Assessment of the Causes of Differences in Centrifugation Protocols as a Fat-Processing Technique: A Systematic Literature Review.

BACKGROUND: Centrifugation has been widely used for fat graft processing. However, numerous different centrifugation protocols have been proposed in different studies. Investigation of these major differences is needed to clarify ambiguities and to achieve standardization. This review aimed to assess the causes of differences in centrifugation protocols as a fat-processing technique. METHODS: Full-text and English-language articles between 1990 and 2020 were included in this study. Articles that assess the effect of centrifugation on fat graft survival with the following research purposes were selected: determination of the effect of centrifugation force/speed, determination of the effect of centrifugation time/duration, and comparison with other fat-processing techniques. RESULTS: Fifty-four full-text, English-language articles were included. The number of articles that assessed centrifugation force/speed was 17 and centrifugation duration/time was 4, and the number of articles that compared centrifugation with other fat-processing techniques was 29 and centrifugation with noncentrifugation techniques was 4. Based on the study design, 25 experiments were performed in vivo, and 41 were performed in vitro. CONCLUSION: Misuse of force (g) and speed (rpm) for defining the centrifugation protocol, differences in selected techniques for the graft harvest and graft transfer steps and differences in the analysis methods for fat graft survival are the main causes of these substantial variations among studies. LEVEL OF EVIDENCE III: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.

The effects of valsartan on scar maturation in an experimental rabbit ear wound model.

INTRODUCTION: In our study, we aimed to search and compare the effects of valsartan and enalapril on the pathological scar formation on the basis of histomorphological parameters. MATERIALS AND METHODS: Nine New Zealand albino male rabbits, which were divided into three groups, were included in the study. A previously described rabbit ear wound model was used. Enalapril was administered 0.75 mg/kg/day on the first group and valsartan was administered 10 mg/kg/day on the second group for 40 days. The third group was the control group. Results were evaluated on the 40th day with scar elevation index calculation and histological studies. Histological studies were done by using Hematoxylin-eosin, Masson trichrome and Sirius Red stains. RESULTS: Enalapril and valsartan groups were both significantly effective on the prevention of pathological scar formation when compared to the control group in terms of fibroblast count, capillary count, type 1/3 collagen ratio, collagen organization, and epithelial thickness. There was no significant difference between the enalapril and control group on the scar elevation index. Valsartan group was more efficient than the enalapril group on the reduction of fibroblast count and epithelial thickness. CONCLUSION: Both Valsartan and Enalapril are found to be effective for the prevention of pathological scar formation.

Management of soft tissue extremity degloving injuries with full-thickness grafts obtained from the avulsed flap.

BACKGROUND: A "degloving injury" is referred to as seperation of cutaneous tissue from the deeper structures of the body. Although many methods have been defined to reform the tissue integrity; defatting and readaptation of the avulsed flap still comprises one of the most effective methods. METHODS: From 2000-2012, we treated a total of nine patients with avulsed extremities with defatting and readaptation of the same flap. The fat compartment of the flaps was removed and the skin was meshed. The patients were followed-up with for an average of 12 months (range: 8-18 months). RESULTS: Total closure of the defect and healing was achieved in seven patients. Although 30% of the total surface area of the graft was lost in one patient, and 10% in another, total epithelialization was achieved later with secondary grafting. CONCLUSION: Defatting, meshing and readaptation of the same flap to its original site is still a valuable option for avulsion injuries because of the relative ease of the procedure, shorter operative times, and usability of the procedure by general surgeons. This technique might be particularly important in places where a reconstructive plastic surgeon is not available.