Post-traumatic pseudoaneurysm of the external carotid artery

Abstract

Our case is about a 24-year-old male who consults in an emergency for a left cervical swelling with a history of a penetrating cervical trauma occurred 15 days before. Computed Tomography (CT) was performed who shows a hypo dense left cervical collection well limited surmounted by a spontaneously hyper dense hematoma (A, B), with intense enhancement on post contrast at arterial time with individualization of communication with a branch of the external carotid artery (C,D) characteristic of the pseudo aneurysm (PA). The PA or false aneurysm is defined by a rupture of the continuity of the arterial wall with creation of an aneurysmal sac thanks to a pseudo-wall formed by the adjacent structures while maintaining continuity with the nourishing artery, PA carotid arteries are often post-traumatic sometimes other cause are involved (vasculitis, local infection, iatrogenic). The interval between trauma and symptoms is very variable, it results in a pulsating and pulsating cervical swelling on palpation with an audible noise on auscultation, ultrasound shows a cystic mass with a turbulence in the blood flow making the yin-yong sign on doppler examination and to-and-fro waveforms on the pulsed Doppler examination. Computed Tomography generally targets a hypo-dense collection with an intense vascular type enhancement in arterial time and a smooth wall which communicates with a nourishing artery. Magnetic resonance imaging (MRI) allows more characterization (morphology, size of collar, study of collaterality). Conventional angiography is an invasive examination which generally presents a therapeutic interest (stenting, embolization) while the surgical indication is reserved for specific cases.