Needle biopsy procedures are common for the diagnosis and the staging of disease. In particular, in endoscopic ultrasound-guided fine needle aspiration (EUS-FNA), the needle is advanced under ultrasound guidance so that the physician may visualize a position of the needle relative to target tissue. A distal end of the needle is then inserted into the target tissue mass to collect a sample of the tissue in a lumen thereof. Thus, EUS-FNA ensures that the correct tissue is sampled while minimizing risk to the patient. Although EUS-FNA is a highly sensitive and specific procedure, it may be difficult to acquire a suitable sample under certain clinical situations. The more cells or tissue that can be acquired, in particular for histological samples, the greater the potential for a definitive diagnosis. Larger gauge needles, however, may be difficult to pass through tortuous anatomy and may acquire samples including more blood, making it more difficult to obtain a diagnosis.
The present disclosure relates to a device for collecting a tissue sample, comprising an outer sheath extending longitudinally from a proximal end to a distal end and including a lumen extending therethrough along with a needle movably housed within the outer sheath, the needle extending longitudinally from a proximal end to a serrated distal end and including a channel extending therethrough, the needle being longitudinally movable relative to the outer sheath between an insertion configuration, in which the distal end of the needle is proximal of the distal end of the outer sheath, and a tissue collecting configuration, in which the distal end of the needle extends distally past the distal end of the outer sheath to penetrate target tissue and to collect a tissue sample in the channel and a drive mechanism rotating a distal portion of the needle about a longitudinal axis thereof as the needle is moved between the insertion configuration and the tissue collecting configuration.
In an embodiment, the drive mechanism may include a helical structure extending about the distal portion of the needle and a corresponding helical structure along an interior surface of a drive collar connected to the distal end of the outer sheath, the helical structure of the needle and the corresponding helical structure of the drive collar engaging one another such that, when the needle is moved longitudinally relative to the outer sheath, the needle is rotated relative to the outer sheath.
In an embodiment, the needle may include a barb extending laterally into the channel to grip tissue received therewithin.
In an embodiment, the barb may be a tab formed by cutting through a wall of the needle and bending the tab laterally into the channel.
In an embodiment, the drive mechanism may include a first ratchet mechanism and a second ratchet mechanism coupling a proximal portion and a distal portion of the needle, the first ratchet mechanism including a rod extending distally from the proximal portion to engage ratchet teeth along an interior surface of the distal portion, and the second ratchet mechanism including a set of teeth about each of a distal end of the proximal portion and a proximal end of the distal portion such that teeth of the first and second ratchet mechanisms are alternatingly engaged to rotate the distal portion relative to the proximal portion.
In an embodiment, the first and second ratchet mechanisms may be alternatingly engaged via a linear oscillation of the proximal portion.
In an embodiment, the device may further comprise a stylet including a protrusion extending laterally therefrom.
In an embodiment, the drive mechanism may include a ratchet mechanism coupling a proximal portion and a distal portion of the needle, the ratchet mechanism including a groove extending along an interior surface of the distal portion of the needle, the protrusion of the stylet engaging ratchet teeth along the groove so that a linear oscillation of the stylet rotates the distal portion relative to the proximal portion.
In an embodiment, the needle may include a proximal portion and a distal portion connected to one another via a pivot joint controlled via a plurality of control wires to pivot the distal portion relative to the proximal portion.
In an embodiment, the needle may include a plurality of holes extending laterally through a distal portion thereof for permitting fluid to leak therethrough as tissue is being cut.
In an embodiment, the device may further comprise a suction source applying a suction force through the channel of the needle to draw tissue thereinto.
The present disclosure also relates to a device for collecting a tissue sample, comprising an outer sheath extending longitudinally from a proximal end to a distal end and including a lumen extending therethrough and a needle slidably housed within the outer sheath, the needle extending longitudinally from a proximal end to a tapered distal end, the needle longitudinally movable relative to the outer sheath between a retracted configuration and a tissue collecting configuration in which the needle is moved distally relative to the outer sheath.
In an embodiment, a tissue sample may be collected in a space between an interior surface of the lumen of the outer sheath and an exterior surface of the needle.
In an embodiment, a suction force may be applied through the space to draw tissue thereinto.
In an embodiment, the needle may be moved between the retracted and tissue collecting configurations via a drive mechanism including a first cam attached to the proximal end of the needle, an second cam housed within a proximal end of the outer sheath and a spring element biasing the device toward the retracted configuration.
