I note you've had no answers, and the reason, I suspect, is that no one wants to tell you that Ceanothus are not long lived shrubs, they do not appreciate frequent cutting, and may well keel over completely in a severe winter, and as such, they are not natural subjects for training as espaliers. They are best planted in a sunny, sheltered position and left to their own devices. Any pruning back should be done immediately after flowering if necessary, also removing any dead wood in spring.

There are other shrubs which will cope with this type of pruning regime - Pyracantha for instance.

Thank you for your reply. I may just cut them back and see how long they last, they have been in for about 4years. When I have to replace them it will have to be something with no thorns as we have a lot of grandchildren!

In that case, why not choose a fruit tree - many of them are suitable for espalier training, though you should select one from the seller grown for that purpose - partial training is already in place.