Biopsy / cytology device for sampling cells or tissues in mammals.

Abstract

An apparatus for detaching cells or tissue from a subject's cavity, the apparatus comprising: an elongated member arranged to move within a lumen of a needle or catheter; and at least one flexible member arranged at a distal end of the elongated member, wherein the flexible member is configured between a first constrained configuration within the lumen of the needle or catheter and a second deployed configuration outside the lumen, wherein the flexible member in the second deployed configuration is configured to conform to the internal geometry of the cavity into which the apparatus is inserted.

Description

Technical Field

[0001] This disclosure generally relates to a device for detaching cells from a subject's cavity and a liquid biopsy / cytology method for sampling cells or tissue from a subject's cavity. The biopsy / cytology method includes introducing and manipulating the device via a hollow catheter or needle to obtain a cell sample. Background Technology

[0002] Pancreatic cancer is currently the fourth leading cause of cancer-related deaths in the West, and its incidence is projected to be the second highest of all cancers by 2030. The prognosis remains poor, with a 5-year survival rate of only 2% to 9%, the lowest of all cancers, because it is often diagnosed at an advanced stage. Pancreatic cystic lesions are precursors to most pancreatic cancers and are present in up to 40% of the general population. Therefore, accurate diagnosis based on the benign or malignant potential of pancreatic cysts is crucial.

[0003] Endoscopic ultrasound (EUS)-guided fine-needle aspiration (FNA) of cystic lesions, followed by fluid cytology analysis, has been used as a diagnostic tool to differentiate between benign, potentially malignant, and malignant pancreatic cysts. While EUS-FNA results are encouraging for solid lesions, they are disappointing for cystic lesions due to the sparse cellularity of the cystic fluid. This sparseness is because EUS-FNA removes the fluid component of the cyst, rather than the cyst membrane or wall that is normally covered by cells. The sensitivity of this method ranges from 65% to 95%, and the specificity from 50% to 100%. The average accuracy is 85%, which results in indeterminate or ambiguous cases in 20% of cases. This lack of information leaves cytopathologists unable to make a diagnosis. An attempt to address this problem was the development of a cytology brush (echo brush; Cook Endoscope, Winston-Salem NC) with a “penetrating needle” for manipulation via a 19G needle, which provided diagnostic material in 85.1% of cases. However, the increased risk of bleeding led to the shutdown of these devices.

[0004] WO 2018 / 053402A1 discloses a pancreatic cyst device that can be deployed into a cyst via a 22-gauge endoscopic ultrasound (EUS) needle. The device is a flexible shaft with a proximal end and a "spiral Q"-shaped distal end designed to conform to the shape of the cyst to maximize the contact area. The proximal end can be connected to a handle to allow an operator to rotate the device within the pancreatic cyst to remove cells from the cystic membrane.

[0005] However, the aforementioned device still carries the risk of damaging the cystic membrane, and the distal helical end may break during operation and retraction into the outer shaft. Furthermore, the entire length of the flexible shaft is made of nitinol, making it expensive to manufacture.

[0006] Therefore, it is necessary to improve known devices and methods to overcome the above-mentioned shortcomings. Summary of the Invention

[0007] Therefore, the purpose of this invention is to provide a minimally invasive biopsy / cytology device and method that reduces tissue damage at the sampling site while increasing the number of cells or tissues collected from the subject's cavity.

[0008] This objective is achieved in a first aspect of this disclosure, in which an apparatus is provided for disengaging cells or tissue from a cavity of a subject, the apparatus comprising: an elongated member arranged to move within a lumen of a needle or catheter; and at least one flexible member arranged at a distal end of the elongated member, wherein the flexible member is configured between a first constrained configuration within the lumen of the needle or catheter and a second deployed configuration outside the lumen, wherein the flexible member in the second deployed configuration is configured to conform to the internal geometry of the cavity into which the apparatus is inserted.

[0009] By providing a device having an elongated member and a flexible member disposed at its distal end, the flexible member being configured to take a shape that conforms to the internal geometry of the cavity into which the device is inserted, the number of cells collected during a sampling procedure can be increased while reducing the risk of damaging tissue at the sampling site.

[0010] In one embodiment, the flexible member is a hyperelastic metal wire, preferably made of a shape memory alloy. Hyperelasticity (particularly shape memory alloys such as nickel-titanium) allows the flexible member to take on the desired shape of the cavity's internal geometry when the device is inserted into a cavity (e.g., a cyst).

[0011] In one embodiment, the flexible member is arranged to form at least one ring in the deployed configuration. This ring allows the flexible member to conform to the desired shape of the cavity's internal geometry in a simple manner. Furthermore, the ring reduces the distance the elongated member needs to advance before reaching its fully deployed deployment configuration.

