Objective: To research the techniques and correlated issues during analogous procedure of human intro-utero fetal cardiac intervention in animal model, so as to impulse the clinical utilizing of cardiac intervention in human fetus with severe cardiovascular malformations.
Methods: Eight bigeminal pregnant ewes in latter 2nd-trimester and 3rd- trimester were taken into the research of fetal cardiac intervention. Under continuous ultrasound guidance, advanced an cannula and stylet needle through the maternal abdomen, uterine wall, and fetal lamb chest wall and into the fetal LV, then imitate human balloon aortic valvuloplasty at valve ring level. Probed into aspects of animal preparation, position of fetal lambs, paracentesis point selecting, main points of intervention, ultrasound utilizing, fetal lambs incubation and protection to placenta as well as umbilical cord.
Results: Eight pregnant ewes were all survival after procedure, 2 was executed after fetus' death, the other 6 continued gestation until spontaneous vaginal delivery after an uneventful pregnancy. After parturition the 6 ewes were in good condition. There were no nick infection, chorioamnionitis and other complications. Eight/sixteen fetal lambs were undergone intro-utero cardiac intervention. The values of body weight and Hct of lambs which were executed, pre-term and full-term delived were (1.77 +/- 0.14) kg vs. (2.15 +/- 0.23) kg vs. (2.41 +/- 0.19) kg and 29%o-33% vs. 27%-35% vs. 37%-41%. In autopsy, hydropericardium was found in 4/8 with 1-2.5 mL and 1/8 with 5 mL. Besides 1/8 with interventricular septum centesis injury, there was no centesis damage to endocardium, valve, chordae tendineae, papillary muscles and sortic tunics intima. Whereas there was no centesis injury to lung, liver and chylostomach, no trace of ericardium and thoracic infection.
Conclusions: Animal model of intra-utero fetal cardiac intervention was setted up successfully, the experiences in this study was worth to be payed attention to in human fetal cardiac intervention.