Self-expanding versus balloon expandable stent for intracranial arterial stenosis: A systematic review and meta-analysis

BACKGROUND AND PURPOSE

There are limited data regarding the comparison of balloon expandable stents (BES) and self-expanding stents (SES) for the treatment of intracranial arterial stenosis.

METHODS

We conducted a systematic review to identify studies that compared SES and BES in patients with symptomatic intracranial arterial stenosis. Data were extracted from relevant studies found through a search of PubMed, Scopus, and Web of Science until from January 1, 2010 to September 28, 2023. Statistical pooling with random-effects meta-analysis was undertaken to compare the rates/severity of postprocedure stenosis, technical success, 30-day stroke and/or death, cumulative clinical endpoints, and restenosis rates.

RESULTS

A total of 20 studies were included. The standardized mean difference (SMD) for postprocedure stenosis (%) was significantly lower (SMD: -0.52, 95% confidence interval [CI]: -0.79 to -0.24, p < .001, 10 studies involving 1515 patients) with BES. The odds for 30-day stroke and/or death were significantly lower (odds ratio [OR] 0.68, 95% CI: 0.50-0.94, p = .019, 15 studies involving 2431 patients), and cumulative clinical endpoints on follow-up were nonsignificantly lower (OR 0.64, 95% CI: 0.30-1.37, p = .250, 10 studies involving 947 patients) with BES. The odds for restenosis during follow-up were significantly lower (OR 0.50, 95% CI: 0.31-0.80, p = .004, 13 studies involving 1115 patients) with BES.

CONCLUSIONS

Compared with SES, BES were associated with lower rates of postprocedure 30-day stroke and/or death with lower rates of restenosis during follow up and the treatment of symptomatic intracranial arterial stenosis.

Safety and efficacy of stenting for symptomatic intracranial artery stenosis: a systematic reveiw and meta-analysis

Background: Stroke is currently the second-leading cause of death just behind ischaemic heart disease. Drug therapy is currently the standard of care for patients with symptomatic intracranial artery stenosis (sICAS). Stenting is an important treatment for the prevention and treatment of ischemic stroke. It has been suggested that vertebral artery stenting might reduce this risk, but operation-related complications limit the application of stenting in the treatment of ischemic stroke. The differences in the safety and efficacy of stenting combined with drugs and drugs alone in the treatment of sICAS are unclear. The aim of this study was to assess the impact of both treatment modalities on the prognosis of patients with sICAS through a systematic review and meta-analysis. Methods: The Chinese databases (CNKI, Wanfang, VIP, CBM, DUXIU) and English databases (Pubmed, Embase, Ovid_medline, Cochrane library, Web of science)were searched to identify all studies describing sICAS. The "Risk of Bias Assessment" tool and the "Jadad Scale" provided by the Cochrane Collaboration were used to evaluate the risk of bias and quality of the collected literature. The risk ratio (RR) and its 95% confidence interval (CI) were determined using Stata statistical software version 14.0. Results: A total of 11 studies were included, comprising a total of 1,915 patients. The combined results of the study showed no significant difference between the incidence of transient cerebral ischemia (TIA)and stroke in patients with sICAS treated with drugs in combination with stents versus drugs alone. The incidence of death or stroke, cerebral haemorrhage, disabling stroke or death was significantly higher in patients receiving stent-combined drug therapy versus drug therapy alone for sICAS. Conclusion: Studies suggest that stenting combined with medication for patients with sICAS may increase the incidence of death or stroke, cerebral haemorrhage, stroke or death, but has no significant effect on the incidence of TIA and stroke. The studies report inadequate and conflicting data and therefore the safety and efficacy of stenting for sICAS should be interpreted with caution. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022377090, identifier CRD42022377090.

A non-linear relationship between lesion length and risk of recurrent cerebral ischemia after stenting for symptomatic intracranial stenosis with hemodynamic impairment

Background

Stent placement can be an effective treatment for patients with symptomatic intracranial stenosis (sICAS) and hemodynamic impairment (HI). However, the association between lesion length and the risk of recurrent cerebral ischemia (RCI) after stenting remains controversial. Exploring this association can help predict patients at higher risk for RCI and develop individualized follow-up schedules.

Method

In this study, we provided a post-hoc analysis of a prospective, multicenter registry study on stenting for sICAS with HI in China. Demographics, vascular risk factors, clinical variables, lesions, and procedure-specific variables were recorded. RCI includes ischemic stroke and transient ischemic attack (TIA), from month 1 after stenting to the end of the follow-up period. Smoothing curve fitting and segmented Cox regression analysis were used to analyze the threshold effect between lesion length and RCI in the overall group and subgroups of the stent type.

