Innovative imaging techniques to guide the prenatal and postnatal management of premature omphalopagus conjoined twins: a case report

The incidence of conjoined twinning is approximately 1:100,000 with omphalopagus anatomy representing 10% of all cases. With an overall survival rate of <10% and a 60% rate of survival in patients who undergo separation, considerable medical, surgical, and ethical planning is required. A 34-year-old mother was identified as having conjoined twins at 9 weeks gestation. She underwent an early fetal Magnetic Resonance Imaging (MRI) to assess potential for viability and a late second trimester MRI – these identified omphalopagus anatomy with shared liver and a Tetralogy sequence in twin B. 3D modeling of these images guided delivery and separation planning. The twins were born prematurely at 29 weeks and 6 days. Neonatal Inteive Care Unit (NICU) management was instituted at birth and the initial cardiorespiratory status of the twins was stable with minimal circulatory mixing noted. Combined fetal weight was 2.6 kg. At 3 weeks of life, significant circulatory deterioration occurred in twin B. Urgent separation to facilitate treatment for twin B best optimized both patients’ survival and was in keeping with parental wishes. Detailed cross-sectional imaging was expedited and used to facilitate successful separation. Pre-op anesthesia time was 127 minutes and Operating Room time was 290 minutes; estimated blood loss was 150 mL. Twin B subsequently underwent emergent catheterization with pulmonary artery dilation and right ventricle outflow tract stenting. Both twins recovered successfully with twin A being discharged from hospital at 14 weeks old and twin B discharged at 15 weeks old. Cross-sectional imaging with 3D modeling helps optimize outcomes for conjoined twins.