Does fetoscopic or open repair for spina bifida affect fetal and postnatal growth?

Advances in Fetal Surgical Repair of Open Spina Bifida

Spina bifida remains a common congenital anomaly of the central nervous system despite national fortification of foods with folic acid, with a prevalence of 2-4 per 10,000 live births. Prenatal screening for the early detection of this condition provides patients with the opportunity to consider various management options during pregnancy. Prenatal repair of open spina bifida, traditionally performed by the open maternal-fetal surgical approach through hysterotomy, has been shown to improve outcomes for the child, including decreased need for cerebrospinal fluid diversion surgery and improved lower neuromotor function. However, the open maternal-fetal surgical approach is associated with relatively increased risk for the patient and the overall pregnancy, as well as future pregnancies. Recent advances in minimally invasive prenatal repair of open spina bifida through fetoscopy have shown similar benefits for the child but relatively improved outcomes for the pregnant patient and future childbearing.

Fetal Neurosurgical Interventions for Spinal Malformations, Cerebral Malformations, and Hydrocephalus: Past, Present, and Future

In this article we review the last 40 years of progress in fetal neurosurgery with special attention to current controversies and upcoming challenges in the field. We surveyed the published literature describing prenatal interventions for spinal malformations, cerebral malformations, and hydrocephalus. Even the most mature treatment paradigm, intrauterine repair of myelomeningocele, stands to benefit from advances in imaging and therapeutic modalities to improve patient selection, refine surgical techniques, validate novel biologic therapies, and streamline postoperative patient care. Other conditions under evaluation include congenital cerebral malformations, such as encephalocele, cerebrovascular malformations, and hydrocephalus. We describe cross-cutting needs for advances in fetal neuroimaging, basic disease models and new therapeutic devices to support further progress across various neurosurgical conditions affecting patients during the fetal period.

Two-port, exteriorized uterus, fetoscopic meningomyelocele closure has fewer adverse neonatal outcomes than open hysterotomy closure

BACKGROUND

In utero closure of meningomyelocele using an open hysterotomy approach is associated with preterm delivery and adverse neonatal outcomes.

OBJECTIVE

This study compared the neonatal outcomes in in utero meningomyelocele closure using a 2-port, exteriorized uterus, fetoscopic approach vs the conventional open hysterotomy approach.

STUDY DESIGN

This retrospective cohort study included all consecutive patients who underwent in utero meningomyelocele closure using open hysterotomy (n=44) or a 2-port, exteriorized uterus, fetoscopic approach (n=46) at a single institution between 2012 and 2020. The 2-port, exteriorized uterus, fetoscopic closure was composed of the following 3 layers: a bovine collagen patch, a myofascial layer, and a skin. The frequency of respiratory distress syndrome and a composite of other adverse neonatal outcomes, including retinopathy of prematurity, periventricular leukomalacia, and perinatal death, were compared between the study groups. Regression analyses were performed to determine any association between the fetoscopic closure and adverse neonatal outcomes, adjusted for several confounders, including gestational age of <37 weeks at delivery.

RESULTS

The fetoscopic closure was associated with a lower rate of respiratory distress syndrome than the open hysterotomy closure (11.5% [5 of 45] vs 29.5% [13 of 44]; P=.037). The proportion of neonates with a composite of other adverse neonatal outcomes in the fetoscopic group was half of that observed patients in the open hysterotomy group; however, this difference did not reach statistical significance (4.3% [2 of 46] vs 9.1% [4 of 44]; P=.429). Here, regression analysis has demonstrated that fetoscopic meningomyelocele closure was associated with a lower risk of respiratory distress syndrome (adjusted odds ratio, 0.23; 95% confidence interval, 0.06-0.84; P=.026) than open hysterotomy closure.

CONCLUSION

In utero meningomyelocele closure using a 2-port, exteriorized uterus, fetoscopic approach was associated with a lower risk of respiratory distress syndrome than the conventional open hysterotomy meningomyelocele closure.

Growth profile assessment of young adults with tethered cord syndrome: a retrospective cohort analysis of Korean conscription data

PURPOSE

Tethered cord syndrome (TCS) is characterized by progressive spinal cord degeneration secondary to congenital spinal dysraphism. The associated accompanying physical inactivity and musculoskeletal deformities have raised interest in the growth profile of adult TCS patients. However, few previous studies have investigated the growth profile of adult TCS patients.

