For valves of same orifice area, allows a comparison of the effective use of the area. Disadvantages include high velocity leading to damage. Flushing away of stagnant blood may reduce clotting. Pyrolitic carbon combines biocompatibility with good wear resistance, especially when it is used to make or coat both parts. Especially bad for metals, but also exists for pyrolytic carbon.
Calcification make tissues stiffer, leading to cracking.
Worse in young patients and those with kidney problems. Seems to be connected to gluteraldehyde. Worst in areas of large flexion.