Outcomes after surgical revascularization for adult Moyamoya disease: A Southeast Asian tertiary centre experience.

There are numerous studies on the natural history and outcomes of adult Moyamoya disease (MMD) in the literature, but limited data from Southeast Asian cohorts. Hence, we aimed to retrospectively review the clinical characteristics and outcomes after surgical revascularization for adult MMD in our Southeast Asian cohort. Patients were included if they were above 18 years old at the first surgical revascularization for MMD, and underwent surgery between 2012 and 2022 at the National University Hospital, Singapore. The outcomes were transient ischemic attack (TIA), ischemic stroke, intracerebral hemorrhage, and all-cause mortality during the postoperative follow-up period. In total, 26 patients who underwent 27 revascularization procedures were included. Most patients were of Chinese ethnicity, and the mean (SD) age at the time of surgery was 47.7 (12.6) years. The commonest clinical presentation was intracerebral hemorrhage, followed by TIA and ischemic stroke. Direct revascularization with superficial temporal artery-middle cerebral artery (STA-MCA) bypass was the most common procedure (24/27 surgeries, 88.9 %). The mean (SD) follow-up duration was 4.2 (2.5) years, during which the overall incidence of postoperative TIA/stroke was 25.9 % (7/27 surgeries), with most cases occurring within 7 days postoperatively. There were no mortalities during the postoperative follow-up period. Risk factors for 30-day postoperative TIA/stroke included a higher number of TIAs/strokes preoperatively (p = 0.044) and indirect revascularization (p = 0.028). Diabetes mellitus demonstrated a trend towards an increased risk of 30-day postoperative TIA/stroke, but this was not statistically significant (p = 0.056). These high-risk patients may benefit from more aggressive perioperative antithrombotic and hydration regimens.

Impact of atrial fibrillation on the treatment effect of bridging thrombolysis in ischemic stroke patients undergoing endovascular thrombectomy: a multicenter international cohort study.

BACKGROUND: The role of bridging intravenous thrombolysis (IVT) before endovascular thrombectomy (EVT) in the treatment of acute ischemic stroke (AIS) remains debatable. Atrial fibrillation (AF) associated strokes may be associated with reduced treatment effect from IVT. This study compares the effect of bridging IVT in AF and non-AF patients. METHODS: This retrospective cohort study comprised anterior circulation large vessel occlusion (LVO) AIS patients receiving EVT alone or bridging IVT plus EVT within 6 hours of symptom onset. Primary outcome was good functional outcome defined as modified Rankin Scale (mRS) 0-2 at 90 days. Secondary outcomes were successful reperfusion defined as expanded Thrombolysis In Cerebral Infarction (eTICI) grading ≥2b flow, symptomatic intracerebral hemorrhage (sICH), and in-hospital mortality. RESULTS: We included 705 patients (314 AF and 391 non-AF patients). The mean age was 68.6 years and 53.9% were male. The odds of good functional outcomes with bridging IVT was higher in the non-AF (adjusted odds ratio (aOR) 2.28, 95% CI 1.06 to 4.91, P=0.035) compared with the AF subgroups (aOR 1.89, 95% CI 0.89 to 4.01, P=0.097). However, this did not constitute a significant effect modification by the presence of AF on bridging IVT (interaction aOR 0.12, 95% CI -1.94 to 2.18, P=0.455). The rate of successful reperfusion, sICH, and mortality were similar between bridging IVT and EVT for both AF and non-AF patients. CONCLUSION: The presence of AF did not modify the treatment effect of bridging IVT. Further individual patient data meta-analysis of randomized trials may shed light on the comparative efficacy of bridging IVT in AF versus non-AF LVO strokes.

Bridging thrombolysis improves survival rates at 90 days compared with direct mechanical thrombectomy alone in acute ischemic stroke due to basilar artery occlusion: a systematic review and meta-analysis of 1096 patients.

