Splenic elasticity measured with real-time tissue elastography is a marker of portal hypertension

Liver stiffness and spleen stiffness predict distinct liver-related events after hepatitis C eradication with direct-acting antivirals

BACKGROUND

/Purpose: This study aimed to directly compare the utility of liver stiffness (LS) and spleen stiffness (SS) at sustained virologic response (SVR) for predicting hepatocellular carcinoma (HCC) and non-HCC events in patients with chronic hepatitis C (CHC) after direct-acting antiviral therapy.

METHODS

This retrospective study included 695 CHC patients who achieved SVR and underwent LS and SS measurements. LS and SS were measured using point shear wave elastography and compared head-to-head.

RESULTS

During a median follow-up of 29.5 months, 49 (7.1%) patients developed liver-related events (LREs), including 28 HCC and 22 non-HCC events after SVR. Multivariable Cox regression analysis revealed that age, albumin level, and LS (≥ versus <1.46 m/s) at SVR (adjusted hazard ratio [aHR]: 5.390; 95% confidence interval [CI]: 2.349-12.364; p < 0.001), but not SS at SVR, significantly predicted the overall risk of post-SVR LREs (n = 49). Furthermore, age and LS (≥ versus <1.46 m/s) at SVR (aHR: 6.759; 95% CI: 2.317-19.723; p < 0.001), but not SS at SVR, independently predicted the risk of post-SVR incident HCC. In contrast, SS (≥ versus <2.87 m/s) at SVR (aHR: 11.212; 95% CI: 1.564-20.132; p = 0.021) and albumin level, but not LS at SVR, significantly predicted the risk of post-SVR non-HCC events.

CONCLUSION

Post-SVR LS better predicts HCC risk. Post-SVR SS helps predict non-HCC risk after antiviral therapy for CHC. LS and SS at SVR provide complementary prognostic information regarding risks of HCC and non-HCC events in the post-SVR setting. Further validation is warranted in larger cohorts.

Enlargement of the Spleen Index Is a Predictor of the Occurrence of Esophageal Varices and Hepatocellular Carcinoma after Administering Direct-acting Antiviral Agents

Objective Direct-acting antiviral agents (DAAs) can eliminate hepatitis C virus at a high rate, although the long-term incidence of portal hypertension and hepatocellular carcinoma (HCC) has not yet been elucidated. In this observational study, we clarified the predictors associated with the incidence of esophageal varices (EVs) and HCC after DAAs treatment based on ultrasound findings and blood examinations. Methods A total of 78 patients treated with DAAs were enrolled in this study. The primary endpoint was to identify the predictors associated with EVs and HCC occurrence using univariate and multivariate analyses. Secondary endpoints were to extract the cutoff values for EVs and HCC occurrence and clarify the changes in liver stiffness (LS), spleen stiffness (SS), spleen index (SI), portal venous flow volume (PVF), and blood examination at 12 weeks after the end of DAAs treatment. Results The mean observation period was 1,402±546 days. SI change (SI after DAAs-SI before DAAs) was a predictor of EVs occurrence in multivariate analysis (p=0.045). The treatment history of HCC, albumin value before DAAs, and SI change were predictors of HCC occurrence in multivariate analysis (p=0.002, p=0.032, and p=0.009, respectively). LS, SS, PVF, SI, and liver function significantly improved after DAAs treatment. Conclusion Portal hypertension seems to improve after DAAs treatment over a long period. Patients with splenomegaly deterioration after DAAs treatment need to be carefully monitored for the occurrence of EVs and HCC.

Spleen stiffness in patients with chronic liver disease evaluated by 2-D shear wave elastography with ultrasound multiparametric imaging

BACKGROUND

The novel 2-D shear wave elastography (2D-SWE) can measure two ultrasound parameters: shear wave dispersion (SWD) and shear wave speed (SWS). We investigated the ability of 2D-SWE in measuring spleen stiffness using ultrasound multiparametric imaging.

METHODS

This cross-sectional study included patients with chronic liver disease who underwent esophagogastroduodenoscopy and ultrasonographic examinations of the spleen between September 2018 and December 2021. In total, 157 patients were enrolled in this study: 81 and 67 patients were included in the pilot set for hepatic venous pressure gradient (HVPG) measurements and validation cohort without HVPG measurements, respectively. To confirm reproducibility between the two examiners, an additional 30 patients were enrolled.

