A new artificial placenta with a centrifugal pump: long-term total extrauterine support of goat fetuses

We tried long-term total extrauterine support of goat fetuses at high pump flow, which was pulsatile and synchronized with the cardiac cycle and at low oxygen tension in the umbilical artery and vein by use of the new artificial placenta.

This system consisted of an arteriovenous extracorporeal membrane oxygenation using umbilical artery and vein and a thermoregulated water bath. Five goat fetuses (125 +/- 0.7 days of gestation, 2.0 +/- 0.9 kg) were incubated in lactated Ringer's solution. Mean pump flow rate ranged from 113 +/- 16 to 193 +/- 13 ml/min/kg, and umbilical arterial oxygen tension was maintained at 20 +/- 3 to 23 +/- 5 mm Hg for five fetuses.

Blood gas analysis echocardiogram showed that fetal circulation and sufficient oxygen consumption could be maintained, and fetal extrauterine support conditions were made as similar as possible to physiologic circulatory conditions. We achieved long-term extrauterine support of goat fetuses up to 237 hours (mean 137 +/- 58 hours).

We believe that this system can be used for experimental models of the fetus and will come into clinical application for fetal extrauterine support systems and backup systems for fetal operations.