Tissue sample devices and methods

Abstract

A tissue sampling system for obtaining samples from a body is disclosed, comprising: an outer tubular member having proximal and distal end regions and defining a lumen extending from the proximal end region to the distal end region; an inner tubular member slidably disposed within the lumen of the outer tubular member, the inner tubular member defining a lumen extending from the proximal end region to the distal end region of the inner tubular member; and an expandable tissue sampling device disposed adjacent the distal end region of the inner tubular member.

Description

[Technical Field]

[0001] FIELD OF THE INVENTION This application relates generally to medical devices for tissue sampling, and more particularly to medical devices for tissue sampling that increase the yield of better cells or other tissue. [Background technology]

[0002]

[0003] Certain medical tests require sampling cells from a target area of ​​a subject's body. For example, a screening test to detect potential precancerous and cancerous tissues in a subject's body may include collecting a tissue or cell sample from a target area of ​​the subject's body. A tissue collection device may be used to collect cells or other tissues from the target area. Collecting tissue from some parts of the anatomical structure can be difficult. There is a constant need to provide alternative medical devices, as well as alternative methods of manufacturing and using medical devices. Summary of the Invention

[0003] The present disclosure provides designs, materials, manufacturing methods, and alternative uses for medical devices. In a first example, a tissue collection system includes an outer tubular member having a proximal end region and a distal end region and defining a lumen extending from the proximal end region to the distal end region, an inner tubular member slidably disposed within the lumen of the outer tubular member, the inner tubular member defining a lumen extending from the proximal end region to the distal end region of the inner tubular member, and a tissue collection device disposed adjacent the distal end region of the inner tubular member, the tissue collection device including an expandable basket. The tissue collection device may be movable between a retracted delivery position and an advanced sample collection position.

[0004] Alternatively or additionally to any of the above examples, in another example, the expandable basket may include a plurality of longitudinally extending struts. Alternatively or additionally to any of the above examples, in another example, one or more edges of at least one strut of the plurality of struts may have a sharp surface.

[0005] Alternatively or additionally to any of the above examples, in another example, a surface of at least one strut of the plurality of struts may be textured. Alternatively or additionally to any of the above examples, in another example, the tissue harvesting system may further comprise one or more barbs coupled to at least one strut of the plurality of struts.

[0006] Alternatively, or in addition to, any of the above examples, in another example, one or more barbs may include a wire wrapped around at least one strut. Alternatively or additionally to any of the above examples, in another example, at least one free end of the wire may extend radially from at least one strut.

[0007] Alternatively or additionally to any of the above examples, in another example, the tissue harvesting system may further comprise one or more teeth extending from at least one strut.

[0008] Alternatively, or in addition to, any of the above examples, in another example, one or more teeth and at least one strut may be formed as a single monolithic structure.

[0009] Alternatively or additionally to any of the above examples, in another example, the plurality of struts may include a plurality of individual filaments, the plurality of individual filaments being bonded to one another at proximal and distal ends of each of the plurality of individual filaments.

[0010] Alternatively, or in addition to any of the above examples, in another example, the tissue harvesting device may comprise a cut tube. Alternatively, or in addition to, any of the above examples, in another example, the tissue harvesting device and inner tubular member may comprise a monolithic structure.

[0011] Alternatively, or in addition to any of the above examples, in another example, a tissue sampling device may be coupled to the inner tubular member. Alternatively, or in addition to any of the above examples, in another example, the tissue harvesting device may be self-expanding.

[0012] Alternatively or additionally to any of the above examples, in another example, the tissue harvesting system may further comprise an actuation mechanism coupled to the proximal or distal end of the tissue harvesting device.

[0013] Alternatively or additionally to any of the above examples, in another example, the inner tubular member may further comprise one or more cut-out regions, and the one or more cut-out regions may be adjacent to the tissue collection device.

[0014] Alternatively or additionally to any of the above examples, in another example, the plurality of struts may have a generally flat, ribbon-like shape. Alternatively or additionally to any of the above examples, in another example, the plurality of struts may have a generally wire-like shape.

[0015] Alternatively or additionally to any of the above examples, in another example, the proximal end of each strut of the plurality of struts may be coupled to a proximal collar and the distal end of each strut of the plurality of struts may be coupled to a distal collar.

[0016] Alternatively or additionally to any of the above examples, in another example, at least one of the proximal collar or the distal collar may be movably positioned over the inner tubular member.

[0017] Alternatively or additionally to any of the above examples, in another example, in the expanded configuration, an intermediate region of each strut of the plurality of struts may be curved so as to protrude radially outward.

[0018] Alternatively or additionally to any of the above examples, in another example, each strut of the plurality of struts may include a proximal end region and a distal end region. Alternatively, or in addition to, any of the above examples, in another example, the proximal end regions of multiple struts may be joined with the distal end regions at intersections.

[0019] Alternatively or additionally to any one of the above examples, in another example, in the expanded configuration, proximal end regions of the plurality of struts may extend at a first angle relative to the longitudinal direction of the expandable basket, and distal end regions of the plurality of struts may extend at a second angle relative to the longitudinal direction of the expandable basket.

[0020] Alternatively or additionally to any one of the above examples, in another example, the first angle may be different from the second angle. Alternatively or additionally to any one of the above examples, in another example, in the expanded configuration, the plurality of struts may be curved to protrude radially outward such that the proximal and distal end regions of the expandable basket extend at a non-parallel angle relative to the longitudinal axis of the expandable basket, and the intermediate region extends approximately parallel to the longitudinal axis of the expandable basket.

[0021] In another example, a tissue collection system includes an outer tubular member having a proximal end region and a distal end region and defining a lumen extending from the proximal end region to the distal end region, an inner tubular member slidably disposed within the lumen of the outer tubular member, the inner tubular member defining a lumen extending from the proximal end region to the distal end region of the inner tubular member, and a tissue collection device disposed adjacent the distal end region of the inner tubular member, the tissue collection device including a radially expandable basket. The radially expandable basket can have a plurality of longitudinally extending struts extending between a proximal collar and a distal collar. The tissue collection device can be movable between a collapsed, retracted delivery position and an expanded, advanced sample collection position.

[0022] Alternatively, or in addition to any of the above examples, in another example, the tissue harvesting device may be a cut tube. Alternatively or additionally to any of the above examples, in another example, at least one strut of the plurality of struts may include a radially extending tissue disruption feature.

[0023] In another example, a tissue collection system may include an outer tubular member having a proximal end region and a distal end region and defining a lumen extending from the proximal end region to the distal end region, an inner tubular member slidably disposed within the lumen of the outer tubular member, the inner tubular member defining a lumen extending from the proximal end region to the distal end region of the inner tubular member, a tissue collection device disposed adjacent the distal end region of the inner tubular member, the tissue collection device including a radially expandable basket having a plurality of longitudinally extending wires extending between a proximal collar and a distal collar, and at least one barb coupled to at least one of the plurality of longitudinally extending wires, the at least one barb having a radially extending free end. The tissue collection device may be movable between a collapsed, retracted delivery position and an expanded, advanced sample collection position.

[0024] The above summary of some exemplary embodiments is not intended to describe each disclosed embodiment or every implementation of the present disclosure. [Brief explanation of the drawings]

[0025] The present disclosure may be more fully understood from the following detailed description of various embodiments, taken in conjunction with the accompanying drawings. [Figure 1] FIG. 1 shows a partial cross-sectional side view of an exemplary tissue harvesting device system for delivering a tissue harvesting device to a target area in a retracted or delivery configuration. [Figure 2] FIG. 2 shows a perspective view of the exemplary tissue harvesting device of FIG. [Figure 3] FIG. 3 shows a perspective view of another exemplary tissue harvesting device. [Figure 4] FIG. 4 shows a side view of another exemplary tissue harvesting device system for delivering a tissue harvesting device to a target area in a deployed configuration. [Figure 5]FIG. 5 is an exemplary flow chart of a method for obtaining a tissue sample using the system of FIGS. DETAILED DESCRIPTION OF THE INVENTION

[0026] While the present disclosure is susceptible to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and will be described in detail. It is to be understood, however, that this is not intended to limit aspects of the disclosure to the particular embodiments illustrated. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present disclosure.

