Stent-assisted embolization of wide-neck anterior communicating artery aneurysms: review of 21 consecutive cases

The safety and clinical outcomes of endovascular treatment versus microsurgical clipping of ruptured anterior communicating artery aneurysms: a 2-year follow-up, multicenter, observational study

Background and objective

Current data on the optimal treatment modality for ruptured anterior communicating artery (AComA) aneurysms are limited. We conducted this multicenter retrospective study to evaluate the safety and clinical outcomes of endovascular treatment (EVT) and microsurgical clipping (MC) for the treatment of ruptured AComA patients.

Methods

Patients with ruptured AComA aneurysms were screened from the Chinese Multicenter Cerebral Aneurysm Database. Propensity score matching (PSM) was used to adjust for baseline characteristic imbalances between the EVT and MC groups. The safety outcomes included total procedural complications, procedure-related morbidity/death and remedial procedure for complication. The primary clinical outcome was 2-year functional independence measured by the modified Rankin scale (mRS) score.

Results

The analysis included 893 patients with ruptured AComA aneurysms (EVT: 549; MC: 346). PSM yielded 275 pairs of patients in the EVT and MC cohorts for comparison. Decompressive craniectomy being more prevalent in the MC group (19.3% vs. 1.5%, p < 0.001). Safety data revealed a lower rate of total procedural complications (odds ratio [OR] = 0.62, 95% CI 0.39-0.99; p = 0.044) in the EVT group and similar rates of procedure-related morbidity/death (OR = 0.91, 95% CI 0.48-1.73; p = 0.880) and remedial procedure for complication (OR = 1.35, 95% CI 0.51-3.69, p = 0.657) between the groups. Compared with that of MC patients, EVT patients had a greater likelihood of functional independence (mRS score 0-2) at discharge (OR = 1.68, 95% CI 1.14-2.50; p = 0.008) and at 2 years (OR = 1.89, 95% CI 1.20-3.00; p = 0.005), a lower incidence of 2-year all-cause mortality (OR = 0.54, 95% CI 0.31-0.93; p = 0.023) and a similar rate of retreatment (OR = 1.00, 95% CI 0.23-4.40; p = 1.000).

Conclusion

Clinical outcomes after treatment for ruptured AComA aneurysms appear to be superior to those after treatment with MC, with fewer overall procedure-related complications and no increase in the retreatment rate. Additional studies in other countries are needed to verify these findings.

Treatment of Ruptured Wide-Necked Aneurysms using a Microcatheter Injectable Biomaterial

Ruptured wide-neck aneurysms (WNAs), especially in a setting of coagulopathy, are associated with significant morbidity and mortality. It is shown that by trapping a sub-millimeter clinical catheter inside the aneurysm sac using a flow diverter stent (FDS), instant hemostasis can be achieved by filling the aneurysm sac using a novel biomaterial, rescuing catastrophic bleeding in large-animal models. Multiple formulations of a biomaterial comprising gelatin, nanoclay (NC), and iohexol are developed, optimized, and extensively tested in vitro to select the lead candidate for further testing in vivo in murine, porcine, and canine models of WNAs, including in a subset with aneurysm rupture. The catheter-injectable and X-ray visible versions of the gel embolic agent (GEA) with the optimized mechanical properties outperform control groups, including a subset that receive a clinically used liquid embolic (Onyx, Medtronic), with and without aneurysm rupture. A combinatorial approach to ruptured WNAs with GEA and FDS may change the standard of medical practice and save lives.

A single-center comparative study with large sample size on stent-assisted coiling versus coiling alone for the ruptured anterior communicating artery aneurysms: Analysis of safety, efficacy, and prognosis based on propensity score matching

OBJECTIVE

To compare the safety, efficacy, and prognosis of stent-assisted coiling (SAC) versus coiling alone (CA) in the treatment of ruptured anterior communicating artery aneurysms (ACoAAs).

METHODS

The clinical and follow-up data of ruptured ACoAAs treated with endovascular treatment in our center from January 2011 to January 2021 were retrospectively collected. Patients were divided into an SAC group and a CA group based on whether stents were used, after which the two groups were matched for propensity scores. The general clinical data, embolization effect, perioperative complications, clinical, and follow-up results after matching were compared.

RESULTS

A total of 354 patients were enrolled, of whom 147 patients (41.5%) received SAC and the rest received CA. Comparison baseline of two groups showed that patients with a larger diameter, wide neck, irregular morphology, and anterior direction were more likely to receive SAC. After propensity score matching, 113 patients were included in each group. Immediately postoperative angiography results showed that the complete embolization rate of patients in the SAC group was significantly lower than that in the CA group (62.8% vs. 76.1%, p = 0.03). There were no significant differences between the two groups in the incidence of perioperative complications, mortality, poor prognosis at discharge or follow-up, mid-term complete occlusion rate and recurrence rate.

CONCLUSION

The stent-assisted treatment of ruptured ACoAAs did not increase the risk of perioperative complications or the probability of poor prognosis, indicating that SAC treatment of ruptured ACoAAs is safe and feasible and has a reliable mid-term cure rate.

Understanding anterior communicating artery aneurysms: A bibliometric analysis of top 100 most cited articles

Bibliometric analysis is of paramount importance in assessing the research impact wherein studies are ranked on the basis of citations received. It also brings out the excellent contribution of authors and journals in adding evidence for future research. This study aimed at evaluating the top 100 most cited articles on anterior communicating artery (ACoA) Aneurysms. Scopus database was searched using title specific search for the aneurysm of ACoA and top 100 most cited articles along with their authors, author IDs, affiliated institutions, countries and funding bodies were identified. Search yielded 841 articles and top 100 articles were identified to include in this analysis which secured 5615 citations. Citations per year was also calculated to minimize the risk of bias. Maximum citations by any article were 242. The United States was the major contributor to the number of articles while Kessler Institute for Rehabilitation became the highest contributing institution. DeLuca J proved to be a pioneer in this specialized area as he penned 6 studies being first author in 4 of them, making him the most frequent author. National Institutes of Health and the U.S. Department of Health and Human Services were the main funding bodies. Subcategory analysis revealed, 50% studies provided evidence for the treatment and the surgical outcome of the aneurysm. Studies like these can aid in better neurological and neurosurgical management in decision making of ACoA aneurysm.

Opposite L-configuration double stenting for rupture of an extremely wide-necked anterior communicating artery aneurysm at the acute stage: illustrative case

BACKGROUND

Wide-necked aneurysms can be treated by double stenting in an X- or Y-configuration or by a double waffle-cone technique. However, some aneurysms remain untreatable.

