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

Study Overview
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Brief Summary
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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.

Detailed Description
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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.

Official Title
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Aortic Valve Replacement Using Closed Extracorporeal Circuit. Minimized Versus Conventional Extracorporeal Circulation Technique: Qualitative Differences

Conditions
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Aortic Valve Stenosis, Extracorporeal Circulation

Intervention / Treatment
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* Procedure: Minimized Extracorporeal Circulation (MECC)
* Procedure: Conventional Extracorporeal Circulation (CECC)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Isolated Severe Aortic Valve Stenosis No other cardiac disease No other coronary heart disease Written informed consent Exclusion Criteria Double valve surgery Concomitant coronary artery bypass surgery Vascular surgery Age < 18 yrs. Age > 80 yrs.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 80 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Conventional Extracorporeal Circulation Technique<br>Conventional Extracorporeal Circulation Technique | Procedure: Conventional Extracorporeal Circulation (CECC)<br>* This group of patients receives surgical aortic valve replacement using CECC.<br>|
| Experimental: Minimized Extracorporeal Circulation Technique<br>Minimized Extracorporeal Circulation Technique | Procedure: Minimized Extracorporeal Circulation (MECC)<br>* This group of patients receives surgical aortic valve replacement using MECC.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Total and interval-related cerebral microembolic load as measured by transcranial Doppler |  | Intraoperative period (start surgical procedure to skin suture, duration approx. 4 hrs) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Cerebral complications, e.g. delirium and stroke as detected clinically |  | In-hospital period (until hospital discharge, duration approx. 7-10 days) | 
| Redo surgery |  | In-hospital period (until hospital discharge, duration approx. 7-10 days) | 
| ICU length of stay |  | In-hospital period (until hospital discharge, duration approx. 7-10 days) | 
| Extubation time |  | In-hospital period (until hospital discharge, duration approx. 7-10 days) | 
| Thromboembolic complications |  | In-hospital period (until hospital discharge, duration approx. 7-10 days) | 
| In-hospital infections |  | In-hospital period (until hospital discharge, duration approx. 7-10 days) | 
| In-hospital Mortality |  | In-hospital period (until hospital discharge, duration approx. 7-10 days) | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Intracranial Embolism, Ultrasonography, Doppler, Transcranial