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Chronic Posttraumatic Pseudoaneurysm of the Thoracic Aorta
Chronic Posttraumatic Pseudoaneurysm of the Thoracic Aorta Igor Pozek, MD, Christopher J. Hurt, MD, and Eric J. Stern, MD
A previously healthy 75-year-old male pedestrian was hit by a car. An initial chest radiograph demonstrated a round “mass” with peripheral calcifications in the aortopulmonary window suggestive of a saccular aneurysm (Fig 1). Computed tomographic (CT) angiography of the chest performed to evaluate the mediastinum (Fig 2) revealed a sharply marginated and smooth-walled, peripherally calcified 3-cm saccular aneurysm along the anteromedial wall of an otherwise normal-appearing, postisthmic descending thoracic aorta. Blood pressure, temperature, serum glucose, triglycerides, and cholesterol were normal. Syphilis serology was nonreactive. Upon further inquiry, the patient revealed that 50 years previously, he sustained multiple chest and head injuries as an unrestrained driver in a high-speed motor-vehicle crash. High-energy deceleration injuries of the thoracic aorta are associated with high mortality. Among longterm survivors, only 2%-5% of traumatic aortic injuries fail initial detection and are discovered later as chronic pseudoaneurysms.1 Typically, chronic posttraumatic aneurysms progressively enlarge and rupture.2 Serendipitous diagnosis is common with a pseudoaneurysm discovered years later on imaging usually performed for unrelated reasons. Potential symptoms associated with chronic pseudoaneurysm are those of any anteroposterior window mass, including chest pain, dysphagia, hoarseness (recurrent laryngeal nerve irritation), and dyspnea or cough due to bronchial or From the Department of Radiology, University of Washington School of Medicine, Harborview Medical Center, Seattle, WA. Current address of Igor Pozek: University Hospital of Respiratory and Allergic Diseases, SI-4202 Golnik, Slovenia. Current address of Christopher J. Hurt: Virtual Radiologic Corporation, Minneapolis, MN. Reprint requests: Igor Pozek, MD, Bolnisnica Golnik KOPA, Golnik 36, 4204 Golnik, Slovenia. E-mail: [email protected]. Curr Probl Diagn Radiol 2012;41:126-127. © 2012 Mosby, Inc. All rights reserved. 0363-0188/$36.00 ⫹ 0 doi:10.1067/j.cpradiol.2011.07.024
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FIG 1. Supine chest radiograph of 75-year-old man with a history of blunt chest trauma 50 years ago is notable for a calcified mass overlying aortopulmonary window.
tracheal compression. Hemoptysis is a rare heraldic and ominous manifestation of aortobronchial fistula.1,2 Due to the risk of rupture, most patients with chronic traumatic pseudoaneurysms are definitively treated. Open surgery with graft placement and/or direct suturing is generally indicated for symptomatic patients or for patients with documented aneurysm growth. Endovascular treatment results are satisfactory, but exhibit limited durability, therefore this treatment is reserved for patients with prohibitive operative risk or limited life expectancy.3 Asymptomatic aneurysms detected 2 years or later after the initial trauma can be safely monitored for symptomatic development or radiographic change.4 Chest radiographs of chronic posttraumatic pseudoaneurysms usually demonstrate ring-like calcification and/or a convex mass in the aortopulmonary window region. Small, nonccalcified aneurysms may be poorly characterized on chest radiographs.1 Thoracic CT typically reveals calcification in saccular
Curr Probl Diagn Radiol, July/August 2012
aneurysms projecting from the medial wall of the proximal descending thoracic aorta, even when calcification is not shown on chest radiographs.1 Posttraumatic pseudoaneurysms must be distinguished from saccular aneurysms due to atherosclerosis (including penetrating ulcers of the descending aorta), infection (mycotic), and vasculitis. Traumatic pseudoaneuryms are similar in appearance to atherosclerotic saccular aneurysms, except for their location at the isthmus and absence of significant atherosclerosis or luminal dilation in the adjacent aorta. Likewise, an isthmic location and peripheral calcifications are much less common in infected and vasculitic saccular aneurysms, and infected aneurysms often show lobulations and adjacent signs of inflammation on CT (adjacent edema or gas) or activity accumulation on labeled white cell scintigraphy.5 In most cases, CT angiography unequivocally confirms the diagnosis of posttraumatic pseudoaneurysm.
REFERENCES 1. Gundry SR, Burney RE, Mackenzie JR, et al. Traumatic pseudoaneurysms of the thoracic aorta. Anatomic and radiologic correlations. Arch Surg 1984;119:1055-60. 2. Finkelmeier BA, Mentzer RM Jr, Kaiser DL, et al. Chronic traumatic thoracic aneurysm. Influence of operative treatment on natural history: An analysis of reported cases, 1950-1980. J Thorac Cardiovasc Surg 1982;84:257-66. 3. Demers P, Miller C, Scott Mitchell R, et al. Chronic traumatic aneurysms of the descending thoracic aorta: Mid-term results of endovascular repair using first and second-generation stentgrafts. Eur J Cardiothorac Surg 2004;25:394-400.
FIG 2. Thoracic CT angiogram. (A) Axial image shows sharply marginated, peripherally calcified pseudoaneurysm of descending thoracic aorta. (B) Sagittal oblique reformation shows calcified saccular pseudoaneurysm along proximal descending aorta.
Curr Probl Diagn Radiol, July/August 2012
4. Kondo N, Koyama M, Wakayama F, et al. Surgical repair for chronic traumatic thoracic aneurysm after 12-year follow-up. Jpn J Thorac Cardiovasc Surg 2004;52:586-8. 5. Macedo TA, Stanson AW, Oderich GS, et al. Infected aortic aneurysms: Imaging findings. Radiology 2004;231:250-7.
