Abstract:
The invention described herein is a device for dripping a tissue sealant and/or adhesive that comprises a) first and second barrels or syringes that contain first and second biocomponents that are disposed between proximal and distal ends; b) a plunger in each barrel and c) a drip tip comprising i) a support having distal and proximal ends and at least two fluid passageways from the distal to the proximal end that are in fluid communication with one of the barrels of the dispensing device on the proximal end; and ii) an endcap that fits over the support having at least two flexible hinges. The present invention is also directed to an assembly for mixing and drip dispensing two reactive biologic components as tissue sealant and/or hemostatic agent and to methods for delivering biologic components to achieve hemostasis and/or tissue sealant by drip dispensing from the device described above.

Description:
The present disclosure relates to flexible drip tip assemblies for use with devices that mix and apply two or more biologic components. More particularly, the present disclosure relates to a drip tip assembly for use with a biologic drip device, wherein the drip tip is capable of self-clearing as a result of a flexible outlet design. 
     BACKGROUND 
     Drip devices for dispensing two or more biocomponents are known. In the medical device field, such devices are typically used for applying bioadhesives, polymers and other synthetic material used in wound closure. Because of the reactant nature of the biocomponents used to form the bioadhesive, mixing of the components does not occur until the solution is ready to be applied. Mixing of the components too soon before application may result in premature hardening of the mixture, thereby making application of the solution impossible. Thus, in known drip devices, the two or more components are maintained separately until just prior to application. The drip devices include one or more mixing means for mixing the two or more solutions prior to application. The mixing means may be passive, i.e., spiral configuration in the tubing, or instead may be active, i.e., mixing blade or impeller. Once mixed, the solution may be applied through a needle-like output or may instead be ejected through a spray assembly. Thorough mixing of the two or more components prior to application is important to ensure that the solution will perform as intended. 
     An exemplary device is taught in U.S. Pat. No. 5,116,315, entitled “Biological Syringe System”, which discloses a system for delivery two fluids in a mixed composition, comprising a manifold and a discharge assembly. The discharge assembly mixes fluids in a mixing space and then atomizes the mixed fluids in a spray delivered from the assembly. Similarly, the device shown in U.S. Pat. No. 5,605,255, entitled, “Apparatus for Spraying a mixture of Two Components’, is an apparatus for spraying a liquid mixture having two syringes, a connecting piece, a premixing chamber, and a reduced volume section downstream from premixing chamber, and an exit aperture for spraying the mixture. The reduced volume section terminates in a homogenization region. U.S. Pat. No. 6,063,055, entitled “Turbulence Mixing Head for a Tissue Sealant Applicator and Spray Head for Same”, illustrates a device in which the mixing is performed in a mixing head. 
     Intermittent use of a biologics spray device, as may be required during a procedure, tends to clog the outlet of the applicator tip. As a result, most applicator assemblies are provided with a number of replacement tips for when clogging of the tip occurs. Replacing clogged applicator tips interrupts the flow of a procedure, is time consuming and is an added expense. The device in published U.S. Patent Application 2010/0096481, “Self-Cleaning Spray Tip”, is described as having the distal end of drip cap assembly with an outlet that changes its configuration—at rest and at a second condition (e.g. during expression). The distal end is described as comprised of a material that permits flexion and expansion. The first and second reactive components are introduced into swirl chambers before mixing and are atomized as ejected through the outlet in a cone-shaped spray 
     SUMMARY 
     The invention described herein is a device for dripping a tissue sealant and/or adhesive that comprises a) first and second barrels or syringes that contain first and second biocomponents that are disposed between proximal and distal ends; b) a plunger in each barrel and c) a drip tip comprising i) a support having distal and proximal ends and at least two fluid passageways from the distal to the proximal end that are in fluid communication with one of the barrels of the dispensing device on the proximal end; and ii) an endcap that fits over the support having at least two flexible hinges, each hinge having a portion of their interior surface resting on a top surface of the distal end of the dual lumen support and distal outlets for the fluid passageways, wherein a mix chamber and an outlet are formed by expansion only when the first and second biocomponents are under sufficient dispensing pressure. 
