Treatment practice of vasospasm during endovascular thrombectomy: an international survey.

BACKGROUND AND AIM: The clinical importance and management of vasospasm as a complication during endovascular stroke treatment (EVT) has not been well studied. We sought to investigate current expert opinions in neurointervention and therapeutic strategies of iatrogenic vasospasm during EVT. METHODS: We conducted an anonymous international online survey (4 April 2023 to 15 May 2023) addressing treatment standards of neurointerventionalists (NIs) practising EVT. Several illustrative cases of patients with vasospasm during EVT were shown. Two study groups were compared according to the NI's opinion regarding the potential influence of vasospasm on patient outcome after EVT using descriptive analysis. RESULTS: In total, 534 NI from 56 countries responded, of whom 51.5% had performed >200 EVT. Vasospasm was considered a complication potentially influencing the patient's outcome by 52.6% (group 1) whereas 47.4% did not (group 2). Physicians in group 1 more often added vasodilators to their catheter flushes during EVT routinely (43.7% vs 33.9%, p=0.033) and more often treated severe large-vessel vasospasm with vasodilators (75.3% vs 55.9%; p<0.001), as well as extracranial vasospasm (61.4% vs 36.5%, p<0.001) and intracranial medium-vessel vasospasm (27.1% vs 11.2%, p<0.001), compared with group 2. In case of a large-vessel vasospasm and residual and amenable medium-vessel occlusion during EVT, the study groups showed different treatment strategies. Group 2 continued the EVT immediately more often, without initiating therapy to treat the vasospasm first (9.6% vs 21.1%, p<0.001). CONCLUSION: There is disagreement among NIs about the clinical relevance of vasospasm during EVT and its management. There was a higher likelihood of use of preventive and active vasodilator treatment in the group that perceived vasospasm as a relevant complication as well as differing interventional strategies for continuing an EVT in the presence of a large-vessel vasospasm.

Diagnostic accuracy of automated occlusion detection in CT angiography using e-CTA.

BACKGROUND AND AIM: The aim of this study was to assess the diagnostic accuracy of e-CTA (product name) (Brainomix) in the automatic detection of large vessel occlusions in anterior circulation stroke. METHODS: Of 487 CT angiographies from patients with large vessel occlusions stroke, 327 were used to train the algorithm while the remaining cases together with 140 negative CT angiographies were used to validate its performance against ground truth. Of these 301 cases, 144 were randomly selected and used for an additional comparative analysis against 4 raters. Sensitivity, specificity, positive and negative predictive value (PPV and NPV), accuracy and level of agreement with ground truth (Cohen's Kappa) were determined and compared to the performance of a neuroradiologist, a radiology resident, and two neurology residents. RESULTS: e-CTA had a sensitivity and specificity of 0.84 (0.77-0.89) and 0.96 (0.91-0.98) respectively for the detection of any large vessel occlusions on the correct side in the whole validation cohort. This performance was identical in the comparative analysis subgroup and was within the range of physicians at different levels of expertise: 0.86-0.97 and 0.91-1.00, respectively. For the detection of proximal occlusions, it was 0.92 (0.84-0.96) and 0.98 (0.94-1.00) for the whole cohort and 0.93 (0.80-0.98) and 1.00 (0.95-1.00) for the comparative analysis, respectively for e-CTA. The range was 0.8-0.97 for sensitivity and 0.97-1.00 for specificity for the four physicians. CONCLUSIONS: The performance of e-CTA in detecting any large vessel occlusions is comparable to less experienced physicians but is similar to experienced physicians for detecting proximal large vessel occlusions.

Dynamics of cerebral perfusion and oxygenation parameters following endovascular treatment of acute ischemic stroke.

BACKGROUND: We studied the effects of endovascular treatment (EVT) and the impact of the extent of recanalization on cerebral perfusion and oxygenation parameters in patients with acute ischemic stroke (AIS) and large vessel occlusion (LVO). METHODS: Forty-seven patients with anterior LVO underwent computed tomography perfusion (CTP) before and immediately after EVT. The entire ischemic region (Tmax >6 s) was segmented before intervention, and tissue perfusion (time-to-maximum (Tmax), time-to-peak (TTP), mean transit time (MTT), cerebral blood volume (CBV), cerebral blood flow (CBF)) and oxygenation (coefficient of variation (COV), capillary transit time heterogeneity (CTH), metabolic rate of oxygen (CMRO2), oxygen extraction fraction (OEF)) parameters were quantified from the segmented area at baseline and the corresponding area immediately after intervention, as well as within the ischemic core and penumbra. The impact of the extent of recanalization (modified Treatment in Cerebral Infarction (mTICI)) on CTP parameters was assessed with the Wilcoxon test and Pearson's correlation coefficients. RESULTS: The Tmax, MTT, OEF and CTH values immediately after EVT were lower in patients with complete (as compared with incomplete) recanalization, whereas CBF and COV values were higher (P<0.05) and no differences were found in other parameters. The ischemic penumbra immediately after EVT was lower in patients with complete recanalization as compared with those with incomplete recanalization (P=0.002), whereas no difference was found for the ischemic core (P=0.12). Specifically, higher mTICI scores were associated with a greater reduction of ischemic penumbra volumes (R²=-0.48 (95% CI -0.67 to -0.22), P=0.001) but not of ischemic core volumes (P=0.098). CONCLUSIONS: Our study demonstrates that the ischemic penumbra is the key target of successful EVT in patients with AIS and largely determines its efficacy on a tissue level. Furthermore, we confirm the validity of the mTICI score as a surrogate parameter of interventional success on a tissue perfusion level.

