Treatment of posterior circulation non-saccular aneurysms with flow diverters: a single-center experience and review of 56 patients

Abstract

Background and purposeNon-saccular aneurysms of the posterior fossa are an uncommon pathology with no clear treatment strategy. The use of flow-diverting stents (FDS) has had mixed results. We sought to evaluate our experience of FDS for the treatment of this pathology.MethodsWe retrospectively reviewed our database of prospectively collected information for all patients treated only with flow diversion for an unruptured non-saccular aneurysm of the posterior circulation between February 2009 and April 2016. The aneurysms were classified as dolichoectasia, fusiform or transitional, and imaging characteristics including maximal diameter, disease vessel segment, MRI features (intra-aneurysmal thrombus, T1 hyperintensity in the aneurysmal wall, infarctions in the territory of the posterior circulation, and mass effect) were recorded alongside clinical and follow-up data.ResultsWe identified 56 patients (45 men) with 58 aneurysms. The average age of the patients was 63.5 years. Twenty-two patients were symptomatic from the aneurysms at presentation. The majority of the lesions were vertebrobasilar in location (44.8%) with isolated vertebral lesions representing 29.3% of aneurysms. Transitional aneurysms were the most common (48.2%). The mean maximal diameter of the aneurysms was 11 mm. Angiographic exclusion of the aneurysms was seen in 57.4% of aneurysms with follow-up (n=47). During the follow-up period nine patients died.ConclusionsTreatment of non-saccular aneurysms of the posterior fossa is technically possible. Early treatment, particularly of the fusiform and transitional subtypes, is recognized, as is treatment prior to the development of symptoms. A ‘watch and wait’ strategy with regular imaging follow-up could be employed for asymptomatic dolichoectasia.

Meta-analysis of treatment outcomes of posterior circulation non-saccular aneurysms by flow diverters

“…Non-saccular posterior circulation aneurysms have varying morphological and etiological characteristics that can influence both natural history and treatment options 8. Understanding the natural history of these lesions is essential to improving patient selection.…”

Hemodynamic Changes Caused by Multiple Stenting in Vertebral Artery Fusiform Aneurysms: A Patient-Specific Computational Fluid Dynamics Study

“…9,10 Although flow-diverter stents have been demonstrated to be an efficient treatment for aneurysms, their safety in posterior fusiform aneurysms still needs to be established by more evidence, especially because some important branches of smaller arteries might become covered. 11 Therefore, stepwise overlapping stent placement is still a safe and feasible choice when dealing with posterior fusiform aneurysms.…”

The Evolution of Flow-Diverting Stents for Cerebral Aneurysms; Historical Review, Modern Application, Complications, and Future Direction

“…With published reports of safe off label use for aneurysms beyond the petrous to ophthalmic ICA and development of second generation FDS, the IFU has since expanded to small (<7 mm) and medium (7-15 mm), wide neck aneurysms of the entire intracranial ICA. To date, safe off-label use has been reported for cerebral aneurysms in most cerebrovascular territories with a parent vessel diameter of 2-5 mm 6,9,10,16,18,21,26,47,73,94,107,120,121) .…”

“…In a subgroup analysis comparing https://doi.org/10.3340/jkns.2020.0034 endovascular reconstruction to FDS treatment, there was a significantly higher occlusion rate in the FDS subgroup (90.8% vs. 67.9%, p=0.03). Bhogal et al 10) reported their single center experience with FDS in 56 non-saccular posterior circulation aneurysms. Among dolichoectatic aneurysms the complete occlusion rate was 66.6% while complete occlusion was achieved in 75% of fusiform aneurysms.…”