This is an early prototype of a curvilinear-shaped artificial heart valve developed by pioneering heart surgeon Dr. Charles Hufnagel (1916-1989) and his team at the Georgetown University.
The materials used to fabricate this prostethic were polypropylene cloth, metal frame and metal leaflets polypropylene coated in silicone. Because the silicone rubber proved to be less flexible than desired, their design was not used extensively.
This is an open cage, sutureless ball valve developed by Harry Cromie, an engineer, and Dr. George Magovern, MD. It uses an open cage design to lower chances of thrombosis. Its components include a Dacron ring and a silicone rubber poppet with barium sulphate (to make the valve radiopaque). There are titanium struts but no legs below the orifice. This valve differs from earlier valves because it can be implanted without sutures. Suturing valves in place often took forty-five minutes to an hour. The patients were sick before surgery, and they were often sick afterwards because of the time their hearts spent hooked up to heart-lung machine. Prolonged clamping of the aorta also caused injury. The longer the procedure, the higher the risk of irreparable heart damage and patient death. With a 90% patient mortality rate, Dr. Magovern was inspired to design something that would save time, and thus, patient's lives. He and Cromie collaborated in the latter's basement to develop a valve that would clamp into place with small teeth. They developed a claw like fixation device that did not require any sewing, and took approximately three to four minutes to attach. The ring has an upper and lower set of curved, pointed metal teeth. These hooks allowed for rapid fixation when time was most critical. The implantation of this valve required a special device--an insertion and removal instrument--that would rotate and engage the fixation pins with the aorta. After the inserting tool is removed, the rubber poppet is placed into the cage. With sutureless valves, there was an increased risk of perivalvular regurgitation (leaking) and postoperative thromboembolism. The production of these valves ceased in 1980. Magovern said, "I wouldn't say I was particularly skillful, but I was fast."
Dr. George Magovern (1924-2013) trained at George Washington University and helped to establish Allegheny General Hospital in Pittsburgh, Pennsylvania. Harry Cromie is an engineer. They both went on to found Surgitool, Incorporated, which at the time became the leading U.S. company for heart-valve design.
This is a demonstration model of the mechanical Regent mitral bivalve artificial heart valve manufactured by St. Jude Medical of Minneapolis, Minnesota. The 23mm valve has prolytic carbon disks and a flexable sewing ring.
This free floating artificial heart valve was the second type of prosthetic designed by pioneering heart surgeon Dr. Charles Hufnagel (1916-1989) and his team at Georgetown University. It was made of polypropylene. The disk initially received a coating of silicone rubber to ensure it did not make a loud noise. The valve could be implanted in the aortic and mitral and tricuspid valves. First clinically used in 1963, many of these early valves were still in use ten years later.
Hufnagel, invented and implanted the first successful artificial heart valve at Georgetown University Hospital in Washington, D.C. He experimented with various materials, but eventually settled on polymethylmethacrylate, a hard, clear plastic more popularly known by the trade name of Plexiglas or Lucite.
This free floating artificial heart valve was the second type of prosthetic designed by pionerring hear surgeon Dr. Charles Hufnagel (1916-1989), and his team at Georgetown University. It was made of polypropylene while the disk initially received a coating of silicone rubber to ensure it did not make a loud noise. The valve could be implanted in the aortic, mitral, and tricuspid valves. First clinically used in 1963, many of these early valves were still in use ten years later.
Hufnagel, invented and implanted the first successful artificial heart valve at Georgetown University Hospital in Washington, D.C. He experimented with various materials, but eventually settled on polymethylmethacrylate, a hard, clear plastic more popularly known by the trade name of Plexiglas or Lucite.
This is a St. Jude Medical (SJM) mechanical demonstration heart valve. It is a bi-leaflet valve with four pivots. The SJM valve was the first all carbon valve in clinical use. All St. Jude valves would be made with pyrolytic carbon, a material and coating recognized for its biocompatibility and thromboresistance (avoidance of blood clots). It quickly became the 'gold standard' for subsequent valves regardless of the manufacture. A white cloth suture ring surrounds the aluminum valve. Etched into the bi-leaflet valve is the word DEMO. Also present are softened, rounded edges of the metal component to resolve prior issues with clotting and thrombus. The first surgical of a SJM artificial heart valve was carried out in October 1977.
St. Jude Medical was founded by Manuel "Manny" Villafaña in 1976, in St. Paul, Minnesota, U.S.A. This popular bi-leaflet valve was developed at the University of Minnesota in 1972 by Dr. Demetre Nicoloff (1934-2003). It differed from previous valves because it was made of pyrolytic carbon, a material that was very durable and could last many years in the body. Dr. Jack Bokros, PhD, a nuclear engineer and founder of OnX Life Technologies Inc., developed this material. Manny Villafaña is a businessman whose first company was Cardiac Pacemakers, Inc.
The label inside the jewelry box in which it is housed reads: "This demo valve has been/ made of anodized aluminum/ which, by its nature, does/ not allow us to machine to/ the necessary tolerances/ and polish of our all/ pyrolytic carbon valve./ It, in no way, manifests/ the true quality, finish, or/ operational characteristics/ of an St. Jude. Medical Valve,/ but only grossly demon-/strates its concept of/ function."
A normal human heart has four chambers. Each chamber has a valve: the tricuspid, the mitral, the aortic, and the pulmonary. As the heart muscle contacts, the mitral and tricuspid valves close and the pulmonary and aortic valves open, directing blood to flow in one direction. When one or more valves do not work properly, they might need to be repaired or replaced.
