Abstract:
A full-core biopsy device comprises an outer cannula hub with an outer cannula coupled at a proximal end to the hub, the outer cannula with a tissue slicing feature defined at the distal tip configured for cutting tissue. The device further comprises an inner member hub and an inner member coaxially disposed within the outer cannula and coupled at a proximal end to the inner member hub. The inner member includes a tubular body, an inner member tip at an opposite distal end thereof and an elongated scoop portion defined between the tubular body and tip. The distal ends of the outer cannula and the scoop portion of the inner member define cooperating forcing cone features.

Description:
REFERENCE TO RELATED APPLICATION 
       [0001]    This application is a continuation-in-part of and claims priority to U.S. application Ser. No. 14/051,595, filed on Oct. 11, 2013, which is a non-provisional of and claims priority to provisional application No. 61/712,441, filed on Oct. 11, 2012 and entitled “Biopsy Device Improvements”, the entire disclosures of which are incorporated herein by reference. 
     
    
     BACKGROUND 
       [0002]    The present disclosure relates to biopsy devices and particularly to core biopsy devices. 
         [0003]    A standard single action biopsy device has an outer cannula needle coaxially disposed over an inner stylet needle. The inner stylet defines a specimen notch near the distal end. The outer cannula and inner stylet are each attached to hubs and the hubs are moveable between three positions via a spring activated mechanism. The first position is a fired or neutral position. The proximal ends of the needles, the spring and carriages are housed within a casing including a handle. A plunger is engaged to the carriages. In use, the plunger is pulled back to charge the device. In the charged condition, the carriages and needles have been pulled back into the casing. When the device is charged the plunger is moveable between back and forward positions. In the forward position, the stylet has been moved forward relative to the outer cannula to expose the notch. Depressing the plunger further fires the device by releasing the outer needle carriage so that the outer needle quickly moves forward to cover the notch and sever tissue to capture a specimen within the notch. 
         [0004]    In a single action Device, the inner stylet with the notch is manually moved with the plunger. In a double action device, both the inner stylet and outer cannula are fired automatically in rapid succession once the trigger is depressed. One advantage of a single action device over a double action device is that manual movement of the inner stylet allows the clinician to directly visualize how far the outer cannula will core tissue by noting the location of the distal point of the inner stylet. This allows the clinician to avoid coring vital structures. Some clinicians also can feel the difference between target or safe tissue and vital structures by manually moving the inner stylet with the plunger. The resistance of such tissue against movement of the stylet tip provides different tactile feedback. Using a double action device, on the other hand requires the clinician to measure the length of the throw to estimate whether the device will core a vital structure. 
         [0005]    Both single action and double action devices reliably deliver core specimens, but they are limited in regard to the amount of tissue specimen by the dimensions of the notch. The BioPince™ device of Argon Medical Devices, Inc., was a major advancement in the field of biopsy because it provided a full rounded core, which was much larger than the specimens delivered by the “side notch” in the stylet of the single action and double action devices. While a major contribution, the BioPince had a relatively large casing and complicated mechanism. 
         [0006]    The DEX360 Full Core Biopsy device of Promex Technologies, Inc., utilized forcing cone technology to deliver a large rounded full core with a simple, elegant mechanism. While the full core performance of both the BioPince and the DEX360 devices deliver clinically significant better cores, both devices operate like double action devices in that the clinician must measure the throw before firing. 
         [0007]    The current invention combines the benefit of manual advancement of the inner member before coring of a single action with the forcing cone feature of a DEX360. When the plunger is advanced, a scoop portion defined in the inner needle is extended for tissue prolapse. The forcing cone in the outer cannula in combination with the scoop captures a rounded core. In some embodiments, the distal end of the scoop includes a sharpened tip, a partial forcing cone or a solid tip. For the present disclosure certain aspect of these improvements are described for use with a full-core biopsy device, such as the device described in U.S. Pat. No. 9,332,970, which was filed on Sep. 13, 2012 and issued on May 10, 2016, pending application Ser. No. 13/190,808, filed on Jul. 26, 2011, and U.S. Pat. No. 9,237,883 which was filed on Dec. 16, 2010, and issued on Jan. 19, 2016, all of which are entitled “Full Core Biopsy Device”. The descriptions of the full core biopsy devices in these applications are incorporated herein by reference, but for the purposes of the present application certain features of the disclosed devices will be described herein. 
