From birth to beyond: predicting incidence and timing of CSF diversion in postnatal MMC closure.

PURPOSE: Up to 87% of individuals with myelomeningocele (MMC) develop shunt-dependent hydrocephalus, and ventriculoperitoneal shunts (VPS) significantly increase lifetime morbidity. This study aimed to identify risk factors, incidence, and timing of VPS placement to improve outcomes and guide family counseling.

METHODS

A retrospective review of 125 patients who underwent postnatal MMC closure at Children's National Hospital between 1998 and 2022 was conducted. Primary outcomes were VPS placement and age at insertion. VPS and shunt-free cohorts were compared using Mann-Whitney U, Welch's t-test, and Fisher's exact test (α = 0.05). Subanalysis examined patients shunted within 2 weeks versus 2 weeks-2 months. Youden's index determined optimal cutoffs for hydrocephalus (HCP) and frontal-occipital horn ratio (FOHR).

RESULTS

Sixty-nine percent of MMC patients received VPS. Among shunted patients, 16% received VPS at closure, 61% within 2 weeks, and 94% within 2 months; no shunts were placed after 1 year. Mean follow-up was 10.7 years. Higher FOHR (p < 0.0001) and HCP (p = 0.01) at birth predicted VPS placement, though only FOHR predicted earlier insertion (0.55 vs 0.48; p = 0.0003). Optimal predictive thresholds were FOHR > 0.48 and HCP > 50%.

CONCLUSION

In this cohort, 69% of MMC patients developed shunt-dependent hydrocephalus. Elevated FOHR at birth predicted earlier VPS placement, and FOHR > 0.48 and HCP > 50% were predictive of VPS need. These measures may aid in family counseling and early identification of patients requiring shunting.