Undersized angioplasty and stenting of symptomatic intracranial tight stenosis with Enterprise: Evaluation of clinical and vascular outcome

Enterprise stents for the treatment of symptomatic non-acute intracranial artery stenosis disease: safety and efficiency evaluation

BACKGROUND

Enterprise stent was approved for the treatment of wide-necked intracranial aneurysms. However, it has been widely used in the endovascular treatment of intracranial artery stenosis, which is still controversial. The purpose of this study was to evaluate the safety and efficiency of the Enterprise stent in the endovascular treatment of intracranial artery stenosis disease.

METHODS

We conducted a retrospective case series of 107 patients with intracranial artery stenosis who received Enterprise stent implantation at Nanjing Drum Tower Hospital from January 2020 to December 2022. The rates of recanalization, perioperative complications, in-stent restenosis at 3-12 months and stroke recurrence were assessed for endovascular treatment.

RESULTS

A total of 107 individuals were included in this study, 88 were followed up, and 19 (17.8%) patients were lost to follow-up. The operation success rate was 100%, During the procedure,4（3.7%）patients had vasospasm, and 2(1.9%) patients showed symptomatic bleeding. The overall perioperative complication rate was 5.6%, including 2.8% distal artery embolism, 0.9% in-stent thrombosis, and 1.9% symptomatic bleeding. 88 (82.2%) patients were followed up from 3 to 12 months, of whom 12 (13.6%) had in-stent restenosis, 4 (4.7%) recurrent strokes and 2 died of pulmonary infection caused by COVID-19. Patients were divided into 3 groups according to the cerebral artery, including the middle cerebral artery group, internal carotid artery group, and vertebrobasilar artery group.

CONCLUSIONS

In this study, the placement of the Enterprise stent in patients with symptomatic non-acute intracranial stenosis was successful. However, the occurrence of periprocedural and long-term complications after stenting remains of high concern.

Short-term outcome of stenting with Enterprise stents for symptomatic intracranial atherosclerotic disease at a single center

OBJECTIVE

To evaluate the safety and efficacy of stenting for symptomatic intracranial atherosclerotic severe stenosis or occlusion with Enterprise stents.

METHODS

Fifty-three consecutive patients with symptomatic intracranial atherosclerotic severe (70%-99%) stenosis or occlusion who underwent endovascular treatment with Enterprise stents between September 2019 and March 2022 were retrospectively analyzed. Primary outcomes included technical stenting success rates, the incidence of complications within 30 days of the procedure, and the in-stent restenosis rates during the follow-up period. These outcomes were further categorized based on lesion location and operation time.

RESULTS

Fifty-seven lesions in 53 patients aged 61.0 ± 10.0 years were treated with Enterprise stents with a technical success rate of 100%. Seven patients (12.3%) had severe complications within 30 days of the procedure: five had a symptomatic ischemic stroke, one had a symptomatic intracerebral hemorrhage, and one had a subarachnoid hemorrhage related to the procedure. No deaths were observed. The rate of in-stent restenosis was 18.2%, with a mean vascular imaging follow-up period of 6.7 months. The 30-day complication and in-stent restenosis rates did not differ significantly between patients with different lesion locations and operation times (P > 0.05).

CONCLUSION

This retrospective study suggests that percutaneous transluminal angioplasty and stenting with Enterprise stents is an effective treatment for symptomatic intracranial arterial stenosis or occlusion with a high technical success rate. It also indicates that stenting during the early nonacute stage after stroke may not increase the incidence of perioperative complications for symptomatic intracranial atherosclerotic stenosis when following strict inclusion criteria.

Sub-satisfactory stenting recanalization of severe vascular stenosis of the posterior circulation can significantly improve cerebral hemodynamic perfusion

PURPOSE

To investigate the effect of sub-satisfactory stenting recanalization of severe vascular stenosis of the posterior circulation on cerebral hemodynamic perfusion.

MATERIALS AND METHODS

Patients with severe vascular stenosis of the posterior circulation who had undergone three-dimensional cerebral angiography before and after stenting were retrospectively enrolled. Computational fluid dynamic (CFD) analysis of hemodynamic parameters at the stenosis, perforating branch, and normal arterial segments proximal and distal to the stenosis were performed.

