Systematic classification and comparison of maternal and obstetrical complications following 2 different methods of fetal surgery for the repair of open neural tube defects

Abstract

In utero repair of open neural tube defect (ONTD) using an open hysterotomy approach (hereafter referred to as "Open") has been shown to reduce the need for ventriculo-peritoneal shunting and to improve motor outcomes for affected infants. Laparotomy-assisted fetoscopic repair (hereafter referred to as "Hybrid") is an alternate approach that may confer similar neurological benefits, while reducing the incidence of hysterotomy related complications. In this study we aimed to analyze procedure related maternal and fetal complications of in-utero repair using the Clavien-Dindo classification, and to compare the outcomes of the Hybrid and Open approaches. This was a retrospective cohort study conducted in a single center between September 2011 and July 2021. All patients who met the MOMS criteria and who underwent either Hybrid or Open fetal surgery were included, Maternal complications were classified using a unique adapatation of the Clavien-Dindo scoring system allowing the development of a comprehensive complication index score specific to fetal surgery. Primary fetal outcome was defined as gestational age at delivery and summarized according to the World Health Organization definitions of preterm delivery. There were 146 fetuses with ONTD who were eligible for, and underwent, in utero repair during the study period. Of these, 102 underwent Hybrid fetoscopic repair and 44 underwent Open hysterotomy repair. Gestational age at the time of surgery was higher in the Hybrid group when compared with the Open group (25.1 vs. 24.8 weeks, p=0.004). Maternal body mass index was lower in the Hybrid compared to the Open group (25.4 vs 27.1 kg\m2, p=0.02). The duration of Hybrid fetoscopic surgery was significantly longer than for the Open repair (250 min vs 164 min, p<0.001). There was a significantly lower Clavien-Dindo grade III complication rate (4.9% vs. 43.2%, p<0.001), as well as a significantly lower overall comprehensive maternal complication index (8.7 vs. 22.6, p=0.021), in the Hybrid group vs. the Open group. Gestational age at delivery was significantly higher in the Hybrid group (38.1 weeks) compared to the Open group (35.8 weeks) p<0.001, and this finding persisted when gestational age at delivery was analyzed using the WHO definitions of preterm delivery. Utilization of our adaptation of the standardized Clavien-Dindo classification to assess the maternal complications associated with in utero ONTD repair provides a new method to objectively assess different fetal surgical approaches. It also provides a much-needed standardized tool to allow objective comparisons between methods, which can be used when counseling patients. The Hybrid ONTD repair was associated with a lower rate of maternal adverse events than the Open approach, and was associated with later gestational age at delivery and less preterm delivery.