Abstract:
The invention features a device for obtaining tissue samples from a site deep within the body having a proximal portion constructed to follow a long torturous path to the site and a distal portion constructed with a jaw arrangement that can be opened and closed to sever a sample, including tissue specimens, polyps and the like, from the surface. The device is constructed for severing and storing at least three successive samples. The device includes a sample storing and retaining element in the space encompassed by the jaws. The element is fixed to maintain an orientation extending generally distally along a selected length to a distal end and has a profile along the length for engaging multiple samples arranged axially in the order in which they were severed from the surface with sufficient frictional force to substantially retain the samples from moving distally from the space encompassed by the jaws when the jaws are opened to sever a successive sample from the surface.

Description:
This is a continuation of application Ser. No. 08/129,653, filed Sep. 30, 1993, now abandoned. 
    
    
     FIELD OF THE INVENTION 
     This invention relates to taking samples of tissue from the body for biopsy analysis. 
     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. 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 a first aspect, the invention features a device for obtaining tissue samples from a site deep within the body having a proximal portion constructed to follow a long torturous path to the site and a distal portion constructed with a jaw arrangement that can be opened and closed to sever a sample, including tissue specimens, polyps and the like, from the surface. The device is constructed for severing and storing at least three successive samples. The device includes a sample storing and retaining element in the space encompassed by the jaws. The element is fixed to maintain an orientation extending generally distally along a selected length to a distal end and has a profile along the length for engaging multiple samples that are arranged axially in the order in which they were severed from the surface. The element engages samples with sufficient frictional force to substantially retain the samples from moving distally from the space encompassed by the jaws when the jaws are opened to sever a successive sample from the surface. 
     In another aspect, the invention features a device for obtaining tissue samples having a distal end constructed with a jaw arrangement that can be opened and closed to sever the sample, including tissue specimens, polyps and the like, from a surface. The device is constructed for severing storing at least five successive samples. The device includes an elongated sample storing and retaining element in the form of an elongated spear-form member in the space encompassed by the jaws. The member is fixed to maintain an orientation extending along a selected length to a distal end constructed to pierce the samples and allow proximal sliding of previous samples along its length during piercing of tissue to take a successive sample. The element includes near its distal end a retaining protrusion extending to diameter larger than the diameter of portions proximal of the protrusion. The protrusion provides sufficient frictional force to substantially retain a sample positioned at least in part proximally of the protrusion from moving distally from the space encompassed by the jaws when the jaws are opened to sever a successive sample from the surface. The length of the protrusion is less than about 15% of the length of element. 
     The features of the aspects above can be combined. Embodiments may include one or more of the following. The element has a profile of smaller diameters distal of the retaining protrusion to facilitate piercing of the tissue. The protrusion is integral with the tissue-piercing profile. The protrusion and tissue piercing profile are about 5 to 15% of the length of the member proximal of the protrusion. The length of the element proximal of the retaining protrusion is about 0.065 inch or longer. The length of the element proximal of the retaining protrusion is about 0.300 inch. The maximum diameter of the retaining protrusion is about 25-250% larger than portions of the element proximal of the protrusion. The element has a substantially constant diameter proximal of the retaining protrusion. The element has a diameter of about 0.010 inch or larger. The protrusion and the tissue piercing profile form an arrow head-type profile. The sample-retaining element is constructed for deattachment from the device at a location proximal of samples stored on the member. The sample-retaining element and device include mating structure so a sample retaining element can be detached and attached to the device. The sample-retaining element and device include a plug and socket-type mating arrangement. The length and profile are constructed for retaining at least five successive samples. The element is of substantially constant diameter for most of its length and includes textural surface on at least part of its length to substantially retain the sample. The element extends proximally from the larger diameter of the retaining protrusion to smaller diameters along a continuous gradual angular profile. The transition between portions of different diameter are rounded for smooth distal sliding release of the samples after removal from the body. 
     In another aspect, the invention features a method of taking multiple biopsy samples. The method includes providing a device as described above and delivering the device deep into the body along a torturous path to a desired site. The method also includes opening the jaw arrangement, extending the device distally to imbed the spear-form element into a tissue surface at the desired site, and closing the jaws to sever a sample from the surface. The opening, extending and closing steps are repeated to take additional samples. The device is removed from the body and the samples removed from the device. 
     In particular aspects, the samples may be recovered from the device by detaching the element. At least five samples may be taken before removing the device from the body. 
    
    
     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; 
     FIGS. 2, 2a-2d illustrate the structure of an embodiment of the invention; 
     FIGS. 3, 3a-3b illustrate the use of an embodiment of the invention; 
     FIGS. 4-8 illustrate additional embodiments of the invention. 
