Prior Thrombectomy Does Not Affect the Surgical Complication Rate of Decompressive Hemicraniectomy in Patients with Malignant Ischemic Stroke.

BACKGROUND: Even though mechanical recanalization techniques have dramatically improved acute stroke care since the pivotal trials of decompressive hemicraniectomy for malignant courses of ischemic stroke, decompressive hemicraniectomy remains a mainstay of malignant stroke treatment. However, it is still unclear whether prior thrombectomy, which in most cases is associated with application of antiplatelets and/or anticoagulants, affects the surgical complication rate of decompressive hemicraniectomy and whether conclusions derived from prior trials of decompressive hemicraniectomy are still valid in times of modern stroke care. METHODS: A total of 103 consecutive patients who received a decompressive hemicraniectomy for malignant middle cerebral artery infarction were evaluated in this retrospective cohort study. Surgical and functional outcomes of patients who had received mechanical recanalization before surgery (thrombectomy group, n = 49) and of patients who had not received mechanical recanalization (medical group, n = 54) were compared. RESULTS: The baseline characteristics of the two groups did significantly differ regarding preoperative systemic thrombolysis (63.3% in the thrombectomy group vs. 18.5% in the medical group, p < 0.001), the rate of hemorrhagic transformation (44.9% vs. 24.1%, p = 0.04) and the preoperative Glasgow Coma Score (median of 7 in the thrombectomy group vs. 12 in the medical group, p = 0.04) were similar to those of prior randomized controlled trials of decompressive hemicraniectomy. There was no significant difference in the rates of surgical complications (10.2% in the thrombectomy group vs. 11.1% in the medical group), revision surgery within the first 30 days after surgery (4.1% vs. 5.6%, respectively), and functional outcome (median modified Rankin Score of 4 at 5 and 14 months in both groups) between the two groups. CONCLUSIONS: A prior mechanical recanalization with possibly associated systemic thrombolysis does not affect the early surgical complication rate and the functional outcome after decompressive hemicraniectomy for malignant ischemic stroke. Patient characteristics have not changed significantly since the introduction of mechanical recanalization; therefore, the results from former large randomized controlled trials are still valid in the modern era of stroke care.

[Intracranial vascular malformations]. / Intrakranielle Gefäßmalformationen.

Intracranial vascular malformations range from incidental asymptomatic vascular alterations up to life-threatening vascular disorders. Arteriovenous malformations and dural arteriovenous fistulas are cerebral vascular malformations with arteriovenous shunting of blood. In the majority of cases they are accompanied by an elevated risk of intracerebral hemorrhage and can cause severe symptoms. They can be treated conservatively or interventionally via microneurosurgery, endovascular embolization and radiation therapy. Cavernous malformations, developmental venous anomalies (DVA) and capillary telangiectasia are cerebral vascular malformations without arteriovenous shunting. Cavernous malformations are rarely symptomatic in the form of cerebral hemorrhage, headache or seizures and in such cases an operative treatment can be indicated. The DVA and capillary telangiectasia are usually asymptomatic and do not require treatment.

Peri-procedural silent cerebral infarcts after left atrial appendage occlusion.

BACKGROUND AND PURPOSE: To determine the rate of peri-interventional silent brain infarcts after left atrial appendage occlusion (LAAO). METHODS: In this prospective, uncontrolled single-center pilot study, consecutive patients with atrial fibrillation undergoing LAAO between July 2013 and January 2016 were included. The Amplatzer Cardiac Plug, WATCHMAN or Amulet device was used. A neurological examination and cranial magnetic resonance imaging (MRI) were performed within 48 h before and after the procedure. MRI was evaluated for new diffusion-weighted imaging (DWI) hyperintensities, cerebral microbleeds (CMBs) and white-matter lesions (WMLs). RESULTS: Left atrial appendage occlusion was performed in 21 patients (mean age, 73.2 ± 9.5 years). Main reasons for LAAO were previous intracerebral hemorrhage (n = 11) and major systemic bleeding (n = 6). No clinically overt stroke occurred peri-interventionally. After the intervention, one patient had a small cerebellar hyperintensity on DWI (4.8%; 95% confidence interval, 0.0-14.3) that was not present on the MRI 1 day before the procedure. Among 11 patients with available MRI just before LAAO, there were no significant changes in the number of CMBs and the severity of WMLs after LAAO. CONCLUSIONS: This study of peri-interventional MRI in LAAO suggests a low rate of silent peri-procedural infarcts in this elderly population. Confirmation in larger studies is needed.

