Abstract:
The biopsy device has a biopsy channel connected to an aspiration and collecting chamber and at least one application channel connected to a dispensing chamber integrally connected with the aspiration chamber. The application channel is formed by a tube centrically slipped over the biopsy channel wall. To enable the collection of tissue specimens without tissue specimens entering and obstructing the application cannula, the distal segment of the application channel forms a close fitting and concentric sheath around the biopsy channel. The proximal end of the application channel has a larger diameter than the distal end allowing for unobstructed flow of the application material past the biopsy channel wall upon retraction of the biopsy channel from the distal segment of the application channel.

Description:
This application claims the benefit of provisional application No. 60/246,029, filed Nov. 6, 2000. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to a biopsy device that takes a biopsy sample of human or animal tissue and delivers a coagulant or other material to the biopsy incision track in order to plug the track and prevent bleeding. 
     BACKGROUND OF THE INVENTION 
     Excision biopsy of the liver has traditionally been the gold standard for assessing the extent of injury and determining prognosis in chronic viral hepatitis and liver cancer. A significant complication that frequently occurs is bleeding from the biopsy site. Significant hemorrhage occurs in 0.35 to 0.5% of all procedures while evidence of sub-clinical bleeding, as detectable by ultrasound 24 hours post biopsy, has been reported in up to 23% of patients. Smaller amounts of surface bleeding is almost universal and is frequently associated with mild to moderate pain. 
     Excision biopsies from other organs, such as the lungs, also exhibit a relatively high complication rate due to hemorrhagic incidents and pneumothorax. Also with kidney biopsies and biopsies of other organs, perfuse bleeding is considered the most important complication. 
     The most common liver biopsy technique is by percutaneously inserting a needle into the liver for a fraction of a second and obtaining a tissue sample. The subsequent procedure for taking the biopsy varies according to whether the biopsy needle is of the aspiration or cutting type. For the cutting needle, the needle is inserted into the liver and followed by the outer sheath. The specimen is entrapped in the recessed section of the cutting needle. The aspiration technique is probably the most widely used technique. The best known aspiration biopsy technique is based on the principle indicated by Menghini. There a hollow needle having an average diameter of 1.4 mm and having a facility for attachment of a syringe is used, by which a negative pressure (suction) is applied upon piercing through the skin and prior to the organ puncture proper. The organ puncture (liver) then is realized with a sustained suction to secure the biopsy sample. 
     In order to obviate the reported complications, it was recommended to subsequently plug the needle track with resorbable material so as to eliminate, in particular, bleeding complications. Such techniques, however, imply a long residence time of the puncture needle in the organ, which again constitutes a cause of complications, in particular with liver punctures. 
     From Austrian Pat. No. 384,165, a biopsy needle device of the initially defined kind is known, with which the cannula has a curved partition wall towards the internal limitation of the cannula lumina. Therein, the partition wall does not reach immediately to the front end of the cannula so that the biopsy channel and the application channel communicate in the region of the tip of the cannula. The multi-lumen biopsy needle according to Austrian Pat. No. 384,165 enables the collection of tissue and the application of substances plugging the puncture track in coordination with the puncturing procedure in one operating cycle, thus largely shortening the time of intervention. 
     U.S. Pat. No. 4,850,373 and related EP patents 243341 A, B1 etc., also describes a biopsy needle device having a two lumen cannula, a biopsy channel of constant cross section and one application channel. The application channel is formed by a tube eccentrically slipped over the biopsy channel wall. Furthermore, the biopsy channel is described as a noncircular tubular structure with its channel wall flattened in cross section such that an application channel is formed between the flattened side of the biopsy channel wall and the outer application tube. In addition, surface contact exists between the non-flattened side of the biopsy channel wall and the application tube. 
