Which factors influence liver stiffness measured by real-time two dimensional shear wave elastography in patients on maintenance hemodialysis?

AIM: To evaluate liver stiffness (LS) by real-time two-dimensional shear wave elastography (RT 2D-SWE) and to assess its correlation with the mean arterial pressure (MAP) in patients on maintenance hemodialysis (MHD). The secondary aim was to identify biological and biochemical parameters associated with elevated LS. METHODS: This study enrolled patients treated with MHD in the Split University Hospital from December 2017 through February 2018. LS was measured after a HD session using RT 2D-SWE. Mean arterial pressure was measured before RT-2D-SWE was performed. RESULTS: The study enrolled 47 patients with the mean±standard deviation age of 68.48±14.33 years. Arterial hypertension was diagnosed in 70.2% of patients. Liver stiffness >7 kPa, suggesting clinically relevant fibrosis, was found in 59.5% of patients. Arterial pressure was significantly correlated with LS (ρ=0.38, P=0.008). C-reactive protein (ρ=0.548, P=0.023), parathyroid hormone (ρ=0.507, P=0.038), and total bilirubin (ρ=0.423, P=0.020) were correlated with elevated LS. CONCLUSION: Mean arterial pressure is correlated with increased LS in patients on MHD. Our results emphasize the importance of proper regulation of arterial blood pressure and indicate that LS should always be interpreted in combination with laboratory parameters. Further prospective studies with larger series are needed.

Impact of hemodialysis on liver stiffness measured with real-time two-dimensional shear wave elastography.

BACKGROUND AND AIMS: The impact of hemodialysis on liver stiffness is still unclear. The aim of the study was to assess liver fibrosis by real-time two-dimensional shear wave elastography (RT 2D-SWE) and to quantify the influence of net fluid withdrawal on liver stiffness during one hemodialysis session. The second aim was to investigate the influence of systolic blood pressure and time spent on dialysis (in years) on liver stiffness measurements. METHODS: This before/after hemodialysis (HD) study in a group of end stage renal disease (ESRD) patients was carried out with patients on regular HD. Measurements of liver stiffness were done using RT 2D-SWE directly before and after a hemodialysis session. RESULTS: In this study 27 patients with mean age 69.4 ± 14.75 years were included. Mean net fluid withdrawal volume per session was 2874.07 ± 778.35 ml. Mean pre-HD and post-HD liver stiffness measurements were 8.15 kPa (95% confidence interval, CI 7.61-8.68) and 6.70 kPa (95% CI 6.10-7.30 kPa), respectively. Mean liver stiffness reduction was 1.448 ± 1.14 kPa. The amount of fluid removed correlated with the decline in liver stiffness values after HD (ρ = 0.523, P = 0.003). There was a positive but statistically not significant correlation between time spent in HD and liver stiffness (ρ = 0.151, P = 0.623) CONCLUSION: Liver stiffness significantly declined after one session of HD. The change in liver stiffness was strongly correlated with the amount of net fluid withdrawal. Random liver stiffness measurements (LSM) by RT 2D-SWE does not precisely show the degree of fibrosis, Furthermore, it is presumed that postdialysis liver stiffness values likely reflect the real degree of liver fibrosis.