Peri-operative risk factors for complications of free flaps in traumatic wounds - a cross-sectional study.

Introduction: Indication of free tissue transfer for limb reconstruction continues to grow, and despite the good results with this treatment option, complications can impair the functional results and cause a raise in health costs, with prolonged hospitalization. Therefore, peri-operative surgical information and comorbidities were described and analyzed, for identification of independent risk factors for complications of free flaps results for traumatic wounds. For our knowledge, intraoperative ischemia time of free flap was not previously studied for post-traumatic limb reconstruction, which could influence results, in these traumatic cases, with the highest rates of complications among microsurgical flap reconstructions.

Methods: From July 2014 to January 2017, all patients with free flaps for limb reconstruction were consecutively included. Data on personal medical history, intra-operative microsurgical procedure, and laboratory tests were collected and complications analyzed. Descriptive and inferential statistics were performed.

Results: Sixty-two free flaps for traumatic limb reconstruction in 60 patients were studied. We observed a higher rate of complications in patients who underwent surgery > seven days after the trauma, patients with obesity, when used recipient veins from the superficial system for drainage of the flap, and in those in whom the ischemia time of the free flap was higher in univariate analyzes. After logistic regression, the remaining independent risk factors for complications were ischemia time of free flap > two hours  and obesity. The presence of thrombocytosis was associated with partial flap loss.

Conclusions: The independent risk factors for complications were ischemia time of free flap > two hours  and obesity.