Week 2

This week was not as busy as last week. I had AP's on Monday and Thursday. I met with Ms. Lima on Tuesday about my internship, what I'm learning, what I like about it, connections to bio, and we started to brainstorm some presentation ideas. On Tuesday and Wednesday, Dr. M was at a conference, so I didn't go to the hospital. Instead, I read "Every Second Counts: The Race to Transplant the First Human Heart" by Donald McRae. The book was recommended to me by Dr. M, and it discusses heart transplants through the ages. The only day I went to the hospital was Friday, where I made rounds at the Cardiac Surgical Intensive Care Unit and the Cardiac Surgical Step-Down Care. Then we went down to surgery, an aortic valve replacement.

Day 5

In morning rounds in Cardiac ICU, I was able to watch a balloon being removed from the Day 4 patient. The balloon was inserted into the patients aorta prior to surgery in order to increase cardiac output. The balloon was inserted into the patient's femoral artery, and we watched them remove the balloon from the artery.

An X-Ray that shows the balloon going from
the femeral artery ro the aorta.

The first surgical case of the day was an ascending aorta replacement. The patient had a large aneurysm in her aorta, which if rupture would cause death in a matter of seconds. The aorta was very enlarged and inflamed, so Dr. M removed it and replaced it with a graft. In order to replace the aorta, the patient was placed on bypass and cooled. Since the all of the blood passes through the aorta (even with bypass), the blood supply eventually needed to be cut off to the body and brain. When the patient is cooled, it slows the metabolism of cells down, and it allows for the patient to survive longer on a little blood supply. The blood of the patient was cooled through the heart/lung machine, frozen sponges were added to the chest cavity, the entire operating room was cold, and ice was placed around the patients head. After an hour of cooling, Dr. M went ahead and cut the blood supply and replaced the aorta. When the patient was placed on bypass again, the heart was shocked with 10 J in order to start beating again. The OR was then raised to 80 degrees and the blood was slowly heated (as to not denature blood cells), and the re-warming process began. This surgery is one of the most major heart surgeries that a patient can endure.

The cloth graft that replaces aorta.

The graft in place.

The second surgical case of the day was a mitral valve repair and coronary artery bypass surgery. First Dr. M harvested the one end of a mammary artery (under the clavicle), and used it for "self-bypass" for the coronary artery. Then he replaced some of the mitral valve chords with gore-tex in order to repair the mitral valve. 

A diagram that shows how the mammary graft is used to bypass blockages in coronary arteries. 

Day 4

Before rounds, I attended an M&M conference. At this conference, the entire Cardiac Surgical team at MGH discusses the cases in which patient death occurred. Doctors present the case, the course of action taken, the results, and in retrospect, what should have happened. It was sort of like Grey's Anatomy!

After rounds, we operated on a man who was having his third open heart surgery. The man previously had a pacemaker placed and a mitral valve replacement, and his mitral valve needed a second replacement. Since the patient had already had his chest cracked open so many times, which allowed for scar tissue to form, gaining exposure of the heart was difficult and it placed the patient at a high risk. Once exposure was finally gained, and the patient was connected to bypass, Dr M removed the old mitral valve and inserted a porcine replacement valve.

Porcine Replacement Valve

Day 2

The rest of my week was spent in the OR with Dr. M. I would meet Dr. M up in the Cardiac ICU at 7:30 for rounds before we would go down to the OR and change into scrubs and watch surgery. In the Cardiac ICU, Dr. M reviews the patients most recent chest X-Rays to look for any changes, he speaks with the doctors and nurses who observed the patients overnight and asks them about heart rate, pressure, urine output, and any changes that occurred. He then goes and checks on the patients himself, looking at their EKGs, making sure their chest tubes and wires are all in place, and asking the patients how they're doing.

This diagram shows how there are two electrical signals in
Atrial Fibrillation. In the cryo-maze procedure, damaging
neurons by freezing them allows to help control the path of
electrical activity, making the heart beat more regular

The first heart surgery I saw was an aortic valve replacement and a cryo-maze procedure to try and fix the patients atrial fibrillation, an abnormal heart rhythm, (see image on the right)  First, Dr. M gained exposure of the heart, and then connected the patient to the bypass machine (heart and lung machine), which occurs by making small incisions on the right atrium and aorta of the heart, so that all of the blood bypasses the heart and lungs. Since there is no blood flow to the heart, the heart can arrest (stop beating), which makes operating on it much easier. Once on bypass, Dr. M started the cryo-maze procedure. In this procedure, a probe is inserted into the different chambers of the heart and it aims to create a "maze" for neuron firing in the heart by freezing parts of the heart. The probe inserted into the heart is about -60 degrees, and this freezes the heart, permanently damaging neurons, and by controlling the damaged neurons, you can create a path, or "maze", for the neurons to fire, which can help fix the irregular heart beat.

After the cryo-maze procedure, Dr. M went on to replace the patients calcified aortic valve (the valve between the aorta and the left ventrical). Dr. M used a valve made from bovine (cow) paracardium to replace the patients leaky valve.

This is an photograph of the new valve
 (the object in the top of the photo) getting sewed in.

Day 1

 Today was my first day working at MGH. On Mondays, Dr. M sees patients in the office. The first case I saw was a post-op quadruple coronary bypass surgery patient who was doing well. The next patient I saw was a pre-op Aortic Stenosis patient who will be getting a bovine aortic valve replacement. Throughout the day, most of the cases I saw were post-op patients who were coming in for a follow up visit. One woman in particular had had retraction and replacement of the Aortic arch and restructuring of her heart and blood flow, which according to Dr. M, is one of the most complex heart surgeries that can happen. The pre-op cases included two cases that aimed to assess whether surgery was recommended, one case was an atrial septal defect (a hole in the heart) and the other a leaky mitral valve. 

One patient I saw was a man with aortic stenosis who we are operating on first thing in the morning. He is receiving a bovine valve replacement. During lunch I got to meet with some of Dr M’s surgical team as they discussed upcoming surgeries this week.

Tomorrow I get to scrub in and observe in the OR!

My ILE

For my ILE, I am shadowing Dr. M, a Cardiac Surgeon at Massachusetts General Hospital. I will be following Dr. M around as he sees patients in the office, visits patients in the Cardiac ICU, attends meetings, and operates on his patients.