The Management of Intracranial Aneurysms: Current Trends and Future Directions.

Intracranial aneurysms represent a major global health burden. Rupture of an intracranial aneurysm is a catastrophic event. Without access to treatment, the fatality rate is 50% in the first 30 days. Over the last three decades, treatment approaches for intracranial aneurysms have changed dramatically. There have been improvements in the medical management of aneurysmal subarachnoid haemorrhage, and there has been an evolution of treatment strategies. Endovascular therapy is now the mainstay of the treatment of ruptured intracranial aneurysms based on robust randomised controlled trial data. There is now an expansion of treatment indications for unruptured intracranial aneurysms to prevent rupture with both microsurgical clipping and endovascular treatment. Both microsurgical and endovascular treatment modalities have evolved, in particular with the introduction of innovative endovascular treatment options including flow diversion and intra-saccular flow disruption. These novel therapies allow clinicians to treat more complex and previously untreatable aneurysms. We aim to review the evolution of treatment strategies for intracranial aneurysms over time, and discuss emerging technologies that could further improve treatment safety and functional outcomes for patients with an intracranial aneurysm.

Bilateral basal ganglia hemorrhage: a systematic review of etiologies, management strategies, and clinical outcomes.

Bilateral basal ganglia hemorrhages (BBGHs) represent rare accidents, with no clear standard of care currently defined. We reviewed the literature on BBGHs and analyzed the available conservative and surgical strategies. PubMed, Scopus, Web of Science, and Cochrane were searched following the PRISMA guidelines to include studies reporting patients with BBGHs. Clinical characteristics, management, and outcomes were analyzed. We included 64 studies comprising 75 patients, 25 (33%) traumatic and 50 (67%) non-traumatic. Traumatic cases affected younger patients (mean age 35 vs. 46 years, p=0.014) and males (84% vs. 71%, p=0.27) and were characterized by higher proportion of normal blood pressures at admission (66% vs. 13%, p=0.0016) compared to non-traumatic cases. Most patients were comatose at admission (56%), with a mean Glasgow Coma Scale (GCS) score of 7 and a higher proportion of comatose patients in the traumatic than in the non-traumatic group (64% vs. 52%, p=0.28). Among the traumatic group, motor vehicle accidents and falls accounted for 79% of cases. In the non-traumatic group, hemorrhage was most associated with hypertensive or ischemic (54%) and chemical (28%) etiologies. Management was predominantly conservative (83%). Outcomes were poor in 56% of patients with mean follow-up of 8 months. Good recovery was significantly higher in the traumatic than in the non-traumatic group (48% vs. 17%, p=0.019). BBGHs are rare occurrences with dismal prognoses. Standard management follows that of current intracerebral hemorrhage guidelines with supportive care and early blood pressure management. Minimally invasive surgery is promising, though substantial evidence is required to outweigh the potentially increased risks of bilateral hematoma evacuation.

Endovascular treatment for anterior inferior cerebellar artery-posterior inferior cerebellar artery (AICA-PICA) common trunk variant aneurysms: Technical note and literature review.

The Anterior Inferior Cerebellar Artery-Posterior Inferior Cerebellar Artery (AICA-PICA) common trunk is a rare variant of cerebral posterior circulation in which a single vessel originating from either the basilar or vertebral arteries supplies both cerebellum and brainstem territories. We present the first case of an unruptured right AICA-PICA aneurysm treated with flow diversion using a Shield-enhanced pipeline endovascular device (PED, VANTAGE Embolization Device with Shield Technology, Medtronic, Canada). We expand on this anatomic variant and review the relevant literature. A 39-year-old man presented to our treatment center with vertigo and right hypoacusis. The initial head CT/CTA was negative, but a 4-month follow-up MRI revealed a 9 mm fusiform dissecting aneurysm of the right AICA. The patient underwent a repeat head CTA and cerebral angiogram, which demonstrated the presence of an aneurysm on the proximal portion of an AICA-PICA anatomical variant. This was treated with an endovascular approach that included flow diversion via a PED equipped with Shield Technology. The patient's post-procedure period was uneventful, and he was discharged home after two days with an intact neurological status. The patient is still asymptomatic after a 7-month follow-up, with MR angiogram evidence of stable aneurysm obliteration and no ischemic lesions. Aneurysms of the AICA-PICA common trunk variants have a high morbidity risk due to the importance and extent of the territory vascularized by a single vessel. Endovascular treatment with flow diversion proved to be both safe and effective in obliterating unruptured cases.

