Novel use of precipitating hydrophobic injectable liquid (PHIL) in pre-operative angioembolisation of a large posterior auricular arteriovenous malformation.

BACKGROUND: Large arteriovenous malformations are often managed via endovascular embolisation followed by surgical resection. We describe the use of a new liquid embolic agent (LEA) - precipitating hydrophobic injectable liquid (PHIL) and its advantages over existing LEAs. CASE: A 60-year-old male presented with a progressively enlarging right post-auricular arteriovenous malformation. He underwent successive angioembolisation with PHIL and subsequent surgical resection on post-embolisation day 1. CONCLUSION: To our knowledge, this is the first reported case of PHIL being used in pre-operative embolization of a large extra-cranial head and neck AVM. Its excellent penetration into small calibre vessels, decreased glare artefact on imaging and decreased skin pigmentation render it a compelling alternative to existing LEAs.

Endovascular treatment of wide-neck bifurcation aneurysms using pCONUS2 HPC bridging device with single antiplatelet: A Case Series.

RATIONALE: Wide neck bifurcation aneurysms (WNBA) are technically challenging for both surgical and endovascular treatments. Endovascular treatment for WNBA often requires dual antiplatelet therapy (DAPT) post stent insertion. Novel devices such as the pCONUS2 HPC neck bridging device have an HPC coating which reduces the device thrombogenicity. This theoretically allows for use of single antiplatelet therapy (SAPT), which would be advantageous, particularly in treating ruptured aneurysms. This case series aims to evaluate the safety of SAPT regimen only post stent insertion, by presenting our center early clinical experience in using pCONUS2 HPC neck bridging device in patients that are not suitable for DAPT. PATIENT CONCERNS: We report the cases of 3 patients (2 females, 1 male; range: 64-71 years old) who underwent coil embolization for WNBA using the pCONUS2 HPC device (2 unruptured WNBA, and 1 ruptured WNBA). As all 3 patients were allergic to Aspirin, they could only be started on SAPT post endovascular therapy. DIAGNOSIS: All 3 patients were diagnosed with WNBA on angiographic studies. Patient 1 had an unruptured left middle cerebral artery aneurysm; Patient 2 had a ruptured basilar tip aneurysm; Patient 3 had an unruptured anterior communicating artery (ACOM) aneurysm. INTERVENTIONS: All 3 WNBA were treated with pCONUS2 HPC neck bridging device. OUTCOMES: There were no immediate complications. The immediate angiographic result of aneurysm treatment in Patient 1 and Patient 2 demonstrated incomplete occlusions, with delayed complete occlusion of aneurysm in Patient 1 and growth of aneurysmal neck in Patient 2 on follow-up angiograms (range: 6-9 months). No major thrombo-embolic or hemorrhagic complications in the first 2 patients. For Patient 3, the immediate angiographic result of the treated aneurysm demonstrated complete occlusion. However, the patient readmitted 11 days post procedure with cerebral infarction, scoring 5 on the modified Rankin scale on discharge. LESSONS: pCONUS2 HPC as a neck bridging device in treating WNBA has yet to be shown superior to traditional techniques and devices. The theoretical advantage of HPC coating reducing its thrombogenicity requiring only SAPT is yet to be proven safe in clinical practice.

World federation of interventional and therapeutic neuroradiology (WFITN) federation assembly neurointerventional surgery safety checklist.

Over the last 10 years, there has been a rise in neurointerventional case complexity, device variety and physician distractions. Even among experienced physicians, this trend challenges our memory and concentration, making it more difficult to remember safety principles and their implications. Checklists are regarded by some as a redundant exercise that wastes time, or as an attack on physician autonomy. However, given the increasing case and disease complexity along with the number of distractions, it is even more important now to have a compelling reminder of safety principles that preserve habits that are susceptible to being overlooked because they seem mundane. Most hospitals have mandated a pre-procedure neurointerventional time-out checklist, but often it ends up being done in a cursory fashion for the primary purpose of 'checking off boxes'. There may be value in iterating the checklist to further emphasize safety and communication. The Federation Assembly of the World Federation of Interventional and Therapeutic Neuroradiology (WFITN) decided to construct a checklist for neurointerventional cases based on a review of the literature and insights from an expert panel.

