Patent Publication Number: US-2020275962-A1

Title: Compressible mixing and delivery system for medical substances

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This is a divisional of U.S. patent application Ser. No. 14/184,478, filed Feb. 19, 2014, which is incorporated herein by reference in its entirety. 
    
    
     BACKGROUND 
     The present invention relates generally to the field of devices and methods for delivering substances to bone. More particularly, the present invention concerns devices and methods for mixing and delivering substances to the interior of fractured or otherwise injured bones, especially to the fracture interface. 
     Present methods of preparing a viscous surgical substance, such as a bone void filler, to be introduced to fractured or injured bones involve cumbersome, multi-step processes. The process to form such a surgical substance requires mixing a bulking agent with a reacting agent to form the substance at the time of use, such as at the time of delivery to the targeted area of the bone. Such methods may require mixing the elements in a separate mixing container and manually transferring the material to a delivery container, such as a syringe. Not only is this method laborious, but can also create a mess at the mixing site. The amount of time used to mix the elements and make this transfer can also add to the increased viscosity of the substance, and make compression of the syringe or delivery device for delivering the substance to a cannula or other delivery apparatus more difficult. Syringes can fail, which may result in waste of the substance therein, or require a further transfer and additional clean-up. Furthermore, the compressive forces necessary to make the transfer from the syringe can be difficult for many users and preparers of the material. 
     SUMMARY 
     Various embodiments of the invention described herein allow for mixing and delivery of a substance (e.g., medication or bone void filler) to be delivered to a target area of the body, such as a fracture site after stabilization of the bone. 
     One embodiment of the invention relates to method of mixing and delivering a substance to a bone including providing a compressible tube having a reservoir and using a mixing apparatus to mix a particulate solid and a mixing liquid to form the substance within the reservoir of the compressible tube. The method further includes using a compressing device to move the substance through an exit port in the compressible tube for delivery to the bone. 
     The method may also include providing the particulate solid in the reservoir of the compressible tube, or alternatively, introducing the particulate solid into the reservoir of the compressible tube. The method may also include introducing the mixing liquid into the reservoir of the compressible tube. The mixing liquid may be introduced to the reservoir through a sealable inlet portion. The compressible tube may include a portal serving as the inlet portion and the exit port. 
     The method may also include moving the substance through the exit port and into a delivery apparatus for delivery directly to the bone. The delivery apparatus may be a cannula positioned within the body and having a distal portion position near the target portion of the anatomy. 
     The substance may be a bone void filler. The compressing device may be positioned on the compressible tube and the method may further include moving the compressing device along the compressible tube to empty the substance from the compressible tube. The compressing device may include a rolling key to roll the compressible tube to empty the substance from the compressible tube. 
     Another embodiment of the invention relates to a mixing and delivery system including a compressible tube having a reservoir configured for mixing and holding a surgical substance. The compressible tube includes an inlet portion for accommodating the introduction of an element of the surgical substance into the compressible tube. The compressible tube also includes an exit port for enabling the delivery of the surgical substance to a target portion of an anatomy. The system further includes a mixing apparatus configured to be received through the inlet portion of the compressible tube for mixing the elements of the surgical substance to form the surgical substance. 
     The mixing and delivery system may also include a compressing device configured to move along the compressible tube and force the surgical substance through the exit port. The exit port may be configured to engage with a delivery apparatus which delivers the surgical substance to the anatomy. The delivery apparatus may be a cannula positioned within the body and having a distal portion position near the target portion of the anatomy. The inlet portion may be sealable. The compressible tube may further include a portal serving as the inlet portion and the exit port. 
     The reservoir of the compressible tube may contain a particulate substance and the fluid introduced through the inlet portion may be a mixing liquid. The surgical substance may be a bone void filler. 
     Yet another embodiment of the invention relates to a kit for mixing and delivering a surgical substance to an anatomy including a compressible tube having a reservoir configured for mixing and holding the surgical substance, the compressible tube containing a particulate solid. The compressible tube includes a portion capable of being opened to receive a mixing liquid introduced into the reservoir. The compressible tube also includes an exit port for enabling the delivery of the surgical material to a target portion of an anatomy. The kit further includes a mixing apparatus configured to be inserted into the compressible tube for mixing the particulate solid and the mixing liquid. The kit may include a plurality of compressible tubes. The kit may also include at least one compressing device configured to ride along the compressible tube and force the surgical substance through the exit port. 
