Explore the vast range of titles available.

Abstract Flow diverters (FDs) have changed the management of brain aneurysms; not only for complex aneurysms (giant, fusiform and blister) refractory to conventional therapies, but also for unruptured lesions previously managed by traditional surgical or coil-based endovascular methods. Since 2011 when the PipelineTM Embolization Device (Medtronic) was cleared by the Food and Drug Administration for adults with large or giant wide-neck intracranial aneurysms of the internal carotid artery proximal to the posterior communicating segment, the role of flow diversion for aneurysm treatment has expanded—supported by favorably low complication and high cure rates compared with alternative treatments. Here we review the key clinical trials and the long term outcomes that have demonstrated safety and efficacy of minimized porosity endoluminal devices in the treatment of cerebral aneurysms.

Abstract BACKGROUND: Neuroform stent-assisted coil embolization facilitates the endovascular treatment of wide-necked intracranial aneurysms. However, the safety and efficacy of its long-term use have not been fully elucidated. OBJECTIVE: To retrospectively examine the long-term results of Neuroform stent usage in conjunction with coil embolization in wide-necked intracranial aneurysms. METHODS: Between November 2002 and December 2010, 79 patients harboring wide-necked intracranial aneurysms were treated with use of the Neuroform stent. The stenting procedure failed in 2 patients. Therefore, 77 patients harboring 79 intracranial aneurysms were included for analysis. Patient and aneurysm characteristics, progression of aneurysm occlusion, and occurrence of complications were analyzed. Follow-up imaging included digital subtraction angiography (DSA) or magnetic resonance angiography (MRA). Kaplan-Meier analysis, as well as univariate analysis were performed to determine the progression of aneurysm occlusion and to examine the predictive factors for complete aneurysm occlusion, respectively. RESULTS: Overall, complete aneurysm occlusion was observed in 42.4% of the cases immediately after treatment and progressed to 96.5% at 7-year follow-up. The mean angiographic follow-up time was 25.8 months (range, 0–84 months). Eleven aneurysms (14%) were re-treated. Sixty-eight patients (88.3%) had favorable clinical outcome with a modified Rankin Scale (mRS) ⩽ 1, 3 patients (3.9%) had an mRS of 2, and 5 patients (6.5%) did not have a clinical follow-up. The mean clinical follow-up time was 45.4 months (range, 3–92 months). One patient (1.3%) died of a procedure-related hemorrhage. CONCLUSION: Neuroform stent-assisted coil embolization of wide-necked intracranial aneurysms prevents hemorrhage and provides a high rate of aneurysm occlusion at long-term follow-up.

In this article, a detailed description of the normal arterial supply and venous drainage of the spinal cord is provided, and the role of catheter angiography and MR angiography in depicting the vascular anatomy of the spinal cord is discussed.

Background The use of minimally porous endoluminal devices (MPEDs) such as the Pipeline Embolization Device (PED) has been described for the treatment of brain aneurysms. The benefit of using MPEDs to assist embolization of a direct high-flow carotid cavernous fistula resulting from a ruptured cavernous carotid artery aneurysm is not well documented. Methods We describe our experience with deploying a tailored multidevice PED construct across the cavernous internal carotid artery (ICA) wall defect in combination with transarterial coil embolization using the “jailed microcatheter” technique. Results A 59-year-old woman presented with acute left-sided ophthalmoplegia. Diagnostic cerebral angiography demonstrated a ruptured giant cavernous carotid aneurysm with fistulous outflow via the ipsilateral left superior ophthalmic vein and into the pterygoid venous plexi bilaterally. Via the Marksman microcatheter, a total of three PEDs measuring 4.5 mm × 18 mm, 4.5 mm × 20 mm, and 4.75 mm × 16 mm were telescoped within the ICA across the aneurysm neck. Coiling of the aneurysm fundus and cavernous sinus via the “jailed” Rapidtransit microcatheter was subsequently achieved. A 2-year follow-up digital subtraction angiography (DSA) demonstrated stable obliteration of the aneurysm and the fistula, coincident with complete resolution of the patient’s symptoms. Conclusions Based on our long-term clinical and angiographic results, we advocate that the presented method be a valid treatment option for selected cases.

The adoption of large language models (LLMs) in healthcare demands a careful analysis of their potential to spread false medical knowledge. Because LLMs ingest massive volumes of data from the open Internet during training, they are potentially exposed to unverified medical knowledge that may include deliberately planted misinformation. Here, we perform a threat assessment that simulates a data-poisoning attack against The Pile, a popular dataset used for LLM development. We find that replacement of just 0.001% of training tokens with medical misinformation results in harmful models more likely to propagate medical errors. Furthermore, we discover that corrupted models match the performance of their corruption-free counterparts on open-source benchmarks routinely used to evaluate medical LLMs. Using biomedical knowledge graphs to screen medical LLM outputs, we propose a harm mitigation strategy that captures 91.9% of harmful content (F1 = 85.7%). Our algorithm provides a unique method to validate stochastically generated LLM outputs against hard-coded relationships in knowledge graphs. In view of current calls for improved data provenance and transparent LLM development, we hope to raise awareness of emergent risks from LLMs trained indiscriminately on web-scraped data, particularly in healthcare where misinformation can potentially compromise patient safety. Large language models can be manipulated to generate misinformation by poisoning of a very small percentage of the data on which they are trained, but a harm mitigation strategy using biomedical knowledge graphs can offer a method for addressing this vulnerability.

