Anterior Choroidal Artery Aneurysms: Influence of Regional Microsurgical Anatomy on Safety of Endovascular Treatment

Intraplexal Aneurysm of the Distal Segment of the Anterior Choroidal Artery: A Case Report and Review of Literature

Aneurysms of the anterior choroidal artery (AChA) are the most common pathology of the vessel. Although proximal aneurysms at the internal carotid artery (ICA) and AChA junction are common, their occurrence in the distal segment of the AChA is quite rare. We report a case of a distal AChA aneurysm occurring in the intraplexal segment of the AChA. To our knowledge, this is the first reported case of an intraplexal distal AChA aneurysm.

Use of a flow diverter in a small-caliber end artery anterior choroidal dissecting pseudoaneurysm: illustrative case

BACKGROUND

Anterior choroidal artery (AChA) fusiform aneurysms are exceedingly rare and associated with high rebleeding and mortality rates. Their difficult anatomy comes with a broad range of treatment options, including bypass, stent-assisted coiling, and flow diversion. Currently, flow diverters are approved for large-caliber internal carotid artery segment aneurysms. However, many institutions have expanded their use to distal small-caliber vessels, which raises questions regarding device sizing and long-term patency. The authors present a dissecting distal AChA fusiform pseudoaneurysm treated successfully with flow diversion.

OBSERVATIONS

A 40-year-old woman with monoclonal gammopathy of unknown significance, lichen sclerosis, and an unspecified connective tissue disease presented with diffuse subarachnoid hemorrhage. She had a dissecting, 5 × 3-mm, left AChA pseudoaneurysm 4 mm distal to the origin of the vessel. A 2.5-mm flow redirection endoluminal device was deployed. There were no procedural complications. A 6-month cerebral angiogram showed device patency and no pseudoaneurysm remnant. These results were maintained at 1 year as seen on head magnetic resonance angiography.

LESSONS

Flow diversion is a successful and safe therapeutic intervention for challenging intracranial aneurysms originating from small-caliber vessels supplying eloquent vascular territories.

Endovascular Treatment and Angiographic Characteristics of Aneurysms at the Origin of the Anterior Choroidal Artery

Background

The information available about the variations and anatomy of the anterior choroidal artery (AchA) with aneurysm at the origin of the vessel and the outcomes of endovascular treatment (EVT) for AchA aneurysms is incomplete.

Materials and Methods

A retrospective study of 54 consecutive patients who were admitted to our hospital with a diagnosis of AchA aneurysm and treated with EVT was performed. The variations and anatomy of the AchA and the outcomes of EVT for AchA aneurysms were analyzed.

Result

The 54 patients were aged 35-82 years (mean age, 56.1 ± 19.7 years) and included 32 females (59.3%, 32/54). Regarding AchA anatomy, 63.5% of AchAs had a typical S-shaped course. The diameter of the AchA origin averaged 0.8 ± 0.3 mm. Of all the AchA aneurysms, 51.9% were ruptured. The diameter of AchA aneurysms averaged 4.1 ± 2.4 mm. Moreover, 40.7% of 54 cases had multiple aneurysms. EVT was assisted with stenting for 25.9% of 54 AchA aneurysms. An immediate Modified Raymond-Roy Classification grade of I was obtained in 96.3% of AchA aneurysm cases. After EVT, the ischemic complication rate was 13%. In total, 83% of patients had good outcomes, with a Glasgow Outcome Scale score of 4-5. Follow-up angiography showed acceptable treatment results in this study.

Conclusion

The study showed that the AchA had a complex angiographic anatomy in cases with aneurysms at the origin of the vessel and that the anatomical features can be helpful in EVT. EVT for aneurysms at the origin of the AchA had good outcomes.

Management of a ruptured intraventricular aneurysm arising from distal anterior choroidal artery (AChA): pediatric case report

Intracranial aneurysms arising from the distal anterior choroidal artery (AChA) are uncommon entities, with less than 30 cases reported. A 4-year-old boy was admitted to the Emergency Department with a sudden onset of severe headache and vomiting. CT scan of the head showed signs of intraventricular hemorrhage (IVH) and subarachnoid hemorrhage (SAH). Cerebral angiography revealed a right AChA aneurysm arising from a distal intraventricular branch with an associated microarteriovenous malformation (microAVM). Following a multidisciplinary assessment, the patient underwent surgical clipping. An ipsilateral transcortical transparietal approach was utilized. Early postoperative deficits were not found, and good clinical and radiological outcomes were assessed at long-term follow-up. Postoperative cerebral angiography showed complete exclusion and resection of both aneurysm and AVM. Surgery for intracranial aneurysms in this location can be challenging; however, good surgical and neurological outcomes can be achieved. The present work highlights the value of multidisciplinary assessment in the decision-making process in complex pediatric neurovascular pathology, especially when facing rare cases like this one, which represents the youngest case of a ruptured distal AChA aneurysm reported in the literature.

