The animal experimental study to examine the availability of fetus surgery in CL/Fr mouse feutses affected with cleft lip and palate

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Purpose : There is a deficiency of a study of wound healing in fetal mice or rats. The present study has been undertaken to examine whether or not fetal healing on surgical suture of clefted lip in CL/Fr mouse fetus affected with cleft lip can occur without an apparent inflammatory response and take place with the deposition of collagen.Material and Method : The experimental model chosen for this study was a through wound of the upper lip, and the animals were followed for 72 hours after surgery. The-mated adult female CL/Fr mouse of ten to fifteen weeks old were anesthetized with enthoren on the 15th day, 16th or 17th day of gestation. A laporotomy was performed in each animal to gain access to the pregnant uterus. Each experimental fetus was partially exteriorized through a small hysterotomy and a through and through surgical wound made in the upper lip approximately 2 mm from the mid line. Each fetus was returned to the lumen of the uterus, and the hysterotomy closed with a purse st … More ring suture. The laparotomy wounds were closed in layrs and the animals allowed to recover from the anesthetic. The pregnancies then continued nntil the fetuses were harvested. The injured fetuses were divided into the following three groups, each containing ten or eleven animals. In the first group, the wounds made on the normal lip of the unaffected fetuses were sutured. In the second group, the clefted lip of the affected fetuses were only sutured wothout wound, while in the third group, the wounds made on the clefted lip of the affected fetuses were sutured using 11/0 nylon and microsurgical techniques. In each group, ten or eleven fetuses were harvested at 24 hours, 48 hours or 72 hours after wounding. Each harvested fetus was fixed in formal saline, and haematoxylin and eosin stained horizontal sections of the upper lip were prepared.Result : A total of 32 fetal mice could be successfully obtained through the fetus surgery experiment of a wound of the upper lip. In each group, four or five fetuses harvested at 72 hours after wounding were subjected to a histological examination. The following results were obtained.1) The mesenchymal elements were connecting each other from both wounded sites in three out of four fetuses for the first group.2) The mesenchymal elements were connecting each other from both wounded sites in only one out of five fetuses for the second group.3) The mesenchymal elements were connecting each other from both wounded sites in two out of five fetuses for the third group.These results suggested the useful possibility for the mesenchymal tissue to regenerate from both incised site of the clefted lip in CL/Fr mouse fetuses. Less