Development of a simulator for training of fetoscopic myelomeningocele surgery

To develop a realistic simulation model for laparotomy‐assisted fetoscopic spina bifida aperta (SBa) surgery, to be used for training purposes and preoperative planning.


What are the novel findings?
� This is the first model for fetoscopic MMC repair that has the option to adjust both the characteristics of uterus and spinal defect. Furthermore, the spinal defect is developed to provide the opportunity to train all essential components of the neurosurgical part of this intervention.
� This low-cost, yet high-fidelity, simulation model could be useful in shortening learning curves, and after further refinement for preoperative planning.
Spina bifida aperta (SBa) is a severe condition, with significant neurological impairment due to local neural damage in combination with central brain abnormalities (Arnold-Chiari II malformation and hydrocephalus amongst others). Fetal surgery can ameliorate postnatal outcomes, but the current gold standard of an 'open' (i.e., requiring maternal laparo-and hysterotomy) procedure comes with substantial maternal risks. 1 The latter has prompted multiple centers to develop a fetoscopic approach. However, these are complex procedures and require a substantial learning curve. 2 Simulation training provides an excellent opportunity to gather sufficient exposure, and thus has become an essential part of training programs for junior surgeons.
Ideally, a simulation model combines both purposes of training and surgical preparation and is realistic, case-specific, low cost, reusable, and of nonanimal origin. This study aimed to create such a training simulator, based on the laparotomy-assisted fetoscopic technique described by Belfort et al. 3 The steps for surgical repair of the SBa defect are: (1)  Additionally, three yes-no questions evaluated the expert opinion on the usefulness of the simulator for training and for case-specific preparation.
The participants were able to perform all tasks on the simulator and all aspects of the simulator were rated between "close to realistic" and "realistic". The content validity was rated through the realism of the performed tasks, which were also rated between "close to realistic" and "realistic". The surgeons all agreed that the simulator is suitable for use as a training model for fetoscopic repair of SBa as well as for case-specific surgical preparation based on the tissues and tissue handlings. They agreed that the simulator can improve cooperation between obstetrician and neurosurgeon.
In this paper, we describe the development and evaluation of a Another simulation model that is commercially available has a realistic appearance of the maternal abdomen and uterine wall; however, the fetal model is basic and has no SBa. 6 Another important consideration is that this simulation model is relatively expensive, especially when compared to the model that we developed.
At the moment, there are two different animal models for fetoscopic SBa surgery. One was created to evaluate a running single suture technique using two-port access. This surgical model consisted of lambs with surgically created SBa defects. 7 The other was developed specifically for the purpose of training the fetoscopic approach. In this leporine model, the abdominal cavity mimics the amniotic cavity and defect repair is practiced on the gastric fundus. 8 While both models are high in fidelity, these uterine analogues are either thinner (sheep) or of a different structure (rabbit abdominal wall) than a gravid uterus and thus less realistic. In addition, animal models are logistically difficult to use repeatedly, are expensive, and come with ethical constraints. Our model can be used repeatedly without the logistical and ethical constraints associated with animal models.
There are several possible applications of our simulator in dedicated fetal surgery centers apart from it is possible role in shortening extensive learning curves. 2 For instance, as it is a desktop SPOOR ET AL.
-357 model with limited preparation time, this simulator provides an easily accessible opportunity for more experienced surgeons to maintain certain surgical skills, and also to rehearse or recreate unusual operative complications. In addition, because the simulator contains a uterus and a fetus, it also provides an opportunity for multidisciplinary practice. The simulator may also provide a standardized environment in which technical improvements and alterations can be evaluated. For example, a 2-port technique can be compared with a 3-port technique in identical settings. But also, adaptations such as the use of a dural patch, as well as instrument or entry port modifications, could be tested using this simulation model. One could also recreate other neural tube defects on the insert, such as myeloschisis, but adaptations of the fetal model for other fetoscopic interventions, such as gastroschisis, are also relatively easy.
Case-specific modifications require processing of ultrasound imaging or MRI, and this can thus far not be done automatically. The materials used in this model negatively influenced the spatial resolution of the ultrasound imaging, and thus, it is currently not possible to fully practice the ultrasound guided parts of the procedure (i.e., determination of fetal position, trocar placement, and fixation).
Regarding the limitations of this study, the evaluation experiment was based on subjective feedback from a small group of participants.
However, we feel that this was sufficient to demonstrate the realistic appearance of the model.
In summary, we describe the development of a low-cost, realistic training simulator for fetal surgery of SBa for which the fetal and maternal anatomy, the intended surgical procedure, design, and production requirements were investigated. Future developments should focus on continuing the refinement of its components, validation as a training device, and evaluation of its role in surgical planning.