The present disclosure generally relates to the field of biopsy and, more specifically, to forceps deployable through a needle.
It has been estimated that 2.8 percent of the entire adult population has pancreatic cysts (GASTROENTEROLOGY Vol. 139, No. 3, September 2010). When diagnosing such cysts to determine whether they present a risk of cancer, a doctor must examine whether the cyst is mucinous and, if so, whether it is benign or malignant. Several methods currently exist to diagnose pancreatic cysts, but all have serious shortcomings. For example, sampling of cyst fluid to test for carcinoembryonic antigen (CEA) can identify mucinous lesions with accuracy, but cannot detect malignancy because the fluid lacks cellular material. Endoscopic-ultrasound (EUS) morphology has a lower than 60 percent accuracy for detecting malignancy. Cytology, because of the small quantity of cells taken, has an even lower accuracy in determining malignancy.
While histology offers the best diagnosis, current histological methods are ineffective when sampling soft pancreatic tissue, or other more rigid tissues such as lymph node tissue, or even necrotic tissue. Traditional forceps, deployed via endoscopic or laparoscopic means are either not strong enough to pierce the outer tissue wall or are too large to effectively pierce the tissue wall without causing unwarranted damage to the tissue. On the other hand, needle biopsies, which may safely pierce the outer wall, do not obtain a sufficient tissue sample and are difficult to precisely control. It is thus difficult to obtain samples from the periphery of a lesion, where abnormal cells most often appear. A needle must often be inserted and retracted several times to obtain a sufficient sample for histology. For example, current practice may require five needle passes for pancreatic masses and 3 for lymph nodes.
There is thus a need in the art for a histological method that can easily and efficiently pierce a harder tissue wall and obtain a sufficient tissue sample within. The present application relates to a forceps device. According to one aspect of the disclosure, a forceps device includes a first jaw, a second jaw rotationally connected to the first jaw by a clevis pin of a clevis, a first linking piece rotationally connected to the first jaw, a second linking piece rotationally connected to the second jaw, and a box slider rotationally connected to both the first and second linking pieces. Moving the box slider distally causes the first and second jaws to rotate to an open position. Moving the box slider proximally causes the first and second jaws to rotate to a closed position. The jaws are deployable from within a needle.
According to another aspect of the disclosure, a forceps device includes a first fixed jaw and a second jaw movable relative to the first jaw, wherein the jaws are deployable from within a needle.
According to a further aspect of the disclosure, a forceps device includes jaws with teeth that increase in height from the proximal end of the jaws to the distal end of the jaws.
According to yet another aspect of the disclosure, a histology and cytology device includes a forceps apparatus deployable from within and removable from the bore of a needle and a suction device. Suction may be achieved through the bore of the needle when the forceps apparatus is removed.
The present disclosure describes embodiments of a microforceps apparatus, which includes a forceps at one end. The microforceps apparatus is small enough to be deployed through a needle, which allows for efficient deployment into tissue with a harder outer wall, such as tissue of pancreas or lymph nodes. In some embodiments, both jaws of the forceps move relative to each other. In some embodiments one jaw as fixed and the other is movable. In some embodiments, the microforceps device includes progressively-sized teeth for increased grasping and tearing strength. The proximal-most teeth slope away from each other to create a gap that prevents the proximal teeth from meshing and lessens wear on the teeth. In further embodiments, after a histological sample is taken using the forceps, the forceps may be removed out from the needle and a cytological sample may be taken using suction through the needle.
