The invention pertains to the field of pathologic staging. More particularly, the invention pertains to apparatus and methods for preparing a biological sample for pathologic staging.
The pathologic stage is an essential piece of diagnostic information which is used to determine a cancer patient's prognosis and treatment, including whether or not the patient will receive chemotherapy.
To determine the pathologic stage of colorectal cancer, the surgeon first resects a section of fatty tissue from the patient's abdomen. This fatty tissue is then sent to the surgical pathologist, whose responsibility is to determine the stage of the illness based on the extent of cancer observed within this tissue. Importantly, the pathologist is not interested in the fat itself, but rather in the fibrous tissue and lymph nodes that are contained within the fatty tissue.
Conventionally, the pathologist meticulously dissects the fatty tissue with a scalpel in search of fibrous material and lymph nodes. The pathologist removes any clearly visible nodes or other relevant fibrous tissue for examination under the microscope. Inevitably, however, some very small or microscopic pieces of tissue are left behind, but the presence or absence of any diagnostically relevant information (which may be microscopic) within the resected tissue may change the patient's prognosis and treatment. To account for this, the pathologist conventionally selects five to ten random samples from the tissue for microscopic study.
In recent years, a team of pathologists in Germany has pioneered a technique that makes this process both more efficient and more accurate (see, for example, Gehoff et al., Am. J. Surg. Pathol., Vol. 36, pp. 202-213, 2012; Basten et al., Pathologe, Vol. 31, pp. 218-224, 2010; and Scheel et al., “Comprehensive lymph node morphometry in rectal cancer using acetone compression”, J. Clin. Pathol., e-published Mar. 16, 2015). Referred to as the “acetone compression method” (ACM), this method allows the pathologist to eliminate the time-consuming dissection process while simultaneously avoiding the risk of missing diagnostically relevant tissue.
In brief, the methodology is as follows:
1. When the pathologist receives the resected fatty tissue in the laboratory, he/she first examines it for any large and clearly-visible pieces of diagnostically-relevant tissue.
2. The pathologist then slices the sample into small (2 to 3 mm) sections and puts this material in acetone to soak overnight. Acetone dissolves lipids without affecting the integrity of fibrous tissue.
3. The following day, the tissue is removed from the acetone bath and loaded into a specialized tube that is perforated with small (1 to 2 mm diameter) holes.
4. An arbor press, which is a mechanical device using a rack and pinion gear to exert a linear force, is then used to compress the sample in the tube. Compressing the sample forces the fatty components to be extruded out of the small holes in the tube.
5. After compression is complete, the only portions of the original sample remaining within the tube are the fibrous components of that tissue. The pathologist has therefore eliminated all diagnostically irrelevant information, i.e. fat, from the tissue sample.
ACM represents a more time-efficient approach for processing the tissue than conventional hand dissection. In addition, ACM eliminates the risk that the pathologist may overlook diagnostically relevant information, therefore increasing the accuracy of the pathologic staging process for cancers of this type.
Lymph nodes are usually the first organs invaded by malignant cells when they metastasize from the primary tumor site. The determination of the presence or absence of metastases in local lymph nodes is critical in determining the prognosis and treatment of the patient. ACM is capable of providing double or even quadruple the number of lymph nodes, compared to the conventional technique of tedious dissection. Not only does ACM relieve the pathologist of most of this dissection, it does a better job by allowing the fat to be processed in an economical and practical manner.
The above-mentioned references are hereby incorporated by reference herein.
In one embodiment, a pathologic staging compression device prepares a biological sample for pathologic staging by compressing the sample to remove liquid fat from the sample. In one embodiment, the apparatus preferably includes a compression tube with flange and a clamping plate to stabilize and align the compression tube, a fat containment and drainage system, a gauge to monitor the extrusion force, use of hydraulic pressure to generate the extrusion force for sample compression, and integrated ejection of the compressed sample and plunger.
In another embodiment, the apparatus preferably includes a compression tube, a drainage planum to hold and align the compression tube, a fat containment and drainage system, a gauge to monitor the extrusion force, use of hydraulic pressure to generate the extrusion force for sample compression, and ejection of the compressed sample after the compression tube has been removed from the drainage planum.
Although the acetone compression method (ACM) was initially described for colon carcinomas, it may be useful in other cancer situations as well, where there is a need to examine fat for evidence of lymph nodes or microscopic deposits of tumor, such as a resected omentum in certain cases of gynecological malignancies. In preliminary testing of a pathologic staging compression apparatus of the present invention, the apparatus was found to be useful in preparing samples for pathologic staging of ovarian cancer in addition to colorectal cancer. In addition to simplifying lymph node examination for various surgical cancer specimens, ACM standardizes and dramatically increases the sensitivity of the pathologic staging process.
