Enterprise stenting for intracranial aneurysm treatment induces dynamic and reversible age-dependent stenosis in cerebral arteries

High-resolution vessel wall imaging for quantitatively and qualitatively evaluating in-stent stenosis of intracranial aneurysms

Background

It is critical to accurately and noninvasively evaluate the stented parent artery of intracranial aneurysms (IAs) with endovascular treatment.

Objective

To investigate high-resolution vessel wall imaging (HR-VWI) for quantitative and qualitative evaluation of in-stent stenosis (ISS) in IAs treated with stent placement (SP).

Methods

Fifty-five patients (58 aneurysms) underwent HR-VWI, contrast-enhanced (CE)-HR-VWI, CE-MR angiography (MRA), time-of-flight (TOF)-MRA, and digital subtraction angiography (DSA) six months after SP, and the reliability of quantitative stent lumen measurements was evaluated by intraclass correlation coefficient (ICC) analysis. Agreement and correlation of quantitative evaluation were estimated by comparing the four MR imaging modalities with DSA. The diagnostic performance for >0%, ≥25%, and ≥50% of ISS degrees and overall diagnostic accuracy for the ISS degrees of the four MR imaging modalities were calculated to qualitative evaluation.

Results

The reliability of CE-HR-VWI and HR-VWI for ISS quantitative measurements was excellent (ICC 0.955-0.989). The agreement and correlation of CE-HR-VWI, HR-VWI versus DSA for ISS quantitative measurements were better than those of CE-MRA and TOF-MRA (p < 0.05). The diagnostic performance for distinguishing the degree of ISS >0%, ≥25%, and ≥50% by CE-HR-VWI and HR-VWI was superior to CE-MRA and TOF-MRA, and their overall diagnostic accuracy was 96.55 and 94.83%, respectively. HR-VWI and CE-HR-VWI were not statistically significant in the quantitative and qualitative evaluation of ISS performance (p > 0.05).

Conclusion

HR-VWI and CE-HR-VWI have similar performance and value in the quantitative and qualitative evaluation of ISS, and HR-VWI without contrast media could be used as an ideal long-term follow-up approach after SP treatment for IAs.

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 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.

Machine learning to predict in-stent stenosis after Pipeline embolization device placement

Background

The Pipeline embolization device (PED) is a flow diverter used to treat intracranial aneurysms. In-stent stenosis (ISS) is a common complication of PED placement that can affect long-term outcome. This study aimed to establish a feasible, effective, and reliable model to predict ISS using machine learning methodology.

Methods

We retrospectively examined clinical, laboratory, and imaging data obtained from 435 patients with intracranial aneurysms who underwent PED placement in our center. Aneurysm morphological measurements were manually measured on pre- and posttreatment imaging studies by three experienced neurointerventionalists. ISS was defined as stenosis rate >50% within the PED. We compared the performance of five machine learning algorithms (elastic net (ENT), support vector machine, Xgboost, Gaussian Naïve Bayes, and random forest) in predicting ISS. Shapley additive explanation was applied to provide an explanation for the predictions.

Results

A total of 69 ISS cases (15.2%) were identified. Six predictors of ISS (age, obesity, balloon angioplasty, internal carotid artery location, neck ratio, and coefficient of variation of red cell volume distribution width) were identified. The ENT model had the best predictive performance with a mean area under the receiver operating characteristic curve of 0.709 (95% confidence interval [CI], 0.697–0.721), mean sensitivity of 77.9% (95% CI, 75.1–80.6%), and mean specificity of 63.4% (95% CI, 60.8–65.9%) in Monte Carlo cross-validation. Shapley additive explanation analysis showed that internal carotid artery location was the most important predictor of ISS.

Conclusion

Our machine learning model can predict ISS after PED placement for treatment of intracranial aneurysms and has the potential to improve patient outcomes.

Hemodynamic and Geometric Risk Factors for In-Stent Restenosis in Patients with Intracranial Atherosclerotic Stenosis

Methods

Severe ICAS patients managed with percutaneous transluminal angioplasty and stenting (PTAS) were included in the retrospective cohort study and were divided into two groups according to whether ISR occurred at follow-up (ISR group and no-ISR group). Computational fluid dynamics models were built based on digital subtraction angiography before and after PTAS to simulate blood flow and quantify hemodynamic parameters. The associations between vessel geometry, hemodynamics, and ISR in ICAS patients were investigated.

