Cardiopulmonary Bypass: How Open Heart Surgery Became A Reality
The heart is a tremendously important organ in the human body. It’s a muscular organ that pumps deoxygenated blood into our lungs for oxygenation and pumps oxygenated blood to be delivered to our tissues, essentially providing life. For the same reason it’s an essential part of human lives, performing surgery on the heart is a tricky problem that took decades to figure out, and is still being perfected today.
Many obstacles were faced on attempts at performing open heart surgery, a surgery on the heart in which the heart and lung are put at rest. The three main concerns were figuring out a way to (1) prevent the blood from coagulating, (2) pump the blood without destructing the red blood cells, and (3) finding a method to oxygenate blood and dissipate carbon dioxide during the time that the heart and lungs were temporarily at rest.
The first attempts of using cardiopulmonary bypass had an appalling mortality rate. Air embolism, postoperative bleeding, and postoperative coagulopathy were among the common early problems. Scientists were essentially asked to build a machine capable of taking over both the lung and heart—a task that could easily be regarded impossible, to which an attempt to reach is futile. But countless people contributing in the discovery weren’t held back by that.
The discovery of anticoagulants, such as heparin, solved the first problem. Different pumps that treated blood more gently were also developed to prevent hemolysis. Finally, oxygenators such as film, rotating disk, and membrane oxygenator (what is now widely used) were discovered and used to solve the last problem, although advancements and new discoveries are still being made to this day.
The first successful open heart surgery using cardiopulmonary bypass was the closure of an atrial septal defect, done by John Gibbon on May 6, 1953 (23 years after he started working on his machine). The patient, Cecelia Bavolek, was alive and well on the 50th anniversary of that surgery in May 2003. Modern CPB machines have systems for monitoring pressures, temperature, oxygen saturation, hemoglobin, blood gases, electrolytes as well as safety features such as bubble detectors, oxygen sensor, and reservoir low-level detection alarm.
The history of bypass surgery—understandably—is a long one, and we’ve come far from where we began. But even with the many brilliant scientists working on it collectively over the course of decades, cardiopulmonary bypass is nowhere close to a real, functioning heart.
The very existence of it is a physical embodiment of humans’ innate curiosity, hard work, and persistence working on a seemingly impossible aim and achieving it, while at the same time a reminder of the Greatness of God and what a truly miraculous gift life is.
Happy World Heart Day 2018!
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Sarkar M, Prabhu V. Basics of cardiopulmonary bypass. Indian journal of anaesthesia. 2017 Sep;61(9):760.