Julio Palmaz

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Julio Palmaz
Born (1945-12-13) December 13, 1945 (age 78)
Education National University of La Plata, Argentina
Occupation(s) Cardiologist, Radiologist
Known forCo-inventor of the Palmaz-Schatz Stent.

Julio Palmaz (December 13, 1945 in La Plata, Argentina) is a doctor of vascular radiology at University of Texas Health Science Center at San Antonio. He studied at the National University of La Plata in Argentina, earning his medical degree in 1971. He then practiced vascular radiology at the San Martin University Hospital in La Plata before moving to the University of Texas Health and Science Center at San Antonio. He is known for inventing the balloon-expandable stent, for which he received a patent filed in 1985. It was recognized in Intellectual Property International Magazine as one of "Ten Patents that Changed the World" in the last century. His early stent research artifacts are now part of the medical collection of the Smithsonian Institution in Washington, DC. He continues to innovate on his initial designs, developing new endovascular devices.

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Education and career

Julio Palmaz was born in December 13, 1945, in La Plata, Argentina; Palmaz's parents were of Italian descent, his father worked as a bus driver. Palmaz received his M.D. in 1971 from the National University of La Plata, Argentina. He joined the San Martin University Hospital in La Plata to practice vascular radiology in 1974. He moved with his family to the United States in 1977 and spent three years training in radiology at the University of California at Davis' Martinez Veterans Administration Medical Center. He has worked as Chief of Angiography and Special Procedures in the radiology department at the University of Texas Health and Science Center at San Antonio (UTHSCSA) since 1983. He currently holds the Ashbel Smith Professorship as a tenured Professor at UTHSCSA. In 2019, Palmaz was part of a team awarded the Russ Prize "for innovations in medical devices that enable minimally invasive angioplasty treatment of advanced coronary artery disease." [1]

Palmaz-Schatz Stent

Background

Coronary artery disease is a condition in which the blood vessels to the heart become clogged. It often leads to heart attacks and is one of the leading causes of death in the United States. Beginning in the mid-1960s, the leading treatment consisted of invasive bypass surgery, in which a healthy blood vessel from another part of the body is grafted onto the coronary artery, forming a detour around the afflicted region. Due to the high cost and risk of this procedure, an alternative was in high demand. In 1977, Andreas Gruentzig performed the first successful percutaneous coronary angioplasty. In this procedure, a catheter attached to a small balloon is inserted into the afflicted artery. The balloon is subsequently expanded, compressing the accumulated plaque to allow increased blood flow. This was a substantial improvement over bypass surgery in terms of invasiveness, but unfortunately restenosis, a recurrence of arterial clogging, occurred in nearly 50% of patients after the balloon was removed.

Conception

Palmaz got the idea for his stent after listening to a lecture by Gruentzig at a conference in New Orleans in 1978. He had an idea then to put a scaffold of sorts inside the vessels, to hold them open and keep them from occluding. He wrote up his ideas in a manuscript – which became important later as a proof of conception – and started to work on prototypes. He began by sticking pins into a pencil and weaving wire around them, but the structure did not maintain form as it was compressed. He then soldered the wires at their junctions, achieving the desired plasticity; however this required two separate metals, which was undesirable for medical use. His solution was inspired by a metal lathe with a structure of staggered openings that a mason had left in his garage: cutting holes in metal tubing would create a collapsible structure that would remain rigid once expanded.

Development

Palmaz succeeded in creating a model that he was able to test in animals, including pigs and rabbits, with promising results; he also began shopping the device around to medical companies, but the response was lukewarm.

In 1983, Dr. Stewart Reuter, Chair of Radiology at UTHSCSA and a mentor to Palmaz, encouraged him to accept a position at the center. Palmaz did so, in part because there he would have access to resources he needed to further his stent development. He eventually succeeded in creating a prototype of a stainless steel, insertable mesh stent that could be expanded once inside the body to hold a blood vessel or artery open and allow blood to flow more freely. He also secured funding from a somewhat unlikely partner: Phil Romano, an entrepreneur who founded restaurant chains such as Fuddruckers and The Macaroni Grill, offered to put up $250,000 in exchange for a stake in the product, which Palmaz began co-developing with Dr. Richard Schatz, a cardiologist at Brooke Army Medical Center.

Commercial Success

The trio, calling themselves the Expandable Graft Partnership, patented the stent technology in 1985 and presented it to a variety of large companies. Those firms included Boston Scientific, which passed on the technology; and Johnson & Johnson, which eventually licensed the stent technology for some $10 million plus royalties. With Johnson & Johnson behind it, and with an additional $100 million invested in its development, the Palmaz stent was approved for use in peripheral arteries in 1991, followed by approval for use in coronary arteries in 1994; Johnson & Johnson quickly captured 90 percent of the market for stents and bought the patent outright from Palmaz, Schatz and Romano in 1998.

Litigation

Palmaz stent patents were the subject of fierce legal battles brought by Johnson and Johnson against several companies manufacturing stents. After 12 years of litigation, the District Court of Delaware ruled in favor of Johnson and Johnson, declaring that the Palmaz patents had been infringed. The damages awarded for the Palmaz patents were the largest ever in patent litigation history.

