Stent-graft placement for mycotic aneurysm of the thoracic aorta: report of a case.

A 66-year-old man was found to have a mycotic aneurysm of the thoracic aorta. It was first suspected to be a pseudoaneurysm of the descending thoracic aorta on computed tomography scan, and the blood cultures were positive for methicillin-resistant Staphylococcus aureus (MRSA). It was subsequently diagnosed as a mycotic aneurysm, but because the patient continued to do so poorly with septicemia, conventional surgery (ie, aortic exclusion and extraanatomic bypass, or surgical placement of in situ graft) was not performed. A stent-graft device composed of several units of self-expandable Z stents covered with ultra-thin woven Dacron was inserted through 21F sheath via the left external iliac artery and aortography showed successful deployment without blood endoleaks. The procedure was completed without incident and the patient has continued to do well. Endovascular stent-grafts may offer significant advantages for patients at high surgical risk.

Possible roles of angiotensin II-forming enzymes, angiotensin converting enzyme and chymase-like enzyme, in the human aneurysmal aorta.

Aortic aneurysm is a chronic degenerative condition associated with atherosclerosis. Recent studies have revealed that angiotensin (Ang) II plays important roles in atherosclerosis. In this study, to investigate the relationship between aortic aneurysm and Ang II, we measured the activities of the angiotensin (Ang) II-forming enzymes, angiotensin converting enzyme (ACE) and chymase-like enzyme, in human aneurysmal and control aortae. Aneurysmal aortic specimens were obtained from 16 aneurysm patients and control aortic specimens were obtained from 16 patients who underwent coronary artery bypass surgery (8 patients in each group were administered ACE inhibitors). The ACE and chymase-like enzyme activities were determined using extracts from vascular tissues. Both the ACE and chymase-like enzyme activities in the aneurysmal aortae were significantly higher than those in the control aortae (p < 0.01). In the patients treated with ACE inhibitors, the ACE activity in the aneurysmal aortae tended to be low, but the chymase-like enzyme activity tended to be high. In the aneurysmal aortae, the chymase-like enzyme activity in the adventitia was significantly higher than that in the intimal or medial layers (p < 0.01), while differences in ACE activity were not observed. Our results suggest that increases in local Ang II formation induced by chymase-like enzymes may play important roles in the pathogenesis of aneurysmal formation.

Left atrial free-floating ball thrombus with recent cardioembolic stroke.

A 67-year-old man was admitted to a local hospital complaining of hemiparesis. Because of coexisting arrhythmia, he was examined by echocardiography and found to have an oval free-floating thrombus in the left atrium concomitant with mitral and aortic stenosis. He was transferred to our hospital for emergency surgery. He underwent an operation on the ninth day from the onset of neurological dysfunction, when a 2.5 x 2.5 x 3.0 cm ball thrombus was removed, and the diseased mitral and aortic valves were replaced. His postoperative course was uneventful, with no neurological sequelae. Though left atrial ball thrombus is rarely found in patients with mitral valve disease, when it is found, then immediate surgical intervention is recommended to avoid sudden death. However, there is a high risk that any cerebral lesion may worsen due to systemic heparinization. Therefore, the optimal time of surgery in a patient with a recent neurological deficit is controversial.