Article Text
Abstract
A 29-year-old man crashed at high speed into another vehicle at traffic lights. He was able to get out of his van but then collapsed after running a few metres. On arrival in the emergency department he was conscious, with a pulse of 140 beats/min and blood pressure of 110/32 mm Hg. He had collapsing arterial pulses and an early diastolic murmur. He had a chest radiograph (figure 1A) and a skeletal survey which demonstrated multiple fractures, involving his left hand, right femur, right calcaneus, and left first and second ribs. A CT scan of the thorax was performed with a radiological contrast agent but without gated images because of the tachycardia (Figure 1B). The blood pressure and pulse were attributed to blood loss into the right thigh. Urgent cardiology review and bedside echocardiography were requested before he had emergency orthopaedic surgery (figure 1C, D) (online supplementary video 1).
Supplementary file 1
Question What is the most likely diagnosis?
Traumatic dissection of the aortic root.
Subaortic membrane or diaphragm.
Traumatic transection of the aorta.
Traumatic rupture of the aortic valve.
Myocardial rupture.
- valvular heart disease
- aortic regurgitation
- cardiac imaging and diagnostics
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Answer: D
Acute deceleration injury typically transects the upper descending thoracic aorta beyond the left subclavian artery, not the proximal aorta. Spontaneous dissection involving the proximal aorta may raise an intimal flap that prolapses through the aortic valve causing severe regurgitation, but blunt trauma causes rupture of vessels or myocardium rather than dissection.1 A congenital membrane in the outflow tract is usually less mobile than the structure seen in this case because of attachments to the septum and/or anterior mitral leaflet. Traumatic rupture of the myocardium would commonly be associated with a pericardial effusion, perhaps with tamponade; neither was observed. Colour flow demonstrated severe aortic regurgitation; the mechanism suggested by transoesophageal echocardiography and confirmed on surgical inspection was traumatic rupture of the aortic valve, with a linear tear of the free margin of the right coronary cusp and avulsion of half of the left coronary cusp along its base (online supplementary figure A,B and video 2). This complication is rare but well described.2 The valve was replaced with a mechanical prosthesis.
An ungated CT scan cannot exclude small aortic dissections or avulsion of a valve cusp. The initial report but not senior review overlooked air in the mediastinum and a small apical pneumothorax (online supplementary figure C); the chest radiograph had shown the same abnormalities. The widened mediastinum was attributed to oesophageal rupture with air in the mediastinum. A 5 mm posterior tear in the lower oesophagus was repaired the next day. The fractured femur was operated later, and the patient was discharged after 61 days.
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Footnotes
Contributors VS wrote the manuscript; AGF and MR reviewed and revised it.
Competing interests None declared.
Patient consent Not required.
Provenance and peer review Not commissioned; externally peer reviewed.