Endovascular treatment of distal anterior cerebral artery aneurysms: technical results and review of the literature

Efficacy of endovascular treatment for distal anterior cerebral artery aneurysms: A multicenter observational study

OBJECTIVES

Distal anterior cerebral artery (DACA) aneurysms account for 1%-9% of all intracranial aneurysms. Microsurgical treatment is generally preferred for DACA aneurysms; however, it presents challenges owing to the anatomical complexities. Advances in neuro-interventional techniques have yielded promising results. This study aims to compare the clinical outcomes of DACA aneurysms treated with microsurgery and endovascular treatment (EVT) to elucidate the efficacy of EVT.

MATERIALS AND METHODS

A multicenter observational registry comprising 16 stroke centers was utilized for this study. Data was retrospectively and prospectively analyzed from 166 patients with DACA aneurysms in our database, which included 4,552 consecutive patients with ruptured or unruptured intracranial aneurysms who underwent microsurgical or endovascular treatment between January 2013 and December 2021.

RESULTS

Surgical clipping was performed in 115 patients, and 51 underwent coil embolization. The median follow-up duration was 15.3 months. No significant differences were observed in patient characteristics between the two treatment modalities. There were no differences in complication-related morbidity between the microsurgical treatment and EVT groups in either unruptured (10.5% vs. 9.1%, p=1.00) or ruptured aneurysms (5.2% vs. 6.9%, p=0.66). Coil embolization resulted in higher recurrence and retreatment rates than surgical clipping did, especially for ruptured aneurysms (2.6% vs. 27.6%, p<0.01).

CONCLUSIONS

Endovascular treatment is an alternative to microsurgery for DACA aneurysms especially in unruptured cases or the patients who have difficulty undergoing craniotomy due to their general condition, albeit with considerations for higher recurrence and retreatment rates, particularly in ruptured cases. Close follow-up is crucial for the effective management of these challenges. Further studies are needed to refine the treatment strategies for DACA aneurysms.

Global outflow angle influences silent ischemic events in coil embolization for unruptured distal anterior cerebral artery aneurysms

BACKGROUND

Distal anterior cerebral artery (DACA) aneurysms are rare, and endovascular treatment of these aneurysms is challenging. Thromboembolic events, including silent ischemic events, are one of the most important complications of coil embolization for cerebral aneurysms. The treatment outcomes and predictors of silent ischemic events in coil embolization for unruptured DACA aneurysms were investigated, focusing on the morphological characteristics of aneurysms, especially the inflow angle (IA) and global outflow angle (GOA).

METHODS

A total of 12 patients with 12 unruptured DACA aneurysms, treated with coil embolization at our institute, were retrospectively investigated. Predictors for silent ischemic events were evaluated by comparing diffusion-weighted imaging (DWI)-positive and DWI-negative patients.

RESULTS

Silent ischemic events detected on DWI were observed in eight aneurysms (66.7%). Comparison of the morphological characteristics of aneurysms between the two groups showed a significantly smaller GOA in the DWI-positive group than in the DWI-negative group (172.6 ± 17.7° vs. 216.8 ± 16.8°, P < 0.01). A multivariate analysis showed that GOA <195° was a significant predictor of silent ischemic events (P = 0.04; odds ratio: 23.62; 95% confidence interval: 1.11-490.39).

CONCLUSION

A small GOA was a significant predictor of silent ischemic events after coil embolization for unruptured DACA aneurysms. While some patients can be treated safely with minimally invasive coil embolization, it is necessary to consider surgical clipping in patients at high risk of thromboembolic events with coil embolization.

Microsurgery and Endovascular Therapy for Distal Anterior Cerebral Artery Aneurysm: A Multicenter Retrospective Cohort Study

BACKGROUND

Distal anterior cerebral aneurysm (DACA) represents 4% of intracranial aneurysms. Two treatment modalities are available: microsurgery and endovascular therapy (EVT).

OBJECTIVE

To compare the results between microsurgery and EVT in a modern French cohort.

METHODS

A multicenter retrospective cohort study of 3 French neurosurgical units was carried out from January 1, 2015, to December 31, 2020. All participants were adult patients who required treatment for a ruptured or unruptured DACA aneurysm.

