Abstract:
An apparatus and method for the biopsy of tissue specimens and, more particularly, a single insertion multiple sample percutaneous biopsy apparatus and method are provided. A tip at a distal end of a vacuum support tube is introduced into a tissue mass. The vacuum support tube is retracted exposing a basket tube bounded by a front washer and a rear washer mounted thereabout forming a tissue basket. The basket tube is supported internally by a thrust tube which provides structure to the apparatus to allow it to penetrate tissue. The thrust tube and the basket tube are in fluid connection and are provided with suction to draw tissue inward. The tissue is then severed by rotating and advancing a knife edge at the distal end of the vacuum support tube. The tissue basket is withdrawn and the tissue sample is removed by rotating the vacuum support tube. The tissue sample is sliced longitudinally, and a stripper scrapes the tissue sample from an opening in the vacuum support tube.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     The present application is a continuation of U.S. application Ser. No. 09/495,665 filed Feb. 1, 2000, now abandoned; which is a continuation of U.S. application Ser. No. 09/157,120 filed Sep. 18, 1998, U.S. Pat. No. 6,050,955; which claims priority to provisional application Serial No. 60/059,547 filed Sep. 19, 1997. 
    
    
     BACKGROUND 
     1. Technical Field 
     This disclosure relates to an apparatus and method for the biopsy of tissue specimens and, more particularly, to a single insertion, multiple sample percutaneous biopsy apparatus and method. 
     2. Background of Related Art 
     It is often necessary to sample tissue in order to diagnose and treat patients suspected of having cancerous tumors, pre-malignant conditions and other diseases or disorders. Typically, in the case of suspected cancerous tissue, when the physician establishes by means of procedures such as palpation, x-ray or ultrasound imaging that suspicious conditions exist, a biopsy is performed to determine whether the cells are cancerous. Biopsy may be done by an open or percutaneous technique. Open biopsy removes the entire mass (excisional biopsy) or a part of the mass (incisional biopsy). Percutaneous biopsy on the other hand is usually done with a needle-like instrument and may be either a fine needle aspiration (FNA) or a core biopsy. In FNA biopsy, individual cells or clusters of cells are obtained for cytologic examination and may be prepared such as in a Papanicolaou smear. In core biopsy, as the term suggests, a core or fragment tissue is obtained for histologic examination which may be done via frozen section or paraffin section. In more recent developments percutaneous techniques have been used to remove the entire mass during the initial procedure. 
     The type of biopsy utilized depends in large part on the circumstances present with respect to the patient and no single procedure is ideal for all cases. Core biopsy, however, is extremely useful in a number of conditions and is being used more frequently. 
     Intact tissue from the organ or lesion is preferred by medical personnel in order to arrive at a definitive diagnosis regarding the patient&#39;s condition. In most cases only part of the organ or lesion need be sampled. The portions of tissue extracted must be indicative of the organ or lesion as a whole. In the past, to obtain adequate tissue from organs or lesions within the body, surgery was performed so as to reliably locate, identify and remove the tissue. With present technology, medical imaging equipment such as stereotactic x-ray, fluoroscopy, computer tomography, ultrasound, nuclear medicine and magnetic resonance imaging, may be used. These technologies make it possible to identify small abnormalities even deep within the body. However, definitive tissue characterization still requires obtaining adequate tissue samples to characterize the histology of the organ or lesion. 
     Mammography can identify non-palpable (not perceptible by touch) breast abnormalities earlier than they can be diagnosed by physical examination. Most non-palpable breast abnormalities are benign but some are malignant. When breast cancer is diagnosed before it becomes palpable, breast cancer mortality can be reduced. It is still difficult to determine if pre-palpable breast abnormalities are malignant, as some benign lesions have mammographic features which mimic malignant lesions and some malignant lesions have mammographic features which mimic benign lesions. Thus, mammography has its limitations. To reach a definitive diagnosis, tissue from within the breast must be removed and examined under a microscope. 
