IMPACT OF FETAL SURGERY ON PROGRESSION OF VENTRICULOMEGALY IN FETUSES WITH SPINA BIFIDA

Objectives Fetal spina bifida is associated with progressive hydrocephalus, leading to postnatal ventriculoperitoneal shunting. The aim of this study was to document the evolution of the size of the fetal lateral ventricles throughout pregnancy in fetuses with spina bifida and to assess whether fetal surgery had a measurable impact on ventricular size. Methods Retrospective analysis of all cases of fetal spina bifida assessed at the Fetal Medicine Unit at Mount Sinai Hospital, Toronto, between 2008 and 2018 who had longitudinal follow-up during pregnancy. The lateral width of the posterior horn of the lateral ventricle was recorded over the course of pregnancy. Results We assessed 72 fetuses. At the time of first presentation, 42 (58.33%) had ventriculomegaly, of which 13 (30.95%) had mild, 15 (35.71%) moderate and 14 (33.33%) severe ventriculomegaly. Eleven fetuses underwent fetal surgery. In fetuses who did not undergo fetal surgery, the mean increase in ventricular width was 0.57 ±0.68mm per week gestation, compared to a postoperative increase of 0.21±1.11mm per week in those that underwent the surgery (p=0.14). Two (18%) fetuses who underwent fetal surgery required shunting postnatally. In fetuses who did not require shunting, the rate of ventricular increase was -0.07±0.92mm (p= 0.008 compared to untreated cohort). Conclusions Fetal spina bifida is associated with progressive ventriculomegaly. In fetuses who undergo in-utero closure of the defect there was a trend towards a slower rate of progression of ventriculomegaly, compared to fetuses who underwent postnatal repair.