Stanford Type A Aortic Dissection Secondary to Infectious Aortitis: A Case Report
An 83-yr-old woman with history of hypertension was admitted emergently with fever, chill, and chest pain for 2 weeks on 8 July 2012. She had been treated with acupuncture on her back and buttock because of chronic back pain before the onset of symptoms. Blood pressure was 80/50 mmHg, heart rate was 94 beats per minute, and body temperature was 38.2℃. Other vital signs were unremarkable. White blood cell count was 27,420/µL with 90% neutrophils and C-reactive protein was 14.78 mg/dL on laboratory examination. Blood and urine culture was done to investigate the focus of fever. Because she complaint of chest pain and mediastinal widening on an initial chest x-ray was documented, chest computed tomogram (CT) was performed to rule out acute aortic syndromes. And it revealed a dissection of the ascending aorta with hemopericardium and an incidentally noted abscess in the right buttock (). Transthoracic echocardiography revealed severely dilated ascending aorta with intimal flap suggestive of aortic dissection, a moderate amount of pericardial effusion without tamponade sign, and no visible vegetations. The left and right ventricular functions were preserved and the cardiac valves had no abnormal findings except mild aortic valve regurgitation. Under the impression of acute aortic dissection with an impending rupture, an emergent operation was performed.\nThe surgery was performed through a median sternotomy and a subclavicular incision. After pericardiotomy, blood with fresh clots was observed and removed securely. On the superior wall of the proximal aortic arch just distal to the innominate artery and beneath the innominate vein, inflamed friable tissue with a hematoma was observed and cultured microbiologically. Cardiopulmonary bypass (CPB) was started and systemic cooling was instituted with arterial cannulation in the right axillary artery and venous cannulation in the right atrium.\nDuring removal of the infected adventitial tissue and sharp dissection of the arch and the ascending aorta, the aorta suddenly ruptured. By careful management of the patient's vital signs, the ruptured aorta was firmly compressed and she was cooled continuously. Left ventricular vent was placed through the right superior pulmonary vein. Upon cardiac fibrillation, a cross-clamp was placed and the aorta was opened by a transverse incision, which revealed circular dissection that reached just above the sinotubular junction leaving the coronary ostia unaffected. Then cardioplegia was antegrade infused into the coronary opening.\nUpon reaching the core temperature to 20℃, CPB was discontinued and a cross-clamp was off. The ascending aorta was opened by vertical incision, which was extended from the previous transverse aortic incision upward to the proximal aortic arch. Antegrade cerebral perfusion of about 10 mL/kg/min was initiated through the arch vessels and adjusted to maintain cerebral perfusion pressures of 60 mmHg.\nDuring selective cerebral perfusion, the infected friable aortic walls and dissecting aneurysm were completely removed and debrided. After false lumen obliteration, distal aortic reconstruction of hemi-arch replacement was performed with an open anastomosis technique using a one-branched graft (InterGard®, Maquet, France). Distal aortic anastomosis was then complete and an additional arterial cannula was inserted into a side-branch of the graft. After vigorous de-airing maneuvers, flow to the head vessels and lower body was resumed and simultaneously rewarming was initiated. Proximal aortic anastomosis was performed at the level of the sinotubular junction during the rewarming period.\nThe patient was easily weaned off bypass, and transesophageal echocardiography showed no abnormal findings.\nHistopathological examination from the ascending aorta, obtained during the operation, showed aortitis without giants cells and caseous necrosis. Cultures from the aortic necrotic materials and blood returned positive for methicillin-sensitive Staphylococcus aureus, for which she received intravenous cefazolin for 6 weeks. And oral Rifampin 600 mg a day was prescribed for 2 weeks after the end of intravenous antibiotic treatment. After surgery, follow-up blood cultures were performed two times a week. In next week, blood cultures were converted to negative. During the antibiotic treatment, biochemical parameters of inflammation were slowly improved and normalized. Additionally the right buttock abscess was progressively improved and subsided without a surgical drainage on physical examination. After 11 days of ICU treatment because of acute renal failure and 46 days of hospitalization, she was discharged. She remains asymptomatic 2 months later without signs of recurrence, and postoperative follow-up chest CT that was performed after 4 weeks revealed the patent bypass grafts ().