Patent Application
20230404551
Unless otherwise indicated herein, the materials described in this section are not prior art to the claims in this application and are not admitted to be prior art by inclusion in this section.
Endoscopic retrograde cholangiopancreatography (ERCP) is a broad group of medical procedures that are applied to solve problems associated with the pancreatobiliary system. A part of this procedure typically involves the procurement of a biopsy from either the pancreatic or biliary ducts. A bile duct biopsy procedure is one in which a sample of tissue or cells is safely extracted to diagnose disease, which is often a preliminary step before determining if the patient needs to have a surgical resection. The tissue sampling technique must have high sensitivity for detecting malignancy while maintaining sufficient specificity; and as with any procedure, ERCP-based sampling techniques should be safe, simple, and relatively inexpensive so they can be widely used. The remote, narrow-branched structure of the bile duct (with an inner diameter typically less than 6 mm) makes it difficult to view constrictions or maneuver the tool to perform the sampling procedure. The current standard for biopsy guided acquisition is use of fluoroscopy to direct the device to areas in question. Studies have demonstrated that biliary stricture sampling specimens acquire miniscule amounts of tissue and frequently contain insufficient cellularity, often leading to false-negative diagnoses. The most common biopsy method in the bile duct is brush sampling of cells for cytology. In this procedure, a guidewire steers a brush passed into a duct which is often constricted. When the guidewire is pulled, the epithelial cells on the duct walls get trapped in the dense bristles and in this way the sample can be obtained. However, the sensitivity of standard biliary brushings historically is low, around 30%-60%. It has been suggested that the low sensitivity of brush cytology is mainly due to inadequate cellular sampling, which may be because many malignancies compress the biliary tree from outside or because of the fibrolamellar growth of many bile duct tumors. In general, it is preferred that epithelial to deeper submucosal tissues be obtained for proper tissue diagnosis.
A less common method of sampling tissue in the biliary ducts is the forceps biopsy procedure. The forceps are a pair of sharp-edged jaws controlled by a coaxial wire within a flexible shaft. These forceps can be opened or closed by pressing and releasing the knob at the end of a shaft which is present in the hands of the operator. In operation, the two sharp edged cups of the forceps are opened, pressed against tissue in question, closed, and then the device is quickly pulled back to rip out a small piece of tissue from the bile duct wall. This technique is more time consuming and more technically challenging than brushing and thus is less commonly used. The forceps are ill-designed for small ducts because the opening process expands the tool which restricts access to the constrictions where diseases often reside. Further, the rigid and linear nature of the forceps preclude directed tissue sampling from straight luminal surfaces. For example, biopsying tissue behind an angled bile duct cannot be performed as the device cannot be angled acutely. In some patients, biopsies are not feasible as the positioning of the endoscope below the stomach does not allow for passage of the standard-sized forceps out of the accessory channel due to the thick and thus more rigid nature of the device.
Current techniques are limited in their ability to provide reassurance in the management of benign disease or targeted therapy in the face of malignancy. Due to the issues with existing procedures outlined above, there is room for improvement in reducing complexity and cost while raising sensitivity and specificity of these biopsy procedures.
The present disclosure provides a biopsy cutting tool deployed by catheter into anatomical ducts, such as the biliary duct or the coronal artery, to collect biopsy specimens from the walls of the anatomical duct.
In particular, in one aspect, a device is provided including (a) a cylindrical member having a distal end and a proximal end, wherein the cylindrical member includes a plurality of longitudinal slits positioned between the distal end and the proximal end to thereby create a plurality of strips positioned between the plurality of longitudinal slits, (b) an elongated hollow tube having a distal end and a proximal end, wherein the elongated hollow tube is coupled to the proximal end of the cylindrical member, and (c) a rod having a distal end and a proximal end, wherein the rod is positioned at least partially within the elongated hollow tube, wherein an axial movement of the rod with respect to the elongated hollow tube causes the cylindrical member to transition from a retracted position in which the plurality of strips are aligned with the distal end and the proximal end of the cylindrical member to an expanded position in which the plurality of strips protrude radially outward from the distal end and the proximal end of the cylindrical member, and wherein a diameter of the cylindrical member in the expanded position is greater than a diameter of the cylindrical member in the retracted position.
In a second aspect, a method is provided. The method may include (a) positioning the cylindrical member of the device of the first aspect adjacent the target anatomy, (b) transitioning the cylindrical member from the retracted position to the expanded position, (c) moving the cylindrical member with respect to the target anatomy to capture the biopsy sample from the target anatomy, (d) transitioning the cylindrical member from the expanded position to the retracted position, and (e) removing the device from the target anatomy.
These as well as other aspects, advantages, and alternatives, will become apparent to those of ordinary skill in the art by reading the following detailed description, with reference where appropriate to the accompanying drawings.
