Artificial intelligence to predict individualized outcome of acute ischemic stroke patients: The SIBILLA project.

INTRODUCTION: Formulating reliable prognosis for ischemic stroke patients remains a challenging task. We aimed to develop an artificial intelligence model able to formulate in the first 24 h after stroke an individualized prognosis in terms of NIHSS. PATIENTS AND METHODS: Seven hundred ninety four acute ischemic stroke patients were divided into a training (597) and testing (197) cohort. Clinical and instrumental data were collected in the first 24 h. We evaluated the performance of four machine-learning models (Random Forest, K-Nearest Neighbors, Support Vector Machine, XGBoost) in predicting NIHSS at discharge both in terms of variation between discharge and admission (regressor approach) and in terms of severity class namely NIHSS 0-5, 6-10, 11-20, >20 (classifier approach). We used Shapley Additive exPlanations values to weight features impact on predictions. RESULTS: XGBoost emerged as the best performing model. The classifier and regressor approaches perform similarly in terms of accuracy (80% vs 75%) and f1-score (79% vs 77%) respectively. However, the regressor has higher precision (85% vs 68%) in predicting prognosis of very severe stroke patients (NIHSS > 20). NIHSS at admission and 24 hours, GCS at 24 hours, heart rate, acute ischemic lesion on CT-scan and TICI score were the most impacting features on the prediction. DISCUSSION: Our approach, which employs an artificial intelligence based-tool, inherently able to continuously learn and improve its performance, could improve care pathway and support stroke physicians in the communication with patients and caregivers. CONCLUSION: XGBoost reliably predicts individualized outcome in terms of NIHSS at discharge in the first 24 hours after stroke.

Preoperative Angiographic Protocol for the Surgical Management of Spinal Dural Arteriovenous Fistulas: A Technical Nuance for Safe Minimally Invasive Surgery.

BACKGROUND: Interruption of the fistulous point is the goal of treatment of spinal dural arteriovenous fistulas (dAVFs). Microsurgery remains a highly efficient treatment in terms of complete occlusion with the lowest risk of recurrence rate. It is reported that the hardest step involves finding the fistulous site itself, potentially extending surgical access and time and increasing potential postoperative surgical-related complications. The accurate preoperative detection of the shunt and spinal level together is crucial for guiding optimal, fast, and safe microsurgical treatment. METHODS: We describe a preoperative angiographic protocol for achieving a safe and simple resection of spinal dural arteriovenous fistulas based on a 6-year institutional experience of 42 patients who underwent minimally invasive procedures. Two illustrative cases are included to support the technical descriptions. RESULTS: The suspected artery associated with the vascular malformation of interest is studied in our angiographic protocol through nonsubtracted selective acquisitions in lateral projection. The resulting frames are reconstructed with three-dimensional rotational angiography. The implementation of the preoperative angiographic protocol allowed 100% of intraoperative identification of the fistulous point in all cases with the use of a minimally invasive approach. CONCLUSIONS: Nowadays, neurosurgeons advocate for minimally invasive procedures and procedures with low morbidity risk for treatment of spinal dural arteriovenous fistulas. Our preoperative approach for accurate angiographic localization of the fistulous point through nonsubtracted and three-dimensional reconstructed angiography allowed us to achieve safe and definitive occlusion of the shunt.

Hug sign in intraprocedural cone-beam-CT to predict short-term response to combined treatment of hepatocellular carcinoma.