Preexisting cognitive impairment in intracerebral hemorrhage.

OBJECTIVES: Preexisting cognitive impairment is a predictor of cognitive decline after ischemic stroke, but evidence in intracerebral hemorrhage (ICH) is limited. We aimed to determine the prevalence of premorbid cognitive impairment in patients with ICH. MATERIALS AND METHODS: We included patients with acute ICH. Pre-ICH cognitive impairment was determined based on the results of the Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE) that uses information from close relatives. Patients were assessed as having been cognitively impaired with an IQCODE score of ≥3.44; an IQCODE ≥4.00 indicated pre-ICH dementia. CT and MRI images were reviewed to determine the extent of white matter lesions and to measure the radial width of the temporal horn as marker of brain atrophy. We investigated differences of cardiovascular risk factors and imaging data between patients with and without pre-ICH cognitive impairment using correlation analyses, uni- and multivariable regression models. Functional neurological state was assessed using the modified Rankin Scale (mRS). The mRS was dichotomized at the level of 3, and a premorbid mRS of 0-2 was considered as functional independency. RESULTS: Among the 89 participants, median age was 70 years (interquartile range 58-78) and 52 (58.4%) were male. IQCODE indicated pre-ICH cognitive impairment in 18.0% (16 of 89), and 83.1% were functionally independent before ICH. Cognitive impairment was associated with a premorbid mRS≥3 (chi squared test, P=0.009). In multivariable analysis, prior stroke/transient ischemic attack (OR 18.29, 95%-CI 1.945-172.033, P=.011) and hematoma volume (OR 0.90, 95%-CI 0.812-0.991, P=.033) were independently associated with pre-ICH cognitive impairment. CONCLUSIONS: In conclusion, cognitive impairment frequently precedes ICH. A higher frequency of cerebrovascular events suggests a role of vascular processes in the development of cognitive impairment before ICH.

Prevalence of atrial fibrillation and association of previous antithrombotic treatment in patients with cerebral microbleeds.

BACKGROUND AND PURPOSE: Cerebral microbleeds (CMBs) are associated with an increased risk of intracerebral hemorrhage. The impact of oral anticoagulation (OAC) on CMBs is not well characterized. Our aim was to assess the prevalence of CMBs in stroke and transient ischaemic attack (TIA) patients with atrial fibrillation (AF) and to analyze the implications of previous treatment with OAC. METHODS: In this retrospective analysis on data from a prospectively recruiting stroke registry, patients with ischaemic stroke or TIA with brain magnetic resonance imaging including susceptibility weighted imaging were consecutively enrolled during a 3-year period. For each patient cardiovascular risk factors, AF history and recent diagnosis of AF, present use of OAC and antiplatelets, the National Institute of Health Stroke Scale and the premorbid modified Rankin Scale score were recorded. Two independent raters identified CMBs according to consensus criteria. CMB location was classified as lobar, deep or in the posterior fossa. RESULTS: In all, 785 patients (mean age 63.9 ± 14.2 years) were included. At least one CMB was detected in 186 (23.7%) patients. CMBs were significantly more frequent in patients with AF (30.5% vs. 22.4%). Patients with previous OAC treatment were more likely to have CMBs (36.7% vs. 22.8%, P = 0.03) and abundant CMBs (n > 10) were more frequent in anticoagulated patients even after adjustment for age. However, age was the only independent factor predicting CMBs (P = 0.001). CONCLUSIONS: Cerebral microbleeds are common in elderly AF patients with acute ischaemic stroke. Previous OAC is associated with a higher number of CMBs predominantly in the lobar location. Establishing a causal relationship requires prospective longitudinal investigation.