RESULTS

The Bland-Altman plots revealed no significant bias in the SWD as measured by two examiners. The splenic SWS (r = 0.752) and SWD (r = 0.444) were correlated with the HVPG. Regarding high-risk varices, as per the Youden index, the cut-off value for splenic SWS was 3.30 m/s, with a sensitivity of 85.7%, specificity of 92.5%, positive predictive value of 85.7%, and negative predictive value of 92.4% in the pilot set. In the validation set, good diagnostic performance by the splenic SWS was observed. However, SWD did not perform as well as SWS.

CONCLUSIONS

The splenic SWS, measured using ultrasound multiparametric imaging, was closely correlated with the HVPG. Thus, SWS is a useful predictive marker for high-risk varices.

Sedative effect with the combination of butorphanol and midazolam on two-dimensional shear wave elastography of pancreas and kidney in healthy dogs

OBJECTIVE

To evaluate the sedative effect of a combination of butorphanol and midazolam on 2-D shear wave elastography (SWE) of the kidneys and pancreas in dogs.

ANIMALS

8 clinically healthy dogs.

PROCEDURES

We conducted a 2-D SWE examination of the bilateral kidneys and the pancreas before and after IV of 0.2 mg/kg butorphanol and 0.1 mg/kg midazolam in each dog. We performed 2-D SWE on the left kidney via a subcostal approach with the dog in right lateral recumbency, on the right kidney via the intercostal approach with the dog in left lateral recumbency, and on the right lobe of the pancreas via the subcostal approach. Subsequently, the pancreas and kidney shear wave velocities (SWV) pre- and postsedation were compared.

RESULTS

On qualitative evaluation using color mapping, the pancreas and kidneys showed a homogeneous blue-to-green color in pre- and post-sedation 2-D SWE. There was no significant difference in SWV pre- and post-sedation in the pancreas and kidneys.

CLINICAL RELEVANCE

Intravenous administration of a combination of 0.2 mg/kg butorphanol and 0.1 mg/kg midazolam did not change the 2-D SWE of the pancreas and kidneys significantly. The combination of butorphanol and midazolam can be used in healthy dogs for 2-D SWE evaluation of the pancreas and kidneys, especially when the patient is uncooperative during the examination.

Non-invasive diagnosis and follow-up of portal hypertension

Compensated advanced chronic liver disease (cACLD) describes the spectrum of advanced fibrosis/cirrhosis in asymptomatic patients at risk of developing clinically significant portal hypertension (CSPH, defined by a hepatic venous pressure gradient (HVPG) ≥10 mmHg). Patients with cACLD are at high risk of liver-related morbidity and mortality. In patients at risk of chronic liver disease, cACLD is strongly suggested by a liver stiffness (LSM) value >15 kPa or clinical/biological/radiological signs of portal hypertension, and ruled out by LSM <10 kPa, or Fibrotest® ≤0.58, or Fibrometer® ≤0.786. Patients with chronic liver disease (excluding vascular diseases) with a LSM <10 kPa are at low risk of developing portal hypertension complications. The presence of CSPH can be strongly suspected when LSM is ≥20 kPa. In a patient without clinical, endoscopic or radiological features of portal hypertension, measurement of the HVPG is recommended before major liver or intra-abdominal surgery, before extra-hepatic transplantation and in patients with unexplained ascites. Endoscopic screening for oesophageal varices can be avoided in patients with LSM <20 kPa and a platelet count >150 G/L (favourable Baveno VI criteria) at the time of diagnosis. There is no non-invasive method alternative for oeso-gastroduodenal endoscopy in patients with unfavourable Baveno criteria (liver stiffness ≥20 kPa or platelet count ≤50 G/l). Platelet count and liver stiffness measurements must be performed once a year in patients with cACLD with favourable Baveno VI criteria at the time of diagnosis. A screening oeso-gastroduodenal endoscopy is recommended if Baveno VI criteria become unfavourable.

Measurement of multiple spleen lengths is not necessary for non-invasive prediction of high-risk esophagogastric varices

AIM

To validate an appropriate spleen size measurement technique for the prediction of high-risk esophagogastric varices.

METHODS

This retrospective cross-sectional study included 369 patients who underwent ultrasonography and computed tomography (CT) of the spleen and esophagogastroduodenoscopy between January 2018 and December 2020. Maximum spleen length, width, and craniocaudal length were measured in a longitudinal view. The two-dimensional (2D) spleen index (maximum length × maximum width in the longitudinal view) was calculated. A three-dimensional (3D) spleen index was then defined as follows: 2D spleen index × maximum length in the transverse view. The similarity in spleen volume measured by CT and ultrasonography (spleen index) was assessed by the correlation coefficient. The diagnostic accuracies of the spleen index, platelet/spleen length, and platelet/spleen index were calculated to determine the overall diagnostic accuracy.

