T

he benefits of semiocclusive dressings versus traditional gauze materials for topical wound management have been well established and include increased healing rates, reduced wound pain, improved cosmesis, and reductions in overall costs of care. Realization of these benefits assumes the selection of an appropriate type of semiocclusive dressing to match the needs of the wound to be dressed.
        While there are hundreds of types and brands of semiocclusive dressings on the market, selection of dressing type is based on its primary function, such as absorbency, hydration, protection, odor control, etc. Determination of wound needs is based on ongoing assessment of local wound conditions, such as exudate levels, tissue types in the wound, periwound skin condition, and physical dimensions as well as management goals.
       Even if selection of a dressing based on its function is appropriate for the condition or needs of the wound, the aforementioned healing benefits are only attained if the dressing stays in place on the wound. While this may sound obvious, there are a wide variety of wound types and conditions that present specific and unique challenges to keeping a dressing in place.

What Constitutes a Difficult-to-Dress Wound?
       Wounds may be considered "difficult to dress" based on specific conditions, such as excessive exudate production, which creates challenges to dressing absorptive capacity and wear time. Wounds with extensive depth or undermining require dressings with the ability to be gently molded or packed into place. Fragility or sensitivity of the intact skin surrounding a wound may place special demands on the adhesive qualities of the dressing or tape.
       Specific anatomical locations may also present dressing dilemmas. Ulcers of the oral or anal mucosa present difficulties in terms of dressing adherence in an area of continual moisture. Wounds in an area of flexion, such as the convex or concave surface of a joint, may offer challenges to dressing adhesion or other forms of securement. Wounds on the hands or fingers may be especially difficult to dress due to frequent movement and use. Wounds of the head--either on the face or the scalp--present unique obstacles in terms of the presence of hair, skin oils, topography, and potential aesthetic concerns of the patient.
       Fortunately, there is a robust assortment of wound dressings on the market, and they possess a broad spectrum of performance characteristics that may address some of the aforementioned wound challenges. There are also nontraditional materials that may be of service in creating solutions for difficult-to-dress wounds.

Dressing Securement to the Wound: Adhesives or Not?
       Many wound dressings have an incorporated adhesive border or an adhesive surface, while others lack adhesive and must be attached to the patient by a secondary device. Their gentleness or skin friendliness characterizes some adhesives while others are known for their tenacity.
       Hydrocolloid dressings in general comprise some of the most versatile and tenacious adhesives for skin. Hydrocolloids are homogenous mixtures of adhesive, elastic, and absorptive components and are unique in their ability to adhere to a moist surface--a quality known as "wet tack." The hydrocolloid adhesive mass actually flows as it warms to body temperature and has greater contact with irregular surface of an intact stratum corneum. Hydrocolloids are known for remaining in position for long periods of time and for their ability to adhere even in moist areas, such as the perineum. However, hydrocolloids may actually be too aggressive for some patients with very fragile skin and have the potential to cause skin tears or skin stripping if changed too frequently.
       For fragile skin, there are adhesive systems that are uniquely gentle due to their formulation or the manner in which they are coated onto the dressing. Certain polyurethane adhesive formulations (found on Tielle Hydropolymer dressings, Johnson & Johnson Wound Management, Somerville, New Jersey) are easily and nontraumatically released with water and may even be repositioned. Silicone-based adhesive systems (found in the Tendra line of dressings, Molnlycke Health Care, Newtown, Pennsylvania) provide secure attachment to dry skin surfaces and subsequent nontraumatic removal. Other products incorporate adhesives, which rather than being applied in a continuous sheet have been coated onto the dressing surface or border in a pattern, creating open areas of no adhesive (found for example on Flexzan foam dressing, Bertek Pharmaceuticals, Inc., Durham, North Carolina, and certain high-permeability transparent films). The open areas in the pattern-coated adhesive allow for increased breathability and movement of the dressing.
       There are also alternatives to adhesives as the mechanism to keep a dressing on the wound. Tubular elastic bandages and netting systems are available in a variety of circumferences to accommodate different body parts, such as fingers, toes, legs, arms, torsos, and heads. There are reusable systems that employ a Velcro closure to encircle the body part with the wound and hold a nonadhesive dressing in place with slight pressure.