     A common surgical material used to control bleeding is Gelfoam®. Gelfoam® is supplied in either a powder form or as an implantable sponge. Sterile sponges, such as Gelfoam®, are prepared in dry sterile sheets that are used as packing material during surgery for control of bleeding. The sponge sheets are left in the surgical site after surgery to stop bleeding and are absorbed by the body in 1 to 6 weeks. A number of techniques have used these absorbable sterile sponge materials to plug a biopsy track to minimize or prevent bleeding. The absorbable sponge provides a mechanical blockage of the track, encourages clotting, and minimizes bleeding though the biopsy track. Despite the advantages of using absorbable sponge to plug a biopsy track this technique has not achieved widespread use because of difficulty in preparing and delivering the sponge material into the biopsy track. 
     One example of a biopsy wound closure device using an implantable sponge is described in U.S. Pat. No. 5,388,588. According to this patent, a circular sponge of an absorbable foam material is precut and inserted into a biopsy site by an applicator rod having the sponge positioned on the end. Once the sponge is implanted, the sponge absorbs blood and swells to fill the track preventing further bleeding at the biopsy site. However, the sponge is difficult to deliver and expands slowly once delivered. In addition, this delivery method can only deliver a sponge of a limited size that provides less local compression than desired and may incompletely fill the target site. Further, bleeding may continue along sections of the biopsy track where no sponge has been delivered. 
     Another example of a Gelfoam® inserting device to facilitate hemostasis is described in U.S. Pat. No. 6,086,607. According to this patent, a method of cutting a piece of Gelfoam® sponge from a sheet of the material, folding the strip to form a pledget with one end of different cross section than the other end, and inserting the pledget in an adapter to compress the pledget and for attachment to a syringe for delivery of the pledget to the tissue. The adapter is attached to a cannula that was previously inserted into the organ being biopsied and the Gelfoam® is inserted into the tissue through the cannula. 
     No previous patents describe the combination of the multi lumen needle containing a biopsy channel and an application channel with a syringe assembly for obtaining the biopsy and delivering the application material. In addition, the prior art does not describe a biopsy needle that translates within the application tube so that the application material will have an unobstructed passage into the biopsy track. The previous patents either describe the biopsy channel as being eccentrically positioned within the application tube as opposed to the disclosed concentric positioned biopsy or a separate device which delivers a hemostatic sponge to the biopsy track. 
     SUMMARY OF THE INVENTION 
     The present invention provides a biopsy device with a view to enabling the collection of tissue specimens for biopsy and to apply auxiliary substances directly in the site of the puncture without tissue specimens getting into the application cannula, thus obstructing the same. 
     In accordance with one aspect of the present invention, a syringe system comprised of a multi chambered unit for taking the biopsy specimen and delivering a coagulating material. The system includes a multi-lumen channel structure with at least one biopsy channel of formed by a tube constant cross section over its entire length and at least one application channel formed by a tube of varying cross section slipped over the biopsy channel wall. The biopsy tube is connected to the end of biopsy syringe and opens to the inner chamber of the system for securing and retrieving the biopsy specimen. The application tube is connected to the end of the outer casing and communicates with the outer chamber containing the application material. When the biopsy syringe is retracted within syringe assembly, the biopsy needle is also retracted within the application channel. 
     The biopsy channel wall projecting out of the application tube with its cutting edge formed by an acute angularly designed end of the biopsy wall channel. 
