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Although there is significant preclinical research supporting early surgery for traumatic spinal cord injury (tSCI), the timing of surgery remains a controversial topic among spine surgeons.
The evidence supporting early surgery consists primarily of retrospective studies and case reviews, but is lacking in randomized controlled trials and high-quality prospective cohort studies. Large, prospective, multicentered spinal cord injury studies are needed to elucidate the effect of surgical timing in tSCI.
The Surgical Timing in Acute Spinal Cord Injury Study is the largest multicenter prospective cohort study in tSCI research. It provides robust support for the benefit of early surgery (<24 hours) for cervical tSCI.
Clinical practice guidelines published in the Global Spine Journal suggest the option of early surgery (≤24 hours after injury) for tSCI in the adult population regardless of the level of injury. These guidelines also support early surgical intervention (≤24 hours) in adult patients with acute traumatic central cord syndrome.
Guidelines published by Eichholz et al. in 2018, supported by the Congress of Neurological Surgeons, recommended early surgery for thoracic and lumbar fractures as an option.
Although spinal cord injury (SCI) can occur as a result of nontraumatic or traumatic causes, the latter has been estimated to account for up to 90% of all cases. Traumatic spinal cord injury (tSCI) is a life-altering condition with the potential to profoundly impair patients’ motor, sensory, and autonomic functions. It is more prevalent in the male population and is most commonly a result of traffic accidents, followed by falls in the elderly. Additionally, tSCI presents a significant financial burden to patients and the health care system as a result of acute care costs, rehabilitation, complications, and reduced employment prospects. For example, tSCI costs the Canadian health care system an estimated $2.67 billion annually, and tSCI patients in the United States face lifetime costs ranging from $1 million to 5 million. , Furthermore, the incidence and prevalence of tSCI vary between developed and developing countries, with the prevalence being highest in the United States (906 per million). The prevalence of this condition is predicted to rise as populations age and there are more elderly individuals, who are prone to fall-related tSCI. Many societies around the world are already witnessing this shift taking place. Recognizing the global burden of tSCI, the purpose of this chapter is to discuss the evidence regarding timing of surgical intervention for traumatic injury to the spinal cord.
The timing of surgery for tSCI has been a controversial topic among spine surgeons around the world. Specifically, there has been debate over the benefit of early surgical decompression. Although there is substantial preclinical research supporting early surgery for tSCI, the clinical evidence is overall inconsistent and unclear. For instance, animal studies suggest that early surgical decompression may improve neurobehavioral outcomes and reduce the risk of secondary injury in a time-dependent fashion. However, these effects of early surgery are not consistently translated to clinical studies. The ambiguity in surgical timing for tSCI is reflected in the considerable variation of operating times reported among spine surgeons in the past. Consequently, the international spine community has launched initiatives aimed toward standardizing the timing of surgery for tSCI. Although controversy remains, significant progress has been made in recent years through the publication of clinical practice guidelines.
This chapter discusses this controversy and outlines the current evidence for early surgery in tSCI. It begins with a brief overview of the classification of SCI and how classification systems can be used to evaluate a patient’s improvement postoperatively. Following that, a detailed discussion of the surgical timing for cervical, thoracic, and thoracolumbar tSCI will be provided, highlighting the evidence from recent research advancements. Concluding remarks will be provided on the limitations and future directions of SCI research. Finally, an illustrative clinical case has been included to demonstrate the benefit of early surgical intervention in tSCI.
Classically, SCIs were categorized as either complete or incomplete injuries. In complete SCI, there is total sensory and motor loss below the level of injury. Conversely, in incomplete SCI there is variable preservation of motor or sensory function. This traditional classification system provided a general understanding of SCI, and although subgroups of incomplete injuries existed, it lacked finer definition in quantifying the level of neurological deficit.
