Timing in the surgical evacuation of spinal epidural abscesses

External Validation of Predictive Models for Failed Medical Management of Spinal Epidural Abscess

OBJECTIVE

There is limited consensus regarding management of spinal epidural abscesses (SEAs), particularly in patients without neurologic deficits. Several models have been created to predict failure of medical management in patients with SEA. We evaluate the external validity of 5 predictive models in an independent cohort of patients with SEA.

METHODS

One hundred seventy-six patients with SEA between 2010 and 2019 at our institution were identified, and variables relevant to each predictive model were collected. Published prediction models were used to assign probability of medical management failure to each patient. Predicted probabilities of medical failure and actual patient outcomes were used to create receiver operating characteristic (ROC) curves, with the area under the receiver operating characteristic curve used to quantify a model's discriminative ability. Calibration curves were plotted using predicted probabilities and actual outcomes. The Spiegelhalter z-test was used to determine adequate model calibration.

RESULTS

One model (Kim et al) demonstrated good discriminative ability and adequate model calibration in our cohort (ROC = 0.831, P value = 0.83). Parameters included in the model were age >65, diabetes, methicillin-resistant Staphylococcus aureus infection, and neurologic impairment. Four additional models did not perform well for discrimination or calibration metrics (Patel et al, ROC = 0.580, P ≤ 0.0001; Shah et al, ROC = 0.653, P ≤ 0.0001; Baum et al, ROC = 0.498, P ≤ 0.0001; Page et al, ROC = 0.534, P ≤ 0.0001).

CONCLUSIONS

Only 1 published predictive model demonstrated acceptable discrimination and calibration in our cohort, suggesting limited generalizability of the evaluated models. Multi-institutional data may facilitate the development of widely applicable models to predict medical management failure in patients with SEA.

Advances in diagnosis and management of atypical spinal infections: A comprehensive review

Atypical spinal infections (ASIs) of the spine are a challenging pathology to management with potentially devastating morbidity and mortality. To identify patients with atypical spinal infections, it is important to recognize the often insidious clinical and radiographic presentations, in the setting of indolent and smoldering organism growth. Trending of inflammatory markers, and culturing of organisms, is essential. Once identified, the spinal infection should be treated with antibiotics and possibly various surgical interventions including decompression and possible fusion depending on spine structural integrity and stability. Early diagnosis of ASIs and immediate treatment of debilitating conditions, such as epidural abscess, correlate with fewer neurological deficits and a shorter duration of medical treatment. There have been great advances in surgical interventions and spinal fusion techniques for patients with spinal infection. Overall, ASIs remain a perplexing pathology that could be successfully treated with early diagnosis and immediate, appropriate medical, and surgical management.

Spinal epidural abscess as predicting factor for the necessity of early surgical intervention in patients with pyogenic spondylitis

BACKGROUND

Pyogenic spondylitis is a condition with low incidence that can lead to neurological sequelae and even life-threatening conditions. While conservative methods, including antibiotics and bracing, are considered the first-line treatment option for pyogenic spondylitis, it is important to identify patients who require early surgical intervention to prevent progressive neurologic deficits or deterioration of the systemic condition. Surgical treatment should be considered in patients with progressive neurologic deficits or deteriorating systemic condition. However, currently, there is a lack of treatment guidelines, particularly with respect to whether surgical treatment is necessary for pyogenic spondylitis. This study aims to analyze the radiological epidural abscess on MRI and clinical factors to predict the need for early surgical intervention in patients with pyogenic spondylitis and provide comprehensive insight into the necessity of early surgical intervention in these patients.

METHODS

This study retrospectively reviewed 47 patients with pyogenic spondylitis including spondylodiscitis, vertebral osteomyelitis, epidural abscess, and/or psoas abscess. All patients received plain radiographs, and a gadolinium-enhanced magnetic resonance imaging (MRI) scan. All patients have either tissue biopsies and/or blood cultures for the diagnosis of a pathogen. Demographic data, laboratory tests, and clinical predisposing factors including comorbidities and concurrent other infections were analyzed.

RESULTS

We analyzed 47 patients, 25 of whom were female, with a mean age of 70,7 years. MRI revealed that 26 of 47 patients had epidural abscesses. The surgical group had a significantly higher incidence of epidural abscess than the non-surgical group (p = 0.001). In addition, both CRP and initial body temperature (BT) were substantially higher in the surgical group compared to the non-surgical group. There was no significant difference between the surgical group and the non-surgical group in terms of age, gender, comorbidities, and concurrent infectious disorders, as well as the number of affected segments and affected spine levels. However, the surgical group had lengthier hospital stays and received more antibiotics.

CONCLUSION

The presence of an epidural abscess on MRI should be regarded crucial in the decision-making process for early surgical treatment in patients with pyogenic spondylitis in order to improve clinical outcomes.

Cervical Spinal Epidural Abscess: Diagnosis, Treatment, and Outcomes: A Case Series and a Literature Review

Although recent diagnostic and management methods have improved the prognosis of cervical epidural abscesses, morbidity and mortality remain significant. The purpose of our study is to define the clinical presentation of cervical spinal epidural abscess, to determine the early clinical outcome of surgical treatment, and to identify the most effective diagnostic and treatment approaches. Additionally, we analyzed studies regarding cervical epidural abscesses and performed a review of the literature. In this study, four patients with spinal epidural abscess were included. There were three men and one woman with a mean age of 53 years. Three patients presented with motor deficits, and one patient was diagnosed incidentally through spinal imaging. All the patients had fever, and blood cultures were positive. Staphylococcus aureus was the most common organism cultured from abscesses. All patients underwent a surgical procedure, and three patients recovered their normal neurological functions, but one remained with mild neurological disability that was resolved two years postoperatively. The mean follow-up period was 12 months, and no deaths occurred in this series. Furthermore, we identified 85 studies in the literature review and extracted data regarding the diagnosis and management of these patients. The timely detection and effective management of this condition are essential for minimizing its associated morbidity and mortality.

Patients Follow-up for Spinal Epidural Abscess as a Critical Treatment Plan Consideration

INTRODUCTION

 Spinal epidural abscess (SEA) is a rare process with significant risk for morbidity and mortality. Treatment includes an extended course of antibiotics with or without surgery depending on the clinical presentation. Both non-operative and surgically treated patients require close follow-up to ensure the resolution of the infection without recurrence and/or progression of neurologic deficits. No previous study has looked specifically at follow-up in the SEA population, but the review of the literature does show evidence of varying degrees of difficulty with follow-up for this patient population.

METHODS

 This retrospective review looked at follow-up for 147 patients with SEA at a single institution from 2012 to 2021. Statistical analyses were performed to assess differences between groups of surgical versus non-surgical patients and those with adequate versus inadequate follow-up.

RESULTS

Sixty-two of 147 (42.2%) patients had inadequate follow-up (less than 90 days) with their surgical team, and 112 of 147 (76.2%) patients had inadequate follow-up (less than 90 days) with infectious disease (ID). The primary statistically significant difference between patients with adequate versus inadequate follow-up was found to be surgical status with those treated surgically more likely to have adequate follow-up than those treated non-operatively.

CONCLUSION

Improved follow-up in surgical patients should be considered as a factor when deciding on surgical versus non-operative treatment in the SEA patient population. Extra efforts coordinating follow-up care should be made for SEA patients.

