Study design: A retrospective study.
Objective: To analyze the cerebrospinal fluid (CSF) leak during the thoracic pedicle screw fixation in spinal deformities, the relative intraoperative neuromonitoring changes and the strategy for management.
Summary of background data: CSF leak may occur during the preparation of trajectory of thoracic pedicle screws in scoliosis surgery. The strategy for management of such situation is controversial. There is limited literature about the CSF leak and concomitant neuromonitoring change.
Methods: A total of 695 patients with spinal deformity subjected to correction by posterior instrumentation using thoracic pedicle screw fixation from 2008 January to 2010 December and followed up for more than 2 years were retrospectively analyzed for CSF leak during pedicle screw placement and the concomitant neuromonitoring changes. The cases with CSF leak and with complete information about neuromonitoring were reviewed.
Results: A total of 7284 thoracic pedicle screws were inserted in the thoracic level (10.4 screws/patient). All the procedures were performed under the intraoperative neuromonitoring. There were 8 cases of CSF leak with the rate of 0.11% during the screw trajectory preparation. Seven of the screws located at the concave side. Five cases presented with concomitant positive intraoperative neuromonitoring changes. The holes were sealed for 3 of them, and patients presented with reversible monitoring changes and intact neurological function. Negligence of the CSF leak and screw insertion caused the deterioration of neuromonitoring even neurological deficit that needed revision surgery. Three cases presented without intraoperative monitoring changes and woke up without neurological deficit.
Conclusion: The factors impacting the safety of screw placement for CSF leak included screw position, segment of vertebra, and concomitant neuromonitoring changes. Commonly, it was not necessary to repair the dural tear and sealing the pedicle hole with bone wax for the case with reversible neuromonitoring changes was all that needed. A lateral entry point to the initial one could be used and to continue the screw placement when neuromonitoring demonstrate reversible positive changes.
Level of evidence: 4.