Fetoscopic Repair of Meningomyelocele

The impact of a biocellulose-based repair of fetal open spina bifida on the need to untether the cord: is it time to unify techniques for prenatal repair?

OBJECTIVE

To report the need for cord untethering after prenatal repair of open spina bifida using a unique biocellulose-based technique performed at a later gestational age.

METHODS

An observational cohort study was conducted to determine the incidence of tethered cord syndrome. Between May 2013 and May 2022, we performed 172 procedures using the percutaneous fetoscopic approach in fetuses at 26-28 weeks of gestation. After placode dissection, a biocellulose patch was placed to cover the placode, a myofascial flap (when possible) was dissected, and the skin was closed. Owing to death or loss to follow-up, 23 cases were excluded. Cord tethering syndrome was defined as symptoms of medullary stretching, and the infants were evaluated and operated on by local neurosurgeons after an magnetic resonance imaging examination. Infants over 30-month had ambulation and neurodevelopment evaluations (PEDI scale).

RESULTS

Among 172 cases operated at a median gestational age of 26.7 weeks and delivered at 33.2 weeks, 149 cases were available for postnatal follow-up, and cord untethering was needed in 4.4% of cases (6/136; excluding 13 cases younger than 12 months). Cerebrospinal fluid diversion and bladder catheterization were needed in 38% and 36% of cases, respectively. Of the 78 cases evaluated at 30 months, 49% were ambulating independently, and 94% had normal social function.

CONCLUSION

The biocellulose-based technique was associated with a low rate of cord tethering, wich may be attributed to the lack of the duramater suture during prenatal repair, the formation of a neoduramater and/or later gestational age of surgery.

Minimally Invasive Fetal Surgery and the Next Frontier

Most patients with congenital anomalies do not require prenatal intervention. Furthermore, many congenital anomalies requiring surgical intervention are treated adequately after birth. However, there is a subset of patients with congenital anomalies who will die before birth, shortly after birth, or experience severe postnatal complications without fetal surgery. Fetal surgery is unique in that an operation is performed on the fetus as well as the pregnant woman who does not receive any direct benefit from the surgery but rather lends herself to risks, such as hemorrhage, abruption, and preterm labor. The maternal risks involved with fetal surgery have limited the extent to which fetal interventions may be performed but have, in turn, led to technical innovations that have significantly advanced the field. This review will examine congenital abnormalities that can be treated with minimally invasive fetal surgery and introduce the next frontier of prenatal management of fetal surgical pathology.

Fetoscopic Myelomeningocele Repair with Complete Release of the Tethered Spinal Cord Using a Three-Port Technique: Twelve-Month Follow-Up-A Case Report

Open spina bifida is one of the most common congenital defects of the central nervous system. Open fetal surgery, which is one of the available therapeutic options, remains the gold standard for prenatal repairs. Fetoscopic closure may lower the number of maternal complications associated with open fetal surgery. Regardless of the approach, the outcome may be compromised by the development of tethered spinal cord (TSC) syndrome. At 24.2 weeks of gestation, a primipara was admitted due to fetal myelomeningocele and was deemed eligible for fetoscopic repair. Fetal surgery was performed at 25.0 weeks of gestation. It was the first complete untethering of the spinal cord and anatomic reconstruction (dura mater, spinal erectors, skin) achieved during a fetoscopic repair of spina bifida. Cesarean section due to placental abruption was performed at 31.1 weeks of gestation. VP shunting, with no need for revision, was performed at 5 weeks postdelivery due to progressing ventriculomegaly. No clinical or radiological signs of secondary tethering were observed. Neurological examination at 11 months postdelivery revealed cranial nerves without any signs of damage, axial hypotonia, decreased muscle tone in the lower extremities, and absent pathological reflexes. Motor development was slightly retarded. Complete untethering of the neural structures should always be performed, regardless of the surgical approach, as it is the only course of action that lowers the risk for developing secondary TSC.

Anesthesia for fetal operative procedures: A systematic review

Objective

The anesthetic management of fetal operative procedures (FOP) is a highly debated topic. Literature on fetal pain perception and response to external stimuli is rapidly expanding. Nonetheless, there is no consensus on the fetal consciousness nor on the instruments to measure pain levels. As a result, no guidelines or clinical recommendations on anesthesia modality during FOP are available. This systematic literature review aimed to collect the available knowledge on the most common fetal interventions, and summarize the reported outcomes for each anesthetic approach. Additional aim was to provide an overall evaluation of the most commonly used anesthetic agents.