The role of radiation therapy in the treatment of spine metastases from hepatocellular carcinoma: a systematic review and meta-analysis.

OBJECTIVE: Spine hepatocellular carcinoma (HCC) metastases severely worsen quality of life and prognosis, with the role of radiotherapy being controversial. The authors systematically reviewed the literature on radiotherapy for spine metastatic HCCs. METHODS: The PubMed, Scopus, Web of Science, and Cochrane databases were searched according to the PRISMA guidelines to include studies of radiotherapy for spine metastatic HCCs. Outcomes, complications, and local control were analyzed with indirect random-effect meta-analyses. RESULTS: The authors included 12 studies comprising 713 patients. The median time interval from diagnosis of HCC to spine metastases was 12 months (range 0-105 months). Most lesions were thoracic (35.9%) or lumbar (24.7%). Radiotherapy was delivered with conventional external-beam (67.3%) or stereotactic (31.7%) techniques. The median dose was 30.3 Gy (range 12.5-52 Gy) in a median of 5 fractions (range 1-20 fractions). The median biologically effective dose was 44.8 Gy10 (range 14.4-112.5 Gy10). Actuarial rates of postradiotherapy pain relief and radiological response were 87% (95% CI 84%-90%) and 70% (95% CI 65%-75%), respectively. Radiation-related adverse events and vertebral fractures had actuarial rates of 8% (95% CI 5%-11%) and 16% (95% CI 10%-23%), respectively, with fracture rates significantly higher after stereotactic radiotherapy (p = 0.033). Fifty-eight patients (27.6%) had local recurrences after a median of 6.8 months (range 0.1-59 months), with pooled local control rates of 61.6% at 6 months and 40.8% at 12 months, and there were no significant differences based on radiotherapy type (p = 0.068). The median survival was 6 months (range 0.1-62 months), with pooled rates of 52.5% at 6 months and 23.4% at 12 months. CONCLUSIONS: Radiotherapy in spine metastatic HCCs shows favorable rates of pain relief, radiological responses, and local control. Rates of postradiotherapy vertebral fractures are higher after high-dose stereotactic radiotherapy.

Intracranial Venous Alteration in Patients With Aneurysmal Subarachnoid Hemorrhage: Protocol for the Prospective and Observational SAH Multicenter Study (SMS).

Background: Arterial vasospasm has been ascribed as the responsible etiology of delayed cerebral infarction in patients with aneurysmal subarachnoid hemorrhage (aSAH), but other neurovascular structures may be involved. We present the protocol for a multicenter, prospective, observational study focused on analyzing morphological changes in cerebral veins of patients with aSAH. Methods and Analysis: In a retrospective arm, we will collect head arterial and venous CT angiograms (CTA) of 50 patients with aSAH and 50 matching healthy controls at days 0-2 and 7-10, comparing morphological venous changes. A multicenter prospective observational study will follow. Patients aged ≥18 years of any gender with aSAH will be enrolled at 9 participating centers based on the predetermined eligibility criteria. A sample size of 52 aSAH patients is expected, and 52 healthy controls matched per age, gender, and comorbidities will be identified. For each patient, sequential CTA will be conducted upon admission (day 0-2), at 7-10 days, and at 14-21 days after aSAH, evaluating volumes and morphology of the cerebral deep veins and main cortical veins. One specialized image collecting center will analyze all anonymized CTA scans, performing volumetric calculation of targeted veins. Morphological venous changes over time will be evaluated using the Dice coefficient and the Jaccard index and scored using the Boeckh-Behrens system. Morphological venous changes will be correlated to clinical outcomes and compared between patients with aSAH and healthy-controls, and among groups based on surgical/endovascular treatments for aSAH. Ethics and Dissemination: This protocol has been approved by the ethics committee and institutional review board of Ethikkommission, SALK, Salzburg, Austria, and will be approved at all participating sites. The study will comply with the Declaration of Helsinki. Written informed consent will be obtained from all enrolled patients or their legal tutors. We will present our findings at academic conferences and peer-reviewed journals. Approved Protocol Version and Registration: Version 2, 09 June 2021.

