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Two major studies, The International Subarachnoid Aneurysm Trial and the Barrow Ruptured Aneurysm Trial, compare the long-term outcomes of clipping and coiling. Although these demonstrated coiling's initial benefits, rebleeding and retreatment rates as well as converging patient outcomes sparked controversy regarding its durability. This article will critically examine the available evidence for and against clipping and coiling of intracranial aneurysms. Critics of endovascular treatment state that the initial benefit seen with endovascular coiling decreases over the duration of follow-up and eventually functional outcomes of both treatment modalities are similar. Combined with the increased rate of retreatment and rebleeding, these trials reveal that coiling is not as durable and not as effective as a long-term treatment compared to clipping. Also, due to the cost of devices following endovascular treatment and prolonged hospitalization following clipping, the financial burden has been considered controversial.Short-term outcomes reveal better morbidity and mortality outcomes following coiling. Despite the higher rates of retreatment and rebleeding with coiling, there was no significant change in functional outcomes following retreatment. Furthermore, examining more recent trials reveals a decreased rate of recurrence and rebleeding with improved technology and expertise. Functional outcomes deteriorate for both cohorts over time while recent results revealed improved long-term cognitive outcomes and levels of health-related quality of life after coiling in comparison to clipping. The expense of longer hospital stays following clipping must be balanced against the expense of endovascular devices in coiling.

INTRODUCTION The global demand for endovascular clot retrieval (ECR) has grown rapidly in recent years creating challenges to healthcare system planning and resource allocation. This study aims to apply our established computational model to predict and optimise the performance and resource allocation of ECR services within regional Australia, and applying data from the state of South Australia as a modelling exercise. METHOD Local geographic information obtained using the Google Maps application program interface and real-world data was input into the discrete event simulation model we previously developed. The results were obtained after the simulation was run over 5 years. We modelled and compared a single-centre and two-centre ECR service delivery system. RESULTS Based on the input data, this model was able to simulate the ECR delivery system in the state of South Australia from the moment when emergency services were notified of a potential stroke patient to potential delivery of ECR treatment. In the model, ECR delivery improved using a two-centre system compared to a one-centre system, as the percentage of stroke patients requiring ECR was increased. When 15% of patients required ECR, the proportion of 'failure to receive ECR' cases for a single-centre system was 17.35%, compared to 3.71% for a two-centre system. CONCLUSIONS Geolocation and resource utilisation within the ECR delivery system are crucial in optimising service delivery and patient outcome. Under the model assumptions, as the number of stroke cases requiring ECR increased, a two-centre ECR system resulted in increased timely ECR delivery, compared to a single-centre system. This study demonstrated the flexibility and the potential application of our DES model in simulating the stroke service within any location worldwide.

BACKGROUND: The literature base for endovascular treatment of brain arteriovenous malformations (BAVMs) has grown exponentially in recent decades. Bibliometric analysis has been used to identify impactful articles in other medical specialties. The aim of this citation analysis was to identify and characterize the top 100 most cited articles in the field of endovascular BAVM treatment. METHODS: The top-cited papers were identified by searching selected keywords (“endovascular treatment,” “interventional treatment,” “brain arteriovenous malformation,” “emboliz(s)ation”) on the Web of Science platform. The top 100 articles were ranked according to their number of citations. Each article was further evaluated to obtain predefined characteristics including citation(s) per year, year of publication, authorship, journal-title and impact factor, article topics, article type, and level of evidence. RESULTS: The top 100 most cited articles for endovascular BAVM treatment were published between 1960 and 2014. The total number of citations for these articles ranged from 56 to 471 (median 85.5). Most articles (76%) were published between 1990 and 2009 in three journals (56%), originated in the USA (52%) followed by France (16%). The most common topic related to embolization agents and the majority of articles constituted level IV or V evidence. CONCLUSIONS: This study provides a comprehensive overview of the most cited articles in the field of endovascular BAVM treatment. Our analysis recognizes key contributions from authors and institutions in the field and leads to a better understanding of the evidentiary framework for BAVM treatment.

Aneurysmal subarachnoid hemorrhage is a cause of profound morbidity and mortality. Its effects extend beyond functional neurological status to neurocognitive and psychological functioning. Endovascular treatment is becoming more prevalent after increasing evidence for its safety and efficacy; however, there is a relative paucity of evidence specific to neurocognitive status after treatment.To assess and compare neuropsychological outcomes after the treatment of ruptured and unruptured intracranial aneurysms.A systematic review of the literature was conducted searching for articles assessing the neuropsychological and cognitive outcomes after the treatment of ruptured and unruptured intracranial aneurysms. Inclusion criteria were English language, publication between January 2000 and October 2020, and discussion of neuropsychological outcomes in adequate detail. Outcomes were categorized into 8 domains: 5 Neurocognitive (Language, Executive Function, Complex Attention, Memory and Learning, and Perceptual motor function), Intelligence Quotient, Affect, and Quality of Life.Twenty-four articles were included comprising 2236 patients (924 surgical clipping, 1095 endovascular coiling, and 217 controls). These studies reported that most tests revealed no significant difference [n = 356/421 (84.56%)] between treatment modalities. More studies reported significantly superior test scores in the fields of language, executive function, and memory and learning after coiling [n = 53/421 tests (12.59%)] compared with clipping [n = 12/421 tests (2.85%)].The current available data and published studies demonstrate a trend toward improved neurocognitive and psychological outcomes after endovascular treatment. Although these findings should be considered when deciding on the optimal treatment method for each patient, drawing definitive conclusions is difficult because of heterogeneity between patients and studies.