Predictors of reoperation after surgery for spinal epidural abscess

BACKGROUND CONTEXT

Spinal epidural abscess is a rare but severe condition with high rates of postoperative adverse events.

PURPOSE

The objective of the study was to identify independent prognostic factors for reoperation using two datasets: an institutional and national database.

STUDY DESIGN/SETTING

Retrospective Review.

PATIENT SAMPLE

Database 1: Review of five medical centers from 1993 to 2016. Database 2: The National Surgical Quality Improvement Program (NSQIP) was queried between 2012 and 2016.

OUTCOME MEASURES

Thirty-day and ninety-day reoperation rate.

METHODS

Two independent datasets were reviewed to identify patients with spinal epidural abscesses undergoing spinal surgery. Multivariate analyses were used to determine independent prognostic factors for reoperation while including factors identified in bivariate analyses.

RESULTS

Overall, 642 patients underwent surgery for a spinal epidural abscess in the institutional cohort, with a 90-day unplanned reoperation rate of 19.9%. In the NSQIP database, 951 patients were identified with a 30-day unplanned reoperation rate of 12.3%. On multivariate analysis in the NSQIP database, cervical spine abscess was the only factor that reached significance for 30-day reoperation (OR=1.71, 95% CI=1.11-2.63, p=.02, Area under the curve (AUC)=0.61). On multivariate analysis in the institutional cohort, independent prognostic factors for 30-day reoperation were: preoperative urinary incontinence, ventral location of abscess relative to thecal sac, cervical abscess, preoperative wound infection, and leukocytosis (AUC=0.65). Ninety-day reoperation rate also found hypoalbuminemia as a significant predictor (AUC=0.66).

CONCLUSION

Six novel independent prognostic factors were identified for 90-day reoperation after surgery for a spinal epidural abscess. The multivariable analysis fairly predicts reoperation, indicating that there may be additional factors that need to be uncovered in future studies. The risk factors delineated in this study through the use of two large cohorts of spinal epidural abscess patients can be used to improve preoperative risk stratification and patient management.

Percutaneous endoscopic drainage for acute long segment epidural abscess following endoscopic lumbar discectomy: A case report

Introduction

Acute epidural abscess after percutaneous endoscopic lumbar discectomy is a rare but grievous complication. When faced with a long-segment epidural abscess, open surgery has traditionally been performed which can lead to huge surgical trauma and unpredictable complications. For this reason, surgeons around the world are constantly looking for more minimally invasive and effective surgical methods.

Patient Concerns

Our patient was a 32-year-old woman who had been receiving percutaneous endoscopic interlaminar discectomy for L5/S1 lumbar disc herniation one week ago. She returned to our institution with a fever and lower back pain.

Diagnoses

Magnetic resonance imaging revealed a long segment epidural abscess accompanied by a paravertebral abscess, and staphylococcus aureus was detected in a bacterial culture of pyogenic fluids extracted from the paravertebral abscess.

Treatments

We performed percutaneous endoscopic drainage (PED) for the epidural abscess. Long-term sensitive antibiotic treatment after surgery.

Outcomes

Immediate pain relief was achieved and the inflammatory reaction subsided after 4 weeks of antibiotic therapy. Re-examination of the lumbar spine MRI after 1 month showed that the epidural abscess disappeared completely.

Conclusion

Percutaneous endoscopy allowed us to approach the epidural abscess directly, enabling the immediate drainage of the abscess with minimal trauma to the patient. The good results obtained show that percutaneous endoscopic drainage is a reliable way to treat a long-segment epidural abscess.

Risk factors for surgical intervention in patients with primary spinal infection on initial presentation

OBJECTIVE

Treatment of primary spinal infection includes medical management with or without surgical intervention. The objective of this study was to identify risk factors for the eventual need for surgery in patients with primary spinal infection on initial presentation.

METHODS

From January 2010 to July 2019, 275 patients presented with primary spinal infection. Demographic, infectious, imaging, laboratory, treatment, and outcome data were retrospectively reviewed and collected. Thirty-three patients were excluded due to insufficient follow-up (≤ 90 days) or death prior to surgery.

RESULTS

The mean age of the 242 patients was 58.8 ± 13.6 years. The majority of the patients were male (n = 130, 53.7%), White (n = 150, 62.0%), and never smokers (n = 132, 54.5%). Fifty-four patients (22.3%) were intravenous drug users. One hundred fifty-four patients (63.6%) ultimately required surgery while 88 (36.4%) never needed surgery during the duration of follow-up. There was no significant difference in age, gender, race, BMI, or comorbidities between the surgery and no-surgery groups. On univariate analysis, the presence of an epidural abscess (55.7% in the no-surgery group vs 82.5% in the surgery group, p < 0.0001), the median spinal levels involved (2 [interquartile range (IQR) 2-3] in the no-surgery group vs 3 [IQR 2-5] in the surgery group, p < 0.0001), and active bacteremia (20.5% in the no-surgery vs 35.1% in the surgery group, p = 0.02) were significantly different. The cultured organism and initial laboratory values (erythrocyte sedimentation rate, C-reactive protein, white blood cell count, creatinine, and albumin) were not significantly different between the groups. On multivariable analysis, the final model included epidural abscess, cervical or thoracic spine involvement, and number of involved levels. After adjusting for other variables, epidural abscess (odds ratio [OR] 3.04, 95% confidence interval [CI] 1.64-5.63), cervical or thoracic spine involvement (OR 2.03, 95% CI 1.15-3.61), and increasing number of involved levels (OR 1.16, 95% CI 1.01-1.35) were associated with greater odds of surgery. Fifty-two surgical patients (33.8%) underwent decompression alone while 102 (66.2%) underwent decompression with fusion. Of those who underwent decompression alone, 2 (3.8%) of 52 required subsequent fusion due to kyphosis. No patient required hardware removal due to persistent infection.

CONCLUSIONS

At time of initial presentation of primary spinal infection, the presence of epidural abscess, cervical or thoracic spine involvement, as well as an increasing number of involved spinal levels were potential risk factors for the eventual need for surgery in this study. Additional studies are needed to assess for risk factors for surgery and antibiotic treatment failure.

The Diagnostic Performance of Multi-Detector Computed Tomography (MDCT) in Depiction of Acute Spondylodiscitis in an Emergency Department

Background: The diagnosis of acute spondylodiscitis can be very difficult because clinical onset symptoms are highly variable. The reference examination is MRI, but very often the first diagnostic investigation performed is CT, given its high availability in the acute setting. CT allows rapid evaluation of other alternative diagnoses (e.g., fractures), but scarce literature is available to evaluate the accuracy of CT, and in particular of multi-detector computed tomography (MDCT), in the diagnosis of suspected spondylodiscitis. The aim of our study was to establish MDCT accuracy and how this diagnostic method could help doctors in the depiction of acute spondylodiscitis in an emergency situation by comparing the diagnostic performance of MDCT with MRI, which is the gold standard. Methods: We searched our radiological archive for all MRI examinations of patients who had been studied for a suspicion of acute spondylodiscitis in the period between January 2017 and January 2021 (n = 162). We included only patients who had undergone MDCT examination prior to MRI examination (n = 25). The overall diagnostic value of MDCT was estimated, using MRI as the gold standard. In particular, the aim of our study was to clarify the effectiveness of CT in radiological cases that require immediate intervention (stage of complications). Therefore, the radiologist, faced with a negative CT finding, can suggest an elective (not urgent) MRI with relative serenity and without therapeutic delays. Results: MDCT allowed identification of the presence of acute spondylodiscitis in 13 of 25 patients. Specificity and positive predictive value were 100% for MDCT, while sensitivity and negative predictive value were 68% and 50%, respectively, achieving an overall accuracy of 76%. In addition, MDCT allowed the identification of paravertebral abscesses (92%), fairly pathognomonic lesions of spondylodiscitis pathology. Conclusions: The MDCT allows identification of the presence of acute spondylodiscitis in the Emergency Department (ED) with a satisfactory accuracy. In the case of a positive CT examination, this allows therapy to be started immediately and reduces complications. However, we suggest performing an elective MRI examination in negative cases in which pathological findings are hard to diagnose with CT alone.

