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Recording available 2/16-5/2
Recording available 2/16-5/2
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Oral Concurrent Session 3 - Fetus and Fetal Intervention

Oral Concurrent Sessions

Oral Concurrent Session 3 - Fetus and Fetal Intervention

(35) Postoperative fetal imaging is predictive of need for CSF diversion after fetal spina bifida repair

Wednesday, February 11, 2026
2:30 PM - 2:45 PM  
Location: Summit 218 - 221
Objective:
Fetal surgery for open neural tube defects (ONTDs) reduces but does not eliminate the need for cerebrospinal fluid (CSF) diversion in the first year of life. While some preoperative factors including lateral ventricle (LV) width have been linked to increased risk of CSF diversion, limited data exist on the predictive value of postoperative fetal imaging.

Study Design:
This was a nested case-control study in a cohort of patients who underwent fetal surgery (open or fetoscopic) for ONTD at a single center between 2020 and 2024. Cases were those requiring CSF diversion within the first year of life; controls did not require diversion. Pre- and postoperative prenatal ultrasound images were reviewed, and growth trajectories of relevant biometric markers were analyzed. Logistic regression and receiver operating characteristic (ROC) curves were used to evaluate predictors of postnatal CSF diversion.

Results:
Thirty patients met inclusion criteria; 27% had fetoscopic repair, and 30% required CSF diversion. Pre- and intraoperative factors, including lesion type, preoperative LV width, gestational age at repair, and surgical approach, did not differ between groups. Preoperative LV growth rates were similar between groups, but postoperative LV growth rates were significantly higher among patients ultimately requiring diversion (0.58 vs. 0.16 mm/week, p< 0.01). While resolution of the “banana sign” was more common in those avoiding diversion, cerebellar growth rates were similar between groups. Postoperative LV growth rate predicted need for CSF diversion with an area under the ROC curve of 0.88 (95% CI 0.74–1.00); the optimal cutoff for prediction of CSF diversion was 0.32 mm/week which had a sensitivity of 100% and specificity of 75%. Each 1 mm/week increase in postoperative LV growth was associated with a 23-fold increase in odds of CSF diversion (OR 22.9, 95% CI 1.46-359.3).

Conclusion:
Postoperative LV growth rate after fetal ONTD repair is a strong predictor of CSF diversion. Serial fetal imaging to assess LV trajectory may improve prenatal counseling and guide postnatal neurosurgical surveillance.