Development of a valid experimental animal model for common carotid arteries crossover bypass

Objective. To develop and validate an in vivo experimental animal model of carotid-carotid crossover bypass for studying hemodynamics, comparing the effectiveness of different types of bypass grafts (autograft and synthetic graft), and improving microsurgical techniques applicable in neurosurgical and vascular practice. Material and methods. Between October 2024 and February 2025, three surgical procedures were performed on Landrace pigs. In two experiments, a 5 mm PTFE GORE-TEX synthetic graft was used as a bypass graft, while in the third, an autograft from the superficial femoral artery was used. The bypass grafts were placed in the retropharyngeal space. Intraoperatively, the patency of the bypass graft and both common carotid arteries (CCA) was assessed, and the blood flow velocity (BFV) was measured using contact Doppler flowmetry (Bioss Angiodin-UK system) before and after bypass grafting. Results. Patent and functional bypass grafts were achieved in all three experiments. The BFV values in the recipient vessels after surgery were comparable to the baseline values, indicating adequate blood flow compensation. The BFV in the donor (left) CCA remained stable, confirming the absence of hemodynamic compromise. In all cases, the animals remained alert and maintained motor activity in the first three days after the procedure. A progressive reduction in operative time and vessel clamping time was observed, confirming the applicability of the model for training purposes. Conclusion. The presented in vivo model of CCA crossover bypass is reproducible, safe, and clinically relevant. It can be used both for research purposes — to evaluate the hemodynamic characteristics of bypass grafts and model various revascularization conditions — and in educational programs to practice surgical techniques in conditions close to clinical settings.