Week 1: Get Pumped

This was the first week of my internship with Dr. Patel, and let me tell you, it was the most educational and exciting week of the year. I got to watch three surgeries, and spend some time visiting patients and studying angiograms in Dr. Patel's office. But before I get into all of the details, lets go over the general anatomy of the human heart.

Here are labeled diagrams showing the pathway of blood through the heart and the four valves:

Valves in the heart (aerial view)

In short, deoxygenated blood travels through the Right Atrium (RA), into the Right Ventricle (RV), and up the Pulmonary Artery (PA) to the lungs to get oxygenated. It returns via the Pulmonary Veins (PV), and travels through the Left Atrium (LA), into the Left Ventricle (LV), and up the Aorta and circulates throughout the body. In the process, the four valves in the heart keep the blood flowing in the right direction.

However, sometimes the function of these valves can be compromised, causing a backflow of blood in the heart. A problem in the Mitral valve, for example, can increase pressure in the left atrium and consequently in the pulmonary veins. Increased pressure may lead to fluid build-up in the lungs which will then affect the pulmonary artery and the right side of the heart. So you can see how a problem with one component of the heart can affect its functioning as a whole.

On Wednesday, I got to observe my first cardiothoracic surgery in the OR! It was an Aortic Valve Replacement (AVR). In this case, the aortic valve failed to close completely after the passage of oxygenated blood, and some of the blood was flowing back into the LV, causing damage. This is called aortic valve regurgitation. In surgery, Dr. Patel performed a median sternotomy (cut through the sternum) to expose the heart, and once the pericardium was open, he put the patient on a cardiopulmonary bypass machine (heart-lung machine) and infused a potassium solution to stop the heart. This machine essentially acts as a heart and lungs, oxygenating and circulating the blood outside the body, while the surgeon replaces the valve. Dr. Patel removed the aortic valve and replaced it with a Pericardial Aortic Bioprosthesis. With the valve in place and the aorta closed, the patient was taken off the heart-lung machine and Dr. Patel closed with steel sutures in the sternum and Braided Vicryl in the skin.

Pericardial Aortic Bioprosthesis

On Thursday, I spent some time in Dr. Patel's office, learning how to identify calcified and blocked arteries on angiograms and meeting patients. It was very interesting to see how Dr. Patel diagnoses his patients and discusses treatment options with them.

Today, I observed two surgeries, a Thoracotomy and an Off-Pump Coronary Artery Bypass Grafting (CABG). In the Thoracotomy, Dr. Patel removed tissues from the lungs for biopsy. It was a very short procedure, lasting only 45 minutes. The Off-Pump CABG, however was much more complex and lengthy. Dr. Patel performed a median sternotomy to expose the heart and visualize the blocked portion of the coronary artery. He used the left internal mammary artery (LIMA) to bypass the left anterior descending artery (LAD). The LAD is the most important of the three main coronary arteries because it supplies over half the heart muscle with blood, so any blockage must be cleared immediately. He also harvested a portion of the saphenous vein from the calf to bypass the obtuse marginal artery, a smaller branch of the left circumflex artery. The open ends of the LIMA and saphenous vein are sewn to the openings in the coronary arteries to create an alternate pathway for blood to nourish the heart. The term "off-pump" means that the patient was not on a heart-lung machine and the heart was beating through surgery. As a result, Dr. Patel used a stabilizer device, as shown below, to limit the motion of the heart as he operated and was very careful when suturing.

Stabilizing device

Coronary arteries

The environment in the OR is very different from what I expected, but not too different from ORs in TV shows such as Grey's Anatomy (except, without the drama and spewing blood). There is always music playing in the background, and the doctors and nurses constantly talk about the craziness of their daily lives and make funny comments while operating. For example, on Wednesday, we talked for almost twenty minutes about bacon. Random, but hilarious. 

Although it has only been one week, I learned so much already! I am looking forward to the next ten weeks with Dr. Patel in and out of the OR.

Shreya