Foetal surgery for spina bifida

Procedure-related complications of open vs endoscopic fetal surgery for treatment of spina bifida in an era of intrauterine myelomeningocele repair: systematic review and meta-analysis

OBJECTIVE

To assess and compare the rate of procedure-related complications after intrauterine treatment of spina bifida by endoscopic surgery and by open fetal surgery.

METHODS

Systematic literature searches in PubMed and SCOPUS databases were performed on 20 September 2015 to identify randomized controlled trials and observational studies on treatment of human spina bifida by endoscopic or open fetal surgery techniques. Only studies with ≥ 10 cases that were published in or after 2000 were included in the meta-analysis in order to reduce the risk of bias. Primary outcomes (complete dehiscence, focal dehiscence and/or markedly thin hysterotomy scar; preterm delivery < 34 weeks; mean gestational age at delivery) and secondary outcomes (oligohydramnios, prelabor rupture of membranes, placental abruption, chorioamnionitis and perinatal death) were assessed for both techniques. Precision of the estimated proportions was evaluated with 95% CIs. Inconsistency was assessed using the I(2) statistic.

RESULTS

The search identified 1080 records that were examined based on title and abstract, of which 28 full-text articles were examined completely for eligibility. Nine records were excluded because cases were also described in other studies, leaving 19 records for analysis. When comparing endoscopic vs open fetal surgery, the rate of complete dehiscence, focal dehiscence and/or markedly thin hysterotomy scar was, respectively, 1% (95% CI, 0-4%) vs 26% (95% CI, 12-42%); preterm delivery < 34 weeks was 80% (95% CI, 41-100%) vs 45% (95% CI, 38-53%); oligohydramnios was 39% (95% CI, 9-75%) vs 14% (95% CI, 7-24%); prelabor rupture of membranes was 67% (95% CI, 12-100%) vs 38% (95% CI, 26-50%); and perinatal death was 14% (95% CI, 1-38%) vs 5% (95% CI, 3-8%).

CONCLUSION

Open fetal surgery for spina bifida seems to show lower rates of procedure-related complications than does endoscopic surgery, but the rate of hysterotomy scar complications is high after open surgery. Because of the low quality of evidence, the conclusions should be interpreted with caution. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.

Myelomeningocele (open spina bifida) - surgical management

Myelomeningocele has been recognized since ancient times although written descriptions began not before the 17th century. Among all serious congenital malformations, myelomeningocele is unique that is has a steady and considerable prevalence while being compatible with life. It has a dismal prognosis when left untreated where virtually all die within the first year while aggressive treatment have a profound effect on survival and quality of life. Effective surgical treatment became possible parallel to the treatment of hydrocephalus in the late 1950s. Advent of the shunt systems undoubtedly changed the morbidity and mortality rates due to associated hydrocephalus. Aggressive and effective treatment improved survival rates but also those suffering physical and mental disabilities have increased as well. Ethical and socioeconomic concerns have led to proposal for selective treatment criteria which have raised arguments on medical and ethico-legal rounds. After the swing of the pendulum between early treatment in all affected children and selective treatment of those who fulfilled the criteria for good prognosis, early myelomeningocele repair is practiced widely unless the infant is critically ill.Incidence of myelomeningocele has been decreasing especially in the Western world, partly due to prenatal diagnosis and elective terminations, dietary folate supplementation. Still, it is the most common central nervous system malformation and one of the leading causes of paraplegia, worldwide. Unfortunately, gains in the management of myelomeningocele have been mainly on antenatal diagnosis and prevention while efforts on understanding its cause, mechanisms involved are still tentative. Concerning the surgical management, no revolutionary modification improving outcome has been introduced unlike other fields of neurosurgery.Medical management of a child with myelomeningocele requires a lifelong effort of several disciplines including urology, orthopedics physical and social therapy besides neurosurgery. The initial and probably the most crucial step begin with proper repair of the lesion. The aim of surgery, with its simplest definition should be towards maintaining the medical condition of the newborn. In other words, consequences of an open spinal cord segment with associated malformations have to be avoided with appropriate measures. Comparable to the surgical treatment of any congenital malformation, myelomeningocele repair consist of reversing the failed steps of normal neural tube closure. This requires a thorough understanding of the normal and abnormal embryological sequence of events in formation of the spinal cord. Although the purpose of this chapter is to describe the basic concepts and technique of myelomeningocele repair, contemporary information and progress on epidemiology, and etiology and embryology is presented with discussion of controversial issues regarding the selection process, optimal time for surgery and technical modifications.