RESULTS

Compared to the other spleen indices, our 3D spleen index was significantly better correlated with spleen volume on CT (r = 0.91, 95% confidence interval 0.89-0.92, p < 0.001). Receiver-operating characteristic curve analyses revealed no significant difference between the 3D and 2D indices (p = 0.228) but did show a significant difference between the 3D and one-dimensional indices (p = 0.020). Although the area under the curve for the platelet count combined with the spleen index or length was higher than that for our 3D index, there was no significant difference between platelet count and spleen index or length (p = 0.078).

CONCLUSIONS

Platelet/spleen length has a reasonable ability to predict high-risk esophagogastric varices, even though measurement of two or three factors can be correlated with spleen volume.

A Primer to the Diagnostic and Clinical Utility of Spleen Stiffness Measurement in Patients With Chronic Liver Disease

Content available: Author Audio Recording.

Accurate reflection of hepatic venous pressure gradient by spleen stiffness measurement in patients with low controlled attenuation parameter values

Background and Aim

Spleen stiffness measurement (SSM) is useful for assessing portal hypertension. It is unclear whether SSM values are appropriate because vibration‐controlled transient elastography (VCTE) does not generate B‐mode images. This study aimed to confirm whether the controlled attenuation parameter (CAP) measured in the spleen can predict the accuracy of SSM.

Methods

This retrospective study enrolled 349 patients who underwent SSM using VCTE from January 2012 to December 2020. Consecutive patients were classified into the pilot set (SSM and hepatic venous pressure gradient [HVPG] were measured) and the validation set (SSM was measured without HVPG). In the pilot set, scatter plots with a nonparametric contour line were created. Logistic regression analysis was performed to predict outliers outside the 50% contour line.

Results

The values of CAP could distinguish the outliers in scatter plots between the HPVG and SSM in both univariate and multivariate analyses (cutoff, 118 dB/m). The correlation of SSM with HVPG (r = 0.718; P < 0.001) was significantly better in the low CAP (≤118 dB/m) group than in the high CAP (>118 dB/m) group (r = 0.330; P < 0.001). The area under the receiver operating characteristic curve of SSM in predicting high‐risk varices was better in the low CAP group than in all patients or in the high CAP group in the pilot set (0.881, 0.854, and 0.843, respectively) and in the validation set (0.893, 0.821, and 0.814, respectively).

Conclusion

For patients with CAP <118 dB/m, SSM is a feasible predictor of HVPG.

Using MR elastography to assess portal hypertension and response to beta-blockers in patients with cirrhosis

BACKGROUND

MR elastography can determine organ-related stiffness, which reflects the degree of fibrosis. Liver stiffness increases in cirrhosis, and stiffness increases further post-prandially due to increased portal blood in-flow. Non-selective beta-blockers (NSBB) reduce the portal venous inflow, but their effect on liver and spleen stiffness are disputed.

AIMS

To assess whether MR elastography of the liver or spleen reflects the severity of cirrhosis, whether treatment with NSBB changes liver and spleen stiffness and whether changes in stiffness can predict the effect of NSBB on portal pressure.

METHODS

Fifty-two patients with cirrhosis underwent liver vein catheterization and two-dimensional (2D) MR elastography on separate days. Thirty-six of the patients had a hepatic venous pressure gradient (HVPG) of ≥12 mmHg and were tested prior to, and after, intravenous infusion of NSBB using HVPG measurement and MR elastography.

RESULTS

HVPG showed a strong, positive, linear relationship with liver stiffness (r²  = 0.92; P < .001) and spleen stiffness (r²  = 0.94; P < .001). The cut-off points for identifying patients with a HVPG ≥ 12 mmHg were 7.7 kPa for liver stiffness (sensitivity 0.78, specificity 0.64) and 10.5 kPa for spleen stiffness (sensitivity 0.8, specificity 0.79). Intravenous administration of NSBB significantly decreased spleen stiffness by 6.9% (CI: 3.5-10.4, P < .001), but NSBB had no consistent effect on liver stiffness. However, changes in spleen stiffness were not related to the HVPG response (P = .75).

CONCLUSIONS

Two-dimensional MR elastographic estimation of liver or spleen stiffness reflects the degree of portal hypertension in patients with liver cirrhosis, but changes in stiffness after NSBB do not predict the effect on HVPG.

Pancreas stiffness in liver cirrhosis is an indicator of insulin secretion caused by portal hypertension and pancreatic congestion

AIM

Portal hypertension induces pancreatic congestion and impaired insulin secretion in patients with liver cirrhosis (LC). However, its mechanism is unclear, with no established noninvasive imaging method for the evaluation of its pathogeneses. The present study focused on pancreas stiffness, as assessed by shear wave elastography (SWE), and examined its association with portal hypertension and insulin secretion.

