Patent Publication Number: US-2021187259-A1

Title: Material application system for tunneling wounds that allows co-delivery of solutions

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of priority to U.S. Provisional Application No. 62/723,245, filed on Aug. 27, 2018, which is incorporated herein by reference in its entirety. 
    
    
     BACKGROUND 
     The present disclosure relates generally to the delivery of treatment materials to a wound. The present disclosure relates more particularly to the delivery of treatment materials into a tunneling wound. 
     Tunneling wounds are secondary wounds leading off from a primary wound. Tunneling wounds typically take the form of channels that extend from the primary wound deeper into the tissue. The channels may be of an irregular shape and may split off into additional tunneling wounds. A conventional treatment for a tunneling wound includes packing the wound with absorbent materials along with an antimicrobial treatment to absorb wound exudate and medicate the wound to promote healing. 
     An alternative to conventional tunneling wound treatments includes using bioresorbable products, which do not need to be removed from the wound after insertion. These bioresorbable products create a healing environment within the wound. However, these products may be challenging to apply as their structure tends to rapidly break down (e.g., gel, etc.) when hydrated. Hydration may result from exposure of the products to excess moisture and/or by wound exudate before and during the delivery process. Devices and methods are desired that improve the delivery of treatment materials for tunneling wounds. 
     SUMMARY 
     One implementation of the present disclosure is a medical delivery device for treating a tunneling wound. The device includes an outer sleeve and a plunger configured to be received within a cavity of the outer sleeve. The plunger includes a shaft and a head that together define an opening extending through a central axis of the plunger. The device additionally includes a hollow tube extending through the opening and configured to deliver a fluid to a wound treatment material contained within the cavity. 
     In some embodiments, the outer sleeve may further include a flap disposed on an end of the outer sleeve. The flap may be reconfigurable between a closed position, in which the flap is configured to shield a cavity opening, and an open position, in which the flap is configured to allow the wound treatment material to be ejected from the cavity through the cavity opening and into the tunneling wound. In some embodiments, the flap may be configured to open upon application of a predetermined force to the flap. 
     In some embodiments, both the outer sleeve and the head of the plunger have a rectangular cross section normal to their central axis. In some embodiments, the wound treatment material is a freeze dried collagen material. In some embodiments, the freeze dried collagen material is provided in a rope form and includes a central axis opening configured to receive the hollow tube. 
     In any of the above embodiments, the hollow tube may additionally include a plurality of perforations disposed proximate to an end of the hollow tube and configured to deliver a fluid from the hollow tube to the wound treatment material along a length of the wound treatment material. The hollow tube may be configured to deliver the fluid after the wound treatment material is deposited in the tunneling wound. In some embodiments, the wound treatment material contains an active component configured to interface with the fluid delivered to the wound treatment material. 
     Another implementation is a method of deploying a wound treatment material into a tunneling wound. The method includes preparing a medical delivery device including an outer sleeve and a plunger. The outer sleeve defines a cavity that is configured to receive both the wound treatment material and the plunger. The method additionally includes depressing the plunger to deliver the wound treatment material from the cavity and into the tunneling wound, delivering a fluid to the wound treatment material by passing a fluid through a hollow tube passing through the plunger and inserted into the wound treatment material, and retracting the hollow tube from the wound treatment material. In some embodiments, the method may additionally include passing a head of the plunger through the cavity and past an end of the cavity, and rotating the plunger to prevent the plunger from being able to retract through the outer sleeve. 
     In some embodiments, the method may additionally include compressing the wound treatment material and inserting the wound treatment material into the cavity. 
     Another implementation is a kit for a medical delivery device used to deploy a wound treatment material into a tunneling wound. The kit includes an outer sleeve defining a cavity and a plunger configured to be received within the cavity. The plunger includes a shaft including a first shaft end and a second shaft end, a head disposed on the first shaft end, and an opening extending through a central axis of the shaft and the head. The kit includes a hollow tube that extends through the opening and one or more freeze dried collagen materials configured to fit within the cavity and around the hollow tube. 
     In some embodiments, a length of the hollow tube may be greater than a combined length of the plunger and 50% of the freeze dried collagen material. 