BACKGROUND: Mechanical thrombectomy (MT) is an effective treatment for patients with acute ischemic stroke (AIS) from basilar artery occlusion (BAO). OBJECTIVE: To compare the clinical outcomes of MT, with and without bridging intravenous thrombolysis (IVT), in acute BAO through a systematic review and meta-analysis of the current literature. METHODS: Systematic searches of Medline, EMBASE, and Cochrane Central were undertaken on August 1, 2022. Good functional outcome defined as 90-day modified Rankin Scale score 0-2 was the primary outcome measure. Secondary outcome measures were 90-day mortality, successful post-thrombectomy recanalization (modified Thrombolysis in Cerebral Infarction score ≥2b), symptomatic intracranial hemorrhage (sICH), and subarachnoid hemorrhage (SAH). RESULTS: Three studies reporting 1096 patients with BAO AIS were included in the meta-analysis. No significant differences in good functional outcome were detected between the two groups (RR=1.28 (95% CI 0.86 to 1.92); p=0.117). However, specifically patients with large artery atherosclerosis (LAA) benefited from bridging IVT (OR=2.52 (95% CI 1.51 to 4.22); p<0.001) with better functional outcomes. There was a significantly lower 90-day mortality rate for patients who underwent bridging IVT compared with MT alone (RR=0.70 (95% CI 0.62 to 0.80); p=0.008). No significant differences were detected in rates of post-treatment recanalization (RR=1.01 (95% CI 0.35 to 2.91); p=0.954), sICH (RR=0.96 (95% CI 0.66 to 1.42); p=0.724), and SAH (RR=0.93 (95% CI 0.31 to 2.83); p=0.563). CONCLUSIONS: In patients with AIS due to BAO, bridging IVT was associated with lower mortality rates at 90 days, compared with direct MT. There were no improved functional outcomes or increased sICH or SAH between both arms, However, patients with LAA benefited from bridging IVT, with better functional outcomes.

Combined balloon guide catheter, aspiration catheter, and stent retriever technique versus balloon guide catheter and stent retriever alone technique: a systematic review and meta-analysis.

BACKGROUND: The use of a combination of balloon guide catheter (BGC), aspiration catheter, and stent retriever in acute ischemic stroke thrombectomy has not been shown to be better than a stent retriever and BGC alone, but this may be due to a lack of power in these studies. We therefore performed a meta-analysis on this subject. METHODS: A systematic literature search was performed on PubMed, Scopus, Embase/Ovid, and the Cochrane Library from inception to October 20, 2021. Our primary outcomes were the rate of successful final reperfusion (Treatment in Cerebral Ischemia (TICI) 2c-3) and first pass effect (FPE, defined as TICI 2c-3 in a single pass). Secondary outcomes were 3 month functional independence (modified Rankin Scale score of 0-2), mortality, procedural complications, embolic complications, and symptomatic intracranial hemorrhage (SICH). A meta-analysis was performed using RevMan 5,4, and heterogeneity was assessed using the I2 test. RESULTS: Of 1629 studies identified, five articles with 2091 patients were included. For the primary outcomes, FPE (44.9% vs 45.4%, OR 1.04 (95% CI 0.90 to 1.22), I2=57%) or final successful reperfusion (64.5% vs 68.6%, OR 0.98 (95% CI 0.81% to 1.20%), I2=85%) was similar between the combination technique and stent retriever only groups. However, the combination technique had significantly less rescue treatment (18.8% vs 26.9%; OR 0.70 (95% CI 0.54 to 0.91), I2=0%). This did not translate into significant differences in secondary outcomes in functional outcomes, mortality, emboli, complications, or SICH. CONCLUSION: There was no significant difference in successful reperfusion and FPE between the combined techniques and the stent retriever and BGC alone groups. Neither was there any difference in functional outcomes, complications, or mortality.

Internal cerebral vein asymmetry is an independent predictor of poor functional outcome in endovascular thrombectomy.

BACKGROUND: Endovascular thrombectomy (EVT) in large vessel occlusion (LVO) in anterior circulation acute ischaemic stroke (AIS) results in good functional outcomes in only approximately 60% of the patients. Internal cerebral veins (ICVs) are easily visible, with a consistent midline location, and are linked to stroke outcomes. We hypothesize that ICV asymmetry on multiphasic CT angiogram (mCTA) can be an adjunctive predictor for poor functional outcomes. METHODS: We studied consecutive AIS patients from 2017 to 2019 with anterior circulation LVO treated with EVT regardless of intravenous thrombolysis. Asymmetrical ICV was defined as the presence of hypodensity (less opacification) on the ipsilateral occlusion side as compared with the contralateral side. The primary outcome was modified Rankin Score (mRS) score at 3 months. Secondary outcomes were good recanalization (modified Thrombolysis In Cerebral Infarction (mTICI) 2b-3), symptomatic hemorrhage, and mortality. RESULTS: A total of 185 patients were included with a median age of 70 years (IQR 59-77); 87 patients (47%) were female. 82 patients (44.3%) achieved good functional outcomes (mRS 0-2) at 3 months. On multivariate analysis, National Institutes of Health Stroke Scale (NIHSS) (OR 1.076, 95% CI 1.015 to 1.140; p<0.013), poor collateral score (OR 0.285, 95% CI 0.162 to 0.501; p<0.001), asymmetrical ICV on the peak venous phase (OR 2.47, 95% CI 1.115 to 5.471; p<0.026), and late venous phase of the mCTA (OR 2.642, 95% CI 1.161 to 6.016; p<0.021) were independent risks factors of poor outcomes. CONCLUSION: ICV asymmetry is a novel radiological sign which is independently associated with poor functional outcomes in EVT, even after correction for collateral circulation. Further studies are needed to validate this finding.