Dressing Conformability--Thickness and Shape
       Wounds with depth or undermining require dressings that are conformable or amorphous to enable gentle packing of the dressing material into the dead space of the wound. Rope forms of alginates, dressings that come in thin strips, or amorphous hydrogels provide this sort of conformability. Wounds on convex or prominent anatomical areas (for example the nose, the ears, and the joints) benefit from thin or low profile dressings that can be folded over and around the anatomy. Transparent films or extra-thin versions of foams and hydrocolloids may be helpful in these areas. If more absorbency is required, these dressings may be used to hold a conformable absorbent material, such as an alginate, in place.
       While dressings of many types have been traditionally manufactured as squares or rectangles, other shapes are also available and may offer an improved fit for certain challenging anatomical locations. Oval or circular adhesive dressings are generally thought to stay in place longer due to their lack of corners. Sharp corners may lift under forces of shear and friction and compromise the overall adhesion and wear time of a dressing. Some dressing shapes are designed with a particular anatomical site in mind. Flower-shaped dressings have extensions from a central core that can be wrapped around the convex surface of an ankle, knee, or elbow to create a cup-like fit. Other dressings may have creases or precut slits that similarly allow the user to shape the dressing over or around a location, such as the heel or elbow. The sacrum is one particular anatomical area that has spawned numerous unique dressing shapes, which attempt to provide a superior fit. Specialized sacral dressings include triangle shapes, heart shapes, and dressings with extended adhesive borders, which may be cut to fit the particular patient anatomy. The concept of unique dressing shapes for the sacral area has been explored in a controlled trial where it was revealed that increased wear times and healing rates were associated with a triangular-shaped hydrocolloid dressing (placed with the point of the triangle pointing towards the rectum).1

Dressing Absorbent Capacity and Wear Times
       In addition to a challenging location, the exudate level of a wound may be the challenging characteristic for dressing. Wounds that produce copious amounts of exudate may require frequent dressing changes, which then create challenges in terms of repeated application and removal of adhesives from the skin, repeated disturbance of the wound, availability of trained caregivers to perform the dressing changes, and product costs. For these reasons, there are a variety of dressing types that have been developed to excel at fluid absorption and management for increased wear times. Foams and alginates are two common types of absorbent dressings, but even these dressings can be overwhelmed in some situations and require multiple changes per day. Many manufacturers have incorporated superabsorbent fibers or powders into their absorbent products. Superabsorbents are chemical ingredients (powders) that are capable of absorbing large amounts of fluid and immobilizing it as a gel. They have traditionally been utilized in diaper, feminine hygiene, and urinary incontinence products. Two examples of dressings that contain superabsorbent ingredients are Tielle Plus Hydropolymer Dressing Plus (Johnson & Johnson Wound Management, Somerville, New Jersey), an adhesive foam, and Combiderm (ConvaTec, Skillman, New Jersey), a hydrocolloid-based dressing. The Tielle dressings are also engineered to actively move exudate through the absorbent portion of the dressing and through the vapor-permeable backing to extend wear times and overall fluid handling capacity.
       In certain cases, due to issues of product availability or patient access to product, actual baby diapers or feminine hygiene products have been used to manage highly exudative wounds (personal experience of the author). If such products are to be used, it is advisable to use a wound contact layer to protect the wound surface since these products were not originally designed to contact exposed tissues.

