Neuroform in-stent stenosis: incidence, natural history, and treatment strategies

Periprocedural thromboembolic complications of LEO baby stent in endovascular treatment of intracranial aneurysms: Experience in 149 patients

OBJECTIVE

To report periprocedural thromboembolic complications of LEO Baby stent-assisted coiling of wide-necked intracranial aneurysms and to analyze the possible influencing factors.

METHODS

We retrospectively identified 149 patients with aneurysms who underwent LEO Baby stent-assisted embolization between October 2018 and March 2022. Clinical and radiographic data of patients were reviewed to determine whether a thromboembolic event had occurred. Multivariate logistic analysis was performed to identify significant factors associated with thromboembolic events.

RESULTS

Successful stent deployment of the stent was achieved in all patients in the target artery. There were 66 patients (44.3%) with acutely ruptured aneurysms and 83 patients (55.7%) with unruptured aneurysms. Fourteen (9.4%, 95% confidence interval: 4.7%-14.1%) patients were confirmed to have developed a thromboembolic event, including nine patients with acute intraoperative thrombosis and five patients with postoperative thromboembolic events. The rate of thromboembolic events was 6.0% (5/83) in patients with unruptured aneurysms and 13.6% (9/66) in patients with acutely ruptured aneurysms. There was a trend toward an increased rate of thromboembolic events in patients with acute ruptured aneurysms (p = 0.087). Thromboembolic events were significantly associated with the parent-artery diameter (p = 0.010).

CONCLUSIONS

Our study demonstrates a low rate of thromboembolic complications in unruptured aneurysms treated with LEO Baby stent. Thromboembolic events appear to be more common in ruptured aneurysms. A small diameter of the parent artery is associated with an increased risk of thromboembolic complications, and more relevant studies are still needed.

Is it safe to discontinue antiplatelet medication after stent-assisted coil embolization? If so, when is the best time?

PURPOSE

Antiplatelet maintenance after stent-assisted coil embolization (SACE) is generally considered essential to avoid post-procedural thromboembolic complications. However, there is still debate as to whether it is safe to discontinue antiplatelet drugs after SACE or when is the best time to do so. We investigate herein the clinical outcomes experienced by patients who discontinue antiplatelet agents after SACE.

METHODS

From a prospective database, we retrieved the data for 120 consecutive patients (harboring 130 aneurysms) in whom antiplatelet agents were discontinued after SACE between January 2010 and December 2019. We defined thromboembolic complications associated with discontinuation as neurologic or radiographic ischemia that occurred within 6 months of discontinuation of antiplatelet agents; the lesion was required to be correlated with the stented artery.

RESULTS

The mean time of discontinuation of antiplatelet medication was 31.4 ± 18.3 months after SACE (median, 26 months). The majority of patients stopped antiplatelet medication between 18 and 36 months after SACE (74 patients, 61.6%). Laser-cut closed-cell stent was most commonly applied in 91 aneurysms (70.0%), followed by braided closed-cell (n=29; 22.3 %) and laser-cut open-cell stent 10 (7.7 %). No patients experienced cerebral ischemia related to discontinuation of antiplatelet medication.

CONCLUSION

Our preliminary study suggests that it may be safe to discontinue antiplatelet medication after SACE in patients at low risk for ischemia. The optimal time to discontinue might be around 18 to 36 months after SACE. Large cohort-based studies or randomized clinical trials are warranted to confirm these results.

Bifurcated Aneurysm Location Predicts In-Stent Stenosis After Neuroform-EZ Stent-Assisted Coiling for Intracranial Aneurysm

Background and Purpose

The Neuroform EZ stent system (Boston Scientific Corporation, Fremont, CA, United States) is a fourth-generation intracranial aneurysm stent designed specifically for the cerebrovasculature to support aneurysm treatment. In this study, we analyzed our consecutive series of patients with aneurysm treated with the Neuroform EZ stent, with special attention to the occurrence of in-stent stenosis (ISS).

Methods

A retrospective review of our center's electronic database was conducted to identify all patients with intracranial aneurysms who underwent aneurysm treatment with the Neuroform EZ stent between January 2016 and October 2018. Patients with at least one digital subtraction angiography (DSA) follow-up in our hospital were enrolled in this study. In-stent stenosis (ISS) was graded as mild (<2–5%), moderate (25–50%), or severe (>50%).

Results

The study included 114 patients (78 women, 68.4%; median age 57.2 ± 9 years) with a total of 116 aneurysms. Of the 116 lesions, 20 were identified with ISS (17.2%) at a mean follow-up of 6.9 ± 1.7 months, and ISS was mild in 30% (6/20), moderate in 50% (10/20), and severe in 20% (4/20). No patients were symptomatic or required further intervention. Patients who developed ISS were younger than those without ISS (52.6 ± 7.8 vs. 57.9 ± 9; p = 0.016). The proportion of aneurysms located at the artery bifurcation was significantly higher in patients with stenosis than located at the sidewall artery (37.9 vs. 10.3%; p = 0.002). In the multivariable analysis, the patients' age (OR = 0.94; 95% CI 0.88–0.998; p = 0.02) and bifurcated aneurysm location (OR = 4.59; 95% CI 1.54–13.67; p = 0.006) were independent predictors of ISS.

Conclusions

In this retrospective study, the incidence of ISS after Neuroform EZ stent placement was 17.2%, and all the ISS cases were asymptomatic. Patients with younger age and bifurcated aneurysm location are more likely to develop ISS. Although Neuroform EZ stent is particularly suitable for bifurcated aneurysms, the ISS for this location should be focused upon.

Clinical and Angiographic Outcomes After Stent-Assisted Coiling of Cerebral Aneurysms With Laser-Cut and Braided Stents: A Comparative Analysis of the Literatures

Introduction: Stent-assisted coiling (SAC) plays an important role in endovascular treatment of intracranial aneurysms (IAs). This comparative analysis examines the safety and efficacy of SAC in general and compares clinical and angiographic outcomes between laser-cut stents and braided stents.

Methods: Relevant English-language studies were identified via a PubMed search for published articles regarding outcomes of SAC using laser-cut stents and braided stents published from 2015 to 2020. Data from 56 studies that met our inclusion criteria were pooled and statistically compared.

Results: A total of 4,373 patients harboring with 4,540 IAs were included. Patients were divided into two groups on the basis of stent type: laser-cut stents (2,076 aneurysms in 1991 patients; mean follow-up, 12.99 months) and braided stents (2,464 aneurysms in 2382 patients; mean follow-up, 18.41 months). Overall, the rates of successful stent deployment, thromboembolic events, stent stenosis, periprocedural intracranial hemorrhage, permanent morbidity, mortality, and recanalization were 97.72, 4.72, 2.87, 1.51, 2.14, 1.16, and 6.06%, respectively. Laser-cut stents were associated with a significantly higher rate of successful deployment (p = 0.003) and significantly lower rate of periprocedural intracranial hemorrhage (p = 0.048). Braided stents were associated with a significantly lower rate of permanent morbidity (p = 0.015).

