Surgery of infrarenal inflammatory aneurysm of abdominal aorta infected with methicillin resistant Staphylococcus aureus in a patient undergoing haemodialysis

Abstract

Inflammatory abdominal aortic aneurysm accounts for 5% to 10% of all cases of abdominal aortic aneurysm and differs from typical atherosclerotic abdominal aortic aneurysm in many important ways. Although both inflammatory and atherosclerotic abdominal aortic aneurysms most commonly affect the infrarenal portion of the abdominal aorta, patients with the inflammatory variant are younger and usually symptomatic, chiefly from back or abdominal pain. Unlike patients with atherosclerotic abdominal aortic aneurysm, most with the inflammatoryvariant have an elevated erythrocyte sedimentation rate or abnormalities of other serum inflammatory markers. Computed tomography and magnetic resonance imaging are both sensitive for demonstrating the cuff of soft tissue inflammation surrounding the aneurysm that is characteristic of inflammatory abdominal aortic aneurysm. Inflammatory abdominal aortic aneurysm can be primarily infected by degenaration of an infected artery (in less than 1% of cases), or can become secondary infected in the already existing aneurysm. Seconadary infection of the pre-existing aneurysm has big inffluence on treatment choice, but is also rare. Clinically non-symptomatic infection, also known as bacterial collonisation, can be very frequent, regarding a greatly increased number of positive intraoperative findings (10-15%). Prolonged intravascular catheterization, vascular grafting, repeated punctures with large bore needles, and decreased immune defence mechanism make uraemic patients undergoing haemodialysis more likely to develop Staphylococcus aureus bacteraemia and its complications. The case shows a gigantic inflammatory aneurysm of the abdominal aorta, localized infrarenally, which was solved successfully by resection of the aneurysm of the abdominal aorta, and interposition of Dacron tubular graft 22 mm. Bacterial examination of the aneurysmal sac was positive: methicillin-resistent Staphylococcus aureus was detected. There were no postoperative complications, and the final outcome was fully satisfactory. Control CT scans after 3, 6 and 12 months were regular, with signs of regression fibrosis of the retroperitoneum.,