In utero repair of myelomeningocele with autologous amniotic membrane in the fetal lamb model

Background

Despite advances in prenatal repair, myelomeningocele (MMC) still produces devastating neurologic deficits. The amniotic membranes (AM) are a biologically active tissue that has been used anecdotally for human fetal MMC repair. This study evaluated the use of autologous AM compared to skin closure in an established fetal MMC model.

Methods

Seven fetal lambs underwent surgical creation of MMC at gestational age of 75 days followed by in utero repair at gestational age of 100 days. Lambs were repaired with an autologous AM patch followed by skin closure (n = 4) or skin closure alone (n = 3). Gross necropsy and histopathology of the spinal cords were performed at term to assess neuronal preservation at the lesion.

Results

An increase in preserved motor neurons and a larger area of spinal cord tissue were seen in AM-repaired lambs, as was decreased wound healing of the overlying skin. Loss of nearly all spinal cord tissue with limited motor neuron preservation was seen in skin only-repaired lambs.

Conclusions

AM-repaired lambs showed increased protection of spinal cord tissue compared to skin only-repaired lambs, but the overlying skin failed to close in AM-repaired lambs. These results suggest a potential role for AM in fetal MMC repair that warrants further study.