[0012] In one embodiment, at least a portion of the flexible member has a generally helical shape, in which the axis of the helix is ​​generally parallel to the general direction of extension of the flexible member. The helical shape provides rough edges to facilitate scraping cells from the inner membrane / wall of the cavity.

[0013] In one embodiment, at least a portion of the flexible member has a serrated structure, for example, exhibiting multiple teeth. Preferably, the serrated structure is achieved by machining or by microstructures arranged on the surface of the flexible member. The serrated structure provides rough edges to increase wear resistance and facilitates the scraping of cells from the inner membrane / wall of the cavity, thereby increasing cell yield.

[0014] In one embodiment, the elongated member and the flexible member are integrally formed as a single structure, wherein the diameter of the flexible member is smaller than the diameter of the elongated member. The smaller diameter of the flexible member allows it to fold in a constrained configuration, thereby reducing the distance required for the elongated member to advance before the flexible member reaches its fully deployed, unfolded configuration.

[0015] In one embodiment, the elongated member includes a mounting interface at its distal end, and the at least one flexible member is attached to the elongated member via the mounting interface. This configuration allows the flexible member to be manufactured separately from the elongated member, for example, in different materials or using different processes.

[0016] In one embodiment, the mounting interface includes: at least one hole for fastening the at least one flexible member to the elongated member; and a weld, adhesive joint, or mechanical interlocking mechanism, or a combination thereof, between the elongated member and the at least one flexible member. Different fastening alternatives can be selected depending on the desired characteristics and / or expected operating conditions of the device. Preferably, the mounting interface is covered with a heat-shrink tubing. The heat-shrink tubing protects the mounting interface from breakage or detachment of the flexible member from the elongated member.

[0017] In one embodiment, the device further includes a tubular sheath disposed outside the elongated member and configured to move along the elongated member within the lumen of the needle or catheter. The tubular sheath protects the flexible member from breakage during advance, operation, and retraction relative to, for example, a hollow needle into which the device is inserted. Preferably, the tubular sheath is made of a polymer such as polyether, polyamide, polyimide, or polytetrafluoroethylene (PTFE), or a metal such as nickel-titanium or stainless steel.

[0018] In one embodiment, the elongated member and / or the flexible member are surface-treated or coated to reduce the coefficient of friction.

[0019] In a second aspect of this disclosure, an apparatus is provided for performing fine-needle aspiration (FNA) or fine-needle biopsy (FNB), the apparatus comprising: a hollow needle; and, according to the first aspect, the apparatus being movably disposed within the lumen of the needle.

[0020] In a third aspect of this disclosure, a method is provided for performing fine-needle aspiration (FNA) or fine-needle biopsy (FNB) to sample cells or tissue from a subject's cavity, the method comprising:

[0021] A hollow needle and a device are provided, the device comprising an elongated member and at least one flexible member, the elongated member being arranged to move within a lumen of the needle, the at least one flexible member being arranged at a distal end of the elongated member, wherein the flexible member is configured between a first constrained configuration within the lumen of the needle and a second deployed configuration outside the lumen, wherein the flexible member in the second deployed configuration is configured to conform to the internal geometry of a cavity into which the device is inserted;

[0022] The needle is inserted into the cavity of the subject;

[0023] The elongated member is advanced through the lumen of the needle, such that the flexible member protrudes from the distal end of the needle and is in a second unfolded configuration within the lumen, contacting the inner wall of the lumen;

[0024] The elongated member is rotated, causing the unfolded flexible member to scrape the inner wall of the cavity;

[0025] The elongated member is retracted into the lumen of the needle, such that the flexible member is in the first constraint configuration, and then re-enters the distal end of the needle;

[0026] Liquid is drawn from the cavity through the lumen of the needle; and

[0027] The needle is retracted from the cavity.

[0028] In one embodiment, the device includes a tubular sheath disposed outside the elongated member and configured to move along the elongated member within the lumen of the needle or catheter, and the method further includes:

[0029] Prior to the step of rotating the elongated member, the tubular sheath is advanced through the needle such that the distal end of the tubular sheath exits the distal end of the needle and contacts the unfolded flexible member; and

[0030] After the step of retracting the elongated member, the tubular sheath is retracted back into the needle.

[0031] In one implementation, the step of inserting the needle into the subject's cavity is performed via endoscopic ultrasound, or EUS guidance. Therefore, sampling can be performed minimally invasively as an EUS-FNA / FNB procedure, for example, to obtain samples from the subject's gastric region. Attached Figure Description

[0032] The invention will now be described by way of example with reference to the accompanying drawings, in which:

[0033] Figure 1 The following are illustrated: an endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) path toward a cyst in the pancreas using a device according to one embodiment of the present disclosure, operating the device outside the human body, and different steps of combining the device with EUS-FNA.

