Patent Application
20080208171
The present invention relates generally to a device and method for removing edema, and more particularly, but not exclusively, to a device and method for removing edema using aciculated components embedded in a porous material to withdraw edema from a tissue through the aciculated components and into the porous material.
A common problem affecting patients is the build up of interstitial fluid between soft tissue cells which can cause swelling and irritation, prevent proper blood flow, and cause significant discomfort. This buildup of interstitial fluid, or edema, can be present in a variety of organ tissues. The medical community has recognized that immobility, sodium, medication, renal and heart problems can aggravate edema, with immobility representing a principal aggravating factor. While a patient's disease or injury may itself cause edema, prolonged immobilization can further instigate the formation of edema.
In addition to immobilization, consumption of excess sodium also upsets the natural balance of interstitial fluid. While consuming salt is usually not sufficient to cause edema by itself, excess sodium can aggravate other edemic conditions. Moreover, in addition to diet, exercise, and medication, edema is often caused by a variety of medical conditions. Problems with the heart can lead to the increase of interstitial fluid. Kidney problems reduce the body's ability to regulate sodium and water. Low protein levels caused by thyroid or liver disease also can lead to edema. Edema can also be caused by problems with the lymphatic system, because the lymphatic system is generally responsible for maintenance of proper interstitial fluid balance. Thus, edema can be caused by a wide variety of factors, and as such, is a prevalent problem among segments of the patient population.
While edema is simply the presence of excess fluid outside of the cells, treating edema has proven to be very difficult. Current treatment regimens include simple steps like reducing sodium intake, losing weight, exercising regularly, avoiding prolonged travel without breaks, the use of diuretics to lower interstitial fluid volume. Current treatments such as these have been helpful in reducing edema for suffering patients, but many of these solutions take a long period of time to produce results and require patients to make lifestyle changes. In many cases, a patient suffering from edema is not capable of exercising regularly, or is not willing to reduce sodium consumption. Patients may not wish to take medications regularly. Thus, many patients still suffer from edema, because they are unwilling or unable to follow indicated treatments. This is particularly true if the patient is suffering from a disease or injury.
While edema can be caused by many factors, edema is a particular problem for patients who have large wounds. Treating large wounds in the skin or subcutaneous tissue presents a physician with a variety of complications. When a patient's skin is badly injured the contents of the skin cells spill out into the surrounding tissue, increasing interstitial fluid. Edema at a wound retards the proper inflow of blood and nutrients to the wound. Without proper blood flow, the tissue becomes ischemic and may die. Dead tissue in combination with a dearth of white blood cells greatly increases the risk for bacterial infection. Infection can cause additional cell death, leading to more cell lysis, and more edema, making healing the wound even more difficult.
For reasons such as these, there remains a need in the medical field to reduce and remove edema.
The present invention relates to a device and method for removing edema from tissues such as subcutaneous tissue, submuscular tissue, and/or intramuscular space, and may be used on intact or broken tissue, e.g., a closed or an open wound. In one exemplary configuration of the present invention, a device for removing edema from an edematous tissue includes at least one aciculated (i.e., needlelike) component structured to pierce an edematous tissue at a treatment location. The aciculated component may comprise a pointed, tubular component, such as a needle or catheter. The aciculated component is structured to fluidically communicate with the edematous tissue to permit the passage of edema through the aciculated component. The device also includes a suction manifold having a treatment surface for placement in facing opposition to the treatment location. The suction manifold is disposed in fluid communication with the at least one aciculated component, so that the suction manifold can receive edema transported through the aciculated component from the edematous tissue. As part of the device, a suction source is provided in fluid communication with the suction manifold to provide a suction force to the suction manifold. The suction force is transmitted through the suction manifold to the at least one aciculated component to withdraw the edema from edematous tissue through the suction manifold and the at least one aciculated component.
The device of the present invention may desirably include a cover disposed over the suction manifold. The cover may be made of a rigid, semi-rigid or flexible material and may serve a variety of functions such as protecting the area from contaminants, stabilizing the aciculated components and suction manifold, and creating an air tight seal. In one particular configuration, the cover may be provided in the form of a flexible self-adhesive sheet. The edema removal device may also include a conduit or tube connecting the suction source to the suction manifold.
