Intra-uterine healing of fetal rat cheek wounds

Cheek wounds, involving skin, mucosa, and muscle, were surgically created in utero on Sprague Dawley rat fetuses at 19 1/2 days gestation. Fifty fetuses were used in the study. Twenty-five fetuses were in the experimental group and 25 in the control. Five fetuses in each group were sacrificed at 0, 6, 12, 18 and 24 hours post-operatively. Serial histological sections in the coronal plane were stained with haematoxylin and eosin. Restoration of continuity and primary epithelialisation of the oral mucosal and skin surfaces of the wound was observed to occur within 24 hours. The continuity of the muscle layer was not restored, but some mitoses were seen in the myeloblasts. There was a complete absence of acute inflammatory cells, and there was no scab formation. Healing occurred without scarring. These findings are discussed in comparison to previous findings on orofacial fetal wound healing (Goss 1976) and in regard to future prospects in intraceptive fetal surgery for the correction of deformities, in particular cleft lip.