Negative Pressure Wound Therapy (NPWT): How It Works, Benefits, Risks, and When We Use It
Negative Pressure Wound Therapy (NPWT)—often called a “wound VAC”—uses gentle, controlled suction over a sealed dressing to help a stalled wound start healing again. The device removes excess fluid, reduces edema, helps draw wound edges together, and promotes healthy granulation tissue.
At the Vein & Wound Center of LA, we offer NPWT when it’s truly indicated, as part of a complete plan that may include surgical debridement, infection control, off-loading/compression, and advanced dressings.
How NPWT Works (in plain English)
- A specialized foam or gauze dressing is placed in the wound and sealed with an adhesive film.
- Tubing connects the dressing to a small pump that applies continuous or intermittent suction.
- The vacuum removes fluid and decreases swelling, which improves local blood flow and helps new tissue grow.
- Dressings are typically changed every 2–3 days in clinic or with a trained home-health nurse.
Where NPWT Helps Most (Evidence Overview)
- Diabetic foot wounds / partial foot amputations: Multiple randomized trials and meta-analyses show NPWT can improve healing rates and reduce amputations compared with standard care, though effect sizes vary by study design and wound severity. PubMedPMCWjgnet
- Closed surgical incisions at high risk of infection (prophylactic NPWT): On primarily closed incisions after major surgery, NPWT probably lowers surgical-site infections compared with standard dressings, with no clear difference in dehiscence. PubMedCochrane
- Pressure injuries (stage III/IV): Contemporary guidelines support NPWT as a safe and effective option in appropriately selected chronic pressure ulcers. PMC
Bottom line: NPWT is not for every wound, but in the right wound, right patient, right time, it can accelerate progress and reduce complications.
Benefits You May Notice
- Faster development of healthy granulation tissue and improved progression to closure
- Better management of heavy exudate and wound odor
- Fewer dressing changes than very high-drainage regimens
- Potential reduction in infection risk on certain high-risk closed incisions (prophylactic use) PubMedCochrane
Risks, Contraindications, and Practical Considerations
Possible risks: skin irritation or blistering from the drape, bleeding, pain with dressing changes, periwound maceration, rare infection or DVT. Proper technique and patient selection minimize these issues. Recent syntheses report no overall increase in adverse events versus standard care for diabetic foot ulcers. Wjgnet
Common contraindications/relative cautions: untreated osteomyelitis in the wound bed, malignant tissue in the wound, necrotic eschar that hasn’t been debrided, exposed unprotected vessels or organs, uncontrolled bleeding disorders.
Coverage/logistics: Many insurers (including Medicare) cover NPWT when criteria are met (qualified wound type, documentation of a comprehensive plan, and regular reassessment). We help coordinate approvals and—when appropriate—arrange home-health nursing for dressing changes. (Coverage specifics vary by plan.)
Our Protocol at Vein & Wound Center of LA
- Diagnosis first: Identify the root cause (arterial/venous disease, diabetes/neuropathy, pressure, infection).
- Optimize the bed: Sharp debridement when indicated; treat bioburden and manage edema/off-loading or compression.
- NPWT selection: Choose foam vs. gauze, continuous vs. intermittent settings, pressure targets, and protective interfaces for delicate structures.
- Follow-through: Weekly measurement, photos, and objective markers of progress; transition to grafts/CTPs or closure when the bed is ready.
Dr. Christopher Kim’s surgical training with a limb-salvage focus and experience managing thousands of wounds helps ensure NPWT is used judiciously—when it will truly move the needle for healing.
Key Studies & Reviews (for the evidence-minded)
- Armstrong et al., 2005 RCT (partial foot amputation in diabetes): NPWT improved healing metrics vs. standard care. PubMedScienceDirect
- Cochrane Review—Diabetic Foot (2018): NPWT may increase wounds healed and reduce time to healing vs. dressings (low-certainty evidence). PMCCochrane
- Cochrane Review—Closed Surgical Incisions (2022): Prophylactic NPWT probably reduces SSIs; dehiscence unchanged (moderate-certainty). PubMedCochrane
- Recent Meta-analyses (2024–2025): Across RCTs in diabetic foot ulcers, NPWT associated with higher healing rates and fewer amputations, without higher adverse events. PMCWjgnet
- WHS Pressure Ulcer Guidelines (2023): Endorse NPWT as safe/effective in chronic stage III/IV pressure injuries. PMC
FAQ: Negative Pressure Wound Therapy
Q: How soon will I see progress with NPWT?
Most appropriate wounds show healthier granulation tissue within 1–2 weeks; complete closure depends on size, blood flow, and comorbidities. (We reassess weekly and adjust.)
Q: Does NPWT hurt?
You may feel suction pressure; we cushion sensitive areas and can adjust settings. Discomfort is most common during dressing changes and is usually manageable.
Q: Can I use NPWT at home?
Yes. Many patients use portable pumps at home. Our team helps with insurance approval, home-health nursing, and education for safe changes.
Q: Is NPWT better than “advanced moist wound care”?
For certain wounds (e.g., diabetic foot ulcers and high-risk closed incisions), evidence shows better healing metrics and fewer infections/amputations with NPWT vs. standard care; results depend on correct indication and comprehensive care. PubMedWjgnet
Q: What if my wound has a lot of dead tissue?
NPWT works best after appropriate debridement. We remove nonviable tissue first, then apply NPWT to build a clean, granulating bed.
