Abstract: 【Abstract】Objective To explore the best operation program for autologous internal arteriovenous fistula using forearm small vessels in patients with chronic renal insufficiency. Methods Two hundred and twentyfour patients intended to undergo an operation for internal arteriovenous fistula but with arteries and veins ≥ 1.5mm and ＜2.0mm in diameter from preoperative vascular color Doppler ultrasonography were enrolled in this study. According to the vascular conditions at operation, one of the 4 operation methods was selected: endto- end anastomosis (n=21), arteriovenous anastomosis (n=14), end-to-side anastomosis (n=110), and modified end-to-side anastomosis (n=79). The diameter of anastomotic stoma was measured and the maturation index was monitored until maturation of the fistula or 12 weeks after the operation. The correlation of operation type with anastomotic stoma diameter, operation success rate and maturation rate was studied and analyzed. Results The success rate and maturation rate were 57.1% and 58.3%, respectively for end-to-end anastomosis, 78.6% and 63.6%, respectively for arteriovenous anastomosis, 80.9% and 84.3%, respectively for end-to-side anastomosis, and 89.9% and 94.4%, respectively for modified end-to-side anastomosis. The success rate and maturation rate was higher in modified end- to- side anastomosis than in end- to-end anastomosis (P＜0.01). The success rate was similar (P＞0.05) but the maturation rate was different (P＞0.05) between modified endto- side anastomosis and routine end-to-side anastomosis. The success rate and maturation rate were significantly higher in internal fistula operation with anastomotic stoma of 10～15mm diameter than in the operation with anastomotic stoma of ＜10～15mm diameter. Conclusions Modified end- to-side anastomosis is the best operation type for internal arteriovenous fistula of small vessels. Enlarging the anastomotic stoma diameter to 10～15mm during operation favors success and maturation of the internal fistula.

Key words: operation for internal arteriovenous fistula, autologous vessel, small vessel, operation program, success rate