ASPECTS Interobserver Agreement of 100 Investigators from the TENSION Study.

PURPOSE: Evaluating the extent of cerebral ischemic infarction is essential for treatment decisions and assessment of possible complications in patients with acute ischemic stroke. Patients are often triaged according to image-based early signs of infarction, defined by Alberta Stroke Program Early CT Score (ASPECTS). Our aim was to evaluate interrater reliability in a large group of readers. METHODS: We retrospectively analyzed 100 investigators who independently evaluated 20 non-contrast computed tomography (NCCT) scans as part of their qualification program for the TENSION study. Test cases were chosen by four neuroradiologists who had previously scored NCCT scans with ASPECTS between 0 and 8 and high interrater agreement. Percent and interrater agreements were calculated for total ASPECTS, as well as for each ASPECTS region. RESULTS: Percent agreements for ASPECTS ratings was 28%, with interrater agreement of 0.13 (95% confidence interval, CI 0.09-0.16), at zero tolerance allowance and 66%, with interrater agreement of 0.32 (95% CI: 0.21-0.44), at tolerance allowance set by TENSION inclusion criteria. ASPECTS region with highest level of agreement was the insular cortex (percent agreement = 96%, interrater agreement = 0.96 (95% CI: 0.94-0.97)) and with lowest level of agreement the M3 region (percent agreement = 68%, interrater agreement = 0.39 [95% CI: 0.17-0.61]). CONCLUSION: Interrater agreement reliability for total ASPECTS and study enrollment was relatively low but seems sufficient for practical application. Individual region analysis suggests that some are particularly difficult to evaluate, with varying levels of reliability. Potential impairment of the supraganglionic region must be examined carefully, particularly with respect to the decision whether or not to perform mechanical thrombectomy.

Optimal thresholds to predict long-term outcome after complete endovascular recanalization in acute anterior ischemic stroke.

BACKGROUND: Despite complete endovascular recanalization, a significant percentage of patients with acute anterior stroke do not achieve a good clinical outcome. We analyzed optimal thresholds of relevant parameters to discern functional independence after successful endovascular recanalization and test their predictive performance. METHODS: Patients with acute anterior ischemic stroke undergoing endovascular treatment between April 2015 and November 2019 were retrospectively analyzed. Only patients with premorbid modified Rankin Scale (mRS) score <3 and complete recanalization (modified Thrombolysis In Cerebral Infarction 2c/3) were included. Optimal thresholds of the most important variables predicting functional independence (mRS 0-2 after 90 days) were calculated using receiver operating characteristic curves and their predictive performance was tested in an independent dataset using machine learning algorithms. RESULTS: Overall, 371 patients met the inclusion criteria. Optimal thresholds for the overall most important variables to predict functional independence were (1) National Institutes of Health Stroke Scale (NIHSS) score ≤5 after 24 hours (area under the curve (AUC) 0.88 (95% CI 0.84 to 0.92)); (2) Alberta Stroke Program Early CT Score (ASPECTS) ≥7 on follow-up CT (AUC 0.72 (95% CI 0.68 to 0.77)); and (3) change in NIHSS score ≥8 after 24 hours (AUC 0.70 (95% CI 0.65 to 0.74)). The performance of these thresholds to predict a good outcome using machine learning in the independent dataset was evaluated for (1) NIHSS score ≤5 after 24 hours (AUC 0.76 (95% CI 0.71 to 0.81)); (2) follow-up ASPECTS ≥7 (AUC 0.64 (95% CI 0.58 to 0.70)); (3) change in NIHSS score ≥8 after 24 hours (AUC 0.61 (95% CI 0.55 to 0.67)); and (4) the combination of all three parameters (AUC 0.84 (95% CI 0.80 to 0.88)). CONCLUSIONS: After complete recanalization in acute anterior circulation ischemic stroke, a good long-term outcome could be accurately predicted reaching NIHSS score ≤5 after 24 hours.

Tandem occlusions in acute ischemic stroke - impact of antithrombotic medication and complementary heparin on clinical outcome and stent patency.

