How To Prevent Periwound Maceration With VAC Therapy
Maintaining an airtight seal with VAC therapy may be difficult for highly exudating wounds and wounds that are irregular in size. Given these challenges, these authors present a novel technique to address this issue and reduce the risk of periwound maceration.
Despite the number of different modalities that exist for the treatment of acute and chronic wounds, VAC therapy (Vacuum Assisted Closure, KCI) has proven to be an effective and valuable tool for treating complex wounds.1-4 The VAC device utilizes the concept of negative pressure wound therapy (NPWT), in which controlled subatmospheric pressure causes mechanical stress to the tissue, which in turn causes the wound to close.5,6
Negative pressure wound therapy removes excess interstitial fluid, causes increased vascularity, decreased bacterial colonization and produces a response on the tissues around the wound through mechanical forces.7 All of these factors assist to increase the rate of healing with very little trauma to the patient.
The VAC therapy device utilizes a reticulated polyurethane foam dressing that one places in contact with the wound, maximizing the potential for tissue ingrowth.7 Additionally, the foam ensures equal distribution of sub-atmospheric pressure to every part of the wound that is in contact with the foam. An adhesive dressing secures the foam. This facilitates a semi-occlusive environment and helps to protect the periwound skin.
The physician then attaches the pump to the adhesive dressing, which is connected to a computerized therapy unit that delivers either intermittent or continuous suction. Settings are adaptable on the unit and the settings depend on the type and complexity of the wound. The fluid is drawn from the pump into a canister located on the VAC therapy unit. Warnings sound when the canister fills, preventing egress of the fluid into the patient. VAC therapy is a very convenient and valuable tool for healing wounds.
Overcoming The Challenge Of Difficult Wounds
Despite the practicality of VAC therapy, foot wounds can be a challenging and difficult area for placement of the VAC therapy device. It can be difficult to maintain an airtight seal for wounds that are in close proximity to other structures such as web spaces, highly exudating wounds or irregular shaped wounds.
Loss of this seal will cause extravasation of fluid, resulting in periwound maceration and an inability of the VAC therapy device to function properly. In a study by Armstrong and colleagues that discussed the outcomes of subatmospheric pressure dressing on diabetic foot wounds, 19.4 percent (six out of 31) of the patients in the study had a complication of periwound maceration.1
To help prevent this complication from occurring, one may create a durable seal with the VAC therapy device by using the Eakin® cohesive seal (TG Eakin Ltd.). The Eakin cohesive seal is a highly moldable, hydrocolloid product, which provides a waterproof and moisture absorbing skin barrier.8 It comes in two sizes (small and large) and helps to stop leakage and absorb moisture, preventing maceration and irritation around skin edges. The cohesive seal provides double-sided adhesion and is completely moldable. One may break, rejoin or layer the seal, and it is easy to remove.