CHICAGO — Decompression of the spinal cord within 24 hours of injury is safe and is associated with improved neurologic recovery, results from an ongoing, prospective, multicenter study suggest.
“Certainly we're not going to be getting a home run with early surgery, but the concept here is to try for the best outcome we can,” Dr. Michael G. Fehlings said of the 1-year results of the Surgical Treatment of Acute Spinal Cord Injury Study (STASCIS).
The study included 170 patients who had a subaxial cervical spinal cord injury (SCI) and evidence of spinal cord or canal compression on MRI or CT. Of these, 44% were defined as an American Spinal Injury Association (ASIA) Impairment grade A with no motor or sensory function preserved; 22% were rated as grade B, 16% as grade C, and 18% as grade D.
Patients received decompression by surgery or traction within 7 days of SCI, and were stratified as “early” if it was within 24 hours of injury or “delayed” if it was after 24 hours.
A total of 94 patients, mean age 40 years, had early decompression surgery, and 76 patients, mean age 42 years, underwent delayed decompression. The investigators assessed outcomes in 108 patients at 6 months, and in 64 patients at 1 year.
At 6 months, 24% of early decompression patients had a 2-grade or greater improvement on the ASIA scale, compared with 4% who had delayed decompression, said Dr. Fehlings, head of the Krembil Neuroscience Centre at the University Health Network in Toronto. There weren't enough patients at 1 year to segregate the data by ASIA grade, but significantly more patients in the early group had a combined 1- and 2-grade improvement on the ASIA scale, compared with those in the delayed-compression group.
Complications, particularly respiratory complications and length of stay in the ICU, were reduced by about 15% in the early decompression group versus the delayed-treatment group (37% vs. 49%).
Dr. Fehlings and coinvestigators hypothesized that traction would be one of the primary means of achieving decompression, but it was used in only 29% of the early group and in 21% of the delayed group. Traction was also not as successful as was anticipated, with only a 50% success rate.
The Spine Study Trauma Group, a group of the world's top 40 spine surgeons, will publish in the next year consensus-based recommendations that patients with acute spinal cord injury without other life-threatening conditions should have early decompression surgery within 24 hours, Dr. Fehlings said in an interview at the annual meeting of the American Association of Neurological Surgeons.
Presentation discussant Christopher Shields of the Kentucky Spinal Cord Injury Research Center in Louisville suggested 8–12 hours may have been a more appropriate cutoff point for early intervention. Dr. Fehlings said that animal studies suggest the time window for optimal decompression after spinal cord injury occurs within 8–24 hours after SCI. Based on the differences in metabolic rate between rats and humans, an 8- to 12-hour window roughly translates into 24 hours for humans. Also, the logistics are substantial in terms of transferring a patient to an SCI treatment facility, and getting that patient medically optimized, imaged, taken to surgery, and decompressed.
“The Spine Trauma Study Group has deemed that 24 hours is the cutoff for early surgical intervention, although my colleagues and I try hard in every case to minimize this time,” said Dr. Fehlings, professor of neurosurgery at the University of Toronto.