Endovascular and Antithrombotic Treatment in Blunt Cerebrovascular Injuries: A Systematic Review and Meta-Analysis.

OBJECTIVES: Ischemic stroke has been estimated to occur in up to 26% of patients with blunt cerebrovascular injury (BCVI). Antithrombotic therapy (AT) may be used for stroke prevention, but the role of endovascular treatment (ET) remains unclear. We systematically reviewed the literature on AT and ET for the treatment of patients with BCVIs. MATERIALS AND METHODS: PubMed, EMBASE, Web of Science, and Cochrane were searched upon the PRISMA guidelines to include studies reporting the use of ET in BCVI patients. Post-ET neurologic outcomes, radiographic responses, and complication rates were assessed. A fixed-effect model meta-analysis was performed to compare treatment-related post-BCVI ischemic stroke rates between AT and ET protocols. RESULTS: We included 16 studies comprising 352 patients undergoing ET for BCVI. Mean post-ET rates of good neurologic outcomes and radiologic responses were 86.9% (range, 63.6-100%) and 94.0% (range 57.1-100%), respectively. Mean post-ET complication rate was 5.2% (range, 0-66.7%). Seven studies compared the roles of AT (delivered in 805 patients) and ET (performed in 235 patients) for preventing the onset of post-BCVI ischemic strokes. No significant difference in rates of post-BCVI ischemic stroke was found between patients receiving AT vs patients undergoing ET (OR 0.71, 95% CI: 0.35-1.42, p = 0.402). CONCLUSION: AT and ET may be comparable in preventing the occurrence of ischemic stroke following BCVIs. AT may be preferred as the less-invasive first-line therapy, but ET showed favorable rates of post-treatment clinical and radiologic outcomes, coupled with low rates of treatment-related complications.

Editor's Choice - Peri-Operative Outcomes of Carotid Endarterectomy are Not Improved on Dual Antiplatelet Therapy vs. Aspirin Monotherapy: A Systematic Review and Meta-Analysis.

OBJECTIVE: A systematic review and meta-analysis of the peri-operative outcomes of carotid endarterectomy (CEA) on dual antiplatelet therapy (DAPT) vs. aspirin monotherapy was carried out, to determine optimal peri-operative management with these antiplatelet agents. DATA SOURCES: The Web of Science, Pubmed, and Embase databases were searched from inception to July 2021. The corresponding authors of excluded articles were contacted to obtain additional data for possible inclusion. REVIEW METHODS: The main outcomes included ischaemic complications (stroke, transient ischaemic attack [TIA], and transcranial Doppler [TCD] measured micro-emboli), haemorrhagic complications (haemorrhagic stroke, neck haematoma, and re-operation for bleeding), and composite outcomes. Pooled estimates using odds ratios (ORs) were combined using a random or fixed effects model based on the results of the chi square test and calculation of I2. RESULTS: In total, 47 411 patients were included in 11 studies, with 14 345 (30.2%) receiving DAPT and 33 066 (69.7%) receiving aspirin only. There was no significant difference in the rates of peri-operative stroke (OR 0.87, 95% confidence interval [CI] 0.72 - 1.05) and TIA (OR 0.78, 95% CI 0.52 - 1.17) despite a significant reduction in TCD measured micro-emboli (OR 0.19, 95% CI 0.10 - 0.35) in the DAPT compared with the aspirin monotherapy group. Subgroup analysis did not reveal any significant difference in ischaemic stroke risk between patients with asymptomatic and symptomatic carotid artery stenosis. DAPT was associated with an increased risk of neck haematoma (OR 2.79, 95% CI 1.87 - 4.18) and re-operation for bleeding (OR 1.98, 95% CI 1.77 - 2.23) vs. aspirin. Haemorrhagic stroke was an under reported outcome in the literature. CONCLUSION: This meta-analysis found that CEA while on DAPT increased the risk of haemorrhagic complications, with similar rates of ischaemic complications, vs. aspirin monotherapy. This suggests that the risks of performing CEA on DAPT outweigh the benefits, even in patients with symptomatic carotid stenosis. The overall quality of studies was low, and improved reporting of CEA outcomes in the literature is necessary.

