Prenatal surgery in fetal myelomeningocele with severe ventriculomegaly

OBJECTIVES

Prenatal myelomeningocele (MMC) repair is performed to decrease risk for treatment of hydrocephalus after birth and to preserve motor function. Some centers may not consider patients candidates for surgery if severe ventriculomegaly is present and there is no expected benefit in decreased risk for hydrocephalus treatment. This study sought to compare postnatal outcomes of fetuses with MMC and severe ventriculomegaly (>15mm) who underwent prenatal repair, with fetuses with severe ventriculomegaly who underwent postnatal repair and fetuses with ventriculomegaly (<15mm) who underwent prenatal repair.

METHODS

This was a retrospective study of fetuses with MMC that underwent prenatal or postnatal repair between 2012 and 2021 at a single institution. The cohort was divided based on preoperative fetal ventricular size into two groups, those with severe ventriculomegaly (≥15 mm) and those without severe ventriculomegaly (<15 mm). Fetal ventricular size was measured by MRI prior to surgery using the standardized approach and the mean of the left and right ventricle was used for analysis. Motor function of lower extremities was assessed at the time of referral by ultrasound and if flexion-extension movements of the ankle were seen, it was considered as preserved S1 motor function. Postnatal outcomes including motor function of lower extremities assessed at birth and need for diversion procedure for hydrocephalus treatment during the first year of life were collected and compared between groups. Data was presented as median and range or number and percentages as appropriate. P value >0.05 was considered statistically significant. Multivariate regression analysis was used to adjust for potential confounders.

RESULTS

154 patients were included in this study: 145 patients underwent fetal surgery (101 fetoscopic and 44 open hysterotomy) and 9 patients with severe ventriculomegaly underwent postnatal repair. Among the 145 patients who underwent fetal surgery, 22 presented with severe ventriculomegaly. Prenatally repaired fetuses with severe ventriculomegaly at referral were at a significantly higher need for hydrocephalus treatment by 12 months than those without severe ventriculomegaly (62% vs. 29%, p<0.01). However, motor function assessment at birth was similar between both prenatally repaired groups (OR=0.92, 95% CI [0.33-2.59], p=0.88) adjusted for the anatomical level of the lesion. The prenatally repaired group with severe ventriculomegaly had better preserved motor function levels at birth compared to the postnatal repair group with severe ventriculomegaly (L3 with 11.1% S1 motor function; p=<0.01 and p=<0.01). Prenatally repaired patients with severe ventriculomegaly had an 18.9 times chance of having an intact motor function at birth [95% CI (1.2 - 290.1)] adjusted for ethnicity, presence of clubfeet at referral, and gestational age at delivery compared to postnatal repair. There was not a significant difference in the need for hydrocephalus treatment in the first year of life between prenatal and postnatal repair of patients with severe ventriculomegaly (61.9% vs 87.5%, p=0.18).

CONCLUSIONS

Although fetuses with MMC and severe ventriculomegaly do not seem to benefit from fetal surgery in terms of postnatal hydrocephalus treatment, they benefit from increased chance of preserved motor function at birth. Results from this study highlight the benefits of having prenatal MMC repair for cases with severe ventriculomegaly at referral to preserve motor function. This article is protected by copyright. All rights reserved.

Fetal growth changes and prediction of selective fetal growth restriction following fetoscopic laser coagulation in twin-to-twin transfusion syndrome

OBJECTIVE

To investigate fetal growth changes and predictive factors for selective fetal growth restriction (sFGR) in patients with twin-to-twin transfusion syndrome (TTTS) after fetoscopic laser coagulation (FLC).

METHODS

This retrospective study included twin-pregnant women with fetal TTTS who underwent FLC at our institution between 2011 and 2020. Twin pairs who survived at least 28 days after FLC and at least 28 days after birth were included. A paired t-test was used to compare the mean discordance between the estimated fetal weights at the FLC and the birth weights. The predictive factors for sFGR after FLC were evaluated using univariate and multivariate logistic regression analyses.