[0027] As used herein, all numerical values, whether explicitly stated or not, are deemed to be modified by the term "about." The term "about" generally refers to a range of numerical values ​​that one of ordinary skill in the art would consider equivalent to the recited value (e.g., having the same function or result). In many instances, the term "about" may be expressed as including numbers that are rounded to the nearest significant figure.

[0028] The recitation of numerical ranges by endpoints includes all numbers within that range (eg, 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5). Although certain preferred dimensions, ranges, and / or values ​​for various components, features, and / or specifications are disclosed, those skilled in the art inspired by this disclosure will understand that the desired dimensions, ranges, and / or values ​​may deviate from those expressly disclosed.

[0029] As used in this specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the content clearly dictates otherwise. As used in this specification and the appended claims, the term "or" is generally used in its sense including "and / or" unless the content clearly dictates otherwise.

[0030] The term "distal" refers to the portion of the device that is furthest from the user when the device is introduced into a patient. Conversely, the term "proximal" refers to the portion of the device that is closest to the user when the device is positioned within a patient. As used herein, the terms "comprises," "comprising," or any other variations thereof are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not necessarily include only those elements, but may include other elements not expressly listed or elements inherent to such process, method, article, or apparatus. Additionally, terms indicating the geometry of components / surfaces refer to exact and approximate shapes.

[0031] The following detailed description should be read with reference to the drawings, in which similar elements in different drawings are numbered the same. The detailed description and drawings, which are not necessarily to scale, depict exemplary embodiments and are not intended to limit the scope of the present disclosure. The exemplary embodiments shown are intended as examples only. Selected features of any exemplary embodiment may be incorporated into additional embodiments, unless expressly stated to the contrary.

[0032] Endoscopic retrograde cholangiopancreatography (ERCP) is a procedure that utilizes both endoscopic and fluoroscopic techniques to diagnose and treat problems occurring in the common bile duct (CBD) and pancreatic duct (PD). One of the main problems treated today is strictures in the CBD due to, but not limited to, primary sclerosing cholangitis (PSC), cholangiocarcinoma, and gallstone damage and scarring within the bile duct. However, biliary structures can have a low sensitivity rate for cancer during ERCP procedures, which can result in false-negative diagnoses. In some cases, low sensitivity may be related to inadequate tissue collection, which is a major limiting factor in detecting potential malignancies. When clinicians need to obtain samples from strictures, one of the most common methods for doing so is with a cytology brush. However, the sensitivity of cytology brushes can be approximately 30–60%. The sensitivity of the cytology brush may be primarily related to insufficient sample volume. One reason for the brush's inability to collect sufficient samples is the use of soft bristles. Another reason may be the loss of sample during the procedure.

[0033] A sample collection device that collects a sufficient amount of sample for better prediction of biliary tract cancer is desired. Although the present disclosure is described with respect to the common bile duct and pancreatic duct, the devices and methods are not limited to such use. For example, the devices and methods described herein can be used in any part of the anatomy as desired. Furthermore, the devices and methods described herein can be used in either endoscopic or non-endoscopic anatomy. Some exemplary anatomy includes, but is not limited to, the mouth, esophagus, stomach, duodenum, other parts of the gastrointestinal tract, the pathway to the lungs, other parts of the respiratory system, the urinary tract, the cervix, other reproductive anatomy, etc.

[0034] FIG. 1 is a partial side cross-sectional view of an exemplary tissue collection device system 10 for delivering a tissue collection device 12 to a target region, such as, but not limited to, the common bile duct or pancreatic duct, in a retracted or delivery configuration. The tissue collection system 10 can include an outer or external elongate shaft or tubular member 14 and an inner elongate shaft or tubular member 16. The inner tubular member 16 can be slidably disposed within a lumen 18 of the outer tubular member 14. The outer tubular member 14 can extend proximally from a distal end region 20 to a proximal end region 22 configured to remain outside the patient's body. A first hub or handle 24 can be coupled to the proximal end region 22 of the outer tubular member 14. In some cases, a port 32, such as an injection port, can be provided on the outer tubular member 14. Other structures can be provided to allow connection to other medical devices (e.g., syringes, stopcocks, Y-adapters, etc.) and provide access to the lumen 18. The inner tubular member 16 may extend proximally from a distal end region 26 to a proximal end region 28 configured to remain outside the patient's body. A second hub or handle 30 may be coupled to the proximal end region 28 of the inner tubular member 16.

[0035] The outer tubular member 14 may include a lumen 18 extending from the distal end region 20 to the proximal end region 22. The lumen 18 may also extend through the first handle 24. The lumen 18 of the outer tubular member 14 and the first handle 24 may be configured to slidably receive the inner tubular member 16. The inner tubular member 16 may include a lumen 40 extending from the distal end region 26 to the proximal end region 28. The lumen 40 of the inner tubular member 16 may also extend through the second handle 30. The lumen 40 of the inner tubular member 16 may be configured to receive a guidewire 42, if desired. In other examples, the guidewire 42 may be received within the lumen 18 of the outer tubular member 14. It is contemplated that the system 10 may be arranged such that the guidewire 42 extends within the lumen along the entire length of the outer tubular member 14 or inner tubular member 16 in an "over-the-wire" manner, or such that the guidewire 42 exits a side port in the outer tubular member 14 distal to the proximal end region 22 of the outer tubular member 14 in a "rapid-exchange" manner.

[0036] The tissue collection device 12 may be disposed around a portion of the inner tubular member 16 at or adjacent the distal end region 26 of the inner tubular member 16, or may be formed as part of the inner tubular member 16. The tissue collection device 12 may extend around the entire circumference of the inner tubular member 16. In other embodiments, the tissue collection devices 12 may be radially spaced around the circumference of the inner tubular member 16 in a uniform pattern or an eccentric manner, as desired. In some embodiments, the tissue collection device 12 may include a radially expanding frame or basket 44 that is transitionable between a collapsed delivery configuration ( FIG. 1 ) and an expanded use configuration ( FIG. 2 ). While the tissue collection device 12 is described as an expandable basket, it is contemplated that other tissue collection devices may be used, as desired.

[0037] With further reference to FIG. 2 , which shows a perspective view of an exemplary tissue harvesting device 12, the expandable basket 44 may include a plurality of longitudinally extending struts 46a-e (collectively 46) extending from a proximal end 48 to a distal end 50. In some embodiments, the proximal end 48 of the basket 44 may extend proximally to a location configured to remain outside the body so that the tissue harvesting device 12 can be manipulated through actuation of the proximal end 48, although this is not required. The expandable basket 44 may include any desired number of struts 46, such as, but not limited to, one, two, three, four, five, six, or more. The plurality of struts 46 may have a generally flat, ribbon-like shape (e.g., having a width greater than a thickness). In other examples, the plurality of struts 46 may have a generally wire-like shape (e.g., having similar widths and thicknesses). However, the plurality of struts 46 may take any desired shape. The plurality of struts 46 may be evenly spaced around the circumference of the expandable basket 44. However, this is not required. In some cases, the plurality of struts 46 may be eccentrically or unevenly spaced.

