Study of Microcirculation During Extracorporeal Circulation in Cardiac Surgery

Study Overview
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Brief Summary
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The aim of the proposed study is to evaluate microcirculatory alterations in patients undergoing open heart surgery under extracorporeal circulation. Positive clinical results evidenced with goal-directed perfusion and cerebral oximetry monitoring could be attributed to preserved microcirculation at tissue level.

Detailed Description
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The aim of the proposed study is to evaluate microcirculatory alterations in patients undergoing open heart surgery under extracorporeal circulation. Microcirculatory changes during cardiac surgery have been investigated mainly during coronary procedures using the conventional extracorporeal circulation. There is no single study in the literature investigating microcirculatory alterations using a perioperative strategy of physiologic perfusion. Positive clinical results evidenced with goal-directed perfusion and cerebral oximetry monitoring could be attributed to preserved microcirculation at tissue level. All patients will follow the same anaesthetic and perfusion protocol. The protocol for the evaluation of microcirculation will be based on: Cerebral near-infrared spectroscopy (rScO2) measurements (INVOS, Covidien-Medtronic Inc.). NIRS-Based Cerebral Autoregulation Monitoring: Analog arterial blood pressure signals will be digitized and then processed with the digital NIRS signals using a personal computer and a special ICM software (University of Cambridge, Cambridge, UK). Monitoring cerebral autoregulation ensures adequate renal perfusion. Hence, brain can be used not just as a target but also as an index organ indicating adequacy of perfusion. Somatic near-infrared spectroscopy (rSsO2) measurements (INVOS, Covidien-Medtronic Inc.). Sublingual mucosal microcirculation measurements during surgery using side dark field (SDF) imaging (MicroScan, Microvision Medical, Amsterdam, The Netherlands). All measurements will be performed at the following time points: T0: after induction of anaesthesia T1: after initiation of cardiopulmonary bypass T2: 10 minutes after cross- clamping the aorta T3: 10 minutes before removing the aortic cross-clamp T4: after weaning from extracorporeal circulation

Official Title
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Study of Microcirculation During Extracorporeal Circulation in Cardiac Surgery; Challenging Near-infrared Spectroscopy With Microvascular Density and Metabolic Parameters

Conditions
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Heart Diseases

Intervention / Treatment
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* Device: NIRS monitoring
* Device: Cox monitoring
* Device: Sublingual microscopy


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: patients aged > 18 and < 85 years with coronary artery disease and/or aortic valve disease undergoing open heart surgery with accepted indications Exclusion Criteria: patients undergoing emergency surgery patients in preoperative cardiogenic shock with evidence of tissue malperfusion patients > 85 years of age patients with severe peripheral vascular disease

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 85 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: Diagnostic
Intervention Model: Single Group Assignment
Interventional Model Description: Patients undergoing open heart surgery with minimal invasive extracorporeal circulation (MiECC) according to accepted indications
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: Study Patients<br>Patients undergoing open heart surgery with minimal invasive extracorporeal circulation (MiECC) according to accepted indications | Device: NIRS monitoring<br>* Cerebral and somatic near-infrared spectroscopy (rScO2) measurements<br>Device: Cox monitoring<br>* Cerebral autoregulation monitoring<br>Device: Sublingual microscopy<br>* Sublingual mucosal microcirculation measurements during surgery using side dark field (SDF) imaging<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Evaluation of microcirculation | Correlation of NIRS values with tissue microvascular activity | During surgery, from induction of anesthesia to weaning of extracorporeal circulation | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Global perfusion | Global perfusion using cerebral NIRS during extracorporeal circulation | During surgery, from induction of anesthesia to weaning of extracorporeal circulation | 
| Cerebral autoregulation | Calculation of cerebral oximetry index (COx) | During surgery, from induction of anesthesia to weaning of extracorporeal circulation | 
| Goal-directed perfusion | Correlation of goal-directed perfusion with microvascular capillary density during extracorporeal circulation | During surgery, from induction of anesthesia to weaning of extracorporeal circulation | 
| Somatic perfusion | Peripheral tissue oxygenation as measured with somatic NIRS | During surgery, from induction of anesthesia to weaning of extracorporeal circulation | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Microcirculation, Cardiac Surgery