Long-term volume retention of breast augmentation with fat grafting depends on weight changes: a three-year prospective MRI study

Background: Fat grafting is increasingly used for breast augmentation. However, long-term volume retention, time to reach steady state, and the effect of postoperative weight changes on these outcomes are not fully understood. Methods: In this prospective study, we included patients undergoing breast augmentation with fat grafting and examined them with MRI preoperatively and up to three years postoperatively. We modeled fat graft retention over time and calculated the time to volumetric steady state of the fat graft. Secondly, we used our model to assess the effect of postoperative weight changes on fat graft retention and to determine the association between the graft/recipient volume ratio and the percentage breast augmentation at steady state. Finally, we assessed patient satisfaction using the BREAST-Q questionnaire. Results: The study included 28 patients (46 breasts). The time to steady state was 253 days (95%CI 185-283) postoperatively, with a volume retention of 46% (95%CI 35-58). Patients with a weight loss of one BMI point after surgery had a volume retention of 22% (95%CI 4.7-38) while those increasing one and two BMI points had retention rates of 57% (95%CI 45-69) and 85% (95%CI 72-98), respectively. Increasing graft/recipient volume ratio was associated with higher percentage augmentation with no plateau in this relationship even up to ratios of 2:1. Postoperative satisfaction with breasts and sexual well-being increased substantially. Conclusions: Breast augmentation with fat grafting reached volumetric steady state after 8 months with a volume retention of 46%. Weight loss following fat grafting leads to significantly lower volume retention.