Abstract:
Biopsy systems, as well as related methods and components, are disclosed. In some embodiments, a biopsy system can include a biopsy gun and a spacer. The biopsy gun can include a housing having a proximal end and a distal end, and a biopsy needle having a proximal end and a distal end. A lumen can extend partially through the housing, and can have a distal end that is defined by the distal end of the housing. A lumen also can extend through the spacer, which can be associated with the distal end of the housing. The biopsy needle can have a first position in which its distal end is disposed within the lumen of the housing or the lumen of the spacer, and a second position in which its distal end is disposed external to the lumen of the housing and the lumen of the spacer.

Description:
TECHNICAL FIELD  
       [0001]     The invention relates to biopsy systems, and to related methods and components.  
       BACKGROUND  
       [0002]     Biopsy systems can be used to obtain a tissue specimen from a subject.  
       SUMMARY  
       [0003]     The invention relates to biopsy systems, and to related methods and components.  
         [0004]     In one aspect, the invention features a biopsy system including a biopsy gun and a spacer. The biopsy gun includes a housing having a proximal end and a distal end, and a biopsy needle having a proximal end and a distal end. A lumen extends partially through the housing, and has a distal end that is defined by the distal end of the housing. A lumen also extends through the spacer, which is associated with (e.g., connected to and/or integrally formed with) the distal end of the housing. In one position, the distal end of the biopsy needle is disposed within the lumen of the housing or the lumen of the spacer. In another position, the distal end of the biopsy needle is disposed external to the lumen of the housing and the lumen of the spacer. In another aspect, the invention features a method that includes delivering the distal end of an introducer sheath into a body of a subject, and contacting the spacer with the proximal end of the introducer sheath.  
         [0005]     In an additional aspect, the invention features an article including an introducer sheath and a spacer. The introducer sheath, which is sized for use with a biopsy gun, has a proximal end, a distal end, and a lumen that extends between the proximal and distal ends. The spacer is associated with (e.g., connected to and/or integrally formed with) the proximal end of the introducer sheath. In a further aspect, the invention features a method that includes delivering the distal end of the introducer sheath into a body of a subject, and contacting the spacer with a biopsy gun including a biopsy needle.  
         [0006]     In another aspect, the invention features an article including an introducer sheath and a spacer. The introducer sheath has a proximal end, a distal end, and a lumen extending between the proximal and distal ends. The spacer is associated with (e.g., connected to and/or integrally formed with) the proximal end of the introducer sheath, and is configured to be connected to a biopsy gun. In an additional aspect, the invention features a method that includes delivering the distal end of the introducer sheath into a body of a subject, and contacting the spacer with a biopsy gun including a biopsy needle.  
         [0007]     In another aspect, the invention features a medical kit that includes a biopsy gun and at least two introducer sheaths. At least one (e.g., two) of the introducer sheaths can be sized to fit the biopsy gun. The introducer sheaths can have the same length or can have different lengths. In an additional aspect, the invention features a method that includes delivering an end of one of the introducer sheaths into a body of a subject, and contacting the introducer sheath with the biopsy gun.  
         [0008]     In a further aspect, the invention features a medical kit that includes a biopsy gun with a housing having a proximal end and a distal end, and at least two spacers. At least one (e.g., two) of the spacers can be adapted to connect to the distal end of the housing. The spacers can have the same length or can have different lengths. In another aspect, the invention features a method that includes delivering the distal end of an introducer sheath into a body of a subject, and contacting one of the spacers with the proximal end of the introducer sheath.  
         [0009]     In an additional aspect, the invention features a medical kit that includes an introducer sheath sized for use with a biopsy gun and having a proximal end and a distal end, and at least two spacers. At least one (e.g., two) of the spacers can be adapted to connect to the proximal end of the introducer sheath. The spacers can have the same length or can have different lengths. In a further aspect, the invention features a method that includes delivering the distal end of the introducer sheath into a body of a subject, and contacting one of the spacers with the proximal end of the introducer sheath.  
         [0010]     In another aspect, the invention features a medical kit that includes a biopsy gun having a housing with a proximal end and a distal end, a first introducer sheath, and a first spacer. The first introducer sheath has a proximal end and a distal end, and is sized for use with the biopsy gun. The first spacer is adapted to connect to the distal end of the housing of the biopsy gun and to the proximal end of the first introducer sheath. In an additional aspect, the invention features a method that includes delivering the distal end of the first introducer sheath into a body of a subject, connecting the proximal end of the first introducer sheath with the first spacer, and contacting the first spacer with the biopsy gun. In a further aspect, the invention features a method that includes connecting the first spacer with the distal end of the housing of the biopsy gun, delivering the distal end of the first introducer sheath into a body of a subject, and contacting the first spacer with the proximal end of the first introducer sheath.  
