In July, 2006, a 59-year-old man from Macedonia presented with a 6-week history of progressive suprapubic pain. The pain was chronic with sharp episodes, and radiated to the back. He also had loss of appetite, recurrent episodes of nausea, 6 kg weight loss, periods of drenching sweats, and experienced burning sensation when urinating. He was a heavy smoker (80 pack-years). On clinical examination our patient was cachectic, was afebrile, had no lymphadenopathy, but had suprapubic tenderness. Peripheral pulses were normal. Laboratory test results showed normocytic anaemia (haemoglobin 132 g/L) with normal leucocyte and platelet counts, monocytosis (10·3%), and a high concentration of C-reactive protein (36 mg/L). Urinanalysis showed leucocytes and many bacteria. Urinary tract infection was suspected; blood cultures and tests for tuberculosis were done. An abdominal CT was requested, in view of the suspicion of malignancy—the scan showed an infrarenal aortic aneurysm (maximum diameter 3·9 cm) with contrast enhancement in the periaortic tissue (fi gure). The vascular surgeon suspected an infl ammatory process with a high risk of rupture; the patient underwent emergency surgery. Intraoperatively, thickened infl ammatory tissue around the aorta was noted. The infrarenal aorta and aortic bifurcation were completely resected. Because the aortic wall looked normal and intraoperative Gram stains were negative, infl ammatory rather than mycotic pathology seemed most likely. Aortic reconstruction was therefore done with a bifurcated polytetrafl uoroethylene prosthesis. However, histological examination of the aortic wall showed infl ammation of the arterial media with microscopic abscess formation, and severe arteriosclerosis, and brucella species was grown from blood cultures and aortic wall biopsy sample, establishing the diagnosis of mycotic aneurysm. We treated our patient with doxycycline and gentamicin for 14 days followed by rifampicin 900 mg/day and doxycycline 200 mg/day for 6 months. Abdominal CT at 6-month and 12-month follow-up showed no signs of relapse; the prosthesis and intra-abdominal lymph nodes appeared normal, and blood cultures showed no microbial growth during the fi rst 12 months. When last seen in July, 2008, the patient was well. Mycotic aneurysms are an infectious degeneration of the arterial wall, caused either by endocarditis with septic emboli to the vasa vasorum or by direct haematogenous spread during bacteraemia. The term “mycotic” was coined by Osler in 1885 to denote funguslike vegetations; this is misleading, because most cases of mycotic aneurysms are caused by bacteria, most commonly Staphylococcus aureus and salmonella species, although many other pathogens have been implicated. Mycotic aortic aneurysms carry a high risk of rupture and death. The classic clinical signs of fever and a tender pulsatile abdominal mass are often not present or not interpreted correctly. Brucellosis (also known as Bang’s disease) is a worldwide zoonosis and is endemic in the patient’s home country of Macedonia—which he visited regularly. The organism is often transmitted via unpasteurised milk products (typically soft cheese). Bacteraemic spread to the liver, spleen, bones, kidneys, lymph nodes, the reproductive system, or heart valves can occur; mycotic aneurysms, however, are rare. Our patient was managed with a prosthetic graft rather than homograft, autologous veins, or extra-anatomic reconstruction; this approach might be considered controversial. Recurrence rates of up to 10% within a year have been described despite correct antibiotic treatment in the absence of prosthetic material; contaminated prosthetic grafts carry a high risk of recurrence. So far, our patient has had a favourable course, therefore, the prosthetic graft has been left in situ, but further follow-up is essential.
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Oct 12, 2023
Luis Carlos Hinojosa Arco + 7
Open Access