Asian Cardiovasc Thorac Ann 1998;6:232-234
© 1998 Asia Publishing EXchange Pte Ltd
Giant Thoracic Aneurysm Associated with Coarctation of the Aorta
Mehmet 
ah Topcuo
lu, MD,
Orhan Kemal Salih, MD,
Bülent Kisacikolu, MD,
Cem Kayhan, MD,
Tümer Ulus, MD
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Department of Cardiovascular Surgery Faculty of Medicine, Çukurova University Adana, Turkey
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For reprint information contact: Mehmet ah Topcuolu, MD Department of Cardiovascular Surgery Faculty of Medicine Çukurova University Balcali, Adana 01330, Turkey Tel: 90 322 338 6627 Fax: 90 322 338 6656
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ABSTRACT
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A 39-year-old male with low back pain, fatigue, and nausea of 2 years duration was referred with a suspected mass in the left lung. Computed tomography and magnetic resonance imaging showed a giant aneurysm associated with a coarctation of the descending thoracic aorta. A Dacron tube graft was interposed. Histopathologic examination revealed atherosclerosis of the aneurysmal wall.
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INTRODUCTION
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Various pathologic entities and pathophysiologic factors may play a role in the etiology of aneurysms of the descending thoracic aorta. Those occurring below or above a coarctation might result from congenital as well as acquired pathologies involving the vascular wall. Schuster and Gross1 reported the incidence of saccular or fusiform aneurysms of the descending thoracic aorta below or above a coarctation to be 15.7%. This report describes a case of giant aneurysm of the descending thoracic aorta arising below a coarctation.
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CASE REPORT
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A 39-year-old male with low back pain, fatigue, and nausea of 2 years duration was sent to our clinic with a suspected mass in the left lung. He had a history of hypertension for 15 years. His blood pressure was 180/100 mm Hg and his pulse rate was 80 beats per minute. A systolic murmur was heard on the left paravertebral area and there was a decrease in magnitude of the femoral pulse. Blood pressure in the lower extremities was 70/50 mm Hg. Biochemical findings were normal. Chest radiograph showed a homogenous mass in the left hemithorax (Figure 1
). No pathological finding was noted in the echocardiographic examination. Contrast computed tomographic scanning showed a giant aneurysm of the descending thoracic aorta. Magnetic resonance imaging showed a coarctation of the aorta and an aneurysm of the descending thoracic aorta below the coarctation (Figure 2). Aortography confirmed a coarctation of the descending thoracic aorta and a giant aneurysm below the coarctation. A hemodynamic study showed that the blood pressure was 190/110 mm Hg proximal to the coarctation and 90/50 mm Hg within the aneurysm.
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Figure 2. Magnetic resonance image showing coarctation of the aorta and a giant descending thoracic aortic aneurysm below the coarctation.
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Surgical treatment was decided and a left posterolateral thoracotomy was performed. An aneurysm (fusiform enlargement) of the descending thoracic aorta was seen. It measured 15 x 18 cm and started from just below the coarctation with no clear margin between the two lesions. A cross-clamp was placed distal to the aneurysm to protect the medulla spinalis. It was noted that there were intercostal arteries draining into the aneurysmal sac. A Dacron tube graft (16 mm in diameter) was anastomosed distal to the aneurysm where the thoracic aorta was of normal size and structure. A cross-clamp was then placed proximal to the aneurysm and the aneurysmal sac was opened. Proximal anastomosis was performed below the left subclavian artery. There were no signs of degenerative disease, infection, dissection, or atherosclerosis on the aneurysmal wall. A full-thickness biopsy was taken from the aneurysmal wall for pathological examination and cultures. The cross-clamp time was 25 minutes.
The patient's postoperative course was uneventful and he was discharged from the hospital 8 days after surgery. The histopathologic examination revealed that atherosclerotic lesions were present in the aneurysmal wall. Immunohistochemical studies did not show vasculitis. Microbiological examination of a culture from the aneurysm wall biopsy was negative.