METHODS

We retrospectively reviewed the demographic data and medical records of 20-year-old Korean conscription examinees who were registered between April 2004 and September 2019. In total, 151 examinees with a diagnosis of TCS were enrolled. The height, weight, and body mass index (BMI) of 300 randomly selected examinees were compared to the TCS group. Obesity was defined by the World Health Organization and Asian-Pacific criteria for BMI and compared between the groups. Growth profile differences according to tethering location and musculoskeletal deformities were analyzed in both groups.

RESULTS

The mean height, weight, and BMI values of the TCS group were lower than those of the control group. The TCS group had a lower proportion of obese and overweight individuals, and a higher proportion of underweight individuals, according to both BMI criteria. The tethering level was not associated with the degree of obesity in the tethered group. The mean height, weight, and BMI were lower in the tethered group regardless of the existence of musculoskeletal deformity.

CONCLUSION

Enrollees with a history of TCS were smaller than controls of the same age. Monitoring of health behaviors, including nutrition, diet, and exercise, is warranted for TCS patients.

Enhanced Recovery after Surgery: Benefits for the Fetal Surgery Patient

BACKGROUND

The fetoscopic approach to the prenatal closure of a neural tube defect (NTD) may offer similar advantages to the newborn compared to prenatal open closure of a NTD, with a reduction in maternal risks. Enhanced recovery after surgery (ERAS) protocols have been applied to different surgical procedures with documented advantages. We modified the perioperative care of patients undergoing in utero repair of myelomeningocele with the goal of enhancing the recovery. A retrospective study comparing traditional management to the ERAS protocol was conducted.

AIMS

Primary aim was to evaluate the length of stay (LOS). Secondary outcomes included pain scores, time to oral intake, opioid-induced side effects, and respiratory complications.

METHODS

Thirty patients who underwent a mid-gestation fetoscopic closure of a NTD were included. Data analyzed include demographics, comorbidities, LOS, anatomical location of the NTD, magnesium sulfate doses and duration of administration, oxygen requirements, duration of the postoperative epidural infusion, duration of surgery and anesthesia, incidence of postoperative nausea and vomiting, respiratory complications, time to oral intake, pain scores, and sedation scores. Differences between the treatment groups were compared using the independent sample t-test or Mann-Whitney Ʋ test.

RESULTS

Of the 30 patients, 10 patients were managed according to the ERAS protocol and 20 patients according to the traditional management (1:2 ratio). The mean gestational age at the time of intervention for the traditional and ERAS groups was 24.9 ± 0.5 weeks and 24.8 ± 0.5 weeks, respectively. Compared to the traditional group, the LOS was reduced in the ERAS group to 112.5 ± 12.6 h (4.7 ± 0.5 days) from 179.7 ± 87.9 h (7.5 ± 3.7 days) (p = 0.012). The time to oral intake was also shorter 502.6 ± 473.4 min versus 1015.6 ± 698.2 min; p = 0.049. Oxygen requirements were prolonged in the traditional group (1843.7 ± 1262.6 min vs. 1051.7 ± 1078.1 min p = 0.052). The total duration of magnesium sulfate was longer for patients in the traditional group (2125.6 ± 727.1 min vs. 1429.5 ± 553.8 min; p = 0.006). No statistically significant difference in pain scores was observed between the groups.

CONCLUSIONS

Establishing an ERAS protocol for fetoscopic in utero repair of NTDs approach is feasible with the advantages of decreased postoperative LOS, reduced oxygen requirements, lower duration of magnesium sulfate infusion, and facilitation of earlier oral intake without compromising the pain scores.

Unique Considerations: Preterm Prelabor Rupture of Membranes in the Setting of Fetal Surgery and Higher Order Pregnancies

Two unique aspects of antenatal care occur in the setting of fetal surgery and multiple gestations. As fetal interventions increase, so do the number of cases of iatrogenic preterm prelabor rupture of membranes (PPROM). Because of the amniotic sac's inability to heal, the risk of PPROM after surgery is directly correlated with the number of interventions, the size of the defect, and the surgery performed. Higher order gestations also carry an increased risk of PPROM. This paper reviews the risks and management of PPROM in the setting of the various prenatal interventions as well as in the setting of multiple gestations.

