Search results
Found 12403 matches for
The Nuffield Department of Surgical Sciences is the academic department of surgery at the University of Oxford, and hosts a multidisciplinary team of senior clinical academic surgeons, senior scientists, junior clinicians and scientists in training.
[Apnea test for assessment of brain death under extracorporeal life support].
BACKGROUND: The fourth edition of the German guideline for the assessment of brain death, published in 2015 by the German Medical Council (Bundesärztekammer), emphasizes the importance of an apnea test. It is also now required under all circumstances of extracorporeal life support. OBJECTIVES: This article is an instruction for the guideline-conforming performance of an apnea test in general and also in cases of extracorporeal life support in different configurations. MATERIALS AND METHODS: A literature review was performed. CONCLUSIONS: The apnea test is an essential part of the bedside examination for the clinical diagnosis of brain death. It is required for all kinds of extracorporeal life support and can be easily performed without endangering the patient. More accurate recommendations for its performance should be considered for the next version of the German guideline for brain death assessment.
Stent jail of the renal arteries in stent graft exclusion of AAA. An in vitro study of 3 different stent types.
BACKGROUND: The success of endoluminal stent grafts (ELG) is critically dependent on secure proximal fixation of the graft. Different types of stent grafts with uncovered proximal portions for transrenal fixation are obtainable. The present in vitro study was designed to elucidate how the flow parameters were altered by stent jail of the renal arteries with respect to different stent design. METHODS: The experiments were performed in an in vitro pulsatile circulation model. An aortic segment with bilateral side branches (like renal arteries) constructed of an ePTFE graft was perfused in the circulation model. The flow measurements were based on the ultrasound transit-time method. By varying the frequency from 30 to 100 bpm the flow parameters were altered and recorded continuously. Renal stent jailing was carried out using different stent types: Gianturco-Z-Stent, Palmaz-Stent, Powerlink Endologix. RESULTS: The flow in the aortic model increased from 1100 ml per minute to 3330 ml per minute depending on the pump frequency. In the control group without stent jail the renal flow was measured between 240 ml per minute up to 810 ml per minute. The ratio of renal flow was between 0.22 and 0.24 of the aortic flow. In the Palmaz group the ratio was between 0.21 and 0.24, in the Gianturco group between 0.23 and 0.25, and in the Powerlink group between 0.24 and 0.25 (unpaired-"t"-test: n.s.). CONCLUSIONS: The covering of the renal arteries and/ or superior mesenteric artery in case of long bared proximal stent raises the question whether the stent jail may result in flow reduction in the arteries covered or not. The present in vitro study demonstrated that the flow in the renal arteries is not decreased by these stent jails.