     Using a prior art biopsy device, a biopsy is achieved according to the invention in that after the tissue specimen is collected in the biopsy channel, the inner tube containing the tissue specimen is retracted within the concentric outer application tube thus allowing the application material to be injected into the biopsy track without obstruction. The retraction of the inner, biopsy tube provides the mechanism by which the application material is forced to be expelled from the outer application tube. This is facilitated according to the invention by a placing the biopsy device in another device which causes the translations and movements of the parts of the fore mentioned biopsy device. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of the assembled biopsy (syringe) and delivery device according to the invention; 
     FIG. 2 is a perspective view of the delivery system with the top removed; 
     FIG. 3A is a cut-away perspective view of the delivery device with the biopsy syringe unit separated from the delivery device; 
     FIG. 3B is an exploded perspective view of the delivery system parts; 
     FIG. 3C is a perspective view of the slide mechanism for the delivery system; 
     FIG. 4 is a perspective view of the biopsy syringe; 
     FIG. 5A is a longitudinal, sectional view of the biopsy syringe; 
     FIG. 5B is a cross sectional end view of the biopsy syringe taken about plane  5 B— 5 B of FIG. 5A; 
     FIG. 5C is a cross sectional view of the biopsy syringe taken about plane  5 C— 5 C of FIG. 5A; 
     FIG. 5D is a sectional view of the near end of the biopsy syringe showing the direction of flow of the coagulant material upon retraction of the coagulant plunger; 
     FIG. 5E is a sectional view of the far end of the biopsy syringe showing the direction of flow of the coagulant material and the biopsy specimen. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The system of the present invention collects and retrieves a biopsy specimen and then delivers, without removal of the biopsy assembly, an absorbable coagulant material to facilitate hemostasis of the biopsy track or other puncture wound in a simple and safe manner. The apparatus for collecting the biopsy specimen and delivering a coagulant material will be described below in connection with procurement of a liver biopsy sample for the diagnosis of liver diseases. However, the invention can be used for the procurement of other biopsy specimens from other vascular organs as well as facilitating hemostasis of other types of puncture wounds or tissue access tracks to prevent bleeding of these wounds. 
     The system  10 , for procuring a biopsy specimen and delivering a coagulant material, includes a multi-chambered syringe assembly  100  for procuring the biopsy, storing the biopsy specimen and coagulant material, and delivering the coagulant material. The system  10  also includes a delivery assembly  500  to enable the operator to manipulate the syringe components for securing the biopsy specimen and dispensing the coagulant material. 
     FIG. 1 illustrates the assembled device  10  of the invention including the syringe assembly  100  and the delivery assembly  500 . The delivery assembly  500  consisting of the top shell  505 , bottom shell  515 , handle  520 , triggers  540 ,  550  and rear slide  590 . 
     FIGS. 2,  3 A,  3 B and  3 C illustrate an overall view of the two assemblies of the invention with the top shell  505  removed. For removal, projections  507  are squeezed inward to release the tabs  506  from the holes  511 . The top shell  505  is mated to the bottom shell  515  by inserting tabs  506  into holes  511  such that opening  508  is positioned over the barrel  120  of the syringe unit  100 . When viewed from the outside, the syringe unit  100  is comprised the outer casing  120 , the needle sheath  200 , the biopsy needle  260 , the outer casing top  300 , the coagulant plunger  290 , and the biopsy plunger  225 . The interior of the syringe assembly  100  is disclosed hereinafter. The syringe assembly  100  is positioned within the delivery unit  500  by inserting the flange  310  of the outer casing top  300  into the slot  574  of the front slide holder  570 . The flange  291  of the coagulant plunger  290  is inserted into the slot  584  of the middle slide holder  580  and the flange  235  of the biopsy plunger  225  is inserted into the slot  594  of the rear slide holder  590 . The movement of the syringe parts is accomplished by the slide holders  570  and  580  which are manually operated by triggers  540 ,  550 , respectively, and rear slide holder  590  which is positioned using the operator&#39;s thumb on handle  595 . The extension arm  555  of the primary trigger  552  is positioned within the yoke  575  of the front slide holder  570  containing the outer casing top  300 . When the trigger  542  is rotated towards the handle  520 , the extension arm  555  contacts the forward portion of the yoke  575  and moves the front holder  570  and syringe outer casing  300  forward along the slide pins  560  mounted within the bottom shell  515 . The slide pins  560  have helical springs  600  placed over them. The springs  600  are positioned between the front slide holder  570  and the wall of the bottom shell  515 . The springs  600  are dimensioned to place sufficient pressure against the front slide holder  570  to place it in the open position, as illustrated in FIG. 1, when not under user applied pressure. Likewise, the extension arm  545  of the biopsy trigger  542  is positioned within the yoke  585  of the holder  580  so that when the trigger  542  is pulled toward the handle  520  the extension arm  545  contacts the forward portion of the yoke  585  and moves the holder  580  and the coagulant plunger  290  forward along the slide pins  560 . The collars  573 ,  583  on the holders  570 ,  580 , respectively prevent the holders from tilting and jamming. 