Results

Among 39 patients, ISR occurred in seven patients (17.95%) after a mean follow-up period of 6.69 ± 3.24 months. Stenting decreased vessel angulation (51.11° [40.07°-67.27°] vs. 15.97° [0.00°-36.16°], P = 0.000) and vessel tortuosity (0.09 [0.06-0.13] vs. 0.01 [0.00-0.03], P = 0.000). Meanwhile, the translational pressure ratio (PR) dramatically increased (0.07 [0.00-0.31] vs. 0.62 [0.41-0.82], P = 0.000) with the wall shear stress ratio decreased (13.93 [8.37-40.30] vs. 2.90 [1.69-4.48], P = 0.000). In the multivariate analysis, smaller Δ tortuosity (P = 0.038) was independently associated with the occurrence of ISR, and smaller post-PTAS translesional PR was also a predictive factor of marginal significance (P = 0.059).

Conclusion

PTAS decreased vessel angulation, vessel tortuosity, and translesional wall shear stress ratio while it increased translesional pressure ratio (PR) dramatically in ICAS patients. Smaller Δ tortuosity was found to be a risk factor for ISR, and smaller post-PTAS translesional PR was also a predictive factor of marginal significance, indicating that both geometric and hemodynamic parameters played important roles in the occurrence of ISR after PTAS.

Imaging Intracranial Aneurysms in the Endovascular Era: Surveillance and Posttreatment Follow-up

While most intracranial aneurysms (IAs) remain asymptomatic over a patient's lifetime, those that rupture can cause devastating outcomes. The increased usage and quality of neuroimaging has increased detection of unruptured IAs and driven an increase in surveillance and treatment of these lesions. Standard practice is to treat incidentally discovered unruptured IAs that confer high rupture risk as well as ruptured IAs to prevent rehemorrhage. IAs are increasingly treated with coil embolization instead of microsurgical clipping; more recently, flow diversion and intrasaccular flow disruption have further expanded the versatility and utility of endovascular IA treatment. Imaging is increasingly used for posttreatment IA follow-up in the endovascular era. While cerebral angiography remains the standard for IA characterization and treatment planning, advances in CT and CT angiography and MR angiography have improved the diagnostic accuracy of noninvasive imaging for initial diagnosis and surveillance. IA features including size, dome-to-neck ratio, location, and orientation allow rupture risk stratification and determination of optimal treatment strategy and timing. The radiologist should be familiar with the imaging appearance of common IA treatment devices and the expected imaging findings following treatment. In distinction to clipping and coil embolization, flow diversion and intrasaccular flow disruption induce progressive aneurysm obliteration over months to years. Careful assessment of the device; the treated IA; adjacent brain, bone, meninges; and involved extracranial and intracranial vasculature is crucial at posttreatment follow-up imaging to confirm aneurysm obliteration and identify short-term and long-term posttreatment complications. An invited commentary by Chatterjee is available online. Online supplemental material and the slide presentation from the RSNA Annual Meeting are available for this article. ^©RSNA, 2022.

Factors affecting in-stent restenosis after angioplasty with the Enterprise stent for intracranial atherosclerotic diseases

This study investigated factors affecting the safety and in-stent restenosis after intracranial stent angioplasty using the Enterprise stent for symptomatic intracranial atherosclerotic stenosis. Between January 2017 and March 2019, patients with intracranial atherosclerotic stenosis treated with Enterprise stent angioplasty were enrolled, including 400 patients in the modeling group and 89 patients in the validation group. The clinical factors affecting in-stent restenosis after Enterprise stent angioplasty in the modeling group were analyzed, and a logistic regression model of these factors was established and validated in the validation group. The receiver operating characteristic (ROC) curve and the area under the ROC curve (AUC) were analyzed. In the modeling group with 400 patients, there were 410 lesions, including 360 stenotic lesions and 50 occluded lesions, with 176 (42.9%) lesions in the anterior circulation and 234 (57.1%) in the posterior circulation. Successful stenting was performed in 398 patients (99.5%). Stenosis was significantly (P < 0.05) improved after stenting compared with before stenting (27.7% ± 2.9% vs. 77.9% ± 8.0%). Periprocedural complications included ischemic stroke (3.25%), hemorrhagic stroke (0.75%), and death (0.50%), with a total periprocedural complication rate of 4.0%. The first follow-up angiography was performed in 348 (87.0%) patients with 359 lesions 3.5-14 months (mean 5.7 months) after stenting. In-stent restenosis occurred in 62 (17.3%) lesions, while the other 295 (82.7%) had no restenosis. Lesion location, calcification degree, balloon expansion pressure, residual stenosis, intraprocedural dissection, and cerebral blood flow TICI grade were significant (P < 0.05) risk factors for in-stent restenosis. The in-stent restenosis prediction model was established as follows: P = 1/[1 + e^{-(-6.070-1.391 location + 2.745 calcification + 4.117 balloon inflation pressure + 2.195 intraprocedural dissection + 1.163 residual stenosis + 1.174 flow TC grade)}]. In the validation group, the AUC in the ROC curve analysis was 0.902 (95% CI: 0.836-0.969), and when the cutoff value was 0.50, the sensitivity and specificity of this model were shown to be 76.92% and 80.26%, respectively, in predicting in-stent restenosis at angiographic follow-up, with a total coincidence rate of 79.78%. In conclusion, in-stent restenosis after intracranial Enterprise stenting is affected by stenosis location, calcification, balloon inflation pressure, intraprocedural arterial dissection, residual stenosis, and cerebral flow grade, and establishment of a logistic model with these factors can effectively predict in-stent restenosis.