Prenatal versus postnatal repair procedures for spina bifida for improving infant and maternal outcomes

BACKGROUND

Spina bifida is a fetal neural tube defect (NTD), which may be diagnosed in utero and is compatible with life postnatally, albeit often with significant disability and morbidity. Although postnatal repair is possible, with increasing in utero diagnosis with ultrasound, the condition has been treated during pregnancy (prenatal repair) with the aim of decreased morbidity for the child. The procedure that is performed during pregnancy does have potential morbidities for the mother, as it involves maternal surgery to access the fetus.

OBJECTIVES

To compare the effects of prenatal versus postnatal repair and different types of repair of spina bifida on perinatal mortality and morbidity, longer term infant outcomes and maternal morbidity.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (31 July 2014).

SELECTION CRITERIA

All published, unpublished, and ongoing randomised controlled trials comparing prenatal and postnatal repair of meningomyelocele for fetuses with spina bifida and different types of prenatal repair.

DATA COLLECTION AND ANALYSIS

Two review authors independently evaluated trials for inclusion and methodological quality without consideration of their results according to the stated eligibility criteria and extracted data.

MAIN RESULTS

Our search strategy identified six reports for potential inclusion. Of those, we included one trial (four reports) involving 158 women, which was at low risk of bias.The one included trial examined the effect of prenatal repair versus postnatal repair. For the primary infant outcome of neonatal mortality, there was no clear evidence of a difference identified for prenatal versus postnatal repair (one study, 158 infants, risk ratio (RR) 0.51, 95% confidence interval (CI) 0.05 to 5.54), however event rates were uncommon and so the analysis is likely to be underpowered to detect differences.Prenatal repair was associated with an earlier gestational age at birth (one study, 158 infants, mean difference (MD) -3.20 weeks, 95% CI -3.93 to -2.47) and a corresponding increase in both the risk of preterm birth before 37 weeks (one study, 158 infants, RR 5.30, 95% CI 3.11 to 9.04) and preterm birth before 34 weeks (one study, 158 infants, RR 9.23, 95% CI 3.45 to 24.71). Prenatal repair was associated with a reduction in shunt dependent hydrocephalus and moderate to severe hindbrain herniation. For women, prenatal repair was associated with increased preterm ruptured membranes (one study, 158 women, RR 6.15, 95% CI 2.75 to 13.78), although there was no clear evidence of difference in the risk of chorioamnionitis or blood transfusion, although again, event rates were uncommon.A number of this review's secondary infant and maternal outcomes were not reported. For the infant: days of hospital admission; survival to discharge; stillbirth; need for further surgery (e.g. skin grafting); neurogenic bladder dysfunction; childhood/infant quality of life. For the mother: admission to intensive care; women's emotional wellbeing and satisfaction with care.

AUTHORS' CONCLUSIONS

This review is based one small well-conducted study. There is insufficient evidence to recommend drawing firm conclusions on the benefits or harms of prenatal repair as an intervention for fetuses with spina bifida. Current evidence is limited by the small number of pregnancies that have been included in the single conducted randomised trial to date.

