Serum interleukin-6 response after spinal surgery: estimation of surgical magnitude

Background. Serum interleukin-6 (IL-6) has been used for quantitative estimation of the surgical magnitude of major cardiac and thoracoabdominal surgery, but there have been few studies assessing IL-6 as a marker of surgical magnitude of spinal surgery. Methods. We investigated the changes in IL-6 response in comparison to other parameters of surgical magnitude and spinal surgery procedures. The study included 40 patients electively undergoing spinal surgery. The patients were divided into four groups: lumbar laminectomy with posterolateral fusion (PLF), lumbar laminotomy, lumbar open discectomy, and cervical laminoplasty. Serum IL-6, C-reactive protein (CRP), creatine kinase (CK), and the white blood cell (WBC) count were determined in venous blood before surgery, at the end of surgery, and 6h and the first, third, and seventh days after surgery. Results. Serum IL-6 peaked on the first day and returned to a normal value by the seventh day. The peak IL-6 concentrations on the first day after surgery significantly correlated with CRP, CK, duration of surgery, and estimated blood loss. Regarding lumbar surgeries, the peak IL-6 for laminectomy/PLF was significantly higher than that for laminotomy/open discectomy or for cervical laminoplasty. Conclusions. Serum IL-6 on the first day varied depending on the surgical procedure used. Therefore, it might be a quantitative marker of surgical magnitude following spinal surgery.