Arteriovenous fistula aneurysm in patients on regular hemodialysis: prevalence and risk factors.

BACKGROUND/AIMS: Compared to all other complications, literature data about vascular access aneurysm (VAA) are the scarcest. The aim of this cross-sectional study was to evaluate the prevalence of arteriovenous fistula (AVF) aneurysms and to confirm the risk factors for their appearance. METHODS: The presence, number and morphological characteristics of AVF aneurysms were confirmed, and according to the score of AVF aneurysm (the sum of the length and width in cm), patients were classified into group 1 (score ≤12) and group 2 (score >12). Analysis included the last data from the medical records including vascular calcifications score. RESULTS: Out of 181 patients, 150 with native fistula were included in this study. Aneurysmatic changes were detected in 90 (60%) patients, and the majority had two or more aneurysms. VAA were more frequent in patients with adult polycystic kidney disease (ADPKD) than in other diagnostic categories. By using forward stepwise logistic regression, we confirmed that patients on high-flux hemodialysis (HD) had 5.3-fold higher risk, and patients with diabetes mellitus had 5.8-fold less risk for developing AVF aneurysm. While vascular calcification score did not influence the incidence of VAA, higher PWV had significant negative influence on formation of AVF aneurysm (OR 1.25, 95% CI 1.003-1.56, p = 0.047). By ROC curve analysis, it was determined that patients who were longer than 5.7 years on HD had greater risk for developing VAA (area = 0.741, p = 0.000). CONCLUSION: This single-center study confirmed the very high prevalence of VAA (60%). Aneurysms were more frequent in patients with ADPKD and in those who had longer dialysis vintage on high-flux membranes with higher blood flow rate.

The influence of various morphologic and hemodynamic carotid plaque characteristics on neurological events onset and deaths.

A group of 72 patients with 111 asymptomatic carotid stenoses (ACS), mean age 65.42 +/- 9.21, and a group of 36 patients with 58 symptomatic carotid stenoses (SCS), mean age 67.63 +/- 8.79, were analyzed prospectively during a 3-year follow-up period. All patients underwent color duplex scan sonography (CDS), carotid arteriography, computed tomography (CT) scan, and neurological examination. The aim of the study was to analyze the correlation between echo plaque morphology (degree and plaque quality), local hemodynamic plaque characteristics, ischemic CT findings, and onset of new neurological events and deaths. The results analysis showed significantly more ACS in the group of 30-49% stenosis (p < 0.001), but significantly more SCS in the group of 70-89% (p < 0.0001) and > or = 90% stenosis (p < 0.05). Fibrous plaque was more frequent in the ACS group (p < 0.001), while ulcerated and mixed plaques were more frequent in the SCS group (both p < 0.0001). In the SCS group, a significantly higher frequency of increased peak systolic and end diastolic velocities was noted at the beginning and end of the study (both p < 0.01), as well as for contralateral common (CCA) or internal carotid artery (ICA) occlusion (p < 0.05 and p < 0.01, respectively), but reduced carotid blood flow volume (p < 0.05) only at the end of the study. In the ACS group, the best correlation with new neurological events and deaths was shown with positive CT findings, peak systolic flow velocity over 210 cm/sec, end diastolic flow velocity over 110 cm/sec, plaque stenosis > or = 70%, plaque ulceration, mixed plaque (all p < 0.0001); stenosis > or = 50% (p < 0.001); and reduced carotid blood flow volume (p < 0.05).