Cerebral air embolism following CT-guided transthoracic splanchnic neurolysis complicated by pneumothorax: a case report

Cerebral air embolism is a rare but potentially devastating complication of thoracic percutaneous procedures. Splanchnic plexus neurolysis is generally safe; however, procedure-related pneumothorax may rarely lead to cerebral air embolism and acute neurologic deficits. A 75-year-old man with metastatic pancreatic ductal adenocarcinoma underwent bilateral computed tomography (CT)-guided greater splanchnic nerve neurolysis via a retrocrural transthoracic approach for refractory abdominal pain. A small right pneumothorax was detected on the post-procedural CT scan. Ten minutes later, upon mobilization to a sitting position, he developed sudden loss of consciousness, hypotension, hypoxia, and subsequently left-sided hemiplegia. Non-contrast brain CT revealed air within the right parietal cortical veins and superior sagittal sinus, consistent with cerebral air embolism. High-flow oxygen, intravenous fluids, and dexamethasone were administered, but hyperbaric oxygen therapy was not available. The patient fully recovered within 24 h without further complications. The intracranial air distribution on CT was venous-predominant, making retrograde cerebral venous air embolism a plausible mechanism. However, given the transthoracic needle trajectory and post-procedural pneumothorax, a thoracic procedure-related systemic arterial source could not be excluded. Position change from supine to sitting may have facilitated air entry or redistribution. This case underscores the importance of meticulous needle handling with continuous occlusion, whole-thorax post-procedural imaging, maintenance of supine positioning after procedures complicated by pneumothorax, and prompt treatment of suspected cerebral air embolism with 100% oxygen and early hyperbaric consultation, where available.