Mycotic aneurysm of the suprarenal aorta due to Streptococcus pneumoniae: case report and literature review

• Published in: Canadian Journal of Surgery 1999-08, Vol.42 (4), p.302-304
• Main Authors: Lussier, N, Girouard, Y, Chapleau, D
• Format: Article
• Language: English
• Subjects: Aged; Aneurysm, Infected - microbiology; Aortic Aneurysm, Abdominal - microbiology; Aortic Diseases - microbiology; Bacteria; Brief Communication; Cardiovascular system; Female; Humans; Pneumococcal Infections - complications
• ISSN: 0008-428X; 1488-2310

Our patient presented with the most common clinical findings, except that her blood cultures were sterile, which may have been due to the antibiotics she had received before admission. The diagnosis was made by arterial wall culture. Interestingly, the arterial wall culture grew the same organism that was isolated from the diaphragmatic abscess, suggesting that the aneurysm infection arose from this adjacent focus. It is probable that a pneumococcal left lower lobe pneumonia developed first and led to the formation of a diaphragmatic abcess, which in turn spread contiguously to the adjacent aortic vessel. This mechanism of mycotic aneurysm formation is very unusual. Brown and associates13 stated that this group constitutes less than 10% of mycotic aneurysms at all locations. Lumbar osteomyelitis, local wound infection, retroperitoneal, pancreatic and mediastinal abscesses, carcinomas and perforation of the gastrointestinal tract, infected lymph nodes and lung infections have all been reported.1,3,9,14-16 However, no case of diaphragmatic abscess was found. The general principles of management involve both antimicrobial therapy and surgery. Drainage and wide debridement of all devitalized tissues with thorough revascularization in situ or extra-anatomic bypass grafting are necessary. The procedure chosen depends on the location of the aneurysm, the purulence observed and the surgeon's preference. The graft can be made with autologous tissue or with prosthetic material. In the present case, there were 3 reasons for using a prosthetic Dacron patch instead of autogenous tissue to correct the defect left by the aneurysm resection. First, the defect was large and would have required a vessel much larger than saphenous vein. Second, by the time the aneurysm was resected, the patient was unstable and speedy closure was essential. Finally, experience has been gathered from cardiac valvular surgery, ascending thoracic aortic surgery and infected infrarenal aortic surgery showing that, given appropriate debridement, prosthetic material can be left in place. Our patient was operated on rapidly after the aneurysm was identified, and her postoperative course was complicated by a hemothorax, which necessitated a second operation. Leaking from the anastomosis site is a well-known complication of aortic angioplasty reconstruction, and graft revision in the early postoperative period is required in 2% of patients."7 Artnip RG. Mycotic aneurysm of the suprarenal abdominal ao