RESUMO
Background: Fat graft surgery is one of the most effective procedures in plastic surgery, and since some patients request multiple surgeries and these cases sometimes take hours, it endangers the viability of the fat graft. In this study, we intend to evaluate the viability of adipose tissue aspirated with a syringe at refrigerator (4°C) and freezer (-20 °C) temperatures. Methods: This was a cross-sectional study. After receiving the ethics committee's approval (IR.MUMS.MEDICAL.REC.1401.423), 17 volunteers entered the study. The harvested fat tissue sample was divided into 3 parts, and each of them was transferred to 3 separate sterile tubes. The first tube was sent to the laboratory for preliminary examination of fresh fat, and the second tube was transferred to a 4°C refrigerator for 72 hours. The sample from the third tube was first passed through a strainer and after drying, it was transferred to a -20°C freezer for 72 hours. After treatment with trypsin, we placed the sample inside the centrifuge using the Coleman method. Finally, 3 layers were formed, and the white middle layer was extracted as a fat cell suspension. Tissue samples were stained with trypan blue, and the percentage of viable cells was calculated using an optical microscope. Results: There was a significant difference between the mean number and percentage of viable cells in all 3 groups. Samples in the 4°C refrigerator had significantly more cellular viability than those in the -20°C freezer (mean difference, 72.842%; P < 0.001). Conclusion: Our findings showed that after 72 hours at 4°C, adipose tissue has significantly higher survival than at -20°C (98.93% vs 75.31%). Since the survival of fat cells is one of the direct determinants of fat retention, it can affect the results after surgery. The present study recommends fresh adipose tissue for immediate transplantation unless there is an urgent need for cold storage.
RESUMO
BACKGROUND: This study aimed to assess the effects of the topical application of tamoxifen on wound healing of burned skin in Wistar rats by evaluating 3 healing characteristics: fibrotic tissue thickness (FTT), scar surface area (SSA), and angiogenesis in the healed scar tissue. METHODS: Eighteen male Wistar rats were used in this study. A third-degree burn wound was made on the shaved animals' back, measuring 2×2×2 cm. In the first group, a 2% tamoxifen ointment was applied to the wound twice daily for 8 weeks. The second group received a placebo ointment during the same period. The third group did not receive any treatment and served as the control group. RESULTS: The median (interquartile range=[Q1, Q3]) FTT was 1.35 (1.15, 1.62) mm, 1.00 (0.95, 1.02) mm, and 1.25 (0.8, 1.5) mm in the control, tamoxifen, and placebo groups, respectively (P=0.069). However, the FTT in the tamoxifen group was less than in the placebo and control groups. The median angiogenesis was 3.5 (3.00, 6.25), 8.00 (6.75, 9.25), and 7.00 (5.50, 8.25) vessels per high-power field for the control, tamoxifen, and placebo groups, respectively (P=0.067). However, the median angiogenesis was higher in the tamoxifen group than in the control group. No significant difference was observed in the mean SSA between the tamoxifen group and the control group (P=0.990). CONCLUSIONS: Local application of tamoxifen increased angiogenesis and decreased the FTT, with no change in the SSA in burned skin areas. These effects are expected to expedite the wound healing process, reducing contracture and preventing hypertrophic scar and keloid formation.
