Health Sciences · Temerty Faculty of Medicine
A small (~2 cm tall) object with a ring-like base covered in a white Dacron fabric. Within this ring is a circular white Teflon disc. This disc is retained by two white Teflon-coated struts that are joined to the base. Together, the struts form a cage that retains the disc.
A white plastic embossed label is tied to the base by a thread.
Accession Number: 2020.med.19
Mechanical Heart Valve (MHV), Cloating Disc Valve, Captive Disc Valve.
Metal (Iron alloy), Plastic (Teflon), Fabric (Dacron velour polyester fibre).
The white plastic embossed label reads as follows: “M/MB64185”.
Dimensions (cm): Height = 2, Max diameter = 3.5.
The Beall 104 heart valve is a cardiac prosthesis that replaces a damaged or insufficient mitral valve that cannot be repaired. The valve is sutured to the heart valve annulus using the fabric sewing ring.
It is an early captive disk design that operates on a similar principle to the earlier captive ball valves. In this case, blood flow causes a disk to alternately descend to the ring, closing the valve, or ascend to the roof of the cage, opening it. The design was introduced principally to address issues with existing ball valves, especially when used as mitral valve replacements (see Shorter, Scully, and Goldman 2022, 182).
The valve was introduced in 1969 and withdrawn by 1975. It had a very high failure rate due to rapid wearing of the Teflon disk and the Teflon coating of the cage.
The valve is intact and in very good condition. The fabric cover is discoloured on its outer surfaces, likely from repeated handling.
Associated Instruments:
Surgitool, Inc. Pittsburgh, Pennsylvania.
Date of Manufacture: 1969 – 1975.
This artifact belongs to a small collection of items related to cardiac surgery that was collected by Dr. Wilfred Gordon “Bill” Bigelow (1913 – 2005). After his death, the collection was donated to the Cardiovascular Sciences Collaborative Program of the University of Toronto, where it is currently on display.
Edward Shorter, Hugh E Scully, and Bernard S Goldman (2022). The Heartbeat of Innovation : A History of Cardiac Surgery at the Toronto General Hospital. University of Toronto Press.
William L. Winters Jr. (2012). “Arthur C. Beall Jr., M.D. August 17, 1929 – December 8, 2002.” Methodist DeBakey Cardiovascular Journal 8, 2: 58.
Malcolm D. Silver and Gregory J. Wilson (1977) “The Pathology of Wear in the Beall Model 104 Heart Valve Prosthesis.” Circulation 56, 4: 617–22.
The Beall 104 prosthetic mitral valve was an early captive disc valve that was introduced in 1969. The captive disc design addressed problems with the earlier Starr-Edwards captive ball prosthesis, especially the rate of thromboembolic complications and the excessive height of the ball valve implant. This could interfere with circulation when used as a mitral valve replacement.
The 104 model was meant to correct the design problems with the earlier 103 model, which suffered from premature wear of the Teflon disk and Teflon coated struts. This resulted in many issues including the tearing of the Dacron Sewing ring, mitral regurgitation due to disc wear, embolism due to Teflon wear particles, and even disk escape.
The 104 model sought to address these issues through a denser Teflon disc that was compression moulded rather than extruded. The thickness of Teflon coating on the struts was doubled and the base was made thicker. The 104 model nevertheless suffered significant wear problems and was withdrawn from the market, along with the 103 model, in 1975. These were replace by the 105 and 106 models that used a pyrolytic carbon coating rather than Teflon.
The challenges with the Teflon models points to the difficulty in drawing conclusions about the in vivo performance of medical implants based on bench top tests. (See Silver and Wilson 1977 for details.)
The Beall 104 Mitral Valve at Toronto General Hospital
Between 1969 and 1972, ninety-seven patients at TGH were implanted with Beall captive disc valves. By July 1978, when the story of the defective valves gained media attention, forty-five had died. The failure of these valves was analyzed by the TGH pathologists Drs. Malcolm D. Silver and Gregory J. Wilson, who published their findings in 1977. They concluded:
We believe that wear in the Beall model 104 prosthesis is inevitable. As a result, all patients who have had their prosthesis in situ for more than five years should be assessed regularly, as “severe” wear may develop rapidly. (Silver and Wilson 1977, 622).
A management protocol was put in place for dealing with affected patients. TGH cardiac surgeons replaced a number of the valves. (For an account of this episode, see see Shorter, Scully, and Goldman 2022, 182-183.)