Along with a growing elderly population, more patients require treatment for end stage renal disease (1). This together with the "Fistula First Initiative" has resulted in a progressive increase of upper arm fistulas (2). In absence of a suitable cephalic vein a basilic vein transposed fistula (BBAVF) is an alternative. The surgical approach can be performed as a one-stage or two-stage procedure. This study aimed to compare the long-term patency and complications of single versus staged BBAVF placement for men and women.

All upper arm BBAVF registered in the national Swedish Renal Registry between 2011-2019 in patients at age ≥ 18 years were included in this retrospective review. Patients were divided into two groups according to one-stage (BB1) or two-stage (BB2) procedure. The performing hospital, surgeon, patency, complications and required interventions were recorded for each group, counted from fistula placement. Complications compiled bleeding, infections, aneurysm/psedoaneurysm, steal syndrome, puncture problems, stenosis of artery, vein and central vein, thrombosis and occlusion. Functional patency assessed as first puncture. The Kaplan-Meier method was used to calculate fistula survival censored for death and death as an event. Cumulative incidence plots were used to display survival of patients and fistula outcome separated by sex. A Cox proportional Hazard regression model and standard deviation (SD) calculated was used to study the effect of patient specific factors on patency and complications.

During the study time, 307 BBAVF were created in 301 patients, BB1 (n=224) and BB2 (n=83, transposed n=60 (80%)). Age, sex, primary kidney disease, comorbidities and pre-dialysis placement were similar between the groups. Surgery was performed in 31 hospitals by 106 surgeons (caseload per surgeon: 1-20). Time from placement to first puncture was for BB1 148.5 days (SD190.2) and BB2 240 days (SD 327.6) respectively (p<0.001). A comparable number of fistulas were used for hemodialysis BB1 n= 152/224 (68%) and BB2 n=59/83 (71%). In the observation period the only registered complication that differed significantly between methods was the rate of venous stenosis with detriment for BB1 0.26 (95%CI [0.22,0.31] n=157) compared to BB2 0.15 (95%CI [0.11,0.21] n=40) (p=0.002). Endovascular reintervention rates were higher in BB1 (0.60/patient year vs 0.31/patient year) (p<0.001). One-year primary patency was in BB1 25 % as compared 42 % in BB2 (p=0.007) (Fig.1) The majority of fistula events occurred during the first year after placement. Secondary patency was similar between groups at one-year BB1 73% and BB2 70% (p=0.128) (Figure 2a). Some 74% of the study population were alive after three years, and survival with a functional fistula were similar between groups (p=0.329) (Figure 2b). Diabetes as comorbidity was associated with inferior primary and secondary patency (HR 1.33[1.02-1.73] (p=0.03) and HR 1.48 [1.08-2.02] (p= 0.02)) Women underwent more interventions (0.6/patient year 95%CI [0.52-0.69] vs men 0.46/patient year 95% CI [0.40,0.52] (p= 0.06)) and displayed a worse secondary patency at one year (66% vs 81%), (p=0.002).

In this long-time national audit secondary patency did not differ between single versus two stage procedures creating a Brachiobasilic fistula. The single stage method required more reinterventions while time to puncture was three months longer in the BB2 group. This study cannot conclude which method is superior, it is reasonable to use both.

1. ERA-EDTA. ERA-EDTA Registry Annual Report 2016. Amsterdam: Academic Medical Center, Department of Medical Informatics, 2018: 69 2. Hedin, U. and G. Welander (2017). "Upper-arm hemodialysis access in Sweden." J Vasc Access 18(Suppl. 1): 110-113.