Early Surgical Decompression Improves Outcomes From Spinal Cord Injuries
Spine Summit 2016 Meeting Highlight: ‘Time is Spine’ in treatment of traumatic SCIs
Early decompression should be considered as a treatment option for adults with traumatic spinal cord injuries, particularly in people with severe injury, said Michael G. Fehlings, MD, PhD, at Spine Summit 2016 held March 16-19 in Orlando, Florida.1 “The concept that I want to emphasize is that ‘time is spine,’ and that timing does matter,” said Dr. Fehlings, who is Professor of Neurosurgery and Co-Director of the Spine Program at the University of Toronto in Ontario and Chair of AOSpine North America and the AOSpine International Spinal Cord Injury Knowledge Forum.
“We can’t reverse the effects of the primary damage; we are fighting to try to deal with the consequences of the secondary damage,” Dr. Fehlings said. Secondary injuries include vasogenic edema, neurogenic shock, loss of autoregulation, and cytotoxic edema, among a host of other negative effects. “As surgeons, we can influence the trajectory of the outcome.”
Preclinical animal studies consistently have shown that surgical decompression following spinal cord injury attenuates secondary injuries and improves neurological outcomes, Dr. Fehlings said. “While it is difficult to extrapolate from animal models to man, there is a strong scientific rationale to consider a role for early surgical decompression for spinal cord injury,” Dr. Fehlings said.
Evidence Supporting Early Surgical Decompression
To understand the effects of early surgical decompression following spinal cord injury, Dr. Fehlings and colleagues conducted a prospective, nonrandomized, multicenter study involving 313 patients with acute cervical spinal cord injury, 182 of whom underwent early surgery at less than 24 hours after injury (mean, 14.2 hours) and 131 of whom underwent late surgery (mean, 48.3 hours).2
Multivariate analysis indicated that the odds of ≥2 grade improvement in American Spinal Injury Association (ASIA) Impairment Scale was 2.8 times higher among patients who received early surgery as compared to those who underwent late surgery (OR = 2.83). This analysis was adjusted for preoperative neurological status and steroid administration.
This study has been misinterpreted to suggest that a patient who arrives early at a hospital could wait up to 24 hours for surgery, Dr. Fehlings noted. He emphasized that surgery should be conducted as early as possible, not just under 24 hours. Unfortunately, barriers to early surgery exist, including delays in referral and lack of operating room/imaging availability.
In another study by Dr. Fehlings and colleagues, the researchers prospectively evaluated outcomes in patients with ASIA Impairment Scale grade A through D spinal cord injuries and found that the early-surgery group (<24 hours) had a significantly greater proportion of patients with at least a 2-grade improvement (P=0.01) and showed significantly greater improvement in ASIA motor score after adjusting for preoperative status and neurological level (P=0.01).3
“One of the errors that I made in the design of the trial was including grade D patients, and I was criticized in a Letter to the Editor for not excluding these patients,” Dr. Fehlings said. “I felt that that would be inappropriate exclude these patients because I thought it would bias the results further toward early surgery, and I did not want to be criticized for that.”
“Clearly, we now recognize that these patients would run into a ceiling effect,” given that the highest grade on this scale (grade E) is just 1 point higher for patients with grade D injury, Dr. Fehlings said.
The timing of surgery was a big controversy at that time, with some research suggesting that 72 hours was [the cutpoint for] early surgery, “which is nonsensical from a biological standpoint,” Dr. Fehlings said. “I think we indicated that early surgery is safe and feasible,” Dr. Fehlings noted.
Dr. Fehlings described other studies that contributed to this emerging evidence on the concept of “time is spine,” including a meta-analysis van Middendorp et al and a 2014 observational study by Dvorak et al.4,5
The evidence supporting early surgery is mirrored by survey result from nearly 1,000 spine surgeons, the majority of whom (≥80%) preferred to decompress the spinal cord within 24 hours of injury, Dr. Fehlings explained.6
Proposed Guidelines for the Management of Acute Spinal Cord Injury
Proposed guidelines have been developed for the management of traumatic spinal cord injury and are being evaluated by the AOSpine group. The multidisciplinary guidelines will focus on a number of controversial issues including the optimal timing of surgical decompression being among the topics. The guidelines are being sponsored by the AANS/CNS Section on Neurotrauma and Critical Care, AOSpine North America and AOSpine International Spinal cord Injury Knowledge Forum.
A systematic literature review conducted by the guideline development group indicated improved outcomes with early intervention, with no significant differences in complications or length of stay with early versus late surgery, Dr. Fehlings explained. In fact, a trend toward reduced postoperative complications was found in the early surgery group.
In developing clinical guidelines “you need to look at the acceptability of what you're proposing, you need to include patient values, you need to look at the benefits versus harm, and you need consider cost,” Dr. Fehlings said. Based on all of these variables, “we suggest that early surgery be considered to be an option in adult patients with traumatic spinal cord injuries, particularly in people with severe injury. In addition, we suggest that early surgery be offered as an option for adult patients with acute spinal cord injuries regardless of level,” he said.