Figure 1
CT, MIP (sagital)
Circumferential calcification in the proximal descending thoracic aorta.
Chronic posttraumatic aortic pseudoaneurysm
SectionChest imaging
Case TypeClinical Cases
AuthorsSantos R, Marques H.
Connected authors
45 years, male
Clinical History
A 45 year old man was referred to CT examination in the diagnostic work-up for a solitary pulmonary nodule. He had no remarkable past personal history, other than a motor vehicle accident 20 years earlier.
Imaging Findings
A 45 year old man was referred to CT examination in the diagnostic work-up for a solitary pulmonary nodule. He had no remarkable past personal history, other than a motor vehicle accident 20 years earlier, without recognisable complications at the time.
Thoracic CT examination was performed and a small, peripheral nodule was found in the posterior segment of the right lower lobe. Additionally, near the aorthic isthmus, in the proximal descending aorta, a saccular aneurysm was identified, whith circumferential parietal calcification.
Thoracic CT examination was performed and a small, peripheral nodule was found in the posterior segment of the right lower lobe. Additionally, near the aorthic isthmus, in the proximal descending aorta, a saccular aneurysm was identified, whith circumferential parietal calcification.
Discussion
Blunt aortic injury is a significant cause of death in trauma patients, estimated to occur in 10–20% of all high-speed deceleration fatalities [1]. It is immediately fatal in 80–90% of cases and most deaths (85%) occur at the scene of the accident [1].
In those patients who initially survive, mortality is high if it goes undetected and increases over time, ranging from 30% mortality at 6 h, to 50% at 24 h and 90% at 4 months [3]. Only 2% of patients with untreated traumatic aortic injury survive long enough to develop a chronic pseudoaneurysm [2].
Posttraumatic aortic aneurysms are typically located at the ligamentum arteriosum, at the aortic isthmus in the proximal descending thoracic aorta and are frequently calcified [2, 3]. There are 2 types of focal dilatation of a blood vessel: true aneurysms, which involve all layers of the vessel wall, and false aneurysms or pseudoaneurysms, which are secondary to dilatation of the outer layers of the vessel wall. Generally, there is a focal penetration of the intima and media, in the context of trauma, surgery, infection, or atherosclerosis. Nevertheless, the adventitia and perivascular connective tissue are spared and contain the process, preventing rupture and exsanguination [4].
Surgery or endovascular stenting is recommended for posttraumatic aortic pseudoaneurysms because these lesions may undergo delayed rupture [5].
Due to the typical location (proximal descending thoracic aorta, near the aortic isthmus) and presentation of the aneurysm (saccular aneurysm with circumferential calcification), and the past history of the patient, the aneurysm was atributted to a deceleration injury from the motor vehicle accident the patient had suffered twenty years before and the patient was proposed for pseudoaneurysm repair.
In those patients who initially survive, mortality is high if it goes undetected and increases over time, ranging from 30% mortality at 6 h, to 50% at 24 h and 90% at 4 months [3]. Only 2% of patients with untreated traumatic aortic injury survive long enough to develop a chronic pseudoaneurysm [2].
Posttraumatic aortic aneurysms are typically located at the ligamentum arteriosum, at the aortic isthmus in the proximal descending thoracic aorta and are frequently calcified [2, 3]. There are 2 types of focal dilatation of a blood vessel: true aneurysms, which involve all layers of the vessel wall, and false aneurysms or pseudoaneurysms, which are secondary to dilatation of the outer layers of the vessel wall. Generally, there is a focal penetration of the intima and media, in the context of trauma, surgery, infection, or atherosclerosis. Nevertheless, the adventitia and perivascular connective tissue are spared and contain the process, preventing rupture and exsanguination [4].
Surgery or endovascular stenting is recommended for posttraumatic aortic pseudoaneurysms because these lesions may undergo delayed rupture [5].
Due to the typical location (proximal descending thoracic aorta, near the aortic isthmus) and presentation of the aneurysm (saccular aneurysm with circumferential calcification), and the past history of the patient, the aneurysm was atributted to a deceleration injury from the motor vehicle accident the patient had suffered twenty years before and the patient was proposed for pseudoaneurysm repair.
Differential Diagnosis List
Chronic posttraumatic aortic pseudoaneurysm
Final Diagnosis
Chronic posttraumatic aortic pseudoaneurysm
References
[1] Bruckner BA, DiBardino DJ, Cumbie TC, Trinh C, Blackmon SH, Fisher RG, Mattox KL, Wall MJ. Critical evaluation of chest computed tomography scans for blunt descending thoracic aortic injury. Ann Thorac Surg. 2006 81 (4):1339-46. (PMID: 16564268)
[2] Steenburg SD, Ravenel JG. Multi-detector computed tomography findings of atypical blunt traumatic aortic injuries: a pictorial review. Emerg Radiol. 2007 Jul;14(3):143-50. (PMID: 17564733)
[3] Van Hise ML, Primack SL, Israel RS, Müller NL. CT in blunt chest trauma: indications and limitations. Radiographics. 1998 Sep-Oct;18(5):1071-84. (PMID: 9747608)
[4] Moktassi A, Merchant N, Konen E. Magnetic resonance imaging of thoracic aortic pseudoaneurysm. Can Assoc Radiol J. 2006 Oct;57(4):238-45. (PMID: 17128892)
[5] Demers P, Miller C, Scott Mitchell R, Kee ST, Lynn Chagonjian RN, Dake MD. Chronic traumatic aneurysms of the descending thoracic aorta: mid-term results of endovascular repair using first and second-generation stent-grafts. Eur J Cardiothorac Surg. 2004 Mar;25(3):394-400. (PMID: 15019666)
Case information
| URL: | https://eurorad.org/case/7147 |
| DOI: | 10.1594/EURORAD/CASE.7147 |
| ISSN: | 1563-4086 |
Figure 2
CT image, MIP
A saccular aneurysm with circumferential parietal calcification in the proximal descending thoracic aorta.
Figure 3
Axial contrast-enhanced CT image
Aneurysm with circumferential parietal calcification at the proximal descending thoracic aorta.
Figure 4
Axial contrast-enhanced CT image
A saccular aneurysm with circumferential parietal calcification at the undersurface of the proximal descending thoracic aorta.
CT, MIP (sagital)
Circumferential calcification in the proximal descending thoracic aorta.
CT image, MIP
A saccular aneurysm with circumferential parietal calcification in the proximal descending thoracic aorta.
Axial contrast-enhanced CT image
Aneurysm with circumferential parietal calcification at the proximal descending thoracic aorta.
Axial contrast-enhanced CT image
A saccular aneurysm with circumferential parietal calcification at the undersurface of the proximal descending thoracic aorta.