Neurosurgery on the web: an analysis of the web-visibility of the European Neurosurgical Societies.

Nowadays, internet provides a great opportunity that allows the research community to constantly increase their scientific collaboration, together with information distribution. Aim of this study is to investigate the European National Neurosurgical Societies (ENNS) web-visibility that represents the necessary basis for diffusion of neurosurgical knowledge to both patients and neurosurgeons. We evaluated the web-visibility of each Neurosurgical Society affiliated to the European Associations of Neurosurgical Societies (EANS) using 3 different parameters: 1) the availability of the full list of all Neurosurgical Centers (NCs) of the country in each ENNS website; 2) the availability of a specific English-written section on the ENNS web-site; and 3) the availability of at least one section titled "news and events" and/or "educational" and/or "patient info" on the ENNS website. The web-visibility was categorized in significant (at least 2 out of 3 items fulfilled), not significant (1 out of 3 only) and insufficient (all not fulfilled). We also evaluated the web-visibility of single NCs, and the availability on the web of society's sections dealing with specific neurosurgical topics for each ENNS. Through the EANS Website we identified 38 ENNS. The rate of ENNS with significant web-visibility was 39%, while 24% of ENNS showed to have a not-significant web-visibility, while 37% had an insufficient visibility. The most unattended criterion was the availability of an English-written section of the website. Among ENNS with a significant web-visibility, this specific criterion was fulfilled in only 53% of cases. This percentage goes down to the 22% for ENNS with a non-significant web-visibility. The full list of NCs was available in 87% of cases for significant profiles and in zero cases for not-significant ones. Finally, the web-visibility rate of single NCs among different ENNS was 80%. Specific sections focusing on specific neurosurgical topics were available in 5 out of 38 ENNS websites (13%). This study highlighted the importance of increasing the ENNS web-visibility to spread the neurosurgical knowledge for patients, neurosurgeons and trainees. This could lead to an easier ENNS interaction, increasing the international collaboration between neurosurgical centers in the clinical, research and educational settings.

Access-site complications in ultrasound-guided endovascular thrombectomy: a single-institution retrospective cohort study.

OBJECTIVE: Mechanical endovascular thrombectomy (EVT) is an increasingly relied-on treatment for clot retrieval in the context of ischemic strokes, which otherwise are associated with significant morbidity and mortality. Despite several known risks associated with this procedure, there is a high degree of technical heterogeneity across both centers and operators. The most common procedural complications occur at the point of transfemoral access (the common femoral artery), and include access-site hematomas, dissections, and pseudoaneurysms. Other interventional fields have previously popularized the use of ultrasound to enhance the anatomical localization of structures relevant to vascular access and thereby reducing access-site complications. In this study, the authors aimed to describe the ultrasound-guided EVT technique performed at a large, quaternary neurovascular referral center, and to characterize the effects of ultrasound guidance on access-site complications. METHODS: A retrospective chart review of all patients treated with EVT at a single center between January 2013 and August 2020 was performed. Patients in this cohort were treated using a universal, unique, ultrasound-guided, single-wall puncture technique, which bears several theoretical advantages over the standard technique of arterial puncture via palpation. RESULTS: There were 479 patients treated with EVT within the study period. Twenty patients in the cohort were identified as having experienced some form of access-site complication. Eight (1.67%) of these patients experienced minor access-site complications, all of which were groin hematomas and none of which were clinically significant, as defined by requiring surgical or interventional management or transfusion. The remaining 12 patients experienced arterial dissection (n = 5), arterial pseudoaneurysm (n = 4), retroperitoneal hematoma (n = 2), or arterial occlusion (n = 1), with only 1.04% (5/479) requiring surgical or interventional management or transfusion. CONCLUSIONS: The authors found an overall reduction in total access-site complications as well as minor access-site complications in the study cohort compared with previously published randomized controlled trials and observational studies in the recent literature. The findings suggested that there may be a role for routine use of ultrasound-guided puncture techniques in EVT to decrease rates of complications.

