Clinical Evaluation Of Large Autologous Free Dermal Fat Graft And Research On Its Histological Fate

Part 1Long-term Follow-up and Clinical Evaluation of Large Autologous Free Dermal Fat Graft in Treating Facial DepressionObjectiveThis study is designed to investigate the clinical effect of large autologous free dermal fat graft (FDFG) for the treatment of facial depression through long-term follow-up. Its advantages and indications will be further identified based on the clinical experience.MethodsFrom August 2008 to September 2015,19 patients with facial depression were treated with large free dermal fat graft, including 11 patients with hemifacial atrophy and 8 with other types of facial depressions. The thicknesses of these grafts ranged from 0.5cm to 1.0cm, while the volume ranging from 20cm3 to 72cm3.ResultsThe patients were followed up for 2 weeks to 3 years. Of all the patients,10 received follow-up more than 6 months. All the wounds at the donor and recipient sites healed primarily without functional morbidity. No fat liquefaction was found by ultrasonography in the early stage after operation. Tardive fat liquefaction only occurred to one dermal fat graft, which was detected at 8 months postoperatively. The shrinkage of grafts mainly occurred in the first 6 months, with the thickness decreased by 25% to 40%. The histological examination showed that the graft basically maintained original structure characteristics of FDFG after 8 months. Conclusions (1) It is safe to perform facial contour augmentation by using large free autologous dermal fat graft with the whole thickness less than lcm.(2) The procedure is easy-to-use and has high success rate.(3) It applies to most patients with large areas of mild facial depression, especially when the patients were also prepared to receive open surgery at the same time. The same holds for patients with poor recipient sites, those with slim figures and younger ones.(4) The most significant atrophy of FDFG occurrs in the first 6 months postoperatively, with the average thickness decreasing by 25-40%.(5) The histological fate of FDFG is not simple fibrosis.Part 2The Clinical Evaluation of Modified Augmentation Phalloplasty by Large Free Dermal Fat GraftObjectiveOur objective is to report on the efficacy and safety of modified augmentation phalloplasty by large free dermal fat graft (FDFG) performed on patients with penile dysmorphophobia and those complaining of small penis after hypospadias repair. The cosmetic and psychological outcomes will be evaluated by objective penile measurements and Male Genital Image Scale. Moreover, the indications for this modified operation are analyzed, as well as superiority of FDFG applied in augmentation phalloplasty. So are the histological fate and variation in thickness of FDFG.MethodsFrom April 2010 and January 2015,38 Chinese adult patients received modified augmentation phalloplasty, which consisted of suprapubic skin advancement-ligamentolysis and girth enhancement by large free dermal fat graft (FDFG). Of them,23 patients were accompanied by penile dysmorphophobia, while 15 patients had recevived hypospadias repairs before. All of them requested an increase in the penile dimension through surgery. Besides objective penile measurement, Male Genital Image Scale was also used to facilitate the selection of patients and evaluation of the outcome. The change and shrinkage of FDFG was evaluated by ultrasound examination and computed tomography.ResultsAll the patients tolerated the surgery well. Neither major complications like infections and fat liquefactions occurred during the 6-months’follow-up, nor did erectile dysfunctions. The shrinkage of FDFG was inconspicuous, and no curvature was observed due to fibrosis.After 6 months, the mean flaccid length of patients with penile dysmorphophobia was increased by 2.27±0.54 cm, while the mean flaccid circumference increased by 1.67±0.46 cm. The length measurements at 6 months revealed an average increase of 3.05±0.66 cm in flaccid-stretched state. Significant improvement of genital satisfaction was also reported during the follow-up, with the average MGIS score rising from 34.35±5.85 to 42.00±4.64.All the patients who received hypospadias repair before had obtained excellent cosmetic results after 6-months’follow-up, with a significant average dimensional increase of 1.53±0.23 cm in flaccid girth and 1.67 ± 0.24 cm in flaccid length. The measurements of length in the stretched flaccid state revealed an average gain of 1.93±0.21 cm. Their perceptions of male genitalia were significantly improved postoperatively, with the average MGIS score ascending from 31.73±4.86 to 40.20±4.54.Conclusions(1) It is safe and reliable to enhance penile size by inserting large free dermal fat strips in the subcutaneous pockets over Buck’s fascia.(2) This modified augmentation phalloplasty is effective and convenient, which can also decrease the risk of unexpected trauma to the urethra and neurovascular bundle in augmentation phalloplasty.(3) With strict patient selection, the dimensional enhancement by FDFG in penis could improve patients’perceptions of male genital.(4) Compared with part of the common materials, FDFG is especially suitable for augmentation phalloplasty owing to its special structure.(5) The FDFG could retain 70% of its orgininal thickenss after 6 months postoperatively without fibrosis.Part 3Experimental Research on the Histological Fate of Large Free Dermal Fat Graft in PigsObjectiveThis study is designed to calculate the volume and weight retention rates of large free dermal fat graft (FDFG) in pigs, follow its histological evolution, as well as to speculate potential mechanism of its survival.Methods and MaterialsA long-term (12-month) experimental study in pigs was designed to elucidate the fate of large free dermal-fat graft. The specimens were taken every 0.5-1 month and evaluated through gross observations, morphologic measures and histological examinations. The retention rates of volume and weight were calculated by objective measuresurements before and after transplantion. And the histological changes were observed by hematoxylin-eosin (HE), Masson and Oil red 0 staining. Furthermore, the ultrastructural alterations were explored by scanning electron microscopy and transmission electron microscopy.Results(1) The volume retention rate experienced an apparent decline in the first 3 months and gradually increased to 69.22% since the 4th months after implantation.(2) The fluctuation of weight retention rate was almost the same with that of volume retention rate. With the rapid decline of weight in the first 3 months, the weight retention rate of FDFG increased to 90.83% at the 8th month.(3) The histological examination showed that the histological fate of FDFG was characterized by the thickened dermis and the "disappearance and reappearance" of adipocytes. In the first 3 months, the adipocytes were infiltrated by inflammatory cells and then disappeared. Since the 4th month, the adipocytes "reappeared" with increasing number. The capillaries and septa of loose connective tissue were found to closely related to this phenomenon.(4) The histological fate of FDFG was not obviously affected by the superficial area of FDFG.Conclusions(1) The volume and weight retention rates are good in FDFG, which also verify the results in clinical studies.(2) The thickened dermis in FDFG contributes more to the volume retention of FDFG in the long term.(3) The histological fate of FDFG is not simple "fibrosis", but characterized by the thickened dermis and "disappearance and reappearance" of adipocytes. And the original structure characteristics of FDFG were almost preserved.(4) The corollary about the survival mechanism of large FDFG:the FDFG is transplanted as a whole and therefore preserves intact subdermal vascular network and septa, as well as more stem cells with adipogenic differentiative potential. The intact vascular network and septa are considered to contribute to the survival and adipogenic differentiation of stem cells by providing necessary nutrition and structural support.