Experimental Study for Extrauterine Incubation and Breathing of Fetal Lambs

[材料与方法]对照胎羊(N=6)：采用经宫颈血管V-A ECMO，于125~140天在人工羊水池中孵化。在孵化6-24小时后，诱导肺呼吸的启动，并尝试从系统断奶。横隔疝模型(N=6)：造模孕75~80天，支持V-A ECMO宫内修补135天。这些胎羊的孵化(6-24小时)和从系统中断奶的过程与对照胎羊相同。在孵化和脱离系统的过程中。监测心电图、血压和中心静脉压，并进行血气分析和多普勒超声检查。[结果]1.在整个孵育过程中，胎儿循环状况保持稳定，不受PDA流量变化的影响。2.胎龄超过135天的对照组胎儿在呼吸后即可脱离孵化系统。3.在V-A ECMO的支持下，宫内腹股沟疝修补术是安全的。[结论]我们通过宫颈血管建立了V-A ECMO胎儿宫外孵化系统。该系统能使胎羊保持在稳定的生理条件下，并安全地修复了横隔疝。这项研究的结果表明，在未来，患有严重肺发育不良的胎儿可能能够在该系统的支持下存活下来。

[Material and Method] Control Fetal lambs (N=6) : Using a V-A ECMO via cervical vessels, fetal lambs were incubated in an artificial amnionic fluid tank at 125-140 gestational days. After Incubation for 6-24hrs, an initiation of lung respiration was induced and weaning from the sytem was attempted. Diaphragmatic Hernia Model (N=6) : Diaphragmatic hernia was created between 75-80 gestational days and repaired in uterus in support of V-A ECMO at 135 gestational days. incubation of these fetal lambs (6-24h) and weaning from the system were done as same as controle fetal lambs. During incubation and weaning from the system. ECG,BP and CVP were monitered and blood gas alnalysis and doppler sonographic examination were performed.[Result] 1. The circulatory condition of fetuses maintained stable throughout the incubation not influenced by change of PDA flow. 2. Control fetuses over 135 gestational days were able to wean from the incubation system after breathing. 3. Diaphragmatic hernia could be repaired safely in utero in support of the V-A ECMO.[Conclusion] We developed an extrauterin fetal incubation system using V-A ECMO via cervical vessels. The fetal lambs could be kept under stable physiological conditions and diaphragmatic hernia was safely repaired with this system. The result of this study suggest that in future, a fetus with severe pulmonary hypoplasia may be able to survive supported by this system.