Predictors of seroma after breast reduction: When should drains be considered?

The use of drains in reduction mammoplasty is highly variable among plastic surgeons. However, there is limited evidence to guide surgeons on the optimal timing and conditions for using drains to reduce the risk of seroma formation. The objective of this study was to identify factors that predict the possibility of developing postoperative seroma formation.

Retrospective review of patients who underwent bilateral reduction mammoplasty without intraoperative drain placement at our institution between January 2016 and July 2021 was performed. Demographics, clinical characteristics, and the rate of seroma that required aspiration or drainage were recorded. Univariate time-to-event analyses using Cox regression were performed to identify the predictors of seroma.

A total of 234 patients (468 breasts) were included. The mean age, body mass index, and resection weight were 40.9±17.6 months; 30.7±5.5 kg/m², and 717.2±388 g, respectively. The superomedial pedicle was used in 268 (57.3%) breast reductions while the inferior pedicle was used in 200 (42.7%) cases. Median follow-up time was 3.2 months (IQR: 2.8 months). Seromas occurred in 17 breasts (3.6%). Patients who were of World Health Organization Obesity Class I (hazards ratio, HR = 15.5, p = 0.01), Class II (HR = 13.9, p = 0.016), and Class III (HR = 27.4, p = 0.004) had increased risk for developing seroma when compared to non-obese patients.

The rate of seroma formation was 3.6% in this cohort. Obesity significantly increased the risk of postoperative seroma formation that required aspiration or surgical drainage; therefore, surgeons who aim to further reduce the risk of seroma should consider using drains for these patients.