Construction and Evaluation of End-to-side Anastomosis Model of Autologous Arteriovenous Fistula in Mice

Abstract

Objective To establish an animal model of autologous arteriovenous fistula in mice and evaluate its effect.Methods The left external jugular vein and common carotid artery of 10 8-week-old male C57BL/6 mice were separated by end-to-side anastomosis of external jugular vein and common carotid artery after anesthesia, and the right jugular vein was exposed without suture as a control, so as to establish an animal model of internal arteriovenous fistula. Doppler ultrasound, HE and Masson staining and immunohistochemical staining were used to observe the hemodynamics, intimal hyperplasia and protein expression of smooth muscle cell proliferation in the outflow vein of the internal arteriovenous fistula and the contralateral control vein, and to evaluate the effect of model construction.Results A total of 10 mice were selected for this study, and 9 mice were successfully modeled, with a success rate of 90%. Ultrasound examinations were performed on the day of surgery, 7 and 14 days after surgery, respectively. The results showed that the flow velocity near the anastomosis was linearly correlated with the diameter of the tube. The higher the flow velocity, the larger the diameter of the tube. There was a positive correlation between peak velocity and lumen diameter (P=0.000 6, R2=0.831 7). After surgery 14 days, HE staining results showed that after autologous arteriovenous fistula molding, the average lumen area of outflow segment vein was significantly decreased (P < 0.000 1), the intima area was significantly increased (P < 0.000 1), the intimal area was significantly increased (P < 0.000 1). On the surgical side of arteriovenous fistula, collagen deposition was significantly increased, and the proportion of Masson-positive regions was significantly increased (P < 0.000 1). Immunohistochemical staining showed that the proportion of collagen 1 positive areas on the surgical side of arteriovenous fistula was significantly upregulated (P < 0.000 1), and α-smooth muscle actin (α-SMA) , proliferating cell nuclear antigen (PCNA) positive cells increased significantly (P < 0.000 1), indicating an increase in local cell proliferation level.Conclusion The established mouse autologous arteriovenous fistula model has the advantages of high success rate, good stability and low cost. The model provides a good carrier for exploring the biological mechanism of intimal hyperplasia in arteriovenous fistulas.

Keywords

• arteriovenous fistula
• animal model
• uremia
• hemodialysis
• intimal hyperplasia
• mice