Amnio-allantoic fluid exchange for the prevention of intestinal damage in gastroschisis. III: Determination of the waste products removed by exchange.

Experimental amnio-allantoic fluid (AAF) exchange has been shown to prevent intestinal damage in the chicken embryo gastroschisis model. AAF contains both urinary and gastrointestinal waste products (UWP and GIWP). An experimental study was performed to find the waste products responsible for this intestinal damage. Gastroschisis was created in 20 chick embryos. Half were treated with AAF exchange, the other half were not treated. AAF samples were obtained for biochemical determination of urea nitrogen and creatinine as UWP, bile acids and bilirubin as GIWP at the end of the incubation. Intestines were evaluated by light microscopy. While GIWP (Bile salts and bilirubin) were significantly removed from AAF by exchange, the levels of UWP (urea nitrogen and creatinine) were unaffected. Intestinal wall thickness was less in the exchange group compared to the untreated group. The unchanged levels of UWP after AAF exchange may be attributed to their relatively rapid production compared to GIWP. Dilution of GIWPs by AAF exchange results in prevention of the intestinal damage in gastroschisis.