Surgical treatment for acute spinal cord injury study pilot study #2: evaluation of protocol for decompressive surgery within 8 hours of injury

Management of Acute Traumatic Spinal Cord Injury: A Review of the Literature

Traumatic spinal cord injury (TSCI) is a debilitating disease that poses significant functional and economic burden on both the individual and societal levels. Prognosis is dependent on the extent of the spinal injury and the severity of neurological dysfunction. If not treated rapidly, patients with TSCI can suffer further secondary damage and experience escalating disability and complications. It is important to quickly assess the patient to identify the location and severity of injury to make a decision to pursue a surgical and/or conservative management. However, there are many conditions that factor into the management of TSCI patients, ranging from the initial presentation of the patient to long-term care for optimal recovery. Here, we provide a comprehensive review of the etiologies of spinal cord injury and the complications that may arise, and present an algorithm to aid in the management of TSCI.

Hydrogel-based local drug delivery strategies for spinal cord repair

Spinal cord injury results in significant loss of motor, sensory, and autonomic functions. Although a wide range of therapeutic agents have been shown to attenuate secondary injury or promote regeneration/repair in animal models of spinal cord injury, clinical translation of these strategies has been limited, in part due to difficulty in safely and effectively achieving therapeutic concentrations in the injured spinal cord tissue. Hydrogel-based drug delivery systems offer unique opportunities to locally deliver drugs to the injured spinal cord with sufficient dose and duration, while avoiding deleterious side effects associated with systemic drug administration. Such local drug delivery systems can be readily fabricated from biocompatible and biodegradable materials. In this review, hydrogel-based strategies for local drug delivery to the injured spinal cord are extensively reviewed, and recommendations are made for implementation.

Factors affecting outcome of acute cervical spine injury: A prospective study

Background:

Injury to the spine and spinal cord is one of the common cause of disability and death. Several factors affect the outcome; but which are these factors (alone and in combination), are determining the outcomes are still unknown. The aim of the study was to evaluate the factors influencing the outcome following acute cervical spine injury.

Materials and Methods:

A prospective observational study at single-center with all patients with cervical spinal cord injury (SCI), attending our hospital within a week of injury during a period of October 2011 to July 2013 was included for analysis. Demographic factors such as age, gender, etiology of injury, preoperative American Spinal Injury Association (ASIA) grade, upper (C2-C4) versus lower (C5-C7) cervical level of injury, imageological factors on magnetic resonance imaging (MRI), and timing of intervention were studied. Change in neurological status by one or more ASIA grade from the date of admission to 6 months follow-up was taken as an improvement. Functional grading was assessed using the functional independence measure (FIM) scale at 6 months follow-up.

Results:

A total of 39 patients with an acute cervical spine injury, managed surgically were included in this study. Follow-up was available for 38 patients at 6 months. No improvement was noted in patients with ASIA Grade A. Maximum improvement was noted in ASIA Grade D group (83.3%). The improvement was more significant in lower cervical region injuries. Patient with cord contusion showed no improvement as opposed to those with just edema wherein; the improvement was seen in 62.5% patients. Percentage of improvement in cord edema ≤3 segments (75%) was significantly higher than edema with >3 segments (42.9%). Maximum improvement in FIM score was noted in ASIA Grade C and patients who had edema (especially ≤3 segments) in MRI cervical spine.

Conclusions:

Complete cervical SCI, upper-level cervical cord injury, patients showing MRI contusion, edema >3 segments group have worst improvement in neurological status at 6 months follow-up.

Early versus delayed decompression in acute subaxial cervical spinal cord injury: A prospective outcome study at a Level I trauma center from India

Aims:

This study was done with the aim to compare the clinical outcome and patients’ quality of life between early versus delayed surgically treated patients of acute subaxial cervical spinal cord injury. The current study was based on the hypothesis that early surgical decompression and fixations in acute subaxial cervical spinal cord trauma is safe and is associated with improved outcome as compared to delayed surgical decompression.

Materials and Methods:

A total of 69 patients were recruited and divided into early decompression surgery Group A (operated within 48 h of trauma; n = 23) and late/delayed decompression surgery Group B (operated between 48 h and 7 days of trauma; n = 46). The patients in both groups were followed up, and comparative differences noted in the neurological outcome, quality of life, and bony fusion.

