Influence of Age, Sex, and Body Mass Index on the Thickness of the Gluteal Subcutaneous Fat: Implications for Safe Buttock Augmentation Procedures

Abstract

Background: The deep intramuscular approach during buttock augmentation with fat grafting has been associated with a significantly increased risk for pulmonary fat embolism. This study was designed to provide guidance for injection into the subcutaneous fat. Methods: The authors investigated 150 Caucasian individuals with an equal distribution of men and women (n = 75 each) and a balanced distribution of age (n = 30 per decade: 20 to 29, 30 to 39, 40 to 49, 50 to 59, and 60 to 69 years) and body mass index (n = 50 per group: ≤24.9 kg/m2, between 25.0 and 29.9kg/m2, and ≥30 kg/m2). Ultrasound-based measurements were conducted of the thickness of the total, superficial, and deep gluteal fatty layers. Results: An increase in body mass index of 1.0 kg/m2 corresponded to an increase of 3 mm of the total gluteal subcutaneous fat of men and a 4-mm increase of the total gluteal subcutaneous fat in women. With increasing age, the thickness of the deep fatty layer increased, whereas with increasing body mass index the thickness of the superficial layer primarily increased. Formulas were generated to estimate the total thickness of the gluteal subcutaneous fatty layer for men [total thickness (in millimeters) = −33.56 + (age × 0.078) + (body mass index × 3.042)] and women [total thickness (in millimeters) = −56.997 + (age × 0.1) + (body mass index × 3.86)]. Conclusions: Knowing the total thickness of the gluteal subcutaneous fat (i.e., the safe space) allows surgeons to estimate their operating range for cannula motion even if no ultrasound machine is available during buttock augmentation with fat grafting. This can increase safety, potentially reducing the number of adverse events.

Performing Distance Measurements in Curved Facial Regions: A Comparison between Three-Dimensional Surface Scanning and Ultrasound Imaging

“…Limiting skin contact minimizes the possibility of surface compression by the transducer and allows more accurate surface length measurements. Additionally, as described in previous studies, [16][17][18][19][20] having no contact between the skin surface and the transducer is of crucial importance when measuring soft tissue thickness or the depth of neurovascular structures.…”

Severe fat embolism after autologous fat grafting in vaginal tightening and breast augmentation surgery

“…Additionally, injection of only a small amount of fat can cause excessive pressure in the narrow space around the vagina. 18 , 20 To summarize, in the absence of solid evidence obtained by performing an anatomical examination, the vaginal fat grafting procedure was the most likely cause of the multiple-organ fat embolisms. Further research is needed to elucidate the anatomical mechanism underlying this phenomenon.…”

The Role of Fat Grafting in Buttock Augmentation

“…18 More recently, many surgeons have been avoiding injecting fat intramuscularly due to the increased risk of fat emboli. 21 Frank et al recently published two formulas-one for men and another for women-to estimate the thickness of gluteal subcutaneous fat in an effort to further reduce the chance of intramuscular injection. This study also showed statistically significant correlations of both high BMI and increased age with increased thickness of subcutaneous fat.…”

“…This study also showed statistically significant correlations of both high BMI and increased age with increased thickness of subcutaneous fat. 21 According to one systematic review, fewer surgeons perform tunneling, a technique in which tunnels are created with the cannula prior to applying suction. 18 While the majority of surgeons endorse injecting small aliquots of fat at a time, the quantities reported range from 0.3 to 20 mL, with multiple surgeons reporting 0.3 mL as their maximum aliquot per pass.…”