SP39. The Association Between Medical Comorbidities and Outcomes After Limb-salvage Procedures Using Free Tissue Transfer

PURPOSE: Lower extremity wounds (LEWs) present significant challenges to the plastic surgeons. Free tissue transfer is a powerful limb salvage technique that can be complicated with total failure and the need for future amputation. Limited data is available on outcomes associated with comorbidities. METHODS: A retrospective cohort study was conducted at a single tertiary medical center. Medical records were used for data collection. Univariate analyses were performed using χ 2 or Fisher’s exact test (n < 7) for categorical variables and Student’s t-test for continuous variables, with statistical significance set at values of p ≤ 0.05. RESULTS: 97 free flaps from 82 patients were included. Etiologies of LEWs include vascular insufficiency (34%), diabetic wounds (30%), trauma (23%), and others (13%). Most flaps were fascio-cutaneous (65%) while the remaining were musculocutaneous or muscle only (35%). Most patients were male (71%), the average age was 56 years (range 19-85), and the average BMI was 28 kg/m2 (range 16-54). Most common complications include need for amputation (15.5%), total flap failure (10.3%), sepsis (6.1%), kidney failure (2.4%), myocardial infarction (3.7%), and stroke (2.4%). Total flap failure occurred within the first month (90%) and was independently associated with end-stage kidney disease (OR= 5.78, p = 0.01) and peripheral vascular disease (OR= 3.8, p = 0.05). Majority of amputations occur after 180 days after flap reconstruction and associated with congestive heart failure (OR= 8.72, p = 0.01), diabetes mellitus type II (OR 5.09, p = 0.01), and kidney disease (OR= 3.79, p = 0.01). Finally, presence of osteomyelitis increases odds of progression to amputation (OR = 4.96, p = 0.040), and this is further increased in those with diabetes (OR = 5.87, p = 0.02). In the absence of diabetes, the presence of osteomyelitis did not increase odds of progression to amputation (OR = 0.5, p > 0.99). CONCLUSION: Comorbidities affect the outcome of free flap coverage for LEWs. Patient comorbidities are important in the decision of limb salvage and prediction of surgical outcomes.