A grading system for intracranial arteriovenous malformations applicable to endovascular procedures

A grading system was designed by the first author (B.S.) specifically to predict the difficulty of endovascular obliteration of an intracranial arteriovenous malformation based on the feeding arterial characteristics, and the venous drainage system. We have retrospectively reviewed our cases of intracranial arteriovenous malformation, with special interest in those underwent endovascular embolization. The grading of the AVM was by either our new proposed system or by a surgically oriented grading system. Both systems were compared from the endovascular point of view. Using the present proposed grading system intracranial arteriovenous malformation may range from grade I to grade V. The difficulty of the endovascular embolization correlated well with the new grading system, while in most cases it did not reflect the degree of difficulty of the procedure when a pure surgical grading system was used. This newly designed grading system has a better prediction value to the difficulty of performing endovascular embolization than does other grading systems.