Daniel Ganger

Assessment of Chronic Hepatitis and Fibrosis: Comparison of MR Elastography and Diffusion-Weighted Imaging

OBJECTIVE The purpose of our study was to compare the utility of MR elastography (MRE) and diffusion-weighted imaging (DWI) in characterizing fibrosis and chronic hepatitis in patients with chronic liver diseases. SUBJECTS AND METHODS Seventy-six patients with chronic liver disease underwent abdominal MRI, MRE, and DWI. Severities of liver fibrosis and chronic hepatitis were graded by histopathologic analysis according to standard disease-specific classifications. The overall predictive ability of MRE and DWI in assessment of fibrosis was compared by constructing a receiver operating characteristic (ROC) curve and calculating the area under the curve (AUC) on the basis of histopathologic analysis. RESULTS Using ROC analysis, MRE showed greater capability than DWI in discriminating stage 2 or greater (≥ F2), stage 3 or greater (≥ F3), and cirrhosis (≥ F4), shown as significant differences in AUC (p = 0.003, p = 0.001, and p = 0.001, respectively). Higher sensitivity and specificity were shown by MRE in predicting fibrosis scores ≥ F2 (91% and 97%), scores ≥ F3 (92% and 95%), and scores F4 (95% and 87%) compared with DWI (84% and 82%, 88% and 76%, and 85% and 68%, respectively). Although MRE had higher ability in identification of liver with fibrosis scores ≥ F1 than DWI, a significant difference was not seen (p = 0.398). Stiffness values on MRE increased in relation to increasing severity of fibrosis confirmed by histopathology scores; however, a consistent relationship between apparent diffusion coefficient (ADC) values and stage of fibrosis was not shown. In addition, liver tissue with chronic hepatitis preceding fibrosis may account for mild elevation of liver stiffness. CONCLUSION MRE had greater predictive ability in distinguishing the stages of liver fibrosis than DWI.

Effect of Body Temperature on Brain Edema and Encephalopathy in the Rat After Hepatic Devascularization

Brain edema is a fatal complication of fulminant hepatic failure and its pathogenesis remains unclear. To determine its presence in a model of ischemic hepatic failure, rats were subjected to a portacaval anastomosis followed by hepatic artery ligation. Brain water was measured using the sensitive gravimetric method. Preliminary studies revealed marked hypothermia in devascularized animals kept at room temperature (26.9 degrees +/- 2.8 degrees C). An additional group of devascularized rats was kept in an incubator. As expected for hypothermia, such animals had a lower arterial pressure and heart rate; the duration of encephalopathy was markedly prolonged. Water content of the cortical gray matter was only increased in normothermic devascularized rats: 80.14% +/- 0.31%, normal; 80.06% +/- 0.22%, portacaval shunt only; 80.42% +/- 0.26%, devascularized at room temperature; 81.29% +/- 0.38%, devascularized at controlled temperature (p less than 0.001). Such differences could not be detected using the dry-weight technique in whole cerebral hemispheres. Astrocyte changes in the cortical gray matter were noted in both edematous and nonedematous devascularized groups, coupled with the presence of vesicles containing horseradish peroxidase in the endothelial capillary cell. This suggests that in this model, brain edema may be due to both a cytotoxic mechanism and changes in the permeability of the blood-brain barrier. Future studies with this widely used model will require strict control of temperature to allow interpretation of experimental results. A therapeutic role for hypothermia in the management of brain edema deserves further attention.

Radiation lobectomy: Time-dependent analysis of future liver remnant volume in unresectable liver cancer as a bridge to resection