Antithrombotic choice in blunt cerebrovascular injuries: Experience at a tertiary trauma center, systematic review, and meta-analysis.

BACKGROUND: Blunt cerebrovascular injuries (BCVIs) may occur following trauma and lead to ischemic stroke if untreated. Antithrombotic therapy decreases this risk; however, the optimal agent has yet to be determined in this population. The aim of this study was to compare the risk-benefit profile of antiplatelet (AP) versus anticoagulant (AC) therapy in rates of ischemic stroke and hemorrhagic complications in BCVI patients. METHODS: We performed a retrospective review of BCVI patients at our tertiary care Trauma hospital from 2010 to 2015, and a systematic review and meta-analysis of the literature. The OVID Medline, Embase, Web of Science, and Cochrane Library databases were searched from inception to September 16, 2019. References of included publications were searched manually for other relevant articles. The search was limited to articles in humans, in patients 18 years or older, and in English. Studies that reported treatment-stratified clinical outcomes following AP or AC treatment in BCVI patients were included. Exclusion criteria included case reports, case series with n < 5, review articles, conference abstracts, animal studies, and non-peer-reviewed publications. Data were extracted from each study independently by two reviewers, including study design, country of origin, sex and age of patients, Injury Severity Score, Biffl grade, type of treatment, ischemic stroke rate, and hemorrhage rate. Pooled estimates using odds ratio (OR) were combined using a random-effects model using a Mantel-Hanzel weighting. The main outcome of interest was rate of ischemic stroke due to BCVI, and the secondary outcome was hemorrhage rate based on AC or AP treatment. RESULTS: In total, there were 2044 BCVI patients, as reported in the 22 studies in combination with our institutional data. The stroke rate was not significantly different between the two treatment groups (OR, 1.27; 95% confidence interval, 0.40-3.99); however, the hemorrhage rate was decreased in AP versus AC treated groups (OR, 0.38; 95% confidence interval, 0.15-1.00). CONCLUSION: Based on this meta-analysis, both AC and AP seem similarly effective in preventing ischemic stroke, but AP is better tolerated in the trauma population. This suggests that AP therapy may be preferred, but this should be further assessed with prospective randomized trials. LEVEL OF EVIDENCE: Review article, level II.

Minimally invasive intrathecal spinal cord imaging with optical coherence tomography.

SIGNIFICANCE: Imaging of the spinal cord is challenging due to the surrounding bony anatomy, physiologic motion, and the small diameter of the spinal cord. This precludes the use of non-invasive imaging techniques in assessing structural changes related to trauma and evaluating residual function. AIM: The purpose of our research was to apply endovascular technology and techniques and construct a preclinical animal model of intrathecal spinal cord imaging using optical coherence tomography (OCT). APPROACH: Five animals (2 Yorkshire Swine and 3 New Zealand Rabbits) were utilized. Intrathecal access was gained using a 16-guage Tuohy, and an OCT catheter was advanced under roadmap technique into the cervical canal. The OCT catheter has a motorized pullback, and a total length of 54 mm of the spinal canal is imaged. RESULTS: Image acquisition was successful for all animals. There were no instances of difficult catheter navigation, enabling OCT imaging rostrally to C2. The thecal sac provided excellent thoroughfare for the OCT catheter. The clear cerebrospinal fluid also provided an excellent medium for image acquisition, with no detectable artifact from the contents of the cerebrospinal fluid. The anatomical space of the spinal canal could be readily appreciated including: dural lining of the thecal sac, epidural veins, pial lining of the spinal cord, arachnoid bands, dentate ligaments, and nerve rootlets/roots. CONCLUSION: Minimally invasive intrathecal imaging using endovascular OCT was feasible in this preclinical animal study. The repurposing of an endovascular device for spinal imaging comes with limitations, and a spine-specific device is necessary.

