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

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

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

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.

minimally invasive cardiac surgery, cardiac surgery, near infrared spectroscopy, mitral valve repair, mitral valve replacement

Clamping of the percutaneously placed superior vena cava line placed for minimally invasive mitral valve repair/replacement.

Unclamped percutaneously placed superior vena cava line placed for minimally invasive mitral valve repair/replacement.

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.

Measure the Mean blood pressure during clamped/unclamped Percutaneous superior vena cava line placement.

Measure the central venous ressure during clamped/unclamped intervention of percutaneous superior vena cava line.

Measure the vacum pressure during clamped/unclamped intervention of percutaneous superior vena cava line.

Measure the venous reservoir level during clamped/unclamped intervention of percutaneous superior vena cava line.

Measure arterial blood gases at baseline at after each intervention clamped(20 min)/unclamped (20 min) of percutaneous superior vena cava line.

Measure the cerebral perfusion pressure (MAP-CVP)during clamped/unclamped intervention of percutaneous superior vena cava line.

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

Bainbridge DT, Chu MW, Kiaii B, Cleland A, Murkin J. Percutaneous superior vena cava drainage during minimally invasive mitral valve surgery: a randomized, crossover study. J Cardiothorac Vasc Anesth. 2015 Feb;29(1):101-6. doi: 10.1053/j.jvca.2014.07.020. Epub 2014 Nov 7.