Impact of Anatomic Features in the Endovascular Embolization of 181 Anterior Communicating Artery Aneurysms

Impact of A1 hypoplasia on endovascular treatment outcomes for anterior communicating artery aneurysms: implications for follow-up strategies

BACKGROUND

A1 hypoplasia is associated with anterior communicating artery (AcomA) aneurysms, but optimal imaging follow-up timing remains unclear. This study aimed to investigate whether concomitant A1 hypoplasia influences the post-treatment outcomes of AcomA aneurysms.

METHODS

This retrospective cohort study (2013-24) included patients treated endovascularly for AcomA aneurysms, grouped by the presence or absence of A1 hypoplasia. Outcome measures included complete occlusion and good clinical outcomes at short term and long term follow-up, aneurysm recurrence, retreatment rates, and procedure related complications. Subgroup analysis compared treatment modalities within the A1 hypoplasia group.

RESULTS

298 AcomA aneurysms were included (median age 58 years, 63% women), with 205 in the symmetric group and 93 in the A1 hypoplasia group. Anterior dome projection was more common with A1 hypoplasia (61% vs 46%; P=0.01), as were recurrence rates (31% vs 15%; P=0.005). A1 hypoplasia correlated with reduced long term complete occlusion rates (OR 0.32, P=0.01). In A1 hypoplasia patients, coiling/balloon assisted coiling showed lower long term occlusion rates (P=0.008), higher recurrence (P=0.049), and a trend toward increased retreatment (P=0.07). Stent assisted coiling was linked with higher long term occlusion rates (P=0.009) and a trend toward reduced retreatment (P=0.07). Flow diverter treatment showed no significant effect.

CONCLUSION

In this study, A1 hypoplasia affected long term outcomes of endovascular treatment for AcomA aneurysms, leading to lower occlusion and higher recurrence rates. Closer long term monitoring is needed in these patients.

Outcomes and predictors of intraprocedural rupture in patients with cerebral aneurysm

BACKGROUND

Intraprocedural rupture (IPR) is a devastating complication of cerebral aneurysm treatment. While several studies have investigated its risk factors and clinical impact, further research with larger populations is warranted.

METHODS

We retrospectively reviewed data from 4,039 patients with 4,233 cerebral aneurysms treated at our institution between January 2009 and December 2018. Multivariate logistic regression with stepwise elimination was performed to identify the independent risk factors of IPR. Unfavorable clinical outcome was defined as a Modified Rankin Scale (mRS) ≥ 3 points at 3 months post-treatment.

RESULTS

IPR occurred in 61 (1.44%) of the 4,233 aneurysms. Multivariate analysis showed that previously ruptured aneurysms (odds ratio [OR] 3.182; 95% confidence interval [CI] 1.851-5.470; p < 0.001), surgical clipping (OR 3.598; 95% CI 1.894-6.836; p < 0.001), and higher aspect ratio (OR 1.310; 95% CI 1.032-1.663; p = 0.024) were independent risk factors for IPR. Patients with IPR had significantly higher rates of unfavorable clinical outcomes (mRS ≥ 3) compared to those without (18.0% vs. 3.3%, p < 0.001). However, within the ruptured aneurysm subgroup, the rate of unfavorable outcomes did not differ significantly between IPR and non-IPR groups (22.7% vs. 19.2%, p = 0.594).

CONCLUSION

Ruptured aneurysms, surgical clipping, and higher aspect ratio were independently associated with IPR. IPR significantly increased the risk of unfavorable clinical outcomes regardless of treatment approach, except in the subgroup of ruptured aneurysms.

Intermediate catheter use is associated with intraprocedural rupture during coil embolization of ruptured intracranial aneurysms: a retrospective propensity score-matched study

Introduction

An intermediate catheter (IMC) may pose a risk of intraprocedural rupture (IPR) during coil embolization of ruptured intracranial aneurysms (RIAs), because the pressure on the microcatheter and coil might be more direct. To verify this hypothesis, this study explored whether use of an IMC might correlate with an increased rate of IPR during coil embolization for RIAs.

Methods

We retrospectively reviewed 195 consecutive aneurysms in 192 patients who underwent initial coil embolization for saccular RIAs at our institution between January 2007 and December 2023. Patients were divided into two groups with aneurysms treated either with an IMC (IMC group) or without an IMC (non-IMC group). To investigate whether IMC use increased the rate of IPR, a propensity score-matched analysis was employed to control for age, sex, maximal aneurysm size, neck size, bleb formation, aneurysm location, proximal vessel tortuosity, balloon-assisted coiling, type of microcatheter, and type of framing coil.

Results

Ultimately, 43 (22%) coil embolization used IMC. In univariate analysis, the incidence of IPR was significantly higher in the IMC group compared with the non-IMC group (14.0 vs. 3.3%, p = 0.016). Propensity score matching was successful for pairs of 26 aneurysms in the IMC group and 52 aneurysms in the non-IMC group. The incidence of IPR was still significantly higher in the IMC group than in the non-IMC group (23.1 vs. 3.8%, p = 0.015). No significant differences in the incidences of ischemic complications and IMC-related parent artery dissection were observed between the two groups.

Discussion

When using IMC for coil embolization of RIAs, the surgeons should be more careful and delicate in manipulating the microcatheter and inserting the coils to avoid IPR.

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.

Risk factors and management of intraprocedural rupture during coil embolization of unruptured intracranial aneurysms: role of balloon guiding catheter

Introduction

Intraprocedural rupture (IPR) is a serious complication of endovascular coil embolization of unruptured intracranial aneurysms (UIAs). Although outcomes after IPR are poor, methods to prevent subsequent neurological deterioration have not yet been investigated. We evaluated the risk factors and management strategies for IPR, particularly the role of balloon guiding catheters (BGCs) in rapid hemostasis.

Methods

We retrospectively reviewed all UIA cases treated with coil embolization at three institutions between 2003 and 2021, focusing on preoperative radiological data, operative details, and outcomes.

Results

In total, 2,172 aneurysms were treated in 2026 patients. Of these, 19 aneurysms in 19 patients (0.8%) ruptured during the procedure. Multivariate analysis revealed that aneurysms with a bleb (OR: 3.03, 95% CI: 1.21 to 7.57, p = 0.017), small neck size (OR: 0.56, 95% CI: 0.37 to 0.85, p = 0.007), and aneurysms in the posterior communicating artery (PcomA) (OR: 4.92, 95% CI: 1.19 to 20.18, p = 0.027) and anterior communicating artery (AcomA) (OR: 12.08, 95% CI: 2.99 to 48.79, p < 0.001) compared with the internal carotid artery without PcomA were significantly associated with IPR. The incidence of IPR was similar between the non-BGC and BGC groups (0.9% vs. 0.8%, p = 0.822); however, leveraging BGC was significantly associated with lower morbidity and mortality rates after IPR (0% vs. 44%, p = 0.033).

Discussion

The incidence of IPR was relatively low. A bleb, small aneurysm neck, and location on PcomA and AcomA are independent risk factors for IPR. The use of BGC may prevent fatal clinical deterioration and achieve better clinical outcomes in patients with IPR.

