(Updates with WRU statement)
LONDON, April 11 (Reuters) - Wales hooker Lloyd Burns has been forced to retire because of a neck injury which may lead to heart surgery, his club Newport Gwent Dragons said on Wednesday.
A club statement said tests from the injury showed damage to the aorta, the body's largest artery, "with possible heart surgery to follow".
Burns, 27, who won seven Wales caps, has not played since January. He made three appearances at last year's World Cup in New Zealand.
Dragons' Director of Rugby Robert Beale said on the club's website (www.newportgwentdragons.com) that Burns's enforced retirement came "as a massive shock to Lloyd and his family".
Welsh Rugby Union head of rugby Joe Lydon added: "Of course the most important issue for Lloyd is his continued good health but he can look back on a playing career in which he truly proved his potential."
Last month, the sporting world was shocked when English Premier League soccer player Fabrice Muamba, of Bolton Wanderers, collapsed on the field after a cardiac arrest during an FA Cup tie against Tottenham Hotspur.
Muamba is expected to be discharged from hospital within the next week but no decision has been made about whether he will be able to resume playing.