Sentinel lymph node biopsy and immediate two-stage implant-based breast reconstruction: A propensity score-matched analysis.

Background: There are important differences between patients requiring sentinel lymph node biopsy (SLNB) and those who do not require axillary surgery at the time of breast reconstruction. We aimed to perform a propensity score-matched analysis to evaluate the impact of SLNB at the time of immediate implant-based breast reconstruction (IBBR) with tissue expanders compared with IBBR alone.

Methods: Consecutive female patients undergoing total mastectomy and immediate two-stage IBBR between January 2011 and May 2021 were included. A 1:1 nearest-neighbor matching method without replacement was implemented with a caliper width of 0.01. Patients were matched for age, diabetes, hypertension, hyperlipidemia, premastectomy radiotherapy, neoadjuvant chemotherapy, the plane of prosthesis placement, mastectomy specimen weight, number of drains, and radiation of the expander.

Results: We included 320 two-stage immediate IBBRs after propensity score matching, 160 reconstructions per group. Relevant surgical variables were comparable between groups. A higher rate of 30-day seroma formation was reported in immediate reconstructions that had SLNB at the time of mastectomy compared with reconstructions that did not have axillary surgery (16.3% versus 8.1%, p = 0.039). The time to complete outpatient expansions and time for expander-to-implant exchange were comparable between patients who underwent IBBRs with SLNB and those who did not.

Conclusion: SLNB performed at the time of mastectomy and IBBR with tissue expander increased the risk of seroma formation compared with reconstructions that did not have axillary surgery. The rate of infection, hematoma, and unplanned procedures to manage complications did not differ between groups.