A case of spontaneous brain arteriovenous malformation occlusion: Imaging analysis and clinical debate.

The spontaneous occlusion of brain arteriovenous malformations (bAVMs) is a rare event, particularly for unruptured ones. Associated factors include single-venous drainage and small nidus size. Most of the previously reported cases were ruptured bAVMs. We report the case of a middle-aged male patient with an unruptured, rolandic, left-sided bAVM associated with a 30-year history of refractory epilepsy. We documented the spontaneous thrombosis of the venous drainage of the AVM without any sign of bleeding. Finally, we underline the difference between ruptured-induced occlusion and truly spontaneous thrombosis of the bAVMs.

Endovascular therapy of acute vertebrobasilar occlusions: influence of first-line strategy in the Endovascular Treatment in Ischemic Stroke (ETIS) Registry.

BACKGROUND: The choice of the first-line technique in vertebrobasilar occlusions (VBOs) remains challenging. We aimed to report outcomes in a large cohort of patients and to compare the efficacy and safety of contact aspiration (CA) and combined technique (CoT) as a first-line endovascular technique in patients with acute VBOs. METHODS: We retrospectively analyzed clinical and neuroradiological data of patients with VBOs from the prospective, multicenter, observational Endovascular Treatment in Ischemic Stroke (ETIS) Registry in France between January 2015 and August 2023. The primary outcome was the first pass effect (FPE) rate, whereas modified Thrombolysis In Cerebral Infarction (mTICI) 2b-3 and 2c-3, number of passes, need for rescue strategy, modified Rankin Scale (mRS) 0-2, mortality, and symptomatic intracranial hemorrhage (sICH) were secondary outcomes. We performed univariate and multivariate analyses to investigate differences between the two groups. RESULTS: Among the 583 included patients (mean age 66.2 years, median National Institutes of Health Stroke Scale (NIHSS) 13, median posterior circulation Alberta Stroke Program Early CT Score (pc-ASPECTS) 8), 393 were treated with CA alone and 190 with CoT. Procedures performed with CA were shorter compared with CoT (28 vs 47 min, P<0.0001); however, no differences were observed in terms of FPE (CA 43.3% vs CoT 38.4%, P=0.99), and successful final recanalization (mTICI 2b-3, CA 92.4% vs CoT 91.8%, P=0.74) did not differ between the two groups. Functional independence and sICH rates were also similar, whereas mortality was significantly lower in the CA group (34.5% vs 42.9%; OR 1.79, 95% CI 1.03 to 3.11). CONCLUSIONS: We observed no differences in FPE, mTICI 2b-3, sICH, and functional independence between the two study groups. First-line CA was associated with shorter procedures and lower mortality rates than CoT.

Unfavorable clinical outcomes in patients with good collateral scores following endovascular treatment for acute ischemic stroke of the anterior circulation: The UNCLOSE study.

BACKGROUND: Patients with acute ischemic stroke secondary to large vessel occlusions and good collaterals are frequently associated with favorable outcomes after mechanical thrombectomy, although poor outcomes are observed also in this subgroup. We aimed to investigate the factors associated with unfavorable outcomes (modified Rankin Scale3-6) in this specific subgroup of patients. METHODS: In total, 219 patients (117 females) with anterior circulation stroke and good collaterals (American Society for Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology grades 3-4), treated by mechanical thrombectomy between 2016 and 2021 at our institution were included in this study. Clinical files and neuroimaging were retrospectively reviewed. Univariate and multivariate analyses were performed to identify the predictors of unfavorable outcomes in the overall population (primary endpoint). Secondary endpoints focused on the analysis of the predictors of unfavorable outcomes in the subgroup of successfully recanalized patients, mortality, and symptomatic intracerebral hemorrhages in the overall population. RESULTS: Poor outcome was observed in 47% of the patients despite the presence of good collaterals. Older age (p < 0.001), higher baseline National Institute of Health stroke scale (p < 0.001), no intravenous thrombolysis administration (p = 0.004), > 3 passes (p = 0.01), and secondary transfers (p < 0.001) were associated with the primary endpoint. The multivariate analysis showed a predictive effect of modified treatment in cerebral infarction 2b-3 and of first pass effect on symptomatic intracerebral hemorrhage. CONCLUSIONS: Despite good collaterals, defined through the American Society for Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology scale, poor outcomes occurred in almost half of the patients. Patients with good collaterals not receiving intravenous thrombolysis were significantly associated with unfavorable outcomes, whereas first pass effect was not significantly correlated with clinical outcome in this specific cohort of patients. Different methods to assess collaterals should also be investigated.

