What does can't exclude a functional bicuspid valve on a echo? i have a mild to moderste aotic stenosis for several years.

Normally the aortic: valve is trileaflet (three leaflets) but in some individuals it is bileaflet (two leaflets.) This is called a bicuspid valve. The interpreter of the ECHO is unable to see the valve clearly enough to make a distinction so he says he can't exclude the possibility that the valve is functioning as though it is bicuspid rather than normal.