Abstract:
An instrument for obtaining tissue samples from a site deep within the body. The instrument has an elongated proximal portion that is constructed to follow a long, torturous path to the site and a distal end constructed to remove a tissue sample from the body, including tissue specimens, polyps or the like. The instrument is constructed to take multiple biopsy samples without being withdrawn from the body by including a storage space along the axis of the device suitable for storage of multiple, successively taken samples. The instrument includes a side-facing sampling element constructed such that it can be actuated in a first, rotational motion about the device axis to separate a tissue sample from the body and a second, axial motion for disposing the sample axially to facilitate positioning the sample in the storage space.

Description:
FIELD OF THE INVENTION 
     This invention relates to taking samples of tissue from the body. 
     BACKGROUND OF THE INVENTION 
     Tissue samples can be examined in a laboratory to determine the presence of a pathological disorder (e.g. malignancy). Often, the samples must be obtained from deep within the body using a medical sampling instrument that is introduced beneath the skin. It is usually best to obtain several samples around the location where the disorder is suspected so that the presence and progress of disease, if any, can be accurately determined. The samples must be catalogued according to the location from which each sample is taken and the integrity of the samples must be maintained for the subsequent laboratory analysis. 
     SUMMARY OF THE INVENTION 
     In an aspect, the invention features an instrument for obtaining tissue samples from a site deep within the body. The instrument has an elongated proximal portion that is constructed to follow a long, torturous path to the site and a distal end constructed to remove a tissue sample from the body, including tissue specimens, polyps or the like. The instrument is constructed to take multiple biopsy samples without being withdrawn from the body by including a storage space along the axis of the device suitable for storage of multiple, successively taken samples. The instrument includes a side-facing sampling element constructed such that it can be actuated in a first, rotational motion about the device axis to separate a tissue sample from the body and a second, axial motion for disposing the sample axially to facilitate positioning the sample in the storage space. 
     Embodiments may include one or more of the following features. The sampling element has an integral, axially adjacent sample-engaging surface for engaging a sample during axial motion of the element. The sampling element is a tube-form including a side-facing cutout defining a cutting surface and the sample engaging surface, and the storage space is defined by a portion of the tube-form adjacent the cutout. The storage space is proximal of the cutting element. The instrument includes a retention formation constructed such that the sample can be moved in a first axial direction by the sampling element into contact with the retention formation. The sampling element can be moved in the second axial direction while the sample is retained axially stationary by the retention formation. The retention formation is a high friction surface. The sampling element is constructed to prevent abrasion of the sample against the retention formation as the sample is moved axially in the first axial direction. The instrument includes an outer sleeve wherein the sampling element is moveable relative to the outer sleeve, and the retention formation is provided on the outer sleeve. The retention formation is provided on a small portion of the interior surface of the outer sleeve that is about equal to or less than the circumferential width and axial length of the side-facing cutout of the sampling element. The sampling element includes a scraping surface constructed to move between a tissue sample and a retention formation to facilitate transfer of the sample into the storage space as the sample element in the second axial direction. The retention formation is formed by sandblasting. The sleeve includes a side-facing opening through which tissue may pass to be engaged by the cutting surface of the sampling member. The interior sample contacting surfaces of the storage space include a low friction coating that allows easy axial relative displacement of the surfaces and the sample. The low friction coating is provided by a hydrogel coating. The instrument includes an axially moveable sample-retaining element constructed to engage and maintain samples in the storage space as the sampling element moves axially into a cutting position. 
     Other features and advantages follow. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     We first briefly describe the drawings. 