[0034] Figure 2 A photograph of the device leaving the 22G needle according to one embodiment of the present disclosure is shown, along with scanning electron microscope (SEM) images of the mounting interface in the form of a knot before and after the placement of the heat shrink tube.

[0035] Figure 3 The following views are shown: a cross-sectional view of the device according to one embodiment of the present disclosure operating in the cavity of a cystic phantom; a side view photograph of the cystic phantom with the device inserted; and axial views of the front and rear portions of the cystic phantom before and after brushing with the device; and the differences between them.

[0036] Figure 4 A schematic diagram of an in vitro test of an apparatus according to one embodiment of the present disclosure in a porcine small intestine model is shown;

[0037] Figure 5a and Figure 5b As shown Figure 4 The absolute cell concentrations and brush efficiencies shown are from the tests conducted.

[0038] Figure 6 A schematic diagram of an in vitro test of an apparatus according to one embodiment of the present disclosure in a bovine follicular cyst is shown, along with images of cell counters without and after brushing.

[0039] Figure 7 Four embodiments of the flexible member according to this disclosure are shown, which are arranged at the distal end of an elongated member;

[0040] Figure 8 A close-up view of a flexible member according to different embodiments of the present disclosure is shown;

[0041] Figure 9Different steps of operating an apparatus according to another embodiment of this disclosure are shown. Detailed Implementation

[0042] The following is a detailed description of the apparatus according to this disclosure. In the accompanying drawings, the same reference numerals denote the same or corresponding elements throughout the various figures. It should be understood that these drawings are for illustrative purposes only and do not limit the scope of the invention in any way.

[0043] In the context of this disclosure, the terms "remote" and "farthest" refer to the position or direction furthest from the operator when using the device according to this disclosure. Correspondingly, the terms "proximal" and "proximal" refer to the position or direction closest to or toward the operator when using the device according to this disclosure.

[0044] Now refer to Figure 1 Figure a) illustrates a schematic diagram of an endoscopic ultrasound-guided fine-needle aspiration / biopsy (EUS-FNA / FNB) procedure according to current practice. The endoscope is inserted through the patient's mouth, esophagus, stomach, and small intestine (duodenum) to reach the pancreas, and the operator inserts a 22G needle into the cyst when it is located by the ultrasound transducer. However, other organs or regions of interest can be targeted, and the endoscope can be inserted through the colon, anus, or rectum. Depending on the procedure, other needle gauges may also be anticipated.

[0045] exist Figure 1 Figure b) illustrates the steps of the procedure used to enhance cell yield. A flexible, ring-brush-like member, initially located within a 22G needle, is inserted into the cyst, conforming to its lumen. Rotating the elongated member causes the ring brush to rotate and scrape cells from the cyst wall, resulting in their release into the cyst fluid. Next, the flexible member is retracted from the needle lumen, and the cyst fluid is aspirated through the needle. The cyst fluid is collected for downstream cytological / pathological or biochemical, molecular, or genetic analysis.

[0046] To verify the mechanical robustness of the device, stress tests were conducted, and the results showed that there was no restriction on the movement of the ring brush when it was introduced, rotated, and removed up to 100 times by a needle through which the slender member with a length of 1200 mm. Figure 1 Photograph c) shows the distal end of an endoscope, which includes a needle and a ring brush.

[0047] Tensile testing of the flexible component showed that mechanical failure occurred when the fracture limit force was greater than 3 N, which is on the order of magnitude of a straight 50 m nitinol wire (SI5). During in vivo operation, the mechanical stress level remained several orders of magnitude below this limit strength.

[0048] Now refer to Figure 2 The present invention illustrates an apparatus according to one embodiment of the present disclosure. Figure 2 Photograph a) illustrates the distal end of the device, where a flexible member is arranged in a loop at the distal end of an elongated member (referred to herein as a guidewire). The flexible member is constructed of a 50 μm fine nitinol wire, formed into a loop with a diameter of 1 cm. Figure 2 As shown in the scanning electron microscope (SEM) image b), the loop is secured to a 280 μm thick nitinol elongated member by a reverse-hand knot. A nitinol wire is passed through a hole therein and knotted with a guide wire. The hole can have a diameter greater than 0.025 mm and less than 5 mm, typically less than 0.50 mm. The hole can be positioned 1 mm or at most 10 mm from the distal end of the elongated member.

[0049] like Figure 2 As shown in SEM image c), after knotting, a heat shrink tube is inserted over the knot, allowing it to shrink by applying heat, thus wrapping the knot. The heat shrink tube can have a diameter greater than 0.1 mm and less than 12 mm, typically greater than 0.2 mm.

[0050] Other means of mounting flexible members to elongated members are foreseeable within the scope of this disclosure, including gluing, welding, and mechanical interlocking. The mounting interface may be combined with heat shrink tubing for wrapping, or may not be combined with heat shrink tubing. In one embodiment, the elongated member and the flexible member are integrally formed as a single structure, i.e., a single piece.