         [0011]     In an additional aspect, the invention features a medical kit that includes a biopsy gun including a biopsy needle, and an article including an introducer sheath and a spacer. The introducer sheath has a proximal end and a distal end, and the spacer is integrally formed with the proximal end of the introducer sheath. In another aspect, the invention features a method that includes delivering the distal end of the introducer sheath into a body of a subject and contacting the spacer with the biopsy gun.  
         [0012]     Embodiments can include one or more of the following features.  
         [0013]     The spacer can include a polymer, a metal, and/or a metal alloy. The spacer can have a length of at least about one millimeter, and/or at most about 20 millimeters. The spacer can be in the form of a luer lock. The spacer can be interlocked with, and/or bonded to, the distal end of the housing and/or the proximal end of the introducer sheath. The spacer can have a lumen extending through it. The spacer can be integrally formed with and/or connected to the proximal end of the introducer sheath and/or the distal end of the housing of the biopsy gun.  
         [0014]     In some embodiments in which there are at least two spacers (e.g., in a medical kit), the spacers can have the same length or can have different lengths. In certain embodiments, the length of one spacer can be from about 0.1 centimeter to about three centimeters (e.g., from about 0.1 centimeter to about 2.5 centimeters, from about 0.1 centimeter to about 1.5 centimeters), and/or the length of the other spacer can be from about 0.1 centimeter to about three centimeters (e.g., from about 0.5 centimeter to about three centimeters, from about 1.5 centimeters to about three centimeters). In some embodiments in which the spacers have different lengths, the difference between the lengths of the spacers can be at least about 0.1 centimeter (e.g., at least about 0.5 centimeter, at least about one centimeter, at least about two centimeters), and/or at most about 2.5 centimeters (e.g., at most about two centimeters, at most about one centimeter, at most about 0.5 centimeter).  
         [0015]     In certain embodiments in which there are at least two spacers (e.g., in a medical kit), the spacers can be adapted to connect to each other.  
         [0016]     The biopsy system can include an introducer sheath. The introducer sheath can be sized for use with the biopsy gun, and/or can be configured to be connected to the spacer. In some embodiments, the introducer sheath can have a proximal end and a distal end, and the spacer can be connected to and/or integrally formed with the proximal end of the introducer sheath. In certain embodiments, an introducer sheath can have a length of at least about five centimeters (e.g., at least about 10 centimeters, at least about 15 centimeters, at least about 20 centimeters, at least about 25 centimeters), and/or at most about 30 centimeters (e.g., at most about 25 centimeters, at most about 20 centimeters, at most about 15 centimeters, at most about 10 centimeters). In some embodiments, an introducer sheath can have a length of from about 9.7 centimeters to about 20.2 centimeters.  
         [0017]     In some embodiments in which there are at least two introducer sheaths (e.g., in a medical kit), the introducer sheaths can have different lengths. In certain embodiments, the length of one introducer sheath can be from about five centimeters to about 15 centimeters, and/or the length of the other introducer sheath can be from about 15 centimeters to about 30 centimeters. In some embodiments, the difference between the lengths of the introducer sheaths can be at least about five centimeters (e.g., at least about 10 centimeters, at least about 15 centimeters, at least about 20 centimeters), and/or at most about 25 centimeters (e.g., at most about 20 centimeters, at most about 15 centimeters, at most about 10 centimeters).  
         [0018]     In certain embodiments in which there are at least two introducer sheaths (e.g., in a medical kit), the introducer sheaths can be adapted to connect to each other.  
         [0019]     The biopsy needle can have a length of at least about 50 millimeters (e.g., at least about 75 millimeters, at least about 100 millimeters, at least about 125 millimeters, at least about 150 millimeters, at least about 175 millimeters, at least about 200 millimeters, at least about 225 millimeters), and/or at most about 250 millimeters (e.g., at most about 225 millimeters, at most about 200 millimeters, at most about 175 millimeters, at most about 150 millimeters, at most about 125 millimeters, at most about 100 millimeters, at most about 75 millimeters). For example, in some embodiments, the biopsy needle can have a length of about 100 millimeters, about 120 millimeters, about 130 millimeters, about 150 millimeters, or about 210 millimeters.  
