I saw a patient recently that made me think about something an attending in medical school had told me — that in children perhaps even moreso than adults, a seatbelt sign on the neck was concerning for the presence of blunt vascular injury, e.g. dissection or pseudoaneurysm or some other kind of damage to the carotid or vertebral arteries, and that this meant you should strongly consider CT angiography in these patients.
The patient in question was well-appearing, otherwise neurologically totally intact, smiling and playful, and had strong pulses in all her extremities. But on the sides of her neck, initially concealed under the cervical immobilization collar, were two nasty-looking abrasions with underlying ecchymoses left by her five-point restraint seat. Did we need to order a CTA on this kid?
I turned to PubMed for some help with this question, and found this article by Desai and colleagues in which they reviewed ten years worth of data in which patients from a few months to 17 years underwent CT Aniography of the neck. There were 85 MVC patients, 42 had a documented cervical seatbelt signs, and none of these had BCVI (positive predictive value = 0). None of the 3 MVC patients who DID have BCVI had a documented cervical seatbelt sign. 22 MVC had “some form of soft-tissue injury to the neck that was not specifically listed as a seatbelt sign”. Of these 22 patients, the one who later died from “severe cerebral edema and hemorrhage with probable upper cervical cord transection, met multiple criteria (EAST criteria) for screening, including a GCS score of 3 and a C4–C5 fracture dislocation injury.”
While this is subject to the same problems as all retrospective database dregs, it is certainly reassuring to know that the majority of children with soft tissue injuries to the neck in an MVC do not end up having a cervical artery or carotid dissection, and that when those things exist, there are often other abnormal findings on exam (e.g. diminished GCS or focal neurologic deficits). This is consistent with other literature describing neurologic emergencies (which dissections in the neck often accompany) in the setting of trauma. My takeaway is that while a seatbelt sign (or any other mark) on the neck should make you consider blunt vascular injury, the idea that it mandates CT of the neck is not supported by this center’s experience and especially given the radiosensitivity of the developing thyroid clinicians should be thoughtful about their imaging in this context.