In another aspect of the present invention, a method is provided for removing edema. The method includes providing an appliance comprising at least one aciculated component and a suction manifold. The aciculated component is structured to pierce an edematous tissue at a treatment location and structured to fluidically communicate with the edematous tissue to permit the passage of edema through the aciculated component. The suction manifold has a treatment surface for placement in facing opposition to the treatment location and is disposed in fluid communication with the at least one aciculated component to receive edema transported through the aciculated component from the edematous tissue. The method also includes placing the appliance at the treatment location and piercing the edematous tissue with the at least one aciculated component. As part of the method, a suction source is operably connected in fluid communication with the suction manifold to provide a suction force to the suction manifold and the at least one aciculated component, and edema is withdrawn from the edematous tissue through the suction manifold and the at least one aciculated component.
In a further aspect of the present invention, a method for removing edema from an edematous tissue is provided comprising the steps of inserting at least one aciculated component into an edematous tissue, attaching the at least one aciculated component in fluid communication with a suction manifold, and applying a suction force through the suction manifold to the at least one aciculated component to draw edema from the edematous tissue through the at least one aciculated component and the suction manifold.
Referring now to the figures, wherein like elements are numbered alike throughout, an exemplary device for removing edema, generally designated 100, is provided, as shown, for example, in
Turning to the figures in more detail,
The aciculated components 20 may be provided in the form of a needle, wick, catheter, angiocath, or combinations thereof, as well as other structures suitable for removing edema from edematous tissue 2. The diameter of the aciculated components 20 may be selected with regard to the type of tissue into which the aciculated components 20 are to be inserted, as well as with regard to the volume and viscosity of the edema to be removed. In addition, the aciculated components 20 may be fenestrated with holes 5 along at least a portion of their length that is in contact with the edematous tissue 2 to assist in the removal of the edema along the fenestrated length of the aciculated components 20, as shown in
The removal of edema from the edematous tissue 2 via the aciculated components 20 is effected by application of a suction force to the aciculated components 20. The suction force is delivered to the aciculated components 20 by a suction manifold 10 disposed in fluid communication with the aciculated components 20, which directs the flow of edema from the edematous tissue 2 into the suction manifold 10. The suction manifold 10 in turn is connected in fluid communication with a suction source 30 which applies a suction force to the suction manifold 10. The aciculated components 20 are directly or indirectly connected to the suction manifold 10 at a treatment surface 14 of the manifold 10 by any method that permits fluid communication between the aciculated components 20 and the suction manifold 10. For example, the aciculated components 20 may have a proximal end 24 embedded or punched into the suction manifold 10. Alternatively, the aciculated components 20 may be attached indirectly via a connector, or screwed or snapped into the suction manifold 10, and so forth, so long as fluid communication is provided between the aciculated components 20 and the suction manifold 10. As shown in
The suction manifold 10 includes one or more passageways to transmit the suction force from the suction source 30 to the aciculated components 20. For example, the suction manifold 10 may desirably include a porous material such as a sponge or open-cell foam, e.g. a polyurethane foam or polyvinyl alcohol foam (PVA), having a series of interconnected pores 11 that form passageways for delivering a suction force to the aciculated components 20. A suction manifold 10 may comprise any material suitable for delivering a suction force and for permitting the flow of edema therethrough. For example, the suction manifold 10 may comprise a polymer material, such as a synthetic polymer material. In addition, the suction manifold 10 may be composed of a material that will dissolve over a period of time, and/or may be composed of an antimicrobial or antibiotic materials. The manifold may desirably include a hydrophobic material to facilitate liquid transfer through the manifold or through the connecting poses or open cells of the manifold. Exemplary materials that may be used for the suction manifold 10, alone or in combination with other materials, include V.A.C.® GranuFoam® and V.A.C.® WhiteFoam™ dressings (Kinetic Concepts Inc. San Antonio, Tex.), and the like.