     During the normal operation of the device, the two triggers  540 ,  550  would be in an open position; rotated away from the handle  540 . With the syringe filled with saline and coagulant for taking a biopsy, the syringe unit  100  is placed in the delivery assembly  500  as described above. The syringe flanges  235 ,  291  and  310  are inserted into holder slots  594 ,  583  and  574 , respectively. 
     The needle  260  and needle sheath  200  are driven through the skin and underlying tissue into the abdominal cavity. With his thumb on the back holder extension  595 , the operator the pushes the extension to flush the needle  260  with saline contained in the biopsy chamber  295 . The assembly is advanced forward until the operator feels the tip of the needle  260  penetrate the organ to be biopsied. The operator then pulls back on the back holder extension  595  to provide a slight amount of negative pressure within the biopsy chamber  295  and to hold the surface of the tissue in the biopsy needle channel. The coagulant trigger handle  542  of the trigger  540  and biopsy trigger handle  552  of the trigger  550  are fixed to the lower shell  515  by a pin  565  extending through fulcrum  543  and fulcrum  553 , respectively. The extension arm  545  of coagulant trigger  540  penetrates yoke  585  to control the movement of holder  580 . Likewise extension arm  555  of trigger  550  intersects with yoke  575  of holder  570 . The trigger handles  542  and  552  are squeezed toward the handle  520 , which advances the syringe assembly  100  forward, and the needle  260  advances deeper into the tissue. The coagulant trigger  540  is released which pulls the coagulant plunger  290  backwards. Retraction of the coagulant plunger  290  forces the coagulant from the middle chamber  136  to the outer chamber  135  and out though the needle sheath  200  as the biopsy needle  260  is withdrawn. Although the inner-outer sheath combination has been described in the prior art, this has only been in conjunction with fixed structures. The complexities of having movable cannulas have not been resolved until the disclosed system. 
     The syringe unit can be also be used independently to obtain a biopsy sample and deliver the coagulant plug. In this embodiment the operation of the syringe is done manually. FIG. 4 illustrates the outer view of the syringe assembly  100  according to the invention and as used independently from the delivery system. The biopsy needle  260  extends from the needle sheath  200  attached to the outer casing  120 . The needle sheath  200  has three distinct regions, a distal segment  210  which has an internal diameter slightly greater than the outer diameter of the biopsy needle  260 , a proximal region  215  that has a substantially larger diameter than the distal segment  210  and a transition segment  220  between the two. The outer casing top  300  provides for concentric guiding of the inner coagulant cylinder  290 , which in turn guides the biopsy plunger  225 . A one-way check valve  140  is located on the outer casing  120  for filling the syringe with coagulant material. A vent hole  125  is also located on the far end of the outer case to allow operation of the coagulant plunger. 