[Technical standards for the interventional treatment of acute ischemic stroke]. / Technische Standards bei der interventionellen Behandlung des akuten ischämischen Schlaganfalls.

Acute ischemic stroke is the leading cause of acquired disability and its treatment is still a major challenge. For more than a decade, various mechanical devices have been developed for the recanalization of proximal artery occlusions in acute ischemic stroke but most of them have been approved for clinical use, only on the basis of uncontrolled case series. Intravenous thrombolysis with recombinant tissue-specific plasminogen activator administered (iv rtPA) within 4.5 h of symptom onset is so far the only approved medicinal treatment in the acute phase of cerebral infarction. With the introduction of stent retrievers, mechanical thrombectomy has demonstrated substantial rates of partial or complete arterial recanalization and improved outcomes compared with iv rtPA and best medical treatment alone in multiple randomized clinical trials in select patients with acute ischemic stroke and proximal artery occlusions. This review discusses the evolution of endovascular stroke therapy followed by a discussion of the current technical standards of mechanical thrombectomy that have to be considered during endovascular stroke therapy and the updated treatment recommendations of the ESO Karolinska stroke update.

Effect of thrombus size on recanalization by bridging intravenous thrombolysis.

BACKGROUND AND PURPOSE: Thrombus length has been reported as an important predictor of successful recanalization by intravenous thrombolysis but its influence on bridging thrombolysis has not been investigated yet. The effect of thrombus length on recanalization rates evaluated by catheter angiography early after intravenous bridging thrombolysis was analyzed. METHODS: Ninety-six consecutive patients with acute cerebral artery occlusion were included. Occlusion site and thrombus length on initial computed tomography angiography or magnetic resonance angiography were related to recanalization after intravenous bridging thrombolysis on the initial series of catheter angiography. RESULTS: Eleven of 96 patients (11.5%) showed successful recanalization (TICI 2a, 2b or 3) after intravenous bridging thrombolysis. Mean thrombus length in these patients was 10.8 mm as opposed to 15.6 mm in patients without successful recanalization. No thrombus longer than 16 mm showed complete recanalization. Binary logistic regression demonstrated a significant influence of thrombus length on probability of recanalization (odds ratio 0.78, 95% confidence interval 0.65-0.95; P = 0.014). CONCLUSIONS: Thrombus length is a significant predictor of recanalization rates after bridging thrombolysis. Overall recanalization rate within the time frame until interventional treatment is started was 11.5% after bridging thrombolysis.

The LVIS Jr. microstent to assist coil embolization of wide-neck intracranial aneurysms: clinical study to assess safety and efficacy.

INTRODUCTION: This study was aimed to assess clinical safety and efficacy of the LVIS Jr. microstent in stent-assisted coil embolization of wide-neck intracranial aneurysms. METHODS: IRB approved single-center interventional clinical study in 22 patients (10 females, 12 males, mean age 55, age range 33-74 years) for the endovascular treatment of wide-neck aneurysms. After obtaining informed consent, patients were included according to the following criteria: aneurysm fundus-to-neck ratio < 2 or neck diameter > 4 mm, and a parent vessel diameter of ≤3.5 mm. Primary end point for clinical safety was absence of death, absence of major or minor stroke, and absence of transient ischemic attack. Primary end point for treatment efficacy was complete angiographic occlusion according to the Raymond-Roy Occlusion Classification (RROC) immediately after the procedure and at follow-up after 3 and 6 months on magnetic resonance imaging (MRI). RESULTS: In 20/22 (91 %) of patients, the primary end point of safety was reached; in the two remaining patients, transient ischemic attack, but no permanent deficit was observed; in 16/22 (73 %), efficient occlusion (RROC1) was reached, and in 6/22 (27 %), a residual neck remained (RROC2). Single [seven with antegrade, two in crossover configuration, and four with "first-balloon-then-stent" (FBTS) technique] or double-stent (eight patients with Y configuration and one patient with X configuration) deployment was technically successful in all cases. CONCLUSION: Deployment of the LVIS Jr. microstent in various single- or double-stent configurations is safe and effective to assist the treatment of intracranial wide-neck aneurysms.