In addition, the suction manifold 10 may include a material that allows for gas and/or liquid exchange between the suction manifold 10 and the tissue, such as skin 3, adjacent the suction manifold 10. In this regard, the suction manifold 10 may be perforated or punched to enhance gas exchange or to reduce the weight of the suction manifold 10. Furthermore, the material of the suction manifold 10 may desirably permit absorption of liquids such as edema, exudate, and perspiration that may contact the suction manifold 10. Such a configuration may be desirable in cases in which the suction manifold 10 is disposed in an open wound 9, as illustrated in
The suction source 30 may be removably connected to the suction manifold 10 by an evacuation conduit 40, with the proximal and distal ends 44, 42 of the conduit 40 permanently or removably attached to or connected with the suction source 30 and suction manifold 10, respectively. The evacuation conduit 40 is provided in a form that promotes a fluid tight and gas tight connection between the suction source 30 and the suction manifold 10, such as a flexible tube, e.g., IV tubing. The distal end 42 of the conduit 40 may be embedded within the suction manifold 10, so that the conduit 40 is in fluid communication with the passageways or the pores 11 of the manifold 10. In addition, the conduit 40 may be fenestrated at the distal end embedded or positioned within the manifold to provide side openings 72 for delivering the suction force to the suction manifold 10 along the fenestrated length of the conduit 40. Further, the conduit 40 may comprise multiple branches disposed throughout the suction manifold 10 to distribute the suction force through the suction manifold 10. For example, as illustrated in
The suction source 30 may include a vacuum pump or other source of suction that can safely and reliably provide a suction force to the suction manifold 10 and aciculated components 20. The suction source 30 may be configured to provide a reduced pressure from 10 mm Hg below atmospheric pressure to 300 mm Hg below atmospheric pressure, for example. The suction source 30 may optionally include a collection device 35 to collect edema and other fluid from the suction manifold 10. Alternatively, a fluid collection device may be provided along the length of the conduit 40 between the suction source 30 and the suction manifold 10. The collection device may be provided in the form of a fluid trap and may include a shut-off for halting the application of the suction force to the suction manifold 10 when the collection device becomes filled with a predetermined amount of fluid. An alarm 33 may be provided to announce or indicate that the collection device is filled to a predetermined or an adjustable level or to indicate or announce a selected malfunction such as loss of suction or clogging of conduit 40. The suction source 30 may desirably include a controller for controlling the suction source 30 and optionally the alarm 33 and for providing intermittent suction in the form of alternating periods of application and non-application of suction.
Upon application of the suction force to the suction manifold 10, the suction manifold 10 may contract and rub against the tissue in contact with the suction manifold 10. Movement between the suction manifold 10 and the tissue contacted by the suction manifold 10 may irritate the contacted tissue, especially during application of intermittent suction. To alleviate potential irritation, the edema removal device 100 of the present invention may optionally include a friction-reducing layer 80 disposed between the suction manifold 10 and the adjacent tissue, such as skin 3, to reduce friction between the suction manifold 10 and the adjacent tissue. The friction-reducing layer 80 may be porous, e.g. a synthetic polymer mesh, or non-porous and may also provide additional protection of the wound from microbes and debris. Various material having a low coefficient of friction can be used to construct the friction-reducing layer 80. For example, the friction-reducing layer 80 may include a non-adherent material, such as an ointment-impregnated gauze or a synthetic or natural polymer material. Exemplary materials suitable for use as the friction-reducing layer 80 include Aquaphor® Gauze (Smith & Nephew, Largo, Fla.), Adaptic® Non-Adherent Dressing (New Brunswick, N.J.), and so forth. The friction-reducing layer 80 may be provided as a separate component disposed between the suction manifold 10 and the adjacent tissue. Alternatively, a friction-reducing coating may be disposed on the lower surface 14 of the suction manifold 10 for contact with adjacent tissue.