A pathologic staging compression apparatus preferably allows surgical pathologists to determine the pathologic stage of certain cancers, including, but not limited to, colorectal, breast, sarcoma, soft tissue and ovarian cancers, with greater accuracy and efficiency than is possible with conventional methods and apparatus. The compression apparatus may be used to pathologically stage any cancer where fatty tissue is present. Use of this apparatus as part of ACM preferably provides higher quality samples for pathologic staging. Any resected fatty tissue mass, human or animal, which is sent to a pathologist may utilize acetone treatment and the compression apparatuses described herein.
The pathologic stage, an essential piece of diagnostic information, is used to determine a cancer patient's prognosis and treatment, including whether or not the patient will receive chemotherapy. Better pathologic staging can help a clinician determine the best chemotherapy dosage for each individual patient. A directed, specific and measured dose of chemotherapy can be individually tailored to the patient based on the diagnostic result indicated in pathologic staging.
Replicating the published ACM as it was described in the literature resulted in the method working as described in the published literature. Many key areas for improving the process were noted, however, from an ease-of-use, safety, accuracy, reliability, and standardization standpoint. A pathologic staging compression apparatus was developed as a result of deficiencies in the prior art apparatus.
A pathologic staging compression apparatus preferably includes a tube flange and a clamping plate for stabilization and alignment of the compression tube, a fat containment and drainage system, monitoring of the extrusion force being applied, use of hydraulic force for generation of the extrusion force for sample compression, and integrated ejection of the sample and plunger as improvements to the prior art apparatus. Being able to measure and monitor the extrusion pressure or extrusion force is essential to standardizing sample processing.
A pathologic staging compression apparatus preferably allows surgical pathologists to perform ACM with greater ease, safety, accuracy, reliability, and replicability than the prior art device described in the academic literature.
In a preferred embodiment, a frame of the pathologic staging compression apparatus supports a hydraulic ram held in alignment with the compression tube of a compression assembly on the frame. A pressure gauge/sensor measures the pressure of the hydraulic fluid being used to actuate the hydraulic ram. A measurement of the force exerted onto the tissue sample can be extrapolated from this value. The compression tube is mounted on a clamping plate between two flanges on the compression tube. The compression tube includes an array of small through-holes through the cylindrical wall of the compression tube. The clamping plate aligns the compression tube with the hydraulic ram and prevents movement of the compression tube during a compression cycle. The clamping plate is mounted onto a riser plate by way of a pair of thumb nuts. The riser plate is mounted to the frame.
In a preferred method of preparing a tissue sample for pathologic staging, the tissue sample presoaked in acetone is placed in the compression tube with the bottom plug press-fit into the bottom of the compression tube. Optionally, a shield is mounted around the compression tube as part of a liquid fat containment system. The compression tube is mounted onto the clamping plates and the plunger is placed on top of the compression tube. Slots in the clamping plates allow the clamping plates to slide between an engaged position and a retracted position. In the engaged position, the clamping plates are slid firmly against the exterior diameter of the compression tube and the thumb nuts are tightened. In the retracted position, the compression plates, slidable when the thumb nuts are loosened, are slid laterally away from the compression tube. In the course of a single operation cycle, the operator places the compression tube on top of the riser plate with the clamping plates in the retracted position. The operator then slides the clamping plates towards the compression tube until they are firmly pressed against the exterior diameter of the compression tube before locking the thumb nuts. This action preferably automatically locates the compression tube on-center in relation to the hydraulic ram; no further adjustment beyond sliding the clamping plates inward and tightening the thumb nuts is necessary.
Optionally, a jack is actuated to raise the compression sub-assembly in the frame until the plunger contacts the hydraulic ram. The hydraulic pump is then actuated to drive the hydraulic ram to compress the tissue sample. Optionally, after compression of the sample is complete, a stop block below the compression tube is removed and the hydraulic ram is further driven to push the bottom plug out the bottom of the compression tube.
Optionally, the bottom plug is then removed and the hydraulic ram is further driven to eject the compressed sample from the bottom of the compression tube. When the operator desires to remove the compression tube, the thumb nuts are loosened and the clamping plates are slid into the retracted position, after which the tube can be lifted off the riser plate.
