Clinical Presentation and Management of Primary Mycotic Aortic Aneurysms: A Single Center Experience and Review of the Literature

Background: Primary mycotic aortic aneurysm (PMAA) is a localized dilation of the aortic wall caused by direct spread of bacteria via the bloodstream to the aortic wall and subsequent development of an aneurysm. The term mycotic aortic aneurysm was first used to describe a patient with four aortic aneurysms which have a mushroom-like appearance, and the term has since been used. Aim: To conduct a literature review and to report a series of cases of infra-renal mycotic aortic aneurysms, their presentation and subsequent outcome and management. Methods: Information was gathered retrospectively from medical records for patients who were over the age of 18 and who had presented with PMAAs at Cumberland infirmary o from April 2016 to July 2022. Results: A total of six patients were assessed in our study, mean age was 57-88 years. Presenting complains were: Back pain (n=2), abdominal pain (n=1), fever (n=4), collapsed (n=2), confusion (n=1) and other clinical presentations were leg pain, feeling unwell and malaise each reported in one patient each. Potential risk factors for PMAA identified were malignancy (n=2), diabetes mellitus (n=2), chronic kidney disease (n=2), immunosuppressive medication (n=2) and alcohol misuse (n=1). Potential sources of infection were retroperitoneal inflammation (n=1), pyelonephritis (n=1), retroperitoneal /psoas infection (n=2), duodenitis (n=1), systemic sepsis (n=1). Management can be surgical intervention such as Endovascular aortic repair (EVAR) (n=2), or axillo-bifemoral bypass (n=2) all of them had post-operative antibiotics or only antibiotics (n=3), however two patients of them died. Conclusion: PMAAs are rare but they have high risk of morbidity and mortality. The diagnosis is challenging but CT A-abdomen and pelvis remains valuable for diagnosis. Surgery, either bypass or EVAR with antibiotics, is a cornerstone for management, however other alternatives can be considered.