Risk factors for unplanned reoperation during the expansion phase in two-stage breast reconstruction in the Dutch Breast Implant Registry

BACKGROUND: The majority of postmastectomy breast reconstructions (PMBRs) are currently performed in two stages using a tissue expander (TE). However, complications during the expansion phase occur regularly, leading to unplanned reoperations and/or reconstruction failure. This study aimed to identify risk factors for unplanned reoperation after TE placement, assessed the time until unplanned and planned reoperation, and investigated indications for unplanned reoperation. METHODS: Patient and surgery-related characteristics of patients who underwent two-stage PMBR between 2017 and 2021 were collected from the Dutch Breast Implant Registry (DBIR). Unplanned reoperation was defined as TE explantation followed by either no replacement or replacement with the same or a different TE. Co-variate adjusted characteristics associated with unplanned reoperation were determined using backward stepwise selection and multivariable logistic regression analyses. RESULTS: In total, 2529 patients (mean age, 50.2 years) were included. Unplanned reoperation occurred in 19.4 percent of all registered TEs (n=3190). Independent factors associated with unplanned reoperation were BMI=25 kg/m 2 (adjusted Odds Ratio [aOR]=1.63;99% Confidence Interval [99%CI]=1.20-2.57 for BMI 25-29.9 kg/m2, aOR=2.57;99%CI=1.74-3.78 for BMI=30 kg/m 2), low institutional volume (aOR=1.51;99%CI=1.06-2.18), no drains (aOR=2.06;99%CI=1.15-3.60), subcutaneous TE placement (aOR=5.71;99%CI=3.59-9.10), and partial pectoralis major muscle coverage (aOR=1.35;99%CI=1.02-1.79). Age<40 years (aOR=0.49;99%CI=0.32-0.74) and delayed PMBR (aOR=0.35;99%CI=0.19-0.60) reduced the risk of unplanned reoperation. Median time until reoperation was 97 days for unplanned and 213 days for planned reoperation. Deep wound infections were most often registered as indication for unplanned reoperation (34.4 percent). CONCLUSION: This study identified several risk factors for unplanned reoperation which may be used to reduce complications in expander-based PMBR