Example methods and systems are described herein. It should be understood that the words “example,” “exemplary,” and “illustrative” are used herein to mean “serving as an example, instance, or illustration.” Any embodiment or feature described herein as being an “example,” being “exemplary,” or being “illustrative” is not necessarily to be construed as preferred or advantageous over other embodiments or features. The example embodiments described herein are not meant to be limiting. It will be readily understood that the aspects of the present disclosure, as generally described herein, and illustrated in the Figures, can be arranged, substituted, combined, separated, and designed in a wide variety of different configurations, all of which are explicitly contemplated herein.
Furthermore, the particular arrangements shown in the Figures should not be viewed as limiting. It should be understood that other embodiments may include more or less of each element shown in a given Figure. Further, some of the illustrated elements may be combined or omitted. Yet further, an example embodiment may include elements that are not illustrated in the Figures.
As used herein, “coupled” means associated directly as well as indirectly. For example, a member A may be directly associated with a member B, or may be indirectly associated therewith, e.g., via another member C. It will be understood that not all relationships among the various disclosed elements are necessarily represented.
In
Unless otherwise indicated, the terms “first,” “second,” etc. are used herein merely as labels, and are not intended to impose ordinal, positional, or hierarchical requirements on the items to which these terms refer. Moreover, reference to, e.g., a “second” item does not require or preclude the existence of, e.g., a “first” or lower-numbered item, and/or, e.g., a “third” or higher-numbered item.
Reference herein to “one embodiment” or “one example” means that one or more feature, structure, or characteristic described in connection with the example is included in at least one implementation. The phrases “one embodiment” or “one example” in various places in the specification may or may not be referring to the same example.
As used herein, a system, apparatus, device, structure, article, element, component, or hardware “configured to” perform a specified function is indeed capable of performing the specified function without any alteration, rather than merely having potential to perform the specified function after further modification. In other words, the system, apparatus, structure, article, element, component, or hardware “configured to” perform a specified function is specifically selected, created, implemented, utilized, programmed, and/or designed for the purpose of performing the specified function. As used herein, “configured to” denotes existing characteristics of a system, apparatus, structure, article, element, component, or hardware which enable the system, apparatus, structure, article, element, component, or hardware to perform the specified function without further modification. For purposes of this disclosure, a system, apparatus, structure, article, element, component, or hardware described as being “configured to” perform a particular function may additionally or alternatively be described as being “adapted to” and/or as being “operative to” perform that function.
As used herein, with respect to measurements, “about” means +/−5%.
As used herein, with respect to measurements, “substantially” means +/−5%.
As used herein, the terms “biopsy sample”, “biological specimen”, “biological tissue sample”, “biopsy”, and “biospecimen” may be used interchangeably to mean a sample of biological tissue taken from a human or animal.
Generally, the present disclosure provides a biopsy cutting device deployed into anatomical ducts, such as the biliary duct or the coronal artery, to collect biopsy specimens from the walls of the anatomical duct. As shown in
With further reference to the Figures,
In use, by pulling on the rod 118 relative to the elongated hollow tube 112, the cylindrical member 102 is compressed, also causing the cylindrical member 102 to expand radially. The expanded cylindrical member 102 bows outward and exposes itself as a plurality of strips 110 surrounding the longitudinal axis of the cylindrical member 102, as shown in
In one example, as shown in
In one example, an outer diameter of the cylindrical member 102 in the retracted position ranges from about 0.5 mm to about 4 mm. In another example, a length of the cylindrical member 102 in the retracted position ranges from about 8 mm to about 15 mm. In one example, the diameter of the cylindrical member 102 in the expanded position ranges from about 2 greater than the diameter of the cylindrical member 102 in the retracted position to about 3 times greater than the diameter of the cylindrical member 102 in the retracted position.
The rod 118 of the device 100 may take a variety of forms. In one example, the rod 118 comprises a braided cable. In one example, the rod 118 is solid such that there is no lumen positioned therein. In another example, the rod 118 includes a lumen 132. In one such example, as shown in
The cylindrical member 102 may take a variety of forms. In one example, the cylindrical member 102 comprises a shape memory material, such as Nitinol as a non-limiting example. In another example, the cylindrical member 102 comprises an elastic material that relaxes back to a cylinder form for withdrawal of the device 100 from the target anatomy. Flexibility may also be manifested in plastic in various forms in parallel with thermal or mechanical means of deployment or temporary change in the physical properties of the plastic. The plastic could be imbued with a hard material as a backbone or embedded for cutting/tearing, such as particulate diamond to enhance the cutting method (e.g., sawing). In another example, the cylindrical member 102 may be inelastic and permanently deformed when transitioned to the expanded position, then re-deformed back to a form suitable for withdrawal of the device 100 from the target anatomy such as the original cylinder or a collapsed form smaller than the original cylinder, or by a material change such as phase change or amalgam of materials. In yet another example, after expansion and cutting is performed, the cylindrical member 102 is relaxed by a heat source for example human body heat or electrical current through the cylindrical member 102.
