Purpose: Our objective is to describe a new experimental model of amniotic band in rats and to show the initial morphological results.
Methods: The model was created by ligation of a hind limb with silk on day 17 of gestation; in selected fetuses ligation was withdrawn on day 19 of gestation. Fetuses were removed by cesarean section on day 21 of gestation, analyzing their weights and morphological characteristics of their hind legs. We used 10 pregnant SD rats, weighing 263 g (231-279). One hundred and thirteen fetuses were analyzed divided into 6 groups: fetuses from control rats (n=28), uterine opening and closing (n=7), band creation (n=28), band creation and subsequent removal (n=14) and not intervened fetuses of the litters in which the band was created (n=19) and that the band was created and removed (n=17). Comparisons between groups were made using parametric tests considering p<0.05 as a threshold for significance.
Results: Operated fetuses (band creation and band creation and removal) showed statistically significant differences in weight (mean=4.56 g and 4.4 g) and length of their hind limbs (mean=3.97 mm and 5.34 mm) compared to the rest of the groups. The rate of abortions in operated fetuses was 16.6% and the rate of amputations was 8.3%.
Discussion: A viable and reproducible experimental model of amniotic band is described, with potential applications in both the study of the disease and the role of fetal surgery thereon.