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A previously healthy 75-year-old male pedestrian was hit by a car. An initial chest radiograph demonstrated a round “mass” with peripheral calcifications in the aortopulmonary window suggestive of a saccular aneurysm (Fig 1). Computed tomographic (CT) angiography of the chest performed to evaluate the mediastinum (Fig 2) revealed a sharply marginated and smooth-walled, peripherally calcified 3-cm saccular aneurysm along the anteromedial wall of an otherwise normal-appearing, postisthmic descending thoracic aorta. Blood pressure, temperature, serum glucose, triglycerides, and cholesterol were normal. Syphilis serology was nonreactive. Upon further inquiry, the patient revealed that 50 years previously, he sustained multiple chest and head injuries as an unrestrained driver in a high-speed motor-vehicle crash. High-energy deceleration injuries of the thoracic aorta are associated with high mortality. Among longterm survivors, only 2%-5% of traumatic aortic injuries fail initial detection and are discovered later as chronic pseudoaneurysms.1 Typically, chronic posttraumatic aneurysms progressively enlarge and rupture.2 Serendipitous diagnosis is common with a pseudoaneurysm discovered years later on imaging usually performed for unrelated reasons. Potential symptoms associated with chronic pseudoaneurysm are those of any anteroposterior window mass, including chest pain, dysphagia, hoarseness (recurrent laryngeal nerve irritation), and dyspnea or cough due to bronchial or From the Department of Radiology, University of Washington School of Medicine, Harborview Medical Center, Seattle, WA. Current address of Igor Pozek: University Hospital of Respiratory and Allergic Diseases, SI-4202 Golnik, Slovenia. Current address of Christopher J. Hurt: Virtual Radiologic Corporation, Minneapolis, MN. Reprint requests: Igor Pozek, MD, Bolnisnica Golnik KOPA, Golnik 36, 4204 Golnik, Slovenia. E-mail: [email protected]. Curr Probl Diagn Radiol 2012;41:126-127. © 2012 Mosby, Inc. All rights reserved. 0363-0188/$36.00 ⫹ 0 doi:10.1067/j.cpradiol.2011.07.024
126
FIG 1. Supine chest radiograph of 75-year-old man with a history of blunt chest trauma 50 years ago is notable for a calcified mass overlying aortopulmonary window.
tracheal compression. Hemoptysis is a rare heraldic and ominous manifestation of aortobronchial fistula.1,2 Due to the risk of rupture, most patients with chronic traumatic pseudoaneurysms are definitively treated. Open surgery with graft placement and/or direct suturing is generally indicated for symptomatic patients or for patients with documented aneurysm growth. Endovascular treatment results are satisfactory, but exhibit limited durability, therefore this treatment is reserved for patients with prohibitive operative risk or limited life expectancy.3 Asymptomatic aneurysms detected 2 years or later after the initial trauma can be safely monitored for symptomatic development or radiographic change.4 Chest radiographs of chronic posttraumatic pseudoaneurysms usually demonstrate ring-like calcification and/or a convex mass in the aortopulmonary window region. Small, nonccalcified aneurysms may be poorly characterized on chest radiographs.1 Thoracic CT typically reveals calcification in saccular
Curr Probl Diagn Radiol, July/August 2012
aneurysms projecting from the medial wall of the proximal descending thoracic aorta, even when calcification is not shown on chest radiographs.1 Posttraumatic pseudoaneurysms must be distinguished from saccular aneurysms due to atherosclerosis (including penetrating ulcers of the descending aorta), infection (mycotic), and vasculitis. Traumatic pseudoaneuryms are similar in appearance to atherosclerotic saccular aneurysms, except for their location at the isthmus and absence of significant atherosclerosis or luminal dilation in the adjacent aorta. Likewise, an isthmic location and peripheral calcifications are much less common in infected and vasculitic saccular aneurysms, and infected aneurysms often show lobulations and adjacent signs of inflammation on CT (adjacent edema or gas) or activity accumulation on labeled white cell scintigraphy.5 In most cases, CT angiography unequivocally confirms the diagnosis of posttraumatic pseudoaneurysm.
REFERENCES 1. Gundry SR, Burney RE, Mackenzie JR, et al. Traumatic pseudoaneurysms of the thoracic aorta. Anatomic and radiologic correlations. Arch Surg 1984;119:1055-60. 2. Finkelmeier BA, Mentzer RM Jr, Kaiser DL, et al. Chronic traumatic thoracic aneurysm. Influence of operative treatment on natural history: An analysis of reported cases, 1950-1980. J Thorac Cardiovasc Surg 1982;84:257-66. 3. Demers P, Miller C, Scott Mitchell R, et al. Chronic traumatic aneurysms of the descending thoracic aorta: Mid-term results of endovascular repair using first and second-generation stentgrafts. Eur J Cardiothorac Surg 2004;25:394-400.
FIG 2. Thoracic CT angiogram. (A) Axial image shows sharply marginated, peripherally calcified pseudoaneurysm of descending thoracic aorta. (B) Sagittal oblique reformation shows calcified saccular pseudoaneurysm along proximal descending aorta.
Curr Probl Diagn Radiol, July/August 2012
4. Kondo N, Koyama M, Wakayama F, et al. Surgical repair for chronic traumatic thoracic aneurysm after 12-year follow-up. Jpn J Thorac Cardiovasc Surg 2004;52:586-8. 5. Macedo TA, Stanson AW, Oderich GS, et al. Infected aortic aneurysms: Imaging findings. Radiology 2004;231:250-7.
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