RESULTS

Sixty-two patients with basilar artery stenosis aged 60.9 ± 9.6 years were enrolled, and stent angioplasty resulted in the reduction of stenosis degree from 85.3 ± 7.2% before to 18.6 ± 6.4% after stenting. After stenting, at the proximal normal artery, the total pressures had significantly (P < 0.05) decreased, whereas all the other parameters (WSS, cell Reynolds number, velocity, vorticity, turbulence intensity, turbulence kinetic energy and dissipation rate) had significantly (P < 0.05) increased. At the stenosis, all hemodynamic parameters had significantly decreased. At the stenosis perforating branch, the WSS, cell Reynolds number, velocity, and vorticity were all significantly decreased, and the total pressure, turbulence intensity, kinetic energy, and dissipation rate were all significantly increased. At the distal normal artery, the total flow pressure (perfusion pressure) and velocity were both significantly (P < 0.05) increased, and the total pressure, WSS, cell Reynolds number, vorticity, turbulence intensity, kinetic energy, and dissipation rate were all significantly (P < 0.05) decreased. The hemodynamic parameters after stenting were closer to those after virtual stenosis repair at all measurements.

CONCLUSION

Sub-satisfactory recanalization has significantly restored the stenosis and improved the hemodynamic parameters near the stenosis and at the root of the perforating branch, thus significantly improving the cerebral perfusion, similar to the changes of hemodynamic status and cerebral perfusion after virtual removal of the vascular stenosis. This may indicate the good effect of sub-satisfactory stenting recanalization of the vascular stenosis at the posterior circulation.

Safety and efficacy of the Low-Profile Visualized Intraluminal Support stent in treating intracranial atherosclerotic stenosis

PURPOSE

The performance of the Low-Profile Visualized Intraluminal Support (LVIS) stent deployed following balloon angioplasty is unknown in treating intracranial atherosclerotic stenosis, and this study was to investigate the safety and efficacy of the LVIS stent in treating intracranial atherosclerotic stenosis in the middle cerebral artery M1 segment.

METHODS

Thirty-five patients were enrolled with 35 atherosclerotic stenoses at the M1 segment. The stenosis was about 75% in 16 patients, 80% in 15, and 90% in the rest four. The LVIS stent was used to treat these patients.

RESULTS

The success rate of stenting was 97.1%. The stenting procedure was failed in one patient because of intraprocedural dissection of the stenotic (75%) segment, resulting in a 30-day periprocedural complication rate of 2.9% (1/35). Before stenting, the stenosis rate ranged 75%-90% (mean 78.9%±4.7%), and after stenting, the diameter of the stented segment was significantly (P<0.0001) increased to 1.5-3.4mm (mean 2.1±0.32mm) ranging 68.2%-100% (mean 94.0%±5.8%) of the normal arterial diameter, with the residual stenosis ranging 0-31.8% (median 4.8%, IQR 2.4%-7.3%). Follow-up was performed at 6-20 months (mean 8.5) after stenting. One patient (2.9%) had occlusion of the stented M1 segment with no symptoms, and two patients (5.7%) had slight asymptomatic instent stenosis (40%) at the M1 segment, with the instent restenosis and occlusion rate of 8.6% (3/35).

CONCLUSION

The braided LVIS stent can be safely applied for treatment of intracranial atherosclerotic stenosis in the middle cerebral artery with good safety and efficacy immediately after stenting and at follow-up.

Optional or optimal? off-label stenting for intracranial atherosclerotic stenosis: A scoping review

BACKGROUND

Intracranial atherosclerotic stenosis is a major cause of ischemic stroke. In addition to the Wingspan stent system, several self-expanding stents have been used off-label to treat intracranial atherosclerotic stenosis lesions. The purpose of this review is to assess the existing data on the off-label use of self-expanding stents in intracranial atherosclerotic stenosis, to highlight methodological limitations in current study designs, and thus providing strategies and precautions for clinical practice.

METHODS

The PubMed, EMBASE, and the Cochrane Library databases were systematically searched for relevant articles published up to April 2022. In addition to the meta analysis of Enterprise, Neuroform EZ and closed cell stent respectively, we used a narrative synthesis to summarize and discuss the appropriate strategies and precautions for the use of each stent.

