Introduction Indirect cavernous carotid fistulae (ICCFs) can present with insidious, non-specific symptoms and prove difficult to diagnose. This study evaluates associations among ICCF symptoms and angiographic findings.

Methods A retrospective analysis was performed of prospectively maintained records at four medical centers to identify patients with ICCFs evaluated with angiography. Patient demographics, symptoms, and angiographic findings were tabulated. Univariate and multivariate analyses were conducted to identify associations among these variables.

Results Records sufficient for review existed for 267 patients evaluated with angiography. Patients were most commonly women, in the sixth or seventh decade of life, and had symptoms for months before a definitive diagnosis. The most common symptoms included proptosis, diplopia, cranial nerve palsy, and chemosis. Cortical venous reflux was most common in patients with chemosis, orbital pain, or bruit. Intracranial hemorrhage was associated with cortical reflux and bilateral inferior petrosal sinus occlusion. Patients with loss of symptoms demonstrated higher rates of inferior petrosal sinus occlusion and a trend towards rupture.

Conclusion A high index of suspicion is needed to promptly diagnose patients with ICCFs. High risk features are more common in the setting of chemosis, orbital pain, bruit, or spontaneous loss of symptoms. Patients with such symptoms warrant expedited angiographic evaluation.