Posted: 09/08/2013 at 09:19
As a precaution, it might be worth sticking a few of the prune pieces in a quiet corner somewhere as cuttings. 12 inches long pieces of the new growth,light brown in colour, pushed into the ground in the shade usually root easily.
As to pruning so viciously, leave about 12 inches minimum of the old stems so there are plenty of budding opportunities. And if the shrub is in deep shade, consider finding a way to get light into the base, otherwise it will not grow.
Cannot help with Rhododendron pruning, we have never lived anywhere where they could be grown so never had to prune them.