Diagnostic Performance of Carotid Ring Sign on CT-Angiography in Internal Carotid True Occlusion.

BACKGROUND: To differentiate between pseudo occlusion (PO) and true occlusion (TO) of internal carotid artery (ICA) is important in thrombectomy treatment planning for patients with acute ischemic stroke. Although delayed contrast filling has been differentiated carotid PO from TO, its application has been limited by the implementations of multiphasic computed tomography angiography. In this study, we hypothesized that carotid ring sign, which is readily acquired from single-phasic CTA, can sufficiently differentiate carotid TO from PO. METHODS: One thousand four hundred and twenty patients with anterior circulation stroke receiving endovascular therapy were consecutively recruited through a hospital- and web-based registry. Two hundred patients with nonvisualization of the proximal ICA were included in the analysis after a retrospective screening. Diagnosis of PO or TO of the cervical segment of ICA was made based on digital subtraction angiography. Diagnostic performances of carotid ring sign on arterial-phasic CTA and delayed contrast filling on multiphasic computed tomography angiography were evaluated and compared. RESULTS: One-hundred twelve patients had ICA PO and 88 had TO. Carotid ring sign was more common in patients with TO (70.5% versus 6.3%; P<0.001), whereas delayed contrast filling was more common in PO (94.9% versus 7.7%; P<0.001). The sensitivity and specificity of carotid ring sign in diagnosing carotid TO were 0.70 and 0.94, respectively, whereas sensitivity and specificity of delayed contrast filling was 0.95 and 0.92 in judging carotid PO. CONCLUSIONS: Carotid ring sign is a potent imaging marker in diagnosing ICA TO. Carotid ring sign could be complementary to delayed contrast filling sign in differentiating TO from PO, in particular in centers with only single-phasic CTA.

Predictors of futile recanalization in basilar artery occlusion patients undergoing endovascular treatment: a post hoc analysis of the ATTENTION trial.

Background: Few studies have focused on factors associated with futile recanalization in patients with an acute basilar artery occlusion (BAO) that was treated with modern endovascular therapy (EVT). The aim of this study was to explore the factors associated with futile recanalization in patients with an acute BAO presented within 12 h. Methods: This is a post-hoc analysis of the ATTENTION trial (The Trial of Endovascular Treatment of Acute Basilar-Artery Occlusion, ClinicalTrials.gov, number NCT04751708). Demographics, clinical characteristics, acute stroke workflow interval times, and imaging characteristics were compared between the futile recanalization and favorable recanalization groups. The favorable outcome was defined as a modified Rankin scale (mRS) score of 0-3 at 90 days, successful reperfusion was defined as thrombolysis in cerebral infarction (TICI) 2b and 3 on the final angiogram, and futile recanalization was defined as failure to achieve a favorable outcome despite successful reperfusion. A multivariate analysis was performed to identify the predictors of futile recanalization. Results: In total, 185 patients were included in the final analysis: 89 (48.1%) patients had futile recanalization and 96 (51.9%) patients had favorable recanalization. In the multivariable logistic regression analysis, older age (OR 1.04, 95% CI 1.01 to 1.08, p = 0.01) and diabetes mellitus (OR 3.35, 95% CI 1.40 to 8.01, p = 0.007) were independent predictors of futile recanalization. Conclusion: Futile recanalization occurred in nearly half of patients with acute BAO following endovascular treatment. Old age and diabetes mellitus were identified as independent predictors of futile recanalization after endovascular therapy for acute BAO.

Application of Balloon AngioplaSty with the dIstal protection of Stent Retriever (BASIS) technique for acute intracranial artery atherosclerosis-related occlusion.

Background: Endovascular therapy (EVT) is complex in the context of intracranial atherosclerosis (ICAS)-related large vessel occlusion (LVO) and the re-occlusion rates are high due to residual stenosis, the procedure time is long and the optimal EVT technique is unclear. The Balloon AngioplaSty with the dIstal protection of Stent Retriever (BASIS) technique is a novel thrombectomy technique that allows emergent balloon angioplasty to be performed via the wire of the retrieval stent. Our study presents our initial experience with the BASIS technique in ICAS-related LVO and assesses its feasibility. Method: In patients with ICAS-related LVO treated with BASIS, clinical and angiographic data were retrospectively analyzed. Angiographic data included first-pass reperfusion (PFR), the rate of residual stenosis, distal emboli, and re-occlusion post-procedure. The Extended Thrombolysis in Cerebral Infarction (eTICI) scale was used to assess reperfusion extent, and an eTICI score ≥2b was defined as successful perfusion. Clinical outcome was evaluated at 3 months (modified Rankin score [mRS]), and an mRS ≤ 2 was defined as a good clinical outcome. Results: A total of seven patients with ICAS-related LVO were included, and the median age of the patients was 76 years. All patients achieved eTICI 3 reperfusion and FPR. The residual stenosis rate ranged from 5 to 10%. None of the patients had re-occlusion post-procedure. The median puncture-to-reperfusion time was 51 min. None of the patients had a symptomatic cerebral hemorrhage, re-occlusion, distal embolism, and dissection. Good clinical outcomes were observed in four patients (4/7, 57.1%), and 1 patient (1/7, 14.3%) died. Conclusion: The BASIS technique is feasible and safe for treating acute ICAS-related LVO.