[News and perspectives in neurocritical care]. / Neuigkeiten und Perspektiven der Neurointensivmedizin.

Neurocritical care is an ever-evolving discipline and its implementation in intensive care leads to reduction in mortality and to improvement of functional outcome in patients with devastating injuries to the nervous system. However, the decisive elements of the complete field of neurocritical care remain relatively unclear, as well as the exact ways to optimize them. During recent years new insights have been gained and new exciting studies have been initiated from which results are soon to be expected. This review focuses on the following management aspects: neuromonitoring, airway and ventilation, endovascular therapy, cerebrospinal fluid drainage, decompressive craniectomy, hematoma evacuation, blood pressure, and targeted temperature management. The application of these measures to brain diseases and injuries frequently treated in neurointensive care units will be addressed in the context of current studies.

Improved clinical outcome after acute basilar artery occlusion since the introduction of endovascular thrombectomy devices.

BACKGROUND: Thrombectomy devices are increasingly used for intra-arterial recanalization therapy in stroke. We analyzed whether the use of these devices modified the outcome of patients with acute basilar occlusion (BAO) at our institution. METHODS: Between 1998 and 2012, one hundred forty-seven consecutive patients with acute BAO received recanalization therapy. In July 2009, for the first time, a thrombectomy device was used and hence the cohort was split into two chronological groups: BAO-1 (before July 2009) and BAO-2 (after July 2009). All patients were treated at a dedicated neurological ICU following institutional standard operating procedures. A good clinical outcome was defined as a modified Rankin scale score of 0-2 after 3 months. Univariate and multivariate analyses were applied using outcome parameters as dependent variables and baseline variables with a significant p value in univariate tests as independent variables. RESULTS: One hundred eleven patients (BAO-1) were treated before and 36 were treated after July 2009 (BAO-2). Patients in the BAO-1 and BAO-2 groups had similar neurological deficits on admission as expressed by the Glasgow Coma Scale (BAO-1: median 4, IQR 5, vs. BAO-2: median 4.5, IQR 8, p = 0.41) and the proportion of patients who were presented intubated and ventilated was similar in both groups as well (49.5 vs. 47.7%, p = 0.85). Bridging concepts with intravenous recombinant tissue plasminogen activator (rtPA) were applied in 18.9% (BAO-1) versus 63.9% (BAO-2, p < 0.001) of cases, whereas glycoprotein IIb/IIIa antagonists were used significantly more frequently in the BAO-1 cohort (57.7 vs. 33.3%, p = 0.034). Thrombectomies were performed in 20 patients (55.5%) of the BAO-2 group but in none of the BAO-1 cohort. Complete recanalization (TICI 3) was achieved in 45.1% (BAO-1) versus 66.7% (BAO-2, p = 0.062) of patients. A good clinical outcome was observed in 13.5% of the BAO-1 group and 30.6% of the BAO-2 cohort (p = 0.026); mortality was 57.7% in the earlier group and 36.1% in the later group (p = 0.034). The frequency of symptomatic intracranial hemorrhage was similar in both groups (8.1% BAO-1 vs. 2.8% BAO-2, p = 0.45). Treatment in the BAO-2 cohort was an independent predictor of good clinical outcome (OR 2.56; 95% CI 1.01-6.78) and mortality (OR 0.36; 95% CI 0.15-0.86) in an adjusted logistic regression model. CONCLUSION: Our results show improved outcomes in patients in the BAO-2 cohort. The treatment approach in this group was an independent predictor of both good outcome and mortality. Especially in patients with BAO - where endovascular treatment strategies are common clinical practice - bridging protocols with rtPA and modern thrombectomy devices should be used more frequently.

The FRESH Study: Treatment of Intracranial Aneurysms with the New FRED X Flow Diverter with Antithrombotic Surface Treatment Technology-First Multicenter Experience in 161 Patients.

