Migrating bullet: A case of a bullet embolism to the pulmonary artery with secondary pulmonary infarction after gunshot wound to the left globe
A 25-year-old male was brought to the emergency department after being found at the side of the road. At presentation, the patient was unconscious. His vital signs were: blood pressure of 145 mmHg systolic over 122 mmHg diastolic, heart rate of 130 beats/min, respiratory rate of 24, and peripheral oxygen saturation of 91% on room air. Physical exam was notable for facial lacerations and a ruptured left globe related to a gunshot entrance wound. No exit wound was identified. A head computed tomography (CT) demonstrated the trajectory of the bullet, which had ruptured his left globe, travelled along the skull base fracturing his carotid canals bilaterally, and was located in the right transverse sinus []. The bullet was round and measured approximately 5 mm in diameter, the characteristic size and shape of a BB gun bullet.\nDue to extensive intracranial haemorrhage, the patient was taken to the operating room for placement of an external ventriculostomy shunt catheter. Post-operatively, contrast enhanced computed tomography angiography of the head was performed, which demonstrated occlusion of the left internal carotid artery []. However, it was also noted that the previously identified bullet was no longer located in the right transverse sinus. At admission, a portable chest radiograph had been unremarkable []. Approximately 2.5 h later, a repeat post-operative chest radiograph showed a new round foreign body resembling a BB that projected over the left hilum with interval development of a wedge shaped pulmonary opacity silhouetting the left hemidiaphragm []. It was suspected that the BB had embolized through the right jugular vein to the patient's heart and to a peripheral branch of a left lower lobe pulmonary artery. Chest CT confirmed that the bullet was now located in a left lower lobe with an associated pulmonary infarct, a small left-sided pneumothorax, and extensive pneumomediastinum [Figure and ]. The patient was admitted to the intensive care unit and evaluated by cardiothoracic surgery. No intervention to remove the bullet was performed as the patient was critically ill from a neurological perspective.