[0051] Now refer to Figure 3 The manipulation of the circular brush within the spherical cavity of an extracorporeal cystic phantom was studied, such as... Figure 3 As shown in Figure a). The flexible member is introduced into the lumen through the 22G needle and then rotated. Figure 3 As shown in photo b). It was observed that the ring brush conforms to the inner wall of the phantom and demonstrates the ability of the flexible component to remove cell-sized talc particles from the rigid inner wall of the cavity, thus revealing the ability to scrub the internal 3D curved surface, as... Figure 3 As shown in photo c).

[0052] Currently, there are no animal models of pancreatic cysts similar in size to human cysts and mimicking cell attachment in tissue, which is crucial for validating the circumferential brush function. Furthermore, pancreatic cysts contain fluids of varying viscosities; higher viscosity indicates a higher degree of malignancy. Therefore, saline or glycerol was used as the liquid medium to construct an isolated porcine small intestine model. (See reference...) Figure 4 This demonstrated the ability of the flexible component to increase cell number after scrubbing. Six intestines (indicated A to F) were used, and each intestine was cut into six test segments (indicated 1 to 6). Figure 4Figure a) shows a schematic diagram of the section cutting position. Figure 4 Figure b) shows a schematic cross-section of cells collected from the model in the following procedures: i) negative control test, i.e., fluid was subsequently added and aspirated without brushing; ii) positive control test, i.e., fluid was subsequently added to the first intestinal segment, brushed with an interdental brush and aspirated; and iii) sample test, i.e., fluid was subsequently added to the second through sixth intestinal segments, brushed with a ring brush and aspirated.

[0053] The cell counts after fluid removal were compared between the loop washing, negative control (no washing), and positive control (washed with an interdental brush). Results are as follows: Figure 5a As shown, that is: Figure 5a The example shows the absolute cell concentration, while Figure 5b The brushing efficiency η is illustrated. Samples from the intestine (denoted A to C) were filled with saline, while samples from the intestine (denoted D to F) were filled with glycerol. The horizontal dashed line represents the detection limit (LOD) of the cell counter. Cell counts below the LOD are presented immediately below the LOD line. Error bars indicate SD.*P<0.05. Rank-sum paired tests of all 15 replicates for the negative control and loop brushing revealed P<0.0001 for both media.

[0054] The brushing efficiency η was defined as the ratio of cell concentration in the ring-brushed sample to that in the negative control sample. LOD values ​​were used instead of negative control values ​​when the negative control sample contained fewer cells than the limit of detection (LOD) of the cell counter. All tests showed η > 1. In the saline model, the mean η was 11 (n = 15); in the glycerol-filled model, the mean η was 65 (n = 15). These results demonstrate that ring brushing can remove cells from the 3D soft tissue surface, which can then be collected by aspiration. After ring brushing, the cell concentrations in the saline and glycerol-filled samples were of similar orders of magnitude, indicating that ring brushing improves cell collection from cyst fluids of different viscosities. Differences in cell content were observed in the negative control measurements between the saline and glycerol-filled models. This difference is attributed to the difference in fluid viscosity, which leads to more turbulent filling conditions for the saline model and more laminar conditions for the glycerol model. That is, the saline-filled model mixes the released cells in the fluid, while the glycerol-filled model keeps these cells close to the intestinal wall.

[0055] Further verification showed that the force applied to the tissue by the flexible component during routine surgical procedures is approximately in the range of 0.1 mN to 0.7 mN (SI7). The use of the circular brush was also validated in a model of a cystic endoscopic path simulating the curves of the gastrointestinal system. Without observing any adverse effects, the circular brush was rotated at 60 rpm for 1 hour against the lumen of a porcine small intestine model.

[0056] Now refer to Figure 6 The ability of brushing an isolated bovine follicular cyst model to increase cell number was tested. Figure 6 As shown in Figure a), the experimental procedure began with fluid sampling without scrubbing (negative control), followed by loop scrubbing, and then a second fluid sampling. Figure 6 Photo b) shows cow ovaries with and without follicular cysts. Figure 6 Photographs c) and d) show color-enhanced cell counter images and their corresponding cell counts for the negative control sample (c) and the ring brush sample (d).

[0057] Compared to the negative control, loop brushing increased cell concentration by at least 10-fold. The presence of cell clusters after brushing makes it difficult to count all cells in the sample, leading to a conservative estimate of this efficiency. These results demonstrate that the flexible member can be successfully manipulated within the cyst through the lumen of a 22G needle, and that it can brush and disperse cells in the fluid environment of the cyst. The ability of the flexible member to gently rub and disperse cells in more than one type of tissue suggests its potential for successful manipulation in diagnostic procedures for pancreatic cancer.