     FIG. 1 is a perspective view of an embodiment of the invention being delivered into the body through an endoscope; 
     FIG. 2 is a cross-sectional view of an embodiment of the invention; FIG. 2a is a top view of the embodiment; FIG. 2b is a greatly enlarged view of the area in circle 2b in FIG. 2; and FIG. 2c is an end on cross section taken along the lines 2c--2c in FIG. 2; 
     FIGS. 3-3e illustrate a use of the embodiment; 
     FIG. 4 is a cross-sectional view of an additional embodiment of the invention; FIG. 4a is a top view of the additional embodiment; 
     FIG. 5-5f illustrate a use of the additional embodiment; 
     FIG. 6 is a cross-sectional view of an additional embodiment; 
     FIG. 6a is a cross-sectional view of an additional embodiment; 
     FIG. 7 is a cross-sectional view of another embodiment; 
     FIG. 8 is a cross-sectional view of another embodiment. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to FIG. 1, the device 10 for multiple biopsy sampling may be delivered into the body through the channel of an endoscope device 11 (e.g., gastroscope, sigmoidoscope, or colonoscope). The endoscope device typically has a length of about 100-250 cm and a channel diameter of 2.0-3.8 mm, typically about 2.8 mm. A distal sampling portion 16 is extended from the endoscope for cutting and storing a sample of tissue from a body surface 18 of a patient (e.g. from a surface in the gastrointestinal tract or bronchial tract). The device has a diameter of preferably around 1.8-2.4 mm, typically about 2.3 mm or less and is of sufficient flexibility so it passes easily though the channel when the endoscope follows a tortuous body passageway. The endoscope includes other lumens for water, air, suction, and viewing. Devices according to the invention can be adapted to be introduced to sites (e.g., urinary tract, reproductive organs, cardiac tissue, or the like) deep within the body by other means. For example, a device can be configured with a lumen so that it can be advanced over a guidewire, e.g., in vascular applications. The device may be passed through an introducer or guiding catheter in, e.g., cardiac applications. The sampling and storage arrangements may be useful in open surgery applications. 
     Referring to FIGS. 2-2c, the sampling portion 16 includes an outer sleeve 24 concentrically positioned about an inner, generally tubular member 20. The sleeve 24 includes a side-facing opening 29 at its distal portion and a generally tubular body at its proximal portion. The inner tubular member 20 has a side-facing cutting member at its distal portion and a generally tubular proximal portion defining a sample storage space 26. The cutting member includes a side-facing opening 31 defined at its periphery by sharp cutting edges 22 and a distal end 23 that extends partially across the radius of the member 20. The member 20 is actuatable in two motions. It can be rotated about the device axis A to cut a sample from a tissue surface. It can also be moved axially to pull the cut sample into the storage space 26 where previous samples can be stored while subsequent samples are being taken, thus allowing multiple samples to be taken without removing the device from the endoscope. 
     Referring particularly to FIG. 2b, the interior walls of member 20 are provided with a low friction surface, for example, by providing a coating 32. Referring as well to FIG. 2c, the sleeve 24 includes a roughened high friction segment 33 along its inner surface at a location adjacent the opening 29. The high friction segment 33 is provided at only a small axial and circumferential portion of the interior wall of the sleeve 24 so it does not interfere with the motions of the member 20. The remaining portions of the inner wall of the member 24 may include a low friction coating to facilitate sample movement and the motions of member 20. As will be discussed further below, the high friction segment 33 on the sleeve, in cooperation with the low friction coating 32 on the interior of the member 20, permits cut samples to be urged into the sample storage space 26 as the member 20 is advanced distally to prepare it for taking further samples. Moreover, the location of the segment and the construction and rotational actuation of the member 20 prevents the sample from being abraded by the segment 33 as it is drawn axially proximally. The member 20 is also provided with a scraping element 41 that extends radially somewhat so that it lightly contacts the interior surface of the sleeve to help guide the sample into the storage space. 
     The device also includes an axially moveable discharge pusher 25 for removing the samples from the storage space. A flexible coil 27 is attached to the proximal portion of the sleeve 24. The coil may be provided within a slippery, flexible polymer sleeve (not shown) as known in the art. The rotational and axial motions of the member 20 can be controlled from the proximal portions of the device outside the body by a torqueable control wire (not shown) that is attached to the distal portions of the member 20 and extends proximally. 