Background Endovascular clot retrieval (ECR) is the standard of care for acute ischemic stroke caused by large vessel occlusion. Reducing stroke symptom onset to reperfusion time is associated with improved functional outcomes. This study aims to develop a computational model to predict and identify time-related outcomes of community stroke calls within a geographic area based on variable parameters to support planning and coordination of ECR services. Methods A discrete event simulation (DES) model to simulate and predict ECR service was designed using SimPy, a process-based DES framework written in Python. Geolocation data defined by the user, as well as that used by the model, were sourced using the Google Maps application programming interface. Variables were customized by the user on the basis of their local environment to provide more accurate prediction. Results A DES model can estimate the delay between the time that emergency services are notified of a potential stroke and potential cerebral reperfusion using ECR at a capable hospital. Variables can be adjusted to observe the effect of modifying each parameter input. By varying the percentage of stroke patients receiving ECR, we were able to define the levels at which our existing service begins to fail in service delivery and assess the effect of adding centers. Conclusions This novel computational DES model can aid the optimization of delivery of a stroke service within a city, state, or country. By varying geographic, population, and other user-defined inputs, the model can be applied to any location worldwide.

Background and Purpose— Mobile stroke units (MSUs) are increasingly used worldwide to provide prehospital triage and treatment. The benefits of MSUs in giving earlier thrombolysis have been well established, but the impacts of MSUs on endovascular thrombectomy (EVT) and effect on disability avoidance are largely unknown. We aimed to determine the clinical impact and disability reduction for reperfusion therapies in the first operational year of the Melbourne MSU. Methods— Treatment time metrics for MSU patients receiving reperfusion therapy were compared with control patients presenting to metropolitan Melbourne stroke units via standard ambulance within MSU operating hours. The primary outcome was median time difference in first ambulance dispatch to treatment modeled using quantile regression analysis. Time savings were subsequently converted to disability-adjusted life years avoided using published estimates. Results— In the first 365-day operation of the Melbourne MSU, prehospital thrombolysis was administered to 100 patients (mean age, 73.8 years; 62% men). The median time savings per MSU patient, compared with the control cohort, was 26 minutes ( P P P P =0.001) for EVT hospital arrival to arterial puncture for MSU patients. Estimated median disability-adjusted life years saved through earlier provision of reperfusion therapies were 20.9 for thrombolysis and 24.6 for EVT. Conclusions— The Melbourne MSU substantially reduced time to reperfusion therapies, with the greatest estimated disability avoidance driven by the more powerful impact of earlier EVT. These findings highlight the benefits of prehospital notification and direct triage to EVT centers with facilitated workflow on arrival by the MSU.

Purpose: Advances in endovascular technology have expanded the treatment options for intracranial aneurysms. Intrasaccular flow diversion is a relatively new technique that aims to disrupt blood inflow at the neck of the aneurysm, hence promoting intrasaccular thrombosis. The Woven EndoBridge device (WEB; MicroVention, Aliso Viejo, CA, USA) is an US Food and Drug Administration approved intrasaccular flow diverter for wide-necked aneurysms. We report the early interim clinical and radiological outcomes of patients with both ruptured and unruptured intracranial aneurysms (IAs) treated using the WEB device in an Australian population.Materials and Methods: A retrospective analysis was done of patients with ruptured or unruptured IAs who received treatment with WEB across 5 Australian neuroendovascular referral centers between May 2017 and November 2020. Angiographic occlusion was assessed with time-of-flight magnetic resonance angiography. Complications were recorded and clinical outcomes were assessed using the modified Rankin scale at follow-up.Results: In total, 66 aneurysms were treated in 63 patients, with successful deployment of the WEB device in 98.5% (n=65). Eighteen (26.9%) ruptured aneurysms were included. Failure of deployment occurred in a single case. Adjunct coiling and/or stenting was performed in 20.9% (n=14) cases. Sixty-two patients with 65 aneurysms using a WEB device were followed up (mean=9.1 months), and 89.4% of these had complete aneurysm occlusion while 1.5% remained patent. Functional independence was achieved in 93.5% of cases.Conclusion: Early results following the use of WEB devices in Australia demonstrate safety and adequate aneurysm occlusion comparable to international literature.

Caesarean scar ectopic pregnancies are rare but growing in incidence due to increasing rates of caesarean deliveries. These cases have historically been treated with either medical or surgical management which both have significant limitations. More recently, uterine artery embolisation (UAE) has shown significant promise in the treatment of this condition. We present the case of a complex patient with a caesarean scar ectopic successfully managed with combined UAE and surgery.

Background Two major studies, The International Subarachnoid Aneurysm Trial and the Barrow Ruptured Aneurysm Trial, compare the long-term outcomes of clipping and coiling. Although these demonstrated coiling’s initial benefits, rebleeding and retreatment rates as well as converging patient outcomes sparked controversy regarding its durability. This article will critically examine the available evidence for and against clipping and coiling of intracranial aneurysms. Critics of endovascular treatment state that the initial benefit seen with endovascular coiling decreases over the duration of follow-up and eventually functional outcomes of both treatment modalities are similar. Combined with the increased rate of retreatment and rebleeding, these trials reveal that coiling is not as durable and not as effective as a long-term treatment compared to clipping. Also, due to the cost of devices following endovascular treatment and prolonged hospitalization following clipping, the financial burden has been considered controversial. Summary/Key Messages Short-term outcomes reveal better morbidity and mortality outcomes following coiling. Despite the higher rates of retreatment and rebleeding with coiling, there was no significant change in functional outcomes following retreatment. Furthermore, examining more recent trials reveals a decreased rate of recurrence and rebleeding with improved technology and expertise. Functional outcomes deteriorate for both cohorts over time while recent results revealed improved long-term cognitive outcomes and levels of health-related quality of life after coiling in comparison to clipping. The expense of longer hospital stays following clipping must be balanced against the expense of endovascular devices in coiling.