Microcatheter-Assisted Protection of the Posterior Inferior Cerebellar Artery During Parent Artery Sacrifice of a Vertebral Artery Dissecting Aneurysm.

Branch vessel occlusion is a major cause of stroke in parent artery sacrifice (PAS) for vertebral artery dissecting aneurysms (VADA). There is now an increasing trend towards preservation of branch vessels during PAS. Stents are commonly employed to achieve this but bring with it the attendant risks of future thrombosis and lifelong antiplatelet use. Although a microcatheter protection technique has been utilised in branch artery protection of wide-necked saccular aneurysms, it has rarely been described in PAS for VADAs. We describe the use of a dual microcatheter technique in the protection and remodelling of the posterior inferior cerebellar artery (PICA) during PAS of the vertebral artery, which also served as a temporary scaffold to support placement of the coils during the embolisation process.

Current state of acute stroke care in Southeast Asian countries.

Acute stroke care systems in Southeast Asian countries are at various stages of development, with disparate treatment availability and practice in terms of intravenous thrombolysis and endovascular therapy. With the advent of successful endovascular therapy stroke trials over the past decade, the pressure to revise and advance acute stroke management has greatly intensified. Southeast Asian patients exhibit unique stroke features, such as increased susceptibility to intracranial atherosclerosis and higher prevalence of intracranial haemorrhage, likely secondary to modified vascular risk factors from differing dietary and lifestyle habits. Accordingly, the practice of acute endovascular stroke interventions needs to take into account these considerations. Acute stroke care systems in Southeast Asia also face a unique challenge of huge stroke burden against a background of ageing population, differing political landscape and healthcare systems in these countries. Building on existing published data, further complemented by multi-national interaction and collaboration over the past few years, the current state of acute stroke care systems with existing endovascular therapy services in Southeast Asian countries are consolidated and analysed in this review. The challenges facing acute stroke care strategies in this region are discussed.

Cerebrofacial arteriovenous metameric syndrome with hypopituitarism: a rare association.

Case of cerebrofacial arteriovenous metameric syndrome (CAMS) in a 9-year-old boy is described with arteriovenous malformation simultaneously involving the brain and face, with characteristic CAMS type 1 and 2 involvement. This patient demonstrates the wide spectrum of clinical manifestations of CAMS, and in this particular case, the patient exhibits features of hypopituitarism-an association that was not previously described in the literature to our knowledge. Awareness of the underlying embryological abnormality and recognition of resultant clinical and radiological presentations are paramount for diagnosis and treatment.

The MERCI Retrieval System for the management of acute ischaemic stroke--the NNI Singapore experience.

INTRODUCTION: Systemic and local intra-arterial thrombolysis in patients with large vessel ischaemic stroke is hampered by poor re-canalisation rates and risk of haemorrhage. The Merci Retrieval System is an endovascular device for removal of acute intracranial thrombus. We present our initial experience using this device in conjunction with existing thrombolytic therapy already in place in our institute. MATERIALS AND METHODS: Prospective data in all patients presenting with large vessel ischaemic stroke treated using the Merci Retrieval System from July 2007 to March 2009 were analysed. Selection criteria for patients were similar to the multi- Merci trial of 2008. We compared re-canalisation rate, National Institutes of Health Stroke Score (NIHSS) and modified Rankin score (mRS) outcomes to the published trial results. RESULTS: Seventeen patients were reviewed; none suffered immediate post-procedural complications. Fifteen underwent successful thrombus retrieval but in 2 cases the device failed due to technical considerations. Sites of vascular occlusion included: ICA/ICA-'T' junctions 27%, middle cerebral artery 13% and vertebrobasilar artery 60%. Of the 15 patients treated by MERCI with or without adjuvant thrombolytic therapy, complete re-canalisation was achieved in 60%, partial re-canalisation in 20%, partial re-canalisation with persistent distal vessel occlusion in 6% and failure of re-canalisation in 14%. Asymptomatic haemorrhage occurred in 33% and there was 1 death (6%) from symptomatic haemorrhage. Pre-treatment median NIHSS was 17.88 and 9.5 immediately post-treatment. Median mRS at 30 days was 2.6 for patients who achieved complete re-canalisation and 4.5 in failure or partial re-canalisation with or without persistent distal vessel occlusion. CONCLUSION: Re-canalisation rates using the Merci Retrieval System was comparable to the multi-Merci trial. Haemorrhagic complications and safety were also found to be satisfactory. Importantly, treatment success with eventual good clinical outcome hinges strongly on the ability of the device to achieve complete re-canalisation.