[0038] The proximal ends of the struts 46 may be secured to a proximal collar 52, and the distal ends of the struts 46 may be secured to a distal collar 54. In some embodiments, the struts 46 and the proximal collar 52 and / or the distal collar 54 may be formed as a single monolithic structure. For example, the struts 46 and the collars 52, 54 may be cut from a single tube. It is further contemplated that the struts 46 and the collars 52, 54 may be formed from or as part of the inner tubular member 16. In other words, the inner tubular member 16, the struts 46, and the collars 52, 54 may be formed as a single monolithic structure. For example, the cut tube may be the inner tubular member 16 or another tube, as desired. In other embodiments, the plurality of struts 46 and one or more of the proximal and distal collars 52, 54 may be formed as separate structures that are coupled to one another. For example, the plurality of struts 46 may be welded, brazed, soldered, glued, etc. to the proximal and / or distal collars 52, 54. Other coupling techniques may be used as desired. It is contemplated that the coupling mechanism may depend, at least in part, on the material of the plurality of struts 46 and / or collars 52, 54. When the expandable basket 44 is a separate component from the inner tubular member 16, at least one of the proximal collar 52 and the distal collar 54 is fixedly attached to the outer surface of the inner tubular member 16, and the other of the proximal collar 52 or the distal collar 54 is movably disposed over the inner tubular member 16 to allow the basket 44 to radially expand. In one example, the proximal collar 52 is fixedly attached to the inner tubular member 16, and the distal collar 54 may be slidably disposed over the inner tubular member 16. In such a configuration, the distal collar 54 can be moved distally to collapse the expandable basket 44 and moved proximally to expand the expandable basket 44.The reverse configuration is also contemplated, in which distal collar 54 may be fixedly attached to inner tubular member 16 and proximal collar 52 may be slidably disposed over inner tubular member 16 .

[0039] The expandable basket 44 may be self-expandable or may require an external force to expand from a collapsed state. The multiple self-expandable members may be formed from any material or structure that is in a compressed state when a force is applied and in an expanded state when the force is released. Such members may be formed, for example, from a shape-memory alloy such as Nitinol or any other self-expandable material. When using such a shape-memory material, the expandable basket 44 may be heat-set in an expanded state and then compressed to fit within the outer tubular member 14, for example. In another embodiment, a spring may be provided to achieve expansion. It is envisioned that a nickel-titanium alloy may be kink-resistant, allowing for self-expansion. In other examples, the expandable basket 44 may be formed using a magnetic alloy, a metal, a metal alloy, a polymer, a composite material, or the like.

[0040] In another example, the expandable basket 44 can be manipulated or actuated between the expanded and collapsed configurations by a manual force applied to the inner tubular member 16. For example, the actuation element can include a central wire or rod extending through the expandable basket 44 and coupled to the distal collar 54. Alternatively, an external force, such as, but not limited to, air pressure, pressurized fluid, a pull wire, a push wire, or a rod, can be employed to expand the expandable basket 44. According to this embodiment, a pulling force applied proximally to the wire can cause the plurality of struts 46 to expand and transition the expandable basket 44 to the expanded state. A pushing force applied distally to the wire can elongate the plurality of struts 46 and / or transition the expandable basket 44 to the compressed or elongated state. Other actuation mechanisms can also be utilized. For example, a guidewire 42 can be used to apply a proximal pushing force to the distal end of the distal collar 52. In such cases, the guidewire 42 may include an enlarged region having a diameter larger than the diameter of the lumen of the tissue harvesting device 12, such that proximal actuation of the guidewire 42 may bring the enlarged region of the guidewire 42 into contact with the distal collar 52, and further proximal actuation of the guidewire 42 may move the distal collar 52 proximally, thereby expanding the expandable basket 44. It is contemplated that manual actuation of the expandable basket 44 using a wire, rod, or the like may impart greater force to the expandable basket 44, thereby allowing for greater engagement of the basket with the target tissue.

[0041] When the tissue collection device 12 is positioned within the outer tubular member 14, the expandable basket 44 can be constrained in a reduced-diameter, compressed or delivery configuration by the outer tubular member 14 surrounding the tissue collection device 12. Alternatively, the expandable basket 44 can assume a collapsed configuration until an actuation force is applied to the expandable basket 44. In the collapsed configuration, the tissue collection device 12 can have a smaller diameter than in the expanded, deployed configuration. The distal end region 20 of the outer tubular member 14 can be positioned so that the outer tubular member 14 surrounds and wraps the length of the tissue collection device 12 during delivery. The outer tubular member 14 can have sufficient hoop strength to hold the tissue collection device 12 in its collapsed state. In the expanded configuration, the intermediate regions of the plurality of struts 46 can flex to project radially outward, causing the plurality of struts 46 to form an arc or curved configuration.

[0042] The tissue collection system 10 can be advanced through the body toward the target site as desired. The tissue collection system 10 can be advanced with or without the use of a guidewire 42. Once the tissue collection device 12 is positioned adjacent to the target area, the restraining forces maintaining the tissue collection device 12 in a radially compressed configuration can be removed and the tissue collection device 12 can be deployed (deployed).

[0043] The tissue collection device 12 can be deployed (deployed) by actuating the second handle 30, e.g., by pushing the second handle 30 distally, while maintaining the first handle 24 in a fixed position. Thus, the inner tubular member 16 can be advanced distally relative to the outer tubular member 14. In other words, the inner tubular member 16 can be advanced distally while the outer tubular member 14 remains stationary. The reverse configuration is also contemplated. For example, the outer tubular member 14 can be retracted proximally while the inner tubular member 16 remains stationary. When the inner tubular member 16 is advanced distally, the biasing force from outside the tissue collection device 12 is removed, and the expandable basket 44 assumes its radially expanded, unbiased, deployed configuration shown in FIG. 2 . Alternatively, the expandable basket 44 can remain collapsed until an actuation force is applied to the expandable basket 44 (e.g., using a pull wire or other actuation mechanism) to transition the expandable basket 44 to the radially expanded, deployed configuration.

[0044] In the radially expanded configuration, the plurality of struts 46 may bend radially outward such that the expandable basket 44 has a generally oval shape. However, the expandable basket 44 may assume other shapes in the expanded configuration, as desired. The expandable basket 44 may be sized and shaped such that the plurality of struts 46 may contact or interact with the harvest site when the expandable basket 44 is in the expanded configuration. In some cases, the expandable basket 44 may be expanded until at least a portion of the plurality of struts 46 contacts the harvest site. It is contemplated that in some cases, the expandable basket 44 may not be fully expanded before contacting the harvest site.

[0045] Once the tissue collection device 12 is deployed from the outer tubular member 14 and the expandable basket 44 is expanded, the second handle 30 can be actuated to repeatedly advance, retract, and / or rotate the tissue collection device 12 distally and proximally along the target collection site. This causes the struts 46 to brush against the tissue surface, dislodging and capturing cells. It is contemplated that the edges 56a, 56b of the struts 46 may be angled or sharpened to scratch the collection site. In the illustrated embodiment, the edges of the struts 46 are not labeled for simplicity and ease of understanding. In some examples, the struts 46 may further include texturing 58, such as, but not limited to, a rough or granular surface, on their outer and / or inner surfaces. The texturing may be configured to release and capture cells from the stenosis. The texturing 58 may be macro-texturing or micro-texturing, as desired. In some examples, the texturing 58 may include holes or machined holes with openings extending partially radially from the surface of the plurality of struts 46, allowing the edges of the machined holes to scrape tissue and guide it into the holes. In yet other examples, the plurality of struts 46 may include barbs. The barbs may extend radially inward or outward from the plurality of struts 46 and may be configured to further disrupt the collection site to release cells for collection. The barbs may be similar in form and function to the barbs 122 shown and described with respect to FIG. 3 . It is further contemplated that one or more of the plurality of struts 46 may include other tissue-engaging features, such as, but not limited to, teeth or bristles, anywhere along the length of the plurality of struts 46.

[0046] The tissue harvesting device 12 may further include one or more optional tissue capture mechanisms 60. The tissue capture mechanisms 60 may include brushes or membranes that can collect or capture cells detached by the expandable basket 44. Some exemplary brushes are described in commonly assigned U.S. patent application Ser. No. 63 / 309,818, entitled "TISSUE SAMPLE DEVICE AND METHODS," the disclosure of which is incorporated herein by reference. It is contemplated that the tissue capture mechanisms 60 may be positioned proximal to the expandable basket, distal to the expandable basket 44, or anywhere along the length of the expandable basket 44, as desired.

[0047] Once the clinician has captured cells from the target site, the inner tubular member 16 may be retracted proximally until the tissue collection device 12 is positioned within the lumen 18 of the outer tubular member 14. If the expandable basket 44 is self-expanding, retracting the inner tubular member 16 proximally may collapse the basket 44 as it is retracted into the lumen 18 of the outer tubular member 14. If the expandable basket 44 is manually expanded, the basket 44 may be transitioned to a collapsed configuration before retracting the inner tubular member 16 proximally. In some embodiments, the inner tubular member 16 may include one or more windows or cut-out regions for capturing cells or tissue therein when the expandable basket 44 is collapsed. The windows may be similar in form and function to the cut-out region 234 described with respect to FIG. 4 .

