing transitioning between a first proximal orientation directed toward the proximal end of the shaft and a second distal orientation directed toward the distal end of the shaft.

[0009] Alternatively or in addition to any one of the above examples, the shaft is loaded with an expandable biliary stent for insertion into the bile duct, and the expandable stent is positioned proximal to one or more wings such that when the shaft is retracted through the loaded stent, the wings transition from a first proximal orientation to a second distal orientation, pushing the stent outward and expanding it.

[0010] Alternatively or in addition to any one of the above examples, the wing has a cross-sectional diameter of 2.3 mm to 4.2 mm in the first proximal orientation. Alternatively or in addition to any one of the above examples, the wing has a cross-sectional diameter of 2.3 mm to 4.2 mm in the second proximal orientation.

[0011] In another embodiment, a method for deploying a biliary stent of any of the above embodiments may include the steps of: loading the stent in a first position onto the shaft of any one of the above embodiments' delivery devices; inserting the distal end of the shaft into the patient's bile duct; positioning the stent within the patient; expanding the stent to a second position; and retracting the shaft, leaving the expanded stent in the bile duct.

[0012] Alternatively or in addition to any one of the above examples, one or more wings at the distal end of the shaft are positioned in a first proximal orientation during insertion of the distal end of the shaft and positioning of the stent. The step of retracting the shaft includes moving the distal end of the shaft through the stent so that the wings transition from the first proximal orientation to the second distal orientation. Stent expansion is a result of the wings pushing the stent outward as the distal end of the shaft moves through the stent.

[0013] Alternatively or in addition to any of the above examples, this method further includes the step of deploying a second stent loaded into the device. These and other features and advantages of this disclosure will be readily apparent from the following detailed description, and the scope of the claimed invention is set forth in the attached claims.

[0014] The accompanying drawings incorporated herein and constituting part thereof illustrate various embodiments and, together with the description, are useful in illustrating the principles of this disclosure. [Brief explanation of the drawing]

[0015] [Figure 1] A diagram showing a medical delivery device. [Figure 2A] A diagram showing a bile duct stent in a contracted position. [Figure 2B] A diagram showing a bile duct stent in a contracted position. [Figure 3A] A diagram showing the bile duct stent in the dilated position. [Figure 3B] Figure showing a bile duct stent in an extended position. [Figure 4] Figure showing the wings of a delivery device in a proximal orientation. [Figure 5] Figure showing the wings in a distal orientation. [Figure 6A] Figure showing the deployment of a bile duct stent loaded onto the shaft of a medical delivery device. [Figure 6B] Figure showing the deployment of a bile duct stent loaded onto the shaft of a medical delivery device. [Figure 6C] Figure showing the deployment of a bile duct stent loaded onto the shaft of a medical delivery device. [Figure 6D] Figure showing the deployment of a bile duct stent loaded onto the shaft of a medical delivery device. [Figure 6E] Figure showing the deployment of a bile duct stent loaded onto the shaft of a medical delivery device.

Best Mode for Carrying Out the Invention

[0016] The present disclosure can accept various modified forms and alternative forms, the details of which are shown by way of example in the drawings and will be described in detail. However, it should be understood that the present invention is not limited to the specific embodiments described. Rather, the intention is to cover all modifications, equivalents, and alternatives that fall within the spirit and scope of the present disclosure.

[0017] The present disclosure is described herein by reference to an exemplary medical system that can be used in endoscopic medical procedures. However, it should be noted that this reference to a specific procedure is provided for convenience only and is not intended to limit the present disclosure. Those skilled in the art will recognize that the concepts underlying the disclosed devices and related methods of use can be utilized in any suitable procedure, medical, or other context. The present disclosure can be understood by reference to the following description and the accompanying drawings, and like elements are referred to by the same reference numbers.

[0018] All numerical values are assumed to be modified by the term "about" in this specification, whether or not explicitly indicated. The term "about" generally refers to a range of numbers that a person of ordinary skill in the art would consider equivalent (e.g., having the same function or result) in the context of the numerical value. In many cases, the term "about" may include numbers rounded to the nearest significant digit. Other uses of the term "about" (in contexts other than numerical values) may be understood from the context of this specification and are assumed to have their normal conventional definitions (if any) consistent with the context of this specification, unless otherwise specified.

[0019] The recitation of numerical ranges by endpoints includes all numbers within that range including the endpoints (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5). Although some appropriate dimensions, ranges, and / or values for various components, features, and / or specifications are disclosed, those skilled in the art will appreciate that the desired dimensions, ranges, and / or values may deviate from those explicitly disclosed.

[0020] Where used herein and in the appended claims, the singular forms “a,” “an,” and “the” include multiple subjects unless otherwise explicitly stated. Where used herein and in the appended claims, the term “or” generally includes “and / or” unless otherwise explicitly stated. For ease of understanding, note that certain features of this disclosure may be described in the singular form even if those features may be multiple or repeated within the disclosed embodiments. Each example of a feature may include a singular disclosure and / or be encompassed by a singular disclosure unless otherwise explicitly stated. For brevity and clarity, not all elements of this disclosure are necessarily shown in each figure or described in detail below. However, it should be understood that the following descriptions may apply equally to any and / or all of the components that exist in pairs or more, unless otherwise explicitly stated. In addition, not all examples of some elements or features are shown in each figure for clarity.