Conclusion: SAC of IAs using laser-cut stents or braided stents was effective and safe. Rates of thromboembolic events, stent stenosis, mortality, and recanalization were comparable between the stent types. Braided stents were associated with lower permanent morbidity while laser-cut stents were associated with more favorable rates of successful deployment and periprocedural intracranial hemorrhage.

Wingspan Stenting for Symptomatic Severe In-Stent Stenosis of a Closed-Cell Stent after Stent-Assisted Coiling of a Ruptured Intracranial Aneurysm

We report the 3-year follow-up result of Wingspan intracranial stenting for symptomatic severe in-stent stenosis after stent-assisted coiling (SAC) for a ruptured left distal internal carotid artery (ICA) aneurysm. A middle-aged male patient visited our hospital for in-stent stenosis of a stent that was placed to treat a ruptured ICA aneurysm. Routine follow-up cerebral angiography, 1 year after SAC, showed in-stent stenosis around the distal markers of the inserted stent at the left M1 proximal segment. Six months later, he developed right dysesthesia. We performed intracranial stenting with Wingspan stent for the in-stent stenosis. Follow-up digital subtraction angiography performed 1 year after the Wingspan stenting showed good patency of the ICA and middle cerebral artery flow without evidence of restenosis. At 3-year follow-up, magnetic resonance angiography showed sufficient middle cerebral artery flow although the stenting segment could not be visualized clearly. Wingspan stenting might be a feasible option in patients with iatrogenic intracranial stenosis resulting from in-stent stenosis who experience the progression of intracranial stenosis with manifestation of neurological symptoms despite dual anti-platelet therapy.

Comaneci device-assisted embolization of wide-necked carotid aneurysms with an unfavorable ratio

Background

Endovascular treatment is the technique of choice for most intracranial aneurysms. However, the treatment of morphologically complex wide-necked aneurysms with an unfavorable anatomy is still a therapeutic challenge.

The purpose of the study is to describe the initial experience with the Comaneci embolization assist device for the treatment of wide-necked aneurysms with an unfavorable ratio for direct embolization.

Methods

We report a retrospective single-center analysis taken from a prospective database of consecutive aneurysms of the anterior circulation treated using the Comaneci device in the period from March 2017 to March 2019.

Results

Eighteen aneurysms were collected from 16 patients (9 women and 7 men) treated using the Comaneci device. The mean age was 48.4 years (range 36–81). Twelve patients had SAH, three were incidental aneurysms and one had compressive symptoms. A complete asymptomatic occlusion rate of 88.8% was obtained. The major complication rate was 5.55%.

Conclusion

The Comaneci embolization assist device is a safe, effective option for endovascular treatment of complex aneurysms with an unfavorable ratio.

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.

The safety and effectiveness of the Woven EndoBridge (WEB) system for the treatment of wide-necked bifurcation aneurysms: final 12-month results of the pivotal WEB Intrasaccular Therapy (WEB-IT) Study

INTRODUCTION

The Woven EndoBridge Intrasaccular Therapy (WEB-IT) Study is a pivotal, prospective, single-arm, investigational device exemption study designed to evaluate the safety and effectiveness of the WEB device for the treatment of wide-neck bifurcation aneurysms.

METHODS

One-hundred and fifty patients with wide-neck bifurcation aneurysms were enrolled at 21 US and six international centers. Angiograms from the index procedure, and 6-month and 1-year follow-up visits were all reviewed by a core laboratory. All adverse events were reviewed and adjudicated by a clinical events adjudicator. A data monitoring committee provided oversight during the trial to ensure subject safety.

RESULTS

One-hundred and forty-eight patients received the WEB implant. One (0.7%) primary safety event occurred during the study-a delayed ipsilateral parenchymal hemorrhage-on postoperative day 22. No primary safety events occurred after 30 days through 1 year. At the 12-month angiographic follow-up, 77/143 patients (53.8%) had complete aneurysm occlusion. Adequate occlusion was achieved in 121/143 (84.6%) subjects.

CONCLUSIONS

The prespecified safety and effectiveness endpoints for the aneurysms studied in the WEB-IT trial were met. The results of this trial suggest that the WEB device provides an option for patients with wide-neck bifurcation aneurysms that is as effective as currently available therapies and markedly safer.

TRIAL REGISTRATION NUMBER

NCT02191618.

Pointwise Encoding Time Reduction with Radial Acquisition with Subtraction-Based MRA during the Follow-Up of Stent-Assisted Coil Embolization of Anterior Circulation Aneurysms

BACKGROUND AND PURPOSE

Time-of-flight MR angiography, though widely used after coil embolization, is associated with limitations owing to magnetic susceptibility and radiofrequency shielding following stent-assisted coil embolization. We evaluated the pointwise encoding time reduction with radial acquisition (PETRA) sequence in subtraction-based MRA (qMRA) using an ultrashort TE relative to TOF-MRA during the follow-up of stent-assisted coil embolization for anterior circulation aneurysms.

MATERIALS AND METHODS

Twenty-five patients (3 men and 22 women; mean age, 59.1 ± 14.0 years) underwent stent-assisted coil embolization for anterior circulation aneurysms and were retrospectively evaluated using TOF-MRA and PETRA qMRA data from the same follow-up session. Two neuroradiologists independently reviewed both MRA findings and subjectively graded flow within the stents (relative to the latest DSA findings) and occlusion status (complete occlusion or neck/aneurysm remnant). Interobserver and intermodality agreement for TOF-MRA and PETRA qMRA were evaluated.

RESULTS

The mean score for flow visualization within the stents was significantly higher in PETRA qMRA than in TOF-MRA (P < .001 for both observers), and good interobserver agreement was reported (κ = 0.63). The aneurysm occlusion status of PETRA qMRA (observer 1, 92.0%; observer 2, 88.0%) was more consistent with DSA than with TOF-MRA (observer 1, 76.0%; observer 2, 80.0%), and there was a better intermodality agreement between DSA and PETRA qMRA than between DSA and TOF-MRA.

CONCLUSIONS

These findings indicate that PETRA qMRA is a useful follow-up technique for patients who have undergone stent-assisted coil embolization for anterior circulation aneurysms.

The safety and effectiveness of the LVIS stent system for the treatment of wide-necked cerebral aneurysms: final results of the pivotal US LVIS trial

Introduction

The LVIS stent system (LVIS and LVIS Junior) is a self-expanding, retrievable, microstent system indicated for the treatment of wide-necked cerebral aneurysms (WNAs). The present pivotal study was performed to evaluate the safety and effectiveness of this device.

Methods

The US LVIS pivotal trial was a prospective, multicenter, single-arm, interventional study conducted at 21 US centers. The study enrolled 153 adults with WNAs of the anterior and posterior circulations. The study was conducted under good clinical practices and included independent adjudication of all adverse events. The primary effectiveness endpoint was defined as successful aneurysm treatment with the LVIS System as evidenced by complete (100%) aneurysm occlusion at 12 months on conventional angiography without retreatment and without significant (≥50%) stenosis of the treated artery at 12 months as determined by an independent core laboratory. The primary safety endpoint was defined as the rate of stroke or death within 30 days, or ipsilateral stroke or neurologic death with 12 months.