[0058] Current results demonstrate the functionality, mechanical robustness, ease of operation, and low tissue stress of the flexible component in the gastrointestinal model, and show its compatibility with current EUS-FNA procedures. Future research should aim to evaluate the safety of this procedure, particularly regarding potential damage to surrounding tissues, and the effectiveness of scrubbing septate cysts—that is, the wall structure that divides the cyst cavity into two or more compartments.

[0059] Now refer to Figure 7 Four embodiments of the annular flexible member according to this disclosure are shown. The flexible member is disposed at the distal end of an elongated member. The elongated member may have a diameter greater than 0.1 mm and less than 12 mm, typically greater than 0.2 mm. The elongated member may be as long as 2 meters and as short as 1 cm, typically greater than 3 cm. In operation, the elongated member can be used to guide the flexible member. For example, the flexible member can be introduced into the lumen, rotated within the lumen, and removed from the lumen as the elongated member advances, rotates, and retracts within the needle lumen. The elongated member can be manipulated by hand or by means of a mechanical / robotic device. This manipulation can be performed on-site or remotely.

[0060] The flexible component can have a diameter greater than 0.025 mm and less than 4 mm, typically less than 0.5 mm, more preferably less than 0.21 mm. The diameter of the ring can be greater than 1 mm, typically greater than 2 mm, and less than 8 cm, typically less than 3 cm.

[0061] In a first embodiment, the flexible member includes a single loop that is generally circular in an unfolded configuration when unconstrained within the lumen of a needle or catheter. An exemplary needle may have an inner diameter greater than 0.1 mm and less than 6 mm, typically less than 5.5 mm. An exemplary catheter may have an inner diameter greater than 0.33 mm and less than 12 mm, typically less than 9 mm. In a second embodiment, the flexible member includes more than one loop, such as the two loops shown herein. In a third embodiment, the flexible member includes at least one serrated portion to create a plurality of teeth or dots in a Z-shaped pattern. The serrated edges of the loops increase friction against the walls of the cyst or other lumen, thereby increasing cell yield. The serrated edges may be formed by the macrostructure of the flexible member; for example, the flexible member may be formed with a serrated structure. In a fourth embodiment, the flexible member is wound into a helical shape and subsequently formed into a loop such that the axis of the helix is ​​generally parallel to the general direction of extension of the flexible member, i.e., the outline of the loop shape.

[0062] Now refer to Figure 8 This image shows a close-up view of the surface of a flexible member according to different embodiments of the present disclosure. In one embodiment, the surface of the flexible member may be generally smooth, such as... Figure 7 As shown in the upper left embodiment. In another embodiment, the surface of the flexible member may include microstructures to increase abrasion resistance, thereby increasing cell yield, similar to... Figure 7 The lower left implementation method. For example... Figure 8 As shown in the intermediate view, the microstructure can be achieved through notches or grooves in the surface of the flexible member. In one embodiment, the microstructure is achieved by means of one or more cylindrical structures having multiple protrusions, such as studs, which are inserted into the flexible member. The cylindrical structures can be rigid, which locally restricts the flexibility of the flexible member. The flexible member can be bent in the portions between the cylindrical structures, thereby improving the conformability of the flexible member relative to the tissue walls of the cavity.

[0063] Now refer to Figure 9This illustration shows the steps of a surgical procedure using a device according to one embodiment of the present disclosure. In step a), a needle comprising a device (which includes an elongated member and a flexible member in a confined configuration within the lumen of the needle) is introduced into a cavity of a subject, such as a cyst. In step b), the elongated member is advanced distally through the lumen of the needle such that the flexible member exits the lumen of the needle and transitions to an unfolded configuration in which the flexible member generally conforms to the internal geometry of the cyst to contact the inner wall. In step c), a tubular sheath is advanced within the lumen of the needle along the elongated member until the distal end of the tubular sheath contacts the unfolded flexible member. The tubular sheath may be made of a polymer such as polyether, polyamide, polyimide, or polytetrafluoroethylene (PTFE) or a metal such as nickel-titanium or stainless steel, and protects the flexible member from the sharp facets of the needle. In step d), the elongated member is rotated within the lumen of the needle, which causes the flexible member to rotate within the cyst and scrape cells from the inner wall. In step e), the elongated member is retracted proximally, allowing the flexible member to re-enter the needle and transition to a constrained configuration. During this stage, the tubular sheath is held in place beyond the needle tip, ensuring the flexible member does not contact the needle during retraction. In step f), the tubular sheath is retracted proximally into the needle lumen. Finally, in step g), the fluid in the cyst, along with cells shed through friction by the flexible member, is aspirated. The fluid content in the lumen can be naturally excreted by the body, such as through urination. The fluid content can also be removed via catheter insertion.

