BAW - here you go. I hope my description does not cross any lines I should not. If I do I appologize in advance.
Definitions:
Artery ? vessel that carries oxygenated blood
Vein ? vessel that carries deoxygenated blood
Aorta ? artery coming off the heart moving blood into the other arteries in the body.
Right Ventricle ? receives deoxygenated blood from the inferior and superior vena cava. All blood returning from the body enters the vena cava and then enters the heart here
Coronary Artery ? artery supplying oxygenated blood to the heart muscle itself. Heart muscle does not actually receive blood from the blood ?inside? the heart itself
Saphenous Vein ? major vein in the medial or inside portion of the leg that runs the entire length of the leg.
Stenosis ? Narrowing of a valve or artery. In the case of this surgery it is a narrowing of the artery due to a blockage of plaque buildup.
CABG ? Procedure to fix the Stenosis, or blockage in the artery, by using veins or arteries from other sites in the body to ?bypass? the blocked artery and supply more blood flow to the heart.
Images and Guides:
1. Right Coronary
2. Left Anterior Descending
4. Superior Vena Cava
5. Inferior Vena Cava
6. Aorta
9. Right Atrium
10. Right Ventricle
11. Left Atrium
12. Left Ventricle
Saphenous Vein:
Procedure Description:
The procedure was a quadruple Coronary Artery Bypass Grafting (CABG, pronounced ?cabbage?), meaning the patient received 4 bypasses. 3 of the Coronary Artery and 1 bypass of the Left Anterior Descending Artery. When the others in the group and I arrived at the observation room, the surgical team had prepped the patient for the procedure, this included shaving any hair on the legs and chest, covering the body with Betadine, this is the orange looking topical solution that I am sure most of you have seen, usually used to prevent against infection in cuts, etc. The body had also been wrapped in a protective covering (I do not remember what this was called) and the sterile fields had all been set up. The patient had also been put to sleep by the anesthesiologist. We did not see these parts so it would be more private for the patient.
When the others and I watching the surgery entered the observation room, the surgical team was ready to get started. The main surgical team included the Surgeon, the RNFA?s (registered nurse first assistant), the Anesthesiologist, the CRNA (the nurse anesthestist), the perfusionist, another scrub nurse or two and a few roaming nurses. Prior to starting the procedure the team counts everything that will be used in the surgery, needles, gauze, etc. All items have to be accounted for before closing the patient. All gauze and towels used to soak up blood when discarded where eventually placed in a hanging holder, which looked like a hanging shoe rack with plastic pockets. Each pocket would hold one towel, piece of gauze, etc.
First thing that was done in the procedure was that the RNFA (this person is a registered nurse, with further schooling, certification and scrub time) starts to harvest the Saphenous Vein out of the leg; the left leg was used on this patient. The RNFA made an incision starting at the ankle and eventually finished up at about the groin. The steps to do this were not just a long incision and pulling the vessel out. A short incision is made; the skin is cut and pulled back, then a pencil like device carrying an electrical current would be used on the surrounding vessels to stop loss of blood. Because this device was used the patient is grounded before the procedure commences. When the end of the Saphenous vein closest to the ankle is completely harvested a small catheter like plug is placed on the end of the vein. This cap is placed on the vessel, so the surgical team always knows which end is the far end. Veins have valves which move blood back up through the body, when these vessels are used the bypass; the valves have to be pointed so they are not obstructing blood flow. The tip placed on the vein allows the surgical team to remain aware of direction; as well, allowing them to push saline through the vein as it is harvested to make sure there is no damage to the vessel. After a small amount of the vein is out, she moved a few more inches up the leg, cutting a small amount, pulling tissue back, then harvesting the vein. This was repeated over and over.
In conjunction with the Saphenous vein harvesting the surgeon has scrubbed in and is about to start work on the thoracic cavity. At this point the leg is opened up and a little bit of the Saphenous Vein has been harvested, the RNFA and the surgeon are working on both parts now at the same time. The surgeon first makes an incision in the skin down the midline; this incision is the length of the majority of the Thoracic cavity. Another electrical pen is used to stop bleeding here as well. At times, when this piece of equipment is being used you can actually see some smoke coming off the patient where the vessels are being closed. Then layers of fat are cut through and pulled back until the surgeon and another RNFA (assisting the surgeon) come to the Sternum (breast bone). Now the Surgeon takes a small handsaw to cut through the Sternum, The saw enters up near the neck and the cut is made going away from the head. Once the ribs were separated the next phase involved separating the ribs and attaining access to the heart. Various retracting devices where used through out the procedure to keep the area open. The ribs are not completely opened up like some people believe, the space is large enough to get a hand in, the ribs however are not pulled all the way back to the table by any means.
