Hijjah 18, 1431/Nov 24, 2010, SPA -- The Custodian of the Two Holy Mosques, King Abdullah bin Abdulaziz Al Saud successfully underwent today back surgery at New York Presbyterian Hospital in the United States of America, the Royal Court said in a statement issued here today. The statement added that thanks to God Almighty, a blood clot was removed and the slipped disc was treated during the successful back surgery.