Tuberculous mycotic aneurysm of the aorta: review of published medical and surgical experience

To define the epidemiology, pathogenesis, pathology, presentation, and management of tuberculous mycotic aneurysm of the aorta (TBAA) in the therapeutic era, we reviewed all of the cases reported in the English language literature from 1945 to the present. To the 39 cases in the published literature, we add two cases of our own. Although it is exceedingly rare, the prevalence of this lesion has remained relatively constant. In 75% of the cases, TBAA appeared to result from erosion of the aortic wall by a contiguous focus; 25% from direct seeding of the aortic intima or of the adventitia or media (via the vasa vasorum). Most of the aneurysms were saccular (90%) and false (88%). The thoracic and abdominal aortas were affected with equal frequency. The mean (+/- SD) age of the patients was 50+/-16 years. Twenty-two were men, and 19 were women. In 63% of the cases, tuberculosis (TB) was diagnosed at presentation. Disseminated TB was present in 46% of the cases. One or more of three clinical scenarios suggested TBAA: persistent pain, major bleeding, and a palpable or radiographically visible para-aortic mass, especially if it is expanding or pulsatile. In turn, each of these findings suggested a complication of TBAA that may be an indication for surgical intervention. Among the patients who were offered both medical and surgical treatment, 20 of 23 (87%) survived. Among those who were offered only one form of treatment or were offered no treatment at all there were no survivors. Both in situ reconstruction with a prosthetic graft, and extra-anatomic bypass appeared to offer excellent results, provided that an effective regimen of antituberculous drugs was delivered postoperatively. We offer our conclusions: (1) symptomatic TBAA is a rare but uniformly fatal lesion if not diagnosed promptly, (2) in the context of active TB, and especially miliary TB, TBAA should be suspected whenever one or more of the three clinical scenarios are present, and (3) combined medical and surgical therapy appears to offer the best chance of a cure.

Surgical treatment of infected thoracic and abdominal aortic aneurysms

Twelve patients with infected aneurysms of the thoracic and abdominal aorta were evaluated. Aneurysmal location, aetiology, bacteriology and treatment modality were analysed to determine the relationship between these factors and outcome. Patients were divided into two groups based on the preoperative states of their infections. Group 1 patients (n = 7) underwent resection after resolution of their active infection. The causative organisms included Staphylococcus epidermidis (two cases). Salmonella spp. (one). Acinetobacter (one), Mycobacterium tuberculosis (one) and unknown organisms (two). Group 2 patients (n = 5) required urgent surgery because of uncontrolled sepsis despite intensive treatment with antibiotics. The causative organisms included Staphylococcus aureus (two cases). Pseudomonas aeruginosa (two) and Salmonella spp. (one). In group 1, three patients underwent closed en bloc excision of the aneurysm with in-situ graft replacement, and four underwent partial resection with in-situ graft replacement. In group 2, three patients underwent resection of the aneurysm with ligation of aorta and extra-anatomic bypass, and two underwent in-situ graft replacement after débridement of infected tissue. Overall, patients in group 1 had a mortality rate of 14% compared with 80% in group 2. These results suggest that the operative approach and method chosen to restore arterial continuity have less of an impact on outcome. The primary determinants of outcome are virulence of the infecting organism and the preoperative state of the infection.