Posterior condylar canal dural arteriovenous fistula: anatomical, symptomatological, and therapeutic considerations in comparison with hypoglossal canal dural arteriovenous fistula

Background Posterior condylar canal dural arteriovenous fistulas (dAVFs) are extremely rare.Methods We report a case series and literature review of posterior condylar canal dAVFs and discuss similarities and differences between posterior condylar and hypoglossal canal dAVFs with respect to the related vascular anatomy, angioarchitecture of the fistula, presentation, and treatment.Results Four cases of posterior condylar canal dAVF were identified at our institutions and six cases were identified in the literature. Posterior condylar canal dAVFs were predominantly frequent in relatively young women. All patients presented with pulsatile tinnitus. There was no history of hemorrhage as there was no cortical venous reflux. This is different from hypoglossal canal dAVFs which can present with myelopathy or hemorrhage from cortical venous reflux. Transvenous embolization was safe and eliminated the symptoms. Palliative transarterial embolization can be an option to mitigate the symptoms, although there is a potential risk of cranial nerve palsy or lateral medullary stroke.Conclusions Posterior condylar canal dAVFs are generally benign lesions. However, intolerable tinnitus may require intervention. Transvenous embolization is effective and safe.