Optical coherence tomography of traumatic aneurysms of the internal carotid artery: report of 2 cases

Abstract

The pathophysiology of extracranial traumatic aneurysm formation has not been fully elucidated. Intraarterial optical coherence tomography (OCT), an imaging modality capable of micrometer cross-sectional resolution, was used to evaluate patients presenting with saccular traumatic aneurysms of the internal carotid artery (ICA). Two consecutive trauma patients diagnosed with saccular traumatic aneurysms of the cervical ICA, per the institutional screening protocol for traumatic cerebrovascular injury, underwent digital subtraction angiography (DSA) with OCT. Optical coherence tomography demonstrated disruption of the intima with preservation and stretching of the more peripheral layers. In 1 patient the traumatic aneurysm was associated with thrombus formation and a separate, more proximal dissection not visible on CT angiography (CTA) or DSA. Imaging with OCT indicates that saccular traumatic aneurysms may develop from disruption of the intima with at least partial preservation of the media and adventitia. This provides in vivo evidence that saccular traumatic aneurysms result from a partial arterial wall tear rather than complete disruption. Interestingly, OCT was also able to detect arterial injury and thrombi not visible on CTA or DSA.

Blunt Traumatic Extracranial Cerebrovascular Injury and Ischemic Stroke

“…However, TCVI differs from spontaneous dissection in several ways. Specifically, (1) most TCVIs are initially asymptomatic and discovered by screening imaging; (2) high-energy TCVI is likely biologically distinct from spontaneous dissections, which are frequently related to underlying connective tissue abnormalities [2]; (3) most blunt trauma patients experience a hypercoagulable state soon after injury [3] that coincides with the time course of ischemic stroke with TCVI, mostly occurring within 72 h of the injury [4]; (4) spontaneous cervical arterial dissections tend to primarily affect the outer arterial wall [5], in contrast to TCVI, in which intimal disruptions are relatively common [6, 7, 8]; and (5) patients with TCVI often have other traumatic injuries, making their management more complex than patients with spontaneous dissection.…”

“…An intimal defect can provide a pathway for blood to enter the layers of the artery wall, causing stenosis or occlusion of the artery. Disruption of the elastic laminae may lead to expansion of the adventitia with traumatic aneurysm formation [8]. The cervical internal carotid artery (ICA) is most vulnerable to stretch injury in the region between the soft tissue of the neck and the petrous canal.…”

Collar Sign in Incompletely Occluded Aneurysms after Pipeline Embolization: Evaluation with Angiography and Optical Coherence Tomography

“…An OCT acquisition over 2.7 seconds was done during power injection of contrast to trigger the internalized automated "pull-back" method that renders catheter manipulation unnecessary during image acquisition and to transiently clear red blood cells from the imaging area. 5,6 Image processing and data analysis were done using a commercially available OCT system (Ilumien System; St. Jude Medical).…”

Endovascular treatment of blunt injury of the extracranial internal carotid artery: the prospect and dilemma

“…In addition, intraarterial optical coherence tomography is a new technique that provides in vivo evidence of arterial injury and thrombi not visible on CTA or DSA [39].…”