Risk factors for shunting at 12 months following open fetal repair of spina bifida by mini-hysterotomy.

Objectives: Open spina bifida (OSB) is the most common neural tube defect. Prenatal repair reduces the need for ventriculoperitoneal shunting (VPS) due to hydrocephalus from 80-90% to 40-50%. We aimed to determine which variables work as risk factors for VPS at 12 months of age in our population.

Methods: Thirty-nine patients underwent prenatal repair of OSB by mini-hysterotomy. The main outcome was occurrence of VPS in the first 12 months of life. Logistic regression was used to estimate the odds ratios (OR) between prenatal variables and the need for shunting.

Results: VPS at 12 months occurred in 34.2% of the children. Larger ventricle size before surgery (62.5% ≥15 mm; 46.2% between 12 and 15 mm; 11.8% <12 mm; p=0.008), higher lesion level (80% >L2, vs. 17.9% ≤L3; p=0.002; OR, 18.4 [2.96-114.30]), and later gestational age at surgery (25.25 ± 1.18 vs. 24.37 ± 1.06 weeks; p=0.036; OR, 2.23 [1.05-4.74]) were related to increased need for shunting. In the multivariate analysis, larger ventricle size before surgery (≥15 mm vs. <12 mm; p=0.046; OR, 1.35 [1.01-1.82]) and higher lesion level (>L2 vs. ≤L3; p=0.004; OR, 39.52 [3.25-480.69]) were risk factors for shunting.

Conclusions: Larger ventricle size before surgery (≥15 mm) and higher lesion level (>L2) are independent risk factors for VPS at 12 months of age in fetuses undergoing prenatal repair of OSB by mini-hysterotomy in the studied population.