Enlarging Trauma-Induced Superficial Temporal Artery Pseudoaneurysm

Introduction Pseudoaneurysm of the superficial temporal artery is rare and most often the result of blunt trauma to the head. Thomas Bartholin first observed and reported on this phenomenon in 1740. Case Report Presented is the case of an 18-year-old man referred for the evaluation of a pulsatile mass over the left temple that developed after an altercation occurring in the preceding 2 months. Methods Duplex ultrasound examination was performed with the use of a Philips IU22 (Bothell, WA) with a 17–5 MHz linear transducer. Results Fusiform dilation of the frontal branch of the superficial temporal artery was noted, measuring 0.6 × 0.8 cm and containing echogenic material. The proximal segment of the artery measured 0.2 × 0.2 cm. A follow-up scan was performed 6 weeks later demonstrating enlargement of the aneurysm to 0.6 × 1.2 cm with additional homogeneous thrombus. The aneurysm was resected, followed by suture ligation of the inflow and outflow arteries. Pathologic description was consistent with a dilated segment of artery filled with organizing granulating tissue and focal areas of thrombosis. The wall of the aneurysm consisted of fibrous tissue only, with no evidence of a muscular layer. No evidence of inflammatory infiltrate or giant cells was identified. Conclusions Aneurysms may be saccular or fusiform and may be true or false. Aneurysmal dilation is identified when a vessel measures 1.5 times the diameter of the proximal segment. A true aneurysm will involve all layers of the vessel wall, whereas a false aneurysm (pseudoaneurysm) is identified when less than all layers of the vessel wall are involved. Aneurysms resulting from a single traumatic event, such as the one described in the present case report, are most often pseudoaneurysms. The superficial temporal artery and its branches are readily and accurately evaluated and characterized by duplex ultrasound.