Clinical Utility of a New Predicting Score for Radiocephalic Arteriovenous Fistula Survival

Abstract

Background: Radiocephalic arteriovenous fistula (RC-AVF) is the recommended first choice for vascular access (VA). The CAVeA₂T₂ scoring system was recently published (ipsilateral central venous catheter access, age >73 years, vein <2.2 mm, lower limb angioplasty, and absent intraoperative thrill). The aim of the present study was to assess the clinical utility of the CAVeA₂T₂ scoring system for predicting RC-AVFs survival in our center and its subsequent application in VA management.

Material and methods: In this single-center retrospective study, all RC-AVFs performed from January 2010 to July 2014 were included. The CAVeA₂T₂ was applied. Primary, assisted primary, and secondary patency rates were measured.

Results: Sixty RC-AVFs were analyzed. Mean age was 64.3 ± 14.7 years. Mean CAVeA₂T₂ score was 1.23 ± 1.2. The median fistula secondary patency was 13.7 ± 1.6 months. Secondary patency was at 6 weeks and at 6, 12, and 24 months: 88.3%, 66.7%, 55%, and 31.7%, respectively. Increasing score (≥2) was associated with a decrease in primary (log-rank, χ² = 16.7, dif = 1, P = 0.0001) and secondary patency rate survival (log-rank, χ² = 5.4, dif = 1, P = 0.0001). In addition, stratification of the CAVeA₂T₂ score into 3 groups (scores 0-1, 2, and 3+) retained its significance for primary (log-rank, χ² = 19.4, dif = 2, P = 0.0001) and secondary patency rate survival (log-rank, χ² = 5.5, dif = 2, P = 0.046) at the end of the study.

Conclusions: In the present study, the CAVeA₂T₂ scoring system has proved to be a useful, easy to apply tool that is highly predictive of RC-AVF survival. Based on our results, we should avoid perform RC-AVFs, in those patients with CAVeA₂T₂ score ≥2 and late nephrology referral. Prospective studies should be designed to establish the management of patients with a higher CAVeA₂T₂ score.