Left ventricular systolic dysfunction is associated with poor functional outcomes after endovascular thrombectomy.

BACKGROUND: Endovascular thrombectomy (ET) has transformed acute ischemic stroke (AIS) therapy in patients with large vessel occlusion (LVO). Left ventricular systolic dysfunction (LVSD) decreases global cerebral blood flow and predisposes to hypoperfusion. We evaluated the relationship between LVSD, as measured by LV ejection fraction (LVEF), and clinical outcomes in patients with anterior cerebral circulation LVO who underwent ET. METHODS: This multicenter retrospective cohort study examined anterior circulation LVO AIS patients from six international stroke centers. LVSD was measured by assessment of the echocardiographic LVEF using Simpson's biplane method of discs according to international guidelines. LVSD was defined as LVEF <50%. The primary outcome was defined as a good functional outcome using a modified Rankin Scale (mRS) of 0-2 at 3 months. RESULTS: We included 440 AIS patients with LVO who underwent ET. On multivariate analyses, pre-existing diabetes mellitus (OR 2.05, 95% CI 1.24 to 3.39;p=0.005), unsuccessful reperfusion (Treatment in Cerebral Infarction (TICI) grade 0-2a) status (OR 4.21, 95% CI 2.04 to 8.66; p<0.001) and LVSD (OR 2.08, 95% CI 1.18 to 3.68; p=0.011) were independent predictors of poor functional outcomes at 3 months. On ordinal (shift) analyses, LVSD was associated with an unfavorable shift in the mRS outcomes (OR 2.32, 95% CI 1.52 to 3.53; p<0.001) after adjusting for age and ischemic heart disease. CONCLUSION: Anterior circulation LVO AIS patients with LVSD have poorer outcomes after ET, suggesting the need to consider cardiac factors for ET, the degree of monitoring and prognostication post-procedure.

Early Decompressive Hemicraniectomy for Malignant Middle Cerebral Artery Infarction in Asian Patients: A Single-Center Study.

INTRODUCTION: Early decompression craniectomy (within 48 hours of stroke onset) in acute and malignant middle cerebral artery (MCA) ischemic stroke (IS) reduces mortality and increases the proportion of patients with favorable functional outcome. Various cultural and social issues among Asians lead to some differences in clinical practice, especially when surgical interventions are involved. Accordingly, decompressive craniectomy in Asian patients with stroke is often delayed. MATERIALS AND METHODS: Data for all patients with acute IS hospitalized in our center were entered into a prospectively maintained registry. In this retrospective analysis, data for all patients with malignant MCA IS who underwent decompressive craniectomy were extracted. Various demographic, clinical, and neuroimaging factors were analyzed for identifying independent predictors of favorable functional outcome at 6 months, which was defined as modified Rankin Scale score of 0-3 points. RESULTS: From January 2005 to December 2014, a total of 75 patients with acute MCA IS underwent decompressive craniectomy. Median age was 55 years (interquartile range 44-64) with male preponderance (66%) and median National Institute of Health Stroke Scale score 21 points (interquartile range 18-24). A considerable proportion of these patients (38.7%) received intravenous thrombolysis. The majority (70%) of patients suffered right MCA IS, and decompressive surgery was performed within 48 hours of symptom onset in 50 (67%) of the patients. Favorable functional outcome was achieved in 25 (33.3%) patients at 6 months. Right MCA stroke (odds ratio 9.158; 95% confidence interval 1.881-44.596, P = 0.006) and early decompression surgery (odds ratio 4.011; 95% confidence interval 1.058-15.208, P = 0.041) were independent predictors of favorable functional outcome at 6 months. CONCLUSIONS: Early decompression craniectomy, especially in right MCA ischemic stroke, is associated with better favorable functional outcome.

Improvement in cerebral hemodynamic parameters and outcomes after superficial temporal artery-middle cerebral artery bypass in patients with severe stenoocclusive disease of the intracranial internal carotid or middle cerebral arteries.

