The surgical principles of conjoined twin separation.

The surgical management of conjoined twin separation is a complex, multidisciplinary process that requires extensive pre operative planning and organization for optimal outcomes. Identification of detailed anatomic relationships is necessary prior to the separation. The use of 3D modeling is extremely helpful for conceptualization of the operation. The principles of the separation are dependent on the type of twin, although each variant of symmetric twins has certain commonalities related to their embryology that can be considered when planning the operation. The use of tissue expansion in the pre operative planning stage is highly recommended due to known issues with closure after separation. In order to ensure a safe, successful operation, we recommend organized pre operative planning meetings with at least one simulation of the separation event with multidisciplinary involvement.