The Effect of Percutaneous Superior Venae Cava Cannulation Clamping on Cerebral Near Infrared Spectroscopy in MICS

Study Overview
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Brief Summary
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The use of minimally invasive cardiac surgery has progressed over the last 5-10 years to allow access to the heart through a small incision in the right chest. This avoids the use of a sternotomy incision through the bone in the front of the chest. The benefits of such an approach are cosmetic (smaller incision not easily visible) and faster recovery. The minimally invasive approach also eliminates the risk of sternal wound infection. Minimally invasive cardiac surgery however poses additional challenges; one of the biggest is access to the large blood vessels which need to be cannulated to allow the heart lung machine to function. In conventional surgery, these vessels are easily accessed as they are entering or leaving the heart. In minimally invasive surgery, the cannula are placed into easily accessible arteries and veins, traditionally the femoral vessels. These vessels are smaller than those by the heart and so require smaller cannula, which provide challenges to the heart lung machine. One way around this is to use more cannulae and so cannulation of a vein in the neck is also performed. This cannula however, has been associated with neck hematoma, tearing of the vein and blood loss. While placement of the cannula in the neck is routine at LHSC now, when this surgery was first performed here 10 years ago, it was done so without the neck cannula and with no injury to patients. The purpose of this study therefore, is to more rigorously study the effect of the neck cannula on heart lung bypass, and more specifically to see if oxygen delivery to the organs, and the brain in particular is sufficient to avoid hypoxia.

Official Title
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The Effect of Percutaneous Superior Venae Cava Cannulation Clamping on Cerebral Near Infrared Spectroscopy During Minimally Invasive Mitral Valve Surgery

Conditions
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Mitral Regurgitation

Intervention / Treatment
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* Procedure: PSVC line clamped


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: 18-80 years of age Elective mitral valve repair or replacement. Scheduled to have minimally invasive approach (right thoracotomy) No contraindication to SVC line placement Exclusion Criteria: Emergency surgery

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: Crossover Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: PSVC line clamped<br>Clamping of the percutaneously placed superior vena cava line placed for minimally invasive mitral valve repair/replacement. | Procedure: PSVC line clamped<br>* A line clamp will be placed on the PSVC line while on cardiopulmonary bypass.<br>|
| No Intervention: Unclamped PSVC<br>Unclamped percutaneously placed superior vena cava line placed for minimally invasive mitral valve repair/replacement. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Mean Near Infrared Saturation of the brain | Measure the NIRs of the brain by placeing NIRs monitoring patches on the forehead during clamped and unclamped intervention of the percutaneous superior vena cava line. | Baseline within 5 minutes of intervention then Intraoperatively during intervention. | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Mean Blood Pressure | Measure the Mean blood pressure during clamped/unclamped Percutaneous superior vena cava line placement. | Intraoperatively during intervention.(every 5 minutes during 40 minute intervention period). | 
| Mean mixed venous saturation (non invasive measure) | Measure the central venous ressure during clamped/unclamped intervention of percutaneous superior vena cava line. | Intraoperatively during intervention.(every 5 minutes during 40 minute intervention period). | 
| CPB pump flow | Measure the pump flow during clamped/unclamped intervention of percutaneous superior vena cava line. | Intraoperatively during intervention.(every 5 minutes during 40 minute intervention period). | 
| Vacuum Pressure | Measure the vacum pressure during clamped/unclamped intervention of percutaneous superior vena cava line. | Intraoperatively during intervention.(every 5 minutes during 40 minute intervention period). | 
| Venous reservoir level | Measure the venous reservoir level during clamped/unclamped intervention of percutaneous superior vena cava line. | Intraoperatively during intervention.(every 5 minutes during 40 minute intervention period). | 
| Arterial blood gas | Measure arterial blood gases at baseline at after each intervention clamped(20 min)/unclamped (20 min) of percutaneous superior vena cava line. | Initial, after first intervention arm(20 min), at end of study period (40 min) | 
| Surgical visualization score | Score of 1-4 1=excellent visualization 4= poor visualization. | Baseline immediately before intervention period , end of each intervention period | 
| cerebral perfusion pressure | Measure the cerebral perfusion pressure (MAP-CVP)during clamped/unclamped intervention of percutaneous superior vena cava line. | Intraoperatively during intervention.(every 5 minutes during 40 minute intervention period). | 
| Central Venous Pressure | Central venous pressure measured in the superior vena cava. | Intraoperatively during intervention.(every 5 minutes during 40 minute intervention period). | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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minimally invasive cardiac surgery, cardiac surgery, near infrared spectroscopy, mitral valve repair, mitral valve replacement