BACKGROUND & AIMS Portal vein embolization (PVE) is a standard technique for patients not amenable to liver resection due to small future liver remnant ratio (FLR). Radiation lobectomy (RL) with (90)Y-loaded microspheres (Y90) is hypothesized to induce comparable volumetric changes in liver lobes, while potentially controlling the liver tumor and limiting tumor progression in the untreated lobe. We aimed at testing this concept by performing a comprehensive time-dependent analysis of liver volumes following radioembolization. METHODS 83 patients with right unilobar disease with hepatocellular carcinoma (HCC; N=67), cholangiocarcinoma (CC; N=8) or colorectal cancer (CRC; N=8) were treated by Y90 RL. The total liver volume, lobar (parenchymal) and tumor volumes, FLR and percentage of FLR hypertrophy from baseline (%FLR hypertrophy) were assessed on pre- and post-Y90 CT/MRI scans in a dynamic fashion. RESULTS Right lobe atrophy (p=0.003), left lobe hypertrophy (p<0.001), and FLR hypertrophy (p<0.001) were observed 1 month after Y90 and this was consistent at all follow-up time points. Median %FLR hypertrophy reached 45% (5-186) after 9 months (p<0.001). The median maximal %FLR hypertrophy was 26% (-14 → 86). Portal vein thrombosis was correlated to %FLR hypertrophy (p=0.02). Median Child-Pugh score worsening (6 → 7) was seen at 1 to 3 months (p=0.03) and 3 to 6 months (p=0.05) after treatment. Five patients underwent successful right lobectomy (HCC N=3, CRC N=1, CC N=1) and 6 HCCs were transplanted. CONCLUSIONS Radiation lobectomy by Y90 is a safe and effective technique to hypertrophy the FLR. Volumetric changes are comparable (albeit slightly slower) to PVE while the right lobe tumor is treated synchronously. This novel technique is of particular interest in the bridge-to-resection setting.

Accuracy of MR Elastography and Anatomic MR Imaging Features in the Diagnosis of Severe Hepatic Fibrosis and Cirrhosis

To compare the diagnostic accuracy of magnetic resonance imaging elastography (MRE) and anatomic MRI features in the diagnosis of severe hepatic fibrosis and cirrhosis.

Unresectable solitary hepatocellular carcinoma not amenable to radiofrequency ablation: Multicenter radiology-pathology correlation and survival of radiation segmentectomy

Resection and radiofrequency ablation (RFA) are treatment options for hepatocellular carcinoma (HCC) <3 cm; there is interest in expanding the role of ablation to 3‐5 cm. RFA is considered high‐risk when the lesion is in close proximity to critical structures. Combining microcatheter technology and the localized emission properties of Y90, highly selective radioembolization is a possible alternative to RFA in such cases. We assessed the efficacy (response, radiology‐pathology correlation, survival) of radiation segmentectomy in solitary HCC not amenable to RFA or resection. Patients with treatment‐naïve, unresectable, solitary HCC ≤5 cm not amenable to RFA were included in this multicenter study. Administered dose, response rate, time‐to‐progression (modified Response Evaluation Criteria in Solid Tumors [mRECIST]), radiology‐pathology correlation and long‐term survival were assessed. In all, 102 patients were included in this study. mRECIST complete response (CR), partial response (PR), and stable disease (SD) were 47/99 (47%), 39/99 (39%), and 12/99 (12%), respectively. Median time‐to‐disease‐progression was 33.1 months. In all, 33/102 (32%) patients were transplanted with a median (interquartile range [IQR]) time‐to‐transplantation of 6.3 months (3.6‐9.7). Pathology revealed 100% and 50‐99% necrosis in 17/33 (52%) and 16/33 (48%), respectively. Median overall survival was 53.4 months. Univariate analysis demonstrated a survival benefit for Eastern Cooperative Oncology Group (ECOG) 0 patients. In the multivariate model, age <65, ECOG 0, and Child‐Pugh A were characteristics associated with longer survival. Conclusion: Radiation segmentectomy is an effective technique with a favorable risk profile and radiology‐pathology outcomes for solitary HCC ≤5 cm. This approach may allow for treatment of HCC in difficult locations. Since RFA and resection are not options given tumor location, there appears to be a strong rationale for this technique as second choice. (Hepatology 2014;60:192–201)

Randomized, double-blind study of intravenous human albumin in hypoalbuminemic patients receiving total parenteral nutrition

