Amniotic fluid exchange for the prevention of neural tissue damage in myelomeningocele: an alternative minimally invasive method to open in utero surgery.

OBJECTIVE

Experimental studies have shown that neural tissue damage in myelomeningocele (MMC) is acquired, resulting from exposure of neural tissue to amniotic fluid (AF). Similar to neural tissue damage in MMC, in gastroschisis, intestines exposed to AF are damaged. In gastroschisis, intestinal damage can be prevented by changing the composition of the AF with partial AF exchanges. An experimental study was performed to investigate whether the neural tissue damage in MMC can be prevented by AF exchange.

METHODS

Thirteen-day-old fertilized chick eggs were used. In group 1, the amnio-allantoic membrane was opened to create a common cavity, and MMC was created (MMC-only group). In group 2, after creation of MMC, amnio-allantoic fluid exchange was performed (MMC-plus-exchange group). Chicks were extirpated for histopathologic examination 5 days later.

RESULTS

While edema, focal calcification, fibrosis, capillary cell proliferation and scattered mononuclear cells were observed in the MMC-only group, histopathologic changes were mild in the exchange group. The number of neuron-specific enolase stainings (+) neural cell count was significantly higher in the exchange group compared to the MMC-only group (p < 0.01).

CONCLUSION

Exposure of MMC to AF causes structural neural tissue damage that can be prevented by AF exchange. AF exchange is minimally invasive compared to open in utero surgery for the closure of MMC. By AF exchange, neural tissue damage that occurs during the gestational period may be prevented.