Mycotic aneurysm presenting as hip pain and severe anaemia

A 15-year-old boy with trisomy 21, moderate left atrioventricular (AV) valve regurgitation and a previously repaired AV septal defect developed Aerococcus urinae infective endocarditis. The infected left AV valve and surrounding tissue were surgically removed and replaced with a prosthetic mitral valve; this was followed by 6 weeks of intravenous antibiotics. Towards the end of his antibiotic course, his C reactive protein level began to rise, and he subsequently developed worsening hip pain and severe anaemia (Hb 3.7 g/dL). An ultrasound scan showed no hip joint effusion but incidentally identified an aortic aneurysm, confirmed by an abdominopelvic MRI scan. CT angiogram showed a large (14 cm) false distal aortic aneurysm with surrounding retroperitoneal haematoma (see figure 1A). Emergency repair of the aneurysm with an aorto-bi-iliac graft was performed. A day later, he developed an ischaemic right leg. CT angiogram showed an occluded right external iliac artery (EIA) (see figure 1B) with reconstitution of the right common femoral artery via collaterals with flow to the foot. Emergency vascular surgery revealed chronic dissection occluding the right EIA origin and an open patch plasty was performed. The patient recovered well