In another preferred embodiment, the riser plate sub assembly of the frame of the pathologic staging compression apparatus is replaced by a drainage planum or platform. The bottom plug is permanently fixed onto the drainage planum in this embodiment. Unlike the riser plate sub-assembly, the drainage planum is preferably removed from the frame of the device during each use cycle.
In a method of preparing a tissue sample for pathologic staging, the user first removes the drainage planum from the frame of the device. The user then places the compression tube onto the drainage planum using the bottom plug affixed to the drainage planum. The tissue sample presoaked in acetone is then placed in the compression tube and preferably subject to an initial hand compression using a hand plunger. Optionally, a shield is placed around the compression tube, its base resting on the surface of the drainage planum as part of a liquid fat containment system. Any fat extruded during the initial hand compression is drawn out of the drainage planum via an integrated drainage hole. Following initial hand compression, the drainage planum is then mounted onto the frame of the device. The drainage planum is preferably located on the frame using locating pins and held in place by fasteners, such as magnets (for example neodymium magnets). Removal of the sample from the device occurs by first removing the compression tube from the drainage planum. The sample is then ejected from the compression tube using a hand plunger.
In some embodiments, instead of tissue samples being placed directly into the compression tube, the tissue samples are placed in a disposable medical grade mesh bag/sleeve. The sleeve is then placed into the compression tube for processing. The use of mesh sleeves simplify cleaning of the compression tube. In other embodiments, a mesh disk/filter acts as the bottom of the compression tube.
The shape and size of the perforations in the compression tube may vary. For example, to accommodate the use of the mesh sleeves or disks, the perforations may be designed to work in conjunction with these mesh devices. In some embodiments, the width/diameter of the perforations may increase and the shape may change from circular perforations to slit-shaped perforations. These slit-shaped perforations may be arranged vertically along the circumference of the compression tube or arranged in some other manner, such as an involute spiral pattern. In embodiments with a mesh disk filter acting as the bottom of the compression tube, the compression tube may lack perforations entirely.
The hydraulic pump of the compression staging apparatus may be mounted directly onto the frame of the device or not mounted directly onto the frame of the device.
Referring to
The compression assembly 8 includes a perforated compression tube 46, a fat containment tube or shield 16, a clamping plate 22, a riser plate 24, fasteners 28 (for example, thumb nuts), a stop block 26, and a drainage tube 20. The shield 16 is preferably made of a clear plastic material. In one preferred embodiment, the shield 16 is made of polycarbonate. Referring to
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In an alternative embodiment, shown in
Details of the bottom plug 82, drainage planum 81 and compression tube 46 of the compression assembly 85 are shown in
Following the initial hand compression (or as the primary compression step if the user decides not to perform an initial hand compression), the drainage planum 81 is then mounted onto the frame 6 of the compression staging apparatus 80. In some preferred embodiments, the drainage planum 81 is reversibly affixed to the frame 6 using locating pins 84 and locating pin holes 89 and held in place by magnets 86 and 87, for example neodymium magnets, as shown in
In the embodiment shown in
In the embodiments shown in
In some embodiments, the hydraulic pump is not mounted directly on the device (for example in the apparatus 10 shown in
In another embodiment, the bottom plug 48, 82 is a mesh disk filter 97, as shown in
In the embodiments described above, tissue samples 9 are preferably placed directly into the compression tube 46 for processing. In alternative embodiments, shown in
In these embodiments, the mesh sleeve 96 in which the sample 9 has been placed is then placed within the compression tube 46 to contain the sample 9 during the compression process, as shown in
While circular perforations 47 are shown in most of the figures, other shapes and patterns may alternatively used in any of the embodiments of the compression staging apparatuses described herein. For example, to accommodate the use of a mesh bag/sleeve or mesh disk filter with the compression tube 46, the shape and size of the perforations in the compression tube 46 may be altered.
Other geometric or free form shapes for the perforations could alternatively be used. The number of perforations, the arrangement of the perforations, the width of the perforations, and/or the diameter of the perforations using any of the shapes described above also may vary.
In some embodiments, the compression tube 106 has no perforations, as shown in
Although specific designs for the frame, the compression assembly, extruded fat handling, and sample ejection is shown in the figures, the frame, compression assembly, fat containment and drainage sub-assembly, or ejection assembly could be a different shape, material, size, configuration, or layout to perform the same function within the spirit of the present invention.
Although a hydraulic pump is shown as supplying the compression force, the compression force may alternatively be provided in any other manner, including, but not limited to, pneumatically, electrostatically, or mechanically. While hydraulic compression mechanisms are discussed herein, alternative compression mechanisms, including, but not limited to, linear actuators, motor driven screw jacks, pneumatic cylinders, solenoid cylinders, or arbor presses could alternatively be used.
