Therapeutic Progress in Treating Vertebral Dissecting Aneurysms Involving the Posterior Inferior Cerebellar Artery

Abstract

Among the variations of vertebral artery dissecting aneurysms (VDAs), VDAs involving the posterior inferior cerebellar artery (PICA), especially ruptured and high-risk unruptured aneurysms, are the most difficult to treat. Because the PICA is an important structure, serious symptoms may occur after its occlusion. Retained PICAs are prone to re-bleeding because VDAs are difficult to completely occlude. There is therefore confusion regarding the appropriate treatment for VDAs involving the PICA. Here, we used the PubMed database to review recent research concerning VDAs that involve the PICA, and we found that treatments for VDAs involving the PICA include (i) endovascular treatment involving the reconstruction of blood vessels and blood flow, (ii) occluding the aneurysm using an internal coil trapping or an assisted bypass, (iii) inducing reversed blood flow by occluding the proximal VDA or forming an assisted bypass, or (iv) the reconstruction of blood flow via a craniotomy. Although the above methods effectively treat VDAs involving the PICA, each method is associated with both a high degree of risk and specific advantages and disadvantages. The core problem when treating VDAs involving the PICA is to retain the PICA while occluding the aneurysm. Therefore, the method is generally selected on a case-by-case basis according to the characteristics of the aneurysm. In this study, we summarize the various current methods that are used to treat VDAs involving the PICA and provide schematic diagrams as our conclusion. Because there is no special field of research concerning VDAs involving the PICA, these cases are hidden within many multiple-cases studies. Therefore, this study does not review all relevant documents and may have some limitations. Thus, we have focused on the mainstream treatments for VDAs that involve the PICA.

Treatment of Unruptured Vertebral Artery Aneurysm Involving Posterior Inferior Cerebellar Artery With Pipeline Embolization Device

“…The sacrifice of PICA will result in severe ischemic stroke and poor clinical outcome. Studies have shown that ischemic complications happened in 21.7% cases in which the PICA is sacrificed ( 8 ). When vertebral artery aneurysm involves the ostium of PICA, the treatment become complicated and challenging and the options are also limited ( 11 ).…”

“…Selection of appropriate treatment modalities for these lesions remains controversial, the most acceptable conventional endovascular methods include internal coil trapping with revascularization of PICA and stent-assisted coiling. However, each method has its own drawback and limitation in terms of retaining the patency of PICA ( 8 ). PED has emerged as a popular treatment option for intracranial aneurysms and achieved promising results ( 9 ).…”

Clinical importance of the occipital artery in vascular lesions: A review of the literature

“…Complex aneurysms of the PICA and VA sometimes require PICA revascularisation. 22 Even if there is a tumour at the craniovertebral junction, an OA-PICA bypass may be performed prior to the tumour resection to prevent ischaemic complications. 23 A 2017 study by Matsushima et al showed that an OA bypass to the p2-5 segments of the PICA was feasible.…”

Flow Diversion for Reconstruction of Intradural Vertebral Artery Dissecting Aneurysms Causing Subarachnoid Hemorrhage—A Retrospective Study From Four Neurovascular Centers

“…Depending on the hemodynamic situation in the posterior circulation and the localization of the ruptured dissecting aneurysm, different endovascular approaches must be considered ( 8 , 9 ). In case the rupture site is associated with a hypoplastic VA, segmental sacrifice, ideally sparing the posterior inferior cerebellar artery (PICA) orifice, has shown promising results ( 8 , 10 ). However, segmental sacrifice and proximal VA occlusion carry significant risk for ischemia and, in some cases, re-bleeding ( 11 ).…”