         [0020]     In certain embodiments, the biopsy needle can include a stylet having a proximal end and a distal end, and/or a cannula. The stylet can be located within the cannula. A region of the stylet that is adjacent the distal end of the stylet can include a notch. The notch can have a length of at least about five millimeters, and/or at most about 20 millimeters. The distal end of the stylet can be pointed and adapted to penetrate tissue (e.g., in the body of a subject).  
         [0021]     The biopsy gun can be a semi-automatic biopsy gun or an automatic biopsy gun. The biopsy gun can be electronically, mechanically, and/or pneumatically activated. In some embodiments, the biopsy gun can include a spring mechanism.  
         [0022]     The medical kit can include at least one (e.g., two, three, four, five) introducer sheath. In some embodiments in which the medical kit includes a first introducer sheath, the medical kit can further include a second introducer sheath that has a proximal end and a distal end, and that is sized for use with the biopsy gun. The second introducer sheath can have a different length from the first introducer sheath. The first spacer can be adapted to connect to the proximal end of the second introducer sheath.  
         [0023]     In some embodiments, the medical kit can further include a spacer that is configured to connect to at least one of the introducer sheaths. In certain embodiments, the medical kit can further include a spacer that is connected to and/or integrally formed with the biopsy gun and/or at least one of the introducer sheaths. In some embodiments in which the medical kit includes a first spacer, the medical kit can further include a second spacer that is adapted to connect to the distal end of the housing of the biopsy gun, the proximal end of the first introducer sheath, and/or the proximal end of the second introducer sheath.  
         [0024]     The method can include delivering the distal end of the introducer sheath into the body of the subject prior to or after contacting the spacer with the biopsy gun. In certain embodiments, the method can include connecting the spacer to the biopsy gun (e.g., to the distal end of a housing of the biopsy gun).  
         [0025]     The method can include advancing the biopsy needle through the introducer sheath. Advancing the biopsy needle through the introducer sheath can include advancing the biopsy needle beyond the distal end of the introducer sheath by a distance of at most about 40 millimeters (e.g., at most about 30 millimeters, at most about 20 millimeters). In some embodiments, the biopsy needle can include a stylet, and the method can include advancing the stylet through the introducer sheath. In certain embodiments, the biopsy needle can include both a stylet and a cannula, and the method can include advancing the cannula over the stylet and through the introducer sheath. In some embodiments, the method can include extracting tissue from the body of the subject.  
         [0026]     Embodiments can include one or more of the following advantages.  
         [0027]     In some embodiments, the biopsy needle can have adjustable throw. The throw of the biopsy needle can be adjusted, for example, by using one or more spacers between the housing of the biopsy gun and the introducer sheath, and/or by varying the size of the introducer sheath. In certain embodiments, a biopsy needle with adjustable throw can be used for multiple different biopsy procedures and/or multiple different subjects. As an example, the throw of the biopsy needle can be adjusted for taking a sample of thyroid tissue, and can thereafter be adjusted for taking a sample of liver tissue and/or kidney tissue. As another example, a biopsy needle with adjustable throw may be appropriate for use on a number of different types of patients. For example, the biopsy needle may be appropriate for use on both a small child and a large adult.  
         [0028]     In some embodiments, the throw of the biopsy needle can be adjusted to limit the likelihood of overshooting or undershooting a target site within a body of a subject. For example, in some embodiments, the throw of the biopsy needle can be adjusted so that a relatively large tissue sample can be obtained as a result of the penetration of the target site by the biopsy needle.  
         [0029]     In certain embodiments, a biopsy gun can be sold in a kit with multiple spacers (e.g., multiple spacers of different lengths, multiple spacers of the same length) and/or multiple introducer sheaths (e.g., multiple introducer sheaths of different lengths, multiple introducer sheaths of the same length). The kit can, for example, allow a physician to conveniently and efficiently adjust the throw of the biopsy needle of the biopsy gun to suit a particular procedure.  
         [0030]     Features and advantages are in the description, drawings, and claims.  
     
    
     DESCRIPTION OF DRAWINGS  
       [0031]      FIG. 1  is a side view in partial cross-section of an embodiment of a biopsy system.  
         [0032]      FIG. 2A  is a perspective view of an embodiment of an article.  
         [0033]      FIG. 2B  is a side cross-sectional view of the article of  FIG. 2A , taken along line  2 B- 2 B.  
         [0034]      FIGS. 3A-3C  illustrate the use of an embodiment of a biopsy gun with the article of  FIGS. 2A and 2B .  
