Partial amniotic carbon dioxide insufflation (PACI) during minimally invasive fetoscopic surgery: early clinical experience in humans

The technical performance of minimally invasive fetoscopic surgery may be severely hindered by poor visualization of intra-amniotic contents. Partial amniotic carbon dioxide insufflation (PACI) allows the visual limitations of operating within the fluid environment to be overcome. When amniotic fluid exchange failed to improve fetoscopic visualization, PACI was attempted during 37 fetoscopic procedures between 17 + 5 and 33 + 2 weeks of gestation. PACI was attempted with filtered carbon dioxide using a commercially available insufflator via one to three trocars that were percutaneously introduced into the amniotic cavity. The maximum pressure during PACI was limited by the maximum insufflation pressure (30 mmHg) generated by the insufflator. Improvement of fetoscopic visualization as well as technical, maternal, and fetal safety aspects surrounding PACI were analyzed. PACI could successfully be instituted in 36 of the 37 procedures. In one case, when in the presence of increased uterine tone the opening pressure exceeded the maximum insufflation pressure of the insufflator, the strategy was abandoned. In all cases where PACI could be instituted successfully, the approach offered far superior visualization of the fetoscopic procedure than would have been possible within amniotic fluid. Acute or chronic maternal or fetal complications were observed in only one case (intraoperative membrane rupture). PACI greatly improves fetal visualization during fetoscopic interventions when fetoscopy within fluid meets with difficulties. Continued assessment of its benefits, risks, and safety margins at specialist centers is required.