Type B (figure 1): The occlusion of the cervical ICA is not tapered but there is a stump where the proximal portion of the cervical ICA lumen is patent. In addition, the cavernous and/or petrous segment is reconstituted by either collaterals from the ECA and/or retrograde filling from the supraclinoid segment. This type is thought to be the second best after type A to technically revascularize using endovascular techniques.