Hi Louie, I wish I had a nickel for every time I have heard this claim.
This is where the confusion for Catholics sets in…
The bishops of Roma never attended the original councils, but they were Metropolitans of high regard. The Councils wanted their findings to be adopted by other Christian communities that were not well represented, so all synods were asked to ratify and adopt the conciliar decrees. Thus Roma as well as other cities were sent copies.
There were other synods which were outside the empire at points in history, these were not usually well represented. Any prelate who could attend would vote, each legate from Metropolitanates further afield would get a vote (yes, other bishops sent legates to Councils too), but this could hardly bind the synods back home. Recall that by the time of the first Council there were already Christians in India, Armenia, Persia and Abyssinia, yet these places were independent of the empire. Some were very poorly represented at the Councils. Western Europe was very rustic in places, and far enough away that it was not well represented either.
Rome was asked, like every other synod was asked, to subscribe to Councils that all may be of one mind. Rome usually followed along.
Even in those rare occasions when the bishop of Rome did not agree they had full force and effect in the east, one example being the famous Canon III of Constantinople 381AD (the bishop of Roma disagreed but the east ignored him, the order of primacy changed anyway). Roma finally reversed itself and agreed with the rest of the church in 1215AD.
The Quinisext Council was never approved by Roma, yet it has had full force and effect in all the rest of the church. The East did not need the approval of the Pope then and does not need it now.
The Sixth Ecumenical Council actually condemned a Pope.
Not one of these Councils was called by a Pope, not one was controlled by a Pope and not one was chaired by a Pope. In each case the church of the west was asked to reaffirm the findings in the same manner that the church of India and other outlying synods were asked, and for the same reason.
What you are asserting here is a myth. It is commonly recited by cyber-Catholics like an urban legend, but it is not true.