Cerebral Embolic Load in Patients Undergoing Surgical Aortic Valve Replacement: A Comparison of the Conventional With the Minimized Extracorporeal Circulation Technique Using Transcranial Doppler Ultrasound

Overview

In this study, the investigators aim to compare cerebral embolic load in patients undergoing surgical aortic valve replacement using either the minimized extracorporeal circulation or the conventional extracorporeal circulation technique. The detection of cerebral emboli is performed not-invasively by transcranial Doppler detection of high-intensity transient signals representing solid or gaseous microembolism in the middle cerebral arteries. The investigators hope to get more insight in the mechanism (incl. quantity) of cerebral embolism during aortic valve surgery using extracorporeal circulation.

Background The gold standard to treat severe aortic valve stenosis is currently the surgical aortic valve replacement (SAVR) using conventional extracorporeal circulation (CECC). SAVR, however, can be performed also on minimized extracorporeal circulation (MECC), which is characterized by reduced priming volume and interfaces between blood and artificial surfaces and blood-air interface, respectively. Further technical developments of the MECC system together with reports on less induction of the coagulation cascade and activation of inflammatory systemic response may account for a reduced incidence of microbubble generation with MECC system. Objective The aim of the is to investigate the procedural-related incidence of high-intensity transient signals (HITS) representing solid or gaseous microembolism reaching the cerebral vessels. Methods Patients undergoing SAVR are included in the study and randomised to either MECC or CECC technique. HITS are continuously bilaterally detected during the entire intraoperative period by transcranial Doppler ultrasound.