OBJECTIVE To determine whether replacement of human albumin will improve a patients prognosis. DESIGN A randomized, double-blind, controlled study in which 25 g of human albumin vs. placebo was administered intravenously daily. SETTING A university-affiliated hospital. PATIENTS Thirty-six patients with hypoalbuminemia (serum albumin of <2.5 g/dL), receiving total parenteral nutrition. None of the patients had known cancer, cirrhosis, or nephrotic syndrome. INTERVENTIONS Each patient received at least 6 days of therapy (6 to 24 days of albumin; 7 to 32 days of placebo). Four subjects were excluded from the study since they received therapy for <6 days. One patient was excluded from the study after nephrotic syndrome was identified. Albumin metabolic rates for those patients receiving albumin were estimated using the formula: Metabolism of albumin = 25 g/day + (albumin 1 - albumin 2)(Vd)/days, where albumin 1 and 2 are the serum albumin concentrations (g/L) at the beginning and end of the serum sampling intervals, respectively; Vd is the volume of distribution (L); and days relates to the number of days of the sampling interval. MEASUREMENTS AND MAIN RESULTS Sixteen patients received albumin; 15 patients received placebo. One patient receiving placebo and two patients receiving albumin died within 30 days. One patient who received placebo and three patients who received albumin developed sepsis or bacteremia; four patients who received placebo and seven patients who received albumin developed pneumonia during the study (NS). The serum albumin increased in all patients receiving intravenous albumin, but one patient received intravenous albumin for only 6 days. The mean serum albumin concentration increased by 1.42 g/dL in the albumin patients, and increased by 0.29 in the placebo patients (p < .0001 by unpaired t-test). Mean initial albumin metabolism was 17.4 g/day (0.3 g/kg/day). At the end of therapy, albumin metabolism was 20.5 g/day (0.36 g/kg/day) (paired t-test, p = .4, NS). CONCLUSIONS a) The administration of intravenous albumin to hypoalbuminemic patients receiving total parenteral nutrition does not improve morbidity or mortality. b) Albumin metabolic rates, initially related to the catabolic state, are high; later, these rates are high related to filling of the albumin space and gluconeogenesis. c) On the basis of the high albumin catabolic rates at the end of the infusion, doses of albumin of <25 g/day might be sufficient to replace albumin stores.

Radioembolization for hepatocellular carcinoma with portal vein thrombosis: Impact of liver function on systemic treatment options at disease progression

BACKGROUND & AIMS Yttrium-90 ((90)Y) radioembolization is a microembolic procedure. Hence, it is commonly used in hepatocellular carcinoma (HCC) patients with portal venous thrombosis (PVT). We analyzed liver function, imaging findings, and treatment options (local/systemic) at disease progression following (90)Y treatment in HCC patients with PVT. METHODS We treated 291 HCC patients with (90)Y radioembolization. From this cohort, we included patients with liver-only disease, PVT and Child-Pugh (CP) score ≤ 7; this identified 63 patients with HCC and PVT (CP-A:35, CP-B7:27). Liver function, CP status, and imaging findings at progression were determined in order to assess potential candidacy for systemic treatment/clinical trials. Survival, time-to-progression (TTP), and time-to-hepatic decompensation analyses were performed using Kaplan-Meier methodology. RESULTS Of 35 CP-A and 28 CP-B7 patients, 29 and 15 progressed, respectively. Median survival and TTP were 13.8 and 5.6 months in CP-A and 6.5 and 4.9 months in CP-B7 patients, respectively. Of the 29 CP-A patients who progressed, 45% maintained their CP status at progression (55% decompensated to CP-B). Of the 15 CP-B7 patients who progressed, 20% improved to CP-A, 20% maintained their CP score and 60% decompensated. CONCLUSIONS Knowledge of liver function and CP score of HCC with PVT progressing after (90)Y is critically relevant information, as these patients may be considered for systemic therapy/clinical trials. If a strict CP-A status is mandated, our study demonstrated that 64% of cases exhibited inadequate liver function and were ineligible for systemic therapy/clinical trials. An adjuvant approach using local therapy and systemic agents prior to progression should be investigated.