[0048] FIG. 3 shows a perspective view of another exemplary tissue harvesting device 100 including an expandable basket 102 in an expanded configuration that may be used with the system 10 of FIG. 1. The expandable basket 102 extends from a proximal end 104 to a distal end 106 and may include a plurality of longitudinally extending struts 108a-g (collectively 108). In some embodiments, the proximal end 104 of the basket 102 may extend proximally to a location configured to remain outside the body so that the tissue harvesting device 100 may be manipulated through actuation of the proximal end 104, although this is not required. The expandable basket 102 may include any desired number of struts 108, such as, but not limited to, one, two, three, four, five, six, seven, or more. The plurality of individual struts 108 may be formed from a wire or filament. Although the struts 108 are described as being formed from wire, the struts 108 may have any number of cross-sectional shapes, including, but not limited to, circular, square, rectangular, polygonal, elliptical, oval, etc. In other examples, the struts 108 may have a generally flat, ribbon-like shape (e.g., having a width greater than a thickness). However, the struts 108 may take any desired shape. The struts 108 may be evenly spaced around the circumference of the expandable basket 102. However, this is not required. In some cases, the struts 108 may be eccentrically or unevenly spaced. The expandable basket 102 may include one or more radiopaque markers positioned anywhere along its length to allow the position of the expandable basket 102 to be viewed on a fluoroscopy screen or another imaging technique.

[0049] The proximal ends of the plurality of struts 108 may be secured to the proximal collar 110, and the distal ends of the plurality of struts 108 may be secured to the distal collar 112. In some embodiments, the plurality of struts 108 and the proximal collar 110 and / or the distal collar 112 may be formed as a single monolithic structure. For example, the plurality of struts 108 and the collars 110, 112 may be cut from a single tube. It is further contemplated that the plurality of struts 108 and the collars 110, 112 may be formed from the inner tubular member 16. For example, the cut tube may be the inner tubular member 16 or a separate tube, as desired. In other embodiments, one or more of the plurality of struts 108 and the proximal and distal collars 110, 112 may be formed as separate structures that are coupled to one another. For example, the plurality of struts 108 may be welded, brazed, soldered, glued, etc. to the proximal and / or distal collars 110, 112. Other coupling techniques may be used, if desired. It is contemplated that the coupling mechanism may depend, at least in part, on the material of the plurality of struts 108 and / or collars 110, 112. When the expandable basket 102 is a separate component from the inner tubular member 16, at least one of the proximal collar 110 and the distal collar 112 is fixedly attached to the outer surface of the inner tubular member 16, and the other of the proximal collar 110 or the distal collar 112 is movably disposed over the inner tubular member 16 to allow the basket 102 to radially expand. In one example, the proximal collar 110 may be fixedly attached to the inner tubular member 16, and the distal collar 112 may be slidably disposed over the inner tubular member 16. In such a configuration, the distal collar 112 may be moved distally to collapse the expandable basket 102 and moved proximally to expand the expandable basket 102. The reverse configuration is also contemplated, in which the distal collar 112 may be fixedly attached to the inner tubular member 16 and the proximal collar 110 may be slidably disposed over the inner tubular member 16. Alternatively, the proximal collar 110 and / or the distal collar 112 may be coupled to a centrally extending tubular member 120.Tubular member 120 may be used in place of or in addition to inner tubular member 16 .

[0050] Each of the plurality of struts 108 may include a proximal end region 114a-g (collectively 114) and a distal end region 116a-g (collectively 116). The proximal end region 114 may be joined with the distal end region 116 at intersections 118a-g. In the expanded configuration, the proximal end region 114 of the plurality of struts 108 may extend at a first angle relative to the longitudinal direction of the expandable basket 102, and the distal end region 116 may extend at a second angle relative to the longitudinal direction of the expandable basket 102. The first angle may be different from the second angle.

[0051] Each of the plurality of struts 108 may include one or more barbs 122a-g (collectively 122) wrapped around the plurality of struts 108. While each strut 108 is shown as including a single barb 122, it is contemplated that each strut 108 may have two or more barbs 122. It is further contemplated that some struts 108 may be devoid of barbs 122. Each of the plurality of struts 108 may have the same number of barbs 122 or different numbers of barbs 122, as desired. In the illustrated embodiment, the barbs 122 may be wire wrapped or wound around the strut 108, with free ends extending radially away from the strut 108. The free ends may extend radially inward, radially outward, or a combination thereof, as desired. It is contemplated that the barbs 122 may be configured to crush and capture tissue from the target collection site.

[0052] The expandable basket 102 may be self-expandable or may require an external force to expand from a collapsed state. The multiple self-expandable members may be formed from any material or structure that is in a compressed state when a force is applied and in an expanded state when the force is released. Such members may be formed, for example, from a shape memory alloy such as Nitinol or any other self-expandable material. When using such a shape memory material, the expandable basket 102 may be heat-treated in an expanded state and then compressed to fit within the outer tubular member 14, for example. In another embodiment, a spring may be provided to achieve expansion. It is envisioned that a nickel-titanium alloy may be resistant to bending and allow for self-expansion. In other examples, the expandable basket 102 may be formed using a magnetic alloy, a metal, a metal alloy, a polymer, a composite material, or the like.

[0053] In another example, the expandable basket 102 can be manipulated or actuated between the expanded and collapsed configurations by a manual force applied to the inner tubular member 16. For example, the actuation element can include a central wire or rod extending through the expandable basket 102 and coupled to the distal collar 112. Alternatively, an external force, such as, but not limited to, air pressure, pressurized fluid, a pull wire, a push wire, or a rod, can be employed to expand the expandable basket 102. According to this embodiment, a pulling force applied proximally to the wire can cause the plurality of struts 108 to expand and transition the expandable basket 102 to the expanded state. A pushing force applied distally to the wire can elongate the plurality of struts 108 and / or transition the expandable basket 102 to a compressed or extended state. Other actuation mechanisms can also be utilized. For example, a guide wire 42 can be used to apply a proximal pushing force to the distal end of the distal collar 110. In such cases, the guidewire 42 may include an enlarged region having a diameter larger than the diameter of the lumen of the tissue harvesting device 100, such that proximal actuation of the guidewire 42 may bring the enlarged region of the guidewire 42 into contact with the distal collar 110, and further proximal actuation of the guidewire 42 may move the distal collar 110 proximally, thereby expanding the expandable basket 102. It is contemplated that manual actuation of the expandable basket 102 using a wire, rod, or the like may impart greater force to the expandable basket 102, thereby allowing for greater engagement of the basket with the target tissue.

[0054] When the tissue collection device 100 is positioned within the outer tubular member 14, the expandable basket 102 may be constrained in a reduced-diameter, compressed or delivery configuration by the outer tubular member 14 surrounding the tissue collection device 100. In other examples, the expandable basket 102 may assume a collapsed configuration until an actuation force is applied to the expandable basket 102. In the collapsed configuration, the tissue collection device 100 may typically have a smaller diameter than in the expanded, deployed configuration. The distal end region 20 of the outer tubular member 14 may be positioned such that the outer tubular member 14 surrounds and wraps the length of the tissue collection device 100 during delivery. The outer tubular member 14 may have sufficient hoop strength to hold the tissue collection device 100 in its reduced-diameter state.

[0055] The expandable basket 102 may be deployed in a manner similar to the expandable basket 44 described herein. In the radially expanded configuration, the plurality of struts 108 bend at the intersections 118, allowing the expandable basket 102 to radially expand. The expandable basket 102 may be sized and shaped such that the plurality of struts 108 may contact or interact with the harvest site when the expandable basket 102 is in the expanded configuration. In some cases, the expandable basket 102 may be expanded until at least a portion of the plurality of struts 108 contact the harvest site. It is contemplated that in some cases, the expandable basket 102 may not be fully expanded before contacting the harvest site.

