Analysis of the protective effect of hydrogen sulfide over time in ischemic rat skin flaps

Analysis of the protective effect of Hydrogen Sulfide over time in ischemic rat skin flaps Introduction and objectives: Ischemia reperfusion (I / R) injury is a very complicated process, with its physiopathological effects not yet fully elucidated, despite many studies. This situation takes place in different parts of the body and tissues. In trauma, replantation and microvascular flap surgery, it may occur due to reasons such as shock, sepsis, organ transplantation, pancreatitis, stent applications, angioplasty, abdominal aortic aneurysm surgery, flap surgery, testicular torsion, intestinal strangulation. Hydrogen sulfide (H2S) is a widely studied gasotransmitter and its protective effect against ischemia reperfusion damage has been explored in the studies. The aim of this study is to examine the effect of hydrogen sulfide by creating ischemia reperfusion injury in the vascular-stemmed island flap prepared from the rat groin area. The parameters in which the effect of hydrogen sulfide (H2S) over time are examined; tissue neutrophil count, biochemical lipid peroxidation product malondialdehyde (MDA), electron microscope apoptosis and cellular activities. This study is aimed to exploring the utilisation of hydrogen sulfide in Plastic, Reconstructive and Aesthetic Surgery practice. Materials and methods: "Wistar albino" rats weighing between 250-300 gr; They were divided into 4 groups (group 1, group 2, group 3, group 4). Each group was divided into 2 subgroups; group a (control), group b (H2S). In each group, skin flaps were elevated as an island flap with a superficial epigastric artery pedicle, 6x4 cm from the groin area. No additional intervention was made to the A groups (control group) before ischemia. In groups B (H2S group), liquid hydrogen sulfide was injected through the tail vein 20 minutes before ischemia at a final concentration of 10µM. According to the ischemia hours of the flaps; group 1 (1 hour), group2 (2 hours), group3 (3 hours), group4 (6 hours), femoral artery and vein blood flows were stopped with separate microclips and left in ischemia. Later, the flaps were elevated according to the ischemia hours (1, 2, 3, 6 hours), microclips were removed and blood flow was provided. After 12 hours of reperfusion, the rats were sacrificed by cervical dislocation and tissue samples were taken. From the samples taken; Neutrophil count in ischemic tissue, MDA (malondialdehyde) measurement, which is one of the end products of lipid peroxidation, and ischemia reperfusion damage in the tissue were evaluated by electron microscopy. Results: Electron microscopy inspection at all hours (1, 2, 3 and 6) Hydrogen sulfide was found to provide protection against ischemia reperfusion damage and apoptosis at the cellular level. There was a statistically significant (p = 0.035) decrease in the tissue neutrophil count at the 1st, 2nd and 3rd hours. In the tissue MDA measurement, a statistically significant (p = 0.026) decrease in hydrogen sulfide was detected at the 1st hour. There was no statistically significant difference in the 6th hour tissue neutrophil count and tissue MDA measurement. Conclusion: In the literature, there is scanty data about the protective effect mechanism and halflife of H2S against skin flaps against I / R damage, and this issue has been examined in detail in our study. As a result of the study, it was observed that hydrogen sulfide had antiapoptotic effects on reperfusion damage in skin flaps at all hours in electron microscopic findings. On the other hand, it was observed that it had a cytoprotective and anti-inflammatory effect in the early period (1st, 2nd, 3rd hours after ischemia) but not in the late period (6th hour). With these findings, it was thought that it would be proper to give H2S with repeated applications or in different doses in order to provide sufficient protective effect against I / R damage. Our opinion is H2S can enter the practice of Plastic, Reconstructive and Aesthetic Surgery, after the further examination of the effects of H2S on skin flaps. Keywords: Hydrogen Sulfide, İschemia, Reperfusion, Rat, Skin flap