Infrarenal Infected Aortic Aneurysm Caused by Streptococcus pyogenes

Abstract

Infectious aneurysm is a rare entity associated with significant morbidity and mortality. Current knowledge on pathogenesis, outcome, diagnosis, management, and follow-up remains debatable. We report the case of a patient with Streptococcus pyogenes aneurysm who was successfully treated with a homograft implant and discuss microbiological characteristics, diagnostic methods, and treatment options currently available for this serious disease.

An Unusual Case of Streptococcus pyogenes Causing Ruptured Aortic Mycotic Aneurysm

“…The risk of mycotic aneurysm is higher in those with atherosclerosis, and arteriovenous fistula and in states of immunosuppression such as diabetes (33%), chronic renal failure (30%), chronic steroid use (16%), and chronic diseases (16%) such as rheumatoid arthritis, non-Hodgkin lymphoma, and multiple myeloma, as they can all increase the risk for hematogenous seeding [1, 23].…”

“…Given the complexity of this assessment, an Infectious Diseases consult can be helpful. Frequently, antibiotics are given for extended duration to treat an infected aneurysm with long-term antimicrobial suppressive therapy to prevent ongoing hematogenous seeding from the graft infection [1, 22].…”

“…The mechanism of spread for Streptococcus pyogenes endovascular infection is often hematogenous from an infected pharynx but can be from any infected site (including skin as in on our case) [2]. To date, only 9 cases of mycotic aneurysm involving the aorta caused by Streptococcus pyogenes have been reported [1, 5, 9–15].…”

“…Mycotic aneurysm is the infection of the arterial wall, caused by either a fungal or bacterial infection [1, 2]. In general, mycotic aneurysm is considered to be very rare, representing less than 2% of all aortic aneurysms [1]. When it does occur, it can often be a result of hematogenous dissemination or septic emboli from infective endocarditis [2].…”

“…When it does occur, it can often be a result of hematogenous dissemination or septic emboli from infective endocarditis [2]. There are no guidelines on the treatment of mycotic aneurysm, and despite the advancement of antimicrobial therapy, the mortality is still very high (10–40%) [1, 3, 4].…”