Evaluation of artificial dermis neovascularization in an avascular wound.

Soft tissue coverage for avascular wounds is necessary in reconstructive surgery. Several authors have demonstrated successful treatment of problem wounds using artificial dermis. This study evaluates in an animal model the potential for neovascularization of artificial dermis in devascularized and avascular wound beds. Forty rats were assigned to four groups: (1) control, full-thickness skin graft was replaced on the vascular wound bed; (2) Integra, Integra placed over the full-thickness wound; (3) fascia, the spinotrapezius fascia exposed and Integra placed over the wound; and (4) fascia/Parafilm, a Parafilm layer placed under the raised fascia with Integra over the fascia. Laser Doppler readings were taken at baseline over the intact skin and then over the created wound beds. Biopsies of the full-thickness skin graft and the neodermis were obtained on postoperative day 14 and histologically evaluated for neovascularization. The laser Doppler readings confirmed the nature of the surgically created, poorly vascularized and avascular wound beds. Subsequent biopsies of the artificial dermis in these wound beds, however, demonstrated active neovascularization. This study demonstrates that Integra artificial dermis can serve as an effective dermal substitute in avascular wounds. Lateral ingrowth of capillaries into the dermal substitute may explain the successful integration of this artificial dermis.

The effect of shock resuscitation fluids on apoptosis.

BACKGROUND: Recent data suggest that the type of resuscitation fluid used to treat hemorrhagic shock contributes to cellular dysfunction METHODS: Rats were hemorrhaged, exposed to a hypovolemic shock period for 75 minutes, and then resuscitated for 1 hour. Treatment animals were assigned randomly to lactate Ringer's solution, normal saline solution, bicarbonate Ringer's solution, hypertonic saline solution, rat plasma solution, ketone Ringer's solution, or nonresuscitation. After resuscitation, lung and liver samples were collected and evaluated for apoptosis by using ligation-mediated polymerase chain reaction. RESULTS: Nonresuscitated shock rats had significantly higher levels of apoptosis in lung and liver. Rats treated with normal saline solution, bicarbonate Ringer's solution, ketone Ringer's solution, and hypertonic saline solution had significantly lower levels of apoptosis in lung compared with nonresuscitated animals. Rats treated with bicarbonate Ringer's solution and ketone Ringer's solution had significantly lower levels of apoptosis in liver tissue when compared with nonresuscitated animals. CONCLUSIONS: Cellular damage results from hemorrhagic shock. The use of resuscitation fluids decreases apoptosis during shock.

Hyperbaric oxygen and wound healing.

Problem wounds, which fail to respond to traditional medical and surgical therapy, can be challenging to the plastic surgeon. Surgical, outpatient, and inpatient wound care costs can be exorbitant. Indirect costs, such as those related to patient productivity, disability, and premature death, can also be significant. The underlying problem in failure of a wound to heal is usually hypoxia and infection. HBO treatments in selected patients can facilitate healing by increasing tissue oxygen tension, thus providing the wound with a more favorable environment for repair. Therefore, HBO therapy can be an important component to any comprehensive wound care program.