Extracranial-intracranial bypass surgery for occlusive atherosclerotic disease of the anterior cerebral circulation: protocol for a systematic review and meta-analysis

The clinical outcome of emergency superficial temporal artery-to-middle cerebral artery bypass in acute ischemic stroke with large vessel occlusion

The role of superficial temporal artery-to-middle cerebral artery (STA-MCA) bypass in acute ischemic stroke (AIS) is contentious, with no evidence in patients with AIS and large vessel occlusion (AIS-LVO). We conducted a cohort study to assess emergency STA-MCA outcomes in AIS-LVO and a meta-analysis to evaluate STA-MCA outcomes in early AIS treatment. From January 2018 to March 2021, we consecutively recruited newly diagnosed AIS-LVO patients, dividing them into STA-MCA and non-STA-MCA groups. To evaluate the neurological status and outcomes, we employed the National Institutes of Health Stroke Scale (NIHSS) during the acute phase and the modified Rankin Scale (mRS) during the follow-up period. Additionally, we conducted a meta-analysis encompassing all available clinical studies to assess the impact of STA-MCA on patients with AIS. In the cohort study (56 patients), we observed more significant neurological improvement in the STA-MCA group at two weeks (p = 0.030). However, there was no difference in the clinical outcomes between the two groups. Multivariable logistic regression identified the NIHSS at two weeks (OR: 0.840; 95% CI: 0.754-0.936, p = 0.002) as the most critical predictor of a good outcome. Our meta-analysis of seven studies indicated a 67% rate for achieving a good outcome (mRS < 3) at follow-up points (95% CI: 57%-77%, I2 = 44.1%). In summary, while the meta-analysis suggested the potential role of STA-MCA bypass in mild to moderate AIS, our single-center cohort study indicated that STA-MCA bypass does not seem to improve the prognosis of patients who suffer from AIS-LVO.

Internal Carotid Artery Occlusion: Management

PURPOSE OF REVIEW

Acute internal carotid artery occlusion (ICAO) is associated with high rates of morbidity and mortality, whereas chronic ICAO can present insidiously with recurrent strokes. In this review, we discuss the medical and surgical management approaches among patients with acute, subacute, and chronic ICAO.

RECENT FINDINGS

We reviewed the recent literature regarding clinical presentation of acute and chronic cases of ICAO, and discuss the current data, accepted guidelines, and prospects. Surgical, endovascular, or a combination (hybrid) revascularization has been shown to be effective in recanalization with improved functional outcomes in patients with ICAO in comparison to systemic thrombolysis or medical therapy alone. Future prospective or randomized clinical trials are warranted to elucidate the procedural superiority for revascularization of patients with ICAO.

Safety and efficacy of transcarotid artery revascularisation versus carotid endarterectomy: protocol for a systematic review and meta-analysis study

INTRODUCTION

In recent years, the transcarotid artery revascularisation (TCAR) with flow reversal technique has been developed to treat carotid artery stenosis. The superiority of TCAR over transfemoral carotid artery stenting has been demonstrated. However, the safety and efficacy of TCAR and carotid endarterectomy remain unclear. This study aims to introduce a protocol for a systematic review and meta-analysis to compare the morbidity and mortality rates between TCAR and carotid endarterectomy in the treatment of atherosclerotic carotid artery stenosis.

METHODS AND ANALYSIS

This protocol was drafted using the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols statement. Herein, major databases will be searched, including Medline, Web of Science, Embase and the Cochrane Library, and randomised controlled trials and high-quality observational studies will be included. We will screen all studies published from January 2000 to March 2021. Bias risk will be evaluated using the Cochrane Collaboration criteria or Methodological Index for Non-randomised Studies criteria, depending on the study type. Two reviewers will select eligible studies and extract the data independently. The primary outcome will include stroke or death during the perioperative period and follow-up. Subgroup and sensitivity analyses will be performed to explore any potential sources of heterogeneity. Specific results will be described in a narrative form when available eligible studies are insufficient for meta-analysis. Publication bias will be assessed using a funnel plot.

ETHICS AND DISSEMINATION

This study will summarise and analyse the existing literature; hence, ethics approval will not be required. The final results may be published at a relevant academic conference or in a journal.

PROSPERO REGISTRATION NUMBER

CRD42020178691.

Factors Influencing Recanalization After Mechanical Thrombectomy With First-Pass Effect for Acute Ischemic Stroke: A Systematic Review and Meta-Analysis

Background: First-pass effect (FPE) is increasingly recognized as a predictor of good outcome in large vessel occlusion (LVO). This systematic review and meta-analysis aimed to elucidate the factors influencing recanalization after mechanical thrombectomy (MT) with FPE in treating acute ischemic stroke (AIS).

