Pre-operative planning<unk>  requires significant forethought before surgery. In particular, the cannulation, cooling, and cardio-protective strategies must be coordinated between the surgeon, anesthesiologist, perfusionist, and nursing staff. Cannulation strategy The cannulation strategy varies on several operation-specific and patient-specific details. The typical arterial cannulation involves the placement of a single cannulation within distal ascending aorta. The most simple form on involves placement of a single cannula (known as a dual-stage cannula) passed through the right atrium and into the inferior vena cava. In some operations, such as those involving the tricuspid or mitral valve, two cannula are used—one is passed through the inferior vena cava and one through the superior vena cava. This is known as bi-caval cannulation. Intra-operative technique A<unk>  circuit must be primed with fluid and all air expunged from the arterial line/cannula before connection to the patient. The circuit is primed with a crystalloid solution and sometimes blood products are also added. Prior to cannulation (typically after opening the pericardium when using central cannulation), heparin or another anticoagulant is administered until the activated clotting time is above 480 seconds. The arterial cannulation site is inspected for calcification or other disease. Preoperative imaging or an ultrasound probe may be used to help identify aortic calcifications that could potentially become dislodged and cause an occlusion or stroke. Once the cannulation site has been deemed safe, two concentric, diamond-shaped pursestring sutures are placed in the distal ascending aorta. A stab incision with a scalpel is made within the pursestrings and the arterial cannula is passed through the incision. It is important the cannula is passed perpendicular to the aorta to avoid creating an aortic dissection. The pursestrings sutures are cinched around the cannula using a tourniquet and secured to the cannula. At this point, the perfusionist advances the arterial line of the<unk>  circuit and the surgeon connects the arterial line coming from the patient to the arterial line coming from the<unk>  machine. Care must be taken to ensure no air is in the circuit when the two are connected, or else the patient could suffer from an air embolism. Other sites for arterial cannulation include the axillary artery, brachiocephalic artery, or femoral artery. Aside from the differences in location, venous cannulation is performed similarly to arterial cannulation. Since calcification of the venous system is less common, the inspection or use of an ultrasound for calcification at the cannulation sites is unnecessary. Also, because the venous system is under much less pressure than the arterial system, only a single suture is required to hold the cannula in place. If only a single cannula is to be used (dual-stage cannulation), it is passed through the right atrial appendage, through the tricuspid valve, and into the inferior vena cava. If two cannula are required (single-stage cannulation), the first one is typically passed through the superior vena cava and the second through the inferior vena cava. The femoral vein may also be cannulated in select patients. If the heart must be stopped for the operation, cardioplegia cannulas are also required. Antegrade cardiopledgia (forward flowing, through the heart's arteries), retrograde cardiopledgia (backwards flowing, through the heart's veins), or both types may be used depending on the operation and surgeon preference. For antegrade cardiopledgia, a small incision is made in the aorta proximal to the arterial cannulation site (between the heart and arterial cannulation site) and the cannula is placed through this to deliver cardiopledgia to the coronary arteries. For retrograde cardiopledgia, an incision is made on the posterior (back) surface of the heart through the right ventricle. The cannula is placed in this incision, passed through the tricuspid valve, and into the coronary sinus. The cardiopledgia lines are connected to the<unk>  machine. At this point, the patient is ready to go on<unk> . Blood from the venous cannula(s) enters the<unk>  machine by gravity where it is oxygenated and cooled (if necessary) before returning to the body through the arterial cannula. Cardiopledgia can now be administered to stop the heart, and a cross-clamp is placed across the aorta between the arterial cannula and cardiopledgia cannula to prevent the arterial blood from flowing backwards into the heart. Once the patient is ready to come off of<unk>  support, the cross-clamp and cannulas are removed and protamine sulfate is administered to reverse the anticoagulative effects of heparin.
Cardiopulmonary bypass
Extracorporeal membrane oxygenation
Extracorporeal cardiopulmonary resuscitation
Minimized extracorporeal circulation
Cardiopulmonary resuscitation
Intra-aortic balloon pump
Ventricular assist device
Resuscitative thoracotomy