Results

One hundred and fifty-three patients enrolled at 21 investigational sites underwent attempted LVIS-assisted coil embolization. The mean age was 58.3±10.5 years and the majority of the participants (110/153, 71.9%) were female. Fifty-seven aneurysms (57/153, 37.3%) arose from the anterior cerebral artery, 43 (43/153, 28.1%) from the internal carotid artery, 17 (17/153, 11.1%) from the middle cerebral artery, 27 (27/153, 17.6%) from the basilar artery, six (6/153,3.9 %) from the PCA, and two from the vertebral artery. A single aneurysm arose from the superior cerebellar artery. The mean aneurysm dome height was 6.0±2.2 mm and mean width 5.5±2.3 mm. Mean neck width was 4.2±1.4 mm. A total of 22 participants presented for re-treatment of a previously ruptured (>30 days prior to treatment) target aneurysm. The primary effectiveness endpoint was observed in 70.6% (108/153) in the intent to treat population (ITT). Of the evaluable participants with follow-up 12-month angiography, 79.1 % (110/139) demonstrated complete occlusion– 92.1% (128/139) in this population demonstrated ≥95% occlusion and 95% demonstrated ≥90% occlusion (132/139). Eight participants (5.2%, 8/153) had at least one primary safety event in the ITT population.

Conclusion

The LVIS stent system allows safe and highly effective coil embolization of WNAs.

Clinical registration number

NCT01793792.

Curative cerebrovascular reconstruction with the Pipeline embolization device: the emergence of definitive endovascular therapy for intracranial aneurysms

Endovascular, endosaccular, coil embolization has emerged as an established therapy for both ruptured and unruptured cerebral aneurysms. However, many aneurysms are not cured using conventional endovascular techniques. Coil embolization often results in incomplete aneurysm occlusion or recanalization in the ensuing months after treatment. The Pipeline embolization device (PED; Chestnut Medical) represents a new generation endoluminal implant which is designed to treat aneurysms by reconstructing the diseased parent artery. Immediately after implantation, the PED functions to divert flow from the aneurysm, creating an environment conducive to thrombosis. With time, the PED is incorporated into the vessel wall as neointimal–endothelial overgrowth occurs along the construct. Ultimately, this process results in the durable complete exclusion of the aneurysm from the cerebrovasculature and a definitive endoluminal reconstruction of the diseased parent artery.

Early experience with a temporary bridging device (Comaneci) in the endovascular treatment of ruptured wide neck aneurysms

Background

The difficulties in obtaining complete and stable endovascular occlusion are most evident for ruptured aneurysms exhibiting a wide neck and unfavorable geometric features. The aim of our study was to present our experience with the Comaneci temporary bridging device in ruptured wide neck aneurysms.

Methods

From May to July 2017, 29 ruptured aneurysms underwent endovascular embolization with the Comaneci device. Angiographic and clinical results were retrospectively analyzed.

Results

29 ruptured intracranial aneurysms from different locations were included. Successful embolization was achieved in all lesions; complete post-procedure occlusion was seen in 25 (86%) cases. Insufficient embolization or neck remnant was observed in four cases (13.7%). Complications probably related, directly related, or indirectly related to the device occurred in 3.44% of patients (1/29 patients). At least one angiographic follow-up was performed in each of the 29 cases. The 12 month follow-up examination has yet to be done.

Conclusion

The Comaneci device offers a new promising and reliable technique that can safely support aneurysm coiling occlusion even in a rupture environment. However, long term monitoring of patients treated by this device is mandatory.

In-stent stenosis in the patient with internal carotid aneurysm after treated by the Willis covered stent: Two case reports and literature review

In-stent stenosis after treated by Willis covered stent-case reports.

BACKGROUND

Advancements in minimally invasive technology have allowed endovascular reconstruction of internal carotid aneurysm. However, in-stent stenosis is an important and well-characterized complication of stenting after the treatment of internal carotid aneurysm.

CASE DESCRIPTION

We would present 2 patients who were diagnosed with in-stent stenosis after the treatment of Willis covered stent. Case 1: A 57-year-old female with 2-week history of headache and vomiting before admission, whose digital subtraction angiography (DSA) demonstrated left internal carotid C6 aneurysm and showed about 20% stenosis 3 months later since operation in the position where Willis covered stent was deployed. Case 2: A 23-year-old male with skull base fracture, subarachnoid hemorrhage, right femoral fracture for 14 days and epistaxis for 9 hours caused by a car accident, whose DSA demonstrated left internal carotid paracliniod pseudoaneurysm. One year later, the patient went to our center again because he had headache and dizziness for 6 months after the interventional operation. His DSA demonstrated about 80% stenosis in the position where Willis covered stent was deployed. The clinical and radiologic characteristics and the experience in dealing with the stenosis are presented.

CONCLUSIONS

In-stent stenosis after treated with Willis covered is uncommon, but not rare. Operators should pay more attention to the in-stent stenosis during the period of follow-up observation and monitor P2Y12 Reaction Unit (PRU) in the antiplatelet period, especially for the Willis covered stent. What is more, the treatment for stenosis ought to be carefully considered.

Stent-Assisted Endovascular Treatment of Anterior Communicating Artery Aneurysms - Literature Review

The anterior cerebral artery is a common location of intracranial aneurysms. The standard coil embolization technique is limited by its inability to occlude wide-neck aneurysms. Stent deployment across the aneurysm neck supports the coil mass inside the aneurysmal sac, and furthermore, has an effect on local hemodynamic and biologic changes. In this article, various management strategies and techniques as well as angiographic outcomes and complications related to stent-assisted endovascular treatment of anterior communicating artery aneurysms are presented. This treatment method is safe and associated with low morbidity and mortality rates.

Factors for Achieving Safe and Complete Treatment for Unruptured Saccular Aneurysm Smaller Than 10 mm by Simple Clipping or Simple Coil Embolization

OBJECTIVE

Reducing complications from unruptured aneurysms (UAs) treatment is important. We clarify the criteria for achieving safe and complete treatment for UAs ≤10 mm by clipping or coil embolization.

METHODS

This study included 59 newly treated UAs in the past 2 years. We prospectively decided on criteria to recommend active treatment. UAs ≤10 mm and in ≤75 year-olds, located at in the internal carotid artery at the paraclinoid portion and the posterior circulation aneurysms except for a vertebral artery-inferior posterior cerebellar artery aneurysm were mainly treated by coil embolization, and those in the internal carotid artery except at the paraclinoid portion, in the anterior or middle cerebral artery, and in the vertebral artery-inferior posterior cerebellar artery were treated preferably by clipping. UAs with a height/neck ratio or a dome/neck ratio ≤1.4 were treated preferentially by clipping. Specific preoperative imaging and careful manipulation were adopted for clipping.