The causes of heart valve malfunction are numerous, and can include congenital malformation or acquired heart disease. Artificial heart valves were the first mechanical replacements of a natural organism in a human.
Pioneering heart surgeon Dr. Charles Hufnagel (1916-1989) began working on the developed of artificial heart valves in 1947, and the first clinical implantation occurred in 1952. The patient's natural valve was left in place and the mechanical valve was placed in the descending aorta, aiding the damaged valve.
Many artificial heart valves were developed in the early 1960s. This Magovern-Cromie caged ball valve was first implanted in a patient in 1962. It was developed by Dr. George Magovern of the University of Pittsburgh and engineer Harry Cromie. The struts and the small hooks are made of titanium. The hooks at the base of the valve replaced the need for sutures and shortened the time of the operation. Thousands of Magovern-Cromie artificial valves were manufactured and implanted until production ceased in 1980.
This box contains various parts of St. Jude Artificial heart valves. There are 5 valves, 4 donuts (with no leaflets or Dacron sewing rings), 1 incomplete valve (lacks a leaflet and cloth suture), and 2 individual leaflets. Demo valves are sometimes made of anodized aluminum instead of pyrolytic carbon. The St. Jude Medical (SJM) valve was the first all carbon valve in clinical use. All St. Jude valves would be made with pyrolytic carbon, a material and coating recognized for its biocompatibility, thromboresistance, and durability. It quickly became the 'gold standard' for subsequent valves regardless of their manufacturer. A white Dacron sewing ring surrounds the valve.
St. Jude Medical was founded by Manuel 'Manny" Villafaña in 1976, in St. Paul, Minnesota, U.S.A. The model for its popular bi-leaflet valve was developed at the University of Minnesota in 1972 by Dr. Demetre Nicoloff (1934-2003). It differed from previous valves because it was made of pyrolytic carbon, a material that was very durable and could last many years in the body. Dr. Jack Bokros, founder of OnX Life Technologies Inc., is the doctor who developed this material. Manny Villafaña is a businessman whose first company was Cardiac Pacemakers, Inc. The first surgical implant with a SJM valve was carried out in October 1977.
Tissue valves are made in bovine and porcine models from the biological tissue of cows and pigs, respectively, as an alternative to mechanical heart valves. This valve is a porcine heart valve manufactured by St. Jude Medical of Minneapolis, Minnesota. Harvested tissue is sewn into a Dacron covered sewing ring, creating leaflets, and then affixed to a polyester covered stent. One advantages of tissue valves is that the patient does not have to rely on anticoagulation medication to prevent blood clots.
This sutureless Lillehei-Kaster bi-leaflet valve was introduced in 1970. the valve is embedded in plastic to be used as an advertising tool. It is made of titanium and pyrolite coated graphite. It had low embolic rate, good hemodynamics, and low hemolysis.
Tilting disc valves were first introduced by Lillehei-Kaster in 1969. Robert Kaster earned his electrical engineering degree from the University of Minnesota (1951). He became interested in designing prostheses while working in Dr. C. Walt. Lillehei's laboratory. It was there that he designed the tilting disc valve. The disc is held in place by two side prongs. Kaster also worked with another valve creator, Jack Bokros, to develop his disc. Lillehei-Kaster valves were produced by Medical Incorporated of Minneapolis. These valves demonstrated high durability due to their pyrolyte composition and had "essentially no valve failures."
This is a St. Jude Medical demonstation mechanical 27mm bi-valve aortic artificial heart valve. The leaflets are made of graphite and coated with pyrolytic carbon. A white polyester cuff or sewing ring is implanted by sewing it into the patient's tissue.
This is a St. Jude Medical demonstation mechanical 23mm bi-valve aortic artificial heart valve. The leaflets are made of graphite and coated with pyrolytic carbon. A white polyester cuff or sewing ring is implanted by sewing it into the patient's tissue.
This is a demostration mechanical mitral heart valve. Its leaflets rotate within the cuff, and are made of graphite coated with pyrolytic carbon. The white polyester cuff or sewing ring attaches the valve to the patient's tissue.
The donor Manuel “Manny” Villafaña entrepreneur and CEO of six companies over many years developed a collection of artificial heart valves. This Japanese mitral valve with a non-tilting disc valve is one example. The development of artificial heart valves took place in many countries around the world, and there were many international collaborations.
This 29.2mm Beall Surgitool Mitral Valve has a free floating titanium disk held in place by two struts. The titanium base is covered in Dacron velour. The Beall mitral valve was developed about 1960 by Dr. Arthur C. Beall, Jr. (1929-2002). Beall received his medical degree in 1953 from Emory University, and did his residency at Baylor from 1954-1959 under Dr. Michael DeBakey. Beall was a Michael E. DeBakey Legacy of Leadership honoree.
This 34.2mm Beall Surgitool Mitral Valve is a free floating titanium disk held in place by two struts. The titanium base is covered in Dacron velour. The Beall mitral valve was developed by Dr. Arthur C. Beall, Jr. (1929-2002) around 1960. Beall received his medical degree in 1953 from Emory University, and did his residency at Baylor from 1954-1959 under Dr. Michael DeBakey. Beall was inducted into the Michael E. DeBakey Legacy of Leadership honoree.
The Beall-Cromie is a caged-disc mitral valve coated with Teflon. it is similar in design to Charles Hufnagel's caged disk valve. In this model, the ring is large and the cage is flimsy. It was designed by Dr. Arthur Beall (1929-2002) of Baylor University College of Medicine and Harry Cromie, an engineer who was involved in designing the sutureless Magovern-Cromie valve. Beall worked with Dr. Michael DeBakey during his residency at Baylor.