Development of a comprehensive and clinically applicable novel projection classification system for anterior communicating artery aneurysms

Various surgical and anatomical classifications have been proposed to date related to ACoA aneurysm projection. Nonetheless, a universally accepted classification system is yet to be established. This study is aimed at establishing a standardized classification system for ACoA aneurysms with utilization 3D technology and defining reference lines for their projections. The goal is to create a simple, understandable, surgically beneficial, and reliable classification system based on neurovascular structures in the region, including safe and hazardous zones. The radiologic data of 96 patients with ACoA aneurysm who were treated in our university hospital between 2012 and 2020 were retrospectively analyzed, and a planned classification scale was developed with the data obtained. The classification aimed to create 9 main projection groups in the sagittal plane: superior, inferior, anterior, and posterior in linear orientation, and anterosuperior, posterosuperior, anteroinferior, posteroinferior, and complex in quadrant orientation. The coronal and axial planes included medial, lateral, and midline classifications, resulting in a 3-dimensional classification system with 25 projections. Among the 96 patients, 32 had linear and 64 had quadrant projections. In the sagittal plane, the linear projection breakdown was as follows: superior (28%), inferior (6.25%), anterior (53%), and posterior (12.5%). For the quadrant projection, the distribution was as follows: anterosuperior (53%), posterosuperior (12.5%), anteroinferior (21.87%), posteroinferior (3.12%), and complex (9.37%). Overall, 35.4% aneurysms were anterosuperior, 17.7% anterior, 14.58% anteroinferior, 9.37% superior, 8.3% posterosuperior, 6.25% complex, 4.16% posterior, 2.08% posteroinferior, and 2.08% inferior projection. Our study proposes a projection classification that utilizes 3D technology for safe surgery based on neurovascular structures in the region and thus better reveals safe and hazardous zones, including three plans, three dimensions, and two orientations. The use of this classification system offers valuable guidance for daily practice in the treatment of ACoA aneurysms.

Safety and Efficacy of Flow Diverters for Treatment of Unruptured Anterior Communicating Artery Aneurysms: Retrospective Multicenter Study

BACKGROUND

The anterior communicating artery (AComm) region is the most common site of intracranial aneurysms, with increased rupture risk compared with other locations. Overall, flow diverters present as a safe and efficacious treatment for intracranial aneurysms, but there is paucity of data for their use in the treatment of unruptured AComm aneurysms. We present the largest multicentric analysis evaluating the outcomes of flow diverters in AComm aneurysm treatment.

METHODS

Databases from 10 centers were retrospectively reviewed for unruptured AComm aneurysms treated with flow diverters. Demographics, clinical presentation, radiographic characteristics, procedural complications, and outcomes were assessed.

RESULTS

A total of 144 patients harboring 147 AComm aneurysms were treated between January 2012 and December 2021. Seventy-four were women (51.4%) and median age was 60 (IQR 50-67) years. All were unruptured AComm aneurysms. Half of the cohort had similar anterior cerebral artery sizes (51.4%). The most common morphology was saccular (94.6%), with a branch involvement in 32.7% of cases. Median vessel diameter was 2.4 mm, and the Pipeline Flex was the most prevalent device (32.7%). Median follow-up time was 17 months, with complete occlusion in 86.4% at the last follow-up. Functional independence (modified Rankin Scale score 0-2) was reported in 95.1%. Intraprocedural complications occurred in 5.6%, and postoperative complications were noted in 9.7% of cases. Combined major complication and mortality rate was 2.1%.

CONCLUSIONS

Our study suggests that flow diverters are a useful treatment for AComm aneurysms. Mid-term results indicated favorable aneurysm occlusion with a good safety profile. Additional prospective studies with longer follow-up periods and independent adjudication are warranted to better assess these results.

Treatment of intracranial bifurcation aneurysms with "X" stent-assisted coiling: A case series and literature review

PURPOSE

To clarify the safety and efficacy of "X" stent-assisted coiling (X-stenting) for the treatment of intracranial bifurcation aneurysms and to review the literature.

METHODS

We retrospectively reported five consecutive patients with six intracranial bifurcation aneurysms who underwent X-stenting between June 2014 and June 2020. The clinical and angiographic results were analyzed. We also performed an extensive PubMed review of medical literature up to June 2021.

RESULTS

Endovascular procedures were successfully applied to all six aneurysms. No procedure-related complications were noted. Follow-up angiograms were available for all patients and revealed occlusion in five aneurysms and improvement in one aneurysm. Clinical follow-up was performed for all patients, and the mRS score at follow-up was 0 in all patients. Thus, good outcomes were achieved in all patients, and no ischemic or hemorrhagic events were observed.

CONCLUSIONS

X-stenting appears to be safe for treating intracranial bifurcation aneurysms and effective in immediate and short-term outcome. Further research is required with well-designed, prospective studies with large sample sizes.

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.

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.

Impact of subcallosal artery origin and A1 asymmetry on surgical outcomes of anterior communicating artery aneurysms

BACKGROUND

Surgical clipping of anterior communicating artery (ACoA) aneurysms remains challenging due to their complex anatomy. Anatomical risk factors for ACoA aneurysm surgery require further elucidation. The aim of this study is to investigate whether proximity of the midline perforating artery, subcallosal artery (SubCA), and associated anomaly of the ACoA complex affect functional outcomes of ACoA aneurysm surgery.

METHODS

A total of 92 patients with both unruptured and ruptured ACoA aneurysms, who underwent surgical clipping, were retrospectively analyzed from a multicenter, observational cohort database. Association of ACoA anatomy with SubCA origin at the aneurysmal neck under microsurgical observation was analyzed in the interhemispheric approach subgroup (n = 56). Then, we evaluated whether anatomical factors associated with SubCA neck origin affected surgical outcomes in the entire cohort (both interhemispheric and pterional approaches, n = 92).

RESULTS

In the interhemispheric approach cohort, combination of A1 asymmetry and aneurysmal size ≥ 5.0 mm was stratified to have the highest probability of the SubCA neck origin by a decision tree analysis. Then, among the entire cohort using either interhemispheric or pterional approach, combination of A1 asymmetry and aneurysmal size ≥ 5.0 mm was significantly associated with poor functional outcomes by multivariable logistic regression analysis (OR 6.76; 95% CI 1.19-38.5; p = 0.03) as compared with A1 symmetry group in the acute subarachnoid hemorrhage settings.

CONCLUSION

Combination of A1 asymmetry and larger aneurysmal size was significantly associated with SubCA aneurysmal neck origin and poor functional outcomes in ACoA aneurysm surgery. Interhemispheric approach may be proposed to provide a wider and unobstructed view of SubCA for ACoA aneurysms with this high-risk anatomical variant.

Endovascular treatment of ruptured anterior communicating aneurysms: a 17-year institutional experience with coil embolization

BACKGROUND

Ruptured anterior communicating artery (ACoA) aneurysms can be challenging to treat via an endovascular procedure. This study analyzed retreatment rates and neurological outcomes associated with ruptured ACoA aneurysms treated via endovascular coiling.

METHODS

All patients with a ruptured ACoA aneurysm treated with endovascular coiling from 2003 to 2019 were retrospectively analyzed at a single center. Two comparisons were performed: no retreatment versus retreatment and coil embolization versus balloon-assisted coil embolization. Outcomes included retreatment and neurological outcome assessed via modified Rankin Scale (mRS).

RESULTS

During the study period, 186 patients with ruptured ACoA aneurysms underwent coil embolization. Treatment included standard coil embolization (68.3%, n=127), balloon-assisted coiling (28.5%, n=53), and stent-assisted embolization (2.7%, n=5). Angiographic outcomes were as follows: class I, 65.1% (n=121); class II, 28.5% (n=53); and class III, 6.5% (n=12). There were no aneurysm reruptures after the index procedure. The mean (SD) mRS score was 2.7 (2.0) at last follow-up (mortality, 19 (10%)). Retreatment occurred in 9.7% (n=18). Patients with retreatment were younger with lower-grade subarachnoid hemorrhage and more favorable functional status at discharge. Patients with aneurysms >7 mm (n=36) were significantly more likely to have recurrence (22.2% vs 6.7%, P=0.005).

