The pathophysiological mechanism of cerebral ischemia/reperfusion injury (CIRI) is complex, and the current treatment methods are limited and the efficacy is not good. Previous therapeutic strategies of CIRI mostly target neurons, but no significant progress has been made. At present, astrocytes are expected to be promising effector cells for the treatment of CIRI. Astrocytes are a "double-edged sword" in the pathological process of CIRI, with both neurotoxic and neuroprotective effects on the central nervous system. How to effectively use astrocytes to treat CIRI has become a research hotspot. In this review, the dual roles of astrocytes in CIRI mechanism were reviewed, and the related mechanisms of astrocytes in relieving oxidative stress induced by CIRI were emphasized, in order to provide new ideas for the treatment of CIRI.

Objective:Based on single-center clinical results of endovascular recanalization for symptomatic non-acute internal carotid artery occlusion (ICAO), a new patient classification method is proposed to distinguish the most suitable ICAO patient subgroups for endovascular recanalization.Methods:A total of 140 patients with symptomatic non-acute ICAO accepted endovascular recanalization in Department of Cerebrovascular Intervention, He'nan Provincial People's Hospital from January 2019 to December 2021 were selected. These patients were divided into low risk group ( n=57), medium risk group ( n=54) and high risk group ( n=29) according to the occlusion segments, occlusion times, plaque features, calcification at the occlusion site and occlusion segment angulation. The immediate postoperative recanalization rate, perioperative complications, perioperative death, and prognoses 90 d after endovascular recanalization (modified Rankin scale scores of 0-2 as good prognosis) were evaluated in the 3 groups. Results:The immediate postoperative recanalization rate was 82.9% (114/140), perioperative complication rate was 11.4% (16/140), and perioperative mortality was 0.7% (1/140). The success recanalization rate decreased gradually from the low risk group to the high risk group (100%, 85.2%, and 37.9%), while the perioperative complication rate was the opposite (0%, 11.1%, and 34.5%), with significant differences ( P<0.05). Ninety d after endovascular recanalization, 109 patients had good prognosis and 27 had poor prognosis; the good prognosis rate in low risk group, medium risk group and high risk group was 98.2%, 79.6% and 34.5%, respectively, with significant differences ( P<0.05). The vascular restenosis rate in low risk group, medium risk group and high risk group was 0%, 8.7% and 18.2%, and re-occlusion rate was 0%, 6.5% and 27.2%, respectively, 90 d after endovascular recanalization, with significant differences ( P<0.05). Conclusion:Endovascular recanalization is technically feasible for patients with symptomatic non-acute ICAO, especially those met the criterions of low and medium risk groups in our study.

Cerebral ischemia/reperfusion (I/R) injury refers to an aggravated brain tissue damage caused by the restoration of blood supply after acute ischemia for a period of time. Its pathogenesis is complex, including oxidative stress, inflammatory response, and excitatory amino acid toxicity. The effective clinical treatments of cerebral I/R injury after ischemic stroke (IS) are limited. Nuclear factor E 2-related factor 2 (Nrf2), the most critical antioxidant transcription factor in cells, can coordinate multiple cytoprotective factors to inhibit oxidative stress. Since Nrf2 signaling pathway is considered to be one of the most important cellular defense mechanisms against oxidative stress, targeting Nrf2 intervention has become an attractive therapeutic strategy in the prevention and treatment of cerebral I/R injury. This review focuses on the structure, regulation and function of Nrf2 signaling pathway, as well as its activation and potential therapeutic targets in cerebral I/R injury. The important role and future potential of Nrf2 pathway in the pathogenesis of cerebral I/R injury were discussed.

Objective:To investigate the safety and effectiveness of Willis covered stent in patients having carotid artery rupture during transnasal endoscopic pituitary tumor resection.Methods:A retrospective analysis was performed. Six patients having carotid artery rupture during transnasal endoscopic pituitary tumor resection admitted to the 3 hospitals from May 2016 to December 2019 were chosen; their clinical data were collected. The surgical processes and complications were concluded, and the prognoses were evaluated by modified Rankin scale (mRS).Results:One patient was treated with intraoperative simple tamponade compression for hemostasis, and died for massive intracranial hemorrhage 2 weeks after surgery. Five patients were occluded by Willis covered stents; the occluded success rate was 100% but ophthalmic arteries were blocked in all. During the perioperative period, diabetes insipidus occurred in one patient and incomplete oculomotor paralysis occurred in one patient; 5 patients were followed up for 3-12 months: MRI indicated subtotal resection of tumor in 4 patients and total resection in one patient, no new bleeding or ischemic stroke events occurred in these 5 patients, and the prognosis was good.Conclusion:Willis covered stent is safe and effective in patients having carotid artery rupture during transnasal endoscopic pituitary tumor resection.

