Rapid Infrarenal Aortic Rupture During Persistent Methicillin-Susceptible Staphylococcus aureus Bacteraemia: Serial CT Evolution and Staged Endovascular Treatment—A Case Report

Background and Clinical Significance: Persistent Staphylococcus aureus bacteraemia can seed an atherosclerotic aorta. Early CT may show only wall thickening and periaortic inflammation, mimicking a degenerative penetrating aortic ulcer (PAU) when no ulcer crater is visible. Case Presentation: An 80-year-old woman (BMI 19.5 kg/m2) presented with hypogastric and lumbar pain. Multiphasic CT showed a calcified infrarenal aorta with periaortic inflammation but no haemorrhage. Blood cultures obtained on two occasions confirmed persistent methicillin-susceptible S. aureus bacteraemia. Interval CT angiography showed an enhancing circumferential cuff and a small anterior contrast focus without a definite ulcer crater. Eight days after the initial CT, hypotension developed; CT angiography showed focal aortic wall disruption, active extravasation, and a large retroperitoneal haematoma. Emergency aorto-bi-iliac EVAR controlled the bleeding. An inferior mesenteric artery-fed type II endoleak filled the fresh rupture cavity and was treated by coil embolisation via mesenteric collaterals. One-month CTA showed a patent graft without endoleak. At six weeks, the patient remained clinically well with healed wounds and no need for further vascular intervention. CRP fell from 148.1 mg/L on postoperative day 5 to 49.4 mg/L at six weeks and 24.2 mg/L at approximately 12 weeks; the next outpatient review was scheduled in three months, although microbiological clearance remained undocumented. Conclusions: Serial imaging and persistent MSSA bacteraemia support probable infective aortitis with focal wall disruption; an infected degenerative PAU remains possible. Persistent bacteraemia, focal pain, and a progressive periaortic cuff should prompt early vascular review and short-interval imaging.