OBJECTIVES: Combined treatment of ablation and chemoembolization for hepatocellular carcinoma represents a promising therapy to increase treatment efficacy and improve patient survival. The "hug sign" is a recently introduced radiological sign consisting in deposition of beads/contrast agent during transarterial chemoembolization in the hyperemic area surrounding the post-ablation volume, seen during intraprocedural unenhanced cone-beam CT, that may indicate intraprocedural success. Aim of our retrospective study was to analyze the usefulness of the "hug sign" at the intraprocedural unenhanced cone-beam CT as an early predictor of response to combined treatment, based on the hug sign angle. MATERIALS AND METHODS: Between January 2017 and September 2021 all patients with hepatocellular carcinoma which underwent a combined treatment of thermal ablation followed by chemoembolization were enrolled. All treated patients underwent immediate post-procedural unenhanced cone-beam CT to evaluate the deposition of contrast agent, lipiodol or radiopaque beads and to assess the percentage of coverage of the ablated area with the contrast agent (hug sign angle). Patients with missing pre-procedural, intra-procedural and/or post-procedural data/imaging, or with poor-quality post-procedural cone-beam CT images were excluded. RESULTS: 128 patients (mean age, 69.3 years ± 1.1 [standard deviation]; 87 men) were evaluated. Our study evidenced that 84.4% (81/85) of patients with a hug sign angle of 360° had no residual tumor at the first 1-/3-months follow-up examination. A hug sign angle of 360° also showed to be an independent protective factor against residual tumor at multivariate analysis. CONCLUSION: Unenhanced cone-beam CT performed at the end of a combined treatment with ablation plus chemoembolization can effectively predict an early treatment response on radiological images, when a hug sign angle of 360° was detected.

Effect of General Anesthesia Versus Conscious Sedation/Local Anesthesia on the Outcome of Patients with Minor Stroke and Isolated M2 Occlusion Undergoing Immediate Thrombectomy: A Retrospective Multicenter Matched Analysis.

BACKGROUND: This study investigates the impact of general anesthesia (GA) versus conscious sedation/local anesthesia (CS/LA) on the outcome of patients with minor stroke and isolated M2 occlusion undergoing immediate mechanical thrombectomy (iMT). METHODS: The databases of 16 comprehensive stroke centers were retrospectively screened for consecutive patients with isolated M2 occlusion and a baseline National Institutes of Health Stroke Scale score ≤5 who received iMT. Propensity score matching was used to estimate the effect of GA versus CS/LA on clinical outcomes and procedure-related adverse events. The primary outcome measure was a 90-day modified Rankin Scale (mRS) score of 0-1. Secondary outcome measures were a 90-day mRS score of 0-2 and all-cause mortality, successful reperfusion, procedural-related symptomatic subarachnoid hemorrhage, intraprocedural dissections, and new territory embolism. RESULTS: Of the 172 patients who were selected, 55 received GA and 117 CS/LA. After propensity score matching, 47 pairs of patients were available for analysis. We found no significant differences in clinical outcome, rates of efficient reperfusion, and procedural-related complications between patients receiving GA or LA/CS (mRS score 0-1, P = 0.815; mRS score 0-2, P = 0.401; all-cause mortality, P = 0.408; modified Treatment in Cerebral Infarction score 2b-3, P = 0.374; symptomatic subarachnoid hemorrhage, P = 0.082; intraprocedural dissection, P = 0.408; new territory embolism, P = 0.462). CONCLUSIONS: In patients with minor stroke and isolated M2 occlusion undergoing iMT, the type of anesthesia does not affect clinical outcome or the rate of procedural-related complications. Our results agree with recent data showing no benefit of one specific anesthesiologic procedure over the other and confirm their generalizability also to patients with minor baseline symptoms.

Preoperative Direct Puncture Embolization Using a Nonadhesive Ethylene Vinyl Alcohol (EVOH) Liquid Embolic Agent for Head and Neck Paragangliomas.

PURPOSE: This retrospective study aimed to assess the safety and technical efficacy of preoperative direct puncture embolization using a nonadhesive ethylene vinyl alcohol (EVOH) copolymer-based liquid embolic agent (LEA) combined with balloon occlusion at the origin of the external carotid artery for head and neck paragangliomas (HNP). METHODS: We conducted a review of all consecutive cases of HNPs treated with direct puncture embolization using EVOH-based LEAs between 2017 and 2022 in 2 tertiary high-volume hospitals. RESULTS: A total of 25 cases of HNPs in 24 patients underwent direct puncture embolization (12 males, 12 females, mean age 50.9 ± 15.6 years). The average lesion volume was 299.95 mm3. The mean procedure time was 139.11 min, and the mean volume of EVOHs used per case was 19.38 mL. Successful complete devascularization was achieved in all cases, with a homogeneous and deep penetration of the embolic agent into the tumor vessel bed regardless of the LEA type. CONCLUSION: Preoperative embolization of HNPs using a direct puncture technique and EVOHs is a safe, efficient, and feasible treatment option with a low risk of complications. This procedure facilitates surgery by transforming tumors into avascular masses that are well-delineated against the surrounding normal tissue.

