Thiel-embalmed porcine placenta: A valid and reusable microsurgical practice model.

Background: Simulation models are increasingly important for skill acquisition during microsurgery training. Prosthetics, living and non-living biological models have been proposed in the literature in the optics of recreating real-life scenarios in a controlled environment. This study aims to validate and prove the reusability of a novel non-living biological model: the porcine placenta.

Methods: A prospective comparative study was carried out to assess face and content validities of the proposed model, as well as the reusability and quality of the Thiel-embalming method. Participants were asked answer a questionnaire for each anastomosis they performed on porcine placental vessels of ≤2mm (small) and 2-4mm (large). Scores were classified according to different subgroups, either small or large vessels and first or second sessions. Reliability analysis of the questionnaire was carried out using Cronbach's α, to ensure an α>0.7. Median scores for each question were analyzed using boxplots and compared amongst each subgroup using a non-parametric independent Mann-Whitney U test.

Results: With nine participants, the Cronbach's α for each category of question was 0.867, 0.778, 0.720 and 0.593. Statistical differences were found between responses of small and large vessels on 5/10 questions, where large vessels reported higher validity. No statistical differences were found between scores of the first and second sessions.

Conclusion: By evaluating face and content validity, the Thiel-embalmed porcine placenta has proven its suitability as a microsurgery model, especially for vessels of larger caliber. Qualities that distinguish this model is its reliable reusability, its low cost-effectiveness, and its ethical acceptability.