         [0008]    One type of core biopsy device  10  is shown in  FIG. 1 . The device  10  includes a housing  12  that defines finger handles  14  to be grasped by the clinician during a biopsy procedure. The device can include an outer cannula or cannula  20  and an inner member  30 , which may be a stylet, needle or cannula, coaxially extending through the outer cannula  20 . The biopsy device  10  incorporates a mechanism for charging and firing the outer cannula relative to the inner member in order to capture a tissue sample. One embodiment of a firing mechanism is incorporated into the SABD™ product and is described in the above-referenced pending applications. In general terms, the mechanism includes carriages that carry the outer cannula and inner member, and a spring arrangement that extends the outer cannula beyond the inner member so that tissue is drawn into and trapped in the tip  26  of the outer cannula. It is noted that this outer-inner cannula relationship is not utilized in the SABD, the inner cannula is extended so tissue can prolapse into the cannula before the outer cannula fires over the inner. In is noted that the scoop cannula of the present disclosure operates in the same manner to accept tissue prolapsed into the scoop portion. 
         [0009]    The mechanism of the full core device includes latch arrangements that allow the biopsy device to be placed in a charged configuration in which the tip  26  of the outer cannula is retracted, and then allow the device to be fired. A plunger  32  may be used to manually charge and fire the biopsy device. It should be appreciated, however, that the components described herein may be used in other types of biopsy devices, such as fully automated or double action devices. 
         [0010]    According to one aspect, the tip  26  of the outer cannula  20  is provided with a tissue penetrating tip. In one specific aspect the tissue penetrating tip is formed as a Franseen tip, as shown in  FIG. 2 , having three or more prongs  27  with sharp cutting edges that permit smooth piercing of the soft tissue as the outer cannula  20  initially advances into the tissue and that provide solid purchase once the outer cannula has been fully advanced. The prongs  27  are configured to advance through the tissue without substantially compressing the tissue. The angled edge surfaces of the prongs  27  act as guillotine cutters to slice cleanly through the tissue as the outer cannula  20  advances. The distal portion of the outer cannula forms a tissue specimen chamber. 
         [0011]    In another aspect, the distal portion of the tissue specimen chamber defines a tissue retention feature in the form of a countersink or forcing cone  28  defined in the inner surface to a depth  29  that is proximal from the valleys of the Franseen tip  26 . The forcing cone has a larger inner diameter than the proximal portion of the tissue specimen chamber. The forcing cone  28  essentially “forces” or squeezes a larger diameter of tissue into the relatively smaller diameter of the tissue specimen chamber of the outer cannula beyond the forcing cone as it is advanced into the tissue, which allows for a larger diameter sample and holds the sample in place as the device is withdrawn from the biopsy site. Employing a forcing cone for the tissue retention feature allows for the entire inner diameter of the outer cannula to be available as the tissue specimen chamber. It is believed that the force of the tissue against the sidewall of the outer cannula is greater than the force folding the cells together at the end of the specimen. Therefore when the needle is withdrawn, the tissue separates at a natural plane making any other tissue separation or retention means redundant. The forcing cone  28  may be incorporated into the outer cannula of different types of biopsy devices, including side notch devices, single or double action devices and coring devices. 
         [0012]    In the charged configuration or position of the biopsy device, the inner member  30  is situated within the outer cannula  20  so that the tip  36  preferably does not extend beyond, or extends only minimally beyond, the base of the valleys of the Franseen tip  26 , as illustrated in  FIG. 3 . It can be appreciated that in the charged position shown in  FIG. 3 , the inner member hub  32  is in position to fire the device  10 . 
       SUMMARY 
       [0013]    In one aspect of the present disclosure, a full core biopsy device comprises an outer cannula hub with an outer cannula coupled at a proximal end to the hub, the outer cannula having a tissue slicing feature defined at the distal tip configured for cutting tissue. The outer cannula includes an angled inner surface at the tip configured to improve tissue draw into the outer cannula when the device is activated. The device further comprises an inner member hub and an inner member coaxially disposed within the outer cannula and coupled at a proximal end to the inner member hub. The device includes a firing mechanism that is operable to advance the outer cannula relative to the inner member to obtain a full core tissue sample. 
         [0014]    In a further aspect, the inner member includes a cylindrical body, which may be solid or hollow, an inner member tip at an opposite distal end thereof and an elongated scoop portion defined between the tubular body and tip. The elongated scoop portion is partially cylindrical or subtends an angle less than 360°, and more particularly subtends an angle of about 180°. The elongated scoop portion may be sized to correspond to the stroke of the device. The distal ends of the outer cannula and the scoop portion of the inner member define cooperating forcing cone features. 
