Similarly, I had triple bypass 4 weeks ago and my voice has been terribly affected since. Is this permanent if not what is the treatment?
What you describe is apparently pretty common. Usually, the voice returns by itself after a few weeks or months. If it does not, voice therapy (basically physical therapy for the voice) can help. Here's more information:
http://www.chdbabies.com/2009/08/vocal-cord-paresis-can-occur-after-open.html
it's due to the intubation. they likely roughed up your vocal chords and it's irritated. i had no voice for almost 2 months and they were going to do a procedure to inject fluid into the paralyzed chord so the other side met it. while i was scheduling this (over a week and a half) my voice started to come back little by little. i did the vocal exercises (saying and repeating the words: Up, Elephant, Elevator, Inside, etc..) i was speaking fully about 2 weeks after it started to come back.