Objective: The purpose of this report was to discuss the overall limitations, safety and efficacy of flow-diverter stenting for intracranial aneurysms. Methods: The authors performed a meta-analysis from January 2009 to September 2014 using the terms “flow diverter” and “intracranial aneurysms.” Additional studies were identified through references in each reviewed article. Data extraction, performed independently by the authors, included demographic data, technical and clinical complications, morbidity and mortality, aneurismal occlusion rates related to flow-diverter devices. The analysis was performed using a fixed effect. Results: Twenty-nine studies with 1524 patients and three to 62 months of follow-up were identified for analysis. The overall technical failure and complication rate was 9.3% (95% CI 6%–12.6%). The rate of procedure-related complication was 14% (95% CI 10.2%–17.9%) and 6.6% (95% CI 4%–9.1%) for morbidity and mortality. Fusiform, dissecting and circumferential aneurysm (OR 3.10, 95% CI 0.93–10.37) were significant risk factors for technical failure and complication. Posterior circulation location (OR 4.03, 95% CI 2.45–6.61), peripheral location (OR 2.74, 95% CI 1.52–4.94) and fusiform, dissecting and circumferential aneurysm (OR 1.95, 95% CI 1.15–3.30) were statistically significant risk factors for procedure-related complications. Posterior circulation location (OR 4.39, 95% CI 2.44–7.90) and peripheral location (OR 3.64, 95% CI 1.74–7.62) were statistically significant risk factors for morbidity and mortality. Conclusions: Fusiform, dissecting and circumferential aneurysm, posterior circulation and peripheral locations have greater procedure-related complications.

This paper reports the incidence of trigeminocardiac reflex (TCR) in endovascular treatment of dural arteriovenous fistulas (DAVFs) with Onyx. The consecutive case histories of 45 patients with DAVFs, treated with Onyx transarterially and transvenously, from February 2005 to February 2008 at Beijing Tiantan Hospital, China, were retrospectively reviewed. The time period was limited as the anesthetic and intravascular procedure was performed under the same standardized anesthetic protocol and by the same team. The TCR rate was subsequently calculated. Of the 45 patients, five showed evidence of TCR during transarterial Onyx injection and transvenous DMSO injection. Their HR fell 50% during intravascular procedures compared with levels immediately before the stimulus. However, blood pressure values were stable in all cases. The TCR rate for all patients was 11.1% (95% CI, 4 to 24%), 7.7% (95% CI, 2 to 21%) in patients treated intraarterially and 33.3% (4 to 78%) in patients treated intravenously. Once HR has fallen, intravenous atropine is indicated to block the depressor response and prevention further TCR episodes. TCR may occur due to chemical stimulus of DMSO and Onyx cast formation under a standardized anesthetic protocol and should be blunted by atropine.

The trigemino-cardiac reflex during Onyx embolization for dural arteriovenous fistula may be caused by mechanical or chemical stimulus to the terminals of the unencapsulated Ruffini-like receptors stemming from A-axons in the dural connective tissue at sites of dural arteries and sinuses. Slow A (Aδ) and fast A (Aβ) neurons may play a role in the stimulus afferent pathway due to their higher mechanosensitivity and chemosensitivity. These afferent pathway nerves are cholinergic innervations of the dura mater, which also contains vasoactive neuropeptides such as calcitonin gene-related peptide, substance P, and neurokinin A. Stimulation of meningeal sensory fibres can evoke cerebral vasodilation through the peripheral release of neuropeptides, which play a role in headache pathogenesis. These myelinated A-fibers terminate in the deep part (laminae III-V) of the spinal dorsal horn. Its efferent pathway has been defined as the acetylcholinergic vagus nerve. The A11 nucleus, located in the posterior hypothalamus, providing the only known source of descending dopaminergic innervation for the spinal grey matter, can inhibit the neurons in the spinal dorsal horn.

