Incidence of unsuspected blunt carotid artery injury

This study attempts to document the incidence of unsuspected blunt carotid artery injury (BCI) in a prospective series of consecutive blunt trauma patients undergoing angiographic evaluation of the aorta. Previous studies have included mainly patients who became symptomatic from BCI, thus documenting a "detected incidence."

During a 22-month period, all patients undergoing angiographic evaluation of the aorta after blunt trauma who were not felt to be at increased risk for BCI were included in the screening protocol. All patients initially suspected of BCI were studied outside the protocol. Angiographic evaluation of the carotid arteries was performed using nonselective contrast injections after aortic injury had been ruled out.

The incidence of BCI among those patients screened under the protocol (n = 119) was 2.5% (3 of 119). Among all patients undergoing aortic evaluation at presentation (n = 171), the detected incidence of BCI was 3.5% (6 of 171). The detected incidence of BCI among all patients during the study period was 0.32% (10 of 3174). No risk factors for BCI were identified beyond the severity of trauma that led to aortic evaluation.

The incidence of BCI found in those patients screened in this study, nearly 10 times the incidence of BCI in our blunt trauma population overall, suggests that these patients represent a subgroup on which to focus screening efforts, regardless of the diagnostic tools employed. The similarity between the angiographic incidence and the detected incidence of BCI in this study argues that few BCIs remain asymptomatic. All blunt trauma patients injured sufficiently to prompt aortic evaluation at presentation should be screened in some manner for BCI.