RIYADH — The medical team of the Saudi Conjoined Twins Program began the eight-hour surgery on Filipino conjoined twins Olivia and Gianna Thursday morning. In implementation of the directives of the Custodian of the Two Holy Mosques King Salman bin Abdulaziz and Crown Prince Mohammed bin Salman, the twins were admitted to King Abdullah Specialized Children's Hospital at King Abdulaziz Medical City, Ministry of National Guard Health Affairs, in Riyadh. During a press statement, Dr. Abdullah Al Rabeeah, Advisor at the Royal Court, Supervisor General of the King Salman Humanitarian Aid and Relief Center (KSrelief), and head of the program’s medical and surgical team, said that the twins —two years and two months old — arrived in the Kingdom on January 27. Following their admission to the hospital, the medical team conducted extensive examinations and held several consultations, concluding that the twins are joined at the chest and abdomen, sharing the liver and possibly part of the intestines. One of the twins also suffers from congenital heart defects that pose a significant health risk. **media[2724492]** Dr. Al Rabeeah noted that a skin expansion procedure had previously been performed by implanting medical balloons beneath the skin to help close the surgical wounds after separation. The operation is expected to last approximately eight hours, and Dr. Al Rabeeha explained that it will be conducted in six stages under a team of 22 consultants, specialists, nurses, and technical staff is participating in the procedure. He added that the surgery is highly delicate, with a success rate expected to exceed 70 percent. Dr. Al Rabeeah further pointed out that this is the fourth separation surgery for conjoined twins from the Philippines and the 72nd operation performed under the Saudi Conjoined Twins Program. Since its establishment in 1990, the program has provided care for 158 sets of conjoined twins from 28 countries across five continents.