A pair of thoracopagus conjoined twins were separated at the age of 3 months at Khon Kaen Regional Hospital, Thailand on November 19, 2004. Pre-operative investigations showed separate hearts, joined duodenum, and fusion of the livers. Separation of the extra-hepatic biliary systems was suspected. Operative findings revealed fusion of the intestines from the second part of the duodenum to the terminal ileum with two normal colons. An intussusception was found at the terminal ileum. Fusion of the livers with only one extra-hepatic biliary system was noted. In one of the twins, the gastrointestinal tract was anastomosed with Roux en- Y enteric loop to one area of good bile drainage at the cut surface of liver. Post operative course was hectic but both twins recovered satisfactorily. Both are doing well at present, two years after the separation. This was the first reported case of thoracopagus conjoined twins with complex biliary tract anomalies in Thailand. From the literature, pre-operative investigations in most cases of these conjoined twins failed to define the precise anatomy of the biliary system and may be misleading as in the presented case. The mortality rate remains high. Meticulous pre-operative planning, decision-making in the operative field and postoperative management as well as a multidisciplinary team are very important for a successful separation.

Keywords: Conjoined twins, Siamese twins, Thoracopagus, Biliary system, Intussusception, Separation