         [0035]      FIG. 4A  is a side view in partial cross-section of an embodiment of a biopsy gun.  
         [0036]      FIG. 4B  illustrates the use of the biopsy gun of  FIG. 4A .  
         [0037]      FIG. 5  illustrates the delivery of a portion of a biopsy system into the body of a subject.  
         [0038]      FIG. 6A  is a side perspective view of an embodiment of a biopsy gun.  
         [0039]      FIG. 6B  is a side view in partial cross-section of the biopsy gun of  FIG. 6A , taken along line  6 B- 6 B.  
         [0040]      FIGS. 6C-6E  illustrate the use of the biopsy gun of  FIGS. 6A and 6B .  
         [0041]      FIGS. 7A-7C  illustrate the use of a biopsy gun with an embodiment of an introducer sheath.  
         [0042]      FIGS. 8A-8C  illustrate the use of the biopsy gun of  FIGS. 7A-7C , with another embodiment of an introducer sheath.  
         [0043]      FIG. 9  is a side cross-sectional view of an embodiment of an article.  
         [0044]      FIG. 10  is a side cross-sectional view of an embodiment of an article.  
         [0045]      FIG. 11  is a side cross-sectional view of an embodiment of an article. 
     
    
     DETAILED DESCRIPTION  
       [0046]     In general, the biopsy systems are designed to include biopsy needles with adjustable throw. The throw of a biopsy needle is the distance by which the biopsy needle extends beyond the distal end of an introducer sheath after the biopsy needle has been deployed through the introducer sheath. In some embodiments, biopsy systems that include biopsy needles with adjustable throw can be used for different types of procedures, and/or on different patients. For example, the throw of a biopsy needle can be adjusted to be relatively short (e.g., less than about 0.5 centimeter, less than about 0.1 centimeter), which can be appropriate when the biopsy needle is used to take a sample of thyroid tissue. Thereafter, the throw of the biopsy needle can be adjusted to be relatively long (e.g., more than about two centimeters, more than about 2.5 centimeters), which can be appropriate when the biopsy needle is used to take a sample of liver tissue and/or kidney tissue. Certain embodiments of the biopsy systems and related components and methods are disclosed below.  
         [0047]     In some embodiments, the throw of a biopsy needle can be adjusted using a spacer. For example,  FIG. 1  shows a biopsy system  8  that includes a biopsy gun  50 , a spacer  18 , and an introducer sheath  12 . Biopsy gun  50  includes a housing  52  having a proximal end  54  and a distal end  56 , a lumen  51  with a proximal end  53  and a distal end  55 , and an activation button  58 . A biopsy needle  64  is located within lumen  51 , and has a proximal end  65  and a distal end  67 . Biopsy needle  64  includes a stylet  60  ( FIG. 3B ) and a cannula  62  ( FIG. 3C ) surrounding stylet  60 . Spacer  18  has a lumen  19 , and introducer sheath  12  has a proximal end  14 , a distal end  16 , and a lumen  15 .  
         [0048]     Spacer  18  can be connected to either or both of biopsy gun housing  52  and introducer sheath  12 . For example,  FIGS. 2A and 2B  show an article  10  in which spacer  18  is connected to proximal end  14  of introducer sheath  12 . Generally, spacer  18  can be connected to introducer sheath  12  using any desired method. Examples of methods include bonding, such as adhesive bonding and/or heat bonding (e.g., using laser heating, using RF heating). For example, in some embodiments, spacer  18  and introducer sheath  12  may be separately formed and then bonded together using an adhesive.  
         [0049]     As shown in  FIGS. 2A and 2B , spacer  18  has a length L 1 . In certain embodiments, length L 1  can be at least about one millimeter (e.g., at least about three millimeters, at least about five millimeters, at least about seven millimeters, at least about 10 millimeters, at least about 15 millimeters), and/or at most about 20 millimeters (e.g., at most about 15 millimeters, at most about 10 millimeters, at most about seven millimeters, at most about five millimeters, at most about three millimeters).  
