Comparison of different anastomosis angles in radiocephalic fistula with modified functional end-to-side anastomosis

OBJECTIVE: Functional vein end to arterial side (ETS) anastomosis uses vein side to arterial side anastomosis with distal vein ligation, which is different from traditional ETS anastomosis. To date, there are no studies concerning different anastomotic angles of fistula with functional ETS anastomosis. The purpose of the study was to analyze the clinical outcomes concerning different anastomotic angles of functional ETS anastomosis in radiocephalic fistula. METHODS: Between January 2018 and December 2020, we performed a prospective cohort study concerning functional ETS anastomosis in radiocephalic fistula. According to vascular anatomy of patients, the anastomosis angles of fistula were designed at 30 ≤ angle ≤ 50°, 50 < angle ≤ 70°, and 135° smooth obtuse angle. The end points were the primary patency rate (PPR), the secondary patency rate (SPR) and the cumulative rate of reintervention (CRR) near anastomotic venous segment. RESULTS: 124 patients with functional ETS anastomosiss were enrolled in this study. Pearson χ(2) test showed that the group of 135°anastomosis angle had the maximum distance between arteries and veins, and the group of 30–50°anastomosis angle had the minimum distance between arteries and veins (P < 0.01). 30–50°anastomosis angle had the highest PPR at 12 months (P = 0.03) and the lowest CRR near anastomotic venous segment at 3 months (P = 0.04) and 12 months (P = 0.01). There were no significant differences among different anastomosis angles concerning the SPR within 12 months (P > 0.05). Kaplan–Meier and log-rank analysis showed that 30–50°anastomosis had the highest PPR (P = 0.03) and the lowest CRR near anastomotic venous segment (P = 0.01). A multivariable Cox model showed anastomotic angle was an independent factor predictive of the PPR (P = 0.04) and the CRR near anastomotic venous segment (P = 0.03). 50–70°anastomosis angle was a risk factor of decreasing PPR (P = 0.03). 50–70° (P = 0.01) and 135° (P = 0.03) anastomosis angle were both obvious risk factors of increasing CRR near anastomotic venous segment. CONCLUSION: 30–50°were the best anastomotic angles for functional ETS anastomosis, which had the highest PPR and lowest CRR near anastomotic venous segment.