Reconstruction of the sphenoid sinus erosion or dehiscence after treatment of unruptured intracavernous aneurysms with flow diverter stents.

BACKGROUND: Intracavernous carotid aneurysms (ICCAs) are rare, frequently asymptomatic, with a low rupture risk, which, however, can lead to life-threatening epistaxis. The aim of this study was to assess the effect of the treatment of asymptomatic ICCAs with flow diverters (FD) on sphenoid bone erosion or dehiscence in a selected cohort of patients. METHODS: We retrospectively reviewed all asymptomatic ICCAs with sphenoid bone erosion or dehiscence detected on cone beam CT (CBCT) and treated with FD between December 2018 and December 2022. Patients were followed-up with CBCT and bone reconstruction was blindly evaluated by two interventional neuroradiologists and classified as unchanged, partial, or complete. RESULTS: A total of 10 patients (women: 90%, mean age 58 years) treated with an FD for an asymptomatic ICCA with associated sphenoid bone erosion or dehiscence were included in this cohort. Sphenoid bone erosion was present in seven patients and dehiscence was observed in the remaining three. After treatment with FD, complete reconstruction of the sphenoid sinus wall occurred in seven cases, and partial reconstruction in two cases. Sphenoid bone erosion remained unchanged after treatment in only one patient. CONCLUSIONS: The decision to treat asymptomatic and unruptured ICCAs remains challenging due to their benign natural history and low hemorrhagic risk. The presence of sphenoid sinus erosion or dehiscence should not be overlooked since it could be considered as an indication for prophylactic treatment of life-threatening epistaxis. The mechanisms of bone erosion by the aneurysm and of reconstruction after treatment are still to be fully elucidated.

Angiographic collateral venous phase: a novel landmark for leptomeningeal collaterals evaluation in acute ischemic stroke.

BACKGROUND: Although recanalization rates constantly increase (>80%), a favorable clinical outcome is achieved in only 45-55% of patients undergoing mechanical thrombectomy (MT) for anterior circulation stroke. Collateral circulation seems to play a major role in determining this discrepancy. The aim of the study was to investigate a novel angiographic landmark assessing the collateral venous phase (CVP) compared with the American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology (ASITN/SIR) score, based on the arterial collateral assessment. METHODS: Two hundred patients with anterior circulation stroke treated by MT between 2016 and 2021 were included. The ASITN/SIR score and the presence of CVP were blindly evaluated by expert neuroradiologists. Three subanalyses were performed comparing patients with good versus poor collaterals, CVP presence versus absence, and a composite analysis including both ASITN/SIR and CVP grading results. RESULTS: Good collateral circulation (ASITN >2) was observed in 113 patients (56.5%) whereas CVP was present in 90 patients (45%) and mostly in patients with good collaterals. Favorable clinical and neuroradiological outcomes were more likely observed in patients with both good collaterals and the presence of CVP than in those with good collaterals and absence of CVP (modified Rankin Scale score 0-2: 77.3% vs 7.9%, p<0.0001; mortality: 9.3% vs 26.3%, p=0.02; 24-hour Alberta Stroke Program Early CT Score: 8 vs 6, p<0.0001), while ASITN/SIR score alone was not significantly associated with clinical outcomes. CONCLUSIONS: The presence of CVP improves the angiographic assessment of collateral circulation. CVP could be proposed as a new imaging landmark to better understand the functionality of collaterals.

Rupture of a detachable-tip microcatheter away from the detachment zone during Onyx 18 embolization of an arteriovenous malformation and management of the complication.