CONCLUSIONS

Endovascular treatment of ruptured ACoA aneurysms is safe and is associated with low mortality and retreatment rates. Younger patients with favorable functional status and larger aneurysm size are more likely to be retreated. Ruptured aneurysms <4 mm, although prevalent in the study (29%), never required retreatment.

Multicenter Retrospective Registry of Anterior Communicating Artery Aneurysms with Endovascular Therapy (MACAARET): safety and efficacy study according to morphological considerations and spatial orientations

AIM

To analyse the safety and efficacy parameters of endovascular treatment of anterior communicating artery (ACoA) aneurysms, according to their morphological considerations and three-dimensional orientation in a multicentric registry.

MATERIALS AND METHODS

A retrospective analysis was undertaken of a prospective database of consecutive patients that underwent endovascular embolisation for ACoA aneurysm in four high-volume neuroradiology interventional departments. The study has been registered in ClinicalTrial.gov. Data were collected regarding the clinico-demographic variables of the patients, anatomical variations of the circle of Willis, morphological considerations and spatial orientation of ACoA aneurysms were recorded. Safety and efficacy variables were also recorded. Associations between anatomical variations of the circle of Willis, morphological considerations, and spatial orientation of the ACoA aneurysms and safety and efficacy variables were assessed.

RESULTS

Data from 122 consecutive patients were collected in the MACAARET study (mean age (±SD) was 55 (±14) and 50.8% (62/122) were male). One hundred and five patients (86.1%) presented with subarachnoid haemorrhage (SAH). ACoA aneurysms with a neck size of >4 mm had less chance of having successful endovascular treatment than those of ≤4 mm (19.8% versus 46.7%; p=0.002) and were also more likely to recanalise during follow-up (61.5% versus 19.5%; p=0.003). Moreover, ACoA aneurysms with an aspect ratio of >1.7 had more chance of having immediate therapeutic success than those with a ratio of ≤1.7 (70.7% versus 44.8%; p=0.012). There were no other associations between the anatomical variables of the ACoA aneurysms and the safety-efficacy variables.

CONCLUSION

ACoA aneurysms are suitable for both endovascular and microsurgical approaches, but more data are required to determine which is the best approach regarding the morphological and spatial orientation of the aneurysm and the anatomical variations of the circle of Willis.

Endoscopic Endonasal Approach for Clipping Anterior Communicating Artery Aneurysms From Cadaver Studies and Three-Dimensional Printed Models to a Clinical Case

OBJECTIVES

Anterior communicating artery (ACoA) aneurysm is one of the most common intracranial aneurysms, and it is also the aneurysm with the highest rupture rate. With the improvement of endoscopic techniques, it is possible to use an endoscopic endonasal approach (EEA) to clip ACoA aneurysms. For further analysis of the EEA for clipping ACoA aneurysms, we used cadaver heads and three-dimensional (3D)-printed models to finish the anatomical study, and we finally selected 1 clinical case to complete the clipping through the EEA.

MATERIALS AND METHODS

We first collected 3 cadaver heads to simulate the EEA. Then, the imaging data of 29 real cases of ACoA aneurysm were collected, and the model of an aneurysm was prepared by 3D printing technology; then, the EEA was used to simulate the clipping of the aneurysm model. Finally, a clinical case with 2 ACoA aneurysms was selected to adopt the EEA for clipping.

RESULTS

Both the cadaver head and 3D-printed aneurysm model could simulate aneurysm clipping with the EEA. The clinical case of the selected ACoA aneurysm can successfully complete the clipping through the EEA.

CONCLUSIONS

3D-printed models are a good method to study the anatomical characteristics of a surgical approach. For specially selected ACoA aneurysms, the EEA is relatively simple method that can be used to clip the aneurysm successfully. The EEA for clipping ACoA aneurysms is a useful complement to the current traditional craniotomy approaches and endovascular embolization.

Evaluation of the Safety and Effectiveness of Coil Embolization for Anterior Communicating and Anterior Cerebral Artery Aneurysms

Objective

Endovascular coil embolization for anterior communicating artery (ACoA) and anterior cerebral artery (ACA) aneurysms is associated with high total and near-total occlusion rates, but the complication rate is high. The development of newer endovascular technologies may improve the clinical outcomes. This study investigated the status of endovascular treatment of ACoA and ACA aneurysms by comparing our results with past reports.

Methods

Between January 2006 and December 2018, we investigated 50 patients who were followed for 12 months or longer to clarify the outcomes of coil embolization. The outcomes of embolization were evaluated using time-of-flight MRA. The safety was evaluated based on procedure-related complications that affected clinical outcomes.

Results

Initial assessments demonstrated complete obliteration in 84% (42 of 50 patients) and a residual neck in 14% (7 of 50 patients). Procedure-related complications developed in 12% (6 of 50 patients). The procedure-related morbidity rate was 2% (1 of 50 patients) and there was no procedure-related death. Recanalization was noted in 14% (7 of 50 patients, median follow-up period, 57 months). The recanalized aneurysms were significantly smaller than the stable aneurysms in maximum size (4.3 mm vs. 5.8 mm; p = 0.017) and height (3.7 mm vs. 4.3 mm; p = 0.035).

Conclusion

We demonstrated the safety and effectiveness of endovascular coil embolization for ACoA and ACA aneurysms. The small size of aneurysms may be related to recanalization.

Success Rate of Simple Coil Embolization in Wide-Neck Aneurysm with Aneurysmal Shoulder

Background and Objective:

Wide-necked intracranial aneurysm (WIA) is one of the challenging diseases for neuro-interventionist to treat by simple coiling technique. The purpose of this study is to identify the morphology associated with successful simple coil embolization in wide neck aneurysm patients.

Materials and Methods:

Between January 2002 and August 2018, 102 patients with total 115 ruptured or unruptured WIA which received endovascular treatment were retrospective reviewed. Data were analyzed including demographics, aneurysm morphology, endovascular technique, angiographic outcome, complication, regrowth, and retreatment rate.

Results:

The mean age of patients was 61.6 years with female predominant (72.5%). Ruptured WIA was diagnosed in 71 patients (61.7%). Majority of aneurysms were located in an anterior circulation which were 74 cases (64.3%), mainly paraclinoid aneurysm (30/115). Endovascular treatment was successful in 113 cases (98.3%) which can be mainly divided into simple coil embolization 50 cases (43.5%), balloon-assisted coil embolization 26 cases (22.6%), and stent-assisted coil embolization 32 cases (27.8%). Complete, subtotal, and incomplete occlusion of WIA was achieved in 32 cases (27.8%), 62 cases (53.9%), and 18 cases (15.7%), respectively. There was 9.6% complication occurred. Regrowth and retreatment were found 20% and 15.7%, respectively.

Conclusion:

WIA with two-sided aneurysmal shoulder or neck width <3.6 mm. are significantly associated with successful coil embolization using simple coiling technique.

Prediction of Clinical Outcome at Discharge After Rupture of Anterior Communicating Artery Aneurysm Using the Random Forest Technique

Background: Aneurysmal subarachnoid hemorrhage (SAH) is a devastating disease. Anterior communicating artery (ACoA) aneurysm is the most frequent location of intracranial aneurysms. The purpose of this study is to predict the clinical outcome at discharge after rupture of ACoA aneurysms using the random forest machine learning technique.

