No superiority of double drains over single drainage after tissue expander-based breast reconstruction: A systematic review and meta-analysis

The optimal number of drains after postmastectomy tissue expander (TE)-based breast reconstruction remains uncertain. Although double-drain placement may theoretically improve fluid clearance and reduce seroma formation, it may also increase patient discomfort, prolong drain-related morbidity, and potentially increase contamination risk. This systematic review and meta-analysis compared postoperative outcomes between single- and double-drain strategies following TE-based breast reconstruction.

PubMed, Embase, and Cochrane Library were searched from inception to May 16, 2026. Comparative studies evaluating single versus double drains after postmastectomy TE-based reconstruction were included. Outcomes of interest included seroma formation, surgical site infection (SSI), hematoma, return to the operating room, skin flap necrosis, drain duration, and TE/implant-related complications. Risk ratios (RRs) and mean differences (MDs) with 95% confidence intervals (CIs) were pooled using random-effects models. Risk of bias was assessed with ROBINS-I and certainty of evidence with the GRADE approach.

Three retrospective observational studies comprising 1350 reconstructions were included, with 660 reconstructions in the single-drain group and 690 in the double-drain group. There were no significant differences between single- and double-drain strategies in seroma formation (RR 0.84, 95% CI 0.47 to 1.49; p = 0.54; I² = 63%), SSI (RR 1.01, 95% CI 0.75 to 1.37; p = 0.93; I² = 39%), hematoma (RR 0.84, 95% CI 0.44 to 1.63; p = 0.61; I² = 0%), return to the operating room (RR 0.66, 95% CI 0.30 to 1.43; p = 0.29; I² = 12%), skin flap necrosis (RR 0.74, 95% CI 0.46 to 1.19; p = 0.22; I² = 0%), or drain duration (MD -3.90 days, 95% CI -12.42 to 4.63; p = 0.37; I² = 97%). Leave-one-out analyses did not materially alter the findings for seroma formation or SSI. Certainty of evidence was low for seroma, SSI, and skin flap necrosis, and very low for hematoma, return to the operating room, and drain duration.

Current evidence does not demonstrate a benefit of routine double-drain placement after TE-based breast reconstruction. The certainty of evidence was low, and these findings indicate a lack of demonstrated benefit rather than equivalence between the two strategies. Selective second-drain placement based on intraoperative findings remains reasonable, and adequately powered prospective studies are needed.