Purpose: Carotid artery stenting (CAS) is an established treatment for symptomatic carotid artery stenosis as an alternative to carotid endarterectomy. A variety of techniques and devices have been devised to minimise periprocedural stroke risk using either proximal or distal embolic protection. This study presents a method of embolic protection during CAS–the CaRotid Artery Filtering Technique (CRAFT).Materials and Methods: The CRAFT technique employs aspects of both proximal and distal embolic protection. The CASPER RX stent (MicroVention, Tustin, CA, USA), which is a double-layered, closed-cell, micromesh nitinol stent, is deployed across the carotid artery stenosis with the assistance of a FlowGate balloon guide catheter (Stryker Neurovascular, Fremont, CA, USA). The partially deployed stent acts as a distal filter while the balloon guide is deflated midway during stent deployment to prevent distal plaque embolisation, followed by completion of stent deployment and angioplasty.Results: A total of 94 patients underwent CAS using the CRAFT technique between June 2016 and March 2021. Successful stent deployment was achieved in all patients. Preliminary results demonstrated acute stent occlusion in 6 patients (6.4%) and distal embolic stroke in 5 patients (5.3%). The median procedural fluoroscopy time was 34 minutes with an interquartile range of 22 to 55 minutes.Conclusion: The CRAFT technique of CAS presented by this study can be applied in the treatment of symptomatic carotid artery stenosis in both emergency and elective procedure settings with a high technical success and low distal embolic stroke risk.

Background Carotid artery stenting (CAS) is an established treatment for carotid artery stenosis, typically in a semielective or elective setting. The growth of mechanical thrombectomy for acute stroke has led to an increased use of emergent carotid artery stenting (eCAS). This single-center retrospective case series evaluates the safety and efficacy of eCAS using a dual-layer micromesh nitinol stent to treat carotid artery stenosis in the acute stroke setting. Methods Ethics approval was granted by the institutional review board. Clinical data of all patients who underwent CAS using the Casper dual-layer micromesh nitinol stent system (MicroVention, Terumo, Tustin, California, USA) at a tertiary level 24-hour endovascular thrombectomy service over a 2-year period (June 2016−June 2018) were retrospectively obtained and reviewed. Results Twenty eCAS procedures were performed in 19 patients over the study period. Most patients had tandem lesions (12/20; 60%). Median National Institute of Health Stroke Scale score on admission was 17 (interquartile range 9–22). Stent deployment was technically successful in all patients. Recanalization rate was 95%. Symptomatic intracranial hemorrhage occurred in 2 patients (10%), both resulting in death. No other procedure-related deaths occurred. Stent thrombosis occurred in 2 patients. One delayed embolic stroke occurred. No other stent-related complications occurred. Median National Institute of Health Stroke Scale score at 24 hours postprocedure was 3 (interquartile range 1–12). Six patients had a good clinical outcome (modified Rankin Scale score between 0 and 2) at 3- to 6-month follow-up (38%). Conclusions eCAS using the Casper stenting system is effective and technically feasible in the acute stroke setting, although the ideal antiplatelet and anticoagulation regime is not clearly established.

Aortic dissection is a complex condition with high morbidity and mortality. Endovascular treatments including percutaneous fenestration can be used to manage branch vessel ischaemia or risk of aortic rupture. A variety of techniques for aortic fenestration have been described. We describe the novel use of the TruePath Chronic Total Occlusion (CTO) device for aortic intimal fenestration to achieve side branch reconnection. We present three cases of aortic dissection presenting with symptoms of aortic side branch occlusion and end organ malperfusion, treated with aortic fenestration using the TruePath CTO device via trans-brachial and trans-femoral approaches. Technical success was achieved in all three cases. No complications were encountered. Flow was restored in compromised visceral branches. Branches remained patent on follow-up CT angiography over a minimum 2.5-year follow-up period. Percutaneous aortic fenestration techniques enable a minimally invasive approach to treat visceral branch malperfusion associated with aortic dissection. The TruePath CTO device improves the control of the fenestration procedure with the potential to improve efficacy and safety.

Objective Since the introduction of endovascular technology to treat thoracic and abdominal aortic aneurysms, there has been a global research effort focused on assessing the effectiveness of treatment. A bibliometric analysis is used to identify the scientific impact of an article, impactful authors, institutions, and collaborative groups. Our objective was to identify and to analyze the 100 most cited articles in the field of endovascular treatment of thoracic and abdominal aortic aneurysms. Methods We performed a retrospective bibliometric analysis in April 2018. Articles were searched on the Science Citation Index Expanded database using Web of Science to identify the most cited articles in endovascular therapy for thoracic and aortic aneurysms since 1945. Use of selected key terms (“AAA,” “aortic aneurysm,” “thoracic aneurysm,” “abdominal aneurysm,” “endovascular,” “endoluminal,” “stent,” “graft,” “repair,” “EVAR,” and “TEVAR”) yielded a total of 23,354 articles. The top 100 articles were identified and analyzed to extract relevant information including year of publication, citation count, journal, authorship country of origin, and article type. Results The earliest articles were published in 1991, with the majority being published in the 2000s (n = 59). The number of citations for the top 100 articles ranged from 151 to 1142, with a median citation count of 212. All articles were cited an average of 22.4 times per year. Almost half (n = 46) of the top 100 articles were published in the Journal of Vascular Surgery. Thirty-nine authors contributed four or more articles, with two being credited on 10 papers to make the list. The majority (n = 62) of the articles arose from the United States, while the United Kingdom contributed 11 articles. There were 7 guidelines and 12 randomized controlled trials, and the majority constituted level III or level IV evidence. Conclusions This study provides a comprehensive and informative analysis of the most cited and impactful research undertaken in the field of endovascular treatment of abdominal and thoracic aortic aneurysms. By quantitatively assessing the 100 most cited articles in the field, we recognize the contributions of key authors, institutions, and collaborative groups and develop an understanding of the strengths of past research and the requirements for future global efforts.

Background Management of coronary artery fistula (CAF) is based on obliterating the fistula communication between the cardiac arteries and other thoracic vessels. Case presentation We describe the presentation of an 85-year-old female with progressive exertional dyspnea on a background of a long standing left anterior descending diagonal to pulmonary artery fistula. We utilized neuro-interventional techniques to perform coil embolization via use of a Scepter XC dual lumen micro catheter. Conclusions Dual lumen balloon catheters allow for super-selective artery interrogation, stability of balloon positioning, with less trauma to vessel architecture and accurate embolization. There were no complications and the patient reported improvement of symptoms on review.

