Validation of an instrument prototype for the minimally invasive fetal surgery of gastroschisis in an inanimate model.

INTRODUCTION

Complex gastroschisis requires timely intervention to protect the fetal intestine from inflammation and strangulation and avoid viscero-abdominal disproportion (VAD). Earlier results in ovine models for the fetoscopic management of gastroschisis highlight the benefits of minimally invasive coverage; yet specialized instruments appear to be needed for better procedural execution. The aim of this study was to create and validate a first prototype instrument for the prenatal covering of the protruded intestines in gastroschisis.

METHODS

A 7-mm diameter fetoscopic instrument was designed to hold and deploy a protective bag over the gastroschisis defect after suture fixation to the fetus. An inanimate model was used to evaluate the instrument's usability and effectiveness: Eleven participants performed bag placement and suturing both with and without the prototype, enabling a comparative assessment of procedural performance. Statistical analysis was conducted to evaluate the duration of the procedure, while product deficiencies were qualitatively assessed using a Likert-scale questionnaire. The overall usability of the prototype was further evaluated using the system usability scale (SUS).

RESULTS

The prototype consistently enhanced bag handling and positioning. Median procedural time slightly increased from 118.5 to 120.5 s with the prototype (p = 0.98), without affecting the overall procedural efficiency. Usability assessments using the SUS (median score: 67.95) and the Likert scale indicated a generally favorable response. Importantly, usability ratings were consistent regardless of participants' prior experience in minimally invasive surgery (p = 0.43), underscoring the intuitive design and ease of adoption of the prototype.

CONCLUSION

Despite a minor increase in procedural time, the prototype enabled secure bag placement and demonstrated moderate usability across all participants. This is particularly relevant for fetal procedures requiring amnioinfusion, as opposed to partial amniotic carbon dioxide insufflation (PACI) used in the inanimate model. However, further mechanical refinement is warranted to enhance performance and address usability concerns.