D24-19 Air Embolism Following Robotic-assisted Bronchoscopic Lung Biopsy With Pulsed Electric Field Tumor Ablation

Abstract Introduction Air embolism is rare but devastating complication of bronchoscopy, with an estimated incidence of 0.02% yet reported mortality exceeding 50% and frequent permanent neurologic morbidity.¹,² Clinical presentations range from delayed awakening to seizures, stroke, or cardiovascular collapse. Reported risk factors include bronchovascular disruption, elevated airway pressures, and gas flow during ablative procedures.3-5 Pulsed electric field (PEF) ablation is a novel, non-thermal modality that induces irreversible electroporation, achieving targeted tumor cell death. Early-phase trials in non-small cell lung cancer (NSCLC) demonstrate encouraging safety and feasibility profiles, including preserved lung function and histopathologic tumor depletion without procedure-related serious adverse events.6,7 Preliminary pilot data suggest potential integration with stereotactic body radiation therapy (SBRT).8 To date, embolic complications have not been described, underscoring the importance of the present case. Case Presentation 63-year-old man with metastatic colorectal adenocarcinoma underwent robotic-assisted bronchoscopy with transbronchial needle aspiration followed by PEF ablation. The procedure was uneventful; however, post-extubation, he developed encephalopathy. Initial head CT revealed no hemorrhage or large-vessel occlusion, but MRI demonstrated bilateral nonhemorrhagic middle cerebral artery infarcts, left greater than right. Continuous EEG showed subclinical status epilepticus. Retrospective review of intra-procedural Cone-Beam CT chest images revealed intravascular air within both arterial and venous circulations, diagnostic of systemic air embolism. Transthoracic echocardiography excluded right-to-left shunt, and transcranial Doppler confirmed absence of ongoing emboli. Cerebrospinal fluid analysis detected HHV-6 by PCR, presumed latent rather than causative. Despite antiseizure therapy and empiric ganciclovir, he remained neurologically impaired, consistent with ischemic injury secondary to cerebral air embolism. Hyperbaric oxygen therapy (HBOT) was not pursued given the absence of intracerebral air, likely reflecting rapid bubble absorption. Discussion This represents the first reported case of systemic air embolism following bronchoscopic PEF tumor ablation. Although PEF is engineered to minimize collateral injury, plausible mechanisms include breath-hold-induced pressure gradients, bronchial occlusion during ablation, and vascular disruption from preceding biopsy. Existing feasibility trials were not powered to detect such rare catastrophic events. HHV-6 detection likely reflected latent viral integration rather than active encephalitis. HBOT remains the standard of care when promptly administered, improving neurologic outcomes by reducing bubble size and enhancing oxygen delivery. While air embolism has been sporadically reported after transbronchial biopsy, its occurrence following PEF ablation warrants caution. This case emphasizes the need for vigilance for acute neurologic changes, early imaging, and rapid escalation of care. As PEF adoption expands, prospective registries should incorporate embolic safety monitoring to clarify true incidence and mechanism. This abstract is funded by: None