Clinical Implications of Gluteal Fat Graft Migration – A Dynamic Anatomic Study.

Background: The intraoperative mortality and overall complication rate for gluteal augmentation with fat transplantation is unacceptably high. The current controversy among experts regarding safety is whether fat should be placed within the gluteus muscle or only limited to the subcutaneous space. The purpose of the present study is to test the hypothesis that under certain pressures, fat injected within the gluteal muscle can actually migrate out of the muscle and into a deeper plane containing critical neurovascular structures, via the process of Deep Intramuscular Migration. Methods: A total of eight human cadaver dissections were performed. Four hemi-buttocks were selected for intramuscular fat injection. The patterns of sub-fascial fat migration were evaluated in three of these hemi-buttocks by direct visual inspection and in one hemi-buttock by endoscopic evaluation. Four other hemi-buttocks were selected for subcutaneous or supra-fascial fat injection. Results: Proxy fat was found to migrate through the muscle and into the deep submuscular space with each intramuscular injection. With subcutaneous injection, no proxy fat was found during dissection in the intramuscular septae or submuscular space. Conclusion: The intramuscular insertion of fat, which up to this point has been considered reasonable to perform in the superficial muscle and even recommended in the literature, is now deemed to be an inexact and risky surgical technique. This technique, because of its migratory nature, should be avoided from further use in fat transplantation to the gluteal region. Disclosures: Rod J. Rohrich, MD receives instrument royalties from Eriem Surgical, Inc and book royalties from Thieme Medical Publishing, he is a Clinical and Research Expert for Allergan, Inc and MTF Biologics, and the Owner of Medical Seminars of Texas, LLC. No funding was received for this article Dr. Del Vecchio is a founder of Surgistem Technologies, LLC; a device company involved in fat transplantation, receives royalties from Microaire, and is a founding member of Peninsula Partners, LLC a consulting firm in the plastic surgery sector. Acknowledgements: Dr. Rod Rohrich Research Fund from UT Southwestern Department of Plastic Surgery, Garret Adams of Stryker for compartment pressure monitor, Jourdan Carboy for illustrations and the Willed Body Program UTSW Corresponding Author: Daniel A. Del Vecchio, MD, 38 Newbury Street, Boston, MA 02116, Fatvsfiction@gmail.com ©2018American Society of Plastic Surgeons