Risk factors for free flap failure in the reconstruction of diabetic foot ulcers.

[BACKGROUND] The aim of study was to investigate the risk factors for free flap failure in the reconstruction of diabetic foot ulcers.

[METHODS] We retrospectively analyzed patient records collected from three teaching hospitals in Japan from April 2007 to March 2019. The exclusion criteria were potentially fatal severe systemic diseases and being unable to ambulate. We evaluated the risk factors associated with free flap failure in the reconstruction of diabetic foot ulcers. Univariate analysis and a multivariate logistic regression were used to identify the independent risk factors for free flap failure.

[RESULTS] A total of 86 patients were enrolled. Among all the records reviewed, 13 patients (15.1%) experienced free flap failure. According to the univariate analysis, 84.6% of patients in the failure group and 49.3% of patients in the success group had peripheral artery disease (PAD), and the difference was statistically significant (p = 0.031). The wound location and tissue donor site were not related to the result of surgery. The p values for sex (p = 0.134), white blood cell count (p = 0.183), serum calcium concentration (p = 0.066), and HbA1c level (p = 0.078) were lower than 0.2. Multivariate logistic regression analysis revealed that PAD was the major independent risk factor for free flap failure (OR = 6.076, 95%CI: 1.031-35.821).

[DISCUSSION] This study revealed that PAD was a major risk factor for free flap failure in the reconstruction of diabetic foot ulcers.