Okuläres Ischämiesyndrom: Diagnostik und Therapie

<b>Background:</b> Treatment of cervical internal carotid artery (ICA) stenosis has contributed to the improvement of ocular ischemic syndrome. However, there have been few cases of visual impairment caused by ocular ischemic syndrome due to intracranial ICA stenosis, which improved through intracranial stent placement. <b>Cas description:</b> A 76-year-old man presented with right-sided paralysis. Radiographic examination revealed severe stenosis of the left intracranial ICA (distal cavernous-infraclinoid portion) and a watershed infarction of the left cerebral hemisphere. Conservative therapy including antiplatelet drugs was initiated, but severe visual acuity disturbance in his left eye occurred 1 month after onset. The antegrade ocular artery flow recovered after urgent intracranial stent placement, and his vision improved immediately after the procedure. <b>Conclusion:</b> Visual impairment presenting as ocular ischemic syndrome can occur due to severe stenosis of the intracranial ICA, and treatment of these lesions could improve the symptoms.

Computational Study of Hemodynamic Changes Induced by Overlapping and Compacting of Stents and Flow Diverter in Cerebral Aneurysms

Purpose: The flow diversion effect of an intracranial stent is closely related to its metal coverage rate (MCR). In this study, the flow diversion effects of Enterprise and low-profile visualized intraluminal support (LVIS) stents are compared with those of a Pipeline flow diverter, focusing on the MCR change. Moreover, the changes in the flow diversion effect caused by the additional manipulations of overlapping and compaction are verified using computational fluid dynamics (CFD) analysis.Methods: CFD analysis was performed using virtually generated stents mounted in an idealized aneurysm model. First, the flow diversion effects of single Enterprise, LVIS, and Pipeline devices were analyzed. The Enterprise and LVIS were sequentially overlapped and compared with a Pipeline, to evaluate the effect of stent overlapping. The effect of compacting a stent was evaluated by comparing the flow diversion effects of a single and two compacted LVIS with those of two overlapped, uncompacted LVIS and uncompacted and compacted Pipeline. Quantitative analysis was performed to evaluate the hemodynamic parameters of energy loss, average velocity, and inflow rate.Results: Statistically significant correlations were observed between the reduction rates of the hemodynamic parameters and MCR. The single LVIS without compaction induced a reduction in all the hemodynamic parameters comparable to those of the three overlapped Enterprise. Moreover, the two overlapped, uncompacted LVIS showed a flow diversion effect as large as that induced by the single uncompacted Pipeline. Compacted stents induced a better flow diversion effect than uncompacted stents. The single compacted LVIS induced a flow diversion effect similar to that induced by the two uncompacted LVIS or single uncompacted Pipeline.Conclusions: The MCR of a stent correlates with its flow diversion effect. Overlapping and compaction can increase the MCR of an intracranial stent and achieve a flow diversion effect as large as that observed with a flow diverter.

Ocular ischemic syndrome due to severe internal carotid artery stenosis improved by intracranial stent placement: A case report

Background: Treatment of cervical internal carotid artery (ICA) stenosis has contributed to the improvement of ocular ischemic syndrome. However, there have been few cases of visual impairment caused by ocular ischemic syndrome due to intracranial ICA stenosis, which improved through intracranial stent placement. Case Description: A 76-year-old man presented with right-sided paralysis. Radiographic examination revealed severe stenosis of the left intracranial ICA (distal cavernous-infraclinoid portion) and a watershed infarction of the left cerebral hemisphere. Conservative therapy including antiplatelet drugs was initiated, but severe visual acuity disturbance in his left eye occurred 1 month after onset. The antegrade ocular artery flow recovered after urgent intracranial stent placement, and his vision improved immediately after the procedure. Conclusion: Visual impairment presenting as ocular ischemic syndrome can occur due to severe stenosis of the intracranial ICA, and treatment of these lesions could improve the symptoms.

Form and Function in Intracranial Neurovascular Stents: A Historical Perspective and State-of-the-Art Clinical Review for the Noninterventionalist

The use of intracranial stents in neurointerventional surgery has been practiced for decades. However, the spectrum of treatable pathology, available devices, and clinical adoption of intracranial stents has exploded in recent years. Diagnostic neuroradiologists play a critical role in the evaluation of these devices after deployment, yet may not be familiar with state-of-the-art intracranial stent devices and indications. This review provides an overview of intracranial stents for cerebrovascular disease, with 3 chief learning objectives: 1) to understand the basic principles of stent design, biomechanics, and deployment, and the resulting influence on cerebrovascular hemodynamics; 2) to be familiar with the spectrum of intracranial pathology amenable to endovascular stent placement; and 3) to recognize the radiographic appearance of successful intracranial stent deployment and intracranial stent‐related complications.Learning Objective: Recognize the key principles of design (form), current indications (function), and potential complications of intracranial stents used in neurointerventional surgery