Two years after operation , the values [ AHI : ( 18.06 2.24 ) times/h ; lowest SaO2 : ( 88.64 10.37 ) % and Tmax : ( 20.5 17.6 ) s ] in UA group were better than that [ AHI : ( 49.73 3.35 ) times/h ; lowest SaO2 : ( 79.56 4.87 ) % and Tmax : ( 41.3 19.7 ) s ] in U group .