    
    
     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. 2-2d, particularly FIG. 2, the sampling portion 16 includes a forceps-type device with a pair of jaw members 30, 30a which are movable with respect to each other (arrow 32) between an open and closed position. The jaw members may include jagged edges 34 around their periphery for cutting a sample of tissue from a body surface. The jaw members are attached to the distal end of the device body 36 at a pivot pin 38. The opening and closing of the jaw members can be controlled from proximal portions of the device using pull wires 40, 42. The jaw members have a length, L 4 , coordinated to accommodate a sample storing and retaining member 44, and open to an angle θ, and a width d 3 . The spear-form sample storing and retaining member 44, formed, e.g., of metal, is positioned within the space encompassed by the jaws and fixed with respect to the body of the device. Sampling retaining member 44 is constructed and oriented for storing multiple samples, at least three, preferably five or more. The jaws may be elongated to accommodate a long member 44 to store a large number of samples. 
     The retaining member 44 includes a proximal portion 46 for attaching the element to the device, an elongated body 48, for storing, e.g., samples 1-4, and a distal portion 50 shaped like an arrow (shown) or barb that is used to pierce the samples and to help retain them on the element as the jaws are opened in preparation to cut another sample from the tissue surface. 
     Referring particularly to FIGS. 2a and 2b, respectively, a top view and a partial cross-sectional side view with the jaws not shown, the proximal portion 46 may include plug members 47, 47a which are mateable with a socket arrangement 49 in body 36 of the device. The plug members 47, 47a extend around and proximal of the pivot pin 38 to feet 53, 53a that lock into cutouts 55, 55a in the body 36. The plug members may be biased outward with respect to the spacing of the socket openings (arrows 57, FIG. 2b) so the members bear on the inside of the openings to prevent rotation or axial motion of the retaining member 44. After a sufficient number of samples have been taken and the device removed from the body, the plug members can be removed from the socket openings by manually overcomming the bias of the legs 47, 47a to remove the feet 53, 53a from the cutouts 55, 55a and then moving the member 44 axially distally. The member 44, holding the samples, can be sent to the lab where the plug members can be removed e.g. by cutting at a location proximal of the samples, (dotted line 43) and slipping the samples off the body 48. Other attachment assemblies, e.g. screw-forms, indents, etc. can also be used to attach the member to the device. For a single-use forceps instrument, the member 44 can simply be removed by cutting at a region proximal of the samples stored on the body 48. 
     The length of the member 44 extending distally of the pivot pin is L 3 . The body portion 48 is of substantially constant diameter, d 1 , over an extended length, L 1 , selected to accommodate a desired number of samples. Referring particularly to FIG. 2c, the body portion is of substantially narrow, uniform, symmetric cross-sectional dimension. 
     The distal portion 50 has a protrusion 51 to diameters larger than the diameter, d 1 , of the body portion proximal of the protrusion. The maximum diameter of the protrusion is d 2 . The proximal edge 54 of the protrusion extends distally with an abrupt profile. The proximal edge 54 may extend substantially perpendicular to the axis of the body 48. Distally and integrally with the protrusion 51, the portion 50 extends along a gradual conical surface to a sharp tip 52 for piercing tissue. Referring particularly to FIG. 2d, the cross-sectional profile of the protrusion and distal portion are narrow and symmetric. The distal portion has a short length, L 2 . The relatively gradual angle of distal conical surface and the abrupt angle in the distal direction of surface 54 allows the member to pierce tissue, then retain tissue samples from slipping off when the jaws are opened while the device is still in the body. 
     In embodiments, the maximum diameter, d 2 , of the protrusion 51 is preferably 25-50% (or more, up to e.g. 250%) larger than the diameter, d 1 , of the body 48. The portion 50 and protrusion 51 are also relatively short compared to the body 48 so that samples may be disposed proximally of the portion 50 and retained against distal motion. The length, L 2 , of the distal portion 50 is about 5-15% of the length, L 1 , of the body 48. The length of the protrusion is less than 15% of the length of the body. 
     Typical embodiments include the following combinations of dimensions. The body 48 of the member has a length, L 1 , about 0.065 to 0.300 inch, and a diameter, d 1 , about 0.010 to 0.035 inch. The distal portion 50 has a length, L 2 , about 0.015 to 0.035 inch and a maximum diameter d 2 , about 0.015 to 0.045 inch. The overall length, L 3 , of the member 44 is about 0.075 to 0.325 inch. The jaw members have a working length of, L 4 , about 0.101 to 0.350 inch. The jaws open to an angle, θ, e.g. about 450 (may vary) with respect to the axis 41 of the device, creating an opening of diameter, d 3 , about 0.225 to 0.350 inch. A particular embodiment for taking five successive samples has body length, L 1 , of about 0.300 inch, a distal portion length, L 2 , of about 0.015 inch, a body diameter, d 1 , of 0.010 inch, a distal portion maximum diameter, d 2 , of about 0.015 inch, and the jaws are elongated to a length, L 4 , of about 0.350 inch. 
