Fat Graft Retention: Adipose Tissue, Adipose-Derived Stem Cells, and Aging.

SUMMARY: Over the past 30 years, there has been a dramatic increase in the use of autologous fat grafting for soft-tissue augmentation and to improve facial skin quality. Several studies have highlighted the impact of aging on adipose tissue, leading to a decrease of adipose tissue volume and preadipocyte proliferation and increase of fibrosis. Recently, there has been a rising interest in adipose tissue components, including adipose-derived stem/stromal cells (ASCs) because of their regenerative potential, including inflammation, fibrosis, and vascularization modulation. Because of their differentiation potential and paracrine function, ASCs have been largely used for fat grafting procedures, as they are described to be a key component in fat graft survival. However, many parameters as surgical procedures or adipose tissue biology could change clinical outcomes. Variation on fat grafting methods have led to numerous inconsistent clinical outcomes. Donor-to-donor variation could also be imputed to ASCs, tissue inflammatory state, or tissue origin. In this review, the authors aim to analyze (1) the parameters involved in graft survival, and (2) the effect of aging on adipose tissue components, especially ASCs, that could lead to a decrease of skin regeneration and fat graft retention. CLINICAL RELEVANCE STATEMENT: This review aims to enlighten surgeons about known parameters that could play a role in fat graft survival. ASCs and their potential mechanism of action in regenerative medicine are more specifically described.

"Reverse tensor fascia latae perforator flap for reconstruction of knee defect: Anatomic study by computed tomographic angiography and a case report".

BACKGROUND: Reverse anterolateral thigh perforator (ALTp) pedicle flap can be used to reconstruct perigenicular defect thanks to the anastomoses between the descending branch of the lateral circumflex femoral artery (LCFA) and the perigenicular network. In a few cases, however, patients do not present any ALTp. We hypothesized that, in such cases, an adjacent perforator, the tensor fascia latae perforator (TFLp), emerging from the LCFA ascending branch, could be used instead. To assess the feasibility of this technique, a radiological study was conducted. A first patient was treated using this option. METHODS: Sixty lower limb computed tomography were analyzed. The first treated patient was a 50-years-old man suffering from a 5-mm chronic bone exposure and osteomyelitis. Other reconstructive options were not indicated since he presented a multiscarry leg, severe arteriopathy, and no ALTp. A TFLp flap was raised, and the LCFA ascending and descending branches were dissected in continuity. After ligation of the LCFA, the blood flow reversed in the descending branch to irrigate the flap through the ascending branch. RESULTS: A TFL perforator was observed in all the cases of the radiological study. The LCFA branching pattern was compatible with achieving a reverse TFL perforator flap in 43 cases (72%). The average pedicle length was 32 cm (22-38 cm). In the first clinical case, the flap covered the defect easily. After three months, the patient showed no evidence of infection recurrence and recovered a painless walk. CONCLUSION: The reverse TFLp flap can be a suitable option for perigenicular reconstruction.