What is Open Heart Surgery ?

Dateline: 10/05/97

Over the past few months, many have asked me this question - "What exactly is OPEN HEART surgery ?".

"Hey, that's easy !", you say. "It's an operation which is done after opening the heart, right ?". Correct. But it's NOT EASY ! Let me try and explain. I've told you earlier about how the heart pumps "pure" blood containing nutrients and oxygen to the entire body. This blood flow is needed for life. If the heart stops, and blood flow stops, life is NOT POSSIBLE.

That then is the challenge - to open the heart and operate inside it. For this it is necessary to STOP THE HEART !

"How can I do this, and still keep a patient alive ?" This question was asked of themselves by many great scientists in the early 1900's. Many dedicated their entire lives to solving this problem. And they came up with different ideas. Some were failures; luckily some succeeded.

Controlled Cross Circulation
One of the most innovative and imaginative ideas was suggested by Dr.WALTON C.LILLEHEI, the Father of modern open heart surgery. Dr.Lillehei thought a parent's heart could be used to help keep blood flowing in the child's body during the time the child's heart was stopped, opened and operations performed inside it ! In 1953, he carried out the first series of operations using this idea - called CONTROLLED CROSS-CIRCULATION. The seven year old child he operated upon first was still alive in 1992, 39 years later !

To understand what a bold and daring surgeon Dr.Lillehei was, consider this fact - IF this operation had failed, it would have been the FIRST time in history that an operation had a TWO HUNDRED PERCENT MORTALITY! That is, not only the patient, but his parent too would have died ! Luckily for all, the operation was a success, and open heart surgery was well on its way to becoming reality.

Mechanical Heart-Lung Bypass
Although controlled cross-circulation was a grand success, others still considered the risk to the parent unacceptably high. They kept working on ideas to develop a machine to do the work of the heart and the lungs. The first person to succeed in these efforts was another great scientist, Dr.JOHN GIBBON Jr., who in 1953 for the first time used an ARTIFICIAL "HEART AND LUNG" MACHINE, to do the work of the heart and lungs while a patient's heart was stopped, opened, and an operation done inside the heart. He closed a "hole" between the upper heart chambers - called an atrial septal defect - in a young woman, with perfect success. With this development, open heart surgery was well and truly established. Future advances occurred with astonishing speed.

Principles of Open Heart Surgery
So let's see how exactly an open heart operation is done. To better understand the operation, you need to know just a little about how a heart and lung machine is built. After all you know about the human heart itself, a machine can't be much more difficult to understand !

The Heart-Lung Machine
As it's name implies, the work of both the heart and lungs is done by the heart-lung machine, which is also called a PUMP OXYGENATOR. It owes this name to the fact that it has a "pump" and an "oxygenator".
What is a pump ? Just what it sounds like. It is a device to pump blood through the arteries to the whole body. In other words, it is an "artificial heart". Many designs were tried out for these pumps. Currently, two types called a "roller-pump" and a "centrifugal-pump" are widely used.
What is an oxygenator ? Simply, something that "oxygenates" blood. You know that oxygen in the air you breathe is a life-giving gas. When the heart is stopped during open heart surgery, and there is no blood flowing to the lungs, oxygen cannot enter the body through the lungs. So the heart-lung machine has a part called the oxygenator which does the work of the lungs. Oxygen is pumped into this machine, and mixes with blood. At the same time, the wastes in the blood are removed by the oxygenator. So the "impure" blue blood returning to the oxygenator is converted to "pure" red blood. The pure blood is then pumped to the rest of the body.
Now, I know you're getting bored, and want to get to the interesting stuff. So here we go...

Technique of Open Heart Surgery
How is open heart surgery performed ? The whole operation is carried out under GENERAL ANESTHESIA - or total unconsciousness. This means that after the first needle prick of an injection, the patient is not aware of anything else until the operation is over !

The first step is to make an opening in the chest to expose the heart. The most common is one down the middle of the chest dividing the breast-bone, though an incision on one side of the chest may be used for some operations. After exposing the heart by dividing its protective covering - the PERICARDIUM - the surgeon will make preparations for CARDIO-PULMONARY BYPASS. (This tongue-twisting term, translated to common English, just means "heart and lung bypass, using the heart-lung machine")

To stop the heart, two things need to be done. Impure "blue" blood returning to the heart from the veins needs to be diverted into the heart-lung machine, where it will be purified. The pure blood from the machine then needs to be pumped back into the body.

To achieve this, the surgeon places tubes (called a CANNULA) made of a special kind of plastic into the veins or right atrium. These tubes "suck" out the impure blood returning from the veins, into the oxygenator. In the oxygenator, the blood is purified by addition of oxygen, and removal of wastes. It is then pumped back into the body. To make this possible, the surgeon places yet another plastic tube into the aorta, which is the largest artery of the body, arising from the left ventricle. The pure blood which enters the body through this tube now flows to all other organs through the arteries.

In this elegantly simple way, the heart is freed from its burden. It can now be stopped, opened, and defects inside it can be repaired. The surgeon has a clear and motionless view of the abnormal area, and can make a perfect repair.

After the operation is over, the heart-lung machine is slowed down, and step by step, the newly repaired heart starts beating and gets back its strength. When it is fully recovered, the heart-lung machine is turned off, and the plastic tubes in the veins and aorta removed.

There are hundreds of other details to be attended to during cardiopulmonary bypass, but that's the work of the heart surgery team. If you really want to know about these things, do what I did - BECOME A HEART SURGEON !

Who are the "team members" in this multi-stage drama ?

SURGEON: The surgeon is of course the co-ordinator of the whole show. He or she is in overall control of the operation.

ANESTHESIOLOGIST: The anesthesiologist is responsible for taking the patient "under", so the patient does not feel any pain or unpleasant sensation during the operation. The anesthesiologist also, in many centers, helps co-ordinate different aspects of the operation.

PERFUSIONIST: The perfusionist controls the heart-lung machine. In other words, he IS the patient's heart and lungs for the duration of the operation !

NURSE: A good nurse is a surgeon's boon. By their efficiency, good nurses can make the surgeon's job a thing of happiness and joy, rather than a battle against the odds.

CARDIOLOGIST: The cardiologist is increasingly becoming involved in the operating room along with the surgeon. New technology is developing which needs the help of the cardiologist at the time of surgery, to give each patient the best possible care.

These then are the people who make the open heart operation possible in the operating room. Of course, there are many more supporting personnel - in the intensive care unit after surgery, for instance.

If you enjoyed reading this article, please send me your comments.