[0021] References in this specification to “one embodiment,” “several embodiments,” and “other embodiments” should be noted to indicate that the embodiments described may include certain features, structures, or characteristics, but not all embodiments necessarily include those features, structures, or characteristics. Furthermore, such phrases do not necessarily refer to the same embodiments. In addition, where certain features, structures, or characteristics are described in relation to an embodiment, it is within the knowledge of those skilled in the art that these features, structures, or characteristics may result in other embodiments, whether explicitly stated or not, unless explicitly stated otherwise. That is, the various individual elements described below are intended to be combinatorial or configurable to form other additional embodiments or to complement and / or enhance the embodiments described, even if not explicitly shown in specific combinations, as will be understood by those skilled in the art.

[0022] For clarity, specific identifying numerical nomenclature (e.g., First, Second, Third, Fourth, etc.) may be used throughout the specification and / or claims to name and / or distinguish various described and / or claimed features. It should be understood that numerical nomenclature is not intended to be limiting, but merely illustrative. In some embodiments, changes and deviations from previously used numerical nomenclature may be made for simplification and clarity. That is, a feature identified as the “First” element may later be referred to as the “Second” element, the “Third” element, and so on, or may be omitted entirely, and / or a different feature may be referred to as the “First” element. The meaning and / or designation in each example will be obvious to those skilled in the art.

[0023] The detailed description is intended to be illustrative, not limiting, of the disclosure. Those skilled in the art will recognize that the various elements described may be arranged in various combinations and configurations without departing from the scope of the disclosure. The detailed description illustrates exemplary embodiments of the disclosure.

[0024] Figure 1 shows a bile duct access device 100 according to several embodiments of the present disclosure. The device 100 includes a distal shaft 102 suitable for insertion into or near the patient's bile duct. The shaft 102 is sized and molded to be fed through an attached channel of an endoscope via a guidewire, along with one or more bile duct stents loaded on the shaft 102. A proximal handle 104 includes any necessary interface components for controlling the distal shaft 102, unloading the bile duct stent, and expanding the stent during deployment, as further described herein. The handle 104 provides control of the shaft 102 during stent delivery and deployment, as well as during the final retraction and removal of the device 100.

[0025] A biliary stent 200 is shown in Figures 2A to 3B. The biliary stent 200 may have a first folded form in which a plurality of lobes 202 are biased inwardly concave between folds 204. In some embodiments, the stent 200 may be formed from an elastic material such as a rigid thermoplastic that maintains its shape. Those skilled in the art will recognize that any biocompatible material may be used, but the suitability of the material may depend on the nature of the procedure and the placement of the stent. In Figures 3A and 3B, the lobes 202 are biased outwardly convex between a plurality of folds 204, significantly expanding the cross-sectional area of ​​the stent 200. In this regard, the folds 204 act as hinge positions for the lobes 202 to transition from a concave inward orientation to a convex outward orientation. By expanding after deployment, as will be further described herein, the stent 200 may have an effective radius larger than the channel to which the stent 200 was delivered when deployed.

[0026] Although the biliary stent 200 is shown having five folds and five lobes of symmetrical arc lengths, a person skilled in the art will recognize that different numbers of lobes are possible, including three, four, six, seven, eight, and so on, and that one or more lobes may be longer than one or more other lobes.

[0027] As shown in Figure 3B, the expanded stent 200 forms an opening with the surrounding bile duct tissue 302, which includes external channels 304. These channels 304 provide drainage along the outside of the stent 200, increasing the effective lifespan of the stent 200 compared to the smooth and symmetrical sidewalls found in conventional plastic tube stents in the art.

[0028] The length and width of the stent 200 may depend on the limitations of its intended placement and / or access device. In some embodiments, the stent may have an axial length of 2 to 20 mm and its cross-sectional diameter may expand from 1 mm to 5 mm when retracted to 2 mm to 10 mm when expanded.

[0029] The deployment of the bile duct stent is assisted by a shaft 400 having wings 402 as shown in Figures 4 and 5, the wings being able to move between a first position oriented proximal to the ground, as shown in Figure 4, and a second position oriented distal to the ground, as shown in Figure 5. The wings 402 may be fabricated integrally with the shaft 400, or they may be attached to the shaft 400 either mechanically or through adhesive.

