Minggu, 14 September 2014

The path to the hearth : What medical experts forgot?

The path to the hearth : What medical experts forgot?

Aila Johanna  ;   The writer is currently studying
at the graduated School of Medicine at Kyoto University
JAKARTA POST, 12 September 2014

                                                                                                                       
                                                      

In 1896, a renowned English surgeon named Sir Stephen Paget made an infamous remark on how the world had seen the peak of heart intervention. He claimed that “no new method, and no new discovery, [could] overcome the natural difficulties that attend a wound of the heart.”

This was an especially intriguing assertion given that the seeds of heart catheterization had been slowly coming together, even at the time. In fact, as early as 1711, Stephen Hales performed the first documented cardiac catheterization on a living organism.

Hales was an English clergyman who took an interest in chemistry as well as plant and animal physiology. He studied the right and left heart of a living horse by inserting brass pipes through its jugular vein and carotid artery.

He wasn’t the only one to find the approach attractive. In 1822, the French physiologist François Magendie suggested that doctors could evaluate venous and arterial blood flow by putting a catheter into the heart chambers. Magendie did not, however, carry out any experiments.

Twenty-five years later, another French physiologist, Claude Bernard, proceeded with the method on the right heart of dogs. Bernard went on to be the first person to accurately record intra-cardiac pressures.

Auguste Chauveau and Étienne-Jules Marey also used the idea of heart catheterization to determine that apex beats occur in time with systole. This was in 1861.

Whether Paget had heard of the studies by Hales, Bernard or Marey, we do not know. He certainly did not predict the work of a young man named Forssmann.

Werner Forssmann was 25 years old; for barely a year he had used the title doctor. As a first-year surgical trainee in Auguste-Viktoria Hospital in Eberswalde, Germany, he was interested in ways to safely gain access to the heart.

As he wrote in his later-to-be pioneering report, physicians of the time tended to postpone intra-cardiac injection due to its many possible complications, thus losing the critical period for direct administration of resuscitative drugs. Prior studies led him to the idea of using heart catheterization for this purpose.

In his quest, Forssmann began to experiment with dogs. With one exception, the living subjects all survived. But the question he sought to answer after was about the human heart. As there was no ethical possibility of using a living human as a subject, Forssmann had to settle for cadavers.

His report that year came as a shock to the medical community — though not because of those studies. In an article on “the exploration of the right heart”, Forssmann described instead the very first heart catheterization procedure on a living human — himself.

Forssmann had brought up the idea of using himself for the experiment to Robert Schneider, the head of the surgical department. Schneider had sensibly refused. Schneider was not aware that Forssmann had subsequently persuaded another first-year surgical intern, Peter Romeis, to do the procedure on him. His colleague asked to stop the procedure when the tube they used caught on the subclavian vein. Had they persevered, they might have torn Forssmann’s vessel wall.

The bleeding could well have been too much for these two to handle in their top-secret operation.

That may have triggered the alarm in Romeis’ head, but Forssmann simply looked for another assistant for his next trial. This time, it was an 18-year-old scrub nurse named Gerda Ditzen.

They proceeded the very next week. Using local anesthetic, Forssmann performed venesection on his own left elbow. He then passed a 65-centimeter urethral catheter all the way in, the length he had estimated to be the distance from his left elbow to his right heart.

To evaluate the path the catheter ran through, as well as to document the study, Forssmann realized the importance of taking x-ray films. As he described in his report, the route from the operation room to the x-ray unit involved climbing stairs with the catheter still placed inside him. On this, his only report was “[…] I was not aware of any unpleasantness.”

He concluded that it was possible to administer a contrast agent to the right heart of a living person, and that “during two experimental trials on the same person […] no unpleasantness or adverse reactions were observed.”

The pioneering work was used in a study by Andre Cournand and Dickinson Richards as the basis for establishing the method as a standard diagnostic and treatment procedure. The three shared the Nobel Prize for Physiology or Medicine in 1956.

Today’s medical community may view these events as simply the chronology leading to the convenience of using the heart “cath” in current practice.

As is the case with learning any history, nevertheless, a resonant theme appears.

Perhaps an emotive message we can absorb from Paget’s short-sightedness is this: that in practically every era, experts emerge offering their negative insights into the future: HIV cannot be cured. There is no way around infertility. Heart failure is irreversible.

Noli tangere cordis. The heart was not to be touched.

But time and time again, medical history has proven otherwise. These gloomy forecasters are wrong for one reason: they do not factor in the potential of human resources.

This is why sharing ideas matter. This is why we emphasize educating the next generation. If we can also find ways to induce young minds to be passionate about picking up knowledge from various sources, we can make a more relevant prognosis: history has not seen the best of medical innovation yet.

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