     Those skilled in the art will appreciate that the summary is illustrative only and is not intended to be in any way limiting. Other aspects, inventive features, and advantages of the devices and/or processes described herein, as defined solely by the claims, will become apparent in the detailed description set forth herein and taken in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is front perspective view of a kit for medical delivery device used deploy a wound treatment material into a tunneling wound, according to an exemplary embodiment. 
         FIG. 2  is a side sectional view of a medical delivery device containing a wound treatment material, according to an exemplary embodiment. 
         FIG. 3  is a partial front perspective view of a hollow tube for a medical delivery device, according to an exemplary embodiment. 
         FIGS. 4A-4F  are front perspective views of a medical delivery device illustrating the delivery of a wound treatment material into a tunneling wound, according to exemplary embodiments. 
     
    
    
     DETAILED DESCRIPTION 
     Overview 
     Referring generally to the FIGURES, a medical delivery device configured for use with treating tunneling wounds is provided, according to various exemplary embodiments. The device is configured to deliver a wound treatment material to a tunneling wound and to minimize exposure of the wound treatment material to exudate from surrounding wounds, entry wounds from which the tunneling wound extends, and/or an entry region of the tunneling wound. The device is configured to eject the wound treatment material from a protective sleeve or outer sleeve, through an opening in the sleeve, and directly into the tunneling wound. The device includes a plunger configured to facilitate delivery of the wound treatment material into the tunneling wound (e.g., the insertion depth of the wound treatment material into the tunneling wound, the speed of delivery, etc.). The device also includes an applicator or hollow tube configured to deliver a fluid to the wound treatment material once inserted into the tunneling wound. Among various alternatives, the fluid may be a hydrating solution or a medicant (e.g., an antimicrobial solution to promote healing, etc.). 
     A method for delivery of the wound treatment material includes preparing the medical delivery device for use with inserting the wound treatment material into the tunneling wound, depressing the plunger to eject the wound treatment material from a cavity defined by the protective sleeve, delivering the fluid to the wound treatment material by passing the fluid through the hollow tube, and retracting the hollow tube from the wound treatment material. The protective sleeve and the plunger for the medical delivery device may be shaped to facilitate the removal of the hollow tube from the wound treatment material without repositioning the wound treatment material. For example, a head of the plunger and an opening defined by the protective sleeve may be substantially rectangular. A method of ejecting the wound treatment material from the cavity may include depressing the plunger such that the head of the plunger passes through the opening in the sleeve and rotating the plunger by approximately 45° such that the head is prevented from being retracted back into the cavity. 
     The device may be provided as part of a kit including a freeze dried collagen material. The freeze dried collagen material may be configured to fit within the cavity and around the hollow tube such that any fluids passing through the hollow tube are received along an inner portion (e.g., a central portion) of the freeze dried collagen material rather than directly upon the tunneling wound. These and other features and advantages of the medical delivery device are described in detail below. 
     Medical Delivery Device Construction 
     Referring now to  FIGS. 1-3 , a medical delivery device  100  is shown, according to an exemplary embodiment.  FIG. 1  shows the medical delivery device  100  configured as part of a kit  10  used for the treatment of tunneling wounds. The kit includes at least one wound treatment material  300 , which is shown separated from the delivery device  100  in  FIG. 1 . The wound treatment material  300  is configured in the shape of a rectangular cuboid whose cross-section, normal to a longitudinal axis of the wound treatment material  300 , is substantially square. 
       FIG. 2  shows a cross-section through a side of a delivery device  100 , which is configured in preparation for the treatment of a tunneling wound. As shown in  FIGS. 1-2 , the delivery device  100  includes an outer sleeve  200  defining an inner cavity  202  within which the wound treatment material  300  is received. A cavity opening, shown as first cavity opening  204  is disposed in a first end  206  of the outer sleeve  200 . The first cavity opening  204  may be covered or shielded by one or more flaps  208 , which are configured to prevent the wound treatment material  300  from being accidentally ejected from the outer sleeve  200 . The one or more flaps  208  also shield the wound treatment material  300  from the environment surrounding the outer sleeve  200 . 
     As shown in  FIG. 2 , the delivery device  100  includes a plunger  400  configured to engage with the wound treatment material  300 . The plunger  400  is received within the cavity  202  of the outer sleeve  200  and positioned in contact with an end of the wound treatment material  300  (i.e., an end of the wound treatment material  300  opposite the first cavity opening  204 ). In the embodiment of  FIG. 2 , the position of the wound treatment material  300  within the inner cavity  202  is adjustable and may be modified by depressing the plunger  400  further into the inner cavity  202  and toward the first cavity opening  204 . 