RESULTS

We identified 17 studies (1091 patients with 1124 lesions) reporting 6 types of off-label self-expanding stents. The most common endpoints reported were incidence of short-term complications (range: 0-15.8%, median: 3.8%), long-term complications (range: 0-12.0%, median: 0%). Potential risks include infeasibility of stenting hard lesions or tortuous vessels, stent migration, and in-stent thrombosis. Less is known about the conditions that are appropriate for an optimal stent (e.g., open-cell, close-cell, hybrid cell). There was considerable heterogeneity across studies with regards to study populations and study designs.

CONCLUSIONS

The potential risks and benefits should be carefully considered when using off-label stents for intracranial atherosclerotic stenosis, particularly given the current evidence power. As a potential option for the Wingspan stent, based on device's approval only, a tailored approach with lesion-specific devices could be beneficial in certain patients.

The effectiveness of enterprise stent use on the treatment of intracranial atherosclerosis disease

OBJECTIVE

To examine the clinical outcome of Enterprise stent in patients with severe and symptomatic intracranial atherosclerosis.

MATERIAL AND METHOD

Twenty-five patients who underwent Enterprise stenting between January 2012 and March 2019 were included in this study. Exclusion criteria were previous intracranial stenting and inadequate follow-up. Technical success rates of the procedures were recorded. Clinical outcome was evaluated with pre- and post-treatment modified Rankin Scale scores. The patients were monitored for 18 months clinically and for 14.3 months radiologically.

RESULTS

The mean age of the 15 males and 10 females was 61.6 ± 8.19. Of these 25 patients, 6 (24%) were in the anterior system and 19 (76%) were in posterior system. The mean degree of pre-treatment stenosis was 86.4% ± 7 with the mean lesion length of 12.5 ± 7.5 mm. The residual stenosis rate was 23.8% ± 8.81. Technical success rate was 100%. There were two major complications within the first 30 days (8%). Late major complications (after 30 days) occurred in one case (4%). Stent restenosis was detected in two patients (8%). No intracranial bleeding or mortality was observed.

CONCLUSION

In this single-center study, we achieved high technical success and tolerable complication rates. Enterprise stent may be a good treatment alternative for severe intracranial stenosis especially in patients resistant to medical treatment when correct patient selection is made. However, further randomized controlled studies, including more cases should be carried out.

Sub-satisfactory recanalization of severe middle cerebral artery stenoses can significantly improve hemodynamics

Purpose

To investigate the effect of sub-satisfactory stent recanalization on hemodynamic stresses for severe stenoses of the middle cerebral artery (MCA) M 1 segment.

Materials and methods

Patients with severe stenoses of the MCA M1 segment treated with endovascular stent angioplasty were retrospectively enrolled. Three-dimensional digital subtraction angiography before and after stenting was performed; the computational fluid dynamics (CFD) analysis of hemodynamic stresses at the stenosis and normal segments proximal and distal to the stenoses was analyzed.

Results

Fifty-one patients with severe stenosis at the MCA M1 segment were enrolled, with the stenosis length ranging from 5.1 to 12.8 mm (mean 9 ± 3.3 mm). Stent angioplasty was successful in all (100%) the patients. The angiography immediately after stenting demonstrated a significant (P &lt; 0.05) decrease in MCA stenosis after comparison with before stenting (31.4 ±12.5% vs. 87.5 ± 9.6%), with residual stenosis of 15–30% (mean 22.4 ± 3.5%). Before stenting, the total pressure was significantly higher (P &lt; 0.0001), while the WSS, velocity, and vorticity were all significantly decreased (P &lt; 0.0001) at the normal arterial segment proximal to the stenosis, and the total pressure, WSS, velocity, and vorticity were all significantly decreased (P &lt; 0.0001) at the normal arterial segment distal to the stenosis compared with those at the stenosis. After sub-satisfactory stenting recanalization, all the hemodynamic stresses proximal or distal to the stenosis and at the perforator root were improved compared with those before stenting and were similar to those after virtual stenosis removal.

Conclusion

Sub-satisfactory recanalization of severe MCA stenoses can significantly improve the hemodynamic status for cerebral perfusion at the stenoses.