Methods

Two systematic literature searches were performed in Embase, Medline, Web of Science Core Collection and Cochrane Central Register of Controlled Trials up to December 2021. To best cover the available evidence, one literature search was mostly focused on fetal surgical procedures; while anesthesia during FOP was the main target for the second search. The following fetal procedures were included: fetal transfusion, laser ablation of placental anastomosis, twin-reversed arterial perfusion treatment, fetoscopic endoluminal tracheal occlusion, thoraco-amniotic shunt, vesico-amniotic shunt, myelomeningocele repair, resection of sacrococcygeal teratoma, ligation of amniotic bands, balloon valvuloplasty/septoplasty, ex-utero intrapartum treatment, and ovarian cyst resection/aspiration. Yielded articles were screened against the same inclusion criteria. Studies reporting anesthesia details and procedures’ outcomes were considered. Descriptive statistical analysis was performed and findings were reported in a narrative manner.

Results

The literature searches yielded 1,679 articles, with 429 being selected for full-text evaluation. A total of 168 articles were included. Overall, no significant differences were found among procedures performed under maternal anesthesia or maternal-fetal anesthesia. Procedures requiring invasive fetal manipulation resulted to be more effective when performed under maternal anesthesia only. Based on the available data, a wide range of anesthetic agents are currently deployed and no consistency has been found neither between centers nor procedures.

Conclusions

This systematic review shows great variance in the anesthetic management during FOP. Further studies, systematically reporting intraoperative fetal monitoring and fetal hormonal responses to external stimuli, are necessary to identify the best anesthetic approach. Additional investigations on pain pathways and fetal pain perception are advisable.

Controversies in Fetal Surgery: Prenatal Repair of Myelomeningocele in the Modern Era

Fetal surgery is a constantly evolving field that showed noticeable progress with the treatment of myelomeningocele (MMC) using prenatal repair. Despite this success, there are ongoing questions regarding the optimal approach for fetal myelomeningocele repair, as well as which patients are eligible. Expansion of the inclusion and exclusion criteria is an important ongoing area of study for myelomeningocele including the recent Management of Myelomeningocele Plus trial. The significant personal and financial burden required of families seeking treatment has likely limited its accessibility to the general population.

Complex gastroschisis: a new indication for fetal surgery?

Gastroschisis (GS) is a congenital abdominal wall defect, in which the bowel eviscerates from the abdominal cavity. It is a non-lethal isolated anomaly and its pathogenesis is hypothesized to occur as a result of two hits: primary rupture of the 'physiological' umbilical hernia (congenital anomaly) followed by progressive damage of the eviscerated bowel (secondary injury). The second hit is thought to be caused by a combination of mesenteric ischemia from constriction in the abdominal wall defect and prolonged amniotic fluid exposure with resultant inflammatory damage, which eventually leads to bowel dysfunction and complications. GS can be classified as either simple or complex, with the latter being complicated by a combination of intestinal atresia, stenosis, perforation, volvulus and/or necrosis. Complex GS requires multiple neonatal surgeries and is associated with significantly greater postnatal morbidity and mortality than is simple GS. The intrauterine reduction of the eviscerated bowel before irreversible damage occurs and subsequent defect closure may diminish or potentially prevent the bowel damage and other fetal and neonatal complications associated with this condition. Serial prenatal amnioexchange has been studied in cases with GS as a potential intervention but never adopted because of its unproven benefit in terms of survival and bowel and lung function. We believe that recent advances in prenatal diagnosis and fetoscopic surgery justify reconsideration of the antenatal management of complex GS under the rubric of the criteria for fetal surgery established by the International Fetal Medicine and Surgery Society (IFMSS). Herein, we discuss how conditions for fetoscopic repair of complex GS might be favorable according to the IFMSS criteria, including an established natural history, an accurate prenatal diagnosis, absence of fully effective perinatal treatment due to prolonged need for neonatal intensive care, experimental evidence for fetoscopic repair and maternal and fetal safety of fetoscopy in expert fetal centers. Finally, we propose a research agenda that will help overcome barriers to progress and provide a pathway toward clinical implementation. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

Fetal open spinal dysraphism repair through a mini-hysterotomy: Influence of gestational age at surgery on children's ability to walk

OBJECTIVE

To analyze the impact of gestational age (GA) at the time of fetal open spinal dysraphism (OSD) repair through a mini-hysterotomy on the ability of children to walk.

METHODS

Children who underwent in utero repair of OSD and had formal neurological assessment after 2.5 years of age were compared regarding their ability to walk in relation to pre-surgical predictors.

RESULTS

Sixty-nine children fulfilled the inclusion criteria. Among them, 63.7% (44/69) were able to walk with or without orthesis. Fetal OSD correction performed earlier in gestation (from 19.7 to 26.9 weeks) was associated with a higher probability of walking with or without orthesis (p = 0.033). The median GA at delivery was 35.3 weeks. Multivariate binary logistic regression showed that the upper anatomical level of the OSD (<L4 or > L5) (p < 0.004; OR: 10.31 [95% CI: 2.07-51.28]) and GA at the time of fetal surgery (p = 0.026; OR = 0.68 [95% CI: 0.48-0.95]) were independent predictors of the postnatal ability to walk with or without orthesis.

