Spinal epidural abscesses: risk factors, medical versus surgical management, a retrospective review of 128 cases.
BACKGROUND
Spinal epidural abscess (SEA) is a rare, serious and increasingly frequent diagnosis. Ideal management (medical vs. surgical) remains controversial.


OBJECTIVE
The purpose of this study is to assess the impact of risk factors, organisms, location and extent of SEA on neurologic outcome after medical management or surgery in combination with medical management.


METHODS
Retrospective electronic medical record (EMR) review.


METHODS
We included 128 consecutive, spontaneous SEA from a single tertiary medical center, from January 2005 to September 11. There were 79 male and 49 female with a mean age of 52.9 years (range, 22-83).


METHODS
Patient demographics, presenting complaints, radiographic features, pre/post-treatment neurologic status (ASIA motor score [MS] 0-100), treatment (medical vs. surgical) and clinical follow-up were recorded. Neurologic status was determined before treatment and at last available clinical encounter. Imaging studies reviewed location/extent of pathology.


METHODS
Inclusion criteria were a diagnosis of a bacterial SEA based on radiographs and/or intraoperative findings, age greater than 18 years, and adequate EMR. Exclusion criteria were postinterventional infections, Pott's disease, isolated discitis/osteomyelitis, treatment initiated at an outside facility, and imaging suggestive of a SEA but negative intraoperative findings/cultures.


RESULTS
The mean follow-up was 241 days. The presenting chief complaint was site-specific pain (100%), subjective fevers (50%), and weakness (47%). In this cohort, 54.7% had lumbar, 39.1% thoracic, 35.9% cervical, and 23.4% sacral involvement spanning an average of 3.85 disc levels. There were 36% ventral, 41% dorsal, and 23% circumferential infections. Risk factors included a history of IV drug abuse (39.1%), diabetes mellitus (21.9%), and no risk factors (22.7%). Pathogens were methicillin-sensitive Staphylococcus aureus (40%) and methicillin-resistance S aureus (30%). Location, SEA extent, and pathogen did not impact MS recovery. Fifty-one patients were treated with antibiotics alone (group 1), 77 with surgery and antibiotics (group 2). Within group 1, 21 patients (41%) failed medical management (progressive MS loss or worsening pain) requiring delayed surgery (group 3). Irrespective of treatment, MS improved by 3.37 points. Thirty patients had successful medical management (MS: pretreatment, 96.5; post-treatment, 96.8). Twenty-one patients failed medical therapy (41%; MS: pretreatment, 99.86, decreasing to 76.2 [mean change, -23.67 points], postoperative improvement to 85.0; net deterioration, -14.86 points). This is significantly worse than the mean improvement of immediate surgery (group 2; MS: pretreatment, 80.32; post-treatment, 89.84; recovery, 9.52 points). Diabetes mellitus, C-reactive protein greater than 115, white blood count greater than 12.5, and positive blood cultures predict medical failure: None of four parameters, 8.3% failure; one parameter, 35.4% failure; two parameters, 40.2% failure; and three or more parameters, 76.9% failure.


CONCLUSIONS
Early surgery improves neurologic outcomes compared with surgical treatment delayed by a trial of medical management. More than 41% of patients treated medically failed management and required surgical decompression. Diabetes, C-reactive protein greater than 115, white blood count greater than 12.5, and bacteremia predict failure of medical management. If a SEA is to be treated medically, great caution and vigilance must be maintained. Otherwise, early surgical decompression, irrigation, and debridement should be the mainstay of treatment.
Department of Orthopaedics and Sports Medicine, University of Washington, 7201 6th Ave. NE #102, Seattle, WA 98115, USA.
Amit R
AR
Patel
Department of Orthopaedics and Sports Medicine, University of Washington, 7201 6th Ave. NE #102, Seattle, WA 98115, USA. Electronic address: altont@uw.edu.
Timothy B
TB
Alton
Department of Orthopaedics and Sports Medicine, University of Washington, 7201 6th Ave. NE #102, Seattle, WA 98115, USA.
Richard J
RJ
Bransford
Department of Orthopaedics and Sports Medicine, University of Washington, 7201 6th Ave. NE #102, Seattle, WA 98115, USA.
Michael J
MJ
Lee
Department of Orthopaedics and Sports Medicine, University of Washington, 7201 6th Ave. NE #102, Seattle, WA 98115, USA.
Carlo B
CB
Bellabarba
Department of Orthopaedics and Sports Medicine, University of Washington, 7201 6th Ave. NE #102, Seattle, WA 98115, USA.
Jens R
JR
Chapman
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D003131:Combined Modality Therapy; D019468:Disease Management; D057286:Electronic Health Records; D020802:Epidural Abscess / Q000188:drug therapy* / Q000382:microbiology / Q000601:surgery*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D019637:Orthopedic Procedures / Q000379:methods* / Q000639:trends*; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D012307:Risk Factors; D055815:Young Adult
D000900:Anti-Bacterial Agents
Epidural abscess; Management; Medical; Motor score; Outcomes; Risk factors; Surgical