Endovascular Treatment of Large Vessel Occlusion Strokes Due to Intracranial Atherosclerotic Disease

Mechanical thrombectomy (MT) has become the gold-standard for patients with acute large vessel occlusion strokes (LVOS). MT is highly effective in the treatment of embolic occlusions; however, underlying intracranial atherosclerotic disease (ICAD) represents a therapeutic challenge, often requiring pharmacological and/or mechanical rescue treatment. Glycoprotein IIb/IIIa inhibitors have been suggested as the best initial approach, if reperfusion can be achieved after thrombectomy, with angioplasty and/or stenting being reserved for the more refractory cases. In this review, we focus on the therapeutic considerations surrounding the endovascular treatment of ICAD-related acute LVOS.

Recurrent in-stent thrombosis following V4 segment of vertebral artery stenting: A case report

INTRODUCTION AND IMPORTANCE

We report a rare case of subacute recurrent in-stent thrombosis after vertebral artery stenting of the left intracranial segment.

CASE PRESENTATION

A 56-year-old man presented with V4 segment severe stenosis of the left vertebral artery. Stent (Apollo, 2.5 mm × 8 mm) implantation was performed for severe stenosis of the left vertebral artery. Approximately 48 h after operation, the patient developed dizziness and drowsiness. DSA showed stent thrombosis, which was treated by PTAS (Apollo, 2.5 mm × 13 mm), and the preoperative symptoms resolved. Two days later, symptoms of posterior circulation ischemia reappeared, DSA showed recurrence of stent thrombosis and CYP2C19 genotypic analysis showed intermediate metabolizers. Revision PTAS (Enterprise, 4.5 mm × 28 mm) was performed followed by administration of Ticagrelor instead of tirofiban. The patient showed good neurological outcomes. CTA performed both one week and four months after the operation showed that the blood flow of the left vertebral artery was unobstructed.

CLINICAL DISCUSSION

Endovascular therapy is an alternative treatment for severe intracranial vascular stenosis, and reocclusion is one of the serious complications.

CONCLUSION

our case report highlights that recurrent in-stent thrombosis maybe be caused by inadequate preoperative assessment and unsuitable therapeutic drug selection for the stents.

Long-Term Outcome of Enterprise Stenting for Symptomatic ICAS in a High-Volume Stroke Center

Background and Purpose: The Enterprise stent has been used for treating intracranial atherosclerotic stenosis (ICAS), but its long-term outcome remains unclear. The purpose of this study was to evaluate the long-term clinical efficacy of the Enterprise stent used for patients with symptomatic ICAS due to hypoperfusion.

Method: Patients with symptomatic ICAS due to hypoperfusion treated with the Enterprise stents from a high-volume stroke center were evaluated. The successful recanalization was defined as the Modified Thrombolysis In Cerebral Infarction (mTICI) ≥ 2b. The stroke and neurological death that occurred within 72 h after the procedure as well as long-term clinical and imaging outcomes were analyzed.

Results: Overall, 130 patients with 130 ICAS treated with the Enterprise stent were included in our study. The successful recanalization rate was 100%. The mean pre- and postprocedural stenosis was 82.9 ± 8.9% vs. 15.1 ± 8.4%. Periprocedural complications occurred in 5 (3.8%) patients within 72 h after the procedure. Clinical follow-up data were available in 125 (96.2%) patients (median, 24 months) and any stroke or neurological death was encountered in 6 (4.8%) patients. Angiographic follow-up data was obtained from 118 (90.8%) patients (median, 13.5 months). In addition, 1-year in-stent restenosis (>70%) was found in 17 (14.4%) patients, and among them, 4 (23.5%) patients were symptomatic.

Conclusion: Deployment of Enterprise stent is safe for ICAS. The short-term and long-term outcomes were acceptable, but the efficacy of the Enterprise stent needs to be further evaluated in future studies.

Endovascular treatment of symptomatic intracranial atherosclerotic stenosis with low profile visualized intraluminal support stent

OBJECTIVE

Severe intracranial atherosclerotic stenosis has become one of the main causes resulting transient ischemic attack and stroke. This study aimed to evaluate the efficacy and safety of low profile visualized intraluminal support (LVIS) stent in treating symptomatic intracranial atherosclerotic stenosis.