     In the embodiment of  FIGS. 1-2 , the plunger  400  includes a shaft  402  and a head  404  coupled thereto. The geometry of the head  404  of the plunger  400  is substantially similar to both the geometry of the wound treatment material  300  and the geometry of the first cavity opening  204 . This allows the head  404  to fully interface with the wound treatment material  300  while also preventing the wound treatment material  300  from bypassing the plunger  400 . 
     As shown in  FIGS. 1-2 , the plunger  400  includes an opening  406  extending through a central axis  408  of the plunger  400  (i.e., through both the head  404  of the plunger  400  and the shaft  402 ). The opening  406  is configured to receive a hollow tube  500  configured to deliver a fluid to the wound treatment material  300 . As shown in  FIG. 2 , the hollow tube  500  extends beyond the plunger  400  and into the wound treatment material  300  such that the fluid may be delivered to an inner portion of the wound treatment material  300 . As shown in  FIGS. 2-3 , the hollow tube  500  includes a plurality of perforations  502  that extend through a wall  504  of the hollow tube  500  proximate to the wound treatment material  300 , which allow the hollow tube  500  to dispense the fluid along a length of the wound treatment material  300 . 
     Outer Sleeve 
     An exemplary embodiment of an outer sleeve  200  for the delivery device  100  is shown in  FIGS. 1-2 . The outer sleeve  200  is made from a single piece of non-permeable material formed in the shape of a rectangular cuboid (i.e., a right rectangular prism having identical cross-sections normal to a central axis of the sleeve  200 ). In other implementations, the shape of the outer sleeve  200  may be different (e.g., the outer sleeve  200  may be formed in the shape of a cylinder, etc.). In some embodiments, the outer sleeve  200  is made from a plastic material such as medical grade polyethylene, polycarbonate, etc. In other embodiments, the outer sleeve  200  is made from another suitable non-permeable material. Among other benefits, using a non-permeable material prevents water and/or wound exudate from penetrating the surfaces of the outer sleeve  200 . 
     As shown in  FIG. 2 , the outer sleeve  200  is configured as a shell including an upper wall  210 , a lower wall  212 , and side walls  214 ,  216  (also see  FIG. 1 ) that together define an inner cavity  202 . The inner cavity  202  is configured to receive at least one wound treatment material  300  and a plunger  400 . As shown in  FIGS. 1-2 , the inner cavity  202  has a cross-sectional geometry, in a direction substantially perpendicular to the longitudinal axis of the inner cavity  202 , that is similar to a cross-sectional geometry of the wound treatment material  300  and/or the head  404  of the plunger  400  (e.g., a square). Among other benefits, this configuration minimizes the unoccupied volume of the outer sleeve  200  and the amount of wound treatment material  300  that may be administered into the tunneling wound for a given device  100  size. 
     The outer sleeve  200  additionally defines an opening at each end of the inner cavity  202 , shown as first cavity opening  204  and second cavity opening  220 . Each of the first cavity opening  204  and the second cavity opening  220  have substantially the same cross-sectional shape as the inner cavity  202  (e.g., a square). In the embodiment of  FIGS. 1-2 , the first cavity opening  204  is configured to receive the wound treatment material  300 , while the second cavity opening  220  is configured to receive the head  404  of the plunger  400 . A length of the outer sleeve parallel to the longitudinal axis of the inner cavity  202  is greater than a combined length of the wound treatment material  300  and the head  404  of the plunger  400 . 
     The outer sleeve  200  may additionally include one or more flaps  208  disposed on an end of the outer sleeve  200 . In the embodiment of  FIGS. 1-2 , four flaps  208  are disposed on the outer sleeve  200 . Each one of the flaps  208  is hingedly coupled to one of the upper wall  210 , lower wall  212 , or one of the side walls  214 ,  216 . In an embodiment, each flap  208  is formed as part of the outer sleeve  200  (e.g., injection molded or otherwise formed with the outer sleeve  200  as a single piece of material). In other embodiments, each flap  208  is a separate piece of material from the outer sleeve  200  and is permanently affixed (e.g., welded, glued, etc.) to the outer sleeve  200 . 
