Patent Application
20210106737
This disclosure relates to medical devices for use in healing large delicate wounds, and in particular, healing of unclosed abdominal wounds, skin graft sites, artificial skin placements, draining wounds which require compressive therapy, and open wounds with enteric fistulas and ostomies.
Surgeons typically attempt full abdominal closure when completing abdominal surgery to include reconnecting the fascia, abdominal muscle layers, and skin. However certain situations arise when a patient's abdominal wall cannot be closed at the time of their initial operation because of trauma, septic abdomen, ischemic bowel, etc. Unfortunately, for many patients, full abdominal closure is impractical or high risk and patients can be left with a large open abdominal wound and exposed bowel.
If the abdominal wall is left open long enough, the body will form a thin layer of granulation tissue over the exposed bowel in an attempt to heal the wound by secondary intent. This healing process can take weeks or months and presents many challenges for the patients and healthcare professionals. These challenges include massive fluid loss, electrolyte imbalances, complex and time-consuming dressing changes, and enteric fistulas when holes in the bowel occur.
Negative Pressure Wound Therapy (NPWT) is often used to facilitate healing of large wounds, however standard NPWT with uncovered foam dressings is not indicated for placement directly on exposed bowel or viscera due to risks of injury to organs and the formation of enteric fistulas.
Two issues involved in treating patients with open abdomens include 1) the mechanical issue of drawing the abdominal wall together to achieve midline closure and 2) the issue that arises when the abdominal wall fails to come together and the underlying viscera is left exposed. Some devices used to address the first issue and provide medial tissue movement and temporary closure of open abdominal wounds include those described in U.S. Patent Publication No. 2014/0221947 A1 to Hunt, U.S. Patent Publication No. 2014/0068914 A1 to Coward, European Patent Publication No. EP 2 538 902 B1 to Lattimore, and International Patent Publication No. WO 2017/019810 A1 to Balasubramaniam, all of which are incorporated herein by reference in their entireties. These devices, however, are typically highly invasive to the body and are used for temporary protection of the bowel and viscera for a relatively short period of time (e.g., 2-10 days). These devices may be utilized between the initial abdominal surgery, while the abdominal cavity is left open, until closure can be achieved. These devices are only designed to facilitate abdominal wall closure and are not designed for use in cases where closure cannot be achieved and the patient is left with an open abdomen with exposed bowel that must heal over an extended period of weeks or months.
Some additional unmet patient needs involve edematous and swollen areas of the body where compression and removal of fluid is the mainstay of treatment. For example, compression with elastic-based materials and fluid absorption is a common treatment for swollen lower extremities with weeping wounds. In these situations, just as with exposed bowel, unprotected NPWT foam dressings are not designed to be placed directly on the skin of the lower extremities.
Traditional NPWT devices are also contraindicated for direct placement over large weeping and swollen wounds involving cutaneous components like swollen lower extremity wounds, scrotal wounds, and any area of the body with wounds and lymphedema. Such NPWT devices are also not appropriate for skin grafts or artificial skin placements.
There exists a need for an improved healing device for large delicate wounds with exposed bowel, skin graft and artificial skin placements, weeping/edematous wounds and swollen extremities with drainage, and open wounds with enteric fistulas and ostomies. Devices are not available that addresses all the issues encountered with these complex wounds: fluid management, wound protection, compression, and ease of use.
This disclosure describes embodiments of a Negative Pressure Wound Therapy (NPWT) wound care device for treatment of large wounds with negative pressure in a way that protects organs, skin grafts, fistulas, underlying tissues, and other delicate structures. The disclosed devices are designed to be easy to apply to the surface of the body by bedside nurses or home healthcare providers without specialized equipment or training. Such devices are also uniquely designed to prevent furthering complications and designed to protect the delicate wound surface and the intact skin around a wound.
In some embodiments, the disclosure describes a NPWT wound care device that includes an open-cell porous foam layer, a skin-safe fluid-permeable contact layer on a bottom surface of the foam layer that is configured to be placed in direct contact with an open wound of a patient, and a top air-sealed layer on an upper surface of the foam opposite of the fluid-permeable contact layer. The wound care device defines an outer perimeter along the edge of the foam layer that forms an air-tight seal with the top air-sealed layer. A skin-safe adhesive is placed along the outer perimeter such that the adhesive may be used to bond the wound care device to a patient's skin and form an air-seal over the foam to both enclosed and seal the foam to the patient, allowing a negative pressure (e.g., vacuum or near vacuum) to be applied to the foam, causing the foam to collapse and form a protective layer over an open wound in the patient's skin. Negative pressure in combination with the adhesive materials on the perimeter of the foam form a barrier around the wound opening in the body of the patient and allow for wound drainage to be drawn through the fluid permeable layer and the foam and into an NPWT pump coupled to the wound care device. The skin-safe contact layer on the base of the device allows the device to be placed on both open wounds, including delicate tissue or viscera, and intact skin. The skin and tissue around a wound will be protected from abrasion by the fluid permeable and porous foam layers and receive protected negative pressure wound therapy to reduce edema and swelling incidental to the wound.