BACKGROUND AND PURPOSE: Flow diverters with antithrombotic coatings are increasingly used to improve the safety of flow diverter treatments of intracranial aneurysms. This study aimed to investigate the safety and short-term efficacy of the new FRED X flow diverter. MATERIALS AND METHODS: Medical charts and procedural and imaging data of a consecutive series of patients with intracranial aneurysms who were treated with the FRED X at 9 international neurovascular centers were retrospectively analyzed. RESULTS: One hundred sixty-one patients (77.6% women; mean age, 55 years) with 184 aneurysms (11.2% acutely ruptured) were included in this study. Most aneurysms were located in the anterior circulation (77.0%), most frequently at the ICA (72.7%). The FRED X was successfully implanted in all procedures. Additional coiling was performed in 29.8%. In-stent balloon angioplasty was necessary in 2.5%. The rate of major adverse events was 3.1%. Thrombotic events occurred in 7 patients (4.3%) with 4 intra- and 4 postprocedural in-stent thromboses, respectively (1 patient had both peri- and postprocedural thrombosis). Of these thrombotic events, only 2 (1.2%) led to major adverse events (ischemic strokes). Postinterventional neurologic morbidity and mortality were observed in 1.9% and 1.2%, respectively. The rate of complete aneurysm occlusion after a mean follow-up of 7.0 months was 66.0%. CONCLUSIONS: The new FRED X is a safe and feasible device for aneurysm treatment. In this retrospective multicenter study, the rate of thrombotic complications was low, and the short-term occlusion rates are satisfactory.

[Vertebral stability in management of spinal metastases. Criteria and strategies for operative interventions]. / "Wirbelkörperstabilität" im spinalen Metastasenmanagement. Kriterien und Strategien zur operativen Intervention.

BACKGROUND: Metastases are responsible for most tumor manifestations of the spine. About 25% are symptomatic; however, due to interdisciplinary management the tumor-associated mortality is regressing. Associated acute spinal cord injury (SCI) syndromes raise patient morbidity with a loss of independence and quality of life associated with a fair potential for recovery. Therefore, the management is focused on the avoidance of SCI. The assessment of mechanical stability of vertebral bodies is a central part of decision-making when considering operative therapy. This review gives an update on the current evidence-based data for metastasis management. DECISION MAKING: The NOMS concept is well established. Especially the parameters origin, neurologic symptoms, stability and vascularization are described and illustrated by clinical cases. OPERATIVE THERAPY CONCEPTS: Evidence-based operative therapy concepts are shown reflecting palliative and curative approaches. ASSESSMENT OF PARAMETERS FOR THERAPY ALGORITHM: Clinical and radiological parameters help to find the individual therapy. Generally a number of scores with significant time expenditure are needed. The spine instability neoplastic score (SINS) simplifies the management. Operative therapy shows the best results for the parameters pain and quality of life. However, potential perioperative and postoperative complications have to be estimated and should be avoided. Using these facts our therapy algorithm is helpful for therapy management. CONCLUSIONS: With rising life expectancy operative therapy is of increasing relevance. Decision-making uses information about tumor origin, neurologic symptoms, stability, prognostic factors and vascularisation to determine the individual therapy.

RAPID CT Perfusion-Based Relative CBF Identifies Good Collateral Status Better Than Hypoperfusion Intensity Ratio, CBV-Index, and Time-to-Maximum in Anterior Circulation Stroke.