     The syringe assembly is illustrated in more detail in FIGS. 5A-5E. FIG. 5A shows a longitudinal cut away view of the syringe assembly  100 . The biopsy needle  260  is attached to the distal end  270  of the coagulant plunger  280 . The channel  261  of the biopsy needle  260  is in fluid communication with the biopsy chamber  221 . The biopsy chamber  221  is formed with the coagulant plunger  280  at the distal end and the biopsy plunger  225  at the proximal end. The biopsy needle  260  passes through an o-ring  165  at the distal end of the inner coagulant cylinder  160  to provide a seal between the outer coagulant chamber  135  and the inner air chamber  265 . The biopsy plunger  225  slides within the coagulant cylinder  290 . The coagulant cylinder  290  is guided within the assembly at the proximal end by the outer casing top  300  and the insert  320 . The o-ring  305  provides a watertight seal within the outer casing top  300 , distal to the insert  320 . At the distal end  270 , the coagulant cylinder  290  is attached to the coagulant plunger  280 , which is guided within the assembly by the middle coagulant cylinder  160 . The o-ring  275  in the coagulant plunger  280  forms a seal for the middle coagulant cylinder  160  to provide a seal between the inner coagulant chamber  136  and the air chamber  265 . The inner coagulant chamber  136  is bounded at the proximal end by the outer casing top  300  that supports the near end of the inner coagulant cylinder  290 . The distal end of the middle coagulant cylinder  160  containing the end  162  is supported by spacers  131  of the outer casing end. the inner air chamber  265 . The biopsy plunger  225  slides within the coagulant cylinder  290 . The coagulant cylinder  290  is guided within the assembly at the proximal end by the outer casing top  300  and the insert  320 . The o-ring  305  provides a watertight seal within the outer casing top  300 , distal to the insert  320 . At the distal end, the coagulant cylinder  290  is attached to the coagulant plunger  270 , which is guided within the assembly by the middle coagulant cylinder  160 . The oaring  275  in the coagulant plunger  270  forms a seal for the middle coagulant cylinder  160  to provide a seal between the inner coagulant chamber  136  and the air chamber  265 . The inner coagulant chamber  136  is bounded at the proximal end by the outer casing top  300  that supports the near end of the inner coagulant cylinder  160 . The distal end of the middle coagulant cylinder  160  containing the end  162  is supported by spacers  131  of the outer casing end  130 , thus forming the coagulant chamber  135 . Passageways  190 , as illustrated in FIG. 5D, within the middle coagulant cylinder  160  allows communication between the inner coagulant chamber  136  and the outer coagulant chamber  135  formed by the outer casing  120 . An air vent  125  is positioned at the far end of the chamber  265  in front of the coagulant plunger  270  to enable air to enter or escape from the chamber  265  as the plunger  270  moves back and forth. The check valve  140  allows the filling of the inner and outer coagulant chambers  136 ,  135  respectively with coagulant. The one-way valve  141  only allows insertion of the fluid and prevents fluid from escaping through the check valve  140  during operation. The needle sheath  200  is attached to the end unit  121  of the outer casing  120  such that the interior channel  205  of the sheath  200  communicates with the outer coagulant chamber  135  at the distal end of the inner coagulant cylinder  160 . 
     The operation of the syringe assembly  100 , method of filling the syringe and obtaining a biopsy are as disclosed herein or through any other method obvious to those skilled in the art when incorporated with this disclosure. The biopsy plunger  225  and coagulant plunger  290  are fully inserted into the lower assembly  500 . The biopsy needle  260  is inserted into a container of sterile saline and the biopsy plunger flange  235  is retracted slowly drawing saline into the biopsy chamber  221 . Upon filling the biopsy chamber  221  with an appropriate amount of saline, the syringe  100  is placed in a vertical orientation with the needle  260  pointing upwards and the biopsy plunger flange  235  depressed slightly to expel any air within the chamber  221 . The syringe assembly  100  is then inverted and a coagulant filled syringe is attached to the check valve  140 . The coagulant material, typically Gelfoam paste (1 gram/25 cc saline), is injected through the check valve  140  into the inner coagulant chamber  136 . When the chamber  136  is filled, the syringe  100  is again inverted and the outer chamber  135  is filled until the Gelfoam can be observed exiting the interior channel  205  located between the outer sheath  200  and the biopsy needle  260 . The Gelfoam syringe is then removed from the check valve  140  and the syringe is ready to take a biopsy. 
