Pseudoaneurysm of the descending aorta caused by Candida albicans

Abstract

Infection of normal arterial intima is very uncommon [1]. Staphylococcus aureus and Salmonella species are the two most common organisms associated with microbial arteritis and pseudoaneurysm formation; Candida arteritis is extremely rare, occurring in less than 1% of all reported cases [2]. Infection with candida is the result of hematogeneous dissemination in patients with impaired cellular immunity [3]. A pseudoaneurysm results from initial hematogeneous seeding of an injured or diseased intima, often by atherosclerosis with endothelial colonization followed by an invasive arterial infection; the arterial wall subsequently weakens with pseudoaneurysm formation [3]. The clinical presentation of patients with pseudoaneurysm or mycotic aneurysm of major arteries is pain in the aneurysm location and clinical bacteriemia signs. An elevated sedimentation rate and leukocytosis are common, but blood cultures are frequently negative [4]. Diagnosis, once suspected, should be pursued vigorously because rupture of such an aneurysm is often fatal [5]. Lifelong antifungal therapy following surgical repair may be necessary to treat these life-threatening infections [6]. A 35-year-old man with a history of intravenous drug abuse was admitted to the hospital with persistent fever and a mucocutaneous candida infection episode three months before the episode described here: the infection cleared without treatment. The patient had suffered from fever with chills and sweats, asthenia, productive cough and chest pain for about 15 days. His physical examination was remarkable for a fever of 39°C, respiratory rate of 25 breaths per minute, blood pressure of 135/80 mmHg and signs of peripheral venous puncture. No mucocutaneous candida infection was found. There were no murmurs on cardiac auscultation. The white blood cell count was 20×109 with neutrophilia, while haemoglobin and platelet counts were normal. The erythrocyte sedimentation rate was 66 mm/h. Chest X-ray showed a left para-hiliar pneumonia and antibiotic treatment with amoxicillin—clavulanic acid was started. Blood, urine and sputum cultures showed no growth for any organims. Human immunodeficiency virus-1 antibody test was negative. Computer tomography revealed a pseudoaneurysm arising from the thoracic descending aorta near the left pulmonar artery and contiguous parenchymatous consolidation consistent with asociated pneumonia in the lower lobe left lung. The patient suffered a massive hemoptysis. He was intubated and kept under mechanical ventilation and subseqently referred to our hospital. Transesophageal echocardiography showed no valvular vegetations, but an aortic pseudoaneurysm arising from the thoracic descending aorta and located 10 cms distal to the subclavian artery. This false aneurysm had an initial echolucent cavity 3×3 cms, connected to the aortic lumen and surrounded by 9×9 cms cavitated tissue mass, consistent with subacute thrombus formation (Fig 1). Color doppler showed flow within the echocardiographic cavities (Fig 2). The patient underwent urgent surgery. A perforated psudoaneurysm was found at the descending aorta, with invasion of lung tissue. The visualized aorta was free of atherosclerotic debris. False aneurysm resection, necrotic tissue debridement and patch repair of the descending aorta was performed. Cultures of the surgical specimen of aorta grew Candida albicans. Postoperatively he was treated with intravenous vancomicin A and amfotericin B (liposomal). The patient recovered and 6 months later is well.