Association of Body Mass Index With Infectious Complications in Free Tissue Transfer for Head and Neck Reconstructive Surgery.

Importance: Elevated body mass index (BMI) has been proposed as a risk factor for morbidity and mortality among patients undergoing surgery. Conversely, an elevated BMI may confer a protective effect on perioperative morbidity. Objective: To examine whether an elevated BMI is an independent risk factor for perioperative and postoperative infectious complications after free tissue transfer in head and neck reconstructive surgery. Design, Setting, and Participants: This cohort study included patients undergoing major head and neck surgery requiring free tissue transfer at a tertiary care center. Data were collected for 415 patients treated from January 1, 2007, through December 31, 2014. Main Outcomes and Measures: The outcome of interest was postoperative infection and complications after head and neck surgery using free flaps. Covariates considered for adjustment in the statistical model included alcohol consumption (defined as >5 drinks per day [eg, 360 mL of beer, 150 mL of wine, or 45 mL of 80-proof spirits]), type 2 diabetes, prior radiotherapy, anesthesia time, hypothyroidism, smoking, American Society of Anesthesiologists classification, antibiotic regimen received (defined as a standard regimen of a first- or second-generation cephalosporin with or without metronidazole hydrochloride vs an alternative antibiotic regimen for patients allergic to penicillin), and primary surgeon. A multiple logistic regression model was developed for the incidence of the infection end point as a function of elevated BMI (>30.0). Results: Among the 415 patients included in this study (277 men [66.7%] and 138 women [33.2%]; mean [SD] age, 61.5 [13.9] years), type 2 diabetes and use of an alternative antibiotic regimen were found to be independently associated with increased infectious complications after free flap surgery of the head and neck, with estimated odds ratios of 2.78 (95% CI, 1.27-6.09) and 2.67 (95% CI, 1.14-6.25), respectively, in the multiple logistic regression model. However, a high BMI was not found to be statistically significant as an independent risk factor for postoperative infectious complication (estimated odds ratio, 1.19; 95% CI, 0.48-2.92). Conclusions and Relevance: Elevated BMI does not seem to play a role as an independent risk factor in postoperative complications in free tissue transfer in head and neck surgery.