OBSERVATIONS

The rupture of a complex wide-necked anterior communicating artery (AcomA) aneurysm that caused acute subarachnoid hemorrhage (SAH) was treated successfully using double stents with an opposite L-configuration as an alternative to the X-stent technique. The aneurysm involved both A1-A2 junctions in the aneurysm neck with acutely oriented A2 segments of the anterior cerebral artery bilaterally. It was densely packed and completely obliterated angiographically with preserved blood flow by implanting each stent in the ipsilateral A1-A2 bilaterally. Blood flow from the left A1 to the right A2 was confirmed through the AcomA on injection of the left internal carotid artery immediately after the procedure without critical infarction in the subthalamic area. Although the AcomA was not demonstrated by injection of the left internal carotid artery on angiography at 3 months or 1 year later, no cerebral infarction was seen on magnetic resonance images at the final hospital visit.

LESSONS

Opposite L-configuration double stenting was used successfully as rescue stent-assisted coiling for a rupture of a complex wide-necked AcomA aneurysm in a patient with acute SAH.

Intra-procedural complications, success rate, and need for retreatment of endovascular treatments in anterior communicating artery aneurysms: a systematic review and meta-analysis

In recent years, intracranial aneurysms have been widely treated with endovascular methods. The anterior communicating artery (Acom) is the most common site of intracranial aneurysms. Despite its effectiveness, endovascular interventions can be associated with various intra-procedural and post-procedural complications. A systematic review of the literature was performed through PubMed, Embase, Scopus, and Web of Sciences databases up to March 18, 2022. The pooled rates of intra-procedural complications, mortality, procedure-related morbidities, the immediate and late aneurysm occlusion, and also the necessity for retreatment were calculated by applying random-effects models. A total of 41 articles with 4583 patients were included in the meta-analysis. The pooled rate of overall intra-procedural complications was 9.6% (95% CI: 7.7 to 11.8%). The initial rupture status and also type of EVT procedure did not affect the overall complication rate. The pooled rate of intra-procedural thrombosis, aneurysm rupture, coil prolapse, and early aneurysm rebleeding were 6.1% (95% CI: 4.5 to 8.2%); 4.2% (95% CI: 3.4 to 5.2%), 4.7% (95% CI: 3.2 to 6.7%), and 2.2% (95% CI: 1.5 to 3.2%), respectively. Our analysis showed that intra-procedural mortality occurred in 1.7% (95% CI: 1.1 to 2.5%) and procedure-related permanent morbidities in 3.3% (95% CI: 2.3 to 4.7%) of patients. Endovascular methods achieved complete and near to complete aneurysm occlusion (Raymond-Roy occlusion classification 1 and 2) in 89.2% (95% CI: 86.4 to 92.5%) of cases post-procedure, and 9.5% (95% CI: 7.3 to 12.4%) of patients needed retreatment due to recanalization in follow-ups. Endovascular treatment can serve as an acceptable method for Acom aneurysms. However, improved endovascular treatment equipment and new techniques provide more satisfactory outcomes for complicated cases.

Long-Term Outcomes of Placement of a Single Transverse Stent through the Anterior Communicating Artery via the Nondominant A1 in Coil Embolization of Wide-Necked Anterior Communicating Artery Aneurysms

Objective

Placement of a single transverse stent via the nondominant A1 across the anterior communicating artery (AComA) into the contralateral A2 can provide sufficient neck coverage for wide-necked bifurcation AComA aneurysms. The authors described the feasibility, safety and long-term outcomes of this technique.

Methods

Between January 2015 and February 2018, placement of a single transverse stent via the nondominant A1 was attempted in 17 wide-necked bifurcation AComA aneurysms. The authors reviewed the medical records and radiological studies.

Results

The technical success rate was 94.1% (16/17). Periprocedural thromboembolic complications occurred in one patient (6.3%) without permanent neurological deficits. The mean clinical follow-up duration was 39.9±9.8 months. No deaths or delayed thromboembolic complications occurred. The mean angiographic follow-up duration was 38.9±9.8 months. The immediate and final follow-up complete occlusion rates were 87.4 and 93.7%, respectively. There was no recanalization during the follow-up period.

Conclusion

Placement of a single transverse stent via the nondominant A1 across the AComA into the contralateral A2 is a feasible and relatively safe endovascular technique for the treatment of wide-necked bifurcation AComA aneurysms, with good long-term occlusion rates and a reasonable complication rate, if only the nondominant A1 is applicable.

Impact of A1 Asymmetry on the Woven EndoBridge Device in Anterior Communicating Artery Aneurysms

BACKGROUND AND PURPOSE

Woven EndoBridge (WEB) devices are increasingly used to treat intracranial aneurysms. A1 asymmetry contributes to anterior communicating artery aneurysm formation and to treatment instability after coiling. We sought to evaluate whether A1 asymmetry had an impact on angiographic outcome in anterior communicating artery aneurysms treated with the WEB.

MATERIALS AND METHODS

Anterior communicating artery aneurysms treated between July 2012 and July 2020 with the WEB from an institutional review board-approved database were reviewed. A1 asymmetry was categorized as the following: absence of the A1 segment on 1 side (unilateral A1) versus bilateral A1. Univariate and multivariable analyses assessed independent predictors of adequate (WEB Occlusion Scale A, B, and C) and complete occlusion (WEB Occlusion Scale A and B).

RESULTS

Forty-eight individual aneurysms (47 patients) were included in the final analysis, of which 16 (33%) were acutely ruptured. The mean size was 6.5 (SD, 2.2) mm. Adequate and complete occlusion was achieved in 33 (69%) and 30 (63%) cases, respectively. Unilateral A1 was associated with significantly higher rates of adequate (92% versus 60% for bilateral A1; P = .03) and complete occlusion (92% versus 50% for bilateral A1; P < .01). Multivariable logistic regression confirmed unilateral A1 as an independent predictor of both adequate (OR = 10.6; 95% CI, 1.6-220.7; P = .04) and complete occlusion (OR = 9.5, 95% CI, 1.5-190.2; P = .04. A sensitivity analysis comparing unilateral "functional" A1 with bilateral "functional" A1 showed similar results. WEB shape modification was not influenced by the unilateral A1 configuration (P = .70).

CONCLUSIONS

Anterior communicating artery aneurysms with a unilateral A1 configuration treated with WEB devices are associated with better angiographic outcome than those with bilateral A1. This finding supports the hypothesis that WEB devices are resistant to unilateral flow in the aneurysm as opposed to coils.

Endovascular Treatment of Ruptured Wide-Necked Anterior Communicating Artery Aneurysms Using a Low-Profile Visualized Intraluminal Support (LVIS) Device

Objective: To evaluate the safety and efficacy of low-profile visualized intraluminal support (LVIS) stent-assisted coiling for the treatment of ruptured wide-necked anterior communicating artery (ACoA) aneurysms.

Methods: The clinical and angiographic data of 31 acutely ruptured wide-necked ACoA aneurysms treated with LVIS stent-assisted coiling between January 2014 and December 2018 were retrospectively reviewed.