Predictors of parenchymal hematoma and clinical outcome after mechanical thrombectomy in patients with large ischemic core due to large vessel occlusion: a retrospective multicenter study.

BACKGROUND: The aim of our study was to find predictors of parenchymal hematoma (PH) and clinical outcome after mechanical thrombectomy (MT) in patients with large vessel occlusion (LVO) and baseline large infarct. METHODS: The databases of 16 stroke centers were retrospectively screened for patients with anterior circulation LVO and baseline Alberta Stroke Program Early CT Score (ASPECTS) ≤5 that received MT. Procedural parameters, including the number of passes during first and second technique of MT, were recorded. Outcome measures were occurrence of PH type 2 and any type of PH after MT, and the 90-day modified Rankin Scale (mRS) score of 0-3 and 0-2. RESULTS: In total, 408 patients were available for analysis. A higher number of passes in the second technique was predictive of PH type 2 (odds ratio (OR) - 3.204, 95% confidence interval (CI) 1.140 to 9.005), whereas procedure conducted under general anesthesia was associated with lower risk (OR 0.127, 95% CI 0.002 to 0.808). The modified thrombolysis in cerebral infarction grade 2c-3 was associated with the mRS score 0-3 (OR 3.373, 95% CI 1.891 to 6.017), whereas occurrence of PH type 2 was predictive of unfavorable outcome (OR 0.221, 95% CI 0.063 to 0.773). Similar results were found for the mRS score 0-2 outcome measure. CONCLUSION: In patients with large ischemic core, a higher number of passes during MT and procedure not conducted under general anesthesia are associated with increased rate of PH type 2, that negatively impact the clinical outcome. Our data outline a delicate balance between the need of a complete recanalization and the risk of PH following MT.

Spinal Dural Arteriovenous Fistulas: A Retrospective Analysis of Prognostic Factors and Long-Term Clinical Outcomes in the Light of the Recent Diagnostic and Technical Refinements.

Spinal dural arteriovenous fistulas (dAVFs) are abnormal connections between the meningeal branches of segmental arteries and a radiculomedullary veins that result in a progressive myelopathy thanks to perimedullary coronal venous plexus congestion. Usually, dAVFs show nonspecific symptoms, thus leading to late clinical suspicion and a difficult MRI diagnosis.Several authors have tried to identify prognostic factors before treatment, but published studies results are often inconsistent and sometimes contradictory.In this study, we reviewed our recent experience of 30 dAVF patients where we collected all demographic, clinical and angioarchitectural features as well as radiological and treatment-related characteristics. The thoracic spine was the most common location, constituting 53.3% of cases, followed by the lumbar roots, comprising 30%. About 83% of patients showed motor deficits, urinary disturbances were present in 70%, and bowel symptoms in 50%.We treated 86.7% of patients with microsurgery and 13.3% with endovascular occlusion with a mean interval between clinical onset and intervention of 10.8 ± 14.2 months.A significant clinical improvement was observed at follow-up in 80% of patients, with a significant reduction in mean G-score, U-score and F-score at a mean follow-up of 105.89 ± 191.9 months.However, none among the principal demographic, clinical and radiological characteristics showed significant prognostic value to the clinical improvement observed at follow-up.

Post-operative segmental cerebral venous sinus thrombosis: risk factors, clinical implications, and therapeutic considerations.