Methods: A total of 607 patients with ruptured ACoA aneurysms were included in this study between December 2007 and January 2016. In addition to basic clinical variables, 12 aneurysm morphologic parameters were evaluated. A multivariate logistic regression analysis was performed to determine the independent predictors of poor outcome. Of the 607 patients, 485 patients were randomly selected for training and the remaining for internal testing. The random forest model was developed using the training data set. An additional 202 patients from February 2016 to December 2017 were collected for externally validating the model. The prediction performance of the random forest model was compared with two radiologists.

Results: Patients' age (odds ratio [OR] = 1.04), ventilated breathing status (OR = 4.23), World Federation of Neurosurgical Societies (WFNS) grade (OR = 2.13), and Fisher grade (OR = 1.50) are significantly associated with poor outcome. None of the investigated morphological parameters of ACoA aneurysm is an independent predictor of poor outcome. The developed random forest model achieves sensitivities of 78.3% for internal test and 73.8% for external test. The areas under receiver operating characteristic (ROC) curve of the random forest model were 0.90 for the internal test and 0.84 for the external test. Both sensitivities and areas under ROC curves of our model are superior to those of two raters in both internal and external tests.

Conclusions: The random forest model presents good performance in predicting the outcome after rupture of ACoA aneurysms, which may aid in clinical decision making.

The Relationships between Anatomical Factors and Treatment Procedures for the Endovascular Treatment of Anterior Communicating Artery Aneurysms

Objective

Endovascular treatment of anterior communicating artery aneurysms is difficult due to their complex anatomical structure. We retrospectively analyzed the relationships among the anatomical features, initial microcatheter positions, and initial occlusion outcomes.

Methods

In all, 66 cases were treated at our hospital. We investigated the relationships among the anatomical features of the aneurysm and A1 segment of the anterior cerebral artery (ACA), treatment procedures, and initial occlusion outcomes. We divided the initial microcatheter positions into greater and lesser curvatures based on the curvature from A1 to the aneurysm, and evaluated the outcomes.

Results

In total, 54 out of 66 patients (82%) achieved complete obliteration (CO) or had residual neck (RN) aneurysms, and 12 had residual aneurysms (RAs: 18%). Neck diameters and superior position aneurysms were correlated with initial occlusion outcomes in the multivariate analysis. The relationship between initial occlusion outcomes and initial microcatheter positions in superior position aneurysms (37 patients) was then examined. Eleven out of 26 patients (42.3%) had residual aneurysms at the greater curvature microcatheter position, whereas no residual aneurysms were detected at the lesser curvature microcatheter position. The A1 angle was not correlated with the outcomes.

Conclusion

Wide-necked aneurysms and superior position aneurysms were identified as factors leading to incomplete occlusion in the endovascular treatment of anterior communicating artery aneurysms. The microcatheter position at the greater curvature in superior position aneurysms was a factor for incomplete occlusion. This suggests that guiding the microcatheter to the lesser curvature position of A1 is important in the treatment of superior position aneurysms.

Prediction of Post-Embolization Recurrence of Anterior Communicating Aneurysms with A1 Segment Asymmetry by Fluid Dynamic Analysis

Objective

The increased surface pressure of the coil mass calculated by computational fluid dynamics (CFD) analysis has been reported to be associated with the recurrence of internal carotid aneurysms after coil embolization. In this study, we investigated the relationship between the pressure on the coil surface and the recurrence of anterior communicating aneurysms.

Methods

Among patients with anterior communicating aneurysms who underwent coil embolization at a volume embolization rate of 20% or more without using a stent, only one proximal anterior communicating artery (A1) was visualized by magnetic resonance angiography (MRA). A virtual post-coiling model was created by eliminating the aneurysm at the neck position from the blood vessel model based on three-dimensional rotational angiography (3D-RA) data before treatment, and the neck plane was defined as the virtual coil plane. Using CFD analysis, the pressure difference (PD) was calculated by subtracting the average pressure of A1 from the maximum pressure on the virtual coil surface and dividing by the dynamic pressure of A1 for normalization. PD was statistically compared between the recurrent group and the non-recurrent group.

Results

Four of 10 patients with anterior communicating aneurysms exhibited recurrence. The PD was 2.54 ± 0.24 and 2.12 ± 0.26 in the recurrent and non-recurrent groups, respectively, and was significantly higher in the recurrent group (p=0.038). In the receiver operating characteristics (ROC) analysis, the area under the curve (AUC) was 0.917, and with a cutoff value of 2.31, the sensitivity was 1.000 and the specificity was 0.833.

Conclusion

PD was considered a predictor of recurrence after coil embolization in anterior communicating aneurysms with asymmetrical A1. Preoperative prediction of recurrence after cerebral aneurysm embolization may be possible using CFD analysis.

Microsurgical Treatment of Unruptured Anterior Communicating Artery Aneurysms: Approaches and Outcomes in a Large Contemporary Series and Review of the Literature

BACKGROUND

With advances in endovascular techniques, the relative roles of microsurgery and endovascular therapy in the management of intracranial aneurysms have become less clear, and data regarding treatment-specific outcomes are increasingly important.

OBJECTIVE

To describe our experience with microsurgery in a large series of unruptured anterior communicating artery aneurysms (ACOMMAAs) and detail our treatment decision-making process based on individual aneurysm morphology.

METHODS

We retrospectively reviewed unruptured ACOMMAAs treated microsurgically at our center between 1997 and 2018, recording aneurysm size, surgical approach, occlusion rates, neurological outcomes, and complications.

RESULTS

We treated 300 unruptured ACOMMAAs in 300 patients, mean age 49 yr, 180 (60.0%) female, including 245 (81.7%) small, 50 (16.7%) large, and 5 (1.7%) giant aneurysms. Most underwent a pterional approach (253, 84.3%), with orbitozygomatic or anterior interhemispheric approaches in 35 (11.7%) and 12 (4%), respectively. Greater than 95% occlusion was achieved in 284 (94.7%), 90% to 95% occlusion in 13 (4.3%), and 3 (1.0%) underwent wrapping. Serious complications occurred in 3 patients (1.0%) resulting in 2 deaths (0.7%), and minor complications in 12 (4.0%). At final follow-up, good neurological outcome was observed in 297 (99.0%) patients.

CONCLUSION

Given clinical equipoise regarding optimal treatment of unruptured ACOMMAAs, this work provides a benchmark for achievable microsurgical outcomes. Future surgical/endovascular studies should separate results of ruptured and unruptured lesions and describe aneurysm morphology to allow for better comparison of outcomes between treatments. We suggest that open microsurgery represents an important option for select, morphologically complex ACOMMAAs, and that a multidisciplinary approach offers optimal patient outcomes.

Long-term Outcomes After Intraprocedural Aneurysm Rupture During Coil Embolization of Unruptured Intracranial Aneurysms

BACKGROUND

The long-term outcomes of patients with intraprocedural aneurysm rupture (IPR) during endovascular coiling of unruptured intracranial aneurysms (UIAs) remain unclear. We investigated the long-term outcomes and predictors of neurological outcomes in patients who sustained IPR during coil embolization of UIAs.

METHODS

We retrospectively analyzed the medical record of 312 untreated UIAs in 284 patients who underwent endovascular coiling between April 2013 and July 2018.

