Time to final drain removal after mastectomy with or without immediate breast reconstruction: a retrospective single-centre cohort study

Drain duration varies across breast operations, while reconstruction, axillary surgery, and clinical selection frequently overlap. We quantified time to final drain removal across mastectomy procedures with or without immediate reconstruction and examined whether associations persisted among patients undergoing axillary lymph node dissection (ALND). This retrospective single-centre cohort included 220 patients treated between 2020 and 2025: simple mastectomy (SM, n = 40), modified radical mastectomy (MRM, n = 106), implant reconstruction (IR, n = 32), and latissimus dorsi (LD) flap reconstruction ( n = 42). Final axillary management was coded as sentinel lymph node biopsy (SLNB) only or ALND; completion ALND after a positive SLNB was classified as ALND. The primary outcome was time to final drain removal; removal after postoperative day 14 was secondary. Adjusted linear and logistic models and an ALND-restricted analysis were performed. Median times were 10 (IQR 9–12), 10 (9–12), 12 (10–15), and 15 (10–20) days for SM, MRM, IR, and LD, respectively ( p < 0.001). In the adjusted continuous model, LD was associated with 3.23 additional days (95% CI 1.11–5.36; p = 0.003); the IR estimate was 0.56 days (95% CI -1.16 to 2.28; p = 0.522). For removal after day 14, LD was associated with higher odds (OR 5.66, 95% CI 2.35–13.65; p < 0.001), whereas IR was not statistically significant (OR 1.97, 95% CI 0.75–5.17; p = 0.170). Among 164 ALND patients, LD remained associated with removal after day 14 (OR 6.25, 95% CI 2.17–18.00; p < 0.001), whereas IR did not. LD reconstruction was associated with longer time to final drain removal, including among ALND patients. The magnitude may support preoperative counselling and drain planning. Because the LD endpoint included donor-site drains and procedure groups reflected non-random clinical selection and patient preference, findings are descriptive associations. Non-significant estimates for ALND, BMI, and clinical stage do not establish absence of effect.