Plug-and-Push Embolisation of a Tentorial Dural Arteriovenous Fistula Using Squid-18 and Squid-12

Dural arteriovenous fistulas (DAVFs) are abnormal shunts between meningeal arteries and dural venous sinuses or cortical veins. Lesions with cortical venous reflux carry a substantial risk of haemorrhage or non-haemorrhagic neurological deficit and therefore require prompt treatment. Endovascular embolisation using ethylene-vinyl alcohol copolymer (EVOH)-based liquid embolic agents is widely employed. Squid, a newer agent available in different viscosities, includes Squid-18 and the lower-viscosity Squid-12, which may improve distal penetration during embolisation. However, reports describing staged viscosity-based embolisation using Squid with the plug-and-push technique remain limited. A male in his 70s presented with several months of progressive unsteadiness culminating in a fall. Computed tomography demonstrated cerebellar calcifications without acute intracranial pathology, while MRI showed dilated cerebellar and perimesencephalic veins. Digital subtraction angiography confirmed a Cognard grade IV tentorial DAVF near the superior vermis, supplied by branches of both external carotid arteries, the left internal carotid artery, and the right vertebral artery, with cortical venous drainage into ectatic cerebellar veins. Endovascular embolisation was performed via the distal temporal branch of the left middle meningeal artery using a Marathon microcatheter. A plug-and-push technique was employed, with formation of an anti-reflux plug using Squid-18, followed by injection of Squid-12 to facilitate deeper penetration of the fistulous network. Complete angiographic occlusion was achieved without complications after a 90-minute embolisation. The patient's mobility improved significantly, and eight-month follow-up angiography demonstrated durable resolution. This case highlights the feasibility of staged viscosity-based embolisation using Squid-18 and Squid-12 to achieve effective occlusion of a complex tentorial DAVF.