Clinical and Microbiological Characteristics of Mycotic Aneurysms in Patients with and without End-Stage Renal Disease in a Medical Center in Taiwan

Abstract

BACKGROUND: This study aimed to investigate the differences in the clinical characteristics of mycotic aneurysms developed in patients with end-stage renal disease (ESRD) and undergoing dialysis, and those without ESRD. METHODS: We retrospectively analyzed patients with mycotic aneurysms hospitalized between January 11, 2002 and November 5, 2013 at a tertiary medical center in southern Taiwan. We investigated the bacteriological differences and outcomes of mycotic aneurysms in patients without ESRD and those with ESRD who were receiving long-term dialysis. RESULTS: There were 49 patients hospitalized during the study period with the diagnosis of mycotic aneurysm. Of this group, 10 patients had ESRD and were undergoing hemodialysis, and 39 patients did not have ESRD. In the non-ESRD group, 34 patients (87.18%) had positive culture results and in the ESRD group, nine patients (90%) had positive culture results. In the non-ESRD group, aerobic gram-negative organisms (n = 22/39, 56.41%), especially Salmonella (n = 18/39, 46.15%), were the predominant pathogens. However, in the ESRD group, aerobic gram-positive organisms, especially Staphylococcus aureus (n = 4/10, 40%), were the main pathogens. The overall mortality rate for the study population was 42.86%; the mortality rate for patients who received invasive intervention (open surgery or endovascular aneurysm repair EVAR) was 5.56%. CONCLUSION: Mycotic aneurysms in patients with and without ESRD have different causative pathogens. In ESRD patients, the dialysis catheter or the dialysis process appears to alter the microbiological flora responsible for the development of mycotic aneurysms. Clinicians need to consider the emergence of Staphylococcus aureus mycotic aneurysm infections in ESRD, and be aware that aggressive intervention may improve the outcome of mycotic aneurysms.