Results:

The early surgery group spent lesser days in the intensive care unit and hospital (Group A 28.6 vs. Group B 35 days) had lesser postoperative complications (Group A 43% vs. Group B 61%) and a reduced mortality (Group A 30% vs. Group B 45%). In Group A, 38% patients had 1 American Spinal Injury Association (ASIA) grade improvement while 31% experienced >2 ASIA grade improvement. In Group B, the neurological improvement was 27% and 32%, respectively (P = 0.7). There was a significant improvement in the postoperative quality of life scores in both groups.

Conclusion:

Early surgery in patients with acute subaxial cervical spine injury should be considered strongly in view of the lesser complications, early discharge, and reduced mortality.

Surgical decompression in acute spinal cord injury: A review of clinical evidence, animal model studies, and potential future directions of investigation

The goal for treatment in acute spinal cord injury (SCI) is to reduce the extent of secondary damage and facilitate neurologic regeneration and functional recovery. Although multiple studies have investigated potential new therapies for the treatment of acute SCI, outcomes and management protocols aimed at ameliorating neurologic injury in patients remain ineffective. More recent clinical and basic science research have shown surgical interventions to be a potentially valuable modality for treatment; however, the role and timing of surgical decompression, in addition to the optimal surgical intervention, remain one of the most controversial topics pertaining to surgical treatment of acute SCI. As an increasing number of potential treatment modalities emerge, animal models are pivotal for investigating its clinical application and translation into human trials. This review critically appraises the available literature for both clinical and basic science studies to highlight the extent of investigation that has occurred, specific therapies considered, and potential areas for future research.

Magnetic resonance imaging in cervical facet dislocation: a third world perspective

Study Design

Retrospective case series.

Purpose

The objective of our study was to determine the change in management brought about by magnetic resonance imaging (MRI) of the cervical spine in alert and awake patients with facet dislocation and spinal cord injury presenting within 4 hours after injury.

Overview of Literature

Spinal cord injury is a common clinical entity. The role of MRI is well established in evaluating spinal trauma. However, the time at which MRI should be used is still controversial.

Methods

Retrospective data from 2002-2010 was evaluated. All of the alert and awake patients with spinal cord injury, based on clinical examination with facet dislocation diagnosed on lateral cervical spine X-rays, were included. A questionnaire was also conducted, the data of which consisted of demographic details including age and sex, the mechanism of injury, clinical examination, X-ray findings, MRI findings, whether or not surgery was performed and the time elapsed since injury. Data was analyzed using SPSS ver. 17.0. Continuous variables such as age were expressed in terms of mean ± standard deviation. Categorical variables such as change in management, X-ray/MRI findings and neurological motor level were assessed in terms of percentage.

Results

Fifty patients participated in our study. All these patients had spinal cord injury with defined motor levels. The mean age was 35.5 ± 8.95 years (range, 20 to 52 years). Fifty percent showed a motor level at C6 level. None of the patients required any change in management based on the MRI.

Conclusions

MRI of the spine in awake patients within 4 hours after injury does not change the management of patients. However, we can hypothesize that such patients can proceed to traction without waiting for the MRI.

Early versus delayed decompression for traumatic cervical spinal cord injury: results of the Surgical Timing in Acute Spinal Cord Injury Study (STASCIS)

Background

There is convincing preclinical evidence that early decompression in the setting of spinal cord injury (SCI) improves neurologic outcomes. However, the effect of early surgical decompression in patients with acute SCI remains uncertain. Our objective was to evaluate the relative effectiveness of early (<24 hours after injury) versus late (≥24 hours after injury) decompressive surgery after traumatic cervical SCI.

Methods

We performed a multicenter, international, prospective cohort study (Surgical Timing in Acute Spinal Cord Injury Study: STASCIS) in adults aged 16–80 with cervical SCI. Enrolment occurred between 2002 and 2009 at 6 North American centers. The primary outcome was ordinal change in ASIA Impairment Scale (AIS) grade at 6 months follow-up. Secondary outcomes included assessments of complications rates and mortality.

