Efficacy and Safety of Fat Grafting in Breast Reconstruction: A Systematic Review and Meta-Analyses of Outcomes Following Mastectomy

Background: Autologous fat grafting (AFG) is increasingly used in post-mastectomy breast reconstruction to enhance contour, improve tissue quality and address radiation induced fibrosis.However, uncertainty remains regarding long term volume retention, complication risk and patient reported outcomes, particularly in oncologic populations.Methods: This PRISMA compliant systematic review and meta-analysis (PROSPERO CRD420251132758) searched MEDLINE, Embase, CENTRAL and Scopus (2010-2025) for comparative studies evaluating complications or volume retention after AFG.Random effects modelling assessed heterogeneity using I 2 and 2 .Sensitivity analyses excluded flap augmented and water jet assisted techniques.Enriched graft methods were synthesised narratively.Results: Thirteen studies were included.Six non-enriched studies reported volume retention, ranging from 26.0% to 74.8% at 3-12 months.The pooled mean retention was 47% (95% Cl, 31.5-62.5;I 2 =99%).Excluding flap-augmented and water-jet studies yielded a lower pooled retention of 35.1% (95% Cl, 25.9-44.3).Follow up time did not significantly moderate retention (p=0.97).Enriched grafting techniques demonstrated higher retention (78-89%) but were too heterogenous for pooling.Seven studies contributed to complication analysis.AFG was associated with a numerically higher rate of fat necrosis (RR 2.37; 95% Cl 0.80 -7.01), though this did not reach statistical significance.No significant differences were observed in any complication category Complication rates were comparable in irradiated cohorts.Patient reported outcomes (primarily BREAST-Q) consistently favoured AFG.Conclusion: AFG is a safe adjunct in post-mastectomy breast reconstruction, demonstrating moderate volume retention without increased postoperative morbidity.Patient satisfaction consistently improves with AFG.Standardised volumetric assessment and technique specific stratification are needed to optimise outcomes.