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DOI: 10.1055/s-0033-1354806
Influence of obstructive cholestasis on liver stiffness measurement using Acoustic Radiation Force Impulse Imaging (ARFI)
Purpose: ARFI is frequently used for non-invasive assessment of liver fibrosis. Some factors were identified impairing the diagnostic accuracy of ARFI elastography. So far, it is unclear whether obstructive cholestasis interferes with ARFI assessment of liver fibrosis. The aim of this prospective study was to evaluate the influence of biliary obstruction and cholangitis on measurement of liver stiffness before and after bile duct drainage.
Material and methods: A total of 42 patients (31 male, mean age 60.2 ± 15.6 years) with obstructive cholestasis were consecutively enrolled. 28 patients (67%) had pre-ERCP cholangitis, indicated by wall thickening of the biliary tree of > 1.5 mm. 38/42 (91%) patients received stents. Liver stiffness was measured by ARFI elastography in all patients before and 1 – 2 days after ERCP. In 25/42 (60%) patients second ARFI follow-up performed 1 – 12 weeks after ERCP.
Results: Liver stiffness decreased significantly in 37/42 (88%) patients after ERCP (from 1.97 m/s to 1.66 m/s, p < 0.0001). During 2nd follow up no further significant changes of liver stiffness found (from 1.68 m/s to 1.67 m/s, p = 0.502, respectively). Mean ARFI values at baseline were not significantly different in patients with or without cholangitis (2.03 m/s vs. 1.82 m/s, p = 0.309, respectively). At 1st follow up the decline of ARFI values was significantly higher in patients without cholangitis than in those with (1.82 to 1.39 m/s vs. 2.03 to 1.81 m/s, p = 0.03, respectively). Moreover, Bilirubin and AP levels decreased significantly from baseline to 1st follow-up (p = 0.032, p = 0.005, respectively). There was no correlation between baseline ARFI and laboratory parameters.
Conclusion: Obstructive cholestasis/cholangitis increases liver stiffness und must be considered when using ARFI elastography. In case of cholangitis, the recovery of liver stiffness is delayed. Thus, an adequate time interval of liver fibrosis assessment after biliary drainage should be prolonged.