Cerebral Arterial Gas Embolism in Cardiovascular and Aortic Procedures: A Narrative Review of the Mechanisms, Diagnosis, Management, and Prevention.

Abstract

Cerebral arterial gas embolism (CAGE) is an uncommon but potentially catastrophic complication of cardiothoracic surgery, extracorporeal circulation, mechanical circulatory support, and catheter-based cardiac interventions. During these procedures, gas may be introduced to the cardiac chambers, aorta, and cerebral arterial circulation through different mechanisms. Clinical presentation ranges from abrupt intraoperative hemodynamic and neurologic deterioration to delayed, subtle focal deficits emerging after an apparently uneventful emergence from anesthesia. As intracranial air is detectable on computed tomography in only a minority of confirmed cases, CAGE remains fundamentally a clinical diagnosis, and a high index of suspicion in the correct procedural context should not be delayed by or dependent on imaging confirmation. Immediate management prioritizes cessation of further gas entry, 100% oxygen, and hemodynamic optimization to preserve cerebral perfusion, with hyperbaric oxygen therapy representing the definitive treatment; outcomes are most favorable when hyperbaric oxygen is initiated within 6 hours of symptom onset, although benefit may still occur with delayed treatment. Most mechanisms of CAGE-inadequate deairing, direct gas introduction, and entrainment-are preventable through meticulous circuit vigilance, standardized deairing protocols, and human factor safeguards. Cavitation and unpredictable outgassing, however, may occur despite optimal technique, placing greater weight on early recognition. This review synthesizes procedure-specific mechanisms, presentation, diagnosis, acute and preventive management across cardiac and aortic surgery, mechanical circulatory support, and catheter-based interventions, with the goal of supporting rapid recognition and coordinated multidisciplinary response by the perfusion, surgical, procedural, and anesthesiology teams. Specific anesthesia considerations and the role of transesophageal echocardiography are discussed.