     Referring to FIGS. 3-3e, particularly to FIG. 3, in use, the device is positioned adjacent a tissue area, such as a polyp feature 19 which is to be sampled. The device may be urged against the tissue surface so that the feature 19 passes through the openings 29, 31 of the sleeve 24 and the member 20. 
     Referring particularly to FIG. 3a, the member 20 is rotated 180° about axis A causing a shearing action of cutting surface 22 upon the tissue surface 18 (arrow 37). The first sample, sample 40, is thus separated from the tissue surface and captured between the cutting portion of the member 20 and the interior walls of the sleeve 24. 
     Referring to FIG. 3b, the member 20 is then moved axially proximally, causing the radially extending end 23 of the member to engage the distal portion of the cut sample 40 and move the sample proximally. During axial motion, the sample is not rubbed against the high friction segment 33 of the sleeve. Instead, with the member 20 oriented as shown, the outer surface of the member 20 is exposed to the high friction segment and the sample 40 engages only the relatively low friction portions of the interior surface of the sleeve. This is an advantage since the sample is not abraded as it moves distally; abrading the sample could damage it and make later biopsy analysis more difficult. The sample is withdrawn proximally until it reaches an axial location that is in alignment with the high friction surface 33. 
     Referring to FIG. 3c, the member 20 is again rotated 180° about its axis. Because of the low friction surfaces on the inner walls of member 20, the member rotates about the sample, which remains substantially axially stationary, although it moves radially somewhat as the member 20 slips around it. By this rotation, the sample 40, extending through the opening 29, is placed in contact with the high friction segment 33 of the sleeve 24. 
     Referring to FIG. 3d, the member 20 is then extended distally to prepare the device for taking another sample. The sample 40 does not travel axially with the member 20 but is instead restrained from axial motion by the segment 33. Moreover, as the member moves axially, the sample slips into storage area 26 of member 20 since it slides easily on the high friction surfaces on the walls of member 20. The scraper 41, which is angled slightly so it engages the segment 33, acts like a spatula to help slip the sample into the storage area as the member 20 moves distally. 
     Referring to FIG. 3e, subsequent samples 42 can be taken without removing the device from the endoscope by repeating the above sequence. Samples are brought into the sample storage space 26 in the order in which they were collected. To remove the samples from the device, the push rod 25 is moved axially distally and each sample is removed through the openings 29 and 31, for example, using forceps. 
     The member 20 and sleeve 24 can be formed of biocompatible materials such as stainless steel, aluminum, or plastics. The length of the member and the sleeve are relatively short, e.g., on the order of about 1 inch, so the device can be passed through tortuous passageways without being hung up because of the stiffness of the end 16. The device is preferably dimensioned to take and store at least five samples before removing it from the body. The high friction segment 33 may be formed, for example, by sandblasting or etching, or it may be formed by depositing a high friction adhesive coating on the inner wall of the sleeve. The low friction surface on the interior walls of the member 20 may be provided by depositing a coating of a polymer such as teflon or, more preferably, a hydrogel. A suitable hydrogel is discussed in Fan U.S. Pat. No. 5,091,205, the contents of which is incorporated herein by reference. For embodiments constructed for use in vascular applications, the hydrogel coating can be made antithrombogenic, as discussed in Sahatjian U.S. Pat. No. 5,135,516, which is also incorporated herein by reference. A low friction coating may also be provided on the outer surfaces of the member 20 and the inner surfaces of the sleeve 24 (except for the segment 33) to reduce frictional resistance to the motions of the member 20. The low friction coating is low compared to the high friction segment 33 of the sleeve 24. In embodiments, the interior walls of the member 20 may have sufficiently low friction without a coating or further treatment. The scraper 41 may also have a high friction inner and/or outer surface. The scraper 41 preferably is a thin extension from the member 20 that has some elasticity that allows it to engage the high friction segment of the sleeve without binding as the member is moved distally. The scraper may be omitted in embodiments where there is sufficiently small clearance, e.g., on the order of 0.001 inch, between the sleeve 24 and the member 20. The proximal portion of the control wire outside the body may include index markings that indicate the axial location of the member 20 relative to the sleeve 24. 