CONCLUSION

Fetuses with OSD who were operated on earlier in pregnancy (range: 19.7-26.9 weeks), were more likely to walk with or without orthesis.

Caring for the Child with Spina Bifida

Care for a child with spina bifida can be complex, requiring multiple specialists. Neurosurgical care centers around the initial closure or repair of the spinal defect, followed by management of hydrocephalus, symptoms of the Chiari 2 malformation, and tethered cord. This article reviews definitions and types of spina bifida, considerations surrounding the initial treatment, including fetal surgery, and the ongoing neurosurgical management of common comorbid conditions. The role of interdisciplinary care is stressed, as well as the importance of coordinated transition to adult care at an appropriate age and developmental stage.

Pediatric neurosurgery at Texas Children's Hospital: the legacy of Dr. William R. Cheek

Texas Children's Hospital opened its doors in 1954, and since that time the institution has remained dedicated to a three-part mission: patient care, education, and research. Dr. William R. Cheek developed an early interest in pediatric neurosurgery, which led to his efforts in building and developing a service at Texas Children's Hospital at a time when the field was just emerging. His work with other early pioneers in the field led to the establishment of organized societies, educational texts, and governing bodies that have led to significant advances in the field over the past 50 years.

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.

Fetoscopic insufflation modeled in the extrauterine environment for neonatal development (EXTEND): Fetoscopic insufflation is safe for the fetus

BACKGROUND

Minimally invasive fetal surgery, or fetoscopy, is an alternative to open fetal surgery to repair common birth defects like myelomeningocele. Although this hysterotomy-sparing approach reduces maternal morbidity, the effects of in utero insufflation on the fetus are poorly understood. Our purpose was to determine the optimal fetal insufflation conditions.

METHODS

Fetal sheep at gestational age 104 to 107 days were studied under insufflation conditions in utero and ex utero. The ex utero fetuses were cannulated via their umbilical vessels into a support device, the EXTra-uterine Environment for Neonatal Development (EXTEND). EXTEND fetuses were exposed to four different insufflation conditions for four hours: untreated carbon dioxide (CO₂) (n=5), warm humidified (whCO₂) (n=4), whCO₂ with the umbilical cord exposed (n=3), and whCO₂ without amniotic fluid (skin and cord exposed) (n=3).

RESULTS

In utero insufflation led to significant increases in fetal CO₂ and reductions in fetal pH. Ex utero insufflation with whCO₂ did not lead to changes in fetal blood gas measurements or cerebral perfusion parameters. Insufflation with whCO₂ with an exposed umbilical cord led to reduced umbilical blood flow.

CONCLUSIONS

Insufflation with warm humidified CO₂ with an amniotic fluid covered umbilical cord is well tolerated by the fetus without significant changes in hemodynamics or cerebral perfusion parameters.

TYPE OF STUDY

Basic science LEVEL OF EVIDENCE: N/A.

Comparison of two fetoscopic open neural tube defect repair techniques: single- vs three-layer closure

OBJECTIVES

We reported previously on an exteriorized-uterus fetoscopic repair for open neural tube defect (ONTD) using a single-layer closure (SLC) technique. However, because SLC was associated with a high rate of cerebrospinal fluid (CSF) leakage at birth, we developed a three-layer closure (3LC) technique comprising a bovine collagen patch, a myofascial layer and a skin layer. The aims of this study were to compare SLC and 3LC in terms of intraoperative, postoperative and obstetric outcomes, as well as short-term neonatal neurologic and non-neurologic outcomes.

METHODS

This was a retrospective analysis of prospectively collected data, from 32 consecutive SLC controls and 18 consecutive 3LC cases, that underwent exteriorized-uterus two-port fetoscopic repair of ONTD at our center, between April 2014 and December 2018. All patients satisfied the Management of Myelomeningocele Study (MOMS) criteria. Obstetric, maternal, fetal and early neonatal outcomes were compared between the SLC and 3LC groups.

RESULTS

Maternal demographics and mean gestational age (GA) at fetal surgery (25.0 ± 0.7 vs 25.0 ± 0.5 weeks' gestation; P = 0.96), and at delivery (36.5 ± 3.5 vs 37.6 ± 3.0 weeks; P = 0.14), were similar between the SLC and 3LC groups, respectively. The rate of preterm prelabor rupture of membranes (PPROM) < 37 weeks (28% vs 29%; P = 0.9), mean GA at PPROM (32.3 ± 3.4 vs 32.7 ± 1.9 weeks; P = 0.83) and rate of vaginal delivery (50% vs 47%; P = 0.84) were similar for the SLC vs 3LC groups, respectively. In pregnancies that had SLC compared with those that had 3LC, there was a significantly higher incidence of CSF leakage at birth (8/32 (25%) vs 0/17 (0%); P = 0.02) and a significantly lower rate of reversal of hindbrain herniation at 6 weeks postoperatively (18/30 (60%) vs 14/15 (93%); P = 0.02). The rate of infants that met the MOMS criteria for shunt placement or died before 12 months of age (23/31 (74%) vs 7/12 (58%); P = 0.31) and those that required treatment for hydrocephalus by 12 months (15/32 (47%) vs 4/12 (33%); P = 0.42) were similar between the SLC and 3LC groups, respectively.

