Efficacy and Safety of External Volume Expansion (EVE) on Fat Grafting: A Systematic Review and Single-Arm Meta-Analysis

The autologous fat grafting is commonly used for reconstructive or aesthetic purposes. However, due to the huge variation in methods, its retention rate varies a lot. External volume expansion (EVE) has been used to treat recipient sites of fat grafting. Concerns have been raised regarding its efficacy and safety.We have searched PubMed, EMBASE, and the Cochrane Library for studies on EVE-assisted fat grafting published from 2000 to 2020. A meta-analysis was conducted to pool the retention rate. The incidence of complications was assessed for reconstructive or aesthetic purposes.The 11 included studies involved 1152 patients with operations on 1794 breasts. Four studies were included in the meta-analysis. The pooled retention rate was 65% [95%CI 49, 79]. Eight studies reported the complications. The total complication incidence was 34%, which is 35% for the aesthetic group and 33% for the reconstructive group. The complication rate was not obviously different between the two groups.The study shows that the EVE-assisted fat grafting has better retention rate than traditional fat grafting. However, the data showed that the complication rate was much higher in the EVE-assisted group.