Aesthetic physicians performing the Brazilian Buttock Lift should not, under any circumstances, perform subfascial or deeper gluteal fat grafting; rather, they should only use subcutaneous injections to avoid injury to the gluteal veins, according to authors of a recently published dynamic anatomical gluteal fat grafting study in Plastic and Reconstructive Surgery.
The authors write their findings and those of others are so profound that this should be the new standard of care for gluteal fat grafting.
Gluteal fat grafting’s popularity continues to climb despite safety concerns, which researchers highlighted in a series of 22 deaths from the procedure published in 2015.
“Autopsy findings have uniformly shown intramuscular and submuscular fat around and in the gluteal vessels; there has never been a death with fat found only in the subcutaneous tissue,” they write.
Researchers, including Plastic and Reconstructive Surgery (PRS) Editor-in-Chief Rod J. Rohrich, M.D., studied four hemi buttocks from two cadavers. They injected proxy fat with different fascia scenarios (1-4):
- In scenario 1, with fascia intact, pressure reached about 125 to 150 mmHg before stabilizing, and proxy fat stayed in the subcutaneous space.
- In scenario 2, they make a random pattern of cannula perforations in the gluteus maximus fascia. Pressure reached 199 mmHg and none of the proxy fat spread deeper into the muscle or under the muscle.
- In scenario 3, researchers created 15 random defects in the gluteus maximus fascia using a 6-mm Baker punch biopsy knife. Pressure increased gradually to 50 mmHg before falling, and there was a significant amount of proxy fat in the submuscular space.
- In scenario 4, they inserted proxy fat into the subcutaneous space with expansion vibration lipofilling technique with fascia intact. Pressure climbed to 30 mmHg and the proxy fat stayed in the subcutaneous space.
“Even with multiple perforations and high injection pressures, the muscle fascia prevented the simulated fat from crossing into the muscle,” according to a PRS press release on the study.
The process of "subcutaneous migration" keeps injected fat from spreading into or under the gluteal muscle, if injected into the subcutaneous "safe zone," according to the release.
But with multiple punctures in the gluteal muscle, large amounts of proxy fat were found under the muscle, demonstrating "deep intramuscular migration," which could damage veins in the area and allow fat cells to enter the circulation, potentially resulting in pulmonary embolism, according to the release.
These authors found in a previous dynamic anatomical study that even the most superficial subfascial injection into any gluteus maximus region can result in large and potentially dangerous volumes of fat migrating into the deep intramuscular area.
They cite surgeons’ concerns with subcutaneous-only injections, including that they limit the amount of fat that can be grafted and that it’s difficult, if not impossible, to stay in the subcutaneous plane.
But, they write, concerns about limited amounts of fat for grafting is not a good reason to risk intramuscular injection and, like with liposuction, it should be technically possible to consistently stay in the subcutaneous plane with gluteal fat grafting.
“Surgeons who are [unsuccessfully] performing subcutaneous-only injections should consider using gluteal implants or performing a composite implant/fat augmentation,” they write.