WOFAPS 2025 8th World Congress of Pediatric Surgery

Jogender, Shilpa Sharma, Varun Arora, M Jassal, AK Agrawal

All India Institute of Medical Sciences (AIIMS) New Delhi) Indian Institute of Technology (IIT) Delhi,

Aim: A high-fidelity surgical simulator for thoracoscopic tracheoesophageal fistula(TEF) surgery training was developed.

Method: The model was made using multiple polymers like polyurethane, PEG and PVA. Phase segregation via solvent evaporation/nonsolvent precipitation/thermal treatment (40–80°C, 30 min–4 h) was done. 0–10 wt.% TiO₂/collagen fibers were added to modulate tear strength (0.5–11.6 MPa) and elastic recovery (72–97%). Fabrication was done with patient-specific molds (DICOM-derived) with laparoscopic ports (3 mm) and hinged ribcage. The model was put to practice in 4 workshops and conferences. 7 candidates did home practice. 25 subjects who practiced on the model were given a feedback questionnaire. 25 pediatric surgeons answered a questionnaire with ratings including: Quality of esophageal suturing (elasticity), Fidelity of the esophagus, Tissue feedback (tensile strength) of the esophagus, Assessment of procedure performance, Tissue feedback of the Azygous vein and design of the model. Feedback was taken for remarks for shortcomings and needed improvements and whether the model will help improve surgical skills for critical operations.

RESULTS: Mechanical properties were composition (15–19 wt.% HWP5 + 5–10 wt.% LWP1), Tensile strength: 7.48 ± 0.62 MPa (vs. literature neonatal esophagus: 1–5 MPa, p < 0.001) and Elastic modulus: 1.58 ± 1.56 MPa (vs. native tissue: 0.8–2.2 MPa, p = 0.12).The suturability was Grade 5 (excellent, comparable to cadavers p > 0.05).TiO₂ nanoparticles (1 wt.%) reduced LWP leaching by 3–5% (p = 0.03).Surgical validation (Type-C TEF repair):Collapsibility/elasticity ratings: 4–5/5 (vs. commercial models: 2–3/5, p < 0.01). Anisotropy: Hysteresis <15% at 50% strain (matching native tissue, p = 0.08). The average ratings by the surgeons out of 5 were as follows: Quality of Suturing (Esophagus): 4.4 ;Fidelity of Esophagus: 4.0 ;Tissue Feedback (Esophagus): 3.8; Assessment of Procedure Performance: 4.6; Tissue Feedback (Azygous vein): 4.2 ;Design of the Model: 4.8 . Additionally, 100% of the respondents who answered the question believe that this model will help in improving surgical skills needed for critical operations.

CONCLUSION: The device offers a biomimetic, tunable platform for pediatric training, validated against native tissue metrics (p < 0.05 for key parameters). The model was well accepted by the surgeons.