RESULTS

The mean follow-up period for the entire cohort was 25.6 months. Twelve patients (3.8%) experienced IPR. The mean aneurysm size in the IPR cohort was significantly smaller than that in the no-IPR cohort (P = 0.045). The IPR cohort had a higher percentage of earlier subarachnoid hemorrhage from another aneurysm (P = 0.019), anterior communicating artery (AComA) aneurysm (P < 0.001), and basilar artery (BA) aneurysm (P = 0.022) than the no-IPR cohort. Neurologic deterioration was observed in 3 patients. The morbidity and mortality rates of the IPR cohort were 25% and 8.3%, respectively. Patients with IPR during coil embolization for AComA aneurysm did not develop neurological deterioration. Two of the 3 patients (66.7%) with a BA aneurysm had neurological deterioration. The proportion of patients with an mRS score of 0-2 at the last follow-up did not differ between the 2 cohorts (P = 0.608).

CONCLUSIONS

The proportion of functionally independent patients did not differ between patients with and without IPR. Patients with BA aneurysms who developed an IPR tended to exhibit more unfavorable clinical courses than patients with AcomA aneurysms.

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.

Angiographic and clinical results of anterior communicating artery aneurysm endovascular treatment

Introduction

The anterior communicating artery (ACoA) is the most common location of intracranial aneurysms, observed in 35% of cases. Endovascular treatment has become an alternative to surgical clipping and the primary method of choice.

Aim

To assess the treatment results of ruptured and unruptured ACoA aneurysms and to assess the incidence of intraprocedural complications and various factors influencing these aspects.

Material and methods

One hundred and eleven embolizations of ACoA aneurysms (80.7% ruptured and 19.3% unruptured) were retrospectively analysed. The methods of embolization were: coiling, balloon-assisted coiling, stent-assisted coiling. Morphology and dimensions of aneurysms were assessed on 3D digital subtraction angiography (DSA) images. Medical records were analysed for patient’s clinical status at admission, intraprocedural complications, follow-up examination and modified Rankin Scale (mRS) score 1 month after discharge.

Results

Immediately after the procedure 56.9% of patients had Raymond-Roy Occlusion Classification (RROC) class I, 37.6% class II and 5.5% class III. The overall intraprocedural complication rate was 6.6%. There were significantly more cases of bleeding (p = 0.012) and coil prolapse (p = 0.012) during the procedures ending with higher packing density. Twenty-eight (25.7%) patients died during hospital stay, 27 (96.4%) with ruptured aneurysm. In the follow-up of 41 patients, RROC was the same or improved in 73.2% of cases and recanalization occurred in 26.8%. Six patients with aneurysm recanalization underwent repeat embolization.

Conclusions

Endovascular embolization of ACoA aneurysms is an effective and safe treatment method. The most powerful factor influencing the incidence of complications is packing density. Superior orientation of the dome, initial incomplete embolization and poor outcome in mRS scale are factors predisposing to ACoA aneurysm recurrence.

Complications of endovascular treatment for intracranial aneurysms: Management and prevention

Endovascular coiling for intracranial aneurysms has become an accepted treatment with good clinical results and provides adequate protection against rebleeding and rupture of aneurysms. However, despite the experience, preparation, or skill of the physician, complications during endovascular treatment still occur. The main complications of endovascular coiling are: procedural aneurysmal perforations by the microcatheter, micro-guidewire, or coil, and thromboembolic events. Such situations are unexpected, complex, and can have devastating consequences. In this article, we present a comprehensive review of the two most common complications, aneurysmal perforation and thromboembolism during endovascular coiling, and how we can prevent or overcome these complications to achieve a satisfactory outcome. In addition, as the flow diverter has been become an important tool for management of large, wide necked, and other anatomically challenging aneurysms, we also describe complications stemming from the use of the tool, which remains a novel treatment option for complex aneurysms.

Clinical relevance of anterior cerebral artery asymmetry in aneurysmal subarachnoid hemorrhage

OBJECTIVE

An asymmetry of the A1 segments (A1SA) of the anterior cerebral arteries (ACAs) is an assumed risk factor for the development of anterior communicating artery aneurysms (ACoAAs). It is unknown whether A1SA is also clinically relevant after aneurysm rupture. The authors of this study investigated the impact of A1SA on the clinical course and outcome of patients with aneurysmal subarachnoid hemorrhage (SAH).

METHODS

The authors retrospectively analyzed data on consecutive SAH patients treated at their institution between January 2005 and December 2012. The occurrence and severity of cerebral infarctions in the ACA territories were evaluated on follow-up CT scans up to 6 weeks after SAH. Moreover, the risk for an unfavorable outcome (defined as > 3 points on the modified Rankin Scale) at 6 months after SAH was assessed.

RESULTS

A total of 594 patients were included in the final analysis. An A1SA was identified on digital subtraction angiography studies from 127 patients (21.4%) and was strongly associated with ACoAA (p < 0.0001, OR 13.7). An A1SA independently correlated with the occurrence of ACA infarction in patients with ACoAA (p = 0.047) and in those without an ACoAA (p = 0.015). Among patients undergoing ACoAA coiling, A1SA was independently associated with the severity of ACA infarction (p = 0.023) and unfavorable functional outcome (p = 0.045, OR = 2.4).

CONCLUSIONS

An A1SA is a common anatomical variation in SAH patients and is strongly associated with ACoAA. Moreover, the presence of A1SA independently increases the likelihood of ACA infarction. In SAH patients undergoing ACoAA coiling, A1SA carries the risk for severe ACA infarction and thus an unfavorable outcome.

Clinical trial registration no.: DRKS00005486 (http://www.drks.de/)

Risk factors for and outcomes of intraprocedural rupture during endovascular treatment of unruptured intracranial aneurysms

BACKGROUND AND PURPOSE

The risk factors for intraprocedural rupture (IPR) of unruptured intracranial aneurysms (UIAs) and the outcomes of IPR itself are unclear. This study was performed to identify the independent risk factors for and outcomes of IPR.

MATERIALS AND METHODS

We retrospectively evaluated the medical records and radiologic data of 1375 patients (1406 UIAs) who underwent coil embolization from January 2001 to October 2016.

RESULTS

IPR occurred in 20 aneurysms of 20 patients (1.4%). Univariate analyses showed that the rate of IPR was significantly higher in the treatment of aneurysms with a small dome size, aneurysms in the anterior communicating artery (AcomA) (6.6%), and patients with a medical history of dyslipidemia. Multivariate analyses showed that a small dome size and aneurysms in the AcomA were independently associated with IPR (p=0.0096 and p=0.0001, respectively). IPR induced by a microcatheter was associated with a higher risk of severe subarachnoid hemorrhage than other causes of IPR (57% vs 0%, respectively). Thromboembolic complications occurred in seven (35%) patients with IPR. Six (30%) patients required external ventricular drainage placement after developing symptoms of acute hydrocephalus. The overall morbidity and mortality rates from IPR were 0.22% and 0.15%, respectively.

CONCLUSIONS

Aneurysms in the AcomA and with a small dome size are likely to be risk factors for IPR. IPR induced by microcatheters can result in poor outcomes. The rate of IPR-associated thromboembolic complications is high, and IPR itself is associated with acute hydrocephalus. If managed appropriately, however, most patients with IPR can survive without neurological deterioration.

Proposed Parent Vessel Geometry Based Classification of Anterior Communicating Artery-Located Aneurysms

BACKGROUND AND OBJECTIVES

The present study is focused on correlation of parent vessels and neck diameters with anterior communicating artery (AComA) aneurysmal depth and growth direction. The study principally aims to suggest a new classification of AComA-located aneurysms based on the physical characteristics of parent vessels.