Objective:To investigate the effect of thrombus burden on the clinical outcome of endovascular recanalization in large vessel occlusive stroke.Methods:Patients with acute anterior circulation occlusion who underwent endovascular treatment within 24 hours after onset in Zhengzhou University People′s Hospital from January 2018 to December 2019 were retrospectively collected. According to the clot burden score (CBS) of DSA, total objectives were divided into CBS≥6 group (24 cases) and CBS<6 group (38 cases). Clinical data of the two groups were collected and the modified Rankin scale (mRS) was used to evaluate the clinical outcome at 90 days after surgery. Independent sample t-test, Wilcoxon rank sum test and χ 2 test were used to compare the clinical data between the two groups. Independent risk factors affecting the clinical outcome were analyzed by binary logistic regression. Results:There were no statistically significant differences in basic demographic data, stroke risk factors and other factors between the CBS≥6 group and CBS<6 group ( P>0.05).The proportion of using tirofiban after surgery in the CBS≥6 group (63.2%, 24/38) was lower than that in the CBS<6 group (87.5%, 21/24) (χ2=4.380, P=0.044). The discharge NIHSS score of the CBS≥6 group was [5.0 (3.3, 7.8) points] lower than CBS<6 group [8.5 (1.8, 14.5) points] ( Z=5.221, P=0.022). The proportion of postoperative mRS 0-2 was (91.7%, 22/24) in the CBS≥6 group higher than CBS<6 group(39.5%, 15/38) (χ2=20.486, P=0.001), there were no statistically significant differences between the two groups ( P<0.05). The results of binary logistics regression analysis showed the CBS groups (OR=0.042, 95%CI 0.007-0.244 , P=0.001) was an independent risk factor affecting good outcome. Subgroup analysis of whether tirofiban was used or not showed there was no statistically significant difference in clinical prognosis between the two groups ( P>0.05). Conclusions:The clinical outcome of CBS≥6 group is significantly better than that of CBS<6 group, and patients with small thrombus burden are more likely to get a good clinical outcome of 90 days.

Objective:To explore the predictive ability of apparent diffusion coefficient (ADC) value in magnetic resonance imaging (MRI) mapping sequences in outcomes of brain tissues in patients with acute ischemic stroke (AIS) who had successful recanalization after endovascular treatment.Methods:A total of 45 patients with AIS who received endovascular treatment and successful recanalization in our hospital from January 2019 to December 2019 were selected. Post-processing software was used to analyze the images of these patients by MRI before surgery and one week after surgery, and the differences of ADC value in the core area of cerebral infarction, lesion reversal area and increased cerebral infarction area displayed by diffusion weighted imaging (DWI) before surgery were measured and compared. Receiver operating characteristic (ROC) curve was used to analyze the predictive ability of preoperative ADC value in the reversal of lesions showed by DWI.Results:Lesion reversal area and increased cerebral infarction area indicated by preoperative DWI existed in all patients after successful recanalization. The preoperative ADC values of the infarct core, lesion reversal area and increased cerebral infarction area were 0.555×10 -3 mm 2/s (0.462, 0.648), 0.637×10 -3 mm 2/s (0.509, 0.765) and 0.948×10 -3 mm 2/s (0.905, 0.991), respectively, with significant differences ( P<0.05). The optimal cut-off point to predict DWI lesion reversal after successful recanalization was 0.57×10 -3mm 2/s, and the accuracy was 87.1% (area under curve=0.871; 95%CI: 0.868-0.875, P=0.000), with sensitivity of 97.2% and specificity of 68.3%. Conclusion:In patients with AIS after successful recanalization, the preoperative ADC values are obviously different in brain tissues with different outcomes, which can be used to predict the final imaging outcomes of the brain tissues.

Objective:To investigate the morphological and hemodynamic stress characteristics of infundibular dilatation of the posterior communicating artery.Methods:From January 2018 to May 2020, 30 patients with infundibular dilatation of the posterior communicating artery (observation group) found by digital substraction angiography (DSA) for suspecting as having equivocal posterior communicating artery aneurysm in our hospital were selected. The angle between posterior communicating artery and internal carotid artery, and hemodynamics stress parameters at the infundibular dilatation of the posterior communicating artery (total pressure and shear force) were measured by DSA and quantitatively analyzed by computational fluid dynamics methods. Thirty patients without intracranial aneurysm and with normal posterior communicating arteries admitted to our hospital at the same period were used as control group.Results:The mean value of the bending angle between the posterior communicating artery and internal carotid artery in the control group was ([80.1±8.4]°), which was significantly higher than that in the observation group ([73.2±5.8]°, P<0.05). The shear force and total pressure of infundibular dilatation of the posterior communicating artery of the observation group ([8.32±0.70] Pa and [85.61±6.04] Pa), which were significantly higher than those of the control group at the same locations ([3.95±0.28] Pa and [25.72±7.18] Pa, P<0.05). Conclusion:There are significant differences in hemodynamic stress between the normal posterior communicating artery and the infundibular dilatation of the posterior communicating artery, which might play an important role in triggering the formation of aneurysms.

