Unveiling rupture risk and clinical outcomes in midline aneurysms: A matched cohort analysis investigating the impact of localization within the anterior or posterior circulation

Intracranial aneurysms (IAs) located in the anterior and posterior circulations of the Circle of Willis present differential rupture risks. This study aimed to compare the rupture risk and clinical outcomes of anterior communicating artery aneurysms (AcomA) and basilar tip aneurysms (BAs); two IA types located along the midline within the Circle of Willis. We retrospectively collected data from 1026 patients presenting with saccular IAs. Only AcomA and BAs with a 3D angiography were included. Out of 186 included IAs, a cohort of 32 BAs was matched with AcomA based on the patients' pre-existing conditions and morphological parameters of IAs. Clinical outcomes, including rupture risk, hydrocephalus development, vasospasm incidence, and patients' outcome, were compared. The analysis revealed no significant difference in rupture risk, development of hydrocephalus, need for ventricular drainage, or vasospasm incidence between the matched AcomA and BA cohorts. Furthermore, the clinical outcomes post-rupture did not significantly differ between the two groups, except for a higher Fisher Grade associated with BAs. Once accounting for morphological and patient factors, the rupture risk between AcomA and BAs is comparable. These findings underscore the importance of tailored management strategies for specific IA types and suggest that further investigations should focus on the role of individual patient and aneurysm characteristics in IA rupture risk and clinical outcomes.

Rathke's cleft cyst discovered with ruptured anterior communicating artery aneurysm: a case report

INTRODUCTION

Rathke's cleft cysts are thought to have a benign clinical outcome apart from associated hypopituitarism and visual defects. Synchronous central nervous system lesions, including pituitary adenoma and intracerebral aneurysms, are rarely reported. Diagnosis of Rathke's cleft cyst after presenting with a subarachnoid hemorrhage due to a ruptured arterial aneurysm is reported only once before.

CASE PRESENTATION

A 33-year-old Sri Lankan female presented with a subarachnoid hemorrhage due to a ruptured anterior communication artery aneurysm. She underwent pterional craniotomy and aneurysm clipping. She was found to have partial cranial diabetes insipidus and hypogonadotropic hypogonadism. She had a cystic lesion occupying enlarged sella turcica with characteristics of a Rathke's cleft cyst. Subsequently, she underwent trans-sphenoidal excision of the sellar lesion. Histology confirmed the diagnosis of Rathke's cleft cyst.

CONCLUSIONS

Rare co-occurrence of a Rathke's cleft cyst and an anterior communicating artery aneurysm would have been missed if subtle manifestations atypical for subarachnoid hemorrhage were not further pursued. This could have led to progressive visual deterioration and hypopituitarism.

Giant anterior communicating artery aneurysm with intrasellar extension

Introduction

Aneurysms extending into the sella are uncommon with only a few cases reported till date. Most of these arise from either the supraclinoidal or infraclinoidal segments of the internal carotid artery.

Research question

Can Anterior communication artery aneurysm present with hypopituitarism due to compression of pituitary gland?

Materials & methods

Case report and literature review.

Results

We discuss this rare presentation in a middle-aged patient its surgical management and the follow-up course with a review of available literature.

Discussion & conclusion

Anterior communicating artery aneurysms extending into the sella are extremely uncommon with only 4 cases reported in literature. They are usually giant aneurysms which are partially thrombosed with presenting with predominantly with mass effect in this case visual impairment and hypofunction of the pituitary.

Risk factors for the rupture of anterior communicating artery aneurysms: Coexistence of fetal-type posterior cerebral artery and A1 segment hypoplasia/agenesis

PURPOSE

To investigate the effect of the coexistence of fetal-type posterior communicating artery (fPCA) and anterior cerebral artery (ACA) A1 segment agenesis/hypoplasia on the rupture of an anterior communicating artery (AComA) aneurysm.

MATERIALS AND METHODS

A total of 216 patients consecutively presenting with AComA aneurysms between January 2014 and December 2021 on digital subtraction angiography were evaluated. Patients without three-dimensional rotational angiography images, those aged under 18 years, those with suspected mycotic aneurysms, and those with dissecting and giant aneurysms were excluded from the study. The aneurysms were divided into two groups as ruptured and non-ruptured. Hemodynamic filling patterns were classified into four different types.

RESULTS

The study included 192 AComA aneurysms, 44.8% (n = 86) ruptured and 55.2% (n = 106) non-ruptured. According to hemodynamic filling patterns, in type 1, the frequency of non-ruptured aneurysms was statistically significantly higher than that of ruptured aneurysms (39.5% vs 18.9%; p = 0.001). In type 4, where fPCA and ACA A1 segment agenesis/hypoplasia coexists, the frequency of ruptured aneurysms was significantly higher than that of non-ruptured aneurysms (10.5% vs 22.7%; p = 0.026). The most common aneurysm size range was 4-7 mm (n = 85; 44.3%). There was no statistically significant difference in size between the ruptured and non-ruptured aneurysms (p = 0.627).

CONCLUSION

According to the hemodynamic filling classification, we observed that the presence of type 4 filling pattern, i.e., the coexistence of ACA A1 segment agenesis/hypoplasia and fPCA, increased the risk of rupture in AComA aneurysms.

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.

The coexistence of anterior communicating artery aneurysm and meningioma: A literature review and illustrative case

Background

Anterior communicating artery (Acom) aneurysm has an association with many types of intracranial lesions. However, its association with meningioma can be challenging, which is not well addressed in the literature. Herein, we described a literature review focused on the association between Acom aneurysm and meningioma, explicitly highlighting the spatial presence between these two pathologies. We analyzed the literature according to that association with particular emphasis on location-based challenges. Furthermore, we present an illustrative case of surgically treating both lesions in one surgery utilizing the same approach.

Methods

A Medline database search was conducted by the following combined formula: (Meningioma [Title/ Abstract]) AND (Aneurysm [Title/Abstract]) AND (((Anterior communicating artery [Title/Abstract]) OR (Acom [Title/Abstract])) OR Acomm [Title/Abstract]))). Additional resources were added after screening the references of the included papers.