         [0050]     Spacer  18  can be formed of, for example, a polymer, a metal, a metal alloy, or a combination of these materials. In some embodiments, spacer  18  can be formed of a combination of polymers. Examples of polymers include polyamides (e.g., nylons), copolymers of polyamides (e.g., nylon-polyether copolymers), polyesters (e.g., polyethylene terephthalate (PET) polymers, polybutylene terephthalate (PBT) polymers), copolymers of polyesters, polyetheretherketones (PEEKs), polyurethanes, polyethylenes, polypropylenes, copolymers and ionomers of ethylene, copolymers and ionomers of polypropylene, polystyrenes and copolymers of polystyrenes. Examples of commercially available polymers include the PEBAX® family of polymers (e.g., PEBAX 5533, PEBAX 2533, PEBAX 7033), commercially available from Atofina (Philadelphia, Pa.), the Hytrel family of polymers (e.g., Hytrel 5556, Hytrel 7246, Hytrel 4056), commercially available from E. I. DuPont de Nemours (Wilmington, Del.), and the Arnitel family of polymers (e.g., Arnitel EM630), commercially available from DSM (Erionspilla, Ind.). Examples of metals include platinum, gold, and tantalum. Examples of metal alloys include nitinol, stainless steel (e.g., 303, 304, 316L), and MP35N (a nickel-cobalt-chromium-molybdenum alloy). In some embodiments, spacer  18  can be made of the same material as introducer sheath  12  and/or housing  52  of biopsy gun  50 .  
         [0051]     As shown in  FIGS. 2A and 2B , introducer sheath  12  has a length L 2 . In some embodiments, length L 2  can be at least about five centimeters (e.g., at least about 10 centimeters, at least about 15 centimeters, at least about 20 centimeters, at least about 25 centimeters), and/or at most about 30 centimeters (e.g., at most about 25 centimeters, at most about 20 centimeters, at most about 15 centimeters, at most about 10 centimeters). In certain embodiments, length L 2  can be from about nine centimeters to about 20 centimeters.  
         [0052]     As  FIG. 3A  shows, during use of biopsy gun  50 , distal end  56  of housing  52  is placed into contact with (e.g., connected to) spacer  18 . As shown in  FIG. 3B , biopsy gun  50  is activated by pressing activation button  58  downward (in the direction of arrow A 1 ), which causes stylet  60  and then cannula  62  to extend through both lumen  19  of spacer  18  and lumen  15  of introducer sheath  12 , as explained in further detail below. Stylet  60  has a pointed distal end  63  and a notch  61  ( FIG. 3B ), which can serve as a containment space for tissue samples, and which has a length L 3 . In some embodiments, length L 3  can be at least about five millimeters (e.g., at least about 10 millimeters, at least about 15 millimeters), and/or at most about 20 millimeters (e.g., at most about 15 millimeters, at most about 10 millimeters).  
         [0053]     As shown in  FIG. 3C , biopsy needle  64  has a throw T 1  which is equal to the distance by which biopsy needle  64  extends beyond distal end  16  of introducer sheath  12 . The presence of spacer  18  causes throw T 1  of biopsy needle  64  to be smaller than it would be if spacer  18  were not present. Typically, the presence of spacer  18  can cause throw T 1  of biopsy needle  64  to be decreased by the value of length L 1  of spacer  18  ( FIGS. 2A and 2B ), relative to what throw T 1  would be if spacer  18  were not used.  
         [0054]     In some embodiments, throw T 1  can be at least about five millimeters (e.g., at least about 10 millimeters, at least about 12 millimeters, at least about 15 millimeters, at least about 17 millimeters, at least about 20 millimeters, at least about 25 millimeters, at least about 30 millimeters, at least about 35 millimeters), and/or at most about 40 millimeters (e.g., at most about 35 millimeters, at most about 30 millimeters, at most about 25 millimeters, at most about 20 millimeters, at most about 17 millimeters, at most about 15 millimeters, at most about 12 millimeters, at most about 10 millimeters).  
         [0055]     The throw of a biopsy needle can be adjusted to be suitable for a particular procedure. In some embodiments, the throw can be adjusted by changing the spacer that is used with the biopsy needle. For example, the throw can be decreased by using a longer spacer, or can be increased by using a shorter spacer. In certain embodiments, the throw can be adjusted by using multiple spacers (e.g., multiple spacers that are adapted to connect to each other). In some embodiments, it may be desirable to adjust the throw of a biopsy needle such that it is relatively short (e.g., less than about 0.5 centimeter, less than about 0.1 centimeter). For example, the throw may be adjusted to be relatively short to limit the likelihood of a biopsy needle extending beyond a target site within the body of a subject. In certain embodiments, it may be desirable to adjust the throw of a biopsy needle such that it is relatively long (e.g., more than about two centimeters, more than about 2.5 centimeters). For example, the throw of a biopsy needle may be adjusted to be relatively long to increase the likelihood of the biopsy needle reaching a distant target site within the body of a subject.  
