Remote Training of Neurointerventions by Audiovisual Streaming : Experiences from the European ESMINT-EYMINT E-Fellowship Program.

BACKGROUND: Remote access of trainees to training centers via video streaming (tele-observership, e­fellowship) emerges as an alternative to acquire knowledge in endovascular interventions. Situational awareness is a summary term that is also used in surgical procedures for perceiving and understanding the situation and projecting what will happen next. A high situational awareness would serve as prerequisite for meaningful learning success during tele-observerships. We hypothesized that live perception of the angiographical procedures using streaming technology is feasible and sufficient to gain useful situational awareness of the procedure. METHODS: During a European tele-observership organized by the European Society of Minimally Invasive Neurological Therapy (ESMINT) and its trainee association (EYMINT), a total of six neurointerventional fellows in five countries observed live cases performed by experienced neurointerventionalists (mentors) in six different high-volume neurovascular centers across Europe equipped with live-streaming technology (Tegus Medical, Hamburg, Germany). Cases were prospectively evaluated during a 12-month period, followed by a final questionnaire after completion of the course. RESULTS: A total of 102/161 (63%) cases with a 1:1 allocation of fellow and mentor were evaluated during a 12-month period. Most frequent conditions were ischemic stroke (27.5%), followed by embolization of unruptured aneurysms (25.5%) and arteriovenous malformations (AVMs) (15.7%). A high level of situational awareness was reported by fellows in 75.5% of all cases. After finishing the program, the general improvement of neurointerventional knowledge was evaluated to be extensive (1/6 fellows), substantial (3/6), and moderate (2/6). The specific fields of improvement were procedural knowledge (6/6 fellows), technical knowledge (3/6) and complication management (2/6). CONCLUSION: Online streaming technology facilitates location-independent training of complex neurointerventional procedures through high levels of situational awareness and can therefore supplement live hands-on-training. In addition, it leads to a training effect for fellows with a perceived improvement of their neurointerventional knowledge.

Dissection-related tandem occlusion may be different from atherothrombotic tandem occlusion.

OBJECTIVES: The optimal endovascular treatment for tandem occlusion in anterior circulation ischaemic stroke remains unknown. The aim of this study was to examine how the aetiology of carotid pathology, dissection versus atherothrombosis, affects clinical outcomes. MATERIALS AND METHODS: Data was obtained from prospectively collected registries from two stroke centres between April 2016 and December 2020. Tandem cases with complete cervical internal carotid artery (ICA) occlusion or near-total occlusion (≥90% stenosis) were included. Patients were divided into two groups based on carotid pathology: dissection versus atherothrombosis. RESULTS: A total of 134 patients were included: 36 were dissection and 98 were atherothrombosis. The dissection group had better clinical outcomes compared to the atherothrombosis group, although after adjusting for age and stroke risk factors differences were non-significant. In the non-stented cohort, the dissection patients achieved a better outcome (modified Rankin scale 0-2) than atherothrombotic patients (57% vs. 34%, p=0.04) at 90-days. CONCLUSION: Dissection-related tandem occlusions appear to have different clinical features from atherothrombotic tandem occlusions which suggests different management strategies are needed.

Intensive therapies of delayed cerebral ischemia after subarachnoid hemorrhage: a propensity-matched comparison of different center-driven strategies.

BACKGROUND: Intensive therapies of delayed cerebral ischemia (DCI) following aneurysmal subarachnoid hemorrhage (aSAH) have still controversial and unproven benefit. We aimed to compare the overall efficacy of two different center-driven strategies for the treatment of DCI respectively with and without vasospasm angioplasty. METHODS: Two hundred consecutive patients with aSAH were enrolled in each of two northern European centers. In an interventional center, vasospasm angioplasty was indicated as first line rather than rescue treatment of DCI using distal percutaneous balloon angioplasty technique combined with intravenous milrinone. In non-interventional center, induced hypertension was the only intensive therapy of DCI. Radiological DCI (new cerebral infarcts not visible on immediate post-treatment imaging), death at 1 month, and favorable outcome at 6 months (modified Rankin scale score ≤ 2) were retrospectively analyzed by independent observers and compared between two centers before and after propensity score (PS) matching for baseline characteristics. RESULTS: Baseline characteristics only differed between centers for age and rate of smokers and patients with chronic high blood pressure. In the interventional center, vasospasm angioplasty was performed in 38% of patients with median time from bleeding of 8 days (Q1 = 6.5;Q3 = 10). There was no significant difference of incidence of radiological DCI (9% vs.14%, P = 0.11), death (8% vs. 9%, P = 0.4), and favorable outcome 74% vs. 72% (P = 0.4) between interventional and non-interventional centers before and after PS matching. CONCLUSIONS: Our results suggest either that there is no benefit, or might be minimal, of one between two different center-driven strategies for intensive treatment of DCI. Despite potential lack of power or unknown confounders in our study, these results question the use of such intensive therapies in daily practice without further optimization and validation.

Aneurysms of the communicating segment of the internal carotid artery with posterior communicating artery agenesis are associated with perforator infarction after embolization.

