For the anastomosis, a fine tube blowing humidified CO2 is used to keep the surgical field clean of blood. Also, a shunt might be used so the blood can travel pass the anastomotic site. After the distal anastomosis are completed, proximal anastomosis to the aorta are constructed with a partially aortic clamp and rest is similar with on-pump CABG. Alternative approaches and special situations
When CABG is performed as an emergency because of hemodynamic compromise after an infraction, priority is to salvage the struggling myocardium. Pre-operatively, an intra-aortic balloon pump (IABP) might be inserted to relieve some of the burden of pumping blood, effectively reducing the amount of oxygen needed by myocardium. Operatively, the standard practice is to place the patient on CPB as soon as possible and revascularize the heart with three saphenous veins. Calcified aorta also poses a problem since it is very dangerous to clamp. In this case, the operation can be done as off-pump CAB utilizing both IMAs or Y, T and sequential grafts, or in deep hypothermic arrest, that is lower the temperature of the body to little above 20 Celsius, can also force the heart stop moving.
In cases were a significant artery is totally occluded, theres a possibility to remove the atheroma, and using the same hole in the artery to perform an anastomosis ·this technique is called endarterectomy and is usually performed at the Right Coronary System.Reoperations of CABG (another CABG operation after a previous one), poses some difficulties: Heart may be too close to the sternum and thus at risk when cutting the sternum again, so an oscillating saw is used. Heart may be covered with strong adhesions to adjusting structures, adding to the difficulty of the procedure. Also, aging grafts pose a dilemma, whether they should be replaced with new ones or not. Manipulation of vein grafts risks dislodgement of atheromatic debris and is avoided. "Minimally Invasive revascularization" (commonly MIDCAB form minimally invasive direct coronary artery bypass) is a technique that strives to avoid a large sternotomy. It utilizes off pump techniques to place a graft, usually LIMA at LAD. LIMA is monilized through a left thoracotomy, or even endoscopically through a thoracoscope placed in the left chest. Robotic Coronary revascularization avoids the sternotomy to prevent infections and bleeding. Both conduit harvesting and the anastomosis are performed with the aid of a robot, through a thoracotomy. There is still no widespread use of the technique though. Usually it is combined with Hybrid Coronary Revascularization, which is the strategy where combined methods of CABG and PCI are employed.