In one example, the plurality of strips 110 of the cylindrical member 102 are coupled to an electrical source to provide heat to the plurality of strips 110 to facilitate cutting of tissue at the target anatomy. In another example, as shown in
In one example, instead of optimization for rotational cutting, the device 100 may be optimized for cutting in the direction of the longitudinal axis of the cylindrical member 102. In one such example, as shown in
In another embodiment, instead of expansion of the cylindrical member 102 by compression, a balloon coupled to the rod 118. Expansion of the balloon would cause the transition of the cylindrical member 102 from the retracted position to the expanded position. In this case, the balloon would be collapsed after cutting to relax the cylindrical member 102 and trap the samples. The balloon may push against an intermediate structure that pushes out the cylindrical member 102 and not against the cylindrical member 102 directly to avoid puncture of the balloon during inflation and the corresponding transition of the cylindrical member 102 from the retracted position to the expanded position.
In one example, the device 100 includes a pre-loaded spring 148 configured to rotate the cylindrical member 102 once the cylindrical member 102 is in the expanded position. In one such example, the pre-loaded spring 148 is automatically triggered once the rod 118 exceeds a certain length of movement in a proximal direction. In another example, the pre-loaded spring 148 may be actuated manually via a button or other trigger mechanism.
In one example, as shown in
In use, the guidewire 150 may inserted into the biliary duct or other small vessel which is extended past the region of interest for biopsy which can be user X-ray fluoroscopy or optical endoscope guidance. The cylindrical member 102 located at tip of the elongated hollow tube 112 is threaded over the guidewire 150 and through the clamp 152 of the hand grip 154. The clamp 152 may be applied to the guidewire 150 by twisting the knobs on the hand piece. The proximal end of hand grip 154 may be extended using the ratchet mechanism 156, which compresses the cylindrical member 102, thereby transitioning the cylindrical member 102 from the retracted position to the expanded position. The ratchet mechanism 156 may include a pawl 158 and a ratchet 160, as an example. The displacement of the guidewire 150 is relative to the proximal end 116 of the elongated hollow tube 112, which does not collapse under the compression with guidewire tension load. With the ratchet mechanism 156 holding the plurality of strips 110 radially outward in the expanded position, the entire hand grip 154 and elongated hollow tube 112 may be pulled to cut the tissue surrounding the cylindrical member 102. Then the ratchet mechanism 156 may be released, which releases the tension on the guidewire 150 which allows the cylindrical member 102 to relax and straighten out to roughly its original shape. In some embodiments, as discussed above, the device 100 is capable of sucking fluid from a port 155 on the hand grip 154, which can be accomplished using an empty syringe and reducing pressure by pulling back on the plunger.
As shown in
As shown in
One method to implement this combined twisting-with-compression is shown in
As shown in
One or more of the cutting edges described above can manufactured by angling of a laser beam used for machining during the manufacturing to create angled edges.
Alternative means for manufacturing other than laser machining is by adding roughness and pitting from electrical discharge machining (EDM). Other manufacturing techniques are possible as well. The cutting edges of the device 100 described above may be sharpened by selective material removal or treated in various ways to enhance the removal of tissue. Some varieties of edge treatment could be similar to the method described below for manufacturing, but not necessarily the same (make the device one way, sharpen it with another). The cutting edges may be enhanced by the addition of a material or application of a process that increases adhesion to the tissue to tear instead of cutting. Enhanced cutting may be addressed by the addition of diamond or other hard particulate matter, possibly in a matrix-base on the plastic or in the plastic itself to provide a sawing action instead with or instead of a directly penetrating force.
In another example, as shown in
In such an example, as shown in
In use, the plurality of strips 110 are manipulated for cutting by either rotation around and/or movement along the axis of the cylinder. Because of the axially-symmetric expansion of the blades pushing against the entire surface of the surrounding luminal walls, the difficulties of obtaining correct blade pressure and aiming to the sampling site with a narrow flexible tool within a viscoelastic duct tissue are mitigated. Cutting tissue under tension can be done more easily with this radial pressure, and the cells and tissue can press through the open slots between the blades. The displacement of the plurality of strips 110 can more easily cut when the cutting edges of the plurality of strips 110 are serrated, as discussed above.
In use, as shown in
Manufacturing of various components of the device 100 may be injection molded or cast in high volumes, while various components of the device 100 may be 3D-printing in small volume manufacturing. The materials can be lubricious smooth plastic surfaces (PTFE, Teflon, or Delrin, as non-limiting examples). Various components of the device 100 may comprise the same materials, or they may comprise different materials.