Findings

A total of 313 patients with acute cervical SCI were enrolled. Of these, 182 underwent early surgery, at a mean of 14.2(±5.4) hours, with the remaining 131 having late surgery, at a mean of 48.3(±29.3) hours. Of the 222 patients with follow-up available at 6 months post injury, 19.8% of patients undergoing early surgery showed a ≥2 grade improvement in AIS compared to 8.8% in the late decompression group (OR = 2.57, 95% CI:1.11,5.97). In the multivariate analysis, adjusted for preoperative neurological status and steroid administration, the odds of at least a 2 grade AIS improvement were 2.8 times higher amongst those who underwent early surgery as compared to those who underwent late surgery (OR = 2.83, 95% CI:1.10,7.28). During the 30 day post injury period, there was 1 mortality in both of the surgical groups. Complications occurred in 24.2% of early surgery patients and 30.5% of late surgery patients (p = 0.21).

Conclusion

Decompression prior to 24 hours after SCI can be performed safely and is associated with improved neurologic outcome, defined as at least a 2 grade AIS improvement at 6 months follow-up.

Spinal cord injury: a systematic review of current treatment options

BACKGROUND

Spinal cord injury (SCI) is a devastating event often resulting in permanent neurologic deficit. Research has revealed an understanding of mechanisms that occur after the primary injury and contribute to functional loss. By targeting these secondary mechanisms of injury, clinicians may be able to offer improved recovery after SCI.

QUESTIONS/PURPOSES

In this review, we highlight advances in the field of SCI by framing three questions: (1) What is the preclinical evidence for the neuroprotective agent riluzole that has allowed this agent to move into clinical trials? (2) What is the preclinical evidence for Rho antagonists that have allowed this group of compounds to move into clinical trials? (3) What is the evidence for early surgical decompression after SCI?

METHODS

We conducted a systematic review of MEDLINE and EMBASE-cited articles related to SCI to address these questions.

RESULTS

As a result of an improved understanding of the secondary mechanisms of SCI, specific clinical strategies have been established. We highlight three strategies that have made their way from bench to bedside: the sodium-glutamate antagonist riluzole, the Rho inhibitor Cethrin, and early surgical decompression. Each of these modalities is under clinical investigation. We highlight the fundamental science that led to this development.

CONCLUSIONS

As our understanding of the fundamental mechanisms of SCI improves, we must keep abreast of these discoveries to translate them into therapies that will hopefully benefit patients. We summarize this process of bench to bedside with regard to SCI.

The development and evaluation of the subaxial injury classification scoring system for cervical spine trauma

BACKGROUND

Fractures and dislocations of the subaxial cervical spine may give rise to devastating consequences. Previous algorithms for describing cervical trauma largely depend on retrospective reconstructions of injury mechanism and utilize nonspecific terminology which thus diminish their clinical relevance add to the difficulty of educating doctors and performing prospective research.

QUESTIONS/PURPOSES

We characterized the potential benefits of the Subaxial Injury Classification (SLIC) scale which considers three major variables that influence spinal stability: morphology, integrity of the discoligamentous complex, and neurologic status. Each category was assigned a certain number of points based on the severity of the injury which are added together to generate a total score; this value provides prognostic information and may also be useful for directing subsequent management (ie, nonoperative treatment versus operative intervention).

METHODS

We examined the individual components that comprise the SLIC paradigm and reviewed the manner in which cervical injuries are scored and stratified. We also critically assessed the preliminary data comparing the SLIC scheme to preexisting classification systems.

RESULTS

The results of a preliminary analysis demonstrate that the intraclass coefficients (ICC) for the three primary components range between 0.49 and 0.90, suggesting that the overall reliability of the SLIC system appears to be at least as good as that of other conventional schemes for classifying subaxial cervical spine trauma (ICC between 0.41 and 0.53).

CONCLUSIONS

This scheme will hopefully facilitate the development of evidence-based guidelines that may influence other aspects of the therapeutic decision-making process (eg, which operative approach is most appropriate for a particular injury). We anticipate its accuracy and reproducibility will increase over time as surgeons become more familiar with the protocol.