Long-term outcomes of wide-necked intracranial bifurcation aneurysms treated with T-stent-assisted coiling

OBJECTIVE

The endovascular treatment of complex bifurcation aneurysms possessing a neck that incorporates multiple side branches remains a surgical challenge. Double-stent-assisted coiling techniques, such as those with stents in an X and Y configuration, enable the endovascular treatment of wide-necked complex intracranial bifurcation aneurysms. However, the intraluminal struts at the intersection point in X- and Y-stents are not amenable to endothelialization, which may lead to thromboembolic complications. Stenting in the T configuration is a relatively new double-stent coiling technique. T-stenting differs from X- or Y-stenting in that there are no overlapping or intersecting stent segments. Promising short-term results of T-stent-assisted coiling were recently reported. However, the long-term results have not yet been demonstrated. This retrospective study investigated the long-term angiographic and clinical results in patients with wide-necked complex intracranial bifurcation aneurysms treated with T-stent-assisted coiling.

METHODS

A retrospective review was performed to identify patients with wide-necked complex intracranial bifurcation aneurysms treated with T-stent-assisted coiling at 4 institutions. The technical success and the initial and follow-up clinical and angiographic outcomes were assessed. Aneurysm filling status was assessed according to the Raymond classification. Periprocedural and delayed complications were reviewed. The neurological status of the patients was evaluated using the modified Rankin Scale (mRS).

RESULTS

One hundred two aneurysms in 102 patients (54 females), whose mean age was 57.9 ± 13.0 years, were included in the study. T-stenting was performed successfully in all patients. Immediate postprocedural angiography revealed complete occlusion in 83.3% of patients. Periprocedural complications developed in 13.7%, resulting in permanent morbidity in 1.9% and death in 1%. Eighty patients (78.4%) had at least one follow-up DSA examination performed at 6 months or later following the endovascular procedure. The mean duration of angiographic follow-up was 30.0 ± 16.3 months. The last follow-up examinations showed complete occlusion in 90.0% of patients. During the follow-up period, only 1 patient (1.3%) required retreatment. Delayed thromboembolic complications were observed in 4 patients (3.9%) without permanent morbidity. The mRS scores of all patients at the last clinical follow-up were between 0 and 2.

CONCLUSIONS

The short-term angiographic findings showed that T-stent-assisted coiling is a feasible and effective endovascular method to treat wide-necked complex bifurcation aneurysms. The long-term angiographic follow-up results suggest that T-stent-assisted coiling provides a durable treatment for wide-necked complex bifurcation aneurysms with favorable clinical outcomes, demonstrating the long-term safety of T-stent-assisted coiling.

Long Term Outcome of In-Stent Stenosis after Stent Assisted Coil Embolization for Cerebral Aneurysm

Objective

The objective of this study was to evaluatelong-term radiologic prognosis and characteristics of in-stent stenosis (ISS) after stent assisted coiling (SAC) for cerebral aneurysm and analyze its risk factors.

Methods

Radiological records of 362 cases of SAC during 10 years were retrospectively reviewed. Patients were included in this study if they had follow-up angiogram using catheter selected angiography at least twice. All subjected were followed up from 12 months to over 30 months. Of 120 patients, 123 aneurysms were enrolled. Patient data including age, sex, aneurysm size, neck size, procedural complication, kinds of stent, ISS associated symptom, ruptured state, location of ISS, degree of ISS, radiologic prognosis of ISS, follow-up period of time, and medical comorbidities such as hypertension, diabetes mellitus (DM), dyslipidemia, and smoking were collected.Statistical comparisons of group clinical characteristics were conducted for the total population.