The present disclosure is also directed to a method for collecting a tissue sample, comprising inserting a tissue collecting device to a target tissue within a patient body via a working channel of an endoscope, in an insertion configuration in which a needle is housed within an outer sheath so that a distal end of the needle is proximal a distal end of the outer sheath and moving the needle distally relative to the outer sheath to a tissue collecting configuration in which the distal end of the needle extends distally beyond the distal end of the outer sheath to be inserted into the target tissue, wherein the needle rotates about a longitudinal axis thereof via a drive mechanism as the needle is advanced distally out of the sheath such that a serrated distal edge of the needle cores a tissue sample from the target tissue collecting the tissue sample therewithin.
In an embodiment, the method may further comprise moving the needle from the tissue collecting position to the retracted position to withdraw the device from the patient body.
In an embodiment, the drive mechanism may include a helical structure extending about a distal portion thereof and a corresponding helical structure along an interior surface of a drive collar connected to the distal end of the outer sheath, the helical structure of the needle and the corresponding helical of the outer sheath engaging one another such that, when the needle is moved longitudinally relative to the outer sheath, the needle is rotated relative to the outer sheath.
In an embodiment, the drive mechanism may include a first ratchet mechanism and a second ratchet mechanism coupling a proximal portion and a distal portion of the needle, the first ratchet mechanism including a rod extending distally from the proximal portion to engage ratchet teeth along an interior surface of the distal portion, and the second ratchet mechanism including a set of teeth about each of a distal end of the proximal portion and a proximal end of the distal portion such that teeth of the first and second ratchet mechanisms are alternatingly engaged to rotate the distal portion relative to the proximal portion.
In an embodiment, the drive mechanism may include a ratchet mechanism coupling a proximal portion and a distal portion of the needle, the ratchet mechanism including a groove extending along an interior surface of the distal portion of the needle to receive a protrusion extending laterally from a portion of a stylet received within the channel, the protrusion of the stylet engaging ratchet teeth along the groove so that a linear oscillation of the stylet rotates the distal portion relative to the proximal portion
The present disclosure may be further understood with reference to the following description and the appended drawings, wherein like elements are referred to with the same reference numerals. The present disclosure is related to devices for obtaining tissue samples and, in particular, EUS-FNA devices. Exemplary embodiments of the present disclosure describe devices comprising needles which rotate about a longitudinal axis thereof and which may include a sharp or serrated distal edge permitting a tissue sample to be cored and collected within a channel thereof. It should be noted that the terms “proximal” and “distal” as used herein, are intended to refer to a direction toward (proximal) and away from (distal) a user of the device.
As shown in
The needle 102 extends longitudinally from a proximal end (not shown) to a distal end 110 and includes the channel 106 extending therethrough. In one embodiment, the needle 102 may be comprised of a longitudinally extending proximal portion (not shown) and a longitudinally extending distal portion 142 connected to one another such that the distal portion 142 is rotatable about the longitudinal axis relative to the proximal portion. An exterior surface 112 of the distal portion 142 of the needle 102 includes a helical structure 114 extending about a length thereof for driving the needle 102 rotationally in and out of the sheath 104. In one embodiment, the helical structure 114 is formed as a helical recess in the exterior surface 112 which engages a corresponding structure on an inner surface of the distal end of the sheath 104 so that, as the needle 102 is advanced longitudinally through the sheath 104, a portion of the longitudinal motion is converted to rotary motion. For example, the structure may include a protrusion extending radially inward from an inner surface of the sheath 104 to engage the helical structure 114 (recess) to rotate the needle 102 as it moves along or past the protrusion. The protrusion may extend along a helical path corresponding to the helical recess or may simply engage a short portion of this recess. Similarly, the needle 102 may include only a structure which is longitudinally short and which rides in or which receives an elongated helical structure formed on an inner surface of the sheath 104.
In another embodiment, the helical structure 114 may be a helically shaped protrusion extending radially outward from the exterior surface 112. The helical structure 114 extends about a distal portion 142 of the needle 102 along a length corresponding to a desired insertion length of the needle 102 into the target tissue and may engage a corresponding groove or recess formed on an inner surface of the sheath 104. For example, the helical structure 114 may extend along a length of the distal portion 142 of the needle 102 selected to enable the collection of a core tissue sample up to 2 cm in length. It will be understood by those of skill in the art, however, that a length of the helical structure 114 may be varied to collect a larger or smaller core tissue sample, as desired.