Compression induces acute demyelination and potassium channel exposure in spinal cord

Crush to the mammalian spinal cord leads to primary mechanical damage followed by a series of secondary biomolecular events. The chronic outcomes of spinal cord injuries have been well detailed in multiple previous studies. However, the initial mechanism by which constant displacement injury induces conduction block is still unclear. We therefore investigated the anatomical factors that may directly contribute to electrophysiological deficiencies in crushed cord. Ventral white matter strips from adult guinea pig spinal cord were compressed 80%, either briefly or continuously for 30 min. Immunofluorescence imaging and coherent anti-Stokes Raman spectroscopy (CARS) were used to visualize key pathological changes to ion channels and myelin. Compression caused electrophysiological deficits, including compound action potential (CAP) decline that was injury-duration-dependent. Compression further induced myelin retraction at the nodes of Ranvier. This demyelination phenomenon exposed a subclass of voltage-gated potassium channels (K(v)1.2). Application of a potassium channel blocker, 4-aminopyridine (4-AP), restored the CAP to near pre-injury levels. To further investigate the myelin detachment phenomenon, we constructed a three-dimensional finite element model (FEM) of the axon and surrounding myelin. We found that the von Mises stress was highly concentrated at the paranodal junction. Thus, the mechanism of myelin retraction may be associated with stress concentrations that cause debonding at the axoglial interface. In conclusion, our findings implicate myelin disruption and potassium channel pathophysiology as the culprits causing compression-mediated conduction block. This result highlights a potential therapeutic target for compressive spinal cord injuries.

Timing of decompressive surgery of spinal cord after traumatic spinal cord injury: an evidence-based examination of pre-clinical and clinical studies

While the recommendations for spine surgery in specific cases of acute traumatic spinal cord injury (SCI) are well recognized, there is considerable uncertainty regarding the role of the timing of surgical decompression of the spinal cord in the management of patients with SCI. Given this, we sought to critically review the literature regarding the pre-clinical and clinical evidence on the potential impact of timing of surgical decompression of the spinal cord on outcomes after traumatic SCI. The primary literature search was performed using MEDLINE, CINAHL, EMBASE, and Cochrane databases. A secondary search strategy incorporated articles referenced in prior meta-analyses and systematic and nonsystematic review articles. Two reviewers independently assessed every study with regard to eligibility, level of evidence, and study quality. Of 198 abstracts of pre-clinical studies, 19 experimental studies using animal SCI models fulfilled our inclusion and exclusion criteria. Despite some discrepancies in the results of those pre-clinical studies, there is evidence for a biological rationale to support early decompression of the spinal cord. Of 153 abstracts of clinical studies, 22 fulfilled the inclusion and exclusion criteria. While the vast majority of the clinical studies were level-4 evidence, there were two studies of level-2b evidence. The quality assessment scores varied from 7 to 25 with a mean value of 12.41. While 2 of 22 clinical studies assessed feasibility and safety, 20 clinical studies examined efficacy of early surgical intervention to stabilize and align the spine and to decompress the spinal cord; the most common definitions of early operation used 24 and 72 h after SCI as timelines. A number of studies indicated that patients who undergo early surgical decompression can have similar outcomes to patients who received a delayed decompressive operation. However, there is evidence to suggest that early surgical intervention is safe and feasible and that it can improve clinical and neurological outcomes and reduce health care costs. Based on the current clinical evidence using a Delphi process, an expert panel recommended that early surgical intervention should be considered in all patients from 8 to 24 h following acute traumatic SCI.

The efficacy of surgical decompression before 24 hours versus 24 to 72 hours in patients with spinal cord injury from T1 to L1--with specific consideration on ethics: a randomized controlled trial

Background

There is no clear evidence that early decompression following spinal cord injury (SCI) improves neurologic outcome. Such information must be obtained from randomized controlled trials (RCTs). To date no large scale RCT has been performed evaluating the timing of surgical decompression in the setting of thoracolumbar spinal cord injury. A concern for many is the ethical dilemma that a delay in surgery may adversely effect neurologic recovery although this has never been conclusively proven. The purpose of this study is to compare the efficacy of early (before 24 hours) verse late (24–72 hours) surgical decompression in terms of neurological improvement in the setting of traumatic thoracolumbar spinal cord injury in a randomized format by independent, trained and blinded examiners.

Methods

In this prospective, randomized clinical trial, 328 selected spinal cord injury patients with traumatic thoracolumbar spinal cord injury are to be randomly assigned to: 1) early surgery (before 24 hours); or 2) late surgery (24–72 hours). A rapid response team and set up is prepared to assist the early treatment for the early decompressive group. Supportive care, i.e. pressure support, immobilization, will be provided on admission to the late decompression group. Patients will be followed for at least 12 months posttrauma.

Discussion

This study will hopefully assist in contributing to the question of the efficacy of the timing of surgery in traumatic thoracolumbar SCI.

