Relationship of A1 Segment Hypoplasia with the Radiologic and Clinical Outcomes of Surgical Clipping of Anterior Communicating Artery Aneurysms

Endovascular treatment of ruptured lobulated anterior communicating artery aneurysms: A retrospective study of 24 patients

BACKGROUND

Lobulated intracranial aneurysm is a special type of aneurysm with at least one additional cyst in the neck or body of the aneurysm. Lobulated intracranial aneurysm is a complex aneurysm with complex morphology and structure and weak tumor wall, which is an independent risk factor for rupture and hemorrhage. Lobular aneurysms located in the anterior communicating artery complex account for 36.9% of all intracranial lobular aneurysms. Due to its special anatomical structure, both craniotomy and endovascular treatment are more difficult. Compared with single-capsule aneurysms, craniotomy for lobular intracranial aneurysms has a higher risk and complication rate.

AIM

To investigate the efficacy and safety of endovascular treatment for ruptured lobulated anterior communicating artery aneurysm (ACoAA).

METHODS

Patients with ruptured lobulated ACoAA received endovascular treatment in Sanming First Hospital Affiliated to Fujian Medical University from June 2020 to June 2022 were retrospectively included. Their demographic, clinical and imaging characteristics, endovascular treatment methods and follow-up results were collected.

RESULTS

A total of 24 patients with ruptured lobulated ACoAA were included, including 9 males (37.5%) and 15 females (62.5%). Their age was 56.2 ± 8.9 years old (range 39-74). The time from rupture to endovascular treatment was 10.9 ± 12.5 h. The maximum diameter of the aneurysms was 5.1 ± 1.0 mm and neck width were 3.0 ± 0.7 mm. Nineteen patients (79.2%) were double-lobed and 5 (20.8%) were multilobed. Fisher's grade: Grade 2 in 16 cases (66.7%), grade 3 in 6 cases (25%), and grade 4 in 2 cases (8.3%). Hunt-Hess grade: Grade 0-2 in 5 cases (20.8%), grade 3-5 in 19 cases (79.2%). Glasgow Coma Scale score: 9-12 in 14 cases (58.3%), 13-15 in 10 cases (41.7%). Immediately postprocedural Raymond-Roy grade: grade 1 in 23 cases (95. 8%), grade 2 in 1 case (4.2%). Raymond-Roy grade in imaging follow-up for 2 wk to 3 months: grade 1 in 23 cases (95.8%), grade 2 in 1 case (4.2%). Follow-up for 2 to 12 months showed that 21 patients (87.5%) had good functional outcomes (modified Rankin Scale score ≤ 2), and there were no deaths.

CONCLUSION

Endovascular treatment is a safe and effective treatment for ruptured lobulated AcoAA.

Geometry and Symmetry of Willis' Circle and Middle Cerebral Artery Aneurysms Development

Background: A relationship between the geometry and symmetry of Willis' circle and intracranial aneurysms was reported for anterior communicating and posterior communicating (PCom) aneurysms. A similar association with the middle cerebral artery (MCA) aneurysms instead appeared weaker. Methods: We reviewed 432 patients from six Italian centers with unilateral MCA aneurysms, analyzing the relationship between the caliber and symmetry of Willis' circle and the presence of ruptured and unruptured presentation. CT-angiograms were evaluated to assess Willis' circle geometrical characteristics and the MCA aneurysm side, dimension and rupture status. Results: The hypoplasia of the first segment of the anterior cerebral artery (A1) was in approximately one-quarter of patients and PCom hypoplasia was in almost 40%. About 9% had a fetal PCom ipsilaterally to the aneurysm. By comparing the aneurysmal and healthy sides, only the PCom hypoplasia appeared significantly higher in the affected side. Finally, the caliber of the internal carotid artery (ICA) and the first segment of MCA (M1) caliber were significantly greater in patients with unruptured aneurysms, and PCom hypoplasia appeared related to the incidence of an ipsilateral MCA aneurysm and its risk of rupture. Conclusions: Although according to these findings asymmetries of Willis' circle are shown to be a risk factor for MCA aneurysm formation and rupture, the indifferent association with ipsilateral or contralateral hypoplasia remains a datum of difficult hemodynamic interpretation, thereby raising the concern that this association may be more casual than causal.