RESULTS

A total of 119 eligible pairs of patients who underwent FLC were analyzed. The weight percentile at birth significantly decreased after FLC in the recipients (53.7±30.4 percentile vs. 43.7±28.0 percentile; P<0.001), but increased in the donors (11.5±17.1 percentile vs. 20.7±22.8 percentile; P<0.001). Additionally, the mean weight discordance of twin pairs significantly decreased after FLC (23.9%±12.7% vs. 17.3%±15.7%; P<0.001). After FLC, Quintero stage ≥3, pre-FLC sFGR, abnormal cord insertion, and post-FLC abnormal umbilical artery Doppler (UAD) were all significantly higher in the sFGR group than the non-sFGR group. The prediction model using these variables indicated that the area under the receiver operating characteristic curve was 0.898.

CONCLUSION

The recipient weight percentile decreased, whereas donor growth increased, resulting in reduced weight discordance after FLC. The Quintero stage, pre-FLC sFGR, and post-FLC abnormal UAD were useful predictors of sFGR after FLC in TTTS.

Feasibility of fetoscopic laser coagulation in triplet pregnancy

OBJECTIVE

To report the experiences of triplet pregnancies complicated by twin-to-twin transfusion syndrome (TTTS) treated with fetoscopic laser coagulation at a single center.

METHODS

Herein, we conducted a retrospective analysis to investigate the management and perinatal outcomes of triplet pregnancies with TTTS treated at a single institution between 2017 and 2022.

RESULTS

Seven of the 98 triplet pregnancies (7.1%) encountered were complicated by TTTS, and all were dichorionic triamniotic triplets. Of the seven triplet pregnancies complicated by TTTS, four were treated with fetoscopic laser coagulation at our center, at a median gestational age of 20 weeks. No procedure-related complications or maternal complications were observed. The survival rate was higher and perinatal outcomes were better in fetoscopic laser coagulation cases than in other management cases. Four donor and four recipient triplets survived, with a median gestational age of 33 weeks at delivery. Although there were no cases of poor neonatal outcomes, one case was diagnosed with white matter injury, suspected to be hypoxic-ischemic encephalopathy on postnatal investigation.

CONCLUSION

Fetoscopic laser coagulation is a feasible treatment option for triplet TTTS, provided the attending specialists have extensive experience with this technique.

The effects of cold, dry and heated, humidified amniotic insufflation on sheep fetal membranes

INTRODUCTION

Uterine distension with pressurised carbon dioxide (CO₂) (amniotic insufflation) is used clinically to improve visibility during keyhole fetal surgery. However, there are concerns that amniotic insufflation with unconditioned (cold, dry) CO₂ damages the fetal membranes which leads to post-operative preterm prelabour rupture of membranes (iatrogenic PPROM). We assessed whether heating and humidifying the insufflated CO₂ could reduce fetal membrane damage in sheep.

METHODS

Thirteen pregnant ewes at 103-106 days gestation underwent amniotic insufflation with cold, dry (22 °C, 0-5% humidity, n = 6) or heated, humidified (40 °C, 95-100% humidity, n = 7) CO₂ at 15 mmHg for 180 min. Twelve non-insufflated amniotic sacs acted as controls. Fetal membrane sections were collected after insufflation and analysed for molecular and histological markers of cell damage (caspase 3 and high mobility group box 1 [HMGB1]), inflammation (interleukin 1-alpha [IL1-alpha], IL8 and vascular cell adhesion molecule [VCAM]) and collagen weakening (matrix metalloprotease 9 [MMP9]).

