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Conjoined Twin Separation: Integration of Three-Dimensional Modeling for Optimization of Surgical Planning

Abstract Conjoined twinning is a rare anomaly, with an incidence of approximately 1 in 100,000 live births. There is a high perinatal mortality rate, but twins who survive pose reconstructive challenges that require meticulous preoperative planning. The authors describe the senior surgeon's career experience with conjoined twin separation, and the evolution of medical modeling and 3-dimensional imaging as a critical component in presurgical planning. The authors performed a retrospective review of all consecutive patients of conjoined twin separation at a single institution from January 2004 to December 2013. Data were collected related to patient demographics, comorbidities, operative technique, perioperative complications, survival, long-term outcomes, and the type of medical modeling system used for preoperative planning. Five sets of conjoined twins underwent separation during the 10-year study period. There were 3 sets of thoraco-omphalopagus twins, 1 set of pyopagus twins, and 1 set of ischiopagus tetrapus twins. The mean age at separation was 70 days, with a mean of 3.5 surgical procedures performed per patient during the first year of life. One set of twins experienced postseparation complications that warranted immediate return to the operating room. The overall survival rate after separation was 70%. The imaging methods used were computed tomography scan with 3-dimensional reconstruction, plaster molds, medical modeling with composite printing, and virtual surgical planning. The use of imaging and medical modeling in presurgical planning has proven to be an important element in optimizing the outcomes for patients with this rare anomaly.