Endovascular Treatment of ICAS Patients: Targeting Reperfusion Rather than Residual Stenosis.

BACKGROUND AND PURPOSE: Previous studies showed that acute reocclusion after endovascular therapy is related to residual stenosis. However, we observed that reperfusion status but not residual stenosis severity is related to acute reocclusion. This study aimed to assess which factor mention above is more likely to be associated with artery reocclusion after endovascular treatment. METHODS: This study included 86 acute ischemic stroke patients who had middle cerebral artery (MCA) atherosclerotic occlusions and received endovascular treatment within 24 h of a stroke. The primary outcomes included intraprocedural reocclusion assessed during endovascular treatment and delayed reocclusion assessed through follow-up angiography. RESULTS: Of the 86 patients, the intraprocedural reocclusion rate was 7.0% (6/86) and the delayed reocclusion rate was 2.3% (2/86). Regarding intraprocedural occlusion, for patients with severe residual stenosis, patients with successful thrombectomy reperfusion showed a significantly lower rate than unsuccessful thrombectomy reperfusion (0/30 vs. 6/31, p = 0.003); on the other hand, for patients with successful thrombectomy reperfusion, patients with severe residual stenosis showed no difference from those with mild to moderate residual stenosis in terms of intraprocedural occlusion (0/30 vs. 0/25, p = 1.00). In addition, after endovascular treatment, all patients achieved successful reperfusion. There was no significant difference in the delayed reocclusion rate between patients with severe residual stenosis and those with mild to moderate residual stenosis (2/25 vs. 0/61, p = 0.085). CONCLUSION: Reperfusion status rather than residual stenosis severity is associated with artery reocclusion after endovascular treatment. Once successful reperfusion was achieved, the reocclusion occurrence was fairly low in MCA atherosclerosis stroke patients, even with severe residual stenosis.

Intra-Arterial Injection of Thrombin as Rescue Therapy of Vessel Perforation during Mechanical Thrombectomy for Acute Ischemic Stroke.

BACKGROUND: Vessel perforation during stent mechanical thrombectomy (MT) is a rare and disastrous complication. A routine rescue strategy includes balloon occlusion for tamponade, procedure suspension, and lowering or normalizing blood pressure. However, this complication is still associated with poor outcome and high mortality. OBJECTIVE: We present our experience with intra-arterial injection of thrombin in the treatment of vessel perforation secondary to microcatheter/microwire perforation, which prevents further deterioration in clinical outcomes. METHODS: Cases with intraprocedural vessel perforation during mechanical thrombectomy were included in the final analysis. Clinical data, procedural details, and radiographic and clinical outcomes were collected. RESULTS: Four patients with intraprocedural vessel perforation were included. Intraprocedural perforations occurred at the distal middle cerebral artery in two cases: the A2 segment in one case and the internal carotid artery terminus in one case. The etiology of four cases was intracranial atherosclerotic stenosis (ICAS). The ruptured vessels were effectively occluded in all cases. Endovascular therapy was continued in three cases, and mTICI ≥ 2b recanalization was achieved in all cases. The culprit artery was kept patent on CTA for 72 h post-operation. No active bleeding was detected on follow-up CT post-operation. During the 90-day follow-up period, one patient died, modified Rankle Scare (mRS) 3 was observed in two patients, and mRS 4 was observed in one patient. CONCLUSIONS: The key benefit of this method is occluding the ruptured vessel without affecting the following MT. We propose that intra-arterial injection of prothrombin may be simple yet effective in managing vessel perforation complications during MT.

Association of baseline core volume and early midline shift in acute stroke patients with a large ischaemic core.

Background: Midline shift (MLS) is troublesome problem that may occur in patients with a large infarct core (LIC) and may be related to the baseline infarct core volume. The purpose of this study was to explore the relationship between baseline infarct core volume and early MLS presence. Materials and methods: Patients with acute intracranial large artery occlusion and a pretreatment relative cerebral blood flow (rCBF) <30% volume ≥50 ml on CT perfusion (CTP) were included, clinical outcomes following endovascular treatment (EVT) were retrospectively analyzed. The primary endpoint was MLS within 48 h (early MLS presence). The association between baseline ICV and early MLS presence was evaluated with multivariable regression. Results: Ultimately, 95 patients were included, and 29.5% (28/95) of the patients had early MLS. The number of patients with a baseline rCBF < 15% volume (median [interquartile range], 46 [32-60] vs. 29 [19-40]; P < 0.001) was significantly larger in the early severe MLS presence group. A baseline rCBF < 15% volume showed significantly better predictive accuracy for early MLS presence than an rCBF < 30% volume (area under the curve, 0.74 vs. 0.64, P = 0.0023). In addition, an rCBF < 15% volume ≥40 ml (odds ratio, 4.34 [95% CI, 1.571-11.996]) was associated with early MLS presence after adjustment for sex, age, baseline National Institutes of Health Stroke Scale score, onset-to-recanalization time. Conclusion: In patients with an acute LIC following EVT, a pretreatment infarct core volume > 40 ml based on an rCBF < 15% showed good predictive value for early MLS occurrence.

