The role of venous pressure variability during hemodialysis in the prediction of impending arteriovenous graft occlusion

Background: Elevated venous pressure during hemodialysis (VPHD) is associated with arteriovenous graft (AVG) stenosis. This study investigated the role of VPHDvariations in the prediction of impending AVG occlusion.Methods: Data were retrieved from 118 operations to treat AVG occlusion (occlusion group) and 149 operations to treat significant AVG stenosis (stenosis group). In addition to analyzing the VPHDvalues for the three hemodialysis (HD) sessions prior to the intervention, VPHDvalues were normalized to mean blood pressure (MBP), blood flow rate (BFR), BFR × MBP, and BFR2× MBP to yield ratios for analysis. The coefficient of variation (CV) was used to measure relative variations.Results: The within-group comparisons for both groups revealed no significant differences in the VPHDmean and CV values among the three HD sessions prior to intervention. However, the CVs for VPHD/MBP, VPHD/(BFR × MBP), and VPHD/(BFR2× MBP) exhibited significant elevation in the occlusion group during the last HD session prior to intervention compared with both the penultimate and antepenultimate within-group HD data (p< 0.05). In the receiver operating characteristic curve analysis, the CV for VPHD/(BFR2× MBP) was the only parameter able to discriminate between the last and the penultimate HD outcomes (p< 0.001). According to a multivariate analysis, after controlling for covariates, CV for VPHD/(BFR2× MBP) >8.76% was associated with a higher risk of AVG thrombosis (odds ratio: 3.17, p< 0.001).Conclusions: Increasing the variation in VPHD/(BFR2× MBP) may increase the probability of AVG occlusion.