The Superficial Anastomosing Veins of the Human Brain Cortex: A Microneurosurgical Anatomical Study.

Introduction: In this microneurosurgical and anatomical study, we characterized the superficial anastomosing veins of the human brain cortex in human specimens. Material and Methods: We used 21 brain preparations fixed in formalin (5%) that showed no pathological changes and came from the autopsy sections. The superficial veins were dissected out of the arachnoid with the aid of a surgical microscope. Results: We dissected nine female and 12 male brain specimens, with an average age of 71 ± 11 years (range 51-88 years). We classified the superficial veins in five types: (I) the vein of Trolard as the dominat vein; (II) the vein of Labbé as the dominant vein; (III) a dominant sylvian vein group, and the veins of Trolard and Labbé nonexistent or only rudimentary present without contact to the Sylvian vein group; (IV) very weak sylvian veins with the veins of Trolard and Labbé codominant; and V) direct connection of Trolard and Labbé bypassing the Sylvian vein group. The vein of Trolard was dominant (Type I) in 21.4% and the vein of Labbé (Type II) in 16.7%. A dominant sylvian vein group (Type III) was found in 42.9%. Type IV and Type V were found in 14.3 and 4.7% respectively. Conclusion: No systematic description or numerical distribution of the superior anastomotic vein (V. Trolard) and inferior anastomotic vein (V. Labbé) has been found in the existing literature. This study aimed to fill this gap in current literature and provide data to neurosurgeons for the practical planning of surgical approaches.

Mechanical thrombectomy and intravascular imaging for cerebral venous sinus thrombosis: a preclinical model.

OBJECTIVE: Although the majority of patients with cerebral venous sinus thrombosis (CVST) will improve with anticoagulation therapy, a portion of patients will either present in a comatose state or continue to deteriorate clinically despite early anticoagulation. In these cases, along with treating the underlying thrombophilia, timely thrombolysis may be beneficial. Repurposed arterial thrombectomy devices may not perform as expected in the cerebral venous sinus, and there are currently no preclinical endovascular thrombectomy (EVT) models for CVST. Contrary to arterial stroke research, preclinical models utilized to test various endovascular techniques and devices are lacking. The purpose of this research was to develop a reliable preclinical animal model for the testing of endovascular strategies to treat CVST. METHODS: Five consecutive male Yorkshire swine weighing 45 kg were utilized. Thrombosis of the superior sagittal sinus was induced with a bovine thrombin injection via a microcatheter under distal balloon occlusion for 15 minutes. Combined arterial injections and superselective sinus injections confirmed the extent of thrombosis. EVT was subsequently performed using a second-generation stent retriever, followed by intravascular optical coherence tomography (OCT) imaging to assess the luminal environment after thrombectomy. RESULTS: Thrombosis of the superior sagittal sinus, EVT, and subsequent OCT imaging were technically successful in 4 of the 5 swine. Recanalization of the sinus with a second-generation stent retriever was successful after one attempt in 3 of 4 swine (75%), and 1 swine required two attempts. OCT imaging after thrombectomy revealed regions of residual sinus luminal thrombus despite complete angiographic recanalization. Thrombosed bridging cortical veins were also observed before draining into the sinus, along with patent cortical veins. CONCLUSIONS: The authors describe a preclinical model to assess endovascular techniques and devices for the treatment of CVST. Repurposed devices from arterial stroke may not perform as expected, given the unique features of venous sinus thrombosis. Residual bridging cortical vein thrombus and residual sinus thrombus, visualized on intravascular OCT, may be present despite complete sinus recanalization on angiography, and this may be the etiology of the poor clinical outcome despite technical success. In the setting of bridging cortical vein thrombus after successful sinus thrombectomy, direct chemical thrombolysis may be warranted to dissolve the remaining clot. This model may be helpful in developing and testing a new generation of devices designed specifically for CVST treatment.