Results

Among 123 casesof aneurysm, 22 cases (17.9%) of ISS were revealed on follow-up angiography. Multiple stenting was performed in three cases and intra-procedural rupture occurred in two cases. Most cases were asymptomatic and symptomatic stenosis was identified in only one case. Sixteen cases were ruptured aneurysm. Mild stenosis was observed in 11 cases. Moderate stenosis was found in eight cases and severe stenosis was identified in three cases. Mean timing of identification of ISS was 8.90 months. The most common type was proximal type. Most cases were improved or not changed on follow-up angiography. Only one case was aggravated from mild stenosis to occlusion of parent artery. Mean follow-up period was 44.3 months. We compared risk factors and characteristic between ISS group and non-ISS group using univariate analysis. Multiple stenting was performed for three cases (13.6%) of the ISS group and four cases (4.0%) of the non-ISS group, showing no statistical difference between the two groups (p=0.108). Additionally, the proportion of patients who had more than two risk factors among four medical risk factors (hypertension, DM, dyslipidemia, and smoking) was higher in the ISS group than that in the non-ISS group, the difference between the two was not statistically significant either (31.8% vs. 12.9%, p=0.05).

Conclusion

Clinical course and long-term prognosis of ISS might be benign. Most cases of ISS could be improved or not aggravated. Control of medical co-morbidity might be important. To the best of our knowledge, our study had more cases with longer follow-up period of time than other reports.

Transient in-stent stenosis: a common finding after flow diverter implantation

Background and purpose

In recent years, implantation of flow diverters has emerged as an option for the endovascular treatment of intracranial aneurysms. One complication of treatment with flow diverters is the occurrence of in-stent stenosis, which has been reported to be partially reversible. The purpose of our study was to assess the incidence and dynamics of in-stent stenosis on angiographic short term and long term follow-up after treatment with flow diverters.

Methods

A retrospective review of our prospectively maintained database identified all patients with intracranial internal carotid artery (ICA) aneurysms treated by flow diverters at our institution between 2014 and 2017. Clinical charts, procedural data, and angiographic results were reviewed.

Results

18 patients were included. The mean short term follow-up was 92±19 days and mean long term follow-up was 449±120 days after treatment. No neurologic complications were observed. There was no procedure related mortality. Long term angiographic results showed complete occlusion in 83.3%, neck remnants in 11.1%, and incomplete occlusion in 5.5% of cases. In-stent stenosis was observed in all cases. Mean stenosis improved significantly from 30% on short term follow-up to 12% on long-term follow-up (P<0.0001).

Conclusion

In-stent stenosis is a common finding on short term follow-up after the treatment with flow diverters but improves over time.

Small Tenuous Intracranial Arteries Can Well Tolerate the Deployment of 2 Stents in Y Configuration or an Overlapping Manner in Treating Intracranial Aneurysms

OBJECTIVE

To investigate parent vessel response to deployment of 2 stents for treatment of cerebral aneurysms.

METHODS

Fifteen patients (11 women and 4 men; age range, 25-83 years) with 18 wide-necked intracranial aneurysms were treated with 2 stents with or without subsequent coiling. The vascular diameter was measured and compared within the native parent artery, and the single stent and double stent were measured and compared before and immediately after stenting and at angiographic follow-up.

RESULTS

Thirty stents were deployed. Before stenting, the mean vessel diameter was 3.4 ± 0.21 mm at point A, 3.06 ± 0.18 mm at point B, 3.16 ± 0.21 mm at point C, 2.67 ± 0.27 mm at point D, and 2.56 ± 0.23 mm at point E. The deployment of 2 stents resulted in statistically significant increases in both the average vascular diameter and cross-sectional area at points C (3.51 ± 0.22 mm, P = 0.0006; and 9.76 ± 1.17 mm², P = 0.001, respectively) and E (2.88 ± 0.32 mm, P = 0.01; and 7.28 ± 1.46 mm², P = 0.02, respectively) compared with prestenting. At angiographic follow-ups, compared with before stenting, significant increases were documented at point C (3.42 ± 0.22 mm and 9.42 ± 1.37 mm², respectively) at first angiographic follow-up but at points A (3.62 ± 0.45 mm and 10.51 ± 2.37 mm², respectively) and B (3.26 ± 0.24 mm and 8.47±1.26 mm², respectively) at second angiographic follow-up. No significant vascular stenosis was demonstrated at the double-stent segment compared with the single-stent or native artery segments.

