What Causes Loss Of Sensation In Private Parts Of Men?

Thank you,my husband had an aeortic aneurism (spelling?) and underwent surgery .He now has trouble feeling in his private parts as he keeps asking if he is -----IN ME---when we are love making- Recently after much encouragement to He is tell me if he was experiencing problems, he said he does not get any pleasure anymore what could be the problem?HE SEEMS VERY UPSET ABOUT THE SITUATION BUT I KNOW HE WILL NOT TELL HIS DOCTOR (FEMALE) ABOUT IT.