Efficacy and mechanisms of vacuum-assisted closure (VAC) therapy in promoting wound healing: a rodent model

Summary Background The vacuum-assisted closure device (VAC) has revolutionised wound care, although molecular mechanisms are not well understood. We hypothesise that the VAC device induces production of pro-angiogenic factors and promotes formation of granulation tissue and healing. Methods A novel rodent model of VAC wound healing was established. Excisional wounds were created on rat dorsa. Wounds were dressed with Tegaderm (control group), VAC Granulofoam ® and Tegaderm (special control group), or VAC Granulofoam ® , T.R.A.C. PAD ® with 125mmHg continuous negative pressure (VAC group). Wound closure rates were calculated as a percentage of initial wound sizes. Rats were sacrificed on postoperative days 3, 5 and 7; harvested tissues were processed for histology [haematoxylin & eosin (HE day 5, 45.3% (VAC) vs 23.7% (control) and 22.5% (special control) (ANOVA, P =0.0003); day 7, 54.4% (VAC) vs 43.0% (control) and 31.5% (special control) (ANOVA; P Conclusion A small animal VAC wound model was established. Wounds treated with a VAC device showed accelerated wound closure rates, increased pro-angiogenic growth factor production and improved collagen deposition. Further application of this model may elucidate other mechanisms.