To standardize the SCI classification, the Frankel scale was developed in 1969. It consists of five grades, with grade A being complete injury and the most severe, whereas grade E is the least severe, with essentially intact sensory and motor strength. Grades B, C, and D represent incomplete SCI with decreasing severity. Although the Frankel classification has been widely used in the spinal cord literature, it has been criticized for not considering the patient’s level of injury and for its unclear definition of “useful” motor strength. To address these limitations in the Frankel scale, the American Spinal Injury Association (ASIA) published the International Standards for Neurological Classification of Spinal Injury in 1982. These standards were gradually refined over the years and eventually became the current ASIA impairment scale (AIS). The AIS consists of five grades, like the Frankel scale, with grade A being complete injury and the most severe, and grade E being the least severe, with preserved sensory and motor strength. Although the grades are similar to those outlined by the Frankel scale, the tests used to determine SCI grade are different. These tests include a motor function test that evaluates 10 myotomes from C5 to T1 and L2 to S1. The AIS also involves a sensory function test, which assesses 28 dermatomes bilaterally for light touch and pain. Furthermore, there are high intra- and interrater correlation coefficients for the AIS. Consequently, the AIS has become the gold standard for classifying SCI. Therefore, in this chapter, when available, we will use AIS grades in the discussion of neurological improvement following SCI.
Cervical tSCI accounts for approximately 40% to 70% of all tSCI cases. Injury to this region can cause considerable neurological and functional impairment. Additionally, high cervical injury can potentially damage the motor innervation to the diaphragm, resulting in respiratory insufficiencies, inability to clear secretions, and, in severe cases, recurrent pneumonia and lifelong ventilator dependency. For several years, the timing of surgery for cervical tSCI has been a controversial subject in the spine community. Several clinical studies demonstrate no significant benefit of early surgery, and systematic reviews have often described the limited evidence available to be primarily class III (retrospective reviews, case series). , As a result, there has been a push toward publishing prospective cohort studies and randomized controlled trials (RCTs) to elucidate if there is indeed a true benefit of early surgery.
To address the limitations in the current literature, the Surgical Timing in Acute Spinal Cord Injury Study (STASCIS) was established. It represents the largest multicenter prospective cohort study in tSCI research and is a landmark publication demonstrating the benefit of early surgery (<24 hours) for cervical tSCI. The study included 182 patients who had early surgery (mean 14.2 ± 5.4 hours) and 131 patients who had late surgery (mean 48.3 ± 29.3 hours). Six months postinjury, there was a two-grade or better improvement in AIS in 19.8% of patients who had early surgery, compared with 8.8% in the late surgery group (odds ratio [OR] = 2.57, 95% confidence interval [CI]: 1.11, 5.97). When performing the multivariate analysis and adjusting for preoperative neurological status and steroid administration, the odds of two-grade or better improvement in AIS were 2.8 times greater in the early surgery group (OR = 2.83, 95% CI: 1.10, 7.28). There was also no significant difference in the complication rate between groups ( P = .21).
A systematic review published by ter Wengel et al. 2019 expanded on this work by investigating the impact of early surgery on complete and incomplete cervical tSCI. Fifteen publications were evaluated, involving a total of 1126 patients. Improvement of at least two AIS grades was more common after early surgery (<24 hours) compared with late surgery (>24 hours) for complete cervical tSCI (OR = 2.6, 95% CI: 1.4, 5.1). In the incomplete cervical tSCI group, the improvement was similar for early and late surgery (OR = 0.9, 95% CI: 0.4, 1.9). This contrasts with existing practice, where surgeons tend to treat complete tSCI patients less urgently than incomplete tSCI patients, based on the poorer outcomes in complete tSCI. The findings of ter Wengel et al.’s 2019 study, therefore, pointed to a paradigm shift in the treatment of complete cervical tSCI.
In an effort to bring consensus to the spine community on the timing of surgery for tSCI, evidence-based clinical practice guidelines were recently developed through an international collaboration of experts in the field. These guidelines, based on a robust systematic review of the current literature and developed through validated methods, recommended the consideration for early surgery (≤24 hours) for adults presenting with acute tSCI ( Table 161.1 ). ,
Injury Type | Recommendation | Evidence Base |
---|---|---|
Cervical traumatic spinal cord injury (tSCI) | Early surgery (≤24 hours) should be considered as an option in adults presenting with acute tSCI | Quality of evidence: Low Strength of recommendation: Weak |
Central cord syndrome | Early surgery (≤24 hours) should be considered an option in adults presenting with traumatic central cord syndrome | Quality of evidence: Low Strength of recommendation: Weak |
Thoracic and thoracolumbar tSCI | Early surgery (≤24 hours) should be considered as an option in adults presenting with acute tSCI | Quality of evidence: Low Strength of recommendation: Weak |
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