Endovascular optical coherence tomography imaging in cerebrovascular disease.

Endovascular optical coherence tomography (OCT) is the highest resolution imaging modality currently available with spatial resolution of 10 µm. Although originally developed for interventional cardiology, the ability to visualize the luminal environment and anatomy, along with the stent-vessel interaction could be of great utility for various cerebrovascular diseases, and the adoption of endovascular OCT imaging in the evolving field of interventional neuroradiology seems instinctive. The purpose of this study is to conduct a systematic review of the literature regarding applications of endovascular OCT in the diagnosis and treatment of cerebrovascular diseases. In addition, the authors report their institutional experience with the use of OCT in carotid atherosclerotic disease, cerebral aneurysms, and acute ischemic stroke. A systematic review of the literature was undertaken. Peer-reviewed articles were collected through MEDLINE, Embase, Scopus, and Cochrane Central Register of Controlled Trials (CENTRAL) searches through March 2020. A total of 34 studies with 598 patients were included in the qualitative synthesis. These include 23 studies of carotid atherosclerotic disease, 7 studies of cerebral aneurysms, and 4 studies of non-aneurysmal posterior circulation pathology. OCT imaging was feasible in 94% of patients with 0.6% complication rate. Endovascular OCT appears to be safe and feasible, allowing clinicians to visualize stent-vessel interactions, aneurysmal healing, and vulnerable atherosclerotic plaque features. OCT carries great promise, however additional investigations are needed before any imposing statement can be made about the role of OCT in cerebrovascular imaging.

Surgical Sparing and Pairing Endovascular Interventions for Carotid-Cavernous Fistula: Case Series and Review of the Literature.

BACKGROUND: Carotid-cavernous fistulas (CCFs) are abnormal communications between the arterial and venous circulation within the cavernous sinus, manifesting in myriad neurological and ophthalmological sequalae. In rare circumstances patients' unique vascular anatomies preclude standard endovascular treatment for this pathology, warranting combined surgical and endovascular approaches wherein the cavernous sinus is accessed via superior ophthalmic vein (SOV) exposure, cutdown, and cannulation. CASE DESCRIPTION: We describe 3 cases of CCF treated at our quaternary neurovascular referral center between 2017 and 2019. The first is a 35-year-old man with symptomatic, traumatic, right-sided CCF, treated with endovascular therapy (transarterial detachable balloon placement). The other cases were treated with contrasting surgical and endovascular combined approaches because of unique vascular challenges. The second is a 71-year-old woman with spontaneous right-sided CCF whose carotid sinus was accessed and embolized through a transpalpebral cutdown of the SOV. The third case is a 70-year-old man with symptomatic, spontaneous bilateral CCF. After unsuccessful transarterial and transvenous endovascular approaches, transorbital (intracranial) SOV cutdown and cannulation were performed to embolize the shunting fistula. CONCLUSIONS: Endovascular approaches are well described as the mainstay of treatment for CCF but are not possible for all patients. In circumstances where individual vascular anatomy is not amenable to transarterial or transvenous access or embolization, a combined surgical and endovascular approach may be appropriate. We describe 3 cases that illustrate the spectrum of interventions for CCF, as well as the technical aspects of treatment for 2 patients with complex, direct CCF, using an embolization approach reliant on SOV cutdown and cannulation.

Angio-architecture of complex cranial dural arteriovenous fistulas: A single centre retrospective review of treatment modalities and outcomes.