RESULTS

A total of 69 patients were included; 16 patients (23.2%) were treated by microsurgery and 53 (76.8%) were treated by EVT. Thirty-one patients (44.9%) had ruptured aneurysms. The complication rate was low, with 1 death and 1 symptomatic ischemia. There was no difference in complications between microsurgery and EVT (P = 0.22). The number of retreatments was higher in EVT (15% vs. 0%) but not significantly (P = 0.18).

CONCLUSIONS

In the specific subgroup of DACA, both treatment modalities are effective in ruptured and unruptured aneurysms, with a low rate of complications. Retreatment may be more frequent in EVT but it does not lead to more complications.

Factors Affecting the Outcome after Surgical Clipping of Ruptured Distal Anterior Cerebral Artery (DACA) Aneurysms

Objective  The purpose of this study is to assess demographic, clinical, and unique morphological characteristics of distal anterior cerebral artery (DACA) aneurysm. The relation of outcome included Glasgow Outcome Scale (GOS) using various independent variables, Hunt and Hess clinical grade (H&H), Miller Fischer grade, intraoperative rupture, and comparison of outcomes at discharge and last follow-up. Methods  Demographic data, aneurysm characteristics, and treatment outcomes were evaluated in 28 ruptured DACA aneurysms operated over a period of 13 years. Association between independent variables and dependent variables (GOS) at discharge and at last follow-up (13 years) was analyzed, and the interrelationship between these factors and outcome was evaluated. GOS was used to assess functional outcomes. Results  Over a period of 13 years, 500 patients harboring ruptured intracranial aneurysms were surgically clipped, and out of them 28 patients (5.6%) had ruptured DACA aneurysms. In this series, 20 (71.4%) patients had low grade and 8 (28.6%) had high grade H&H. Out of the 28 patients, 19 (67.8%) had good recovery, 6 (21.5%) were severely disabled, and 3 (10.7%) died at the time of discharge. On the last follow-up (13 years), smoking ( p -value 0.03) and use of temporary clip ( p -value 0.00) were significant predictors for unfavorable outcome. Conclusion  The results of our case series show that even with ruptured aneurysm excellent overall outcome after microsurgical clipping can be achieved, even though among cerebral aneurysms, DACA aneurysm is considered to have less favorable outcome. Alcohol consumption and use of temporary clip were the predictors for unfavorable outcome at the time of discharge. On the last follow-up, smoking and use of temporary clip were found to be the risk factors for unfavorable outcome. Although the small sample size of this study is a limitation, smoking and use of temporary clip play an important role on the overall outcome. The aim of this study was to analyze data to determine factors which may influence outcome after surgical clipping of ruptured DACA aneurysms.

Morphological Characteristics of Pericallosal Artery Aneurysms and Their High Propensity for Rupture

BACKGROUND

Compared with intracranial aneurysms (IAs) at other locations, pericallosal artery aneurysms (PAAs) have demonstrated an extremely high risk of rupture. However, owing to their rarity, our understanding of their morphological characteristics has been limited, and whether the morphological characteristics of PAAs contribute to this high rupture risk has remained unexplored. In the present study, we aimed to provide a detailed description of the morphological characteristics of PAAs and investigate the association between its morphology and rupture risk compared with anterior circulation IAs at other locations.

METHODS

A total of 40 patients with 45 PAAs and 348 patients with 392 anterior circulation IAs at other locations were recruited. The clinical and radiological data for these patients were retrospectively reviewed. The differences in the morphological parameters, including the aneurysm diameter, neck width, height, width, parent artery diameter, inflow angle, aspect ratio (AR), size ratio (SR), and aneurysm diameter/width ratio, between PAAs and other IA groups were compared.

RESULTS

Of the 45 PAAs, 22 (48.9%) had ruptured. The proportion of ruptured aneurysms was greater for PAAs than for anterior circulation IAs at other locations. For both ruptured and unruptured anterior circulation IAs, PAAs had the highest AR and SR among all IA groups and had the largest inflow angle.

CONCLUSION

The morphological characteristics of PAAs are unique. Compared with other anterior circulation IAs, PAAs have significantly increased ARs, SRs, and inflow angles, which, ultimately, promote their high propensity toward rupture.

