IMAGES FOR SURGEONS

Clostridial Infection of the Abdominal Aorta

Mark Davies, BSc, MRCS, John Byrne, MCh, FRCSI (Gen), John S Harvey, MPhil, FRCS,University Hospital of Wales, Cardiff, UK

A 63-year-old man presented to the emergency unit after1 week of worsening back pain, fever, general malaise,and lethargy. His past medical history was unremark-able. On examination he was febrile and had a tenderexpansile mass on abdominal palpation. CT evaluationof his abdomen showed a 7-cm infrarenal abdominalaortic aneurysm. The wall of the aneurysm was unusual;it was markedly thickened and contained gas (A and B),suggesting infection by a gas-forming organism such asClostridia.

Intravenous broad-spectrum antibiotics were startedimmediately and urgent surgical intervention carriedout the next day. The aneurysm was resected and thenonaffected proximal abdominal aorta and common il-iac vessels were oversewn. The adjacent tissues were ex-tensively debrided and an axillobifemoral bypass wasconstructed. The patient died on the second postopera-tive day from myocardial complications. Clostridiumsepticum was grown from the tissue samples.

Mycotic aortic aneurysms account for approximately1.3% of all abdominal aneurysms and have a high mor-tality of about 70%.1 The most common presentingsymptom is back pain.2 Features such as pyrexia and aleucocytosis, encountered in this case, are frequently re-ported in the literature. Staphylococcus aureus and Salmo-nella are the organisms responsible for more than half of

all cases. Clostridial infections are less common and,associated with hematologic and gastrointestinal malig-nancies, have a much worse prognosis.3-6

The diagnosis of clostridial aortitis is made by CT,which is usually confirmatory. Surgical management isprompt extensive debridement of the infected tissue,followed by construction of an extraanatomic bypassgraft (or in situ vein bypass) with prolonged antibiotictherapy.7

REFERENCES

1. VonSegesser L, Vogt P, Genoni M, et al. The infected aorta.J Cardiac Surg 1997;12(2 Suppl):256–260.

2. Monera G, Taylor L, Yeager R, et al. Surgical treatment of infectedaortic aneurysm. Am J Surg 1998;175:396–399.

3. Semel L, Aikman W, Parker F, Marvasti M. Nontraumatic clos-tridial myonecrosis and mycotic aneurysm formation. New YorkState J Med 1984;84:195–196.

4. Messa C, Kulkarni M, Arous E. Double Clostridial mycotic an-eurysms of the aorta. Cardiovasc Surg 1995;3:687–692.

5. Sailors D, Eidt J, Gagne P, et al. Primary Clostridium septicumaortitis: a rare cause of necrotizing suprarenal aortic infection. Acase report and review of the literature. J Vasc Surg 1996;23:714–718.

6. Montoya F, Weinstein-Moreno L, Johnson C. Mycotic thoracicaneurysm due to Clostridium septicum and occult adenocarci-moma of the cecum. Clin Infect Dis 1997;24:785.

7. Simsir S. Clostridium septicum infection of the aorta. Am J Surg2001;181:577–578.

331© 2003 by the American College of Surgeons ISSN 1072-7515/03/$21.00Published by Elsevier Inc. doi:10.1016/S1072-7515(03)00424-1