BACKGROUND AND PURPOSE: Information of collateral flow may help to determine eligibility for thrombectomy. Our aim was to identify CT perfusion-based surrogate parameters of good collateral status in acute anterior circulation ischemic stroke. MATERIALS AND METHODS: In this retrospective study, we assessed the collateral status of 214 patients who presented with acute ischemic stroke due to occlusion of the MCA M1 segment or the carotid terminus. Collaterals were assessed on dynamic CTA images analogous to the multiphase CTA score by Menon et al. CT perfusion parameters (time-to-maximum, relative CBF, hypoperfusion intensity ratio, and CBV-index) were assessed with RAPID software. The Spearman rank correlation and receiver operating characteristic analyses were performed to identify the parameters that correlate with collateral scores and good collateral supply (defined as a collateral score of ≥4). RESULTS: The Spearman rank correlation was highest for a relative CBF < 38% volume (ρ = -0.66, P < .001), followed by the hypoperfusion intensity ratio (ρ = -0.49, P < .001), CBV-index (ρ = 0.51, P < .001), and time-to-maximum > 8 seconds (ρ = -0.54, P < .001). Good collateral status was better identified by a relative CBF < 38% at a lesion size <27 mL (sensitivity of 75%, specificity of 80%) compared with a hypoperfusion intensity ratio of <0.4 (sensitivity of 75%, specificity of 62%), CBV-index of >0.8 (sensitivity of 60%, specificity of 78%), and time-to-maximum > 8 seconds (sensitivity of 68%, specificity of 76%). CONCLUSIONS: Automated CT perfusion analysis allows accurate identification of collateral status in acute ischemic stroke. A relative CBF < 38% may be a better perfusion-based indicator of good collateral supply compared with time-to-maximum, the hypoperfusion intensity ratio, and the CBV-index.

Material-Specific Roadmap Modes Can Improve the Visibility of Liquid Embolic Agents for Endovascular Embolization: A Systematic In Vitro Study.

BACKGROUND AND PURPOSE: Endovascular embolization using liquid embolic agents is a safe and effective treatment option for AVMs and fistulas. Because reliable visibility of these liquid embolic agents is essential for intraprocedural visual control to prevent complications, novel angiographic systems are equipped with material-specific roadmap modes. The aim of this study was the systematic in vitro comparison of conventional and material-specific roadmap modes regarding the visibility of the most used liquid embolic agents. MATERIALS AND METHODS: A recently introduced in vitro model, resembling cerebral vessels, was embolized with Onyx 18, Squid 18, PHIL 25%, and n-BCA mixed with iodized oil (n = 4 for each liquid embolic agent), as well as with contrast medium and saline, both serving as a reference. Imaging was performed in conventional and material-specific roadmap modes. The visibility of the liquid embolic agents in both modes was compared quantitatively and qualitatively. RESULTS: Significant differences between conventional and material-specific roadmap modes regarding the visibility of the liquid embolic agents were observed for all study groups. All liquid embolic agents were better visible in the material-specific roadmap modes compared with the conventional mode in qualitative and quantitative analyses (eg, Onyx in conventional-versus-material-specific modes along the 1.0-mm sector: mean contrast-to-noise ratio, 5.69 [SD, 0.85] versus 47.18 [SD, 5.72]; P < .001, respectively). CONCLUSIONS: In this in vitro study, we demonstrated a better visibility of all investigated liquid embolic agents by using material-specific roadmap modes compared with the conventional roadmap technique. Especially in complex anatomic situations, these novel roadmap modes could improve the visual control and thus the safety and efficacy of embolization procedures in clinical practice.

Learning Curve for Flow Diversion of Posterior Circulation Aneurysms: A Long-Term International Multicenter Cohort Study.

BACKGROUND AND PURPOSE: Flow diversion has gradually become a standard treatment for intracranial aneurysms of the anterior circulation. Recently, the off-label use of the flow diverters to treat posterior circulation aneurysms has also increased despite initial concerns of rupture and the suboptimal results. This study aimed to explore the change in complication rates and treatment outcomes across time for posterior circulation aneurysms treated using flow diversion and to further evaluate the mechanisms and variables that could potentially explain the change and outcomes. MATERIALS AND METHODS: A retrospective review using a standardized data set at multiple international academic institutions was performed to identify patients with ruptured and unruptured posterior circulation aneurysms treated with flow diversion during a decade spanning January 2011 to January 2020. This period was then categorized into 4 intervals. RESULTS: A total of 378 procedures were performed during the study period. Across time, there was an increasing tendency to treat more vertebral artery and fewer large vertebrobasilar aneurysms (P = .05). Moreover, interventionalists have been increasingly using fewer overlapping flow diverters per aneurysm (P = .07). There was a trend toward a decrease in the rate of thromboembolic complications from 15.8% in 2011-13 to 8.9% in 2018-19 (P = .34). CONCLUSIONS: This multicenter experience revealed a trend toward treating fewer basilar aneurysms, smaller aneurysms, and increased usage of a single flow diverter, leading to a decrease in the rate of thromboembolic and hemorrhagic complications.