Cerebral venous sinus thromboses (CVSTs) are rare complications of neurosurgical interventions and their management remains controversial as most of cases appear clinically silent. Here, we analyzed our institutional series of patients with CVSTs evaluating clinical and neuroradiological characteristics, risk factors, and outcome. From the analysis of our institutional PACS, we collected a total of 59 patients showing postoperative CVSTs after supratentorial or infratentorial craniotomies. For every patient, we collected demographics and relevant clinical and laboratory data. Details on thrombosis trend were retrieved and compared along the serial radiological assessment. A supratentorial craniotomy was performed in 57.6% of cases, an infratentorial in 37.3%, while the remaining were a single cases of trans-sphenoidal and neck surgery (1.7%, respectively). A sinus infiltration was present in almost a quarter of patients, and in 52.5% of cases the thrombosed sinus was exposed during the craniotomy. Radiological signs of CVST were evident in 32.2% of patients, but only 8.5% of them developed a hemorrhagic infarct. CVST-related symptoms were complained by 13 patients (22%), but these were minor symptoms in about 90%, and only 10% experienced hemiparesis or impaired consciousness. The majority of patients (78%) remained completely asymptomatic along the follow-up. Risk factors for symptoms occurrence were interruption of preoperative anticoagulants, infratentorial sinuses involvement and evidence of vasogenic edema and venous infarction. Overall, a good outcome defined mRS 0-2 was observed in about 88% of patients at follow-up. CVST is a complication of surgical approaches in proximity of dural venous sinuses. CVST usually does not show progression and courses uneventfully in the vast majority of cases. The systematic use of post-operative anticoagulants seems to not significantly influence its clinical and radiological outcome.

Hybrid treatment of large extracranial carotid artery aneurysm.

An extracranial carotid artery aneurysm (ECAA) is a rare condition. The major complications are rupture and thromboembolism. Therefore, treatment is generally recommended. We report the case of a young woman affected by an ECAA, with a cervical pulsatile mass. A multidisciplinary evaluation was performed to ensure the best treatment in terms of safety and efficacy, and the patient underwent hybrid treatment. The 6-month computed tomography angiogram revealed patency of the carotid artery stents and the venous graft, in the absence of any relevant complications. An ECAA is a serious clinical condition. The treatment is challenging, and a multidisciplinary evaluation and precise planning are recommended.

Timing of Antithrombotic Secondary Prevention in Patients with Intracranial Hemorrhage after Stroke Thrombolysis and Thrombectomy.

In patients with acute ischemic stroke, hemorrhagic transformation (HT) of infarcted tissue frequently occurs after reperfusion treatment. We aimed to assess whether HT and its severity influences the start of secondary prevention therapy and increases the risk of stroke recurrence. In this retrospective dual-center study, we recruited ischemic stroke patients treated with thrombolysis, thrombectomy or both. Our primary outcome was the time between revascularization and the start of any secondary prevention therapy. The secondary outcome was ischemic stroke recurrence within three months. We compared patients with vs. without HT and no (n = 653), minor (n = 158) and major (n = 51) HT patients using propensity score matching. The delay in the start of antithrombotics or anticoagulants was median 24 h in no HT, 26 h in minor HT and 39 h in major HT. No and minor HT patients had similar rates of any stroke recurrence (3.4% (all ischemic) vs. 2.5% (1.6% ischemic plus 0.9% hemorrhagic)). Major HT patients had a higher stroke recurrence at 7.8% (3.9% ischemic, 3.9% hemorrhagic), but this difference did not reach significance. A total of 22% of major HT patients did not start any antithrombotic treatment during the three-month follow-up. In conclusion, the presence of HT influences the timing of secondary prevention in ischemic stroke patients undergoing reperfusion treatments. Minor HT did not delay the start of antithrombotics or anticoagulants compared to no HT, with no significant difference in safety outcomes. Major HT patients remain a clinical challenge with both a delayed or lacking start of treatment. In this group, we did not see a higher rate of ischemic recurrence; however, this may have been censored by elevated early mortality. While not reaching statistical significance, hemorrhagic recurrence was somewhat more common in this group, warranting further study using larger datasets.