[0064] In one embodiment, the aspirated liquid content can be expelled from the needle lumen by advancing the elongated and flexible members distally. In one embodiment, the liquid content can be expelled from the needle lumen by pushing a wire (e.g., a probe) forward within the needle. In one embodiment, the liquid content can be expelled from the needle lumen by passing air or liquid through a syringe. The flexible member can be cut after liquid removal and subsequently used for cytological, pathological, biological, or chemical analysis. The liquid content can then be used for cytological, pathological, biological, or chemical analysis. The cytological analysis is, for example, for cell morphology analysis. The pathological analysis is, for example, for tissue morphology analysis. The chemical analysis is, for example, for proteins, glycoproteins, enzymes, DNA, cancer markers, or immunoassays.

[0065] In one embodiment, the surfaces of elongated members, flexible members, and / or tubular sheaths may be treated or coated to reduce the coefficient of friction, thereby facilitating forward movement, retraction, and rotation.

[0066] Ring brush manufacturing

[0067] In one embodiment, the ring brush consists of three main components: a 280 μm nitinol elongated member (probe wire obtained from Boston Scientific, USA, Expect™ Slimline EUS-FNA device M00555510), a 50 μm nitinol wire knotted to form a ring (NiTi#1 wire 0.002″±0.0001″ straight annealed light oxide, Weinberg Metals, Ireland), and a PET medical heat shrink tube (103-0510, Nordson Medical, USA) with an inner diameter of 460 μm before shrinkage to protect the knotted area.

[0068] To create the loop brush, a 150 μm hole is drilled through the distal end of an elongated member. Without covering the hole, the elongated member is inserted through a 2 cm section of a heat-shrinkable tube. Then, the same end of a 50 μm nitinol wire is passed through the hole twice to form a loop. The loop is wound around an ice cylinder with a diameter of 1 cm, and a reverse knot is made using both ends of the 50 μm nitinol wire. This ensures the knot's position relative to the elongated member and the 1 cm loop diameter. The ice cylinder is then left to melt at room temperature for 20 minutes, and excess wire ends are trimmed to facilitate knotting, leaving approximately 1 cm of wire end. Finally, the shrinkable tube is manually pushed forward to cover the nitinol wire end and the knot, and heated at 70°C for 30 seconds to shrink the tube. The shrinkable tube serves two functions: protecting the knot by preventing it from unraveling during the loop brush's movement, and shaping the loop form, which is achieved by keeping a portion of the loop wire straight inside the shrinkable tube, thus forming a loop shape outside the tube.

[0069] In vitro cyst phantom and scrubbing test

[0070] By milling 2×2×2cm 3 The PMMA cube creates the cystic phantom by producing a spherical cavity with a diameter of 1 cm. The PMMA cube is made in two parts. The front part contains one half of the sphere, and the rear part contains the other half. A 5 mm hole is drilled in the rear part to create the phantom entrance. Figure 3 b shows an image of the brush inside the cystic phantom.

[0071] By Apply permanent double-sided tape (2346832, Odyssey) to the surface of the ball for 1 minute, then remove the tape and... Talc (7322338361053, Apotea, Sweden) was placed on the surface and then bonded to the cystic phantom in preparation for a scrubbing test.

[0072] Excess talcum powder was removed by colliding the two parts 20 times to bring the cavities face to face. Before brushing, the cavities were imaged using a Leica M205 C microscope with each part of the cube fixed in its position holder and the cavity facing the microscope. The two parts were then assembled with two alignment pins and secured with clamps. The ring brush was inserted into a 22G hypodermic needle (4710007040, Henke-Sass-Wolf, Germany), which was held in place at the front of the phantom inlet. For ease of testing, the elongated ring brush component was secured by a wire retainer outside the needle. The wire retainer was welded to the shaft of a Robotzone 101rpm@12V DC motor (638194, ServoCity, Switzerland).

[0073] The washing chamber is activated by starting the motor at 60 rpm for 1 minute. After washing, the two parts of the sphere are separated and imaged again. Camera settings remain constant throughout all image acquisition processes.

[0074] To measure the difference between before and after brushing, Python code (SI4) was used to align the post-brushing image with its corresponding pre-brushing image. After image alignment, all images were converted to 16-bit grayscale, and for each sphere, an image representing the difference between the pre-brushing and post-brushing images was obtained. This was done using the difference function in ImageJ (version 1.52a, National Institutes of Health).

[0075] pig intestinal cyst model

[0076] Pig small intestine passes through immediately after death Slakteri AB (Sweden) Remove the intestines and place them in DMEM (10313021, Thermo Fisher Scientific, Sweden) medium containing 10% FBS (Gibco™ 10270106, Thermo Fisher Scientific, Sweden) and 1% penicillin-streptomycin (15070063, Thermo Fisher Scientific, Sweden) to prevent tissue decomposition. Store the intestines at 4°C until use within 24 hours post-mortem.

