Massive venous air embolism in the semi-sitting position during surgery for a cervical spinal cord tumor: anatomic and surgical pitfalls.

Although venous air embolism (VAE) in neurological surgery is mainly associated with posterior fossa procedures, this complication may also occur, with comparable severity, in the posterior cervical spine approach in patients who are semi-sitting. We report a patient with a massive VAE that occurred in the semi-sitting position during a posterior approach to an extended cervical-thoracic level (C3-T2) intramedullary tumor, which interrupted the surgical procedure. We discuss the possible causes of air embolism, the anatomic and pathogenetic mechanisms, treatment and preventive measures.