[0030] Figures 6A–6E show the deployment of the biliary stent 200 on the shaft 400. As the shaft 400 retracts through the stent 200, the wing 402 transitions from proximal to distal orientation by contact with the stent 200, and then passes through an intermediate orientation between the proximal and distal orientations. The wing 402 has sufficient elasticity and diameter so as not to fold completely against the body of the shaft 400, and as the wing 402 passes, it pushes the stent 200 outward, opening the stent 200 and reorienting the stent 200 from a folded state with the lobes inwardly concave orientation to an expanded state with the lobes outwardly convex orientation. Since the wing 402 is flexible and may tend to flatten due to the resistance provided by the folded stent 200, in some embodiments, the use of multiple wings in series may be used to enhance the effectiveness of the leading wing. The reason is that the next wing in the series acts as a barrier, thus enhancing the ability of the leading wing to overcome the resistance of the folded stent.

[0031] The cross-sectional diameter of the wing 402 is related to the cross-sectional diameter of the stent 200 both before and after expansion, and may be the same or different when oriented in the first or second position. In some embodiments, each of the first and second wing positions may have a cross-sectional diameter of 2.3 mm to 4.2 mm.

[0032] In some embodiments, the wing 402 may be biased to return naturally to a distal orientation relative to the shaft 400 when the stent 200 is extended and deployed. In some embodiments, a mechanism such as a guidewire or string may be provided to fold the wing 402 relative to the shaft 400. Some stents 200 may be loaded onto one shaft 400 for deployment during a single operation.

[0033] The stent 200 may be made from any biocompatible material, such as polyethylene plastic, having sufficient flexibility and elasticity. The wing 402 may similarly be made from any material that allows for proper transition between positions. In some embodiments, the wing 402 may be made from a material that is more rigid than the stent 200 to ensure the correct deployment interaction between the two.

[0034] It should be understood that this disclosure is, in many respects, merely illustrative. Modifications may be made in detail, particularly with respect to shape, size, and step arrangement, without exceeding the scope of this disclosure. This may, to the appropriate extent, include the use of any of the features of one exemplary embodiment used in other embodiments. The scope of the invention is, of course, defined by the language in which the appended claims are expressed.

Claims

1. A biliary stent comprising multiple folds and multiple lobes arranged alternately in the radial direction, Each of the plurality of lobes has a first contracted position biased inward from the plurality of folds such that the bile duct stent has a first cross-sectional diameter, and Each of the plurality of lobes has a second expanded position biased outward from the plurality of folds such that the bile duct stent has a second cross-sectional diameter larger than the first cross-sectional diameter. Bile duct stent.

2. The biliary stent according to claim 1, wherein the plurality of lobes are of the same length so that the stent is symmetrical.

3. A biliary stent according to claim 1 or 2, comprising a biocompatible plastic.

4. The biliary stent according to any one of claims 1 to 3, wherein each of the lobes forms a convex curve having adjacent folds when in the second expansion position, so that adjacent lobes form the side wall of an external channel of the biliary stent when the biliary stent is expanded.

5. The bile duct stent according to any one of claims 1 to 4, wherein the stent in the first contracted position has a cross-sectional diameter of 1 mm to 5 mm.

6. The bile duct stent according to any one of claims 1 to 5, wherein the stent in the second expansion position has a cross-sectional diameter of 2 mm to 10 mm.

7. The stent is a bile duct stent according to any one of claims 1 to 6, having an axial length of 2 mm to 20 mm.

8. A shaft sized to be inserted into the patient's bile duct, One or more wings at the distal end of the shaft, each wing transitions between a first proximal orientation directed toward the proximal end of the shaft and a second distal orientation directed toward the distal end of the shaft. A bile duct stent delivery device equipped with [specific feature].

9. The device according to claim 8, wherein the shaft is loaded with an expandable biliary stent for insertion into the bile duct, and the expandable stent is positioned proximal to one or more wings such that when the shaft is retracted through the loaded stent, the wings transition from the first proximal orientation to the second distal orientation, pushing the stent outward and expanding it.

10. The device according to claim 8 or 9, wherein the expandable bile duct stent is the stent according to any one of claims 1 to 7.

11. The device according to any one of claims 8 to 10, wherein the wing has a cross-sectional diameter of 2.3 mm to 4.2 mm in the first proximal orientation.

12. The device according to any one of claims 8 to 11, wherein the wing has a cross-sectional diameter of 2.3 mm to 4.2 mm in the second distal orientation.

13. The steps include loading the stent in the first position onto the shaft of the delivery device according to any one of claims 8 to 12, The steps include inserting the distal end of the shaft into the patient's bile duct, The steps include positioning the stent within the patient, The steps include extending the stent to the second position, The steps include retracting the shaft and leaving the expanded stent inside the bile duct, A method for deploying a bile duct stent according to any one of claims 1 to 7, including the following:

14. The one or more wings at the distal end of the shaft are positioned in the first proximal orientation during insertion of the distal end of the shaft and positioning of the stent. The step of retracting the shaft includes moving the distal end of the shaft through the stent so that the wing transitions from the first proximal orientation to the second distal orientation, The method according to claim 13, wherein the step of expanding the stent is a result of the wings pushing the stent outward as the distal end of the shaft moves through the stent.

15. The method according to claim 13 or 14, further comprising the step of deploying a second stent loaded onto the device.

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