     The present invention is in one embodiment directed to a device for mixing and drip dispensing two reactive biologic components as tissue sealant and/or hemostatic agent with a syringe support having holding elements for at least two syringes and an associated handle; at least a pair of syringes each having an outlet and containing a reactive biologic component; a first piston and second piston within the first and second syringes, respectively; a support having two separate fluid channels in communication with the syringe outlets for the first and second syringes; and an endcap that is positioned at the outlet of the support having an open proximal end and a closed distal end with a flexible diaphragm. The flexible diaphragm in combination with the distal face of the dual lumen support define a first volume and a second volume and a dispensing passageway, wherein said first volume is substantially zero and said second volume is sufficient to allow the two reactive biologic components to mix just prior to and/or during dispensing. Further, the dispensing passageway is closed when the first volume is substantially zero. The first volume of the flexible diaphragm transitions to said second volume in response to a dispensing pressure from the reactive biologic components flowing through the two fluid channels and transitions back to said first volume in response to a reduction of pressure acting on the biologic components within the fluid channels. The distal end of the endcap can be substantially circular, while the flexible diaphragm can be at least two flexible flaps that are circumferentially affixed to the endcap. Preferably, at least a portion of an interior-facing edge from each flexible flap is not affixed to the circumference of the endcap. The dispensing passageway through the endcap is preferably a linear gap as the flexible diaphragm expands distally in response to pressure from the lumens to dispense the components from the mixing volume. 
     In one embodiment, a polymeric layer or silicone oil is applied over at least one surface of the flexible diaphragm. The polymeric layer can contain a poly-para-xylylene material and/or derivatives thereof. 
     In another embodiment, the first syringe contains thrombin and the second syringe contains fibrinogen. Hence, the present invention is also directed to a method for delivering biologic components to achieve hemostasis and/or tissue sealant by drip dispensing from the device described above. The biologic components are preferably delivered in a surgical setting. 
     In another embodiment, the present invention is directed to an assembly for mixing and drip dispensing two reactive biologic components as tissue sealant and/or hemostatic agent having an endcap having a proximal end and distal end, wherein the proximal end is open and the distal end has a flexible diaphragm covering outlet of fluid passages, said flexible diaphragm in combination with the distal face of fluid passage outlets, defining a first volume and a second volume and a dispensing passageway, wherein said first volume is substantially zero and said second volume is sufficient to allow the two reactive biologic components to mix just prior to and/or during dispensing; and a support having at least two fluid passages that is positioned in the distal end of the endcap. Further, the dispensing passageway is closed when the first volume is substantially zero, and said first volume transitions to said second volume in response to a dispensing pressure from the reactive biologic components flowing through the fluid passages and transitions back to said first volume in response to a reduction of pressure acting on the biologic components within the fluid passages. The distal end of the endcap can be substantially circular while the flexible diaphragm can be at least two flexible flaps that are circumferentially affixed to the endcap. Preferably, at least a portion of an interior-facing edge from each flexible flap is not affixed to the circumference of the endcap. In one embodiment, a polymeric layer or silicone oil is applied over at least one surface of the flexible diaphragm. The polymeric layer is preferably poly-para-xylylene polymeric material and/or derivatives thereof. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the disclosure and, together with a general description of the disclosure given above, and the detailed description of the embodiment(s) given below, serve to explain the principles of the disclosure, wherein: 
         FIG. 1  illustrates the inventive device. 
         FIG. 2  illustrates a biologics loading device. 
         FIG. 3  illustrates a manifold section of the inventive device. 
         FIG. 4  illustrates an exploded view of the inventive drip cap assembly. 
         FIG. 5  illustrates an assembled drip cap assembly. 
         FIG. 6  illustrates the drip cap assembly under pressure. 
         FIG. 7  illustrates the drip cap assembly without pressure. 
     
    
    
     DETAILED DESCRIPTION 
     Referring initially to  FIGS. 1 and 2 , a spray device including a spray tip according the present invention is shown generally as spray device  10 . Spray device  10  comprises two supply containers provided as commercially available syringes  12  for solutions of biologic agents, such as proteins, such as fibrinogen, and of fibrinolytic substances, such as thrombin, of a two-component tissue glue. Each syringe  12  comprises a hollow cylindrical syringe body  14  having a front end  16  with an outlet opening  18  and connecting pieces  20 , and an open rear end  22  (not shown). Arranged in each syringe body  14  is a piston or plunger  24  in sealing abutment on the inner surface of syringe body  14 . Piston  24  is held by a piston rod  26  guided out of syringe body  14  through the rear end  22 . The piston rods  26  extend respectively in the longitudinal direction of the syringe bodies  14  and beyond open rear end  22 . The free ends  30  of piston rods  26  facing away from piston  24  have annular flanges  32  formed thereon. These annular flanges  32  are mechanically connected to each other by a connecting element  34 . Connecting element  34  is formed with two receiving recesses  36  which are laterally open and suited for insertion of the annular flanges  32  thereinto. The two syringe bodies  14  are connected to each other by a clip holding means  38  (hereinbelow referred to as a holding element). 