Trial Registration

RCT registration number: ISRCTN61263382

Critical roles of decompression in functional recovery of ex vivo spinal cord white matter

Object

The correlations between functional deficits, the magnitude of compression, and the role of sustained compression during traumatic spinal cord injury remain largely unknown. Thus, the functional outcome of this type of injury with or without surgical intervention is rather unpredictable. To elucidate how severity and duration of compression affect cord function, the authors have developed a method to study electrophysiological characteristics and axonal membrane damage in white matter from guinea pig spinal cord.

Methods

Ventral white matter strips isolated from adult guinea pigs were compressed by a compression rod at a level of either 60 or 80% and held briefly, for 30 minutes, or for 60 minutes. In half the experimental groups, a decompression phase consisting of probe withdrawal and 30 minutes of recovery was also applied. For all cord samples, functional response was continuously monitored through compound action potential (CAP) recording. In addition, axonal membrane damage was assessed by a horseradish peroxidase (HRP) exclusion assay.

Results

After 30 minutes of sustained compression at levels of 60 or 80%, a spinal cord decompression procedure caused a significant CAP recovery, with specimens reaching 97.5 ± 6.84% (p < 0.05) and 56.2 ± 6.14% (p < 0.05) of preinjury amplitude, respectively. After 60 minutes of compression, the amount of CAP recovery following the decompression stage was only 65.5 ± 9.33% for 60% compression (p < 0.05) and 29.8 ± 6.31% for 80% compression (p < 0.05). Unlike the CAP response, HRP uptake did not increase during sustained compression, and the data showed that HRP staining was primarily time dependent.

Conclusions

The degree of axonal membrane damage is not exacerbated during sustained compression. However, the electrical conductivity of the cord white matter weakens throughout the duration of compression. Therefore, decompression is a viable procedure for preservation of neurological function following compressive injury.

Efficacy of surgical decompression in regard to motor recovery in the setting of conus medullaris injury

BACKGROUND/OBJECTIVE

An assessment of neurological improvement after surgical intervention in the setting of traumatic conus medullaris injury (CMI).

METHODS

A retrospective evaluation of a cohort of patients with a blunt traumatic CMI from T12 to L1. The neurologic and functional outcomes were recorded from the acute hospital admission to the most recent follow-up. Data collected included age, level of injury, neurologic examination according to the Frankel grading system and motor index score, and the mechanism and timing of CMI decompression.

RESULTS

A total of 24 patients with a mean age of 27 years (men, 87%) were identified. The most common level of bony injury was L1, and the most frequent mechanism of injury was a motor vehicle crash. Before surgical intervention, 16 of 24 patients (66.7%) had a complete neurological deficit below the level of injury. The median interval from injury to surgery was 6 days (range, 7 hours to 390 days). Decompression, fusion, and adjunctive internal fixation were the most common surgical procedures. Median length of follow-up was 32 months after surgery. Improvement in spinal cord and bladder function was seen in 41.6% and 63.6% of patients, respectively. Root recovery was seen in 83.3% of patients.

CONCLUSIONS

In the setting of CMI, no correlation between the timing of surgical decompression and motor improvement was identified. Root recovery was more predictable than spinal cord and bladder recovery.

Efficacy of surgical decompression in the setting of complete thoracic spinal cord injury

BACKGROUND/OBJECTIVE

An assessment of neurological improvement after surgical intervention in the setting of traumatic thoracic spinal cord injury (SCI).

METHODS

A retrospective evaluation of a nonconsecutive cohort of patients with a thoracic SCI from T2 to T11. The analysis included a total of 12 eligible patients. The neurologic and functional outcomes were recorded from the acute hospital admission to the most recent follow-up. Data included patient age, level of injury, neurologic examination according to the Frankel grading system, the performance of surgery, and the mechanism of the time-related SCI decompression.

RESULTS

All patients had a complete thoracic SCI. The median interval from injury to surgery was 11 days (range, 1-36 days). Decompression, bone fusion, and instrumentation were the most common surgical procedures performed. The median length of follow-up was 18 months after surgery (range, 9-132 months). Motor functional improvement was seen in 1 patient (Frankel A to C).

CONCLUSION

Surgical decompression and fusion imparts no apparent benefit in terms of neurologic improvement (spinal cord) in the setting of a complete traumatic thoracic SCI. To better define the role of surgical decompression and stabilization in the setting of a complete SCI, randomized, controlled, prospective studies are necessary.