This will be a short description of Nancy’s open heart surgery. I’ve used notes from the surgeon and information taken from the internet. I’ve changed most of the medical terms to simple English and in the process reduced the accuracy. I’ve added links where I’ve found helpful drawings and information.
When the operation was completed Nancy had a new valve and two replaced sections of artery leading to parts of her heart.
This link shows the location of the parts of the heart. Note the location of the ‘left atrium’ because that is how one approaches the mitral valve.
http://en.wikipedia.org/wiki/Mitral_valve
The heart needs oxygen rich blood that is provided by arteries and when these become narrowed by disease the muscle of the heart suffers or dies. Two arteries needed to be replaced. One of the larger heart arteries is called the “left anterior descending” (LAD) coronary artery. Its location is shown on this page:
http://www.texheartsurgeons.com/cad.htm
From the main arteries are branches or “diagonals” and one of these also had reduced blood flow from clogging.
To get to these arteries and the mitral valve Nancy’s chest had to be opened. This is done with a reciprocating saw with the same basic design of a wood worker’s tool you buy at the hardware store. The design is more refined and the blade is short – it only has to be slightly longer than the breast bone (sternum) is thick. The location of the sternum is shown here:
http://en.wikipedia.org/wiki/Sternum
A photograph of one brand of sternum saw is shown here:
http://www.terumo-cvs.com/products/ProductDetail.aspx?groupId=6&familyID=114&country=1
You will sometimes hear of “breaking” the chest bone but the instrument of choice is a saw and not a hammer. Here is a link to a video that shows the chest being opened. There is some blood, but not a lot, and you get a look at a beating heart. If you feint at the sight of blood skip this or sit down in a comfy chair.
http://www.youtube.com/watch?v=r7RsB0BA4EI
Once the surgical team gets the chest open the blood flow to the body is maintained by bypassing the heart with a “heart lung machine.” The concept is shown here:
http://biomed.brown.edu/Courses/BI108/BI108_2004_Groups/Group03/HeartLungMachine.jpg
And here is a picture of the real thing.
http://heatherwritesablog.files.wordpress.com/2009/06/heart-and-lung-machine.jpg
Much more complex. The issue is to take the heart “off line” and repair it while maintaining blood flow to the rest of the body. You can read about it here:
http://en.wikipedia.org/wiki/Cardiopulmonary_bypass
An issue in all of this is that you do not want the patient to get blood clots while doing the surgery so an anticoagulation chemical is necessary but you then need to put the parts back together with sufficient clotting ability in the blood so that they don’t leak around every suture.
Nancy managed to complicate this already complex issue because of her serious allergic reaction to heparin, the anticoagulant of choice. For her they used a chemical called Angiomax.
The next issue is that the heart will be stopped and disconnected from the blood supply and both the patient and her heart will fare better if all this is done at a lower temperature. So she was cooled from a normal 98.6o F. to 86o F. (37o C. to 30o C.).
Her heart was stopped by using cold blood (with added potassium) put into it by way of both the main artery and vein and kept cold by repeating this every 10 minutes. This is called “cold potassium blood cardioplegia” with the last word meaning “paralysis of the heart.”
A vein from near the surface on the inside of her left leg, above the ankle, was “harvested” and used to replace the “diagonal” artery. The vein used is called the “saphenous” vein (clearly seen) as it is close to the surface of the body and can be seen under the skin. When the body is too hot the body shunts blood from the deep veins to the superficial veins, to facilitate heat transfer to the surroundings. Normally this vein doesn’t get a lot of blood volume and so can be removed without harm.
Next the “left anterior descending” or LAD was bypassed. For this they used an artery found within the chest cavity called “left internal mammary artery” or LIMA. There is also one on the right side. These unique blood vessels run along the inside edges of the sternum, sending off small branches to the bones, cartilage, and soft tissues of the chest wall. For unclear reasons, the IMAs are remarkably resistant to cholesterol buildup and thus a good choice for replacing an important heart artery. Read more about the IMAs here:
http://www.hsforum.com/stories/storyReader$1491
To replace the mitral valve the left side of the heart has to be opened. This is called “left atriotomy” — meaning cutting open the upper chamber on the left side of the heart (the atrium). Nancy’s mitral valve was in need of replacement and (apparently) dead bacterial ‘vegetation’ from last summer’s endocarditis was also found there. The attachments that make the valve work were shaved some to make them work better. The old valve was cut out and a replacement from a pig (a 33 mm Hancock II porcine prosthesis) was set in and sutured into place.
With the new valve in place the surgeon than had to close the opening in the heart. As they worked their way back out of the chest cavity they re-warmed Nancy’s entire body and sent warm blood back into the heart. Her heart came back to life with a single electrical shock. It started with a normal rhythm, which in medical terms is called “sinus rhythm” but the use of the term ‘sinus’ likely derives from a mistaken idea and so has only historical context for its continued usage. She was on the heart-lung machine for 100 minutes.
On a normal patient the surgery would be about over at this point. But for Nancy there was a long wait ahead. The blood thinning issue meant she would stay in danger of excessive bleeding for some time. With all the major and minor cuts and sutures in her chest cavity there were lots of places for something to leak. So they waited. First they waited for 3 hours with an open chest, watching and monitoring the instrumentation, and testing the clotting time (ACT = activated clotting time). Then they closed the chest and stayed with her in the operating room for another hour. She spent from 9 in the morning until about 4 in the afternoon with the operating team. Then she was returned to the ICU, a room full of instruments, and watchful nurses.
The operation was on a Tuesday. Watchful waiting lasted into Thursday.
Then the ventilator was taken away and slowly other sensors and monitors were removed. About Friday Noon the ever-vigilant nurses started to relax.
Nurses from earlier days, doctors, and many others started coming by, standing at the foot of her bed, smiling, and giving her 2-thumbs up.