RESULTS

Exposure to cold, dry CO₂ increased mRNA levels of caspase 3, HMGB1, IL1-alpha, IL8, VCAM and MMP9 and increased amniotic epithelial caspase 3 and HMGB1 cell counts relative to controls. Exposure to heated, humidified CO₂ also increased IL8 levels relative to controls however, HMGB1, IL1-alpha and VCAM mRNA levels and amniotic epithelial HMGB1 cell counts were significantly lower than the cold, dry group.

DISCUSSION

Amniotic insufflation with cold, dry CO₂ damaged the amniotic epithelium and induced fetal membrane inflammation. Heated, humidified insufflation partially mitigated this damage and inflammation in sheep and may prove an important step in reducing the risk of iatrogenic PPROM following keyhole fetal surgery.

Intrauterine fetoscopic closure of myelomeningocele: Clinical case and literature review

OBJECTIVE

Spina bifida (SB) is a congenital birth defect defined as a failure of the neural tube formation during the embryonic development phase. Fetoscopic repair of SB is a novel treatment technique that allows to close spinal defect early and prevent potential neurological and psychomotor complications.

CASE REPORT

We present a case report of a 32-year-old-multigravida whose fetus was diagnosed with lumbosacral myelomeningocele at 23rd week. Fetoscopic closure of MMC was performed at 26 weeks. At 32 weeks, due to premature amniorrhexis and placental abruption, an emergency C-section was performed. Newborn's psychomotor development was within normal limits.

CONCLUSION

Although intrauterine treatment has an increased risk of premature labor, placental abruption, prenatal closure is associated with improved postnatal psychomotor development. Prenatal surgery decreases the risk of Arnold-Chiari II malformation development and walking disability. Fetoscopic closure of SB is becoming a choice for treatment with beneficial outcomes for mother and fetus.

Fetal heart rate monitoring during fetoscopic repair of open spinal neural tube defects: a single-centre observational cohort study

BACKGROUND

During fetal surgery, the haemodynamic stability of the fetus depends on the haemodynamic stability of the mother. The primary objective of this study was to assess changes in fetal heart rate (FHR) throughout the different stages of surgery. The secondary objective was to assess potential changes in maternal physiological parameters and their association with FHR.

METHODS

This was a single-center observational cohort study conducted between 2015 and 2019 in 26 women undergoing intra-uterine fetoscopic repair of open spina bifida. The primary outcome was FHR. Maternal physiologic parameters were measured at the beginning, during and after surgery. The linear mixed-effects model fitted by maximum likelihood was used to assess changes in each variable at specific times throughout the surgery, and the repeated measures correlation coefficient was used to study the association between FHR and maternal physiological parameters.

RESULTS

One (3.8%) case of fetal bradycardia (FHR <110 beats per minute) required the administration of intramuscular atropine. No other significant FHR changes were observed during surgery. Maternal oesophageal temperature (P <0.001), lactate levels (P=0.002), and mean arterial pressure (P=0.016) changed significantly during surgery, although none of these changes was clinically relevant. The FHR showed a significant association with maternal carbon dioxide tension (r=0.285, 95% CI 0.001 to 0.526) and maternal heart rate (r=0.302, 95% CI 0.025 to 0.535).

CONCLUSION

The FHR remained stable during intra-uterine fetoscopic repair of open spina bifida. Maternal carbon dioxide tension and heart rate may have a mild influence on FHR.

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.

Development of a Core outcome set for fetal Myelomeningocele (COSMiC): study protocol

BACKGROUND

Open spina bifida (OSB) is one of the most common congenital central nervous system defects and leads to long-term physical and cognitive disabilities. Open fetal surgery for OSB improves neurological outcomes and reduces the need for ventriculoperitoneal shunting, compared to postnatal surgery, but is associated with a significant risk of prematurity and maternal morbidity. Fetoscopic surgery comes with less maternal morbidity, yet the question remains whether the procedure is neuroprotective and reduces prematurity. Comparison of outcomes between different treatment options is challenging due to inconsistent outcome reporting. We aim to develop and disseminate a core outcome set (COS) for fetal OSB, to ensure that outcomes relevant to all stakeholders are collected and reported in a standardised fashion in future studies.

