Unusual Case of Mycotic Aneurysms

Abstract

Introduction: There are many causes of mycotic aneurysm mainly Salmonella shigella, E. coli, Brucella. We present an extremely uncommon cause of treatable mycotic aneurysm by Yersinia enterocolitica with no gastrointestinal symptoms. Case Presentation: 57-year-old male was admitted with complains of right sided groin pain with weakness, fatigue, dyspnea, decreased exercise tolerance and chills for 3 weeks. On admission, he was afebrile, mildly tachycardic with normal blood pressure. Physical exam was remarkable for suprapubic tenderness with voluntary guarding, a large pulsatile mass in the right groin, and edema in the lower extremities. Complete blood count was significant for increased white cell count with normal hemoglobin and platelet count. Transaminases were mildly elevated. Computed tomography scan of the abdomen revealed a 6 cm right Iliac artery aneurysm; a 5 cm left iliac artery aneurysm and a 3.2 cm distal abdominal artery aneurysm. He was evaluated by vascular service and was started on Vancomycin and piperacillin/tazobactam. Due to the concern of endocarditis, a transesophageal echocardiogram was done, which did not show any vegetations. Patient was taken for surgery where they found a contained rupture of the right sided aneuryms previously seen in the CT scan. Aorto-bi-iliac bypass with a synthetic graft was performed and cultures were sent from retroperitoneal fluid and the contained thrombus of the right iliac artery aneurysm. Shortly after surgery, the cultures became positive for Yersinia enterocolitica. The patient's initial antibiotics were then switched to levofloxacin based on susceptibility tests. He improved clinically and was discharged home in stable condition. Discussion: Yersinia enterocolitica is a gram-negative bacillus that is distributed worldwide and has been isolated from soil, fresh water, contaminated foodstuffs and a wide variety of animals. Transmission to humans is predominantly via the oral route. The most frequent manifestations are enteritis, enterocolitis, mesenteric adenitis and terminal ileitis. Metastatic focal infections can occur with or without apparent bacteremia and can affect any organ system; however, only 11 cases of mycotic aneurysm caused by Yersinia enterocolitica have been reported, occuring mostly in elderly men with vascular disease. Patients usually present with 1 week of symptoms that includes fevers or malaise. Serotypes 03 and 08 are most commonly isolated and mortality is high for untreated cases. Aminoglycoside and fluoroquinolones and 3rd generation cephalosporins are the antibiotics of choice.