METHODS

A retrospective analysis was performed of 155 patients with ruptured AComA-located aneurysms. The percentage of difference between both A1 arteries was measured on computed tomography angiography images and neck locations were determined. Accordingly, AComA-located aneurysms were classified into 2 groups. In both groups, A1 and A2 arteries and neck size diameters were measured and their relation with aneurysmal depth was studied. The aspect ratio was calculated.

RESULTS

Eleven patients in which the aneurysm neck originates from the AComA proper with almost equal A1s were classified as the true AComA aneurysm group whereas 144 patients in whom the aneurysm neck originates at the dominant A1 bifurcation into the AComA and A2 with the average difference between both A1s of about 84.44% were classified as the dominant A1-bifurcation group. There is significant correlation between aneurysmal depth and neck diameter in both groups (P ≤ 0.05, P < 0.001). The aspect ratio was calculated as equal to 1.166.

CONCLUSIONS

The dominant A1 bifurcation type is the most common type of AComA-located aneurysm. The present classification provides clinical value in understanding how AComA aneurysms grow and behave. It helps to understand the geometry of multilobulated aneurysms such as ruptured blebs locations during treatment procedures respecting the direction of the dominant A1 axis in group II. Multiple anatomic variations of this complex AComA area can clarify future subtypes of these 2 groups. Thus, further investigation of more patients is needed.

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.

Safety of coil occlusion of the parent artery for endovascular treatment of anterior communicating artery aneurysm

Many studies lay emphasis on the clinical importance of perforating branches of the anterior communicating artery (ACoA) and report that vascular damage of the perforators from ACoA aneurysm during surgery cause subsequent postoperative amnesia. The purpose of our study was to analyze the safety of parent artery occlusion for ACoA aneurysm coiling based on the anatomical features of the ACoA complex in 13 patients with 13 ACoA aneurysms. All patients underwent coiling of the aneurysm sac and ACoA. Aneurysm characteristics including size, dome-to-neck ratio, anterior/posterior orientation of the aneurysm dome with respect to the axis of the pericallosal artery, location of the aneurysm neck with respect to the A1-A2 segment of the anterior cerebral artery (ACA) or the ACoA, and the presence of hypoplasia/aplasia of A1 segment were assessed. The aneurysm neck was located directly on the ACoA in five aneurysms (38%), whereas eight (62%) had the neck located at the A1-A2 junction. Of the five patients whose aneurysm neck was located in the ACoA, four patients had infarcts in the basal forebrain. Three of the patients complained of amnesia. None of the aneurysms with the neck located at the A1-A2 junction were associated with infarction. There has been little evidence thus far that parent vessel occlusion of ACoA aneurysms is a safe method for the treatment of aneurysms. Patients with the aneurysm neck located at the A1-A2 junction and without A1 aplasia, who were treated with aneurysm sac and ACoA embolism, were potentially safe.

Diagnostic Impact of Bone-Subtraction CT Angiography for Patients with Acute Subarachnoid Hemorrhage

BACKGROUND AND PURPOSE

Detection and evaluation of ruptured aneurysms is critical for choosing an appropriate endovascular or neurosurgical intervention. Our aim was to assess whether bone-subtraction CTA is capable of guiding treatment for cerebral aneurysms in patients with acute SAH and could replace DSA.

MATERIALS AND METHODS

We prospectively studied 116 consecutive patients with SAH with 16-detector row bone-subtraction CTA and DSA before intracranial aneurysm treatment. Two independent neuroradiologists reviewed the bone-subtraction CTA blinded to DSA (reference standard). We determined the accuracy of bone-subtraction CTA for aneurysm detection and the measurement of aneurysm dimensions and compared the radiation doses of the 2 imaging modalities.

RESULTS

Seventy-one patients (61%) had 74 aneurysms on DSA. Bone-subtraction CTA detected 73 of these aneurysms, but it detected 1 additional aneurysm. On a per-aneurysm basis, sensitivity, specificity, and positive and negative predictive values for bone-subtraction CTA were 99%, 98%, and 99% and 98%, respectively. For aneurysms of ≤3 mm, sensitivity was 94% (95% CI, 73%-99%). Bone-subtraction CTA slightly overestimated neck and dome diameters by <0.2 mm and overestimated the dome-to-neck ratios by 2% on average. Dose-length product was 565 ± 201 mGy × cm for bone-subtraction CTA and 1609 ± 1300 mGy × cm for DSA.

CONCLUSIONS

Bone-subtraction CTA is as accurate as DSA in detecting cerebral aneurysms after SAH, provides similar information about aneurysm configuration and measures, and reduces the average effective radiation dose for vascular diagnostics by 65%. Diagnostic equivalence in association with dose reduction suggests replacing DSA with bone-subtraction CTA in the diagnostic work-up of spontaneous SAH.

Predictor and Prognosis of Procedural Rupture during Coil Embolization for Unruptured Intracranial Aneurysm

Objective

The objectives of this study was to determine the incidence and outcomes of procedural rupture (PR) during coil embolization of unruptured intracranial aneurysm (UIA) and to explore potential risk factors.

Methods

This retrospective study evaluated 1038 patients treated with coil embolization between January 2001 and May 2013 in a single tertiary medical institute. PR was defined as evidence of rupture during coil embolization or post procedural imaging. The patient's medical records were reviewed including procedure description, image findings and clinical outcomes.

Results

Twelve of 1038 (1.1%) patients showed PR. Points and time of rupture were parent artery rupture during stent delivery (n=2), aneurysm rupture during filling stage (n=9) and unknown (n=1). Two parent artery rupture and one aneurysm neck rupture showed poor clinical outcomes [modified Rankin Scale (mRs) >2] Nine aneurysm dome rupture cases showed favorable outcomes (mRS ≤2). Location (anterior cerebral artery) of aneurysm was associated with high procedural rupture rate (p<0.05).

Conclusion

The clinical course of a patientwith procedural aneurysm rupture during filling stage seemed benign. Parent artery and aneurysm neck rupture seemed relatively urgent, serious and life threatening. Although the permanent morbidity rate was low, clinicians should pay attention to prevent PR, especially when confronting the anterior cerebral artery aneurysm.

Eleven Year's Single Center Experience of Endovascular Treatment of Anterior Communicating Artery Aneurysms: Focused on Digital Subtraction Angiography Follow-Up Results

Objective

Anterior communicating artery (AcomA) aneurysms represent the most common intracranial aneurysms and challenging to treat due to complex vascularity. The purpose of this study was to report our experience of endovascular treatment of AcomA aneurysms.

Methods

Between January 2003 and December 2013, we retrospectively reviewed the medical records of 134 AcomA aneurysm patients available more than 6 months conventional angiographic and clinical follow-up results. We focused on aneurismal or AcomA vascular characters, angiographic and clinical follow-up results, and retreatment.

Results

The rate of ruptured cases was 75.4%, and the small (<10 mm) aneurysms were 96.3%. Based on the subtypes defined by dominance of A1, 79 patients (59%) had contralateral A1 hypoplasia or agenesis. The immediate post-procedural angiography confirmed complete occlusion in 75.4%, partial occlusion in 24.6%. Procedure related complications were observed in 25 (18.6%) patients. Most of the adverse events were asymptomatic. Follow-up conventional angiography at ≥6 months was performed in all patients (mean 16.3 months) and major recanalization was noted in 6.7% and regrowth in one case. The aneurysm size (p=0.016), and initial treatment results (p=0.00) were statistically significant risk factors related to aneurysm recurrence. An overall improvement in mRS was observed during the clinical follow-up period and no rebleeding episode occurred.

