Tuberculous Aortitis Complicated with Pseudoaneurysm Formation in the Descending Thoracic Aorta: A Case Report
A 51-year-old male was transferred to Asan Medical Center with sustained fever for 2 months. Being suspected of having an upper respiratory infection, he had been treated with antipyretic medication in a primary clinic, but the fever persisted. Consequently, the patient was referred to a regional tertiary hospital a month earlier, and was found to have multiple tiny nodular lesions in both lung fields on computed tomography (CT), which was compatible with military tuberculosis. On the CT evaluation, a 1.0×1.5 cm out-pouching pseudoaneurysm of the proximal descending thoracic aorta into the left upper lobe of the lung was found (). Being assessed as military tuberculosis complicated by aortitis with pseudoaneurysm formation, anti-tuberculous medications (isoniazid, rifampicin, and ethambutol) were started, and were maintained for the following four weeks. As the fever persisted despite the medications, he was transferred to Asan Medical Center.\nAt the time of admission, his vital signs were stable without fever (36.3℃). The findings of the physical examination were unremarkable. Laboratory studies revealed hemoglobin of 14.3 g/dL, a white blood cell count of 5,200/mm3, platelets of 279,000/mm3, and C-reactive protein of 1.82 mg/dL. Sputum staining and culture for acid-fast bacilli were negative.\nAs the size of the aortic pseudoaneurysm had decreased significantly on follow-up CT evaluation (), provision of the anti-tuberculous medications continued. On the fifth day, however, another follow-up CT evaluation showed increased size of the pseudoaneurysm in the descending thoracic aorta, suggestive of a contained rupture (). Consequently, an emergency operation on the descending thoracic aorta was undertaken.\nA double-lumen endotracheal tube was used for anesthesia. The descending thoracic aorta was exposed through the 5th intercostal space via a left lateral thoracotomy. Diffuse adhesion of the left upper lobe of the lung to the proximal descending aorta was very tight, and the contained rupture of the aorta was surrounded by the necrotic left upper lobe. Systemic heparinization was performed with a single dose of 6,000 IU, intravenously. For the distal perfusion during the aortic replacement, a left heart bypass was used with a centrifugal pump; blood was drained via a left atrial cannula that was placed through the inferior pulmonary vein, and oxygenated blood returned through a cannula placed at the distal descending thoracic aorta. Adhesiolysis then proceeded on the lesion. Since an aortic rupture is highly likely to occur with adhesiolysis, the aorta was clamped first, and then the adhesiolysis was completed. The aortic clamp was placed in the left subclavian artery, the distal arch between the left common carotid artery and the left subclavian artery, and the mid-descending thoracic aorta.\nThere was a 1 cm opening in the distal aortic arch covered with necrotic lung parenchyma. En bloc resection of the diseased aortic segment and the necrotic lung parenchyma was performed in the form of wedge resection of the lung. Then the resected distal arch and the proximal descending aorta were replaced with a 22 mm artificial graft (Hemashield Platinum; Maquet Inc., Wayne, NJ, USA).\nThe durations of the total bypass, the descending aorta clamping, and the total operation were 78 minutes, 73 minutes, and 209 minutes, respectively. Extubation was performed at post-operative 19 hours. On post-operative day 2, the patient was transferred to the general ward. Pathologic examination of the resected specimen (both the aorta and lung) showed chronic inflammation with granuloma and multinucleated giant cells (), and polymerase chain reaction of mycobacterial tuberculosis was positive. Postoperative CT revealed patency of the graft without residual aortopathy (). On post-operative day 12, the patient was discharged without complications. Four weeks later, tissue culture study confirmed the growth of acid-fast bacillus. Anti-tuberculous medications (isoniazid, rifampicin, and pyridoxine) were continued for 6 months. During the one year follow-up, the patient was doing well without any complications or recurrence of tuberculosis.