AB0899 COMPUTER TOMOGRAPHY GUIDED BIOPSY YIELD IN PYOGENIC VERTEBRAL OSTEOMYELITIS. AN EXAMINATION OF INFLUENCING FACTORS

Background Vertebral Osteomyelitis (VO) is an infectious disease that could involve intervertebral space (discitis), which it is avascular in adults. VO and discitis may occur together or independently. Both are frequently the result of a spreading of a distant focus, such as infectious endocarditis or soft tissue infection. Due to the lack of direct blood supply, reliability of blood cultures is low, so biopsy is highly encouraged by current guidelines. Treatment includes long term antibiotic (ATB), that should be initiated after biopsy (if possible) and sometimes, further surgery is needed. Objectives To analyze which factors influence the result of a CT-guided biopsy in patients with VO. Methods Retrospective observational study including adult patients diagnosed of VO based on the combination of clinical presentation with either a definitive bacteriologic diagnosis or pathological and/or imaging studies, who underwent CT-guided biopsy from January 2010 to January 2019. Demographic features, concurrent diseases, clinical history (length of pain and fever prior to admission), laboratory findings, microbiological diagnosis and radiological data were compiled. Days until biopsy from admission, prior antibiotic exposure was also collected. We considered as immunosuppressed patients those who had rheumatic or inflammatory bowel disease undertaking immunomodulatory drugs, solid organ transplantation receptors, and patients with an active malignancy or Human Immunodeficiency Virus (HIV) infected. Clinical and radiological history of lumbar stenosis or disc herniation was considered as prior spine pathology. Spinal infections after surgery, Fungal and tuberculous disease were excluded. We considered deaths attributive to PVO those which were directly caused by the infectious picture and/or its complications during the next year after diagnosis. Results Seventy-two of 109 patients with VO underwent biopsy (66.06%). Thirty-nine brought a positive culture (54.2%). Basal demographic and clinical features are exposed in table 1. Positive cultures included 33 cases (84.61%) of Gram+ infection (23 Staphylococcus and 6 Streptococcus ) and 6 (15.39%) by Gram- bacilli (3 cases of Pseudomona aeruginosa , 2 Escherichia coli and 1 Brevundimona spp ). Conclusion In our population, it has been observed that not a single variable collected showed influence on culture result, although a negative tendency is observed in cases of prior antibiotic exposure, with no signification. Since CT guided biopsy is a safe technique, offering an acceptable reliability, our results support its use even in those cases that empirical antibiotic had been already initiated. Disclosure of Interests None declared