[0077] For each experiment, the small intestine was dissected using a scalpel to separate it into six 8cm segments, starting approximately 3cm from the pylorus. These segments were then axially cut to fully expose the luminal side of the intestine. All exposed segments were rinsed with tap water for 1 minute, while simultaneously being gently scrubbed manually to remove any remaining residue. Each intestinal segment was placed in a container of tap water, where the tissue was kept intact for 20 minutes until testing.

[0078] For the scrubbing test, a hemispherical mold with a radius of 2.5 cm was used to hold the intestinal fragments. This mold had five 1 mm diameter drill holes connected to a vacuum line, allowing for outward contact with the lumen from the side. Figure 4 In case b), keep the intestinal segment in place.

[0079] The test without brushing (negative control) was performed after the tissue was fixed in the mold by placing 300 μL of 0.9% saline (786-561, G-Biosciences, Sweden) or glycerol (G9012, Sigma-Aldrich, Sweden) on the tissue. The liquid was allowed to stand for 1 minute, and then 100 μL of liquid was carefully aspirated using a pipette, taking care not to touch the intestinal wall during this time. This method preceded each loop brushing and positive control experiment and revealed the number of cells that naturally detached into the culture medium through sample cutting, cleaning, processing, and / or placing culture medium on the sample. Therefore, a negative control test was performed on each intestinal segment before the loop brushing test on the same intestinal segment. Loop brushing was performed on five of the six intestinal segments. Then, after the negative control test, loop brushing was initiated by adding an additional 100 μL of liquid to the tissue section, thus maintaining the liquid volume throughout the test. After the negative control test, a positive control brushing was performed on the remaining tissue sections while an additional 100 μL of liquid was added to the tissue section. An interdental brush (Dentalux, Sweden) was used as a positive control. This brush was gently pressed against the intestinal lumen for 1 minute without rotation, then applied to the center of the intestinal segment at 0.5 cm. 2 Move the brush back and forth axially within the area. After brushing, aspirate another 100 μL of liquid.

[0080] Bovine follicular cyst model

[0081] The reproductive system of cattle is immediately restored after death. Slakteri was removed and placed in DMEM-based medium containing 10% FBS and 1% penicillin-streptomycin to prevent tissue degradation, and stored at 4°C for 24 hours before excision.

[0082] Using a scalpel, one ovary without follicular cysts and one ovary containing follicular cysts were removed from the bovine reproductive system and fixed in a Piper dish. Figure 5b Experimental design as follows: Figure 5aAs illustrated in [reference needed], the procedure was performed as follows: First, the follicular cyst was punctured, and 1.5 mL of fluid was aspirated using a 22G hypodermic needle and syringe. Next, the follicular cyst was punctured again, and the 22G hypodermic needle with a pre-installed circular brush was inserted. The brush was then manually rotated at approximately 60 rpm for 1 minute, and the brush was removed. Finally, 1.5 mL of cystic fluid was aspirated through the needle using a syringe. After homogenization, a 100 μL aliquot of the 1.5 mL sample was taken for further cell analysis.

[0083] Liquid sample processing

[0084] The aspirated liquid sample was transferred to a test tube (0030120086, Eppendorf, Sweden) and then mixed with 500 μL of StemPro™ Accutase™ (A1110501, Thermo Fisher Scientific, Sweden). The liquid was then gently homogenized by pipetting and dispensing at 2-second intervals for 30 seconds, and incubated at 37°C for 5 minutes. Next, the samples (except for bovine samples) were filtered using a 70 μm cell filter (431751, CorningQR, Netherlands) and centrifuged at 11,000 rpm for 4 minutes using a Micro-Star 17R centrifuge (VWR, Sweden). The supernatant was removed, and a fluorophore solution containing 0.05% v / v diphenylmethyleneamine 33342 (H3570, Thermo Fisher Scientific, Sweden) in saline was added to each sample. Mix the positive control with 100 μL of solution, and mix the negative control and loop-washed sample with 50 μL of solution to accommodate the particle size. Finally, wrap the sample with aluminum foil for 20 minutes, then unfold it again to prepare for cell counting.

[0085] Cell counter analysis

[0086] Cell counting was performed using a Countess II FL automated cell counter (Thermo Fisher Scientific, Sweden) coupled with an EVOSTM DAPI light cube (AMEP4650, Thermo Fisher Scientific, Sweden). All samples were gently homogenized with pipettes, and 10 μL samples were placed on a Countess™ cell counting chamber slide (C10228, Thermo Fisher Scientific, Sweden). Intestinal cell counting was performed using the DAPI light cube with the following settings: size between 4 μm and 14 μm, brightness between 0 a.u. and 255 a.u., ring size of 0.67, and autofocus. Follicular cyst cell counting was also performed using the DAPI light cube with the following settings: size between 6 μm and 29 μm, brightness between 0 a.u. and 255 a.u., ring size of 0.78, and autofocus. Finally, dilution calculations were performed on the intestinal and follicular cyst samples, with a final volume of 50 μL.