RESULTS

Fifty-seven (96.6%) achieved modified Rankin scale (mRS) 0-1, 2 (3.4%) mRS 2-5, and 0 had mRS 6. Fifty-three UAs (89.8%) achieved complete occlusion (CO) and 7 (10.1%) had neck remnants (NR). Forty-one UAs (100%) within the criteria achieved mRS 0-1, 40 (98%) achieved CO, and 1 (2%) NR. The odds ratio of NR for those outside the criteria was 18.5 (95% confidence interval, 1.83-186.6) (P < 0.05). CO treated within the criteria was 39 and NR was 1. CO treated outside the criteria was 14 and NR was 5 (P < 0.05). The mRS 0-1 with age ≤75 years was 55 and the mRS 2-6 was 0. The mRS 0-1 with age ≥76 years was 2 and the mRS 2-6 was 2 (P < 0.01).

CONCLUSIONS

The treatment for UAs within the criteria, with the most recent points of concern, can lead to safe and complete results.

Outcomes of Stent-assisted Coil Embolization of Wide-necked Intracranial Aneurysms Using the Solitaire™ AB Neurovascular Remodeling Device

Objective

This retrospective study presents our experience with respect to the clinical and angiographic outcomes of patients treated with stent-assisted coil embolization using Solitaire™ AB stents.

Materials and Methods

From March 2011 to December 2014, 50 patients with 55 wide-necked and/or complex intracranial aneurysms were evaluated. Four patients presented with an acute subarachnoid hemorrhage. Stent deployment was performed with a standard coiling procedure in 49 aneurysms. Three patients underwent bailout stenting, 2 patients were treated by temporary stenting and one patient was treated only by stenting without coiling for dissecting aneurysm.

Results

Successful placement of the Solitaire AB stent was achieved in all the cases. Based on the postprocedural angiographic results, a Raymond 1 was obtained in 32 (59%) of 54 aneurysms, excluded by one case of dissecting aneurysm, and a Raymond 2 in 13 (24%), and a Raymond 3 in 9 (17%). There was one thromboembolic (2%) and three hemorrhagic complications (6%). However, procedure-related morbidity or mortality was not found. Annual follow-up angiographic results from the embolization were obtained in 40 (74.1%) of 54 cases. These results were represented as Raymond 1 in 27 (67.5%), class 2 in 9 (22.5%), and class 3 in 4 (10%) cases. Angiographic improvement associated with progressive thrombosis of the aneurysm was obtained in 10 aneurysms. Four aneurysms were recanalized without requiring additional treatment. In-stent stenosis was found in one aneurysm, but stent migration was not seen on follow-up angiography.

Conclusion

Stent-assisted coil embolization using the Solitaire AB stent for treating wide-necked and/or complex intracranial aneurysms was found to be safe and effective immediately post-embolization and after follow-up. Long-term follow-up will be required to identify the effect of the Solitaire AB stent on recanalization rates.

Morphologic and Clinical Outcome of Intracranial Aneurysms after Treatment Using Flow Diverter Devices: Mid-Term Follow-Up

Flow diverters (FDs) are designed for the endovascular treatment of complex intracranial aneurysm configurations. From February 2009 to March 2013 28 patients (22 females, 6 males) were treated with FD; mean age was 57 years. Data, including aneurysm features, clinical presentation, history of previous bleeding, treatment, and follow-up results, are presented. Early postinterventional neurological deficits (transient: n = 3/enduring: n = 1) appeared in 4/28 patients (14%), and early improvement of neurological symptoms was observed in 7 patients with previous restriction of cranial nerve function. The overall occlusion rate was 20/26 (77%; 59% after 3 months). 77% achieved best results according to O'Kelly-Marotta score grade D with no contrast material filling (70% of those after 3 months). In 4/6 patients who did not achieve grade D, proximal and/or distal stent overlapping ≥5 mm was not guaranteed sufficiently. During follow-up we did not detect any aneurysm recurrence or haemorrhage. In-stent stenosis emerged as the most frequent complication (4/27; 15%) followed by 2 cases of vascular obliteration (AICA/VA). In conclusion endovascular reconstruction using a FD represents a modern and effective treatment in those aneurysms that are not suitable for conventional interventional or surgical treatment. The appearance of severe complications was rare.

Stent-Assisted Coiling of Wide-Neck Intracranial Aneurysms Using Low-Profile LEO Baby Stents: Initial and Midterm Results

BACKGROUND AND PURPOSE

Low-profile self-expandable stents were recently introduced for the treatment of wide-neck intracranial aneurysms. This study investigated the initial and midterm clinical and angiographic results of LEO Baby stent-assisted coiling in the treatment of wide-neck intracranial aneurysms.

MATERIALS AND METHODS

A retrospective review was performed to identify patients who were treated with LEO Baby stent-assisted coiling. Eighty patients with 80 wide-neck intracranial aneurysms were included in the study. Eleven patients (13.8%) presented with subarachnoid hemorrhage. All patients were treated with LEO Baby stent-assisted coiling. Technical success and immediate postprocedural clinical and angiographic outcomes were evaluated. Seventy-three patients attended angiographic and clinical follow-up for a mean duration of 7.2 ± 3.8 months. Periprocedural and delayed complications were reviewed. Preprocedural and follow-up clinical statuses were assessed by using the modified Rankin Scale.

RESULTS

The technical success rate of the procedure was 97.5%. The immediate postprocedural angiography revealed a complete occlusion of the aneurysm in 75% of the 80 patients. The last follow-up angiograms showed complete occlusion in 85.7% of the 77 patients with an angiographic follow-up. Of the 77 patients with a follow-up angiography, 6.5% showed an increase in the filling status of the aneurysm and 5.2% required retreatment. The overall procedure-related complication rate, including asymptomatic complications, was 11.3%. The permanent morbidity rate was 3.8%. There was no mortality in this study.

CONCLUSIONS

This case series demonstrates the relative safety, efficacy, and midterm durability of the LEO Baby stent-assisted coiling procedure for the treatment of wide-neck intracranial aneurysms.

Stent-Assisted Coil Embolization of Intracranial Aneurysms: Complications in Acutely Ruptured versus Unruptured Aneurysms

BACKGROUND AND PURPOSE

The use of stents in the setting of SAH is controversial because of concerns about the efficacy and risk of dual antiplatelet therapy. We compare complications of stent-assisted coil embolization in patients with acutely ruptured aneurysms with complications in patients with unruptured aneurysms.

MATERIALS AND METHODS

Between February 2007 and March 2015, 45 acutely ruptured aneurysms and 47 unruptured aneurysms were treated with stent-assisted coiling. Patients with ruptured aneurysms were not pretreated with antiplatelet medication but received intravenous aspirin during the procedure. Thromboembolic events and early rebleeds were recorded.