Conclusion

This study demonstrated that endovascular treatment is an effective treatment modality for AcomA aneurysms with low morbidity. Patients should take long term clinical and angiographic follow-up in order to assess the recurrence and warrant retreatment, especially ruptured, large, and initially incomplete occluded aneurysms.

Impact of Aneurysmal Neck Position in Endovascular Therapy for Anterior Communicating Artery Aneurysms

Anterior communicating artery (ACoA) aneurysms have a complex architecture and many variations, making endovascular therapy more difficult in some cases. The aim of this study was to investigate whether the neck position of an aneurysm was identifiable for determining the immediate angiographic success and procedural complications in the coiling of the ACoA aneurysms. We conducted a retrospective case review of 40 patients with ACoA aneurysms treated by endovascular therapy from 2008 to 2015. The mean age was 66.8 years. Thirty-five aneurysms were ruptured; five were unruptured. For the analysis, the patients were divided into two groups according to the neck position of aneurysms: the true ACoA group, 9 patients with the neck located on the ACoA itself; and the other ACoA group, 31 patients with the neck at the junction of the A1 and A2 portions of an anterior cerebral artery. Morphological characteristics (dome size, dome direction, rate of wide neck, and angulation of aneurysms in relation to the parent artery) were analyzed along with immediate angiographic results, volume embolization ratio (VER), and procedural complications. Small aneurysms with superior dome projection and acute angulation of the aneurysm direction occurred more often in the true ACoA group. The rates of complete obliteration, VER, and procedural complications were 33.3%, 32.3%, and 22.2% in the true ACoA group and 54.8%, 36.3%, and 6.5% in the other ACoA group, respectively. True ACoA aneurysms could present an anatomical difficulty in endovascular coiling. Aneurysmal neck position should be accurately assessed to achieve successful embolization of the ACoA aneurysms.

HydroCoils Are Associated with Lower Angiographic Recurrence Rates Than Are Bare Platinum Coils in Treatment of "Difficult-to-Treat" Aneurysms: A Post Hoc Subgroup Analysis of the HELPS Trial

BACKGROUND AND PURPOSE

The HydroCoil Endovascular Aneurysm Occlusion and Packing Study was a randomized controlled trial that compared HydroCoils to bare platinum coils. Using data from this trial, we performed a subgroup analysis of angiographic and clinical outcomes of patients with "difficult-to-treat" aneurysms, defined as irregularly shaped and/or having a dome-to-neck ratio of <1.5.

MATERIALS AND METHODS

Separate subgroup analyses comparing outcomes of treatment with HydroCoils to that of bare platinum coils were performed for the following: 1) irregularly shaped aneurysms, 2) regularly shaped aneurysms, 3) aneurysms with a dome-to-neck ratio of <1.5, and 4) aneurysms with a dome-to-neck ratio of ≥1.5. For each subgroup analysis, the following outcomes were studied at the last follow-up (3-18 months): 1) any recurrence, 2) major recurrence, 3) re-treatment, and 4) an mRS score of ≤2. Multivariate logistic regression analysis was performed to determine if the HydroCoil was independently associated with improved outcomes in these subgroups.

RESULTS

Among the patients with an irregularly shaped aneurysm, the HydroCoil was associated with lower major recurrence rates than the bare platinum coils (17 of 66 [26%] vs 30 of 69 [44%], respectively; P = .046). Among the patients with an aneurysm with a small dome-to-neck ratio, the HydroCoil was associated with lower major recurrence rates than the bare platinum coils (18 of 73 [24.7%] vs 32 of 76 [42.1%], respectively; P = .02). No difference in major recurrence was seen between HydroCoils and bare platinum coils for regularly shaped aneurysms (42 of 152 [27.6%] vs 52 of 162 [32.1%], respectively; P = .39) or aneurysms with a large dome-to-neck ratio (41 of 145 [28.3%] vs 50 of 155 [32.3%], respectively; P = .53).

CONCLUSIONS

This unplanned post hoc subgroup analysis found that HydroCoils are associated with improved angiographic outcomes in the treatment of irregularly shaped aneurysms and aneurysms with a dome-to-neck ratio of <1.5. Because this was a post hoc analysis, these results are not reliable and absolutely should not alter clinical practice but, rather, may inform the design of future randomized controlled trials.

Endovascular Treatment of 429 Anterior Communicating Artery Aneurysms Using Bare-Platinum Coils : Clinical and Radiologic Outcomes at the Long-term Follow-up

Objective

We reviewed the feasibility, safety and efficacy as well as the clinical outcome and long-term angiographic results of endovascular treatment (EVT) of the anterior communicating artery (ACoA) aneurysms.

Methods

A total of 429 ACoA aneurysms in 426 patients were treated using coil embolization between March 1996 and October 2010 in a single institution. Pretreatment aneurysmal features were checked using angiogram. We had usually used tailored steam shaped microcatheter according to individual angiographic architectures. Immediate postembolization outcomes were evaluated using an angiographic outcome scale and clinical evaluation was performed using the Glasgow Outcome Scale (GOS).

Results

Postembolization angiograms demonstrated total occlusion of aneurysm in 290 of 429 (67.6%) aneurysms, neck remnant in 80 (18.6%) and body filling in 59 (13.8%). Dome direction and aneurysm angle was not associated with initial angiographic outcomes. The procedure-related morbidity rate was 0.9% (4 of 429). Clinical and imaging follow-up more than 6 months were available in 382 (89.0%) patients with a mean of 26.2 months. Overall rate of major recanalization was 7.9% (30 of 382) and all of them were retreated without complications. At the last follow-up, 233 (99.2%) of 235 patients had GOS of 5 in unruptured group, and 152 (79.5%) of 191 patients showed good clinical outcomes (GOS of 4 or 5) in ruptured group.

Conclusion

Tailored steam shaping of the microcatheter is vital to achieve good angiographic outcomes regardless of aneurysmal direction. EVT is feasible and safe for most ACoA aneurysms with acceptable immediate and long-term outcomes.

Effects of circle of Willis anatomic variations on angiographic and clinical outcomes of coiled anterior communicating artery aneurysms

BACKGROUND AND PURPOSE

Anterior communicating artery aneurysms account for one-fourth of all intracranial aneurysms and frequently occur in the context of A1 vessel asymmetry. The purpose of this study was to correlate circle of Willis anatomic variation association to angiographic and clinical outcomes of anterior communicating aneurysm coiling.

MATERIALS AND METHODS

The Cerecyte Coil Trial provides a subgroup of 124 cases with anterior communicating artery aneurysms after endovascular coiling. One hundred seventeen of 124 anterior communicating artery aneurysms had complete imaging and follow-up for clinical outcome analysis, stability of aneurysm coil packing, and follow-up imaging between 5 and 7 months after treatment. Clinical outcomes were assessed by the mRS at 6 months.

RESULTS

Anterior cerebral artery trunk-dominance was seen in 91 of 124 (73%) anterior communicating artery aneurysms and codominance in 33 of 124 (27%) anterior communicating artery aneurysms. There was no significant difference (P > .5) in treatment success at 5-7 months for anterior communicating artery aneurysms between the anterior cerebral artery trunk-dominant (49 of 86, 57%) and anterior cerebral artery trunk-codominant (19 of 31) groups. Angiographic follow-up demonstrates a statistically significant increase in neck remnants and progressive aneurysm sac filling with the A1 dominant configuration (n = 21, 24% at follow-up versus n = 11, 12% at immediate posttreatment, P = .035). There was no statistically significant difference in clinical outcomes between types of anterior cerebral artery trunk configuration (P > .5).