     Alternative exemplary embodiments relate to other features and combinations of features as may be generally recited in the claims. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
       The disclosure will become more fully understood from the following detailed description, taken in conjunction with the accompanying figures, wherein like reference numerals refer to like elements, in which: 
         FIG. 1  illustrates a bone with a stabilizing wire and a hole in the bone around the stabilizing wire. 
         FIG. 2  illustrates the bone and stabilizing wire shown in  FIG. 1  with a cannula introduced over the stabilizing wire, for delivery of a surgical substance to a fracture in the bone. 
         FIG. 3  illustrates a longitudinal section view of a cannula with a cap used in connection with a delivery system according to an exemplary embodiment. 
         FIG. 4  illustrates a compressible delivery tube according to an exemplary embodiment. 
         FIG. 5  illustrates a mixing apparatus according to an exemplary embodiment. 
         FIG. 6  illustrates a pinching apparatus to be used with the delivery system according to an exemplary embodiment. 
         FIG. 7  illustrates a pinching apparatus used on the compressible tube in accordance with an exemplary embodiment of the delivery system. 
     
    
    
     DETAILED DESCRIPTION 
     Before turning to the figures, which illustrate the exemplary embodiments in detail, it should be understood that the application is not limited to the details or methodology set forth in the description or illustrated in the figures. It should also be understood that the terminology is for the purpose of description only and should not be regarded as limiting. For example, a femur is illustrated in the drawings, but the devices and methods described herein may be used in connection with any bone in the body, including but not limited to bones in the spine, arms, hands, legs, and feet. Furthermore, it should be understood that the exemplary embodiments described herein can also be used for the storage and mixing of other materials and substances. For example, though the description is directed to storing, mixing, and delivery of bone void fillers and similar substances, the delivery system disclosed herein may also be used for the storage of stem cells or bone marrow aspirate, and may accommodate mixing with other substances upon harvesting or at the time of delivery. 
     Referring to  FIG. 1 , a bone  10  includes a fracture  2 . The fracture  2  separates the bone into portions  10 A and  10 B. In surgical procedures to repair fractured bones, a stabilizing wire  4  may be used to hold bone portions together. The stabilizing wire  4  may be any type of wire used to temporarily or permanently secure portions of bone together, such as Kirschner wires or Steinmann pins. The stabilizing wire  4  is often placed in a fractured bone  10  prior to insertion of a more permanent bone implant, such as a bone screw, nail, or other fixation structure. In addition to stabilizing the bone portions  10 A and  10 B, the stabilizing wire  4  may serve as a guide for a cannula, drill or bone implant. 
     Various delivery apparatuses can be introduced over the stabilizing wire  4  to deliver a surgical substance, such as a bone void filler to the fractured area of the bone, or other target area of the anatomy. Such delivery apparatuses may be elongated cannulas that carry the surgical substance from the fluid/substance source, to the target area of the anatomy, and may be such cannulas as described in U.S. patent application Ser. No. 13/270,072, titled “Method and Device for Delivering Medicine to Bone,” filed Oct. 10, 2011, and hereby incorporated by reference herein in its entirety. 
     Referring to  FIG. 2 , according to an exemplary embodiment, a multichannel cannula  200  having, in a preferred embodiment, two or more channels may be introduced over the stabilizing wire  4  to deliver substances to the interior of bone  10 . In one embodiment, the multichannel cannula is introduced over the stabilizing wire  4  after creation of hole  6 , but prior to placement of a bone implant into the hole  6 . A first channel of the multichannel cannula receives the stabilizing wire  4 . The other channels of the multichannel cannula may be used for delivering the surgical substance to the interior of bone  10 . The substance delivered using the multichannel cannulas described herein may be any type of substance a user desires to deliver to the interior of a bone, including growth factors or medication such as bone void fillers, calcium phosphate paste, an antibiotic, pain medication, or a chemotherapeutic agent. 
     The cannulas described herein can be made of any material suitable for placement into a bone without harmful effects on the patient. In one embodiment, the cannula is made of stainless steel or other type of metal. In another embodiment, the cannula is made of a rigid plastic, such as polyethylketone, that cannot be easily bent or manipulated into alternative configurations. A rigid cannula may be advantageous to provide stability when introducing the cannula into a hole  6  in a bone  10 . Furthermore, a rigid cannula provides stability for various procedures that a more flexible cannula may not provide. For example, if a surgeon desires to use a plunger or other device to push a substance from the cannula and into the bone, a rigid cannula may be more desirable. As another example, a rigid cannula is able to withstand more significant forces than a flexible cannula (e.g., forces applied to the cannula by a delivery device or a suction device, and the forces resulting from movement of substances through the channels and through any open portals in the cannula). 