Results

The non-linear relationship between lesion length and RCI was observed in the overall population and subgroups; however, the non-linear relationship differed by subgroup of stent type. In the balloon-expandable stent (BES) subgroup, the risk of RCI increased 2.17-fold and 3.17-fold for each 1-mm increase in the lesion length when the lesion length was <7.70 mm and >9.00 mm, respectively. In the self-expanding stent (SES) subgroup, the risk of RCI increased 1.83-fold for each 1-mm increase in the lesion length when the length was <9.00 mm. Nevertheless, the risk of RCI did not increase with the length when the lesion length was >9.00mm.

Conclusion

A non-linear relationship exists between lesion length and RCI after stenting for sICAS with HI. The lesion length increases the overall risk of RCI for BES and for SES when the length was <9.00 mm, while no significant relationship was found when the length was >9.00 mm for SES.

Intracranial Stenting: Is It Still an Option for Treatment of Patients With Intracranial Atherosclerosis?

Intracranial atherosclerotic disease (ICAD) is considered a major cause of recurrent cerebrovascular events. ICAD continues to be a disease without an effective method of reducing the risk of recurrent stroke and death, even with aggressive, highly monitored medical treatment. We reviewed data from three randomized controlled studies that published data comparing intracranial stenting vs. medical treatment for symptomatic severe-ICAD. Ethnic, demographic, clinical, and procedural differences were observed among the data from these trials that might influence their results. Future research should aim at establishing refined selection criteria that can identify high-risk ICAD patients who may benefit from intracranial stenting.

Peri-procedural stroke or death in stenting of symptomatic severe intracranial stenosis

BACKGROUND AND PURPOSE

There are limited data on predictors of 30-day stroke or death in patients with symptomatic intracranial atherosclerosis (sICAS) undergoing stenting. We aim to determine the factors associated with stroke or death at 30 days in the stenting arm of the SAMMPRIS trial.

METHODS

This is a post-hoc analysis of the SAMMPRIS trial including patients who underwent angioplasty/stenting. We compared patient-specific variables, lesion-specific variables, procedure-specific variables, and FDA-approved indications between patients with and without the primary outcome (stroke or death at 30 days). Logistic regression analyses were performed to evaluate associations with the primary outcome.

RESULTS

We identified 213 patients, 30 of whom (14.1%) met the primary outcome. Smoking status and lesion length were associated with the primary outcome: the odds of stroke or death for non-smokers versus smokers (adjusted OR 4.46, 95% CI 1.79 to 11.1, p=0.001) and for increasing lesion length in millimeters (adjusted OR 1.20, 95% CI 1.02 to 1.39, p=0.029). These had a modest predictive value: absence of smoking history (sensitivity 66.7%, specificity 65.4%) and lesion length (area under curve 0.606). Furthermore, event rates were not significantly different between patients with and without the FDA-approved indication for stenting (15.9% vs 12%, p=0.437).

CONCLUSION

In SAMMPRIS patients who underwent angioplasty/stenting, neither clinical and neuroimaging variables nor the FDA indication for stenting reliably predicted the primary outcome. Further work in identifying reliable biomarkers of stroke/death in patients with sICAS is needed before considering new clinical trials of stenting.

TRIAL REGISTRATION NUMBER

SAMMPRIS NCT00576693; Results.

Lesion stability characteristics outperform degree of stenosis in predicting outcomes following stenting for symptomatic intracranial atherosclerosis

BACKGROUND

Intracranial atherosclerotic disease (ICAD) causes substantial morbidity and mortality. Treatment decisions have most commonly been driven by the degree of luminal stenosis. This study compares ICAD lesion stability features with percentage stenosis for associations with adverse outcomes following treatment with stents.

MATERIALS AND METHODS

Retrospective analysis was performed of prospectively maintained procedure logs. Lesions were classified by symptom type as hypoperfusion, non-hypoperfusion, or indeterminate, and pretreatment asymptomatic intervals were noted. Hypoperfusion lesions and indeterminate or non-hypoperfusion lesions with ≥14 days of asymptomatic interval were classified as stable. Percentage stenosis was calculated and compared against these other symptom features for value in predicting technical complication, ischemic stroke, disability, or death at 90 days and 2 years using univariate and multivariate analysis.

RESULTS

130 lesions were treated in 124 patients. The only statistically significant percent stenosis finding was lesions with 60-99% stenosis were less likely to have technical complications. In univariate analysis, stroke at 2 years was less common with hypoperfusion and stable lesions. In multivariate analysis, only hypoperfusion status was associated with lower stroke rates at 2 years.