Results

Nine patients with coexistence of Acom aneurysm and meningioma were found in the literature. The coexistence of both pathologies was found in seven females and two males. The presence of an aneurysm was found to be solitary in 66.67% (n = 6/9). Furthermore, meningioma was found to be an isolated lesion in all included cases, and in 22.2% (n = 2/9), they were located ipsilaterally. The location of the meningioma to the aneurysm seems to be in proximity.

Conclusion

Acom aneurysm can coexist with intracranial meningioma; this association can be spatially related intracranially. Such coexistence entails a variety of nuances and challenges that neurosurgeons encounter during the management of these complex lesions.

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.

Long-Term Outcomes of Placement of a Single Transverse Stent through the Anterior Communicating Artery via the Nondominant A1 in Coil Embolization of Wide-Necked Anterior Communicating Artery Aneurysms

Objective

Placement of a single transverse stent via the nondominant A1 across the anterior communicating artery (AComA) into the contralateral A2 can provide sufficient neck coverage for wide-necked bifurcation AComA aneurysms. The authors described the feasibility, safety and long-term outcomes of this technique.

Methods

Between January 2015 and February 2018, placement of a single transverse stent via the nondominant A1 was attempted in 17 wide-necked bifurcation AComA aneurysms. The authors reviewed the medical records and radiological studies.

Results

The technical success rate was 94.1% (16/17). Periprocedural thromboembolic complications occurred in one patient (6.3%) without permanent neurological deficits. The mean clinical follow-up duration was 39.9±9.8 months. No deaths or delayed thromboembolic complications occurred. The mean angiographic follow-up duration was 38.9±9.8 months. The immediate and final follow-up complete occlusion rates were 87.4 and 93.7%, respectively. There was no recanalization during the follow-up period.

Conclusion

Placement of a single transverse stent via the nondominant A1 across the AComA into the contralateral A2 is a feasible and relatively safe endovascular technique for the treatment of wide-necked bifurcation AComA aneurysms, with good long-term occlusion rates and a reasonable complication rate, if only the nondominant A1 is applicable.

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.

Delayed oculomotor nerve palsy associated with a ruptured anterior communicating aneurysm: Case report

BACKGROUND AND IMPORTANCE

Oculomotor nerve palsy (ONP) is usually associated with posterior communicating (PCOM) aneurysms. ONP in patients with anterior circulation aneurysms are extremely rare, with only a handful of such published cases to date. There is currently no accepted mechanism to explain this clinical finding.

CLINICAL PRESENTATION

We describe a case of a 60-year-old female that benefitted from endovascular coiling of a ruptured anterior communicating (ACOM) aneurysm. In the following days, she clinically deteriorated and benefitted from another digital subtraction angiography (DSA) with intravascular verapamil for suspected vasospasm, and subsequently developed a right ONP.

CONCLUSION

Although classically related to PCOM aneurysm, ONP may be associated with ACOM aneurysms. The causative mechanism is unclear, but vasospasm may alter the microvascularisation of the oculomotor nerve, leading to ischemia.

Clinical and morphological risk factors for the recurrence of anterior communicating artery aneurysms after clipping or coiling

BACKGROUND

The aim of this study was to evaluate clinical and morphological factors associated with recurrence in anterior communicating artery (AcomA) aneurysms after clipping or coiling.

METHODS

We retrospectively reviewed the clinical and radiologic features of consecutive 214 patients with AcomA aneurysms treated between January 2012 and December 2016 in a single tertiary institute. Univariate and multivariate analyses were performed to identify the relationship between clinical and morphological variables and recurrence.

RESULTS

Of 214 patients, 166 were unruptured aneurysms and 109 were treated with coiling. Overall recurrence rate was 13% (28 out of 214 aneurysms) during mean 36.9 ± 18.4-month follow-up. Multivariate logistic regression analysis showed that size greater than 10 mm (OR = 5.651; 95% CI, 1.317-24.242; p = 0.020), smoking (OR = 3.474; 95% CI, 1.342-8.996; p = 0.010), coiling (OR = 2.98; 95% CI, 1.005-8.832; p = 0.049), and anterior direction of aneurysm (OR = 3.77; 95% CI, 1.12-12.66; p = 0.032) were significantly associated with recurrence of AcomA aneurysms after treatment.

CONCLUSIONS

The results of this study demonstrated that coiling, large aneurysm, anterior direction, and smoking history may be independent risk factors for the recurrence of AcomA aneurysms. Therefore, careful follow-up should be needed especially in large AcomA aneurysms with anterior direction after coiling.

Interhemispheric Approach with Early A1 Exposure for Clipping Anterior Communicating Artery Aneurysms: Operative Techniques and Outcomes

BACKGROUND

The interhemispheric approach (IHA) provides an excellent surgical corridor for clipping anterior communicating artery aneurysms (AcoAAs). However, an important disadvantage of the approach is obtaining proximal control at A1 in the last stage of dissection, especially in anterior or superior projecting AcoAAs and ruptured cases. We describe and evaluate the microsurgical clipping of AcoAAs using the IHA with early A1 exposure.

METHODS

This was a retrospective descriptive study in patients with AcoAA who received microsurgical clipping through the IHA with early A1 exposure between April 2016 and May 2019. Aneurysm morphology, projection, completeness of clipping, surgical complications, and outcomes were collected from medical records.

RESULTS

Twenty-five patients with AcoAA received microsurgical clipping via the IHA with early A1 exposure. Twenty-three patients (92%) presented with subarachnoid hemorrhage. Intraoperative rupture while dissecting the interhemispheric fissure occurred in 2 cases, for which proximal control via subfrontal route was effectively performed. Of the patients, 100% achieved complete obliteration of their aneurysms. Postoperative anosmia was detected in 22.7%. In ruptured cases, 16 (88.9%) of the good grade patients achieved a good outcome (Glasgow Outcome Scale scores of 4 and 5) at 3 months after the operation.

CONCLUSIONS

The IHA with early A1 is safe and effective for clipping AcoAAs.

Contralateral Vasospasm in an Uncomplicated Elective Anterior Communicating Artery Aneurysm Clipping

BACKGROUND

Cerebral vasospasm following clipping of an unruptured aneurysm is a rare phenomenon. When it does occur, cerebral vasospasm usually occurs on the side ipsilateral to the surgical intervention.

CASE DESCRIPTION

A 68-year-old man underwent right-sided pterional craniotomy for clipping of an unruptured anterior communicating artery aneurysm and experienced contralateral vasospasm 5 days later.

