1428. Comparing Outcomes of Diabetic Foot Infections Requiring Amputation, Negative vs. Positive Margins

Abstract

BackgroundThis was a retrospective, observational cohort study of patients with diabetes and lower extremity osteomyelitis requiring amputation. Patients were categorized as having negative margins (without residual osteomyelitis or with joint disarticulation), or positive margins (with residual osteomyelitis). Health outcomes were compared between groups. The primary outcomes were relapse of infection at one year and reintervention at one year. Secondary outcomes include mortality at 30 days, 90 days, and 1 year; treatment failure at one year; and a composite of relapse of infection at one year, reintervention at 1 year, and death at 1 year.MethodsCPRS ICD-10 codes were reviewed from patients at Audie L. Murphy VA with amputation for osteomyelitis between July 2, 2015 and July 13, 2017. Pathology reports were reviewed for the presence or absence of residual osteomyelitis, and outcomes were determined by chart review. Patient characteristics were recorded, such as age, serum albumin, presence of diabetes, hemoglobin A1c, organism on culture, peripheral vascular disease, and occurrence of a peripheral vascular intervention.ResultsThe ALMVA is a 500-bed medical center with an active BMT program. Clinical data from 146 patients were obtained and analyzed. There were no significant differences in primary or secondary outcomes relative to patients with positive margins or negative margins. A lack of consistency in margin reporting by Pathology was seen. Albumin level and number of patients with residual osteomyelitis were significantly different between the two groups (table).ConclusionThere were no significant differences in outcomes between amputations with positive margins and those with negative margins. Based on current IDSA guidelines, treatment varies significantly for patients with positive or negative margins, with the former requiring 6 weeks of parenteral antibiotic therapy. Extended courses of parenteral antibiotics increase risk for treatment-associated morbidity, and more evidence is needed to support these recommended durations. A quality improvement project is underway with the ID, Podiatry and Pathology departments to resolve issues related to obtaining and processing surgical samples, as well as interpreting and reporting margin results. Disclosures All authors: No reported disclosures.