Abstract BACKGROUND Middle meningeal artery (MMA) embolization has emerged as a promising treatment for chronic subdural hematoma (cSDH). OBJECTIVE To determine the safety and efficacy of MMA embolization. METHODS Consecutive patients who underwent MMA embolization for cSDH (primary treatment or recurrence after conventional surgery) at 15 centers were included. Clinical details and follow-up were collected prospectively. Primary clinical and radiographic outcomes were the proportion of patients requiring additional surgical treatment within 90 d after index treatment and proportion with > 50% cSDH thickness reduction on follow-up computed tomography imaging within 90 d. National Institute of Health Stroke Scale and modified Rankin Scale were also clinical outcomes. RESULTS A total of 138 patients were included (mean age: 69.8, 29% female). A total of 15 patients underwent bilateral interventions for 154 total embolizations (66.7% primary treatment). At presentation, 30.4% and 23.9% of patients were on antiplatelet and anticoagulation therapy, respectively. Median admission cSDH thickness was 14 mm. A total of 46.1% of embolizations were performed under general anesthesia, and 97.4% of procedures were successfully completed. A total of 70.2% of embolizations used particles, and 25.3% used liquid embolics with no significant outcome difference between embolization materials (P > .05). On last follow-up (mean 94.9 d), median cSDH thickness was 4 mm (71% median thickness reduction). A total of 70.8% of patients had >50% improvement on imaging (31.9% improved clinically), and 9 patients (6.5%) required further cSDH treatment. There were 16 complications with 9 (6.5%) because of continued hematoma expansion. Mortality rate was 4.4%, mostly unrelated to the index procedure but because of underlying comorbidities. CONCLUSION MMA embolization may provide a safe and efficacious minimally invasive alternative to conventional surgical techniques. Graphical Abstract Graphical Abstract

BackgroundThere is limited data on predictors of symptomatic intracranial haemorrhage (sICH) in patients who underwent mechanical thrombectomy. In this study, we aim to determine those predictors with external validation.MethodsWe evaluated mechanical thrombectomy in a derivation cohort of patients at a comprehensive stroke centre over a 30-month period. Clinical and radiographic data on these patients were obtained from the prospective quality improvement database. sICH was defined using the European Cooperative Acute Stroke Study III. We compared clinical and radiographic characteristics between patients with and without sICH using χ2 and t tests to identify independent predictors of sICH with p<0.1. Significant variables were then combined in a multivariate logistic regression model to derive an sICH prediction score. This score was then validated using data from the Blood Pressure After Endovascular Treatment multicentre prospective registry.ResultsWe identified 578 patients with acute ischaemic stroke who received thrombectomy, 19 had sICH (3.3%). Predictive factors of sICH were: thrombolysis in cerebral ischaemia (TICI) score, Alberta stroke program early CT score (ASPECTS), and glucose level, and from these predictors, we derived the weighted TICI-ASPECTS-glucose (TAG) score, which was associated with sICH in the derivation (OR per unit increase 1.98, 95% CI 1.48 to 2.66, p<0.001, area under curve ((AUC)=0.79) and validation (OR per unit increase 1.48, 95% CI 1.22 to 1.79, p<0.001, AUC=0.69) cohorts.ConclusionHigh TAG scores are associated with sICH in patients receiving mechanical thrombectomy. Larger studies are needed to validate this scoring system and test strategies to reduce sICH risk and make thrombectomy safer in patients with elevated TAG scores.

Background and Purpose While the thrombotic complications of COVID-19 have been well described, there are limited data on clinically significant bleeding complications including hemorrhagic stroke. The clinical characteristics, underlying stroke mechanism, and outcomes in this particular subset of patients are especially salient as therapeutic anticoagulation becomes increasingly common in the treatment and prevention of thrombotic complications of COVID-19. Methods We conducted a retrospective cohort study of patients with hemorrhagic stroke (both non-traumatic intracerebral hemorrhage and spontaneous non-aneurysmal subarachnoid hemorrhage) who were hospitalized between March 1, 2020, and May 15, 2020, within a major healthcare system in New York, during the coronavirus pandemic. Patients with hemorrhagic stroke on admission and who developed hemorrhage during hospitalization were both included. We compared the clinical characteristics of patients with hemorrhagic stroke and COVID-19 to those without COVID-19 admitted to our hospital system between March 1, 2020, and May 15, 2020 (contemporary controls), and March 1, 2019, and May 15, 2019 (historical controls). Demographic variables and clinical characteristics between the individual groups were compared using Fischer’s exact test for categorical variables and nonparametric test for continuous variables. We adjusted for multiple comparisons using the Bonferroni method. Results During the study period in 2020, out of 4071 patients who were hospitalized with COVID-19, we identified 19 (0.5%) with hemorrhagic stroke. Of all COVID-19 with hemorrhagic stroke, only three had isolated non-aneurysmal SAH with no associated intraparenchymal hemorrhage. Among hemorrhagic stroke in patients with COVID-19, coagulopathy was the most common etiology (73.7%); empiric anticoagulation was started in 89.5% of these patients versus 4.2% in contemporary controls ( p  ≤ .001) and 10.0% in historical controls ( p  ≤ .001). Compared to contemporary and historical controls, patients with COVID-19 had higher initial NIHSS scores, INR, PTT, and fibrinogen levels. Patients with COVID-19 also had higher rates of in-hospital mortality (84.6% vs. 4.6%, p  ≤ 0.001). Sensitivity analyses excluding patients with strictly subarachnoid hemorrhage yielded similar results. Conclusion We observed an overall low rate of imaging-confirmed hemorrhagic stroke among patients hospitalized with COVID-19. Most hemorrhages in patients with COVID-19 infection occurred in the setting of therapeutic anticoagulation and were associated with increased mortality. Further studies are needed to evaluate the safety and efficacy of therapeutic anticoagulation in patients with COVID-19.