     The syringe bodies  14  are supported for sliding displacement on the holding element  38 , because the resilient elastic holding clamps  40  extend by more than 180° and preferably by up to 200° around the syringe bodies  14  and thus enclose the syringe bodies  14  with a clamping force allowing for a relative displacement. The holding element  38  is arranged to bear on laterally protruding flanges  46  on the rear ends  22  of the syringe bodies  14 , thus providing for a mutual abutment of holding element  38  and syringe body  14 . 
     As evident from  FIG. 2 , the slightly conical connecting pieces  20  on the front ends  16  of the syringe bodies  14  are respectively connected to a fluid control device  48 . Each fluid control device  48  is provided with a connector for receiving the conical connecting piece  20  of a syringe both  14 . Each fluid control device  48  is provided with an outlet connecting piece  52  opposite to a connector. Further, each fluid control device  48  is provided with a receiving adaptor  54  comprising a fluid conduit member  56 . The receiving adaptor  54  is configured for insertion of a medicinal vessel thereinto, with the fluid conduit member, formed as a puncturing needle, penetrating the rubber closure plug of a vessel  42  and extending into the interior of the vessel  42 . Each fluid control device  48  has a floor control member rotatably supported therein. This flow control member can be rotated from outside, which is performed particularly by rotating the adaptor  54 . By rotating the flow control member, the flow control member can be moved from a first fluid control position wherein a fluid path exists between a syringe body  14  and the medicinal vessel, into a second fluid control position wherein the syringe body  14  is in fluid connection with the outlet connecting piece  52  of fluid control device  48 . In an alternative embodiment, a spray device  10  can use pre-filled syringes so that the fluid control devices are not required to enable filling and subsequent use. 
     With reference now to  FIG. 3 , manifold  60  includes a substantially Y-shaped member having a first and a second proximal extension  62 ,  64  and a distal extension  66 . Proximal extensions  62 ,  64  are configured for operable engagement with a first and a second source of component (not shown), e.g., syringes. Distal extension  66  is configured for operable engagement with elongated shaft  68 , as will be discussed in further detail below. Manifold  60  further includes first and second component channels (not shown). First and second component channels fluidly communicate the first and second sources of components with a first and a second lumen  73 ,  75  formed in elongated shaft  68  as shown in  FIG. 4 . While manifold  60 , as shown, is configured to receive only two sources of component, it is envisioned that manifold  60  may be configured to receive more than two sources of biological/medicinal components. 
     Referring back to  FIG. 3 , elongated shaft  68  may define a substantially solid body of silicone, plastic, polymer or other flexible material. As noted above, elongated shaft  68  includes first and second component lumens  73 ,  75  extending the length thereof. A wire (not shown) composed of a malleable material can also extend the length of elongated shaft  68 . Wire  76  can maintain elongated shaft  68  in a bent or flexed configuration after elongated shaft  68  has been bent or flexed to accommodate a given procedure. Elongated shaft  68  is secured to distal extension  66  of manifold  60  such that first and second component lumens  73 ,  75  align with first and second component channels. Alternatively, elongated shaft  68  may be integrally formed at a distal end of manifold  60 . 
     With reference now to  FIGS. 4 and 5 , drip cap assembly  80  defines a substantially cylindrical body  82  having an open proximal end  82   b  and a substantially closed distal end  82   a  Open proximal end  82   b  is configured to receive distal end of elongated shaft  68  as shown in  FIG. 5 . Cylindrical body  82  is affixed to elongated shaft  68 , preferably by heat sealing. Cylindrical body  82  can be removable or permanently attached. Alternative means for securing cylindrical body  82 , such as via a twist or screw-on configuration or a snap-fit over a detent ring can also be used. As will be discussed in further detail below, distal end  82   b  includes a slit outlet  89  that is configured to eject a thoroughly mixed solution. Slit outlet  89  has at least two flexible flaps  83 ,  85  that, in the absence of pressure, rest immediately against outlets for component lumens  73 ,  75  through elongated shaft  68 . Slit outlet  89  preferably is a central dividing line between the outlets for first and second component lumens  73 ,  75 . In an alternative embodiment (not illustrated), slit outlet  89  can be moved from a central location to be positioned relatively upward or down from the central axis line both bisecting lumen  73 ,  75 . In a still further embodiment (also not illustrated), slit outlet  89  can be rotated so as to be oriented along a line that divides lumen  73 ,  75  or at an angle thereto. An optional cap  90  having a cylindrical shape with two open ends can be provided that slides over and fits along the exterior surface of drip cap assembly  80 . 