METHODS

Data of 31 patients with at least 70% stenosis treated with LVIS stent in our center were retrospectively collected between July 2017 and November 2020. Further evaluation of lesion characteristics, technical success rate, preoperative complication, clinical and angiographic follow-up outcome, delayed in-stent stenosis were conducted.

RESULTS

Stent delivery and deployment were successfully achieved in all 31 patients (100%). 22 cases (71%) were located in anterior circulation and 9 cases (29%) were located in posterior circulation. The mean degree of stenosis lesion before stent deployment was 85.6 ± 9.4%, while after stenting was 11.2 ± 11.8%. One patient suffered from ischemic complication in stenting procedure, and timely delivery of rt-PA successfully recanalized the artery. Clinical follow-up was available in all 31patients (100%) with mean follow-up time 15.0 ± 12.1(3-45) months. No patients experienced the recurrence of stroke or TIA or death after discharge. Angiographic follow-up was available in 21patients (67.7%) with mean follow-up time 11.43 ± 6.8 (6-36) months. 19 patients (90.5%) were stable while 2 patients (9.5%) developed ISR in their last angiographic follow-up. The 2 patients received balloon angioplasty and reached satisfactory results after retreatment.

CONCLUSION

This preliminary study suggests that LVIS stent deployment was a feasible approach in treating intracranial atherosclerotic stenosis with satisfactory procedure success rate, low complication rate and favorable long-term outcome.

A Comparison of Safety and Effectiveness Between Wingspan and Neuroform Stents in Patients With Middle Cerebral Artery Stenosis

Background: Percutaneous transluminal angioplasty and stenting with the Wingspan stent has proven safe and effective in patients with middle cerebral artery stenosis (MCAS), but the off-label use of the Neuroform stent might be an alternative treatment. This study aimed to compare the safety and effectiveness of the above two intracranial stents in patients with MCAS. Methods: We retrospectively analyzed consecutive patients with symptomatic MCAS who had been treated with the Neuroform EZ or the Wingspan stent. A propensity score was generated to control for differences in baseline characteristics. The endpoints were the rate of peri-procedural complications within 30 days after stenting, the in-stent restenosis rate, and any target-vessel-related stroke or deaths during follow-up. Results: After matching for propensity score, the peri-procedural complication rate in the Wingspan group was 7.4% compared with 5.6% in the Neuroform group (p = 1.00), while the follow-up in-stent restenosis rates were 23.3 vs. 14.3%, respectively (p = 0.41). In the restenosis group, the patients tended to be younger (p < 0.01) and the degree of artery stenosis before stenting was higher (p < 0.01). Conclusion: This study indicated that in patients with symptomatic MCAS, Neuroform EZ stents are an alternative to Wingspan. Moreover, younger age and higher degree of artery stenosis before stenting might be a risk factor of in-stent restenosis.

Safety and efficacy of the Low-Profile Visualized Intraluminal Support stent in treating intracranial atherosclerotic stenosis

PURPOSE

The performance of the Low-Profile Visualized Intraluminal Support (LVIS) stent deployed following balloon angioplasty is unknown in treating intracranial atherosclerotic stenosis, and this study was to investigate the safety and efficacy of the LVIS stent in treating intracranial atherosclerotic stenosis in the middle cerebral artery M1 segment.

METHODS

Thirty-five patients were enrolled with 35 atherosclerotic stenoses at the M1 segment. The stenosis was about 75% in 16 patients, 80% in 15, and 90% in the rest four. The LVIS stent was used to treat these patients.

RESULTS

The success rate of stenting was 97.1%. The stenting procedure was failed in one patient because of intraprocedural dissection of the stenotic (75%) segment, resulting in a 30-day periprocedural complication rate of 2.9% (1/35). Before stenting, the stenosis rate ranged 75%-90% (mean 78.9%±4.7%), and after stenting, the diameter of the stented segment was significantly (P<0.0001) increased to 1.5-3.4mm (mean 2.1±0.32mm) ranging 68.2%-100% (mean 94.0%±5.8%) of the normal arterial diameter, with the residual stenosis ranging 0-31.8% (median 4.8%, IQR 2.4%-7.3%). Follow-up was performed at 6-20 months (mean 8.5) after stenting. One patient (2.9%) had occlusion of the stented M1 segment with no symptoms, and two patients (5.7%) had slight asymptomatic instent stenosis (40%) at the M1 segment, with the instent restenosis and occlusion rate of 8.6% (3/35).

