Endovascular treatment of distal anterior cerebral artery aneurysms: Long-term results

Current state of endovascular treatment of anterior cerebral artery aneurysms

The locations of anterior cerebral artery (ACA) aneurysms vary, and various aneurysms can occur along the course of the ACA. Ruptured and some unruptured ACA aneurysms may require aggressive treatment to avoid bleeding or rebleeding. Although open surgery is an effective treatment for ACA aneurysms, endovascular treatment (EVT) is becoming an alternative treatment in select cases. EVT techniques for ACA aneurysms often vary and are performed on a case-by-case basis according to the nature and location of the aneurysm. To better understand the EVT strategy for ACA aneurysms, it is necessary to review EVT for ACA aneurysms. In this review, the following topics are discussed: ACA anatomy and anomalies, classifications of ACA aneurysms, the natural history of ACA aneurysms, open surgery and EVT statuses for ACA aneurysms, EVT techniques for various ACA aneurysms, and the prognosis and complications of EVT for ACA aneurysms. According to our review and experience, traditional coiling EVT is still the preferred therapy for most ACA aneurysms. For A1 aneurysms, EVT is challenging. After the selection of appropriate cases, deployment of a flow diverter and Woven EndoBridge device can result in a good prognosis for patients with ACA aneurysms. In addition, parent artery occlusion can be used to treat A1 aneurysms with good collateral circulation and some distal ACA aneurysms. In general, EVT is gaining popularity as an alternative treatment option for ACA 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.

Contralateral transradial access for coil embolization of distal anterior cerebral artery aneurysm associated with a steep ipsilateral A1-A2 angle

OBJECTIVE

Endovascular treatment of distal anterior cerebral artery aneurysms is commonly addressed via the ipsilateral A1 segment of the anterior cerebral artery. However, when the parent pericallosal artery has a sharp ipsilateral A1-A2 angle, catheterization through the ipsilateral A1 segment can potentially result in vessel injury, catheter kinking, and/or compromised/stagnant anterior cerebral artery flow. Here, we present a case of a distal anterior cerebral artery aneurysm associated with a steep ipsilateral A1-A2 angle treated with contralateral transradial coil embolization.

CASE PRESENTATION

A 91-year-old woman presented with a ruptured left distal anterior cerebral artery aneurysm at the A3 segment. The parent pericallosal artery had a steep ipsilateral A1-A2 angle. To safely achieve coil embolization of the aneurysm, a contralateral transradial system via the right A1 segment was employed. Although a secondary ipsilateral transradial system was required for contrast injection, aneurysm obliteration was successfully achieved without vessel injury or system instability.

CONCLUSION

The A1-A2 angle can be a key anatomical factor in the endovascular treatment of distal anterior cerebral artery aneurysms. The contralateral transradial system is a useful treatment option for distal anterior cerebral artery aneurysms associated with sharp ipsilateral A1-A2 angles. However, if the distal anterior cerebral artery aneurysm cannot be clearly visualized through the contralateral system, an ipsilateral system will be required for contrast injection.

Transradial quadraxial system for coil embolization of distal anterior cerebral artery aneurysms: A radial-first center case series and literature review

PURPOSE

Endovascular treatment is technically challenging as distal anterior cerebral artery (DACA) aneurysms have distal location, small-caliber parent artery, and small size/wide neck. This study evaluated the feasibility and safety of the transradial approach (TRA) with a radial-specific neurointerventional guiding sheath as the first-line technique for DACA aneurysms.

METHODS

We retrospectively analyzed an institutional database of consecutive patients with DACA aneurysm who underwent coil embolization using TRA. Ten consecutive patients were included in this study. After the radial-specific 6F Simmons guiding sheath (0.088″ inner diameter) was completely engaged into the target common carotid artery, a quadraxial system (6F Simmons guiding sheath/6F intermediate catheter/3.2F intermediate catheter/single microcatheter) was used for embolization. Then, we assessed for procedural success, angiographic outcomes, and procedure-related or vascular access site complications.

