A proposal for a new pial arteriovenous fistulas grading scale for neuroendovascular procedures and literature review

Pial arteriovenous fistulas are an unusual type of cerebrovascular lesion. The vascular supply of this type of injury comes from cortical and pial vessels which are not located in the dura leaflets. With the aim to make a grading scale for this type of injury, we conducted a literature search using the keywords "pial arteriovenous fistulas", "embolization" associated with "outcome". Angiographic and imagenological characteristics typically found in pial arteriovenous fistulas were taken and was developed a preliminary classification system that must be validated in future studies. Pial arteriovenous fistulas are associated with a poor natural history and the establishment of an individualized therapeutic strategy can provide a good prognosis. The endovascular management of these lesions is safe and effective.