The Outcomes of Surgical Separation in Thoracopagus Twins with Conjoined Hearts: An Analysis of the Literature

We sought to perform a comprehensive review of reported cases of conjoined thoracopagus twins with cardiovascular conjunction to determine the overall survival after separation and factors that might be associated with survival. We performed a systematic review of cases of thoracopagus twins with conjoined cardiovascular systems reported in the English medical literature using Embase, PubMed, Web of Science, and Scopus. We employed standard statistical methods to analyze differences among groups. We identified 102 unique cases of thoracopagus twins (69% female) with some degree of cardiovascular conjunction who had undergone surgical separation. We identified 6 distinct types of cardiovascular union. Median age was 47 days (IQR 12, 120). Survival to at least hospital discharge occurred in 51% (105/204). Median age at separation was lower in emergent (9 days, IQR 1, 25) versus elective cases (93 days, IQR 49, 180) (p < 0.0001). Survival to hospital discharge was higher in those who underwent elective separation (70%, 93/132 total children versus 17%, 12/72) (p < 0.0001). Survival was associated with the type of cardiovascular union (p < 0.0001). The separation of thoracopagus twins with cardiovascular conjunction is higher than expected. Increased survival is associated with elective separation, older age, and shared pericardium only. These findings suggest survival could be improved with better delineation of degree of union and delayed separation.