RESULTS

In ruptured aneurysms, 9 of 45 patients had thromboembolic complications. Four patients remained asymptomatic, 4 developed infarctions, and 1 patient died. The permanent complication rate in ruptured aneurysms was 11% (95% CI, 4%-24%). Five of 45 patients (11%; 95% CI, 4%-24%) had an early rebleed from the treated aneurysm after 3-45 days, and in 4, this rebleed was fatal. In 46 patients with 47 unruptured aneurysms, thromboembolic complications occurred in 2. One patient remained asymptomatic; the other had a thalamus infarction. The complication rate in unruptured aneurysms was 2.2% (1 of 46; 95% CI, 0.01%-12%). No first-time hemorrhages occurred in 46 patients with 47 aneurysms during 6 months of follow-up.

CONCLUSIONS

The complication rate of stent-assisted coiling with early adverse events in ruptured aneurysms was 10 times higher than that in unruptured aneurysms. Early rebleed accounted for most mortality. In ruptured aneurysms, stent-assisted coil embolization is associated with increased morbidity and mortality and should only be considered when less risky options have been excluded.

Early surgical removal of migrated coil/stent after failed embolization of intracranial aneurysm

OBJECT

Distal coil or stent migration is a rare, but potentially morbid complication of intracranial aneurysm embolization. At present, there is no established standard of surgical evacuation of displaced material-in particular, there is no consensus on the optimum time for such intervention. The authors report their positive experiences with an ultra-early surgical evacuation of 2 migrated coils and a flow-diverter stent.

METHODS

Uncontrolled coil or stent migration occurred in 3 (0.75%) of approximately 400 patients treated between 1999 and 2012 in the authors' institution. In all 3 cases, the materials moved from their intended position to the middle cerebral artery (MCA). Surgical evacuation was started immediately (within half an hour) after a futile attempt of removing them via intraarterial route, under the same anesthesia and with no active reversal of heparinization.

RESULTS

No excessive bleeding was observed. Displaced coils were extracted through an incision of a branch of MCA-the anterior temporal artery, the stent was removed through a direct incision of MCA. Recombinant tissue plasminogen activator (rtPA) was injected to the stem of the internal carotid artery toward the end of the procedure, with no discernible adverse effects. Two patients were discharged with no deficit (Glasgow Outcome Scale [GOS] Score 5); the other patient was conscious with mild hemiparesis (GOS Score 4) at discharge.

CONCLUSIONS

The experiences of these 3 cases suggest that immediate removal of a migrated stent/coil is feasible and may be effective. Indirect access to the MCA through its branch helps to shorten the time of temporary clipping of the artery to a minimum. Maintaining active heparinization and direct intraarterial injection of rtPA are helpful in promoting blood flow in the MCA.

Solitaire AB stent-assisted coiling of wide-necked intracranial aneurysms: mid-term results from the SOLARE Study

BACKGROUND

Endovascular treatment of intracranial aneurysms can be technically difficult when the neck is wide. The Solitaire AB stent (Covidien, Irvine, California), the only fully retrieved stent, assists in the coiling of wide-neck intracranial aneurysms.

OBJECTIVE

To evaluate the mid-term angiographic follow-up of wide-necked aneurysms treated with the Solitaire AB stent.

METHODS

SOLARE (SOLitaire Aneurysm Remodeling) is a consecutive, prospective study conducted in 7 European centers. A core laboratory evaluated the postoperative and mid-term (6 month ± 15 days) angiographic results by using the Raymond classification Scale. Recanalization was defined as worsening, and progressive thrombosis was defined as improvement in the Raymond scale score.

RESULTS

The mean width of the aneurysm sac was 7.5 mm, and the mean diameter of the aneurysm neck was 4.7 mm. Angiographic mid-term follow-up was obtained in 55 of 65 aneurysms (85.9%). Complete occlusion was achieved in 33 aneurysms (60%); a neck remnant was seen in 16 aneurysms (29.1%) and an aneurysm remnant in 6 aneurysms (10.9%). Of 55 aneurysms, recanalization was observed in 8 aneurysms (14.5%), and progressive thrombosis was observed in 17 aneurysms (30.9%). No bleeding or rebleeding was observed during the follow-up period.

CONCLUSION

Stent-assisted coiling of wide-necked intracranial aneurysms was found to be safe and effective with the Solitaire AB stent at 6-month follow-up. Angiographic results improve with time due to progressive thrombosis of the aneurysm.

Very late in-stent thrombosis 9 years after double stent treatment of fusiform basilar artery aneurysm

Endovascular treatment seems to be the best approach to posterior circulation fusiform aneurysms. Double stent techniques are frequently used to occlude basilar artery dilations. Unfortunately, there is a limited number of studies that have followed up with patients over prolonged periods of time in order to evaluate delayed complications, such as stenosis, thrombosis or migration of stents. We present an unusual case of in-stent thrombosis 9 years after basilar artery aneurysm treatment to caution about complications associated with double stent implantation.

Multiple overlapping stent-assisted coiling of complex aneurysms: a single-center experience

OBJECTIVES

Coil embolization of wide-necked and fusiform aneurysms is challenging and is frequently associated with recanalization despite assistance of any additional device. The purpose of this study was to evaluate the feasibility and mid-term outcomes of complex aneurysms after multiple overlapping stent-assisted coiling (OSAC).

METHODS

We retrospectively evaluated 26 wide-necked and fusiform atherosclerotic or dissecting aneurysms that were treated with multiple OSAC. Eight aneurysms (30·8%) presented with subarachnoid hemorrhage and one (3·9%) with intracranial hemorrhage.

RESULTS

Complete embolization was achieved in 15 of the 26 aneurysms (57·7%), while remnant neck was identified in nine (34·6%) and remnant aneurysm was noted in two (7·7%). Immediate procedure-related complications were observed in five patients (19·2%) including two with asymptomatic in-stent thrombosis, one with transient right-sided weakness, one with decreased mentality, and one with aphasia and quadriplegia. A procedure-related permanent neurologic deficit (modified Rankin scale scores of 1 and 5) was noted in two patients (7·7%). Angiographic follow-up (mean duration 23·9 months) after OSAC was carried out in 18 patients (69·2%): 11 (61·1%) were stable, 3 (16·7%) improved, 3 (16·7%) had minor compaction, and 1 had major recanalization (5·5%). One recurred aneurysm after OSAC and two recanalized aneurysms after single stenting were re-treated using additional stent-assisted coiling, and there was no recanalization in these three aneurysms during the 25·7 months after re-treatment.

CONCLUSIONS

Multiple OSAC is feasible and effective for complex aneurysms and recurrent aneurysms after stent-assisted coiling.

