Hepatitis C virus reinfection in liver transplant patients: evaluation of liver damage progression with echo-color Doppler

Management of Portal Hypertension After Liver Transplantation

INTRODUCTION

Post-transplantation portal hypertension has severe complications, such as esophageal varix bleeding, therapy refractory ascites, extreme splenomegaly, and graft dysfunction. The aim of our study was to analyze the effectiveness of the therapeutic strategies and how to visualize the procedure.

METHODS

A retrospective study involving liver transplantation patients from the Semmelweis University Department of Transplantation and Surgery was performed between 2005 and 2015. The prevalence, etiology, and leading complications of the condition were determined. The applied interventions' effects on the patients' ascites volume, splenic volume, and the occurrence of variceal bleeding were determined. Mean portal blood flow velocity and congestion index values were calculated using Doppler ultrasonography.

RESULTS

The prevalence of post-transplantation portal hypertension requiring intervention was 2.8%. The most common etiology of the disease was portal anastomotic stenosis. The most common complications were esophageal varix bleeding and therapy refractory ascites. The patients' ascites volume decreased significantly (2923.3 ± 1893.2 mL vs. 423.3 ± 634.3 mL; P < .05), their splenic volume decreased markedly. After the interventions, only one case of recurrent variceal bleeding was reported. The calculated Doppler parameters were altered in the opposite direction in cases of pre-hepatic versus intra- or post-hepatic portal hypertension. After the interventions, these parameters shifted towards the physiologic ranges.

CONCLUSION

The interventions performed in our clinic were effective in most cases. The patients' ascites volume, splenic volume, and the prevalence of variceal bleeding decreased after the treatment. Doppler ultrasonography has proved to be a valuable imaging modality in the diagnosis and the follow-up of post-transplantation portal hypertension.

Contrast-Enhanced Ultrasound Using Perfluorobutane-Containing Microbubbles in the Assessment of Liver Allograft Damage: An Exploratory Prospective Study

This prospective study investigated the usefulness of contrast (perfluorobutane-containing microbubbles)-enhanced ultrasound in the non-invasive assessment of liver allograft damage. Forty-one liver recipients underwent contrast-enhanced ultrasound followed by a liver biopsy. The hepatic filling rate (time between the arrival of contrast agent in the right hepatic artery and the maximum intensity of hepatic parenchyma) and parenchymal intensity difference before and after instantaneous high-power emission in the Kupffer phase were measured. Patients with allograft damage had higher hepatic filling rates and lower parenchymal intensity differences than those without damage (42.0 ± 16.9 vs. 30.5 ± 7.7 s, p = 0.005; 6.1 ± 7.4 vs. 16.6 ± 16.1 dB, p = 0.047, respectively). In the diagnosis of liver allograft damage, hepatic filling rate and parenchymal intensity difference had sensitivities of 61.5% and 90.9% and specificities of 92.6% and 63.6% using cutoffs of >38.5 s and ≤10.3 dB, respectively. In conclusion, contrast-enhanced ultrasound may be a promising tool in the detection of liver allograft damage.

Progression of liver fibrosis in post-transplant hepatitis C: mechanisms, assessment and treatment

Liver fibrosis results from an excessive wound healing response in most chronic liver diseases, such as hepatitis C. Despite great advances in antiviral therapy in recent years, progressive liver fibrosis remains a major problem for patients with recurrent hepatitis C after liver transplantation. Liver biopsy remains a central tool in the management of HCV-positive liver transplant recipients, but reliable non-invasive methods for the assessment of liver fibrosis, such as ultrasound elastography, are increasingly being incorporated in the management of post-transplant patients, helping predict prognosis, guide treatment decisions, and stratify patients for emerging antifibrotic therapies. In this manuscript, we will review the natural history as well as tools to monitor fibrosis progression in the HCV-positive liver transplant recipient, the mechanisms underlying rapid fibrosis progression in up to 30% of these patients, the effect of antiviral therapies and highlight promising antifibrotic approaches.

