Effect of subatmospheric pressure on the acute healing wound

Purpose: Vacuum-assisted closure (VAC), originally developed as an adjunct to wound care, has gained popularity in managing complex, chronic wounds. This study was designed to compare VAC with traditional saline-wet-to-dry (WD) dressings on acute wound healing in a pig model. Methods: Nine animals were divided into groups of 3. Three rows of 2, 4-cm diameter circular defects were excised on each animal. Vacuum-assisted closure therapy was applied to 2 adjacent wound beds, WD dressings were applied to 2 adjacent wound beds, and ventilated transparent dressing covered the 2 remaining wounds as controls. Random members from each group had their wounds harvested on postoperative days (POD) number 4, 7, and 9, respectively. The specimens were histopathologically evaluated and graded with regard to immature granulation tissue, mature granulation tissue, necropurulent surface crust, proliferating cell nuclear antigen (PCNA), and collagen deposition. Results: The WD-treated wounds had less necropurulent material on the surface compared with the VAC and control groups (p < 0.05). Day 9 specimens demonstrated increased immature collagen in the VAC and WD groups compared with control. No other statistically significant variations existed between the treatment groups. Conclusions: Under the conditions of this study, the histopathologic observations do not support more rapid wound healing for the acutely injured VAC-treated wound compared with the WD-treated wound in young healthy pigs.