     The introduction of stereotactic guided percutaneous breast biopsies offered alternatives to open surgical breast biopsy. With time, these guidance systems have become more accurate and easier to use. Biopsy guns were introduced for use in conjunction with these guidance systems. Accurate placement of the biopsy guns was important to obtain useful biopsy information because only one small core could be obtained per insertion at any one location. To sample the lesion thoroughly, many separate insertions of the instrument had to be made. 
     Biopsy procedures may benefit from larger tissue samples being taken, for example, tissue samples as large as 10 mm across. Many of the prior art devices required multiple punctures into the breast or organ in order to obtain the necessary samples. This practice is both tedious and time consuming. 
     One further solution to obtain a larger tissue sample is to utilize a device capable of taking multiple tissue samples with a single insertion of an instrument. An example of such a device is found in U.S. Pat. No. 5,195,533 to Chin et al. which describes a technique for extracting multiple samples with a single insertion of the biopsy device. Generally, such biopsy instruments extract a sample of tissue from a tissue mass by either drawing a tissue sample into a hollow needle via an external vacuum source or by severing and containing a tissue sample within a notch formed on a stylet. Typical of such devices utilizing an external vacuum source are U.S. Pat. No. 5,246,011 issued to Cailouette and U.S. Pat. No. 5,183,052 issued to Terwiliger. Such devices generally contemplate advancing a hollow needle into a tissue mass and applying a vacuum force to draw a sample into the needle and hold the same therein while the tissue is extracted. 
     When extracting multiple samples with a single insertion of the biopsy device using suction to either draw in tissue or remove the tissue from the body, it is important that the vacuum path remain unclogged. If the vacuum path clogs, the sample removal will become difficult or impossible. This may necessitate multiple insertions of the device or reduce the sample mass per extraction. 
     Therefore, a continuing need exists for percutaneous biopsy apparatus and methods which can reliably extract adequate biopsy sample(s) with a single insertion of the biopsy instrument. 
     SUMMARY 
     The present disclosure describes an apparatus and method for the biopsy of tissue specimens and, more particularly, to a single insertion multiple sample percutaneous biopsy apparatus and method. A tip at a distal end of a vacuum support tube is introduced into a tissue mass. The vacuum support tube is retracted exposing a basket tube bounded by a front washer and a rear washer mounted thereabout forming a tissue basket. The basket tube is supported internally by a thrust tube which provides structure to the apparatus to allow it to penetrate tissue. The thrust tube and the basket tube are in fluid communication and are provided with suction to draw tissue inward. The tissue is then severed by rotating and advancing a knife edge at the distal end of the vacuum support tube. The tissue basket is withdrawn and the tissue sample is removed by rotating the vacuum support tube. The tissue sample is sliced longitudinally, and a stripper scrapes the tissue sample from an opening in the vacuum support tube. 
     The surgical biopsy apparatus disclosed includes a base portion having a proximal and a distal end. Desirably, the base portion further comprises a nose support, a center support and a back support. 
     The apparatus further includes a first elongated tubular member having a proximal and a distal end and is removably supported in the base portion and further defines a fluid passageway. The proximal end of the first elongated member is supported at the proximal end of the base portion. The first elongated tubular member includes a tip portion disposed at its distal end and adapted to penetrate tissue and a plurality of openings formed adjacent its distal end and in fluid communication with the fluid passageway. Preferably, the distal end of the first elongated tubular member is supported at the back support of the base portion. Most preferably, the tip has a tapered closed distal end and a stepped proximal end configured to cooperatively engage the distal end of the first elongated tubular member. 
     A suction junction is fixedly supported at the proximal end of the base portion and removably mounted to the proximal end of the first elongated tubular member and in fluid communication therewith. 
     The apparatus also includes a second elongated tubular member having a proximal and a distal end and is reciprocatingly disposed coaxially about the first elongated tubular member and is movable from a retracted position to an extended position. The distal end of the second elongated tubular member is disposed laterally adjacent to the plurality of openings of the first elongated member and supported at the proximal end of the base portion. The second elongated tubular member defines a tissue receiving portion disposed adjacent to its distal end and further defines a plurality of openings in fluid communication with the plurality of openings of the first elongated member. Preferably, the second elongated tubular member is supported at the back support of the base portion. 