CONCLUSIONS

We further discuss the pathophysiology underlying vasospasm after uncomplicated craniotomy and nonhemorrhagic aneurysm clipping.

Cognitive outcome after surgical clipping versus endovascular coiling in patients with subarachnoid hemorrhage due to ruptured anterior communicating artery aneurysm

Ruptured anterior communicating artery aneurysms are commonly associated with deficits in memory and executive functions. However, little studies are available on the effect of surgical clipping (SC) and endovascular coiling (EC) on cognitive functioning. This study evaluates cognitive functioning in 35 patients with subarachnoid hemorrhage after ruptured anterior communicating artery aneurysm (ACoA) compared to 20 healthy controls (HC) and assesses the effect of SC (n = 19) compared to EC (n = 16) on cognitive performances. All participants were investigated with an extensive neuropsychological test battery assessing attention, memory and visuospatial and executive functions. The strength of this study is an in-depth investigation of several cognitive domains together and several memory functions together within the auditory-verbal and visuospatial memory domain for unrelated and related information. The ACoA group was significantly more deficient in attention, auditory-verbal and visuospatial memory and executive functions compared to HCs. No significant differences were found between both groups concerning visuospatial functions. Within the patient group, the SC group, as compared to the EC group, showed a significantly worse performance for auditory-verbal and visuospatial memory. No significant differences could be detected between both groups with regard to attention and visuospatial and executive functions. In conclusion, this study provides evidence for the advantage of EC in ACoA patients over SC in terms of cognitive outcome.

Clinical and morphological profile of aneurysms of the anterior communicating artery treated at a neurosurgical service in Southern Brazil

Background:

The aim of the study was to characterize the clinical profile of patients with anterior communicating artery (ACoA) aneurysms and examine potential correlations between clinical findings, aneurysm morphology, and outcome.

Methods:

A review of medical records and diagnostic neuroimaging reports of patients treated at a neurosurgical service in Porto Alegre, Brazil, between August 2008 and January 2015 was performed.

Results:

During the period, 100 patients underwent surgery for ACoA aneurysms. Fifteen had unruptured aneurysms and 85 had ruptured aneurysms. Ruptured aneurysms had a higher aspect ratio than unruptured ones (2.37 ± 0.71 vs. 1.93 ± 0.51, P = 0.02). Intraoperative rupture occurred in 3%, and temporary clipping was performed in 15%. Clinical vasospasm occurred in 43 patients with ruptured aneurysms (50.6%). Overall, mortality was 26%; 25 patients in the ruptured group (29.4%) and one in the unruptured group (6%). The Glasgow Outcome Scale (GOS) was favorable (GOS 4 or 5) in 54% of patients, significantly more so in those with unruptured aneurysms (P = 0.01). In patients with ruptured aneurysms, mortality was associated with preoperative Hunt and Hess (HH) score (P < 0.001), hydrocephalus (P < 0.001), and clinical complications (P < 0.001). Unfavorable outcomes were associated with HH score (P < 0.001), Fisher grade (P = 0.015), clinical vasospasm (P = 0.012), external ventricular drain (P = 0.015), hydrocephalus (P < 0.001), and presence of clinical complications (P = 0.001). In patients with unruptured aneurysms, presence of clinical complications was the only factor associated with mortality (P < 0.001).

Conclusion:

Despite advances in the management of subarachnoid hemorrhage and surgical treatment of aneurysms, mortality is still high, especially due to clinical complications.

A1 asynchrony, a potential risk factor for the rupture of anterior communicating artery aneurysms: A computational fluid dynamics study

INTRODUCTION AND OBJECTIVES

The anterior communicating complex is one the most common locations for aneurysm development. It receives blood from both carotid circulations and the effect of synchrony on the arrival of blood flow has not been previously studied. The objective of this study was to compare the asynchrony conditions of the A1 pulse and its effects on the haemodynamic conditions of anterior communicating artery (ACoA) aneurysms.

MATERIALS AND METHODS

From 2008 to 2017, 54 anterior communicating artery aneurysms treated at our centre were included in the study. Computational fluid dynamics (CFD) techniques were employed and simulations consisted of complete conditions of synchrony and introducing a delay of 0.2s in the non-dominant A1 artery. Time-averaged wall shear stress (TAWSS), low shear area (LSA), A1 diameter and ACoA angles were measured.

RESULTS

The difference in the LSA in conditions of synchrony and asynchrony resulted in a broad range of positive and negative values. The symmetry index (p=0.04) and A1/A2 angle on the dominant artery (p=0.04) were associated with changes in LSA.

CONCLUSIONS

In asynchrony, LSA increased in the absence of A1 asymmetry and low A1/A2 angles, potentially increasing the risk of aneurysm rupture in this location.

Increased tortuosity of ACA might be associated with increased risk of ACoA aneurysm development and less aneurysm dome size: a computer-aided analysis

Objectives

We decided to perform computer-aided analysis of the anterior cerebral artery (ACA) to check for a potential correlation with anterior communicating artery (ACoA) aneurysm presence and growth.

Methods

We retrospectively analyzed the ACA anatomy of 121 patients with ACoA aneurysms along with 121 age, risk factors, and vessel side-matched control patients without an ACoA aneurysm. We obtained their medical history and digital subtraction angiography (DSA) data from their medical records. For each patient’s DSA, we extracted curve representing the course of their ACA and calculated its relative length (RL), sum of angle metrics (SOAM), triangular index (TI), product of angle distance (PAD), and inflection count metrics (ICM).

Results

Patients with ACoA aneurysm had significantly higher RL (0.64 ± 0.23 vs. 0.56 ± 0.22; p < 0.01), SOAM (0.27 ± 0.19 vs. 0.18 ± 0.15; p < 0.01), PAD (0.12 ± 0.13 vs. 0.09 ± 0.11; p = 0.02), and TI (0.57 ± 0.14 vs. 0.44 ± 0.15; p < 0.01). In multivariate logistic regression analysis, after adjustment for possible confounders, SOAM (OR, 1.34; 95% CI, 1.12–1.63; p < 0.01) and TI (OR, 1.84; 95% CI, 1.47–2.35; p < 0.01) remained independently associated with higher risk of ACoA aneurysm. Additionally, we found significant negative correlations between TI and aneurysm dome size (R = − 0.194; p = 0.047).