CONCLUSIONS

Lesion stability features, particularly non-hypoperfusion symptomatology, outperform percentage stenosis in predicting outcomes following treatment of ICAD with stents. Further examination is needed to better classify the natural history of ICAD and more precisely classify lesion stability.

Diabetes mellitus does not increase the risk of adverse long-term outcomes after intracranial stent placement

The present study is to investigate whether diabetes mellitus (DM) increases risk of adverse long-term outcomes after intracranial stent placement. Patients receiving intracranial stenting were assigned to DM group and non-DM group according to diabetes status. The long-term follow-up endpoint was composite of any stroke and death within 30 days, any ischemic stroke beyond 30 days, and transient ischemic attack in the territory of the stented artery at any time. A total of 44 stenoses in 43 patients were retrospectively analyzed. The cumulative probability of the composite outcomes were 15.4% (95% CI 15.3-47.3%) at 1 year and 30.8% (95% CI 26.5-33.6%) at 2 years for DM group; 17.5% (95% CI 16.0-31.2%) at both 1 year and 2 years for non-DM group (log-rank test, P = 0.424). After adjusting for the confounders, the risk of DM versus non-DM for composite outcomes remained insignificant (hazard ratio: 2.84, 95% CI 0.46-17.66; P = 0.26). Our results showed that there is no significant difference between patients with DM and without DM in cumulative probability of the composite outcomes. It suggests that based on our data, there is no evidence that DM increases the risk of adverse long-term outcomes after intracranial stent placement.

Reviving Intracranial Angioplasty and Stenting "SAMMPRIS and beyond"

We review the methods and results of Stenting and Aggressive Medical Management for Preventing Recurrent Stroke (SAMMPRIS) and provide a critical review of its strengths and limitations. In SAMMPRIS, the aggressive medical treatment arm (AMT arm) did substantially better than the Wingspan Stenting plus aggressive medical management arm (WS+ arm). Complications in the first 30 days post intervention led to the disparity between treatment arms. A major contribution of SAMMPRIS was the added value that AMT and lifestyle change may provide, when compared to a precursor trial, Warfarin–Aspirin Symptomatic Intracranial Disease (WASID), designed to prevent stroke in persons with high-grade symptomatic intracranial occlusive disease, however, the results of neither of these two trials have ever been reproduced. On the other hand, we argue that technical limitations of the Wingspan stent system (WS System) and lack of an angioplasty only intervention arm may have led to a premature launch of the trial and early termination of the study. Future randomized trials with different devices and modified patient selection criteria are warranted.

The case for angioplasty in patients with symptomatic intracranial atherosclerosis

Intracranial atherosclerotic disease (ICAD) is likely the most common cause of stroke worldwide and remains highly morbid even with highly monitored medical therapy. Recent results of the SAMMPRIS trial, which randomized patients to stenting plus aggressive medical management versus aggressive medical management alone have shown that additional treatment of intracranial atherosclerotic lesions with the Wingspan stent is inferior to aggressive medical management alone. In light of these results, there has been renewed interest in angioplasty alone to treat symptomatic ICAD. This article will briefly review the natural history of ICAD and discuss the possible future for endovascular treatment of ICAD with primary intracranial angioplasty in appropriately selected patients.

Off-label use of drugs and devices in the neuroendovascular suite

SUMMARY

The off-label use of drugs and devices in neuroendovascular procedures is common. Neurointerventionalists should be well aware of the level of evidence available in support of the off-label use of drugs and devices in their practice and some of the potential adverse events associated with them. These uses are categorized as I or II if they have been evaluated as primary or ancillary interventions in prospective trials/registries of neuroendovascular procedures and III if they were evaluated in case series. Category IV use is based on evaluation as primary or ancillary interventions in prospective trials/registries of non-neuroendovascular procedures. Physicians are allowed to use off-label drugs and procedures if there is strong evidence that they are beneficial for the patient. The neurointerventional professional societies agree that off-label use of drugs and devices is an important part of the specialty, but practicing providers should base their decisions on sound evidence when using such drugs and devices.

Is there a future for endovascular treatment of intracranial atherosclerotic disease after Stenting and Aggressive Medical Management for Preventing Recurrent Stroke and Intracranial Stenosis (SAMMPRIS)?

The Stenting and Aggressive Medical Management for Preventing Recurrent Stroke and Intracranial Stenosis (SAMMPRIS) trial, a randomized clinical trial comparing aggressive medical management to stenting with aggressive medical management for symptomatic intracranial stenosis, was prematurely halted when a high rate of periprocedural events was found in the stent arm. The trial also demonstrated a high rate of stroke with medical management. This article explores possible reasons for these outcomes and discusses some weaknesses of the trial. Against this background endovascular therapy should continue to be explored in the treatment of this disease.