Etiology of carotid cavernous fistula in Japanese

Background  A carotid cavernous fistula (CCF) develops spontaneously or after trauma, and older publications suggest that the majority of CCF cases are caused by trauma. However, more recent reports question the prevalence of CCFs caused by trauma. Methods  The clinical records of 37 consecutive patients diagnosed with a CCF were reviewed. The disease etiology, patient demographics, anatomical classification, and clinical course were investigated. Results  The CCF was spontaneous in 30 patients, and was related to head or neck trauma in seven patients. The mean age of all patients was 65.8 ± 10.5 years, and 30 (81.1%) were women. Eight had diabetes and 14 had hypertension. The major signs and symptoms were congestion (86.4%), diplopia (81.1%), bruit (59.5%), and headaches/orbital pain (62.2%). Exophthalmos (67.6%) and elevated intraocular pressure (40.5%) were also frequently noted. In the Barrow classification, seven patients were classified as type A, four as type B, three as type C, and 20 as type D. The classification could not be established in three patients who did not undergo angiography. Of note, almost all patients had consulted an ophthalmologist before the diagnosis. Conclusion  Spontaneous/low-flow CCF is more prevalent than previously reported. The role of ophthalmologists is important because the majority of patients initially consult ophthalmologists, and the signs of low-flow CCF are subtle and may be overlooked.