Antibiotic-Resistant Spondylodiscitis With Canal Invasion and Aggressive Evolution to Epidural Abscess: A Case Series of Spontaneous Occurrence in 16 Patients

Background: The study aimed to assess the effectiveness of antibiotic treatment for spondylodiscitis, its failure rates, and the need for surgical intervention. Methods: This is a retrospective study of patients who presented with spontaneous deep spinal infections and spondylodiscitis between 2011 and 2013. Clinical, bacteriologic, and radiographic data during hospitalization were analyzed. Results: A total of 16 patients presented with deep spinal infections during the study period; 15 of them presented with spontaneous pyogenic spondylodiscitis, and 1 presented with epidural abscess. Median age was 68 years (range, 50–80 years), and 6 (38%) were healthy young laborers. None of the patients were immunocompromised. On admission all patients presented with pain, there was fever in 3 patients (19%), and there was elevated blood C-reactive protein, white blood cell count and erythrocyte sedimentation rate, with a mean of 147 ± 83.1 mg/L, 11.65 ± 5.6 × 103/μL, 93.6 ± 35.1 mm/h, respectively. A total of 15 patients (94%) developed infections that were refractory to appropriate culture-specific intravenous antibiotic treatment (mean, 10.2 days); 8 patients (50%) deteriorated neurologically and required wide surgical decompression. Complications included widespread epidural free gas in 2 patients (12%), multiple bilateral psoas abscesses in 2 patients (12%), kyphotic segmental instability in 4 patients (25%), and inferior vena cava septic thrombi in 1 patient (6%). A total of 3 patients (19%) died within 6 months; 7 of 13 surviving patients still had residual neurologic deficits at the 6-month follow-up. Conclusions: Spondylodiscitis may be resistant to antibiotic treatment and may evolve into epidural abscess via extension of the infection and pus into the spinal canal, necessitating repetitive surgical treatment due to neurologic and clinical deterioration, and expansion of the persistent infection with a mass effect. Increased vigilance for this condition and its misleading initial presentations is warranted.