     The syringe  100  can either be placed in the delivery system  500  or used manually; the operation of the components is identical. The manual operation will be described as the operation of the delivery system was described previously. Upon identification of the proper biopsy site, the skin is pierced with the needle extended and inserted through the tissue layers into the abdominal cavity. The biopsy plunger  235  is depressed slightly to expel any tissue that may have gotten into the needle track during the insertion process. The unit is advanced until the needle  260  contacts the outer surface of the organ to be biopsied and inserted slightly. The biopsy plunger  235  is retracted slightly to provide a negative pressure in the biopsy chamber  221  and “hold” on to the surface of the biopsy material  150  within the needle channel  261 . The needle  260  is further advanced into the tissue to a desired depth, usually  2  centimeters. While maintaining the negative pressure in the biopsy chamber  221 , the coagulant plunger  290 , along with the biopsy plunger  225  and attached needle  260 , are retracted. As the coagulant plunger is retracted, FIG. 5D, the coagulant material within the inner coagulant chamber  136  and outer coagulant chamber  135  is slightly pressurized. When the biopsy needle  260  has been retracted past the diameter reduction point  220  of the sheath  200 , the coagulant material will flow out through the inner channel  205  of the sheath  200  into the tissue. As the coagulant plunger  290  is retracted, the coagulant flows, following the direction of the arrows  155 , rearward in the inner chamber  136  and then reverses direction as it passes through the portals  190  of the inner coagulant cylinder  160  and forward in the outer coagulant chamber  135 . The coagulant finally flows outward through the inner channel  205  into the biopsy site. 
     With the biopsy site filled with coagulant, the needle portion of the needle assembly  100  is withdrawn from the body. The coagulant plunger is pushed back into the assembly so that the biopsy needle  260  extends out past the tip of the sheath  210 . The biopsy plunger  235  is then also pushed back into the coagulant plunger  290  expelling the biopsy sample. 
     As described above, the coagulant can be delivered to the biopsy track by holding the needle sheath  200  stationary and injecting the coagulant through the inner channel  205 . According to an alternative embodiment of the invention, the method of delivering the coagulant into the biopsy track can include withdrawing the needle sheath  200  during delivery of the coagulant in an elongated trail that follows the biopsy track. This technique places the absorbable coagulant material in a trail that fills the entire biopsy track and provides the added benefit of providing hemostasis along the entire biopsy track. This is particularly helpful for stopping the bleeding of biopsy tracks in organs that tend to have excessive bleeding such as the liver, kidney, spleen, and other vascular organs. 
     The absorbable coagulant may also be used to deliver a beneficial agent, such as contrast agent, thrombin, radiation treatment, or the like. The coagulant can also be used to deliver therapeutic agents, such as radioactive isotopes for localized treatment of tumors, anti-cancer agents, anti-metastatic agents, and the like. Examples of anti-cancer agents include 5-fluorouracil, cisplatin, prednisone, and others described in U.S. Pat. No. 4,619,913, which is incorporated herein by reference. 
     The commercially available Gelfoam material will be absorbed by the body within 1 to 6 weeks. However, the material may be designed to provide different rates of absorption. For example, Gelfoam can be designed to be absorbed at different rates by varying the degree of cross-linking. Preferably, the coagulant material is designed to be absorbed in less than one month. 
     The treatment of a biopsy track with an injectable absorbable coagulant to facilitate homeostasis in conjunction with procuring a biopsy provides substantial advantages in comfort over external pressure methods or the insertion of a pledget of Gelfoam foam as described in U.S. Pat No. 6,086,607. In U.S. Pat No. 6,086,607, the pledget must be inserted through a catheter previously inserted. The insertion of a catheter involves a longer procedure and the risk of the catheter shifting while the operator switches or disconnects from the aspiration biopsy syringe to the coagulant delivery syringe as described in the referenced patent. In addition, the present invention also provides advantages over the insertion of an absorbable sponge material in a dry state with an applicator. A dry piece of sponge material must be cut to the particular size of the biopsy track and does not swell to fill the track until the blood has sufficiently saturated the sponge material which can take significantly longer and provides inadequate local compression. 
     The present invention may be employed to deliver other materials other than coagulant material into a biopsy track or used to drain and fill an abscess. Additionally, the triggers can be replaced with a motor having exterior controls. 
     While the invention has been described in detail with reference to the preferred embodiments thereof, it will be apparent to one skilled in the art that various changes and modifications can be made and equivalents employed, without departing from the present invention.