The risk factors of postoperative infarction after surgical clipping of unruptured anterior communicating artery aneurysms: anatomical consideration and infarction territory

PURPOSE

An anterior communicating artery is a common location for both ruptured and unruptured intracranial aneurysms, and microsurgery is sometimes necessary for their successful treatment. However, postoperative infarction should be considered during clipping due to the complex surrounding structures of anterior communicating artery aneurysms. This study aimed to evaluate the risk factors of postoperative infarction after surgical clipping of unruptured anterior communicating artery aneurysms and its clinical outcomes.

METHODS

The data of patients who underwent microsurgical clipping of an unruptured anterior communicating artery aneurysm in our hospital between January 2008 and December 2020 were retrospectively analyzed. The patients' demographic data, anatomical features of the anterior communicating artery complex and aneurysm, surgical technique, characteristics of postoperative infarction, and its clinical course were evaluated.

RESULTS

Notably, among 848 patients, 66 (7.8%) and 34 (4%) patients had radiologic and symptomatic infarctions, respectively. Univariate and multivariate logistic regression analyses showed that hypertension (odds ratio (OR), 1.99; [Formula: see text]), previous stroke (OR, 3.89; [Formula: see text]), posterior projection (OR, 5.58; [Formula: see text]), aneurysm size (OR, 1.17; optimal cut-off value, 6.14 mm; [Formula: see text]), and skull base-to-aneurysm distance (OR, 1.15; optimal cut-off value, 11.09 mm; [Formula: see text]) were associated with postoperative infarction. In the pterional approach, a closed A2 plane was an additional risk factor (OR, 1.88; [Formula: see text]). Infarction of the subcallosal and hypothalamic branches was significantly associated with symptomatic infarction ([Formula: see text]).

CONCLUSION

Hypertension, previous stroke, posteriorly projecting aneurysms, aneurysm size, and highly positioned aneurysms are independent risk factors for postoperative infarction during surgical clipping of an unruptured anterior communicating artery aneurysm. Additionally, a closed A2 plane is an additional risk factor of postoperative infarction in patients undergoing clipping via the pterional approach.

Anatomical variations in the Circle of Willis and the formation and rupture of intracranial aneurysms: A systematic review and meta-analysis

Background

The anterior (AcomA) and posterior communicating arteries (PcomA) are two of the most frequent sites for intracranial aneurysms. Anatomical variations in the Circle of Willis (COW) are frequently observed in patients with AcomA and PcomA aneurysms. Strong evidence is needed to determine the pooled estimate of the effect of COW variations on the formation and rupture of these aneurysms.

Aim

This systematic review and meta-analysis aimed to establish the effect of COW variations on the formation and rupture of AcomA and PcomA aneurysms using available studies.

Summary of review

PubMed, Embase, and Web of Science databases were systematically searched for studies published in English before September 21, 2022. Studies investigating AcomA aneurysms and the hypoplastic/aplastic A1 segment of the anterior cerebral artery and PcomA aneurysms and hypoplastic/aplastic PcomA or fetal-type posterior cerebral artery (FTP) were included. The heterogeneity of the studies was assessed using Cochran Q-test and I² statistic. Pooled estimate was assessed using either a random- or fixed-effects model based on the heterogeneity of the studies. Among the 4,932 studies, 21 were eligible and included in the analysis. The presence of hypoplastic/aplastic A1 was significantly correlated with the formation [OR (95% confidence interval [CI]) = 7.97 (5.58, 11.39), P < 0.001] and rupture [OR (95%CI) = 1.87 (1.29, 2.72), P < 0.001] of AcomA aneurysms. Significant associations between FTP and both the formation [OR (95%CI) = 2.15 (1.41, 3.30), P < 0.001] and rupture [OR (95%CI) = 1.72 (1.26, 2.36), P < 0.001] of PcomA aneurysms were observed.

Conclusions

Significant associations were observed between COW variations and both the formation and rupture of AcomA and PcomA aneurysms. This can help in determining interventions for patients with aneurysms.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=225149, identifier: CRD42021225149.

Surgical outcomes of patients after treatment of ruptured anterior communicating artery aneurysms: "real-world" evidence from southern Thailand

Background

Anterior communicating artery (AComA) aneurysm rupture is the most common cause of subarachnoid hemorrhage worldwide. In this study, we aimed to determine the factors associated with a poor clinical outcome in patients with ruptured AComA aneurysms undergoing microsurgical clipping.

