High-Fidelity Low-Cost Synthetic Training Model for Fetoscopic Spina Bifida Repair

BACKGROUND: Fetoscopic Spina Bifida repair (fSB-repair) is increasingly being practiced, but limited skill acquisition poses a barrier to widespread adoption. Extensive training in relevant models, including both ex- and in-vivo models may help. To address this, a synthetic training model that is affordable, realistic and allows skill analysis would be useful.OBJECTIVE: To create a high-fidelity model for training the essential neurosurgical steps of fetoscopic spina bifida repair using synthetic materials. Additionally, we aimed to obtain a cheap and easily reproducible model.STUDY DESIGN: We developed a three-layered silicon-based model resembling the anatomical layers of a typical myelomeningocele lesion. It allows for filling the cyst with fluid and conducting a water tightness test post-repair. A compliant silicon ball mimics the uterine cavity, and is fixed to a solid 3D printed base. The fetal back with the lesion (single-use) is placed inside the uterine ball, which is reusable and repairable to allow practicing port insertion and fixation multiple times. Following cannula insertion, the uterus is insufflated, and clinical fetoscopic, robotic or prototype instruments can be used. Three skilled endoscopic surgeons each did six simulated fetoscopic repairs following the surgical steps of an open repair. The primary outcome was surgical success, based on water tightness of the repair, operation time &lt;180 minutes and an Objective-Structured-Assessment-of-Technical-Skills (OSATS)-score of ≥ 18/25. Skill retention was measured using a competence commulative sum (C-CUSUM) analysis on composite binary outcome for surgical success. Secondary outcomes were cost and fabrication time of the model.RESULTS: We made a model for simulating spina bifida repair neurosurgical steps with anatomical details, port insertion, placode release and descent, undermining of skin and muscular layer, and endoscopic suturing. The model is made with reusable 3D-printed molds with easily accessible materials. The one-time startup cost was 211€, and each single-use simulated MMC-lesion costs 9.5€ in materials and 50 min working hours. Two skilled endoscopic surgeons performed six simulated three-port fetoscopic repairs, while a third used a Da-Vinci surgical robot. Operation times decreased over 30% from the first to last trial. Six experiments per surgeon did not show an obvious OSATS-score improvement. C-CUSUM analysis confirmed competency for each surgeon.CONCLUSION: This high-fidelity low-cost spina bifida model allows simulated dissection and closure of a myelomeningocele lesion.</p

Reducing invasiveness of fetal spina bifida repair - Towards novel techniques.

