The Effect of Intrauterine Myelomeningocele Repair on the Incidence of Shunt-Dependent Hydrocephalus

Abstract

Background: Intrauterine myelomeningocele repair (IUMR) was first successfully performed in 1997. Preliminary reports suggest that this procedure reduces the incidence of shunt-dependent hydrocephalus when compared to conventional postnatal therapy. However, the existing cohort of IUMR patients has not yet been systematically compared to a comparable group of conventionally treated controls. Methods: Patients 1 year old or greater who had undergone IUMR at either Vanderbilt University or the Children’s Hospital of Philadelphia (CHOP) were compared to a group of conventionally treated historical controls treated and followed at CHOP. In order to measure any differences between the groups, patients were stratified according to the level of the myelomeningocele lesion and the gestational age at the time of IUMR. Results: One hundred and four IUMR patients were compared to 189 conventionally treated controls. IUMR resulted in statistically significant reductions in the incidence of shunt-dependent hydrocephalus at both lumbar and sacral lesion levels. When lumbar lesion levels were further stratified, from L1 to L5, it appeared that the benefit of IUMR was statistically significant only at levels below L2. Other factors with a significant impact on hydrocephalus were estimated gestational age and ventricular size at the time of surgery. In particular, statistically significant differences compared to controls were seen in the younger (≤25 weeks) group but not in the older (>25 weeks) group. Conclusions: IUMR appears to substantially reduce the incidence of shunt-dependent hydrocephalus when compared to conventional treatment even when lesion level is taken into account. Patients with lesions above L3 may not share in this benefit. IUMR cannot be justified in fetuses older than 25 weeks of gestation. Additional improvements might be obtained by further reducing the average age at which fetuses are operated upon. It remains to be determined whether this benefit outweighs the potential risks of intrauterine surgery.

Vascular and apoptotic changes in the placode of myelomeningocele mice during the final stages of in utero development

“…4 The clinical outcomes of in utero surgery have suggested clear improvement in some neurological lesions, namely in the reversal of ectopic cerebellar tonsils of the MMC-associated Chiari malformation, decreasing it from 95 to 38%, with a consequent reduction in the need for a ventricular shunt from 91 to 59%. 3,[31][32][33][34] In contrast, deficits in the lower limbs and in urodynamic function in patients submitted to MMC correction, through either fetal or classic postnatal surgery, were similar to those of controls. 14,30,27 Attending to these data, the potential benefits of in utero repair of MMC are under scrutiny in a randomized trial designed to compare the clinical outcomes of patients with MMC treated with either fetal or postnatal surgery.…”

Comparison between two surgical techniques for prenatal correction of meningomyelocele in sheep

“…The simplified technique also allowed better preservation of the spinal cord cytoarchitecture. Several previous studies on the intrauterine correction of myelomeningocele had already suggested that prenatal correction led to a better preservation of the spinal cord and better clinical results (10)(11)(12)(13) .The MOMS study demonstrated that the intrauterine correction reduced the need of ventriculoperitoneal shunting from 82 to 40% comparing postnatal with prenatal correction, respectively. That study also showed better cognitive and motor skills up to 30 months of age in the group submitted to prenatal correction (6) .…”

“…That study also showed better cognitive and motor skills up to 30 months of age in the group submitted to prenatal correction (6) . As to the uterine approach, some studies showed that open surgery greatly increased the risk of premature labor and maternal complications (6,10,12) . In the MOMS study, average gestational age at birth was 34.1 weeks in cases of prenatal surgery versus 37.3 weeks in postnatal surgery.…”

Hydrocephalus in spina bifida

“…[5][6][7] Recent data show a decrease in the rate of Chiari II malformation and subsequent hydrocephalus in patients in whom the spinal defect is repaired in utero. [8][9][10] However, this remains controversial. The open system of cerebrospinal fluid (CSF) circulation resulting from open spinal dysraphism (with fluid production in the ventricular system and passage down and out through the spinal defect) is thought to play a central role in hindbrain descent and subsequent hydrocephalus.…”