P02.07: Fetal cardiac intervention—is the chick embryo a suitable animal model?

Abstract

Babies with hypoplastic left (HLHS) or right heart syndrome and associated hypoplasia of the great arteries continue to be a challenge in terms of survival. Early knowledge of these conditions encourages some researchers to explore new minimal invasive therapeutic options with a view to in utero cardiac palliation. The upcoming expansion of fetal cardiac interventions to ameliorate critically progressive fetal cardiac lesions intensifies the need to address issues about the adequacy of technology assessment in a suitable animal model. Methods: 13 intracardiac interventions were performed in chick embryos 3 days prior to hatching using transamniotic local anesthesia and fentanyl for fetal analgesia. After cutting a window in the shell above the previously candled embryo transamniotic intraventricular access was obtained using 22 gauge needles under ultrasound guidance. All hearts were evaluated by histological preparation after hatching. Results: All procedures were technically successful, however four of the study objects did not survive the first 24 hours after the procedure. Neither the myocardial or endocardial layers nor the outflow tract morphology of the surviving animals showed any signs of structural damage. Conclusions: Transamniotic intracardiac access is technically feasible and allowed survival to term in 9 of the 13 embryos studied.