153 Carotid-Cavernous Fistula Causing Bradycardia Following Maxillofacial Trauma: A Case Report

A 53-year-old male presented to the local A&E department with a fractured mandible following a single punch to the lower face, and was admitted under Oral & Maxillofacial Surgery. A subsequent finding was chemosis, relative afferent pupillary defect, minimal soft exophthalmos, reduced visual acuity and colour vision in one eye, but with no associated trauma to the orbits. A CT scan showed no sign of other injury, no blood collection, and the small amount of orbital emphysema didn’t appear to be the cause of symptoms. A heart rate of 40bpm was observed, with ECG and telemetry ruling out cardiac causes of bradycardia. With this clinical picture and no orbital space occupying lesion or collection identified on the CT scan, an MRI of the head was requested, which showed superior ophthalmic vein occlusion, resulting in a diagnosis of a direct carotid-cavernous fistula (CCF). The proptosis increased slowly over 24 hours and became pulsatile. The patient was subsequently referred to the tertiary centre for treatment with endovascular embolisation using coils, which resulted in full resolution of the signs and symptoms. This case presents a rare acute presentation of CCF after indirect trauma. It is assumed that bradycardia was caused via the oculo-cardiac reflex. This presentation could have led to a clinical diagnosis of retrobulbar haemorrhage or tension pneumo-orbit, triggering surgical or needle decompression of the orbit. Such treatment would have had catastrophic consequences. This is a reminder to consider this rare diagnosis and cause of bradycardia after facial trauma.