The_Invention_of_Surgery

DeWall’s bubble oxygenator was inexpensive and reproducible, and
more importantly ... worked. During the proving grounds of 1954, while
using cross-circulation, Lillehei had shown that open-heart surgery was
possible, but by the middle of 1955, the bubble oxygenator became the
chief method of sustaining life during the groundbreaking operations.
Today, in every major hospital in the Western world, cardiopulmonary
bypass machines are the vehicles that keep humans alive while surgeons
operate on the heart. The full history of the development of the bypass
machine is beyond the scope of this book, but not unlike the development
of any device, occurred across continents, was pioneered by self-financed
tinkerers, and was finally achieved after many, many failures. For a time,
the only open-heart operations being performed were at the University of
Minnesota and ninety miles away, at the Mayo Clinic. As successful as the
operations themselves were, there was still one critical issue:
postoperative complete heart block.
Scientists have been fascinated for centuries with the concept of the
electrical nature of the human body and nowhere more so than the heart.
The electrical impulse from the Sinoatrial node, also known as the natural
“pacemaker of the heart,” communicates to the Atrioventricular node,
which drives the contraction of the ventricles. Your brain does not tell
your heart to contract—it has its own metronome, a built-in electrical
timer, rhythmically firing across the muscles of the heart. Put your hand
on your chest, and the slight flutter you feel is your heart contracting and
squeezing the blood to your entire body. Slide your hand up to your neck,
and feel the pulse by your windpipe—that rhythmic beating is the echo of
your heart valves slamming shut, in regularity, in response to the
syncopated muscular contractions of the heart. In complete heart block,
wherein the electrification of the heart has gone haywire, the patient
suffers severe bradycardia (low heart rate), hypotension (low blood
pressure), and extremely compromised cardiac function. In essence, the
muscular pump that is the heart is uncoordinated and dysfunctional, and
unless properly electrified, unable to sustain life. The Minnesota surgical
team had been researching ways of dealing with cardiac pacing
emergencies, and were able to save a child’s life using a simple laboratory
electrical testing device, the Grass Stimulator.
In Minneapolis in January 1957, following open-heart surgery to repair
a ventricular septal defect, a child was crippled with complete heart block.