High Resistance Index in the Feeding Arteries of Indirect Carotidcavernous Fistulae: A Diagnostic Pitfall.

Abstract

Carotid-cavernous fistulae (CCFs) are classified into the direct and indirect types, which can be attributed to trauma, atherosclerosis, hypertension, diabetes mellitus, pregnant or postmenopausal status(1). Cerebral angiography is the gold standard for the diagnosis of CCFs. Doppler ultrasound, which typically reveals increased blood flow velocity and decreased resistance index (RI) in the feeding arteries, can assist in the diagnosis(2-3). We herein report a case of indirect CCF presenting with high RI in the feeding arteries, which is mainly attributed to the generalized atherosclerotic change, and is regarded as a diagnostic pitfall of the CCFs.