Association between interhospital transfer and increased in-hospital mortality in patients with spinal epidural abscesses

BACKGROUND CONTEXT

Spinal epidural abscess (SEA) is an uncommon yet serious infection, associated with significant morbidity and mortality. Patients diagnosed with SEA often require surgical interventions or critical care services that are not available at community hospitals and are therefore transferred to tertiary care centers. Little is known about the effects of interhospital transfer on acute outcomes for patients with SEA.

PURPOSE

To study the effects of interhospital transfer on acute outcomes for patients with SEA.

STUDY DESIGN

Cross sectional analysis using the 2009 to 2017 National Inpatient Sample (NIS).

PATIENT SAMPLE

Using the 2009 to 2017 NIS, we identified cases of SEA using ICD, Ninth, or Tenth Revision diagnosis codes 324.1 & G06.1.

OUTCOME MEASURES

Our primary endpoint was in hospital mortality.

METHODS

The association between interhospital transfer and inpatient mortality was assessed using multivariable logistic regression to adjust for potential covariates. Patient and hospital factors associated with interhospital transfer were assessed in a secondary analysis.

RESULTS

A total of 21.5% of patient with SEA were treated after transfer from another hospital. After adjusting for covariates, those who presented after transfer had higher odds of death during hospitalization (OR: 1.51, 95% CI 1.27-1.78, p<.001). Transferred patients were significantly more likely to live in rural communities (11.4 % vs. 5.3 % for nontransferred patients).

CONCLUSIONS

Interhospital transfer, which occurred more frequently in patients from rural hospitals, was associated with death even after controlling for disease severity. Addressing healthcare delivery disparities across the US, including across the rural-urban spectrum, will require better understanding of the observed increased mortality of interhospital transfer as a preventable source of in-hospital mortality for SEA.

Methicillin-Resistant Staphylococcus aureus Spinal Epidural Abscess: Local and Systemic Case Management

Spinal epidural abscess (SEA) is a rare condition with complex pathophysiology and highly variable clinical presentation. While it is known to cause focal peripheral nerve symptoms such as muscle weakness, paresthesia, or pain, these are typically accompanied by complaints of back or spine pain and systemic symptoms indicative of infection. In our case, a 53-year-old male initially presented with unilateral pain and swelling in his right hand, with no fever at presentation and no complaints of back pain. Blood culture confirmed methicillin-resistant Staphylococcus aureus (MRSA)for which he was given vancomycin. The patient later endorsed back pain and diagnostic imaging revealed a spinal epidural abscess spanning the T5-T9 vertebrae. The abscess was drained, and vancomycin was placed in the subfascial and epifascial compartments. The hand was debrided in the same operation and showed no gross purulence. Two days after the procedure, intraoperative cultures remained negative, and the patient was subsequently managed with daptomycin.

Baseline parameters and the prediction of treatment failure in patients with intravenous drug use-associated spinal epidural abscesses

OBJECTIVE

Despite the increasing incidence of spinal epidural abscess (SEA), the baseline parameters potentially predictive of treatment failure remain poorly characterized. In this study, the authors identify the relevant baseline parameters that predict multimodal treatment failure in patients with either intravenous drug use (IVDU)-associated SEA or non-IVDU-associated SEA.

METHODS

The authors reviewed the electronic medical records of a large institutional series of consecutive patients with diagnosed SEA between January 2011 and December 2017 to characterize epidemiological trends as well as the complement of baseline measures that are predictive of failure after multimodal treatment in patients with and without concomitant IVDU. The independent impact of clinical and imaging factors in detecting treatment failure was assessed by performing stepwise binary logistic regression analysis.

RESULTS

A total of 324 consecutive patients with diagnosed SEA were identified. Overall, 226 patients (69.8%) had SEA related to other causes and 98 (30.2%) had a history of recent IVDU. While non-IVDU SEA admission rates remained constant, year-over-year admissions of patients with IVDU SEA nearly tripled. At baseline, patients with IVDU SEA were distinct in many respects including younger age, greater unemployment and disability, less frequent diabetes mellitus (DM), and more frequent methicillin-resistant Staphylococcus aureus infection. However, differences in length of stay, loss to follow-up, and treatment failure did not reach statistical significance between the groups. The authors constructed independent multivariate logistic regression models for treatment failure based on identified parameters in the two cohorts. For the non-IVDU cohort, the authors identified four variables as independent factors: DM, hepatitis B/C, osteomyelitis, and compression deformity severity. In contrast, for patients with IVDU, the authors identified three variables: albumin, endocarditis, and endplate destruction. Receiver operating characteristic and area under the curve (AUC) analyses were undertaken for the multivariate models predicting the likelihood of treatment failure in the two cohorts (AUC = 0.88 and 0.89, respectively), demonstrating that the derived models could adequately predict the risk of multimodal treatment failure. Treatment failure risk factor point scales were derived for the identified variables separately for both cohorts.

CONCLUSIONS

Patients with IVDU SEA represent a unique population with a distinct set of baseline parameters that predict treatment failure. Identification of relevant prognosticating factors will allow for the design of tailored treatment and follow-up regimens.

Neurosurgical Management and Outcome Parameters in 237 Patients with Spondylodiscitis

Surgical treatment of spondylodiscitis allows for rapid mobilization and shortens hospital stays, which makes surgical treatment the first-line therapy. We aim to describe our experiences with operative treatment on spondylodiscitis and to determine the parameters that are important in the prediction of outcomes. A retrospective review identified 237 patients who were operatively treated for spondylodiscitis in our institution between January 2010 and December 2018. Clinical data were collected through review of electronic records and relevant imaging. In all cases, contrast-enhancing MRI from the infected region of the spine was obtained. Leukocyte count and C-reactive protein concentrations (CRP) were determined in all the patients. We included 237 patients in the study, 87 female (36.7%) and 150 male (63.3%), with a mean age of 71.4 years. Mean follow-up was 31.6 months. Forty-five patients had spondylodiscitis of the cervical, 73 of the thoracic, and 119 of the lumbosacral spine. All the patients with spondylodiscitis of the cervical spine received instrumentation. In thoracic and lumbar spine decompression, surgery without instrumentation was performed in 26 patients as immediate surgery and in a further 28 patients in the early stages following admission, while 138 patients received instrumentation. Eighty-nine patients (37.6%) had concomitant infections. Infection healing occurred in 89% of patients. Favorable outcomes were noted in patients without concomitant infections, with a normalized CRP value and in patients who received antibiotic therapy for more than six weeks (p < 0.05). Unfavorable outcomes were noted in patients with high CRP, postoperative spondylodiscitis, and recurrent spondylodiscitis (p < 0.05). Application of antibiotic therapy for more than six weeks and normalized CRP showed a correlation with favorable outcomes, whereas concomitant infections showed a correlation with unfavorable outcomes. A detailed screening for concomitant infectious diseases is recommended.