The microforceps apparatus 100 may be deployable through a lumen, cannula, catheter, endoscope, laparoscope or the like. The needle 106 of the microforceps apparatus 100 allows a user to deploy the apparatus into tissue (e.g., the pancreas or lymph nodes) multiple times using the forceps assembly 102 within to obtain multiple tissue samples before removing the needle 106. The needle 106 may be the type of hollow needle used for fine needle aspiration (FNA) cytology. FNA typically results in a core sample of tissue in an attempt to ensure that a “false positive” is avoided where healthy tissue is only sampled instead of potentially malignant tissue. This is achieved by preventing healthy cells from entering the stylet of the needle once it is deployed. The diameter of the spring sheath 104 and forceps assembly 102 (in a closed state) should not exceed the inner diameter of the needle 106 so that the spring sheath 104 and forceps assembly 102 may deploy from and retract into the needle 106. Typically, FNA needles have a 19 gauge (approximately 0.9 mm) diameter channel. Thus, if the typical FNA needle size is used, the spring sheath 104 and forceps assembly 102 should have a diameter no larger than 0.84 mm. These sizes are exemplary and not meant to limit the scope of the present disclosure as it is contemplated that larger gauge needles (and thus larger diameter needles) and/or smaller gauge needles (with a smaller forceps assembly) may be employed in the present invention.
The arm 114a of jaw 110a includes two spaced walls 115a and 115b, with the space between the walls 115a and 115b being wide enough to accept a single wall 115c of arm 114b of jaw 110b between. Each wall 115a, 115b and 115c of arms 114a and 114b includes a hole, for example holes 116a and 116b. The arm 114a further includes cylindrical pillar 117 spanning between the inner sides of the walls 115a and 115b and connects to 122 on the single link 120. The arm 114b further includes an additional linking hole 118 at its proximal end that connects to 132 on linkage 130.
A first linking piece 120 includes a first linking hole 122. The first linking piece is thin enough to fit between the walls of the arm 114a. When assembled, the first linking piece 120 is rotationally connected by a cylindrical pillar 117 spanning between the inner sides of the walls 115a and 115b inserted through the first linking hole 122. The second linking piece also includes a second linking hole 124 for further connection to linking pin 134 on linkage 130.
A second linking piece 130 includes a first linking pin 132 that fits through the linking hole 118 of the arm 114b to rotationally connect the second linking piece 130 to the arm 114b. The second linking piece 130 also includes a second linking pin 134 for further connection to both linkage hole 124 and linking members 142a and 142b.
A box slider 140 includes pair of linking members 142a and 142b, each having a hole. The box slider also includes one or more guide members, such as guide member 144, on one or more sides of the box slider 140. The box slider 140 is placed within a clevis 150 having one or more guide channels, for example guide channel 152, such that a respective guide member 144 fits within the guide channel 152. The box slider 140 may then slide from the distal end of the guide channel 152 to the proximal end of the guide channel 152 (or vice versa).
A clevis pin 154 fits between the holes 116a and 116b of the jaws 110a and 110b to rotationally secure the jaws 110a and 110b to the clevis 150. The second linking hole 124 of the linking piece 120 is inserted between and aligned with the holes of the linking members 142a and 142b of the box slider 140. The second linking pin 132b of the second linking piece 130 fits through all three holes 116a, 116b, 124, thus rotationally securing the box slider 140 to both linking pieces 120 and 130. In this arrangement, when the box slider 140 slides toward the distal end of the clevis 150, the linking pieces 120 and 130 are pushed apart, in turn causing the jaws 110a and 110b to rotate apart from each other into an open position. Conversely, when the box slider 140 slides toward the proximal end of the clevis 150, the linking pieces 120 and 130 are drawn together, causing the jaws 110a and 110b to rotate toward each other into a closed position.
The clevis 150 is attached the distal end of the spring sheath 104, which fits around a collar 156 at the proximal end of the clevis 150. A drive wire 158 controls forward and backward movement of the box slider 140 within the clevis 150. The drive wire 158 should be small enough to move through the diameter of the spring sheath 104. In one exemplary embodiment the drive wire is a 0.0115″ OD wire. In one embodiment the drive wire is made from nickel titanium (i.e., Nitinol). The drive wire 158 may be attached to the box slider 140 via weld, and the box slider 140 may include a hole for receiving the distal end of the drive wire 158, in which the drive wire 158 is welded or otherwise affixed to the box slider 140.
The linking piece 210 includes a first linking hole 216. The linking piece 210 is thin enough to fit between the walls of the arm 208. When assembled, the linking piece 210 is rotationally connected via cylindrical pillar 232 and through the first linking hole 216. The linking piece 210 also includes a second linking hole 218 for further connection to clevis pin 224.