METHODS

Shear wave elastography and contrast-enhanced ultrasonography were utilized to evaluate pancreas stiffness and congestion, respectively. A glucagon challenge test was used for insulin secretion assessment. Furthermore, rat models of carbon tetrachloride (CCl₄ )-induced LC and portal hypertension were used to identify the direct effects of pancreatic congestion. Immunohistochemistry staining of the pancreas was carried out on human autopsy samples.

RESULTS

Pancreas stiffness measured by SWE was higher in patients with LC than in controls and showed significant correlation with pancreatic congestion. The glucagon challenge test indicated a lower value for the change in C-peptide immunoreactivity in the LC group, which was inversely correlated with pancreas stiffness and congestion. Additionally, portal hypertension and insulin secretion dysfunction were confirmed in CCl₄ rat models. Autopsy of human samples revealed congestive and fibrotic changes in the pancreas and the relationship between insulin secretion and their factors in patients with LC.

CONCLUSIONS

In patients with LC, pancreas stiffness measured by SWE could be a potential noninvasive test for evaluating pancreatic congestion and fibrosis due to portal hypertension. Moreover, it was associated with impaired insulin secretion, and could aid in guiding the treatment for hepatogenous diabetes.

Elucidation of spleen elasticity and viscosity in a carbon tetrachloride rat model of liver cirrhosis using a new ultrasound elastography

PURPOSE

Measurement of spleen stiffness (SS) using ultrasound (US) elastography is useful for predicting portal hypertension. However, the mechanism leading to increased SS remains unclear. We jointly developed a new US elastography system (Aplio i-series, Canon Medical Systems) that can easily measure organ viscosity (dispersion slope: DS). We analyzed the cause of increased SS by calculating the shear wave speed (SWs, which reflects fibrosis) and DS of the spleen in carbon tetrachloride (CCL₄) rat liver cirrhosis models.

METHODS

A total of 13 Sprague-Dawley rats were randomly divided into four groups (C group: 3 rats as control, 2D group: 3 rats injected with CCL₄ twice in 1 week, 4D group: 4 rats injected 4 times in 1 week, 6W group: 3 rats injected twice a week for 6 weeks). The SWs and the DS of each group were calculated, and histopathological analysis was performed.

RESULTS

The spleen SWs of the 6W group was significantly higher than that of the C group (p = 0.044). The spleen DS did not change after CCL₄. The liver SWs of the 4D and 6W groups was significantly higher than that of the C group (p = 0.012 and 0.007, respectively) with fibrosis change on histopathology, and the DS of the 4D group was significantly higher than that of the C group (p = 0.033). Splenic fibrosis was confirmed in the 6W group, but inflammation and necrosis were not seen.

CONCLUSION

SS increased due to fibrosis and can be predicted based on SWs and DS values.

Approaches to the Diagnosis of Portal Hypertension: Non-Invasive or Invasive Tests?

Portal hypertension is the main driver of complications in patients with advanced chronic liver disease (ACLD) and is defined by values of hepatic venous pressure gradient measurement (HVPG) >5 mmHg. Values of HVPG ≥10 mmHg determine the presence of clinically significant portal hypertension (CSPH), the main predictor of the risk of variceal bleeding, hepatic decompensation, and mortality. However, its measurement is invasive and requires high expertise, so its routine use outside third level centers or clinical trials is limited. In the last decades, several non-invasive tests (NITs) have been developed and validated for the diagnosis of portal hypertension. Among these, liver (LSM) and spleen stiffness measurement (SSM) are the most promising tools available, as they have been proven accurate to predict CSPH, high-risk esophageal varices, decompensation, and mortality in patients with ACLD. In the last Baveno VI Consensus proceedings, LSM evaluation was recommended for the first time for diagnosis of CSPH (LSM >20-25 kPa) and the screening of patients with a low probability of having high-risk varices (LSM <20 kPa and platelet count >150.000/mm³). In this review, we aimed to summarize the growing evidence supporting the use of non-invasive tests for the evaluation of portal hypertension in patients with chronic liver disease.

Development of a method for measuring spleen stiffness by transient elastography using a new device and ultrasound-fusion method

Background

Hepatic venous pressure gradient (HVPG) is the gold standard index for evaluating portal hypertension; however, measuring HVPG is invasive. Although transient elastography (TE) is the most common procedure for evaluating organ stiffness, accurate measurement of spleen stiffness (SS) is difficult. We developed a device to demonstrate the diagnostic precision of TE and suggest this technique as a valuable new method to measure SS.

