Outcomes after stenting for symptomatic intracranial arterial stenosis: a systematic review and meta-analysis

Clinical evidence in ischemic stroke: Where we have gone so far and hopes for the future

OBJECTIVE

Ischemic stroke is a significant cause of disability and death worldwide. Randomized clinical trials (RCTs) are important in changing guidelines and treatment strategies. This study aimed to analyze the progress of RCTs in ischemic stroke and to guide future research directions.

METHODS

Ischemic stroke-related RCT articles were identified in six high-impact medical journals using the Web of Science Core Collection database. Google Scholar was used to check whether relevant articles were included in the guidelines. The characteristics of these articles were analyzed and future research hotspots were predicted.

RESULTS

389 relevant articles were included in the analysis. The number of articles increased rapidly from 1972 to 2022, from 5 (1.3%; 1972-1982) to 208 (53.5%; 2013-2022) articles. 338 (86.9%) articles were included in relevant guidelines. According to corresponding author location, Europe was the source of the highest number of publications (183; 47.0%), followed by the Americas (152; 39.1%) and the Western Pacific (54; 13.9%). The number of publications steadily increased over time in the USA, England, Canada, Australia, Germany, and France, and surged in China and Spain, especially in the last 5 years. In recent years, endovascular therapy has accounted for the majority of ischemic stroke-related RCT articles.

CONCLUSIONS

Numerous RCTs related to ischemic stroke have been conducted in recent decades, and both the number of articles and their contribution to guideline updates are increasing. Also, a shift in research topics was observed. However, great regional imbalances in this research exist, calling for more research to be conducted in specific regions to promote the generalizability of trial conclusions.

Long-term outcome and factors associated with restenosis after combination therapy of balloon angioplasty and stenting for symptomatic intracranial stenosis

BACKGROUND

The optimal treatment for intracranial artery stenosis (ICAS) has not been established. We retrospectively examined the initial and long-term outcomes associated with restenosis of a combination therapy of balloon angioplasty and stenting for symptomatic atherosclerotic ICAS.

METHODS

Consecutive patients who underwent balloon angioplasty and/or stenting for ≥ 70% ICAS between 2006 and 2020 were analyzed. Patients within 48 h of stroke onset were excluded. The following procedures were established as standards at our institution: (1) primary balloon angioplasty alone was initially performed; (2) stenting for insufficient dilatation, recoiling, or dissection was conducted; and (3) stenting was considered for restenosis. Intracranial ischemic and hemorrhagic complications within 30 days after treatment were used to evaluate periprocedural safety. Recurrent ischemic events, restenosis and restenosis related factors were used to be evaluate the long-term outcome.

RESULTS

A total of 160 patients were recruited. Initial treatment consisted of balloon angioplasty (n = 101) and stenting (n = 59). Intracranial complications within 30 days after treatment were ischemic in five (3.1%) and hemorrhagic in four patients (2.5%). The incidence of these complication was 3.1% in the stenting group and 2.5% in the balloon angioplasty group. The mean follow-up period was 53.9 months. Restenosis was found in 42 patients (26%). Recurrent ischemic events during follow-up were noted in 14 patients (8.8%), of which six patients had TIA and eight patients had ischemic stroke. Restenosis-associated factors included diabetes, coronary artery disease, percent stenosis after treatment, and balloon angioplasty in logistic univariate analysis. Multivariate Cox regression analysis showed that diabetes (HR: 2.084, CI: 1.039-4.180, p = 0.0386), length of lesion (HR; 1.358, CI: 1.174-1.571, p < 0.0001), and balloon angioplasty (HR: 4.194, CI: 1.083-16.239, p = 0.0379) were independent predictors for restenosis.

CONCLUSION

Combination therapy of balloon angioplasty and stenting for symptomatic ICAS had a low perioperative stroke rate and may improve long-term outcome. Balloon angioplasty, diabetes, and length of lesion were significantly associated with restenosis.

Balloon Angioplasty vs. Stenting for Symptomatic Intracranial Arterial Stenosis

Aims

We performed a meta-analysis to indirectly compare the treatment effectiveness of balloon angioplasty and stenting for patients with intracranial arterial stenosis.

Methods

Literature searches were performed in well-known databases to identify eligible studies published before January 04, 2021. The incidence of restenosis, transient ischemic attack (TIA), stroke, death, and dissection after balloon angioplasty or stenting were pooled. An indirect comparison of balloon angioplasty vs. stenting was performed, and the ratios of incidence (RIs) with 95% confidence intervals (CIs) were calculated using the random-effects model.

Results

120 studies that recruited 10,107 patients with intracranial arterial stenosis were included. The pooled incidence of restenosis after balloon angioplasty and stenting were 13% (95%CI: 8-17%) and 11% (95%CI: 9-13%), respectively, with no significant difference between them (RI: 1.18; 95%CI: 0.78–1.80; P = 0.435). Moreover, the pooled incidence of TIA after balloon angioplasty and stenting was 3% (95%CI: 0–6%) and 4% (95%CI: 3%-5%), and no significant difference was observed (RI: 0.75; 95%CI: 0.01–58.53; P = 0.897). The pooled incidence of stroke after balloon angioplasty and stenting was 7% (95%CI: 5–9%) and 8% (95%CI: 7–9%), respectively, and the difference between groups was found to be statistically insignificant (RI: 0.88; 95%CI: 0.64–1.20; P = 0.413). Additionally, the pooled incidence of death after balloon angioplasty and stenting was 2% (95%CI: 1–4%) and 2% (95%CI: 1–2%), with no significant difference between groups (RI: 1.00; 95%CI: 0.44–2.27; P = 1.000). Finally, the pooled incidence of dissection after balloon angioplasty and stenting was 13% (95%CI: 5–22%) and 3% (95%CI: 2–5%), respectively, and balloon angioplasty was associated with a higher risk of dissection than that with stenting for patients with intracranial arterial stenosis (RI: 4.33; 95%CI: 1.81–10.35; P = 0.001).