     A third elongated tubular member is included having a proximal and an open distal end and is slidably mounted to the base portion and rotatably and reciprocatingly disposed coaxially about the first and second elongated tubular members. The third elongated tubular member includes a cutting edge formed at the open distal end and a lateral tissue discharge port. The third elongated tubular member is movable from an extended position wherein the cutting edge is disposed adjacent the tip portion of the first elongated tubular member and a retracted position wherein the lateral tissue discharge port is disposed laterally adjacent the tissue receiving portion of the second elongated tubular member. A vacuum port assembly is fixedly mounted to the proximal end of the second elongated tubular member and in fluid communication therewith. Preferably, a control member is mounted to its proximal end. Most preferably, the control member has a circular configuration and defines a knurled outer peripheral surface. 
     In a preferred embodiment, the apparatus includes a latch plate assembly attached to the base portion between the center and back supports. The latch plate assembly includes a first latch having a cantilevered portion and a camming surface resiliently biased against the control member. The cantilevered portion releasably locks the third elongated tubular member at its distalmost position. 
     In another preferred embodiment, the latch plate assembly further comprises a second latch having a cantilevered portion and a camming surface resiliently biased against the vacuum port assembly. The cantilevered portion releasably locks the vacuum port assembly at its distalmost position. 
     In yet another preferred embodiment, the second elongated tubular member defines a fluid passageway in fluid communication with the vacuum port assembly. Preferably, the second elongated tubular member further includes a front washer and a rear washer that define the tissue receiving portion therebetween. The rear washer further defines a plurality of transverse openings spaced radially thereabout in fluid communication with the fluid passageway of the second elongated tubular member. 
     In one particular embodiment, a cutting element is longitudinally attached to an exterior surface of the first elongated tubular member and positioned to sever a tissue sample. Preferably, the second elongated tubular member defines a slot for receiving the cutting element. 
     In another embodiment, the apparatus comprises a tissue stripping member mounted to the base portion and disposed between the nose support and the center support. The tissue stripping member includes a flexible extended portion configured and dimensioned to enter the tissue discharge port of the third elongated tubular member upon alignment of the tissue discharge port with the tissue receiving portion of the second elongated tubular member. Preferably, the tissue stripping member includes a friction reducing coating formed thereon to reduce friction with body tissue coming in contact with the tissue stripping member. 
     A method of performing a surgical biopsy is disclosed comprising the steps of: inserting a biopsy apparatus into the tissue of a patient, the biopsy apparatus including: a first elongated tubular member defining a fluid passageway and having a tip portion at the distal end for penetrating tissue and further defining a plurality of openings formed adjacent the distal end and in fluid communication therewith, a second elongated tubular member defining a tissue receiving portion and a plurality of openings in fluid communication with the plurality of openings of the first elongated tubular member, and a third elongated tubular member having a cutting edge formed at an open distal end and defining a lateral tissue discharge port, extending the second elongated tubular member to align the plurality of openings of the first elongated tubular member and the plurality of openings of the second elongated tubular member, retracting the third elongated tubular member to expose the tissue receiving portion of the second elongated tubular member, applying suction to the fluid passageway of the first elongated tubular member in fluid communication with the plurality of openings of the first elongated tubular member and thereby in fluid communication with the plurality of openings of the second elongated tubular member to pull tissue into the tissue receiving portion, severing tissue disposed within the tissue receiving portion by extending the third elongated tubular member to adjacent the closed distal tapered end portion of the first elongated tubular member such that a cutting surface formed on the open distal end of the third elongated tubular member rotates as it passes over the tissue receiving portion, and removing the severed tissue sample from the tissue sampling site by applying suction to a fluid passageway defined in the second elongated tubular member in fluid communication with a plurality of openings defined within a rear washer of the second elongated tubular member, retracting the second elongated tubular member and thereby pulling the severed tissue sample until the tissue receiving portion is aligned with the lateral discharge port of the third elongated tubular member wherein a tissue stripping plate urges the tissue sample out of the tissue receiving portion. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Various embodiments are described herein with reference to the drawings, wherein: 
