Morykwas 1997 - Ann Plast Surg - VAC

Summary

This paper presents a series of animal studies examining the effects of subatmospheric pressure dressing, or vacuum-assisted closure (VAC), on wound healing. The authors developed a technique applying controlled negative pressure to wounds using an open-cell polyurethane foam dressing connected to a vacuum pump.

In a porcine model, they first measured blood flow around wounds treated with varying levels of negative pressure. Results showed 125 mmHg increased blood flow four-fold, while higher pressures decreased flow. Intermittent application further increased blood flow.

Next, they compared granulation tissue formation in VAC-treated versus saline gauze-treated wounds. VAC increased granulation tissue growth significantly, by 63% with continuous and 103% with intermittent application.

To test bacterial clearance, wounds were inoculated with S. aureus or S. epidermidis. VAC decreased bacterial counts to below infectious levels five days sooner than controls.

Finally, the effect of VAC on flap survival was measured. Flaps treated with VAC pre- and post-operatively increased survival by 21% compared to controls.

Overall, the studies demonstrate VAC enhances local blood flow, accelerates granulation, decreases bacterial load, and improves skin flap survival in this porcine model. The authors conclude subatmospheric pressure creates an optimal environment promoting wound healing.

This important foundational work introduced the VAC technique for advanced wound care. It provided early evidence of VAC's efficacy in extracting exudate, stimulating granulation tissue and enabling earlier grafting. The paper paved way for wider clinical adoption of VAC for various wound treatments.