Unusual presentation of heteropagus attached to the thorax

Thoracic heteropagus conjoined twins associated to an omphalocele: Report of a case and complete review of the literature

Heteropagus twins are an extremely rare event with an incidence of 1-2 million live births that represents, sometimes, a real challenge for paediatric surgeons. The majority of cases have complete or partial duplication of the pelvis and/or lower extremities. Thoracic heteropagus conjoined twins is a rare condition in which a grossly defective foetus (the parasite) is attached to the thorax of the main foetus (the autosite). We describe a case of a parasitic heteropagus attached at the chest wall with a rare presentation of giant exomphalos on the autosite. In this situation, the separation procedure was simple after a well-done anatomic study using X-ray, ultrasonography, magnetic resonance and echocardiogram are performed.

Heteropagus (parasitic) twins: a review

Heteropagus, or "parasitic," twins are asymmetric conjoined twins in which the tissues of a severely defective twin (parasite) are dependent on the cardiovascular system of the other, largely intact twin (autosite) for survival. The estimated incidence of heteropagus twins is approximately 1 per 1 million live births. Isolated case reports comprise most of published work on this rare congenital anomaly. In the past, review articles have focused narrowly on one particular anatomical subtype of parasitic twin and/or on the anatomicopathology observed. Here, we present the epidemiology, proposed pathoembryogenic origins, anatomical abnormalities, management, and outcomes of the wide array of heteropagus twins described in the English language literature.

Thoracopagus parasites in two sets of twins: evidence for the fusion theory

We report two sets of parasitic twins attached in the thoracic region. Exomphalos major in the autosite was present in both cases. While in case 1, the autosite could be salvaged after easier dissection, in case 2, the autosite could not be salvaged due to the presence of the life-threatening anomalies. The presence of a right-angled communication between the gastrointestinal tracts of the autosite and the independent tactile responses of the parasite from that in the autosite supports the 'fusion theory' to explain the fusion of the embryos that could have led to this defect. The presence of the ano-rectal malformation and common bile duct dilatation exclusively in the parasite appears to be the result of the abnormalities in the endodermal-mesodermal interactions, probably due to the relative positioning of the parasite with respect to the autosite.

Bizarre Presentation of Epigastric Heteropagus: Report of a Case

We report an unusual case of epigastric heteropagus in a female neonate. The parasite had a single lung as well as a liver, stomach, intestine, pancreas, ovaries, a single kidney, and a bladder. These visceral organs were located in the abdominal and pelvic space of the autosite, and the pelvic bone and lower legs of the parasite were fused with the respective organs in the autosite. The infant underwent operations to remove the central leg and some of the intra-abdominal organs of the parasite, but she must still undergo further surgery to remove the genitourinary organs and pelvic bones of the parasite, and repair her very abducted and rotated right leg.