Methods

Of 292 consecutive patients enrolled in this single-centre, translational, cross-sectional study from June through September in 2019, 200 underwent SS measurement (SSM) using an M probe (training set, n = 130; inspection set, n = 70). We performed TE with B-mode imaging using an ultrasound-fusion method, printed new devices with a three-dimensional printer, and attached the magnetic position sensor to the convex and M probes. We evaluated the diagnostic precision of TE to evaluate the risk of esophagogastric varices (EGVs).

Results

The median spleen volume was 245 mL (range, 64–1,720 mL), and it took 2 minutes to acquire a B-mode image using the ultrasound-fusion method. The median success rates of TE were 83.3% and 57.6% in patients with and without the new device, respectively (p<0.001); it was 76.9% and 35.0% in patients with and without splenomegaly (<100 mL), respectively (p<0.001). In the prediction of EGVs, the areas under the receiver operating characteristic curve were 0.921 and 0.858 in patients with and without the new device, respectively (p = 0.043). When the new device was attached, the positive and negative likelihood ratios were 3.44 and 0.11, respectively. The cut-off value of SSM was 46.0 kPa. Data that were similar between the validation and training sets were obtained.

Conclusions

The SS can be precisely measured using this new device with TE and ultrasound-fusion method. Similarly, we can estimate the bleeding risk due to EGV using this method.

Spleen Stiffness Probability Index (SSPI): A simple and accurate method to detect esophageal varices in patients with compensated liver cirrhosis

INTRODUCTION AND OBJECTIVES

Recent findings pointed out that even low-risk esophageal varices (EVs) are markers of severe prognosis. Accordingly, we analyzed spleen stiffness (SS) as a non-invasive method to predict EVs of any grade in a cohort of patients with compensated liver cirrhosis.

METHOD

We measured SS and liver stiffness (LS) using point-Shear-Wave Elastography (pSWE) with Philips Affiniti 70 system in 210 cirrhotic patients who had undergone endoscopic screening for EVs. We compared SS and LS predictive capability for EVs of any grade.

RESULTS

SS was higher in cirrhotic patients with EVs if compared to patients without EVs (p<0.001). The cut-off analysis detected 31kPa (100% sensitivity and negative predictive value) as the value to rule-out EVs and 69kPa (100% specificity and positive predictive value) to rule-in EVs. Besides, we developed the Spleen Stiffness Probability Index (SSPI), that can provide a probability of presence/absence of EVs. SSPI was the best model according to all discriminative and calibration metrics (AIC=120, BIC=127, AUROC=0.95, Pseudo-R2=0.74). SS demonstrated higher correlation with spleen bipolar diameter and spleen surface (r=0.52/0.55) if compared to LS (r=0.30/0.25) - and with platelet count as well (r=0.67 vs r=0.4).

CONCLUSION

SS showed significantly higher performance than other parameters, proving to be the best non-invasive test in the screening of EVs: by directly applying SS cut-off of 31kPa, our department could have safely avoided endoscopy in 36% of patients. Despite cut-off analyses, it was possible to create a probability model that could further stratify low-risk from high-risk patients (for any grade of EVs).

Endogenous motion of liver correlates to the severity of portal hypertension

BACKGROUND

Degree of portal hypertension (PH) is the most important prognostic factor for the decompensation of liver cirrhosis and death, therefore adequate care for patients with liver cirrhosis requires timely detection and evaluation of the presence of clinically significant PH (CSPH) and severe PH (SPH). As the most accurate method for the assessment of PH is an invasive direct measurement of hepatic venous pressure gradient (HVPG), the search for non-invasive methods to diagnose these conditions is actively ongoing.

AIM

To evaluate the feasibility of parameters of endogenously induced displacements and strain of liver to assess degree of PH.

METHODS

Of 36 patients with liver cirrhosis and measured HVPG were included in the case-control study. Endogenous motion of the liver was characterized by derived parameters of region average tissue displacement signal (d_antero, d_retro, d_RMS) and results of endogenous tissue strain imaging using specific radiofrequency signal processing algorithm. Average endogenous strain µ and standard deviation σ of strain were assessed in the regions of interest (ROI) (1 cm × 1 cm and 2 cm × 2 cm in size) and different frequency subbands of endogenous motion (0-10 Hz and 10-20 Hz).