Results: All stents were successfully deployed. The immediate angiographic results were modified Raymond-Roy class I in 27 cases, modified Raymond-Roy class II in 2 cases, and modified Raymond-Roy class IIIa in 2 cases. Intraoperative thrombosis and postoperative aneurysmal rebleeding occurred in one case each. Two patients (6.5%) who were admitted due to poor clinical grade conditions died during hospital admission as a result of initial bleeding. Angiographic follow-up (mean: 12.9 months) was performed for 26 patients, the results of which demonstrated that 25 aneurysms were completely occluded and one was class II. The last clinical follow-up (mean: 25.3 months) outcomes demonstrated that 27 patients had favorable clinical outcomes and two had poor clinical outcomes.

Conclusion: LVIS stent-assisted coiling for ruptured wide-necked ACoA aneurysms was safe and effective, with a relatively low rate of perioperative complications and a high rate of complete occlusion at follow-up.

Effect of Straightening the Parent Vessels in Stent-Assisted Coil Embolization for Anterior Communicating Artery Aneurysms

BACKGROUND

Stent-assisted coil embolization (SAC) for treating anterior communicating artery (AcomA) aneurysms is safe and effective. Straightening of parent vessels by stent placement can lead to progressive thrombosis. We describe our experience with SAC for AcomA aneurysms and demonstrate the effect of straightening the parent vessels.

METHODS

A total of 26 patients with AcomA aneurysms were treated using SAC in our institute between July 2010 and December 2017. Follow-up digital subtraction angiography was performed 6 months after treatment, magnetic resonance angiography was performed every year, and outcomes were analyzed.

RESULTS

From all aneurysms (n = 24), 12 (50.0%) were neck remnant, and 12 (50.0%) were dome-filling types immediately after the procedure. At the 6-month digital subtraction angiography follow-up (n = 22), 13 (59.1%) aneurysms were complete obliteration, 8 (36.4%) were neck remnant, and 1 (4.5%) was dome filling. The median parent vessel angle was measured preoperatively at 98.1°, increased to 124.8° immediately after stent deployment, and further increased to 149.6° at the 6-month follow-up. Progressive thrombosis was observed in 13 of 22 (59.1%) aneurysms. The parent vessel angle change immediately after stent deployment in the progressive thrombosis group tended to be larger than that observed in the no thrombosis group; this change was significant at the 6-month follow-up. The median follow-up term was 18 months. No patients required retreatment.

CONCLUSIONS

Good SAC outcomes were achieved for AcomA aneurysms, and hemodynamic changes related to straightening of the parent vessels is a consideration in SAC.

Efficiency and complications of Woven EndoBridge (WEB) devices for treatment of larger, complex intracranial aneurysms-a single-center experience

BACKGROUND

Several recently published multicenter studies have reported high treatment feasibility, high safety, and good 6-month to 1-year efficiency when treating smaller intracranial aneurysms (IA) with WEB deployment. The purpose of the study was to evaluate the long-term efficiency and complications related to WEB treatment of larger, complex intracranial aneurysms in a small single-center cohort.

METHODS

Patients with ruptured and unruptured IA were treated with WEB devices; data were collected prospectively and analyzed retrospectively. The study evaluates complications and clinical and radiological findings at immediate and last available follow-up.

RESULTS

The study included 16 patients with 16 aneurysms and a median follow-up time of 36 months, range 13-49 months; 9/16 were females. Median age 59 with range 39-71 years. Mean aneurysm size 11.3 ± 1.7 mm, predominant location at the basilar artery bifurcation and anterior communicating artery. Three out of sixteen IAs were ruptured. Even though 75% of the IAs were immediately occluded completely, retreatment was eventually necessary in 7/15 (46.7%). Increasing neck remnants and recurrences were mainly observed past 1-year follow-up. The WEB device showed modifications over time, with six devices showing signs of compression in the long term. There was one fatality due to aneurysm rupture after 4 years.

CONCLUSIONS

The long-term efficiency of WEB deployment in larger, complex aneurysms is low with about half of the cases needing at least one retreatment. A large fraction of WEB collapse past 1-year follow-up.

Stent-assisted coil embolization of anterior communicating artery aneurysms: safety, effectiveness, and risk factors for procedural complications or recanalization

INTRODUCTION

Stent-assisted coil (SAC) embolization is an alternative treatment option for anterior communicating artery (AcoA) aneurysms. This study was undertaken to assess the safety and effectiveness of SAC embolization in treating AcoA aneurysms and to determine risk factors for related procedural complications or recanalization.

METHODS

Between August 2008 and December 2016, 184 patients with AcoA aneurysms were treated with SAC embolization. Cumulative medical record and radiologic data were analyzed using binary logistic regression to identify factors predisposing to procedural complications or recanalization.

RESULTS

Contralateral A1 segment hypoplasia was observed in 59 patients (32.1%). Three types of stents (LVIS, Enterprise, and Neuroform) were variably placed by one of two routes: (1) ipsilateral A1 to ipsilateral A2 (75.5%) or (2) ipsilateral A1 to contralateral A2 (24.5%). Procedural complications occurred in 17 patients (thromboembolism 12; procedural leakage 3; both 2), showing a significant relation to subarachnoid hemorrhage at presentation (OR 57.750; P<0.01). Occlusion was documented immediately after embolization in 130 aneurysms (70.6%) and, in 23 (13.1%) of 175 AcoA aneurysms followed by angiography (median 25.9±18.5 months), recanalization developed (minor, 15; major, 8). Stent configuration (ipsilateral A1 to contralateral A2, P=0.024), maximum aneurysm size (>7 mm, P<0.01), and A1 segment hypoplasia (P=0.039) were identified as risk factors for recanalization.

CONCLUSION

SAC embolization is a safe and effective method of treating unruptured AcoA aneurysms, regardless of anatomic or clinical features. However, in the event of rupture, procedural complications are likely. Stent configuration, aneurysm size, and A1 segment hypoplasia were identified as significant risk factors for recanalization.

Changing Paradigms in the Endovascular Management of Ruptured Anterior Communicating Artery Aneurysms

BACKGROUND

Approximately 17% of ruptured anterior communicating artery (ACoA) aneurysms were deemed unsuitable for coil embolization during the Barrow Ruptured Aneurysm Trial (BRAT), most commonly due to unfavorable dome-to-neck ratio or small size.

OBJECTIVE

To compare patients treated by coil embolization for ruptured ACoA aneurysms during the trial to those treated after the trial to determine whether advances in endovascular techniques have allowed for effective treatment of these lesions.

METHODS

All cases of ruptured ACoA aneurysms treated by endovascular modalities during BRAT (2003-2007) and post-BRAT (2007-2012) were reviewed for patient and aneurysm characteristics, treatment types, and clinical and angiographic outcomes at 3-yr or last follow-up.

RESULTS

The BRAT ACoA cohort included 39 patients treated with coiling (excluding those crossed over to clipping). The post-BRAT cohort included 93 patients who were significantly older (mean age, 59.5 vs 52.8 yr, P = .005) than the BRAT cohort; there were no significant cohort differences in sex, Hunt and Hess grade, or mean aneurysm size. The use of balloon remodeling was significantly higher in the post-BRAT cohort (31.2% [29/93] vs 5.1% [2/39], P = .001), as was the proportion of wide-necked aneurysms treated (66.7% [62/93] vs 30.8% [12/39], P < .001). There was no significant difference in clinical outcome or retreatment rate between the 2 cohorts (P = .90 and P = .48, respectively).

