Muscle Amplification With the Ultrasound-guided Rectus Abdominis Fat Transfer Technique: Assessment of Intramuscular Graft Evolution.

Background: Muscle enhancement through autologous fat grafting has become an important aspect of body contouring procedures, targeting several muscle groups, including the rectus abdominis, deltoids, biceps, trapezius, longissimus, hamstrings, and vastus muscles. Methods: Patients who underwent the ultrasound-guided rectus abdominis fat transfer technique were evaluated using preoperative and postoperative magnetic resonance imaging (MRI) scans to assess the anatomy of the rectus abdominis muscles. Preoperative MRI measured the muscle thickness of the middle and lower rectus abdominis segments on both sides, as they were the most representative. Postoperative imaging was performed 6 months after surgery, assessing the total thickness of the rectus abdominis segments (including fat graft and muscle), the muscle thickness alone, and the remaining fat graft thickness. Results: The ultrasound-guided rectus abdominis fat transfer technique was performed on 20 patients between September 2022 and April 2023. Of these, 6 were men and 14 were women, with a mean age of 37.05 years (range: 25-57 y). Postoperative MRI revealed a statistically significant increase in the total thickness of the muscle segments (including muscle and fat) compared with preoperative measurements. Conclusions: Ultrasound-guided fat grafting is a safe and effective procedure currently used in abdominal etching. Long-term MRI assessments showed significant fat retention and rectus abdominis muscle enhancement.