Tilting disc valves

An extensive study of the literature was undertaken, and results from over 450 articles in both the medical and engineering literature were utilized (14). The results for the following heart valve prostheses are summarized in this paper (a) Starr-Edwards ball valves, (b) Kay-Shiley disc valve, (c) Beall disc valve, (d) Bjork-Shiley tilting disc valve, (e) Hancock porcine valve, and (f) St. Jude bi-leaflet valve. These valve prostheses shown in Figures 1 through 6 were chosen because of their past and/or present popularity in clinical use. They also encompass all the basic designs of valve prostheses used during the past two decades. 

Figure 4. Bjork-Shiley tilting disc valve...

Good, long term clinical follow-up data exists only for the following valve types studied O ) Starr-Edwards ball valves, (ii) Bjork-Shiley tilting disc valve, (iii) Lillehei-Kaster tilting disc valve, and (iv) Hancock porcine valve. 

FIGURE 44.2 (a) Photograph of a typical tilting disc valve prosthesis. (Courtesy of Medtronic Heart Valves,... 

Minneapolis, MN.) (b) Chitra tilting disc valve prosthesis with the occluder made of ultra high molecular weight polyethylene. (Courtesy of Sree Chitra Tirunal Institute for Medical Sciences and Technology, India.)... 

FIGURE 44.5 Cavitation bubbles visualized on the inflow side of the valves in vitro [Chandran et al 1994a] (a) Medtronic-Hall tilting disc valve (b) Edwards-Duromedics bileaflet valve (c) CarboMedics bileaflet valve. 

Tilting disc valves Valves with a single leaflet tilting open and shut. 

T. Larmi, P. Karkola, Shrinkage and degradation of the Delrin occluder in tilting-disc valve prosthesis, J. Thorac. Cardiovasc. Surg. 68 (1974)66-69. 

In Fig. 7 some photographs of flow patterns are illustrated the first shows the flow patterns in the device without the valve and the second the flow patterns of a bioprosthesis while the last two show the flow patterns of a HK and a Sorin tilting disc valves. Without the valve, the flow patterns are rectilinear and parallel to each other and there is no turbulence. With the bioprosthesis the zone of rectilinear flow is smaller, but central the turbulent flow appears only close to the aortic wall. The two mechanical valves show a dissymmetrical flow with a great zone of turbulence over the disc hence their hemodynamics is worse than that of the bioprosthesis. It is interesting to note the presence of vortexes inside the sinuses of Valsalva in all the photographs. Such vortexes are important for the closing mechanics of the natural leaflets ... 

Khalighi B, Chandran KB, Chen CJ (1983) Steady flow development past valve protheses in a model human aorta - I. Centrally occluding valves and II. Tilting disc valves. Biomech 16 1003-1018... 

Figure 3. Exploded view of the components of Baylor left ventricular bypass pump a) polycarbonate connectors, b) Lille-hei-Kaster tilting disc valves, c) top of polycarbonate pump housing, d) polyether urethane (Biomer) bladder, e) bottom of polycarbonate pump housing ("dome") with sensor electrode attached which monitors pump filling.

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