A Wound VAC, or Vacuum-Assisted Closure, is a specialized form of wound treatment also known as Negative Pressure Wound Therapy (NPWT). This system applies controlled sub-atmospheric pressure to the wound bed using a foam dressing sealed with a clear film and connected to a pump. The primary purpose of NPWT is to manage complex or chronic wounds by drawing out excess fluid and promoting an environment conducive to healing. All decisions regarding the initiation or discontinuation of this medical device must be determined by a qualified healthcare professional.
Therapeutic Goals of Wound VAC Treatment
The application of negative pressure achieves specific biological and physical changes within the wound environment. The immediate goal is the mechanical removal of excess fluid, or exudate, which reduces localized swelling (edema). Reducing this fluid buildup improves blood flow to the surrounding tissues, delivering necessary oxygen and nutrients for repair.
This increased perfusion stimulates cell growth and proliferation. The tension created by the vacuum, often called microstrain, physically pulls the wound edges closer together. Ultimately, the therapy aims to reduce the overall dimensions of the wound, preparing it for the next phase of treatment.
Another objective is the promotion of healthy granulation tissue, the pink, bumpy tissue that fills the wound cavity. This new tissue is rich in blood vessels and forms the foundation for final closure. Success is measured by converting a complex, open wound into a smaller, shallower wound with a clean, well-vascularized base.
Key Clinical Indicators That Signal Discontinuation
The decision to discontinue NPWT is based on meeting predetermined healing goals assessed through clinical examination. A definitive sign is achieving sufficient granulation tissue coverage across the entire wound base, often aiming for 75 to 100 percent coverage.
The wound’s physical dimensions must also show adequate progression in reduced depth and size. Once the wound is shallow and small, it is ready for alternative closure methods. Minimal drainage output is another indicator, signifying that surrounding tissue edema has resolved and the wound is no longer producing large amounts of exudate.
The wound is typically prepared for definitive closure, such as a skin graft, skin flap, or simple primary suturing. If the wound demonstrates this readiness, the NPWT phase is complete, and the device is removed. Discontinuation may also be considered if a wound shows insufficient healing progress, defined as less than a 30 percent reduction in size over a four-week period.
Situations Requiring Immediate Removal
While most discontinuations follow successful wound preparation, certain complications necessitate the immediate removal of the device for patient safety. The most serious concern is active bleeding or hemorrhage within the wound, indicated by the sudden appearance of bright red blood in the collection canister. This requires immediate attention and removal of the system to control the bleeding manually.
The development of a new or worsening wound infection that cannot be managed with the device in place also mandates discontinuation. Signs of infection include fever, escalating pain, increasing warmth or redness around the wound edges, or the presence of pus. Continued use of NPWT over an unmanaged infection can trap bacteria and hinder antibiotic effectiveness.
Additionally, the unexpected development of a fistula, an abnormal connection to an internal organ, requires prompt removal. NPWT is not suitable for wounds with unexplored fistulas due to the risk of fluid loss or contamination. Finally, if a patient experiences severe, unmanageable pain while the device is operating, the therapy must be stopped to assess the underlying cause.
Post-Discontinuation Wound Management
Once the Wound VAC has been successfully removed, the wound enters a transitional phase focused on maintaining the progress achieved. The immediate step is to switch the wound to a standard, non-negative pressure moist wound dressing. This new dressing, which may be a foam, hydrocolloid, or alginate dressing, protects the newly formed granulation tissue while maintaining a moist environment.
This transition allows the clinician to closely monitor the wound bed for any signs of regression or potential infection following the removal of the vacuum system. Continued monitoring for increased exudate, changes in tissue color, or unexpected pain is important during this period. The wound may then proceed to definitive closure, such as a planned skin graft or flap procedure.
If surgical closure is not required, the wound continues the process of healing by secondary intention, guided by the standard moist dressings. For certain lower extremity wounds, specialized physical therapy or rehabilitation may be implemented to manage swelling and maintain circulation, which supports the long-term integrity of the healed area.