     Referring to  FIGS. 5 ,  6 , and  7 , drip cap assembly  80  has two operational states depending on whether or not the two biocomponents are under sufficient dispensing pressure. The first operational state exists when the two components are not under sufficient dispensing pressure as shown in  FIGS. 5 and 7 . In this state, the interior surfaces of flaps  83 ,  85  of drip cap assembly  80  rest in direct contact with surface  79  and the outlets for first and second lumens  73 ,  75 . The second operational state exists when the two components are under pressure as result of operator acting on connecting element  34  that transmits force through piston rods  26  and plungers  24 . The pressure exerted by the liquid components creates a mixing volume  88  and outlet  89  as shown in  FIG. 6  between drip cap assembly  80  and the outlets for first and second lumens  73 ,  75 . 
     Mixing volume  88  is created as a result of pressure from the incoming biologic components flowing through first and second lumens  73 ,  75  that flexes and expands flaps  83 ,  85 , while it holds the remainder of drip cap assembly  80  stays in place. Mixing volume  88  will exist for so long as sufficient pressure is applied against drip cap assembly  80 . In the absence of sufficient pressure from the liquid components, drip cap assembly returns to the first operational state in which there is no liquid component mixing in mixing volume  88 . 
     Mixing volume  88 , when present, defines a substantially curved conical volume having a flat proximal surface formed by the outlets from first and second lumens  73 ,  75 . The shape and volume mixing volume  88  must be sufficient to allow mixing of the two liquid components. Additionally, in order to ensure drip cap assembly  80  and flaps  83 ,  85  retain sufficient flexibility and functionality, it has been found that a coating of Parylene, silicone oil or similar materials should be applied. Parylene is the generic name for members of a specific polymer series. The basic members of the series, called Parylene N, is poly-para-xylylene, a completely linear, highly crystalline material. Parylene C is produced from the same monomer modified only by the substitution of a chlorine atom for one of the aromatic hydrogens. Parylene D is produced from the same monomer modified by the substitution of the chlorine atom for two of the aromatic hydrogens. Parylene coatings are applied by vacuum deposition. The Parylene series of polymers are known in the art and commercially available. Additionally, it has been found desirable to ensure complete curing of the flexible diaphragm prior to placement of the slit so that subsequent sterilization activities do not induce further curing or crosslinking reactions that can cause the slit to reseal. 
     The operation of spray device  10  will now be described as relates to the figures. Prior to use, drip cap assembly  80  is affixed to the distal end of elongated shaft  68 . First and second holders ( 23 ,  24 ) with vessels  42  for sources of first and second component are next connected to first and second fluid control devices  48  and drawn into syringes  12 . Once secured to manifold  60 , first and second components may be activated by depression of syringe plungers (not shown), to initiate the flow of first and second components within first and second component channels  63 ,  65 , respectively. The first and second components flow through first and second component channels  62 ,  64 , through first and second component lumen  73 ,  75 , respectively, and into drip cap assembly  80 . The first and second components flowing from first and second component lumens  73 ,  75  enter mixing volume  88  where they are mix and are directed out through flaps  83 ,  85  and outlet  89 . 
     During operation of drip cap assembly  80 , momentary stoppages in the application of pressure for a period of time could result in the formation of a clog or obstruction that may obstruct outlet  89 . However, as pressure is released, drip cap assembly  80  returns to its first operational state in which flaps  83 ,  83  rest directly against the outlets for first and second lumens  73 ,  75  to eliminate any clog or obstruction. 
     Although the illustrative embodiments of the present disclosure have been described herein with reference to the accompanying drawings, it is to be understood that the disclosure is not limited to those precise embodiments, and that various other changes and modifications may be effected therein by one skilled in the art without departing from the scope or spirit of the disclosure.