A 57-year-old man with a large cavity of the right upper lobe of the lung was referred to our institution for further diagnostic, after a diagnosis had not been able to be made during a hospital stay in another clinic. Several noninvasive diagnostics for pulmonary tuberculosis were negative. A flexible bronchoscopy with bronchial wash cytology, an aspiration cytology, and an endobronchial forceps biopsy were performed and also revealed neither tuberculosis nor tumour.
A percutaneous lung biopsy was requested. For this purpose, the patient was positioned left-lateral, that is, on the contra-lateral side, and a percutaneous biopsy under CT guidance was performed using a core needle biopsy system with a 17/18-gauge sized coaxial needle (Bard Magnum Biopsy System, Bard TruGuide Disposable Coaxial Needle; C. R. Bard, Tempe, USA). The guiding needle was placed 17 mm intrapulmonarily in the dorsal cavity wall and four cutting biopsies in slightly different directions were performed, each with a penetration depth of 22 mm (Figure 1). During these procedures, a one-time coughing episode of the otherwise clinically unremarkable patient was noticed. After the biopsies control-scans were performed, as it was routinely done in our institution until the described case, that is, with only a few selected scans in the area of the lesion and the midfield of the lungs to rule out pneumothorax or relevant bleeding, failing to detect any complication. After this the patient was turned back into the supine position and put into his bed, where he sat up. This manoeuvre immediately made him become unconscious. A promptly performed cranial CT scan showed a cerebral air embolism (Figure 2). After being intubated and ventilated in a Trendelenburg position, as far as was practically possible on the CT table, a control-scan of the entire thorax was performed to rule out air in the left heart or ascending aorta.
The patient was monitored in the intensive care unit and within few hours transferred to another facility where he received hyperbaric oxygen therapy. After five days, he was transferred back to our hospital. Follow-up cranial CT showed no signs of ischemia or cerebral infarction. Subjectively the patient became completely free of complaints, but neurological examination showed signs of a minor neurological deficit in the form of a pyramidal tract syndrome on the right side.
Lung biopsy specimens showed an inflammatory disorder but did not indicate presence of a tumour. The patient was dismissed 18 days after the incident.
Recapitulating this case, at least four risk factors for air embolism due to CT-guided lung biopsy can be pointed out: a cavitary lesion, coughing during the procedure, location of the lesion above the level of the left atrium, and use of a coaxial needle in the conventional manner, that is, with opening the outer cannula to the atmosphere several times.