     The cannulae that may be used to deliver the substance to the bone are substantially elongated structures with, in preferred embodiments, two or more channels. The multichannel cannula  200  depicted in  FIG. 2  and described herein includes a first channel  201  having an open proximal end  224  and an open distal end  222 . The open proximal end and open distal end allow the first channel to be threaded over a stabilizing wire  4 . Thus, the first channel  201  is configured to receive a stabilizing wire  4 . In one embodiment, the first channel  201  is substantially cylindrical and has a diameter slightly larger than the diameter of the stabilizing wire. The side wall of the cylindrical first channel (as distinguished from the open ends of the first channel) may be continuous, meaning there are no open portals or other openings along the side wall of the first channel. In one embodiment, liquid cannot penetrate the side wall of the first channel. 
     The multichannel cannula shown in  FIG. 2  further includes a second channel  202 . The second channel  202  includes at least one inlet portal  220  and at least one exit portal (e.g., open distal end  210 ). In some methods described herein, the inlet portal  220  of the second channel  202  serves as an inlet for the surgical substance to be delivered to the interior of a bone. In these embodiments, the exit portal  210  of the second channel serves as an outlet for the substance. The inlet portal and exit portal of the second channel are thus in fluid communication to allow substances or materials to be delivered to the interior of a bone. 
     As shown in  FIG. 3 , multichannel cannula  200  may also include a cap  320 . The cap  320  has a housing portion with a channel for coupling to a portion of the proximal end of cannula  200 . The channel of the cap  320  may extend from first end through a second end of the housing portion for receiving the stabilizing wire  4  therethrough. In a preferred embodiment, the cap  320  is affixed to the multichannel cannula  200 , such as during production of the cannula  200 . In an alternative embodiment, the cap  320  may be removable. The cap  320  may be positioned at the site of the hole in the bone, such as hole  6 , in order to serve as a plug. In this way, cap  320  can plug the hole  6  and may prevent irrigation or other substance being delivered to the site from coming back up through the hole  6  in the bone. In another embodiment, a separate temporary plug or seal may be added to the cannula to plug the hole  6  in the bone. In the embodiment shown, cap  320  also has a delivery portal  322 . The delivery portal  322  is coupled to an inlet portal of the second channel  202  such that a substance can flow from the delivery portal  322 , through the inlet portal, and into the second channel  202 . 
     Various delivery systems can be coupled to the delivery portal  322  to assist in delivering substances to the second channel  202  of multichannel cannula  200 , and ultimately to the bone. Tubing may be used to connect the delivery system to the delivery portal  322 . The type of delivery system selected by a user may depend on the type of substance to be delivered to the bone. 
     One such delivery system is a mixing and delivery system  400 , as depicted in  FIGS. 3-7 . While shown in use with the cannula  200 , the delivery system  400  according to various exemplary embodiments can also be used with other delivery apparatuses, other than the cannulas shown and described above, such as a different cannula, a catheter, or a delivery needle. 
     As shown in  FIG. 4 , the mixing and delivery system  400  includes a flexible, compressible tube  401 . The compressible tube  401  includes a reservoir  402  that is configured to hold and/or receive elements to be mixed together for forming a surgical substance. In one embodiment, the elements for forming a bone void filler are a particulate substance and a mixing liquid, such as a bulking agent and a reacting agent. In another embodiment, one of the elements may be a component containing stem cells or bone marrow aspirate that may be mixed with a second element at the time of harvest, or prior to delivery. In yet another embodiment, the first element may be a prepared paste or fluid, to be mixed with a second fluid element. The reservoir  402  is of sufficient size and shape such that the mixing of the elements to form the surgical substance can take place therein. The reservoir  402  is in fluid communication with at least one portal  404  of the compressible tube  401 . The portal  404  may serve as both an inlet and an exit portal, or the delivery tube may have more than one portal, one serving as an inlet portion separate from and in addition to an exit portal. The portal  404 , or an alternative inlet portion such as a sealable opening, allows for introduction of, for example, the mixing liquid to the particulate solid held in the reservoir  402 . The portal  404  is preferably sealable so as to contain the first element, such as a particulate solid, and/or the surgical substance within the reservoir when introduction of the second element, such as the mixing liquid, or delivery of the surgical substance is not taking place. The compressible tube  401  also has an exit portal, which may also be portal  404 , through which the mixed and prepared surgical substance is delivered to a delivery apparatus, such as the cannula  200  discussed herein, directly to a target area, or to another device to hold the surgical substance. 
