Indications for alternative endovascular techniques in carotid-cavernous fistulas: A 20-year single-center experience

Abstract

Background: While coiling is considered the standard treatment for carotid-cavernous fistulas (CCFs), studies demonstrating excellent results using new materials, especially flow diverter (FD) stents and liquid embolisates, are becoming more frequent. The indications and effectiveness of these alternative endovascular techniques remain unclear.

Methods: A total of 22 direct and 20 indirect CCFs were included in the study. These were further subdivided based on the embolic material used: coils versus FD stents for direct and coils versus liquid embolisates for indirect CCFs. The subgroups were subjected to statistical analysis.

Results: An angiographic cure was achieved in 88% of all CCFs, 93% of patients' experienced clinical improvement or remained stable. Direct CCFs were treated with coiling (41%) or with both coils and FD stents (55%). One (4%) patient with a direct CCF was treated with FD stent alone. Statistical analysis comparing these subgroups revealed a significantly higher complete occlusion rate immediately after treatment in the coiling subgroup (67% vs. 23%, p = 0.0409). The occlusion rates at the last follow-up were similar (89% vs. 85%). Indirect CCFs were treated with coiling (35%) or liquid embolisates (65%). All three periprocedural ischemic complications were recorded within the liquid subgroup, resulting in a significantly higher clinical deterioration rate (p = 0.0333).

Conclusion: FD stents in direct and liquid embolisates in indirect fistulas did not demonstrate better angiographic or clinical outcomes compared to convetional coiling. Liquid agents carried a higher risk of ischemic complications. Alternative embolization materials should be reserved for CCFs that cannot be treated with simple coiling.

Keywords: Carotid-cavernous fistula; embolization; flow-diverter devices; liquid embolisates.

Figure 1.

Illustrative case of flow diversion in direct fistula. Upper left: postraumatic direct carotid-cavernous fistula shown on angiogram, anteroposterior view; upper right: unsatisfactory result after transarterial coiling (black arrow) with persistent high-flow venous drainage (empty arrows) shown on angiogram, anteroposterior view; lower left: anteroposterior X-ray scan after coiling (black arrow) and flow-diverter (white arrows) insertion; lower right: follow-up angiogram, anteroposterior view, demonstrating complete closure of the fistula.

Figure 2.

Ilustrative case of liquid embolic agent use in indirect fistula. Upper left: indirect carotid-cavernous fistula with superior ophthalmic vein drainage (black arrow) and cortical venous drainage (empty arrow), angiogram, lateral view; upper right: unsatisfactory result after transvenous coiling (white arrow) with persistent high-flow venous drainage (black arrow), angiogram, lateral view; lower left: subsequent use of liquid embolic agent (white arrows), angiogram, lateral view; lower right: Complete occlusion of the fistula on follow-up angiogram, lateral view.