Experimental fetal endoscopic tracheal occlusion in rhesus and cynomolgus monkeys: nonhuman primate models.

ABSTRACT

OBJECTIVE: The monkey model is the best model to investigate some physiological response to the fetal transitory tracheal occlusion but it has never been described in Macaca monkeys. The aim of this study was to evaluate the feasibility of fetal endoscopic tracheal occlusion (FETO) in a non-human primate model. METHODS: Pregnant rhesus monkeys and cynomolgus were tested as a potential experimental model for FETO in the third trimester of pregnancy, by performing fetal tracheoscopies with and without tracheal occlusion. RESULTS: A total of 22 pregnancies were followed in 16 monkeys and underwent fetal surgery. Percutaneous endoscopic access to the uterine cavity was possible in 20 cases (91%). Of these 20 pregnant monkeys, fetal tracheoscopy could be achieved in 15 cases (75%). In rhesus monkeys, the time between the onset of endoscopy and tracheal penetration decreases as operator experience increases. Neither maternal morbidity nor mortality was related to surgery. Two fetal losses were possibly due to the procedure. CONCLUSION: FETO is feasible in the non-human primate, which closely reflects procedures in humans. The non-human primate model for FETO, specially the rhesus monkeys, may be useful for future studies concerning the mechanisms related to the lung growth after transitory fetal tracheal occlusion.