     Each one of the flaps  208  is reconfigurable between an open position, in which the flap  208  is configured to allow the wound treatment material  300  to be ejected from the inner cavity  202  through the first cavity opening  204 , and a closed position, in which the flap  208  is configured to shield the first cavity opening  204 . In the embodiment of  FIGS. 1-2 , each of the flaps  208  is shaped such that, in the closed position, the flaps  208  contact one another and completely block off the first cavity opening  204 . Among other benefits, in the closed position the flaps  208  prevent any moisture from the environment surrounding the outer sleeve  200  from penetrating through the outer sleeve  200  and into the wound treatment material  300 . In alternative embodiments, the flaps  208  may be configured to only partially occlude the first cavity opening  204  in the closed position. For example, the flaps  208  may only shield the wound treatment material  300  around a perimeter of the wound treatment material  300  (e.g., near surfaces of the wound treatment material  300  that are in contact with the outer sleeve  200 ), and thereby limit the amount of gelling or structural degradation of the wound treatment material  300  prior to insertion of the wound treatment material  300  into the tunneling wound. 
     The flaps  208  are configured to move from the closed position to the open position upon application of a predetermined force to the flaps  208 . To secure the flaps  208  over the first cavity opening  204  in the closed position, the flaps  208  may be folded over one another, interlocked with one another, or configured to removably engage with the outer sleeve  200 . In an exemplary embodiment, one or more flaps  208  may include a slot that is configured to engage with another flap  208  in the closed position. In other embodiments, the outer sleeve  200  may include features (e.g., slots, clips, etc.) configured to receive one or more flaps  208  in the closed position. In yet other embodiments, one or more flaps  208  may be removably coupled to one another using an adhesive product in the closed position. 
     Plunger 
     A plunger  400  for the medical delivery device  100  is shown in  FIGS. 1-2 , according to an exemplary embodiment. The plunger  400  is configured to reposition the wound treatment material  300  relative to the outer sleeve  200  during delivery of the wound treatment material into the tunneling wound. The plunger  400  includes a shaft  402  and a head  404  coupled thereto. As shown in  FIG. 2 , the shaft  402  includes a first shaft end  410  and a second shaft end  412 . The head  404  is disposed to the first shaft end  410 . The head  404  may be formed with the shaft  402  as a single piece of material (e.g., via an injection molding process) or coupled to the first shaft end  410  (e.g., via gluing, welding, a clip feature, and/or a threaded interface between the head  404  and the shaft  402 ). The plunger  400  may be made from a variety of different materials including medical grade polyethylene, polycarbonate, etc. In some embodiments, the plunger  400  is made from a similar material as the outer sleeve  200 . 
     As shown in  FIG. 2 , the head  404  of the plunger  400  is received within the second cavity opening  220  of the outer sleeve  200 . The head  404  of the plunger  400  has a cross-sectional shape normal to a central axis  408  of the plunger  400  that is similar to a cross-sectional shape of the wound treatment material  300  and/or the inner cavity  202  of the outer sleeve  200  (e.g., a square). A length and width of the head  404 , normal to the central axis of the plunger  400 , are dimensioned to fill the space of the inner cavity  202 , while also permitting the head  404  to slide freely along a length of the inner cavity  202 . This configuration prevents the wound treatment material  300  from being forced through any gaps between the perimeter surfaces of the head  404  and the outer sleeve  200 , while also preventing the head  404  from becoming lodged or stuck in a single position within the outer sleeve  200  during operation. As shown in  FIG. 2 , a forward surface  414  of the head  404  is configured to contact the wound treatment material  300 . 
     The plunger  400  includes an opening  406  extending along a full length of the plunger  400  parallel to its central axis  408 . In the embodiment of  FIG. 2 , the central axis  408  of the plunger  400  is located in the same position as a central axis for the shaft  402  and the head  404  of the plunger  400 . The opening  406  is configured to receive the hollow tube  500  for the medical delivery device  100 . In the embodiment of  FIG. 2 , the opening  406  has a cross-sectional geometry that is similar to a cross-sectional geometry of the hollow tube  500  (e.g., circular). As shown in  FIG. 2 , the opening  406  is alignable with a corresponding opening, shown as central axis opening  302 , in the wound treatment material  300 . 
