[Management of the goat fetus in water using membrane oxygenator by V-A bypass through the cervical vessels--comparison with the A-V bypass method through umbilical vessels].

Fourteen goat fetuses were totally sustained in water by extracorporeal perfusion using a membrane oxygenator. The two groups which underwent perfusion methods may be described as follows: One was an A-V bypass through umbilical vessels which has been reported previously, and the other was a new method, a V-A bypass through cervical vessels. Ten fetuses were perfused by an A-V bypass and the longest survival time was 9 hours. Three fetuses suddenly died shortly after perfusion was started. Four fetuses were perfused by a V-A bypass and the longest survival time was 27 hours. Cardiovascular dynamics were stable from the beginning of perfusion. Autopsy revealed hepatomegaly and bloody ascites in A-V bypassed fetuses but not in the fetuses perfused by a V-A bypass. The A-V bypass through umbilical vessels resembles physiological fetal circulation, and the cannulation technique is not difficult but it needs strict control, especially in the early stages of perfusion. A V-A bypass through cervical vessels doesn't seem to be close to a physiological perfusion for fetuses and the cannulation technique is difficult. But the cardiovascular dynamics are stable, so they are employed for clinical uses in neonatal ECMO. The V-A bypass method seems to be an adequate technique for managing extremely premature fetuses in water.