How can the Eustacian tube be kept open?

When I was a kid, I had three surgeries in my left ear because of chronic infections. These days, I m not hearing out of it as well as I should.

I ve noticed that if I perform the Valsalva maneuever, I can hear much better for about 30 seconds to a minute, before I feel it close back up and my hearing goes back to normal. If I do the Valsalva maneuver and then keep moving my jaw around, I can prolong the effect, but not forever.

Is there anything I can do to help it stay open without having more surgery?