A drive arm 220 includes a clevis 222 with a clevis pin 224 at its distal end. The drive arm 220 also includes one or more guide members, such as guide members 226a and 226b, on one or more sides of the drive arm 220.
The fixed jaw 204 includes a clevis pin 240 proximal to the cup of the jaw. The clevis pin 240 rotationally secures the movable jaw 202 to the fixed jaw 204 by placing the pin 240 through the holes 212a and 212b of the movable jaw 202. The drive arm 220 is inserted within an enclosure 234 at the proximal end of the fixed jaw 204. The enclosure 234 includes one or more guide channels, for example guide channel 236, such that a respective guide member 226a, 226b fits within the guide channel 236. The drive arm 220 may then slide from the distal end of the guide channel 236 to the proximal end of the guide channel 236 (or vice versa).
The clevis pin 224 of the drive arm 220 is inserted into the second linking hole 218 of the linking piece 210, thereby rotationally securing the drive arm 220 to the linking piece 210. In this arrangement, when the drive arm 220 slides toward the distal end of the enclosure 234, the linking piece 210 and proximal end of the movable jaw 202 are pushed together and out away from the enclosure 234, in turn causing the distal end of the movable jaw 202 to rotate apart from the distal end of the fixed jaw 204. Conversely, when the drive arm 220 slides toward the proximal end of the enclosure 234, the linking piece 210 and proximal end of the movable jaw 202 are pulled apart and into the enclosure 234, causing the movable jaw 202 to rotate toward the fixed jaw 204 and into a closed position.
The fixed-arm forceps assembly of
In order to prevent over-travel when closing the jaws 202 and 204, the movable jaw 202 includes stop projections, such as stop projection 214. Over-travel is prevented when closing the jaws 202 and 204 as follows. As the movable jaw 202 is rotated into a closed position and the stop projection 214 bumps up against the inside of the enclosure 234, which prevents the jaw 202 from rotating further.
To prevent over-travel when opening the jaw 202, the distal ends of the clevis 222 move toward the back of the arm 208 of the movable jaw 202 as the drive arm 220 is pushed forward. Once the drive arm 220 is pushed far enough, it will bottom against the arm 208 and prevent further forward motion of the drive arm 220.
As another measure for preventing over-travel when opening the jaw 202, the proximal end of the fixed jaw 204 includes a collar 238. The proximal end of the drive arm 222 has a larger circumference than its distal end (where the clevis 222 is located). The circumference of the proximal end of the drive arm 220 is larger than the circumference of the collar 238, which prevents the drive arm from moving further into the enclosure 234, thereby the jaw 202 is blocked from opening further and into an over-travel position.
The collar 238 also has a circumference designed to fit within a spring sheath (not shown) as described for earlier embodiments. The spring sheath may be attached to the collar and/or proximal end of the fixed jaw 204 by a weld or appropriate attachment mechanism. Movement of the drive arm 220 back and forth in the enclosure 234 may be effectuated by a drive wire (not shown) as described above for previous embodiments. The drive wire may be attached to the drive arm 220 via weld (or any other suitable connection as is known), and the drive arm 220 may include a hole for receiving the distal end of the drive wire, in which the drive wire is welded or otherwise affixed to the drive arm 220.
The above described embodiments pertain to drive mechanisms and configurations for opening and closing the forceps without regard to the type of jaws on the forceps.
Because the exemplary forceps described above are small enough to fit through an FNA needle, the forceps may lack sufficient strength to grasp, tear and retain a tissue sample. Thus, as described below, it may be beneficial to include teeth on the jaws specifically arranged to maximize the grip of the forceps.
