In a CABG, arteries or veins from elsewhere in the patient’s body are used to graft to the coronary arteries to bypass atherosclerotic narrowings and improve the blood supply to the coronary circulation supplying the myocardium (heart muscle). I watched the PA (physician assistant) cut open the patient’s legs and use a scope to locate and harvest the veins that would be used for grafting. Meanwhile, the cardiothoracic surgeon made an incision in the patient’s chest, cut apart his sternum (breast bone) with a saw, and proceeded to dissect the internal mammary artery from the chest wall to use as a bypass conduit.
I was in awe when I stood at the head of the patient and looked down at his beating heart. I teared up as I witnessed this amazing site and marveled at how advanced technology has become. My face was two feet above his chest, and I had the privilege of watching the surgeon and PA stitch one end of the vein graft to the aorta and the other end to the coronary artery just past the blocked area. The surgeon pointed out to me the area he’d bypassed in the left anterior coronary artery (LAD), and then I watched as he injected blood through the new graft to test the patency. It was amazing to see how the blood is redirected through the vein graft, detouring the blocked or narrowed artery and increasing blood flow to that region of the heart.
Due to the difficulty operating on a beating heart, this part of the operation required that the patient’s heart be stopped. This was achieved by feeding a serum containing a concentrated solution of potassium ions into the coronary artery, which feeds the heart muscle. Significantly increasing potassium in the body causes a defect in the heart’s rhythm and can lead to ceasing of the heart function. Feeding the coronary artery rapidly with a rich potassium solution causes the heart to stop within a few seconds and allows the surgeon to perform the operation on a non-functioning, motionless heart.
This necessitates the usage of cardiopulmonary bypass (CPB). The nurse explained to me that CPB (heart-lung machine) temporarily takes over the function of the heart and lungs during surgery, maintaining the circulation of blood and the oxygen content of the body. CPB can also be used for the induction of total body hypothermia, a state in which the body can be maintained for up to 45 minutes without perfusion (blood flow). If blood flow is stopped at normal body temperature, permanent brain damage normally occurs in three to four minutes and death may follow shortly afterward. This explains why the surgical technicians occasionally threw ice onto the patient’s heart while the surgeon operated on it. They then used CBP to rewarm the patient when his heart was restarted, and the potassium was reduced to a normal level. Once the heart beats normally, the patient can be removed from the CPB machine.
I was impressed by the plethora of tools and supplies that were set out and used for this operation. To prevent the possibility of something disappearing into the patient being operated on, everything was counted repeatedly. Even every piece of gauze used was saved and accounted for until the surgery was complete. At one point the surgical tech notified the surgeon that a piece of gauze was missing; fortunately, after digging around the heart with some forceps, the surgeon located and extracted it. Crisis averted. He used a wire sternotomy suture to close up the sternum, while the PA used sutures to close up the chest and leg wounds. The surgery itself took about four hours.
The following video is a good representation of what I witnessed in the OR today. Do not watch it if you are at all squeamish (ahem, Brent).
Other nursing students with whom I’ve spoken mentioned they became somewhat dizzy, lightheaded, and nauseous from being in the OR. Thankfully I didn’t have issues with any of it. The camaraderie and synergy among the OR staff was great. The atmosphere was relaxed as we listened to Elton John, Lady Gaga, and Eric Clapton–compliments of the surgeon’s iPhone. The entire experience was amazing, and I feel very fortunate that the particular operation I was able to witness was open heart surgery. I have long been fascinated with the intricacy, synergy, and complexity of the human body; to actually see some of this presented in a living human was incredible.