The patient was a 91-year-old man with a medical history of chronic obstructive pulmonary disease and benign prostatic hyperplasia.
While driving, he accidentally stepped on the accelerator pedal instead of the brake and he crashed into a wall. His car's airbag deployed but it was not clear whether he had been wearing a seatbelt. After the accident the patient visited a nearby orthopedic surgeon. He was discharged with a diagnosis of rib fracture, but 6 h later he fainted at home and was admitted to our hospital. His vital signs at that time were: heart rate, 145 b.p.m.; blood pressure, 123/86 mmHg; respiratory rate, 26 breaths/min; body temperature, 36.1 C; and Glasgow Coma Scale 15. Paradoxical breathing was apparent. Physical findings showed a bruise on the upper part of the sternum and depressed chest on the left lower side of the sternum. No symptoms related to shock, such as pale or clammy skin, were evident.
A chest X-ray showed an enlargement of the upper mediastinum. Arterial phase of contrast-enhanced computed tomography (CT) revealed a mediastinal hematoma with active arterial hemorrhage (Fig. 1A). In addition, a sternum fracture, multiple rib fractures, and a bilateral hemothorax were observed. Based upon the arterial phase of contrast-enhanced CT, injury to the descending branch of the ThIA, which possibly originated from the brachiocephalic artery (Fig 1B), was suspected.
We undertook transcatheter arterial embolization (TAE) because the mediastinal hematoma was large enough to result in exacerbation of obstructive and/or hemorrhagic shock. Angiography showed that the ThIA did indeed originate from the brachiocephalic artery (Fig. 2). To carry out TAE, the brachiocephalic artery was selected with 5-Fr catheterization (Headhunter catheter; Medikit, Tokyo, Japan) and then the ThIA branch was selected with a 2-Fr microcatheter (LIGHTHOUSE; Piolax, Yokohama, Japan). Extravasation was imaged (Fig. 2). Transcatheter arterial embolization of the descending branch of the ThIA was carried out with a gelatin sponge and two micrometal coils (2 mm x 4 cm and 2.5 mm x 6 cm). Hemostasis was successful and the patient's heart rate decreased to 87 b.p.m. No complications related to the catheterization procedure arose. However, the next day, the patient required ventilator support. Although surgery for flail chest was undertaken on the 8th day of hospitalization, tracheostomy was ultimately required due to prolonged ventilator dependence. Subsequently, the patient was transferred to a different hospital for rehabilitation.