Clinical Study On The Establishment Of Autogenous Arteriovenous Fistulae In Small Blood Vessels By Multi-segment Balloon Dilation Technique

Objective:To investigate the effect of dilating small blood vessels using a balloon dilation technique on the occurrence of arteriovenous fistula(AVF)in terms of patency,and blood flow,and vein diameter.Methods:Patients included in this study required arteriovenous fistulae surgery due to chronic renal failure.They were recruited from the Department of Nephrology,the Third Hospital of Shanxi Medical University,Shanxi,China,between August 1,2015 and September 1,2020.Patients with anastomotic vein diameters less than 2 mm were included as study subjects.They were either assigned treatment using balloon dilation group,or a control group received liquidity dilation.The differences between the two groups were analyzed in terms of patency,internal fistula blood flow,and internal fistula vessel diameter at 1 year follow-up.Results:A total of 22 patients were enrolled in the balloon dilatation group,and 20 patients in the control liquidity dilatation group.There were no statistically significant differences between the two groups with regards to gender(p=0.721),age(p=0.811),BMI(p=0.564),the presence of diabetes(p=0.768),or combined hypertension(p=0.588).The internal diameters of cephalic veins(mm)of the experimental and control group were compared at various time points: immediately post-operation 2.89±0.42 vs.1.99±0.28(p<0.001),one week later 3.16±0.59 vs.2.66±0.60(p=0.022),one month later 3.76±0.91 vs.3.18±0.83(p=0.087),and two months later 4.08±1.15 vs.3.38±1.13(p=0.169).Brachial artery flows(m L/min)of experimental and control groups at various time points were: immediately postoperation 413.49±145.09 vs.235.61±87.77(p<0.001),one week later 563.26±206.83 vs.331.30±126.78(p<0.001),one month later 679.34±218.56 vs.376.79±156.25(p<0.001)and two months later 736.31±202.61 vs.394.60±161.96(p<0.001).The patency was calculated and described using the Kaplan-Meier method.The one year primary patency of experimental and control groups were 61.9% vs.11.1%(p=0.045 by Breslow test).One year secondary patency of experimental and control groups were 90.5% vs.55.6%(p=0.030 by Breslow test).Using the Cox hazard proportional model to calculate the corrected hazard ratio,the adjusted hazard ratio values for primary and secondary patency within 1 year were0.219(95.0% CI = 0.069-0.691)and 0.079(95.0% CI = 0.007-0.898),respectively.Conclusion:Balloon dilation has obvious advantages over liquid dilation for chronic renal failure patients with small veins in establishing AVF in terms of fistulae patency and internal fistula blood flow.