Percutaneous vertebroplasty is a minimally invasive technique to treat patients with symptomatic vertebral hermangiomata.We present a single-operator series of cases to demonstrate the clinical outcomes and complication profiles for this technique.This is a retrospective multi-center cohort study.Procedures were performed across multiple hospitals in Italy by a single proceduralist.All patients with symptomatic vertebral hermangiomata that had percutaneous vertebroplasty over a 14-year period (March 1999 to April 2013) by a single proceduralist were included in this study. Information collected included demographic data, vertebral level of intervention, cement volume used, and the Visual Analogue Score for pain that was assessed pre- and post-intervention. Patients were followed up for a minimum of one year.Percutaneous vertebroplasty was performed for 50 patients. All patients had an improvement in pain, with 39 patients (78%) reporting complete pain relief. A unipedicular approach was undertaken in 41 cases (82%), and bipedicular approach in 8 patients (16%), while a transoral approach was used in one patient. The mean cement volume per vertebral level was 6.8 mL (1 - 18 mL). Recurrent symptoms occurred in 2 patients (4%) requiring repeat vertebroplasty. There were no cases of symptomatic cement leak, and no cases of procedural morbidity or mortality.As a multicenter study conducted over a 14-year time period, there may be heterogeneity in procedural technique and rehabilitation protocols. There were no cases of cement leakage in our study, which could be an underreporting of cases. This is could be due to none of our patients receiving a post procedural computerized tomography scan, which is more sensitive in detecting cement leakage when compared to procedural fluoroscopy.Percutaneous vertebroplasty is associated with good post-procedural outcomes in patients with vertebral hermangiomata. Complications such as neurological injury and cement leakages are rare.

Background Visceral and renal artery aneurysms (VRAAs) are uncommon but are associated with a high mortality rate in the event of rupture. Endovascular treatment is now first line in many centres, but preservation of arterial flow may be difficult in unfavourable anatomy including wide necked aneurysms, parent artery tortuosity and proximity to arterial bifurcations. Endovascular stenting, and in particular flow-diversion, is used in neurovascular intervention to treat intracranial aneurysms but is less often utilised in the treatment of VRAAs. The CASPER stent is a low profile dual-layer braided nitinol stent designed for carotid stenting with embolic protection and flow-diversion properties. We report the novel use of the CASPER stent for the treatment of VRAAs. We present a case series describing the treatment of six patients with VRAAs using the CASPER stent. Results Six patients with unruptured VRAAs were treated electively. There were three splenic artery aneurysms and three renalartery aneurysms. Aneurysms were treated with the CASPER stent, with or without loose aneurysm coil packing or liquid embolic depending on size and morphology. All stents were successfully deployed with no immediate or periprocedural complications. Four aneurysms completely occluded after serial imaging follow up with one case requiring repeat CASPER stenting for complete occlusion. In one patient a single aneurysm remained patent at last follow up, A single case was complicated by delated splenic infarction and surgical splenectomy. Conclusion Preliminary experience with the CASPER stent suggests it is technically feasible and effective for use in the treatment of VRAAs.

Introduction Mechanical thrombectomy has become the standard of care for management of most large vessel occlusion (LVO) strokes. When patients with LVO present with minor stroke symptomatology, no consensus on the role of mechanical thrombectomy exists. Methods A systematic review and meta-analysis were performed to identify studies that focused on mechanical thrombectomy, either as a standalone treatment or with intravenous tissue plasminogen activator (IV tPA), in patients with mild strokes with LVO, defined as a baseline National Institutes of Health Stroke Scale score ≤5 at presentation. Data on methodology, quality criteria, and outcome measures were extracted, and outcomes were compared using odds ratio as a summary statistic. Results Five studies met the selection criteria and were included. When compared with medical therapy without IV tPA, mechanical thrombectomy and medical therapy with IV tPA were associated with improved 90-day modified Rankin Scale (mRS) score. Among medical patients who were not eligible for IV tPA, those who underwent mechanical thrombectomy were more likely to experience good 90-day mRS than those who were not. There was no significant difference in functional outcome between mechanical thrombectomy and medical therapy with IV tPA, and no treatment subgroup was associated with intracranial hemorrhage or death. Conclusions In patients with mild strokes due to LVO, mechanical thrombectomy and medical therapy with IV tPA led to better 90-day functional outcome. Mechanical thrombectomy plays an important role in the management of these patients, particularly in those not eligible for IV tPA.

Objective Selection of patients with acute ischemic stroke for endovascular thrombectomy (EVT) is complex and time-critical. Benefits of EVT are well established for patients with small core infarcts. The aim of this study was to compare clinical outcomes of EVT in patients with larger established infarcts (Alberta Stroke Programme Early CT Score [ASPECTS] ≤6) with patients with smaller infarcts (ASPECTS 7–10). Methods The study included 355 patients with acute ischemic stroke due to large vessel occlusion who underwent EVT. ASPECTS was assigned to baseline noncontrast computed tomography, and collateral perfusion scores were assigned to multiphase computed tomography angiography. Baseline stroke severity, collateral grading, and clinical outcome data (complication rate, symptomatic intracranial hemorrhage and 90-day modified Rankin Scale score) were compared between patients with borderline (≤6) and high (7–10) ASPECTS. Results There were 34 (10%) patients with borderline ASPECTS. There was no difference in rate of good clinical outcome (37% vs. 46%, P = 0.852), symptomatic intracerebral hemorrhage (9% vs. 9%, P = 0.984), or mortality (20% vs. 22%, P = 0.818) between patients with borderline ASPECTS and high ASPECTS at 90 days. Moreover, there was no significant difference in collateral perfusion grade. Conclusions This study identifies similar clinical benefit of EVT in patients with acute large vessel occlusion stroke with borderline ASPECTS and high ASPECTS.