RESULTS

Four parameters showed statistically significant (P < 0.05) correlation with HVPG measurement. The strongest correlation was obtained for the standard deviation of strain (estimated at 0-10 Hz and 2 cm × 2 cm ROI size). Three parameters showed statistically significant differences between patient groups with CSPH, but only d_retro showed significant results in SPH analysis. According to ROC analysis area under the curve (AUC) of the σ_{ROI[0…10Hz, 2 cm × 2 cm]} parameter reached 0.71 (P = 0.036) for the diagnosis of CSPH; with a cut-off value of 1.28 μm/cm providing 73% sensitivity and 70% specificity. AUC for the diagnosis of CSPH for µ_{ROI[0…10Hz, 1 cm × 1 cm]} was 0.78 (P = 0.0024); with a cut-off value of 3.92 μm/cm providing 73% sensitivity and 80% specificity. D_retro parameter had an AUC of 0.86 (P = 0.0001) for the diagnosis of CSPH and 0.84 (P = 0.0001) for the diagnosis of SPH. A cut-off value of -132.34 μm yielded 100% sensitivity for both conditions, whereas specificity was 80% and 72% for CSPH and SPH respectively.

CONCLUSION

The parameters of endogenously induced displacements and strain of the liver correlated with HVPG and might be used for non-invasive diagnosis of PH.

Diagnostic accuracy of spleen stiffness to evaluate portal hypertension and esophageal varices in chronic liver disease: a systematic review and meta-analysis

Objectives

To systematically review studies on the diagnostic accuracy of spleen stiffness measurement (SSM) for the detection of clinical significant portal hypertension (CSPH), severe portal hypertension (SPH), esophageal varices (EV), and high-risk esophageal varices (HREV) in patients with chronic liver diseases (CLD).

Methods

Through a systematic search, we identified 32 studies reporting the accuracy of SSM for the diagnosis of portal hypertension (PH) and/or EV in adults with CLD. A bivariate random-effects model was performed to estimate pooled sensitivity, specificity, likelihood ratio, positive predictive value (PPV), negative predictive value (NPV), and diagnostic odds ratios (DOR). The clinical utility of SSM was evaluated by Fagan plot.

Results

A total of 32 studies assessing 3952 patients were included in this meta-analysis. The pooled sensitivities of SSM were 0.85 (95% confidence interval (CI), 0.69–0.93) for CSPH; 0.84 (95% CI, 0.75–0.90) for SPH; 0.90 (95% CI, 0.83–0.94) for any EV; and 0.87 (95% CI, 0.77–0.93) for HREV. The pooled specificities of SSM were 0.86 (95% CI, 0.74–0.93) for CSPH; 0.84 (95% CI, 0.72–0.91) for SPH; 0.73 (95% CI, 0.66–0.79) for EV; and 0.66 (95% CI, 0.53–0.77) for HREV. Summary PPV and NPV of SSM for detecting HREV were 0.54 (95% CI, 0.47–0.62) and 0.88 (95% CI, 0.81–0.95), respectively.

Conclusions

Our meta-analysis suggests that SSM could be used as a helpful surveillance tool in management of CLD patients and was quite useful for ruling out the presence of HREV thereby avoiding unnecessary endoscopy.

Key Points

• SSM could be used to rule out the presence of HREV in patients with CLD thereby avoiding unnecessary endoscopy.

• SSM has significant diagnostic value for CSPH and SPH with high sensitivity and specificity in patients with CLD.

• SSM could be used as a helpful surveillance tool for clinicians managing CLD patients.

Electronic supplementary material

The online version of this article (10.1007/s00330-020-07223-8) contains supplementary material, which is available to authorized users.

The Role of Spleen and Liver Elastography and Color-Doppler Ultrasound in the Assessment of Transjugular Intrahepatic Portosystemic Shunt Function

The reference standard for assessing transjugular intrahepatic portosystemic shunt (TIPS) function is venography with portosystemic pressure gradient (PPG) measurement. This procedure is invasive and expensive; thus, we assessed the feasibility, reproducibility and diagnostic accuracy of color-Doppler ultrasound (CDUS) and spleen and liver stiffness (LS) measurements for identifying TIPS dysfunction. Twenty-four patients (15 undergoing TIPS placement and nine undergoing TIPS revision) consecutively underwent CDUS examination and LS and spleen stiffness (SS) determination by transient elastography (TE) and point shear-wave elastography (pSWE). All parameters were taken before TIPS placement/revision (1-15 d before) and 24 h after, just before revision by venography. pSWE inter-observer agreement was assessed by intra-class correlation coefficient (ICC). CDUS and elastographic data were correlated (Pearson coefficient) with pressure gradients (hepatic venous pressure gradient [HVPG], PPG). Main determinants of TIPS dysfunction were investigated by linear regression. Forty-nine paired examinations were performed in total: 49 (100%) SS reliable measurements by pSWE and 38 (88%) by TE. The ICC for pSWE values was 0.90 (95% confidence interval [CI] 0.81‒0.94). SS values significantly correlated with HVPG and PPG (R = 0.51, p = 0.01). The area under the Receiver-Operating Characteristic (AUROC) curve of SS for diagnosing TIPS dysfunction was 0.86 (95% CI 0.70‒0.96) using a 25 kPa cutoff. At multivariate analysis, the flow direction of the intrahepatic portal vein branches and SS values were independently associated to TIPS dysfunction. The intrahepatic portal vein branches flow direction and SS value are two simple, highly sensitive parameters accurately excluding TIPS dysfunction. SS measurement by pSWE is feasible, reproducible and both positively and significantly correlates with HVPG and PPG values.

