#3215 RHE EFFECT OF ANASTOMOTIC ANGLE ON MATURATION OF AUTOGENOUS ARTERIOVENOUS FISTULA AFTER END-TO-SIDE ANASTOMOSIS OF CEPHALIC VEIN AND RADIAL ARTERY
Authors: Li Le , Pai Ming-Chu Pearl , He Haiyan , Ma Xuejuan , Cui Liwen 
Published: June 2023

Abstract

Background and Aims
Arteriovenous fistula (AVF) is the preferential choice of haemodialysis (HD) access, but failure of maturation of AVF is common. A previous French study had demonstrated reduced primary patency of radial-cephalic fistula with anastomotic angles &lt; 30°. We have designed a study to determine if the angle of anastomosis affects the maturation of AVF in Chinese patients.

Method
We retrospectively studied our chronic patients who underwent the first cephalo-radial end-to-side anastomosis of AVF surgery at our Hospital from November 2019 to September 2022. All AVFs have been constructed by two of our dedicated nephrologists. The nephrologists performed the dissection and construction of the anastomosis according to the patient's anatomy. The angle of the anastomosis was not decided a priori and special care was given not to kink or twist the vein during the procedure. The AVF was defined as mature at 3 months if the blood flow was ≥ 500 ml/min and/or if the AVF was able to support adequate dialysis thrice a week. The patients were divided into two groups for evaluation using 45° of the AFV's anastomotic angles as cut-offs. The study has been approved by the local research and ethics committee. Statistics analysis: The IBM SPSS Statistics 26 software was used. The baseline characteristics of the two groups were analyzed using univariate analysis to find out if there was any statistical difference. The K-M curve was used to analyze if there was any statistical difference in AVF maturation between the two groups. Logistic regression was used to analyze the rate of maturation between the two groups, adjusted for confounding factors (including baseline characteristics and variables that have been shown as risk factors in previous studies, such as age, female gender, diabetes, preoperative vessel diameter, etc.), to determine whether the angle of anastomosis was an independent factor.

Results
A total of 159 Chinese patients were included in the study. The overall AVF maturation rate at 3 months was 93.08% (148/159 cases). Table 1 showed the patients’ baseline characteristics based on the AVF outcome. Table 2 showed the patients’ parameters in relation to different anastomotic angles (group 1: anastomotic angle ≤45°; group 2: &gt;45°). The median time to AVF maturation of either group was 5 weeks (P = 0.9057, 95% CI 0.725-1.421) with no statistical difference. There was no statistical difference between the two groups in terms of age, gender, preoperative venous and arterial diameters, states of diabetes, coronary heart disease, peripheral vascular diseases, smoking, or biochemical parameters. Multivariate logistic regression analysis showed that there was no statistical difference between the two groups in AVF maturation rate at 3 months (OR = 0.976, 95% CI 0.273-3.489, P = 0.971). There was also no statistical difference after adjustment (OR = 0.863, 95% CI 0.231-3.233, P = 0.827).

Conclusion
This study has not established nor confirmed to any meaningful degree any relationship between the anastomotic angle using 45° as a cut-off and the maturation rate of AVF in Chinese patients at 3 months. Our overall AVF maturation rate was very high and none of the traditional risk factors for failed AVF nor the degree of anastomotic angle have any demonstrable effect on AVF maturation. The success might have been in part due to the skill and dedication of the nephrologists as operators. A prospective study involving a bigger patient group is necessary to further explore the effect of anastomotic angle on AVF maturation if any.