Can Kidneys Recover To Normal Level After Bilateral Hydronephrosis Caused By Enlarged Prostrate?

My Dad has bilateral hydronephrosis caused by enlarged prostate blocking the uretha. His caroten levelsrose to 14 however are now below 1 and he has undegone 2 dyalisis, but now he seems well and according to his doctor the kidneys are slowly shrinking back. What is the prognosis in this case please? Can kidneys recover to acceptable level? One is worse than the other. Thank you.