List of variables from both studies.

IntroductionOne of the drawbacks of fetoscopic endoluminal tracheal occlusion (FETO) for congenital diaphragmatic hernia is the need for a second invasive intervention to reestablish airway patency. The “Smart-TO” (Strasbourg University-BSMTI, France) is a new balloon for FETO, which spontaneously deflates when positioned near a strong magnetic field, e.g., generated by a magnetic resonance image (MRI) scanner. Translational experiments have demonstrated its efficacy and safety. We will now use the Smart-TO balloon for the first time in humans. Our main objective is to evaluate the effectiveness of prenatal deflation of the balloon by the magnetic field generated by an MRI scanner.Material and methodsThese studies were first in human (patients) trials conducted in the fetal medicine units of Antoine–Béclère Hospital, France, and UZ Leuven, Belgium. Conceived in parallel, protocols were amended by the local Ethics Committees, resulting in some minor differences. These trials were single-arm interventional feasibility studies. Twenty (France) and 25 (Belgium) participants will have FETO with the Smart-TO balloon. Balloon deflation will be scheduled at 34 weeks or earlier if clinically required. The primary endpoint is the successful deflation of the Smart-TO balloon after exposure to the magnetic field of an MRI. The secondary objective is to report on the safety of the balloon. The percentage of fetuses in whom the balloon is deflated after exposure will be calculated with its 95% confidence interval. Safety will be evaluated by reporting the nature, number, and percentage of serious unexpected or adverse reactions.ConclusionThese first in human (patients) trials may provide the first evidence of the potential to reverse the occlusion by Smart-TO and free the airways non-invasively, as well a safety data.引言 胎儿镜下气管腔内封堵术（fetoscopic endoluminal tracheal occlusion, FETO）用于治疗先天性膈疝（congenital diaphragmatic hernia）的一大缺陷在于，需实施第二次有创操作以恢复气道通畅。“Smart-TO”（法国斯特拉斯堡大学-BSMTI研发）是一款用于FETO的新型球囊，当其处于强磁场（例如磁共振成像（magnetic resonance image, MRI）扫描仪产生的磁场）环境中时可自行泄气。前期转化实验已证实其有效性与安全性，本次研究将首次在人体中应用Smart-TO球囊。本研究的主要目标为评估MRI扫描仪产生的磁场对球囊实施产前泄气的有效性。 材料与方法 本研究为首批人体临床试验，分别在法国安托万-贝克莱尔医院胎儿医学科与比利时鲁汶大学医院（UZ Leuven）胎儿医学科开展。研究方案同步构思，经当地伦理委员会修订后存在少量细微差异。两项试验均为单臂介入可行性研究。法国队列招募20名受试者，比利时队列招募25名受试者，所有受试者均接受Smart-TO球囊行FETO手术。球囊泄气计划于孕34周实施，若临床有需求可提前至34周前。主要终点为暴露于MRI磁场后Smart-TO球囊成功泄气。次要目标为评估该球囊的使用安全性。研究将计算球囊暴露后成功泄气的胎儿占比及其95%置信区间。安全性评估将通过统计严重意外反应或不良反应的类型、数量及占比完成。 结论 本次首批人体临床试验或可为Smart-TO球囊封堵术的逆转（即通过非侵入性方式解除气道梗阻）提供首个临床证据，并补充相关安全性数据。