Early neurological deterioration in patients with minor stroke due to isolated M2 occlusion undergoing medical management: a retrospective multicenter study.

BACKGROUND: Patients with minor stroke and M2 occlusion undergoing best medical management (BMM) may face early neurological deterioration (END) that can lead to poor long-term outcome. In case of END, rescue mechanical thrombectomy (rMT) seems beneficial. Our study aimed to define factors relevant to clinical outcome in patients undergoing BMM with the possibility of rMT on END, and find predictors of END. METHODS: Patients with M2 occlusion and a baseline National Institutes of Health Stroke Scale (NIHSS) score≤5 that received either BMM only or rMT on END after BMM were extracted from the databases of 16 comprehensive stroke centers. Clinical outcome measures were a 90-day modified Rankin Scale (mRS) score of 0-1 or 0-2, and occurrence of END. RESULTS: Among 10 169 consecutive patients with large vessel occlusion admitted between 2016 and 2021, 208 patients were available for analysis. END was reported in 87 patients that were therefore all subjected to rMT. In a logistic regression model, END (OR 3.386, 95% CI 1.428 to 8.032), baseline NIHSS score (OR 1.362, 95% CI 1.004 to 1.848) and a pre-event mRS score=1 (OR 3.226, 95% CI 1.229 to 8.465) were associated with unfavorable outcome. In patients with END, successful rMT was associated with favorable outcome (OR 4.549, 95% CI 1.098 to 18.851). Among baseline clinical and neuroradiological features, presence of atrial fibrillation was a predictor of END (OR 3.547, 95% CI 1.014 to 12.406). CONCLUSION: Patients with minor stroke due to M2 occlusion and atrial fibrillation should be closely monitored for possible worsening during BMM and, in this case, promptly considered for rMT.

Correlation between Thrombus Perviousness and Distal Embolization during Mechanical Thrombectomy in Acute Stroke.

PURPOSE: Thrombus permeability has been related to clot composition and treatment outcomes in stroke patients undergoing reperfusion therapies. The aim of this study was to evaluate whether thrombus perviousness, evaluated by multiphase computed tomography angiography (mCTA), is associated with distal embolization risk. METHODS: We interrogated our dataset of acute ischemic stroke (AIS) patients involving the M1 segment of the middle cerebral artery (MCA) who had undergone mechanical thrombectomy, and we calculated thrombus average attenuation measurement (dHU) on non-contrast CT (NCCT) and clot perviousness on mCTA. dHU was calculated as the difference between the thrombus HU average value (tHU) and the HU average value on the contralateral side (cHU), while perviousness was calculated as the difference in mean clot density on mCTA and NCCT both in arterial (Perviousness pre-post-1) and delayed (Perviousness pre-post 2) phases. RESULTS: A total of 100 patients (53 females (53%), mean age 72.74 [± 2.31]) with M1 occlusion were available for analysis. Perviousness, calculated between baseline and arterial phase of mCTA (Perviousness pre-post1), was lower in patients with distal embolization (p = 0.05), revealing an association between reduced perviousness and distal embolization risk. Logistic regression showed that thrombus perviousness calculated on the arterial phase of mCTA (OR, 0.66; 95% CI, 0.44-0.99] (p = 0.04)) and the contact aspiration technique (OR, 0.39; 95% CI, 0.15-1.02] (p = 0.05)) were protecting factors against distal embolization. CONCLUSION: Our study showed an association between reduced perviousness and distal embolization, suggesting that perviousness evaluation may be a useful neuroimaging biomarker in predicting distal embolization risk during mechanical thrombectomy.

Mechanical thrombectomy in minor stroke due to isolated M2 occlusion: a multicenter retrospective matched analysis.