Isolated and ventriculomegaly-associated cases of spina bifida in genetic counseling: focus on fetal pathology

Cases of spina bifida alone and in association with ventriculomegaly represent important but different malformations according to clinical characteristics. In our study, we analyzed the data on pregancies terminated because of isolated cases (n=307) and ventriculomegaly-associated cases (n=372) of spina bifida. In spina bifida cases in association with hydrocephalus, positive obstetric history was found approximately 1.5 times more frequently than in the isolated ones. The incidence of positive genetic history was nearly two-fold in the latter cases. In isolated cases of spina bifida, associated malformations were more common than in cases of spina bifida and ventriculomegaly together. The most frequent associated malformations were those of the urogenital system (in cases of spina bifida: 11.1%; in cases of SB+V: 9.14%). The risk of recurrence of SB+V is significantly higher than that of isolated SB (8.9% vs. 2.1%). It can be concluded that positive genetic history is more common in cases of isolated spina bifida. Malformations out of the nervous system are more commonly observed in cases of isolated spina bifida. During the prenatal diagnostics of spina bifida, sonography must focus on malformations of the urogenital system.

In utero surgery--current state of the art--part II

Background

Fetal surgery, also referred to as in utero, prenatal or intrauterine surgery, consists of treatment of congenital malformations during the fetal period. The idea of treating malformations diagnosed in the course of intrauterine life dates back to 1963, when Lilly performed the first blood transfusion in a fetus. Since then it has been introduced as a treatment option in a series of lethal malformations. Efforts are being made to treat nonlethal malformations by means of fetal surgery.

Material/Methods

A comprehensive search of the literature using MEDLINE and PubMed between 1925 and February 2009 was performed. Search terms for MEDLINE and PubMed were: fetal surgery, foetal surgery, in utero surgery, prenatal surgery, and in utero treatment. In addition, information was obtained at Web sites of the International Medicine and Surgery Society and the University of California Fetal Treatment Centre.

Results

Authors’ attention focused on the survey of indications to intrauterine operations. We outline potential directions of its development, quoting the groundwork of the most experienced researchers and clinicians. Moreover, owing to the authors’ interest in plastic surgery, some remarks on the role of intrauterine medicine and surgery in this branch of medicine are made.

Conclusions

In utero surgery may be regarded as an efficient tool of preventive medicine. It offers some advantages that no other branch of medicine may offer. However, its implementation is more troublesome than in the past, therefore only selected cases may benefit from its advantages. Nevertheless, current tendencies are to include, after thorough evaluation of benefit-risk ratio, some new indications for fetal surgery.

Intrauterine myelomeningocele repair postnatal results and follow-up at 3.5 years of age--initial experience from a single reference service in Brazil

PURPOSE

Present the outcomes of six cases submitted to intrauterine myelomeningocele (MMC) repair.

METHODS

Descriptive observational study of six children submitted to antenatal surgical repair of MMC between 26 and 27 weeks gestation. All deliveries were through cesarean section. The following neonatal variables were assessed: gestational age at delivery, birth weight, Apgar scores, need for intubation, duration of hospital stay and need for postnatal shunt procedures. After 3.5 years, the children were evaluated using the Columbia Mental Maturity Scale or Denver II tests and the Hoffer Ambulation Scale.

RESULTS

All deliveries were preterm at a mean gestational age of 32 + 4 weeks and mean birth weight was 1,942 g. Two infants had Apgar scores <7 at 1 min and 1 at 5 min. Ventricular-peritoneal shunts were placed in two cases. All six children are alive: five have normal cognitive development and one has a neuropsychomotor developmental delay. Two children had normal leg movements, a sacral functional level and are community ambulators. Three children had upper lumbar anatomical level lesions and one had a lower thoracic level lesion at the time of fetal surgery. One child, with an L1-L2 anatomical level lesion, in noambulatory and fully dependent on a wheelchair for mobility.

CONCLUSION

Antenatal surgical repair of MMC reduced the need for postnatal shunt placements. Despite preterm delivery, the cognitive development of most children at 3.5 years was normal. Antenatal surgery seemed to improve lower limb motor function in these cases.

Muscle ultrasound density in human fetuses with spina bifida aperta

BACKGROUND

In fetal spina bifida aperta (SBA), leg movements caudal to the meningomyelocele (MMC) are transiently present, but they disappear shortly after birth. Insight in the underlying mechanism could help to improve treatment strategies. In fetal SBA, the pathogenesis of neuromuscular damage prior to movement loss is still unknown. We reasoned that prenatal assessment of muscle ultrasound density (fetal-MUD) could help to reveal whether progressive neuromuscular damage is present in fetal SBA, or not.