Conclusion

This study found that the treatment effectiveness of balloon angioplasty and stenting were similar for patients with symptomatic intracranial arterial stenosis.

Long-term clinical and angiographic outcome from angioplasty and stenting for intracranial stenosis

BACKGROUND

Severe intracranial atherosclerotic stenosis (ICAS) is a major cause of stroke. Although percutaneous transluminal angioplasty and stenting (PTAS) treatment methods have increased over the last decade as alternative therapies, there is debate regarding the best method of treatment, with medical and surgical therapies often suggested.

METHODS

We analyzed the long-term follow-up results from 5 years of intracranial stenting for intracranial stenosis from three stroke centers. The primary endpoints were early stroke complications or death within 30 days after stent insertion, and the secondary endpoint was a recurrent stroke between 30 days and 60 months. Correlating factors and Kaplan-Meier survival curves for recurrent stroke and in-stent restenosis (ISR) were also obtained.

RESULTS

Seventy-three PTAS in 71 patients were examined in this study. The primary and secondary endpoints were all 8.2% (n = 6), and restenosis was 13.7% (n = 10) during the 5-year follow-up. The primary endpoints were significantly frequent in the high National Institutes of Health Stroke Scale (NIHSS) and early stent (≤ 7 days after dual antiplatelet medication) groups. Secondary endpoint and ISR were identically frequent in the younger age group and in the presence of tandem stenosis in other major intracranial arteries. The cumulative probability of recurrent stroke and ISR at 60 months was 16.4% and 14.1%, respectively.

CONCLUSIONS

This study shows that PTAS is safe and effective for major ICAS. Reducing the early complication rate is still an important factor, despite the fact that long-term stroke recurrence was low.

Intracranial Angioplasty with Enterprise Stent for Intracranial Atherosclerotic Stenosis: A Single-Center Experience and a Systematic Review

Background

The high rate of periprocedural complications for the endovascular stent procedure in the Stenting Versus Aggressive Medical Management Therapy for Intracranial Arterial Stenosis (SAMMPRIS) trial resulted in it being less recommended than medical therapy to treat intracranial atherosclerotic stenosis (ICAS). Because Enterprise stent use might reduce the incidence of complications in ICAS treatment compared to other frequently used stents, this paper evaluated the safety and effectiveness of the Enterprise stent for the treatment of ICAS.

Methods

We performed a comprehensive literature search for reports on intracranial angioplasty using the Enterprise stent for ICAS treatment from the earliest date available from each database to May 2020 for PubMed, EMBASE, Web of Science, Cochrane, and Clinical Trials databases. We also reviewed the single-center experience of the First Affiliated Hospital of Harbin Medical University. We extracted information regarding periprocedural complications, procedure-related morbidity, mortality, immediate angiographic outcome, and long-term clinical and angiographic outcomes, among others. Event rates were pooled across studies using random-effects or fixed-effects models depending on the heterogeneity.

Results

Five hundred fifty-seven patients with 588 lesions from seven studies, including the institutional series, were included in the analysis. The incidence of stroke or death within 30 days was 7.4% (95% confidence interval (CI), 5.5%-10.1%). The incidence of ischemic stroke or TIA in the territory of the qualifying artery beyond 30 days and during follow-up was 3.2% (95% CI, 1.1%-9.5%). The incidence of in-stent restenosis was 10.1% (95% CI, 4.6%-22.2%), and the incidence of symptomatic restenosis was 4.1% (95% CI, 1.7%-9.9%).

Conclusions

Intracranial angioplasty utilizing the Enterprise stent for ICAS treatment was relatively safe and effective but required further verification using additional sources for evidence.

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

BACKGROUND

Occlusive atherosclerotic disease of the anterior cerebral circulation is one of the most common causes of anterior circulation ischemia and stroke. Treatment options include medical therapies (including antiplatelet use, blood pressure control, lipid reduction, and lifestyle modification) and extracranial-intracranial bypass surgery (such as superficial temporal artery-middle cerebral artery bypass). However, the optimal treatment remains unclear. The objective of this study will be to compare the efficacy of and extracranial-intracranial bypass surgery with that of other medical therapy in adult patients with occlusive atherosclerotic disease of the anterior cerebral circulation.

METHODS

This is the study protocol for a systematic review. We will search MEDLINE, EMBASE, Web of Science, and the Cochrane Library (from January 1980 onwards). We will include randomized controlled trials, quasi-experimental studies (non-randomized, interrupted time series), and observational studies (e.g., cohort studies and case-control studies), examining the efficacy of extracranial-intracranial bypass surgery compared to other treatments for adult patients with occlusive atherosclerotic disease of anterior cerebral circulation. Two team members will independently screen all citations, full-text articles, and abstract data. Potential conflicts will be resolved through discussion. The primary outcome will include stroke or death. The secondary outcomes will include intracranial hemorrhage, transient ischemic attack, and myocardial infarction. The study methodological quality (or bias) will be appraised using appropriate tools. If feasible, we will conduct random effects meta-analysis. Additional analyses will be conducted to explore the potential sources of heterogeneity (e.g., study design, geographical location, or risk of bias).

DISCUSSION

This review will evaluate the evidence on the efficacy of extracranial-intracranial bypass surgery for adult patients with occlusive atherosclerotic disease of the anterior cerebral circulation. We anticipate that our findings will be of interest to patients, their families, caregivers, healthcare professionals, and in making optimal treatment selection. Implications for future clinical and epidemiological research will be discussed.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42018105513.