Anatomical Preservation and Function of the Cavernous Sinus in Direct Carotid-cavernous Fistulas: Approach to the “Sinusoid Directly Involved” with One or Two Coils & Onyx

Abstract

Direct Carotid-cavernous fistulas (CCFs) are abnormal communications, and they can contain an anomalous fistulous duct. There are several techniques to treat CCFs. Notwithstanding, they can be associated with some complications (ocular motor paralysis, painful ophthalmoplegia, ischemic stroke). Direct CCFs are related to one or more venous sinusoids of the cavernous sinus. Combining Onyx with coils through the transarterial route for direct CCFs is a known technique. Still, it has few descriptions, and no studies mention the sinusoid directly involved (SDI). Here, we represent and expound on the SDI in CCFs not previously described approached with only 1–2 Coils and Onyx. A retrospective database of patients who underwent endovascular transarterial approach of CCFs from 2010 to 2020. All cases were treated using only 1 or 2 Coils over the SDI in arterial-venous shunt and Onyx in the interstitial gaps it leaves. During the Endovascular procedure, the angiographic frame rate was 30 per second for adequate recognition of the SDI. We examined nine patients, eight male, and one female, with a mean age of 36.1 (15–64) years, with direct CCF detected by angiography. All were managed via transarterial endovascular, approaching the SDI/s, with only 1 (55%) or 2 (44%) Coils and approximately 0.92 (0.6–1.2) ml of Onyx. All of them presented neuro-ophthalmic symptoms and signs, such as proptosis (100%), chemosis (66%), diplopia (11%), and ptosis (11%). Cranial nerve involvement was found in 5 patients (55%), with the compromise of the III (40%) and IV (20%), respectively. The mean duration of the procedures was 156 (76–240) minutes. Without new neurological deficits after the endovascular procedure, with remission of 100% of the symptoms and improvement of visual acuity in (88%) at 6-month of follow-up. From the beginning of surgical treatment of CCFs, several types of endovascular treatments appear for CCFs. Nevertheless, it may be associated with complications during or after the Endovascular procedure or even compromise the CS anatomy with adjacent neurovascular structures. Therefore, only approaching the SDIs that it is proximal to the internal carotid artery preserves this anatomy of the CS. The endovascular technique that we described emphasizes recognizing this Sinusoid to be approached. Understanding perfectly the cavernous anatomy and the endovascular anatomical concept of “Sinusoid directly involved” allows an approach to this little CS compartment with only 1 or 2 Coils and Onyx, reducing costs, with a low incidence of complications and relapses.