Though not a lethal condition, the prenatal correction of open spina bifida aperta (SBA) was proposed, because it could halt its in utero progressive nature hence prevent severe postnatal morbidity. In 1995, fetal surgery was proven safe and effective in the fetal lamb model. After initial exploratory clinical trials demonstrating feasibility and safety, in 2011 the randomized clinical trial (Management Of Myelomeningocele Study, MOMS) demonstrated the efficacy of midgestational anatomical SBA fetal repair. Prenatal, rather than postnatal repair, reduces the brain shunt rate at 12 months, increases the likelihood of walking at 30 months and reduces intermittent catheterization rates at school age. This comes at the expense of an increased risk for prematurity and maternal morbidity, both in the index and subsequent pregnancies. The hysterotomy, through which the procedure is done, is responsible in subsequent pregnancies for a 10% risk of rupture with concomitant fetal death in nearly one in two cases. To reduce these side effects, the concept of fetoscopic SBA repair was reintroduced. Though theoretically attractive, we thought we could not embrace it clinically without proper preclinical validation. We first conducted a systematic review in chapter 4 showing that in fetal lambs, a two-layer SBA repair through hysterotomy is safe and effective. However, functional assessment methods were lacking in this model, and the lesion was induced in different ways and used to study either the effects on the spinal cord or the brain. In chapter 5, we showed that motor evoked potentials recording and analysis in neonatal lambs is feasible and can reliably assess neuromotor function. Furthermore in chapter 6 we demonstrated that prenatal myelotomy replicates the full phenotype of a lumbar myeloschisis. We eventually reported in chapter 7 that a layered watertight compared to non-watertight fetal repair achieves in this model more neuroprotection and better brain and spinal cord neuromorphology. In preparation for clinical implementation, we investigated whether such watertight repair could be done by fetoscopy. In chapter 8 a systematic review of the clinical literature indicated that, in its early experience, fetoscopy was not safe yet neuroprotective. One factor explaining lack of safety was the use of CO2 for amnio-insufflation, which in lambs induces fetal acidosis and hypercapnia. We therefore assessed the feasibility and safety of fetoscopic repair using humidified and heated CO2. In chapter 9, we showed this was feasible and safe using an anesthetic technique that maintains maternal physiological homeostasis. In parallel, we performed in chapter 10 a meta-analysis to determine the learning curve of open and fetoscopic approaches and assess the need for training. Surgeons reach competency after 35 cases for standard hysterotomy. For percutaneous fetoscopy, competency is not reached prior to 56 cases. We then designed a five-step training program for fetoscopic SBA repair on a pelvic trainer, rabbit cadavers, a high-fidelity model in rabbits, fetal lambs and finally human fetuses. We trained three fetal surgeons and showed in chapter 11 that ≥33 procedures may be necessary to reach competency. Eventually, our fetal team successfully performed three human fetoscopic SBA repair and propose to implement this training program more broadly.status: publishe

Etiopathogènie et traitements de quatre malformations congénitales curables en anténatal

DIJON-BU Médecine Pharmacie (212312103) / SudocSudocFranceF

Maternal-fetal surgery for myelomeningocele: some thoughts on ethical, legal, and psychological issues in a Western European situation

The results of the Management of Myelomeningocele Study (MOMS) randomized controlled trial have demonstrated that maternal-fetal surgery (MFS) for myelomeningocele (MMC) compared to postnatal MMC repair has clear neurological benefits for the child at 12 and 30 months of age. Level I evidence nevertheless does not provide answers to many questions in this delicate field. Since the beginning of 2012, our fetal center has been offering MFS for spina bifida aperta (SBA) to patients from different European and non-European countries, in a societal context where termination of pregnancy is the option chosen by most patients when being informed of this diagnosis.status: publishe

Implementation of Robotic Surgery in a Pediatric Hospital: Lessons Learned

Since the late 1980s, minimally invasive surgery (MIS) has been one of the fastest growing approaches for surgical procedures. However, its development has reached a plateau. One of the reasons is the difficulty to operate on more complex cases, such as neonatal procedures. Some experts report outstanding outcomes for complex operations, but not all surgeons may be able to achieve the same results. Is robotic surgery (RS) a solution? Methods: To answer this question, we reviewed the current indications of RS for the pediatric population and the steps needed to incorporate the robotic surgical system in a children's hospital. We reported our experience and presented our first results and the encountered problems. Results: After a year and a half of experience with RS, several lessons were learned: (1) the current robotic surgical system cannot yet be considered a replacement to conventional MIS, (2) docking is less time consuming than expected, (3) postoperative pain is significantly decreased, (4) the absence of haptic feedback is still a matter of concern, and (5) costs can be afforded by sharing the RS with adult surgeons. Conclusions: Based on our experience, the advantages seem to outweigh the drawbacks as it encourages team building and increases overall comfort for the surgeon. However, the current literature fails to prove that RS gives better results for pediatric patients. New advances in technology will probably help to overcome the encountered difficulties and the high costs.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

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.status: publishe

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.status: publishe

Safety and efficacy of fetal surgery techniques to close a spina bifida defect in the fetal lamb model: a systematic review

To determine the safety and efficacy of different neurosurgical techniques for closure of spina bifida (SB) in the fetal lamb model.status: publishe