     The shaft  402  of the plunger  400  extends through the second cavity opening  220  of the outer sleeve  200 . The shaft  402  may be manipulated by a user to reposition the plunger  400  with respect to the outer sleeve  200 . A length of the shaft  402 , in a direction substantially parallel to the central axis of the plunger  400 , is greater than a combined length of the outer sleeve and the head  404  of the plunger  400  (i.e., the length of the shaft  402  is sufficient to allow the user to push the head  404  of the plunger  400  through an entire length of the inner cavity  202  and beyond the first cavity opening  204 ). 
     The shaft  402  may be configured in a variety of different shapes. For example, the shaft  402  may be cylindrical, triangular, etc. In the embodiment of  FIG. 2 , the shaft  402  is configured in the shape of a rectangular cuboid whose outer surfaces are substantially parallel to the walls  210 ,  212 ,  214 ,  216  of the outer sleeve  200 . Among other benefits, the orientation of the outer surfaces of the shaft  402  relative to the walls  210 ,  212 ,  214 ,  216  of the outer sleeve  200  may be used as a visual guide enabling a user to approximate a rotational position of the head  404  relative to the outer sleeve  200 . The shaft  402  may also include ergonomic features (e.g., contoured surfaces, etc.) and/or a position indicator (e.g., indicator marks along an outer surface of the shaft  402 , etc.) to facilitate repositioning of the shaft by the user. 
     Hollow Tube 
     A hollow tube  500  for the medical delivery device  100  is shown in  FIGS. 2-3 , according to an exemplary embodiment. The hollow tube  500  may be formed in a variety of different shapes and sizes, depending on the desired characteristics of the medical delivery device  100 . As shown in  FIG. 3 , a cross-sectional geometry of the hollow tube  500 , in a direction substantially perpendicular to a primary axis of the hollow tube  500 , is similar to the cross-sectional geometry of the opening  406  in the plunger  400  (e.g., circular). As shown in  FIG. 2 , the length of the hollow tube  500 , in a direction oriented substantially parallel to a primary axis of the hollow tube  500 , is greater than a combined length of the plunger  400  and 50% of a length of the wound treatment material  300 . An outer diameter of the hollow tube  500  is dimensioned slightly smaller than the inner diameter of the opening  406  in the plunger  400  to allow the hollow tube  500  to move freely with respect to the plunger  400  during operation. 
     The hollow tube  500  is configured to deliver a fluid through the device  100  and into the wound treatment material  300 . The fluid may be one or a combination of a hydrating solution to wet an interior portion of the wound treatment material  300  (e.g., to facilitate gelling of the wound treatment material  300  onto the surfaces of the tunneling wound) and a medicant such as an antimicrobial solution. In an exemplary embodiment, the hollow tube  500  is configured to provide a wound irrigation solution such as Prontasan to the wound treatment material  300 . In another embodiment, the hollow tube  500  is configured to provide a solution configured to interact and/or react with one or more active components in the wound treatment material  300  (e.g., the solution could contain glucose, which could interact with glucose oxidase in the wound treatment material  300  to generate hydrogen peroxide, etc.). 
     As shown in  FIG. 3 , the fluid is discharged from the hollow tube  500  into an inner portion of the wound treatment material  300  through an opening, shown as end opening  506 . The hollow tube  500  additionally includes a plurality of perforations  502  that extend through a wall  504  of the hollow tube  500 . As shown in  FIGS. 2-3 , the perforations  502  are located proximate to an end of the hollow tube  500  that is configured to be received within the inner portion of the wound treatment material  300  (i.e., an end of the hollow tube  500  proximate to the end opening  506 ). The pitch, size, and shape of each perforation  502  may be different depending on the desired flow rate and distribution along a length of the wound treatment material  300 . In the embodiment of  FIGS. 2-3 , the perforations  502  are configured as circular holes of uniform diameter. In other embodiments, the diameter of the perforations may vary along the length of the hollow tube  500  (e.g., starting small near an end of the wound treatment material  300  and getting larger moving toward an opposing end of the wound treatment material  300  to promote flow uniformity along the length of the hollow tube  500 ). In yet other embodiments, the shape of each of the perforations  502  may be different along the length of the hollow tube  500 . 