RESULTS

Embolization procedures were conducted using simple coiling in eight and stent-assisted coiling with the trans-cell approach in two patients. The embolization procedure was successful in all patients (n = 10). Moreover, none presented with catheter kinking, parent artery flow stagnation, or system instability during the procedure. Immediate postprocedural angiography revealed complete obliteration in six and residual neck in four patients. Then, eight patients underwent follow-up angiography at a mean of 7.1 months, and none developed recanalization or required retreatment. The postprocedural course was uneventful, and there were no complications.

CONCLUSION

The transradial quadraxial system had the ability to achieve sufficient stability and kink resistance in DACA aneurysm embolization. Thus, this method was feasible and safe and had a high success rate.

Distal anterior cerebral artery aneurysms treated with flow diversion: experience of a large-volume center and systematic review of the literature

BACKGROUND

Evidence about the safety and the efficacy of flow diversion for distal anterior cerebral artery (DACA) aneurysms is scant. To provide further insight into flow diversion for aneurysms located at, or distal to, the A2 segment.

METHODS

Consecutive patients receiving flow diversion for DACA aneurysms were retrieved from our prospective database (2014-2020). A PRISMA guidelines-based systematic review of the literature was performed. Aneurysm occlusion (O'Kelly-Marotta=OKM) and clinical outcomes were evaluated.

RESULTS

Twenty-three patients and 25 unruptured saccular DACA aneurysms treated with flow diversion were included. Aneurysm size ranged from 2 mm to 9 mm (mean size 4.5 mm, SD ±1.6). Mean parent artery diameter was 1.8 mm (range, 1.2-3 mm, SD ±0.39). Successful stent deployment was achieved in all cases. Angiographic adequate occlusion (OKM C-D) at follow-up (14 months) was 79% (19/24 available aneurysms). No cases of aneurysm rupture or retreatment were reported. Univariate analysis showed a significant difference in diameter among aneurysms with adequate (4 mm) vs incomplete occlusion (7 mm) (P=0.006).There was one transient perioperative in-stent thrombosis, and three major events causing neurological morbidity: two stent thromboses (one attributable to the non-adherence of the patient to the antiplatelet therapy); and one acute occlusion of a covered calloso-marginal artery.Results from systematic review (12 studies and 107 A2-A3 aneurysms) showed 78.6% (95% CI=70-86) adequate occlusion, 7.5% (95% CI=3.6-14) complications, and 2.8%, (3/107, 95% CI=0.6-8.2) morbidity.

CONCLUSIONS

Flow diversion among DACA aneurysms is effective, especially among small lesions. However, potential morbidity related to in-stent thrombosis and covered side branches should be considered when planning this strategy.

Recanalization of Embolized Endovascular Intracranial Aneurysms and Changes in the Blood Viscosity: A Pilot Study

Background

The purpose of our research was to evaluate the relationships between blood viscosity and recanalization of coiled intracranial aneurysms.

Material/Methods

The study included consecutives patients treated endovascularly by a team of experienced neurosurgeons and neuroradiologists due to brain aneurysm. A total of 50 patients (the average age was 57.48 years, SD=13.71) were assigned to 2 groups: group A with recanalization (4 male and 8 female patients) and group B without recanalization (10 male and 28 female patients) were examined. All patients underwent a 6-month follow-up of the whole-blood viscosity test with a Brookfield DV III+pro cone-plate viscometer using the Rheocalc program. Differences between groups were assessed using the Statistica 12 computer program (StatSoft Inc., Tulsa, OK, USA).

Results

Studies have shown no significant difference in the age range between group A and B (P=0.31). In group A, higher viscosity values were found for whole blood [median: 4.14 dyn×sec/cm² (mPa×sec) quartile range 0.42], compared to group B [median: 3.92 dyn×sec/cm² (mPa×sec); quartile range 0.40; (P=0.04)]. This difference was significant (P=0.04). Additionally, the level of hematocrit was positively related with recanalization, the higher the hematocrit, the more frequent recanalization. A very strong and statistically significant relationship occurred between the frequency of recanalization and smoking (P<0.001).

Conclusions

The occurrence of higher values of whole blood viscosity which increase turbulent flow through the vessels may be a risk for recanalization of the coiled intracranial aneurysm.