A Rapidly Progressive Aortic Aneurysm Due to Escherichia Coli.

An 82-year-old woman presented with intermittent fever and left rib pain for the past several weeks. She had been diagnosed with polymyalgia rheumatica 18 months prior and was taking prednisolone; she also had a history of urinary tract infection with Escherichia coli 6 months earlier. Physical examination did not reveal a heart murmur. Laboratory investigations showed noticeably elevated inflammatory markers (C-reactive protein, 26 mg/dL; erythrocyte sedimentation rate, 103 mm/h). Plain chest computed tomography showed no significant findings related to the chief complaints (FigureA). However, 3 months later, she presented with a sore throat and hematemesis. Contrast-enhanced computed tomography showed rapid enlargement of a 61 × 40 mm saccular, irregular aortic aneurysm protruding rightward from the aortic arch with surrounding fluid effusion and soft-tissue swelling (FigureB). Upper gastrointestinal endoscopy showed lateral compression and erosion of the cervical esophagus (FigureC). The patient underwent emergency total arch replacement with omental patch closure and gastrostomy for imminent thoracic aortic aneurysm rupture with an esophageal fistula. Histologic examination of the aorta showed fibrous thickening, and media atheroma were detected without transmural or adventitial inflammation; E. coli was detected in the aortic wall culture. Finally, an infected aortic aneurysm was diagnosed. Antibiotics were administered postoperatively for >6 weeks. The patient recovered from the operation but died a year later. Infected aortic aneurysms are rare (prevalence of 0.7%-2.6% of all aortic aneurysms), and associated with a high mortality rate due to rupture without appropriate interventions.1Ishizaka N Sohmiya K Miyamura M et al.Infected aortic aneurysm and inflammatory aortic aneurysm—in search of an optimal differential diagnosis.J Cardiol. 2012; 59: 123-131Abstract Full Text Full Text PDF PubMed Scopus (52) Google Scholar Infectious aortic aneurysms present with fever, chest pain, and sore throat, but occasionally may be asymptomatic until aneurysm formation.2Lopes RJ Almeida J Dias PJ Pinho P Maciel MJ Infectious thoracic aortitis: a literature review.Clin Cardiol. 2009; 32: 488-490Crossref PubMed Scopus (134) Google Scholar Staphylococcus, Enterococcus, Streptococcus, and Salmonella species are the most common causative organisms,2Lopes RJ Almeida J Dias PJ Pinho P Maciel MJ Infectious thoracic aortitis: a literature review.Clin Cardiol. 2009; 32: 488-490Crossref PubMed Scopus (134) Google Scholar but a less common organism should always be considered in compromised hosts. Especially, Gram-negative bacteria can induce more aggressive arterial infection, making the aneurysm more susceptible to rupture and increasing mortality.3Young-Wook K Infected aneurysm: current management.Ann Vasc Dis. 2010; 3: 7-15Crossref PubMed Google Scholar Frequent follow-up imaging should be performed. Radiological findings suggestive of infectious aortic aneurysms include rapidly dilating irregular-shaped saccular aneurysms, with fluid effusion and soft-tissue swelling adjacent to the aorta.4Macedo TA Stanson AW Oderich GS Johnson CM Panneton JM Tie ML Infected aortic aneurysms: imaging findings.Radiology. 2004; 231: 250-257Crossref PubMed Scopus (182) Google Scholar