     Wound Treatment Material 
     A wound treatment material  300  configured for delivery by the medical delivery device  100  is shown in  FIGS. 1-2 , according to an exemplary embodiment. Among other functions, the wound treatment material  300  provides a wound filler to support the tunneling wound and thereby prevent the tunneling wound from being deformed while a patient is moving. The wound treatment material  300  may also be used to help manage wound conditions such as moisture, pH, protease activity, bioburden, etc. Advantageously, the wound treatment material  300  may be bioresorbable, which eliminates the need to remove the material  300  from the tunneling wound at a later time after treatment. 
     Similar to the outer sleeve  200  and the head  404  of the plunger  400 , the wound treatment material  300  is configured in the shape of a rectangular cuboid having uniform cross-section along its length. A cross-sectional geometry of the wound treatment material  300 , normal to a central axis for the wound treatment material  300 , is approximately the same as the cross-sectional geometry of the inner cavity  202  and the head  404  of the plunger  400 . In the embodiment of  FIG. 2 , a width and a length of the wound treatment material  300 , normal to the central axis of the wound treatment material  300 , is slightly smaller than a corresponding height and width of the inner cavity  202  such that the wound treatment material  300  completely fills the cavity into which it is inserted. In other embodiments, the wound treatment material  300  may be compressed prior to insertion into the outer sleeve  200  and configured to expand in dimension when exposed to a fluid (e.g., a hydrating solution and/or a medicant). In this latter embodiment, the wound treatment material may expand after delivery into the tunneling wound to better fill and protect the wound site. 
     As shown in  FIG. 2 , the wound treatment material  300  is provided in a rope form and includes a central axis opening  302  configured to receive the hollow tube  500  of the delivery device  100 . A length of the wound treatment material  300  may vary depending on the size (e.g., depth) of the tunneling wound. For example, the length of the wound treatment material  300  may be approximately equal to the depth of the tunneling wound, etc. As shown in  FIG. 2 , the length of the wound treatment material  300  is less than the length of a portion of the outer sleeve  200  contained between the forward surface  414  of the head  404  of the plunger  400  and the first cavity opening  204 . 
     The central axis opening  302  extends throughout the length of the wound treatment material  300  and provides access to an inner portion and/or a central portion of the wound treatment material  300 . The central axis opening  302  may be configured in a variety of different shapes. In the embodiment of  FIGS. 1-2 , the central axis opening  302  is cylindrical with a circular cross-section normal to the central axis of the wound treatment material  300 . As shown in  FIG. 2 , the central axis opening  302  has a diameter that is slightly larger than the outer diameter of the hollow tube  500 , which allows the hollow tube  500  to slide freely along a length of the wound treatment material  300 . 
     In an exemplary embodiment, the wound treatment material  300  is composed of a freeze dried collagen material (i.e., an oxidized regenerated cellulose/collagen (ORC) or collagen/ORC/silver-ORC) such as Promogran or Prisma. The wound treatment material  300  may additionally contain active components such as antimicrobials, antioxidants, and/or anti-inflammatories to enhance the healing benefits of the material  300 . The wound treatment material  300  may alternatively or additionally contain active components that are configured to interact with and/or react with a fluid delivered by the hollow tube  500  to wound treatment material  300 . For example, the wound treatment material  300  may contain glucose oxidase, which interacts with glucose to generate hydrogen peroxide. 
     Delivery of Wound Treatment Material 
     A method of deploying a wound treatment material  300  into a tunneling wound  20  is illustrated in  FIGS. 4A-4F , according to an exemplary embodiment. The method includes preparing a medical delivery device  100  for use in inserting the wound treatment material  300  into the tunneling wound  20 . The method of preparation may include inserting the wound treatment material  300  into an inner cavity  202  of an outer sleeve  200  for the medical delivery device  100  through one of a first cavity opening  204  and a second cavity opening  220 . A plurality of flaps  208  may be reconfigured into a closed position such that the flaps  208  at least partially shield the wound treatment material  300  from an environment surrounding the outer sleeve  200  (e.g., from external moisture, exudate from surrounding wounds, and/or entry wounds from which the tunneling wound  20  extends). The method of preparation may further include inserting a plunger  400  through the second cavity opening  220  such that a head  404  (see also  FIGS. 1-2 ) of the plunger  400  is brought into contact with the wound treatment material  300 . The method of preparation may also include inserting a hollow tube  500  through an opening  406  in the plunger  400  and a central axis opening  302  in the wound treatment material  300 . 
