[A study of the feasibility and efficacy of fetal surgical closure of spontaneous cleft lip in CL/fraser mice].

Cleft lip with or without cleft palate is one of the most common human craniofacial congenital malformations. Failure to form a continuous tissue in the upper lip during the early embryonic period results in cleft lip. There has been an increasing interest in the possibility of in-utero correction of life threatening fetal abnormalities. In the present study, the feasibility and efficacy of surgical suturing of the fetal mouse lip was examined by using CL/Fraser mouse fetuses (spontaneous of cleft lip) at embryonic 15, 16 or 17 days. The obtained results were as follows. #1. Abortion rate of pregnant dam applied inhalation of Ethrane was less than that of intraperitoneal injection of Nembutal. #2. Successful delivery rate of fetal mouse surgically treated at the embryonic 16 day or 17 day is higher than that on the embryonic 15 day. #3. Fusion rate of mouse fetal lip surgically treated on the embryonic 16 day was higher after 60 hours in dam's uteri than that after 36 hours. These results suggest that inhalation of Ethrane is more recommendable, and that the optimal timing of fetal surgery of spontaneous cleft lip in CL/Fr. mouse fetus is an embryonic 16 day, and that the average time of 60 hours after surgical operation is enough for sutured lip to fuse in dam's uteri.