CONCLUSIONS

Compared to SLC, 3LC preserves the fetal and obstetric benefits of fetoscopic repair and shows improved rates of CSF leakage and reversal of hindbrain herniation at 6 weeks postoperatively. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Fetal Surgery in the Era of SARS-CoV-2 Pandemic: A Single-Institution Review

Objective

To cope with the changing health care services in the era of SARS-CoV-2 pandemic. We share the institutional framework for the management of anomalous fetuses requiring fetal intervention at Mayo Clinic, Rochester, Minnesota. To assess the success of our program during this time, we compare intraoperative outcomes of fetal interventions performed during the pandemic with the previous year.

Patients

We implemented our testing protocol on patients undergoing fetal intervention at our institution between March 1, and May 15, 2020, and we compared it with same period a year before. A total of 17 pregnant patients with anomalous fetuses who met criteria for fetal intervention were included: 8 from 2019 and 9 from 2020.

Methods

Our testing protocol was designed based on our institutional perinatal guidelines, surgical requirements from the infection prevention and control (IPAC) committee, and input from our fetal surgery team, with focus on urgency of procedure and maternal SARS-CoV-2 screening status. We compared the indications, types of procedures, maternal age, gestational age at procedure, type of anesthesia used, and duration of procedure for cases performed at our institution between March 1, 2020, and May 15, 2020, and for the same period in 2019.

Results

There were no statistically significant differences among the number of cases, indications, types of procedures, maternal age, gestational age, types of anesthesia, and duration of procedures (P values were all >.05) between the pre–SARS-CoV-2 pandemic in 2019 and the SARS-CoV-2 pandemic in 2020.

Conclusions

Adoption of new institutional protocols during SARS-CoV-2 pandemic, with appropriate screening and case selection, allows provision of necessary fetal intervention with maximal benefit to mother, fetus, and health care provider.

New Trends in Fetal Anesthesia

Fetal anesthesia teams must understand the pathophysiology and rationale for the treatment of each disease process. Treatment can range from minimally invasive procedures to maternal laparotomy, hysterotomy, and major fetal surgery. Timing may be in early, mid-, or late gestation. Techniques continue to be refined, and the anesthetic plans must evolve to meet the needs of the procedures. Anesthetic plans range from moderate sedation to general anesthesia that includes monitoring of 2 patients simultaneously, fluid restriction, invasive blood pressure monitoring, vasopressor administration, and advanced medication choices to optimize fetal cardiac function.

Prenatal counseling for myelomeningocele in the era of fetal surgery: a shared decision-making approach

OBJECTIVE

The Management of Myelomeningocele Study demonstrated that fetal surgery, as compared to postnatal repair, decreases the rate of hydrocephalus and improves expected motor function. However, fetal surgery is associated with significant maternal and neonatal risks including uterine wall dehiscence, prematurity, and fetal or neonatal death. The goal of this study was to provide information about counseling expectant mothers regarding myelomeningocele in the era of fetal surgery.

METHODS

The authors conducted an extensive review of topics pertinent to counseling in the setting of myelomeningocele and introduce a new model for shared decision-making to aid practitioners during counseling.

RESULTS

Expectant mothers must decide in a timely manner among several potential options, namely termination of pregnancy, postnatal surgery, or fetal surgery. Multiple factors influence the decision, including maternal health, fetal heath, financial resources, social support, risk aversion, access to care, family planning, and values. In many cases, it is a difficult decision that benefits from the guidance of a pediatric neurosurgeon.

CONCLUSIONS

The authors review critical issues of prenatal counseling for myelomeningocele and discuss the process of shared decision-making as a framework to aid expectant mothers in choosing the treatment option best for them.