CONCLUSION

ACoA lesions thought unamenable to endovascular therapy in an earlier randomized trial are now successfully coiled with increased use of adjunctive techniques, without sacrificing patient outcome or treatment durability.

Long term follow-up of bifurcation aneurysms treated with braided stent assisted coiling and complex T- and Y- stent constructs

Background

Stent assisted coil embolization (SACE) of bifurcation aneurysms is challenging. Heterogeneous results have been achieved to date, but largely for laser cut stents. While braided stents offer multiple technical advantages, their long term efficacy has yet to be validated.

Objective

To report the first long term 18 month results for the durability of bifurcation aneurysms treated with braided stents.

Materials and methods

Over a 4 year period, 59 consecutive patients with 60 bifurcation aneurysms underwent elective braided SACE across three Australian neurovascular centers. 17 of these aneurysms underwent T- or Y-shaped stent constructs. All patients had immediate, 6 month and 18 month clinical and radiological follow-up. Radiological assessment was made on modified Raymond–Roy occlusion scores while clinical assessment was based on the modified Rankin Scale. Subgroup analysis of 17 aneurysms treated with multi-stent constructs was conducted.

Results

6 month follow-up data were available for 59 aneurysms and 18 month follow-up data for 58 aneurysms. Satisfactory aneurysm occlusion was achieved in 97% at inception and at 6 months, and 98% at 18 months. Good neurological outcomes were achieved in 95% at 18 months. Similar satisfactory results were achieved with the multi-stent construct cohort. Intraprocedural thromboembolic events were recorded in 5% and delayed events in 2%. Technical complications were found in 5%. All complication rate was 13%.

Conclusion

Braided SACE was safe, efficacious, and durable at the long term 18 month follow-up, including for multi-stent constructs. Preliminary results indicate favorable clinical and radiological outcomes compared with laser cut stents.

Stent-assisted embolization of wide-neck anterior communicating artery aneurysms: Review of consecutive 34 cases

OBJECTIVE

We report our experience with stent-assisted coiling of anterior communicating artery aneurysms with special consideration of angiographic and clinical outcomes, retreatment rate and periprocedural complications.

MATERIALS AND METHODS

The analysis included 34 consecutive ruptured and unruptured wide-neck aneurysms. The aneurysm size ranged from 2 to 18mm (mean 5.47). Clinical examinations with the use of modified Rankin Score and angiographic outcomes were evaluated initially post-embolization and at a minimum follow-up of 6 months.

RESULTS

Initial post-treatment complete and near-complete aneurysm occlusion was achieved in 32 (94%) and 2 (6%) cases, respectively. Imaging follow-up, performed in 28 (82%) patients, showed no change in the degree of occlusion in 25 (89%) cases and coil compaction in 3 (11%) patients. Of these, one (3.6%) patient underwent a second coil embolization. The periprocedural severe complication rate was 2.9% (1/35) and was associated with prolonged attempt of retrieval of migrated coil resulting in anterior cerebral artery infarct with serious clinical consequences. In another 3 patients periprocedural adverse events without delayed clinical consequences were noticed. The clinical follow-up evaluation achieved in 33 (97%) patients showed no change in 30 (91%) cases, one patient (3%) with clinical improvement and two (6%) cases of neurological deterioration.

CONCLUSIONS

The use of stent is feasible and effective for coil embolization of wide-necked anterior communicating artery aneurysms. Although periprocedural complications resulting in severe morbidity are rare, they should be noted, since in terms of thromboembolic events some of them presumably have a potential to be avoidable.

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.

Stent-assisted coiling versus coiling alone of ruptured anterior communicating artery aneurysms: A single-center experience

OBJECTIVE

Endovascular coiling of anterior communicating artery (ACoA) aneurysms has evolved; however, stent-assisted coiling of ruptured aneurysms remains controversial. We aimed to compare periprocedural complications, angiographic and clinical outcomes after stent-assisted coiling with coiling alone of ruptured ACoA aneurysms.

METHODS

We performed a retrospective review of consecutive 222 patients with ruptured ACoA aneurysms treated with endovascular coiling within 7 days after ictus. Patients were grouped into stent-assisted coiling and coiling alone groups. Baseline characteristics, periprocedural complications, clinical outcomes, and angiographic results were compared between the two groups.

RESULTS

63 (28.4%) patients underwent stent-assisted coiling and 159 (71.6%) underwent coiling alone. There were no statistically significant differences in age, sex, clinical grading and Fisher grade. Larger aneurysms (P=0.002) and wider-neck aneurysms (P<0.001) were more often treated with stent-assisted coiling within 72h (P=0.025). Intraprocedural aneurysm rupture occurred in 6 (9.5%) patients treated with stent-assisted coiling compared with in 5 (3.1%) treated with coiling alone (P<0.048). Thrombus formation occurred in 10 (15.9%) patients after stent-assisted coiling compared with 6 (3.8%) after coiling alone (P=0.002). Stent-assisted coiling achieved a lower rate of immediate occlusion than coiling alone (P=0.045). Postoperative complications, clinical outcomes, and follow-up aneurysm occlusion did not significantly differ.

CONCLUSIONS

Stent-assisted coiling of ruptured ACoA aneurysms was associated with a higher rate of intraprocedural complications and associated with a lower immediate occlusion rate. However, Postoperative complications and clinical outcomes did not differ. Long-term angiographic results require further study.

Single-center experience in the endovascular treatment of wide-necked intracranial aneurysms with a bridging intra-/extra-aneurysm implant (pCONus)

Purpose

To retrospectively evaluate the safety and efficacy of the endovascular treatment of wide-necked intracranial aneurysms assisted by a novel intra-/extra-aneurysm stent-like implant (pCONus).

Methods

Initial and follow-up angiographic and clinical results are presented of 25 patients with 25 unruptured and ruptured wide-necked intracranial aneurysms treated by reconstruction of the aneurysm neck using the pCONus implant followed by coil occlusion of the fundus.

Results

Successful intra-/extra-aneurysm deployment of the pCONus with coil occlusion of the fundus was achieved in all but one case. Procedure-related ischemic complications were observed in three cases with permanent deterioration in one. Acceptable aneurysm occlusion was achieved in all cases. Follow-up angiography revealed sufficient occlusion in 81.0% of the aneurysms. Intimal hyperplasia in the stented segment of the parent artery or device migration has not been observed to date.

Conclusions

The pCONus device offers a promising treatment option for complex wide-necked bifurcation intracranial aneurysms. Acute or delayed dislocations of coils into the parent artery are successfully avoided.

A Reappraisal of Anterior Communicating Artery Aneurysms

BACKGROUND:

Wide-necked anterior communicating artery aneurysms represent a subset of lesions with challenging endovascular treatment despite new endoluminal and intrasaccular devices.

