What Is a Wound VAC and How Does It Work After Foot Surgery?

Being told you’ll go home with a pump attached to your foot can feel like a setback. It usually isn’t one. In the foot, a wound VAC is mostly used after an operation has done the hard part, to help the wound that surgery left behind heal sooner. Here is what it is, how it works, what the trials show, and what living with one is like.

What is a wound VAC and how does it work?

VAC stands for vacuum-assisted closure. A wound VAC has three parts:

• A foam dressing cut to fit inside the wound. It is usually black polyurethane or white polyvinyl alcohol foam.⁠^[1]
• A clear, airtight film that seals the foam in place.
• A tube and pump. The pump applies suction, either nonstop or in cycles, at pressures up to 125 mm Hg (a unit of pressure).⁠^[1] Wound fluid is pulled away into a canister.⁠^[3]

That steady pull reduces swelling and encourages granulation tissue, the red, grainy tissue that fills a wound from the bottom up.⁠^[1] The dressing can be put on in the operating room, at the bedside or in an exam room, and small battery-powered or disposable units are made for smaller wounds in people who are up and about.⁠^[1]

Why is a wound VAC a surgical tool?

A VAC can’t clear infection or dead tissue on its own. The diabetic foot infection guideline suggests not using it, with or without rinsing, to treat the infection itself, and it advises considering surgery within 24 to 48 hours to remove infected and dead tissue in moderate and severe infections.⁠^[4] So the order is: surgery first, then the VAC.

Surgery that saves a foot can leave a large wound open on purpose, after draining an abscess, removing infected bone or performing a toe, ray or transmetatarsal amputation (removing part of the forefoot). That wound needs a healthy bed before it can be closed or covered with a skin graft, and that is where suction helps.

What the trials show

• After partial foot amputation. At 18 US centers, 162 people with diabetes and amputation wounds up to the transmetatarsal level, with adequate blood flow, were randomly assigned to suction or standard moist dressings. With suction, 56% of wounds healed, against 39%. Wounds closed faster, and granulation tissue formed faster.⁠^[5] A Cochrane review calculated that median healing time in this trial was 21 days shorter with suction.⁠^[3]
• Diabetic foot ulcers. In a trial of 335 people, 43.2% of ulcers closed within 112 days with suction, against 28.9% with advanced moist dressings, and fewer people needed a later amputation.⁠^[6] A 2026 review of 19 studies (2,046 patients) found suction made complete healing about 1.4 times as likely.⁠^[7]
• Holding a skin graft. Across 12 studies of 653 people with split-thickness skin grafts (thin layers of skin), suction over a fresh graft raised the share of graft that took and cut repeat operations by about 72%.⁠^[8]

Dr. Efe Ozturk is a Foot and Ankle Surgeon, double board certified, including in wound care (FAPWH). He drains infection, removes dead tissue and infected bone, performs toe and partial foot amputations, and closes wounds with skin grafts or local flaps. He uses a wound VAC for the wounds that need it. See negative pressure wound therapy, toe and partial foot amputation and skin grafts and flaps.

What is a VeraFlo wound VAC?

VeraFlo is one brand of wound VAC that adds instillation and a dwell time: a rinsing solution, such as saline, is put into the wound and left to sit for a set time (the “dwell”) before suction resumes.⁠^[9,1] In a review of 13 studies (871 patients) of orthopedic and plastic surgery wounds, instillation was linked with more wounds closing and fewer complications than standard suction or ordinary dressings, though not with fewer operations.⁠^[10] In a randomized study of 100 people with infected wounds that needed surgical cleaning, plain saline appeared to work as well as an antiseptic rinse.⁠^[11] Instillation is still an add-on to surgery, not a replacement for it.⁠^[4]

What is it like to live with a wound VAC?

• At home. Much of the treatment happens at home. In the large ulcer trial, about 9 in 10 days of suction therapy were home-care days.⁠^[6] The FDA advises that you and your caregiver are taught how the system works, which problems to watch for and what to do if one happens.⁠^[12]
• Dressing changes. In the amputation trial, dressings were changed every 48 hours.⁠^[5]
• Daily life. The pump goes everywhere with you. A review of patient experiences found it can limit daily routines and social life and cause worry, though some people reported a better quality of life.⁠^[13]

What are the limits of a wound VAC?

Not every trial found a benefit. A German trial in everyday practice found no significant difference in how many diabetic foot wounds closed or how fast, and more people had at least one medical problem with suction (96 vs 72), though only 16 problems were related to it.⁠^[14] A 2026 UK trial of 686 people with open surgical wounds, 80% of them on the foot, found median healing took 187 days with suction and 195 days without, no clear difference, at a higher cost.⁠^[15] The guideline rates the overall evidence as low certainty.⁠^[2] The FDA has reported rare but serious bleeding, especially in people with blood vessel grafts, infected wounds or blood thinners, and when dressings stuck to tissue are removed.⁠^[12] Tell us about every blood thinner you take.

Common questions

What is a wound VAC used for?

On the foot, mainly for open wounds after surgery: after an infection is drained, infected bone is removed or part of the foot is amputated, and to hold a skin graft in place while it takes.⁠^[2,8] See surgery for diabetic foot infection.

Can a wound VAC be done at home?

Yes. Most people go home with a portable pump, and in one trial about 9 in 10 therapy days were at home.⁠^[6] You’ll be shown how the alarms work and whom to call.⁠^[12]

Do wound VACs hurt?

Dressing changes can be uncomfortable, and the type of dressing used makes a real difference to pain.⁠^[13] In the UK trial, wound pain scores were no different with suction than with usual dressings.⁠^[15] Tell us if a change hurts, so we can adjust the plan.

Can a wound VAC cause infection?

In the amputation trial, side effects (most often wound infection) were about as frequent with suction as with dressings.⁠^[5] In the ulcer trial, infection, skin infection and bone infection rates at 6 months did not differ significantly.⁠^[6] FDA reports tied most VAC-related infections to pieces of dressing left in the wound, one reason dressings are counted at each change.⁠^[12]

The bottom line

A wound VAC is gentle suction that helps an open wound fill in. On the foot, it belongs after surgery has removed what can’t heal, as a bridge to closing the wound or holding a graft. If you have a deep or stalled foot wound, see a surgeon early, so the operation and the VAC can work together. Ozturk Foot & Ankle explains its approach to wound care.