Diagnostic Accuracy of Hepatic Vein Resistive Index in Detection of Hepatic Fibrosis in Patients of Chronic Liver Disease

Introduction: If we could prove the diagnostic accuracy of hepatic vein resistive index in detecting liver fibrosis in chronic liver disease patients, this would be beneficial for the patients as it is a non-invasive, readily available, and cost-effective technique for the diagnosis of liver fibrosis. This will help the physicians in the early initiation of definitive management. 
Materials and Methods: Seventy-five (n=75) patients with hepatitis B aged between 18-50 years were enrolled. Hepatic vein resistive index and liver biopsy were performed in even-patients. Sensitivity, Specificity, PPV, NPV, and overall accuracy of the hepatic vein resistive index was calculated. 
Results: Average age group studied was  38y ± 8.2 SD. 57.3 % (N=43) were males and 42.7% (n=32) patients were females respectively. Data of this work Exhibits various statistical indicators 77%. 96.7%. 97.2%. 74.3% and 85.3% respectively. 
Conclusion: Hepatic vein resistive index measured by ultrasonography can detect liver fibrosis in CLD with overall sensitivity, Specificity, PPV, NPV, and accuracy of 77.7%. 96.7%. 97.2%. 74.3% and 85.3% respectively.


Introduction
Chronic liver disease is a progressive condition that leads eventually to liver fibrosis and liver failure. [1][2] Hepatobiliary disorders are commonly seen in clinical practice nowadays among which patients with hepatitis B and C arc most commonly encountered. [3][4] Hepatic fibrosis is characterized by the formation of hepatic scars which leads to cirrhosis. 5 Chronic liver disease has many causative etiologies including viral infections, alcohol overdose, steatotic liver disease, primary sclerosing cholangitis, autoimmune disease, and hemochromatosis. [6][7][8] The incidence of hepatitis B infection depends upon geographical location and is increasing annually ranging between 3% and 9%. 9 The predictors of rising mortality in hepatitis B virusassociated mortality patterns are age over 45 years at the time of diagnosis, male sex, and history of alcoholism and nosocomial risk factors. [10][11] The overall burden of Hepatitis B Virus infection is being recognized increasingly. [12][13] As liver cirrhosis progresses, there is an alteration in the liver parenchyma, and this fibrosis also affects the walls of hepatic veins which increases resistance in the hepatic veins thus leading to an increase in the resistive index on color Doppler examination which helps detect stage fibrosis/cirrhosis. [14][15][16][17] Hepatic venous Doppler is a readily available, cheap, simple, and non-invasive procedure. Local studies are deficient in cirrhosis determined by HVRI compared with liver biopsy. 18 Depending upon the results of this study, the Hepatic vein resistive index by Doppler ultrasound can reliably be applied to avoid undue liver biopsies.

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Patients with e antigen-positive having a viral load of 20,000 IU/ml.

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Patients with e antigen-negative having a viral load of 2000 IU/ml. 2) Age between 18 years and 50 years (both gender). b) Exclusion Criteria: 1) Patients having splenomegaly.
2) Patients who are on interferon therapy. 3) Patients having esophageal varices. Data collection procedure: After approval by the ethical committee of Rawalpindi medical college and Allied hospitals, patients fulfilling the inclusion criteria were subjected to Doppler ultrasound of hepatic vein. Informed consent was obtained from all the patients and the procedure was explained to all patients. The procedure was carried out with a pulsed Doppler flowmeter by using a 5MHz convex curvilinear transducer. Hepatic vein resistive index is calculated by using the formula "maximum negative velocity minus minimum negative velocity (or positive velocity in case of a triphasic flow signal)/maximum negative velocity". HVRI=maximum negative velocity-minimum negative velocity Maximum negative velocity F0=1.45 ± 0.02 F1=1.26 ± 0.05 F2=1.06 ± 0.06 F3=0.87 ± 0.08 F4=0.46 ± 0.12 In my study fibrosis stage, F2 ≥ will be considered positive for fibrosis. The results were then compared with a liver biopsy performed by the medicine department MU1 and histological staging analyzed by the pathology department of the same hospital. A liver biopsy specimen was obtained by a pathologist and blindly reviewed. The METAVIR staging system of the degree of fibrosis and cirrhosis was used in liver biopsy specimen interpretation by the pathology department. Fibrosis is staged from 0 to 4 (Table 3). Liver biopsy results showed that 60% (n=45) of patients were positive and 40% (n=30) were negatives as per criteria defined in our operational definition (Table 4). Cross-tabulation of ultrasound (HVRI) and liver biopsy results are shown in (Table 5).

Discussion
Liver biopsy remains the typical procedure to diagnose the level of fibrosis in chronic liver disease but it is an invasive procedure and may lead to serious complications if not performed properly. 19 The hepatic venous resistive index has been investigated using color Doppler ultrasonography as a non-invasive technique in CLD, especially in subjects having portal hypertension, portal vein thrombosis, and also in Budd-chiari-syndrome. Doppler examination protocols however differ because no standard technique has been established so far. 19 Liver surface assessment using ultrasound showed reasonable diagnostic precision in studies that confirmed good research practice. Further procedures however have proven variable or mild to moderate diagnostic accuracy. In our study, we have tried hepatic venous resistive index measurements through They concluded that this increased stiffness of hepatic parenchyma leads to loss of plasticity in hepatic veins due to impairment of hepatic venous compliance and this incidence of the flattened waveform was associated with the severity of cirrhosis. Venous waveform dampening is more frequently seen in cirrhosis. 20 Similar results are seen in our study. Figures 1 and 2 showing the dampening of venous waveform with the advancement in the stage of fibrosis. Reports published in the literature to date and the results of this study showed its encouraging potential role in the detection of liver fibrosis.

Conclusion
Hepatic vein resistive index is a reliable noninvasive method in the detection of patients with liver fibrosis and can detect liver fibrosis in patients of CLD with overall sensitivity, specificity, PPV, NPV, and accuracy of 77.7%, 96.7%, 97.2%, 74.3%, and 85.3% respectively.