     
    
     
       DESCRIPTION OF THE FIGURES 
         [0015]      FIG. 1  is a top view of a coring biopsy device. 
           [0016]      FIG. 2  is an enlarged perspective view of the cutting top of the biopsy device shown in  FIG. 1 . 
           [0017]      FIG. 3  is an enlarged side view of the end of the biopsy device of  FIG. 1  shown with the outer cannula retracted. 
           [0018]      FIG. 4  is an enlarged side view of the end of the biopsy device of  FIG. 1  shown with the outer cannula extended. 
           [0019]      FIG. 5A  is a perspective view of the end of a scoop cannula having a solid body according to one aspect of the present disclosure. 
           [0020]      FIG. 5B  is a perspective view of the end of a scoop cannula having a hollow body according to a further aspect of the present disclosure. 
           [0021]      FIG. 6  is a perspective view of the scoop cannula shown in  FIG. 5  incorporated into the outer cannula of the biopsy device shown in  FIG. 1 . 
           [0022]      FIG. 7  is a perspective view of the scoop cannula and outer cannula shown in  FIG. 6  depicted with the scoop cannula retracted within the outer cannula. 
           [0023]      FIG. 8  is an enlarged cross-sectional view of the end of the scoop portion of the scooped cannula shown in  FIGS. 5-7 . 
           [0024]      FIG. 9  is an end perspective view of an outer cannula for use with the scoop cannula shown in  FIG. 5  in another aspect of the present disclosure. 
           [0025]      FIG. 10  is a side perspective view of the scoop cannula of  FIG. 5  incorporated into the outer cannula shown in  FIG. 9 . 
           [0026]      FIG. 11  is an end perspective view of a scoop cannula incorporating a forcing cone feature, according to a further aspect of the present disclosure. 
           [0027]      FIG. 12  is an end view of the scoop cannula of  FIG. 11  incorporated into the outer cannula shown in  FIG. 9 . 
           [0028]      FIG. 13  is a side perspective view of an inner scoop cannula according to further aspect of the present disclosure. 
           [0029]      FIG. 14  is an end perspective view of the inner scoop cannula shown in  FIG. 13 . 
           [0030]      FIG. 15  is a side perspective view of the inner scoop cannula of  FIG. 13  incorporated into the outer cannula of  FIG. 9  shown with the inner scoop cannula in a partially extended position. 
           [0031]      FIG. 16  is a side perspective view of the inner scoop cannula and outer cannula of  FIG. 15  shown with the inner scoop cannula in its fully retracted position. 
           [0032]      FIG. 17  is an end perspective view of the inner scoop cannula according to a further embodiment. 
       
    
    
     DETAILED DESCRIPTION 
       [0033]    For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiments illustrated in the drawings and described in the following written specification. It is understood that no limitation to the scope of the invention is thereby intended. It is further understood that the present invention includes any alterations and modifications to the illustrated embodiments and includes further applications of the principles of the invention as would normally occur to one skilled in the art to which this invention pertains. 
         [0034]    In accordance with the present disclosure, the inner stylet, needle or cannula  30  of the biopsy device  10  described above can be modified as shown in  FIGS. 5-7 . In particular, the biopsy device  10  may be provided with an inner member  40  that includes a main body  42 . The main body may be a solid stylet or needle configuration, as shown in  FIG. 5A  or may constitute a tubular body defining a lumen  48  as shown in  FIG. 5B . In the latter case, the lumen may be integrated with an irrigation or suction feature. 
         [0035]    In one aspect of the present disclosure, the inner member includes a scoop portion  44  extending from the main body to a distal end  46  that is configured to penetrate tissue at the biopsy site. As seen at the distal end  46 , the scoop portion  44  is defined by a partially cylindrical wall that extends for about half the circumference of the tubular body. Thus, in the illustrated embodiment the scoop portion  44  subtends an angle of about 180° to form a trough that can hold tissue. Other subtended angles are contemplated, although it is preferable that the scoop wall be configured or manufactured for sufficient rigidity and resistance to flexure as the device is introduced into a biopsy site or when the device is fired as described above. 