Fetal surgical intervention for myelomeningocele: lessons learned, outcomes, and future implications

Fetal myelomeningocele (fMMC) closure (spina bifida aperta) has become a care option for patients that meet inclusion criteria, but it is clear that fetal intervention, while improving outcomes, is not a cure. This review will: (1) focus on the rationale for fMMC surgery based on preclinical studies and observations that laid the foundation for human pilot studies and a randomized controlled trial; (2) summarize important clinical outcomes; (3) discuss the feasibility, efficacy, and safety of recent developments in fetal surgical techniques and approaches; and (4) highlight future research directions. Given the increased risk of maternal and fetal morbidity associated with prenatal intervention, accompanied by the increasing number of centres performing interventions worldwide, teams involved in the care of these patients need to proceed with caution to maintain technical expertise, competency, and patient safety. Ongoing assessment of durability of the benefits of fMMC surgery, as well as additional refinement of patient selection criteria and counselling, is needed to further improve outcomes and reduce the risks to the mother and fetus. WHAT THIS PAPER ADDS: High-quality prospective studies are needed to broaden the indication for fetal surgery in the general myelomeningocele population. Innovative minimally invasive approaches have had promising results, yet lack comprehensive and robust experimental or clinical evaluation. Important information to help families make informed decisions regarding fetal surgery for myelomeningocele is provided.

Fetal open spinal dysraphism repair through a mini-hysterotomy: Influence of gestational age at surgery on the perinatal outcomes and postnatal shunt rates

OBJECTIVE

To analyze the impact of gestational age (GA) at the time of fetal open spinal dysraphism (OSD) repair through a mini-hysterotomy on the perinatal outcomes and the infants' ventriculoperitoneal shunt rates.

METHODS

Retrospective study of cases of fetal OSD correction performed from 2014 and 2019.

RESULTS

One hundred and ninety women underwent fetal surgery for OSD through a mini-hysterotomy, and 176 (176/190:92.6%) have since delivered. Fetal OSD correction performed earlier in the gestational period, ranging from 19.7 to 26.9 weeks, was associated with lower rates of postnatal ventriculoperitoneal shunting (P: .049). Earlier fetal surgeries were associated with shorter surgical times (P: .01), smaller hysterotomy lengths (P < .001), higher frequencies of hindbrain herniation reversal (P: .003), and longer latencies from surgery to delivery (P < .001). Median GA at delivery was 35.3 weeks. Multivariate binary logistic regression showed that both fetal lateral ventricle-to-hemisphere ratio (%; P < .001; OR: 1.14 [95% CI: 1.09-1.21]) and GA at the time of fetal surgery (P: .016; OR: 1.37 [95% CI: 1.07-1.77]) were independent predictors of postnatal ventriculoperitoneal shunting.

CONCLUSION

Fetuses with OSD who were operated on earlier in the gestational interval, which ranged from 19.7 to 26.9 weeks, were less prone to receiving postnatal ventriculoperitoneal shunts.

Neurosurgery guidelines for the care of people with spina bifida

Myelomeningocele (MMC) arises from an early neural developmental anomaly and results in a variety of structural abnormalities and associated functional neurologic deficits. As such, neurologic issues are central to virtually all clinical problems. Neurosurgical intervention strives to correct or improve these defects and prevent secondary complications. These interventions include closure of the open myelomeningocele and management (across the life span) of hydrocephalus, the Chiari II malformation (C2M) and tethered spinal cord (TSC). The development of pre-natal closure techniques and reports of improved outcome with in-utero closure (IUMC) have revolutionized the neurosurgical approach to myelomeningocele. Controversies remain surrounding patient selection, maternal risks, technique of IUMC (endoscopic vs. open) and long-term outcomes. However, real gains include reduced rates of hydrocephalus, modestly improved motor capabilities and reduction in C2M morbidity. For many decades, the cornerstone of treatment of hydrocephalus for many decades has been the placement and support of ventricular shunts. Endoscopic third ventriculostomy (ETV) with or without choroid plexus coagulation (ETV/CPC) is an appealing alternate strategy that avoids the morbidity and complications associated with shunts. The exact criteria for ETV-CPC candidacy and best metrics for outcome analysis remain active areas of debate and controversy. Similarly, neurosurgical management C2M, has centered upon the indications and clinical thresholds for performing posterior fossa surgical decompression. Tethered spinal cord management incorporates the diagnosis and surgical management of adhesions formed at the initial closure site, the consequent longitudinal traction related stress on the cord and the resulting neurologic signs and symptoms.

Anesthesia for Fetal Surgery and Fetal Procedures

Advances in imaging and technique have pushed the boundaries of the types of surgical interventions available to fetuses with congenital and developmental abnormalities. This review focuses on fundamental aspects of fetal anesthesia, including the physiologic changes of pregnancy, uteroplacental perfusion, and fetal physiology. We discuss the types of fetal surgeries and procedures currently being performed and discuss the specific anesthetic approaches to different categories of fetal surgeries. We also discuss ethical aspects of fetal surgery and anesthesia.