Conclusions

Increased tortuosity of ACA might increase the risk of ACoA aneurysm development and decrease the risk of aneurysm growth.

Key Points

• Anterior cerebral artery’s sum of angle metrics is associated with hypertension as well as with history of ischemic stroke and myocardial infarction.

• Increased tortuosity of anterior cerebral artery might be associated with anterior communicating artery aneurysm development.

• Tortuosity of anterior cerebral artery is negatively correlated with anterior communicating artery aneurysm dome size.

Oculomotor Nerve Palsy Associated with Duplication of Middle Cerebral Artery, Anterior Communicating Artery Aneurysm, and Parietal Meningioma

A 61-year-old male presents with diplopia of acute onset and progressive course. He has a history of previous intracranial haemorrhage that was surgically evacuated 7 years ago and was also associated with diplopia. Examination revealed left complete oculomotor nerve paralysis with a fixed and dilated left pupil. Computed tomography (CT) revealed encephalomalacia, evidence of previous craniotomy, and an incidental left parietal convexity meningioma. CT angiography of the brain revealed a left tortuous duplicate middle cerebral artery with fenestration of its proximal part, an anterior communicating artery aneurysm, and a characteristic capillary blush of the meningioma. Possible mechanisms of oculomotor nerve involvement are discussed.

Microsurgical clipping of a large ruptured anterior communicating artery aneurysm

Background:

Anterior communicating artery (AComA) aneurysms are the most complex aneurysms of the anterior cerebral circulation. They mostly arise between the dominant A1 and the AComA, and are associated with intraventricular hemorrhage or other aneurysms in around 20%–30% of the cases. Giant and fusiform aneurysms are rare in this location in contrast to the common small ruptured aneurysms. Throughout the treatment, branches of A1–A2 complex such as the orbitofrontal artery, the frontopolar artery, the recurrent artery of Heubner, medial lenticulostriate arteries, and small perforators from the A1–A2 junction should be preserved. The orientation of the aneurysm, undefined in case of tortuous A1, but usually to the contralateral side of the dominant A1, might be downward, forward, upward, backward, or even of a complex morphology. Moreover, the evaluation of the chiasm and skull base, the site of possible rupture, the presence of intraluminal thrombosis, vascular calcifications, or anatomic variations of A1 and A2 segments is required. Since the angle between the AComA perforators and the A2s varies between 30° and 180°, parallel application of the clip along the AComA is unrecommended.

Technique:

The patient with large ruptured AComA aneurysm underwent supine position. The head, placed above the cardiac level, was minimal extended, and slightly tilted and rotated to the opposite side according to the projection of the aneurysm dome. A left lateral supraorbital approach was performed. The carotid cistern and the lamina terminalis were opened to release cerebrospinal fluid. Arachnoid bands extending from the olfactory triangle to the lateral side of the optic nerve were carefully dissected to find the ipsilateral A1 and the aneurysm. Skillful dissection of the AComA complex under repeated temporary and pilot clips allowed a safe definitive clipping. Occasionally, aneurysm remodeling and shrinking under bipolar coagulation might be required. Intraoperative angiography and/or Doppler ultrasound determine complete occlusion of the aneurysm and patency of the vessels.

Conclusion:

Skillful microneurosurgery is required for the management of challenging ruptured AComA aneurysms.

Videolink:

http://surgicalneurologyint.com/videogallery/ruptured-acoma-aneurysm-14

Interhemispheric Approach to Anterior Communicating Artery Aneurysm: A Case Illustration

There are two main types of approaches for anterior communicating artery (AcomA) aneurysms, namely pterional approach, and an interhemispheric (IH) approach. Pterional approach is the most common for anterior circulation aneurysms. However, this approach cannot be used without resection of gyrus rectus when aneurysm is located high within the IH fissure and directed posterosuperiorly, which is better handled with IH approach. In this article, we will describe the tricks of IH approach with a case illustration.

Wall Shear Stress and Flow Patterns in Unruptured and Ruptured Anterior Communicating Artery Aneurysms Using Computational Fluid Dynamics

Objective

The goal of this study was to compare several parameters, including wall shear stress (WSS) and flow pattern, between unruptured and ruptured anterior communicating artery (ACoA) aneurysms using patient-specific aneurysm geometry.

Methods

In total, 18 unruptured and 24 ruptured aneurysms were analyzed using computational fluid dynamics (CFD) models. Minimal, average, and maximal wall shear stress were calculated based on CFD simulations. Aneurysm height, ostium diameter, aspect ratio, and area of aneurysm were measured. Aneurysms were classified according to flow complexity (simple or complex) and inflow jet (concentrated or diffused). Statistical analyses were performed to ascertain differences between the aneurysm groups.

Results

Average wall shear stress of the ruptured group was greater than that of the unruptured group (9.42% for aneurysm and 10.38% for ostium). The average area of ruptured aneurysms was 31.22% larger than unruptured aneurysms. Simple flow was observed in 14 of 18 (78%) unruptured aneurysms, while all ruptured aneurysms had complex flow (p<0.001). Ruptured aneurysms were more likely to have a concentrated inflow jet (63%), while unruptured aneurysms predominantly had a diffused inflow jet (83%, p=0.004).

Conclusion

Ruptured aneurysms tended to have a larger geometric size and greater WSS compared to unruptured aneurysms, but the difference was not statistically significant. Flow complexity and inflow jet were significantly different between unruptured and ruptured ACoA aneurysms.

Stent-assisted coil embolization of anterior communicating artery aneurysms using the LVIS Jr stent

BACKGROUND AND PURPOSE

This retrospective study evaluates the safety and mid-term and long-term effectiveness of stent-assisted coil embolization of anterior communicating artery (Acomm) aneurysms treated with the LVIS Jr stent.

MATERIALS AND METHODS

All patients treated with the LVIS Jr stent for Acomm aneurysms between June 2015 and March 2018 were included in the analysis. Details of the procedure's periprocedural adverse events, immediate aneurysm occlusion rates, and clinical and angiographic follow-up assessment were collected.

