Application of neuromuscular blockade and intraoperative 3D imaging in the reduction of basilar invagination: Technical note

Object. The treatment of basilar invagination in the pediatric age group is dependent on the possibility of preoperative reduction. Reducible lesions obviate a ventral decompression and require a dorsal-only approach for stabilization with or without a suboccipital decompression. Methods. The authors describe a technique of intraoperative reduction of basilar invagination with the use of general anesthesia and neuromuscular blockade in the presence of crown halo traction. Using the O-arm device, a 3D CT scan is generated in the sagittal plane to demonstrate the reduction intraoperatively. This technique was successful in 6 pediatric patients with basilar invagination. Results. The average age of the patients was 10.8 years, and they were followed for a mean period of 8.5 months. The patients had mild basilar invagination or partial reduction in extension on preoperative MR imaging. Intraoperative reduction was demonstrated in all patients by using the reported technique with intraoperative CT. All patients underwent occipitocervical fusion, and all but one underwent a suboccipital decompression. There were no complications related to the operation, and all but one reported improvement of symptoms on the last postoperative visit. Conclusions. Intraoperative reduction performed using neuromuscular blockade and intraoperative traction is an effective method for further reduction of basilar invagination in the pediatric age group. This is the first reported application of intraoperative CT imaging performed using the O-arm device in craniocervical surgery in which successful reduction is demonstrated in detail.