Methods: Main databases were searched for relevant randomized controlled trials (RCTs) and observational studies reporting influencing factors of MT with FPE in AIS. Recanalization was assessed by the modified thrombolysis in cerebral ischemia (mTICI) score. Both successful (mTICI 2b-3) and complete recanalization (mTICI 2c-3) were observed. Risk of bias was assessed through different scales according to study design. The I² statistic was used to evaluate the heterogeneity, while subgroup analysis, meta-regression, and sensitivity analysis were performed to investigate the source of heterogeneity. Visual measurement of funnel plots was used to evaluate publication bias.

Results: A total of 17 studies and 6,186 patients were included. Among them, 2,068 patients achieved recanalization with FPE. The results of meta-analyses showed that age [mean deviation (MD):1.21,95% confidence interval (CI): 0.26–2.16; p = 0.012], female gender [odds ratio (OR):1.12,95% CI: 1.00–1.26; p = 0.046], diabetes mellitus (DM) (OR:1.17,95% CI: 1.01–1.35; p = 0.032), occlusion of internal carotid artery (ICA) (OR:0.71,95% CI: 0.52–0.97; p = 0.033), occlusion of M2 segment of middle cerebral artery (OR:1.36,95% CI: 1.05–1.77; p = 0.019), duration of intervention (MD: −27.85, 95% CI: −42.11–13.58; p < 0.001), time of onset to recanalization (MD: −34.63, 95% CI: −58.45–10.81; p = 0.004), general anesthesia (OR: 0.63,95% CI: 0.52–0.77; p < 0.001), and use of balloon guide catheter (BGC) (OR:1.60,95% CI: 1.17–2.18; p = 0.003) were significantly associated with successful recanalization with FPE. At the same time, age, female gender, duration of intervention, general anesthesia, use of BGC, and occlusion of ICA were associated with complete reperfusion with FPE, but M2 occlusion and DM were not.

Conclusion: Age, gender, occlusion site, anesthesia type, and use of BGC were influencing factors for both successful and complete recanalization after first-pass thrombectomy. Further studies with more comprehensive observations indexes are need in the future.

Mechanical Thrombectomy in Nonagenarians: a Systematic Review and Meta-analysis

This systematic review and meta-analysis aimed to summarize the current literature on mechanical thrombectomy (MT) in nonagenarians and to provide updated clinical evidence of its feasibility, effectiveness, and safety in nonagenarians. PubMed, EMBASE, the Cochrane Library, and Web of Science were searched for relevant randomized controlled trials and observational studies that reported the clinical outcomes of nonagenarians with acute ischemic stroke after undergoing mechanical thrombectomy. Risk of bias was assessed using different scales. I² statistic was used to evaluate the heterogeneity of the results, while meta-regression and sensitivity analyses were performed to investigate the source of heterogeneity. Thirteen studies and 657 patients were included. The estimated rate of successful revascularization was 80.82% (95% confidence interval [CI]: 77.48-83.97%), and the rate of favorable outcome (modified Rankin score [mRS] 0-2) was 21.60% (95% CI: 13.81-30.41%). The rate of good outcome (mRS score 0-3) was 23.08% (95% CI: 18.88-27.55%). The estimated risk of death during hospitalization was 20.55% (95% CI: 15.93-25.55%), while the mortality rate at 3 months was 44.38% (95% CI: 33.66-55.36%). The rate of intracranial hemorrhage (ICH) occurrence was 12.84% (95% CI: 5.27-22.68%), while the rate of symptomatic intracranial hemorrhage (sICH) was 3.52% (95% CI: 1.67-5.85%). The rate of hospital-related complications was 26.93% (95% CI: 10.53-47.03%). MT in nonagenarians demonstrated a high rate of successful revascularization. Conversely, the rate of futile revascularization is high with a low functional independence proportion. Therefore, MT should not be indiscriminately advocated in nonagenarians. Satisfactory results require careful selection of patients. Further high-quality studies are needed to clarify the selection algorithm.

Endovascular treatment versus standard medical treatment for acute basilar artery occlusion: protocol for a systematic review and meta-analysis

INTRODUCTION

Acute basilar artery occlusion (BAO) can cause posterior circulation stroke. There are two predominant therapies for BAO: standard medical treatment (SMT) and SMT plus endovascular thrombectomy (EVT). However, a conclusive systematic comparison of the safety and efficacy of SMT and those of SMT plus EVT for the treatment of BAO is lacking. Thus, a systematic review and meta-analysis is needed to evaluate the safety and efficacy of SMT and SMT plus EVT for the treatment of BAO.