[0056] Once the tissue collection device 100 is deployed from the outer tubular member 14 and the expandable basket 102 is expanded, the second handle 30 can be actuated to repeatedly advance the tissue collection device 100 distally, retract proximally, and / or rotate it along the target collection site. This can cause the struts 108 to scrape the tissue surface, detaching and capturing cells. It is contemplated that the edges of the struts 108 can be angled or sharpened to scratch the collection site. In the illustrated embodiment, the edges of the struts 108 are not labeled for simplicity and ease of understanding. In some examples, the struts 108 can further include texturing, such as, but not limited to, a rough or granular surface, on their outer and / or inner surfaces. The texturing can be configured to release and capture cells from the stenosis. The texturing can be macro-texturing or micro-texturing, as desired. It is further contemplated that one or more of the plurality of struts 108 may include other tissue-engaging features, such as, but not limited to, teeth or bristles, anywhere along the length of the plurality of struts 108.

[0057] The tissue harvesting device 100 may further include one or more optional tissue capture mechanisms (not explicitly shown). The tissue capture mechanism may include a brush or membrane that can collect or capture cells detached by the expandable basket 102. Some exemplary brushes are described in commonly assigned U.S. patent application Ser. No. 63 / 309,818, entitled "TISSUE SAMPLE DEVICE AND METHODS," the disclosure of which is incorporated herein by reference. It is contemplated that the tissue capture mechanism may be positioned proximal to the expandable basket, distal to the expandable basket 102, or anywhere along the length of the expandable basket 102, as desired.

[0058] Once the clinician has captured cells from the target site, the inner tubular member 16 may be retracted proximally until the tissue collection device 100 is positioned within the lumen 18 of the outer tubular member 14. If the expandable basket 102 is self-expanding, retracting the inner tubular member 16 proximally may collapse the basket 102 as it is retracted into the lumen 18 of the outer tubular member 14. If the expandable basket 102 is manually expanded, the basket 102 may be transitioned to a collapsed configuration before retracting the inner tubular member 16 proximally. In some embodiments, the inner tubular member 16 and / or the central tubular member 120 may include one or more windows or cutout regions for capturing cells or tissue therein when the expandable basket 102 is collapsed. The windows may be similar in form and function to the cutout region 234 described with respect to FIG. 4 .

[0059] FIG. 4 is a side view of another exemplary tissue collection device system 200 for delivering a tissue collection device 202 to a target region, such as, but not limited to, the common bile duct or pancreatic duct, in a retracted or delivery configuration. The tissue collection system 200 can include an outer or external elongate shaft or tubular member 204 and an inner elongate shaft or tubular member 206. The inner tubular member 206 can be slidably disposed within a lumen 208 of the outer tubular member 204. The outer tubular member 204 can extend proximally from a distal end region 210 to a proximal end region (not explicitly shown) configured to remain outside the patient's body. A first hub or handle, similar in form and function to the handle 24 described herein, can be coupled to the proximal end region of the outer tubular member 204. In some cases, a port, such as an injection port, can be provided on the outer tubular member 204. Other structures may be provided to allow connection to other medical devices (e.g., syringes, stopcocks, Y-adapters, etc.) and to provide access to lumen 208. Inner tubular member 206 may extend proximally from distal end region 212 to a proximal end region (not explicitly shown) configured to remain outside the patient's body. A second hub or handle (not explicitly shown) may be coupled to the proximal end region of inner tubular member 206.

[0060] The outer tubular member 204 may include a lumen 208 extending from the distal end region 210 to the proximal end region. The lumen 208 may also extend through the first handle. The lumen 208 of the outer tubular member 204 and the first handle may be configured to slidably receive the inner tubular member 206. The inner tubular member 206 may include a lumen 214 extending from the distal end region 212 to the proximal end region. The lumen 214 of the inner tubular member 206 may also extend through the second handle. The lumen 214 of the inner tubular member 206 may be configured to receive a guidewire 216, if desired. In other examples, the guidewire 216 may be received within the lumen 208 of the outer tubular member 204. It is contemplated that the system 200 may be configured such that the guidewire 216 extends within the lumen along the entire length of the outer tubular member 204 or inner tubular member 206 in an "over-the-wire" fashion, or such that the guidewire 216 exits a side port 218 in the outer tubular member 14 distal to the proximal end region 22 of the outer tubular member 204 in a "rapid-exchange" fashion.

[0061] The tissue collection device 202 may be disposed around a portion of the inner tubular member 16 at or adjacent the distal end region 212 of the inner tubular member 206, or may be formed as part of the inner tubular member 16. The tissue collection device 202 may extend around the entire circumference of the inner tubular member 206. In other embodiments, the tissue collection devices 202 may be radially spaced around the circumference of the inner tubular member 206 in a uniform pattern or an eccentric manner, as desired. In some embodiments, the tissue collection device 202 may include a radially expanding frame or basket 220 that is transitionable between a collapsed delivery configuration (not explicitly shown) and an expanded use configuration ( FIG. 4 ). While the tissue collection device 202 is described as an expandable basket, it is contemplated that other tissue collection devices may be used, as desired.

[0062] The expandable basket 220 may include a plurality of longitudinally extending struts 224a-c (collectively 224) extending from a proximal end region (not explicitly shown) to a distal end 222. In some embodiments, the proximal end of the basket 220 may extend proximally to a location configured to remain outside the body so that the tissue harvesting device 202 can be manipulated through actuation of the proximal end, although this is not required. The expandable basket 220 may include any desired number of struts 224, such as, but not limited to, one, two, three, four, five, six, or more. The plurality of struts 224 may have a generally flat, ribbon-like shape (e.g., having a width greater than a thickness). In other examples, the plurality of struts 224 may have a generally wire-like shape. However, the plurality of struts 224 may take on any desired shape. The plurality of struts 224 may be evenly spaced about the circumference of the expandable basket 220. However, this is not required. In some cases, the multiple struts 224 may be eccentrically or unevenly spaced. The expandable basket 220 may include one or more radiopaque markers positioned anywhere along its length to allow the position of the expandable basket 220 to be visualized on a fluoroscopy screen or another imaging technique.

[0063] The proximal ends of the plurality of struts 224 may be secured to the proximal collar 226, and the distal ends of the plurality of struts 224 may be secured to the distal collar 228. In some embodiments, the plurality of struts 224 and the proximal collar 226 and / or the distal collar 228 may be formed as a single monolithic structure. For example, the plurality of struts 224 and the collars 226, 228 may be cut from a single tube. Although not explicitly shown, it is further contemplated that the plurality of struts 224 and the collars 226, 228 may be formed from the inner tubular member 206. For example, the cut tube may be the inner tubular member 206 or a separate tube, as desired. In other embodiments, the plurality of struts 224 and one or more of the proximal and distal collars 226, 228 may be formed as separate structures that are coupled to one another. For example, the struts 224 may be welded, brazed, soldered, glued, etc. to the proximal and / or distal collars 226, 228. Other bonding techniques may be used as desired. It is contemplated that the bonding mechanism may depend, at least in part, on the material of the struts 224 and / or collars 226, 228. When the expandable basket 220 is a separate component from the inner tubular member 206, at least one of the proximal collar 226 and the distal collar 228 is fixedly attached to the outer surface of the inner tubular member 206, and the other of the proximal collar 226 or the distal collar 228 is movably disposed over the inner tubular member 206 to allow the basket 220 to radially expand. In one example, the proximal collar 226 may be fixedly attached to the inner tubular member 206, and the distal collar 228 may be slidably disposed over the inner tubular member 206. In such a configuration, the distal collar 228 can be moved distally to collapse the expandable basket 220 and moved proximally to expand the expandable basket 220. The reverse configuration is also contemplated, in which the distal collar 228 can be fixedly attached to the inner tubular member 206 and the proximal collar 226 can be slidably disposed over the inner tubular member 206.

