Benchmarking against the MOMS Trial: Zurich Results of Open Fetal Surgery for Spina Bifida

INTRODUCTION

The Management of Myelomeningocele Study, a.k.a. the MOMS trial, was published in 2011 in the New England Journal of Medicine. This prospective randomized controlled trial proved to be a milestone publication that provided definitive evidence that fetal surgery is a novel standard of care for select fetuses with spina bifida aperta (SB). The goal of our study is to assess whether our center can match these benchmark results.

MATERIALS AND METHODS

Our study was conducted according to the MOMS protocol using the same inclusion and exclusion criteria and looked at the same outcome parameters that were used in the MOMS trial. Zurich and MOMS results were compared.

RESULTS

We enrolled 20 patients between December 2010 and May 2015 all of whom underwent fetal surgery for SB. Among 51 different outcome variables, there were only 3 favorable (multiplicity-adjusted) significant differences (gestational age at birth, hindbrain herniation, and psychomotor development). There were no statistically significant differences regarding any other parameters.

CONCLUSION

Our findings confirm that rigorous apprenticeship, training, and comprehensive prospective data collection enable centers like the Zurich Center for Fetal Diagnosis and Therapy to achieve benchmark results for open fetal surgery for myelomeningocele and myeloschisis. These results justify the existence and continuation of our program. Outcome documentation is an essential element of quality management. It is medically and ethically fundamental for fetal medicine and surgery centers offering high-end innovative medical care.

In utero Plastic Surgery in Zurich: Successful Use of Distally Pedicled Random Pattern Transposition Flaps for Definitive Skin Closure during Open Fetal Spina Bifida Repair

BACKGROUND

One of the intraoperative challenges of fetal spina bifida repair is skin closure when there is an extended skin defect. Thus, we examined whether distally pedicled random pattern transposition flaps (TFs) are a valid option to overcome this problem.

SUBJECTS AND METHODS

All patients undergoing in utero repair of spina bifida with application of a TF for back skin closure were analyzed focusing on intraoperative flap characteristics and postoperative flap performance.

RESULTS

In 30 (70%) of the 43 fetuses a primary skin closure was achieved, in 5 (12%) a skin substitute was used, and in 8 (18%) a TF was applied. Flap raising and insertion was uneventful and perfusion was sufficient in all 8 fetuses (100%). In 3 fetuses (37%) the donor sites were closed primarily, and in 5 (63%) a skin substitute was used for coverage. At birth, 7 flaps were viable and provided robust skin coverage over the center of the former lesion. Complications included a small skin defect with CSF leakage in 1 patient (13%).

CONCLUSION

During open fetal spina bifida repair, TFs can be safely and efficaciously used to obtain solid and durable skin coverage over lesions too large to allow conventional primary skin closure.

Abnormal anisotropic diffusion properties in pediatric myelomeningocele patients treated with fetal surgery: an initial DTI study

PURPOSE

To investigate white matter microstructural abnormality based on diffusion tensor imaging (DTI) in pediatric patients with fetal repair for myelomeningocele (MMC).

METHODS

This was a retrospective analysis of DTI data from 8 pediatric patients with prenatal MMC repair (age range 1.64-33.70 months; sex 3F/5M) and 8 age-matched controls (age 2.24-31.20 months; sex 5F/2M). All participants were scanned on 1.5T GE Signa MR scanner (GE Healthcare, Milwaukee, WI) with the same sequence specifications. Two DTI measures, including fractional anisotropy (FA) and mean diffusivity (MD), were calculated from the genu of corpus callosum (gCC) and the posterior limb of internal capsule (PLIC). DTI values and fronto-occipital horn ratio (FOHR) were tested for group difference based on two-tailed paired t test.

RESULTS

The ventricle size based on FOHR in patients with prenatal MMC repair was significantly larger than that in the age-matched control group (p < 0.001). Statistically significant group difference in DTI (lower FA and higher MD in patient group) was found in gCC (p = 0.007 and 0.003, respectively). A trend level increase in MD was also found (p = 0.065) in PLIC in patients when compared with the age-matched controls.

CONCLUSION

Our data showed white matter abnormality based on DTI in pediatric patient with fetal repair for MMC. The sensitivity of DTI in detecting white matter abnormality, as shown in the present study, may help to serve as an imaging biomarker for assessing hydrocephalus and improve and optimize decision making for the treatment of hydrocephalus in this patient population.

Multidisciplinary spina bifida clinic: the Chicago experience

Open spina bifida (open SB) is the most complex congenital abnormality of the central nervous system compatible with long-term survival. Multidisciplinary care is required to address the effect of this disease on the neurological, musculoskeletal, genitourinary, and gastrointestinal systems, as well as the complex psychosocial impact on the developing child. Individuals with SB benefit from the involvement of neurosurgeons, orthopedic surgeons, urologists, physical medicine and rehabilitation specialists, pediatricians, psychologists, physical/occupational/speech therapists, social workers, nurse coordinators, and other personnel. Multidisciplinary clinics are the gold standard for coordinated, optimal medical and surgical care. Ann and Robert H. Lurie Children's Hospital, formerly known as Children's Memorial Hospital, was one of the first hospitals in the USA to manage patients with this complex disease in a multidisciplinary manner. We describe the longitudinal experience of the multidisciplinary Spina Bifida Center at our institution and highlight the advances that have arisen from this care model over time. This clinic serves as an exemplar of organized, effective, and patient-centered approach to the comprehensive care of people living with open SB.

