Validation of a high-fidelity training model for fetoscopic spina bifida surgery

Luc Joyeux,Sebastien Ourselin,Emmanuel Vander Poorten,Geertje Callewaert,Jan Deprest,Paolo De Coppi,Rebecca S Degliuomini,Frank Van Calenbergh,Mary P Eastwood,Talita Micheletti,Felix R De Bie,Gert Van Den Bergh,Simen Vergote,Allan Javaux

doi:10.1038/s41598-021-85607-6

Abstract

Open fetal surgery for spina bifida (SB) is safe and effective yet invasive. The growing interest in fetoscopic SB repair (fSB-repair) prompts the need for appropriate training. We aimed to develop and validate a high-fidelity training model for fSB-repair. fSB-repair was simulated in the abdominal cavity and on the stomach of adult rabbits. Laparoscopic fetal surgeons served either as novices (n = 2) or experts (n = 3) based on their experience. Technical performance was evaluated using competency Cumulative Sum (CUSUM) analysis and the group splitting method. Main outcome measure for CUSUM competency was a composite binary outcome for surgical success, i.e. watertight repair, operation time ≤ 180 min and Objective-Structured-Assessment-of-Technical-Skills (OSATS) score ≥ 18/25. Construct validity was first confirmed since competency levels of novices and experts during their six first cases using both methods were significantly different. Criterion validity was also established as 33 consecutive procedures were needed for novices to reach competency using learning curve CUSUM, which is a number comparable to that of clinical fSB-repair. Finally, we surveyed expert fetal surgeons worldwide to assess face and content validity. Respondents (26/49; 53%) confirmed it with ≥ 71% of scores for overall realism ≥ 4/7 and usefulness ≥ 3/5. We propose to use our high-fidelity model to determine and shorten the learning curve of laparoscopic fetal surgeons and retain operative skills.

Highlights

Open fetal surgery for spina bifida (SB) is safe and effective yet invasive
We report on the development and validation of a high-fidelity training model for fSBA-repair in a living and breathing rabbit and its use to determine the number of cases needed for a laparoscopic fetal surgeon to achieve competency
For the construct and criterion validity, we performed C- and learning curve (LC)-Cumulative Sum (CUSUM) analysis using an algorithm that we developed in MATLAB software (Mathworks, Natick, MA, USA) based on and verified with the model of Biau et al.[7]

Summary

Introduction

Open fetal surgery for spina bifida (SB) is safe and effective yet invasive. The growing interest in fetoscopic SB repair (fSB-repair) prompts the need for appropriate training. A valid training model would reduce the LC and avoid or limit training on clinical subjects[8,9,10,11] Such simulator would accelerate the safe and ethically acceptable transition from the open approach to fetoscopy or its implementation in a center without experience based on the available case volumes. We report on the development and validation of a high-fidelity training model for fSBA-repair in a living and breathing rabbit and its use to determine the number of cases needed for a laparoscopic fetal surgeon to achieve competency

Objectives

Results

Conclusion