OBJECTIVE:

To assess the long-term clinical and angiographic outcomes of stent-assisted embolization for wide-necked anterior communicating artery aneurysms.

METHODS:

Between March 2008 and March 2014, 32 patients with unruptured wide-necked AComm aneurysms were treated using stent-assisted embolization. The Glasgow Outcome Scale was reviewed at the time of discharge and at latest follow-up. Ischemic and hemorrhagic events were also recorded and analyzed. Aneurysm occlusion was evaluated post-intervention and on subsequent follow-up evaluations.

RESULTS:

Successful stent deployment was achieved in all cases, but in 1 patient the coils could not be contained inside the aneurysm, and the procedure was aborted without complications. The distal segment of the stent was positioned in the ipsilateral A2 in 16 patients, in the contralateral A2 in 15 patients, and in the contralateral A1 in 1 patient. There were no periprocedural thromboembolic or hemorrhagic complications. The rate of major complications was 6%. One patient developed intracranial hemorrhage related to antiplatelet therapy and another had ischemic events due to in-stent stenosis. Angiographic follow-up was available for 26 aneurysms and during a mean follow-up of 22 months, 81% of the lesions were completely occluded and 8% had a small residual neck. The retreatment rate for residual aneurysms was 3%.

CONCLUSION:

Our long-term results suggest that stent-assisted embolization for anterior communicating artery aneurysms may be considered an excellent treatment option with an adequate combination of safety profile and effectiveness.

Complications in Stent-Assisted Endovascular Therapy of Ruptured Intracranial Aneurysms and Relevance to Antiplatelet Administration: A Systematic Review

BACKGROUND AND PURPOSE

Despite the increasing use of stent-assisted coiling for ruptured intracranial aneurysms, there is little consensus regarding the appropriate antiplatelet administration for this. The objectives of this systematic review were to provide an overview of complications and their association with the method of antiplatelet administration in stent-assisted coiling for ruptured intracranial aneurysms.

MATERIALS AND METHODS

A comprehensive search of the literature in the data bases was conducted to identify studies reporting complications of stent-assisted coiling for ruptured intracranial aneurysms. The pooled event rate of preprocedural thromboembolisms, hemorrhages, and mortality was estimated from the selected studies. Subgroup analyses were performed by the method of antiplatelet administration (pre-, postprocedural, and modified). Meta-analysis was conducted to compare periprocedural complications and mortality between ruptured intracranial aneurysms and unruptured intracranial aneurysms.

RESULTS

Of the 8476 studies identified, 33 with 1090 patients were included. The event rates of thromboembolism and intra- and postprocedural hemorrhage were 11.2% (95% CI, 9.2%-13.6%), 5.4% (95% CI, 4.1%-7.2%), and 3.6% (95% CI, 2.6%-5.1%), respectively. Subgroup analyses of thromboembolism showed a statistically significant difference between groups (P < .05). In the preprocedural and modified antiplatelet groups, the risk for thromboembolism in stent-assisted coiling for ruptured intracranial aneurysm was not significantly different from that for unruptured intracranial aneurysm, though this risk of the postprocedural antiplatelet group was significantly higher in ruptured intracranial aneurysms than in unruptured intracranial aneurysms.

CONCLUSIONS

On the basis of current evidence, complications of stent-assisted coiling for ruptured intracranial aneurysm may be affected by the method of antiplatelet administration.

Endovascular treatment of wide-neck anterior communicating artery aneurysms using the LVIS Junior stent

We performed this retrospective study to assess the clinical safety and efficacy of the low-profile visualized intraluminal support junior (LVIS Jr.; MicroVention, Aliso Viejo, CA, USA) stent placement in anterior communicating artery (ACA) aneurysms. ACA aneurysms are some of the most common intracranial aneurysms. Stent placement is particularly difficult due to the complexity of the vascular anatomy and the small vessels of the ACA complex. From November 2013 and June 2014, LVIS Jr. stent-assisted coiling was performed in 11 patients with 12 wide-neck ACA aneurysms. Patient demographics, morphologic features of the aneurysm, clinical results and follow-up results are presented. Successful deployment of the LVIS Jr. stent in the targeted artery was achieved in all patients. Complete occlusion was achieved in seven patients, neck remnant in three, and partial occlusion in two. The angiographic follow-up of nine patients (mean 4.4 months) showed that all aneurysms remained stable or improved. There was no in-stent stenosis, recurrence or retreatment. The modified Rankin scale score at discharge was 0 in eight patients and 1 in three patients. The LVIS Jr. stent provided excellent trackability and deliverability and is safe and effective for the treatment of wide-necked ACA aneurysms. Further follow-up is needed to assess the long-term efficacy of LVIS Jr. stent placement in ACA.

Rates of local procedural-related structural injury following clipping or coiling of anterior communicating artery aneurysms

Background

Surgical clipping and endovascular coiling yield similar functional outcomes for the treatment of saccular aneurysms of the anterior communicating (ACOM) artery. However, surgical treatment may be associated with greater rates of cognitive impairment due to injury of adjacent structures. We aimed to quantify the rates of injury (infarction/hemorrhage) for both clipping and coiling of ACOM aneurysms.

Methods

This was a retrospective dual-center radiological investigation of a consecutive series of patients with ruptured and unruptured ACOM aneurysms treated between January 2011 and October 2014. Post-treatment CT or MRI was assessed for new ischemic or hemorrhagic injury. Injury relating to the primary hemorrhage or vasospasm was differentiated. Univariate analysis using χ2 tests and multivariate analysis using binary logistic regression was used.

Results

66 patients treated with clipping were compared with 93 patients treated with coiling. 32/66 (48.5%) patients in the clipping group suffered treatment-related injury (31 ischemic, 1 hemorrhagic) compared with 4/93 (4.4%) patients in the coiling group (3 ischemic, 1 hemorrhagic) (p<0.0001). For patients with subarachnoid hemorrhage, the multivariate OR for infarction for clipping over coiling was 24.42 (95% CI 5.84 to 102.14), p<0.0001. The most common site of infarction was the basal forebrain (28/66 patients, 42.4%), with bilateral infarction in 4. There was injury of the septal/subcallosal region in 12/66 patients (18%).

Conclusions

Clipping of ACOM aneurysms is associated with significantly higher rates of structural injury than coiling, and this may be a reason for superior cognitive outcomes in patients treated with coiling in previously published studies.

Navigation of Stents across Communicating Arteries for Aneurysm Embolization

Introduction:

Endovascular coiling of aneurysms crossing the Circle of Willis has been described in small case series. The technical challenges in manipulating a stent across the Circle of Willis lie in negotiating difficult angles and small arteries. We present our experience with treating aneurysms by stent assistance in which the Circle of Willis was crossed to facilitate optimal stent deployment.

Materials and methods:

We retrospectively reviewed the cases in our institution from January 2009 to June 2012 in which the Circle of Willis was traversed to facilitate optimal stent deployment. We measured the diameter of the communicating arteries traversed, caliber of the target arteries in which the stent was deployed and the most acute angle negotiated (“critical angle”). We compare our results with other published series in the literature.