AIM

To reveal whether prenatal neuromuscular damage is progressively present in SBA.

PATIENTS/METHODS

In SBA fetuses (n=6; 22-37 weeks gestational age), we assessed fetal-MUD in myotomes caudal to the MMC and compared measurements between myotomes cranial to the MMC and controls (n=11; 17-36 weeks gestational age). Furthermore, we intra-individually compared MUD and muscle histology between the pre- and postnatal period.

RESULTS

Despite persistently present fetal leg movements caudal to the MMC, fetal-MUD was higher caudal to the MMC than in controls (p<0.05). Fetal-MUD caudal to the MMC did not increase with gestational age, whereas fetal-MUD in controls and cranial to the MMC increased with gestational age (p<0.05). In 5 of 6 patients assessed, comparison between pre- and postnatal MUD and/or muscle histology indicated consistent findings.

CONCLUSIONS

In fetal SBA, persistent leg movements concur with stable, non-progressively increased fetal-MUD. These data may implicate that early postnatal loss of leg movements is associated with the impact of additional neuromuscular damage after the prenatal period.

Simplified correction of a meningomyelocele-like defect in the ovine fetus

PURPOSE: To develop a simplified technique for antenatal correction of a meningomyelocele -like defect in fetal sheep to allow direct skin closure. METHODS: A spinal defect was surgically created at 75 days of gestation in the fetuses of 36 pregnant sheep, 23 survived the surgery. At 102 days gestation, the defect was corrected in 14 cases (9 were left untreated). Skin surrounding the defect was dissected below the dermis to permit its edges to be approximated and sutured, without interposing any material to its edges. An interface material intended to protect the neural tissue from skin adhesion was used and the skin defect was completely closed over it. Pregnancy was allowed to continue up to 138 days gestation, the fetuses were submitted to macroscopic and microscopic analysis. RESULTS: The defect was successfully corrected in 90.9% in the experimental group, and spontaneous closure occurred in 22.3% in the control group (p < 0.05). The survival rate after the creation and correction of the defect was 63.4% and 78% respectively. CONCLUSION: This simplified technique was successful in the correction a meningomyelocele-like defect, in the fetal sheep.

Characteristics of a spina bifida population including North American Caucasian and Hispanic individuals

BACKGROUND

Meningomyelocele (MM) is a common human birth defect. MM is a disorder of neural development caused by contributions from genes and environmental factors that result in the NTD and lead to a spectrum of physical and neurocognitive phenotypes.

METHODS

A multidisciplinary approach has been taken to develop a comprehensive understanding of MM through collaborative efforts from investigators specializing in genetics, development, brain imaging, and neurocognitive outcome. Patients have been recruited from five different sites: Houston and the Texas-Mexico border area; Toronto, Canada; Los Angeles, California; and Lexington, Kentucky. Genetic risk factors for MM have been assessed by genotyping and association testing using the transmission disequilibrium test.

RESULTS

A total of 509 affected child/parent trios and 309 affected child/parent duos have been enrolled to date for genetic association studies. Subsets of the patients have also been enrolled for studies assessing development, brain imaging, and neurocognitive outcomes. The study recruited two major ethnic groups, with 45.9% Hispanics of Mexican descent and 36.2% North American Caucasians of European descent. The remaining patients are African-American, South and Central American, Native American, and Asian. Studies of this group of patients have already discovered distinct corpus callosum morphology and neurocognitive deficits that associate with MM. We have identified maternal MTHFR 667T allele as a risk factor for MM. In addition, we also found that several genes for glucose transport and metabolism are potential risk factors for MM.

CONCLUSIONS

The enrolled patient population provides a valuable resource for elucidating the disease characteristics and mechanisms for MM development.

