ABSTRACT
AIM OF THE STUDY: We retrospectively analyzed the results of operations conducted for aortic prosthetic valve endocarditis in a single center over 19 years. MATERIAL AND METHODS: From February 1992 to January 2011, we performed operations on 27 patients with aortic prosthetic valve endocarditis. Seventeen patients (63.0%) were male, and the mean age was 39.1 ± 14.2 (16-67) years. Blood cultures were positive in 11 patients (40.7%), and the most commonly identified microorganism was Streptococcus (7 patients, 25.9%). The mean duration of follow-up was 8.6 ± 4.7 years (0.5-18.2), adding up to a total of 136.9 patient/years. RESULTS: Forty procedures were performed on these 27 patients. The most commonly performed procedure was aortic valve replacement with a prosthetic valve - 16 patients (59.3%). Fifteen patients were operated on during the active phase of infection. In-hospital mortality was observed in 11 patients (40.7%). Postoperatively, 12 patients (44.4%) had low cardiac output, 3 (11.1%) suffered from a heart block; none of them required permanent pacemaker implantation. The actuarial survival for 1 and 5 years was 55.6 ± 9.6% and 47.6 ± 9.7%, respectively. CONCLUSIONS: Prosthetic valve endocarditis of the aortic valve is a challenging situation for the surgeon. The surgical treatment carries a high mortality rate and long-term survival is low. Among the survivors, however, recurrence and the need for reoperation are unlikely.
ABSTRACT
Reperfusion injury is a consequence of inadequate energy supply and acidosis in ischemic tissues and a chain of events triggered by oxygen-derived free radicals released in response to exposure of oxygen. In this study, we aimed to assess the effects of clopidogrel, an antithrombotic agent, on experimental ischemia-reperfusion model in rats. The ischemia was performed by blockade of the circulation of right lower extremity at trochanter major level for 6 hours. Then, the extremity was reperfused for 4 hours. Another group of rats pretreated with clopidogrel (0.2 mg/kg/day) for 10 days prior to ischemia-reperfusion. After the reperfusion period, all rats were anesthetized with ketamine. Blood and tissue samples from the gastrocnemius muscle, liver and lungs were taken for the measurement of malondialdehyde (MDA), glutathione (GSH) levels and superoxide dismutase (SOD) activity. The results revealed that clopidogrel prevented the increase in MDA level and the decrease in GSH level and SOD activity caused by ischemia-reperfusion both in tissue samples and plasma. These findings suggest that clopidogrel is beneficial in prevention of ischemia-reperfusion injury probably via its effects on inflammatory cells, platelets, and endothelial cells.