IntroductionEndovascular interventions for intracranial aneurysms have evolved substantially over the past several decades. A citation rank list is used to measure the scientific and/or clinical impact of an article. Our objective was to identify and analyze the characteristics of the 100 most cited articles in the field of endovascular therapy for intracranial aneurysms.MethodsWe performed a retrospective bibliometric analysis between July and August 2017. Articles were searched on the Science Citation Index Expanded database using Web of Science in order to identify the most cited articles in the endovascular therapy of intracranial aneurysms since 1945. Using selected key terms (‘intracranial aneurysm’, ‘aneurysm’, ‘aneurysmal subarachnoid’, ‘endovascular’, ‘coiling’, ‘stent-assisted’, ‘balloon-assisted’, ‘flow-diversion’) yielded a total of 16 314 articles. The top 100 articles were identified and analyzed to extract relevant information, including citation count, authorship, article type, subject matter, institution, country of origin, and year of publication.ResultsCitations for the top 100 articles ranged from 133 to 1832. All articles were cited an average of 27 times per year. There were 45 prospective studies, including 7 level–II randomized controlled trials. Most articles were published in the 2000s (n=53), and the majority constituted level III or level IV evidence. Half of the top 100 articles arose from the USA.ConclusionThis study provides a comprehensive overview of the most cited articles in the endovascular management of intracranial aneurysms. It recognizes the contributions made by key authors and institutions, providing an important framework to an enhanced understanding of the evidence behind the endovascular treatment of aneurysms.

Background Hepatic arteriovenous malformations (HAVMs) are rare congenital lesions consisting of multiple high-pressure arteries feeding into low-pressure veins via a central nidus. Massive haemorrhage, portal hypertension and hepatic insufficiency can ensue. Endovascular embolization is increasingly a first line treatment method although there is no general consensus or guidelines on the most effective embolic agent or approach. We describe the novel treatment of two dogs with congenital hepatic AVMs using a modified version of the ‘pressure cooker’ technique often utilised in neurointervention with the DMSO-based PHIL embolic agent delivered via the DMSO compatible Scepter-XC dual lumen balloon catheter. Case presentation Two paediatric dogs were diagnosed with hepatic AVMs. Both dogs presented with ascites and abnormal liver function tests. CT angiograms revealed hepatic arterio-portal malformations arising from an enlarged celiac artery. Selective catheterisation of the artery supplying the AVM was achieved via a femoral artery approach. A Scepter XC dual-lumen compliant balloon microcatheter and Traxcess 0.014 guidewire combination was advanced to the nidus via through the 5Fr guide catheter towards the nidus. Inflation of the balloon occluded arterial inflow and PHIL was injected under continuous fluoroscopic screening until the PHIL embolic agent penetrated into the draining portal vein beyond the nidus. In patient 1, normal portal venous waveform was restored with reversal of severe hepatic insufficiency. Whilst there was initial improvement post-operatively in patient 2 with normalisation of portal vein pressures and flow, opening of collateral nidus vessels re-established the high-pressure communication, and euthanasia was elected by the owner. Conclusions The ‘pressure cooker’ technique is a safe and efficacious approach to the treatment of canine HAVMs. The novel use of PHIL and the Scepter XC balloon catheter has several advantages over conventional endovascular approaches. Translational application to human paediatric interventions for similar conditions where embolic and contrast agent volume constraints are similar can be considered.

Introduction Carotid artery stenting (CAS) is an effective treatment for clinically significant carotid artery stenosis in selected patients. The increasing utilisation of endovascular management for acute ischaemic stroke has led to the use of CAS in the emergent setting for patients presenting with acute stroke and concomitant carotid artery stenosis. A variety of carotid artery stents are available and differ in material, shape and cell geometry. Microporous stents represent a new type of stent with significantly reduced cell size. We present a single-centre retrospective case series of emergent CAS (eCAS) procedures using a dual-layer micromesh nitinol stent in the acute stroke setting. Materials and methods Ethics approval was granted by the institutional review board. Clinical data of all patients who underwent CAS using the Casper stent (Microvention, Terumo, Tustin, CA, USA) at a tertiary level 24-hour mechanical thrombectomy (MT) service over a two-year period (June 2016-June 2018) were retrospectively obtained and reviewed. Data collected included patient demographics, presenting symptoms, pre- and postprocedural National Institute of Health Stroke Scale (NIHSS) score, imaging findings including severity of stenosis or presence of tandem occlusion, use of intravenous thrombolysis (IV tPA) and/or antiplatelet agents, thrombectomy device and stents used, modified thrombolysis in cerebral infarction (mTICI) score and follow-up modified Rankin scale (mRS) data. Any complications were identified and categorised. All eCAS procedures were performed using the Casper dual-layer micromesh nitinol stent system. Results Twenty eCAS procedures were performed in nineteen patients during this period. Patients received between 1 and 2 Casper stents of varying sizes. The majority of patients had tandem lesions (12/20; 60%) and carotid lesions were most commonly located in the proximal ICA (n=15; 75%). Median NIHSS score on admission was 17 (IQR 9–22). IV tPA was administered prior to six eCAS procedures (30%). Stent deployment was technically successful in all patients and was performed concurrently with MT in fifteen cases (75%). Recanalization rate was 95%. No intraprocedural complications occurred. Symptomatic intracranial haemorrhage (sICH) occurred in two patients (10%) and both resulted in death. No other procedure-related deaths occurred. Stent thrombosis occurred in two patients. No other stent-related complications occurred. Non-neurological complications included coagulopathy (3/20; 15%), hypotension (2/20; 10%), acute kidney injury (1/20; 5%) and aspiration pneumonia (1/20; 5%). Median NIHSS score at 24 hours postprocedure was 3 (IQR 1–12). Thirty-eight percent of patients had a good clinical outcome (modified Rankin scale between 0–2) at 3–6 month follow up. Conclusion eCAS using the Casper stenting system is effective and technically feasible in patients presenting with acute stroke and concomitant carotid artery stenosis. Disclosures A. Lamanna: None. J. Maingard: None. H. Kok: None. C. Barras: None. A. Jhamb: None. V. Thijs: None. R. Chandra: None. D. Brooks: None. H. Asadi: None.

