Andromeda is heading towards us, so when it gets here, some systems might get hit, planets ejected from a system or two, but only the outer rim. Milky drameda will form, once a spiral galexy, then maybe a hook/ curve galexy, basicaly it will make the galexy into a different shape, barely or serious change depending on the contact, ejected planets from the milky way stolen by Andromeda, after a while the galexy will become more, this might have happened before, who knows