Clinical characteristics and preoperative ultrasound parameters related to low patency in radio-cephalic arteriovenous fistulas.

Introduction: Our objective is to describe the clinical characteristics and preoperative ultrasound mapping parameters associated with primary and secondary patency of radio-cephalic arteriovenous fistulas (RCF).

Methods: A retrospective, single-center, descriptive study, including patients undergoing a RCF creation between 2015 and 2019. Socio-demographic data and ultrasound parameters were collected and an analysis of primary and secondary patency was performed.

Results: Eighty-four patients were included in this study. Mean age was 65.6 (±13.9) years; 76.6% were male. Mean preoperative ultrasound parameters: forearm cephalic vein diameter was 2.8 (±0.57) mm, radial artery diameter was 2.6 (±0.42) mm, radial artery systolic peak velocity was 68 (±14.3) cm/s radial artery resistance index was 0.76 (±0.9). At the end of the 4 years the follow-up, the mean primary and secondary patency were 47.2% and 80% respectively. Only female sex was significantly associated with a decrease in both primary patency (p = 0.043, HR = 0.48) and secondary patency (p = 0.021, HR = 0.023). Furthermore, radial artery systolic peak velocity (p = 0.007, HR = 2.6) showed a significant association with decreased primary patency and forearm cephalic vein diameter showed a borderline significant association with decreased secondary patency (p = 0.046, HR = 8.2).

Conclusions: A standardized evaluation by a vascular surgeon or nephrologist represent a key in the preoperative assessment of AVF candidates. Based on our results, we will consider to avoid distal vascular access in both female patients with lower radial artery systolic peak velocity (less than 68 cm/s) and borderline forearm cephalic vein diameter (less than 2.8 mm) after initial assessment in our clinical practice. Our results could encourage new studies in order to stablish the potential role of these parameters in the RCFs patency rates.