Background Endovascular thrombectomy is the standard of care for acute ischaemic stroke caused by large vessel occlusion. Reducing stroke symptom onset to reperfusion time is associated with improved functional outcomes. In this study we aimed to develop a computational model to predict and identify time-related outcomes of community stroke calls within an area based on variable parameters. Method A model to simulate and predict EVT service delivery at capable hospital within a geographic area, city or state was designed using SimPy, a Python based discrete event simulation framework. Geolocation data defined by the user as well as that used by the model is sourced using the Google Maps Application Programming Interface (API) and GeoPy. Variables are customized by the user based on their local environment to provide more acute prediction. Result This algorithm can predict the delay between the time that emergency services are notified of a potential stroke and cerebral reperfusion using EVT at capable hospital. Factors including area size and population, number of EVT capable hospitals, number of available angiography machines, availability of ambulances and time of patient can be adjusted to observe the effect of modifying each parameter input. Conclusion This model, made available as an open source web-based application, provides a mean of predicting resource utilisation and wait times for stroke service delivery planning. By modifying parameter inputs, the delivery and coordination of a stroke service within an area, city or state may be optimised and aid the development of new EVT service protocols. Disclosures Y. Ren: None. M. Phan: None. J. Maingard: None. C. Seah: None. J. Wu: None. P. Luong: None. D. Shell: None. M. Burney: None. K. Zhou: None. A. lamanna: None. H. Kok: None. R. Chandra: None. A. Jhamb: None. V. Thijs: None. D. Brooks: None. H. Asadi: None.

Vertebral compression fractures (VCFs) are a common cause of back pain and disability and are usually osteoporotic in nature. Therapy aims to adequately control pain and allow early mobilisation and return of function while preventing additional fractures. A proportion of patients do not achieve adequate pain relief using conservative measures alone. Unwanted adverse effects from medications may also ensue. Vertebroplasty represents an alternative treatment option for VCFs. Patients with acute VCFs (≤6 weeks old) may gain the most benefit from vertebroplasty as healed fractures are not as amenable to cement injection. High-quality studies have reported conflicting results regarding the use of vertebroplasty in the treatment of acute VCFs. Despite high-quality evidence, varying study designs and heterogenous patient cohorts make interpretation of this data difficult. Only one sham-controlled randomised controlled trial (RCT) has evaluated vertebroplasty exclusively in patients with acute VCFs, reporting favourable results. Pooled data from RCTs also suggest vertebroplasty to be safe. This article provides a concise and critical review of the current literature regarding vertebroplasty for the treatment of acute VCFs.

Background and purposeEndovascular thrombectomy (EVT) has revolutionized the management of acute ischemic stroke. Landmark clinical trials have shown EVT to be one of the most efficacious interventions in clinical medicine over the past 5 years. A method of recognition for an article in the scientific community is to use a citation rank list, in order to identify the seminal works in the academic medical literature. The objective of this study was to characterize the 100 most highly cited articles assessing endovascular management of acute ischemic stroke.MethodsWe conducted a retrospective bibliometric analysis using the Web of Science Citation Index Expanded database for the most cited works in the endovascular management of acute ischemic stroke. Citation count was used to rank the top 100 articles, which were then analyzed for authorship, year of publication, subject, study type, level of evidence, and subject.ResultsThe mean number of citations was 245 (range 65–1726) and 394 on Google Scholar. The top 100 articles were cited an average of 43.9 times per year and published in 21 journals in the past two decades. The majority of papers (62) were classified as constituting levels 1, 2, or 3 evidence, and included 17 randomized controlled trials. Approximately two-thirds of the top 100 articles originated from the USA.ConclusionsThis study details the most cited articles in the endovascular management of acute ischemic stroke, and furthermore shows that a high proportion of level I evidence exists for this intervention.

The spleen is a commonly injured organ and the splenic vasculature is also susceptible to inflammation and trauma, often resulting in aneurysm formation. Splenic artery aneurysms carry a high risk of rupture and are associated with high mortality and morbidity. Due to the advances in endovascular techniques and devices, endovascular management of splenic vascular pathologies is now considered a first-line strategy. Endovascular embolisation and advance techniques including balloon- or stent-assisted coil embolisation enables minimally invasive management option while preserving splenic function.

Both carotid endarterectomy (CEA) and carotid artery stenting (CAS) are common treatments for carotid artery stenosis. Several randomized controlled trials (RCTs) have compared CEA to CAS in the treatment of carotid artery stenosis. These studies have suggested that CAS is more strongly associated with periprocedural stroke; however, CEA is more strongly associated with myocardial infarction. Published long-term outcomes report that CAS and CEA are similar. A reduction in complications associated with CAS has also been demonstrated over time. The symptomatic status of the patient and history of previous CEA or cervical radiotherapy are significant factors when deciding between CEA or CAS. Numerous carotid artery stents are available, varying in material, shape and design but with minimal evidence comparing stent types. The role of cerebral protection devices is unclear. Dual antiplatelet therapy is typically prescribed to prevent in-stent thrombosis, and however, evidence comparing periprocedural and postprocedural antiplatelet therapy is scarce, resulting in inconsistent guidelines. Several RCTs are underway that will aim to clarify some of these uncertainties. In this review, we summarize the development of varying techniques of CAS and studies comparing CAS to CEA as treatment options for carotid artery stenosis.