In some embodiments the disclosed wound care devices may include channels, cross channels, or the like (e.g., discernible airgaps) in the porous foam layer. The open channels may help to facilitate placement around cylindrical body surfaces and limbs. In this way, the channels enable bending and flexibility along one or more axes while also allowing negative pressure communication throughout the entire device. Additionally, or alternatively, the shape and design of the channels may help direct the lateral (e.g., in-plane) movement of the foam layer during the negative pressure application to help constrict the surface area of the wound care device and help to at least partially close the open wound.
In some embodiments, the foam layer may include channels and cross channels that help facilitate placement on uneven body surfaces. The channels and cross channels may be designed in a way that enables bending and flexibility along at least two axes while also allowing negative pressure communication throughout the entire device.
In some embodiments, the wound care device may be wrapped circumferentially around a limb or the body such that the device at least partially overlaps with itself. In some such examples, the device may attach to itself by fastening the adhesive exterior perimeter over the air-sealed layer in a spiral fashion. Negative pressure wound therapy is then supplied to the foam to compress the overlapped device around the patient's limb or body to help treat circumferential type injuries.
In some embodiments, the disclosed wound care device may be selectively cut to size (e.g., trimmable) to fit the wound. After cutting to size, the outer perimeter of the foam layer may be sealed to the skin with using skin-safe adhesive materials to create the airtight seal. Additionally, or alternatively, the device may be self-sealing such that the perimeters of the wound care device may be sealed prior to or after the device has been cut to size.
In some embodiments, a fistula and ostomy drainage isolator may be embedded in the foam layer for use in open wounds with a fistula, ostomy, or other draining wounds. An opening through the layers of the wound care device and drainage isolator may allow intestinal and other bodily fluid effluent to pass through the device and away from the patient's body for collection into an ostomy pouch-type appliance while maintaining protected negative pressure to the remainder of the wound. In some such examples, the wound care device may be selectively puncturable to allow placement of a fistula and ostomy drainage isolator at any location in the device.
The above summary is not intended to describe each illustrated embodiment or every implementation of the subject matter hereof. The figures and the detailed description that follow more particularly exemplify various embodiments.
Subject matter hereof may be more completely understood in consideration of the following detailed description of various embodiments in connection with the accompanying figures, in which:
While various embodiments are amenable to various modifications and alternative forms, the embodiments have been shown by way of example in the drawings and will be described in further detail below. It should be understood, however, that the intention is not to limit the claimed inventions to the particular embodiments described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the subject matter as defined by the claims.
In the following description, reference is made to the accompanying drawings that form a part hereof and in which are shown by way of illustration several specific embodiments. The following reference numbers are used throughout the drawings:
The present disclosure describes embodiments of a device for treatment of large wounds with Negative Pressure Wound Therapy (NPWT) in a way that protects bowel, skin graft sites, fistulas and other delicate structures. The device is designed to be easy to apply to the surface of the body by bedside nurses or home healthcare providers without specialized equipment or training. The device may also be designed to be cut to size or overlapped on itself as needed to fit specific patient wound shapes and sizes.
Unless otherwise indicated, all numbers expressing feature sizes, amounts, ranges, and physical properties are to be understood as being modified by the term “about.” Accordingly, unless indicated to the contrary, the numerical parameters set forth are approximations that can vary depending upon the desired properties sought to be obtained by those skilled in the art utilizing the teachings disclosed herein.
As used herein, the singular forms “a”, “an”, and “the” encompass embodiments having plural referents, unless the content clearly dictates otherwise. As used in this specification and the appended claims, the term “or” is generally employed in its sense including “and/or” unless the content clearly dictates otherwise.
The terms “top,” “upper,” “bottom,” or “lower” are used to refer to the relative position of two or more components within the device or a patient's skin.