Spinal hemorrhages are associated with early neonatal motor function loss in human spina bifida aperta

BACKGROUND

In spina bifida aperta (SBA), leg movements caudal to the meningomyelocele are present in utero, but they disappear shortly after birth. It is unclear whether leg movements disappear by impact of the neuro-developmental malformation or by superimposed traumatic damage. If superimposed traumatic damage is involved, targeted fetal intervention could improve motor outcome.

AIM

To characterize neuromuscular pathology in association with perinatal motor function loss in SBA.

PATIENTS/METHODS

In fetal SBA (n=8; 16-40 weeks GA), the median time interval between ultrasound registrations of fetal motor behavior and post-mortem histology was 1 week. Histology was assessed cranial, at and caudal to the meningomyelocele and compared with findings in fetal controls (n=4).

RESULTS

Despite fetal movements caudal to the meningomyelocele (5/6), histology indicated muscle fiber alterations (6/6) that concurred with neuro-developmental and traumatic spinal defects [Neuro-developmental defects: spinal ependymal denudation (3/8), reduced amount of (caspase3-negative) lower motor neurons (LMNs; 8/8), aberrant spinal vascularization (8/8). Traumatic defects: gliosis (7/8), acute/fresh spinal hemorrhages near LMNs (8/8)].

CONCLUSION

In all delivered SBA patients, recent spinal hemorrhages were superimposed upon pre-existing defects. If early therapeutic strategies can prevent these superimposed secondary spinal hemorrhages, motor outcome may improve.

Delayed intrauterine repair of an experimental spina bifida with a collagen biomatrix

BACKGROUND/PURPOSE

The aim of the study was to evaluate whether a collagen biomatrix is useful for delayed intrauterine coverage of a surgically created spina bifida in a fetal lamb.

METHODS

In 20 fetal lambs, surgery was performed at 72 or 79 days' gestation. In 15 lambs a spina bifida was created surgically. In 8 lambs it was covered with a collagen biomatrix 2 weeks later and in 7 lambs it was left uncovered. Five lambs served as sham operated controls. Neurological examination was performed at 1 week of age and afterwards the lambs were sacrificed for further histological evaluation.

RESULTS

None of the 5 surviving lambs with the defect covered showed loss of spinal function and the architecture of the spinal cord was preserved in 4 of the 5 lambs. In the uncovered group, 1 of the 4 surviving lambs had loss of spinal function, 5 lambs were available for histological evaluation and 4 of them showed disturbance of the architecture of the spinal cord.

CONCLUSIONS

Collagen biomatrices can be used for intrauterine coverage of an experimental spina bifida and can preserve the architecture of the spinal cord. Neurological outcome is not different between fetuses with their spinal cord covered and fetuses with uncovered cords.

Scanning electron microscopy of fetal murine myelomeningocele reveals growth and development of the spinal cord in early gestation and neural tissue destruction around birth

BACKGROUND

Previous studies demonstrated that the spinal cord within a fetal myelomeningocele (MMC) lesion suffers progressive destruction during gestation. This study aims at elucidating this pathophysiologic feature on a cellular and ultrastructural level in a model of genetically determined MMC.

METHODS

Curly tail/loop tail mouse fetuses at various gestational stages and neonates were analyzed electron-microscopically to document time-point and nature of neural tissue development and pathologic alterations within the MMC.

RESULTS

At embryonic day (E) 8.5 and E9.5, round cells displaying multiple microvilli covered the entire region of interest, and some specimens showed initial stages of neurulation. At E10.5, neurulation was terminated in normal animals, whereas the neural placode remained unfolded in MMC fetuses and became distinguishable from adjacent epidermal layers. At E15.5, an apparently normal differentiation was found. Until this time-point, there was no tissue damage or inflammation. Thereafter, increasingly severe tissue alterations were identified with ongoing gestation leading to almost complete loss of neural tissue at birth.

CONCLUSION

We show here in fetal mice with MMC that, apart from absent neurulation, growth and development of the otherwise perfectly intact exposed spinal cord appear normal in early gestation, whereas later, the unprotected neural tissue is progressively destroyed.

