The Syrian Siamese twins named (Toqa and Yaqeen) will undergo a separation operation at King Abdullah Specialist Children's Hospital at King Abdulaziz Medical City of the Ministry National Guard here on next Sunday morning with the participation of a number of prominent Saudi consultants from several disciplines. The twins share in the head area and this kind of conjoining is the most difficult and complicated. The surgery is expected to take 12 hours in row and a success percentage up to 60%. This was announced by Dr. Ahmed Al-Feriyan, Consultant of neurosurgery and head of the medical team to participate in the Syrian Siamese twin separation surgery.