Analysis of Closed-Cell Intracranial Stent Characteristics Using Cone-Beam Computed Tomography With Contrast Material

Abstract

The intracranial nitinol stent named the Enterprise Vascular Reconstruction Device has poor radiographic visibility. The characteristics of closed-cell intracranial stents were investigated and the efficacy of intraoperative stent visualization examined with the 80 kV high-resolution XperCT protocol, which is a flat detector C-arm volume acquisition functionality system integrated with the angiography equipment. We treated 39 aneurysms with stent-assisted coil embolization. The aneurysms were located on the internal carotid artery in 24 cases, the anterior communicating artery (AcomA) in three, the basilar artery (BA) in 10, and the vertebral artery in two. Intraoperative 80 kV XperCT was performed in all cases after deposition of the stent. We evaluated the coverage of the aneurysm neck, incomplete stent apposition (ISA), and shift of vessels. Accurate stent visualization was achieved in 29 of the 39 cases without coil and delivery wire artifact. Coverage of the aneurysm neck succeeded in 28 cases; there was one case of BA top Y-configuration stenting in which the stent was dislocated into the aneurysm. ISA was detected in nine cases, including seven kinks and one flattening in the carotid siphon and one kink in the BA top. We detected linearization of vessels due to stent deployment in three AcomA cases and three BA top cases. We conclude that intraoperative 80 kV XperCT is an efficient modality for the evaluation of ISA. Stent kinking in the carotid siphon and linearization in distal vessels can be detected with this protocol.

High-Resolution C-Arm CT and Metal Artifact Reduction Software: A Novel Imaging Modality for Analyzing Aneurysms Treated with Stent-Assisted Coil Embolization

“…Ovalization or kinking of the deployed stent in the parent artery is another limitation. [5][6][7][8] This phenomenon, also called "inappropriate stent apposition," can hinder the growth of neointimal coverage on the stent. 9 Consequently, treated patients are required to undergo a prolonged postprocedural antiplatelet therapy.…”

Evaluation of Estimated Exposure of the Lens Due to Cone-beam CT and Area Detector CT

“…Since the estimated exposure of the lens decreases by 30% at a tube voltage of 110 kV compared with 80 kV, the dose at the lens decreases at high tube voltages ( Table 6). Low-voltage imaging, by which contrast is expected to be enhanced, is often employed for delineation of intracranial stents, 11) but high-voltage imaging is preferred for the important to select appropriate scanning conditions by specifying the objective.…”

Usefulness of Cone Beam Intra-Arterial CTA for Evaluation of Flow Diverters: A Practical Approach for Daily Use

“…Radiological evaluation of flow diverter braid expansion and conformability to the vessel wall has become useful in preventing complications carrying important clinical applicability [3,4]. Common scenarios such as incomplete coverage of an aneurysm neck, kinking, or incomplete expansion and malapposition of a stent carry a significant risk for thromboembolic events [3,4].…”

“…Common scenarios such as incomplete coverage of an aneurysm neck, kinking, or incomplete expansion and malapposition of a stent carry a significant risk for thromboembolic events [3,4]. Conventional cerebral angiography (digital subtraction angiography, DSA), CT angiography (CTA), and magnetic resonance angiography (MRA) of the head techniques have been applied for intra-and postprocedural visualization of flow diverters; however, these techniques have limitations [3,5,6].…”

“…Initially used as a CT scan for evaluation of intraprocedural complications such as hemorrhage, it has evolved to provide details of implanted devices such as flow diverters. This imaging modality has been used to provide meaningful radiological information with regard to the neurovascular anatomy and morphology as well as implanted devices [1,4,7].…”