Conjoined thoracopagus twins: A systematic review of the anomalies and outcome of surgical separation

Thoraco-Omphalopagus Conjoined Twins: A Case Report

A conjoined twin is an uncommon congenital condition that has a very high morbidity and mortality prevalence. Identical twins united in utero are known as conjoined twins. It's an uncommon occurrence that poses a special difficulty for paediatric surgeons and obstetricians. Conjoined twins are a complicated by-product of monozygotic twinning, which raises the risk of death in the womb. One of the more prevalent varieties of conjoined twins is the thoraco-omphalopagus type, in which the heart is involved in an anterior, chest-based fusion. This case involves a 26-year-old woman who was diagnosed at 19 weeks with conjoined thoraco-omphalopagus twins using ultrasonography.

Phenotypically Discordant Anomalies in Conjoined Twins: Quirks of Nature Governed by Molecular Pathways?

A multitude of additional anomalies can be observed in virtually all types of symmetrical conjoined twins. These concomitant defects can be divided into different dysmorphological patterns. Some of these patterns reveal their etiological origin through their topographical location. The so-called shared anomalies are traceable to embryological adjustments and directly linked to the conjoined-twinning mechanism itself, inherently located within the boundaries of the coalescence area. In contrast, discordant patterns are anomalies present in only one of the twin members, intrinsically distant from the area of union. These dysmorphological entities are much more difficult to place in a developmental perspective, as it is presumed that conjoined twins share identical intra-uterine environments and intra-embryonic molecular and genetic footprints. However, their existence testifies that certain developmental fields and their respective developmental pathways take different routes in members of conjoined twins. This observation remains a poorly understood phenomenon. This article describes 69 cases of external discordant patterns within different types of otherwise symmetrical mono-umbilical conjoined twins and places them in a developmental perspective and a molecular framework. Gaining insights into the phenotypes and underlying (biochemical) mechanisms could potentially pave the way and generate novel etiological visions in the formation of conjoined twins itself.