The clinical importance of the trimethadione tolerance test as a method for quantitative assessment of hepatic functional reserve in patients with biliary atresia

A noninvasive index to predict liver cirrhosis in biliary atresia

BACKGROUND

Biliary atresia is a progressive obliterative cholangiopathy affecting both extrahepatic and intrahepatic biliary trees, resulting in fibrous obliteration of the biliary tract and subsequent development of cirrhosis.

OBJECTIVE

The aim of this study was to find noninvasive indices to predict the status of hepatic fibrosis in children with biliary atresia.

MATERIALS AND METHODS

We retrospectively measured the volume of the hepatic lobes and spleen from MR images, obtained biochemical data and analyzed the relationship between the imaging and biochemical indices, and the pathological status of hepatic fibrosis in 35 children with biliary atresia.

RESULTS

A combined index was obtained by logistic regression: logit (likelihood of cirrhosis) = 0.00043 x age at MR examination + 1.67 x aspartate aminotransferase and platelet ratio index (APRI) + 0.0029 x body-surface-area-adjusted left liver lobe volume (BSA adLLV) - 6.57 (log-likelihood chi-square P<0.05, pseudo-R²=0.59). The area under the receiver operator characteristic curve of age at MR examination, APRI, BSA adLLV and the combined index for prediction of cirrhosis were 0.91, 0.86, 0.83 and 0.94, respectively. The optimal cut-off value (sensitivity and specificity) of age at MR examination, APRI, BSA adLLV and combined index were 132 (86% and 92%), 1.3 (91% and 85%), 855.5 (96% and 62%) and 0.689 (91% and 92%). The accuracy of age at MR examination, APRI, BSA adLLV and combined index were 89%, 89%, 83% and 91%, respectively.

CONCLUSION

A combined noninvasive index of age, aspartate aminotransferase and platelet ratio index, and the body-surface-area-adjusted left liver lobe volume measured from MR images is a potential marker of liver cirrhosis in children with biliary atresia.

Hepatic ADC map as an adjunct to conventional abdominal MRI to evaluate hepatic fibrotic and clinical cirrhotic severity in biliary atresia patients

OBJECTIVES

Hepatic apparent diffusion coefficient (ADC) values and ADC-related indices were correlated with the Mayo risk score for primary biliary cirrhosis (MRSPBC) and METAVIR scores of liver specimens to determine the clinical and pathological significance of diffusion-weighted magnetic resonance imaging (DWMRI).

METHODS

Thirty-two patients with biliary atresia (BA; mean age 461 days, range 11-4616 days) received magnetic resonance examinations from March 2009 to August 2013. A free-breathing DWMRI sequence was performed with the single-shot echo-planar imaging technique with b = 0 and 500 s/mm(2) in all 32 BA patients and 24 controls. We used the ordinal logistic regression test and Spearman rank correlation test to analyse the relationships between the MRSPBC and METAVIR fibrosis scores and right liver-to-psoas ADC ratios (LTPARs).

RESULTS

BA patients had significantly lower LTPARs in both hepatic lobes than controls (p < 0.01). Right LTPARs, showing moderate intraobserver agreement (intraclass correlation coefficient = 0.736) and interobserver reliability (intraclass correlation coefficient = 0.659), were negatively correlated with MRSPBC and METAVIR fibrosis scores (R(2) = 0.398, p = 0.024 and R(2) = 0.628, p < 0.001, respectively).

CONCLUSION

Right LTPARs may be used for long-term follow-up of cirrhosis severity in BA patients.

KEY POINTS

• Hepatic ADC values by DWI correlates well with clinical/pathologic fibrosis scores • Periodic, non-invasive, quantitative imaging follow-up of patients with biliary cirrhosis is feasible • Information on cirrhosis severity could help decide on management options in children with BA • ADC values may be useful in this regard.

How much liver resection is too much?

BACKGROUND

Hepatic failure occurring after liver resection carries a poor prognosis and is a complication dreaded by surgeons. Inadequate reserve in the remaining parenchyma leads to a steady decrease in liver function, inability to regenerate, and progression to liver failure. For this reason, many methods to quantify functional hepatic reserve have been developed.

METHODS

This article reviews the main methods used in the assessment of hepatic reserve in patients undergoing hepatectomy and their use in operative decision making.

RESULTS

A range of methods to categorically quantify the functional reserve of the liver have been developed, ranging from scoring systems (such as the Child-Pugh classification) to tests assessing complex hepatic metabolic pathways to radiological methods to assess functional reserve. However, no one method has or is ever likely to emerge as a single measure with which to dictate safe limits of resectability.

CONCLUSIONS

In the future, the role of residual liver function assessment may be of most benefit in the routine stratification of risk, thus enabling both patient consent to be obtained and surgical procedure to be performed, with full information and facts regarding operative risks. However, there is no one single test that remains conclusively superior.