Leakage of liquid embolic material is a rare but dreaded complication during embolization of an arteriovenous malformation (AVM). We describe the rupture of a microcatheter away from the detachment site and the successful removal of the cast of Onyx 18 in the carotid artery by aspiration. A young adult patient diagnosed with a right temporal unruptured AVM underwent endovascular embolization using Onyx 18. The AVM was approached using an Apollo microcatheter. After 4 min of Onyx 18 injection, leakage of Onyx 18 in the petrous segment of the internal carotid artery was noticed while the distal tip of the microcatheter remained patent. The plug of Onyx was successfully removed using an aspiration technique via the Envoy DA catheter. Analysis of the microcatheter confirmed that the rupture occurred away from the detachment site. However, no definite cause for the rupture has been identified.

Endovascular Stroke Treatment of Acute Tandem Occlusion: A Single-Center Experience.

PURPOSE: To evaluate outcomes and prognostic factors in patients with acute ischemic stroke caused by tandem internal carotid artery/middle cerebral artery occlusion undergoing endovascular treatment. MATERIALS AND METHODS: Characteristics of consecutive patients with tandem occlusion (TO) were extracted from a prospective registry. Collateral vessel quality on pretreatment computed tomographic (CT) angiography was evaluated on a 4-point grading scale, and patients were dichotomized as having poor or good collateral flow. Outcome measures included successful reperfusion according to Thrombolysis In Cerebral Infarction score, good outcome at 3 months defined as a modified Rankin scale score ≤ 2, symptomatic intracranial hemorrhage (ICH; sICH), and mortality. RESULTS: A total of 72 patients with TO (mean age, 65.6 y ± 12.8) were treated. Intravenous thrombolysis was performed in 54.1% of patients, and a carotid stent was inserted in 48.6%. Successful reperfusion was achieved in 64% of patients, and a good outcome was achieved in 32%. sICH occurred in 12.5% of patients, and the overall mortality rate was 32%. Univariate analysis demonstrated that good outcome was associated with good collateral flow (P = .0001), successful reperfusion (P = .001), and lower rate of any ICH (P = .02) and sICH (P = .04). On multivariate analysis, good collateral flow (odds ratio [OR], 0.18; 95% confidence interval [CI], 0.04-0.75; P = .01) and age (OR, 1.08; 95% CI, 1.01-1.15; P = .01) were the only predictors of good outcome. The use of more than one device for thrombectomy was the only predictor of sICH (OR, 10.74; 95% CI, 1.37-84.13; P = .02). CONCLUSIONS: Endovascular treatment for TO resulted in good outcomes. Collateral flow and age were independent predictors of good clinical outcomes at 3 months.

CT angiography-based collateral flow and time to reperfusion are strong predictors of outcome in endovascular treatment of patients with stroke.

BACKGROUND: Collateral flow (CF) is an effective predictor of outcome in acute ischemic stroke (AIS) with potential to sustain the ischemic penumbra. However, the clinical prognostic value of CF in patients with AIS undergoing mechanical thrombectomy has not been clearly established. We evaluated the relationship of CF with clinical outcomes in patients with large artery anterior circulation AIS treated with mechanical thrombectomy. METHODS: Baseline collaterals of patients with AIS (n=135) undergoing mechanical thrombectomy were independently evaluated by CT angiography (CTA) and conventional angiography and dichotomized into poor and good CF. Multivariable analyses were performed to evaluate the predictive effect of CF on outcome and the effect of time to reperfusion on outcome based on adequacy of the collaterals. RESULTS: Evaluation of CF was consistent by both CTA and conventional angiography (p<0.0001). A higher rate of patients with good collaterals had good functional outcome at 3-month follow-up compared with those with poor collaterals (modified Rankin Scale (mRS) 0-2: 60% vs 10%, p=0.0001). Patients with poor collaterals had a significantly higher mortality rate (mRS 6: 45% vs 8%, p=0.0001). Multivariable analyses showed that CF was the strongest predictor of outcome. Time to reperfusion had a clear effect on favorable outcome (mRS ≤2) in patients with good collaterals; in patients with poor collaterals this effect was only seen when mRS ≤3 was considered an acceptable outcome. CONCLUSIONS: CTA is a valid tool for assessing the ability of CF to predict clinical outcome in patients with AIS treated with mechanical thrombectomy. Limiting time to reperfusion is of definite value in patients with good collaterals and also to some extent in those with poor collaterals.