[So-called "primary" infected aneurysms of the sub-renal abdominal aorta. Five observations]. / Les anévrismes infectieux dits "primitifs" de l'aorte abdominale sous-rénale. A propos de cinq observations.

The authors describe 5 cases of mycotic aneurysms of the infrarenal abdominal aorta. These relatively rare lesions raise problems which are not so much diagnostic but above all therapeutic and etiopathogenic. They are rare lesions, with a striking clinical picture and often very spectacular radiological appearances, in particular by CT scan and angiography. Indications for surgery as well as the technique used thus comply with rigorous norms. However, despite everything, and in particular despite increasingly early positive diagnosis, rapid surgical management and advances in vascular surgery techniques, the mortality associated with such lesions remains very high, even in the context of cold aneurysm surgery, when compared with ordinary atherosclerotic aneurysms, dealt with under the same conditions.

[Mycotic aneurysms]. / Les anévrysmes mycotiques.

Mycotic aneurysms are aneurysms infected by bacteria or fungi. These may be secondary to an endocarditis, or they may be primary, and then are developed from a septicemia or bacteremia. The diagnosis, often difficult, is sometime only made during complications, the most severe of which is rupture. This diagnosis must be aided by new imaging techniques such as ultrasonography, tomodensitometry, magnetic resonance imaging. The treatment is medical (antibiotics) and surgical.

Classification and management of mycotic aneurysms.

After a review of 14 patients with extracranial mycotic aneurysms, a classification of mycotic aneurysms has been proposed based upon the pre-existing pathologic condition of the artery and on the pathogenesis. Ten aneurysms resulted from an infection due to intravascular sources and four, due to extravascular sources. Ten patients in this series were treated surgically, and of these, eight were cured. All four patients who did not undergo a surgical procedure died. Early diagnosis, appropriate antibiotic therapy and prompt surgical intervention are recommended in the management of these aneurysms. Excision or exclusion of aneurysms is preferred. If necessary, the circulation to the distal part of the extremity can be restored by vascular reconstruction using an autogenous bypass graft, preferably through a noninfected field.

Infected aortic aneurysms: imaging findings.

PURPOSE: To determine the imaging characteristics of infected aortic aneurysms. MATERIALS AND METHODS: Review of records of patients with surgical and/or microbiologic proof of infected aortic aneurysm obtained over a 25-year period revealed 31 aneurysms in 29 patients. This study included 21 men and eight women (mean age, 70 years). One radiologist reviewed 28 computed tomographic (CT) studies (22 patients underwent CT once and three patients underwent CT twice), 12 arteriograms (12 patients underwent arteriography once), eight nuclear medicine studies (six patients underwent nuclear medicine imaging once and one patient underwent nuclear medicine imaging twice), and three magnetic resonance (MR) studies (three patients underwent MR imaging once). Features evaluated included aneurysm size, shape, and location; branch involvement; aortic wall calcification; gas; radiotracer uptake on nuclear medicine studies; and periaortic and associated findings. The location of infected aortic aneurysms was compared with that of arteriosclerotic aneurysms. RESULTS: Aneurysms were located in the ascending aorta (n = 2, 6%), descending thoracic aorta (n = 7, 23%), thoracoabdominal aorta (n = 6, 19%), paravisceral aorta (n = 2, 6%), juxtarenal aorta (n = 3, 10%), infrarenal aorta (n = 10, 32%), and renal artery (n = 1, 3%). Two patients had two infected aortic aneurysms. CT revealed 25 saccular (93%) and two fusiform (7%) aneurysms with a mean diameter at initial discovery of 5.4 cm (range, 1-11 cm). Paraaortic soft-tissue mass, stranding, and/or fluid was present in 13 (48%) of 27 aneurysms, and early periaortic edema with rapid aneurysm progression and development was present in three (100%) patients with sequential studies. Other findings included adjacent vertebral body destruction with psoas muscle abscess (n = 1, 4%), kidney infarct (n = 1, 4%), absence of calcification in the aortic wall (n = 2, 7%), and periaortic gas (n = 2, 7%). Angiography showed 13 saccular aneurysms with lobulated contour in 10 (77%). Nuclear medicine imaging showed increased activity consistent with infection in six (86%) of seven aneurysms. MR imaging showed three saccular aneurysms. Adjacent abnormal vertebral body marrow signal intensity was seen in one (33%) of three patients. CONCLUSION: Saccular aneurysms (especially those with lobulated contour) with rapid expansion or development and adjacent mass, stranding, and/or fluid in an unusual location are highly suspicious for an infected aneurysm.