CONCLUSION

The braided LVIS stent can be safely applied for treatment of intracranial atherosclerotic stenosis in the middle cerebral artery with good safety and efficacy immediately after stenting and at follow-up.

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.

The Enterprise2 Stent for Endovascular Treatment of Intracranial Aneurysms: Short-Term Results From a Single Center Experience

Background: Self-expanding devices, such as the Enterprise VRD (EP-VRD) have widely used for stent-assisted coiling treatment in wided-necked aneuryms while some thromboembolic complications were reported due to its incomplete stent apposition (ISA). We report our experiences on the novel Enterprise2 (EP-VRD2) stent in vivo in the treatment of intracranial and cranial cervical junction aneurysms.

Methods: Twenty-five consecutive patients with intracranial or cranial cervical junction aneurysms were treated with EP-VRD2 stents retrospectively collected in our institution. We use the ‘jailing' technique in all cases and deployed the stent by using pushing over the outer curve technique. The 3- or 6-monthS follow-up was done regularly by DSA.

Results: Twenty-five EP-VRD2 stents were implanted to treat 21 aneurysms at the siphon segment of internal carotid artery (ICA), one at the petrous segment, two at the cervical segment, one at the verteral artery with five accompanied with stenosis. Two patients had kinking during the procedure and were solved by microwire or microcatheter massaging. Four patients with a larger arc angle and a smaller radius of the parent vessel was detected ISA. No patient underwent the ischemic event after the operation. Twenty-three of 25 patients were evaluated after 3- or 6-months by DSA, 22 showed complete occlusion (RROC1), one slight re-stenosis in the follow-up within those five patients with stenosis. A length of 23 mm seemed associated with ISA (p < 0.01).

Conclusion: The EP-VRD2 performed well in our small patient series; however, ISA could still occur with a sharp angle of the parent vessel.

Incidence and Risk Factors of In-Stent Restenosis for Symptomatic Intracranial Atherosclerotic Stenosis: A Systematic Review and Meta-Analysis

BACKGROUND

In-stent restenosis affects long-term outcome in patients with intracranial atherosclerotic stenosis.

PURPOSE

The aim of this meta-analysis was to evaluate the incidence and risk factors of in-stent restenosis.

DATA SOURCES

All literature that reported in-stent restenosis was searched on PubMed, Ovid EMBASE and Ovid MEDLINE data bases.

STUDY SELECTION

Original articles about stents for symptomatic intracranial atherosclerotic stenosis were selected.

DATA ANALYSIS

Meta-analysis was conducted to derive the pooled in-stent restenosis using a random-effects model. Meta-regression was performed to explore the risk factors predisposing to in-stent restenosis.

DATA SYNTHESIS

In total, 51 studies with 5043 patients were included. The pooled incidence rate of in-stent restenosis was 14.8% (95% CI, 11.9%-17.9%). Among the lesions with in-stent restenosis, 28.8% of them led to (95% CI, 22.0%-36.0%) related neurologic symptoms. The series in the United States had a higher in-stent restenosis rate (27.0%; 95% CI, 20.6%-33.9%) compared with those from Asia (13.6%; 95% CI, 10.3%-17.2%) and other regions as a whole (7.6%; 95% CI, 1.1%-18.1%) (P < .01). Multiregression analysis revealed that younger patient age was related to high in-stent restenosis rates (P = .019), and vertebrobasilar junction location (P = .010) and low residual stenosis (P = .018) were 2 independent risk factors for symptomatic in-stent restenosis rate.

LIMITATIONS

The heterogeneity of most outcomes was high.

CONCLUSIONS

Our study showed promising results of in-stent restenosis for symptomatic atherosclerotic stenosis. Studies are needed to further expatiate on the mechanisms by which younger patient age, vertebrobasilar junction location, and low residual stenosis could increase in-stent restenosis and symptomatic in-stent restenosis, respectively.

Thirty-Day Outcomes of the Enterprise Stent in Treating Hypoperfusion of Symptomatic Intracranial Stenosis

OBJECTIVE

To evaluate the 30-day outcomes of using the Enterprise stent to treat patients with hypoperfusion of symptomatic severe intracranial stenosis.

