Reversal of Hindbrain Herniation after Maternal-fetal Surgery for Myelomeningocele Subsequently Impacts on Brain Stem Function

Abstract

The aim of our study was to delineate whether the reversal of hindbrain herniation (HH) following fetal myelomeningocele (fMMC) closure subsequently reduces the incidence and severity of HH-associated brainstem dysfunction (BSD). Prior to the NIH-sponsored Management of Myelomeningocele Study (MOMS) trial, 54 children underwent fMMC closure at our institution. Forty-eight (89%) families participated in a structured survey focusing on HH-associated BSD (e.g., apnea, neurogenic dysphagia [ND], gastro-esophageal reflux disease [GERD], neuro-ophthalmologic disturbances [NOD]). Median age at follow-up was 72 months (range: 46-98). Fifty-percent required shunting. HH-related symptoms were completely absent in 15 (63%) non-shunted and 10 (42%) shunted children (P=0.15). No HH-related death occurred and none developed severe persistent cyanotic apnea. ND was reported in 2 (8%) non-shunted and 9 (38%) shunted infants (P=0.03). Mild GERD (medically managed) developed in 2 (8%) without and 6 (25%) with shunt placement (P=0.24). NOD was found in 6 (25%) and 13 (54%) of non-shunted and shunted children, respectively (P=0.07). The majority of fMMC children developed no or only mild BSD at follow-up. Our data support the hypothesis that neurodevelopmental deficits associated with MMC are at least partially acquired and that reversal of HH following fMMC surgery may help to reduce the incidence and severity of BSD.

A Randomized Trial of Prenatal Versus Postnatal Repair of Myelomeningocele

“…[24][25][26][27][28] However, since comparisons between infants who were treated in utero and historical controls are subject to substantial bias, results from a randomized trial were needed to confirm benefits and inform risks. In our study, prenatal surgery for myelomeningocele reduced the need for shunting and improved motor outcomes at 30 months, but the early intervention was associated with both maternal and fetal morbidity.…”

Current views on fetal surgical treatment of myelomeningocele — the Management of Myelomeningocele Study (MOMS) trial and Polish clinical experience

“…Their early reports confirmed the theoretical and experimental assumption that in utero protection of the nerve fibers suppresses CM II evolution, resulting in HH reduction, stationary HC and maintaining motor function of the lower extremities [18,19]. In the follow-up study, the VPS implantation rate was lower in the IUMR group as compared to the group treated postnatally (90% vs. 46%).…”

Fetal Surgery for Myelomeningocele: Patient Selection, Perioperative Management and Outcomes

“…Compared to historical controls, it was estimated that fMMC surgery may reduce the need for ventriculoperitoneal shunt placement from 80-90 to 40% [9] . The functional significance of the more normal position of the hindbrain, reduced shunt rate and restoration of nearnormal CSF hydrodynamics [68,69] is that the vast majority of fMMC children demonstrated absent to mild brain stem dysfunction symptoms at 6 years of follow-up [70,71] .…”