I had a chronic eustatian tube disorder (my right ear always felt stuffed up as if on an airplane). My ENT proposed what was apparently a newish procedure to dilate the tube (this was 2018) where a balloon is inserted in the tube, expanded, and then removed. It was a surgical procedure under anesthesia but very short. It worked in the sense that the constant pressure feeling was gone, which alone was worth doing, but my hearing did not improve. This was a disappointment to my doctor and me.