     FIG. 1 is a perspective view of a biopsy apparatus; 
     FIG. 2 is an exploded perspective view of the biopsy apparatus of FIG. 1; 
     FIG. 3 is a perspective view of an area of detail indicated in FIG. 2; 
     FIG. 4 is a perspective view of an area of detail as indicated in FIG. 2; 
     FIG. 5 is an exploded perspective view of a cutting tube; 
     FIG. 6 is an exploded perspective view of a thrust tube and a razor blade; 
     FIG. 7 is an enlarged view of the razor blade of FIG. 6; 
     FIG. 8 is an exploded perspective view of a basket tube and a vacuum port; 
     FIG. 9 is a rotated exploded perspective view of the basket tube and the vacuum port of FIG. 8; 
     FIG. 10 is an exploded perspective view of a base with supports and a latch plate; 
     FIG. 11 is a cross sectional view of the biopsy apparatus of FIG. 1; 
     FIG. 12 is a cross-sectional view of an area of detail indicated in FIG. 11; 
     FIG. 13 is a cross-sectional view of an area of detail indicated in FIG. 11; 
     FIG. 14 is an enlarged perspective view of a tip portion of the biopsy apparatus of FIG. 1 with the cutting tube broken away; 
     FIG. 15 is an enlarged perspective view of a tip portion of the biopsy apparatus of FIG. 1 with the cutting tube and the basket tube broken away; 
     FIG. 16 is a side view of the biopsy apparatus of FIG. 1 prior to insertion into a breast; 
     FIG. 17 is a side view of the biopsy apparatus of FIG. 1 after insertion into the breast; 
     FIG. 18 is a cross sectional view of the biopsy apparatus of FIG. 1 showing the cutting tube retracted to accept a tissue sample; 
     FIG. 19 is a cross-sectional view of an area of detail indicated in FIG. 18; 
     FIG. 20 is a cross-sectional view of the area of detail indicated in FIG. 18 showing the cutting tube advanced and rotated; 
     FIG. 21 is a perspective view showing a tissue sample severed and disposed in a basket portion; 
     FIG. 22 is a perspective view showing a tissue sample being sliced longitudinally; 
     FIG. 23 is a cross-sectional view of the biopsy apparatus of FIG. 1 showing the tissue sample ready to be removed from the cutting tube; 
     FIG. 24 is a cross-sectional view of an area of detail indicated in FIG. 23; 
     FIG. 25 is a cross-sectional view taken along section line  25 — 25  of FIG. 24; 
     FIG. 26 is a cross-sectional view showing forceps removing the tissue sample; 
     FIG. 27 is a cross-sectional view showing a stripping plate removing the tissue sample; 
     FIG. 28 is a perspective view of a biopsy apparatus having a stripping plate attached thereto; 
     FIG. 29 is a perspective view of a basket converter; 
     FIG. 30 is an enlarged perspective view of a tip portion showing a basket converter mounted therein; and 
     FIG. 31 is a cross-sectional view taken along section lines  31 — 31  of FIG.  30 . 
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     Referring now in specific detail to the drawings, in which like reference numerals identify similar or identical elements throughout the several views, and initially to FIG. 1, a biopsy apparatus constructed in accordance with the present disclosure is shown generally as biopsy apparatus  10 . Biopsy apparatus  10  includes an insertion portion  12  and a base portion  14 . 
     Referring to FIGS. 2,  3  and  4 , a tip  13  is rigidly mounted to distal end  15  of a thrust tube  16 . Thrust tube  16  is disposed in a basket tube  18  which slides longitudinally along thrust tube  16 . Basket tube  18  has a front washer  20  and a rear washer  22  mounted thereon. Front washer  20  and rear washer  22  are spaced a predetermined distance apart bounding a basket portion  19  of basket tube  18 . Basket portion  19  has a smaller diameter than basket tube  18 . Basket portion  19 , front washer  20  and rear washer  22  are dimensioned to fit within a cutting tube  24  and form a tissue basket  27  for receiving tissue therein. Basket portion  19  has a plurality of holes  114  provided therethrough in order to be able to communicate with suction provided through thrust tube  16  during operation. A vacuum port  28  attaches to a proximal end of basket tube  18  for providing an attachment to a vacuum source (not shown). A razor blade  106  is longitudinally attached to an exterior surface  108  of thrust tube  16  and extends therefrom in a radially outward direction. A suction knob  66  is shown for attaching to a proximal end of thrust tube  16 . 
