The evolution of endovascular treatment of carotid cavernous fistulas: a single-center experience

Abstract

Objective: Carotid-cavernous fistulas (CCFs) are pathologic arteriovenous shunts between the carotid artery and cavernous sinus. The resulting venous congestion within the cavernous sinus accounts for the classic ocular symptoms associated with these lesions. Endovascular treatment of CCFs has evolved over time to include a variety of transarterial and transvenous embolization techniques. The present series comprises our institutional experience with the endovascular treatment of CCF.

Methods: We reviewed our prospectively maintained clinical database for patients with CCF who were evaluated between December 1995 and August 2012. Clinical and demographic data were extracted from medical records, operative notes, and radiographic reports. Cerebral angiograms were reviewed.

Results: The study included 100 (42 direct CCF [dCCF], 58 indirect [iCCF]) patients. Of the 42 patients with dCCF, endovascular treatment was possible in 40 (95%), with an overall 8% morbidity and 2% mortality. Before March 2004, dCCFs were primarily treated with the use of detachable balloons. After the withdrawal of detachable balloons from the market, coil embolization emerged as the first-line treatment. It was accomplished either transarterially or transvenously and often incorporated balloon or stent protection of the parent vessel. After initial treatment, 33 patients (82%) exhibited complete obliteration of their fistula, whereas an additional four (10%) patients demonstrated fistula thrombosis on follow-up angiography. Endovascular access was achieved in 48 (83%) of the 58 patients with iCCF. In this cohort, the morbidity rate was 8%, and there were no deaths. Transvenous approaches were used to treat 88% of these patients and included both transfemoral venous access to the cavernous sinus and direct access through the ophthalmic veins. Immediate fistula occlusion was observed in 37 (77%) patients, and 1 of the 11 patients with a residual fistula progressed to thrombosis on follow-up. Transarterial embolization alone was used in six cases, and five required combined transvenous/transarterial approaches.

Conclusions: For dCCF, the lack of availability of detachable balloons led to the adoption of both transarterial and transvenous coil embolization with adjunctive techniques of parent vessel protection. For iCCF, advances in techniques of venous access have facilitated treatment of lesions with restricted venous outflow. Treatment strategies for CCF continue to evolve with advances in endovascular techniques.

Keywords: CCF; Carotid-cavernous fistula; Direct CCF; EVOH; Embolization; Endovascular; Ethylene vinyl alcohol copolymer; ICA; Indirect CCF; Internal carotid artery; Transarterial; Transvenous; dCCF; iCCF.