Current thought regarding the mechanism of action of negative pressure wound therapy with reticulated open cell foam.

There are currently 2 main theories regarding the mechanism of action of negative pressure wound therapy with reticulated open cell foam (NPWT/ROCF) as delivered by V.A.C.(R) Therapy (KCI, San Antonio, TX). The first is based on the stimulatory effect of microstrain on cellular mitogenesis, angiogenesis, and elaboration of growth factors. This is the same mechanism that is operational in controlled Ilizarovian distraction or in tissue expansion. The second is based on the enhancement of the dynamics of microcirculation by active evacuation of excess interstitial fluid in the form of edema. Physiologically, there is a lowering of the heightened capillary afterload and a qualitative dilution of contained microcontaminants, bacteria, and proinflammatory cytokines. Based on these effects, the use of NPWT/ROCF has found a place in the management of high-energy traumatic wounds and certain high-risk elective surgical wounds.