BACKGROUND: The purpose of this study was to evaluate the effectiveness of mechanical thrombectomy (MT) in patients with isolated M2 occlusion and minor symptoms and identify possible baseline predictors of clinical outcome. METHODS: The databases of 16 high-volume stroke centers were retrospectively screened for consecutive patients with isolated M2 occlusion and a baseline National Institutes of Health Stroke Scale (NIHSS) score ≤5 who received either early MT (eMT) or best medical management (BMM) with the possibility of rescue MT (rMT) on early neurological worsening. Because our patients were not randomized, we used propensity score matching (PSM) to estimate the treatment effect of eMT compared with the BMM/rMT. The primary clinical outcome measure was a 90-day modified Rankin Scale score of 0-1. RESULTS: 388 patients were initially selected and, after PSM, 100 pairs of patients receiving eMT or BMM/rMT were available for analysis. We found no significant differences in clinical outcome and in safety measures between patients receiving eMT or BMM/rMT. Similar results were also observed after comparison between eMT and rMT. Concerning baseline predicting factors of outcome, the involvement of the M2 inferior branch was associated with a favorable outcome. CONCLUSION: Our multicenter retrospective analysis has shown no benefit of eMT in minor stroke patients with isolated M2 occlusion over a more conservative therapeutic approach. Although our results must be viewed with caution, in these patients it appears reasonable to consider BMM as the first option and rMT in the presence of early neurological deterioration.

Degenerative Disc Disease of the Spine: From Anatomy to Pathophysiology and Radiological Appearance, with Morphological and Functional Considerations.

Degenerative disc disease is a common manifestation in routine imaging of the spine; this finding is partly attributable to physiological aging and partly to a pathological condition, and sometimes this distinction is simply not clear. In this review, we start focusing on disc anatomy and pathophysiology and try to correlate them with radiological aspects. Furthermore, there is a special focus on degenerative disc disease terminology, and, finally, some considerations regarding disc morphology and its specific function, as well as the way in which these aspects change in degenerative disease. Radiologists, clinicians and spine surgeons should be familiar with these aspects since they have an impact on everyday clinical practice.

Comparison between rupture/growth risk scores and treatment recommendation scores application to aneurysmal subarachnoid hemorrhage patients: A multicenter cross-reliability assessment study.

BACKGROUND: Two score families were introduced to help clinicians about the decision-making regarding intracranial aneurysms management. The first family estimates the growth/rupture risk (GRS), whereas the second provides straightforward recommendation (RS) for treatment decisions. However, both remain poorly validated and little is known about their agreement. In this paper, we performed a retrospective concordance analysis among the two scores families through their application to a multicenter cohort of SAH patients. METHODS: Demographical, clinical and radiological data were extracted in conformance with the variables included in PHASES, UCAS, ELAPSS, Juvela's growth score (JGS), UIATS and Juvela's treatment score (JTS). Individual patients' score were calculated for both score families, and pooled data were then analyzed. RESULTS: Overall, 146 patients were included. True positive rates were: 51.4% for PHASES; 71.9% for UCAS; between 60.3% and 90.4% for JTS; and between 27.4% and 68.5% for UIATS. In patients showing UIATS unclear recommendation and low JTS score (RS), UCAS outperformed PHASES (GRS) in identifying aneurysms at higher risk of rupture. Same results we found for patients with conservative UIATS recommendation and very low JTS score. Forty-to-sixty percent of aneurysms with unclear or conservative RS recommendation would have been identified as at high risk with GRS. CONCLUSIONS: Retrospectively applied, JTS appeared outperforming UIATS in correctly recommending treatment in a higher percentage of patients. UIATS and JTS appeared agreeing more with UCAS than PHASES predictions. Around 50% of patients with unclear or conservative UIATS/JTS recommendations were been classified as at higher growth risk by ELAPSS and JGS.

Mechanical thrombectomy in acute ischemic stroke due to large vessel occlusion in the anterior circulation and low baseline National Institute of Health Stroke Scale score: a multicenter retrospective matched analysis.

