A wound VAC (vacuum assisted closure) is a device which allows people to conduct negative pressure wound therapy (NPWT). The device consists of a dressing which is fitted with a tube and attached to the wound VAC. Negative pressure wound therapy is most commonly used with chronic wounds which are not responding to other forms of treatment, and sometimes with surgical wounds which have reopened. It usually requires the supervision of a nurse, although people do not need to be hospitalized to use a wound VAC.
The exact processes behind the functioning of a wound VAC on a biological level are not well understood. Numerous studies, however, have shown that using a wound VAC can decrease the amount of time required to heal and reduce the risk of infections and other complications.
To use the device, the wound is carefully cleaned, and a piece of sterile sponge is cut to fit inside the wound. Then, the sponge is sealed in place, usually with clear film, and a small slit is cut to allow a tube to project into the sponge. The tube is sealed in place and connected to a wound VAC, and the device is turned on, with the pressure being chosen by the wound care specialist who is in charge of the case. Periodically, the device is turned off for a dressing change in which the wound is also inspected.
For drainage, a wound VAC can be highly beneficial. The amount of time between dressing changes can be extended because the vac pulls out fluids which seep into the wound. This also keeps the environment unfriendly for bacteria. Using a wound VAC appears to increase perfusion, keeping circulation high and ensuring that blood reaches all areas of the wound. It also reduces edema or swelling, and appears to promote rapid tissue granulation, an important stage in the healing process.
Even with a wound VAC, a wound can take weeks or months to heal. The devices are usually designed to be portable so that patients can carry or wear them, allowing patients to go about their daily business while undergoing negative pressure wound therapy. Some patients are also taught to handle their own bandage changes, while others may go to a nurse or schedule regular visits from a home nurse for wound care. It is important to follow directions with this type of wound therapy to make sure that it is conducted properly.