Angioplasty and stenting were developed to save lives and improve quality of life for cardiovascular patients. You may think of development of the procedures as dating back to the 1980s and 90s, but a series of crucial steps from the 1920s onward made angioplasty and stenting possible. These advances were brought about by the creativity and determination of physicians and scientists, who often had to persist against mainstream medical thinking before their ideas were ultimately embraced by the profession. Read on to learn more about the history of angioplasty and stenting.
Angioplasty
Angioplasty and stenting are part of the bigger field of interventional cardiology, which addresses cardiovascular problems through catheter-based procedures. A catheter is a thin, flexible tube that is inserted into a patient’s artery, a large blood vessel that carries blood throughout the body. A range of treatments can then be delivered within the blood vessel by the catheter, including reopening of a blocked artery through angioplasty and insertion of a stent – a tiny, metal mesh tube – to prop a cleared artery open and prevent it from collapsing.
Angioplasty and stenting and other catheter-based procedures were developed, and continue to be refined, by physicians seeking innovative solutions to problems encountered when treating cardiovascular patients. Today, medical companies research and design complicated medical devices, but the origins were much more humble – though inspired – and can be said in some respects to have begun at the kitchen table of German cardiologist Dr. Andreas Gruentzig.
Dr. Gruentzig, as a young cardiologist working in Zurich, Switzerland, in the mid 1970s, learned methods first introduced by Dr. Charles Dotter a decade earlier in Portland, Oregon. Dr. Dotter pioneered the use of catheters to reopen blockages in the peripheral arteries– arteries in the arms, legs, and feet. He did so by feeding progressively wider catheters in the blood vessel and through the blockage. While this technique was dismissed by the larger medical community in the United States, doctors in Europe continued to be interested in the gains made by Dr. Dotter.
Dr. Gruentzig built upon this advance by adding a balloon to a catheter and using it not in the peripheral arteries, but in the coronary arteries to treat heart disease. This is how balloon angioplasty was born! Because no appropriate medical device existed, Dr. Gruentzig began carefully crafting balloon catheters at home in his kitchen. His early research testing the procedure on animals was not broadly accepted at first in the cardiology field. However, his accomplishments were finally recognized after he performed a successful balloon angioplasty on a human patient in 1977. That patient, Dolf Bachmann is alive and well today.
Dr. Gruentzig, like every great scientist, owed a great deal to his predecessors in medicine, including Dr. Dotter. However, documented uses of catheters have been discovered dating back to long before either of these scientists were working – all the way back to ancient India for use in treating bladder conditions and to Egypt for use on human cadavers. It was not until 1929 that it was proven that a catheter could be safely advanced into a living human heart. This discovery was made by Dr. Werner Forssmann, a German doctor who inserted a catheter into his own heart and proved it with x-ray images. Dr. Forssman’s accomplishment was dismissed by medical professionals as reckless, but when the significance of his work was realized, he was later awarded the Nobel Prize.
Also key to the development of the field of interventional cardiology was the discovery of a method by which the coronary arteries and heart could be viewed from the inside and without a need for open-heart surgery. That discovery was made by accident by Dr. F. Mason Sones at the Cleveland Clinic in 1958. He was performing a heart procedure when a catheter slid and entered a chamber of the patient’s heart. Contrast dye, which is used for imaging, was injected into the chamber. Until this time, cardiologists thought contrast dye could not be safely injected into the heart. This accident led to the angiogram , a diagnostic test still used today to view blood vessels. Dr. Sones went on to co-found the Society for Cardiovascular Angiography and Interventions (SCAI), the organization that hosts this website.
Dr. Gruentzig took this earlier work as a foundation for his historic first coronary angioplasty in a human. After this success, he then popularized balloon angioplasty by teaching his methods to other cardiologists. He also established a means for tracking the outcomes of all performed procedures. Coronary angioplasty has become ever more sophisticated in the decades since Dr. Gruentzig’s death in 1985 but owes much to the methods he established.
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Stents
Early practitioners of balloon angioplasty in the 1970s–80s began to notice a couple of complications in some patients: the artery would sometimes collapse at the blockage site after a balloon catheter had cleared the blockage, or in about a third of patients the artery would become blocked again by the growth of scar tissue, a process called restenosis.
A search for innovative solutions within the field of interventional cardiology led to the development of the coronary stent. A stent is a metal, mesh tube that is small enough to be inserted with a catheter to fit inside an artery to prop it open and prevent it from collapsing. One major difference between angioplasty and stenting is that in angioplasty, the balloon (after it has been inflated to push plaque that is causing the blockage aside) is then removed, and nothing is left behind in the patient’s vessel at the end of the angioplasty procedure. In contrast, a stent is permanently implanted in the patient’s vessel. Stents for blood vessels are not removed later.
The first stent was approved for use in the United States by the Food and Drug Administration (FDA) in 1994. These bare metal stents (BMS) were highly effective at preventing an artery from collapsing after angioplasty. However, these stents were only slightly effective in inhibiting the growth of scar tissue. The human body was responding to these stents as it would to any “injury,” but and the challenge facing medicine was how to stop this response and prevent a heart attack or other serious outcome from restenosis.
The answer came in the form of drug-eluting stents (DES), which dramatically reduce the risk of restenosis. These stents, which were approved by the FDA in 2003, are coated with a drug to inhibit the growth of scar tissue. In contrast, the BMS do not have a drug coating.
Both bare metal stents and drug-eluting stents are used today, depending on the needs of the individual patient. Stents still carry a small risk of thrombosis – a serious complication in which a blood clot forms on the stent. To lower the risk of stent thrombosis, patients who receive bare metal stents are required to take medications such as either clopidogrel (Plavix) or prasugrel (Effient) for at least one month after the procedure. Patients who receive drug-eluting stents are recommended to take the same medications for at least one year after the procedure to prevent blood clot formation. In addition, patients should generally be on lifelong aspirin if they have had a coronary stent.
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History of Angioplasty and Stenting Timeline
- 1929: Dr. Werner Forssman in Germany advanced a catheter into his own heart, proving that it could be safely done.
- 1958: Dr. F. Mason Sones, while performing a procedure at the Cleveland Clinic, discovered that contrast dye could be injected into the heart without harm to a patient. This discovery led to the angiogram, a test used to gather images of the heart’s blood vessels.
- 1964: Dr. Charles Dotter in Portland, Oregon, used catheters to open blockages in peripheral arteries.
- 1977: Dr. Andreas Gruentzig performed the first balloon angioplasty procedure in a human patient in Switzerland.
- 1978: The Society for Cardiovascular Angiography and Interventions (SCAI), the primary professional association for interventional cardiologists, was founded under the guidance of Drs. F. Mason Sones and Melvin P. Judkins.
- 1994: The first stent was approved by the Food and Drug Administration (FDA) for use in the United States.
- 2003: The FDA approved use of drug-eluting stents that were developed in answer to the tendency of bare metal stents to close off from growth of scar tissue (restenosis).
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