Results:

Eight patients fulfilled the criteria: 5 males (45-66 years). There were three anterior and five posterior circulation aneurysms. Four of the aneurysms were ruptured. The PCOM was traversed in five cases, the ACOM in three cases. The mean diameter of the communicating artery was 1.17mm. The mean diameter of target arteries was 1.27mm. The “critical angle” was 72-147 degrees. In all patients, there was satisfactory obliteration of the aneurysm. There were two cases of minor SAH post procedure.

Conclusion:

Utilizing the Circle of Willis for optimal stent placement in aneurysm remodeling is technically feasible but challenging. This technique can be performed successfully in patients with acute SAH. The procedural risk must be balanced against potential complications such as SAH.

"Y" and "X" stent-assisted coiling of complex and wide-neck intracranial bifurcation aneurysms

BACKGROUND AND PURPOSE

Stent-assisted coiling with two stents has been described in some series for the treatment of complex and wide-neck bifurcation aneurysms. Our aim was to report our experience of a stent-assisted coiling technique with double stents in "Y" and "X" configurations, with emphasis on safety, feasibility, and efficacy.

MATERIALS AND METHODS

Clinical and angiographic outcomes of patients for whom the strategic therapeutic option was the stent-assisted coiling technique in a Y or X configuration for neck scaffolding from June 2006 to June 2013 were retrospectively analyzed.

RESULTS

One hundred five aneurysms in 97 patients were treated during 100 consecutive procedures. There were 54.2% (57/105) MCA, 28.6% (30/105) anterior communicating artery, 16.2% (17/105) basilar tip, and 1.0% (1/105) ICA termination aneurysms. A Y stent placement was used to treat 87 aneurysms in 85 procedures; an X stent placement was used to treat 7 aneurysms in 6 procedures, while 9 procedures failed for 11 aneurysms. There were 10.0% (10/100) procedure-related permanent neurologic deficits and 1.0% (1/100) death. The immediate angiographic controls showed a complete occlusion in 47.6% (50/105) of the aneurysms and a partial (neck or sac remnant) occlusion in 52.4% (55/105). To date, 81.0% (85/105) of the aneurysms have been followed up (mean, 17 months) with angiography, disclosing a recanalization in 5.9% (5/85) and an improvement in 42.4% (36/85). At discharge and follow-up, the mRS score was 0 in 83.5% (81/97) of patients, 1 in 4.1% (4/97), 2 in 3.1% (3/97), 3 in 4.1% (4/97), 4 in 3.1% (3/97), and 6 in 2.1% (2/97).

CONCLUSIONS

Y and X stent-assisted coiling of complex and wide-neck intracranial bifurcation aneurysms is an effective technique.

Feasibility and efficacy of endovascular therapy for ruptured distal anterior cerebral artery aneurysms

Surgical clipping has been the primary treatment option for ruptured distal anterior cerebral artery (DACA) aneurysms. Therefore, the literature on endovascular therapy is sparse. The present study investigated the feasibility and efficacy of endovascular therapy for ruptured DACA aneurysms in 31 patients, 26 females and 5 males (mean age 63.2 ± 12.6 years). Mean aneurysm size and neck width were 4.8 ± 2.3 mm and 2.2 ± 0.7 mm, respectively. The Hunt and Hess (H/H) grades just prior to the treatment were scored as H/H grades 1-3 in 20 patients and H/H grades 4-5 in 11 patients. Fifteen patients had an intraparenchymal hematoma (IPH) surrounding the ruptured aneurysm on the initial computed tomography. Overall, 22 patients had a modified Rankin scale (mRS) score of 0-2 and 9 had a mRS score of 3-6 at discharge. H/H grade was closely related to the clinical outcomes, whereas the presence of IPH was not. Overall immediate angiographic outcomes were complete occlusion in 15, residual neck in 11, and residual aneurysm in 5. The overall recurrence rate was 35.3%. Complications including posttreatment rebleeding occurred in 5 patients. Symptomatic vasospasm occurred in 1 of the 18 patients with H/H grades 1-3. Endovascular therapy of ruptured DACA aneurysms is feasible and effective. However, the risks of recurrence and posttreatment bleeding remain to be resolved.

Endovascular treatment with flow diverters may fail to occlude experimental bifurcation aneurysms

INTRODUCTION

Animal models may explain how stents and flow diverters (FDs) may succeed or fail to treat bifurcation aneurysms.

METHODS

In vitro studies were designed to anticipate device deformations in bifurcations. Large, wide-necked bifurcation aneurysms were constructed in 21 animals and treated 4-8 weeks later using stents and FDs in various combinations, forming four main groups: parent artery to right branch flow diversion (RBFD, n = 6), parent artery to left branch flow diversion (LBFD, n = 6), Y flow diversion (YFD, n = 4), and compared with high-porosity Y-stenting (YHPS, n = 4). The results include immediate and follow-up angiography at 3 months, followed by grading of the extent of neointimal coverage of devices at pathology.

RESULTS

In vitro, all braided devices showed varying porosities according to characteristic zones. FDs can be compacted to decrease porosities, but a limiting factor is the constant presence of a more porous transition zone. In vivo, 3/6 RBFD, 4/6 LBFD, and 2/4 YFD treated aneurysms had decreased in size by 3 months, while those treated with YHPS increased in size (P = 0.15). There was a significant correlation between device porosities and extent of neointimal coverage (r = 0.639, P = 0.002), and between porosities and angiographic evolution (r = -0.655, P = 0.002), but not between neointima formation and angiographic evolution (r = -0.278, P = 0.235). Failures could be explained in all cases by the presence of leaks or holes in the neointima at the level of the transition zones.

CONCLUSION

FDs did not successfully treat most bifurcation aneurysms, at least in this animal model.

Management for the case of twice ruptured anterior communicating artery aneurysm: from nursing perspective

The anterior communicating artery (ACoA) is the most common site of cerebral aneurysms, accounting for as much as 36% of aneurysms. Microsurgical clipping and coil embolization are treatment modalities for ruptured and nonruptured cerebral aneurysms. Compared with surgical clipping, coil embolization has a relatively lower mortality and incidence of cognitive impairment in patients. However, successful management of the patient with twice ruptured ACoA aneurysm is facing critical challenges.This article has described a case of twice ruptured aneurysm with the first rupture occurring when the patient was admitted and the second rupture occurring during coil embolization. Perioperative nursing assessment, monitoring, intervention, patient teaching, and the nurse's role are discussed from a nursing perspective.

