Sixty studies (at least 4,601 women, range one to 880) were included in the review. Fifty-eight studies were observational: 37 case reports or case series, seven retrospective cohort studies, 12 prospective cohort studies, one diagnostic validation cohort study and one case control study. Two studies were clinical trials that did not describe the method of randomisation. Four studies were classified as moderate quality, 33 were low quality and 23 were very low quality. Mean follow-up ranged from three to 37 months, where reported.
Clinical outcomes: Thirty studies (930 patients) used fat grafting for aesthetic augmentation and 41 studies (3,646 patients) used fat grafting for breast reconstruction. Clinical complications were identified in 155 out of 4,601 patients (60 studies). Nodularity and/or induration was the most common complication (60%) followed by deep infection (12.3%). In the studies of better quality (21 studies) the incidence of clinical complications was 3.9% (117 out of 3,015 patients).
Radiographic changes: Among all 60 studies, 299 abnormal radiographic changes were identified; 74.6% were cysts and 13.4% were microcalcification. In the studies of better quality (17 studies), the overall rate of abnormal radiological findings during follow-up was 13.0% (332 out of 2,560 patients).
Breast cancer risk: Fourteen recurrent cancers were identified (2.3%) in three studies that evaluated 616 patients with mean follow-up of 45.2 months.