Brain edema in rabbits with galactosamine-induced fulminant hepatitis: Regional differences and effects on intracranial pressure

Abstract Brain edema and intracranial hypertension are major complications of fulminant hepatic failure. We investigated the development of brain edema and monitored intracranial pressure in rabbits with toxic hepatitis induced by galactosamine. Using a gravimetric technique to assay small tissue samples, we found that brain water was increased in cortical grey matter, but not in subcortical, mesencephalic, and pontine white matter, or in the cerebellum. The proportion of water in cerebral grey matter in control animals was 80.96% ± 0.49% with significant elevations to 81.96% ± 0.47% and 82.95% ± 1.49% in mild and severe encephalopathy, respectively. This corresponds to mean increases in tissue volume of 5.5% and 11.7%. The hippocampal grey matter also accumulated water in severe encephalopathy with a 30% increase in mean tissue volume. The regional increase in brain water was confirmed by the wet-dry weight method. Neither hypotension, hypoxia, nor severe hypoglycemia were present to account for the edema. Intracranial pressure was monitored continuously in unanesthetized rabbits via an intraventricular cannula as encephalopathy developed. The pressure was normal in the mild stage, but was intermittently elevated in animals with severe encephalopathy. The normal range of intracranial pressure was 2–9 mmHe and the ranee or peak values in galactosamine-treated rabbits was 18–55 mmHg. The regional differences in brain water accumulation suggest that cellular swelling and abnormalities in the movement of water across the blood-brain barrier may account for the brain edema in this model.

Hemodynamic evaluation of isosorbide dinitrate in alcoholic cirrhosis: Pharmacokinetic-hemodynamic interactions

Isosorbide dinitrate, a long-acting organic nitrate, has been shown to decrease portal pressure in the experimental animal and humans. We conducted a double-blind randomized hemodynamic evaluation of the effects of placebo and 10 mg and 20 mg isosorbide dinitrate in stable individuals with alcoholic cirrhosis. Baseline values for all three groups were similar. Isosorbide dinitrate resulted in a peak reduction of the hepatic venous gradient of 24.7% +/- 3.0%, with significantly decreased values 4 h after the administration of the 20-mg dose. A reduction of arterial pressure and cardiac index (peak decrease of 25.7% +/- 1.5%) was well tolerated by 13 of 15 patients. Changes in mean arterial pressure were not predictive of modifications in the hepatic vein wedge pressure. There was no relation between the area under the plasma isosorbide dinitrate concentration curve and hemodynamic changes. Levels of isosorbide-5-mononitrate, a vasoactive metabolite, were detectable for an 8-h period. Isosorbide dinitrate significantly reduced portal pressure in stable cirrhotics, in association with systemic hemodynamic changes. Thus, titration of isosorbide dinitrate is required to maximize hemodynamic benefits in individual patients. As the decrease in portal pressure is more predictable than the effect of previously tested pharmacologic agents, isosorbide dinitrate should be evaluated for its efficacy in the management of portal hypertension.

Detection of anti‐isoniazid and anti–cytochrome P450 antibodies in patients with isoniazid‐induced liver failure

Isoniazid (INH)‐induced hepatotoxicity remains one of the most common causes of drug‐induced idiosyncratic liver injury and liver failure. This form of liver injury is not believed to be immune‐mediated because it is not usually associated with fever or rash, does not recur more rapidly on rechallenge, and previous studies have failed to identify anti‐INH antibodies (Abs). In this study, we found Abs present in sera of 15 of 19 cases of INH‐induced liver failure. Anti‐INH Abs were present in 8 sera; 11 had anti–cytochrome P450 (CYP)2E1 Abs, 14 had Abs against CYP2E1 modified by INH, 14 had anti‐CYP3A4 antibodies, and 10 had anti‐CYP2C9 Abs. INH was found to form covalent adducts with CYP2E1, CYP3A4, and CYP2C9. None of these Abs were detected in sera from INH‐treated controls without significant liver injury. The presence of a range of antidrug and autoAbs has been observed in other drug‐induced liver injury that is presumed to be immune mediated. Conclusion: These data provide strong evidence that INH induces an immune response that causes INH‐induced liver injury. (Hepatology 2014;59:1084–1093)