METHODS AND ANALYSIS

This protocol is drafted referring to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses for Protocols guidelines. We will search eligible studies from four main databases including MEDLINE, Web of Science, Cochrane Library and Embase. Randomised controlled trials (RCTs) and observational studies published before 1 October 2020 will be included. Two reviewers in our team will conduct the study selection and data extraction independently. Risk of bias will be assessed by Cochrane Collaboration criteria and the Newcastle-Ottawa scale for RCTs and observational studies, respectively. We will assess the good functional outcomes defining the modified Rankin scale score ≤2 at 90 days after treatment, short-term stroke severity as National Institutes of Health Stroke Scale score at 24 hours after intervention, and successful recanalisation as a modified Thrombolysis in Cerebral Infarction scale score of ≥2b after intervention. Also, safety outcomes will be assessed. The performance of this meta-analysis will depend on the quantity of included studies. The assessment of study heterogeneity will be performed by the I² statistic. If there is mild heterogeneity (I²<20%) of intervention outcomes in included studies, the fixed-effect model will be applied; otherwise, the random-effect model will be performed. Subgroup analyses and an assessment of publication bias will also be conducted with sufficient data.

ETHICS AND DISSEMINATION

No collection of primary data from patients is needed. Therefore, the ethical approval is unnecessary. The results may be presented in a peer-reviewed journal and related conferences.

PROSPERO REGISTRATION NUMBER

CRD42020176764.

Influence of first-pass effect on recanalization outcomes in the era of mechanical thrombectomy: a systemic review and meta-analysis

PURPOSE

This systematic review and meta-analysis summarized the current literature to compare the safety and efficacy between first-pass effect (FPE) and multiple-pass effect (MPE) for thrombectomy in treatment of acute ischemic stroke (AIS).

METHODS

Major databases were searched for studies which reported clinical outcomes regarding successful or complete recanalization after first pass of mechanical thrombectomy in AIS. The assessment of bias was performed using different scales. I² statistic was used to evaluate heterogeneity between reviewers. Subgroup, meta-regression, and sensitivity analyses were conducted to explore the source of heterogeneity. Visualization of funnel plots was used to evaluate publication bias.

RESULTS

A total of 9 studies were eligible for final analysis. For successful recanalization (mTICI 2b-3), favorable outcomes were seen in 49.7% (95% confidence interval (CI): 40.5-58.9%) and 34.7% (95% CI: 26.8-42.7%) of FPE and MPE patients, respectively. Mortality at 3 months was 13.8% (95% CI: 10.8-16.9%) and 26.0% (95% CI: 17.7-34.2%), respectively. For complete recanalization (mTICI 2c-3), proportion of favorable outcomes were 62.7% (95% CI: 51.2-74.2%) and 47.7% (95% CI: 37.4-58.0%) in FPE and MPE; mortality was seen in 11.5% (95% CI: 4.9-18.2%) and 17.0% (95% CI: 5.2-28.7%), respectively. For AIS with successful recanalization, FPE had more favorable outcome (odds ratio (OR): 1.85, 95% CI: 1.48-2.30; p < 0.01; I² = 0%) and lower mortality than MPE (OR: 0.58, 95% CI: 0.42-0.79; p = 0.001; I² = 61.9%). Similar results were seen in a subgroup analysis of patients with complete recanalization, with FPE having better outcome (OR: 1.79, 95% CI: 1.40-2.28; p < 0.01; I² = 0%) and lower mortality risk (OR: 0.61, 95% CI: 0.44-0.86; p = 0.005; I² = 0%) compared to MPE.

CONCLUSION

FPE is associated with better outcomes than MPE after achieving successful or complete recanalization.

Clinical outcomes of radiation-induced carotid stenosis: A systematic review and meta-analysis

OBJECTIVES

Clinical outcomes of radiation-induced carotid stenosis are still unclear. Therefore, a systematic review and meta-analysis is needed to evaluate the short- and long-term outcomes after interventions to treat radiation-induced carotid stenosis.

METHODS

PubMed, EMBASE, the Cochrane Library and Web of Science were searched from 1 January 2000 for relevant RCTs and observational studies which reported outcomes after carotid endarterectomy (CEA) and carotid angioplasty and stenting (CAS) for carotid stenosis induced by radiation. Risk of bias were assessed through different scales according to study design. I² statistic were used to evaluate the heterogeneity, and meta-regression were performed to investigate the source of heterogeneity. Visual inspection of funnel plots was used to judge publication bias.

RESULTS

A total of 26 studies with 1002 patients were included. CEA was performed in 364 patients and CAS in 638 patients. The overall estimated rate of short-term stroke was 0.19% (95% CI: 0-0.90%), and the rate of long-term stroke was 2.68 % (95% CI: 1.19-4.57%). The rate of cranial nerve injury in CEA group was significantly higher than that in CAS group [risk ratio (RR): 6.03, 95% CI: 1.63-22.22, P = .007]. The univariate regression analysis showed that the risk of stroke in CAS group were significantly higher than CEA group in both short- and long-term [incidence rate ratio (IRR): 3.62, 95% CI: 1.21-10.85, P = 0.22; IRR: 2.95, 95% CI: 1.02-8.59, P = .046, respectively].

CONCLUSIONS

This systematic review provided the worldwide profile of outcome of treatment for radiation-induced carotid stenosis, and also found that CEA can yield better results for these patients than CAS. Nonetheless, as large-scale studies have not yet been conducted, and there is a definite need for further studies in the future.