         [0036]    The distal end  46  of the scoop portion  44  may include a sharpened cutting edge to facilitate passage through tissue and clean slicing of the tissue as the scooped catheter is introduced into the biopsy site. In one embodiment, the sharpened cutting edge is formed at the inner surface of the cannula. In other words, the outer surface  44   a  of the cannula may have a constant radius throughout the entire length of the cannula, including the tubular body  42 , while the inner surface  44   b  defines an angled surface  47  at the tip  46 , as shown in  FIG. 8 , to produce a sharp cutting edge. The angled surface  47  may define an angle of 3-5° to facilitate introduction of tissue into the scooped cannula. In one feature, the scoop forcing cone completes the forcing cone formed by the outer cannula. 
         [0037]    In one embodiment, the inner member  40  may be formed by performing an O.D. grind at the end of a stylet or a needle and then cutting a notch along the end of the cannula to form the scoop  44 . Alternatively, the scoop  44  may be created by wire EDM on bar stock. The notch may be cut so that the scoop portion  44  has a predetermined length from the opening of the lumen  48  of the tubular body  42  to the distal end  46 . This predetermined length may correspond to the stroke or throw of the outer cannula  20  when the device is fired. For example, in one specific embodiment the length of the scoop portion  44  may be about 2 cm. It is contemplated that the inner member  40  can be formed using other suitable techniques. 
         [0038]    In certain uses of the device  10  it is desirable to have an indication of the extent of the outer cannula stroke when the device is introduced into a biopsy site. Thus, the scoop portion  44  may have a length approximately equal to the stroke of the biopsy device. The firing mechanism of the device may be configured to allow the inner member to be extended beyond the distal end  26  of the outer cannula in situ after the device is charged but prior to firing, as illustrated in  FIG. 6 . With the scooped cannula  40  extended beyond the outer cannula the inner member  40  can act as an introducer for the biopsy device and, at least initially, as an anchor for orienting the device relative to the desired biopsy site. The position of the scoop can be visualized, such as by x-ray, to provide an indication of the tissue sample that will be extracted when the device is fired. The inner member can be retracted to the position shown in  FIG. 7  prior to firing the device, in the case of a double action device, or may be retained in the extended position for a single action device as the device is fired. 
         [0039]    In other embodiments, the scoop portion  44  may be attached to or formed as part of a solid stylet to form the inner member  40 . The scoop portion may be removably attached to be removed along with the tissue sample after a biopsy procedure. In further embodiments, a solid tip may be formed on or attached to the distal end  46  of the scoop portion. The solid tip may be in the form of a Trocar, a bevel, a conical “pencil point” configuration or other known tip designs. 
         [0040]    The inner member  40  and scoop portion  44  disclosed herein are configured for passage through a full core outer cannula  20 , but it is understood that the same inner member may be used with other biopsy devices, such as the SABD™ discussed above. In some uses it may be desirable to block the lumen  48  when the device is fired to prevent the tissue sample from being drawn into the inner member. In this instance a plug, such as an obturator, may be introduced into the inner member  40  prior to firing. Alternatively, the lumen can remain open and the obturator may be used to help expel the tissue sample when the device is removed from the patient. 
         [0041]    In an alternative embodiment, an outer cannula  50  is provided that can be used with the inner member  40 . The outer cannula, as shown in  FIG. 9 , includes an inner wall  52  that defines a lumen to receive the inner member  40 . Whereas the distal end of the outer cannula  20  includes a countersink or forcing cone  28  that extends around the entire inner circumference at the tip of the cannula, the distal end  54  of the outer cannula  50  includes a forcing cone or countersink  56  that extends only over less than the entire inner circumference. This circumferentially truncated forcing cone can be matched with a forcing cone defined on the inner member, as discussed below. This forcing cone can also define a sharp cutting edge  57  at the distal end of the cannula. The truncated forcing cone  56  subtends a circumferential angle that is complementary to the circumferential angle subtended by the partially cylindrical wall of the inner member. Thus, if the partially cylindrical wall forming the scoop portion subtends the lower 180° of the circumference, the forcing cone  56  of the outer cannula subtends the upper 180° of the circumference. 