CONCLUSIONS

The small tenuous cerebral arteries can well tolerate the deployment of 2 stents for the treatment of intracranial aneurysms.

Age-related outcomes following intracranial aneurysm treatment with the Pipeline Embolization Device: a subgroup analysis of the IntrePED registry

OBJECT

The association between age and outcomes following aneurysm treatment with flow diverters such as the Pipeline Embolization Device (PED) have not been well established. Using the International Retrospective Study of the Pipeline Embolization Device (IntrePED) registry, the authors assessed the age-related clinical outcomes of patients undergoing aneurysm embolization with the PED.

METHODS

Patients with unruptured aneurysms in the IntrePED registry were divided into 4 age groups: ≤ 50, 51–60, 61–70, and > 70 years old. The rates of the following postoperative complications were compared between age groups using chi-square tests: spontaneous rupture, intracranial hemorrhage (ICH), ischemic stroke, parent artery stenosis, cranial neuropathy, neurological morbidity, neurological mortality, combined neurological morbidity and mortality, and all-cause mortality. The association between age and these complications was tested in a multivariate logistic regression analysis adjusted for sex, number of PEDs, and aneurysm size, location, and type.

RESULTS

Seven hundred eleven patients with 820 unruptured aneurysms were included in this study. Univariate analysis demonstrated no significant difference in ICH rates across age groups (lowest 1.0% for patients ≤ 50 years old and highest 5.0% for patients > 70 years old, p = 0.097). There was no difference in ischemic stroke rates (lowest 3.6% for patients ≤ 50 years old and highest 6.0% for patients 50–60 years old, p = 0.73). Age > 70 years old was associated with higher rates of neurological mortality; patients > 70 years old had neurological mortality rates of 7.4% compared with 3.3% for patients 61–70 years old, 2.7% for patients 51–60 years old, and 0.5% for patients ≤ 50 years old (p = 0.006). On multivariate logistic regression analysis, increasing age was associated with higher odds of combined neurological morbidity and mortality (odds ratio 1.02, 95% confidence interval 1.00–1.05; p = 0.03).

CONCLUSIONS

Increasing age is associated with higher neurological morbidity and mortality after Pipeline embolization of intracranial aneurysms. However, the overall complication rates of PED treatment in this group of highly selected elderly patients (> 70 years) were acceptably low, suggesting that age alone should not be considered an exclusion criterion when considering treatment of intracranial aneurysms with the PED.

Coil embolization of intracranial saccular aneurysms using the Low-profile Visualized Intraluminal Support (LVIS™) device

INTRODUCTION

The novel Low-profile Visualized Intraluminal Support (LVIS™, LVIS and LVIS Jr.) device was recently introduced for stent-supported coil embolization of intracranial aneurysms. Periprocedural and midterm follow-up results for its use in stent-supported coil embolization of unruptured aneurysms are presented herein.

METHODS

In this prospective multicenter study, clinical and radiologic outcomes were analyzed for 55 patients with saccular aneurysms undergoing LVIS-assisted coil embolization between October 2012 and February 2013. Magnetic resonance angiography or digital subtraction angiography was performed to evaluate midterm follow-up results.

RESULTS

The standard LVIS device, deployed in 27 patients, was more often used in internal carotid artery (ICA) aneurysms (n=19), whereas the LVIS Jr. (a lower profile stent, n=28) was generally reserved for anterior communicating artery (n=14) and middle cerebral artery (n=8) aneurysms. With LVIS-assisted coil embolization, successful occlusion was achieved in 45 aneurysms (81.8 %). Although no instances of navigation failure or stent malposition occurred, segmentally incomplete stent expansion was seen in five patients where the higher profile LVIS was applied to ICA including carotid siphon. Procedural morbidity was low (2/55, 3.6 %), limited to symptomatic thromboembolism. In the imaging of lesions (54/55, 98.2 %) at 6-month follow-up, only a single instances of major recanalization (1.9 %) occurred. Follow-up angiography of 30 aneurysms (54.5 %) demonstrated in-stent stenosis in 26 (86.7 %), with no instances of stent migration. Only one patient suffered late delayed infarction (modified Rankin Scale 1).

CONCLUSION

The LVIS device performed acceptably in stent-assisted coil embolization of non-ruptured aneurysms due to easy navigation and precise placement, although segmentally incomplete stent expansion and delayed in-stent stenosis were issues.