Medical Impact

Within four years of its FDA approval, the balloon-expandable stent was used in over 80% of percutaneous coronary interventions, a virtually unparalleled success. Currently approximately one million stents are implanted annually worldwide. The balloon angioplasty augmented with the use of the stent has become the preferred treatment for atherosclerosis. However, the stent has not completely done away with restenosis after angioplasty, and improved procedures continue to be sought. The drug-eluting stent, which releases chemicals that inhibit restenosis, has shown marked success and seems to be replacing the bare-metal stent in America, though Europeans have resisted the change due to the expense.

Business Ventures

Palmaz formed Advanced Bio Prosthetic Surfaces (ABPS) in 1999, with Christopher Banas, as a private R&D enterprise to develop advanced biomaterials for implantable medical devices. In early 2008, Dr. Palmaz, Steve Solomon, and other principals, along with private investors formed Palmaz Scientific to acquire thin-film and related intellectual property, equipment, employees and related assets from Nitinol Development (NDC), a Johnson & Johnson / Cordis company which has licensed ABPS technology. The company, which operates out of Dallas, will design, manufacture and sell implantable bio prosthetic devices.

Palmaz also created the largest wine cave in Napa Valley, Palmaz Vineyards. It is entirely gravity operated.

Personal life

Palmaz is married to fellow Argentine Amalia Palmaz and has two children, Florencia and Christian. He lives in San Antonio and Napa, and enjoys collecting vintage Porsches. He owns the famous Porsche 917-023, the car that earned Porsche its first victory at Le Mans in 1970. His son Christian Palmaz owns and flies a 2015 Bell 429 Global Ranger N665PV.

Related Research Articles

<span class="mw-page-title-main">Angioplasty</span> Procedure to widen narrow arteries or veins

Angioplasty, also known as balloon angioplasty and percutaneous transluminal angioplasty (PTA), is a minimally invasive endovascular procedure used to widen narrowed or obstructed arteries or veins, typically to treat arterial atherosclerosis.

<span class="mw-page-title-main">Stent</span> Type of medical device

In medicine, a stent is a tube usually constructed of a metallic alloy or a polymer. It is inserted into the lumen of an anatomic vessel or duct to keep the passageway open. Stenting refers to the placement of a stent. The word "stent" is also used as a verb to describe the placement of such a device, particularly when a disease such as atherosclerosis has pathologically narrowed a structure such as an artery.

<span class="mw-page-title-main">Angiography</span> Medical imaging technique

Angiography or arteriography is a medical imaging technique used to visualize the inside, or lumen, of blood vessels and organs of the body, with particular interest in the arteries, veins, and the heart chambers. Modern angiography is performed by injecting a radio-opaque contrast agent into the blood vessel and imaging using X-ray based techniques such as fluoroscopy.

In surgery, a percutaneous procedure is any medical procedure or method where access to inner organs or other tissue is done via needle-puncture of the skin, rather than by using an "open" approach where inner organs or tissue are exposed.

<span class="mw-page-title-main">Coronary catheterization</span> Radiography of heart and blood vessels

A coronary catheterization is a minimally invasive procedure to access the coronary circulation and blood filled chambers of the heart using a catheter. It is performed for both diagnostic and interventional (treatment) purposes.

<span class="mw-page-title-main">Restenosis</span> Recurrence of stenosis, a narrowing of a blood vessel

Restenosis is the recurrence of stenosis, a narrowing of a blood vessel, leading to restricted blood flow. Restenosis usually pertains to an artery or other large blood vessel that has become narrowed, received treatment to clear the blockage, and subsequently become re-narrowed. This is usually restenosis of an artery, or other blood vessel, or possibly a vessel within an organ.

<span class="mw-page-title-main">Interventional cardiology</span> Catheter-based treatment of structural heart diseases

Interventional cardiology is a branch of cardiology that deals specifically with the catheter based treatment of structural heart diseases. Andreas Gruentzig is considered the father of interventional cardiology after the development of angioplasty by interventional radiologist Charles Dotter.

Andreas Roland Grüntzig was a German radiologist and cardiologist, with foundational interest, training and research in epidemiology and angiology. He is known for being the first to develop successful balloon angioplasty for expanding lumens of narrowed arteries. He was born in Dresden.

<span class="mw-page-title-main">Percutaneous coronary intervention</span> Medical techniques used to manage coronary occlusion

Percutaneous coronary intervention (PCI) is a minimally invasive non-surgical procedure used to treat narrowing of the coronary arteries of the heart found in coronary artery disease. The procedure is used to place and deploy coronary stents, a permanent wire-meshed tube, to open narrowed coronary arteries. PCI is considered 'non-surgical' as it uses a small hole in a peripheral artery (leg/arm) to gain access to the arterial system, an equivalent surgical procedure would involve the opening of the chest wall to gain access to the heart area. The term 'coronary angioplasty with stent' is synonymous with PCI. The procedure visualises the blood vessels via fluoroscopic imaging and contrast dyes. PCI is performed by an interventional cardiologists in a catheterization laboratory setting.