As shown in
The sheath 104 extends longitudinally from a proximal end (not shown) to the distal end 120 and includes a lumen extending therethrough. The lumen is sized and shaped to slidably receive the needle 102 therein. In particular, the needle 102 is rotatable and longitudinally movable within the lumen of the sheath 104. The distal end 120 of the sheath 104 includes a drive collar 122 extending distally therefrom and including a lumen axially aligned with the lumen of the sheath 104 for receiving the needle 102 therethrough.
As shown in
According to an exemplary method using the device 100, the device 100 may be inserted to a target tissue within a patient's body via, for example, a working channel of an endoscope. To prevent damage to the working channel and to non-targeted tissue, the device 100 is inserted through the working channel in the insertion configuration with the distal edge 108 of the needle 102 received within the sheath 104. Once the device 100 has reached the target tissue site, the needle 102 is driven longitudinally distally so that it is driven distally out of the sheath 104 and rotated about the longitudinal axis relative to the sheath 104 in the first direction into the target tissue. In particular, as the needle 102 is moved distally relative to the sheath 104, the distal portion 142 of the needle 102 rotates about the longitudinal axis via the engagement between the helical structure 114 and the corresponding helical structure 124 of the sheath 104. Rotation of the distal portion 142 of the needle 102 as it is driven distally out of the sheath 104 causes the serrated distal edge 108 to core a tissue sample from the target tissue and to receive and trap the tissue sample within the channel 106. The tissue sample is moved proximally into the channel 106 beyond the barbs 116 so that it is held therein. Once the desired tissue sample has been received within the channel 106, the needle 102 may be retracted into the sheath 104 by drawing the needle 102 proximally. As the needle 102 is drawn proximally, the helical structure 114 interfaces with the corresponding helical structure 124 to rotate the needle 102 in the second direction opposite the first direction. The barbs 116 traps and hold the tissue sample within the channel 106 as the needle 102 is retracted proximally into the sheath 102.
As shown in
Although a stylet is not explicitly shown or described, it will be understood by those of skill in the art that the device 100 may further comprise a stylet. The stylet may be received within the channel 106 of the needle 102 during insertion of the device 100 into the body to prevent non-targeted tissue from entering the channel 106. Once the device 100 has reached the target tissue site, the stylet may be removed therefrom to facilitate collection of the tissue sample within the channel 106.
As shown in
The needle 202, however, includes a proximal portion 240 and a distal portion 242 connected to one another via a first ratchet mechanism 244 including a rod 246 rigidly coupled to the proximal portion 240 and which includes an engaging end 248 slidably received in a groove 250 formed on an inner surface of the distal portion 242. Each of the groove 250 and the engaging end 248 include a set of teeth 245 thereabout, which selectively engage one another to control rotation of the distal portion 242 relative to the proximal portion 240. The needle 202 further includes a second ratchet mechanism 252 for controlling the rotation of the distal portion 242 relative to the proximal portion. The second ratchet mechanism 252 includes a set of teeth 254 on each of a distal end 256 of the proximal portion 240 and a proximal end 258 of the distal portion 242.
A length of the groove 250 is longer than a length of the engaging end 248 so that the engaging end 248 is movable therein between a proximal position and distal position. When the rod 246 is advanced distally, as shown in
As shown in
The groove 250′ formed on an inner surface of the distal portion 242′. The groove 250′ includes a series of projecting portions each of which extends along a portion of a helix so that as the stylet 246′ is advanced distally relative to the distal portion 242′, the engaging portion 248 rides in a helical portion of the groove 250′ to rotate the distal portion 242′ relative to the proximal portion 240′ through an angle corresponding to a portion of the circumference of the distal portion 242′ corresponding to a width of a single tooth so that, as the distal portion 242′ is rotated over a single tooth of the ratchet mechanism 244′ along the proximal portion 240′, the subsequent tooth engages the distal portion 242 to prevent its rotating in the opposite direction back to its original position. Then, when the stylet 246′ is withdrawn proximally until the protrusion 248′ reaches a proximal end of the helical portion of the groove 250′, the protrusion 248′ rotates through a circumferential portion of the groove 250′ under its natural bias to reach a second helical portion of the groove 250′ so that as the process is repeated, each distal advancement of the stylet 246′ rotates the distal portion 242′ relative to the proximal portion 240′ by an amount corresponding to the width of one of the teeth.