INTRODUCTION: Cranial dural arteriovenous fistulas (DAVFs) are rare vascular lesions that often harbour complex angio-architectural features. This subtype of DAVF may require multiple, multimodality, or hybrid treatments. In this paper we aim to identify specific angio-architectural features that are present in complex cranial DAVFs and we report our series with respect to treatment modalities and outcomes. METHODS: Twenty-five cranial Borden type II and III cranial DAVFs were treated at our Institution from 2013 to 2017. We classified nine (36%) as complex based on specific angio-architectural features. Treatment strategies were based on fistula location, angiographic features and patient's presenting condition. Phone interviews were used to confirm outcome at 6 and 12 months. RESULTS: Four patients (45%) presented with acute hydrocephalus, and 3 (33%) with intracranial hemorrhage. Multiple and combined treatment sessions were needed for all complex DAVFs. Five patients required 2 endovascular procedures each. One patient had 2 surgeries. The first line of treatment was endovascular in 6 cases (67%) and surgery in 3 (33%). Two treatment-related (22%) complications occurred. Complete disconnection was achieved in 5 out of 9 patients (55%). Two patients with an incomplete disconnection refused further treatment and were well at last follow up, with a partially treated fistula and persistent CVR. The other 3 patients concluded treatment after the end of our data collection period. At 1 year, 7/9 patients had stable or improved clinical symptoms, and 8/9 patients had GOS of 4 or 5. CONCLUSIONS: Complex cranial DAVF often require a multidisciplinary approach and multiple treatment sessions should be expected. Specific angio-architectural features that increase DAVF complexity include multiple arterial feeders, especially transosseous or pial, reflux into multiple cortical veins, sinus occlusion/entrapment, venous aneurysms, segmental stenosis, medial or deep location, and association with the deep venous system.

Outcomes of Endovascular Thrombectomy for Basilar Artery Occlusion.

BACKGROUND AND PURPOSE: Large prospective observational studies have cast doubt on the common assumption that endovascular thrombectomy (EVT) is superior to intravenous thrombolysis for patients with acute basilar artery occlusion (BAO). The purpose of this study was to retrospectively review our experience for patients with BAO undergoing EVT with modern endovascular devices. METHODS: All consecutive patients undergoing EVT with either a second-generation stent retriever or direct aspiration thrombectomy for BAO at our regional stroke center from January 1, 2013 to March 1, 2019 were included. The primary outcome measure was functional outcome at 1 month using the modified Rankin Scale (mRS) score. Multivariable logistic regression was used to assess the association between patient characteristics and dichotomized mRS. RESULTS: A total of 43 consecutive patients underwent EVT for BAO. The average age was 67 years with 61% male patients. Overall, 37% (16/43) of patients achieved good functional outcome. Successful reperfusion was achieved in 72% (31/43) of cases. The median (interquartile range) stroke onset to treatment time was 420 (270-639) minutes (7 hours) for all patients. The procedure-related complication rate was 9% (4/43). On multivariate analysis, posterior circulation Alberta stroke program early computed tomography score and Basilar Artery on Computed Tomography Angiography score were associated with improved functional outcome. CONCLUSION: EVT appears to be safe and feasible in patients with BAO. Our finding that time to treatment and successful reperfusion were not associated with improved outcome is likely due to including patients with established infarcts. Given the variability of collaterals in the posterior circulation, the paradigm of utilizing a tissue window may assist in patient selection for EVT. Magnetic resonance imaging may be a reasonable option to determine the extent of ischemia in certain situations.

Machine vision augmented reality for pedicle screw insertion during spine surgery.

Implementing pedicle safe zones with augmented reality has the potential to improve operating room workflow during pedicle screw insertion. These safe zones will allow for image guidance when tracked instruments are unavailable. Using the correct screw trajectory as a reference angle for a successful screw insertion, we will determine the angles which lead to medial, lateral, superior and inferior breaches. These breaches serve as the boundaries of the safe zones. Measuring safe zones from the view of the surgical site and comparing to the radiological view will further understand the visual relationship between the radiological scans and the surgical site. Safe zones were measured on a spine phantom and were then replicated on patients. It was found that the largest causes for variance was between each of the camera views and the radiological views. The differences between the left and right cameras were insignificant. Overall, the camera angles appeared to be larger than the radiological angles. The magnification effect found in the surgical site result in an increased level of angle sensitivity for pedicle screw insertion techniques. By designing a virtual road map on top of the surgical site directly using tracked tools, the magnification effect is already taken into consideration during surgery. Future initiatives include the use of an augmented reality headset.