BACKGROUND AND PURPOSE: Surgical treatment of VA-PICA dissecting aneurysms is difficult and complication of LCNP is common. These lesions can be approached easily with endovascular technique, but complete obliteration can only be achieved in a small number of cases. Our aim was to report the clinical outcomes of VA-PICA dissecting aneurysms treated by endovascular embolization. MATERIALS AND METHODS: Between 2001 and 2007, the authors treated 22 consecutive patients (15 men and 7 women; ranging in age from 12 to 59 years; mean age, 43 years) with VA-PICA dissecting aneurysms. Diagnosis of VA-PICA dissecting aneurysm was based on clinical, MR imaging, and cerebral angiography studies. RESULTS: Of the 22 patients, 6 had unruptured aneurysms. One patient presented with headaches, whereas the remaining 5 patients showed brain stem ischemia. Four were treated with stent-only or stent-coil embolization, and 2 were treated with unilateral VA occlusion. Among 16 patients presenting with SAH, 10 were treated with stent-only or stent-coil embolization. The other 6 patients with SAH were treated by using unilateral endovascular VA occlusion. One patient could not return to his previous daily activities. CONCLUSIONS: VA-PICA aneurysms are rare lesions associated with significant morbidity, and endovascular treatment strategies for these lesions were stent deployment with or without coil embolization and VA occlusion. Favorable clinical outcomes can be achieved with endovascular techniques.

Background: Though flow diverter is a safe and efficient modality, some patients can experience delayed aneurysmal rupture. The mechanism of delayed rupture is still obscure to us. Methods: We performed a systematic search in the PubMed database for patients with delayed rupture of intracranial aneurysms after flow diverter placement. Results: A total of 36 articles reporting on 60 patients were included in the final analysis. Of the 49 patients with description of presenting symptoms, six (12.2%) patients were incidentally diagnosed, 39 (87.8%) patients were admitted for aneurysmal rupture or mass effect. Multiple flow diverters were used in 38.3% (18/47) of the patients. Coil assistance was applied in 13.0% (7/54) of the patients. Delayed aneurysmal rupture led to intracranial hemorrhage or carotid–cavernous sinus fistula (CCF) in 76.8% (43/56) and 23.2% (13/56) of the patients, respectively. Of the 55 patients with description of outcome, 14 (25.5%) patients achieved good recovery, one (1.8%) patient was severely disabled, 40 (72.7%) patients died. All of the patients in the CCF group survived and experienced good recovery. Conclusion: Increased intra-aneurysmal pressure, destabilization of the aneurysm wall by intra-aneurysmal thrombus, persistent residual intra-aneurysmal flow, characteristics of the specific aneurysm, and mechanical injury by the flow diverter might conjointly contribute to the final delayed rupture. There has been no established preventive measure to decrease the incidence of delayed rupture yet. The treatment and outcome depend on the presentation of delayed rupture. Patients presenting with aneurysm-related intracranial hemorrhage have a dismal outcome. Those presenting with CCFs usually have a satisfactory recovery.

We report our experience in treating patients with seizures associated with brain arteriovenous malformations (AVM) without a clinical history of intracranial hemorrhage. Between 2001 and 2003, the neurovascular unit at Beijing Tiantan Hospital treated 109 patients with brain AVM endovascularly. Thirty patients (27.5%) experienced seizures before treatment. We studied the following factors: sex, age, AVM size, AVM location, seizure type, duration of seizure history, endovascular treatment and AVM obliteration. Clinical follow-up was via telephone interview. Thirty patients with seizure disorders due to brain AVMs were endovascularly treated. The age of the patients ranged from eight to 55 years. There were 22 males and eight females. The AVMs were smaller than 3 cm in five patients, between 3 cm and 6 cm in 22, and larger than 6 cm in three. The most frequent location of the AVMs was in the frontal, followed by the parietal, temporal and occipital lobes. Sixty-seven embolization procedures were performed and total obliteration was achieved in four patients. Two patients developed a hemiparesis and three suffered temporary dysphasia after embolization. Two patients had visual field deficits. There were no deaths. The results of post-embolization seizure control during the average follow-up period of 80 months were excellent in 21 patients, good in four, fair in two and poor in three. Successful seizure control can be obtained with endovascular embolization.