[0064] The expandable basket 220 may be self-expandable or may require an external force to expand from a collapsed state. The multiple self-expandable members may be formed from any material or structure that is in a compressed state when a force is applied and in an expanded state when the force is released. Such members may be formed, for example, from a shape memory alloy such as Nitinol or any other self-expandable material. When using such a shape memory material, the expandable basket 220 may be heat-treated in an expanded state and then compressed to fit within the outer tubular member 204, for example. In another embodiment, a spring may be provided to achieve expansion. It is envisioned that a nickel-titanium alloy may be resistant to bending and allow for self-expansion. In other examples, the expandable basket 220 may be formed using a magnetic alloy, a metal, a metal alloy, a polymer, a composite material, or the like.

[0065] In other examples, the expandable basket 220 can be manipulated or actuated between the expanded and collapsed configurations by a manual force applied to the inner tubular member 206. For example, the actuation element can include a central wire or rod extending through the expandable basket 220 and coupled to the distal collar 228. Alternatively, an external force, such as, but not limited to, air pressure, pressurized fluid, a pull wire, a push wire, or a rod, can be employed to expand the expandable basket 220. According to this embodiment, a pulling force applied proximally to the wire can cause the plurality of struts 224 to expand and transition the expandable basket 220 to the expanded state. A pushing force applied distally to the wire can elongate the plurality of struts 224 and / or transition the expandable basket 220 to a compressed or extended state. Other actuation mechanisms can also be utilized. For example, a guidewire 216 can be used to apply a proximal pushing force to the distal end of the distal collar 226. In such cases, the guidewire 216 may include an enlarged region having a diameter larger than the diameter of the lumen of the tissue harvesting device 202, such that proximal actuation of the guidewire 216 brings the enlarged region of the guidewire 216 into contact with the distal collar 226, and further proximal actuation of the guidewire 216 moves the distal collar 226 proximally, thereby expanding the expandable basket 220. It is contemplated that manual actuation of the expandable basket 220 using a wire, rod, or the like may impart greater force to the expandable basket 220, thereby allowing for greater engagement of the basket with the target tissue.

[0066] When the tissue collection device 202 is positioned within the outer tubular member 204, the expandable basket 220 can be constrained in a reduced-diameter, compressed or delivery configuration by the outer tubular member 204 surrounding the tissue collection device 202. In other examples, the expandable basket 220 can assume a collapsed configuration until an actuation force is applied to the expandable basket 220. In the collapsed configuration, the tissue collection device 202 can have a smaller diameter than in the expanded, deployed configuration. The distal end region 210 of the outer tubular member 204 can be positioned such that the outer tubular member 204 surrounds and wraps the length of the tissue collection device 202 during delivery. The outer tubular member 204 can have sufficient hoop strength to hold the tissue collection device 202 in its reduced-diameter state.

[0067] The tissue collection system 200 can be advanced through the body toward the target site as desired. The tissue collection system 200 can be advanced with or without the use of a guidewire 216. Once the tissue collection device 202 is positioned adjacent to the target area, the restraining forces maintaining the tissue collection device 202 in a radially compressed configuration can be removed and the tissue collection device 202 can be deployed (deployed).

[0068] The tissue collection device 202 can be deployed by actuating the second handle, e.g., by pushing the second handle distally, while maintaining the first handle in a fixed position. Thus, the inner tubular member 206 can be advanced distally relative to the outer tubular member 204. In other words, the inner tubular member 206 can be advanced distally while the outer tubular member 204 remains stationary. The reverse configuration is also contemplated. For example, the outer tubular member 204 can be retracted proximally while the inner tubular member 206 remains stationary. When the inner tubular member 206 is advanced distally, the biasing force from outside the tissue collection device 202 is removed, and the expandable basket 220 assumes its radially expanded, unbiased, deployed configuration, shown in FIG. 4 . Alternatively, the expandable basket 220 may remain collapsed until an actuation force is applied to the expandable basket 220 (e.g., using a pull wire or other actuation mechanism) to transition the expandable basket 220 to a radially expanded, deployed configuration.

[0069] In the radially expanded configuration, the plurality of struts 224 can be curved to protrude radially outward such that the proximal and distal end regions of the expandable basket 220 extend at a non-parallel angle relative to the longitudinal axis of the expandable basket 220 and the intermediate region extends generally parallel to the longitudinal axis of the expandable basket 220. However, the expandable basket 220 may assume other shapes in the expanded configuration, as desired. The expandable basket 220 can be sized and shaped such that the plurality of struts 224 can contact or interact with the harvest site when the expandable basket 220 is in the expanded configuration. In some cases, the expandable basket 220 can be expanded until at least a portion of the plurality of struts 224 contacts the harvest site. It is contemplated that in some cases, the expandable basket 220 may not be fully expanded before contacting the harvest site.

[0070] Once the tissue collection device 202 is deployed (deployed) from the outer tubular member 204 and the expandable basket 220 is expanded, the second handle can be actuated to repeatedly advance the tissue collection device 202 distally, retract proximally, and / or rotate it along the target collection site. This can cause the struts 224 to scrape against the tissue surface, dislodging and capturing cells. It is contemplated that the edges 230 a, 230 b of the struts 224 can be angled or sharpened to scratch the collection site. In the illustrated embodiment, the edges of the struts 224 are not labeled for simplicity and ease of understanding. In some examples, the struts 224 can further include texturing, such as, but not limited to, a rough or granular surface, on their outer and / or inner surfaces. The texturing can be configured to release and capture cells from the stenosis. The texturing can be macro-texturing or micro-texturing, as desired. In yet other examples, the plurality of struts 224 may include a plurality of barbs. The barbs may extend radially inward or outward from the plurality of struts 224 and may be configured to further disrupt the collection site to release cells for collection. The barbs may be similar in form and function to the plurality of barbs 122 shown and described with respect to FIG. 3. It is further contemplated that one or more of the plurality of struts 224 may include other tissue-engaging features, such as, but not limited to, bristles, anywhere along the length of the plurality of struts 224.

[0071] The plurality of struts 224 may include one or more teeth 232a-c (collectively 232) extending from one or more of the plurality of struts 224. The teeth 232 and struts 224 may be formed as a single monolithic structure. For example, the struts 224 and teeth 232 may be formed from a cut tube, where the struts 224 and teeth 232 are formed by cutting a region from the tube. The teeth 232 may be coupled to the struts 224 at their first ends and extend to a free end. The free end may be pointed to engage tissue at the harvest site. However, this is not required. In some embodiments, the free end may be rounded or take on another form as desired. While each strut 224 is shown as including three teeth 232, it is contemplated that the plurality of struts 224 may include fewer or more than three teeth 232 as desired. In some examples, one or more of the plurality of struts 224 may not include teeth 232. It is further contemplated that the plurality of struts 224 may have a different number of teeth 232. Additionally, although the plurality of teeth 232 are shown as being located in a mid-region of the struts 224, the plurality of teeth 232 may be positioned anywhere along the length of the struts 224 as desired.

[0072] The tissue collection device 202 may further include one or more optional tissue capture mechanisms (not explicitly shown). The tissue capture mechanism may include a brush or membrane that can collect or capture cells detached by the expandable basket 220. Some exemplary brushes are described in commonly assigned U.S. patent application Ser. No. 63 / 309,8208, entitled "TISSUE SAMPLE DEVICE AND METHODS," the disclosure of which is incorporated herein by reference. It is contemplated that the tissue capture mechanism may be positioned proximal to the expandable basket, distal to the expandable basket 220, or anywhere along the length of the expandable basket 220, as desired.

[0073] Once the clinician has captured cells from the target site, the inner tubular member 206 may be retracted proximally until the tissue collection device 202 is disposed within the lumen 208 of the outer tubular member 204. If the expandable basket 220 is self-expanding, retracting the inner tubular member 206 proximally may collapse the basket 220 as it is retracted into the lumen 208 of the outer tubular member 204. If the expandable basket 220 is manually expanded, the basket 220 may be transitioned to a collapsed configuration before retracting the inner tubular member 206 proximally. In some embodiments, the inner tubular member 206 may include one or more windows or cutout regions 234 for capturing cells or tissue therein when the expandable basket 220 is collapsed. The cutout area 234 may be generally aligned with the tissue collection device 202 such that when the tissue collection device 202 is collapsed or retracted, the collapsed tissue collection device 202 draws cells or tissue into the cutout area 234. In some embodiments, the plurality of tines 232 may be located within the cutout area 234. It is contemplated that the guidewire 216 may be removed from the lumen 214 of the inner tubular member 206 before the expandable basket 220 is collapsed, allowing more tissue or cells to be drawn into the cutout area 234.