Spinal Epidural Abscess: Diagnosis, Management, and Outcomes

An infection of the spinal epidural space, spinal epidural abscess (SEA) is a potentially devastating entity that is rising in incidence. Its insidious presentation, variable progression, and potential for precipitous neurologic decline make diagnosis and management of SEA challenging. Prompt diagnosis is key because treatment delay can lead to paralysis or death. Owing to the nonspecific symptoms and signs of SEA, misdiagnosis is alarmingly common. Risk factor assessment to determine the need for definitive MRI reduces diagnostic delays compared with relying on clinical or laboratory findings alone. Although decompression has long been considered the benchmark for SEA, considerable risk associated with spinal surgery is noted in an older cohort with multiple comorbidities. Nonoperative management may represent an alternative in select cases. Failure of nonoperative management is a feared outcome associated with motor deterioration and poor clinical outcomes. Recent studies have identified independent predictors of failure and residual neurologic dysfunction, recurrence, and mortality. Importantly, these studies provide tools that generate probabilities of these outcomes. Future directions of investigation should include external validation of existing algorithms through multi-institutional collaboration, prospective trials, and incorporation of powerful predictive statistics such as machine learning methods.

Risk factors for residual neurologic deficits after surgical treatment for epidural abscess in the thoracic or lumbar spine

BACKGROUND CONTEXT

Spinal epidural abscess (SEA) can cause neurologic deficits and needs urgent surgical intervention. Many clinical factors had been proposed to predict surgical outcomes in patients with SEA, but the predictive radiographic risk factors for residual neurologic deficits were not addressed sufficiently.

PURPOSE

To analyze the clinical and radiographic risk factors for residual neurologic deficit in patients with SEA after surgical intervention of the thoracic or lumbar spine.

STUDY DESIGN/SETTING

A retrospective consecutive case series.

PATIENT SAMPLE

From January 2005 through December 2014, 53 patients with primary SEA, confirmed by culture or histopathology, in the thoracic or lumbar spine who underwent posterior-only approach surgery at our hospital.

OUTCOME MEASURES

Neurologic status was assessed using the Frankel grading system preoperatively, postoperatively, and at final follow-up.

METHODS

The patients were allocated into two groups based on the presence of postoperative residual neurologic deficits. Patients' demographic, clinical, and factors based on magnetic resonance imaging (MRI) were analyzed for their influence on residual neurologic deficits. Clinical factors included age, sex, diabetes, comorbidities, pathogens, affected spinal levels, the interval between onset of symptoms to surgery, preoperative neurologic status, presence of cauda equina syndrome, and surgical procedures. MRI factors included the distribution of abscesses within the spinal canal, presence of ring enhancement, presence of paravertebral abscess or psoas abscess, canal compromise anteroposterior (AP) ratio and cross-sectional area ratio, abscess length, and abscess thickness.

RESULTS

Thirty-five of the 53 patients (66%) had preoperative neurologic deficits, and 21 of 53 patients (40%) had postoperative residual neurologic deficits. Patients' neurologic status improved significantly after the surgery (p<.001). Risk factors including age, diabetes, cauda equina syndrome, presence of anterior with posterior (A+P) dural abscess, canal compromise AP ratio, cross-sectional area ratio, abscess length, and abscess thickness were significantly correlated with postoperative residual neurologic deficits. In multivariate logistic regression analysis, age ≥70 years, preoperative cauda equina syndrome, abscess length ≥5.5 cm and abscess thickness ≥0.8 cm were the four most significant factors related to residual neurologic deficits.

CONCLUSIONS

In patients with SEA of the thoracic and lumbar spine, age ≥70 years, preoperative cauda equina syndrome, abscess length ≥5.5 cm and abscess thickness ≥0.8 cm were the most significant preoperative risk factors for residual neurologic deficits after surgery.

[Spondylodiscitis]

Spondylodiscitis is an infection of the spine that first affects the vertebral endplates ("spondylitis") and then spreads to the adjacent intervertebral disc ("spondylodiscitis"). As it is a potentially life-threatening systemic disease rapid, often surgical treatment is required. Due to the multimorbidity of the patients and the complexity of the therapy, a multidisciplinary approach is essential. The vast majority of the cases heals under conservative therapy. An absolute indication for surgical therapy is given for acute septic courses or if there are new relevant neurological deficits. In addition, urgent surgical treatment is required for epidural abscesses that can be diagnosed by means of magnetic resonance imaging. In developed countries, over 90% of all spondylodiscitis cases come to a complete recovery.

Early versus Delayed Surgery for Spinal Epidural Abscess : Clinical Outcome and Health-Related Quality of Life

Objective

Spinal epidural abscess (SEA) is a severe and life-threatening disease. Although commonly performed, the effect of timing in surgical treatment on patient outcome is still unclear. With this study, we aim to provide evidence for early surgical treatment in patients with SEA.

Methods

Patients treated for SEA in the authors’ department between 2007 and 2016 were included for analysis and retrospectively analyzed for basic clinical parameters and outcome. Pre- and postoperative neurological status were assessed using the American Spinal Injury Association Impairment Scale (AIS). The self-reported quality of life (QOL) based on the Short-Form Health Survey 36 (SF-36) was assessed prospectively. Surgery was defined as “early”, when performed within 12 hours after admission and “late” when performed thereafter. Conservative therapy was preferred and recommend in patients without neurological deficits and in patients denying surgical intervention.

Results

One hundred and twenty-three patients were included in this study. Forty-nine patients (39.8%) underwent early, 47 patients (38.2%) delayed surgery and 27 (21.9%) conservative therapy. No significant differences were observed regarding mean age, sex, diabetes, prior history of spinal infection, and bony destruction. Patients undergoing early surgery revealed a significant better clinical outcome before discharge than patients undergoing late surgery (p=0.001) and conservative therapy. QOL based on SF-36 were significantly better in the early surgery cohort in two of four physical items (physical functioning and bodily pain) and in one of four psychological items (role limitation) after a mean follow-up period of 58 months. Readmission to the hospital and failure of conservative therapy were observed more often in patients undergoing conservative therapy.

Conclusion

Our data on both clinical outcome and QOL provide evidence for early surgery within 12 hours after admission in patients with SEA.

Spinal Epidural Abscess: A Review of Presentation, Management, and Medicolegal Implications

Spinal epidural abscess (SEA) is a rare condition associated with significant morbidity and mortality. Despite advances in diagnostic medicine, early recognition of SEAs remains elusive. The vague presentation of the disease, coupled with its numerous risk factors, the diagnostic requirement for obtaining advanced imaging, and the necessity of specialized care constitute extraordinary challenges to both diagnosis and treatment of SEA. Once diagnosed, SEAs require urgent or emergent medical and/or surgical management. As SEAs are a relatively rare pathology, high-quality data are limited and there is no consensus on their optimal management. This paper focuses on presenting the treatment modalities that have been successful in the management of SEAs and providing a critical assessment of how specific SEA characteristics may render one infection more amenable to primary surgical or medical interventions. This paper reviews the relevant history, epidemiology, clinical presentation, radiology, microbiology, and treatment of SEAs and concludes by addressing the medicolegal implications of delayed treatment of the disease.

