Fat Processing Techniques: A Narrative Review

Combining High-Density Fat and Condensed Low-Density Fat Injections for Precise Facial Rejuvenation

BACKGROUND

Facial aging involves ptosis, adipose atrophy, and skeletal resorption. Depletion of adipose tissue primarily affects the deep facial fat compartment, leading to facial depression or ptosis, accompanied by atrophy of the superficial compartment. Restoring volume in the deep fat compartment is crucial for facial rejuvenation, while enhancing its supportive properties is also important. The superficial fat compartment contains small-sized adipocytes, and autologous fat grafting is a popular approach. However, variability in fat retention, homogeneity, and processing methods can impact outcomes, necessitating careful selection of a suitable fat processing material for precise facial fat grafting.

METHOD

A retrospective study was conducted on 50 patients who underwent facial augmentation using combined transplantation of high-density fat (HDF) and condensed low-density fat (CLDF) and 25 patients who underwent conventional Coleman fat grafting. Coleman fat was harvested by standard technique and the adipose tissue was divided into HDF and CLDF fractions through centrifugation. Subsequently, the low-density fat fraction was subjected to a process involving physical disruption followed by additional centrifugation to obtain CLDF. The CLDF fraction was consequently injected into the pre-SMAS subcutaneous layer of the superficial fat compartments. Patient satisfaction was evaluated using a typical Likert scale. Photographs were taken and imageological examinations were performed before and after treatment.

RESULT

The CLDF+HDF grafting group demonstrated a significantly shorter duration of swelling (6.0 ± 1.2 to 12.6 ± 3.3 days) and higher level of patient satisfaction when compared to the Coleman fat group. No serious complications were observed among all the patients who received the injections.

CONCLUSION

The use of this new treatment approach allows for precise fat transplantation in facial regions. The use of high-concentration fat filling for deep facial layers and CLDF filling for superficial layers is a safe and effective treatment plan for facial rejuvenation.

LEVEL OF EVIDENCE IV

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[Diagnosis and management of fat necrosis after autologous fat transplantation of breast]

Objective

To review the diagnosis and management of fat necrosis after autologous fat transplantation of breast.

Methods

Based on the latest related literature, the pathology, clinical and radiographic examinations, influence factors, as well as the management of fat necrosis after autologous fat transplantation for breast augmentation and reconstruction were summarized.

Results

Fat necrosis after breast autologous fat transplantation is histologically manifested as hyaline degeneration, fibrosis, and calcification. The diagnosis of fat necrosis includes clinical examination, imaging examination (ultrasound, mammography, and MRI), and biopsy. The occurrence of fat necrosis is closely related to patient's own reason and fat transplantation technology. Optimizing the process of fat acquisition, purification, and transplantation can reduce the occurrence of fat necrosis. Intervention or not after fat necrosis depends on the nature of the nodules. According to the nature of the the nodules, various methods such as simple aspiration, vibration amplification of sound energy at resonance liposuction, or direct excision can be selected.

Conclusion

Fat necrosis after autologous fat transplantation of breast are difficult to control. How to process fat to minimize the injury and maximize the activity of grafted fat needs further researches.