Risk Factors for In-Stent Stenosis After Flow Diverter Treatment of Intracranial Aneurysms: A Systematic Review and Meta-Analysis of 2350 Patients.

BACKGROUND AND OBJECTIVES: Recent advances in flow diverter (FD) therapy for intracranial aneurysms have highlighted the need to evaluate risk factors for in-stent stenosis (ISS), a potentially serious complication. This meta-analysis aims to identify risk factors associated with an increased risk of ISS after FD treatment. METHODS: PubMed, Web of Science, Embase, and SCOPUS databases were systematically searched for studies reporting ISS rates and risk factors after FD therapy for intracranial aneurysms. Odds ratios were calculated using random-effects models to assess potential risk factors associated with ISS. RESULTS: Ten studies involving 2350 patients with 2441 aneurysms were included. Younger age (P = .006) and male sex (P = .003) were associated with higher ISS risk. Smoking also increased the risk (P = .02). Aneurysm location in the posterior circulation (P < .00001) and fusiform morphology (P < .00001) were significant risk factors for ISS, as were ruptured aneurysms (P = .05). Hypertension, hyperlipidemia, diabetes, allergies, and alcohol abuse, as well as aneurysm size, neck width, and parent artery diameter, did not affect ISS risk. Procedural factors like balloon angioplasty, multiple FDs, or FD/coil combinations were not significantly associated with ISS. CONCLUSION: This meta-analysis identified both nonmodifiable (younger age, male sex) and modifiable (smoking) patient factors, as well as high-risk aneurysm characteristics (posterior circulation, fusiform, ruptured), associated with an increased risk of ISS after FD treatment. These findings highlight the importance of tailored monitoring and management approaches for optimizing outcomes in FD therapy.

Management of Previously Failed Coiling and Clipping of a Middle Cerebral Artery Aneurysm.

Endovascular coiling techniques have emerged as an alternative and effective approach for treating intracranial aneurysms. However, in some cases, previously coiled aneurysms may require secondary treatment with surgical clipping, presenting a more complex challenge compared with the initial intervention.1,2 We present the case of a 39-year-old man with a residual class III Raymond-Roy occlusion partially coiled aneurysm at the left middle cerebral artery bifurcation (Video 1). Faced with the risks of rerupture, the patient underwent microsurgical treatment after providing consent. Despite successful initial microsurgical clipping, postoperative complications arose due to coil protrusion into the middle cerebral artery bifurcation, resulting in thrombotic occlusion of the frontal M2 branch. Emergency repeat microsurgical intervention and administration of a thrombolytic agent were performed to address complications, ultimately preserving blood flow. Subsequent endovascular placement of a flow-diverting stent 7 weeks after discharge confirmed complete occlusion of the aneurysm. The patient had no neurological deficit on follow-up. When planning microsurgical clipping of an aneurysm previously treated with coils, it is critical to consider coil placement, as there is a risk of prolapse if the coil is in the neck of the aneurysm. Thrombosis of the cerebral arteries is a potential complication of microsurgical clipping of partially coiled intracranial aneurysms, and injection of a fibrinolytic agent into thrombosed arterial branches may be an effective intraoperative method for treating intra-arterial thrombosis.3 This case illustrates the challenges associated with treating partially coiled aneurysms, highlighting the significance of careful planning when considering microsurgical treatment.

A unique anatomic variant: Left anterior choroidal artery arising proximal to fetal posterior communicating artery.

Anomalous vascular variants pose unique challenges in clinical management, especially in the context of neuroendovascular intervention. We present a case report detailing an extremely rare anatomic variant involving the left anterior choroidal artery, which arises proximal to the fetal posterior communicating artery. Our patient presented with confusion and speech abnormalities following a benzodiazepine overdose. Subsequent computed tomography of the head revealed an aneurysm originating from the left supraclinoid carotid artery. This aneurysm was located 2 mm more proximal to the origin of the left posterior communicating artery and was initially misidentified as originating from the left posterior communicating artery due to its proximity. Further diagnostic cerebral angiography revealed an extremely rare anatomical variant where the left anterior choroidal artery anomalously arose proximal to a fetal posterior communicating artery, with the aneurysm being correctly identified as arising from the left anterior choroidal artery. The patient underwent successful detoxification and has since shown remarkable improvement, with plans for elective endovascular flow diversion treatment under dual antiplatelet therapy. Considering the critical role of the anterior choroidal artery in supplying vital cerebral structures, awareness of such variants is paramount to prevent inadvertent vascular injury and optimize patient outcomes. This case highlights the necessity of meticulous pre-procedural imaging and multidisciplinary collaboration in managing neurovascular anomalies effectively.

Bihemispheric ischemic strokes in patients with COVID-19.

BACKGROUND: There is emerging evidence that COVID-19 can trigger thrombosis because of a hypercoagulable state, including large-vessel occlusion ischemic strokes. Bihemispheric ischemic stroke is uncommon and is thought to indicate an embolic source. Here, we examine the findings and outcomes of patients with bihemispheric stroke in the setting of COVID-19. METHODS: We performed a retrospective cohort study at a quaternary academic medical center between March 1, 2020, and April 30, 2020. We identified all patients with laboratory-confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection who presented with simultaneous bihemispheric ischemic strokes. RESULTS: Of 637 COVID-19 admissions during the 2-month period, 13 had a diagnosis of acute ischemic stroke, including 5 who developed bihemispheric cerebral infarction. Three of those 5 (60%) were female, median age was 54 (range 41-67), and all five were being managed for severe COVID-19-related pneumonia complicated by acute kidney injury and liver failure before the diagnosis of cerebral infarction was established. Five presented with elevated ferritin, lactate dehydrogenase, and interleukin-6 (IL-6) levels, and four had lymphopenia and elevated D-dimer levels. All patients underwent neuroimaging with computed tomography for persistent depressed mentation, with or without a focal neurologic deficit, demonstrating multifocal ischemic strokes with bihemispheric involvement. Outcome was poor in all patients: two were discharged to a rehabilitation facility with moderate-to-severe disability and three (60%) patients died. CONCLUSIONS: Stroke is implicated in SARS-CoV-2 infection. Although causality cannot be established, we present the imaging and clinical findings of patients with COVID-19 and simultaneous bihemispheric ischemic strokes. Multifocal ischemic strokes with bihemispheric involvement should be considered in COVID-19 patients with severe infection and poor neurologic status and may be associated with poor outcomes.