Hui, Ferdinand

Background The eccentric stenosis morphology in patients with intracranial atherosclerotic stenosis (ICAS) has a critical impact on the efficacy of endovascular treatment. This study aimed to establish a rabbit model of eccentric carotid atherosclerotic stenosis that mimics the pathophysiological and morphological characteristics of eccentric plaques in humans. Methods Rabbits received localized cryoinjury of the right carotid artery after 2 weeks of a high fat, high cholesterol diet, followed by an additional 8 weeks on the same diet. On the experimental endpoint, comprehensive analyses of the model’s pathological changes were conducted using serum lipid analysis, DSA, optical coherence tomography (OCT), histopathological analysis, and immunohistochemistry. Results The high fat, high cholesterol diet significantly elevated serum lipid levels in rabbits. Hematoxylin and eosin staining results at 24 hours postoperatively revealed focal intimal damage induced by 5 s of cryoinjury. After localized cryoinjury and high fat, high cholesterol diet feeding, DSA results demonstrated significant carotid stenosis, with a stenosis degree of 47±5% and a length of approximately 9 mm. OCT images revealed eccentric fibrous plaque formation at the stenotic site. Morphological analysis of the plaque samples demonstrated a plaque eccentricity index of 0.66±0.05 and a plaque burden of 60.68±7.41%. Histopathological analysis showed that atherosclerotic lesions developed in all rabbits of the model group. Among them, three rabbits had intermediate lesions, one rabbit had atheroma, and eight rabbits had fibroatheroma. Conclusions This study successfully established a rabbit model of eccentric carotid atherosclerotic stenosis, providing a novel experimental platform for transformation research of neurointerventional devices.

Objective Cognitive impairment is increasingly recognized in patients with cerebral venous congestion (CVC), yet the cognitive tools used are largely adapted from stroke and dementia research. This review examines current literature on cognitive function in CVC, including conditions such as cerebral venous sinus thrombosis (CVST), idiopathic intracranial hypertension (IIH), and dural arteriovenous fistulas (dAVFs). Special emphasis is placed on the limitations of common screening tools like the Montreal Cognitive Assessment (MoCA) and Mini-Mental State Examination (MMSE). Cognitive dysfunction—primarily affecting executive function, processing speed, and attention—is reported in up to 86% of CVC cases, yet only about 20% of studies use validated cognitive testing tools, most of which may lack sensitivity for CVC-specific deficits. Emerging techniques such as ocular motor testing and physiological markers show promise but require further validation. There is an urgent need for standardized, CVC-specific cognitive assessment protocols that reflect the unique pathophysiology of venous disorders. Future research should prioritize the development of targeted cognitive batteries and integrate objective physiological measures to enhance diagnostic accuracy.

Background Nickel hypersensitivity is the most common metal related allergy. Nickel containing alloys are frequently used in endovascular devices. The use of intracranial stents in patients with nickel hypersensitivity appears to be safe, but these small series only evaluated arterial stent placement. This case series aimed to assess the safety of intracranial venous stent placement in patients with documented nickel allergy. Methods In this retrospective multicenter case series, patients with idiopathic intracranial hypertension and documented nickel allergy underwent treatment with a permanently implanted nickel containing stent in the dural venous sinuses. Results Nine patients with nickel allergy were included. All patients reported clinical improvement in their idiopathic intracranial hypertension symptoms. Of the five patients who had follow-up intracranial venous imaging, all stents remained patent. No patients experienced intraoperative, postoperative, or long term procedure related complications, with follow-up ranging from 1.8 weeks to 49.1 months. Conclusion In this limited case series, the use of nickel containing stents in intracranial venous sinuses in patients with nickel allergy did not result in any allergic reaction or adverse outcome.

BACKGROUND: Several collateral venous pathways exist to assist in cranial venous drainage in addition to the internal jugular veins. The important extrajugular networks (EJN) are often readily identified on diagnostic cerebral angiography. However, the angiographic pattern of venous drainage through collateral EJN has not been previously compared among patients with and without idiopathic intracranial hypertension (IIH). OBJECTIVE: To quantify EJN on cerebral angiography among patients both with and without IIH and to determine whether there is a different EJN venous drainage pattern in patients with IIH. METHODS: Retrospective imaging review of 100 cerebral angiograms (50 IIH and 50 non-IIH patients) and medical records from a single academic medical center was performed by 2 independent experienced neuroendovascular surgeons. Points were assigned to EJN flow from 0 to 6 using an increasing scale (with each patient's dominant internal jugular vein standardized to 5 points to serve as the internal reference). Angiography of each patient included 11 separately graded extrajugular networks for internal carotid and vertebral artery injections. RESULTS: Patients in the IIH group had statistically significant greater flow in several of the extrajugular networks. Therefore, they preferentially drained through EJN compared with the non-IIH group. Right transverse-sigmoid system was most often dominant in both groups, yet there was a significantly greater prevalence of codominant sinus pattern on posterior circulation angiograms. CONCLUSION: Patients with IIH have greater utilization of EJN compared with patients without IIH. Whether this is merely an epiphenomenon or possesses actual cause-effect relationships needs to be determined with further studies.