METHODS

The COS will be developed using a validated Delphi methodology. A systematic literature review will be performed to identify outcomes previously reported for prenatally diagnosed OSB. We will assess maternal (primary and subsequent pregnancies), fetal, neonatal and childhood outcomes until adolescence. In a second phase, we will conduct semi-structured interviews with stakeholders, to ensure representation of additional relevant outcomes that may not have been reported in the literature. We will include patients and parents, as well as health professionals involved in the care of these pregnancies and children (fetal medicine specialists, fetal surgeons, neonatologists/paediatricians and allied health). Subsequently, an international group of key stakeholders will rate the importance of the identified outcomes using three sequential online rounds of a modified Delphi Survey. Final agreement on outcomes to be included in the COS, their definition and measurement will be achieved through a face-to-face consensus meeting with all stakeholder groups. Dissemination of the final COS will be ensured through different media and relevant societies.

DISCUSSION

Development and implementation of a COS for fetal OSB will ensure consistent outcome reporting in future clinical trials, systematic reviews and clinical practice guidelines. This will lead to higher quality research, better evidence-based clinical practice and ultimately improved maternal, fetal and long-term childhood outcomes.

TRIAL REGISTRATION

International Prospective Register of Systematic Reviews (PROSPERO) CRD42018104880 . Registered on December 5, 2018. Core Outcome Measures in Effectiveness Trials (COMET): 1187.

Error traps in fetal surgery

The growth of the field of fetal surgery over the last two decades driven by new indications and data from prospective randomized trials supporting prenatal intervention has resulted in techniques protocols and methodologies that have gained confidence by insuring good outcomes. Error traps are methods or techniques that usually work well in most of the cases, but which are apt to fail under certain specific circumstances. The very confidence the surgeon develops in these techniques or methodologies makes them a trap for the unwary surgeon. The purpose of this article is to discuss common error traps in fetal interventions, including ultrasound guided procedures, fetoscopic surgery, open fetal surgery and EXIT procedures. Awareness of these error traps and approaches to avoid them may enhance fetal surgical outcomes and reduce complications rates.

Pediatric medical device development by surgeons via capstone engineering design programs

BACKGROUND

There is a need for pediatric medical devices that accommodate the unique physiology and anatomy of pediatric patients that is increasingly receiving more attention. However, there is limited literature on the programs within children's hospitals and academia that can support pediatric device development. We describe our experience with pediatric device design utilizing collaborations between a children's hospital and two engineering schools.

METHODS

Utilizing the academic year as a timeline, unmet pediatric device needs were identified by surgical faculty and matched with an engineering mentor and a team of students within the Capstone Engineering Design programs at two universities. The final prototypes were showcased at the end of the academic year and if appropriate, provisional patent applications were filed.

RESULTS

All twelve teams successfully developed device prototypes, and five teams obtained provisional patents. The prototypes that obtained provisional patents included a non-operative ureteral stent removal system, an evacuation device for small kidney stone fragments, a mechanical leech, an anchoring system of the chorio-amniotic membranes during fetal surgery, and a fetal oxygenation monitor during fetoscopic procedures.

CONCLUSIONS

Capstone Engineering Design programs in partnership with surgical faculty at children's hospitals can play an effective role in the prototype development of novel pediatric medical devices.

LEVELS OF EVIDENCE

N/A - No clinical subjects or human testing was performed.

Minimally Invasive Fetal Surgery

Fetal surgery corrects severe congenital anomalies in utero to prevent their severe consequences on fetal development. The significant risk of open fetal operations to the pregnant mother has driven innovation toward minimally invasive procedures that decrease the risks inherent to hysterotomy. In this article, we discuss the basic principles of minimally invasive fetal surgery, the general history of its development, specific conditions and procedures used to treat them, and the future of the field.