As seen in
For the exemplary top jaw 400 of
In this embodiment, the proximal-most tooth 402 is 0.001 in larger than its opposing counterpart tooth 302 (i.e., there is no tooth similarly sized to tooth 302 on the top jaw). A second-most proximal tooth 404 is the same size as tooth 402. The valley between the teeth 402 and 404 is sized to receive opposing tooth 304. A third tooth 406 is 0.001 in longer, being 0.002 in longer than the shortest tooth 302 of the opposing jaw 300. The valley between the teeth 404 and 406 is sized to receive tooth opposing 306. Then, moving toward the distal end of the jaw 400, each tooth is 0.001 in longer than the last. Thus, tooth 408 is 0.003 in longer than the shortest tooth 302, tooth 410 is 0.004 in longer than tooth 302, tooth 412 is 0.005 in longer, and tooth 414 is 0.006 in longer. The distal most tooth 416 is the same length as tooth 414, also being 0.006 in longer than the shortest tooth 302.
In the above described exemplary embodiment, the teeth increase linearly in height from a proximal point to the distal ends of the jaw. In some embodiments the proximal point may be the most proximal tooth (i.e., all teeth increase in height with respect to the previous tooth). In some embodiments several proximal teeth have the same height and only a few of the distal teeth increase in height with respect to one another. In further embodiments only the distal-most tooth is longer than the more proximal teeth. In even further embodiments the increase in height from tooth-to-tooth may be non-linear, for example parabolic or arbitrary. In each of these embodiments, the opposing jaw may include valleys between each tooth to receive a corresponding tooth from an opposing jaw. It is not necessary the all teeth mesh at substantially the same time when the jaws are closed. In fact, the proximal-most tooth of each jaw may not mesh at all with opposing jaw, so as to prevent grinding and wear as the jaws are opened and closed.
In further embodiments described below, the teeth of the top and bottom jaws may include one or more sub-teeth. The inside of the cups of jaws further include a stacked layer pattern that has an increased surface area that helps hold a tissue sample inside the cups. The layer variations further act as smaller teeth to help grip and maintain a sample in place.
In the embodiment of
Turning to
For the exemplary top jaw 400 of
Turning to
The forceps assemblies of the above embodiments may be made from any suitable material, such as nickel, Valloy-120™ (a nickel-cobalt alloy), or a polymeric material. In one embodiment, the components of the forceps assembly are separately manufactured and assembled. In another embodiment, the entire forceps assembly is “grown” via a method called Physical Vapor Deposition (PVD) making the individual components interlocked with one another. Such a procedure is described in U.S. Pat. No. 7,291,254, which is incorporated herein by reference.
Turning to
In some embodiments, the forceps assembly 102 itself may serve a functional stylet to perform the above described procedure. As such, the forceps assembly 102 may create a capillary pull or vacuum to create a better aspirate for cytology. The forceps assembly 102 has the ability to open slightly and create static pressure against the walls of the lumen of needle 106. Thus, the forceps assembly 102 may create a better pull or vacuum because the lumen may be better occluded with this type of action.
Once the needle 106 penetrates the lesion 500, samples may be gathered from around the peripheral aspect 502, which is typically where abnormal cells reside. In some embodiments, histological sampling via the forceps assembly 102 may be followed by or used intermittently with or used in conjunction with cytology sampling via suction. For example, the forceps assembly 102 may be fully retracted into the needle and out through the proximal end of the lumen, catheter, or cannula, through which the microforceps device is deployed. A suction device (not shown) may then be connected to the proximal end of the needle, lumen, catheter, or cannula, to suck cells inside. The ability to reach peripheral cells and well as the histological/cytological combination may increase cellular yield and lead to more accurate test results.
While the present invention has been illustrated by the description of embodiments thereof, and while the embodiments have been described in considerable detail, it is not the intention of the applicants to restrict or in any way limit the scope of the invention to such details. Additional advantages and modifications will readily appear to those skilled in the art. Accordingly, departures may be made from such details without departing from the spirit or scope of the applicant's general inventive concept.
This application is a continuation of U.S. patent application Ser. No. 14/636,895, filed Mar. 3, 2015, of which is hereby incorporated by reference in its entirety.
Number | Date | Country | |
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Parent | 14636895 | Mar 2015 | US |
Child | 17190996 | US |