     Other Embodiments 
     Referring to FIGS. 4-4a and 5-5e, in another embodiment, the sampling portion 16 includes an axially moveable sample indexer 50 with a sample engaging head 52. In this embodiment, the high friction segment of the sleeve 24 may be omitted. Samples move proximally when engaged by the head but because the indexer 50 is narrow and may include a low friction coating samples do not move distally when the head is advanced (FIG. 4a). 
     Referring to FIGS. 5-5f, particularly FIG. 5, in use, cutting surface 22 is first brought close to tissue surface 18 where a sample is to be taken. The sample indexer is extended axially such that the head 52 does not substantially obstruct the opening 29. 
     Referring particularly to FIG. 5a, member 20 is rotated about axis A causing a shearing action of cutting surface 22 upon tissue surface 18. The sample is separated from the tissue and first sample 40 is collected. 
     Referring to FIG. 5b, both member 20 and sample indexer 50 are pulled axially proximally. The head 52 and the distal end 23 of the member 20 engage the sample and pull it axially proximally. Referring to FIG. 5c, the member 20 is then again rotated about axis A. 
     Referring to FIG. 5d, the member 20 is then pushed axially distally to prepare to take another sample. While the member 20 is being pushed axially distally, sample indexer 50 remains in its proximal position to retain sample 40 in sample storage space 26. 
     Referring to FIG. 5e, the sample indexer is then advanced axially distally to its original position. Subsequent samples can then be taken. 
     Referring to FIG. 5f, subsequent samples 42 and 44 can be taken without removing the device from the endoscope by repeating the above sequence. The samples are brought into the sample storage space in the order in which they were collected. To remove samples from the device, push rod 25 is moved axially distally and each sample is removed through access hole 28, for example, using forceps. 
     Referring to FIG. 6, in other embodiments, member 20 and sleeve 24 are modified by placing a hole through their distal ends so that sample indexer 50 can thus be advanced to push the head 52 distally through the end 23 of the member 20 and sleeve 24 allowing more room for sample capturing and for sample access during sample removal. Referring to FIG. 6a, in embodiments, sample indexer 50 also carries a sample discharge surface 54 that can be used to remove samples from the storage space by extending the indexer distally. 
     Referring to FIG. 7, in embodiments, member 20 has index points 60 in the storage space. The index points 60 are flexible radial extensions from the inner wall of the member 20 that are angled to be easily bent when samples are urged proximally but inhibit the samples from moving distally. The index points 60 can be bent (elastically in a multi-use device) distally to remove the samples from the storage space when greater force is applied by the discharge pusher 25. 
     Referring to FIG. 8, in still further embodiments, proximal portions of member 20 are removed to reduce the frictional contact with the inner surface of the sleeve 24. The sample space 26 is defined by the remaining arc-form of the member 20 and the proximal portions of the sleeve 24. 
     A system for taking multiple biopsy samples is taught in Chu &#34;Instruments for Collecting Multiple Biopsy Specimens&#34;, U.S. Ser. No. 062,671, filed May 17, 1993, now abandoned, the entire contents of which is hereby incorporated by reference. Another system is taught in U.S. Ser. No. 08/124,272, now abandoned, filed Sep. 20, 1993, which is also incorporated herein by reference. Another system is taught in U.S. Ser. No. 08/129,653, now abandoned, filed Sep. 30, 1993 which is also incorporated herein by reference. Another system is taught in pending U.S. Ser. No. 08/146,447, filed Oct. 29, 1993, which is hereby incorporated by reference. Another system is taught in an application entitled &#34;Moveable Sample Tube Multiple Biopsy Sampling Device&#34;, by Banik et al , filed the same day as this application, which is hereby incorporated by reference. Another system is taught in an application entitled &#34;Multi-Motion Cutter Multiple Biopsy Sampling Device&#34;, by Banik and Robinson, filed on the same day as this application, which is also incorporated herein by reference. 
     Still other embodiments are within the following claims. For example, a barbed spear-form can also be used to hold samples in the storage area. 
     Other embodiments follow.