Imaging Artifacts of Liquid Embolic Agents on Conventional CT in an Experimental in Vitro Model.

BACKGROUND AND PURPOSE: Endovascular embolization using liquid embolic agents is a safe and effective treatment option for AVMs and dural arteriovenous fistulas. The aim of this study was to assess the degree of artifact inducement by the most frequently used liquid embolic agents in conventional CT in an experimental in vitro model. MATERIALS AND METHODS: Dimethyl-sulfoxide-compatible tubes were filled with the following liquid embolic agents (n = 10, respectively): Onyx 18, all variants of Squid, PHIL 25%, PHIL LV, and n-BCA mixed with iodized oil. After inserting the tubes into a CT imaging phantom, we acquired images. Artifacts were graded quantitatively by the use of Hounsfield units in a donut-shaped ROI using a customized software application that was specifically designed for this study and were graded qualitatively using a 5-point scale. RESULTS: Quantitative and qualitative analyses revealed the most artifacts for Onyx 18 and the least artifacts for n-BCA, PHIL 25%, and PHIL LV. Squid caused more artifacts compared with PHIL, both for the low-viscosity and for the extra-low-viscosity versions (eg, quantitative analysis, Squid 18: mean ± SD, 30.3 ± 9.7 HU versus PHIL 25%: mean ± SD, 10.6 ± 0.8 HU; P < .001). Differences between the standard and low-density variants of Squid were observed only quantitatively for Squid 12. There were no statistical differences between the different concentrations of Squid and PHIL. CONCLUSIONS: In this systematic in vitro analysis investigating the most commonly used liquid embolic agents, relevant differences in CT imaging artifacts could be demonstrated. Ethylene-vinyl alcohol-based liquid embolic agents induced more artifacts compared with liquid embolic agents that use iodine as a radiopaque component.

Periprocedural Safety and Feasibility of the New LVIS EVO Device for Stent-Assisted Coiling of Intracranial Aneurysms: An Observational Multicenter Study.

BACKGROUND AND PURPOSE: Stent-assisted treatment techniques can be an effective treatment option for intracranial aneurysms. The aim of this study was to evaluate the periprocedural feasibility and safety of the new LVIS EVO stent for the treatment of intracranial aneurysms. MATERIALS AND METHODS: Patients with intracranial aneurysms treated with the LVIS EVO in 11 European neurovascular centers were retrospectively reviewed. Patient and aneurysm characteristics, procedural parameters, immediate grade of occlusion, and technical and clinical complications were assessed. RESULTS: Fifty-seven patients with 59 aneurysms were treated with the LVIS EVO device; 57.6% of the aneurysms were incidental; 15.3% were acutely ruptured; 15.3% were recanalized or residual aneurysms; and 11.9% were treated for symptoms other than acute hemorrhage. The most frequent aneurysm locations were the middle cerebral artery (25.4%) and the anterior communicating artery (22.0%). The rate of immediate successful deployment was 93.2%. In 6.8% (n = 4) of cases, additional in-stent angioplasty was needed. The immediate complete occlusion rate was 54.2%, while there was a residual aneurysm in 35.6% and a residual neck in 10.2%. Periprocedural technical complications occurred in 7/59 treatments (11.9%; the most frequent technical complication [n = 3] was thrombus formation), which all resolved completely without clinical sequelae. Postprocedural neurologic complications occurred after 4/59 treatments (6.8%; 2 transient ischemic attacks, 1 minor stroke, 1 major stroke), of which only 1 persistent complication was directly related to the procedure (minor stroke in the vascular territory distal to the stent). CONCLUSIONS: The LVIS EVO stent is a safe, feasible device for the treatment of intracranial aneurysms.