BACKGROUND AND PURPOSE: The benefit of mechanical thrombectomy (MT) in patients with acute ischemic stroke (AIS) due to large vessel occlusion (LVO) and baseline mild neurological symptoms remains unclear. The purpose of this study was to evaluate the effectiveness of MT in this subgroup of patients. METHODS: The databases of 9 high-volume Italian stroke centers were retrospectively screened for patients with LVO in the anterior circulation and a baseline National Institute of Health Stroke Scale (NIHSS) score ≤ 5 that received either immediate MT or best medical management (BMM) with the possibility of rescue MT upon neurological worsening. Primary outcome measure was a modified Rankin Scale score of 0-1 at 90 days. Propensity score matching (PSM) analysis was used to estimate the treatment effect of immediate MT compared to BMM/rescue MT. RESULTS: Two hundred and seventy-two patients received immediate MT (MT group). The BMM/rescue MT group included 41 patients. The primary outcome was achieved in 78.6% (n = 246) of overall patients, with a higher proportion in the MT group (80.5% vs. 65.9%, p = 0.03) in unadjusted analysis. After PSM, patients in the MT group had a 19.5% higher chance of excellent outcome at 90 days compared to the BMM/Rescue MT group with a similar risk of death from any cause. CONCLUSIONS: Our experience is in favor of a potential benefit of MT also in patients with LVO and a NIHSS score ≤ 5 at the time of groin puncture. Nonetheless, this issue waits for a clear-cut recommendation in a dedicated clinical trial.

Mechanical thrombectomy beyond the circle of Willis: efficacy and safety of different techniques for M2 occlusions.

BACKGROUND: M2 segment occlusions represent approximately one-third of non-lacunar ischemic stroke and can lead to permanent neurological deficits. Various techniques are available for mechanical thrombectomy beyond the circle of Willis, but data evaluating their effectiveness and safety are lacking. METHODS: A retrospective review of patients with ischemic stroke undergoing mechanical thrombectomy for M2 occlusions from 13 centers in North American and Europe was performed. Tandem or multiple-territory occlusions were excluded. The primary outcome was 90-day modified Rankin Scale and reperfusion rates across stent-retriever, direct aspiration and combined techniques. RESULTS: There were 465 patients (mean age 71.48±14.03 years, 53.1% female) with M2 occlusions who underwent mechanical thrombectomy. Stent-retriever alone was used in 133 (28.6%), direct aspiration alone in 93 (20.0%) and the combined technique in 239 (51.4%) patients. Successful reperfusion was achieved with the combined technique in 198 (82.2%; OR 2.6 (1.1-6.9)), with stent-retriever alone in 112 (84.2%; OR 9.2 (1.9-44.6)) and with direct aspiration alone in 62 (66.7%; referencecategory). Intraprocedural subarachnoid hemorrhages (iSAH) were 36 (7.7%) and were more likely to occur in patients treated with the stent-retrievers (OR 5.0 (1.1-24.3)) and combined technique (OR 4.6 (1.1-20.9)). Good clinical outcome was achieved in 260 (61.8%) patients, while 59 (14.0%) patients died. Older age, higher baseline NIHSS (National Institutes of Health Stroke Scale), parenchymal hemorrhage and iSAH were associated with poor outcome while successful recanalization and higher baseline ASPECTS (Alberta Stroke Program Early CT Score) were associated with good outcome. No differences were found among the three techniques in terms of clinical outcome. CONCLUSION: Stent-retrievers and a combined approach for M2 occlusions seem more effective than direct aspiration, but with higher rates of iSAH. This leads to no detectable difference in clinical outcome at 3 months.

Endovascular Treatment of Cavernous Sinus Dural Arteriovenous Fistulas. Institutional Series, Systematic Review and Meta-Analysis.