The increasing frequency of intravenous drug abuse-associated spinal epidural abscesses: a case series

OBJECTIVEFew studies have been published specifically examining intravenous drug abuse (IVDA)-associated spinal epidural abscesses (SEAs), an unfortunate sequela of the opioid crisis in the United States. Here, the authors examined a series of patients with IVDA-associated SEAs in order to shed light on this challenging disease entity.METHODSThis study is a retrospective chart review of patients presenting with IVDA-associated SEAs at the authors' institution from 2013 to 2018, spanning the statewide implementation of opioid-prescribing restrictions.RESULTSA total of 45 patients presented with IVDA-associated SEAs; 46.5% presented with a neurological deficit. Thirty-one patients underwent surgery for neurological deficit, failure of medical therapy, or both. Nineteen surgical patients underwent a fusion procedure along with decompression. The complication rate was 41.9%, and the mortality rate was 6.7%. The average length of stay was 27.6 days. Patients who underwent surgery within 24 hours of onset of neurological symptoms trended toward more improvement in their American Spinal Cord Association Impairment Scale grade than those who did not (0.5 vs -0.2, p = 0.068). Methicillin-resistant Staphylococcus aureus was isolated as the causative pathogen in 57.8% of patients. Twenty-three patients (51.5%) kept their scheduled clinic follow-up appointments. Of the fusion patients with adequate follow-up, 5 showed bony arthrodesis and 3 had pseudarthrosis. The rate of IVDA-associated SEAs increased after opioid-prescribing restrictions were put in place, from 0.54 cases per month to 1.15 cases per month (p = 0.017).CONCLUSIONSPatients with IVDA-associated SEAs are challenging to treat, with high complication rates and poor follow-up. This disease is increasing in frequency, and opioid-prescribing restrictions did not slow that rise. Community outreach to promote prevention, early medical attention, and medication compliance would benefit this largely publicly funded patient population.

Primary Spinal Epidural Abscesses Not Associated With Pyogenic Infectious Spondylodiscitis: A New Pathogenetic Hypothesis

Introduction: Spinal epidural abscess (SEA) incidence is rising. However, most series do not differentiate between SEAs associated with pyogenic infectious spondylodiscitis (PS) and SEAs limited to the epidural space.

Methods: We retrospectively reviewed the records and radiological images of all patients admitted to our institutions with a diagnosis of SEA not associated with PS between January 2013 and December 2018.

Results: We found three males and four females; five of the seven were intravenous drug users. All patients presented with pain: in six, it was associated with acute motor and sensory deficits, while one had only pain and paresthesias. Staphylococcus aureus was cultured from abscesses and/or from multiple blood cultures in four patients. Abscesses were localized to the cervical spine in one patient, thoracic in three, lumbar in one, and in two, the SEAs involved multiple segments. All patients but one underwent urgent open surgery. This patient had a multisegmental abscess and was successfully treated by percutaneous aspiration when pain became intractable. After abscess evacuation, the neurological deficits improved in all patients except one. The patients that were treated without spine instrumentation did not develop delayed kyphosis or instability at follow-up.

Conclusion: Patients with SEAs not associated with PS are likely to present with pain and motor deficits, appear to benefit from urgent abscess evacuation, and seem to be less dependent on spine instrumentation to avoid delayed spinal deformities compared to SEA associated with PS. Finally, the lack of initial involvement of bone and intervertebral disks may suggest that at least some of the SEAs without PS originate from infection of epidural lymphatic vessels that are not present inside those structures.

Readmission after spinal epidural abscess management in urban populations: a bi-institutional study

OBJECTIVE

The incidence of spinal epidural abscess (SEA) is rising, yet there are few reports discussing readmission rates or predisposing factors for readmission after treatment. The aims of the present study were to determine the rate of 90-day readmission following medical or surgical treatment of SEA in an urban population, identify patients at increased risk for readmission, and delineate the principal causes of readmission.

METHODS

Neurosurgery records from two large urban institutions were reviewed to identify patients who were treated for SEA. Patients who died during admission or were discharged to hospice were excluded. Univariate analysis was performed using chi-square and Student t-tests to identify potential predictors of readmission. A multivariate logistic regression model, controlled for age, body mass index, sex, and institution, was used to determine significant predictors of readmission.

RESULTS

Of 103 patients with identified SEA, 97 met the inclusion criteria. Their mean age was 57.1 years, and 56 patients (57.7%) were male. The all-cause 90-day readmission rate was 37.1%. Infection (sepsis, osteomyelitis, persistent abscess, bacteremia) was the most common cause of readmission, accounting for 36.1% of all readmissions. Neither pretreatment neurological deficit (p = 0.16) nor use of surgical versus medical management (p = 0.33) was significantly associated with readmission. Multivariate analysis identified immunocompromised status (p = 0.036; OR 3.5, 95% CI 1.1-11.5) and hepatic disease (chronic hepatitis or alcohol abuse) (p = 0.033; OR 2.9, 95% CI 1.1-7.7) as positive predictors of 90-day readmission.

CONCLUSIONS

The most common indication for readmission was persistent infection. Readmission was unrelated to baseline neurological status or management strategy. However, both hepatic disease and baseline immunosuppression significantly increased the odds of 90-day readmission after SEA treatment. Patients with these conditions may require closer follow-up upon discharge to reduce overall morbidity and hospital costs associated with SEA.

Anterior cervical spine surgical site infection and pharyngoesophageal perforation. Ten-year incidence in 1475 patients

BACKGROUND

Surgical site infection is reputed to be infrequent in anterior cervical spine surgery. Data on pathophysiological mechanism and risk factors are sparse. The relationship between local site infection and pharyngoesophageal perforation is unclear. The present study aimed: (1) to estimate the incidence of surgical site infection in anterior cervical spine surgery, (2) estimate the incidence of associated pharyngoesophageal perforation, and (3) suggest a decision-tree for early management of this two-fold issue.

HYPOTHESIS

Although with very low incidence, anterior cervical spine surgical site infection and pharyngoesophageal perforation are frequently associated.

MATERIAL AND METHODS

A 2-center retrospective study included all anterior cervical spine surgeries between January 1, 2007 and December 31, 2016. Data were provided by the two medical information departments. Patients undergoing anterior revision surgery on the cervical spine were included. Files were analyzed to determine whether the revision surgery was secondary to surgical site infection.

RESULTS

In total, 1475 patients with anterior cervical spine surgery were identified: 1180 in center A (80%) and 295 in center B (20%). The rate of revision surgery for surgical site infection was 0.34% (5/1475). There were 3 cases of pharyngoesophageal perforation (0.2%).

DISCUSSION

The incidence of revision surgery for anterior cervical spine surgical site infection was comparable to rates in the international literature (0.07-1.6%). An association between surgical site infection and pharyngoesophageal perforation was frequent, but not statistically significant. This complication is extremely serious, requiring urgent multidisciplinary management.