         [0056]     As  FIG. 3C  shows, biopsy needle  64  has a length L 4 . In certain embodiments, length L 4  can be at least about 50 millimeters (e.g., at least about 100 millimeters, at least about 150 millimeters), and/or at most about 250 millimeters (e.g., at most about 200 millimeters, at most about 150 millimeters, at most about 100 millimeters). For example, length L 4  can be about 100 millimeters, about 120 millimeters, about 130 millimeters, about 150 millimeters, or about 210 millimeters.  
         [0057]     Biopsy gun  50  can be, for example, an automatic or semi-automatic biopsy gun, and/or can be electronically, mechanically, and/or pneumatically activated. In some embodiments, a biopsy gun such as biopsy gun  50  can be activated by a spring mechanism. For example,  FIGS. 4A and 4B  show a biopsy gun  400  including a housing  402  having a proximal end  404  and a distal end  406 , a lumen  408  having a proximal end  410  and a distal end  412 , and an activation button  428 . A biopsy needle  414  located within lumen  408 , and includes a stylet  416  partially surrounded by a cannula  418 . A spring  420  contacts stylet  416  and is held under tension by a lever  424 . A spring  422  contacts cannula  418  and is held under tension by a lever  426 . As shown in  FIG. 4B , when activation button  428  is pressed downward in the direction of arrow A 2 , activation button  428 , which is mechanically connected to levers  424  and  426 , causes levers  424  and  426  to press downward, allowing springs  420  and  422  to spring toward distal end  412  of lumen  408 , thereby moving stylet  416  and cannula  418  through lumen  408  and past distal end  406  of housing  402 .  
         [0058]     Biopsy guns (e.g., biopsy guns having spring mechanisms) are described, for example, in Bates et al., U.S. Pat. No. 4,958,625, and Chu et al., U.S. Pat. No. 5,989,196. Examples of commercially available biopsy guns include the Easy Core™ Biopsy System and the ASAP™ Biopsy System, both available from Boston Scientific Corp.  
         [0059]      FIG. 5  shows biopsy system  8  being used in the body  500  of a subject  502 . As shown in  FIG. 5 , distal end  16  of introducer sheath  12  is inserted into body  500 , and spacer  18  contacts both proximal end  14  of introducer sheath  12  and distal end  56  of housing  52  of biopsy gun  50 . Biopsy systems such as biopsy system  8  can be used, for example, on soft tissue (e.g., lung, kidney, liver, breast, thyroid), and/or on hard lesions (e.g., hard cancerous lesions) or bone.  
         [0060]     While spacers that are connected to introducer sheaths have been shown, in some embodiments, a spacer can be connected to a biopsy gun.  
         [0061]     For example,  FIGS. 6A and 6B  show a biopsy system  201  including a biopsy gun  200  and a spacer  210  with a lumen  211 . Biopsy gun  200  has a housing  202  with a proximal end  204  and a distal end  206 . Biopsy gun  200  also includes a biopsy needle  220  ( FIG. 6E ) including a stylet  216  ( FIG. 6D ) and a cannula  218  ( FIG. 6E ). Biopsy gun  200  further includes an activation button  208 . Spacer  210  is connected to distal end  206  of housing  202  using, for example, any of the methods described above with reference to the connection of spacer  18  to introducer sheath  12 . Spacer  210  can be formed of, for example, any of the materials described above with reference to spacer  18 . In some embodiments, spacer  210  can be formed of the same material as housing  202  of biopsy gun  200 .  
         [0062]     As shown in  FIG. 6C , prior to and/or during use of biopsy gun  200 , spacer  210  contacts (e.g., is connected to) the distal end  212  of an introducer sheath  214  having a lumen  221 . As shown in  FIGS. 6D and 6E , biopsy gun  200  is then activated by pressing down on activation button  208  in the direction of arrow A 3 , thereby causing stylet  216  and cannula  218  to extend through lumen  221  of introducer sheath  214 .  
         [0063]     Biopsy needle  220  has a throw T 2  ( FIG. 6E ). In some embodiments, throw T 2  can be at least about five millimeters (e.g., at least about 10 millimeters, at least about 12 millimeters, at least about 15 millimeters, at least about 17 millimeters, at least about 20 millimeters), and/or at most about 21 millimeters (e.g., at most about 20 millimeters, at most about 17 millimeters, at most about 15 millimeters, at most about 12 millimeters, at most about 10 millimeters).  
