The evaluation of subatmospheric pressure and hyperbaric oxygen in ischemic full-thickness wound healing

We evaluated the efficacy of subatmospheric pressure and hyperbaric oxygen (HBO) as adjuncts in the treatment of hypoxic full-thickness wounds in a ra bbit model. We hypothesized that subatmospheric pressure and HBO independen tly are effective in improving wound healing in the ischemic wound model an d that when they are used in combination there is an increased positive eff ect on wound healing. Using a standard ischemic wound model four full-thick ness wounds were created on each ear of 41 male New Zealand white rabbits ( N = 82 ears). On each rabbit one ear was dressed with the vacuum-assisted c losure (VAC) device and connected to suction; the other was dressed identic ally without the suction and suction tubing. Twenty rabbits were treated wi th HBO daily for 10 days at 2.0 atmospheres absolute for 90 minutes plus de scent and ascent times. Necropsy on all rabbits was performed on postoperat ive day 10. Four ischemic wound treatment groups were evaluated: Group 1 (N = 21) VAC dressing alone; Group 2 (N = 20) VAC dressing plus HBO; Group 3 (N = 21) VAC dressing to suction alone; and Group 4 (N = 20) VAC dressing t o suction and HBO. Using light microscopy a veterinary pathologist blinded to treatment groups quantified peak granulation tissue, granulation tissue gap, and epithelialization tissue gap. Data were analyzed by analysis of va riance with significance indicated by P < 0.05. Statistical significance wa s found in a comparison of VAC dressing to suction and VAC dressing alone f or peak granulation tissue and granulation tissue gap both with and without use of HBO. VAC device use appears to increase the rate of healing in a ra bbit ischemic wound model. HBO therapy did not significantly affect the rat e of healing in this model.