Safety and Efficacy of the Pipeline Embolization Device Use in the Outside Circle of Willis Located Intracranial Aneurysms: A Single-Center Experience

Background

The use of Pipeline Embolization Device (PED) is approved by the US Food and Drug Administration (FDA) to treat aneurysms located between the petrous and superior hypophyseal segments of the internal carotid artery. The purpose of this study is to evaluate the feasibility and efficacy of treating aneurysms outside the FDA approved anatomical locations. Furthermore, we analyze the safety of our antiplatelet protocol.

Methods

Data on all patients treated with PED at our center from March 2015 to December 2017 were reviewed. Only patients with aneurysms treated with PED as off label use were included. Procedural complications and long-term functional outcome measured by modified Rankin Scale (mRS) were recorded. Tirofiban maintenance infusion was administered intravenously after PED deployment. None of the patients had platelet function testing.

Results

A total of 36 patients harboring 36 aneurysms were included in the study. Mean age was 58.2 years ±14.6. Nineteen were women (52.8%) and most aneurysms were unruptured (80.6%). There were no intraoperative complications. Five patients experienced postoperative complications - 4 ischemic strokes and one groin hematoma. None led to any significant disability at follow-up. Thirty-one patients (86.1%) achieved an mRS of 0-2 at follow-up. A Raymond-Roy classification of 1 was achieved in 78.9% of patients.

Conclusion

The use of PED to treat aneurysms located outside the circle of Willis is feasible and effective. Our novel antiplatelet protocol did not require platelet function assay testing and did not lead to a higher rate of thrombo-embolic events compared to what has been previously reported.

Endovascular Management of Ruptured Distal Anterior Cerebral Artery (DACA) Aneurysms: A Retrospective Review Study

OBJECTIVE

Distal anterior cerebral artery (DACA) aneurysms are rare, and their treatment by either surgical clipping or endovascular treatment poses technical difficulties. Earlier studies have reported higher complication rates in DACA aneurysms compared with other aneurysms in the circle of Willis. Therefore, endovascular management of DACA aneurysms still remains a challenge. The aim of this report is to review clinical presentation, angiographic presentation of DACA aneurysms, complications, and outcome of their endovascular treatment in our institutional experience.

METHODS

A retrospective review of 186 patients with intracranial aneurysms treated with endovascular management from September 2009 to December 2013 in the Max Superspecialty Hospital, New Delhi, India, 11 patients (5.9%) with 12 DACA aneurysms were studied retrospectively. We report the clinical presentations, cerebral angiographic findings, endovascular treatment, complications, and outcomes. The clinical and angiographic outcomes were assessed using modified Rankin scales and the Raymond scale, respectively.

RESULTS

Of 11 patients, 54.5% were female and 45.5% were male; the mean age was 48.4 years (range, 33-65 years). All patients had subarachnoid hemorrhage that indicated ruptured DACA aneurysm. All the DACA aneurysms were small. Postcoiling angiograms showed complete occlusion in 9 patients. Two patients had intraprocedural aneurysm rupture but without any clinical sequelae, and 1 patient had thrombus formation, which was thrombolysed at the end of coiling. All patients had good outcomes.

CONCLUSIONS

Our experience with 11 patients showed that endovascular management of small DACA aneurysms, though associated with higher intraprocedural events, is associated with good outcome.

Off-label uses of the Pipeline embolization device: a review of the literature

The Pipeline embolization device (PED) is the most widely used flow diverter in endovascular neurosurgery. In 2011, the device received FDA approval for the treatment of large and giant aneurysms in the internal carotid artery extending from the petrous to the superior hypophyseal segments. However, as popularity of the device grew and neurosurgeons gained more experience, its use has extended to several other indications. Some of these off-label uses include previously treated aneurysms, acutely ruptured aneurysms, small aneurysms, distal circulation aneurysms, posterior circulation aneurysms, fusiform aneurysms, dissecting aneurysms, pseudoaneurysms, and even carotid-cavernous fistulas. The authors present a literature review of the safety and efficacy of the PED in these off-label uses.

Safety and Efficacy of Surgical and Endovascular Treatment for Distal Anterior Cerebral Artery Aneurysms: A Systematic Review and Meta-Analysis

BACKGROUND

Aneurysms of the distal anterior cerebral artery (DACA) are rare, representing between 1% and 9% of all intracranial aneurysms. The best treatment strategy for these aneurysms continues to be debated.

OBJECTIVE

We conducted a systematic review of the literature to evaluate the safety and efficacy of treatment strategies of DACA aneurysms.