Spleen Stiffness as Predictor of Esophageal Varices in Cirrhosis of Different Etiologies

The purpose of this study is to determine whether esophageal varices (EV) can be identified through the evaluation of spleen stiffness (SSM) via acoustic radiation force impulse (ARFI). A total of 135 patients suffering from cirrhosis underwent a clinical exam, laboratory tests, abdominal ultrasound, liver stiffness (LSM) measurement, SSM evaluation and upper gastrointestinal endoscopy. Based on the endoscopy results, the patients were classified into three groups: those with no evident EV, those with small EV and those with varices needing treatment (VNT). Patients with EV of any grade had significantly higher average SSM values over those with no EV (3.37 m/s versus 2.79 m/s, p-value < 0.001), while patients with VNT showed an even greater difference (3.96 m/s versus 2.93 m/s, p-value < 0.001). SSM proved to be an excellent method of predicting patients with VNT.

Role of Spleen Stiffness Measurement by 2D-Shear Wave Elastography in Ruling Out the Presence of High-Risk Varices in Cirrhotic Patients

BACKGROUND AND AIM

To evaluate if spleen stiffness measurement (SSM) can rule out the presence of high-risk varices in patients with cirrhosis, avoiding an upper gastrointestinal endoscopy (UGE).

METHODS

We enrolled 71 cirrhotic patients irrespective of liver disease's etiology. 2D shear wave elastography (SWE) of spleen and UGE was performed. High-risk varices (HRV) were defined as esophageal varices ≥ 5 mm and/or red spots and any gastric varices.

RESULTS

Esophageal varices were documented in 37 (52.1%) and HRV in 25 (35.2%) patients. SSM was not technically feasible in 7/71 patients (9.8%). From the remaining 64 patients, when those with cholestatic liver disease were excluded (n = 17), SSM < 35.8 kPa was found to exclude well the existence of HRV offering an AUROC of 0.854 (p < 0.001), sensitivity 88.9%, negative predictive value (NPV) 91.3%, specificity 72.4%, and positive predictive value (PPV) 66.7%. Only 2/47 patients (4.3%) were misclassified, and 23 (48.9%) could avoid endoscopy. In the total cohort of 64 patients, SSM < 33.7 kPa was found to exclude well the presence of HRV offering AUROC 0.792 (p < 0.001), sensitivity 91.7%, specificity 60%, NPV 92.3%, and PPV 57.9%. The misclassification rate was 3.1% (2/64), while 26/64 (40.6%) could avoid endoscopy.

CONCLUSIONS

2D-SWE of spleen is a reliable method for ruling out the presence of HRV in cirrhotic patients. If larger studies confirm our results, a large number of endoscopies could be avoided.

Evaluation of portal hypertension in the cirrhotic patient: hepatic vein pressure gradient and beyond

Portal hypertension (PH) is a major complication of liver cirrhosis, as it predisposes to the development of serious clinical manifestations such as ascites, hepatic encephalopathy and variceal bleeding. Till now, the measurement of hepatic vein pressure gradient (HVPG) is the gold standard method to ascertain the presence and significance of PH, as many studies have shown its correlation with the appearance of varices and the possibility of variceal bleeding. However, the invasiveness of this procedure makes it difficult to be used in daily clinical practice. Several noninvasive methods with adequate capability of evaluating liver fibrosis, including elastographic techniques, are currently used as alternatives to HVPG in order to assess the presence and the severity of PH. The aim of this paper is to express an overview of the literature about the actual role of HVPG and all available noninvasive tests on the prediction of development of PH complications, to highlight their advantages and their potential limitations, and to provide the latest trends on clinical practice.

Accuracy of liver stiffness, spleen stiffness, and LS-spleen diameter to platelet ratio score in detection of esophageal varices: Systemic review and meta-analysis

BACKGROUND AND AIM

There is increasing evidence of non-invasive measurement using elastography such liver stiffness (LS), spleen stiffness (SS), and LS-spleen diameter to platelet ratio score (LSPS) for detection of esophageal varices (EV); however, data regarding comparison between these three parameters are limited.

