Sung Joon Kim

Background: In postmastectomy radiotherapy, radiation reaches an already-reconstructed breast, and implant-based reconstruction remains feasible in selected patients. Far less studied is reconstruction within a previously irradiated field: after breast-conserving therapy, ipsilateral breast tumor recurrence (IBTR), and salvage mastectomy. We compared implant-based and autologous reconstruction in this setting and propose a hypothesis-generating treatment algorithm. Methods: From 2219 consecutive breast reconstructions (2012–2026), we cross-matched implant-removal, radiotherapy, and local-recurrence registries to identify all immediate total reconstructions of a previously irradiated breast after salvage mastectomy for IBTR (n = 13; 8 implant-based [all stand-alone, without vascularized flap coverage], 5 autologous [all latissimus dorsi-based]). The primary endpoint was reconstruction failure, defined in a modality-neutral manner as definitive loss or abandonment of the reconstruction; implant-based reconstructions of breasts not previously irradiated at the time of reconstruction (n = 689) served as a descriptive institutional reference cohort. Results: Seven of eight implants (87.5%) were removed at 3 to 51 months; the single retained implant has a persistent wound; none achieved complication-free success. Failure modes comprised early envelope necrosis, periprosthetic infection, and late attritional failure; chronic retained-capsule seroma followed removal without capsulectomy. All five autologous reconstructions healed without failure or unplanned reoperation (reconstruction failure, 7/8 [87.5%; 95% CI, 47.3–99.7%] vs. 0/5 [0%; 95% CI, 0–52.2%], p = 0.005; log-rank p = 0.039; median follow-up, 32.0 vs. 10.9 months; failure or major complication, 8/8 vs. 0/5, p = 0.0008). The implant-removal rate also exceeded that of the institutional reference cohort (87.5% vs. 11.2%; unadjusted, descriptive comparison). Conclusions: In this small consecutive series, stand-alone implant-based reconstruction of the previously irradiated breast was associated with a very high failure rate, whereas reconstruction importing well-vascularized autologous tissue healed in every case, a pattern biologically consistent with chronic radiation injury. These findings constitute a strong cautionary signal rather than definitive evidence. Our findings support an autologous-first approach after salvage mastectomy of the irradiated breast; stand-alone implant-based reconstruction should be offered only to carefully selected, fully counseled patients, and the proposed algorithm requires external validation.