Methods

We retrospectively reviewed the clinical and radiologic features as well as clinical outcomes of 150 consecutive patients with ruptured AComA aneurysm who underwent surgical clipping during the 11-year study period. Logistic regression analysis was performed to identify independent factors associated with unfavorable clinical outcomes (defined as a modified Rankin scale score of 3–6).

Results

The study included 83 male and 67 female patients, with a mean age of 51.3 ± 11.5 years. At admission, most of the patients had good neurological status, including 97 (64.7%) patients with a Hunt and Hess grade of 1 or 2 and 109 (72.6%) patients with a World Federation of Neurosurgical Societies grade of 1 or 2. Unfavorable outcomes at 6 months were observed in 23 (22.0%) patients, and the 6-month mortality rate was 8.0%. Multivariate analysis showed that preoperative intraventricular hemorrhage (odds ratio [OR], 19.66; 95% confidence interval [CI], 5.10–75.80; P < 0.001), A1 hypoplasia (OR, 8.90; 95% CI, 2.82–28.04; P < 0.001), and postoperative cerebral infarction (OR, 3.21; 95% CI, 1.16–8.88; P = 0.025) were strong independent risk factors for unfavorable outcomes.

Conclusions

Proper management of preoperative intraventricular hemorrhage, A1 hypoplasia, and intensive care for postoperative brain infarction are warranted for improved surgical outcomes in patients with ruptured AComA aneurysm undergoing surgical clipping.

Morphologic Variations in the Circle of Willis as a Risk Factor for Aneurysm Rupture in the Anterior and Posterior Communicating Arteries

BACKGROUND

Intracranial aneurysms are acquired abnormal vascular dilations. The most dangerous complication of a cerebral aneurysm is its rupture, with a high rate of mortality. This study aimed to determine whether there is an association between anatomic variations in the circle of Willis and ruptured aneurysms in the anterior and posterior communicating arteries.

METHODS

A cross-sectional study of adult patients with a diagnosis of intracranial aneurysm was carried out between March 2015 and March 2019. The patients were divided into groups of ruptured or unruptured aneurysm in the anterior and posterior communicating arteries.

RESULTS

A total of 132 patients with anterior and posterior communicating artery aneurysms were included. The presence of anatomic variation in the circle of Willis presented a statistically significant association with ruptured aneurysms (odds ratio [OR], 2.28; 95% confidence interval [CI], 1.11-4.65; P = 0.024). There was a statistically significant difference between the presence of nonspherical aneurysm and rupture (OR, 6.9; 95% CI, 3.12-15.48; P < 0.0001). Multivariate logistic regression observed smoking (OR, 2.4; 95% CI, 1.01-5.9; P = 0.4), anterior complex variations (OR, 2.68; 95% CI, 1.01-7.18; P < 0.04), and nonspherical morphology (OR, 4.7; 95% CI, 1.93-11.45; P = 0.001) presented a statistically significant association with the rupture.

CONCLUSIONS

Our results suggest that the studied variations of the circle of Willis and nonspherical morphology, in addition to playing a role in the development of cerebral aneurysms, may contribute to their rupture.

Anterior Communicating Artery Aneurysms: Anatomical Considerations and Microsurgical Strategies

Anterior communicating artery aneurysms account for 23–40% of ruptured intracranial aneurysms and 12–15% of unruptured aneurysms and are the most common intracranial ruptured or unruptured aneurysms. Because they have relatively complex anatomical structures and anatomical variations and are adjacent to important blood vessels and structures, in the process of microsurgical exposure of an Anterior communicating artery aneurysm, attention should be paid not only to the anatomical characteristics of the aneurysm itself but also to the adjacent important blood vessels and perforating arteries; therefore, both surgical clipping and endovascular embolization are serious challenges for neurosurgeons. No matter which treatment is chosen, it is necessary to determine the structure of the Anterior communicating artery and its perforating arteries as well as whether there is a fenestration deformity of the Anterior communicating artery and the relationship between bilateral A1-A2 before surgery. The shape and size of the aneurysm itself and its location relative to adjacent blood vessels also need to be considered to better complete the procedure, and this is especially true for microsurgical clipping. Clarifying the anatomy before surgery is helpful for better selecting the surgical approach and surgical side, which could affect the intraoperative exposure of the aneurysm and adjacent arteries, the surgical difficulty, the resection rate, and the postoperative complications. Therefore, starting with Anterior communicating artery aneurysms and their adjacent structures and variations, this paper reviews the latest progress in surgical treatment based on anatomic specificity as well as the most recent clinical studies.

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.