Separation of omphalopagus twins.

The study and successful separation of a pair of omphalopagus twins weighing 1690 g at birth is presented. The test of greatest usefulness was an oral glucose tolerance test that demonstrated an absence of parasitism. Subsequently, it was found that the twins had a joined liver but separate GI and GU tracts. The time for separation was determined by observing the twins' toleration of compression of the bridge. Initially, obliteration of the tunnel-like connection would cause considerable respiratory distress. However, in the month before surgery, the tunnel could be compressed to the point of obliteration without causing tachypnea or other signs of respiratory distress. The change in toleration of compression was related to unequal growth of the twins and their connecting bridge. Though the weight of the twins quintupled in their first 6 mo, the circumference of the bridge remained the same. The surgery was carried out on a single table without frames. The twins were draped using self-adhering plastic. Intravenous fluoroscein was used to demarcate the large liver juncture, thus expediting the separation.