BACKGROUND: While anatomic features associated with the risk of posterior communicating artery (PcoA) occlusion after embolization of aneurysms of the PcoA segment of the internal carotid artery (ICA) are well known, the link between perforator origin and perforator infarction has only been reported following neurosurgical clipping. The aim of this study was to determine the origin of anterior thalamic perforators and correlate it with risk of perforator infarction after embolization of PcoA segment aneurysms. METHODS: One-hundred-and-ninety consecutive patients treated for PcoA segment aneurysms between 2017 and 2019 were included. PcoA and anterior thalamic perforator origin anatomy was assessed with computed tomography (CT) angiography, digital subtracted angiography, and high-resolution three-dimensional rotational cone-beam CT angiography (CBCT-A) by two independent interventional neuroradiologists. The presence of perforator infarction after embolization was ascertained from the patient's notes and follow-up imaging. RESULTS: CBCT-A was superior in demonstrating the origin of perforators (P<0.001). The prevalence of perforator origin was estimated at 86% (95% CI 81%-92%) for PcoA, 8% (95% CI 4%-13%) for aneurysm wall, and 5% (95% CI 2%-9%) for ICA. The aneurysm wall origin was exclusively associated with PcoA agenesis, as well as higher risk of perforator infarction after aneurysm coiling compared with other variants (OR=14, 95% CI 2-88, P=0.006). CONCLUSIONS: Our study suggests that anterior thalamic perforators may arise from aneurysm wall when there is no PcoA. Anatomic association between PcoA agenesis and perforator arising from ICA could underlie such findings, and careful consideration is essential before aneurysm repair to anticipate the risk of thalamic infarction in such cases.

Association of spontaneous cerebrospinal fluid rhinorrhea with transverse venous sinus stenosis: a retrospective matched case-control study.

BACKGROUND: A significant proportion of spontaneous cerebrospinal fluid (sCSF) leaks are associated with idiopathic intracranial hypertension (IIH). The aim of this study was to assess the association between sCSF rhinorrhea and transverse venous sinus stenosis (VSS), a feature commonly observed in IIH with a proposed role in its pathophysiology. METHODS: In this single-center, retrospective, matched case-control study, venous and pituitary imaging data of consecutive patients undergoing endoscopic surgery for sCSF rhinorrhea over the last 10 years were retrospectively reviewed. Measurement of the height of the pituitary gland was used to assess empty sella and VSS was quantified as the ratio between the minimal area of the transverse sinus and the cross-sectional area of the sigmoid sinus. VSS was considered significant when it was ≥50% and bilateral. Cases were compared with 1:1 age- and sex-adjusted controls explored for causes other than IIH, intracranial mass effect, or venous thrombosis. RESULTS: Twenty-nine patients were included (median age 56 years, females 69%, body mass index [BMI] 33.8 kg/m2 ). Cases had a significantly lower height of the pituitary gland than controls (2.5 mm vs 6.6 mm, p < 0.001). Bilateral VSS was found in 23 of 29 cases (79%; 95% confidence interval [CI], 65% to 94%) vs 3 of 29 controls (10%; 95% CI, 0% to 21%), with p < 0.001. CONCLUSION: In this retrospective study, sCSF leaks were strongly associated with VSS. This novel finding provides a rationale for further investigation of the role of VSS in the onset of sCSF leaks and of the potential interest in venous stenting after the surgical repair of leaks.

Unilateral hearing loss in a 94-year-old patient.

A case report of a 94-year-old, previously well male patient who presented with fever thought to be caused by community acquired pneumonia, new unilateral hearing loss and reduced consciousness. Despite antibiotic treatment he continued to deteriorate. Brain imaging with computer tomography and magnetic resonance imaging revealed a left otomastoiditis with osteomyelitis of the skull base, associated with an adjacent subdural empyema. He was also found to have a venous sinus thrombosis, most likely secondary to otitis media. He was managed with intravenous antibiotics, anticoagulation, grommet insertion and a hearing aid and he made a good recovery. This case reminds us to consider otitis media in older patients who present with hearing loss and fever. Otitis media can lead to serious complications including subdural empyema and osteomyelitis of the skull base.

Incidence and outcome of functional stroke mimics admitted to a hyperacute stroke unit.

BACKGROUND: Some patients admitted to acute stroke units are diagnosed as stroke mimics. A minority have a functional neurological disorder ('functional mimics'). AIMS: To determine the incidence of functional stroke mimics admitted to a hyperacute stroke unit (HASU); to compare their clinical characteristics with medical mimics and stroke cases and obtain information about outcomes. METHODS: Patients admitted to the King's College Hospital HASU between 2011 and 2012 were analysed. Data were obtained from the Stroke Improvement National Audit Programme (SINAP) database. Expert consensus diagnosis was used to classify functional mimics. Follow-up information was obtained from a retrospective case series in primary care over the year following discharge. RESULTS: 1165 patients were admitted to the HASU; 904 patients with stroke (77.6%), 163 medical mimics (14%) and 98 functional mimics (8.4%). Functional mimics were significantly more likely to be female (63.3%) versus 49.7% medical mimics and 45.5% stroke, and younger (mean age (SD)) 49.1 (18.8) than medical mimic (63.5 years (16.7)) and stroke cases (71 years (15.5)). Weakness and slurred speech were the commonest presentations of functional mimics and diagnostic MRI was used more often. Clinician recorded visual and speech symptoms and neglect were significantly more frequent in patients with stroke than either mimic group. Of the 68 functional mimics on whom follow-up information was obtained, 40 (59%) were referred to another service most often for a psychologically-based intervention. CONCLUSIONS: Functional stroke mimics are an important subgroup admitted to acute stroke services and have a distinct demographic and clinical profile. Their outcomes are poorly monitored. Services should be developed to better diagnose and manage these patients.