[0074] FIG. 5 is an exemplary flowchart of a method 200 for obtaining a tissue sample using the system 10,200 and / or tissue collection device 12,100,202 of FIGS. 1-4. Initially, as shown in block 310, the tissue collection system 10,200 can be advanced to a target site within the body. In some embodiments, the tissue collection system 10,200 can be advanced through a working channel of an endoscope, with its distal end positioned near the target site. For example, to obtain a sample from the common bile duct, the endoscope can be advanced through the esophagus, through the stomach, and into the duodenum. The tissue collection system 10,200 can be positioned within the endoscope while it is being positioned, or can be advanced through the endoscope thereafter. The guidewire 42,216 of the tissue collection system 10,200 can then be advanced distally to cannulate the common bile duct. The tissue collection device 12, 100, 202 can then be deployed (positioned) by advancing the inner tubular member 16, 206 distally over the guidewire, as shown in block 320. As described above, the inner tubular member 16, 206 can be advanced distally while the outer tubular member 14, 204 remains stationary, so that the tissue collection device 12, 100, 202 exits the outer tubular member 14, 204. Because the guidewire 42, 216 is centrally located within the tissue collection system 10, 200, it is anticipated that the inner tubular member 16, 206 will not be biased to one side, as is the case with tissue collection systems that advance a brush through a channel separate from the guidewire. The coaxial arrangement of the guidewire 42, 216 and inner tubular member 16, 206 allows the tissue collection device to easily pass through ampullae, bends, and strictures. In other examples, the tissue collection system 10, 200 and / or tissue collection device 12, 100, 202 may be attached to the side of an endoscope.

[0075] Once the tissue collection device 12, 100, 202 is positioned at the target site, the inner tubular member 16, 206 can be actuated (e.g., using the second handle 30) back and forth (e.g., proximally and distally) to drag the struts 46, 18, 208, 224 along the collection site and collect cells, as shown in block 330. In some cases, the inner tubular member 16, 206 can be rotated in addition to or instead of the proximal and distal movement. Once the sample has been collected, the inner tubular member 16, 206 can be retracted proximally to retract the tissue collection device 12, 100, 202 back into the lumen 18, 208 of the outer tubular member 14, 204, as shown in block 340. The tissue collection system 10, 200 can then be removed from the body, as shown in block 350. Next, as shown in block 360, the inner tubular member 16, 206 may be cut (e.g., using wire cutters or other cutting device) at a location proximal to the tissue collection device 12, 100, 202 so that the tissue collection device 12, 100, 202 may be placed into a sample container.

[0076] The various components of the medical device system 10, 200 (and / or other systems disclosed herein) and materials that may be used for the various elements thereof disclosed herein may include those commonly associated with medical devices. For simplicity, the following discussion will refer to the tissue harvesting system 10, 200 and / or tissue harvesting device 12, 100, 202. However, this is not intended to limit the devices and methods described herein, and the discussion may apply to other elements, members, components, or devices disclosed herein, such as, but not limited to, the inner tubular member 16, 206 and outer tubular member 14, 204, the handles 24, 30, the guidewire 42, 216, etc., and / or elements or components thereof.

[0077] In some embodiments, the tissue harvesting system 10, 200, tissue harvesting device 12, 100, 202, and / or components thereof may be made from metals, metal alloys, polymers (some examples of which are disclosed below), metal-polymer composites, ceramics, combinations thereof, and the like, or other suitable materials.

[0078] Some examples of suitable polymers include polytetrafluoroethylene (PTFE), ethylene tetrafluoroethylene (ETFE), fluorinated ethylene propylene (FEP), polyoxymethylene (POM, e.g., DELRIN® available from DuPont), polyether block esters, polyurethanes (e.g., Polyurethane 85A), polypropylene (PP), polyvinyl chloride (PVC), polyetheresters (e.g., ARNITEL® available from DSM Engineering Plastics), ether or ester-based copolymers (e.g., butylene / poly(alkylene ether) phthalates and / or other polyester elastomers such as HYTREL® available from DuPont), polyamides (e.g., DURETHAN® or Elf® available from Bayer), and the like. CRISTAMID® available from Atochem), elastomeric polyamides, block polyamide / ethers, polyether block amides (PEBA, e.g., available under the trade name PEBAX®), ethylene vinyl acetate copolymer (EVA), silicone, polyethylene (PE), Marlex® high density polyethylene, Marl Marlex® low density polyethylene, linear low density polyethylene (e.g., REXELL®), polyester, polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polytrimethylene terephthalate, polyethylene naphthalate (PEN), polyether ether ketone (PEEK), polyimide (PI), polyetherimide (PEI), polyphenylene sulfide (PPS), polyphenylene oxide (PPO), polyparaphenylene terephthalamide (e.g., KEVLAR®), polysulfone, nylon, nylon-12 (e.g., EMS American GRILAMID® available from Grilon), perfluoro(propyl vinyl ether) (PFA), ethylene vinyl alcohol, polyolefins, polystyrene, epoxies, polyvinylidene chloride (PVdC), poly(styrene-b-isobutylene-b-styrene) (e.g., SIBS and / or SIBS50A), polycarbonates, ionomers, biocompatible polymers, other suitable materials, or mixtures, combinations, copolymers, polymer / metal composites, and the like.

[0079] Some examples of suitable metals and alloys include stainless steels such as 304V, 304L, and 316LV stainless steel, mild steel, nickel-titanium alloys such as linear elastic and / or superelastic nitinol, other nickel alloys such as nickel-chromium-molybdenum alloys (e.g., UNS: N06625 such as INCONEL® 625, UNS: N06022 such as HASTELLOY® C-22®, HASTELLOY® C276®, etc.), and the like. and other HASTELLOY® alloys), nickel-copper alloys (e.g., UNS:N04400 such as MONEL® 400, NICKELVAC® 400, and NICORROS® 400), nickel-cobalt-chromium-molybdenum alloys (e.g., UNS:R30035 such as MP35-N®), nickel-molybdenum alloys (e.g., HASTELLOY® ALLOY®), B2®, UNS:N10665), other nickel-chromium alloys, other nickel-molybdenum alloys, other nickel-cobalt alloys, other nickel-iron alloys, other nickel-copper alloys, and other nickel-tungsten or tungsten alloys, cobalt-chromium alloys, cobalt-chromium-molybdenum alloys (e.g., UNS:R30003, such as ELGILOY® and PHYNOX®), platinum strengthened stainless steel, titanium, and combinations thereof, or any other suitable material.

[0080] As mentioned herein, within the family of commercially available nickel-titanium or nitinol alloys, there is a category referred to as "linear elastic" or "non-superelastic," which may be chemically similar to traditional shape memory and superelastic varieties but may exhibit distinct and useful mechanical properties. Linear elastic and / or non-superelastic nitinol may be distinguished from superelastic nitinol in that linear elastic and / or non-superelastic nitinol does not exhibit a substantial "superelastic plateau" or "flag region" in its stress / strain curve as does superelastic nitinol. Instead, in linear elastic and / or non-superelastic nitinol, as recoverable strain increases, stress continues to increase in a substantially linear manner until plastic deformation begins, or in a relationship that is somewhat linear but not necessarily entirely linear, or at least more linear than the superelastic plateau and / or flag region that may be seen in superelastic nitinol. Thus, for purposes of this disclosure, linear elastic and / or non-superelastic nitinol may also be referred to as "substantially" linear elastic and / or non-superelastic nitinol.

