Endovascular Treatment of Posterior Cerebral Artery Trunk Aneurysm: The Status Quo and Dilemma

Dissecting and fusiform aneurysms of the superior cerebellar artery: anatomy, clinical presentation, and treatment outcomes

The management of superior cerebellar aneurysms is still controversial. Although several techniques are available, the deep localization of the lesion and the limited number of cases increase the complexity of decision-making for optimal treatment. Only a few cases of dissecting and fusiform aneurysms of the superior cerebellar artery (SCA) are described in the literature, many of which are without long follow-ups. The study aims to offer an exhaustive retrospective analysis of patients affected by SCA fusiform and dissecting aneurysms treated at our institution from 2008 to 2023, highlighting outcomes and complications. Moreover, a comprehensive narrative review was performed. A total of seven patients were treated at our institution. After a title and abstract screen, fifty-five papers met the criteria for inclusion in the review. In our case series, conservative treatment was proposed as the first therapeutic option in four cases (57.1%), while endovascular treatment (EVT) was in three cases (42.9%). A good recovery was observed in 66% of patients presenting with subarachnoid hemorrhage (SAH), while every patient without SAH achieved a good clinical outcome. A poor outcome was observed only in one patient with a dissecting aneurysm causing SAH, who also suffered a pontine infarction. In the literature review, conservative treatment was proposed as a first therapeutic option in eleven cases (16.6%), open microsurgical techniques in 19 patients (28.8%), and EVT in 31 patients (46.9%). Fatal outcome was documented in five patients (7.5%), all characterized by the rupture of the vascular lesion, while 6.1% of cases had non-fatal poor outcomes.

The off-label uses of pipeline embolization device for complex cerebral aneurysms: Mid-term follow-up in a single center

OBJECTIVE

To describe the off-label uses of pipeline embolization device for a variety of types of aneurysms including ruptured aneurysms, posterior circulation aneurysms, small aneurysms, distal aneurysms, and recurrent aneurysms.

METHODS

Clinical and angiographic data of patients who underwent pipeline embolization device treatment on off-label use at our center were retrospectively reviewed. For categorical variables, Fisher's exact test was used, and a two-sample Wilcoxon rank-sum test was used for patients' age to analyze the correlation with outcomes.

RESULTS

In this study, 121 aneurysms in 107 patients received off-label pipeline embolization device treatments. The overall rate of complete aneurysm occlusion was 77.8% (28/36 in 35 patients) for posterior circulation aneurysms and 95.3% (81/85 in 72 patients) for anterior circulation aneurysms. The posterior circulation aneurysms have a lower rate of aneurysm occlusion (p = 0.0372). The small aneurysms have a higher rate of aneurysm occlusion (p = 0.0104). The patient's sex, age, and aneurismal size were associated with ischemic stroke complications (p = 0.0397, 0.0166, and 0.0178). In posterior circulation aneurysm patients, only two basilar apex aneurysms underwent pipeline embolization device treatment, both of whom died of thrombotic complications. There was no difference in mortality between posterior circulation aneurysm patients (8.6%, 3/35) and anterior circulation aneurysm patients (1.4%, 1/72) (p = 0.1015). Patients of older age have a higher risk of death rate (p = 0.0053).

CONCLUSIONS

The off-label use of pipeline embolization device is often performed in clinical practice and can achieve efficacy in complex aneurysms. The off-label use of pipeline embolization device was found to carry an increased rate of mortality in older patients. Excluding basilar apex aneurysms, the pipeline embolization device is as safe as anterior circulation aneurysms in the treatment of posterior circulation aneurysms elsewhere.

Bypass surgery for ruptured dissecting aneurysms of the proximal posterior cerebral artery: illustrative case

BACKGROUND

Posterior cerebral artery (PCA) dissecting aneurysms commonly occur in the proximal PCA and are considered rare. The treatment of proximal PCA dissecting aneurysms is challenging because of the existence of perforators supplying the vital neural structures. Recently, endovascular intervention has been used; however, concerns for ischemic or hemorrhagic complications exist.

OBSERVATIONS

A 54-year-old woman presented with subarachnoid hemorrhage due to dissecting aneurysm rupture at the P1-P2 junction of the PCA. The thalamoperforating artery (TPA) and medial posterior choroidal artery (MPchA) originated from the proximal end and the distal end of the aneurysm, respectively. Additionally, the posterior communicating artery (PcomA) connected with the dissected segment. To preserve these perforators, we performed surgical trapping combined with superficial temporal artery (STA) PCA anastomosis. Clips were applied for trapping the proximal and distal end of the aneurysm, with preservation of the TPA and MPchA origin. PcomA was left open for blood flow preservation to the perforators directly arising from the aneurysm. The postoperative course was uneventful, and the patient was discharged.

LESSONS

Surgical trapping using STA-PCA bypass could be a treatment of choice for proximal PCA dissecting aneurysms, considering its potential for cure and prevention of ischemic complications.

A rare case of fusiform basilar trunk aneurysm

Aneurysms in the posterior circulation and distal sites are more common among the pediatric population than among adults, with a male predominance. Symptoms of an aneurysm in the posterior circulation can include a stiff neck or severe headache due to a ruptured aneurysm, whereas an unruptured aneurysm can cause mass effects or neurological deficits. However, in children, the complete occlusion of the aneurysm while preserving the flow of the main artery can be difficult to achieve when attempting a stent-assisted coil embolization technique. A 25-month-old girl presented with left hemiparesis and was diagnosed with a basilar artery aneurysm 10 months prior, but she did not receive any specific treatment. No history of trauma and no significant familial history were recorded. Angiography showed a fusiform aneurysm on the basilar artery trunk, which was successfully occluded using stent-assisted coiling following dual antiplatelet therapy with clopidogrel and aspirin. She was discharged with the complete restoration of motor deficits.

Clinical Importance of the Persistent Primitive Trigeminal Artery in Vascular Lesions and Its Role in Endovascular Treatment

The persistent primitive trigeminal artery (PPTA) extends from the internal carotid artery to the basilar artery between the origins of the anterior inferior cerebellar artery and superior cerebellar artery. PPTAs have complex anatomical characteristics. Salas and Saltzman classifications are most often used in PPTAs. The PPTA can play many roles in vascular lesions, including intracranial aneurysms, brain arteriovenous malformations, trigeminal artery-cavernous fistulas, Moyamoya disease, and large vessel occlusion. For these lesions, surgical treatment is difficult due to the deep location and complex anatomy of the PPTA, but endovascular treatment (EVT) has emerged as a good alternative. Currently, a complete review of the clinical importance of the PPTA in terms of its role in the development and EVT of vascular lesions is lacking. Therefore, we conducted a PubMed search, performed a review of the relevant extracted literature and cataloged our experience with PPTAs. By review, we found that a thorough understanding of the anatomical and angiographic features of this PPTA is of utmost importance when making therapeutic decisions for any of these pathological conditions.