In utero topographic analysis of astrocytes and neuronal cells in the spinal cord of mutant mice with myelomeningocele

OBJECT

Myelomeningocele (MMC) is the most severe form of spina bifida causing severe neurological deficits. Injury to the placode has been attributed to in utero aggression. In this study, glial and neuronal cell changes in both number and topography in mice with MMC were investigated during gestation.

METHODS

The curly tail/loop-tail mice model of MMC was used, and fetuses were harvested using caesarean surgery at Days 14.5, 16.5, and 18.5 (full gestation at 19 days). Immunohistochemical analyses of the MMC placodes and the normal spinal cords from the control group were performed using anti-glial fibrillary acidic protein (astrocytes) and mouse anti-neuronal nuclear (neurons) antibodies. Light microscopy was used along with computer-assisted morphometric evaluation. Progressive increases in astrocytes in the spinal cord of all mouse fetuses were found between Days 14.5 and 18.5 of gestation. This increase was significantly higher in the placodes of mice with MMC than in those of normal mice, particularly in the posterior region. Neuronal labeling at Day 14.5 of gestation was similar between mice with MMC and control mice. At Day 16.5 of gestation there was a deterioration of neural tissue in MMC fetuses, mainly in the posterior region, progressing until the end of gestation with a marked loss of neurons in the entire MMC placode.

CONCLUSIONS

This study delineated the quantitative changes in astrocytes and neurons associated with MMC development during the late stages of gestation. The detailed topographic analysis of the MMC defines the timing of the intrauterine insult and how the placode lesions progress. This study supports the current concept of placode protection through in utero surgery for fetuses with MMC.

Fetal spina bifida in a mouse model: loss of neural function in utero

OBJECT

The devastating neurological deficit associated with myelomeningocele has previously been assumed to be a direct and inevitable consequence of the primary malformation-failure of neural tube closure. An alternative view is that secondary damage to the pathologically exposed spinal cord tissue in utero is responsible for the neurological deficiency. If the latter mechanism were shown to be correct, it would provide an objective rationale for the performance of in utero surgery for myelomeningocele, because coverage of the exposed spinal cord could be expected to alleviate or perhaps prevent neurodegeneration. To examine this question, the authors studied the development of neuronal connections and neurological function of mice during fetal and neonatal stages in a genetic model of exposed lumbosacral spina bifida.

METHODS

The persistently exposed spinal cord of mouse fetuses carrying both curly tail and loop-tail mutations exhibited essentially normal anatomical and functional hallmarks of development during early gestation (embryonic Days 13.5-16.5), including sensory and motor projections to and from the cord. A significant proportion of fetuses with spina bifida at early gestation exhibited sensorimotor function identical to that seen in age-matched healthy controls. However, at later gestational stages, increasing neurodegeneration within the spina bifida lesion was detected, which was paralleled by a progressive loss of neurological function.

CONCLUSIONS

These findings provide support for the hypothesis that neurological deficit in human myelomeningocele arises following secondary neural tissue destruction and loss of function during pregnancy.

The occurrence of obstructive vs absorptive hydrocephalus in newborns and infants: relevance to treatment choices

BACKGROUND AND OBJECTIVE

The classification of hydrocephalus in newborns and in infants is different from the classification in adulthood. This difference exists due to disparity in the source pathologies that produce the hydrocephalus, and the practical distinctions in prognosis and treatment choices. The objective of this paper is to present the spectrum of obstructive-communicating hydrocephalus, which is more complex in the pediatric group, and to propose the relevance of this particular classification to treatment options.

MATERIALS AND METHODS

The authors categorized infants with active hydrocephalus at time of presentation into the following four groups along the spectrum of communicating vs obstructive HCP. Group 1: patients with a purely absorptive (communicating) HCP. In these patients, tetraventricular dilatation is usually observed with occasional extraaxial fluid accumulation. An extracranial CSF diversion (shunt) is the treatment of choice. Group 2: patients with an obstructive component together with a persistent absorptive component. In these patients, a technically successful endoscopic procedure will not prevent progression of clinical symptoms of HCP. An extracranial CSF diversion (shunt) should be the treatment of choice even though some of these patients are currently treated by endoscopy. Group 3: patients with an obstructive component together with a temporary absorptive component. In these patients, a technically successful ETV should be followed by temporary CSF drainage [via LP, continuous spinal drainage (CLD), or ventriculostomy] with or without supplemental medical treatment (i.e., Diamox) for several days. Such temporary drainage may decrease failure rate in this subgroup. Group 4: patients with a purely obstructive HCP. In these patients, an endoscopic procedure (ETV) is the treatment of choice. According to this spectrum classification, the authors classify different entities with representative cases and discuss relevancy to treatment options and prognosis.

