Evaluation of portal hypertension and varices by acoustic radiation force impulse imaging of the liver compared to transient elastography and AST to platelet ratio index.

BACKGROUND: Acoustic radiation force impulse imaging (ARFI) is a new method of liver stiffness measurement (LSM). The aim was to compare ARFI, transient elastography (TE) and AST to platelet ratio index (APRI) for the noninvasive diagnosis of clinically significant portal hypertension (CSPH, hepatic venous pressure gradient; HVPG ≥ 10 mmHg) and esophageal varices (EV). MATERIALS AND METHODS: LSM via ARFI and TE was performed in 88 consecutive patients with cirrhosis prior to HVPG measurement. The mean liver stiffness for ARFI was calculated out of 5 measurements for each lobe. RESULTS: LSM by TE and ARFI was not successful in 22 (25%) patients and 1 (1 %) patient, respectively, due to ascites or obesity. Both TE (r = 0.765; p < 0.001) and ARFI (r = 0.646; p < 0.001) correlated significantly with HVPG. At the optimal cut-off (16.8 kPa), TE (area under the curve, AUC 0.870) yielded a sensitivity and specificity of 89.7% and 75%, respectively, for predicting CSPH. At the optimal cut-off (2.58 m/s), the sensitivity and specificity for ARFI (AUC 0.855) were 71.4% and 87.5%, respectively. Using an APRI (AUC 0.838), the sensitivity and specificity were 69% and 87.5%, respectively. The AUC for the diagnosis of EV was 0.802 for TE (cut-off: 27.9 kPa), 0.743 for ARFI (cut-off: 2.74 m/s), and 0.805 for APRI (cut-off: 1.90). CONCLUSION: ARFI shows a higher applicability particularly in obese and ascitic patients. All three investigated methods show a high diagnostic accuracy for CSPH. Notably, APRI performed not significantly different compared to ARFI for the diagnosis of CSPH.

Von Willebrand Factor as a new marker for non-invasive assessment of liver fibrosis and cirrhosis in patients with chronic hepatitis C.

BACKGROUND: Staging of liver fibrosis in patients with chronic hepatitis C (CHC) is recommended prior to anti-viral therapy. As vWF-Ag was shown as a predictor of portal hypertension, decompensation and mortality in patients with liver cirrhosis, we performed this study to investigate if vWF-Ag is able to predict different fibrosis stages and if it is comparable to other fibrosis scores. AIM: To investigate if vWF-Ag is able to predict different fibrosis stages and if it is comparable to other fibrosis scores. METHODS: We analysed 294 patients with chronic hepatitis C who underwent biopsy. We assessed stage of liver fibrosis according to Metavir, measured vWF-Ag and calculated different fibrosis scores (APRI, FCI, FORNS, FI, Fib-4) and compared them by AUCs. We also calculated a new score: vWF-Ag/thrombocytes (VITRO score) for prediction of fibrosis. RESULTS: vWF-Ag levels were increasing with stage of fibrosis: F0: vWF-Ag was median 136.5%, FI 140.6%, FII 157.5%, FIII 171.0%, FIV 252.0%; P < 0.001. vWF-Ag and VITRO score produced AUCs of 0.7 and 0.72 for ≥F2, comparable to the AUCs of APRI, Fib-4, FORNS with 0.75, 0.65 and 0.64 (P > 0.05). For ≥F3 AUCs were 0.79 and 0.86 for vWF-Ag and VITRO score, comparable with AUCs of 0.79, 0.86 and 0.87 for APRI, Fib-4 and FORNS. Cirrhosis shows AUCs of 0.84 and 0.89 for vWF-Ag and VITRO score, APRI, Fib-4 and FORNS showed similar results with AUCs of 0.82, 0.88 and 0.87. CONCLUSIONS: vWF-Ag and VITRO score offer an easy possibility to evaluate the stage of fibrosis to diagnose subclinical cirrhosis in patients with chronic hepatitis C. Both vWF-Ag and VITRO score show equal performance in comparison to other fibrosis scores assessed in our study.

Prevalence of flat lesions in a large screening population and their role in colonoscopy quality improvement.

BACKGROUND AND STUDY AIMS: Flat lesions pose new challenges for endoscopists, but the importance of detecting them is still controversial. Most screening studies do not survey macroscopic polyp morphology. The aims were to evaluate the percentage of flat polyp findings in a large asymptomatic adult screening population (n = 52 521), to assess the impact of shape and size on malignant transformation, and to assess the role of flat lesions regarding quality assurance in colorectal cancer prevention. MATERIAL AND METHODS: Retrospective analysis of screening colonoscopies performed between 2007 and 2011 according to the Austrian "Quality management for colon cancer prevention" program. RESULTS: 17 771 patients with polyps were included in the study. Patients with flat polyps represented 24.2 % (n = 4293), 62.4 % (n = 11 097) were classified as having sessile and 13.4 % (n = 2381) as pedunculated polyps. Among those with flat polyps 51.4 % had adenomas (n = 2207). High grade dysplasia (HGD) was found in 2.1 % (n = 47) of flat adenomas, in 1.5 % (n = 89) of sessile adenomas and 4.7 % (n = 92) of pedunculated adenomas (P < 0.0001. The risk for containing HGD was 1.0 % for flat lesions ≤ 10 mm in size compared with 10.3 % for lesions > 10 mm, and 1.0 % for polypoid lesions ≤ 10 mm compared with 9.3 % for lesions > 10 mm (P < 0.0001). Multivariable logistic regression showed that polyp size (P < 0.0001) but not polyp shape (P = 0.438) is an independent predictor for HGD. Adenoma detection rate (ADR) correlated weakly with the flat polyp detection rate (Pearson r = 0.24). CONCLUSION: Malignant potential of polyps is mostly affected by size but not by shape. Since flat polyp detection rate only correlates poorly with ADR we do not recommend its incorporation in quality assured screening colonoscopy.