Evaluation of Three Sources of Validity Evidence for a Synthetic Thoracoscopic Esophageal Atresia/Tracheoesophageal Fistula Repair Simulator.

PURPOSE: Thoracoscopic esophageal atresia (EA)/tracheoesophageal fistula (TEF) repair is technically challenging. We have previously reported our experiences with a high-fidelity hybrid model for simulation-based educational instruction in thoracoscopic EA/TEF, including the high cost of the tissue for these models. The purposes of this study were (1) to create a low-cost synthetic tissue EA/TEF repair simulation model and (2) to evaluate the content validity of the synthetic tissue simulator.

MATERIALS AND

METHODS

Review of the literature and computed tomography images were used to create computer-aided drawings (CAD) for a synthetic, size-appropriate EA/TEF tissue insert. The inverse of the CAD image was then printed in six different sections to create a mold that could be filled with platinum-cured silicone. The silicone EA/TEF insert was then placed in a previously described neonatal thorax and covered with synthetic skin. Following institutional review board-exempt determination, 47 participants performed some or all of a simulated thoracoscopic EA/TEF during two separate international meetings (International Pediatric Endosurgery Group [IPEG] and World Federation of Associations of Pediatric Surgeons [WOFAPS]). Participants were identified as "experts," having 6-50 self-reported thoracoscopic EA/TEF repairs, and "novice," having 0-5 self-reported thoracoscopic EA/TEF repairs. Participants completed a self-report, six-domain, 24-item instrument consisting of 23 5-point rating scales and one 4-point Global Rating Scale. Validity evidence relevant to test content and response processes was evaluated using the many-facet Rasch model, and evidence of internal structure (interitem consistency) was estimated using Cronbach's alpha.

RESULTS

A review of the participants' ratings indicates there were no overall differences across sites (IPEG versus WOFAPS, P=.84) or experience (expert versus novice, P=.17). The highest observed averages were 4.4 (Value of Simulator as a Training Tool), 4.3 (Physical Attributes-chest circumference, chest depth, and intercostal space), and 4.3 (Realism of Experience-fistula location). The lowest observed averages were 3.5 (Ability to Perform-closure of fistula), 3.7 (Ability to Perform-acquisition target trocar sites), 3.8 (Physical Attributes-landmark visualization), 3.8 (Ability to Perform-anastomosis and dissection of upper pouch), and 3.9 (Realism of Materials-skin). The Global Rating Scale was 2.9, coinciding with a response of "this simulator can be considered for use in neonatal TEF repair training, but could be improved slightly." Material costs for the synthetic EA/TEF inserts were less than $2 U.S. per insert.

CONCLUSIONS

We have successfully created a low-cost synthetic EA/TEF tissue insert for use in a neonatal thoracoscopic EA/TEF repair simulator. Analysis of the participants' ratings of the synthetic EA/TEF simulation model indicates that it has value and can be used to train pediatric surgeons, especially those early in their learning curve, to begin to perform a thoracoscopic EA/TEF repair. Areas for model improvement were identified, and these areas will be the focus for future modifications to the synthetic EA/TEF repair simulator.