LAUSR

Arterial infections due to Listeria monocytogenes are rare. We present two cases treated at our site. Case 1: 80-year-old male patient, under follow-up by our department following the implantation of a right aorto-uni-iliac endograft (Endurant ® , Medtronic), left hypogastric artery embolisation and a femorofemoral bypass due to the rupture of an infrarenal abdominal aortic aneurysm. Three years later, the patient was seen with lumbar and abdominal pain that had begun two months prior, with no fever. Laboratory tests showed raised C-reactive protein (CRP) levels of 105 mg/dl. Computed tomography angiography (CTA) revealed an increase in periaortic soft tissues and fraying of locoregional fat. In light of suspected aortitis, blood cultures were obtained and broad-spectrum antibiotics were initiated via the parenteral route, with piperacillin/tazobactam. A whole body scan was performed with gallium-67 labelled leukocytes; no pathological deposit was observed at the level of the aortic endograft. After 14 days of empirical treatment and sterile blood culture results, the patient was discharged with scheduled follow-up visits and no antibiotics. After one month, his control CTA revealed no significant changes in relation to the one before. After two months, he was readmitted with diarrhoeal stools, pain in the hypogastric region and fever. Laboratory tests showed that CRP levels were still high, with no leukocytosis. Another CTA also revealed increased periaortic inflammation (Fig. 1A) and gas bubbles inside the aneurysm sac (Fig. 1B). Once the blood cultures were obtained, empirical antibiotic therapy was initiated (intravenous ceftriaxone and vancomycin), followed by emergency surgery involving the removal of the aortic endograft and the conduct of a right aorto-uni-iliac bypass with a silver-impregnated graft (Maquet Intergard Silver Knitted, Maquet Spain, SLU) (Fig. 1C and D). L. monocytogenes was isolated on the aortic endograft culture. Four weeks of ampicillin and gentamicin was followed with oral co-trimoxazole treatment. Given the risk of an infectious relapse, we decided to continue lifelong suppressive antibiotics with oral co-trimoxazole.