Defrosted versus fresh human placenta models for microvascular bypass training: A comparative study in surgical simulation

Objectives: The objective of this study was to evaluate and compare the effectiveness of defrosted (frozen) versus fresh refrigerated human placenta models for microvascular anastomosis training using a standardized scoring system and participant feedback. Materials and Methods: A randomized, double-blind study was conducted involving 17 neurosurgical participants (nine trained and eight untrained). Each participant performed end-to-end, end-to-side, and side-to-side microvascular anastomoses using either a defrosted or refrigerated human placenta model. Performance was assessed using a modified Northwestern objective microanastomosis assessment tool (NOMAT) and a survey evaluating face and content validity. Statistical analysis included Fisher’s exact test and multiple linear regressions. Results: There were no statistically significant differences in NOMAT scores or survey responses between the defrosted and fresh refrigerated placenta groups ( P > 0.05). Both models were rated similarly in realism, vessel consistency, and training value by trained and untrained participants. Over 90% of participants agreed that the placenta model was beneficial for improving microsurgical technique, regardless of preservation method. Conclusion: Defrosted human placenta offers comparable training utility to fresh refrigerated placenta for microvascular anastomosis practice. Its extended shelf life and ease of preparation make it a practical alternative for neurosurgical training, particularly in resource-limited or logistically constrained environments.