The penumbra coil 400 system for treatment of wide-necked intracranial aneurysms: initial single-center experience

Endovascular treatment of wide-necked intracranial aneurysms frequently requires stent- or balloon-assisted coiling to prevent coil herniation into the parent artery. Provided that coils can be securely deployed within the aneurysm sac, these adjunctive devices and their associated risk can be avoided. The Penumbra 400 Coil (PC-400) has a larger diameter than conventional coils and is constructed completely of metal, a feature that increases the coil stability and may improve its ability to respect the aneurysm neck. The purpose of this study was to examine the frequency of adjunctive stent usage when coiling wide-necked intracranial aneurysms with the PC-400 in comparison with conventional coils. We examined consecutive patients with unruptured wide-necked aneurysms treated at our institution with endovascular coils. Aneurysm characteristics and procedural outcomes were compared between patients treated with PC-400 compared with a control group treated with conventional coils. Thirty-eight patients met criteria for this study. Stent-assisted coiling was required in 34 % fewer cases using PC-400 compared with conventional coils (P = .049). Fewer coils and less length were required with the PC-400 to obtain the same packing densities, occlusion types, and short-term stability. This may reduce treatment cost and prove to be valuable in patients with contraindications to dual antiplatelet therapy.

The effectiveness of 3T time-of-flight magnetic resonance angiography for follow-up evaluations after the stent-assisted coil embolization of cerebral aneurysms

BACKGROUND

Artifacts introduced by stents limit the value of magnetic resonance (MR) imaging as a follow-up modality after the stent-assisted coil embolization of cerebral aneurysms.

PURPOSE

To investigate the usefulness of 3 Tesla (3T) time-of-flight (TOF) MR angiography (MRA) for the follow-up evaluation.

MATERIAL AND METHODS

Twenty-two aneurysms of 20 patients treated with stent-assisted coil embolization were followed up with 3T TOF MRA and digital subtraction angiography (DSA) with three-dimensional rotational angiography (3DRA). The status of coiled aneurysms was compared with 3T TOF MRA and DSA with 3DRA in terms of complete occlusion, residual neck, and residual aneurysm. TOF MRA at 3T was performed 1 day before DSA with 3DRA, with a mean follow-up period of 20.1 ± 10.8 months.

RESULTS

Twenty (90.9%) of 22 cases were concordant between the two modalities. The degree of agreement and correlation between them were high (κ=0.771, P<0.001; r=0.832 and P<0.001). When evaluating the status of residual neck, the sensitivity was 80% (4/5 cases); specificity was not available because there were no cases of complete occlusion. For the status of residual aneurysm, the sensitivity and specificity were 94.1% (16/17 cases) and 100% (all 5 cases), respectively.

CONCLUSION

TOF MRA at 3T with source images could be useful as a non-invasive follow-up modality after the stent-assisted coil embolization of cerebral aneurysms. Further study with a larger patient sample is needed to confirm the effectiveness of 3T TOF MRA.

Stent-assisted coil embolization of ruptured wide-necked aneurysms in the acute period: incidence of and risk factors for periprocedural complications

OBJECT.: The purpose of this study was to report the authors' experiences in stent-assisted coil embolization (SAC) of ruptured wide-necked aneurysms in the acute period and to evaluate the incidence of and risk factors for periprocedural complications.

METHODS

A total of 72 patients were recruited for this study between March 2007 and June 2012. All patients met the following criteria: 1) the presence of ruptured intracranial wide-necked saccular aneurysms, and 2) the patient underwent SAC for treatment of those aneurysms within 72 hours of rupture. All of the patients with clinically poor grades or acute hydrocephalus underwent external ventricular drainage (EVD) before SAC. The incidence of and risk factors for periprocedural complications were retrospectively evaluated.

RESULTS

Of the 72 patients included in this study, periprocedural complications occurred in 14 (19.4%), including asymptomatic complications in 4 (5.6%) and symptomatic complications in 10 (13.9%); there were symptomatic thromboembolic complications in 5 patients (6.9%), and symptomatic hemorrhagic complications in 5 (6.9%). The authors observed no subacute or delayed thromboembolic complications during the follow-up period of 18.8 months. Use of EVD (OR 1.413, 95% CI 0.088-2.173; p = 0.046) was the only independent risk factor for periprocedural complications on multivariate logistic regression analysis.

CONCLUSIONS

The periprocedural complication rate during SAC was 19.4% among 72 patients. Because of the high complication rate, microsurgical clipping or endovascular treatment with another technique (multiple-microcatheter or balloon-assisted technique) may be a more appropriate option for first-line treatment than SAC, especially in patients requiring EVD.

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.

Analysis of closed-cell intracranial stent characteristics using cone-beam computed tomography with contrast material

The intracranial nitinol stent named the Enterprise Vascular Reconstruction Device has poor radiographic visibility. The characteristics of closed-cell intracranial stents were investigated and the efficacy of intraoperative stent visualization examined with the 80 kV high-resolution XperCT protocol, which is a flat detector C-arm volume acquisition functionality system integrated with the angiography equipment. We treated 39 aneurysms with stent-assisted coil embolization. The aneurysms were located on the internal carotid artery in 24 cases, the anterior communicating artery (AcomA) in three, the basilar artery (BA) in 10, and the vertebral artery in two. Intraoperative 80 kV XperCT was performed in all cases after deposition of the stent. We evaluated the coverage of the aneurysm neck, incomplete stent apposition (ISA), and shift of vessels. Accurate stent visualization was achieved in 29 of the 39 cases without coil and delivery wire artifact. Coverage of the aneurysm neck succeeded in 28 cases; there was one case of BA top Y-configuration stenting in which the stent was dislocated into the aneurysm. ISA was detected in nine cases, including seven kinks and one flattening in the carotid siphon and one kink in the BA top. We detected linearization of vessels due to stent deployment in three AcomA cases and three BA top cases. We conclude that intraoperative 80 kV XperCT is an efficient modality for the evaluation of ISA. Stent kinking in the carotid siphon and linearization in distal vessels can be detected with this protocol.

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

BACKGROUND

Although intracranial stenting has been associated with in-stent stenosis, the vascular response of cerebral vessels to the deployment of the Enterprise vascular reconstruction device is poorly defined.

OBJECTIVE

To evaluate the change in parent vessel caliber that ensues after Enterprise stent placement.

METHODS

Seventy-seven patients with 88 aneurysms were treated using Enterprise stent-assisted coil embolization and underwent high-resolution three-dimensional rotational angiography followed by three-dimensional edge-detection filtering to remove windowing-dependence measurement artifact. Orthogonal diameters and cross-sectional areas (CSAs) were measured proximal and distal on either side of the leading stent edge (points A, B), trailing stent edge (points D, E), and at mid-stent (point C).

RESULTS

Enterprise stent deployment caused an instant increase in the parent artery CSA by 8.98% at D, which was followed 4-6 months later by significant in-stent stenosis (15.78% at A, 27.24% at B, 10.68% at C, 32.12% at D, and 28.28% at E) in the stented artery. This time-dependent phenomenon showed resolution which was complete by 12-24 months after treatment. This target vessel stenosis showed significant age dependence with greater response in the young. No flow-limiting stenosis requiring treatment was observed in this series.

CONCLUSIONS

Use of the Enterprise stent is associated with a significant dynamic and spontaneously resolvable age-dependent in-stent stenosis. Further study is warranted on the clinical impact, if any, of this occurrence.