<span class="mw-page-title-main">Drug-eluting stent</span> Medical implant

A drug-eluting stent (DES) is a tube made of a mesh-like material used to treat narrowed arteries in medical procedures both mechanically and pharmacologically. A DES is inserted into a narrowed artery using a delivery catheter usually inserted through a larger artery in the groin or wrist. The stent assembly has the DES mechanism attached towards the front of the stent, and usually is composed of the collapsed stent over a collapsed polymeric balloon mechanism, the balloon mechanism is inflated and used to expand the meshed stent once in position. The stent expands, embedding into the occluded artery wall, keeping the artery open, thereby improving blood flow. The mesh design allows for stent expansion and also for new healthy vessel endothelial cells to grow through and around it, securing it in place.

Phosphorylcholine is the hydrophilic polar head group of some phospholipids, which is composed of a negatively charged phosphate bonded to a small, positively charged choline group. Phosphorylcholine is part of the platelet-activating factor; the phospholipid phosphatidylcholine and sphingomyelin, the only phospholipid of the membrane that is not built with a glycerol backbone. Treatment of cell membranes, like those of RBCs, by certain enzymes, like some phospholipase A2, renders the phosphorylcholine moiety exposed to the external aqueous phase, and thus accessible for recognition by the immune system. Antibodies against phosphorylcholine are naturally occurring autoantibodies that are created by CD5+/B-1 B cells and are referred to as non-pathogenic autoantibodies.

The history of invasive and interventional cardiology is complex, with multiple groups working independently on similar technologies. Invasive and interventional cardiology is currently closely associated with cardiologists, though the development and most of its early research and procedures were performed by diagnostic and interventional radiologists.

<span class="mw-page-title-main">Coronary stent</span> Medical stent implanted into coronary arteries

A coronary stent is a tube-shaped device placed in the coronary arteries that supply blood to the heart, to keep the arteries open in patients suffering from coronary heart disease. The vast majority of stents used in modern interventional cardiology are drug-eluting stents (DES). They are used in a medical procedure called percutaneous coronary intervention (PCI). Coronary stents are divided into two broad types: drug-eluting and bare metal stents. As of 2023, drug-eluting stents were used in more than 90% of all PCI procedures. Stents reduce angina and have been shown to improve survival and decrease adverse events after a patient has suffered a heart attack—medically termed an acute myocardial infarction.

<span class="mw-page-title-main">Bare-metal stent</span>

A bare-metal stent is a stent made of thin, uncoated (bare) metal wire that has been formed into a mesh-like tube. The first stents licensed for use in cardiac arteries were bare metal – often 316L stainless steel. More recent "second generation" bare-metal stents have been made of cobalt chromium alloy. While plastic stents were first used to treat gastrointestinal conditions of the esophagus, gastroduodenum, biliary ducts, and colon, bare-metal stent advancements led to their use for these conditions starting in the 1990s.

<span class="mw-page-title-main">Pulmonary artery stenosis</span> Medical condition

Pulmonary artery stenosis (PAS) is a narrowing of the pulmonary artery. The pulmonary artery is a blood vessel moving blood from the right side of the heart to the lungs. This narrowing can be due to many causes, including infection during pregnancy, a congenital heart defect, a problem with blood clotting in childhood or early adulthood, or a genetic change.

<span class="mw-page-title-main">Atherectomy</span> Surgical removal of atherosclerosis from the walls of arteries

Atherectomy is a minimally invasive technique for removing atherosclerosis from blood vessels within the body. It is an alternative to angioplasty for the treatment of peripheral artery disease, but the studies that exist are not adequate to determine whether it is superior to angioplasty. It has also been used to treat coronary artery disease, albeit without evidence of superiority to angioplasty.

<span class="mw-page-title-main">Purshotam Lal</span> Indian cardiologist

Dr Purshotam Lal is an Indian Interventional cardiologist who has to his credit the pioneering of over 20 interventional cardiology procedures for the first time in India, some of which were the first time in the World. Trained in UK, US and Germany, and he has held various faculty positions including Professor, Advisor, etc.

Ulrich Sigwart is a German retired cardiologist known for his pioneering role in the conception and clinical use of stents to keep blood vessels open, and introducing a non-surgical intervention, alcohol septal ablation for the treatment of hypertrophic obstructive cardiomyopathy.

A dual therapy stent is a coronary artery stent that combines the technology of an antibody-coated stent and a drug-eluting stent. Currently, second-generation drug-eluting stents require long-term use of dual-antiplatelet therapy, which increases the risk of major bleeding occurrences in patients. Compared to drug-eluting stents, dual therapy stents have improved vessel regeneration and cell proliferation capabilities. As a result, dual therapy stents were developed to reduce the long-term need for dual-antiplatelet therapy.

Harvinder Sahota is an Indian American cardiologist. He is the inventor of the FDA-approved Perfusion Balloon Angioplasty known as "Sahota Perfusion Balloon".

References

  1. "2019 Fritz J. and Dolores H. Russ Prize Recipients". National Academy of Engineering. Retrieved 3 September 2019.