Treatment of postburn scar and scar contracture using various modified local flaps

Application of local flaps for releasing postburn scar contracture has been limited because of a problem of invisible loss, difficulty to obtain the satisfactory result against correction of limitation of motion and possibility of contour deformity. However, proper use of local flaps, accurate designs and complete wound compression for a long term after operation enable to obtain good results in correction of some cases of postburn scar contracture. It will be related to reduce unsightly scaring when contractures are released. For this purpose, we have used a modified planimetric Z-plasty, a subcutaneous pedicle flap, a new classification V-Y plasties which was proposed based on the new concept and their combination. Proper application of local flaps corresponding to the degree of contracture and shape of burn scar have enabled to increase the use of local flaps against correction of postburn scar contracture during our past 15 years, from 1982 to 1997, we treated 235 cases of postburn scar or scar contracture in various regions except for the face. Of these, 177 cases were applicated with local flaps and we could have a good results in both aspects of function and appearance. We report our operative methods, a criterion to application of local flaps and representative results.

Involvement of nitric oxide in post ischemic injury of rat island skin flap

A free radical gas, nitric oxide NO), has many useful functions when produced under physiological conditions by neurons and endothelial cells. However, excess NO has been reported to exert cytotoxic effects by direct toxicity or by reaction with superoxide. Nitric oxide can react with superoxide to generate peroxynitrite which is as reactive as the hydroxyl radical. This study was attempted to observe formation of peroxynitrite and change in amount of NO synthase(NOS) in reperfused skin flap of rats following ischemia. 3-nitro-L-tyrosine, as direct evidence of peroxynitritemediated tissue damage, as well as endothelial and inducible NO synthase(eNOS and iNOS) were studied in ischemic and reperfused skin using western blot analysis. In addition, HNE-modified proteins, as direct evidence of oxidative tissue damage by reactive oxygen species(ROS), was also evaluated. Skin specimens were obtained over time from island skin flaps(3x3 cm2) of rats under the following two conditions: 1) reperfusion following 5 hours of ischemia, and 2) reperfusion following 10 hours of ischemia. In reperfused skin after 5 hours of ischemia, formation of 3-nitro-L-tyrosine and HNE-modified proteins was decreased 1 hour after reperfusion. However, they were thereafter increased and reached a maximum (3-nitro-L-tyrosine: 142%,HNE-modified proteins:237%) 6 hours after reperfusion. In reperfused skin after 10 hours of ischemia, formation of 3-nitro-L-tyrosine and HNE-modified proteins was increased 3 hours post reperfusion, and reached a maximum (3-nitro-L-tyrosine:178%, HNE-modified proteins: 204%) 6 hours after reperfusion. eNOS and iNOS were decreased 1,3 and 6 hours reperfusion following both 5 and 10 hours of ischemia. These results indicate that peroxynitrite-mediated cytotoxicity is involved in ischemic reperfused skin despite the fact that the amounts of both iNOS and eNOS are decreased.