         [0042]    The remaining portion of the circumference  58  does not have any countersink and instead is formed at the same inner radius as the inner wall  52  proximal to the countersink  56 . In one specific embodiment, the portion  58  without the forcing cone is co-extensive with the scoop portion  44  of the inner member  40  ( FIG. 5A ), as illustrated in  FIG. 10 . In the embodiment described above, the scoop portion  44  subtends an angle of 180°, so the portion  58  of the outer cannula  50  also subtends an angle of about 180°. It can be appreciated that the distal edge of the outer cannula is blunt at the portion  58 , although the end can be beveled to form a sharpened edge. However, in this embodiment, the distal end  46  of the inner member  40  can be provided with a sharpened edge  47  ( FIG. 8 ) to sever tissue upon introduction of the inner member, in which case the blunt edge of the portion  58  can follow the path already prepared by the inner member. On the other hand, since the upper forcing cone  56  of the outer cannula is passing through tissue that has not yet been severed, the sharpened cutting edge  57  facilitates passage of the outer cannula through the tissue. The forcing cone  56  further acts in the manner of the forcing cone  28  of the outer cannula  20  to help force tissue collected by the scoop into the outer cannula and retain that tissue within the outer cannula as the device is withdrawn from the biopsy site. 
         [0043]    The inner member may be modified to cooperate with the forcing cone  56  of the outer member  50 . In particular, a modified inner member  40 ′, shown in  FIG. 11 , includes the same scoop portion  44 ′ but the distal end  46 ′ is modified so that the angled surface  47 ′ is defined at an angle that matches the angle of the forcing cone  56  of the outer member. Thus, in one embodiment, the two forcing cones  56  and  47 ′ may be defined at an angle of 1-5° and be substantially coextensive over a length of 1-5 mm (0.04-0.21 in.) to facilitate introduction of tissue into the scooped cannula. The two forcing cones cooperate, as shown in  FIG. 12 , to avoid any gap between the inner and outer members gap that might trap tissue 
         [0044]    In a further embodiment, an inner member  60 , shown in  FIGS. 11-12 , includes a scoop portion  64  similar to the scoop portion  44  of the inner member  40 . However, in this embodiment, the distal end  66  of the inner member  60  terminates in a sharpened tip  68 . The sharpened tip  68  may be, for instance, a trocar tip, or others known in the art. The proximal end  62  of the inner member is preferably a solid body, so that the inner member  60  has the characteristics of a full core side notch device. The tip  66  is configured to readily penetrate tissue as the inner member  60  is advanced into the biopsy site. Once the inner member is in position, the surrounding tissue prolapses into the scoop portion  64 , in the manner of a side notch device. The inner member  60  may be used with any of the outer cannula described above, including the outer cannula  20  and the outer cannula  50 . With the tissue prolapsed into the scoop portion  64 , the outer cannula is advanced toward the distal end  66  of the inner member to capture the tissue within the outer cannula. 
         [0045]    The inner member  60  incorporates additional features to coincide with the outer cannula  50 . In particular, the distal end  66  is configured to mate with the distal end of the outer cannula, and in particular with the forcing cone  56  and non-forcing cone portion  58  ( FIG. 9 ). The distal end  66  thus includes an upper portion  70  that projects proximally from a cylindrical body  74  of the distal end. The upper portion further defines a tapered surface  72  that corresponds with the countersink or forcing cone  56  of the outer cannula. The body  74  defines an annular proximally-facing ledge  76  that is arranged to contact the edge of the non-forcing cone portion  58  of the outer cannula. Thus, the ledge  76  is contiguous with the portion  58 , which in the illustrated embodiment subtends an angle of 180°. Similarly, the upper portion  70  is contiguous with the countersink or forcing cone of the outer cannula. The distal end  66  is thus configured so that the body  74  essentially fully closes the distal end of the outer needle as the upper portion  70  nests within the countersink  56 . It can be appreciated that the countersink or forcing cone  56  of the outer cannula  50  performs as described above to force the tissue captured in the scoop portion into the outer cannula as the cannula is advanced toward the distal end  66  of the inner member  60 . 
         [0046]    In a further embodiment, the inner member  80  can include a proximal end  62  and scoop portion  64  similar to the previous embodiments. However, the distal end  86  of the inner member  80  is modified to a nib configuration  88 . The nib configuration extends from the half-circumference of the scoop portion  84  with the circumferential extent gradually decreasing to a sharpened point  89 . The distal end  88  is thus configured to be easily introduced into tissue. 
         [0047]    The foregoing detailed description of one or more embodiments of the biopsy device with an inner member disposed within an outer cannula has been presented herein by way of example and not limitation. It will be recognized that there are advantages to certain individual features and functions described herein. Moreover, it will be recognized that various alternatives, modifications, variations or improvements of the above-disclosed embodiments and other features and functions, or alternatives thereof, may be desirably combined into many other different embodiments, systems or applications. Presently unforeseen or unanticipated alternatives, modifications, variations or improvements therein may be subsequently made by those skilled in the art which are also intended to be encompassed by the appended claims.