Screening for coronary artery disease is recommended before heart procurement in marginal donors, but is often lacking. Performing a coronary angiographic imaging ex situ heart perfusion could be an alternative. This video provides a detailed description of this method.
Nonconventional views are needed for coronary imaging since the heart is inverted in the perfusion module. Second, the components of the module can create artifacts for inadequate imaging. And last, the toxicity of contrast agent remains questionable since it's not eliminated from the perfusion module.
Performing coronary angiographic imaging ex situ heart perfusion is easily reproducible and can exclude stenosis of the main coronary vessels. Coronary angiography on an insulated perfusion is not a common procedure for interventional cardiologist. Providing a detailed protocol of reproducible views can help to reduce exposure to contrast agent, which can be harmful.
A better assessment of coronary artery disease will increase the location of marginal grafts and could therefore reduce the organ shortage. To begin, use a scalpel to cut open the skin along the midline of an anesthetized pig. Open the subcutaneous tissue with a monopolar cautery.
Then use a semilunar sternal saw to open the sternum. Dissect and open the thymus. With a pair of Metzenbaum scissors, expose the pericardium.
Use 4/0 polypropylene sutures to perform purse string sutures on the right atrium and aortic root. Cannulate the right atrium with a 32 French 2 stage venous cannula. Now connect a previously heparinized sterilized bag to the right atrium cannula.
Collect 1, 500 milliliters of blood. Clamp the aorta, then infuse 1000 milliliters of cold cardioplegia solution. Next, remove the aortic and venous cannulas.
Section the left azygos vein, the two vena cavi, the distal ascending aorta, the pulmonary artery trunk, and the four pulmonary veins to excise the heart. Place the heart in cold saline solution. Check the aortic valve to confirm normal coaptation.
Place four pledgeted sutures around the distal section of the ascending aorta. Then insert the appropriate aortic cannula and fix it with a hose clamp. Next, insert a 30 French pulmonary artery cannula.
Secure it with a 4/0 purse string suture. Finally, place an intracardiac sump through the mitral orifice to vent the left ventricle. Elevate a perfusion machine by 25 centimeters with a platform.
Rotate it 90 degrees to the left. Prime the perfusion machine with 500 milliliters of priming solution. Then add 1, 500 milliliters of the collected porcine blood.
Oxygenate the blood with a membrane oxygenator. Then warm the blood to 34 degrees Celsius with a heater cooler. Collect an initial blood sample for blood gas analysis ionagram and lactate level.
Reduce the pump flow of the perfusion machine to 1000 milliliters per minute. Then remove the shunt between the aortic and venous lines. Now de air the aorta.
Connect the aortic cannula to the aortic line. Massage the heart gently until it is warmed. Place the heart for optimal normal thermic XC to perfusion.
Use an external pacemaker to pace the heart at 80 beats per minute. Slowly increase the pump flow to an aortic pressure of 65 milliliters of mercury. Close the inferior vena cava with a 4/0 polypropylene running suture.
Purge and connect the pulmonary artery cannula to the venous line to continuously assess coronary flow. Next, flush the 5 French introducer and the 5 French judkins right 3.5 coronary angiography catheter with serum. Insert a 5 French introducer through the valve orifice of the machine.
Advance the guide wire into the coronary angiography catheter up to the distal orifice. Then perform a coronary angiography. Catheterize the right coronary artery using the given views.
Then capture the images of the right coronary artery, proximal right coronary artery, and distal right coronary artery networks. Similarly, catheterize the left coronary artery and capture the images of the left anterior descending artery, spider view, and marginal coronary artery networks.