RESULTS

A total of 25 patients with 25 aneurysms were included. Eighteen aneurysms were found incidentally. Seven patients presented with seven ruptured aneurysms: Six were remotely ruptured and one acutely ruptured. Twenty-four patients were treated successfully and one technical failure is reported. The parent arteries measured 1.4 mm to 2.9 mm in diameter (mean, 2.3 mm). Intraprocedural thromboembolic complications occurred in two patients (8%) and an intraoperative aneurysm rupture in one patient (4%). Immediate complete aneurysm occlusion was noted in 18 out of 25 patients (72%). Clinical follow-up ranged from three months to 36 months (mean, 15.8 months) and the imaging follow-up ranged from two to 35 months (mean, 14.2 months). Complete aneurysm occlusion was achieved in 14 out of 20 patients (70%) at last angiographic follow-up. Of the two patients with in-stent thrombosis, one patient had an acutely ruptured aneurysm and the other patient was treated with an LVIS Jr stent in a Y configuration. Neurological morbidity and mortality rate were 0%.

CONCLUSIONS

Complex, wide-necked Acomm aneurysms can be effectively treated with stent-assisted embolization using LVIS Jr stents.

The role of wall shear stress in the parent artery as an independent variable in the formation status of anterior communicating artery aneurysms

OBJECTIVES

The study aimed to determine which hemodynamic parameters independently characterize anterior communicating artery (AcomA) aneurysm formation and explore the threshold of wall shear stress (WSS) of the parent artery to better illustrate the correlation between the magnitude of WSS and AcomA aneurysm formation.

METHODS

Eighty-one patients with AcomA aneurysms and 118 patients without intracranial aneurysms (control population), as confirmed by digital subtraction angiography (DSA) from January 2014 to May 2017, were included in this cross-sectional study. Three-dimensional-DSA was performed to evaluate the morphologic characteristics of AcomA aneurysms. Local hemodynamic parameters were obtained using transcranial color-coded duplex (TCCD). Multivariate logistic regression and a two-piecewise linear regression model were used to determine which hemodynamic parameters are independent predictors of AcomA aneurysm formation and identify the threshold effect of WSS of the parent artery with respect to AcomA aneurysm formation.

RESULTS

Univariate analyses showed that the WSS (p < 0.0001), angle between the A1 and A2 segments of the anterior cerebral artery (ACA) (p < 0.001), hypertension (grade II) (p = 0.007), fasting blood glucose (FBG; > 6.0 mmol/L) (p = 0.005), and dominant A1 (p < 0.001) were the significant parameters. Multivariate analyses showed a significant association between WSS of the parent artery and AcomA aneurysm formation (p = 0.0001). WSS of the parent artery (7.8-12.3 dyne/cm²) had a significant association between WSS and aneurysm formation (HR 2.0, 95% CI 1.3-2.8, p < 0.001).

CONCLUSIONS

WSS ranging between 7.8 and 12.3 dyne/cm² independently characterizes AcomA aneurysm formation. With each additional unit of WSS, there was a one-fold increase in the risk of AcomA aneurysm formation.

KEY POINTS

• Multivariate analyses and a two-piecewise linear regression model were used to evaluate the risk factors for AcomA aneurysm formation and the threshold effect of WSS on AcomA aneurysm formation. • WSS ranging between 7.8 and 12.3 dyne/cm ² was shown to be a reliable hemodynamic parameter in the formation of AcomA aneurysms. The probability of AcomA aneurysm formation increased one-fold for each additional unit of WSS. • An ultrasound-based TCCD technique is a simple and accessible noninvasive method for detecting WSS in vivo; thus, it can be applied as a screening tool for evaluating the probability of aneurysm formation in primary care facilities and community hospitals because of the relatively low resource intensity.

Horizontal distance of anterior communicating artery aneurysm neck from anterior clinoid process is critically important to predict postoperative complication in clipping via pterional approach

Background:

The difficulty of clipping aneurysm of the anterior communicating artery (AcomA) depends on the size, direction, positional relationship with the parent artery, and height from the anterior frontal base. Cases of clipping unruptured AcomA aneurysm through pterional approach were analyzed to investigate the importance of the horizontal distance from the base of the anterior clinoid process.

Methods:

Twenty-six consecutive unruptured AcomA aneurysms were treated by clipping through pterional approach in 10 males and 11 females aged 37–77 years (mean 61.8 years). Size and direction of the aneurysm, and vertical distance from the anterior frontal base and horizontal distance from the base of the anterior clinoid process were measured by preoperative three-dimensional computed tomography angiography (3D-CTA). Correlations with occurrence of clinical complications and computed tomography (CT) abnormalities after operation were investigated.

Results:

The aneurysms had a mean size of 4.7 mm (range 2.1–8.9 mm). Three patients suffered complications and all had anosmia. Three patients had CT abnormality and all were contusion. The mean horizontal distance from the base of the anterior clinoid process was −4.7 mm (range −12.3–3.5 mm). The patients were divided into the anterior and posterior groups with the boundary set at −5 mm. There were no significant complications between two groups (P = 0.26). There were statistically significant CT abnormalities in posterior group (P = 0.025).

Conclusion:

The horizontal distance from the base of the anterior clinoid process is important to predict CT abnormalities and complications in clipping of AcomA aneurysm through pterional approach.

Stent-assisted embolization of wide-neck anterior communicating artery aneurysms: Review of consecutive 34 cases

OBJECTIVE

We report our experience with stent-assisted coiling of anterior communicating artery aneurysms with special consideration of angiographic and clinical outcomes, retreatment rate and periprocedural complications.

MATERIALS AND METHODS

The analysis included 34 consecutive ruptured and unruptured wide-neck aneurysms. The aneurysm size ranged from 2 to 18mm (mean 5.47). Clinical examinations with the use of modified Rankin Score and angiographic outcomes were evaluated initially post-embolization and at a minimum follow-up of 6 months.

RESULTS

Initial post-treatment complete and near-complete aneurysm occlusion was achieved in 32 (94%) and 2 (6%) cases, respectively. Imaging follow-up, performed in 28 (82%) patients, showed no change in the degree of occlusion in 25 (89%) cases and coil compaction in 3 (11%) patients. Of these, one (3.6%) patient underwent a second coil embolization. The periprocedural severe complication rate was 2.9% (1/35) and was associated with prolonged attempt of retrieval of migrated coil resulting in anterior cerebral artery infarct with serious clinical consequences. In another 3 patients periprocedural adverse events without delayed clinical consequences were noticed. The clinical follow-up evaluation achieved in 33 (97%) patients showed no change in 30 (91%) cases, one patient (3%) with clinical improvement and two (6%) cases of neurological deterioration.