     Turning now to FIG. 5, a knob  44  is rigidly mounted to a proximal end  46  of cutting tube  24 . Knob  44  is used to rotate cutting tube  24 . The surface of knob  44  can be knurled to improve grip when rotating cutting tube  24 . A distal end  48  of cutting tube  24  is stone ground to form a sharpened edge  50  thereabout. Distal end  48  receives a stepped portion  52  of tip  13  of thrust tube  16  (FIG.  6 ). Distal end  48  and stepped portion  52  (FIG. 6) are dimensioned to provide a shearing action therebetween. Cutting tube  24  has an opening  102  located thereon for retrieving tissue samples from therein. 
     Referring to FIG. 6 and 7, thrust tube  16  has a plurality of holes  112  near distal end  15 . Distal end  15  of thrust tube  16  is rigidly attached to tip  13 . Razor blade  106  attaches to thrust tube  16  by brazing, welding or other compatible process. A leading edge  109  of razor blade  106  can be placed proximally to plurality of holes  112  in thrust tube  16  to place razor blade  106  in a position to cut a tissue sample when basket portion  19  is retracted. A tab  107  is formed on a distal end portion  113  of razor blade  106 . 
     Referring to FIGS. 8 and 9, vacuum port  28  defines a suction port  32 , a basket tube port  34  and a through hole  36  for thrust tube  16 . Suction port  32 , basket tube port  34  and through hole  36  fluidly communicate within vacuum port  28 . Basket tube  18  has a proximal end  26  which is rigidly mounted within basket tube port  34 . Basket tube  18  fluidly communicates with vacuum port  28  through a hole  29  formed on basket tube  18 . Vacuum port  28  is connected to a vacuum source (not shown) by a fitting  31  which connects to suction port  32 . An O-ring cap  40  of vacuum port  28  is removable to aid in assembly of basket tube  18 . An O-ring  38  is supported by O-ring cap  40  which has a bore  41  therein to prevent air leakage between O-ring cap  40  and vacuum port  28 . O-ring  38  is preloaded and secured by O-ring cap  40  which is attached to vacuum port  28  thereby compressing O-ring  38  therebetween. 
     FIG. 10 illustrates base portion  14  of FIG.  1 . Cutting tube  24  (FIG. 2) is supported by a nose support  54  and a center support  56  through bores  55 . Nose support  54  and center support  56  allow axial translation and rotation of cutting tube  24 . Nose support  54  is attached at a distal end  58  of a base  60  and center support  56  is spaced apart. and mounted to base  60  at a predetermined distance from nose support  54 . Base  60  has a back support  62  attached at a proximal end  64 . Back support  62  has a bore  63  therethrough which receives suction knob  66  (FIG. 2) therein. Suction knob  66  is rigidly mounted on a proximal end  68  of thrust tube  16  (FIG.  2 ). A latch plate  72  is attached to base  60  between back support  62  and center support  56 . 
     Referring to FIGS. 11 and 12, latch plate  72  has a distal end portion  74  having a first latch  76  cantilevered therefrom. First latch  76  has a camming surface  78  thereon which has a high point  80  distally disposed. Latch plate  72  has a proximal end portion  88  with a second latch  90  cantilevered therefrom. Second latch  90  has a camming surface  92  thereon which has a high point  94  distally disposed. Vacuum port  28  and knob  44  are shown in their distalmost positions. Suction knob  66  is disposed in bore  63  of back support. 