LEVEL OF EVIDENCE

IV, retrospective study.

Assessment of postoperative outcomes in spinal epidural abscess following surgical decompression

BACKGROUND CONTEXT

A spinal epidural abscess (SEA) is a serious condition that may be managed with antibiotics alone or with decompressive surgery combined with antibiotics.

PURPOSE

The objectives of this study were to assess the clinical outcomes of SEA after surgical management and to identify the patient-level factors that are associated with outcomes following surgical decompression and removal of SEA.

STUDY DESIGN/SETTING

Retrospective chart review analysis.

PATIENT SAMPLE

An analysis of 154 consecutive patients who initially presented to a tertiary-care, academic medical center with SEA, and were subsequently treated with surgery between 2010 and 2015 was performed.

OUTCOME MEASURES

Postoperative predischarge American Spinal Injury Association Impairment Scale (AIS) scores, 6-month follow-up encounter AIS scores, need for revision surgery, and mortality during SEA surgery were the primary outcomes.Physiological Measures: AIS scores.

METHOD

Fisher's exact and Wilcoxon rank-sum tests were used to assess the associations between patient-level factors and surgical outcomes. Moreover, an interactive, predictive model for postoperative predischarge AIS score was developed using a proportional odds regression model. There was no funding secured for this study and there is no conflict of interest-associated biases.

RESULTS

One hundred fifty-four patients (mean age of 58 years) were treated using surgical decompression in addition to antibiotics. The majority of patients were Caucasian (81%) and male (61%). No intraoperative mortality was reported. A second SEA surgery was performed in 8% of patients. A comparison of the preoperative and postoperative predischarge AIS scores showed that 49% of patients maintained a score of E or improved, while 45% remained at their preoperative status and 6% worsened. Among a subset of patients (n=36; 23%) for whom a 6-month follow-up encounter occurred, 75% maintained an AIS score of E or improved, 19% remained at their preoperative status, and 6% worsened. Both the presence and longer duration of preoperative paresis was associated with an increased risk of remaining at the same AIS score or worsening at the predischarge encounter (both p< .001). A predictive model for predischarge AIS scores was developed based on several patient characteristics.

CONCLUSIONS

Surgical decompression can contribute to improving or maintaining AIS scores in a high percentage of SEA patients. The presence and duration of preoperative paresis are prognostic for poorer outcomes and suggest that rapid surgical intervention before paresis develops may lead to improved postoperative outcomes. Our modeling tool enables an estimation of probabilities of patients' predischarge condition.

Neurological Outcomes After Surgical or Conservative Management of Spontaneous Spinal Epidural Abscesses: A Systematic Review and Meta-Analysis of Data From 1980 Through 2016

STUDY DESIGN

This is a meta-analysis.

OBJECTIVE

Perform a systematic review and quantitative meta-analysis of neurological outcomes from all available spinal epidural abscess (SEA) literature published between 1980 and 2016.

SUMMARY OF BACKGROUND DATA

Current literature on SEAs lacks large-scale data characterizing prognostic factors and surgical indications.

MATERIALS AND METHODS

PubMed was queried for studies reporting neurological outcomes from patients undergoing conservative or surgical management for spontaneous SEA. Inclusion criteria included outcomes data measured ≥6 months after presentation, ≥10 human subjects, and diagnosis by magnetic resonance imaging or Computed tomography-myelogram. Where available, demographic data, abscess location, comorbidities, pretreatment neurological deficits, treatment methods, bacterial speciation, and complications were extracted from each study. Potential outcome predictors represented by continuous variables were compared using student t test and categorical variables were compared using the Pearson χ test. Variables identified as potentially associated with outcome (P≤0.05) were subjected to meta-analysis using Cochran-Mantel-Haenszel testing to calculate odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

In total, 808 patients were analyzed from 20 studies that met inclusion criteria. 456 (56.3%) patients were treated with surgery and antibiotics, and 353 (43.7%) patients were managed with antibiotics alone. Neither surgical intervention (OR=1.01, 95% CI=0.40-2.59), lumbosacral location (OR=1.51, 95% CI=0.23-9.79), nor neurological deficit on presentation (OR=0.88, 95% CI=0.40-1.92) were significantly associated with good (stable or improved) or bad (worsened) neurological outcome, whereas delayed surgery was significantly associated with bad outcome (OR=0.01, 95% CI=0.02-0.62) and cervicothoracic location approached significance for predicting bad outcome (OR=0.41, 95% CI=0.15-1.09).

CONCLUSIONS

Current literature does not definitively support or oppose surgical intervention in all SEA cases. Therefore, until better evidence exists, the decision to operate must be made on an individual case-by-case basis with the goals of preventing neurological decline, obtaining source control after failed conservative treatment, or restoring spinal stability.

Vertebral Osteomyelitis: A Comparison of Associated Outcomes in Early Versus Delayed Surgical Treatment

Background

The recommended timing of surgical intervention for vertebral osteomyelitis (VO) is controversial; however, most studies are not sufficiently powered. Our goal was to investigate the associated effects of delaying surgery in VO patients on in-hospital complications, neurologic deficits, and mortality.

Methods

Retrospective review of the National Inpatient Sample. Patients who underwent surgery for VO from 1998 to 2013 were identified using codes from the International Classification of Disease, Ninth Revision, Clinical Modification. Patients were stratified into groups based on incremental delay of surgery: 0-day delay (same-day surgery), 1-day delay, 2-day delay, 3- to 6-day delay, 7- to 14-day delay, and 14- to 30-day delay. Univariate analysis compared demographics and outcomes between groups. Multivariate logistic regression models calculated independent predictors of any complication, mortality, and neurologic deficits. A 0-day delay was the reference group.

Results

A total of 34 465 patients were identified. Delayed groups were older (same day: 53.5 vs. 7-14-day delay: 61.1) and had a higher Deyo-Charlson score (same day: 0.4901 vs. 14-30-day delay: 1.66), length of stay (same day: 4.2 vs. 14-30-day delay: 34.04 days), and total charges (same day: $63,390.78 vs. 14-30-day delay: $245,752.4), all P < .001. Delayed groups had higher surgical combined-approach rates (same day: 9.1% vs. 14-30-day delay: 31.5%) and lower anterior-approach rates (same day: 42.4% vs. 14-30-day delay: 24.2%). Delayed groups had increased mortality and complication rates. Regressions showed delayed groups as the strongest independent indicators of any complication (14-30-day delay: odds ratio [OR] 3.384), mortality (14-30-day delay: OR 10.658), and neurologic deficits (14-30-day delay: OR 3.464), all P < .001.

Conclusion

VO patients who operate within 24 hours of admission are more likely to have desirable outcomes. Patients with delayed surgery had a significantly increased risk of developing any complication, mortality, and discharging with neurologic deficits.

Level of Evidence

III.

Clinical Relevance

Medically fit patients may benefit from earlier surgical management in order to reduce risk of postoperative complications, improve outcomes, and reduce overall hospital costs.

Etiology and Surgical Management of Cervical Spinal Epidural Abscess (SEA):: A Systematic Review

STUDY DESIGN

Systematic analysis and review.