An Unreported Complication After Fetoscopic Myelomeningocele Closure

Myelomeningocele (MMC) is a type of open neural tube defect characterized by exposure of the spinal cord through a defect in the skin and posterior hindbrain herniation through the foramen magnum. Outcomes vary but common morbidities include paraplegia, hydrocephalus, neurogenic bladder, scoliosis, and tethered cord. Fetal surgery, although not a cure, has been shown to decrease the risk of associated morbidity.A study of a neonate born at 39 5/7 weeks gestation status-post in utero fetoscopic MMC repair at 24 weeks gestation was presented in this study along with a concise review of the literature. Fasciocutaneous advancement flaps were made in utero to facilitate a tension-free midline closure and were left to heal secondarily. The neonate underwent uncomplicated spontaneous vaginal delivery but was noted to have a right flank hernia through the relaxing incision in addition to delayed healing of the left relaxing incision. According to authors, iatrogenic flank hernia following fetoscopic MMC repair has not been previously reported in the literature. Both defects were repaired primarily in layers with undermining and retroperitoneal domain was reestablished with imbrication of the overlying muscle on the right side. The authors report their experience to contribute to the scarce literature describing postnatal complications arising from this novel procedure.

[Fetal surgery for myelomeningocele: Obstetric evolution and short-term perinatal outcomes of a cohort of 21 cases]

Objetivo:

Describir la técnica quirúrgica, evolución obstétrica y resultados perinatales de una cohorte de pacientes sometidas a cirugía intrauterina para reparación de una disrafia fetal abierta (DFA).

Métodos:

Análisis prospectivo de 21 casos consecutivos de DFA con diagnóstico y tratamiento quirúrgico prenatal en nuestra institución entre 2015 y 2017. La técnica de la cirugía fetal (QF) fue similar a la descripta en el estudio MOMS, excepto que se utilizó histerotomía con asa bipolar. Los cuidados postoperatorios, nacimiento y cuidados neonatales se realizaron en la misma institución. Se analizaron complicaciones perioperatorias de la QF, la evolución obstétrica y los resultados perinatales.

Resultados:

La QF se realizó a una edad gestacional media de 25.8 semanas (24.1-27.6). La edad gestacional media al nacer fue 34.2 semanas (29.2-37.1). El tiempo quirúrgico medio fue 138 min (101-187) con tendencia descendente y el tiempo de internación medio, 7.1 días (4-32). El 52% (11/21) de las pacientes experimentó rotura prematura de membranas (RPM). Ninguna paciente requirió transfusiones postcesárea. No hubo casos de desprendimiento placentario, rotura uterina ni muertes maternas. La cicatrización de la histerorafia fue normal en 95% de las pacientes. La sobrevida perinatal fue del 95% (20/21, una muerte intrauterina secundaria a banda amniótica). La necesidad de cierre cutáneo postnatal (CCP) fue del 5%. Ninguno de los casos (20) reparados con tejidos fetales requirió CCP. El 70% (14/20) de los pacientes no requirió ningún tratamiento para hidrocefalia. Cuatro pacientes (20%) requirieron una derivación ventriculoperitoneal (DVP) y dos adicionales, una tercer ventriculostomía endoscópica (ETV) (10%). El nivel funcional motor neonatal (NFN) fue mejor que el nivel anatómico prenatal (NAP) en 45% (9/20), igual en 50% (10/20) y peor en 5% (1/20).

Conclusiones:

El presente estudio confirma que la cirugía fetal de disrafias abiertas se asocia a un mayor riesgo de parto prematuro y rotura prematura de membranas, pero reduce significativamente la necesidad de tratamiento postnatal de hidrocefalia y mejora la función motora a corto plazo. Nuestros resultados son similares a los publicados en el ensayo aleatorizado MOMS.

Fetal surgery for spina bifida aperta

Spina bifida aperta (SBA) is one of the most common congenital malformations. It can cause severe lifelong physical and neurodevelopmental disabilities. Experimental and clinical studies have shown that the neurological deficits associated with SBA are not simply caused by incomplete neurulation at the level of the lesion. Additional damage is caused by prolonged exposure of the spinal cord and nerves to the intrauterine environment and a suction gradient due to cerebrospinal fluid leakage, leading to progressive downward displacement of the hindbrain. This natural history can be reversed by prenatal repair. A randomised controlled trial demonstrated that mid-gestational maternal-fetal surgery for SBA decreases the need for ventriculoperitoneal shunting and hindbrain herniation at 12 months and improves neurological motor function at 30 months of age. This came at the price of maternal and fetal risks, the most relevant ones being increased prematurity and a persistent uterine corporeal scar. Recently minimally invasive fetal approaches have been introduced clinically yet they lack extensive experimental or clinical trials. We aim to provide clinicians with the essential information necessary to counsel SBA parents as the basis for considering referral of selected patients to expert fetal surgery centres. We review the reported clinical outcomes and discuss recent developments of potentially less invasive fetal SBA approaches.