CONCLUSIONS

The use of stent is feasible and effective for coil embolization of wide-necked anterior communicating artery aneurysms. Although periprocedural complications resulting in severe morbidity are rare, they should be noted, since in terms of thromboembolic events some of them presumably have a potential to be avoidable.

Elderly age associated with poor functional outcome after rupture of anterior communicating artery aneurysms

The effect of age on patient outcomes after rupture of the anterior communicating artery (Acom) aneurysms is not well-defined. We performed a retrospective cohort study of patients presenting to our institution with a ruptured Acom aneurysm between 2003 and 2012. Patients were divided into two groups on the basis of age at presentation, with patients 65years and older categorized as the elderly group. The effect of elderly age on patient outcomes was then evaluated using multivariate logistic regression analysis. There were 147 patients presenting with a ruptured Acom aneurysm. Of these, 41 (27.9%) were 65years or older. Patients in the elderly group were more likely to be female (68.3% vs. 40.6%, p=0.0026), and less likely to be active smokers (22.0% vs. 60.4%, p<0.0001) or to abuse alcohol (7.3% vs. 21.7%, p=0.0404). Elderly patients were more likely to have a history of hypertension (70.7% vs. 52.8%, p=0.0487) and coronary artery disease (19.5% vs. 2.8%, p=0.0006). Elderly patients were more likely to require a ventriculostomy (61.0% vs. 37.7%, p=0.0109) and ultimately to require permanent cerebrospinal fluid diversion (36.6% vs. 17.0%, p=0.0106). On adjusted analysis, age 65 years or older was associated with a greater likelihood of poor outcome at last follow-up within 1year of aneurysmal subarachnoid hemorrhage (odds ratio=3.76, 95% confidence interval: 1.30-11.78, p=0.0144). Our results suggest that elderly age is an independent risk factor for poor functional outcome after rupture of an Acom aneurysm.

Twin-like appearance of an unruptured intracerebral anterior communicating artery (ACom) aneurysm in a male sibling of a patient with a ruptured ACom aneurysm

BACKGROUND

Increased risk of intracranial aneurysm rupture with subsequent subarachnoid haemorrhage (SAH) is related to several possible factors, including first-grade familial aneurysms.

METHODS AND RESULTS

Here we present a case of one ruptured and one unruptured identical twin-like anterior communicating artery (ACom) aneurysm present in two male siblings, without any proven genetic predisposition. According to evidence-based scores, aneurysm rupture risk for the younger (51 years old) sibling (with an unruptured ACom aneurysm) would be low, leaving the decision for either treatment or clinical follow-up to the discretion of the treating physician.

CONCLUSIONS

From a clinical neurosurgical perspective, however, especially since his older brother suffered an aneurysmal SAH at age 57 (i.e. 6 life-years later) from a twin-like-appearing ACom aneurysm, in our opinion rupture seems almost inevitable, thus prompting treatment at an early stage.

The Expanded Endoscopic Endonasal Approach to Anterior Communicating Artery Aneurysms: A Cadaveric Morphometric Study

OBJECTIVE

The purpose of this study was to explore the endoscopic endonasal approach to the anterior communicating artery complex.

DESIGN

Anatomic, morphometric analysis of human cadaver heads.

SUBJECTS

Fifteen latex-injected adult cadaver heads.

MAIN OUTCOME MEASURES

The anatomic boundaries of the operative field and the dimensions of exposure of the anterior communicating artery (ACoA) complex were measured and clip placement feasibility was assessed.

RESULTS

Exposure of the ACoA and bilateral A1 and A2 segments was accomplished in all 15 cadaver heads. Average length of the exposed ACoA was 3 ± 1 mm, the left A1 was 5 ± 3 mm and right A1 was 5 ± 1 mm, while the A2 segment was 5 ± 2 mm bilaterally. The average distance from the alar floor to the ACoA was 95 mm, while proximal lateral limit measured between the alar floor margins was 36 mm. The distal lateral limit as defined by the distance between the lateral most exposed margins of the chiasm was 19 mm. Clip placement was accomplished for the ACoA and the A1 and A2 segments bilaterally in all specimens.

CONCLUSION

The endoscopic, endonasal transtuberculum, transplanum approach is an anatomically feasible alternative to treating select aneurysms of the ACoA complex.

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.

A Large Ruptured Anterior Communicating Artery Aneurysm Presenting with Bitemporal Hemianopsia

Anterior communicating artery (ACoA) aneurysms sometimes present with visual symptoms when they rupture or directly compress the optic nerve. Giant or large ACoA aneurysms producing bitemporal hemianopsia are extremely rare. Here we present an unusual case of bitemporal hemianopsia caused by a large intracranial aneurysm of the ACoA. A 41-year-old woman was admitted to our neurosurgical department with a sudden-onset bursting headache and visual impairment. On admission, her vision was decreased to finger counting at 30 cm in the left eye and 50 cm in the right eye, and a severe bitemporal hemianopsia was demonstrated on visual field testing. A brain computed tomography scan revealed a subarachnoid hemorrhage at the basal cistern, and conventional cerebral catheter angiography of the left internal carotid artery demonstrated an 18×8 mm dumbbell-shaped aneurysm at the ACoA. Microscopic aneurysmal clipping was performed. An ACoA aneurysm can produce visual field defects by compressing the optic chiasm or nerves. We emphasize that it is important to diagnose an aneurysm through cerebrovascular study to prevent confusing it with pituitary apoplexy.

Intraoperative head rotation for clipping anterior communicating artery aneurysms

Background:

The anterior interhemispheric approach provides wide exposure of the anatomy around the anterior communicating artery aneurysm. A disadvantage of this approach is that splitting the interhemispheric fissure is a complicated surgical maneuver. One solution is to hold the fissure horizontally in the operation field. Surgical procedures for bicoronal scalp incision and craniotomy are difficult in the horizontal head position. We developed a modified low anterior interhemispheric approach to minimize damage to the frontal lobe and olfactory nerve by rotating the head after opening the dura.

