Stent-graft for Recurrent Melioidosis Mycotic Aortic Aneurysm

Mycotic aneurysms due to Burkholderia pseudomallei in Far North Queensland, tropical Australia: A case series and review of the literature

Since 2019, Burkholderia pseudomallei has been the most common cause of mycotic aneurysm at Cairns Hospital in tropical Australia. Among 233 culture-confirmed cases of melioidosis since this time, 8 (3.4 %) were diagnosed with a mycotic aneurysm. All 8 patients had at least 1 risk factor for melioidosis, all 8 had either established vascular disease (or risk factors for it) and all 8 presented during the local wet season or shortly thereafter. Although the patients were managed in a well-resourced, high-volume melioidosis centre, the diagnosis of mycotic aneurysm was frequently delayed. The patients had a turbulent course: 6/8 (75 %) required intensive care unit admission and 7/8 (88 %) required surgical intervention. While all 8 patients survived to hospital discharge, 2 (25 %) ultimately died as a result of their B. pseudomallei infection, a high case-fatality rate by contemporary Australian standards. Adverse drug reactions were documented in 4/7 (57 %) who commenced oral trimethoprim-sulfamethoxazole (TMP-SMX) eradication therapy; an additional 2 patients were unable to adhere to their prescribed TMP-SMX, one of whom died from relapsed melioidosis. Mycotic aneurysm is an infrequent manifestation of B. pseudomallei infection, is challenging to diagnose and has a high attributable mortality. The diagnosis should be considered in older patients who reside in, or who have travelled to, endemic areas and who present with fever and abdominal or back pain and who have risk factors for melioidosis and vascular disease. Early, comprehensive imaging, thorough microbiological evaluation, prompt vascular surgery review, targeted antimicrobial therapy, close longitudinal follow-up and strategies to ensure patients' retention in care are crucial to achieve optimal outcomes.

Mycotic Thoracic Aortic Aneurysm: Epidemiology, Pathophysiology, Diagnosis, and Management

Mycotic thoracic aortic aneurysm (MTAA) is an aneurysm of the aorta caused by infection of the vessel tissue through microbial inoculation of the diseased aortic endothelium. It is most commonly caused by bacteria. Rarely, it can be caused by fungi. However, viral aortic aneurysm has never been reported. Depending on the area and time period investigated, the infections organism discovered may vary significantly. Little is known about the natural history of MTAA due to its rarity. It is not known if they follow the same pattern as other TAAs. However, it is unclear whether MTAA follows a similar clinical course. The combination of clinical presentation, laboratory results, and radiographic results are used to make the diagnosis of MTAA. Treatment of MTAA is complex since patients frequently present at a late stage, frequently with fulminant sepsis, as well as concomitant complications such as aneurysm rupture. While medical treatment, including antibiotics, is recommended, surgery is still the mainstay of management. Surgery to treat MTAA is complicated and carries a high risk of morbidity and mortality and includes both open repairs and endovascular ones. In this review, we explore the etiology, pathogenesis, clinical presentations, diagnostic modalities as well as treatment management available for MTAA.

A case of Burkholderia pseudomallei mycotic aneurysm linked to exposure in the Caribbean via whole genome sequencing

Melioidosis, an infection caused by Burkholderia pseudomallei, has a very high risk of mortality when treated, with an even higher risk of fatality if undiagnosed or not treated appropriately. It is endemic to Asia, Australia, South America, and the Caribbean; however, the number of melioidosis cases reported in the United States has been increasing. Therefore, physicians should be aware of this clinical entity and its possible presentations. Mycotic aneurysms due to B. pseudomallei are extremely rare accounting for approximately 1-2% of cases. Here we describe a rare case of melioidosis presenting as a mycotic aneurysm in the United States; highlight the potential for diagnostic challenges and epidemiologic concerns; as well as provide a review of mycotic aneurysm cases due to B. pseudomallei published to date.

Mycotic aneurysm secondary to melioidosis in China: A series of eight cases and a review of literature

Burkholderia pseudomallei is the causative agent of melioidosis, endemic in Southeast Asia and Northern Australia, and increasingly recognized in southern China, especially in Hainan Province. Mycotic aneurysm caused by B. pseudomallei is a rare but potentially severe illness with a high mortality rate. The clinical features of the mycotic aneurysm secondary to melioidosis have not been illustrated in China. Over a seven-year period (2013 to 2019), 159 patients with bacteremic melioidosis were retrospectively analyzed in Hainan province, China, of whom eight patients were confirmed to have mycotic aneurysm through the combination of imaging examination, pathologic examination and aneurysm tissue culture. We summarized these eight patients' clinical characteristics, demographical features, treatments and outcomes. The susceptibilities to five commonly-used antibiotics for these eight B. pseudomallei isolates were also determined by E-test strips. Furthermore, the mycotic aneurysm cases secondary to melioidosis retrieved from the literature were also reviewed. Of the eight cases, six had abdominal mycotic aneurysms, one had a left iliac aneurysm, and the other one had an infectious mesenteric aneurysm. They were aged from 48 to 69 years old, and had the underlying risk factors of diabetes mellitus (2 patients), long-term smoking (4 patients), hypertension (6 patients), and soil and water contact history (6 patients), respectively. The positive arterial aneurysm imaging was observed in all patients via computed tomography (CT) or angiography. Eight B. pseudomallei isolates collected from both blood and mycotic aneurysm tissues remained 100% susceptible to imipenem and ceftazidime. After surgery combined with antibiotic administration, six patients survived, with a mortality rate of 25%. In melioidosis endemic areas, the mycotic aneurysm secondary to melioidosis might be underdiagnosed, and increased awareness of predisposing risk factors and clinical features of the mycotic aneurysm is required. Following a positive B. pseudomallei blood culture, the diagnosis of mycotic aneurysm should be under consideration in those with abdominal pain and/or hypertension. Imaging by CT or angiography is indispensable for its timely diagnosis and management.

Non-infectious aortitis in an immunosuppressed renal transplant recipient with IgA nephropathy

A 54-year-old woman presented with atypical chest pain, fever and malaise. She was immunosuppressed with three agents following a living-donor kidney transplant 1 year previously. Her native kidney failure was secondary to biopsy-demonstrated crescentic IgA nephropathy, with systemic involvement. A CT pulmonary angiogram revealed an inflammatory cuff of soft tissue around the descending thoracic aorta suggesting aortitis. Inflammatory markers were elevated. Given her immunosuppression, the patient was screened extensively for infective causes and was empirically commenced on intravenous meropenem. After 72 hours of no clinical or serological response to antibiotic therapy, negative microbiological investigations and worsening inflammation on serial imaging, she was commenced on high-dose methylprednisolone for presumed inflammatory aortitis. Symptoms and inflammatory markers rapidly normalisedand the patient was discharged home on oral prednisolone. A clinical diagnosis of IgA-related aortitis was made. Imaging 3 months later showed complete resolution of the aortitis.