     In an exemplary embodiment, the portal  404  is both the inlet and the exit portal. In an alternative exemplary embodiment, the portal  404  serves as an exit portal only, and the opposing end  405  is open, or able to be opened and resealed, such that introduction of the mixing liquid and performance of the mixing (described below) can be accomplished through the opposing end  405 . 
     In certain embodiments, the compressible tube  401  has a false bottom, wherein the tube has an internal partition constituting a wall of the reservoir  402  portion of the compressible tube  401 . In other embodiments, the reservoir  402  comprises the entirety of the area within the compressible tube  401  structure. The compressible tube  401 , in preferred embodiments, is made of a transparent material to enable visualization of the mixing of the surgical substance. In this way, a practitioner is able to witness and guide the progress of the mixing and determine when the surgical substance is appropriately formed. 
     Referring to  FIG. 5 , in an exemplary embodiment, mixing and delivery system  400  also includes a mixing apparatus  410 . The mixing apparatus  410  may be a blender or other device suitable for mixing the particulate solid with the mixing liquid. The mixing apparatus  410  may be any blender, agitator, or mixer suitable for mixing medical substances. As shown in the embodiment of  FIG. 5 , the mixing apparatus  410  includes a handle/housing portion  412  for managing and manipulating the mixing apparatus  410  and a mixing portion  414 . The mixing portion  414 , as shown, is an elongated portion that is configured to be received through the inlet portion of the compressible tube  401 , such that the mixing and forming of the surgical substance can take place within the reservoir  402 . 
     Mixing and delivery system  400  may also include a compressing device, such as the compressing device  420  shown in  FIG. 6 . The compressing device  420  may have a slotted portion  422  configured to receive a portion of the compressible tube  401  therethrough. The compressing device  420  may be separate from the compressible tube  401 , or may be integrated into the compressible tube  401 . The compressing device  420  is configured to move along the length of the compressible tube  401 , compressing the compressible tube  401  so as to force the surgical substance through the exit portal of the compressible tube  401 , as shown in  FIG. 7 , and to the cannula, catheter, needle, or other chosen delivery apparatus. In particular, the compressing device  420  may have a rolling key  424  that moves along or rolls the compressible tube  401  by way of manual manipulation of a key flange  426 , and that causes the compression of the compressible tube  401  and forces the surgical substance from the reservoir  402 . 
     One method of mixing and delivering a surgical substance to bone, such as a bone void filler, according to an exemplary embodiment includes providing a compressible delivery tube, such as compressible tube  401 , wherein the compressible tube  401  has a reservoir  402 . The compressible tube  401  may be provided with a first element therein, such as particulate solid or a prepared paste or fluid, or the first element may be introduced into the reservoir  402  through the portal  404 . A mixing apparatus  410 , such as a blender, mixing, or agitator, is introduced to the reservoir  402  of the compressible tube  401  after or during introduction of a second element, such as the mixing liquid to the reservoir  402 . As described above, the second element, such as the mixing liquid, may be introduced through the portal  404  or through an alternative inlet portion of the compressible tube  401 . The mixing apparatus  410 , likewise, may be introduced through the portal  404  or through an alternative inlet portion of the compressible tube  401 . The method further includes moving the surgical substance through the exit port of the compressible tube  401  for delivery to the body. Delivery to the body may take place through a cannula as described above, or may alternatively take place through a catheter, delivery needle, or other delivery apparatus. Moving the surgical substance through the exit port of the compressible tube  401  may use a compressing device  420  which moves along the length of the compressible tube  401  to force the surgical substance through the portal  404  of the compressible tube  401 . 
     The construction and arrangement of the devices and methods as shown in the various exemplary embodiments are illustrative only. Although only a few embodiments have been described in detail in this disclosure, many modifications are possible (e.g., variations in sizes, dimensions, structures, shapes and proportions of the various elements, use of materials, orientations, etc.). For example, the position of elements may be reversed or otherwise varied and the nature or number of discrete elements or positions may be altered or varied. Accordingly, all such modifications are intended to be included within the scope of the present disclosure. The order or sequence of any process or method steps may be varied or re-sequenced according to alternative embodiments. Other substitutions, modifications, changes, and omissions may be made in the design, operating conditions and arrangement of the exemplary embodiments without departing from the scope of the present disclosure.