OBJECT: Both the older and the recent extracranial-intracranial (EC-IC) bypass trials for symptomatic carotid occlusion failed to demonstrate a reduction in stroke recurrence. However, the role of superficial temporal artery (STA)-middle cerebral artery (MCA) bypass in patients with symptomatic intracranial stenoocclusive disease has been rarely evaluated. The authors evaluated serial changes in various cerebral hemodynamic parameters in patients with severe stenoocclusive disease of the intracranial internal carotid artery (ICA) or middle cerebral artery (MCA) and impaired cerebral vasodilatory reserve (CVR), treated by STA-MCA bypass surgery or medical treatment. METHODS: Patients with severe stenoocclusive disease of the intracranial ICA or MCA underwent transcranial Doppler (TCD) ultrasonography and CVR assessment using the breath-holding index (BHI). Patients with impaired BHI (< 0.69) were further evaluated with acetazolamide-challenge technitium-99m hexamethylpropyleneamine oxime ((99m)Tc HMPAO) SPECT. STA-MCA bypass surgery was offered to patients with impaired CVR on SPECT. All patients underwent TCD and SPECT at 4 ± 1 months and were followed up for cerebral ischemic events. RESULTS: A total of 112 patients were included. This total included 73 men, and the mean age of the entire study population was 56 years (range 23-78 years). (99m)Tc HMPAO SPECT demonstrated impaired CVR in 77 patients (69%). Of these 77 patients, 46 underwent STA-MCA bypass while 31 received best medical treatment. TCD and acetazolamide-challenge (99m)Tc HMPAO SPECT repeated at 4 ± 1 months showed significant improvement in the STA-MCA bypass group. During a mean follow-up of 34 months (range 18-39 months), only 6 (13%) of 46 patients in the bypass group developed cerebral ischemic events, as compared with 14 (45%) of 31 patients receiving medical therapy (absolute risk reduction 32%, p = 0.008). CONCLUSIONS: STA-MCA bypass surgery in carefully selected patients with symptomatic severe intracranial stenoocclusive disease of the intracranial ICA or MCA results in significant improvement in hemodynamic parameters and reduction in stroke recurrence.

Changes in cerebral hemodynamic and cognitive parameters after external carotid-internal carotid bypass surgery in patients with severe steno-occlusive disease: a pilot study.

BACKGROUND: The direct impact of external carotid-internal carotid (EC-IC) bypass surgery on cognition of patients with severe steno-occlusive disease of internal carotid (ICA) or middle cerebral artery (MCA) is unknown. In this pilot study, we evaluated changes in cerebral hemodynamic and cognition in these patients. METHODS: Patients with severe steno-occlusive disease and impaired cerebral vasodilatory reserve (CVR) with transcranial Doppler (TCD) breath holding index (BHI) and acetazolamide-challenged HMPAO-Single Photon Emission Tomographic (SPECT) imaging were offered EC-IC bypass surgery. CVR and cognitive performance using a formal neuropsychological battery were evaluated before and 3-6 months after surgery. RESULTS: Nine patients and 9 matched controls were recruited. Significant CVR improvement from TCD-BHI [median 0 (Inter-quartile range IQR 0.45) to 1.10 (IQR 0.73), p<0.001] and SPECT (p<0.001) was observed in surgery patients. EC-IC bypass patients had significant improvement in verbal memory (p=0.037) and executive function (p=0.043) and a trend of improvement in visual memory (p=0.052) compared to controls. CONCLUSION: EC-IC bypass surgery in carefully selected patients could improve cerebral hemodynamics and verbal memory and executive function.

Safety of transcranial Doppler 'bubble study' for identification of right to left shunts: an international multicentre study.

BACKGROUND AND PURPOSE: A recent retrospective study using an online list service established by the American Academy of Neurology has suggested that ischaemic cerebrovascular events may occur in patients who undergo 'bubble studies' (BS) with either transcranial Doppler (TCD) or transoesophageal echocardiography (TOE). The safety of TCD-BS for right to left shunt (RLS) identification was evaluated prospectively in an international multicentre study. METHODS: Consecutive patients with cerebral ischaemia (ischaemic stroke or transient ischaemic attack (TIA)) were screened for potential ischaemic cerebrovascular events following injection of microbubbles during TCD-BS for identification of RLS at three tertiary care stroke centres. TCD-BS was performed according to the standardised International Consensus Protocol. TOE-BS was performed in selected cases for confirmation of TCD-BS. RESULTS: 508 patients hospitalised with acute cerebral ischaemia (mean age 46±12 years, 59% men; 63% ischaemic stroke, 37% TIA) were investigated with TCD-BS within 1 week of ictus. RLS was identified in 151 cases (30%). TOE-BS was performed in 101 out of 151 patients with RLS identified on TCD-BS (67%). It was positive in 99 patients (98%). The rate of ischaemic cerebrovascular complications during or after TCD-BS was 0% (95% CI by the adjusted Wald METHOD: 0-0.6%). Structural cardiac abnormalities were identified in 38 patients, including atrial septal aneurysm (n=23), tetralogy of Fallot (n=1), intracardiac thrombus (n=2), ventricular septal defect (n=3) and atrial myxoma (n=1). CONCLUSION: TCD-BS is a safe screening test for identification of RLS, independent of the presence of cardiac structural abnormalities.