An experimental approach to reversible 'endovascular aortic valve placement'.

Background And Aim Of The Study: Beating heart aortic valve (re)placement without thoracotomy would be a desirable therapeutic strategy. In the present study, the feasibility of an endovascular aortic valve (re)placement was evaluated in an animal model.

Methods: A self-expandable stent-valve and two different non-obstructive delivery devices were designed.

Bronchoscopic surfactant administration preserves gas exchange and pulmonary compliance after single lung transplantation in dogs.

Background: Surfactant abnormalities have been implicated in reperfusion injury and respiratory failure in lung transplantation.

Methods: We investigated the efficacy of bronchoscopic administration of a bovine natural lung surfactant extract (Alveofact) to improve gas exchange and lung mechanics after heterologous left lung transplantation in foxhounds (+4 degrees C ischemia for 24 hours, conservation with Euro-Collins solution). Animals received either no surfactant therapy (untreated controls, n = 6) or 50 mg/kg body weight (prior to explantation, only graft) and 200 mg/kg body weight Alveofact (immediately after reperfusion, both lungs, n = 6).

Tumor necrosis factor-alpha production in whole blood after cardiopulmonary bypass: downregulation caused by circulating cytokine-inhibitory activities.

Objectives: Cardiopulmonary bypass is associated with the release of proinflammatory cytokines (tumor necrosis factor alpha, interleukin 1beta, interleukin 6, and interleukin 8) and anti-inflammatory cytokines (interleukin 10 and transforming growth factor beta(1)). On the one hand this cytokine release is related to the postoperative systemic inflammatory response syndrome, and on the other hand it is related to deterioration of the immune system, for example in monocyte or polymorphonuclear neutrophil function, leading to an increased susceptibility to infections. To gain further insight into the alterations of immune cell reactivity and possible regulatory mechanisms, we studied lipopolysaccharide-induced tumor necrosis factor alpha synthesis in whole blood from cardiac surgical patients.

Pulmonary blood flow is inhomogeneously reduced after Euro Collins-preservation and lung transplantation.

Background: Vasoconstriction after lung transplantation is a well-known phenomenon, but only limited information is available on blood flow distribution after ischemia and reperfusion. The aim of our study was to determine the regional flow characteristics in transplanted and native dog lungs after 24 hours of cold storage and preservation with Euro Collins-solution.

Methods: Six pairs of weight-matched Foxhounds (25 to 30 kg) were used.

Ischemic pre-conditioning of 5 minutes but not of 10 minutes improves lung function after warm ischemia in a canine model.

Background: Protection from reperfusion injury by ischemic pre-conditioning (IPC) before prolonged ischemia has been proven for the heart and the liver. We now assess the efficacy of IPC to protect lungs from reperfusion injury.

Methods: Eighteen foxhounds (25 to 30 kg) were anesthetized, intubated, and ventilated with a fraction of inspired oxygen of 0.