Negative Pressure Wound Therapy after partial diabetic foot amputation: a multicentre, randomised controlled trial
Armstrong D.G., Lavery L.A., Lancet 2005; 366:1704-10 (Study funded by KCI.)
Objective: "To determine whether NPWT delivered by the VAC system was clinically efficacious in treating amputation wounds of the diabetic foot to improve the proportion of wounds with complete closure." Assessment of the rate of wound healing or facilitation of surgical wound closure, foot salvage, and treatment related complications.
Methods: Patients with diabetic wounds secondary to amputation (up to transmetatarsal level) (n= 162) V.A.C.® Therapy, 77 patients; Control, 85 patients.
- Multi-center randomized controlled trial with 112-day active treatment phase.
- Study groups: V.A.C.® Therapy versus standardized moist wound treatment guidelines (alginates, hydrocolloids, foams, hydrogels)
- All patients received off-loading therapy (pressure relief walker/sandal)
- Independent blinded evaluators evaluated wounds with respect to planimetric measurements from digital photographs taken at every study visit (day 0,7, 14, 28, 42, 56, 84, 112)
- Granulation tissue formation was estimated and recorded as 0-25%, 26-50%, 51-75%, 76-100% at every study visit.
No masking of treatment assignment for investigator or patient. Independent evaluators were blinded as to treatment assignment when they evaluated the digital photographs.
Results: Percentage of patients with healed wounds: V.A.C.® Therapy, 56%; Control, 39%; p=. 04; V.A.C.® Therapy group had complete wound closure in a significantly shorter time than Control ( p=.005). Median time to wound closure: V.A.C.® Therapy, 56 days; Control, 77 days; Median time to reach 76-100% granulation tissue formation: V.A.C.® Therapy: 42 days, Control: 84 days, p=.002; Percentage of patients with a second amputation: V.A.C.® Therapy: 3%, Control: 11%, p=.06; 6% of control group had a high level secondary amputation and 0% in V.A.C.® Therapy group, p=.06.