Endovascular treatment of ruptured tiny, wide-necked posterior communicating artery aneurysms using a modified stent-assisted coiling technique

The endovascular treatment of patients with tiny, wide-necked aneurysms is technically challenging, due to the small volume for microcatheterization and coil stabilization inside the aneurysm sac. We performed a retrospective study to evaluate the feasibility, effectiveness, and safety of stent-assisted embolization for patients with ruptured, tiny, wide-necked posterior communicating artery (PcomA) aneurysms. Between January 2007 and August 2011, 17 tiny, wide-necked PcomA aneurysms that had ruptured were treated at our institution using a modified stent-assisted technique, with delivery of the first coil inside the aneurysm followed by placement of a self-expanding stent via a second microcatheter. All patients were treated successfully using this modified stent-assisted coiling technique. Initial results showed aneurysm occlusion of Raymond Class 1 in 10 patients, Class 2 in four patients, and Class 3 in three patients. The angiographic follow-up results for 13 patients (mean, 12.5 months) showed that all aneurysms remained stable or improved, without any in-stent stenosis or recurrence. Of the other four patients, three refused angiography for economic or personal reasons, and one was lost in follow-up. Clinical follow-up of 16 patients for a mean of 23.8 months showed no death or rebleeding. These results imply that endovascular treatment of ruptured tiny, wide-necked PcomA aneurysms using our modified stent-assisted coiling technique is safe and feasible. This technique improves the long-term outcomes of these aneurysms by increasing the packing density and diverting the intra-aneurysmal blood flow.

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.

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.

In vitro studies for stent-assisted coiling of terminus aneurysms by straight-on intra-aneurysmal stent deployment

OBJECTIVE

Deployment of a Neuroform microstent (NFM; Boston Scientific/Target, Freemont, California, USA) within acutely angled geometry may result in substantial deformations. This in vitro study was conducted to validate a novel alternative technique, consisting of intentional deployment of a NFM straight on into a terminus aneurysm, by assessing the mechanics, feasibility, and stability of the coils.

METHODS

Silicon models of wide-neck terminus aneurysms were constructed. Straight-on deployment of a NFM from the afferent vessel into the aneurysm was compared with conventional cross-neck deployment at a right angle position followed by Guglielmi detachable coil embolization simulation. The supporting forces of the two different methods of deployment were compared by the use of side-wall eccentric and en-face compression tests.

RESULTS

Straight-on deployment of a NFM at a wide-neck terminus aneurysm was a relatively simple technique compared with cross-neck right angle deployment. Good stability of the coil mass was consistently achieved with adequate preservation of the parent vessel lumen. A larger residual neck space at the side without the stent and much coil mass protruding into the parent vessel were observed in cross-neck stent deployment. Compression tests revealed a larger supporting force of the NFM with straight-on deployment compared with the side-wall radial force (P < 0.05). A potential problem with this technique is the possible inability or difficulty in retrieving a partially deployed coil.

CONCLUSIONS

Stent-assisted coiling of wide-neck terminus aneurysms with straight-on deployment of NFM consistently achieved a stable NFM-coil complex. The NFM also had a better supporting force in a straight position. Some technical difficulties may be encountered during subsequent coiling. This alternative technique to conventional cross-neck bridging appears to be another strategy for wide-neck terminus aneurysm coiling.

Stent-assisted coiling of bifurcation aneurysms may improve endovascular treatment: a critical evaluation in an experimental model

BACKGROUND AND PURPOSE

Endovascular treatment of wide-neck bifurcation aneurysms often results in incomplete occlusion or aneurysm recurrence. The goals of this study were to compare results of coil embolization with or without the assistance of self-expandable stents and to examine how stents may influence neointima formation.

MATERIALS AND METHODS

Wide-neck bifurcation aneurysms were constructed in 24 animals and, after 4-6 weeks, were randomly allocated to 1 of 5 groups: 1) coil embolization using the assistance of 1 braided stent (n = 5); 2) coil embolization using the assistance of 2 braided stents in a Y configuration (n = 5); 3) coil embolization without stent assistance (n = 6); 4) Y-stenting alone (n = 4); and 5) untreated controls (n = 4). Angiographic results were compared at baseline and at 12 weeks, by using an ordinal scale. Neointima formation at the neck at 12 weeks was compared among groups by using a semiquantitative grading scale. Bench studies were performed to assess stent porosities.

RESULTS

Initial angiographic results were improved with single stent-assisted coiling compared with simple coiling (P = .013). Angiographic results at 12 weeks were improved with any stent assistance (P = .014). Neointimal closure of the aneurysm neck was similar with or without stent assistance (P = .908), with neointima covering coil loops but rarely stent struts. Y-stent placement alone had no therapeutic effect. Bench studies showed that porosities can be decreased with stent compaction, but a relatively stable porous transition zone was a limiting factor.

CONCLUSIONS

Stent-assisted coiling may improve results of embolization by allowing more complete initial coiling, but these high-porosity stents did not provide a scaffold for more complete neointimal closure of aneurysms.

Waffle-Cone Technique Using Solitaire AB Stent

The waffle-cone technique is a modified stent application technique, which involves protrusion of the distal portion of a stent into an aneurysm fundus to provide neck support for subsequent coiling. The authors report two cases of wide necked basilar bifurcation aneurysms, which were not amenable to stent assisted coiling, that were treated using the waffle-cone technique with a Solitaire AB stent. A 58-year-old woman presented with severe headache. Brain CT showed subarachnoid hemorrhage and angiography demonstrated a ruptured giant basilar bifurcation aneurysm with broad neck, which was treated with a Solitaire AB stent and coils using the waffle-cone technique. The second case involved an 81-year-old man, who presented with dizziness caused by brain stem infarction. Angiography also demonstrated a large basilar bifurcation unruptured aneurysm with broad neck. Solitaire AB stent deployment using the waffle-cone technique, followed by coiling resulted in near complete obliteration of aneurysm. The waffle-cone technique with a Solitaire AB stent can be a useful alternative to conventional stent application when it is difficult to catheterize bilateral posterior cerebral arteries in patients with a wide-necked basilar bifurcation aneurysm.

Stent-assisted coil embolization of complex wide-necked bifurcation cerebral aneurysms using the "waffle cone" technique. A review of ten consecutive cases

Endovascular treatment of complex, wide-necked bifurcation cerebral aneurysms is challenging.  Intra/extra-aneurysmal stent placement, the "waffle cone" technique, has the advantage of using a single stent to prevent coil herniation without the need to deliver the stent to the efferent vessel. The published data on the use of this technique is limited. We present our initial and follow-up experience with the waffle cone stent-assisted coiling (SAC) of aneurysms to evaluate the durability of the technique. We retrospectively identified ten consecutive patients who underwent SAC of an aneurysm using the waffle cone technique from July 2009 to March 2011. Clinical and angiographic outcomes after initial treatment and follow-up were evaluated. Raymond Class I or II occlusion of the aneurysm was achieved in all cases with the waffle cone technique. No intraoperative aneurysm rupture was noted. The parent arteries were patent at procedure completion. Clinical follow-up in nine patients (median 12.9 months) revealed no aneurysm rupture. Two patients had a transient embolic ischemic attack at 18 hours and three months after treatment, respectively. Catheter angiography or MRA at six-month follow-up demonstrated persistent occlusions of aneurysms in seven out of eight patients. Another patient had stable aneurysm occlusion at three-month follow-up study. Our experience in the small series suggests the waffle cone technique could be performed on complex, wide-necked aneurysms with relative safety, and it allowed satisfactory occlusions of the aneurysms at six months in most cases.

