[Effects of vacuum drainage combined with heparin irrigation for treatment of scald burns with seawater immersion in rabbits].

OBJECTIVE: To investigate the effect of closed vacuum drainage combined with heparin irrigation in the treatment of scald burns with seawater immersion in rabbits. METHODS: Twenty New Zealand rabbits were subjected to deep partial-thickness scald burns in 4 regions on the bilateral skin of the spine. The wounds were managed with common dressing (group A), common dressing after seawater immersion (group B), closed vacuum drainage after seawater immersion (group C), or closed vacuum drainage combined with heparin irrigation after seawater immersion (group D). Wound effusion and tissue necrosis were observed at 1, 3, 5 and 7 days after the burns. Tissue samples were collected from the wounds for HE staining and immunohistochemistry for VEGF and CD31, and the changes of capillary endothelial cells in the wound were observed using electron microscopy. The water content in the wound tissues was determined, and the wound healing rate was calculated after the injury. RESULTS: Sea water immersion of the wound results in earlier onset of edema and more extensive tissue necrosis in the scalded rabbits. The mean necrotic area in groups C and D was smaller than that in group B early after the burns, and vacuum drainage promoted necrotic tissue elimination and accelerated wound healing. Early after the burns, water content in the tissues increased with time in all the groups and reached the highest level at 3 days, and was significantly lower in groups C and D than in group B. Pathologically, vascular endothelial cell damage at the wound site was worsened after seawater immersion. In group D, the basement membrane damage was milder and the endothelial cell membrane remained intact at the wound site, where new blood vessels occurred at 3 days after the burns, a time earlier than that in the other 3 groups with also the highest vascular density. CONCLUSIONS: Closed vacuum drainage combined with heparin irrigation can relieve edema at the scald wound with seawater immersion, improve microcirculation, accelerate the removal of necrotic tissue, and promote the growth of new blood vessels.