Current perspective and scope of fetal therapy: part 1

Fetal therapy term has been described for any therapeutic intervention either invasive or noninvasive for the purpose of correcting or treating any fetal malformation or condition. Fetal therapy is a rapidly evolving specialty and has gained pace in last two decades and now fetal intervention is being tried in many malformations with rate of success varying with the type of different fetal conditions. The advances in imaging techniques have allowed fetal medicine persons to make earlier and accurate diagnosis of numerous fetal anomalies. Still many fetal anomalies are managed postnatally because the fetal outcomes have not changed significantly with the use of fetal therapy and this approach avoids unnecessary maternal risk secondary to inutero intervention. The short-term maternal risk associated with fetal surgery includes preterm labor, premature rupture of membranes, uterine wall bleeding, chorioamniotic separation, placental abruption, chorioamnionitis, and anesthesia risk. Whereas, maternal long-term complications include risk of infertility, uterine rupture, and need for cesarean section in future pregnancies. The decision for invasive fetal therapy should be taken after discussion with parents about the various aspects like postnatal fetal outcome without fetal intervention, possible outcome if the fetal intervention is done, available postnatal intervention for the fetal condition, and possible short-term and long-term maternal complications. The center where fetal intervention is done should have facility of multi-disciplinary team to manage both maternal and fetal complications. The major issues in the development of fetal surgery include selection of patient for intervention, crafting effective fetal surgical skills, requirement of regular fetal and uterine monitoring, effective tocolysis, and minimizing fetal and maternal fetal risks. This review will cover the surgical or invasive aspect of fetal therapy with available evidence and will highlight the progress made in the management of fetal malformations in last two decades.

Prenatal regenerative fetoscopic interventions for congenital anomalies

Fetal intervention has progressed in the past two decades from experimental proof-of-concept to practice-adopted, life saving interventions in human fetuses with congenital anomalies. This progress is informed by advances in innovative research, prenatal diagnosis, and fetal surgical techniques. Invasive open hysterotomy, associated with notable maternal-fetal risks, is steadily replaced by less invasive fetoscopic alternatives. A better understanding of the natural history and pathophysiology of congenital diseases has advanced the prenatal regenerative paradigm. By altering the natural course of disease through regrowth or redevelopment of malformed fetal organs, prenatal regenerative medicine has transformed maternal-fetal care. This review discusses the uses of regenerative medicine in the prenatal diagnosis and management of three congenital diseases: congenital diaphragmatic hernia, lower urinary tract obstruction, and spina bifida.

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.

Prenatal and postnatal MRI findings in open spinal dysraphism following intrauterine repair via open versus fetoscopic surgical techniques

PURPOSE

The purpose of the study is to examine MRI findings of the brain and spine on prenatal and postnatal MRI following intrauterine repair of open spinal dysraphism (OSD) by open hysterotomy and fetoscopic approaches.

MATERIALS AND METHODS

This study is a single-center HIPAA-compliant and IRB-approved retrospective analysis of fetal MRIs with open spinal dysraphism from January 2011 through December 2018 that underwent subsequent prenatal repair of OSD.

RESULTS

Sixty-two patients met inclusion criteria: 47 underwent open repair, and 15 underwent fetoscopic repair, with an average gestational age of 22.6 ± 1.4 weeks at initial MRI. On postnatal MRI, spinal cord syrinx was seen in 34% (16/47) of patients undergoing open versus 33.3% (5/15) undergoing fetoscopic repair (P = 0.96). Postnatally, there was no significant difference in hindbrain herniation between the open versus fetoscopic repair groups (P = 0.28). Lateral ventricular size was significantly larger in the open (20.9 ± 6.7 mm) versus the fetoscopic repair (16.1 ± 4.9 mm) group (P = 0.01).

CONCLUSION

Though lateral ventricular size in the open repair group was larger than the fetoscopic repair group, this can likely be explained by initial selection criteria used for fetoscopic repair. Other postoperative imaging parameters on postnatal MRI were not significantly different between the two groups.

Heated humidified carbon dioxide for partial uterine insufflation in fetoscopic myelomeningocele repair: insights from animal model

Linked Comment: Ultrasound Obstet Gynecol 2018; 53: 340-347.