105 The Impact of Flap Timing and Mechanism of Injury on Flap Complications in Acute Burn Patients

Abstract

Abstract Introduction Burn wounds are often amenable to excision and grafting, but pedicled and free flaps are sometimes necessary to achieve closure of complex wounds. Flap coverage of exposed bone, tendons and cartilage has classicaly been delayed in acute burn patients due to concern of progressive tissue necrosis, microvascular thrombosis and percieved high failure rates. More recently, a number of reports have demonstrated that the use of flaps is safe earlier in acute burn care. We aim to elucidate the role of flaps in primary burn woud coverage leveraging national US data. Methods Acute burn patients with known % total body surface area were extracted from the Nationwide/National Inpatient Sample from 2002–2014 based on International Classification of Disease (ICD) Codes 9th edition. Flap procedures were identified based on ICD-9 procedure codes. Flap and non-flapped patients were compared using multivariable analysis. Variables included age, gender, race, Elixhauser comorbidity index, %TBSA, burn mechanism, inhalation injury, and location of burn. Flap complication was defined by ICD-9 procedure code 8675, return to OR for revision of flap. Multivariable analysis evaluated predictors of flap compromise based on stepwise logistic regression with backwards elimination. Results The weighted sample included 306,924 encounters of which 526 received a flap (0.17%). The mean age of encounters receiving a flap was 45.0 (SD 21.2) years versus 35.5 (SD 24.2) years in the non flap group (p=0.023). 7.8% of patients who received a flap suffered electric injury compared to 2.7% of non-free flap encounters (OR 3.76, 95% CI 1.95–7.24, p< 0.001). Patients who underwent flap wound coverage were more likely to have a lower extremity burn; 55.3% of encounters versus 43.1% in non- flap patients (OR 2.26, 95% CI 1.05–2.15, p=0.024). There were no significant differences in gender, race, Elixhauser comorbidity index, %TBSA, or inhalation injury. The mean hospital day of the flap procedure was 10.1 (SD 10.7) days. Flap complications occurred in 6.4% of flap encounters. The only independent predictor of flap complication was electrical injury (OR 40.49, 95% OR 2.98–550.64, p=0.005). The time to flap coverage and location were not associated with complications. Conclusions Electrical injury was an independent predictor of flap complications compared to other mechanisms. Flap timing was not associated with return to surgery for complications. This suggests that the use of flaps is safe in acute burn care to achieve burn wound closure with an understanding that electrical injuries may deserve particular consideration to avoid failure. Applicability of Research to Practice Inform surgeon decision making when deciding candidacy for flap surgery in acute burn patients.