BACKGROUND AND PURPOSE: Mechanical thrombectomy (MT) and acute carotid stenting (ACS) of patients with acute ischemic stroke due to tandem occlusions (TO) of the anterior circulation was proven to be safe and effective, but the implications of periprocedural antithrombotic medications are only known to a limited extent. METHODS: We conducted a retrospective analysis of 162 consecutive patients who presented with TO and were treated with MT and ACS in our center. Patients initially either received dual antiplatelet therapy (DAT) or tirofiban periprocedurally. Some patients were also treated with unfractionated heparin. The frequency of intracranial hemorrhages (ICH), as well as the impact on clinical outcome and stent patency of different medical regimes, were evaluated using univariate tests and adjusted multivariate logistic regressions. RESULTS: Patients who received supportive treatment with heparin had significantly higher occurrences of any (OR, 2.46; 95% CI, 1.15 to 5.28) and symptomatic ICH (OR, 3.71; 95% CI, 1.18 to 14.95). Additionally, these patients were less likely to have a moderate clinical outcome after 90 days (modified Rankin scale 0-3; OR, 0.33; 95% CI, 0.15 to 0.72), but were more likely to have a fatal outcome after 90 days (OR, 2.84; 95% CI 1.10 to 7.31). These findings persisted in patients who received both DAT and heparin, but not for patients who received both tirofiban and heparin. CONCLUSION: Supportive administration of heparin in patients with TO and treatment with MT and ACS should be carefully considered, especially in patients who primarily receive DAT.

Prediction of intracranial hemorrhages after mechanical thrombectomy of basilar artery occlusion.

BACKGROUND: Mechanical thrombectomy (MT) achieves high recanalization rates in basilar artery occlusion (BAO). A severe complication of MT in BAO is intracranial hemorrhage (ICH). Yet, knowledge of risk factors for ICH after MT in BAO is limited. OBJECTIVE: To evaluate clinical and procedural parameters of patients treated with MT owing to BAO to identify potential risk factors for ICH-in particular, symptomatic ICH (sICH), and assess their clinical relevance. METHODS: We conducted a retrospective analysis of 101 consecutive patients presenting with BAO, who were treated with MT in our centre. Important clinical and procedural parameters were analysed as possible predictors for any ICH and sICH according to the Heidelberg Bleeding Classification using univariate tests and multivariate logistic regressions. RESULTS: ICH occurred in 25 (24.8%) patients, with a total of 7 (6.9%) developing sICH. Treatment with glycoprotein IIb/IIIa (GPIIb/IIIa) inhibitors was independently associated with any ICH (OR=24.67, 95% CI 4.90 to 124.03) and sICH (OR=7.08, 95% CI 1.36 to 36.78). Also, a longer onset-to-recanalization time increased the risk of both any ICH (OR=1.17, 95% CI 1.07 to 1.31) and sICH (OR=1.22, 95% CI 1.08 to 1.42). Higher serum glucose levels were associated with a higher incidence of any ICH (OR=1.39, 95% CI 1.06 to 1.85) and a higher risk of a fatal outcome (OR=1.03, 95% CI 1.01 to 1.05). CONCLUSION: Administration of GPIIb/IIIa inhibitor during the course of MT of BAO was identified as an important risk factor in the development of any ICH and sICH.

Simplified selection criteria for patients with longer or unknown time to treatment predict good outcome after mechanical thrombectomy.

OBJECTIVE: To identify simplified selection criteria for mechanical thrombectomy (MT) in longer and unknown time windows. METHODS: Patients with large vessel occlusion (LVO) in the anterior circulation who underwent MT between January 2014 and November 2017 were identified from the local registry. Patients were selected for analysis if they met the current guideline recommendation for MT treatment except for time window (HERMES-like) and were divided according to time they were last seen well (LSW): LSW <6 hours or LSW >6 hours before MT. The primary endpoint, good outcome, was modified Rankin scale score 0-2 on day 90. Safety outcomes were mortality on day 90 and symptomatic intracranial hemorrhage (sICH). Univariate and multivariate analysis were performed for good outcome in HERMES-like patients. RESULTS: In total, 752 patients were identified and 390 patients (51.9%) fulfilled the HERMES-like criteria. Despite differences in baseline parameters, more diffusion-weighted imaging (DWI) (43.9% vs 11.3%, p<0.001) and fewer cases of thrombolysis (32.7% vs 77%, p<0.001), patients LSW >6 hours (n=107) did not differ in the primary and secondary endpoints: good outcome (44.9% vs 44.9%, p=1.0), mortality (14% vs 15.2%, p=0.87), and sICH (5.6% vs 6%, p=1.0). After multivariate regression analysis, independent predictors of good outcome remained: age, OR=0.96 (95% CI 0.95 to 0.98); National Institutes of Health Stroke Scale score, OR=0.92 (95% CI 0.89 to 0.96); Alberta Stroke Programme Early CT Score (ASPECTS), OR=1.26 (95% CI 1.06 to 1.49); general anesthesia, OR=0.2 (95% CI 0.04 to 0.99), and successful recanalization, OR=12 (95% CI 4.7 to 30.5); but not treatment time and DWI or CT perfusion at baseline. CONCLUSION: Patients with proven LVO in unknown and longer time windows may be selected for MT based on ASPECTS and clinical criteria.