Superficial Temporal Artery Pseudoaneurysm: Diagnosis and Preoperative Planning with CT Angiography

Images from the case of a 50-year-old man who presented with a pulsatile preauricular mass 4 weeks after undergoing pterional craniotomy for aneurysm repair.

A, Axial 2.5-mm source CT angiogram shows the inner enhancing component (single white arrow) of the STA pseudoaneurysm. The surrounding soft tissue attenuation (triple white arrows) represents peripheral thrombus and adjacent inflammatory change.

B, Coronal oblique 2D reformat CT angiogram shows the relationship of the main trunk of the STA (single white arrow) to the pseudoaneurysm (black arrow). The frontal branch of the STA (double white arrows) is seen superior to the pseudoaneurysm.

C, 3D volume-rendered CT angiogram depicts the main trunk of the STA (single white arrow), the STA pseudoaneurysm (yellow arrow), and the frontal branch of the STA (double white arrows). Note the relationship of the pseudoaneurysm to the zygomatic arch. The STA ventral to the pseudoaneurysm is difficult to distinguish from the enhanced component of the pseudoaneurysm.

D, Intraoperative digital photograph shows the STA pseudoaneurysm. Note the normal STA (short white arrows), ventral to the pseudoaneurysm. A small tear in the main trunk of the STA (double white arrows) was the origin of the pseudoaneurysm.

E, Elastic Van Gieson stain (original magnification, ×20). The dark staining internal (black arrow) and external (black arrowhead) elastic laminae are seen in the normal STA. The absence of elastic fibers in the wall (asterisks) of the organized thrombus confirmed the diagnosis of pseudoaneurysm.