Multimodality Imaging and Management of a Giant Vertebral Artery Pseudoaneurysm: A Case Report and Review of Literature.

Vertebral artery pseudoaneurysms (VAPAs) are rare but life-threatening lesions that present significant diagnostic and therapeutic challenges. Often resulting from trauma, infection, or iatrogenic injury, VAPAs can lead to severe morbidity due to their risk of rupture. This case report highlights a delayed diagnosis of VAPA in a male patient in his sixties presenting with recurrent falls, dysarthria, and bilateral limb paresthesia. Despite initial magnetic resonance imaging (MRI) findings suggestive of a nerve sheath tumor, subsequent computed tomography angiography (CTA) revealed a giant, partially thrombosed right VAPA. Advanced imaging techniques such as MRI and CTA were critical in accurately diagnosing this pseudoaneurysm. While MRI provided detailed soft tissue contrast, its interpretation was challenging. CTA offered clearer delineation of vascular structures, enabling better diagnostic accuracy and treatment planning. The patient underwent successful endovascular treatment with balloon test occlusion (BTO) and coiling, resulting in aneurysm occlusion while preserving the posterior circulation. Follow-up MRI, magnetic resonance angiography (MRA), and CTA confirmed stability post-procedure. This case underscores the importance of multimodal imaging for the accurate diagnosis of VAPAs. Additionally, it highlights the utility of endovascular approaches, including vessel sacrifice and coiling, in managing giant VAPAs. Tailored treatment strategies, based on vascular anatomy and collateral circulation, remain critical to optimizing patient outcomes.