Pericallosal aneurysm: A difficult challenge for microsurgery and endovascular treatment

Treatment and outcome analysis of patients with ruptured distal anterior cerebral artery aneurysms: a multicenter real-world study

Objective

To reveal the safety and efficacy of clipping and coiling in patients with ruptured distal anterior cerebral artery aneurysms (DACAA) and to calculate the risk factors affecting the two-year survival rate in follow-up patients.

Methods

A retrospective study was conducted on the data of 140 patients (21 were lost to follow-up) with DACAA rupture who were treated by neurosurgery at 12 medical centers over a 2-year period, from January 2017 to December 2020. Univariate analysis was used to examine factors contributing to poor patient prognosis and to compare the prognosis of coiling and clipping treatments. Survival analysis was employed to compare survival rates between coiling and clipping, and risk factors affecting patient survival were analyzed using multivariate Cox regression analysis.

Results

Out of 140 patients with ruptured DACAA, 80 (57.1%) were male, and 60 (42.9%) were female. A total of 111 (79.3%) patients were classified under Hunt-Hess scale grades I-III, while 95 (67.9%) were graded I-III according to the WFNs classification. Among them, 63 (45%) were treated with clipping, and 77 (55%) underwent coiling. Within 2 years of discharge from the hospital, 31 (59.6%) patients who underwent clipping and 54 (80.6%) who underwent coiling had a good prognosis. Multivariate Cox regression analysis revealed that only WFNs classification (I-III) was a protective factor influencing the 2-year survival of patients with ruptured DACAA.

Conclusion

In the reality of medical practice, neurosurgeons are more likely to choose clipping as the treatment for cases with WFNs classification than or equal to III. There was no difference between clipping and coiling in the two-year prognosis at discharge. High priority should be given to DACAA cases with WFNs grading (I-III), as better outcomes can be achieved. The sample size will continue to be enlarged in the future to obtain more accurate findings. Abstracts for reviews, technical notes, and historical vignettes do not need to be separated into sections. They should begin with a clear statement of the paper's purpose followed by appropriate details that support the authors' conclusion(s).

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.

The evolution of intracranial aneurysm treatment techniques and future directions

Treatment techniques and management guidelines for intracranial aneurysms (IAs) have been continually developing and this rapid development has altered treatment decision-making for clinicians. IAs are treated in one of two ways: surgical treatments such as microsurgical clipping with or without bypass techniques, and endovascular methods such as coiling, balloon- or stent-assisted coiling, or intravascular flow diversion and intrasaccular flow disruption. In certain cases, a single approach may be inadequate in completely resolving the IA and successful treatment requires a combination of microsurgical and endovascular techniques, such as in complex aneurysms. The treatment option should be considered based on factors such as age; past medical history; comorbidities; patient preference; aneurysm characteristics such as location, morphology, and size; and finally the operator’s experience. The purpose of this review is to provide practicing neurosurgeons with a summary of the techniques available, and to aid decision-making by highlighting ideal or less ideal cases for a given technique. Next, we illustrate the evolution of techniques to overcome the shortfalls of preceding techniques. At the outset, we emphasize that this decision-making process is dynamic and will be directed by current best scientific evidence, and future technological advances.

Current treatment options and prognostic factors for ruptured distal anterior cerebral artery aneurysms

Background:

Distal anterior cerebral artery (ACA) aneurysms are rare, representing 1–9% of all intracranial aneurysms. The best treatment strategy for these aneurysms continues to be debated. We clarified the clinical features and treatment outcomes of patients with ruptured distal ACA aneurysms according to the treatment options at our institute.

Methods:

Thirty-seven consecutive patients (26 women; mean age, 65.2 years) with ruptured distal ACA aneurysms who underwent surgical clipping or coil embolization between 2012 and 2018 were included in the study. Clinical presentations, radiographic findings, and outcomes were retrospectively reviewed and compared between patients who underwent either surgical clipping or coil embolization. Risk factors associated with poor outcomes (modified Rankin Scale 4–6) were analyzed using multiple regression analysis.

Results:

Nineteen patients (51.4%) had World Federation Neurological Surgeons (WFNS) Grade IV-V, 18 (48.7%) had frontal lobe hematomas, and 13 (35.1%) had multiple aneurysms. Surgical clipping and endovascular coiling were performed in 28 (75.7%) and nine (24.3%) patients, respectively. Aneurysms located at the A4-5 portions were mainly treated by surgical clipping (P = 0.04). There were no significant between-group differences in procedure-related morbidity and mortality; however, the complete occlusion rate was higher in the surgical group (P < 0.01). Overall, a favorable neurological outcome at discharge (mRS 0–3) was obtained in 23 patients (62.5%). Multiple regression analysis revealed that WFNS Grade IV-V and frontal lobe hematomas were risk factors for poor outcomes (mRS 4–6).

Conclusion:

Acceptable outcomes were obtained in 62.5% of cases, and there were no significant between-group differences in treatment results between clipping and coiling. A poor WFNS grade and intracerebral hematomas were risk factors for a poor prognosis.

Four simultaneous anterior cerebral artery aneurysms (three initially unsuspected) with surgical treatment

Distal anterior cerebral artery aneurysms are rare, comprising approximately 6% of all intracranial aneurysms. These aneurysms tend to be smaller in size, broad-based, associated with additional aneurysms and at arterial branching sites, which can make both diagnosis and treatment difficult. Here we report a case of a 63-year-old female who presented with headache and perioral paresthesia determined to be Hunt & Hess scale grade 1. Computed tomography angiography discovered a medium-sized left A2 trunk saccular aneurysm. Intraoperatively 2 additional small blister type aneurysms not noted on initial computed tomography were discovered and treated via clipping and wrapping, respectively. Postoperatively a cerebral angiogram revealed an additional small right A2 trunk broad-based aneurysm. Preoperative evaluation of cerebral vasculature with a cerebral angiogram or high-resolution digital subtraction angiography is essential as multiple aneurysms are commonly associated with anterior cerebral artery aneurysms. The patient was successfully treated without any operative or postoperative complications and has remained symptom-free at 1 year follow up.

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 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.