Unique Solutions for Wounds in Unique Locations
       Wound care discussions often focus specifically on a small variety of chronic wounds that occur in predictable locations, such as lower-extremity venous ulcers, plantar neuropathic foot ulcers, and pressure ulcers over bony prominences. But there are many types of acute wounds that occur in unique anatomical areas and also present challenges for successful topical dressing.
       Scalp wounds. Open wounds of the scalp are difficult to dress due to the presence of hair preventing adhesive dressings from sticking, curvature of the skull, and shearing forces resulting from movement of the head during sleep. In most cases, scalp wound dressings are attached with the use of some sort of tubular bandage or turban or the hair may be shaved to facilitate the use of adhesive tapes. But hair grows back and may lift the tape and bandages over the entire head and present issues of comfort and cosmesis.
       Several authors have described methods of using the hair itself to secure the dressing. One technique involves clipping a border of hair around the wound to a height of about 6cm or 2.5 inches.2 Then, a polymerizing foam (Silastic, Dow Corning, Midland, Michigan) is poured over the wound as well as the border of clipped hair. The foam polymerizes or "sets" and covers the wound while also becoming firmly enmeshed in the hair-border. It is thought that the inclusion of the hair in the foam will discourage the patient from manipulating the dressing. Removal of this dressing is achieved by cutting the hair border close to its base.
       Another method involves placing a dressing over the scalp wound and then gathering portions of hair around the wound's circumference into a ponytail to effectively hold the dressing on by pressure and provide a measure of aesthetic acceptability to the patient.3 The dressing is removed by clipping the rubber band holding the ponytail. A third method is specific for primarily closed wounds of the scalp4 and comprises leaving the suture ends long enough to tie and knot over a rolled gauze pad placed over the approximated wound edges.
       Whole-face wounds. Whole-face wounds are commonly encountered after cosmetic dermatological procedures, such as dermabrasion or laser abrasion. These wounds tend to be very shallow but highly exudative for the first 48 hours or so when management of the exudate is critical to avoid crust formation (which may lengthen epithelialization time). After this initial exudative phase, a hydrated environment facilitates rapid epithelialization. Whole face wounds present obvious challenges in maintaining dressing securement. Various semiocclusive dressing materials as well as creams and ointments have been evaluated in clinical trials with these types of whole face wounds.5,6 Adhesive, extrathin foam (Flexzan) has performed well in these trials, offering excellent conformability and exudate management. Silicone-coated mesh (Mepitel, Molnlycke) covered by absorptive dressings has also produced rapid healing and improved patient comfort.
       Fistulas. Fistulae in ano are usually treated with fistulotomy and various surgical flaps. Use of autologous fibrin glues as well as commercial fibrin sealants has been reported to yield reasonable success in the management of these unique wounds. Commercial preparations are preferred to autologous ones based on improved performance and consistency of bonding due to higher fibrinogen content and reduced preparation times. In a recent prospective study, 29 patients with draining anal fistulae were treated with a commercial fibrin sealant.7 Primary and secondary openings of the anal fistulae were identified in the operating room and the fistula tract cleaned. The two components of the fibrin sealant were injected into the secondary opening of the tract until it was seen exiting from the primary opening. A petrolatum gauze dressing was placed over the injection site, and the patient was sent home. Follow-up visits at one week, one month, three months, and one year were performed to check for stability of the sealant or presence of abscess. Four of the 29 patients were lost to follow up, while 17 (68%) of the remaining 25 patients had successful closure of their fistulae.
       Wounds of the oral mucosa. Wounds of the oral mucosa present challenges to dressing due to the continuously moist environment of the wound as well as its surrounding intact tissues. Tissue adhesives based on cyanoacrylate chemistry have shown promise for wound management in this environment.
       In one prospective, controlled clinical trial, 60 patients undergoing oral surgery for molar extractions were randomized to either an experimental group where a n-butyl-2-cyanoacrylate adhesive was used to approximate the wound edges or to a control group where standard sutures were used.8 Follow up was done at 30 minutes and one week. Outcomes assessed include hemostasis, inflammation, dehiscence, and infection. The only difference between the control group and the experimental group was the onset of hemostasis--immediate for the latter and 20 to 30 minutes for the former. Another observed benefit for the cyanoacrylate was ease of application and elimination of need for suture removal, which is often painful and causes minor reinjury. The cyanoacrylate adhesive simply flaked off within one week with no tissue reaction. Patients reported pain relief and less eating discomfort with the cyanoacrylate adhesive.
       In the case of aphthous ulcers of the mouth (or canker sores), topical management is often achieved by the use of barrier ointments and liquids for pain relief and protection of the ulcer. A 2-octyl-cyanoacrylate adhesive has demonstrated a superior ability to stay in place, relieve pain, and facilitate healing of oral aphthous ulcers.9

Summary
       Difficult-to-dress wounds manifest in both chronic and acute etiologies. Sources of difficulty include anatomical location or local wound and/or periwound skin condition. Considerations for dressing these wounds should include dressing securement by adhesive or alternate means, type of adhesive if used, absorbent capacity of the dressing material, and conformability of the dressing material. Tissue adhesives, such as fibrin glues and cyanoacrylates, may hold promise for certain types of wounds, especially those located in mucous membranes.