         [0064]     In some embodiments, a biopsy gun can be a component of a medical kit that includes multiple (e.g., two, three, four, five) spacers. The medical kit can include spacers of the same length and/or spacers of different lengths. In certain embodiments, the spacers may be adapted to connect to each other. In some embodiments, the medical kit can include an introducer sheath, and the spacers can be adapted to connect to the biopsy gun and/or the introducer sheath.  
         [0065]     In certain embodiments, a medical kit can include a spacer having a length of from about 0.1 centimeter to about three centimeters (e.g., from about 0.1 centimeter to about 2.5 centimeters, from about 0.1 centimeter to about 1.5 centimeters), and another spacer having a length of from about 0.1 centimeter to about three centimeters (e.g., from about 0.5 centimeter to about three centimeters, from about 1.5 centimeters to about three centimeters). In some embodiments in which spacers in a medical kit have different lengths, the difference between the length of one spacer in the medical kit and the length of another spacer in the medical kit can be at least about 0.1 centimeter (e.g., at least about 0.5 centimeter, at least about one centimeter, at least about two centimeters), and/or at most about 2.5 centimeters (e.g., at most about two centimeters, at most about one centimeter, at most about 0.5 centimeter). In certain embodiments in which spacers in a medical kit have the same length, the spacers can each have a length of from about 0.1 centimeter to about two centimeters (e.g., from about 0.1 centimeter to about one centimeters, about 0.5 centimeter).  
         [0066]     While the adjustment of the throw of a biopsy needle using a spacer has been described, in certain embodiments, the throw of a biopsy needle can be adjusted using introducer sheaths of different lengths. For example,  FIGS. 7A-7C  and  8 A- 8 C illustrate the use of introducer sheaths of different lengths with the same biopsy needle.  
         [0067]      FIGS. 7A-7C  illustrate the use of a biopsy gun  250  with an introducer sheath  252  having a lumen  254  and a length L 5 . In some embodiments, length L 5  can be at least about 15 centimeters (e.g., at least about 20 centimeters, at least about 25 centimeters), and/or at most about 30 centimeters (e.g., at most about 25 centimeters, at most about 20 centimeters).  
         [0068]     Biopsy gun  250  includes a biopsy needle  262  ( FIG. 7C ) with a stylet  258  ( FIG. 7B ) and a cannula  260  ( FIG. 7C ). When biopsy gun  250  is activated by pressing down on its activation button  256  in the direction of arrow A 4  ( FIG. 7B ), stylet  258  and cannula  260  extend through lumen  254  of introducer sheath  252 . Biopsy needle  262  has a throw T 3  ( FIG. 7C ). In certain embodiments, throw T 3  can be at least about five millimeters (e.g., at least about 10 millimeters, at least about 12 millimeters, at least about 15 millimeters, at least about 17 millimeters, at least about 20 millimeters), and/or at most about 21 millimeters (e.g., at most about 20 millimeters, at most about 17 millimeters, at most about 15 millimeters, at most about 12 millimeters, at most about 10 millimeters).  
         [0069]      FIGS. 8A-8C  also show the use of biopsy gun  250 ; however,  FIGS. 8A-8C  show the use of biopsy gun  250  with an introducer sheath  300  that is shorter than introducer sheath  252  of  FIGS. 7A-7C . As shown in  FIG. 8A , introducer sheath  300  has a lumen  301  and a length L 6 . In some embodiments, length L 6  can be at least about five centimeters (e.g., at least about 10 centimeters), and/or at most about 15 centimeters (e.g., at most about 10 centimeters).  
         [0070]     When biopsy gun  250  is activated by pressing down on activation button  256  in the direction of arrow A 5  ( FIG. 8B ), stylet  258  and cannula  260  extend through lumen  301  of introducer sheath  300 . Biopsy needle  262  has a throw T 4  ( FIG. 8C ). In some embodiments, throw T 4  can be at least about 10 millimeters (e.g., at least about 12 millimeters, at least about 15 millimeters, at least about 17 millimeters, at least about 20 millimeters, at least about 25 millimeters, at least about 30 millimeters), and/or at most about 35 millimeters (e.g., at most about 30 millimeters, at most about 25 millimeters, at most about 20 millimeters, at most about 17 millimeters, at most about 15 millimeters, at most about 12 millimeters).  