OBJECTIVE

Evaluation of the presentation, etiology, management strategies (including both surgical and nonsurgical options), and neurological functional outcomes in patients with cervical spinal epidural abscess (SEA).

METHODS

The PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) criteria were used to create a framework based on which articles pertaining to cervical SEA were chosen for review following a search of the Ovid and PubMed databases using the search terms "epidural abscess" and "cervical." Included studies needed to have at least 4 patients aged 18 years or older, and to have been published within the past 20 years.

RESULTS

Database searches yielded 521 potential articles in PubMed and 974 potential articles in Ovid. After review, 11 studies were ultimately identified for inclusion in this systematic review. Surgery appears to be a well-tolerated management strategy with limited complications for patients with cervical SEA. However, the quantity of data comparing medical and surgical treatment of cervical SEA is limited and the bulk of the data is derived from low quality studies.

CONCLUSION

Data reporting was heterogeneous among studies making it difficult to draw discrete conclusions. Early surgical intervention may be appropriate in selected patients with cervical epidural abscess, but it is not clear what distinguishes these patients from those who are successfully managed nonoperatively.

Evaluation and Management of Pyogenic and Tubercular Spine Infections

PURPOSE OF REVIEW

To review the most current diagnostic tools and treatment options for pyogenic and tubercular spine infection.

RECENT FINDINGS

Recent studies have focused on risk factors for failed nonoperative management in order to improve patient selection. Also, spine instrumentation and different grafting options have been safely utilized in the setting of an active infection without increasing the incidence of reoccurrence. However, the optimal surgical technique has yet to be established and instead should be patient specific. Spine infections include a broad spectrum of disorders including discitis, vertebral osteomyelitis, and spinal epidural abscess. It is paramount to recognized spine infections early due to the potential catastrophic consequences of paralysis and sepsis. The management of spine infections continues to evolve as newer diagnostic tools and surgical techniques become available. Magnetic resonance imaging with contrast is the imaging study of choice and computed tomography-guided biopsies are crucial for guiding antibiotic selection. Antibiotics are the mainstay of treatment and surgery is indicated in patients with neurological deficits, sepsis, spinal instability, and those who have failed nonoperative treatment.

Recent Developments in the Treatment of Spinal Epidural Abscesses

Spinal epidural abscess (SEA) is a serious condition that can be challenging to diagnose due to nonspecific symptomology and delayed presentation. Despite this, it requires prompt recognition and management in order to prevent permanent neurologic sequelae. Several recent studies have improved our understanding of SEA. Herein, we summarize the recent literature from the past 10 years relevant to SEA diagnosis, management and outcome. While surgical care remains the mainstay of treatment, a select subset of SEA patients may be managed without operative intervention. Multidisciplinary management involves internal medicine, infectious disease, critical care, and spine surgeons in order to optimize care.

Minimally invasive spine surgery in lumbar spondylodiscitis: a retrospective single-center analysis of 67 cases

BACKGROUND

Minimally invasive surgical techniques have been developed to minimize tissue damage, reduce narcotic requirements, decrease blood loss, and, therefore, potentially avoid prolonged immobilization. Thus, the purpose of the present retrospective study was to assess the safety and efficacy of a minimally invasive posterior approach with transforaminal lumbar interbody debridement and fusion plus pedicle screw fixation in lumbar spondylodiscitis in comparison to an open surgical approach. Furthermore, treatment decisions based on the patient´s preoperative condition were analyzed.

METHODS

67 patients with lumbar spondylodiscitis treated at our department were included in this retrospective analysis. The patients were categorized into two groups based on the surgical procedure: group (MIS) minimally invasive lumbar spinal fusion (n = 19); group (OPEN) open lumbar spinal fusion (n = 48). Evaluation included radiological parameters on magnetic resonance imaging (MRI), laboratory values, and clinical outcome.

RESULTS

Preoperative MRI showed higher rates of paraspinal abscess (35.5 vs. 5.6%; p = 0.016) and multilocular location in the OPEN group (20 vs. 0%, p = 0.014). Overall pain at discharge was less in the MIS group: NRS 2.4 ± 1 vs. NRS 1.6 ± 1 (p = 0.036). The duration of hospital stay was longer in the OPEN than the MIS group (19.1 ± 12 days vs. 13.7 ± 5 days, p = 0.018).

CONCLUSION

The open technique is effective in all varieties of spondylodiscitis inclusive in epidural abscess formation. MIS can be applied safely and effectively as well in selected cases, even with epidural abscess.

[Spondylodiscitis : Current strategies for diagnosis and treatment]

Spondylodiscitis is a severe infectious disease of the intervertebral discs and of the adjacent parts of the vertebral bodies, culminating in destruction of the mobile segment. It is accompanied by a mortality rate of approximately 15%. Severe courses of the disease can also lead to abscess formation and dispersal of sepsis. Malpositioning of the axis organ and deficits in neurological function up to paraplegia are also possible complications. Timely diagnostics and targeted therapy contribute to minimizing the risk of significant health disorders. This review article gives a summary of important algorithms in the diagnostics and treatment and discusses them against the background of currently available literature. According to the current state of knowledge the surgical treatment of spondylodiscitis provides many advantages and is therefore the method choice, even if a conservative approach can be successful in selected cases. The endpoints of treatment are cleansing of the infection with normalization of laboratory parameters of inflammation and the osseous fusion of the mobile segment.

Cervical Spondylodiscitis: Presentation, Timing, and Surgical Management in 59 Patients

BACKGROUND

Cervical spondylodiscitis is thought to carry a significant risk for rapid neurologic deterioration with a poor response to nonsurgical management.

METHODS

A retrospective surgical case series of the acute surgical management of cervical spondylodiscitis is reviewed to characterize the neurologic presentation and postoperative neurologic course in a relatively uncommon disease.

RESULTS

Fifty-nine patients were identified (mean age, 59 years [range, 18-83 years; SD ± 13.2 years]) from a single-institution neurosurgical database. The most common levels of radiographic cervical involvement were C4-C5, C5-C6, and C6-C7, in descending order. Overall, statistically significant clinical improvement was noted after surgery (P < 0.05). Spinal cord hyperintensity on T2-weighted magnetic resonance imaging was significantly associated with a worse preoperative neurologic grade (P = 0.036), but did not correlate with a relatively worse neurologic outcome by discharge. No significant difference was noted between potential preoperative predictors (organism cultured, presence of epidural abscess, tobacco use, early surgery within 24 hours of clinical presentation) and preoperative American Spinal Injury Association injury scale, with the exception of the duration between symptom onset and surgical intervention. A negative correlation between increased preoperative duration of symptoms and magnitude in motor improvement was observed. Relative to anteroposterior decompression and fusion, anterior treatment alone demonstrated a relatively greater effect in neurologic improvement.

CONCLUSIONS

Cervical spondylodiscitis is a rare disease that typically manifests with preoperative motor deficits. Surgery was associated with a significant improvement in motor score by hospital discharge. Significant predictors of neurologic improvement were not observed. Prolonged symptomatic duration was correlated with a significantly lower likelihood of motor score improvement.

Anterior Cervical Infection: Presentation and Incidence of an Uncommon Postoperative Complication

STUDY DESIGN

Retrospective multi-institutional case series.