Partial amniotic carbon dioxide insufflation for fetal surgery

Partial amniotic carbon dioxide insufflation (PACI) involves insufflating the amniotic sac with carbon dioxide (CO₂ ) and, in some cases, draining some of the amniotic fluid. The creation of a gaseous intra-amniotic compartment improves visualization, even in the presence of limited bleeding, and creates the work space required for complex fetoscopic procedures. Clinically, PACI is mostly used to perform fetoscopic myelomeningocele (MMC) repair, enabling a minimally invasive alternative to open fetal surgery. However, evidence of the fetal safety of PACI is limited. Previous animal experiments in sheep demonstrate that PACI induces fetal hypercapnia and acidosis with largely unknown short and longer term implications. In this review, we examine the literature for the physiological effects of intrauterine insufflation pressure, duration, humidity, and the role of maternal hyperventilation on fetal physiology and well-being.

Fetoscopic two-layer closure of open neural tube defects

OBJECTIVE

Fetoscopy for closure of open neural tube defects (NTD) remains controversial, as the use of patches or single-layer closure is not considered to meet the standards of good neurosurgical reconstruction. In this study, we describe a fetoscopic two-layer (myofascial and skin) closure technique for the treatment of NTD in five patients and report the preliminary anatomical outcome at birth.

METHODS

From February to September 2017, five pregnant women with a fetus with a NTD, including three cases of myelomeningocele and two cases of myelocele, were operated on using a fetoscopic two-layer closure technique. In this technique, with the uterus exteriorized and using three 10-Fr ports, the placode is dissected from the surrounding tissue and detethered, removing the cystic tissue. The skin is undermined by blunt dissection and the defect is sutured to the midline in two layers (myofascial and skin) using a running 4/0 resorbable barbed suture.

RESULTS

Median gestational age at the procedure was 24 + 3 (range, 23 + 5 to 27 + 3) weeks. Surgery was successful in all cases, without any intraoperative complications. Median time in surgery was 180 (range, 140-180) min and median time for fetoscopy was 105 (range, 65-120) min. In terms of obstetric complications, three cases of premature rupture of membranes and one case of chorioamnionitis were recorded. Median gestational age at delivery was 34 + 1 (range, 25 + 4 to 37 + 2) weeks and two patients delivered vaginally. The closed defect was watertight with good quality tissue in all cases.

CONCLUSION

Fetoscopic two-layer closure of NTD may improve the quality of the tissue covering the defect, diminishing the need for postnatal surgical revision, and preserving the well-documented beneficial effects of prenatal closure on the neural tissue and hindbrain herniation. However, this technique may not be appropriate for those cases with wide diastasis of the myofascial layer or with a low quantity of available tissue. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Fetal interventional procedures and surgeries: a practical approach

The identification of congenital birth defects and fetal malformations continues to increase during the antenatal period with improved imaging techniques. Understanding of how to treat specific fetal conditions continues to improve outcomes from these treatment modalities. In an effort to further improvement in this field, we provide a review that begins with a brief background of fetal surgery including the history of fetal surgery, ethics surrounding fetal surgery, and considerations of how to treat the fetus during intervention. A synopsis of the most commonly encountered disease processes treated by fetal intervention/surgery including definitions, treatment modalities, and outcomes following fetal intervention/surgery is then provided. Within the sections describing each disease process, methodology is described that has helped with efficiency and success of procedures performed at our institution.

Low-Fidelity Simulator for the Standardized Training of Fetoscopic Meningomyelocele Repair

BACKGROUND

Fetoscopic meningomyelocele repair in a gas-filled uterus is a new technique performed in very few centers. There are few opportunities as well as ethical prohibitions on the initial development and subsequent refinement of innovative fetal surgery techniques in humans, and using an animal model is both very expensive and logistically difficult.

METHOD

We developed a low-fidelity endoscopic fetal surgery simulation using a plastic doll and pieces of chicken breast to simulate a fetal meningomyelocele, and a polyurethane ball to simulate a gas-filled uterus, along with a standard endoscopy system and instruments.

EXPERIENCE

A unique two-port technique with significant differences from the standard laparoscopic surgery procedure was developed and refined through an iterative phase into a standardized methodology, and the simulator was then used to train three other teams to perform standardized fetoscopic meningomyelocele repair.

CONCLUSION

A low-fidelity fetoscopic surgery simulator is a useful tool for developing new fetoscopic operations and for training multidisciplinary fetal surgery teams without the need for extensive use of an animal model. This simulator may be used to further explore the human uterus as a new surgical space for additional fetal surgeries.

Early postnatal bladder function in fetoscopic myelomeningocele repair patients

PURPOSE

Prenatal repair of myelomeningocele (MMC) via hysterotomy has demonstrated neurosurgical and motor benefits, when compared to postnatal repairs. Urologic benefits, however, remain to be seen. The purpose of this study was to review early postnatal bladder function in patients undergoing a novel endoscopic approach for MMC repair using an exteriorized uterus.

