It is generally accepted that a vascular accident in utero during the fetal period plays an important role in the occurrence of intestinal atresia. An experimental study, making use of chick embryos was made to induce intestinal atresia by
vascular
occlusion or ligation of a loop of intestine. A study using the chick embryos made it relatively easy to obtain the experimental group. Its advantages are a short incubation period(21 days) and many operations can be performed with only a limited
supply
of surgical instruments. Physiologic umbilical hernia of the chick embryo is present form the 9th to the 18th day of development. We used chick embryos between 9th to 15th day of development to perform experiments. In group I, as a control group,
round
shaped opening was made in the eggshell, shell membrane and chorioallantoic membrane with diameter of 1 cm, and then closed with transparent tape. In group II, the mesenteric artery was ligated with prolene 7~0. In the group III, a loop of
intestine was
ligated with prolene 7~0. The survival rate of group I was 35.7%(50/140), group II, 5.1%(36/700) and group III was 7.6%(53/700)(p<0.001). The intestinal atresia in hatched embryos showed no case in group I, 14 cases out of 36cases in Group
II(type
II
5cases. type III 9cases), and all cases in Group III(type I 3cases, type II 29cases, type III 21 cases). There was no significant relation between experimental group and typ0e of intestinal atresia(p=0.09).
In this experiments, the survival rate and incidence of intestinal atresia of group III were higher than group II. We concluded that vascular accident of intestine during fetal period was a factor in development of intestinal atresia, but,
mechanical
obstruction of intestinal loop was more important.
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