Methods:

The head is fixed in a prerotated Sugita head holder in a neutral head position. Bicoronal scalp incision and frontal craniotomy are performed and the head holder is rotated 30 degrees clockwise to allow gravity to retract the right frontal lobe. The surgeon can then move to the right side of the patient to obtain a horizontal operation field parallel to the interhemispheric fissure.

Results:

This method was used for 12 patients in the past 6 years. All aneurysms were successfully clipped without any complications related to the procedure. Damage to the frontal lobe was avoided and the olfactory nerve was preserved in all the patients.

Conclusion:

Intraoperative head rotation minimizes surgical damage to the neural structures in the anterior interhemispheric approach.

Pupil sparing oculomotor nerve paresis after anterior communicating artery aneurysm rupture: False localizing sign or acute microvascular ischemia?

Background:

We describe a rare case of solitary pupil sparing oculomotor nerve paresis following rupture of anterior communicating artery (ACom) aneurysm and discuss the pertinent literature. Oculomotor nerve paresis caused by an ACom aneurysm rupture is an uncommon occurrence. Also, partial paresis affecting only fibers of superior division of oculomotor nerve is never reported before.

Case Description:

A 55-year-old female, known hypertensive presented 5 days after an episode of acute severe headache, with Glasgow Coma Scale (GCS) of E2V2M5, left ptosis, normal pupils, paraparesis, and computed tomography (CT) scan showed diffuse subarachnoid hemorrhage (SAH). CT angiography revealed ACom aneurysm pointing antero-superiorly toward right. Patient later underwent endovascular coiling of the aneurysm. Subsequently there was partial improvement of ptosis in 3 weeks.

Conclusion:

Though pupil sparing oculomotor nerve paresis may not have much localizing value, it helps to understand acute microvascular spasm with potential therapeutic implications.

The energy loss may predict rupture risks of anterior communicating aneurysms: a preliminary result

Anterior communicating artery (ACoA) aneurysms are well documented to have a higher rupture risk compared with aneurysms at other locations. However, the risk predicting factors for these aneurysms still remain unclear due to the complex arteries geometries and flow patterns involved. The authors introduce a comprehensive method to quantitatively illustrate the development of ACoA aneurysms using a computational fluid dynamics (CFD) approach. Seven ACoA aneurysms, which included 2 ruptured and 5 unruptured aneurysms, were employed. Patient-specific whole anterior circulation geometries were segmented to simulate the real circumstances in vivo. The energy losses (EL) and flow architectures of these 7 aneurysms were evaluated using an algorithm modality. Overall, the 2 ruptured aneurysms, along with 1 unruptured aneurysm that was defined as highly likely to rupture due to ACoA location and a bleb sitting at the top of the dome, had a significantly larger EL and more complex and unstable flow architecture than the others. Two aneurysms had a negative value of EL indicating that the geometries with aneurysms of the anterior communicating complex (ACC) had a smaller loss of energy than the geometries without aneurysms. Despite a small sample size resulting in a low statistical significance, EL may serve as a development predictor of ACoA aneurysms.

Effect of clipping anterior communicating artery aneurysms via pterional approach contralateral to supply of dominant blood: report of 15 patients

BACKGROUND AND PURPOSE

Anterior communicating artery aneurysm (ACoAA) is a common cerebrovascular disease. This research is to observe the curative effect and safety of clipping anterior communicating artery (ACoA) aneurysms by microsurgery through the pterional approach contralateral to supply of dominant blood.

MATERIALS AND METHODS

Before the surgery, three-dimensional-DSA (3D-DSA) was performed to study the regional anatomy of ACoA complexes in all 15 patients with ACoA aneurysms. According to 3D-DSA, the aneurysms and ACoA complexes could be satisfactorily exposed by the microsurgery through the pterional approach contralateral to the supply of dominant blood. And then the microsurgery through the pterional approach contralateral to the supply of dominant blood was performed in 15 patients with ACoA aneurysms.

RESULTS

Clipping of ACoA aneurysms were successfully performed in all patients. The aneurysms and ACoA complexes were satisfactorily exposed via 3D-DSA. Among 15 patients with ACoA aneurysms, 14 cases were cured and 1 case need further care.

CONCLUSIONS

The ideal side of pterional approach may be cheese via simulation of pterional approach with 3D-DSA. The ACoA complex and aneurysm can be clearly exposed, and the aneurysm may be smoothly clipped safely by the microsurgery through the ideal side pterional approach contralateral to supply of dominant blood in the patients with ACoA aneurysms.

Risk factors and consequences of unexpected trapping for ruptured anterior communicating artery aneurysms

Background:

While clipping cerebral aneurysms at the neck is optimal, in some cases this is not possible and other strategies are necessary. The purpose of this study was to describe the incidence, risk factors, and outcomes for inability to clip reconstruct ruptured anterior communicating artery (ACoA) aneurysms.

Methods:

Of the 70 cases of ruptured ACoA aneurysms between January 2006 and December 2013, our institutional experience revealed four cases of small ACoA aneurysms that had been considered clippable prior to operation but required trapping. When a unilateral A2 segment of anterior cerebral artery (ACA) was compromised by trapping, revascularization was performed by bypass surgery. Clinical presentation, angiographic characteristics, operative approach, intraoperative findings, and treatment outcomes were assessed.

Results:

Very small aneurysm under 3 mm was a risk factor for unexpected trapping. The reason for unexpected trapping was laceration of the aneurysmal neck in two cases, and lack of clippaple component due to disintegration of entire aneurysmal wall at the time of rupture in the others. Aneurysms with bilateral A1 were treated with sole trapping through pterional approach in two cases. The other two cases had hypoplastic unilateral A1 segment of ACA and were treated with combination of aneurysm trapping and revascularization of A2 segment of ACA through interhemispheric approach. No patients had new cerebral infarctions of cortical ACA territory from surgery. Cognitive dysfunction was observed in three cases, but all patients became independent at 12-month follow up.

Conclusions:

Unexpected trapping was performed when ruptured ACoA aneurysms were unclippable. Trapping with or without bypass can result in reasonable outcomes, with acceptable risk of cognitive dysfunction.

Application of endovascular coiling and subsequent Onyx 34 embolization in anterior communicating artery aneurysms with adjacent hematoma

OBJECTIVE

Small anterior communicating artery aneurysms with recurrent bleeding and adjacent hematoma may have a high risk of post-operative rebleeding. This clinical study summarizes our preliminary experience with this subset of aneurysms, which were treated with endovascular coiling and subsequent Onyx 34 embolization.