The device 10A may be applied in over the patient's open abdomen, skin graft or other wound with the contact layer 56 directly against the patient's body and covering the open wound. The skin-safe adhesive exterior perimeter 44 and the air impermeable layer 47 form a seal with the patient's skin to enclose both foam layer and contact layer 56 against the patient. The pump 40 creates a vacuum pressure P2 less than atmospheric pressure P1. This negative pressure is then supplied to the foam layer 46 via the air tube 42 and negative pressure connector 48 to compress the foam 46 and affix the device 10A to the patient. The negative pressure helps draw wound drainage through the contact layer 56 and the porous foam 46 where the drainage is collected in the reservoir (not shown) via pump 40.
The fluid-permeable non-adherent skin contact layer 56 protects the bowel, skin grafts, fistulas, or any other delicate structures (e.g., delicate organs) under device 10A, while allowing Negative Pressure Wound Therapy to control wound drainage and facilitate healing and the formation of granulating tissue.
In some examples, the NPWT may help protect and promote healing of the underlying wound. For example, the wound contact layer 56 may help to distribute the negative pressure and forces over the entirety of the open would while still promoting fluid drainage and closure of the wound. With conventional NPWT, an open cell foam is placed directly on an open wound. The negative pressure applied, in conjunction with the open cell structure of the foam, stimulates the underlying tissue to promote healing. This stimulation, while effective for certain types of tissue, may be too aggressive for delicate tissue (e.g., exposed bowels, organs, or viscera) and is contraindicated for such injuries. Including the wound contact layer 56 between the foam layer 46 and open wound of the patient may provide a convenient system that is minimally invasive and allows for the benefits of NPWT to be applied to such injuries without having the open cell foam directly contact such delicate tissue. Further, as the wound care device 10A may be provided as a unitary system, (e.g., as opposed to using separate and independent medical devices and articles) the device offers an all-in-one convenient system that helps reduce the complexity and duration of applying the wound care device to the patient.
In some embodiments, wound care device 10A may be provided as singular, prefabricated device wherein wound contact layer 56, foam layer 46, and air-sealed layer 47 are provided as a ready to use device that does not need to be assembled prior to use. Such a device 10A may significantly reduce the complexity and duration during wound care applications and changes, particularly in comparison to modulated systems that require multiple components to be sourced and applied (e.g., independent foam materials, independent adhesive drapes, and the like). In some examples, negative pressure connector 48, adhesive layer perimeter 44, and the like may also be provided as part of prefabricated device 10A or may be provided separate of device 10A or as part of a kit. In some such examples, a release liner may be applied to the adhesive layer and optionally the contact layer 56 to protect one or both layers during shipment. Additionally, wound care device 10A may be provided in a sterile pouch that can be opened prior to application to the patient.
The various layers and components of wound care device 10A may be construed using any suitable materials, films, foams, and the like including commercially available materials as will be recognized by those skilled in the art. For example, foam layer 46 may be formed from one or more biocompatible, sterilizable, materials including, for example, reticulated open cell foam used for medical purposes. In some examples, air-sealed layer 47 may be formed from one or more biocompatible, sterilizable, materials including, for example, adhesive plastic drape or film. Fluid-permeable contact layer 56 may be formed from one or more biocompatible, sterilizable, materials including, for example, non-adherent films, plastics, rubbers, silicones, polyester or other fabrics with pores, slits, porosities, or general permeability that allow the passage of fluid into the foam layer 46. In some examples, the contact layer 56 may itself be formed of a continuous layer of fluid permeable material such as commercially available materials Adaptic Touch, Mepitel One, Conformant 2, UrgoTul, Tegaderm, or the like. Additionally, or alternatively, the contact layer 56 may include perforations in the layer to allow for fluid to be drawn through the layer. In some embodiments, foam layer 46, contact layer 56, or both may contain antimicrobial materials, for example, silver or antibiotics.
In some embodiments, air-sealed layer 47 and wound contact layer 56 may be laminated together such that foam layer 46 is completely enclosed between the two layers. Additionally, or alternatively, air-sealed layer 47 may extend beyond the perimeter of foam layer 46 and or contact layer 56 such that air-sealed layer 47 forms the outer perimeter 44 of device 10A. The skin-safe adhesive may be deposited along this perimeter region to bond air-sealed layer 47 to a patient's skin, thereby enclosing the foam layer 46 and contact layer 56 underneath.
In some embodiments skin-safe adhesive exterior perimeter 44 may be formed from one or more biocompatible, sterilizable, materials including, for example, hydrocolloids, silicones, or adhesive plastic drapes or films. Depending on the perimeter construction of air-sealed layer 47 and contact layer 56, skin-safe adhesive may be deposited on air-sealed layer 47, contact layer 56, or both, to provide an air seal in conjunction with air-sealed layer 47 against a patient's skin.