METHODS

A systematic search of Medline, Embase, Scopus, and Web of Science was performed for studies published from January 2000 to August 2015. We included studies describing treatment of DACA aneurysms with ≥10 patients. Random effects meta-analysis was used to pool the following outcomes: complete occlusion, technical success, periprocedural morbidity/mortality and stroke rates, aneurysm recurrence/rebleed, and long-term neurologic morbidity/mortality.

RESULTS

Thirty studies with 1329 DACA aneurysms were included. Complete occlusion was 95% (95% confidence interval [CI], 91.0%-97.0%) in the surgical group and 68% (95% CI, 56.0%-78.0%) in the endovascular group (P < 0.0001). Aneurysm recurrence occurred in 3% (95% CI, 2.0%-4.0%) after surgery and in 19.1% (95% CI, 12.0%-27.0%) after endovascular treatment (P < 0.0001). Overall neurologic morbidity and mortality were 15% (95% CI, 11.0%-21.0%) and 9% (95% CI, 7.0%-11.0%) after surgery and 14% (95% CI, 10.0%-19.0%) (P = 0.725) and 7% (95% CI, 5.0%-10.0%) (P = 0.422) after endovascular treatment, respectively. Overall long-term favorable neurologic outcome was 80% and it was equal in both groups (80%; 95% CI, 73.0%-85.0% in the surgical group and 80%; 95% CI, 72.0%-87.0% in the endovascular group) (P = 0.892).

CONCLUSIONS

Our meta-analysis showed that both treatment modalities are technically feasible and effective with sufficient long-term aneurysm occlusion and acceptable recurrence/rebleed rates. Surgical treatment is associated with superior angiographic outcomes. There were no substantial differences in procedure-related morbidity and mortality. These findings are important because they suggest that therapy of DACA aneurysms should be performed on a selective, case-by-case basis to maximize patient benefits.

Use of flow diverters in the treatment of unruptured saccular aneurysms of the anterior cerebral artery

BACKGROUND

Few publications have dealt exclusively with the use of flow diverter stents for the treatment of aneurysms of the anterior cerebral artery (ACA).

OBJECTIVE

To determine the efficacy of flow-diverting stents in the treatment of small, unruptured aneurysms of the ACA.

METHODS

We retrospectively reviewed our database of prospectively collected information for all patients treated with flow diversion for an unruptured saccular aneurysm of the ACA between September 2009 and July 2016. The aneurysm fundus size, neck size, number and type of flow-diverting stent (FDS), complications, and follow-up data were recorded.

RESULTS

In total 26 patients, with 27 aneurysms were identified that matched our inclusion criteria (11 male and 15 female). The average age of the patients was 59.3 years (range 27-77 years). All patients, except one, had a single aneurysm affecting the ACA. Fourteen aneurysms were located on the left (51.9%). The average aneurysm fundus size was 2.9 mm (range 2-6 mm). Twenty patients had follow-up angiographic studies. In total, 16 aneurysms were completely excluded, 1 aneurysm showed a very small remnant, and no follow-up angiographic data are available for the remaining patients. One patient had a treatment-related complication.

CONCLUSIONS

Treatment of aneurysms arising from the ACA with flow diverters is technically feasible and carries a high degree of success with low complication rate.

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.

The role of endovascular treatment for ruptured distal anterior cerebral artery aneurysms: comparison with microsurgical clipping

BACKGROUND AND PURPOSE

The purpose of this study was to compare clinical outcomes and treatment-related complications between coiling and clipping for ruptured distal anterior cerebral artery (DACA) aneurysms.

METHODS

Eighty-four consecutive patients (M:F = 36:48; mean 53.8 years) with ruptured DACA aneurysms were treated by either clipping (n = 46, 54.8%) or coiling (n = 38, 45.2%). The clinical outcomes and procedure-related complications were evaluated and compared between the two groups.

RESULTS

Procedure-related complications tend to occur more frequently in the clipping (n = 6, 13.0%) than coiling group (n = 1, 2.6%) (P = .121). At discharge, 51 patients (60.7%) had favorable outcomes (Glasgow outcome scale [GOS], 4 or 5). There was no significant difference between the two groups in favorable outcome (63.2% vs. 58.7%; P = .677). Hunt and Hess (HH) grade (P < .001; 95% CI, 3.354-29.609) and treatment modality (P = .044; 95% CI, 1.039-16.325) were independent risk factors for poor outcome (GOS, 1-3).