     Referring to FIG. 12, knob  44  (as seen in FIG. 11) in its distal most position corresponds to tissue basket portion  19  being fully enclosed within cutting tube  24 . Edge  50  of cutting tube  24  receives stepped portion  52  of tip  13 . Rear washer  22  is disposed within the distal end of basket tube  18 . Basket tube  18 , front washer  20  and rear washer  22  are dimensioned and configured to fit within cutting tube  24 . An annular region  21  is formed between cutting tube  24  and basket portion  19 . Thrust tube  16  is disposed within basket tube  18  such that plurality of holes  114  in basket tube  18  are substantially aligned with plurality of holes  112  in thrust tube  16  and holes  114  and holes  112  fluidly communicate with annular region  21 . 
     Referring to FIG. 13, opening  102  cutting tube  24  is closed by basket tube  18  when vacuum port  28  (FIG. 11) is fully advanced distally. Razor blade  106  is shown in phantom disposed on thrust tube  16 . 
     Referring to FIGS. 14 and 15, razor blade  106  is dimensioned to fit inside cutting tube  24 . Basket tube  18  has a slit  111  which allows tab  107  of razor blade  106  to fit therethrough. A longitudinal slot  110  continues through front washer  20  (in phantom), basket portion  19  and rear washer  22 . Razor blade  106  prevents relative rotation between thrust tube  16  and basket tube  18 . Rear washer  22  has a plurality of holes  116  therethrough for fluidly communicating between basket portion  19  and basket tube  18  when disposed within cutting tube  24 . 
     Referring to FIGS. 16 and 17, during a biopsy procedure a patient&#39;s breast  140  is disposed between a movable clamp  142  and a stationary clamp  144 . Movable clamp  142  is moved toward stationary clamp  144  capturing breast  140  therebetween. Upon securing breast  140  in position a guidance system (not shown) locates a target tissue mass  146  within breast  140 . Assembly  10  is aimed at target tissue mass  146  such that insertion portion  12  is aligned with the direction of advancement of base portion  14 . Stationary clamp  144  defines an opening  148  therethrough to allow insertion portion  12  to enter breast  140 . Before insertion into breast  140 , vacuum port  28  and cutting tube  24  are fully advanced distally to locate tissue basket  19  adjacent to tip  13  and to enclose basket portion  19 , respectively, as shown in FIGS. 11 and 12. Knob  44  is secured by first latch  76  in the distalmost position of knob  44 . A nick at the point of insertion of tip  13  is desirable for easy entry into breast  140 . Tip  13  is inserted at the location of the nick into breast  140 . Guidance systems are employed for determining the location of tip  13  inside the patient&#39;s body, and typically include x-rays and stereotactic devices. Insertion portion  12  is advanced distally into breast  140  until basket portion  19  is located adjacent to or within target tissue mass  146  as desired. 
     Referring to FIGS. 18 and 19, front washer  20  of basket portion  19  is held in contact with tip  13  inside cutting tube  24 . Vacuum port  28  is in its distalmost position and secured in place by second latch  90 . First latch  76  is deflected in the direction of arrow “A” by pressing down on first latch  76 , thereby releasing knob  44  and allowing knob to move proximally. Cutting tube  24  is retracted by moving knob  44  proximally, thereby exposing tissue basket  19  to target tissue mass  146 . 
     Suction is applied through thrust tube  16  which is communicated through plurality of holes  112  at distal end  15 . Plurality of holes  112  at distal end  15  of thrust tube  16  communicate with plurality of holes  114  in basket portion  19 . Suction draws target tissue mass  146  into tissue basket  19  circumferentially about tissue basket  19 . Target tissue mass  146  is now prepared for severing. 
     When a predetermined period of time has elapsed suction is applied to vacuum port  28  as well. Vacuum port  28  communicates with basket tube  18  which communicates with plurality of holes  116  through rear washer  22 . This draws target tissue mass  146  against rear washer  22  and secures the tissue mass thereto. 
