Singer Sam Smith39s operation on his haemorrhaged vocal cords was a success, according to an official of the Massachusetts General Hospital, the facility where he was treated.The "Stay with me" hitmaker, who was forced to cancel a string of Australian shows last month and put recording his upcoming album on hold, is expected to make a full recovery after undergoing surgery on his vocal cords in Boston on May 14, reports femalefirst.co.uk."Sam Smith underwent vocal cord microsurgery by Steven Zeitels, MD, to stop recurrent vocal cord haemorrhage bleeding. This condition is the result of unstable blood vessels in the vocal cord that can rupture and prevent vocal performance."Sam came to Boston to consult and undergo corrective voice surgery with Zeitels, the director of the Massachusetts General Hospital Voice Centre... Zeitels has performed this unique procedure for many vocalists -- including Steven Tyler, Lionel Richie, and Adele -- allowing them to return to full performance. "...Zeitels expects Sam to make a full recovery from his laser microsurgery," the spokesperson of Massachusetts General Hospital said in a statement.The "Lay me down" hitmaker, who celebrated his 23rd birthday on Tuesday, warned fans he would not be able to speak for three weeks following the procedure.In a post on Instagram, he wrote: "Enjoying my last day of speaking. After today no speaking for three weeks. So if you see me on the streets sorry if you think I39m a dhead and can39t say hello. Also gonna be silent for my birthday. Sounds fun aye? sic"