Isolated Mandibular Fractures and the Risk of Blunt Cerebrovascular Injuries
Studies published in the general surgery trauma literature (1, 2) suggest that mandible fractures resulting from blunt trauma are an indication for additional diagnostic tests to rule out blunt cerebrovascular injuries (BCVI, defined as injury to the carotid or vertebral arteries). The referenced studies are flawed because their patient populations include only patients with known BCVI, from which they assessed risk factors based on concomitant injuries. This approach fails to establish the true prevalence of BCVI in patients with mandibular fractures. These studies also included only those patients who were admitted to the hospital through the emergency department, excluding any patient who was seen in an outpatient clinic, discharged home from the emergency department, or transferred from an outside hospital. In this study, the records of all patients at Denver Health Medical Center and its associated community clinics diagnosed with a mandible fracture and/or BCVI during the period from January 1, 2010, to March 31, 2012, were reviewed. Patients who suffered a blunt force injury and were 18 years old or older were included, regardless of admission status. Records were excluded if the patient died in the emergency department, the visit was a follow-up for a previously diagnosed injury, the initial diagnosis was later refuted, or the injury was more than 3 days old. Patients were grouped according to facial fracture location (mandible, nasal, maxillary, orbital) and vascular injury location (vertebral artery, carotid artery). Facial fractures and/or BCVI were diagnosed during 1,661 separate patient encounters. Of that group, 15% (n=249) included an isolated mandible fracture without other facial fractures; 3.8% (n=63) included injury to the carotid artery; and 3.1% (n=51) encounters included injury to the vertebral artery. Of the 249 isolated mandible fractures, 1.6% (n=4) were diagnosed with a BCVI. Based on these results, we recommend against including mandible fractures as absolute indicators for angiography, including computed tomographic angiography, to rule out BCVI. In deciding whether to test for BCVI, the mechanism and severity of injury to the head, face, and neck should be weighed against the radiation exposure, intravenous contrast load, expense, and the potential for false positive or incidental findings.
References
1) J Trauma Acute Care Surg. 2012 Feb; 72(2):330-337. Blunt cerebrovascular injuries: redefining screening criteria in the era of noninvasive diagnosis. Burlew CC, Biffl WL, Moore EE, Barnett CC, Johnson JL, Bensard DD.
2) J Trauma Injury, Infection, and Critical Care. 2009 December; 67:1150-1153. Western Trauma Association Critical Decisions in Trauma: Screening for and Treatment of Blunt Cerebrovascular Injuries. Biffl WL, Cothren CC, Moore EE, Kozar R, Cocanour C, Davis JW, McIntyre RC Jr., West MA, Moore FA.