[Use of vasoactive substances in prevention of skin necroses]

The nutritional blood flow to the tissue is the principle factor determining the outcome of reconstructive procedures in plastic surgery. Beside vasoconstriction, thrombocytes aggregation, leukocytes activation, followed by production of oxygen free radicals and release of proteases, impaired fluidity of erythrocytes and swelling of the microvascular endothelium are responsible for impaired perfusion following ischemia/reperfusion. Therefore, vasoactive drugs known to improve nutritional blood flow are of particular interest in the prevention and therapy of skin flap necrosis. Several methods have been employed to quantify nutritional blood flow in skin flaps but none of them have elucidated the mechanisms underlying potential tissue protection by these drugs. We have developed two skin flap models in the hairless mouse, in which nutritional blood flow can be directly assessed at capillary level by means of intravital microscopy. In the arterial skin flap model, the efficacy of three vasoactive drugs (naftidrofuryl [4.5 mg/kg/day], pentoxifylline [17.0 mg/kg/day] and buflomedil [3.0 mg/kg/day]) to prevent and/or reduce tissue necrosis was investigated. Buflomedil provided the most efficient tissue protection, a phenomenon also verified in a random skin flap model. It was demonstrated that preoperative application of buflomedil preserves functional vascular density in the distal part of skin flaps more efficiently compared to postoperative application. However, there were no significant differences in amount of skin necrosis between the two groups. The tissue protection effect was also observed in random pattern flaps rendered ischemic for six hours after flap elevation.(ABSTRACT TRUNCATED AT 250 WORDS)