     Referring to FIGS. 3-3a, particularly FIG. 3, in use, after the device has been delivered into the body, the jaws 30, 30a are placed in the open position. The protrusion 51 on the distal portion 50 prevents previously-taken samples 1-4 from slipping distally off the retaining member 44. Referring to FIG. 3a, the spear-form retaining member is advanced into a tissue surface 18 at a location where an additional sample is to be taken. As the element 44 is advanced the pressure applied in the distal direction displaces (arrow 54), the previous samples, samples 1-4, distally along the long narrow body 48 of the member 44. The member 44 is advanced distally such that the entire short distal portion, beyond the protrusion 51, is inside tissue. 
     Referring to FIG. 3b, the jaws 30, 30a are closed and the cutting edge 34 cuts or evulses the next sample, sample 5, from the tissue surface 18. The protrusion 51 holds sample 5 and the other samples axially in place. The device can be removed from the body and the samples recovered for laboratory analysis or, if sufficient retaining element length is provided, the process above can be repeated for taking still additional samples. After a sufficient number of samples have been taken, the device is removed from the body and the sample recovered (e.g. by removing the element 44 as discussed above) and sent to a laboratory for analysis. In cases where structure is provided for reattachment, a new element is installed in the jaws for further sampling. 
     OTHER EMBODIMENTS 
     Referring to FIG. 4, in another embodiment, a sample retaining member 60 includes a distal portion 61 with an angular surface 62 extending distally to smaller diameters and a sharp tip 64. Proximal of a retaining region 66, the member includes a continuous gradual angular storage surface 68 that extends to smaller diameters in the proximal direction. In this embodiment, the angle of the surface 68 may be more gradual than the angle of surface 62; the profile and length of the surface 68 discourages samples from slipping beyond the retaining region 66 when the jaws are opened in preparation for taking an additional sample. 
     Referring to FIG. 5, a retaining element 70 includes a short distal portion 71 that includes a surface 72 extending distally to smaller diameter, such as to a sharp point 74, and a rounded surface near a retaining region 76. The rounded surface gradually transitions into a relatively abrupt angular surface 78, that extends to a body 79 of substantially constant diameter. The shape and diameter difference between the body 79, transitioning along surface 78 to the region 76, is sufficient to discourage previously taken samples from slipping distally. Yet, after the device has been removed from the body, the samples can be removed without damage by pulling them distally over the gradually contoured surfaces. 
     Referring to FIG. 6, a retaining element 80 includes a distal portion 81 having a rounded or spherical shape that atraumatically pierces soft tissue. 
     Referring to FIG. 7, an element 90 includes a distal portion 91 having a block-form shape. The body 92 has a gradual slope to smaller diameter in the distal direction causing a ledge 93 that retains samples from sliding proximally. 
     Referring to FIG. 8, in another embodiment, a member 100 has a distal portion 101 with a diameter no greater than a body portion 102. The surface of element includes a texture 103 formed, e.g. by sandblasting, for increasing frictional force between the surface and stored samples. The distal portion 101 includes a sharpened tip 104 and is (optionally) not textured to improve piercing of tissue. Further embodiments do not include a textured surface or a retaining protrusion. The distal portions have a diameter substantially equal to the bodies. The length and diameter of the bodies is selected such that sufficient frictional force exists between the body and the sample to discourage the sample from slipping off distally when the jaws are opened to take an additional sample. Yet, the dimensions of the body are not so large as to detrimentally reduce the sample size. 
     In various embodiments, the cross-sectional shape of the retaining member is preferably round, but may be of other, preferably symmetric, geometrical configurations, e.g. square, etc. Long, narrow retaining members have the advantage that relatively large samples can be taken, e.g., when not used in a multiple biopsy mode. Other embodiments employ features discussed in &#34;Multiple Biopsy Sampling Device&#34; by Bruce H. Diamond, Donald E. Robinson, Alyssa J. Dassa and Charles Warich, filed Sep. 20, 1993, the entire contents of which is hereby incorporated by reference. The general structure of a typical forceps device is discussed in Bales et al. U.S. Pat. No. 5,133,727, which is also hereby incorporated by reference. A biopsy forceps device that could be modified by the addition of retaining members taught herein is available Radial Jaw™ from Boston Scientific Corporation, Watertown, Mass. 
     Still further embodiments are in the following claims.