         [0071]     In certain embodiments, the difference between throw T 3  and throw T 4  can be at least about one millimeter (e.g., at least about three millimeters, at least about five millimeters, at least about 10 millimeters, at least about 15 millimeters, at least about 20 millimeters, at least about 25 millimeters), and/or at most about 30 millimeters (e.g., at most about 25 millimeters, at most about 20 millimeters, at most about 15 millimeters, at most about 10 millimeters, at most about five millimeters, at most about three millimeters).  
         [0072]     In some embodiments, a biopsy gun such as biopsy gun  250  can be a component of a medical kit that also includes multiple (e.g., two, three, four, five) introducer sheaths of different lengths, such as introducer sheaths  252  and  300 . For example, the medical kit can include an introducer sheath having a length of from about five centimeters to about 15 centimeters, and another introducer sheath having a length of from about 15 centimeters to about 30 centimeters. In certain embodiments, the difference between the length of one introducer sheath in the medical kit and the length of another introducer sheath in the medical kit can be at least about five centimeters (e.g., at least about 10 centimeters, at least about 15 centimeters, at least about 20 centimeters), and/or at most about 25 centimeters (e.g., at most about 20 centimeters, at most about 15 centimeters, at most about 10 centimeters).  
         [0073]     Introducer sheaths such as introducer sheaths  252  and  300  can be formed, for example, of one or more polymers. Examples of polymers include silicones, thermoplastic polymers, thermoset polymers, polyetheretherketones (PEEKs), and high density polyethylene (HDPE). Examples of commercially available polymers include the PEBAX® family of polymers, the Hytrel family of polymers, and the Arnitel family of polymers.  
         [0074]     While certain embodiments have been described, the invention is not so limited.  
         [0075]     As an example, while biopsy guns and introducer sheaths that are connected to a single spacer have been shown, in some embodiments, multiple spacers (e.g., two, three, four, five) can be used with a biopsy gun and/or an introducer sheath. The spacers may have the same length or may have different lengths. As an example, in some embodiments, a spacer can be connected to the distal end of a biopsy gun, and another spacer can be connected to the proximal end of an introducer sheath that also is used with the biopsy gun. As another example, in certain embodiments, a spacer can be connected to another spacer and to the distal end of a biopsy gun.  
         [0076]     As another example, in certain embodiments, a spacer can interlock with an introducer sheath (e.g., the spacer can be in the form of a luer lock) and/or a biopsy gun housing. For example,  FIG. 9  shows an article  100  that includes an introducer sheath  102  having a proximal end  104  and a distal end  106 , and a spacer  108  interlocked with proximal end  104 .  
         [0077]     As a further example, in some embodiments, a spacer can include a ledge that accommodates an introducer sheath or an end of a biopsy gun housing. For example,  FIG. 10  shows an article  122  that includes an introducer sheath  124  having a proximal end  126  and a distal end  128 . At proximal end  126 , introducer sheath  124  contacts a ledge  130  of a spacer  132 .  
         [0078]     As an additional example, in some embodiments, a spacer can be integrally formed (e.g., molded, extruded) with an introducer sheath and/or a biopsy gun housing. For example,  FIG. 11  shows an article  150  that includes an introducer sheath  152  having a proximal end  154  and a distal end  156 , and a spacer  158  integrally formed with introducer sheath  152  at its proximal end  154 .  
         [0079]     As a further example, in certain embodiments, a medical kit can include a biopsy gun, multiple spacers (e.g., multiple spacers of different lengths, multiple spacers of the same length), and multiple introducer sheaths of different lengths. In some embodiments, the spacers can be adapted to connect to the biopsy gun (e.g., to the distal end of the housing of the biopsy gun), and/or to at least one (e.g., all) of the introducer sheaths (e.g., to the proximal end of one of the introducer sheaths).  
         [0080]     As another example, while the adjustment of the throw of a biopsy needle by using multiple spacers has been described, in some embodiments, multiple introducer sheaths can be used to adjust the throw of a biopsy needle. In certain embodiments, the introducer sheaths may be adapted to connect to each other.  
         [0081]     As a further example, while medical kits including multiple introducer sheaths of different lengths have been described, in some embodiments, a medical kit can include multiple (e.g., two, three, four, five) introducer sheaths of the same length.  
         [0082]     As another example, in some embodiments, a spacer, a biopsy gun, and/or an introducer sheath can have the same color (e.g., blue, green, red), and/or can be provided together in a kit. In certain embodiments, the color of a spacer can provide a signal (e.g., to a physician) as to which biopsy gun(s) and/or introducer sheath(s) are adapted to be connected to the spacer.  
         [0083]     Other embodiments are in the claims.