METHODS

We retrospectively reviewed the data of 9 patients suffering from small anterior communicating artery aneurysms treated with the combination of coils and Onyx. The clinical characteristics, angiographic outcomes, and follow-up results are reviewed.

RESULTS

Endovascular coiling and Onyx embolization were successfully accomplished in all 9 cases. The Raymond scale ratings of the treatments are all class I with the parent arteries kept patent. One patient died of severe brain edema on the 5th post-operative day. The modified Rankin scale (mRS) score for the other 8 patients at follow-ups (6m to 26m, 15.8m on average) was 0 in 5 cases, 1 in 2 cases, and 3 in 1 case. Seven of 8 patients (87.5%) underwent angiographic follow-up that demonstrated persistent durable occlusion with no recanalization.

CONCLUSIONS

Endovascular coiling and subsequent Onyx 34 embolization may be effective in treating anterior communicating artery aneurysms with adjacent hematoma. Further studies with larger sample size and adequate follow-up are required to verify its safety and efficacy as well as to evaluate the long-term outcome.

Rupturing Anterior Communicating Artery Aneurysm during Computed Tomography Angiography: Three-Dimensional Visualization of Bleeding into the Septum Pellucidum and the Lateral Ventricle

Computed tomography angiography (CTA) is commonly used in setting of subarachnoid hemorrhage, but imaging features of aneurysm rupturing taking place at the time of scanning has rarely been described. The author reports a case of actively rebleeding aneurysm of the anterior communicating artery with intraventricular extravasation on the hyperacute CTA imaging. The rebleeding route, not into the third ventricle but into the lateral ventricles, can be visualized by real-time three-dimensional CT pictures. The hemorrhage broke the septum pellucidum and the lamina rostralis rather than the lamina terminalis.

Cadaveric study of the endoscopic endonasal transtubercular approach to the anterior communicating artery complex

The endoscopic transnasal approach to the anterior communicating artery (ACoA) complex is not widely performed. This cadaveric study investigated the surgical relevance of the anterior endoscopic approach to the treatment of ACoA aneurysms. Bi-nasal endoscopic transtubercular surgery was carried out on fresh adult cadavers. Primary outcomes measures incorporated dimensions of the endonasal corridor (operative field depth, lateral limits, size of the transplanum craniotomy and dural opening); vascular exposure (proximal and distal anterior cerebral arteries [ACA], ACoA, clinoidal internal carotid artery [ICA] segment); and operative manoeuvrability defined by clip placements (ipsilateral and contralateral). Eight cadaver heads were used (mean age 84±7years, range 76-94 years, 75% female). Mean operative depth was 97±4mm. The lateral corridors were limited proximally by the alar rim openings (31±2mm), and distally by the optic nerves (22±6mm). The endonasal craniotomy dimensions were 21±5mm anteroposteriorly, and 22±4mm laterally. Vascular exposure was achieved in 100% of subjects for the ACoA segment and the ACA segments proximal to the ACoA (A1). The ACA segments distal to the ACoA (A2) were accessible only in 40% of subjects. Endonasal clip placement across the ACoA segment, clinoidal ICA, A1 and A2 were 100%, 90%, 90%, and 30%, respectively. The ventral endoscopic endonasal approach to the ACoA complex provides excellent vascular visualisation without brain retraction or gyrus rectus resection. However, the limitation in access to the A2 for temporary clip placement may prove to be a significant limitation of this approach.

Acute Retrobulbar Optic Neuropathy as the Sole Manifestation of Subarachnoid Haemorrhage from a Ruptured Anterior Communicating Artery Aneurysm

Anterior communicating artery aneurysm is the most common form of intracranial aneurysm and subarachnoid haemorrhage (SAH) is the common presenting feature of anterior communicating artery aneurysms. In general, patients with SAH from anterior communicating artery aneurysm present with neurological deficit. We report an interesting case of a 60-year-old man who presented with acute monocular vision loss accompanied by periorbital pain without any neurological deficit, finally diagnosed with SAH from ruptured anterior communicating artery aneurysm. Five months after immediate craniotomy with aneurysm neck clipping, his visual acuity was improved to 20/63 with a pale optic disc appearance. Acute retrobulbar optic neuropathy may be the sole manifestation of SAH from ruptured anterior communicating artery aneurysm. Unilateral decrease of visual acuity with periorbital pain, in the absence of other neurological change, may be the initial and isolated sign.

Influence of clinical and anatomic features on treatment decisions for anterior communicating artery aneurysms

OBJECTIVE

The purpose of this study was to analyze the clinical and anatomic features involved in determining treatment modalities for anterior communicating artery (AcoA) aneurysms.

METHODS

The authors retrospectively evaluated 112 AcoA aneurysms with pretreatment clinical features including age, Hunt and Hess grade, medical or neurological comorbidity, and anatomical features including aneurysm size, neck size, dome-to-neck ratio, vessel incorporation, multiple lobulation, and morphologic scoring system. Post-treatment clinical results were classified according to the Glasgow Outcome Scale, and anatomic results in coiled patients were classified according to the modified Raymond scale. Using multivariate logistic regression, the probabilities for decision making between surgical clipping and coil embolization were calculated.

RESULTS

Sixty-seven patients (60%) were treated with surgical clipping and 45 patients (40%) with endovascular coil embolization. The clinical factor significantly associated with treatment decision was age (≥65 vs. <65 years) and anatomical factors including aneurysm size (small or large vs. medium), dome-to-neck ratio (<2 vs. ≥2), presence of vessel incorporation, multiple lobulation, and morphologic score (≥2 vs. <2). In multivariate analysis, older patients (age, >65 years) had significantly higher odds of being treated with coil embolization relative to clipping (adjusted OR=3.78; 95% CI, 1.39-10.3; p=0.0093) and higher morphological score patients (≥2) had a higher tendency toward surgical clipping than endovascular coil embolization (OR=0.23; 95% CI, 0.16-0.93; p=0.0039).

CONCLUSION

The optimal decision for treating AcoA aneurysms cannot be determined by any single clinical or anatomic characteristics. All clinical and morphological features need to be considered, and a collaborative neurovascular team approach to AcoA aneurysms is essential.