     As shown in  FIG. 4A , the method of preparation includes placing an end of the outer sleeve  200  (e.g., an end of the sleeve  200  proximate to the flaps  208  and the first cavity opening  204 ) at an entrance to the tunneling wound. 
     In various alternative embodiments, the method of preparing the device  100  may further include compressing the wound treatment material  300  and inserting the wound treatment material  300  into the inner cavity  202  of the outer sleeve  200 . 
     The method of deploying the wound treatment material  300  includes depressing the plunger  400  to deliver the wound treatment material  300  from the inner cavity  202  and into the tunneling wound  20 . As shown in  FIG. 4B , the plunger  400  is depressed toward the tunneling wound  20  against the wound treatment material  300 , which presses against the flaps  208  shielding the first cavity opening  204 . Upon application of a predetermined force to the flaps  208  by the wound treatment material  300 , the flaps  208  begin to rotate away from the first cavity opening  204  and toward an open position. As the flaps  208  separate, the wound treatment material  300  emerges from the outer sleeve  200  and into the entrance of the tunneling wound  20 . During this process, the flaps  208  effectively extend the length of the outer sleeve  200  into the entrance of the tunneling wound  20 , further shielding the wound treatment material  300  from wound exudate. 
     The operation of depressing the plunger  400  continues until the wound treatment material  300  is completely inserted into the tunneling wound  20 . As shown in  FIG. 4C , the plunger  400  is depressed a sufficient distance toward the tunneling wound  20  that the head  404  of the plunger  400  is extended just beyond the flaps  208  (i.e., such that the head  404  of the plunger  400  clears the flaps  208 ). In this position, the flaps  208  may be allowed to at least partially retract toward the first cavity opening  204 . In other embodiments, the flaps  208  may remain fixed in position during this operation. The wound treatment material  300  remains coupled to the medical delivery device  100  via the hollow tube  500 , which runs along the length of the plunger  400  and extends through at least a portion the wound treatment material  300 . 
     The method of deployment further includes delivering a fluid to the wound treatment material  300  by passing the fluid through the hollow tube  500 . This operation allows fluid to be introduced into an inner portion of the wound treatment material  300 . The fluid may provide a form of hydration to the wound treatment material  300  or serve as a medicant (e.g., an antimicrobial solution such as Prontasan) to promote healing of the tunneling wound  20 . 
     The method of deployment additionally includes retracting the hollow tube  500  from the wound treatment material  300 . A method for retracting the hollow tube  500  from the wound treatment material  300  as illustrated in  FIGS. 4D-4F , according to an exemplary embodiment. As shown in  FIG. 4D , both the outer sleeve  200  and the head  404  of the plunger  400  have a substantially rectangular cross-section normal to a feed direction for the wound treatment material  300 . The plunger  400  may be secured in position relative to the outer sleeve  200  by rotating the plunger  400  by a suitable angle. Among other benefits, rotating the head  404  of the plunger  400  prevents the wound treatment material  300  from moving or becoming dislodged from the tunneling wound  20  when retracting the hollow tube  500 . 
     In the embodiment of  FIG. 4D , the plunger  400  is rotated by approximately 45° such that a surface of the plunger  400  contacts each of the flaps  208  of the outer sleeve  200 . Note that the angle of rotation used to prevent the head  404  from retracting back into the outer sleeve  200  may vary depending on the geometry of the head  404  and the outer sleeve  200 . As shown in  FIG. 4E , once the plunger  400  is secured in position the hollow tube  500  may be completely retracted from both the wound treatment material  300  and the plunger  400 . 
     As shown in  FIG. 4F , the method of deployment may further include removing the medical delivery device  100  from the entrance to the tunneling wound  20  by pulling on the shaft  402  of the plunger  400 . 
     Configuration of Exemplary Embodiments 
     The construction and arrangement of the systems 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, values of parameters, mounting arrangements, use of materials, colors, orientations, etc.). For example, the position of elements can be reversed or otherwise varied and the nature or number of discrete elements or positions can 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 can be varied or re-sequenced according to alternative embodiments. Other substitutions, modifications, changes, and omissions can be made in the design, operating conditions and arrangement of the exemplary embodiments without departing from the scope of the present disclosure.