METHODS

Patients with symptomatic severe intracranial stenosis (70%-99%) who underwent Enterprise stent intervention between August 2014 and November 2018 were retrospectively analyzed. The 30-day primary outcomes included the success rate of stenting and the incidence of complications, including ischemic stroke, cerebral hemorrhage, and death. The 30-day complication rates of patients with different lesion locations and classifications of Mori morphology were compared.

RESULTS

Sixty-eight patients were treated using 70 Enterprise stents. The success rate was 100%. The 30-day complication rate was 4.4%. The rates of ischemic stroke, cerebral hemorrhage, and death were 1.5%, 2.9%, and 0%, respectively. No significant difference was found in the 30-day complication rate between patients with different lesion locations and classifications of Mori morphology (P > 0.05).

CONCLUSION

Enterprise stents were relatively safe in treating patients with hypoperfusion of symptomatic severe intracranial stenosis.

Medium-term results of undersized angioplasty and stenting for symptomatic high-grade intracranial atherosclerotic stenosis with Enterprise

PURPOSE

The aim of this retrospective study is to evaluate medium-term results of undersized balloon angioplasty and stenting for symptomatic high-grade (70-99%) stenosis of a major intracranial artery with Enterprise stent.

METHODS

This study included 68 consecutive symptomatic (recurrent transient ischemic attack (TIA) or ischemic stroke under dual antiplatelet treatment) patients with high-grade (70-99%) stenosis of a major intracranial artery who were endovascularly treated with undersized balloon angioplasty and Enterprise stent deployment between July 2012 and December 2017. Primary outcomes were any stroke or death within 30 days after procedure. Secondary outcomes were technical success rates, stroke and restenosis during the follow-up period.

RESULTS

A total of 68 lesions in 68 patients (mean age: 62 ± 7 years) were treated with a technical success rate of 99%. The degree of pre-procedural stenosis was 92 ± 6% and dropped to 12 ± 10% after stent deployment. No patient developed any stroke or death during the periprocedural period. Intracranial hemorrhage was observed in 1 (1.5%) patient. In 60 (88%) patients with available imaging follow-up in-stent restenosis was observed in 2 patients. Mean follow-up period was 22 ± 17 months (range 6-72) and none of the patients experienced recurrent TIA or stroke during the follow-up period.

CONCLUSION

In this retrospective single-center study undersized balloon angioplasty and deployment of a self-expandable stent with relatively low radial force was safe and effective for endovascular treatment of high-grade intracranial arterial stenosis with high technical success rate, low periprocedural complication rates and favorable medium-term follow-up results.

Endovascular Metal Devices for the Treatment of Cerebrovascular Diseases

Cerebrovascular disease involves various medical disorders that obstruct brain blood vessels or deteriorate cerebral circulation, resulting in ischemic or hemorrhagic stroke. Nowadays, platinum coils with or without biological modification have become routine embolization devices to reduce the risk of cerebral aneurysm bleeding. Additionally, many intracranial stents, flow diverters, and stent retrievers have been invented with uniquely designed structures. To accelerate the translation of these devices into clinical usage, an in-depth understanding of the mechanical and material performance of these metal-based devices is critical. However, considering the more distal location and tortuous anatomic characteristics of cerebral arteries, present devices still risk failing to arrive at target lesions. Consequently, more flexible endovascular devices and novel designs are under urgent demand to overcome the deficiencies of existing devices. Herein, the pros and cons of the current structural designs are discussed when these devices are applied to the treatment of diseases ranging broadly from hemorrhages to ischemic strokes, in order to encourage further development of such kind of devices and investigation of their use in the clinic. Moreover, novel biodegradable materials and drug elution techniques, and the design, safety, and efficacy of personalized devices for further clinical applications in cerebral vasculature are discussed.

Reperfusion therapy in acute ischemic stroke: dawn of a new era?

Following the success of recent endovascular trials, endovascular therapy has emerged as an exciting addition to the arsenal of clinical management of patients with acute ischemic stroke (AIS). In this paper, we present an extensive overview of intravenous and endovascular reperfusion strategies, recent advances in AIS neurointervention, limitations of various treatment paradigms, and provide insights on imaging-guided reperfusion therapies. A roadmap for imaging guided reperfusion treatment workflow in AIS is also proposed. Both systemic thrombolysis and endovascular treatment have been incorporated into the standard of care in stroke therapy. Further research on advanced imaging-based approaches to select appropriate patients, may widen the time-window for patient selection and would contribute immensely to early thrombolytic strategies, better recanalization rates, and improved clinical outcomes.