As shown in
The distal portion 342 includes a distal edge 308 that may be substantially similar to the distal edge 108 of the needle 102. In particular, the distal edge 308 may include serrations which, when the needle 302 is advanced distally into the target tissue via a rotation thereof about the longitudinal axis, core a tissue sample from the target tissue into which it is inserted, collecting the tissue sample in a channel 306 thereof. The distal portion 342 may also include a plurality of holes 348 extending laterally through a wall thereof. The holes 348 may be particularly configured to allow for some fluid to leak therepast during the cutting of the target tissue.
The device 300 may further comprise a suction source for applying a suction force through the channel 306 of the needle 302 to suction tissue into the channel 306, holding the tissue therein during the cutting thereof. Once the tissue sample has been cored from the target tissue, the target tissue is held within the channel 306 during removal of the device 300 from the patient body.
As shown in
The needle 402 extends longitudinally from a proximal end 409 to a distal end 410 and includes a channel 406 extending therethrough for collecting the tissue sample therein. The distal end 410 may include a beveled or tapered tip 408 for piercing the target tissue into which the needle 402 is inserted. The outer sheath 404 extends longitudinally from a proximal end 419 to a distal end 420 and includes a lumen 422 extending therethrough for slidably receiving the needle 402 therein. In a retracted position, the needle 402 is housed within the outer sheath 404 such that the distal end 410 of the needle 402 is proximal of the distal end 420 of the outer sheath 404. In a tissue insertion position, the distal end 410 of the needle 402 extends distally past the distal end 420 of the outer sheath 404 to pierce the target tissue with the tapered tip 408, coring and collecting the target tissue within the channel 406.
The drive mechanism 442 includes a first cam 444 connected to the proximal end 409 of the needle 402 and a second cam 446 housed within the lumen 422 at the proximal end 419 of the outer sheath 404. A proximal end 448 of the second cam 446 is connected to the pin 440, which extends proximally past the proximal end 419 of the outer sheath 404 to be accessible by a user of the device 400. The drive mechanism 442 also includes a spring element 450 housed within the outer sheath 404 distally of the first cam 444, between the first cam 444 and a shoulder 452 extending radially into the lumen 422.
When the pin 440 is pushed distally relative to the outer sheath 404, the second cam 446 moves distally to interface with the first cam 442, pushing the needle 402 distally out of the outer sheath 404 from the retracted position to the tissue penetration position. The distal movement of the first and second cams 444, 446 relative to the outer sheath 404 also causes the spring element 450 distal of the first cam 444 to become compressed so that, upon release of the pin 440 by the user, the spring element 450 is released to revert to its biased configuration, moving the first cam 444 and the needle 402 proximally relative to the outer sheath 404, into the retracted position. Thus, a simple press and release of the pin 440 inserts and retracts the needle 402, allowing a tissue sample to be collected into the channel 406 in a single motion.
As shown in
In an insertion configuration, the tapered tip 508 of the needle 502 extends slightly distally beyond the beveled edge 521 of the outer sheath 504 such that the tapered tip 508 and beveled edge 521 together permit seamless insertion of the device 500 into target tissue. Once the device 500 has been inserted into the target tissue, the needle 502 is moved distally relative to the outer sheath 504, causing portions of the target tissue to be moved into the space 506 between the outer sheath 504 and the needle 502. A suction force may be applied through the space 506 to draw the target tissue into the space 506. The radial pressure of the target tissue on the beveled edge 521 of the outer sheath 504 when the needle 502 is moved distally relative to the outer sheath 504 and the suction force applied through the space 506 move the target tissue into the space 506. Once a desired tissue sample has been collected in the space 506, the outer sheath 506 is moved distally over the needle 502. The beveled edge 521 then cuts the tissue sample from the surrounding tissue such that the device 500 may be removed from the patient body with the tissue sample collected therein.
It will be apparent to those skilled in the art that variations can be made in the structure and methodology of the present disclosure, without departing from the scope of the disclosure. Thus, it is intended that the present disclosure cover the modifications and variations of this disclosure provided that they come within the scope of the appended claims and their equivalents.
The present disclosure claims priority to U.S. Provisional Patent Application Ser. No. 62/052,166 filed Sep. 18, 2014; the disclosure of which is incorporated herewith by reference.
Number | Date | Country | |
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62052166 | Sep 2014 | US |