Various techniques of stent-assisted coil embolization of wide-necked or fusiform artherosclerotic and dissecting unruptured vertebrobasilar artery aneurysms for reducing recanalization: mid-term results

BACKGROUND

Coil embolization of wide-necked or fusiform vertebrobasilar aneurysms is challenging and tends to involve frequent recanalization.

PURPOSE

The aim of our study was to evaluate complications and mid-term outcomes of complex vertebrobasilar artery aneurysms after stent-assisted coiling with various techniques.

METHODS

We retrospectively evaluated 28 cases of unruptured vertebrobasilar aneurysm treated by stent-assisted coiling.

RESULTS

Forty-four of the 45 stents placed in 28 patients were deployed at the desired location (97.8 %). Single stent-assisted coiling was performed in 14 aneurysms, a stent-within-a-stent (SWS) technique was used in 12 aneurysms, and Y-stent-assisted coiling was employed in four basilar tip aneurysms. Two basilar tip aneurysms treated by single stent-assisted coiling recurred and were retreated by SWS and Y-stent-assisted coiling. Complete embolization was achieved in 19 aneurysms (67.8 %), and remnant neck persisted in eight aneurysms (28.6 %) and remnant aneurysm was noted in one aneurysm (3.6 %). Permanent neurologic deficit (Modified Rankin Scale 1 and 4) was noted in two patients (7.1 %). Angiographic follow-up (mean follow-up period: 20.8 months) was performed in 20 patients. Major recanalization occurred in two basilar tip aneurysms (10 %) and minor compaction was noted in one superior cerebellar artery aneurysm. The remaining 17 aneurysms were stable or improved (85 %).

CONCLUSIONS

Complex vertebrobasilar aneurysm embolization with stent-assisted techniques was effective and feasible as a method for reducing recanalization during midterm angiographic follow-up. Large and wide-necked basilar tip aneurysms showed frequent major recanalization, and compact packing with single or Y-stent-assisted coiling is needed to prevent recanalization even if coiling will be done without stenting.

Stent-assisted coiling in endovascular treatment of 500 consecutive cerebral aneurysms with long-term follow-up

BACKGROUND AND PURPOSE

Stent-assisted coil embolization has become one of the most preferred techniques in the treatment of wide-neck intracranial aneurysms; however, long-term patency and safety of the self-expanding neurostents and their role in durability of the endovascular treatment has remained ambiguous. We sought to retrospectively examine the long-term results of self-expanding stent usage in conjunction with coil embolization in treatment of wide-neck cerebral aneurysms.

MATERIALS AND METHODS

We coiled 500 wide-neck cerebral aneurysms with different types of self-expanding neurostent assistance in 468 patients. Patient and aneurysm characteristics, pharmacologic therapy protocol, complications, and initial occlusion grades were analyzed. Patients underwent angiographic follow-up at 6 months to 7 years after treatment. DSA or MRA images of all patients were analyzed to assess the occlusion rate of aneurysms and patency of the parent artery.

RESULTS

Enterprise (n = 340), Solitaire (n = 98), Wingspan (n = 41), LEO (n = 16), and Neuroform (n = 5) stent systems were used in this series. Stent-related thromboembolic events occurred in 21 patients and intraoperative rupture occurred in 4 patients. Initially, complete occlusion was achieved in 42.2% of the aneurysms, and, according to the last follow-up data, the rate had progressed to 90.8%. Recanalization rate at 6 months was 8%, whereas the late recanalization rate was 2%.

CONCLUSIONS

The use of stents in endovascular treatment provides high rates of complete occlusion and low rates of recurrence at a long-term follow-up study.

Clinical and Angiographic Outcomes of Wide-necked Aneurysms Treated with the Solitaire AB Stent

OBJECTIVE

This study investigated the clinical and angiographic outcomes of treatment with stent-assisted coil embolization using the Solitaire AB stents for wide-necked intracranial aneurysms.

METHODS

From October 2010 to December 2011, 22 patients with aneurysms were treated with the Solitaire AB stent. One patient with a dissecting aneurysm was excluded, thus 21 patients with 21 wide-necked saccular aneurysms were included in this study. The technical success rate, procedure-related complications, initial and follow-up angiographic results, and clinical outcomes were retrospectively collected.

RESULTS

THE LOCATIONS OF ANEURYSMS WERE AS FOLLOWS: paraclinoid in 14, distal internal carotid artery in 4, and vertebral artery in 3 patients. All aneurysms were unruptured and less than 10 mm-sized. The mean dome-to-neck ratio of the aneurysms was 1.00 (range: 0.45-1.81). The mean follow-up duration was 12.1 (7-15) months after the initial procedure. The technical success rate was 21 (95.5%) of 22 patients with aneurysms. Fortunately, there were no procedure-related complications. Follow-up angiography showed that the rate of complete occlusion was 57.1%, neck remnants 38.1%, and incomplete occlusion 4.8%.

CONCLUSION

We suggest that using Solitaire AB stent is technically feasible and safe in the stent-assisted coil embolization for wide-necked saccular intracranial aneurysms. To evaluate the long-term effects of this stent, further follow-up angiography is needed.

In-stent stenosis after stent-assisted coiling: incidence, predictors and clinical outcomes of 435 cases

BACKGROUND

Neuroform and Enterprise are widely used self-expanding stents designed to treat wide-necked intracranial aneurysms.

OBJECTIVE

To assess the incidence, clinical significance, predictors, and outcomes of in-stent stenosis (ISS).

METHODS

Angiographic studies and hospital records were retrospectively reviewed for 435 patients treated between 2005 and 2011 in our institution. A multivariable regression analysis was conducted to determine the predictors of ISS.

RESULTS

The Neuroform stent was used in 264 patients (60.7%) and the Enterprise in 171 patients (39.3%). A total of 11 patients (2.5%) demonstrated some degree of ISS during the follow-up period at a mean time point of 4.2 months (range, 2-12 months). The stenosis was mild (< 50%) in 8 patients (1.8%), moderate (50-75%) in 2 patients (0.5%), and severe (> 75%) in 1 patient (0.2%). No patients were symptomatic or required further intervention. There was complete ISS resolution in 2 patients, partial resolution in 2 patients, and no change in 5 patients on follow-up angiography. Patients developing ISS were significantly younger than those without ISS (40.3 vs. 54.9 years; P < .001). ISS rates were 2.7% with the Neuroform and 2.3% with the Enterprise stent (P = .6). In multivariable analysis, younger patient age (odds ratio = 0.92; P = .008), carotid ophthalmic aneurysm location (odds ratio = 7.7; P =0.01), and carotid terminus aneurysm location (odds ratio = 8.1; P = .009) were strong independent predictors of ISS. The type of stent was not a predictive factor.

CONCLUSION

Neuroform and Enterprise ISS is an uncommon, often transient, and clinically benign complication. Younger patients and those harboring anterior circulation aneurysms located at ophthalmic and carotid terminus locations are more likely to develop ISS.