Once access to the heart has been gained, fatty tissue has been cut through as have some of the other protective layers of the heart, the procedure becomes much more interesting. At this point you can see the heart beating, pumping blood throughout the body. It is amazing really to watch this organ work and move around completely exposed. The amount of movement that the heart has is unreal and would make this procedure very difficult if left beating. To accommodate for this the surgical team places the patient on a heart-lung machine to create a cardiopulmonary bypass (blood bypassing oxygenation in the lungs), in effect using artificial lungs and heart. Once the cardiopulmonary bypass is established, (which I will describe below) the heart slowly stops, and the machine oxygenates and pumps the blood throughout the body. Blood is returned to the machine, re-oxygenated and sent to the body again over and over while the patient is hooked into the machine.. In the case I saw, the patients heart was stopped for 1 hour and 50 minutes. During this time the heart-lung machine keeps the person alive.
In order to get the patient on the heart-lung machine, blood flow has to be diverted to and from the heart. To do this, the main trunk of Aorta is clamped off, an incision is made into the Aorta and a stitch is sewn in a circle around the Aorta. A large catheter, called a Cannula, is then placed in the Aorta; the stitch is pulled tight around the catheter and tied off to keep the catheter in place. The lines are cleared of air by running a bit of blood through the end of the catheter. This is done prior to hooking the catheter up to tubing running to the heart-lung machine. Blood that is run through the end of the catheter is let off into a sterile pan, eventually collected and run through a machine that purifies the blood (separating blood from saline and other fluids). This blood will eventually be given back to the patient. This same purification process is used for blood that is suctioned off the patient during the procedure.
The same procedure is performed on the Right Atrium, where blood returns to the heart, to divert deoxygenated blood to the machine. The only difference between the catheter in the Aorta and the Right Atrium is that the catheter in the right atrium is larger to account for the volume of blood. Once these two catheters are established and hooked up to the heart-lung machine, the perfusionist will start the machine, which takes over for the patient?s heart for a little while. Prior to being hooked up to the heart-lung machine the patient receives a large does of Heparin, which is an anticoagulant to prevent clotting in the machine and tubing running to and from the machine. On a side note, I had to administer myself Heparin when I was at home doing my IV antibiotics last month for bacterial meningitis. I had to do this for the same reason, to keep my PICC line from clotting up.
Once the heart was stopped, it has to be kept cool in order to slow down the metabolic rate, keeping the heart healthy. To keep the heart cool, a slushy mix was poured over the heart. Ice chips are not used as that could damage heart tissues. The slush is soft so that puncturing or tearing of the heart tissue will not occur. There is a machine in the room that actually makes the slush throughout the procedure. At about this same time, the RNFA had finished harvesting the Saphenous vein, which is a few feet long. She then started to suture the patient?s leg wound back together. While the RNFA working on the leg was doing this, the other RNFA, assisting the surgeon, stepped away and another surgeon came into OR to assist the primary surgeon with the bypass grafts. The procedure I watched, in addition to using the Saphenous vein for a graft, also used the Internal Thoracic Artery (better know as the Left Internal Mammary Artery) for a bypass graft, since this vessel was used it had to he separated from the chest wall before any of the grafting got underway. The Left Internal Mammary Artery (LIMA) is used to bypass the Left Anterior Descending Artery (LAD), when this happens, the procedure is known as LIMA to LAD. The left anterior descending artery is on the left side of the heart, the LIMA is sewn from the LAD to the Aorta bypassing the blockage. After the LIMA to LAD graft was sewn into the artery, the surgeon cuts the Saphenous vein into various lengths, for each bypass graft he will use it for. The length is important because if the vein is too long or too short various blood flow problems can arise. This will be double-checked once the patient is off the heart-lung machine and before being closed up. If there are length issues they are corrected at that time. The coronary bypasses are performed on both sides of the heart, so an additional nurse scrubbed in and helped hold the heart when it needed to be flipped over. In both the Saphenous Vein Grafts (SVG?s) and the LIMA to LAD graft, the vessels were sewn into the coronary arties and left anterior descending artery, then all four unattached ends were attached to the Aorta.
After all the grafts were completed the patient was slowly taken off the heart-lung machine. As blood started to be returned to the heart, the catheters were removed eventually as the heartbeat is gradually restored to a normal level. Watching the heartbeat come back was, well, amazing. Once blood flow returned, the heart just automatically started contracting again (if it does not then it is shocked) Very slowly at first, but it picked up pretty quick.. 21 beats a minute, then 27, then in the 30?s and so on and so forth until it was back up to 70 beats or so a minute. Before the patient is completely taken off the heart-lung machine the non-clotting effects of the Heparin have to be reversed, so the patient is given a pretty large dose of Protamine. The area was then double-checked, cleaned up, checked some more, etc. Any remaining blood was suctioned off for purification so it could be given back to the patient. Chest tubes were then inserted to drain the area. This is to keep any fluid build up from impeding the space the heart needs to function properly.
Once the chest tubes where in the patient?s sternum needed to be tied back together. This was done with a permanent wire, which pulls both sides of the sternum together. After the sternum wiring is completed the surgeon and the assistant both start suturing the skin back together and the procedure is more or less completed. Once the chest wound was nearly completed we left, but the patient is then taken to ICU for recovery.
If anyone has any interest in watching one of these I would encourage you to go check it out.