Differences in Clinical Features Between Osseous and Nonosseous Arteriovenous Fistulas in the Cavernous Sinus

Although the characteristics of osseous shunted pouches of cavernous sinus (CS) arteriovenous fistula (AVF) have recently been a focus of investigation, few studies have reported details of CS AVF possessing nonosseous shunted pouches. We therefore compared detailed characteristics between osseous and nonosseous AVFs in the CS.

A total of 31 patients who underwent rotational angiography in our department between 2012 and 2023 were reviewed. We divided anatomical shunted pouches into 3 types: extraosseous, intraosseous, and mixed. We analyzed and compared characteristics and treatment results between types.

Of the 31 CS AVF patients, 14 showed extraosseous type, 10 showed mixed type, and 7 showed intraosseous type. The mean ages of patients with these types were 70.0 ± 7.9 years, 73.6 ± 8.5 years, and 76.9 ± 5.3 years, respectively, showing no significant differences. However, when limited to female patients, the mean ages were 68.3 ± 6.0 years, 75.1 ± 3.4 years, and 76.9 ± 5.3 years, respectively, showing significant differences among types. The number of single shunts was significantly lower with mixed type, and the incidence of cortical venous reflux was significantly lower with extraosseous type. Ten cases of extraosseous type (71%), 7 cases of mixed type (70%), and 5 cases of intraosseous type (71%) were treated with selective transvenous embolization of the shunted pouch. Ten extraosseous-type cases (71%), 5 mixed-type cases (50%), and 6 intraosseous-type cases (86%) were completely occluded by embolization.

Restricted to women, high age was significantly associated with intraosseous-type CS AVF. Although significant differences were evident in the number of shunted pouches and incidence of cortical venous reflux among groups, treatment method did not depend on the type of CS AVF.