Relationship between hepatic haemodynamics assessed by Doppler ultrasound and liver stiffness

AIM

We tested the relationship between hepatic haemodynamics assessed by Doppler ultrasonography and liver stiffness assessed by Transient Elastography in hepatitis C related chronic liver disease.

METHODS

Three liver Doppler ultrasound parameters (hepatic artery resistance index, splenic artery resistance index and waveform pattern in hepatic veins) and liver stiffness measured by Transient Elastography were analysed in one hundred consecutive patients affected by hepatitis C related chronic liver disease.

RESULTS

Hepatic and splenic arteries resistance indexes correlate significantly (p<0.0001 for both) with liver stiffness. A hepatic artery resistance index cut-off value of 0.64 provided sensitivity and specificity respectively of 84.4% and 69.1% for predicting liver stiffness ≤or >13 kPa, whereas a splenic artery resistance index cut-off value of 0.56 provided sensitivity and specificity respectively of 81.3% and 48.5%. The coincidental finding of both resistance indexes above the respective cut-off values showed a good accuracy in identifying patients with liver stiffness values >13 kPa (accuracy=78%, +LR=2.90, -LR=0.31). A significant difference in liver stiffness values was evident between patients with triphasic and bi- or monophasic waveform pattern (p=0.005).

CONCLUSIONS

Hepatic and splenic arteries resistance indexes and the hepatic veins waveform pattern assessed by Doppler ultrasound may provide information similar to that of Transient Elastography in hepatitis C related chronic liver disease.

Splenic Doppler impedance indices estimate splenic congestion in patients with right-sided or congestive heart failure

Splenic Doppler impedance indices are measurements of splenic congestion in chronic liver disease. It is not known whether they can also assess splenic congestion in patients affected by right-sided or congestive heart failure. We analyzed splanchnic hemodynamics with Doppler ultrasound and systemic hemodynamics with right-sided heart catheterization in patients with heart failure. Splenic pulsatility index (PI) was higher in patients with heart failure (48 patients) compared with healthy subjects (39 patients) (1.19 ± 0.41 vs. 0.73 ± 0.11, p < 0.0001) and was related to hepatic vein diameter (p = 0.02). Splenic PI was not related to systemic arterial pressure, cardiac output, systemic vascular resistance or splenic arterial resistance, whereas it was related to right atrial mean pressure (p = 0.0003) and to right ventricle end-diastolic pressure (p = 0.011) (34 patients). In conclusion, splenic PI is a measurement of splenic congestion caused by an increase in venous outflow resistance. It can estimate splenic congestion in patients with right-sided or congestive heart failure.

Management of posttransplant hepatitis C infection

PURPOSE OF REVIEW

Chronic hepatitis C virus (HCV) infection is the leading cause of liver transplantation. Outcome of HCV-associated liver transplantation has been worse than transplantation from other causes. This is mostly related to universal recurrence of HCV in the allograft leading to graft and patient loss or retransplantation. Current antiviral therapies (AVTs) are inadequate and ineffective in the vast majority of the patients with intolerable side effects in most. However, a sustained virologic response (SVR) is associated with improved graft and patient survival. New specifically targeted AVTs for HCV (STAT-C) agents in development will significantly improve the success of AVT. This review focuses on recent data in peritransplant management of HCV with special emphasis on predictors of outcome, diagnosis, prevention and control of reinfection with newer treatments on the horizon.

RECENT FINDINGS

In the immediate pretransplant setting, AVT should be considered in select patients to eradicate the virus. Careful donor selection, immunosuppression (IMS) modulation with steroid and calcineurin inhibitor (CNI) minimization, avoidance of T-cell-depleting treatments and acute rejection episodes, and control of metabolic syndrome can improve allograft outcomes and improve the response to AVT. AVT prior to significant damage to the allograft is strongly recommended.

SUMMARY

With modified novel IMS protocols, careful donor selection, and AVT prior to significant damage to the allograft we can improve the outcome of posttransplant hepatitis C infection. Albeit there are no available data on new antiviral agents, STAT-Cs will have a significant impact in this setting in the near future.