Mastectomy Skin Flap Necrosis after Implant-Based Breast Reconstruction: Intraoperative Predictors and Indocyanine Green Angiography.

BACKGROUND

Nipple-sparing mastectomy (NSM) carries significant risk of mastectomy skin flap necrosis, which can compromise oncologic, surgical, and quality-of-life outcomes. Prospective data on intraoperative predictors of mastectomy skin flap necrosis could help to mitigate this risk.

METHODS

This was a single-institution prospective trial of patients undergoing NSM implant-based reconstruction for breast cancer or prophylaxis (2021 to 2024). Flap perfusion was evaluated using clinical assessment, and indocyanine green (ICG) angiography perfusion values and angiogram patterns. Ischemic complications up to 90 days postoperatively were documented. Patient, operative factors, and perfusion analyses were evaluated with univariate and multivariate analysis.

RESULTS

A total of 188 patients underwent 274 NSMs. Eight percent of breasts (22 of 274) developed nipple or skin flap necrosis. Among these, 27.3% had superficial, 31.8% had partial-thickness, and 40.9% had full-thickness necrosis. Multivariate analysis identified previous radiotherapy (hazard ratio [HR], 2.17; 95% CI, 0.92 to 4.11; P = 0.037), ICG angiography absolute perfusion value of 14 units or less (HR, 2.53, 95% CI, 1.43 to 3.6; P = 0.014), ICG angiography relative perfusion value of 30% or less (HR, 1.2; 95% CI, 0.2 to 1.95; P = 0.047), and absence of a second intercostal perforator vessel as independent factors (HR, 2.81; 95% CI, 1.13 to 3.44; P = 0.046) associated with necrosis. Mastectomy incision type, clinical assessment of flap perfusion, mastectomy weight, and initial tissue expander fill ratio were not found to be independent factors associated with necrosis.

CONCLUSIONS

Preservation of the second intercostal perforator vessel was identified as a modifiable intraoperative factor that may decrease the risk of necrosis after NSM. Poor intraoperative perfusion, as detected by ICG angiography, was associated with a greater likelihood of necrosis.