Initial Clinical Experience of Repeat Thrombectomy with a Retrieval Stent (RTRS) with Continuous Proximal Flow Arrest by Balloon Guide Catheter for Acute Intracranial Carotid Occlusion.

BACKGROUND: Balloon guide catheters (BGCs) have good performance in terms of radiological outcomes in acute ischemic thrombectomy. It is not uncommon for BGCs to be blocked by thrombi, especially in cases with acute intracranial internal carotid artery (ICA) occlusion. Our initial experience using repeat thrombectomy with a retrieval stent (RTRS) with continuous proximal flow arrest by BGC for acute intracranial ICA occlusion is presented. METHODS: In patients with acute intracranial ICA occlusion treated with RTRS, clinical data, including the National Institutes of Health Stroke Scale (NIHSS) score at admission and modified Rankin Scale (mRS) score at 90 days, and procedural data, including the Extended treatment in Cerebral Infarction (eTICI) score, procedural time, and complications, were analyzed. RESULTS: Thirty-two consecutive patients (12 men (37.5%); mean age: 73 years) were treated with RTRS using a BGC. The median NIHSS score was 19. The median puncture-to-reperfusion time was 46 minutes (range: 22-142 minutes). All patients were successfully revascularized; eTICI 2c or better recanalization was achieved in 30 (93.8%) patients. No procedure-related complications or symptomatic intracranial hemorrhage occurred. Two cases (6.3%) had distal emboli, but none had emboli to the anterior cerebral artery. Fourteen patients (43.8%) achieved a good outcome with an mRS score of 0-2 at 90 days, and 8 patients (25.0%) died. CONCLUSIONS: In patients with intracranial ICA occlusion, RTRS with proximal flow arrest by BGC is effective and safe, achieving good clinical and angiographic outcomes. This method may reduce the incidence of distal emboli in thrombectomy with stent retrievers.

Stent-unsheathed effect predicts acute distal middle cerebral artery atherosclerotic disease-related occlusion.

BACKGROUND: The differentiation of intracranial atherosclerosis (ICAS) and embolism is important. OBJECTIVE: In cases of ICAS, we observe a phenomenon that we call the "post-stent-deployment effect"; that is, all major branches are clearly visible beyond the occlusion segment when the stent is deployed at the site of occlusion. Our objective is to evaluates whether this post-stent-deployment effect can be used to differentiate ICAS from embolism in the distal M1 segment occlusion. METHODS: We conduct a retrospective study which reviewed consecutive patients with acute distal M1 segment and in whom recanalization was achieved by endovascular treatment. The post-stent-deployment effect was assessed in these patients. The sensitivity, specificity, positive predictive values (PPV), and accuracy of the post-stent-deployment effect for prediction of ICAS were assessed. RESULTS: From January 2015 to July 2018, a total of 80 patients were evaluated. The post-stent-deployment effect was more frequently observed in patients with ICAS than in those with embolism (100% vs 15.0%, P < .001). For identifying ICAS in distal M1 segment, the sensitivity, specificity, PPV, and accuracy of the post-stent-deployment effect were 100%, 85.0%, 69.0%, and 88.7%, respectively. CONCLUSION: Our study finds that the sensitivity and accuracy of the post-stent-deployment effect in predicting distal M1 segment ICAS occlusion in patients with acute symptoms was high, and it may be useful in identifying ICAS lesion.

Clinical significance of common-stem lenticulostriate arteries in patients with internal watershed infarction.

BACKGROUND: A common-stem origin of lenticulostriate arteries (CS-LSAs) is an anatomical variation that supplies a moderate to large section of the basal ganglia. We hypothesized that CS-LSAs with a patent orifice are located at distal positions of the acute-occluded middle cerebral artery (MCA) and that the blood flow of CS-LSAs is supplied by pail arterial anastomoses and results in hypoperfusion of CS-LSAs, similar to a deep watershed (DWS) infarction. OBJECTIVE: Our study evaluated the possibility of CS-LSAs in patients with DWS infarction and MCA occlusion and also assessed the safety of endovascular therapy (ET) in these patients. METHODS: A cohort of consecutive patients with DWS infarction and MCA occlusion and in whom full recanalization via ET was achieved were identified. Patients were divided into two groups based on the presence of CS-LSAs observed during ET. In addition, radiological and clinical data were retrospectively analyzed. RESULTS: Thirty-three patients were included, and CS-LSAs were observed in 48.5% (16/33) of patients. The possibility (72.2%, 13/18) of CS-LSAs was high in patients with DWS infarction companied with basal ganglia infarction. A good clinical outcome was similar in patients with CS-LSAs and basal ganglia infarction and in patients without CS-LSAs and basal ganglia infarction (69.2% vs. 81.8%, P = 0.649). CONCLUSIONS: The possibility of CS-LSAs was 48.5% in patients with DWS infarction and MCA occlusion, and the revascularization procedure was safe and feasible in these patients despite the moderate-to-large basal ganglia infarction.