[0081] In some cases, linear elastic and / or non-superelastic nitinol can also be distinguished from superelastic nitinol in that linear elastic and / or non-superelastic nitinol can accommodate a maximum of about 2 to 5% strain while remaining substantially elastic (e.g., before plastic deformation), while superelastic nitinol can accommodate a maximum of about 8% strain before plastic deformation. Both of these materials can be distinguished from other linear elastic materials, such as stainless steel (which can also be distinguished based on its composition), which can accommodate only about 0.2 to 0.44 percent strain before plastic deformation.

[0082] In some embodiments, a linear elastic and / or non-superelastic nickel-titanium alloy is an alloy that does not exhibit a martensite / austenite phase change detectable by differential scanning calorimetry (DSC) and dynamic metal thermal analysis (DMTA) analysis over a wide temperature range. For example, in some embodiments, a linear elastic and / or non-superelastic nickel-titanium alloy may not exhibit a martensite / austenite phase change detectable by DSC and DMTA analysis over a temperature range from about -60 degrees Celsius (°C) to about 120°C. Thus, the mechanical bending properties of such materials may generally be inert to the effects of temperature over this temperature range. In some embodiments, the mechanical bending properties of a linear elastic and / or non-superelastic nickel-titanium alloy at ambient or room temperature are substantially the same as those at body temperature, e.g., in that they do not exhibit a superelastic plateau and / or flag region. In other words, over a wide temperature range, a linear elastic and / or non-superelastic nickel-titanium alloy maintains its linear elastic and / or non-superelastic characteristics and / or properties.

[0083] In some embodiments, the linear elastic and / or non-superelastic nickel-titanium alloy may range from about 50 to about 60 weight percent nickel, with the remainder essentially titanium. In some embodiments, the composition may range from about 54 to about 57 weight percent nickel. One example of a suitable nickel-titanium alloy is FHP-NT alloy, commercially available from Furukawa Techno Material Co., Ltd., Kanagawa Prefecture, Japan. Other suitable materials may include ULTANIUM™ (available from Neo-Metrics) and GUM METAL™ (available from Toyota). In some other embodiments, a superelastic alloy, such as superelastic nitinol, may be used to achieve desired properties.

[0084] In at least some embodiments, the tissue collection system 10, 200, tissue collection device 12, 100, 202, and / or some or all of their components may also be doped with, made from, or otherwise include a radiopaque material. A radiopaque material is understood to be a material capable of producing a relatively bright image on a fluoroscopy screen or another imaging technique during a medical procedure. This relatively bright image aids the user of the tissue collection system 10, 200 and / or tissue collection device 12, 100, 202 in determining its location. Some examples of radiopaque materials may include, but are not limited to, gold, platinum, palladium, tantalum, tungsten alloys, polymeric materials filled with radiopaque fillers, and the like. Additionally, other radiopaque marker bands and / or coils may be incorporated into the design of the tissue collection system 10, 200 and / or tissue collection device 12, 100, 202 to achieve the same results.

[0085] In some embodiments, a degree of magnetic resonance imaging (MRI) compatibility is imparted to the tissue collection system 10, 200 and / or the tissue collection device 12, 100, 202. For example, the tissue collection system 10, 200, the tissue collection device 12, 100, 202, and / or components or portions thereof may be made of materials that do not substantially distort images or produce substantial artifacts (e.g., gaps in the images). For example, certain ferromagnetic materials may not be suitable because they may produce artifacts in MRI images. The tissue collection system 10, 200 and / or the tissue collection device 12, 100, 202, or portions thereof, may also be made of materials that can be imaged by an MRI machine. Some materials that exhibit these properties include, for example, tungsten, cobalt-chromium-molybdenum alloys (e.g., UNS:R30003, such as ELGILOY® and PHYNOX®), nickel-cobalt-chromium-molybdenum alloys (e.g., UNS:R30035, such as MP35-N®), and nitinol, among others.

[0086] In some embodiments, the exterior surfaces of the medical device system 10 (including, for example, the exterior surfaces of the delivery system) may be treated with sandblasting, bead blasting, sodium bicarbonate blasting, electropolishing, or the like. In these and some other embodiments, a coating, such as a lubricious, hydrophilic, protective, or other type of coating, may be applied over a portion or the entire outer sheath, or, in embodiments without an outer sheath, over a portion of the delivery system or other portions of the medical device system 10. Hydrophobic coatings, such as fluoropolymers, provide dry lubricity, which improves device handling and device exchange. Lubricious coatings improve steerability and lesion crossing capabilities. Suitable lubricious polymers are well known in the art and may include hydrophilic polymers such as silicones (e.g., high-density polyethylene (HDPE), polytetrafluoroethylene (PTFE), polyarylene oxides, polyvinylpyrrolidone, polyvinyl alcohol, hydroxyalkyl cellulose, algin, saccharides, caprolactone, etc.), and mixtures and combinations thereof. Hydrophilic polymers can be blended among themselves or with amounts of water-insoluble compounds (including some polymers) to obtain coatings with suitable lubricity, binding, and solubility properties.

[0087] The coating and / or sheath can be formed, for example, by coating, extrusion, coextrusion, interrupted layer coextrusion (ILC), or by fusing several segments end-to-end. The layers can have uniform or tapered stiffness from their proximal to distal ends. The tapered stiffness can be continuous, as with ILC, or gradual, as with fusing separate extruded tubular segments together. The outer layer can be impregnated with a radiopaque filler material to facilitate visualization by radiography. Those skilled in the art will recognize that these materials can vary widely without departing from the scope of this disclosure.

[0088] It will be understood that this disclosure is, in many respects, merely illustrative. Changes may be made in details, particularly in matters of shape, size, and arrangement of steps, without exceeding the scope of the disclosure. This may include, to the extent appropriate, using any of the features of one illustrative embodiment in other embodiments. The scope of the present disclosure is, of course, defined in the language in which the appended claims are expressed.

Claims

1. 1. A tissue sampling system comprising: an outer tubular member having a proximal end region and a distal end region and defining a lumen extending from said proximal end region to said distal end region; an inner tubular member slidably disposed within the lumen of the outer tubular member, the inner tubular member defining a lumen extending from a proximal end region to a distal end region of the inner tubular member; a tissue harvesting device disposed adjacent the distal end region of the inner tubular member, the tissue harvesting device including an expandable basket; A tissue sampling system, wherein the tissue sampling device is movable between a retracted delivery position and an advanced sample sampling position.

2. The tissue harvesting system of claim 1 , wherein the expandable basket includes a plurality of longitudinally extending struts.

3. The tissue harvesting system of claim 2 , wherein one or more edges of at least one strut of the plurality of struts have a sharp surface.

4. The tissue harvesting system of claim 2 or 3, wherein a surface of at least one strut of the plurality of struts is textured.

5. The tissue sampling system of any one of claims 2 to 4, further comprising one or more barbs coupled to at least one strut of the plurality of struts.

6. The tissue harvesting system of claim 5 , wherein the one or more barbs comprise a wire wrapped around the at least one strut.

7. The tissue harvesting system of claim 6 , wherein at least one free end of the wire extends radially from the at least one strut.

8. The tissue harvesting system of any one of claims 2 to 7, further comprising one or more teeth extending from at least one strut.

9. The tissue harvesting system of claim 8 , wherein the one or more teeth and the at least one strut are formed as a single monolithic structure.

10. 10. The tissue harvesting system of claim 2, wherein the plurality of struts comprises a plurality of individual filaments, the plurality of individual filaments being joined to one another at proximal and distal ends of each of the plurality of individual filaments.

11. The tissue sampling system of any one of claims 1 to 9, wherein the tissue sampling device comprises a cut tube.

12. The tissue sampling system of any one of claims 1 to 9 or 11, wherein the tissue sampling device and the inner tubular member comprise a monolithic structure.

13. The tissue sampling system of any one of claims 1 to 11, wherein the tissue sampling device is coupled to the inner tubular member.

14. The tissue sampling system of any one of claims 1 to 13, wherein the tissue sampling device is self-expanding.

15. The tissue sampling system of any one of claims 1 to 13, further comprising an actuation mechanism coupled to the proximal or distal end of the tissue sampling device.

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