Vacuum-Assisted Wound Closure - Indications, Contraindications, Benefits, and Risks

What Is Vacuum Assisted Wound Closure?

Vacuum-assisted closure is a technique used for wound closure that can help promote wound healing by creating negative pressure on the wound or surgical site. The pressure on the wound should be less than the atmospheric pressure. This technique is also called negative pressure wound therapy.

This technique reduces air pressure on the wound by applying a vacuum-assisted closure device to pull the wound edges together. This can eliminate the extravascular fluid from the wound, improve blood circulation, and promote granulation tissue formation, thereby enhancing wound healing.

This technique is widely used in abdominal, vascular, gynecological, and plastic surgery. This technique is as effective as a conventional technique in wound closure by decreasing swelling, promoting granulation tissue formation, and preventing infections.

What Are the Indications for Vacuum Assisted Wound Closure?

• Traumatic wound.

• Chronic wound.

• Surgical wound.

• Poor healing wounds in patients with diabetes.

• Large-sized wound.

• Wound with a recent skin graft.

• Burns.

• Cesarean section.

• Pressure ulcers.

What Are the Contraindications for Vacuum Assisted Wound Closure?

This technique should be avoided in patients having

• Higher risk of bleeding.

• Active wound infection.

• Dead tissue in the wound.

• Active systemic infection.

• Exposed vital tissue and vessels.

• Cancer.

• Very fragile tissue.

• Allergic reaction.

• Minimal blood flow to the wound.

• A wound in the joints or close to the joints.

What Is the Technique for Vacuum Assisted Wound Closure?

VAC Device

VAC device comprises a vacuum pump, a canister with tubing, pored foam, and a semi-occlusive dressing. Numerous devices are available for wound suction, called negative pressure wound therapy. The pored foam is made of polyvinyl alcohol, which is white and non-adherent, to relieve pain. It has a pore size of about 400 to 600nm. This foam can be cut and placed in the wound based on its size. This foam is used mainly to manage diabetic feet, pressure sores, and skin grafts.

A canister is attached to a tube to remove and collect fluids from the wound. The vacuum pump helps remove extracellular fluid and infections from the wound by creating negative pressure. The tube is connected to the reticulated foam. The use of reticulated foam is to spread the pressure equally over the entire wound. The dressing is done by placing the cut foam on the wound based on its size and then sealing it with an adhesive film with an excess of 3 to 5cm for an intact seal. The tube connects the wound and the vacuum pump by embedding it in the foam; thereby, it helps collect extracellular fluid from the wound.

Steps in the vacuum-assisted wound closure technique include:

• Gently remove the debris, necrotic tissue, or previous dressing, then thoroughly cleanse the wound in and around it. Later, dry the wound and the peri-wound area by achieving hemostasis. The desired foam is chosen based on the size of the wound and the sponge kit appropriate for cavity filling.

• Then the drape or adhesive film is shaped to seal the wound intact by cutting the adhesive film or drape to a slightly larger size than the wound size, thereby securing the foam. Then gently cover the wound base with foam, and the tube is connected to the foam. Later, cover the foam with adhesive tape or a drape to keep the wound intact.

• The tube's other end communicates with the vacuum-assisted device's canister. The vacuum pump works throughout the day during the healing period. The setup for a VAC device might differ from person to person, depending on the wound vacuum system used.

What Are the Benefits of Vacuum Assisted Wound Closure?

This technique helps heal wounds faster by

• Decrease Swelling and Remove Exudates: Swelling occurs in the wound area mostly due to edema,, which may compress the cells within the extracellular matrix, leading to reduced proliferative capacity. The vacuum-assisted device helps apply negative pressure over the entire wound, thereby removing exudates. This can reduce swelling and promote wound closure.

• Reduce Inflammation: This technique helps reduce inflammation by improving blood circulation and removing exudates.

• Decrease Bacterial Count: Bacterial counts in the wound can be reduced by altering the foam, and the foam can be treated with silver, which may reduce bacterial colonization over the wound.

• Approximate Wound: The skin and soft tissue naturally pull apart when an incision is made through them. Wound approximation helps improve wound closure through delayed primary or secondary intention. The foam effectively removes the exudates from the wound and transmits the pressure evenly over the wound. Depending on the tissues treated, a Vacuum-assisted closure device exerts effects on the surrounding tissues that can lead to deformability of the tissues. Wound shrinkage is associated with the deformability of the surrounding tissues. Hence, the foam has to be cut accordingly to allow the approximation of wound edges together, thereby enhancing wound closure.

• Improve Blood Circulation: The interstitial fluid movements depend on the changes in pressure. The rapid change in pressure makes the rapid interstitial fluid movements, and if there is a slow change in the pressure, then that can cause gradual movement of interstitial fluid and also reduce the stress over the cells. The optimal setup for a vacuum-assisted device is 125mmHg pressure with five minutes on and two minutes off cycle, thereby increasing the blood circulation and proliferation capacity.

• Decrease the Frequency of Dressings: This technique also reduces the frequency of dressings by using an adhesive film or drape that can keep the wound intact.

• Keep the Wound Intact: This technique uses an adhesive film or drape that has the capacity for minimal permeability to gases and water vapor and is impermeable to proteins and microorganisms, thereby reducing scab formation. This technique promotes wound healing by reducing dressing frequency, and scab formation and eliminating extracellular fluid from the wound.

What Are the Risks Associated With Vacuum-Assisted Wound Closure?

The risks associated with vacuum-assisted wound closure are

• Sepsis.

• Hemorrhage.

• Bleeding.

• Bacterial infections.

• Poor wound healing in some cases.

• Enteric fistula (an abnormal connection between the skin and intestinal tract).

• Macerated wound (moistening wound leads to softening and breaking of skin).

Conclusion:

Vacuum-assisted wound closure is an effective technique used for managing wounds. This technique helps in stabilizing the wound, reducing swelling and bacterial colonization, and stimulating the proliferation of new tissues thereby promoting wound healing and achieving faster recovery than conventional dressing techniques.