RESULTS

The data suggest that obstructive hydrocephalus in the very young population may be rather a combination of obstructive and absorptive problem. The outcome of the patient depends mainly not only on the basic pathology causing the hydrocephalus but also on the treatment that is chosen and its complications. While bleeding and infection represent the major causes for communicating hydrocephalus, patients with complex pathologies of congenital type and intra- or interventricular obstructions may reflect obstructive hydrocephalus. Treatment of these patients may be successful by shuntless procedures if the absorptive problem is not the major component. In transient absorptive hydrocephalus, temporary measures were effective in many cases leading to successful procedures of ETV and/or posterior-fossa decompression in selected cases.

CONCLUSIONS

Shuntless procedures are the dream of a pediatric neurosurgeon provided it solves the problem and does not imply unacceptable risk. However, the benefit has to be evaluated years after the procedure is performed, as only prospective multicenter studies will truly show which procedure may have the best overall results in the developing child. Until such studies are available, understanding the basic pathology or the combination of pathologies leading to hydrocephalus in a given child may open the window of opportunities for other than shunt surgery in many hydrocephalic children with major obstructive component.

Movement analysis in neonates with spina bifida aperta

INTRODUCTION

In neonates with spina bifida aperta (SBA), leg movements by myotomes caudal to the meningomyelocele (MMC) are transiently observed. It is unclear whether these leg movements relate to functional neural conduction through the MMC. For optimal therapeutical intervention, pathophysiological insight in these transient leg movements seems relevant. If leg movements by myotomes caudal to the MMC concur with the execution of general movements (GMs), functional neural conduction through the MMC is implicated.

OBJECTIVE

In neonates with SBA, we aimed to determine whether the transiently present leg movements caudal to the MMC indicate functional neural conduction through the MMC.

METHODS

During the perinatal period, fetuses and neonates with SBA (n = 7 and n = 13, respectively) were longitudinally analysed for concurrency between leg movements caudal to the MMC and GMs. To address the integrity of the reflex arc in spinal segments (at, or) caudal to the MMC, tendon leg reflexes were assessed during the first postnatal week.

RESULTS

At postnatal day 1, leg movements caudal to the MMC concurred with GMs in 12 of 13 infants. Isolated leg movements were observed in only 3 of these 12 infants (isolated vs. concurrent; p < 0.005). Leg movements concurring with GMs lasted longer than isolated leg movements (median duration = 11 s vs. 2 s; p < 0.05). Between days 1 and 7, tendon leg reflexes (at, or) caudal to the MMC had disappeared in all but 1 neonate. However, leg movements caudal to the MMC remained concurrently present with GMs in all five neonates available for follow-up after day 7. Comparing these leg movements between days 1 and 7 indicated a decreased duration (-44%, p < 0.05).

CONCLUSIONS

In neonates with SBA, leg movements caudal to the MMC concur with GMs, indicative of functional neural conduction through the MMC. The disappearance of these leg movements is caused by lower motor neuron dysfunction at the reflex arc, whereas neural conduction through the MMC is still functional.

Current status of fetal surgery

The allure of fetal surgery is the possibility of interrupting in utero progression of an otherwise treatable condition. In spite of advances in prenatal diagnosis and refinements in surgical techniques, this field has not yet got off the ground because the risks to the mother and fetus, during and after the procedure far outweigh the benefits, and the infrastructure required to support such activity is prohibitively expensive. The various surgical conditions in which fetal surgery has been attempted and the present status of this specialty are discussed.