Abstract BACKGROUND: Despite increasing acceptance of endovascular coiling for treating intracranial aneurysms, incomplete occlusion remains a limitation. Attempts to reduce recanalization have prompted creation of polyglycolic/polylactic acid-coated (Matrix) coils shown to improve neointima formation; however, previous publications demonstrate conflicting results regarding their efficacy. Few studies account for factors influencing recurrence, and only 4 studies include bare platinum (BP) coil control groups. OBJECTIVE: To compare initial and short- and mid-term occlusion as well as retreatment rates using Matrix compared with BP coils. METHODS: Retrospective review of patients undergoing coiling of cerebral aneurysms from 2001 to 2005 was performed. Analysis included a multivariate logistic regression model designed to detect a 35% absolute difference in initial occlusion between coil treatment groups with 80% power. RESULTS: Complete initial occlusion was achieved in 64% of BP (n = 45) and 63% of Matrix (n = 56) cases (P = 1.0). Follow-up occlusion rates in the short term and mid term were 52% and 60%, respectively, for BP cases and 42% and 67%, respectively, for Matrix cases (P = .24 and P = .38, respectively). After adjusting for size, morphology, volumetric packing density, location, rupture, and balloon remodeling, no difference in initial and subsequent occlusion or retreatment rates for BP coils versus Matrix coils was appreciated. CONCLUSION: After controlling for factors influencing recanalization, this investigation failed to show a significant difference between coil groups.

To evaluate the midterm results of intracranial stent-assisted coil embolization in the treatment of wide-necked cerebral aneurysms and to assess the efficacy of various strategies used in stent deployment. A retrospective study of 42 patients with 46 wide-necked cerebral aneurysms enrolled in a prospective single-center registry of patients treated with a Neuroform stent (Boston Scientific/Target, Fremont, CA), a flexible self-expanding nitinol stent, was performed. Twenty-seven of 46 aneurysms were unruptured aneurysms, 14 were recanalized aneurysms, and five were acutely ruptured. Thirty-nine aneurysms were located in the anterior and seven in the posterior circulation. Mean aneurysm size was 9.8 mm. Stenting before coiling was performed in 13 of 45 aneurysms (29%), coiling before stenting in 27 of 45 aneurysms (60%), and stenting alone in five of 45 aneurysms (11%). The balloon remodeling technique for coiling before stenting was performed in 77% of patients. Angiographic and clinical follow up was available in 31 patients with 33 aneurysms and ranged from 3 to 24 months. Neuroform stenting was attempted in 46 wide-necked aneurysms (42 patients). Forty-nine stent sessions were performed, including three poststent retreatments. In 46 of 49 sessions (94%), successful deployment of 47 stents for 45 aneurysms was obtained. In 40 aneurysms treated with stent-assisted coiling, angiographic results showed 14 (35%) aneurysm occlusions, 18 (45%) neck remnants, and eight (20%) residual aneurysms. In five recanalized aneurysms treated with stenting alone, no changes were observed in four (80%) aneurysms and one (20%) neck remnant reduced in size. At angiographic follow-up in 30 aneurysms treated with stent-assisted coiling, there were 17 (57%) aneurysm occlusions, seven (23%) neck remnants, and six (20%) residual aneurysms. In three recanalized aneurysms treated with stent alone, two (67%) neck remnants remained unchanged and one (33%) neck remnant decreased in size. Procedural morbidity was observed in two of 42 patients (4.8%) and one patient died. On clinical follow-up, the modified Rankin Scale score was 0 in 27 patients (87%), 1 in three patients (10%), and 2 (3%) in one patient. No aneurysm bled during the follow-up period. These results indicate that Neuroform stent-assisted coil embolization is a safe and effective technique in the treatment of wide-necked cerebral aneurysms. Further studies are needed to evaluate the long-term durability of stent-assisted aneurysm occlusion and tolerance to the stent.