The safety and efficacy of stenting in the treatment of complex posterior cerebral artery aneurysms: a seven-case report and literature review

OBJECTIVE

To investigate the safety and efficacy of stenting with coil in the endovascular treatment of complex posterior cerebral artery (PCA) aneurysms.

METHODS

The data on PCA aneurysms treated with stents were retrospectively reviewed from a prospectively collected intervention database. The literature was reviewed concerning the use of stents for PCA aneurysms.

RESULTS

Seven cases with complex PCA aneurysms (male: female = 6:1; ruptured: unruptured = 4:3) were retrieved from our database. Three aneurysms were localized at the junction of P1 and P2 segments (P1-2), two at P1, and two at P2A. Four were wide-necked saccular aneurysms, while the other three were dissecting ones. A total of nine stents (one Neuroform and eight Enterprise stents) were successfully deployed. Two aneurysms were totally eliminated, three were with neck residues and two were partially occluded. No procedure-related complications occurred. All patients recovered well. Angiographic follow-ups (FU) showed that three aneurysms achieved total obliterations, one got improved, two remained stable, and one recurred. The recurred aneurysm caused no symptom and was treated with two stents. Clinical FU demonstrated no neurological deterioration or bleeding. In literature review, the procedure-related mortality is 5.3 % (2/38). The incidence of permanent neurologic deficit is 2.6 % (1/38). Three (3/23) aneurysms recurred, of which one caused rebleeding. Four (4/23) in-stent stenoses were all asymptomatic. No other hemorrhagic or ischemic event occurred in clinical FU.

CONCLUSION

Stent offers a therapeutic alternative for complex PCA aneurysms especially when PVO cannot be tolerated. Long-term therapeutic efficacy requires further observations in clinical series with larger case numbers.

Angiographic lumen changes associated with oversized intracranial stent implantation for aneurysm treatment

BACKGROUND

The effect of oversized intracranial stent implantation, and potential excessive neointimal hyperplasia from the chronic outward radial force, has not been reported. We sought to compare the angiographic narrowing associated with implantation of oversized stents.

METHODS

We reviewed an aneurysm database and identified patients treated with stent-assisted embolization involving a vessel size transition. Demographics and lesion characteristics were extracted. The relationship between lumen diameter and stent oversizing was compared.

RESULTS

Twenty vessels were identified in 18 patients, providing 80 paired data points. Mean follow-up time was 8 months (SD 6). The average oversizing in the smaller diameter parent vessel landing-zone was 1.75 mm. Mean change in lumen size from pre-stent implantation was not significantly different for any of the four sites. There was a significant difference in change of lumen size at the stent tines when compared with the respective mid-stent segment for both the proximal (P = 0.02) and distal (P = 0.0004) landing zones.

CONCLUSIONS

A small significant lumen loss occurs at stent tines when compared to midstent struts. However, there is no overall significant stenosis from highly oversized stents. Persistent luminal gain from the oversized stent radial force likely predominates over any neointimal hyperplasia.

Use of stent-assisted coil embolization for the treatment of wide-necked aneurysms: A systematic review

Background:

The use of stent-assisted coiling (SAC) has been shown to be a treatment option for complex aneurysms. We reviewed systematically the immediate and mid-term angiographic results following treatment of wide-necked aneurysms with self-expanding stents and coils, as well as the peri- and postprocedural rate of complications.

Methods:

A computerized database search was conducted from 01/2000 to 04/2011 using appropriate indexed terms on Pubmed. Inclusion criteria were: (1) homogeneous populations of ≥10 patients with wide-necked aneurysms; (2) use of a self-expandable neurovascular stent and coils for aneurysm treatment; (3) immediate and follow-up angiographic results; and (4) periprocedural and delayed thrombotic complications.

Results:

Seventeen studies were included, containing retrospectively collected data on 656 patients/702 aneurysms. The target aneurysm was located on the anterior circulation in 78.4% of patients. The immediate rate of complete occlusion was 46.3%, (19.3-98.1%). The intra- and postprocedural rate of intrastent thrombosis or thromboembolic event was 4.6% and 4.3%, respectively. Complete occlusion was documented in 71.9% at last angiographic follow-up. The rate of recanalization was 13.2% of aneurysms (0-28.8%). Delayed in-stent stenosis occurred in 5.3% cases (0-20.6%).

Conclusion:

SAC has been considered a treatment option for selected wide-necked aneurysms in some institutions. The use of intracranial stents should take into consideration the risk of ischemic complications, recanalization, delayed in-stent stenosis; and the currently unknown lifetime risks for stenosis, vascular injury, device failure, and aneurysm recurrence related to intracranial stenting. There is an evident need for a prospective multicenter registry for all treated patients with SAC.

Delayed in-stent occlusion due to stent-related changes in vascular geometry after cerebral aneurysm treatment

Stent-assisted coil embolization has been recently accepted as a treatment option for wide-neck or complex cerebral aneurysms. Delayed in-stent occlusion is described due to stent-related changes in vascular geometry. A 66-year-old man underwent stent-assisted coil embolization for an unruptured aneurysm of the vertebral artery. The treatment was successfully performed using the Enterprise stent. Follow-up angiography at 6 months showed asymptomatic in-stent occlusion. Three-dimensional analysis of the vascular geometry revealed that the left vertebral artery was straightened by 40° due to the stent placement. Such straightening of the vessel presumably caused kinking and occlusion of the vessel. Stent-related changes in vascular geometry may cause kinking of a vessel and result in occlusion after the treatment of cerebral aneurysms. Pre-treatment strategy may avoid this risk.

Rescue stenting in endovascular treatment of acutely ruptured cerebral aneurysms

Thromboembolic events and major artery occlusion following cerebral aneurysm coiling may lead to serious complications and even death if not treated. The use of an intracranial stent in the setting of subarachnoid hemorrhage (SAH) is risky due to the need for antiplatelet therapy. However in some conditions it could be an effective solution for this major problem. This study describes a revascularization technique using a Solitaire stent for treatment of anterior cerebral artery (ACA) occlusion following coiling of anterior communicating artery (Acom) aneurysms. Three cases of ruptured Acom aneurysms treated during the course of SAH underwent unplanned deployment of an intracranial stent. Complete occlusion of the ACA at the origin of the A2 segment developed during or shortly after coiling. Emergent CT brain scan was done in two cases to exclude rebleeding. Follow-up CT or MRI scans were performed 24 hours after stenting. Technical success was achieved in all cases. Complete revascularization of the Acom was achieved post stent deployment (TIMI grade 3). Time from onset of symptoms to full revascularization in the three cases was 35 minutes, one hour 50 minutes and two hours 40 minutes respectively. No intracranial bleeding occurred in any case following the procedure. No neurological changes occurred in case 1; mild neurological and radiological changes occurred in cases 2 and 3. Deployment of an intracranial stent achieved complete revascularization of the occluded Acom. Its use in a context of SAH is relatively risky but the technique resulted in a significant improvement of symptoms following flow restoration and probably helped prevent symptoms worsening, major disability or even death. A study on a larger patient sample with long-term follow-up will be of value.