Purpose Endovascular treatment of neurovascular disorders is now well established as effective and safe; however, the nature of the intracranial vasculature poses unique challenges. The unintentional dislodgement or fracture of a device and its migration within cerebral vessels is a complication with serious potential morbidity that must be managed urgently. In this series, the authors describe 7 cases of a stentriever being used to remove foreign objects from within the cerebral vasculature. Methods A retrospective search of all interventional neurovascular procedures performed in 2017 at a tertiary metropolitan hospital was performed to identify cases of dislodged devices. Results Five dislodged endovascular coils, 1 microcatheter, and 1 fractured stentriever were technically successfully retrieved. In 6 of the cases, the foreign object was successfully removed with a stentriever alone, whereas 1 case used a J-tip wire and a “J-tip flick” to manipulate the coil and facilitate retrieval. Stentrievers, particularly when used alone, confer the advantages of speed, cost, as well as being tailor-made for cerebral vessels. They also allow continuous blood flow when deployed, a critical advantage when considering cerebral perfusion. Critical techniques include the gradual deployment of the stentriever alongside the foreign object to allow its entanglement and partial resheathing, so that the foreign object can become pinned within the microcatheter. Stentrievers do remain limited by vessel caliber and are less able to entangle larger, stiffer devices. Conclusion The migration of foreign devices during neurointerventional procedures is a serious complication requiring urgent treatment. This case series highlights the efficacy and advantages of using a stentriever and suggests its consideration as a first-line technique in recovering dislodged foreign bodies in the cerebral vasculature.

Background Endovascular Clot Retrieval (ECR) is the standard of care for acute stroke due to a large vessel occlusion. It is a time critical and complex process involving many specialized care providers and resources. Maximizing patient benefit while minimizing cost of this service requires optimization of human and physical assets. The aim of this study was to develop a computer simulation of an ECR service designed to optimize resource allocation. Method Using Simmer-a Discrete Event Simulation (DES) software- as frequently employed in complex logistical operations, we have developed a comprehensive computational model that closely mimics the environment of an ECR service from presentation to emergency department to the angio suite. This model was tested using real data collected from a quaternary institution with ECR service. Results Our model assesses the impact of available services, and aids optimization of resource distribution and access, allowing comparison of various competing strategies. In this simulation, the numbers of different human or capital resources such as stroke physicians, neuro-interventionists, and angiography equipment can be varied to assess the impact on efficiency and availability of service delivery. Other factors and variables such as equipment breakdown, servicing or times taken during components of an individual stroke management pathway can also be integrated, to identify sources of systemic delay and cost-points, with a view to service improvement. Conclusion A novel computer simulation is proposed to assess resource allocation, directed at optimizing the timely, effective and equitable application of human and physical resources. This model can provide clinically important data to help existing ECR services, in targeting optimum service delivery and best patient outcomes. Disclosures S. Huang: None. J. Maingard: None. H. Kok: None. C. Barras: None. V. Thijs: None. R. Chandra: None. D. Brooks: None. H. Asadi: None.

PURPOSE: The evidence for endovascular therapy and choice of technique in distal middle cerebral artery (MCA) M2 segment occlusions in acute ischemic stroke remains controversial. We aimed to conduct a systematic review and meta-analysis primarily comparing reperfusion rates of stent-retrieval versus contact aspiration for M2 occlusions. MATERIALS AND METHODS: Study selection included cohorts of patients with distal MCA occlusions in acute ischemic strokes treated with an endovascular approach including stent-retrieval or contact aspiration. Twelve studies were selected for meta-analysis for a total of 835 cases. Meta-analysis by proportions was conducted on parameters including baseline and procedural characteristics, thrombolysis in cerebral infarction (TICI) 2b-3 outcomes, and 90-day modified Rankin scale (mRS) outcomes. RESULTS: Hypertension and hyperlipidemia were more prevalent in stent-retriever patients. Pooled baseline National Institute of Health Stroke Scale scores and Alberta Stroke Program Early Computed Tomography Score imaging scores were similar. Pooled time onset of symptoms to door arrival was higher for the stent-retrieval group (154 vs. 97.4 minutes, P=0.01), as was time to groin puncture (259.9 vs. 156.2 minutes, P=0.02), but there was no difference in procedure time. The TICI 2b-3 recanalization rate was similar (80.5% vs. 86.8%, P=0.168). The frequency of mRS 0-2 at 90-day was also similar (74.5% vs. 59.9%, P=0.120), and an excellent mRS 0-1 was lower for stent-retrievers (39.9% vs. 65.6%, P=0.003). A significant negative correlation was found between onset to groin puncture time and the proportion of patients with a good mRS (r=-0.71, P=0.048). CONCLUSION: Both endovascular techniques achieved recanalization rates greater than 80% and 90-day outcomes of minimal disability with similar complication rates. The literature is skewed by aspiration cases being performed sooner after onset of stroke compared to stent-retriever cases.

Spinal metastases are the most commonly encountered tumour of the spine, occurring in up to 40% of patients with cancer. Each year, approximately 5% of cancer patients will develop spinal metastases. This number is expected to increase as the life expectancy of cancer patients increases. Patients with spinal metastases experience severe and frequently debilitating pain, which often decreases their remaining quality of life. With a median survival of less than 1 year, the goals of treatment in spinal metastases are reducing pain, improving or maintaining level of function and providing mechanical stability. Currently, conventional treatment strategies involve a combination of analgesics, bisphosphonates, radiotherapy and/or relatively extensive surgery. Despite these measures, pain management in patients with spinal metastases is often suboptimal. In the last two decades, minimally invasive percutaneous interventional radiology techniques such as vertebral augmentation and radiofrequency ablation (RFA) have shown progressive success in reducing pain and improving function in many patients with symptomatic spinal metastases. Both vertebral augmentation and RFA are increasingly being recognised as excellent alternative to medical and surgical management in carefully selected patients with spinal metastases, namely those with severe refractory pain limiting daily activities and stable pathological vertebral compression fractures. In addition, for more complicated lesions such as spinal metastasis with soft tissue extension, combined treatments such as vertebral augmentation in conjunction with RFA may be helpful. While combined RFA and vertebral augmentation have theoretical benefits, comparative trials have not been performed to establish superiority of combined therapy. We believe that a multidisciplinary approach as well as careful pre-procedure evaluation and imaging will be necessary for effective and safe management of spinal metastases. RFA and vertebral augmentation should be considered during early stages of the disease so as to maintain the remaining quality of life in this patient population group.

