Abstract OBJECTIVE: To demonstrate the role of intraoperative multichannel electromyographic (EMG) monitoring to reduce postoperative deterioration and achieve full untethering of complex occult dysraphisms. METHODS: A retrospective analysis was performed on 66 patients who underwent operation for lumbosacral lipomas. Twenty recent cases were submitted to EMG monitoring and stimulation. RESULTS: All patients presented symptoms at the time of surgery, and 74% exhibited progressive deterioration during the lengthy preoperative period. Postoperative surgery-related deterioration was observed in 6% of patients. This number was reduced to zero with the introduction of intraoperative EMG monitoring. CONCLUSION: Intraoperative multichannel EMG monitoring can be carried out and requires only minimal changes to anesthetic procedures. With this method, it is possible to better identify the neural structures of complex malformations, reducing the risks of surgical damage and incomplete detethering.