Safety and efficacy of human umbilical cord-derived mesenchymal stromal cells in fetal ovine myelomeningocele repair

BACKGROUND

The aim of this study was to assess the safety and efficacy of human umbilical cord mesenchymal stromal cells (hUC-MSCs) patch used as an adjuvant therapy in fetal myelomeningocele (MMC) surgery in the ovine model.

METHODS

hUC-MSCs were isolated from human umbilical cords (UC) using the explant method, cultured and characterized. hUC-MSCs were then embedded in a fibrin patch. MMC were surgically created at 75 days of gestation and repaired at 89 days of gestation in sheep fetuses. Two groups were compared: the hUC-MSCs group in which MMC was repaired using a cellular patch and the control group, in which MMC was repaired using an acellular patch. Safety was evaluated by clinical ewes' monitoring during gestation, and clinical and histological examinations of lambs after birth. Efficacy was assessed by clinical neurological evaluation at 2 and 24 h of life using the sheep locomotor rating scale and by histological analyses.

RESULTS

Among the 17 operated lambs, nine were born alive: six in the hUC-MSCs group and three in the control group. Overall fetal loss was 47% (8/17) without differences between the two groups. No fever was reported in ewes. No tumors were detected in clinical and histological examinations in the lambs. At 24 h of life, mean Sheep Locomotor Rating score was higher in the hUC-MSCs group than in the control group: 15.0 versus 2.0 (p = 0.07). Histological analyses showed a higher large neurons density in the hUC-MSCs group in comparison with the control group: 9.9 versus 6.3/mm2 of gray matter (p = 0.04). Lambs in the hUC-MSCs group had lower fibrosis around the spinal cord and at the level of the MMC scar: 70.9 versus 253.7 μm (p = 0.10) and 691.3 versus 1684.4 μm (p = 0,18), respectively.

CONCLUSIONS

Ovine fetal repair of MMC using human UC-MSCs seems to be an effective and safe procedure.

Complex Cervicomedullary Junction Malformation and Hypoplastic Cerebellar Tonsils following Fetal Repair of Myelomeningocele: Case Report and Literature Review

BACKGROUND

Following the publication of the Management of Myelomeningocele study (MOMS), fetal repair of myelomeningocele (MMC) has become increasingly prevalent worldwide. However, limited case presentations exist illustrating the potential mechanical and embryological effects of fetal repair. We present a unique case report of a complex embryological cervicomedullary junction (CMJ) malformation and cerebellar hypoplasia following fetal repair of MMC.

CASE DESCRIPTION

A 1-day-old female was referred to the paediatric neurosurgical team after having successful surgical intrauterine closure of MMC abroad at 25 weeks gestation. The patient was born by emergency caesarean section at 33 weeks gestation and had a ventricular-peritoneal shunt inserted at 25 days old due to resulting hydrocephalus. Neonatal MRI scans revealed a complex number of malformations that included a split cord located at the CMJ, hypoplasia of the cerebellum and vermis, and a Chiari type II malformation.

CONCLUSION

It is possible that the clefting of the upper cervical spinal cord was undetected at preoperative MRI; however, this is unlikely given the antenatal images. It is our hypothesis that the malformation may have exhibited mechanical change after the repair, as the preoperative MRI showed only a Chiari II malformation without any of the complex abnormalities being present and the split cord was already there but not obvious. There are no existing reports of such a complex malformation following antenatal surgery in the literature. This should be further explored as more cases and trials become available.

Fetal Surgery for Myelomeningocele: Neurosurgical Perspectives

More than 30 years have elapsed since it was recognised that folic acid supplementation could substantially reduce the risk of open neural tube defects (ONTDs). During that time, many countries have adopted policies of food fortification with demonstrable reduction in the incidence of both cranial and spinal ONTDs. Improved prenatal detection and termination has also resulted in a reduction in the number of affected live births. Nonetheless, in the USA about 1500 children, and in the UK around 500 children are born each year with myelomeningocele (MMC) and so the management of MMC and its complications continues to constitute a significant clinical workload for many paediatric neurosurgical units around the world.Until recently, the options available following antenatal diagnosis of MMC were termination of pregnancy or postnatal repair. As a result of the MOMS trial, prenatal repair has become an additional option in selected cases (Adzick et al., N Engl J Med 364(11):993-1004, 2011). Fetal surgery for myelomeningocele is now offered in more than 30 centres worldwide. The aim of this chapter is to review the experimental basis of prenatal repair of MMC, to critically evaluate the neurosurgical implications of this intervention and to describe the technique of 'open' repair, comparing this with emerging minimally invasive alternatives.