PURPOSE: Endovascular treatment represents the first-line therapy for cavernous sinus dural arteriovenous fistulas (CS-dAVF); however, different approaches and embolic agents as well as occlusion rates, complications and clinical outcomes are reported among the published series. In this study we performed a comprehensive meta-analysis to investigate clinical and radiological outcomes after endovascular treatment of CS-dAVFs. METHODS: PubMed, Ovid Medline, Ovid EMBASE, Scopus, and Web of Science were screened for a comprehensive literature review from 1990 to 2020 regarding series of patients treated for CS-dAVF with endovascular approaches. We performed a proportion meta-analysis estimating the pooled rates of each outcome also including data of patients treated in our center. RESULTS: A total of 22 studies reporting 1043 patients and 1066 procedures were included. Chemosis was reported in 559 out of 1043 patients (45.9%), proptosis in 498 (41.5%), and ophthalmoplegia in 344 (23.5%). A transvenous embolization was preferred in 753 cases (63.2%) and coils were used in 712 out of 1066 procedures (57.8%). Overall, 85% (95% confidence interval, CI 69.5-96.1%) of patients had a complete resolution of symptoms, while complications occurred in 7.75% (95% CI 3.82-12.7%) with minimal permanent deficits (0.15%). The mortality rate was 1 out of 1043 patients (< 0.001). CONCLUSION: A transvenous coiling is the most common endovascular approach for CS-dAVF, achieving a high percentage of radiological and clinical resolution and low complication rates. Transvenous approaches show less complications than transarterial ones, and coils appear safer than liquid embolic agents.

Clot evaluation and distal embolization risk during mechanical thrombectomy in anterior circulation stroke.

INTRODUCTION: Clot features along with patients' clinical features may influence thrombus compactness predisposing at distal embolization during thrombectomy. The aim of this study was to evaluate thrombus features assessed by radiological and histopathological analysis along with patient-related features to predict distal embolization during thrombectomy. METHODS: We performed a retrospective analysis of a prospectively maintained dataset of a tertiary stroke center inclusive of all cases of endovascular treatment for acute ischemic stroke involving anterior circulation occlusion. All patients underwent head and neck CT-angiography (CTA) at baseline. Patients were enrolled if thrombus material was suitable for histopathologic analyses. RESULTS: A total of 327 patients underwent mechanical thrombectomy between March 2017 and May 2020. Among them, 133 (40.7%) had thrombus material suitable for histopathological analysis but 11 patients were excluded due to posterior circulation occlusion. A total of 122 patients were included in the analysis. A distal embolism was documented in 27 patients (28.4%). Multivariable analysis with distal embolism as dependent variable showed an adjusted OR of 2.64 (95%CI: 0.9-7.73; p-value: 0.08) for anticoagulant therapy, an adjusted OR of 1.38 (95%CI: 1.01-1.91; p-value 0.05) each 5-mm increasing of thrombus length at CTA. No association was found with age, sex, thrombolysis and first thrombectomy technique used. CONCLUSION: The combined effect of anticoagulant therapy and thrombus length may have a potentially harmful effect on reperfusion during mechanical recanalization, causing distal embolization and this aspect should be taken into account in patient's risk assessment and when planning treatment strategy.

Posterior Circulation Endovascular Thrombectomy for Large Vessels Occlusion in Patients Presenting with NIHSS Score ≤ 10.

Mechanical thrombectomy (MT) is currently the gold standard treatment for ischemic stroke due to large vessel occlusion (LVO). However, the evidence of clinical usefulness of MT in posterior circulation LVO (pc-LVO) is still doubtful compared to the anterior circulation, especially in patients with mild neurological symptoms. The database of 10 high-volume stroke centers in Europe, including a period of three year and a half, was screened for patients with an acute basilar artery occlusion or a single dominant vertebral artery occlusion ("functional" BAO) presenting with a NIHSS ≤10, and with at least 3 months follow-up. A total of 63 patients were included. Multivariate analysis demonstrated that female gender (adjusted OR 0.04; 95% CI 0-0.84; p = 0.04) and combined technique (adj OR 0.001; 95% CI 0-0.81; p = 0.04) were predictors of worse outcome. Higher pc-ASPECTS (adj OR 4.75; 95% CI 1.33-16.94; p = 0.02) and higher Delta NIHSS (adj OR 2.06; 95% CI 1.16-3.65; p = 0.01) were predictors of better outcome. Delta NIHSS was the main predictor of good outcome at 90 days in patients with posterior circulation LVO presenting with NIHSS score ≤ 10.