Awake craniotomy for brain tumors: Indications, benefits, types of anesthesia and surgical techniques

Background: Awake brain surgery is used to treat brain tumors and epileptic seizures near areas that control language, movement or cognition, movement disorder, and recently during neurovascular surgery.
Methods: Preoperative airway evaluation should be performed in all patients. There are two commonly used anesthetic methods for awake craniotomy: monitored anesthesia care (MAC) and asleep-awake-asleep (AAA) technique, after the tumor resection, sedation is often sufficient until completion of the surgery. In our institution at Mount Lebanon hospital-Balamand university hospital, the combination of propofol and remifentanil has been considered as the standard protocol for sedation during the first stage of awake craniotomy because of the ease of use and reliability. The application of neuro-navigation, and intraoperative electrical mapping are a reliable method to minimize the risk of permanent deficit during surgery for brain tumors in eloquent areas.
Results: Whether sedation or an asleep-awake-asleep technique is chosen, it is crucial to apply adequate local anaesthesia on the skin incision what we call elliptic block using combinations of lidocaine and bupivacaine with epinephrine. If we perform awake-asleep-awake anesthesia type than similar to the pre-awake phase, one can also choose awake, spontaneous ventilation under light or deep sedation, or GA with airway control. Sedation often suffices. The patient usually requires lower rates of sedative infusions during the postawake phase than during the pre-awake phase as patients are often fatigued, and there is a lower level of painful stimuli during skull closure.
Conclusion: Patients receiving awake craniotomy have better outcomes in many aspects. The improvements in anesthetic agents and techniques, the application of neuro-navigation, and intraoperative electrical mapping are a reliable method to minimize the risk of permanent deficit during surgery. Appropriate patient selection, perioperative psychological support, and proper anesthetic management for individual patients in each stage of surgery are crucial for procedural safety, success, and patient satisfaction.