METHODS

A prospective urologic assessment of patients undergoing fetoscopic MMC repair and receiving subsequent care at our facility, was performed. Patients were managed and urodynamic studies risk-stratified according to the Centers for Disease Control and Prevention Urologic and Renal Protocol for the Newborn and Young Child with Spina Bifida.

RESULTS

Fetoscopic MMC repair was performed in 14 patients. No patients had hydronephrosis or bladder thickening at birth. Detrusor overactivity was observed in nine (64.3%) patients. Impaired compliance was seen in eight (57.1%) patients. No patients had a detrusor leak point pressure of > 40 cm H2O or evidence of detrusor sphincter dyssynergia. Three (21.4%) patients had vesicoureteral reflux, seven (50.0%) had an open bladder neck, and none had trabeculated bladders.

CONCLUSION

In this early experience with fetoscopic MMC repair, postnatal bladder function does not appear to be any worse than that of previously reported prenatal or postnatal closures.

New directions in fetal surgery for myelomeningocele

The treatment of children with myelomeningocele (MMC) has improved over time, from supportive management to early postnatal closure to prenatal repair of the defect. The Management of Myelomeningocele Study (MOMS) showed that prenatal repair of MMC resulted in improved neurological outcomes compared to postnatal closure. Follow-up studies showed that prenatal repair was, as with any other fetal intervention, associated with higher rates of obstetrical complications. There was no significant difference in urological outcomes. Long-term follow-up of ambulatory status, executive functioning, and urological outcomes is needed to determine the durable effects of fetal MMC repair on mobility, functional independence, and the prevalence of renal insufficiency in patients with MMC who survive to adulthood. The future of fetal MMC repair consists of developing strategies to reduce maternal morbidity and improve infant outcomes. Fetoscopic MMC repair has been suggested as an alternative to open repair that may reduce obstetrical complications and the need for cesarean delivery in subsequent pregnancies. Translational research using mesenchymal stromal cells to augment fetal repair of ovine MMC has shown improvement in motor function.

Fetoscopic patch coverage of experimental myelomenigocele using a two-port access in fetal sheep

PURPOSE

This study aims to assess the feasibility and the effectiveness of a fetoscopic myelomeningocele (MMC) coverage using a sealed inert patch through a two-port access, in the sheep model.

METHODS

Forty-four fetuses underwent surgical creation of a MMC defect at day 75 and were divided into four groups according to the MMC repair technique, performed at day 90. Group 1 remained untreated. Group 2 had an open surgery using suture of the defect. Groups 3 and 4 underwent defect coverage using a Gore®-polytetrafluoroethylene patch secured with surgical adhesive (Bioglue®), with an open approach (group 3) and a fetoscopic one (group 4). Lambs were killed at term, and histological examinations were performed.

RESULTS

Fetoscopic patch coverage was achieved in all the lambs of group 4. All the fetuses of group 2 had a complete closure of the defect whereas only 38% in group 3 and 14% in group 4. Fetal loss rate seems to be lower in group 4 than in groups 2 and 3.

CONCLUSION

Fetoscopic coverage of MMC defect can be performed using a sealed patch through a two-port access, but the patch and glue correction may not be the ideal technique to repair fetal MMC.

Fetal surgery: a critical review

Therapeutic fetal surgical procedures are predicated upon the ability to make an accurate fetal diagnosis. The earliest open fetal surgical procedures were introduced in the 1960s to treat Rh isoimmunisation. They were introduced when it became possible to predict impending fetal demise. Open procedures were abandoned when percutaneous approaches proved superior. The introduction of fetal ultrasound allowed the diagnosis of other congenital anomalies, some being amenable to fetal interventions. Open fetal surgical procedures were initially utilised, with significant maternal morbidity. For some anomalies, percutaneous approaches became favoured. In general, all of these procedures involved significant risks to the mother, to save a baby that was likely to die before or shortly after birth without fetal intervention. Fetal repair for myelomeningocele was a "sea change" in approach. The same maternal risks were taken to improve the quality of life of the affected fetus, not save its life. The completion of the "MOMs Trial" has occasioned a "tsunami" of centres in North America applying this approach. Others are attempting percutaneous repairs, with mixed results. This paper reviews the history of fetal surgery, focusing on the themes of the tension between accurate diagnosis and prognosis and open versus "minimally invasive" approaches.

Advances in fetal surgery

Historically, the gold standard for the treatment of congenital malformations has been planned delivery at tertiary care center with attempted post-natal repair or amelioration of the lesion. Over the last few decades however, rapid advances in imaging and instrumentation technology combined with superior knowledge of fetal pathophysiology has led to the development of novel intrauterine interventions for most common fetal anomalies. Great success has already been seen the treatment of previous devastating anomalies such as myelomeningocele (MMC), congenital cystic malformations of the lung, twin-twin transfusion, and sacrococcygeal teratomas. Although still limited, these innovative techniques have unique potential to improve outcomes in the most devastating fetal anomalies.

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.