Topographic bone thickness maps to evaluate the intuitive placement of titanium miniplates for nasal prostheses.

The aim of this study was to evaluate the intuitive placement of titanium miniplates. The hypothesis was that virtual planning can improve miniplate placement. Twenty patients were included in the study. These patients were fitted with 21 titanium miniplates (16 y-plates, three t-plates, and two u-plates) to retain nasal prostheses between 2005 and 2017. Colour-coded topographic bone thickness maps (TBTMs) were created in fused pre- and postoperative computed tomography. Implants were virtually transposed at the position of highest bone thickness. The bone thickness index (BTI) was calculated as the sum of points assigned at each screw (1 point per millimetre up to 4 mm, and 5 points for greater values) divided by the number of screws. One plate broke after 2.8 years, thus plate survival after 5 years was 91% using the Kaplan-Meier method. The BTI for all 21 plates increased from 3.4 to 4.1 points using virtual transposition (P<0.001). No significant changes were observed in t- and u-plates, but the median BTI increased from 3.1 to 4.1 points (P<0.0005) in 16 y-plates. The change was substantial (≥0.5 points) in 9/16 y-plates. Therefore, the hypothesis that virtual planning improves implant placement was accepted.

Measurement of bone thickness at the site of titanium miniplates used to retain nasal prostheses in fused computed tomographic data.

Our aim was to investigate the bone thickness at the site of titanium miniplates inserted to retain nasal prostheses. We studied 13 patients who had had titanium miniplates inserted for retention of nasal prostheses with a total of 60 titanium bone screws. A trajectory along each bone screw was segmented in fused computed tomographic (CT) data. Bone thickness was measured along this trajectory on the preoperative CT. The median bone thickness at the positions of the screws implanted on the frontal process of the maxillary bone was 1.4 (range 0.2-6.9) mm (mean 1.8). The median (range) values for men and women were 1.4 (0.2-6.9) mm and 1.3 (0.2-3.3) mm, respectively. The thickest bone was at the cranial part of the frontal process of the maxilla with a median of 2.0 (range 0.3-4.1) mm. However, differences in sex and position were not significant. None of the implant miniplates lost osseointegration. Despite the low bone stock at the lateral aspect of the pyriform aperture, survival of implanted titanium miniplates was 100% in this study group.

Treatment of Ruptured Blister-Like Aneurysms with the FRED Flow Diverter: A Multicenter Experience.

BACKGROUND AND PURPOSE: Treatment of ruptured blister-like aneurysms is technically challenging. This study aimed at analyzing the safety and efficacy of the Flow-Redirection Endoluminal Device (FRED) in the treatment of ruptured blister-like aneurysms. MATERIALS AND METHODS: In a retrospective multicenter study, all patients treated with the FRED due to a ruptured intracranial blister-like aneurysm between January 2013 and May 2019 were analyzed. The primary end points for clinical safety were mRS 0-2 at 6 months after treatment and the absence of major ipsilateral stroke or death. The primary end points for efficacy were the absence of rebleeding after treatment and complete angiographic occlusion according to the O'Kelly-Marotta classification at 6 months after treatment. RESULTS: In total, 30 patients with 30 ruptured blister-like aneurysms were treated. Immediate complete aneurysm obliteration (O'Kelly-Marotta classification D) with the FRED was achieved in 10 patients (33%). Of the 26 patients with follow-up, complete obliteration was achieved in 21 patients (80%) after 6 months and in 24 patients (92%) in the final follow-up (median, 22 months). Twenty-three patients (77%) achieved mRS 0-2 at 6 months. Major stroke or death occurred in 17%. Two patients died due to pneumonia, and 2 patients died due to infarction following cerebral vasospasm. There was no case of rebleeding after FRED implantation. There was 1 case of delayed asymptomatic stent occlusion. CONCLUSIONS: Treatment of ruptured blister-like aneurysms with the FRED is safe and effective.