Although the compression force is shown as being monitored by a pressure gauge, the compression force may alternatively be monitored by any other force monitoring apparatus appropriate for the type of compression force being used, including, but not limited to, a pressure sensor, a force sensor, or a load cell.
Automation may be introduced in the device, which complements the compression. In some embodiments, an automated control system directs the compression process by actuating and controlling the output of the hydraulic pump while monitoring the position of the force actuator (for example, a hydraulic ram) and monitoring the compression force to perform the compression under predetermined conditions. In some embodiments, the compression is done by the automated control system under predetermined compression force parameters to assure reproducibility between different samples. In a preferred embodiment, the parameters for the automated compression are selected for producing an optimum compressed sample for pathologic staging or other applications.
In some embodiments, the automated control system is integrated by way of a motor powering a force generator, which may include, but is not limited to, an electric hydraulic pump, a pneumatic/hydraulic pump, or a worm-gear driven screw jack. The motor is outfitted with a controller, which may be a pulse-width-modulation (PWM) style controller. After a relationship between the electrical current delivered to the motor and the mechanical force output of the motor is established, the controller is programmed to limit the maximum current delivered to the motor to a level that corresponds to the maximum desired ramming force. The maximum current/force in the system may be preset to a single fixed value or the system may allow the user to select a value from multiple present values or any value from within a spectrum of values bounded by a minimum and maximum value. In some embodiments, the control system includes one or more sensors that allow the system to respond in real time to sample parameters, including, but not limited to, sample density, sample viscosity, and sample volume.
The user interface 160 may be any user interface including, but not limited to, a digital display or a series of buttons. The microcontroller 140 provides information according to user instructions to a force applicator 105. One example of a force applicator 105 is the hydraulic ram 4 discussed above. Other examples of force applicators 105 include, but are not limited to, a pneumatic ram, a screw jack, or any other force-applying mechanism. The force applicator 105 applies force to the sample 9 and this process is monitored in real time by both a position sensor 120, which detects the location of the force applicator 105, and a force sensor 130, which monitors the degree of force being applied 110 at any given moment. The information collected by these sensors 120, 130 feeds back 150 into the microcontroller 140, which uses this information to make adjustments to the operation of the force applicator 105 in accordance with user-generated settings. When the sample 9 has been compressed to the degree indicated by the user, the sensors 120, 130 signal to the microcontroller 140 that the use cycle is complete. The microcontroller 140 is also connected to a storage apparatus 170, which is designed to store and deliver preset user settings as well as record data about each use cycle. This sample data 180 is retrievable for purposes of quality control monitoring. In the case of the medical application of this device, the data is “patient” sample data, 180, but the sample data 180 could be any type of industry-specific sample data 180.
Although a pathologic staging compression apparatus has been used for staging of colorectal cancer and ovarian cancer, further use and adoption of the apparatus is expected to lead to additional diagnostic applications where separating tissues of different densities is advantageous.
While the compression apparatus is described herein for use on tissue samples for staging cancer, the compression device could alternatively used in any applications where fatty tissue needs to be separated. Some examples include gynecological, breast, and other areas of the body with fatty tissues. Other surgical disciplines where fatty tissue can be collected may also find the compression apparatus helpful to decrease time throughout the process of resection (including any type of surgical resection including, but not limited to, abdnominal resections) and pathologic staging. A surgical oncologist may change their process for surgical resection to incorporate the compression devices described herein. Using the compression apparatuses described herein on these types of tissues decreases specimen pathology testing time. In addition, the compression apparatus could be used on other types of samples, including, but not limited to, food samples, botanical samples, and artificial substances.
Accordingly, it is to be understood that the embodiments of the invention herein described are merely illustrative of the application of the principles of the invention. Reference herein to details of the illustrated embodiments is not intended to limit the scope of the claims, which themselves recite those features regarded as essential to the invention.
This application claims one or more inventions which were disclosed in Provisional Application No. 62/160,003, filed May 12, 2015, entitled “PATHOLOGIC STAGING COMPRESSION APPARATUS AND METHODS”. The benefit under 35 USC § 119(e) of the United States provisional application is hereby claimed, and the aforementioned application is hereby incorporated herein by reference.
Filing Document | Filing Date | Country | Kind |
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PCT/US16/31743 | 5/11/2016 | WO | 00 |
Number | Date | Country | |
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62160003 | May 2015 | US |