CONCLUSIONS

Coiling was more favorable to clipping in clinical outcomes and incidence of treatment-related complications for ruptured DACA aneurysms.

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.

Endovascular treatment of distal anterior cerebral artery aneurysms: single-center experience and a systematic review

In this study, a single center's experience of 20 patients and a systematic review and a meta-analysis of 16 studies, including 279 patients/aneurysms, assessed the safety and efficacy of endovascular treatment of distal anterior cerebral artery aneurysms. The authors conclude that endovascular treatment of distal anterior cerebral artery aneurysms is associated with high angiographic occlusion rates, but the complication rates are higher compared with other aneurysms in the circle of Willis.

Endovascular management of distal ACA aneurysms: single-institution clinical experience in 22 consecutive patients and literature review

BACKGROUND AND PURPOSE

Distal ACA aneurysms remain difficult to treat with endovascular therapy, but improved technology and experience allows for the treatment of some of these aneurysms with excellent results. The purpose of this study was to assess the status of endovascular treatment of distal ACA aneurysms by comparing our results with recent endovascular and microsurgical series of distal ACA aneurysms.

MATERIALS AND METHODS

Between 2000 and 2008, a total of 22 consecutive patients (14 women; mean age, 58.4 years) with distal ACA aneurysms underwent coil placement at Barrow Neurological Institute. Clinical presentations, radiographic findings, endovascular management, and outcomes were reviewed retrospectively.

RESULTS

Of the 22 patients, 13 (59%) presented with subarachnoid hemorrhage. Six patients were HH grade I or II, 1 was grade III, 5 were grade IV, and 1 was grade V. Frontal lobe hematomas occurred in 5 patients with ruptured aneurysms. The mean aneurysm size was 7.5 mm (range, 2.8-25 mm); 55% were smaller than 7 mm. Twelve aneurysms (55%) arose from the origin of the callosomarginal artery (55%). Complete occlusion was achieved in 50% of the cases and near-complete occlusion in 45%. The few periprocedural complications included 1 retroperitoneal hematoma and 1 intraoperative rupture. Four patients had thromboembolic events adequately treated intraprocedurally with abciximab. No deaths occurred in the patients treated.

CONCLUSIONS

The characteristics of the patients and aneurysms treated in our series were comparable to previous reports of endovascular treatment of ACA aneurysms with respect to rupture status. Periprocedural morbidity and mortality rates in our series fared well compared with previous reports, as did our combined rate of complete or near-complete occlusions. Recent advances in endovascular devices and techniques have improved outcomes of distal ACA aneurysms.

Outcomes analysis of ruptured distal anterior cerebral artery aneurysms treated by endosaccular embolization and surgical clipping

Although endovascular surgery is now widely used to treat intracranial aneurysms, no comparative studies of clipping versus endovascular surgery to address distal ACA aneurysms at the same institution are available. We compared the results of these treatment modalities to address distal ACA aneurysms at our institution. We treated 68 patients with ruptured distal ACA aneurysms (endovascular surgery, n=13; clipping surgery, n=55). We performed a retrospective comparison of the treatment outcomes. To study the efficacy of endovascular surgery we classified all our cases into three types: type A were small-necked aneurysms, type B were wide-necked aneurysms on the parent artery, and type C were aneurysms in which the A3 portion of the ACA arose from the aneurysmal dome near the neck. Intraoperative hemorrhage occurred in 7.7% of aneurysms treated by endovascular surgery and in 34.5% treated by clipping surgery. In 7.7% of the endovascularly-treated aneurysms we noted coil migration during embolization surgery; venous infarction due to cortical vein injury occurred in 7.3% of clipped aneurysms. Of the endovascularly-treated aneurysms, 7.7% manifested post-embolization hemorrhage; 23.1% manifested coil compaction. In clipping surgery, postoperative rerupture occurred in 1.8% of the aneurysms; one patient presented with postoperative acute epidural hematoma. Clip dislocation was noted in 1.8% of aneurysms. Angiography was indicative of post-treatment vasospasm in 7.7% of aneurysms treated endovascularly and in 50.9% of the clipped aneurysms. The clinical outcome showed no significant difference between endovascular surgery and clipping surgery.