Visceral and renal artery aneurysms (VRAAs) are an uncommon clinical entity but carry a risk of rupture with associated morbidity and mortality. The rupture risk is particularly high when the aneurysms are large, of unfavourable morphology or in the setting of pregnancy and perioperative period. Endovascular approaches are now first line in the treatment of VRAA, but conventional techniques may be ineffective in excluding aneurysms with unfavourable anatomy such as those with wide necks or at arterial bifurcation points. The neurovascular Comaneci neck-bridging device is used to temporarily cover the neck of intracranial aneurysms without occluding forward arterial flow during endovascular coiling. We report the novel use of the Comaneci neck-bridging device for the treatment of complex peripheral VRAAs. We describe the treatment of two patients with renal and splenic artery aneurysms demonstrating unfavourable anatomic morphology for conventional endovascular approaches. In the first patient, the renal artery aneurysm was situated at the intrarenal bifurcation of the main renal artery in the setting of a solitary kidney. In the second patient, the splenic artery aneurysm was situated close to the splenic hilum at the distal splenic arterial bifurcation. The Comaneci neck-bridging device was successfully used in both cases to assist coil embolisation with visceral preservation. The Comaneci neck-bridging device is potentially safe and effective for the treatment of peripheral VRAA with unfavourable anatomic characteristics that would have been deemed unsuitable for treatment using conventional techniques. Level 4, Technical Report.

inferior phrenic, or renal arteries (1). There can also be multiples of each adrenal artery branch. This is further complicated by the frequent occurrence of variant anatomy of the renal arteries. Variant renal artery anatomy is divided into early-dividing renal arteries and supernumerary renal arteries. The prevalence of variant renal artery anatomy is generally between 28% and 30% (4). The anatomic variant described in the present case makes a thorough diagnostic angiogram critical before adrenal embolization, as it was in this case. The most common complications of adrenal artery embolization are flank pain and low-grade fever in the 48 hours following the procedure. In summary, an adrenal myelolipoma is a benign lesion that can lead to retroperitoneal hematoma spontaneously or following trauma. In this case, adrenal artery embolization was an effective alternative to adrenalectomy, which was not performed in view of the patient’s cardiovascular risk profile. Further prospective data are needed to determine the long-term safety and efficacy of adrenal embolization of hemorrhagic adrenal lesions in patients who are unsuitable for surgery.

The rapid progression of medical imaging technology and the ability to leverage knowledge from non-invasive imaging means that Interventional Radiologists (IRs) and Interventional Neuroradiologists are optimally placed to incorporate minimally invasive interventional paradigms into clinical management to advance patient care. There is ample opportunity to radically change the management options for patients with a variety of diseases through the use of minimally invasive interventional procedures. However, this will need to be accompanied by an increased clinical role of IRs to become active partners in the clinical management of patients. Unfortunately, the development of IR clinical presence has lagged behind and is reflected by declining rates of IR involvement in certain areas of practice such as vascular interventions. Current and future IRs must be willing to take on clinical responsibilities; reviewing patients in clinic to determine suitability for a procedure and potential contraindications, rounding on hospital inpatients and be willing to manage procedure related complications, which are all important parts of a successful IR practice. Increasing our clinical presence has several advantages over the procedure-driven model including enhanced patient knowledge and informed consent for IR procedures, improved rapport with patients and other clinical colleagues through active participation and engagement in patient care, visibility as a means to facilitate referrals and consistency of follow-up with opportunities for further learning. Many of the solutions to these problems are already in progress and the use of IR as a "hired gun" or "technician" is a concept that should be relegated to the past, and replaced with recognition of IRs as clinicians and partners in delivering modern high quality multidisciplinary team-based patient care. The following article will review the history of IR, the challenges facing this rapidly evolving profession and discuss recent developments occurring globally that are essential in maintaining expertise, securing future growth and improving patient outcomes in the modern multidisciplinary practice of medicine.

Management of intractable haematuria and obstructive urosepsis from upper tract urothelial carcinoma can be problematic in patients not suitable for surgery, chemotherapy or radiotherapy. Interventional radiology techniques provide alternative approaches in this setting, such as complete kidney embolization to cease urine output, percutaneous nephrostomy, antegrade injection of sclerotherapy agents and sterilisation of the upper collecting system. Related approaches have been successfully employed to sclerose renal cysts, lymphoceles, chyluria and intractable lower tract haemorrhage. No reports of percutaneous, antegrade sclerotherapy in the upper urinary tract have previously been published. We present a case of recurrent haematuria and obstructive urosepsis caused by invasive upper tract urothelial carcinoma in a non-operative patient, which was treated with renal embolisation and percutaneous upper tract urothelial sclerotherapy.

This report presents a series of five patients unsuitable for surgery who had nonretrievable self-expanding metallic stents deployed along the cystic duct as treatment for benign and malignant causes of gallbladder obstruction. Techniques are described for draining cholecystitis, removing gallstones, bypassing gallbladder obstructions, and inserting metallic stents across the cystic duct to restore permanent antegrade gallbladder drainage in acute and chronic cholecystitis. Symptoms resolved in all cases, and stents remained patent for as long as 22 months. This procedure may be an effective alternative to cholecystectomy or long-term gallbladder drainage for patients in inoperable condition.

Knotting of intravascular catheters is an uncommon but a well-recognized occurrence. The Swan-Ganz catheter (SGC) is the one that knots most commonly. A case of a knotted SGC is described in a patient with a persistent left-sided superior vena cava, and we propose that the presence of a left-sided superior vena cava is a risk factor for knot formation not previously reported. We review the published work on the risk factors for knot formation and on the techniques used to remove knotted SGC. We describe a technique using a gooseneck snare and Omni Flush catheter (Angiodynamics, Queensbury, NY, USA) to loosen and untie a knotted SGC.