Operative Nuances of Blind Catheterization of Occluded Sinuses Using Negative Road Map Technique: 2-Dimensional...

Dural arteriovenous fistula (DAVF) are often treated with endovascular transvenous embolization. DAVFs though, are often associated with intracranial venous sinus occlusion, which limits the transvenous route.  Here, we present the operative nuances of blind catheterization of an occluded dural venous sinus in 2 different cases with DAVF. First case is a 72-yr-old patient with indirect right carotid-cavernous fistula associated with an occluded inferior petrosal sinus, with severe orbital congestion. Second patient is a 79-yr-old patient with a new external carotid to a trapped transverse sinus fistula (Cognard IIA + B), extensive cortical venous reflux in the setting of an occluded sigmoid sinus. In both cases, the transarterial route was limited because of small arterial feeders thus, after obtaining patients' consent, we performed transvenous sacrifice of the isolated sinus. In both cases, the occluded sinus was transvenously blindly retrograde probed using a 0.035 inch Terumo Glidewire (Terumo Medical Corporation, Somerset, New Jersey). Once the occluded segment was probed, a dark roadmap was acquired with the wire in place. This created a negative roadmap once the guidewire is removed. This negative roadmap is used to navigate the microcatheter-microwire into the isolated sinus. In the first case, the cavernous sinus and the superior ophthalmic veins were sacrificed with coils. In the second patient, the entrapped left transverse sinus was embolized using Onyx. In both cases, complete occlusion of the fistula was attained.  In this neuroendovascular video, we demonstrate the nuances of blind catheterization of an occluded sinus using a negative roadmap technique as guidance for the micro-catheterization.  Institutional Review Board approved. Patient consent not required due to retrospective nature of manuscript, based on medical chart and imaging reviews, anonymized in the video.