     Referring to FIGS. 20 and 21, knob  44  is used to translate and rotate cutting tube  24  simultaneously. Knob  44  is translated distally to allow edge  50  of cutting tube  24  to sever a tissue sample  150  from target tissue mass  146 . Knob  44  is rotated and advanced distally in a simultaneous motion to sever target tissue mass  146  about tissue basket  19 . Target tissue mass  146  is cut with edge  50  of cutting tube  24  to form an annular tissue sample  150 . Knob  44  moves up camming surface  78  of first latch  76  as knob  44  is advanced and finally knob  44  is locked in its distalmost position by first latch  76 . The distalmost position of knob  44  corresponds with edge  50  engaging stepped portion  52  of tip  13  completing the severing of tissue sample  150  and closing off tissue basket  19 . As cutting tube  24  severs tissue sample  150 , suction through basket tube  18  and rear washer  22  provides an opposing force against the distal motion of cutting tube  24  to allow tissue sample  150  to be severed. First latch  76  secures knob  44  and cutting tube  24  in the distalmost position. When edge  50  of cutting tube  24  has reached tip  13 , tissue sample  150  is severed and may be removed from breast  140 . 
     Referring to FIGS. 22 and 23, after tissue sample  150  is severed, suction may be removed from thrust tube  16 . Second latch  90  is deflected in the direction of arrow “B” by pressing down on second latch  90 , thereby releasing vacuum port  28  and allowing vacuum port  28  to be moved proximally. With suction maintained on basket tube  18  through vacuum port  28 , vacuum port  28  is moved proximally thereby retracting basket tube  18  and tissue basket  19 . As basket tube  18  and tissue basket  19  are retracted, razor blade  106 , disposed within slot  110 , slices tissue sample  150  longitudinally. Suction through plurality of holes  116  in rear washer  22  provides an opposing force to allow tissue sample  150  to be sliced. 
     Referring to FIGS. 24,  25  and  26 , tissue sample  150  may be accessed for removal through opening  102 . Razor blade  106  has provided tissue sample  150  with a longitudinal slit to allow tissue sample  150  to be peeled from basket portion  19 . 
     During tissue sample  150  removal, tip  13  and cutting tube  24  remain adjacent to tissue mass  146 . Upon removal of a first tissue sample  150 , tissue basket  19  may be reintroduced adjacent to tip  13  within the patient&#39;s body. Cutting tube  24  is retracted to accept more tissue mass  146  and the process as described hereinabove is repeated until enough tissue samples are collected or the targeted tissue mass  120  is removed, as necessary. A single insertion of biopsy apparatus  10  can therefore remove multiple tissue samples. 
     Referring to FIG. 27, a stripper plate  200  is mounted to base  60  between nose support  54  and center support  56 . Opening  102  of cutting tube  24  is disposed between nose support  54  and center support  56  when knob  44  is in its distalmost position. Opening  102  corresponds to a stripping surface  204  on stripper plate  200  which also aligns with basket portion  19  such that tissue samples may be removed when basket portion  19  is rotated by turning thrust tube  16 . Basket portion  19  is aligned with opening  102  and stripper plate  200  when vacuum port  28  and therefore basket tube  18  are in a proximalmost position. 
     Suction is removed from thrust tube  16  and vacuum port  28 . Stripping plate  200  acts as a spring and enters opening  102  when tissue basket  19 , with its reduced diameter, is adjacent thereto. 
     Referring to FIGS. 29,  30  and  31 , a basket converter  130  may be introduced into basket portion  19 . Basket converter  130  is a hollow cylinder defining an open longitudinal potion  132 . Open longitudinal portion  132  can be a section between 10 and 130 degrees about the basket converter  130 , preferably  120  degrees. Basket converter  130  snaps over basket portion  19  to reduce the exposed area of basket portion  19 . This serves to concentrate tissue mass removal to a more specific location. Tissue sampling is performed as mentioned above, however, open longitudinal portion  132  must not interfere with slot  110  and razor blade  106 . Open longitudinal portion  132  must therefore be positioned over slot  110  in basket portion  19 . Further an outside diameter  134  of basket converter  130  must be dimensioned to fit inside cutting tube  24 . 
     It will be understood that various modifications may be made to the embodiments disclosed herein. For example, basket converter  130  may have different size openings therein to allow for more specialized tissue sampling. Therefore, the above description should not be construed as limiting, but merely as exemplifications of preferred embodiments.