Multi-detector computer tomography angiography in the initial assessment of patients acutely suspected of having intracranial aneurysm rupture.

INTRODUCTION: Multi-detector computer tomography angiography (CTA) provides a fast non-invasive assessment of the cerebral vessels, is readily available in an acute setting and can potentially replace invasive digital subtraction angiography (DSA) for the diagnosis of intracranial vascular lesions in an emergency setting. We report our experience in the use of emergent cerebral CTA versus DSA in the assessment of patients presenting acutely with symptoms suspicious of brain aneurysm rupture. MATERIALS AND METHODS: Thirty-seven consecutive patients presenting acutely with clinical suspicion of brain aneurysm rupture were evaluated over a 4-month period from January to April 2008. CTA with peripheral intravenous contrast injection was performed on a 32 slice helical scanner. DSA was performed within 48 hours for all cases when CTA was the initial assessment. Studies were assessed via radiology reports using DSA or surgery as the gold standard. RESULTS: All except for 3 patients had CTA as the initial study. There were 26 cerebral aneurysms detected by CTA in these 37 patients, with 9 negative studies. There were 2 patients with arteriovenous malformations (AVM), 1 with AV fistula (AVF), 1 tumoral bleed, 2 vertebral dissections, and 1 missed sagittal sinus thrombosis (CVT) on CTA. Based solely on CTA assessment, 3 patients had direct surgical clipping of the aneurysm, while 4 proceeded to direct endovascular coiling. CONCLUSION: Emergent CTA is a non-invasive, reliable and viable alternative to emergent DSA for the assessment of the cerebral vessels in the acute assessment of patients presenting with symptoms suspicious of brain aneurysm rupture. Where positive, it can serve as a guide to therapeutic decisions. Review of CTA source data is essential, especially for small lesions and for post-clipping assessment.

Impact of aneurysmal geometry on intraaneurysmal flow: a computerized flow simulation study.

INTRODUCTION: This study was performed to assess the effect of aneurysm geometry on parameters that may have an impact on the natural history of intracranial aneurysms, such as intraaneurysmal flow pressure and shear stress. METHODS: Flow was simulated in 21 randomly selected aneurysms using finite volume modeling. Ten aneurysms were classified as side-wall aneurysms, with either single-sided or circumferential involvement of the parent artery wall, and 11 as bifurcation aneurysms (symmetric or asymmetric), with an axis either perpendicular or parallel to the parent artery. The flow patterns were classified as either jet or vortex types (with regular or irregular vortex flow). Pressures and shear stresses were characterized as evenly or unevenly distributed over the aneurysm wall and neck. RESULTS: All side-wall and four of the bifurcation aneurysms with a perpendicular axis had a vortex type flow pattern and seven bifurcation aneurysms with a parallel axis (four symmetric and two asymmetric) had a jet flow pattern. Jet type flow was associated with an uneven pressure distribution in seven out of seven aneurysms. Vortex type flow resulted in an even pressure distribution in five out of six aneurysms with an irregular flow pattern and six out of eight with a regular flow pattern. No firm relationship could be established between any geometrical type and shear stress distribution. Only 1 of 14 aneurysms with a perpendicular axis, but 4 of 7 aneurysms with a parallel axis, had ruptured. CONCLUSION: Aneurysm geometry does have an impact on flow conditions. Aneurysms with a main axis parallel to the parent artery have a tendency to have a jet flow pattern and uneven distribution of unsteady pressure. These aneurysms may have a higher rate of rupture as than those with a main axis perpendicular to the parent artery.