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DISCUSSION
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Hemodynamic effects, dissection, atherosclerosis, mycotic factors, and vasculitis have been implicated in the formation of aneurysms in the descending thoracic aorta.2 In coarctation of the aorta, an aneurysm can occur in the 3rd and 4th intercostal arteries as well as in the aortic wall. An aneurysm associated with coarctation could remain asymptomatic until old age. However, it may be detected during investigations for hypertension, incidentally by chest radiography, or from symptoms caused by compression of the adjacent organs as in our patient.3 In a review of 500 cases, the incidence of aneurysms of the descending aorta below or above a coarctation was found to be 15.7%.1 These aneurysms were reported to be small or as big as an orange but in our patient there was a giant aneurysm of 18 x 15 cm. Skandalakis and colleagues4 found that aneurysms were located above a coarctation in 32% of cases, whereas only 6% had an aneurysm below the coarctation.
Aneurysms can be diagnosed by computed tomography scanning and magnetic resonance imaging, while aortography is the most useful diagnostic tool. Although the cause of aneurysm formation in association with coarctation is unclear, hypertension could be responsible for aneurysms in the upper segment. This is not the case with aneurysms below a coarctation where a role has been suggested for bacterial endocarditis in some instances, aided by eddy currents in low-flow areas. In addition, poststenotic aneurysms have been attributed to the jet stream of blood coming through the narrowed segment and impinging on the distal aortic wall.5 In patients who are in the second or third decade, a loss of elasticity of the artery is evident. Aneurysms in general may be explained by the evidence of destruction of elastic tissue in the tunica media of the arterial wall together with an alteration in the mucopolysaccharide matrix.
Macroscopic and histopathologic examinations of the wall of an aneurysm can give valuable information about its etiopathogenesis. Atherosclerosis, dissection, or infection of the aortic wall can be seen in gross pathological examinations of aneurysms but definitive diagnosis must be made by histopathological and immunohistochemical studies of a specimen from the aneurysmal wall. Non-specific inflammation can take place in the aortic wall in the presence of atherosclerosis. An inflammatory process may cause progressive destruction of the lamina elastica of the media. This inflammatory process plays an especially important role in aneurysms that reach a huge size.
In our case, there was no macroscopically evident dissection, infection, or atherosclerosis but pathologic investigation revealed atherosclerosis of the aneurysmal wall that was considered to be involved in the etiology of the aneurysm. In addition, the age factor and a loss of elasticity of the aortic wall due to the hemodynamic effects of the coarctation may have contributed to the formation of the giant aneurysm. There appears to be a strong association between coarctation of the aorta and distal aneurysm formation. The combination of coarctation and an aneurysm greatly increases the risk of aortic rupture and prompt treatment is mandatory.
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REFERENCES
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Schuster SR, Gross RE. Surgery for coarctation of the aorta. A review of 500 cases. J Thorac Cardiovasc Surg
1962;43:54–70.
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Kirklin JW, Barratt-Boyes BG. Coarctation of the aorta and interrupted aortic arch. In: Kirklin JW, Barratt-Boyes BG, editors. Cardiac surgery. 2nd ed. New York: Churchill Livingstone, 1993:1263–319.
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Coselli JS. Thoracoabdominal aortic aneurysm. In: Rutherford RB, editor. Vascular surgery. 4th ed. Philadelphia: Saunders, 1995;1069–87.
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Skandalakis JE, Edwards BF, Gray SW, Davis BM, Hopkins WA. Coarctation of the aorta with aneurysm. Surg Gynecol Obstet
1960;111:307–26.
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Mitchell IM, Pollock JCS. Coarctation of the aorta and post-stenotic aneurysm formation. Br Heart J
1990;64:332–3.[Abstract/Free Full Text]
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ABSTRACT
INTRODUCTION
