Week 5: Home Is Where the Heart Is

Hey guys! The first procedure I observed this week was a redo surgery and on-pump mitral valve repair. This was the first open heart case that I have observed since week 3 and it is so exciting to be back at it again! Don't get me wrong, thoracic cases are very interesting, but it is just thrilling to see beating hearts in all of their glory every week! 😃

This on-pump MVR was a little different from the one I described in my second post from week 3 because it was a redo surgery. Also, the patient had a coronary artery bypass surgery in the past, so there are risks associated with doing another surgery such as hemorrhaging, graft injuries, and scar tissue adhesions. Thus, this mitral valve repair was performed with extreme caution and different techniques to avoid these problems.

The cardiopulmonary machine was still necessary in this surgery, but instead of stopping the heart with cardioplegic solution, Dr. Patel shocked it into an abnormally fast sinus rhythm (atrial fibrillation) in order to prevent air embolism. Air embolism occurs when a blood vessel is blocked by pockets of oxygen in the blood, and can cause a stroke if they travel to the brain. This was also avoided during surgery by flooding the thoracic cavity with carbon dioxide because it dissolves faster than oxygen does in the blood. Thus, it is less likely to occlude blood flow and cause a stroke.

In order to access and repair the mitral valve in a bloodless field, Dr. Patel induced atrial fibrillation where the electrical signals in the heart fire rapidly, causing weak, fast, and irregular contractions of each chamber in the heart. In this state, the heart moves so fast it just slightly wiggles, making it easy to access the valve. Also, blood flowing through the cardiopulmonary machine was cooled to around 25 or 30 degrees celsius to sustain fibrillation, lower the body's demand for oxygen, and protect the heart.

In atrial fibrillation, each chamber of the heart will beat rapidly and irregularly as shown by the photo above.

Other than shocking the heart into fibrillation and sustaining a state of hypothermia, the procedure was carried out the same way as the one I described before. Dr. Patel fixed the annuloplasty ring into place around the mitral valve to pull the walls of the heart closer together and prevent regurgitation.

In my next post, I will talk about the surgeries I will see in the next two days and the advantages and disadvantages of monofilament nylon sutures. Until next time!