Prediction of traumatic carotid-cavernous sinus fistula via noncontrast computed tomography by fracture pattern and abnormality of venous system

BACKGROUND Traumatic carotid-cavernous sinus fistula (tCCF) is infrequent but with high morbidity if delayed diagnosed or managed. Because of the lack of screening criteria and requirement of advanced and invasive radiological examinations, diagnosis is often delayed or underdiagnosed. METHODS A matched case-control study with univariate and multivariate analyses was conducted to predict tCCFs. Forty-six patients diagnosed with tCCFs were included and matched with 138 patients of craniofacial trauma without tCCF as control at a ratio of 1:3. RESULTS The diagnostic diameter of superior ophthalmic vein (SOV) in tCCF was 4 mm with area under curve of 0.89. In multivariate analysis, engorgement of SOV and cavernous sinus (odds ratio [OR], 35.39; 95% confidence interval [CI], 13.56-104.84; p < 0.001) and lateral impact (ipsilateral temporal and sphenoid sinus fractures) (OR, 3.96; 95% CI, 1.10-14.91; p = 0.028) were identified significant, whereas basilar skull fracture (OR, 1.58; 95% CI, 0.53-4.75; p = 0.300) and injuries to ocular nerves (cranial nerves III, IV, and VI) (OR, 1.77; 95% CI, 0.38-7.88; p = 0.055) were insignificant. CONCLUSION Presence of SOV or cavernous sinus engorgement on noncontrast computed tomography and lateral impact were demonstrated as independent predictors to tCCF and warrant further radiological evaluation. Injury to ocular nerves is not predictive but as an essential differential diagnosis with reversible outcome. LEVEL OF EVIDENCE Diagnostic, level III.