Ruptured mycotic thoracoabdominal aortic aneurysms: a report of three cases and a systematic review.

We report three cases of ruptured mycotic thoracoabdominal aortic aneurysms (TAAAS) and a review of the literature. Escherichia coli and Streptococcus pneumoniae (2 patients) were the responsible organisms. Surgical management consisted of wide debridement of necrotic tissue and in situ repair with a Dacron graft. Antibiotics were administered intravenously in the hospital and continued orally after discharge for at least 6 weeks, until clinical and laboratory parameters were normalized. A review of the literature showed that Gram-negative microorganisms are found in 47% of mycotic TAAAs. A trend toward increased mortality for these organisms, compared with Gram-positive microorganisms, was observed (P =.09). Lifelong antimicrobial therapy is controversial. No difference in survival or recurrence rate was found between series advocating lifelong therapy and those suggesting prolonged (6 weeks to 12 months) therapy (median follow-up period, 18 and 19 months, respectively). In situ repair with synthetic material can be successful if prompt confirmation of infection is obtained, all possibly infected tissue is resected, and antibiotic therapy based on sensitivity data is administered for a prolonged period. A short-term survival rate as high as 82% can be expected with this strategy, but data on long-term survival rates are limited. Polytetrafluoroethylene-expanded grafts, homografts, and antibiotic-bonded grafts may offer advantages over Dacron grafts, but data are insufficient to draw conclusions. Careful long-term follow-up is an important element of the treatment of these patients. We suggest antibiotic treatment until biochemical parameters of inflammation (white cell count, erythrocyte sedimentation rate, or C-reactive protein) return to normal and a computerized tomography scan every 3 months for 1 year, then annually.

Kommerell's diverticulum and aneurysmal right-sided aortic arch: a case report and review of the literature.

Right-sided aortic arch is a rare variant of the thoracic vascular anatomy that may be accompanied by an aberrant origin of the left subclavian artery. We report a true aneurysm of the distal arch and descending thoracic aorta in a patient with right-sided arch and review previous descriptions of aneurysms of anomalous right-sided aortas. In our patient, the left subclavian artery originated at the junction between the distal arch and the descending thoracic aorta located in the right chest and was aneurysmal (Kommerell's diverticulum); the thoracic aorta was also aneurysmal. Extra-anatomic left subclavian-to-carotid transposition was performed before the intrathoracic procedure. Subsequently, a right thoracotomy provided adequate exposure for repairing the aortic aneurysm and oversewing the aneurysmal origin of the subclavian artery. Because the distal aortic arch was involved, deep hypothermia and circulatory arrest were used. Only five previous instances of true aneurysms of a right-sided aortic arch have been reported; four of these patients underwent operative repair (via bilateral thoracotomy, median sternotomy, or right thoracotomy). We believe that a right thoracotomy provides good exposure and avoids the morbidity associated with bilateral thoracotomy. The reconstruction of the subclavian artery has not previously been reported in this setting. Performing subclavian reconstruction as an extrathoracic procedure before the intrathoracic repair would be expected to reduce the subsequent risk of distal ischemia or subclavian steal without increasing the overall morbidity associated with the procedure.