After finding the general internet woefully scant of information on the how aortic valves work, I turn to you answertariat.

From what I can tell, the three leaflets in the valve are inelastic/nonextensible but flexible. The "edge" of the leaflet (the part that flaps around) is fixedly attached at the interface with the the vessel wall. The entire leaflet (the "base") is anchored at a slightly lower point.

First, please correct any of the above. I don't know my anatomy well.

Second, the question: Given a pressure differential, what holds the leaflets in place? Could there be a better solution with a similarly low parts count?

A couple ideas on my part:
(1) Pressure forces the half-sacks created by the difference in attachment points to push against one another, sealing the valve.

(2) A tendon attached to the inside of the leaflets applies the closing force.

(3) Could we use elastic cantilevers running down the leaflets to force a seal?

Thanks!