Comparison of devices used for stent-assisted coiling of intracranial aneurysms

Introduction

Two self-expandable stents, the Neuroform and the Enterprise stent, are widely used for stent-assisted coiling (SAC) of complex shaped intracranial aneurysms. However, comparative knowledge about technical feasibility, peri- and post-procedural morbidity and mortality, packing densities as well as follow-up data is limited.

Material and Methods

We conducted a retrospective study to investigate differences in aneurysms stented with the Enterprise or Neuroform stents. Angiographic follow-up (mean 19.42 months) was available in 72.6% (61/84) of aneurysms treated with stent-assisted coiling. We further sought to compare stent-assisted coiling to a matched patient population with aneurysms treated by conventional coil embolization.

Results

The stenting success rate of the Enterprise was higher compared to the Neuroform stent (46/48 and 42/51, respectively). In 5 of 9 cases in which the Neuroform stent was not navigable to the landing zone, we successfully deployed an Enterprise stent instead. Eventually, 42 aneurysms were coiled after stenting in each group. We observed no significant differences in peri-procedural complication rate, post-procedural hospital stay, packing density, recurrence rate or number of in-stent stenosis. Strikingly, 36.1% of followed aneurysms in the SAC group showed progressive occlusion on angiographic follow-up imaging. The packing density was significantly higher in aneurysms treated by SAC as compared to conventionally coiled aneurysms, while recanalization rate was significantly lower in the SAC group.

Conclusion

The procedural success rate is higher using the Enterprise, but otherwise both stents exhibited similar characteristics. Lower recurrence frequency and complication rates comparable to conventional coil embolization emphasize the importance of stent-assisted coiling in the treatment of complex aneurysms. Progressive occlusion on angiographic follow-up was a distinct and frequent observation in the SAC group and may in part be due to flow diversion.

Stent application for the treatment of cerebral aneurysms

Rapid and striking development in both the techniques and devices make it possible to treat most of cerebral aneurysms endovascularly. Stent has become one of the most important tools in treating difficult aneurysms not feasible for simple coiling. The physical features, the dimensions, and the functional characteristics of the stents show considerable differences. There are also several strategies and tips to treat difficult aneurysms by using stent and coiling. Nevertheless, they require much experience in clinical practice as well as knowledge of the stents to treat cerebral aneurysms safely and effectively. In this report, a brief review of properties of the currently available stents and strategies of their application is presented.

Vascular geometry change because of endovascular stent placement for anterior communicating artery aneurysms

BACKGROUND AND PURPOSE

Hemodynamics have been shown to play an important role in the initiation and progress of intracranial aneurysms, and are considered well-related to vascular configuration. The purpose of this study was to quantify the vascular geometry change due to intracranial stent placement and to discuss its potential effects on hemodynamics.

MATERIALS AND METHODS

Imaging data of patients with wide-neck AcomA aneurysms, treated with stent-assisted coiling between January 2005 and January 2010, were retrospectively analyzed. The angle between the afferent vessels (A1 segment) and the efferent vessels (ipsilateral or contralateral A2 segment) was calculated to determine the exact change in the angle after stent placement.

RESULTS

In all 20 patients, the stent caused a distinct change in the geometry of the parent vessel. Stent-related vascular angle change ranged from 7.60 to 74.88°, with an average of 29.95°. In 10 cases, the angle changed by >30°. In the 12 patients with the distal segment of the stent placed in the ipsilateral A2 segment, the mean postoperative A1-A2 angle increased by 27.71 ± 13.17° (from 7.60° to 48.29°). In the other 8 patients with the distal segment of the stent placed in the contralateral A2 segment, the mean postoperative A1-AcomA-A2 angle increased by 33.29 ± 21.89°(from 15.49° to 74.88°).

CONCLUSIONS

In addition to serving as a scaffold to contain coils, stent placement for AcomA aneurysms has a substantial effect on the vascular geometry, which may result in local hemodynamic changes.

Flow changes after endovascular treatment of a wide-neck anterior communicating artery aneurysm by using X-configured kissing stents (cross-kissing stents) technique

Endovascular treatment for a wide-neck anterior communicating artery (AcomA) aneurysm remains technically challenging. Stent-assisted embolization has been proposed as an alternative of treatment of complex aneurysms. The X-configuration double-stent-assisted technique was used to achieve successful coiling of wide-neck AcomA aneurysm. Implanted stent can alter intra-arterial flow. Follow-up angiograms 4 months later showed flow changes due to used X-technique of stents implantation and filling of the anterior cerebral artery from the opposite internal carotid artery.

X-configured stent-assisted coiling in the endovascular treatment of complex anterior communicating artery aneurysms: a novel reconstructive technique

Incomplete initial occlusion rates and relatively less long-term durability remain as major problems of endovascular treatment of cerebral aneurysms. Stent-assisted coiling is a well-established current solution to overcome these problems. Double-stent treatment with a Y-configuration has been previously reported to improve the application of coiling to wide-neck bifurcation aneurysms. Herein, a novel technique of X-configured stent-assisted coiling for treatment of wide-neck and complex AcomA aneurysms is described.

Endovascular treatment of wide-neck middle cerebral artery aneurysms with stents: a review of 16 cases

BACKGROUND AND PURPOSE

MCA aneurysms are common and often pose technical challenges to interventionalists. Intracranial stents are widely used in treating wide-neck aneurysms in other locations. To evaluate the feasibility, effectiveness, and safety of stent placement in MCA aneurysms, we performed this retrospective study.

MATERIALS AND METHODS

Between October 2003 and May 2009, 16 patients with 16 wide-neck MCA aneurysms were treated with stents at our institution. We retrospectively collected and analyzed the data for these patients, including demographics, morphologic features of the aneurysms, treatment results, and follow-up.

RESULTS

Seventeen stents, including 12 Neuroform, 4 LEO, and 1 Enterprise, were successfully deployed in this series. Of the 13 aneurysms treated with stent-assisted embolization, complete occlusion was achieved in 9 aneurysms; residual neck remained in 1, and residual aneurysm was present in 3. Contrast stasis in the aneurysm sac was observed in the other 3 aneurysms treated with stent alone. Procedure-related complication occurred in 1 patient, leading to no permanent effect. The mRS score at discharge was 0-2 in 14 patients and 3-6 in 2. The angiographic follow-up results of 9 patients (mean, 5.6 months) showed that all aneurysms remained stable or improved; there was no in-stent stenosis, recurrence, or retreatment. The clinical follow-up (mean, 20.1 months) demonstrated no neurologic deterioration or rebleeding.

CONCLUSIONS

Our preliminary experience demonstrates that stent placement for the treatment of selected wide-neck MCA aneurysms is feasible. However, its safety and efficacy should be further evaluated by larger case series and more adequate follow-up.