The rocker was admitted to hospital earlier this month (Jun15) to undergo treatment for Marfan syndrome, a disorder which affects the tissues of organs including the heart, and he has been under the care of cardiologists at Stanford Hospital in California.

Carlile took to his Twitter.com page on Monday (15Jun15) to tell fans he was going in for a "big" operation which he hopes will help him recover enough to go home.

He writes, "About to head into the big operation now! Hopefully this will be the most effective of all the procedures they've tried thus far and will... Get me back on my feet and home again! Even when I finally do get back home, there's still progress to be had from there. Small steps!"

The outcome of the surgery was not known as WENN went to press. Of Mice & Men cancelled the remaining shows of their Full Circle tour after Carlile fell ill in early June (15).