Targeted embolisation for coexisting conus medullaris arteriovenous malformation and cauda equina arteriovenous fistulas with a varix on a shared drainer ^†

Background: The coexistence of vascular malformations in the conus medullaris and cauda equina has been rarely reported, and the complex angioarchitecture in multiple arteriovenous lesions remains poorly understood. Case description: A 17-year-old woman presented with a sudden-onset, stepwise worsening of weakness and pain in the bilateral legs. Angiography revealed conus medullaris arteriovenous malformation and cauda equina arteriovenous fistulas. One of the drainers was shared between the coexisting lesions and harboured a varix. Targeted embolisation of a fistulous point in the conus lesion was performed with precaution to prevent occluding the common drainage route, which led to symptom improvement with angiographical diminishment of the varix. Conclusions: Recognising that communications between drainers can be observed in multiple spinal arteriovenous lesions is important in facilitating a safe embolisation. Cautious assessment of angiogram with fusion images of cone-beam computed tomography and volumetric T2 magnetic resonance imaging can help in establishing the diagnosis and treatment strategy.