The plurality of strips 110 can be molded in place (by either deformation or some form of casting), embossed or punched, etched by various means including chemical, electrical, plasma, or other volumetric fields. Another approach is the use of directed-energy sources such as lasers, or high-energy particle beams. The energy source for the etching may also be a volumetric field or flux applied to a mask on the material to change the material properties that result in non-uniform properties across the body of the device. The plurality of strips 110 can also be milled by mechanical means such as cutting, or grinding. Any of the above may be combined with another process during some phase of the construction. The entire cylindrical member 102 may also be built up by layers, either concentrically accumulated from cylindrical forms, or by layer with various methods including vapor deposition or other chemical means such as plating for example in a solution.
In addition, for the method 200 and other processes and methods disclosed herein, the block diagram shows functionality and operation of one possible implementation of present embodiments. In this regard, each block may represent a module, a segment, or a portion of program code, which includes one or more instructions executable by a processor or computing device for implementing specific logical functions or steps in the process. The program code may be stored on any type of computer readable medium, for example, such as a storage device including a disk or hard drive. The computer readable medium may include non-transitory computer readable medium, for example, such as computer-readable media that stores data for short periods of time like register memory, processor cache and Random Access Memory (RAM). The computer readable medium may also include non-transitory media, such as secondary or persistent long term storage, like read only memory (ROM), optical or magnetic disks, compact-disc read only memory (CD-ROM), for example. The computer readable media may also be any other volatile or non-volatile storage systems. The computer readable medium may be considered a computer readable storage medium, for example, or a tangible storage device.
Initially, at block 202, the method 200 includes positioning the cylindrical member 102 of the device 100 described above adjacent the target anatomy 101. At block 204, the method 200 includes transitioning the cylindrical member 102 from the retracted position to the expanded position. At block 206, the method 200 includes moving the cylindrical member 102 with respect to the target anatomy 101 to capture the biopsy sample from the target anatomy 101. At block 208, the method 200 includes transitioning the cylindrical member 102 from the expanded position to the retracted position. At block 210, the method 200 includes removing the device 100 from the target anatomy. In one example, the target anatomy 101 comprises a bile duct.
In one example, the step of moving the cylindrical member 102 with respect to the target anatomy 101 to capture the biopsy sample from the target anatomy 101 comprises rotating the cylindrical member 102 about a longitudinal axis of the cylindrical member 102. In another example, the step of moving the cylindrical member 102 with respect to the target anatomy 101 to capture the biopsy sample from the target anatomy 101 comprises moving the cylindrical member 102 in a proximal direction with respect to the target anatomy 101. In another example, the step of moving the cylindrical member 102 with respect to the target anatomy 101 to capture the biopsy sample from the target anatomy 101 comprises simultaneously rotating the cylindrical member 102 about a longitudinal axis of the cylindrical member 102 and moving the cylindrical member 102 in a proximal direction with respect to the target anatomy 101.
In one example, the method 200 further includes (i) positioning a guidewire 150 adjacent the target anatomy, and (ii) loading the device 100 onto the guidewire 150 to thereby position the cylindrical member 102 of the device 100 adjacent the target anatomy 101.
In yet another example, the method 200 further includes applying suction to a sheath 136 that is removably positioned over at least a portion of the elongated hollow tube 112 and at least a portion of the cylindrical member 102 to thereby remove the biopsy sample from the cylindrical member 102.
It should be understood that arrangements described herein are for purposes of example only. As such, those skilled in the art will appreciate that other arrangements and other elements (e.g. machines, interfaces, functions, orders, and groupings of functions, etc.) can be used instead, and some elements may be omitted altogether according to the desired results. Further, many of the elements that are described are functional entities that may be implemented as discrete or distributed components or in conjunction with other components, in any suitable combination and location, or other structural elements described as independent structures may be combined.
While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope being indicated by the following claims, along with the full scope of equivalents to which such claims are entitled. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting.
Since many modifications, variations, and changes in detail can be made to the described example, it is intended that all matters in the preceding description and shown in the accompanying figures be interpreted as illustrative and not in a limiting sense. Further, it is intended to be understood that the following clauses (and any combination of the clauses) further describe aspects of the present description.
This application claims priority to U.S. Provisional Patent Application No. 63/115,269, filed Nov. 18, 2020, the contents of which are hereby incorporated by reference in their entirety.
This invention was made with government support under Grant No. R01 CA200007, awarded by the National Institutes of Health (NIH). The government has certain rights in the invention.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US2021/059881 | 11/18/2021 | WO |
| Number | Date | Country | |
|---|---|---|---|
| 63115269 | Nov 2020 | US |