OBJECTIVE

The anterior cervical discectomy and fusion (ACDF) affords the surgeon the flexibility to treat a variety of cervical pathologies, with the majority being for degenerative and traumatic indications. Limited data in the literature describe the presentation and true incidence of postoperative surgical site infections.

METHODS

A retrospective multicenter case series study was conducted involving 21 high-volume surgical centers from the AOSpine North America Clinical Research Network, selected for their excellence in spine care and clinical research infrastructure and experience. Medical records for 17 625 patients who received cervical spine surgery (levels from C2 to C7) between January 1, 2005, and December 31, 2011, inclusive, were reviewed to identify the occurrence of 21 predefined treatment complications. Patients who underwent an ACDF were identified in the database and reviewed for the occurrence of postoperative anterior cervical infections.

RESULTS

A total of 8887 patients were identified from a retrospective database analysis of 21 centers providing data for postoperative anterior cervical infections (17/21, 81% response rate). A total of 6 postoperative infections after ACDF were identified for a mean rate of 0.07% (range 0% to 0.39%). The mean age of patients identified was 57.5 (SD = 11.6, 66.7% female). The mean body mass index was 22.02. Of the total infections, half were smokers (n = 3). Two patients presented with myelopathy, and 3 patients presented with radiculopathic-type complaints. The mean length of stay was 4.7 days. All patients were treated aggressively with surgery for management of this complication, with improvement in all patients. There were no mortalities.

CONCLUSION

The incidence of postoperative infection in ACDF is exceedingly low. The management has historically been urgent irrigation and debridement of the surgical site. However, due to the rarity of this occurrence, guidance for management is limited to retrospective series.

Spinal Epidural Abscess: A Review with Special Emphasis on Earlier Diagnosis

Spinal epidural abscess (SEA) is an uncommon but serious condition with significant morbidity and mortality. The prognosis of SEA is highly dependent on the timeliness of its diagnosis before neurological deficits develop. Unfortunately, often due to its nonspecific presentation, such as back pain, the diagnosis of SEA may be delayed in up to 75% of cases. Although many risk factors for SEA can be found in the published literature, their utility is limited by their frequent lack of objective evidence, numerousness, and absence in a significant proportion of cases. In this review, we call for a more discriminate evidence-based use of the term "risk factor" when discussing SEA and explore several approaches to its earlier diagnosis, including a simple algorithm based on its pathophysiology and serum C-reactive protein or erythrocyte sedimentation rate.

What are we waiting for? An argument for early surgery for spinal epidural abscesses

Background:

In the article: Timing and prognosis of surgery for spinal epidural abscess (SEA): A review, Epstein raises one major point; it is imperative that spinal surgeons “take back decision-making” from our medical cohorts and reinstitute early surgery (<24 h) to better treat SEAs.

Methods:

Spine surgeons recognize the clinical triad (e.g., fever [50%], spinal pain [92–100%], and neurological deficits [47%]) for establishing the diagnosis of an SEA. We also appreciate the multiple major risk factors for developing SEA; diabetes (15–30%), elevated white blood cell count (>12.5), high C-reactive protein (>115), positive blood cultures, radiographic cord compression, and significant neurological deficits (e.g., 19–45%).

Results:

Recognizing these risk factors should prompt early open surgery (<24 h from the onset of a neurological deficit). Open surgery better defines the correct/multiple organisms present, and immediately provides adequate/thorough neurological decompression (with fusion if unstable). Although minimally invasive surgery may suffice in select cases, too often it provides insufficient biopsy/culture/irrigation/decompression. Most critically, nonsurgical options result in unacceptably high failure rates (e.g., 41-42.5-75% requiring delayed surgery), while risking permanent paralysis (up to 22%), and death (up to 25%).

Conclusion:

As spine surgeons, we need to “take back decision-making” from our medical cohorts and advocate for early surgery to achieve better outcomes for our patients. Why should anyone accept the >41-42.5 to up to the 75% failure rate that accompanies the nonsurgical treatment of SEA, much less the >25% mortality rate?

Timing and prognosis of surgery for spinal epidural abscess: A review

Background:

The nonsurgical versus surgical management of spinal epidural abscesses (SEAs) remains controversial. Even with the best preoperative screening for multiple risk factors, high nonoperative failure rates are attended by considerable morbidity (e.g., irreversible paralysis) and mortality. Therefore, the focus remains on early surgery.

Methods:

Most papers promote early recognition of the clinical triad (e.g., fever [50%], spinal pain [92–100%], and neurological deficits [47%]) for SEA. They also identify SEA-related risk factors for choosing nonsurgical versus surgical approaches; advanced age (>65 or 80), diabetes (15–30%), cancer, intravenous drug abuse (25%), smoking (23%), elevated white blood cell count (>12.5), high C-reactive protein >115, positive blood cultures, magnetic resonance imaging/computed tomographic documented cord compression, and significant neurological deficits (e.g., 19–45%).

Results:

Surgical options include: decompressions, open versus minimally invasive biopsy/culture/irrigation, or fusions. Up to 75% of SEA involve the thoracolumbar spine, and 50% are located ventrally. Wound cultures are positive in up to 78.8% of cases and are often (60%) correlated with positive blood cultures. The most typical offending organism is methicillin resistant Staphylococcus aureus, followed by methicillin sensitive S. aureus. Unfortunately, the failure rates for nonoperative treatment of SEA remain high (e.g., 41–42.5%), contributing to significant morbidity (22% risk of permanent paralysis), and mortality (3–25%).

Conclusion:

The vast majority of studies advocated early surgery to achieve better outcomes for treating SEA; this avoids high failure rates (41–42.5%) for nonoperative therapy, and limits morbidity/mortality rates.

Retropharyngeal abscess with secondary osteomyelitis and epidural abscess: proposed pathophysiological mechanism of an underrecognized complication of unstable craniocervical injuries: case report

Because of the proximity of the oropharynx (a naturally contaminated region) to the spinal structures of the craniocervical junction, it is possible that small mucosal lacerations in the oropharynx caused by unstable traumatic craniocervical injuries may become contaminated and lead to secondary infection and osteomyelitis. In this report, the authors describe the case of a previously healthy and immunocompetent patient who developed a large retropharyngeal abscess with spinal osteomyelitis after a high-energy craniocervical injury. This unusual report of osteomyelitis with a delayed presentation after a high-energy traumatic injury of the craniocervical junction highlights the possibility of direct injury to a specific area in the oropharyngeal mucosa adjacent to the osteoligamentous structures of the craniocervical junction, an overall underrecognized complication of unstable craniocervical injuries.

Distribution of HIV-1 in the genomes of AIDS patients

The localization of HIV-1 proviruses in compositional DNA fractions from 27 AIDS patients during the chronic phase of the disease with depletion of CD4+ and different levels of viremia showed the following. (1) At low viremia, proviruses are predominantly localized in the GC-richest isochores, which are characterized by an open chromatin structure; this result mimics findings on HIV-1 integration in early infected cells in culture. (2) At higher viremia, an increased distribution of proviruses in GC-poor isochores (which match the GC poorness of HIV-1) was found; this suggests a selection of cells in which the 'isopycnic' localization leads to a higher expression of proviruses and, in turn, to higher viremia. (3) At the highest viremia, integrations in GC-rich isochores are often predominant again, but generally not at the same level as in (1); this may be the consequence of new integrations from the extremely abundant RNA copies.