Enterprise stent in recanalizing non-acute atherosclerotic intracranial internal carotid artery occlusion

OBJECTIVE

To investigate the safety and effectiveness of recanalization in non-acute occlusion of intracranial internal carotid arteries using the flexible Enterprise self-expanding stent.

PATIENTS AND METHODS

From June 2014 to June 2016, 12 consecutive patients with non-acute occlusion of intracranial internal carotid arteries received endovascular recanalization with Enterprise stenting. All patients received medication for anti-platelet aggregation therapy before and after the operation. The perioperative complications and recanalization efficacy were evaluated with the modified Rankin scoring system and digital subtraction angiography (DSA) follow-up, respectively.

RESULTS

Endovascular recanalization was successfully performed in 10 out of 12 patients with Enterprise stenting. Stent implantation following balloon dilatation failed in one patient because the lumen diameter was too small. Another recanalization failed because the guide wire could not pass through the occlusion. No perioperative mortality was observed. One case of acute thrombosis and one case of intraoperative carotid spasm occurred, but these were resolved with thrombolytic therapy by microcatheter exposure treatment and antispasmodic medications, respectively. DSA follow-up in seven patients revealed no re-occlusion. One stroke event occurred in the 10 patients who completed the follow-up. A meaningful improvement in the modified Rankin score during follow-up was suggested by Wilcoxon signed-rank test results.

CONCLUSION

The Enterprise stent was shown to be safe and efficient in recanalizing non-acute atherosclerotic intracranial internal carotid artery occlusion. However, the long-term outcomes need to be further investigated.

Advances in endovascular therapy for ischemic cerebrovascular diseases

Endovascular therapy for ischemic cerebrovascular diseases has developed rapidly in recent years. The latest clinical trials of acute ischemic stroke have shown promising results with the continued advancement of concepts, techniques, and materials. Mechanical thrombectomy is recommended in the treatment of acute ischemic stroke caused by large vessel occlusion of the anterior circulation, according to the guidelines updated in Europe, USA, and China. The long-term therapeutic efficacy of endovascular stenting for carotid artery stenosis has also been proved noninferior to that of carotid endarterectomy. However, the latest clinical trials have shown that the efficacy of stenting for intracranial artery and vertebral artery stenosis is inferior to that of medical treatment alone, which needs urgent attention through further development and studies.

One-pass endovascular treatment of intracranial atherosclerotic stenosis with a novel PTA balloon and self-expanding microstent

INTRODUCTION

We present a novel endovascular technique to treat intracranial atherosclerotic stenosis (ICS) with the specific potential to reduce the procedure-related complications which so far limited safety and efficacy of endovascular ICS intervention.

METHODS

Six consecutive patients were included in this study with the following criteria of inclusion: (1) failure of dual antiplatelet therapy defined as recurrent TIA or ischemic stroke, (2) presence of ICS of ≥70 %, and (3) endovascular accessibility of the target lesion as judged by CTA or MRA. Technical feasibility, safety, and efficacy were observed for the first-ballon-then-stent (FBTS) technique using the percutaneous transluminal angioplasty (PTA) balloon microcatheter over which a self-expandable microstent can be directly delivered obviating the need to exchange microcatheters.

RESULTS

FBTS was performed in six patients (four female, median age 69, median stenosis 82.5 %) all refractory to best medical treatment: three V4, two M1, and one supraclinoid ICA stenosis. PTA and stent deployment were technically feasible in all patients and immediately effective with a median postprocedural stenosis grade of 10 %. Angiographic and clinical safety measures were met with no occult or clinically evident hemorrhage or ischemic complications (four patients discharged without alteration in mRS, two patients with significant clinical improvement). No occurrence of TIA, stroke, or death was observed during follow-up.

CONCLUSION

The FBTS method in this series appeared to be safe and effective for the endovascular treatment of ICS. It bears the specific potential to reduce wire perforations, which so far have been linked to major procedure-related adverse events of endovascular ICS treatment.