PubMed · 4679039
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E Frogé, J Campana. [Anesthesia and liability].. https://pubmed.ncbi.nlm.nih.gov/4679039/
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Distension of the uterus in anaesthetized pigs has been shown to cause a reflex regional vasoconstriction and an increase in plasma renin activity (PRA) through efferent sympathetic mechanisms which respectively involved alpha- and beta-adrenergic receptors. The present study was undertaken to determine the possible contribution of the activation of the renin-angiotensin system (RAS) to the observed regional vasoconstrictive responses to uterus distension. In pigs anaesthetized with alpha-chloralose, blood flow in the left circumflex or anterior descending coronary, superior mesenteric, left renal and left external iliac arteries was assessed using electromagnetic flowmeters. Distension of the uterus for periods of 30 min was performed by injecting 20 ml of warm Ringer solution into balloons positioned within the viscus before and after blockade of angiotensin II receptors with losartan. Changes in heart rate and renal blood flows were respectively prevented by atrial pacing and injection of phentolamine into the renal arteries. Changes in baroreceptors activity and in regional perfusion pressure were minimized by section of cervical vagus nerves and denervation of carotid sinuses and by an aortic constriction. PRA was assessed during the last minute of distension by radioimmunoassay of angiotensin 1. Before blockade of angiotensin II receptors, in six pigs, distension of the uterus decreased coronary blood flow by 19%, and in other six pigs, decreased mesenteric and iliac blood flows by 13.1% and 29.4% in the absence of changes in arterial perfusion pressure. After losartan, these decreases were significantly reduced to 11.7%, 8.2% and 18%. These results showed that the activation of the RAS significantly contributed to the alpha-adrenergic receptor-mediated regional vasoconstrictive responses reflexly elicited by distension of the uterus.
Two-photon microscopy has enabled anatomical and functional fluorescence imaging in the intact brain of rats. Here, we extend two-photon imaging from anesthetized, head-stabilized to awake, freely moving animals by using a miniaturized head-mounted microscope. Excitation light is conducted to the microscope in a single-mode optical fiber, and images are scanned using vibrations of the fiber tip. Microscope performance was first characterized in the neocortex of anesthetized rats. We readily obtained images of vasculature filled with fluorescently labeled blood and of layer 2/3 pyramidal neurons filled with a calcium indicator. Capillary blood flow and dendritic calcium transients were measured with high time resolution using line scans. In awake, freely moving rats, stable imaging was possible except during sudden head movements.
BACKGROUND: The introduction of robotic enhanced surgery demanded stepwise development of performed procedures on the basis of growing experience of the operating team. METHODS AND RESULTS: Between May 1999 and January 2001, this new wrist-enhanced instrumentation was used in 201 patients (156 men and 45 women, median age 64+/-10.5 years, left ventricular ejection fraction 68+/-12.4%). During the development of robotic enhanced CABG, the patients were divided into 3 groups. Group A (n=156) consisted of patients in whom the robotic system was used to harvesting the left or right internal mammary artery, or both, whereas the anastomoses were performed directly through a small chest incision. In group B (n=37), the harvest of the internal mammary arteries and the coronary anastomoses were performed totally endoscopically. In a third early group C, patient (n=8) were treated with robotic enhanced CABG via a median sternotomy already preoperatively planned, whereas gradual step-by-step application of robotic instrumentation and its feasibility were assessed. The survival rate was 99.4%. One patient (0.6%) died due to pneumonia on postoperative day 16. Conversion rate to median sternotomy was 5%. The left and right internal mammary artery conduits could be successfully harvested in 98% and 100%, respectively. The time of dissection of the left internal mammary artery could be significantly reduced alone by increasing experience. All patients were discharged from the hospital after a mean of 7 days. In 9 patients (4.5%), bleeding required reexploration. CONCLUSIONS: The introduction of this new surgical tool enables the development of new endoscopic procedures. Our results gained during the development of robotic enhanced CABG motivate us to establish a set standard for the totally endoscopic treatment of patients with 1-vessel coronary artery disease.