To assist in the application of the suction force by the suction manifold 10, the edema removal device 100 may desirably include a cover 50 disposed over the suction manifold 10 and sealed in location to tissue, such as skin 3, proximate the edematous tissue 2 so that the cover 50 promotes containment of the suction force thereunder. The contained suction force under the cover 50 may desirably create a negative pressure (or sub-atmospheric) environment about the treatment location to provide negative pressure therapy at the treatment location. For example, if the treatment location is an open wound 9, the introduction of a suction force under the sealed cover 50 may provide negative pressure wound therapy at the wound 9. The cover 50 includes a port through which the conduit 40 communicates with the space under the cover 50. The port may comprise an edge 62 of the cover 50 under which the conduit 40 passes, such as a mesentery, for example. Alternatively, the port may be provided as an opening 60, such as a nipple or plug, disposed at the surface of the cover 50, or other suitable structure.
The use of a cover 50 may be particularly desirable in the case where the suction manifold 10 comprises a porous open-cell material having passageways which communicate with exterior surfaces of the suction manifold 10. In such a case, the cover 50 may seal the ends of passageways that terminate at the upper and side surfaces of the suction manifold 10, leaving the passageways at the outer periphery open only at the lower treatment surface 14 of the suction manifold 10 facing the edematous tissue 2. The inclusion of a cover 50 may also help prevent debris from entering the treatment site and may provide a compression force against the suction manifold 10 and the treatment site. If the edema removal device 100 is used over an open wound 9, the cover 50 may also provide protection against infection. The selection of an appropriate cover material will be influenced by factors such as durability, the ability to protect the wound, gas permeability, and the ability to maintain the relative position of the suction manifold 10 to the edematous tissue 2.
The cover 50 may be conveniently provided in the form of a self-adhesive cover 50, such as a flexible polymer sheet or surgical drape, for example. Exemplary self-adhesive drapes include Ioban® drape (3M Corporation, St. Paul, Minn.), OpSite® drape (Smith & Nephew, Largo, Fla.), and so forth. Providing the cover 50 in the form of a flexible sheet or surgical drape may be particularly desirable for use in applications where the cover 50 should conform to the treatment site. Further, the use of a flexible sheet or drape may be particularly desirable in weight dependent locations. Providing a self-adhesive cover 50 may simplify the application of the cover 50 to the tissue surrounding the edematous tissue 2 and may conveniently permit the cover 50 to be attached to and/or immobilize other components of the edema removal device 100 that the cover adhesive contacts, such as suction conduit 40 or suction manifold 10. Instead, if a non-adhesive cover 50 is used, a separately applied adhesive or other suitable material may be used to secure and/or seal the cover 50 to the treatment site. The adhesive may be disposed along an entire surface of the cover 50 or may be disposed only about the periphery of the cover 50. In addition to adhesives, the cover 50 may also be secured by other methods such as bands, straps, ties, casts, and so forth.
In an exemplary use, the optional friction-reducing layer 80 is placed at the treatment location against the skin 3 or the wound bed. Then, the suction manifold 10, with aciculated components 20 and conduit 40 attached is placed against the friction-reducing layer 80 and pressed so that the aciculated components 20 pierce the friction-reducing layer 80 and the tissue to be treated. Alternatively, the friction-reducing layer 80 may be provided on the surface of the manifold. Furthermore, the conduit 40 may be attached to the suction manifold 10 either before or after the aciculated components 20 are inserted in the edematous tissue 2. A self-adhesive cover 50 is applied over the suction manifold 10, the skin 3, and the conduit 40. The adhesive secures the cover 50 to the suction manifold 10, the skin 3, and conduit 40 to form a seal at the treatment location. The conduit 40 is attached to the suction source 30, which may then be activated to withdraw edema from the edematous tissue 2. Suction is applied at a desired suction pressure and is maintained until the desired amount of edema is removed.
These and other advantages of the present invention will be apparent to those skilled in the art from the foregoing specification. Accordingly, it will be recognized by those skilled in the art that changes or modifications may be made to the above-described embodiments without departing from the broad inventive concepts of the invention. It should therefore be understood that this invention is not limited to the particular embodiments described herein, but is intended to include all changes and modifications that are within the scope and spirit of the invention as set forth in the claims.
