Long-Term Survivability of Surgical and Non-Surgical Management of Spinal Epidural Abscess

Abstract

Spinal epidural abscess (SEA) is a rare and life-threatening infection within the epidural space with significant functional impairment and morbidity. Active debate remains over whether to operate for SEAs, with limited existing data comparing the long-term survivability after surgical versus nonsurgical management. This study aims to determine the long-term survival of patients who underwent surgical and nonsurgical management for SEA. Retrospective cohort study. A total of 250 consecutive SEA patients. Survival and mortality rates, complications. All patients treated at a tertiary medical center for a primary SEA from January 2000 to June 2020 are identified. Data collection is by retrospective chart review. Cox proportional hazards regression models are used for all survival analyses while controlling for potential confounding variables and with multiple testing corrections. A total of 35 out of 250 patients died with an overall all-cause mortality of 14%. More than half of all deaths occurred within 90 days after treatment. The 90-day, 3-year, and 5-year survival rates are 92.8%, 89.2%, and 86.4%, respectively. Among surgery patients, the all-cause mortality was 13.07%, compared to 16.22% for medically-managed patients. Surgical treatment (decompression, fusion, debridement) significantly reduced the risk of death by 62.4% compared to medical therapy (p=.03), but surgery patients experienced a significantly longer mean length of stay (p=.01). Risk factors of short-term mortality included hypoalbuminemia (<3.5 g/dL), American Society of Anesthesiologists (ASA) 4+, and cardiac arrest. Risk factors of long-term mortality were immunocompromised state, elevated WBC count >12,000, sepsis, septic shock, ASA 4+, and cardiac arrest (p<.05). In terms of complications, surgically-managed patients experienced a higher proportion of deep vein thrombosis (p<.05). The overall long-term survivability of SEA treatment is relatively high at (86% at 5-year) in this study. The following SEA mortality risk factors were identified: hypoalbuminemia (short-term), immunocompromised state (long-term), leukocytosis (long-term), sepsis and septic shock (long-term), ASA 4+ and cardiac arrest (overall). For primary SEA patients, surgical management may reduce mortality risk compared to nonsurgical management.