Background: Although obesity is a well-known risk factor for complications in immediate expander–implant breast reconstruction, no studies have identified risk factors for non-obese patients. The purpose of this study was to identify risk factors for complications in non-obese patients. Methods: A retrospective analysis of prospectively collected data from 397 consecutive immediate expander–implant breast reconstructions in 367 non-obese patients at a single institution over a 5-year period was conducted. Univariable and multivariable analysis were performed to determine the influence of six patient-related and eight procedure-related characteristics on complications. Results: Mean BMI was 21.7 ± 2 kg/m2 and median mastectomy weight was 298.0 g (range: 40–1164 g). Multivariable analysis showed that neither BMI nor the use of acellular dermal matrix was a predictor for complications. Adjuvant radiation (odds = 3.12, p < 0.001) and mastectomy weight (p < 0.001) were independent risk factors for complications. A 100 g increase in the mastectomy weight was significantly associated with a 23 % increase in the odds of overall complications (p = 0.003), major complications (p = 0.004), and skin flap complications (p = 0.007), as well as a 28 % increase in the odds of seroma (p = 0.044), but was not associated with reconstruction failure. Adjuvant radiation (p < 0.001) and hypertension (p < 0.001) were risk factors for reconstruction failure. Conclusions: Breast size was an independent risk factor for complications in non-obese patients while BMI was not. In the reconstruction of large breasts, greater attention and additional adjunctive procedures would be needed to prevent complications. Level of Evidence III: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.
- Breast size
- Tissue expander