CONJOINED TWINS - THE CAPE-TOWN EXPERIENCE

This paper records our experience in the management of 25 sets of conj oined twins seen over a 32 year period (1964-1996). The twins were cla ssified into 14 complete and symmetrical sets and 11 incomplete or het eropagus. The 14 symmetrical sets included 9 thoracopagus, 2 ischiopag us, 1 craniopagus and 1 omphalopagus twins. In the incomplete heteropa gus group there was ischiopagus, one twin being anencepahlic, 2 dipygu s, 5 parasitic, 2 fetus-in-fetu and I cranial and caudal. The manageme nt is detailed case by case. Overall 10 of 14 symmetrical sets underwe nt attempts at separation with 16 surviving the procedure, but there w ere 3 late deaths. In the incomplete group 10 of II were operated on w ith 9 survivors. The importance of a multi-disciplinary approach, the extensive investigations required pre-operatively to define areas of o rgan and bony conjuction, congenital anomalies of each twin and surgic al teamwork is emphasized. Specific problems encountered were identifi ed. In thoracopagus twins the hearts were of paramount importance as c onjuction was usually fatal, being associated with major congenital de fects. The greater the extent of thoracic cage fusion the greater the chance of associated severe anomaly. Skin expansion to assist coverage of the defects after separation was of great assistance, as was the u se of collagen coated vicryl. Evaluation of the liver and pancreatico- biliary systems with isotope excretion scanning was crucial to pre-ope rative planning. Where there was fusion of the duodenum a single pancr eatico-biliary system could be expected and prior strategies for separ ation and Roux-en-Y enteric drainage of both pancreatic and biliary se cretion should be planned. Gastro-oesophageal reflux led to considerab le morbidity in both twins of a thoraco-omphalopagus set. In ischiopag us and dipygus conjoined twins bilateral posterior iliac osteotomies w ere an essential component to anatomic reconstruction of the pelvic ri ng and wound closure. Also in this group, due to the frequency and ext ent of shared genital, urinary and ano-rectal structures, long-term mo rbidity was expected and a component of this might be due to spinal co rd tethering , or as in one of our cases, a progressive hydrosyringomy elia. Timing of separation was ideally set at between 5 and 9 months w ith 6 to 8 weeks of prior tissue expansion but earlier operation was f requently required because of cardio-respiratory problems or organ fai lure in one twin. In most cases the goal of obtaining separate, indepe ndent and intact individuals was achieved.