LAUSR

BACKGROUND Primary defatting is suggested as an effective and appealing technique for achieving flap thinning. There has been a long-standing concern regarding its potential adverse effects on flap perfusion, for which limited clinical evidence exists. This study aimed to investigate whether primary defatting negatively influences the outcomes of free perforator flap reconstruction. METHODS Patients who underwent upper or lower extremity reconstruction using free perforator flaps between 2002 and 2020 were investigated. They were categorized into two groups according to whether they underwent primary defatting. The association of primary defatting with the development of perfusion-related complications was evaluated. RESULTS A total of 421 patients were included in the analysis. Perfusion-related complications developed in 61 (14.5%) cases, including 12 cases (2.9%) of total flap loss. In total, 302 patients underwent primary defatting and 119 did not. The patients who underwent primary defatting had a higher body mass index (BMI), lower rate of comorbidities, and smaller harvested flaps than the controls. Both groups had similar rates of perfusion-related complications (13.9% vs. 16.0%, p = .589), including total flap loss (3.0% vs. 2.5%, p = .799). In the multivariate analyses, primary defatting was not associated with the development of perfusion-related complications (p = .957). In the subgroup analyses, the rate of perfusion-related complications did not differ between the two groups regardless of the BMI (≥25 or <25 kg/m2 ), comorbidities, and flap size (≥200, 100-200, or <100 cm2 ). CONCLUSIONS Primary defatting does not appear to be associated with the development of perfusion-related complications in free perforator flap extremity reconstruction.