International Center for Limb Lengthening Logo

Negative Pressure Wound Therapy (Wound VAC)

What is negative pressure wound therapy?

Negative pressure wound therapy or “wound vac therapy” is a special type of dressing to treat large or complex open wounds. It consists of a sealed dressing to provide suction or “negative pressure” to promote healing in both acute and chronic wounds. There are several companies that manufacture such FDA approved devices for negative pressure wound therapy. Most provide similar treatment but offer minor variation in available dressings for different wounds, therapy settings and portability of the vacuum device.

How does negative pressure wound therapy work?

Under negative pressure, wound healing is facilitated through a few different mechanisms. The constant suction provided by the machine works to remove excess exudate or “wound drainage” as well any infectious material that may be present in the wound. This helps provide an ideal and clean environment to promote healing. The second way in which negative pressure promotes healing is by stimulating blood flow to the wound surface. Increasing the blood flow brings healthy cells to the wound and accelerates the formation of new tissues, allowing faster wound healing when compared to other methods. The negative pressure dressings are water-tight closures over the wound, so no drainage can soil the suture dressings. All drainage gets removed by a closed tube leading to a closed canister. As the canister fills with drainage fluid, it is changed.

When is negative pressure wound therapy a good option?

Negative pressure wound therapy systems are indicated for use in hospitals as well as home care settings for treatment of all types of wounds. Wound vacs can be applied for a short period of time to remove excess drainage and infectious material and to promote granulation tissue formation to prepare the wound for primary closure by your surgeon. Such secondary closures can be done in the operating room. Negative pressure therapy can also be used for longer periods of time to allow a wound to fully heal from the base or “inside out.” This is typically reserved for severe burns, large chronic wounds or ulcers in patients with diabetes or venous insufficiency, and wounds where chronic infection is present, creating an environment that is not safe to primarily close with sutures. Upon completion of therapy in these wound types, the surfaces are now covered with a healthy layer of granulation tissue and may then be definitively covered by a skin graft.

How long does negative pressure wound therapy last?

The wound vac may be applied continuously or intermittently depending on the type of wound that is being treated. Wound vacuum dressings are typically applied for the first time in the operating room at the completion of a procedure and then typically changed 2 or 3 times per week. Depending on the depth and severity of the wound, the first few dressing changes may be performed in the operating room. Eventually, these dressing changes may be comfortably performed at the bedside, without anesthesia.

How long must patients stay in the hospital after negative pressure wound therapy is started?

Rarely do patients remain in the hospital solely for the use of negative pressure wound therapy. Once planned surgeries are completed and you are medically safe for discharge from the hospital, your medical team will coordinate for a transition to home where wound vac therapy can be continued. These units are typically smaller in size and more portable. All necessary supplies are delivered to your home or rehab location. Nursing staff is given specific orders on dressing changes and ongoing care. For patients who go home after their hospital stay or surgery, home health nursing is arrange for assistance with continued wound care. Depending on the size and severity of the wound, patients or their family members may also be taught how to perform their own vac dressing changes at home.