[0087] Statistical analysis

[0088] The intestinal cell count results were applied to a one-sided rank-sum test with a paired signed-rank significance level of 5% to test for statistical significance between using and not using a circular brush. This was performed using GraphPad Prism 8 software (GraphPad, CA, USA).

[0089] in conclusion

[0090] A ring brush designed to extract cells from the inner wall of a pancreatic cyst and hollow cavity in conjunction with EUS-FNA was successfully tested. No adverse effects were observed when the ring brush was introduced, rotated, and removed from the cyst using a 22G needle. Cell content in fluids extracted from ex vivo cyst models before and after brushing with the ring brush was compared. Cell content increased 54-fold when using low-viscosity water as the fluid in soft tissue cavities; it increased up to 174-fold when using high-viscosity glycerol; and at least 10-fold in bovine ovarian cysts. The ring brush demonstrates a powerful, minimally invasive, and versatile tool capable of manipulation in conjunction with EUS-FNA and of brushing cyst cells in both soft and hard cyst models, as well as in serous or viscous fluids.

[0091] A circular brush test was performed using a brush connected to a DC motor, similar to the in vitro cyst phantom test. The distal end of the brush was gently pressed against the intestinal lumen, 0.5 cm from the center of the intestinal segment. 2 Rotate the intestinal segment at 60 rpm for 1 minute within the designated area. Afterward, aspirate 100 μL of liquid using a pipette. Between each experiment, discard the used intestinal segment and clean the mold with ethanol and wipe it with cleanroom paper.

[0092] A preferred embodiment of an apparatus for detaching cells or tissues from a subject's cavity, according to this disclosure, has been described. However, those skilled in the art will recognize that variations may be made within the scope of the appended claims without departing from the spirit of the invention.

[0093] Without departing from the spirit of this invention, all the above alternative implementation methods or parts of the implementation methods can be freely combined as long as the combinations are not contradictory.

Claims

1. An apparatus for performing fine-needle aspiration (FNA) or fine-needle biopsy (FNB), the apparatus comprising: Hollow needle; An elongated member, which is movably arranged inside the lumen of the needle; and At least one flexible member is disposed at the distal end of the elongated member, wherein the flexible member has a first constraint configuration within the lumen of the needle, and after the elongated member has advanced through the lumen of the needle, the flexible member has a second deployment configuration outside the lumen, wherein the flexible member is arranged to form at least one loop in the second deployment configuration. The device is characterized in that it further includes a tubular sheath disposed outside the elongated member and configured to move along the elongated member within the lumen of the needle to contact the unfolded ring outside the lumen.

2. The apparatus according to claim 1, wherein, The flexible component is a superelastic metal wire.

3. The apparatus according to claim 1, wherein, The flexible component is made of shape memory alloy.

4. The apparatus according to any one of claims 1 to 3, wherein, The ring is circular in the second unfolding configuration.

5. The apparatus according to any one of claims 1 to 3, wherein, At least a portion of the flexible member has a helical shape, wherein the axis of the helix is ​​parallel to the extension direction of the flexible member.

6. The apparatus according to any one of claims 1 to 3, wherein, At least a portion of the flexible member has a serrated structure.

7. The apparatus according to claim 6, wherein, The serrated structure is achieved by machining or arranging microstructures on the surface of the flexible member.

8. The apparatus according to any one of claims 1 to 3, wherein, The elongated member and the flexible member are integrally formed into a single structure, wherein the diameter of the flexible member is smaller than the diameter of the elongated member.

9. The apparatus according to any one of claims 1 to 3, wherein, The elongated member includes a mounting interface at its distal end, and the at least one flexible member is attached to the elongated member via the mounting interface.

10. The apparatus according to claim 9, wherein, The mounting interface includes: at least one hole for fastening the at least one flexible member to the elongated member; a weld, adhesive joint, or mechanical interlocking mechanism between the elongated member and the at least one flexible member; or a combination thereof.

11. The apparatus according to claim 9, wherein, The mounting interface is covered with heat shrink tubing.

12. The apparatus according to claim 1, wherein, The tubular sheath is made of polymer or metal.

13. The apparatus according to claim 12, wherein, The polymer is polyether, polyamide, polyimide or polytetrafluoroethylene, and the metal is nickel-titanium or stainless steel.

14. The apparatus according to any one of claims 1 to 3, wherein, The elongated member and / or the flexible member are surface-treated or coated to reduce the coefficient of friction.

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