Ventricle width and cerebrospinal fluid diversion rate after open fetal spina bifida repair – a four year follow-up

Objective: To assess the postnatal cerebrospinal fluid diversion (CSFD) rates and associated prenatal risk factors (RF) in patients with open fetal spina bifida (fSB) repair over a 4-year follow-up. Methods: In 185 patients, CSFD rate was determined at one year, and incremental risk (IR) for CSFD at 2 and 4 years. Characteristics of children without CSFD were compared to those with CSFD, and multiple regression analysis evaluated RF. Results: Sixty-four children (35%) needed CSFD within the first year. These children had larger head circumference (HC) at screening (p=0.001) and before delivery (p<0.001), and larger ventricles at screening (Vp-screening), and before delivery (Vp-delivery) (each p<0.001). Multiple regression identified only Vp-screening, Vp-delivery and their delta as independent RF for CSFD. Vp values were higher in children needing CSFD within the first year compared with years 2-4 (p<0.001 and p=0.01), and larger Vp was associated with earlier CSFD in the first year (p = 0.02). IR for CSFD declined over follow-up. Conclusion: The 1-year CSFD rate after open fSB repair was 35%, with decreasing IR through year four. Larger Vp at screening and before delivery, and their delta, were independent RF for CSFD, while HC was not.