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Reaktive Sauerstoffspezies und Gefäßdegeneration

Background: In the current considerations of the genesis of cardiovascular degeneration, reactive oxygen species (ROS) have come into focus as a potential key factor. Several models of nutritive and enzymatic approaches have tried to analyze its causative role; however, they are accompanied by systemic effects and unforeseeable interaction patterns. Objective: This study analyzed the photodynamic reaction (PDR) regarding its potential to initiate a focal, non-systemic impact of oxidative stress. The induced processes and results were characterized by comparing them with the current perception of atherosclerotic vascular degeneration. Material and methods: A PDR was applied to the infrarenal aorta of rats by the combination of rose bengal and a low-power laser. The rats in the ROS and control groups (each n = 5) where killed at six points of time. All specimens were analyzed regarding gross morphological changes as well as detailed cell composition and the dynamics of cell migration. Results: Contrary to the controls, the ROS groups displayed an initial thrombus formation that disappeared not later than at t = 8 days. After a period of morphological latency accompanied by a significantly increased matrix metalloproteinase (MMP) activity, the ROS-exposed area displayed a significant thickening of the media (p < 0,001) as well as a significant focal calcification (p < 0.01). This was accompanied by a focally reduced alpha-smooth muscle actin (alpha-SMA) expression. Conclusion: The PDR induces morphological short-term effects that disappear after not later than 8 days. After a latency period, certain aspects of an atherosclerotic degeneration were obvious. In contrast, key aspects, such as increased inflammation and foam cells were missing. Nevertheless, the established concept is a suitable model to investigate the role of ROS in vascular degeneration

Is simultaneous splenectomy an additive risk factor in surgical treatment for active endocarditis?

Purpose: Splenic abscess formation is a serious complication in the setting of active endocarditis, and splenectomy is recommended. However, the optimal timing for splenectomy is yet undetermined. The purpose of this study was to evaluate the role of a one-stage splenectomy and valve surgery for active endocarditis. Methods: Among 202 consecutive endocarditis patients, 18 had splenic lesions on preoperative abdominal screening, who underwent cardiac surgery and splenectomy as a one-stage procedure (group A) and were compared to patients with unremarkable abdominal screening (group B, n = 184) undergoing sole cardiac surgery. Results: No difference was observed regarding preoperative characteristics (age, gender, New York Heart Association [NYHA] grade, diabetes, coronary artery disease, redo surgery, adiposity, smoking), intubation time, and prolonged ventilation. There were 23 early postoperative deaths in group B (12.5%) vs. none in group A. At 180 days, survival was significantly higher for patients in group A (94.4%) vs. group B (67.9%, p = 0.016), although this difference did not reach statistical significance (log-rank test, p = 0.073). Multivariate Cox proportional hazards regression revealed age above 50 years (hazard ratio [HR] 3.327, 95% confidence interval [CI] 1.279-8.650) and NYHA class above III (NYHA III or IV: HR 3.117, 95% CI 1.119-8.683, p = 0.030; NYHA IV: HR 3.678, 95% CI 1.984-6.817, p < 0.001) as independent risk factors for mortality at 180 days. A trend towards a protective factor was observed for simultaneous splenectomy (HR = 0.171, 95% CI 0.023-1.255). Conclusion: Simultaneous valve surgery and splenectomy is an approach for active endocarditis complicated by splenic lesions with a low 180-day mortality. Despite the expected risk elevation by septic lesions and the additive trauma of a laparotomy, patients with simultaneous splenectomy had a favourable outcome regarding early mortality and mortality at 6 months