Análise dos efeitos da ginkgo biloba em ratos submetidos a retalho cutâneo dorsal e tratados previamente com nicotina

Abstract

The use of skin flaps is a very common feature in plastic surgery, and necrosis is the most feared complication. The available literature not only refers to a large number of references in which the random flap tissue necrosis is associated to the habit of smoking, as well as several experiments with the use of substances capable to diminish nicotine’s harmful effects. Among these substances we highlight the Ginkgo biloba (GB), whose antioxidant properties are widely described in the literature. GB also has anti-inflammatory effect and stimulating for the synthesis of collagen and fibronectin, suggesting a protective effect against tissue injury. Bearing in mind the large number of surgical procedures performed on smokers, nicotine's effects on skin flaps in rats attenuated by GB can be considered an important tool for analyzing the action of this drug. Thus this study aims to understand better the action, in macro and microscopic levels, of GB over the effects of nicotine on cutaneous flaps. Male adult Wistar rats were treated as follows: with nicotine in preoperative (PRE) and nicotine and saline normal solution in the postoperative phase (POST), and with nicotine in PRE and with nicotine and GB in the POST phase, and whith saline normal solution in the PRE and POST. PRE period consisted of ten days and POST of seven days and the administration of treatment was subcutaneously (SC). Surgical procedure consisted of performing a dorsal random pattern skin flap, cranially based with an interposal of an impermeable plastic barrier between the flap and its donor bed before stitching over. After sampling, images of inner sides of flaps were taken for analysis and fragments of their edges were processed according to routine histological techniques. The action of GB microscopically showed areas of necrosis in the distal region, inflammatory infiltration and granulation tissue in the transition region and mild congestion in the region near the pedicle. Analysis showed that the macroscopic necrosis in the group receiving medical preoperative and postoperative nicotine presented 12,72cm2 area of retail necrotic and that is 33.8%, while the group that received PRE nicotine and POST GB showed 6.80 cm2 area retail necrotic and that is 8.9%. We confirmed that nicotine itself has a deleterious effect on reperfusion of the tissue of the flap, with an increase of necrosis. However it can be attenuated by the use of GB. The other disturbances observed are factors that can influence the skin flap revascularization. This model may markedly provide basis for further studies that incorporate the use of substances that potentially neutralizes or inhibits the effects of nicotine in skin flaps.