CONCLUSIONS

Anterior communicating artery aneurysms with anterior cerebral artery trunk-dominant circle of Willis configurations show less angiographic stability at follow-up than those with anterior cerebral artery trunk-codominance similar to other "termination" type aneurysms. This supports the hypothesis that anterior cerebral artery trunk-dominant flow contributes to aneurysm formation, growth, and instability after coiling treatment.

Flow diversion versus traditional endovascular coiling therapy: design of the prospective LARGE aneurysm randomized trial

BACKGROUND AND PURPOSE

The goal of aneurysm treatment is occlusion of an aneurysm without morbidity or mortality. Using well-established, traditional endovascular techniques, this is generally achievable with a high level of safety and efficacy. These techniques involve either constructive treatment of the aneurysm (coils with or without an intravascular stent) or deconstruction (coil occlusion) of the aneurysm and the parent artery. While established as safe and efficacious, the constructive treatment of large and giant aneurysms with coils has typically been associated with relatively lower rates of complete occlusion and higher rates of recurrence. Parent artery deconstruction, though immediately efficacious in achieving complete and durable occlusion, does require occlusion of a major intracranial blood vessel and is associated with risk of stroke.

MATERIALS AND METHODS

Flow diversion represents a new technology that can be used to constructively treat large and giant aneurysms. Once excluded successfully, the vessel reconstruction and aneurysm occlusion appears durable. The ability to definitively reconstruct cerebral blood vessels is an attractive approach to these large and giant complex aneurysms and allows the treatment of some aneurysms which were previously not amenable to other therapies. By comparison, conventional coiling techniques have traditionally been used for endovascular treatment of large aneurysms. Large and giant aneurysms that are amenable to either flow diversion or traditional endovascular treatment will be randomized to either therapy with FDA (or appropriate regulatory body) approved devices.

RESULTS

The trial is currently enrolling and results of the data are pending the completion of enrollment and follow-up.

CONCLUSIONS

This paper details the trial design of the LARGE trial, a blinded, prospective randomized trial of large anterior circulation aneurysms amenable to either traditional endovascular treatments using coils or reconstruction with flow diverters.

Balloon remodeling of complex anterior communicating artery aneurysms: technical considerations and complications

INTRODUCTION

Reports of the limitations and feasibility of balloon remodeling for treatment of complex anterior communicating artery (ACoA) aneurysms are scarce.

METHODS

Ninety-nine patients were treated with balloon-assisted coil embolization for ACoA aneurysms between August 2004 and October 2012. Records were reviewed for aneurysm characteristics, balloon trajectory (vessel and side), bilateral access, treatment-related complications, and aneurysm recurrence determined by magnetic resonance angiography (MRA). Morphological outcomes following treatment were categorized into Raymond class I, II, or III.

RESULTS

Fifty-three aneurysms (53.5%) were unruptured and 46 (46.4%) were ruptured. Aneurysmal occlusion (Raymond I or II) was achieved in 89 patients (89.9%); three (3.0%) were incompletely embolized and treatment was aborted in six (6.1%). Balloon trajectories were from the A1 to either the ipsilateral or contralateral A2. In 17 cases (17.2%), bilateral A1 access was used to achieve balloon protection of the contralateral A2. In four cases (4.0%), balloon remodeling was aborted due to technical difficulty. There were 15 (15.2%) treatment-related complications; five (5.1%) were intraoperative ruptures, one of which resulted in a neurological deficit and another in death. All other complications were clinically silent, producing a permanent complication rate of 2.0%. Mean radiographic follow-up was 2.5 years, and six patients (6.1%) were retreated for recurrence or known remnant.

CONCLUSIONS

Balloon remodeling should be considered for broad-based complex ACoA aneurysms. This technique provides a high rate of aneurysm occlusion with an acceptable complication profile, and avoids the need for dual antiplatelet therapy. The balloon trajectory will depend on aneurysm morphology and bilateral access may be useful in selected cases.

Computational modeling of an endovascular approach to deep brain stimulation

OBJECTIVE

Deep brain stimulation (DBS) therapy currently relies on a transcranial neurosurgical technique to implant one or more electrode leads into the brain parenchyma. In this study, we used computational modeling to investigate the feasibility of using an endovascular approach to target DBS therapy.

APPROACH

Image-based anatomical reconstructions of the human brain and vasculature were used to identify 17 established and hypothesized anatomical targets of DBS, of which five were found adjacent to a vein or artery with intraluminal diameter ≥1 mm. Two of these targets, the fornix and subgenual cingulate white matter (SgCwm) tracts, were further investigated using a computational modeling framework that combined segmented volumes of the vascularized brain, finite element models of the tissue voltage during DBS, and multi-compartment axon models to predict the direct electrophysiological effects of endovascular DBS.

MAIN RESULTS

The models showed that: (1) a ring-electrode conforming to the vessel wall was more efficient at neural activation than a guidewire design, (2) increasing the length of a ring-electrode had minimal effect on neural activation thresholds, (3) large variability in neural activation occurred with suboptimal placement of a ring-electrode along the targeted vessel, and (4) activation thresholds for the fornix and SgCwm tracts were comparable for endovascular and stereotactic DBS, though endovascular DBS was able to produce significantly larger contralateral activation for a unilateral implantation.

SIGNIFICANCE

Together, these results suggest that endovascular DBS can serve as a complementary approach to stereotactic DBS in select cases.

Endovascular Coil Embolization of Distal Anterior Cerebral Artery Aneurysms: Angiographic and Clinical Follow-up Results

Purpose

This study is an overview of the clinical and angiographic outcomes of patients who undergo treatment for distal anterior cerebral artery aneurysms.

Materials and Methods

Between January 2009 and March 2012, 444 cerebral aneurysms were treated using endovascular coil embolization at our institute. Among them, 217 aneurysms were followed-up with angiography at least six months later. Of these, there were 16 distal anterior cerebral artery (ACA) aneurysms in 16 patients. We conducted a retrospective review of clinical and radiological follow-up results of all patients with distal ACA aneurysms. The clinical and angiographic outcomes were assessed using the modified Rankin scale (mRS) and the Raymond classification scale, respectively.

Results

The mean age was 54.7 ± 10.2 years (41-75 years). The mean follow-up period was 20.6 ± 9.64 months (6-37 months). Three patients presented with acute rupture. The average aneurysm size was 4.98 ± 1.39 mm (3.0-8.1 mm), and eight of 16 aneurysms (50%) had aspect ratios < 2.0. All 16 patients presented with complete obliteration immediately after the procedure. However, two patients had procedure-related complications, one with coil extrusion to the subarachnoid space without hemorrhage and one with thromboembolism subsequent to chemical thrombolysis. In the follow-up angiography, one major and five minor recurrences (for a total of six recurrences, 37.5%) were detected. However, the differences between the ACA aneurysm group and others were not statistically significant. Clinical outcomes were good for all of the patients at the time of discharge (mean mRS: 0.25, 0 to 1) and at the follow-ups (mean mRS: 0).

Conclusion

Despite a comparatively high recurrence rate, the endovascular treatment of distal anterior cerebral aneurysms is feasible and has a good clinical outcome.