A New Classification of Anterior Choroidal Artery Aneurysms and Its Clinical Application

Background and Purpose: The aim of this study was to compare the different subtypes of anterior choroidal artery (AChoA) aneurysm based on a new classification and to analyze the risk factors according to individual endovascular treatment (EVT).

Methods: In the new classification, AChoA aneurysms are classified into independent type (I type) and dependent type (II type) based on the relationship between the AChoA and the aneurysm. II type aneurysms have three subtypes, IIa (neck), IIb (body), and IIc (direct). We retrospectively analyzed 52 cases of AChoA aneurysm treated in our center between 2015 to 2019. There were 13 (25.0%) I type aneurysms, 24 (46.2%) IIa aneurysms, 15 (28.8%) IIb aneurysms, and no IIc type; 28 cases had a subarachnoid hemorrhage. According to our preoperative EVT plan for the different subtypes: II type should achieve Raymond-Roy Occlusion Class 1 (RROC 1) where possible. To protect the AChoA, it is best to preserve the neck of the IIa type aneurysms (RROC 2), and RROC 3 is enough for IIb type.

Results: Ten asymptomatic cases with minimal aneurysms were treated conservatively. Of the other cases, 42 were treated with individualized EVT (26 with a simple coil, 6 with balloon-assisted coiling, 7 with stent-assisted coiling, and 3 by flow diverter. Different subtypes had different RROC (Z = 14.026, P = 0.001). IIb type aneurysms (χ² = 7.54, P = 0.023) were one of the factors related to temporary or permanent AChoA injury during surgery. Overall, two patients (IIa = 1, IIb = 1) developed contralateral hemiparesis.

Conclusions: The new classification diagram clearly shows the features of all types of AChoA aneurysm and makes EVT planning more explicit. The II type (particularly IIb) was a potential risk factor for AChoA injury.

Sphenoid dural arteriovenous fistulas

Sphenoid wing dural AVFs represent a rare clinical entity. These lesions may be asymptomatic or present with focal neurologic deficits, intracranial venous hypertension, or intracranial hemorrhage. Diagnosis is based on clinical findings and diagnostic imaging. They are alternatively classified as lesions of either the greater or lesser wings of the sphenoid bone. We performed a search of the PubMed database of studies evaluating the clinical behavior and surgical and endovascular therapies of these lesions. Dural AVFs draining into the superficial middle cerebral vein and/or laterocavernous sinus, or rather, lesions of the greater wing of the sphenoid, exhibit a greater likelihood of developing an aggressive clinical course, with higher probability of cortical venous reflux and consequent intracranial venous hypertension, intracranial hemorrhage, and symptomatic presentation. Dural AVFs of the sphenoparietal sinus, that is, lesions of the lesser wing of the sphenoid, typically exhibit a more benign clinical course, as there is a prominent epidural venous drainage into the cavernous sinus, reducing the risk of cortical venous reflux, and consequently, the probability of intracranial venous hypertension, hemorrhage, and floridly symptomatic presentation. These lesions may be treated via surgical clipping of the fistulous point, transarterial or transvenous embolization, and/or stereotactic radiosurgery. Though surgical intervention was the principal therapy due to facility of craniotomy access to the fistulous point, embolization has become standard of care permitted by innovation in endovascular technology. The natural history, clinical presentation, angioarchitecture, diagnosis, and management of these lesions are reviewed and discussed.

The Posterior Perforated Substance: A Brain Mystery Wrapped in an Enigma

BACKGROUND

There is a dearth of published information on the posterior perforated substance as compared to the anterior perforated substance. We managed to glean facts about the posterior perforated substance that can serve as a landmark for surgical operations in the adjacent regions of the midbrain and the vessels passing through it. Moreover, the posterior perforated substance contains the interpeduncular nucleus responsible for the mental state of the individual.

OBJECTIVES

1) To describe the topography of the blood vessels supplying the posterior perforated substance area from the surgical point of view; 2) to investigate the functions of the interpeduncular nucleus.

METHODS

We assembled and analyzed results from source databases by Elsevier, NCBI MedLine, Scopus, Scholar. Google and Embase. Each article was studied in detail for practically useful information about the posterior perforated substance.

RESULTS

The P1-segment perforating branches of the posterior cerebral artery supply the posterior perforated substance. This area is especially vulnerable in the case of vascular pathologies. The posterior communicating artery can block the surgeon's view and impede maneuverability of the tool in the area of the posterior perforated substance, which may be addressed using the separation technique, which can lead to positive results. In addition, the medial habenula-interpeduncular nucleus in the posterior perforated substance is associated with various addictions and psychiatric conditions.

CONCLUSION

The posterior perforated substance area is of great interest for surgical interventions. Future studies of the interpeduncular nucleus anticipate the development of drugs to affect different types of dependencies and some mental diseases.