Experiences with the Sitting Position in Posterior Fossa Surgery in 310 Patients

Abstract

Introduction: The sitting position for lesions in the posterior fossa has been controversially discussed in the literature because of high risk of air embolism. We report our experience with the sitting position and evaluate the risk of air embolism. Material and Methods: We performed a retrospective analysis of patient charts (N=310), surgical and anesthesiological reports to evaluate the occurrence of intraoperative complications. Pre and post-operative MRIs were also evaluated for occurrence of embolic infarctions. The patients were operated in our department from 2009–2013. Results: Only 0.6% of patients suffered from embolic infarctions. Most of the complications were similar to the complications which occur in the lateral oblique position. Preoperatively, all patients were evaluated with echocardiography to exclude a patent foramen ovale (those patients were not operated in the sitting position). Conclusion: The sitting position is excellent for surgery in the posterior fossa since blood is washed out and does not intervene with the surgical field. The risk of air embolism is very low when a patent foramen ovale has been excluded. Intraoperatively, a right ventricular catheter is inserted to aspirate air if needed. Meticulous coagulation, irrigation of the surgical domane and application of bone wax to the craniotomy edges reduces the risk of venous air embolism.