Effects of Remote Ischemic Preconditioning on Biochemical Markers and Neurologic Outcomes in Patients Undergoing Elective Cervical Decompression Surgery

BACKGROUND: Remote ischemic preconditioning (RIPC) may protect the spinal cord from ischemic injury. This randomized clinical trial was designed to assess whether a large clinical trial testing the effect of RIPC on neurologic outcome in patients undergoing spine surgery is warranted. This trial was registered with ClinicalTrials.gov, number NCT00778323. METHODS: Forty adult cervical spondylotic myelopathy patients undergoing elective decompression surgery were randomly assigned to either the RIPC group (n=20) or the control group (n=20). Limb RIPC consisted of three 5-minutes cycles of upper right limb ischemia with intervening 5-minute periods of reperfusion. Neuron-specific enolase and S-100B levels were measured in serum at set time points. Median nerve somatosensory-evoked potentials (SEPs) were also recorded. Neurologic recovery rate was evaluated using a Japanese Orthopaedic Association scale. RESULTS: RIPC significantly reduced serum S-100B release at 6 hours and 1 day after surgery, and reduced neuron-specific enolase release at 6 hours, and then at 1, 3, and 5 days after surgery. No differences were observed in SEP measurements or the incidence of SEP changes during surgery between the control and RIPC groups. Recovery rate at 7 days, and at 1 and 3 months after surgery was higher in the RIPC group than in the control group (P<0.05). CONCLUSIONS: Our results for markers of neuronal ischemic injury and rate of recovery suggest that a clinical trial with sufficient statistical power to detect an effect of RIPC on the incidence of neurologic complications (paresis, palsy, etc) due to spinal cord ischemia-reperfusion injury after spine surgery is warranted [corrected].