In some examples, the size and shape of channels 50 may be designed to help with the direction of lateral force (e.g., within the plane of device 10B) exerted by the device 10B during the NPWT. Such forces may be used to help draw the wound close as compared to an otherwise continuous sheet of foam.
In such examples, wound care device 10B may be wrapped in a circumferential or spiral pattern around the limb or body of the patient to overlap with itself. A spirally-wrapped pattern may be of particular use when covering large open wounds such as those that span the entire length of a patient's leg. In some such examples, the width of device 10B need not be required to span the whole wound because perimeter edge 44 of the outer-wrapped layers of the device 10B will form an air-seal against the lower-wrapped air-sealed layer 47. Further, because the overlapping perimeter will form parts of the seal, portions of the lower-wrapped layers may be trimmed as needed. For example, portions of device 10B that would otherwise cause the adhesive perimeter 44 to directly contact the open wound may be trimmed away without sacrificing the seal integrity of the device 10B. Additionally, or alternatively, one skilled in the art will recognize the ability of multiple wound care 10 devices being used collectively together to cover a single large wound.
The fistula and ostomy drainage isolator 70 may be embedded in the foam layer 46 and sealed to the air impermeable layer 47 and contact layer 56. An opening 58 through device 10C and drainage isolator 70 allows intestinal and other bodily fluid effluent 34 to pass through the drainage isolator 70 and away from the patient's body for collection into an ostomy pouch-type appliance. In some embodiments, drainage isolator 70 may be prefabricated within device 10C or inserted within the device 10C by the caregiver prior to patient application. For example, a caregiver may cut an opening through air-sealed layer 47, foam layer 46, and optionally contact layer 56. Drainage isolator 70 may then be inserted and sealed against air-sealed layer 47 to maintain the integrity of the negative pressure environment. A hole or cross slit may be placed within contact layer 56 to allow passage through opening 58 while also optionally providing a contact buffer layer between drainage isolator 70 and the wound surface.
In some embodiments, fistula and ostomy drainage isolator 70 may be formed from one or more biocompatible, sterilizable, materials including, for example, plastics or rubbers or silicone rubber. Other materials may be used, for example, a flexible thermoplastic. Preferably, fistula and ostomy drainage isolator 70 is formed using a non-fluid permeable and/or non-porous flexible material. Examples of such isolators 70 include the Fistula Funnel and Wound Crown available from KCI.
Further, as will be recognized by those skilled in the art, all parts of device 10C can be sized and shaped to accommodate all different sizes and shapes of wounds.
Device 10C also includes optional channels 50 and cross channels 52 within foam layer 46. These channels 50 and 52 may be designed in a way that enables bending and flexibility along two axes while also preserving optional foam bridges 54 that allow negative pressure communication through the entire device 10C.
In some examples, the disclosed devices 10 may be sterilized for use in a surgical environment. Additionally, or alternatively device 10 subcomponents may be a provided as a kit that includes negative pressure pump 40 which may be sterilized and packaged in a sealed pouch or container that preserves sterility and can be opened by the patient or clinician.
Various embodiments of systems, devices, and methods have been described herein. These embodiments are given only by way of example and are not intended to limit the scope of the claimed inventions. It should be appreciated, moreover, that the various features of the embodiments that have been described may be combined in various ways to produce numerous additional embodiments. Moreover, while various materials, dimensions, shapes, configurations and locations, etc. have been described for use with disclosed embodiments, others besides those disclosed may be utilized without exceeding the scope of the claimed inventions.
Persons of ordinary skill in the relevant arts will recognize that the subject matter hereof may comprise fewer features than illustrated in any individual embodiment described above. The embodiments described herein are not meant to be an exhaustive presentation of the ways in which the various features of the subject matter hereof may be combined. Accordingly, the embodiments are not mutually exclusive combinations of features; rather, the various embodiments can comprise a combination of different individual features selected from different individual embodiments, as understood by persons of ordinary skill in the art. Moreover, elements described with respect to one embodiment can be implemented in other embodiments even when not described in such embodiments unless otherwise noted.
For purposes of interpreting the claims, it is expressly intended that the provisions of 35 U.S.C. § 112(f) are not to be invoked unless the specific terms “means for” or “step for” are recited in a claim.
The present application claims the benefit of U.S. Provisional Application No. 62/913,918 filed Oct. 11, 2019, which is hereby incorporated herein in its entirety by reference.
| Number | Date | Country | |
|---|---|---|---|
| 62913918 | Oct 2019 | US |