Objective:To investigate the efficacy and safety of endovascular recanalization treatment for acute vertebral basilar artery occlusion (AVBAO) underlying intracranial atherosclerotic disease (ICAD) using a balloon-mounted stent.Methods:A total of 16 cases of consecutive AVBAO patients who underwent endovascular treatment with the balloon-mounted stent within 24 h after onset were retrospectively enrolled in Henan Provincial People′s Hospital from February 2017 to August 2019. And the recanalization rate, operation-related complications, symptomatic intracranial hemorrhage, the improvement of 1 week National Institutes of Health Stroke Scale (NIHSS) score and 3 months modified Rankin Scale (mRS) after treatment were recorded.Results:In all of the 16 patients, 4 patients underwent direct stenting angioplasty, 12 patients received salvage stenting. Stent placement was successful in all 16 patients. Balloon-mounted stent were implanted in basilar artery of 4 cases, in intracranial segment of vertebral artery of 8 cases, and in origination segment of vertebral artery of 4 cases. Recanalization was successful (thrombolysis in cerebral infarction grade 2b and 3) in 15 patients. The time between arterial puncture and recanalization was 79.0 (72.3, 109.3) min. One patient experienced distal thrombosis during surgery. Two patients suffered symptomatic intracranial hemorrhage within 48 h after surgery. The scores of the NIHSS were improved more than 4 points at 1 week after operation in 8 patients. At 3 months follow-up, 9 patients had a good outcome (mRS 0-3 points) and 4 patients died.Conclusion:Selective stenting angioplasty treatment with a balloon-mounted stent seems to be feasible and safe for AVBAO patients underlying ICAD.

Objective:To investigate the safety and efficacy of endovascular treatment in acute anterior circulation massive cerebral infarction and its prognostic factors.Methods:A retrospective analysis was performed on clinical data of 34 patients with acute anterior circulatory massive cerebral infarction who received intravascular treatment in our hospital from February 2018 to December 2019. The perioperative hemorrhage rate and mortality rate were analyzed in these patients. Modified Rankin scale (mRS) scores were taken as the evaluation standard in the prognoses of these patients during the 90 d of follow up, and the influencing factors affecting the prognoses of patients with massive cerebral infarction were analyzed.Results:The operation was successful in 30 patients (88.2%); the operation time was (97.41±54.58) min, and the number of thrombolysis was (1.91±0.75) times. Distal embolization occurred in 4 patients (11.8%); there were 3 patients with non-symptomatic hemorrhage (8.8%) and 3 patients with symptomatic hemorrhage (8.8%). Cerebral hernia occurred in 7 patients (20.6%); there were 5 deaths (14.4%). During the 90 d of follow up, 13 patients (38.2%) had good prognosis, and 21 (61.8%) had poor prognosis; there were statistically significant differences in NIHSS scores at admission, infarction locations in diffusion weighted imaging, vascular occlusion locations in DSA, pecentages of patients accepted preoperative intravenous thrombolysis and patients with cerebral hernia between the two groups ( P<0.05). NIHSS scores at admission ( OR=0.817, 95% CI: 0.682-0.980, P=0.029), thrombus load scale scores ( OR=5.981, 95%CI: 1.827-19.575, P=0.003), vascular occlusion locations in DSA ( OR=0.031, 95% CI: 0.003-0.311, P=0.003) and pecentage of patients accepted preoperative intravenous thrombolysis ( OR=0.092, 95% CI: 0.010-0.838, P=0.034) were independent factors influencing the prognoses of emergency intravascular treatment. Conclusions:Endovascular recanalization can achieve a relatively good prognosis in patients with massive cerebral infarction. Patients with low NIHSS scores, high thrombotic load scale scores, and middle cerebral artery occlusion, and patients accepted direct intravascular treatment have relatively good prognosis.

Objective To evaluate the efficacy and safety of intracranial stenting as a rescue therapy for acute anterior large vessel occlusive stroke after stentriever thrombectomy failure.Methods A total of 60 patients with acute anterior large vessel occlusive stroke failed to stent retriever thrombectomy in our hospital from January 2014 to December 2017 were chosen in our study.Among the 60 patients with stent retrieval failure,43 patients received stent placement as rescue therapy (stenting rescue group),and 17 patients received other methods as rescue therapy (non-stenting rescue group).Modified thrombolysis in cerebral infarction grading was applied to evaluate vascular re-canalization immediately after operation;modified Rankin scale (mRS) was applied to determine the prognoses of the patients 90 d after operation;the occurrences of symptomatic intracranial hemorrhage and stent re-stenosis within 6 months after operation were recorded in the two groups.Results As compared with those in the non-stenting rescue group,the rate of immediate postoperative vascular re-canalization and favorable prognosis rate in the stenting rescue group (35.29％ vs.81.40％ and 23.53％ vs.53.49％)were statistically higher (P＜0.05).There were no statistically significant differences in proportions of symptomatic intracranial hemorrhage and death between the stenting rescue group and non-stenting rescue group (11.76％ vs.13.95％;29.41％ vs.23.26％,P＞0.05).DSA follow-up showed that 4 patients in the stenting rescue group had stent re-stenosis,but all of them were asymptomatic.Conclusions Intracranial stenting as a rescue therapy for acute anterior large vessel occlusive stroke after failure of retrieval stent is feasible and safe.