Subdermal nitrous oxide delivery increases skin microcirculation and random flap survival in rats

Random skin flaps are essential tools in reconstructive surgery. In this study, we investigated the effect of subdermal nitrous oxide (N₂O) application on random flap survival. In this experimental study, we used 21 female rats in three groups. In the N₂O and air groups, gases were administrated under the proposed dorsal flap areas daily for seven days. Following the treatment period, flaps were raised and inserted back into their place from the dorsal skin. In the control group, the flaps were elevated and inserted back to their place without any pretreatment. Calculation of necrotic flap areas, histological examination and microangiography was performed to evaluate the results 7 days after the flap surgery. The average of necrotic flap area in the N₂O, air and control group was 13.45%, 37.67% and 46.43%, respectively. (N₂O vs air p = .044; N₂O vs control p = .003). The average number of capillary formations identified in the histological analysis was 7.0 ± 1.58, 3.75 ± 2.36 and 4.4 ± 0.54 in the N₂O, air and control group, respectively. (N₂O vs air p = .017; N₂O vs control p = .037). The average number of capillary structures identified in the angiography images were 6.3 ± 1.52, 1.6 ± 1.15 and 1.3 ± 0.57 in the N₂O, air and control group, respectively. (N₂O vs air p = .04; N₂O vs control p = .02). We conclude that subdermal N₂O application increases random flap survival through an increase in the skin microcirculation and could be promising for future clinical applications.