METHODS

We performed a systemic review and meta-analysis of studies evaluating performance of LS, SS, and LSPS for detection of EV and high risk/clinically significant EV (HREV). Pooled sensitivity, specificity, log diagnostic odd ratio (LDOR), and area under the receiver operating characteristic curve (AUC) of LS, SS, and LSPS for detection of EV and HREV were analyzed and compared. Publication bias was assessed by Deeks' funnel plot.

RESULTS

SS and LSPS were superior to LS for detection of EV with higher sensitivity (0.90 and 0.91 vs 0.85), specificity (0.73 and 0.76 vs 0.64), LDOR (3.24 and 3.35 vs 2.26), and AUC (0.899 and 0.851 vs 0.817). For HREV, SS had the highest sensitivity (0.87) followed by LS (0.85) and LSPS (0.82); however, SS had the lowest specificity (0.52), LDOR (2.09), and AUC (0.807) whereas LSPS had the highest specificity (0.77), LDOR (2.74), and AUC (0.861).

CONCLUSION

For detection of EV, we prefer using LSPS and SS over LS when available, while LS, SS, and LSPS cannot be recommended for detection of HREV due to their moderate sensitivity and specificity.

Performance of spleen stiffness measurement in prediction of clinical significant portal hypertension: A meta-analysis

AIM

Our purpose was to evaluate the correlation between spleen stiffness (SS) measured by ultrasound-based elastography and hepatic venous pressure gradient (HVPG) and assess the accuracy of SS in detecting clinical significant portal hypertension (CSPH) and severe portal hypertension.

METHOD

Nine studies were included from thorough literature research and selection processes. A random model was used to analyze the correlation between HVPG and SS. We adopted the bivariate mixed effects model to assess the diagnostic performance.

RESULTS

Regarding to correlation between SS and HVPG, the summary correlation coefficient was 0.72 (95% confidence interval [CI], 0.63-0.80). In detection of CSPH, the sensitivity, specificity, AUC and DOR were: 0.88 (0.70-0.96), 0.84 (0.72-0.92), 0.92 (0.89-0.94) and 38 (17-84) for CSPH, respectively; and 0.92 (0.82-0.96), 0.79 (0.72-0.85), 0.87 (0.84-0.90) and 41 (17-100) for severe portal hypertension, respectively.

CONCLUSION

Correlation between SS and HVPG was good. Although SS showed good sensitivity and specificity, the different cut-off values and techniques among studies might limit the impact of our results on clinical practice. Therefore, more high-quality prospective studies are required to evaluate the role of SS in predicting portal hypertension.

Νon-invasive screening for esophageal varices in patients with liver cirrhosis

Esophageal varices are one of the main complications of liver cirrhosis. Upper gastrointestinal endoscopy is the gold standard for the detection of esophageal varices. Many less invasive methods for screening of varices have been investigated and the most recent Baveno VI guidelines suggest that endoscopy is not necessary in patients with liver stiffness <20 kPa and platelets >150,000/μL. A critical review of the literature was performed concerning non-invasive or minimally invasive methods of screening for esophageal varices. Liver and spleen elastography, imaging methods including computed tomography, magnetic resonance imaging and ultrasound, laboratory tests and capsule endoscopy are discussed. The accuracy of each method, and its advantages and limitations compared to endoscopy are analyzed. There are data to support the Baveno VI guidelines, but there is still a lack of large prospective studies and low specificity has been reported for the liver stiffness and platelet count combination. Spleen elastography has shown promising results, as there are data to support its superiority to liver elastography, but it needs further assessment. Computed tomography has shown high diagnostic accuracy and can be part of the diagnostic work up of cirrhotic patients in the future, including screening for varices.

Clinical applications of spleen ultrasound elastography - a review

In the last few years, notable technical progress has taken place in ultrasound elastography. Qualitative methods have been replaced by quantitative ones, such as: transient elastography, acoustic radiation force impulse and shear wave elastography. Owing to the fact that the spleen is superficially located, it is possible to obtain reliable measuring accuracy of its hardness using sonoelastography. Lately, many researchers have been investigating how spleen elasticity changes in patients infected with hepatitis B virus or hepatitis C virus and in patients suffering from liver fibrosis, portal hypertension, esophageal varices or myelofibrosis. In this article, we review the role and current status of accessible qualitative ultrasound elastography methods, including recent advances in the evaluation of spleen stiffness and its clinical utility. As study results demonstrate, spleen stiffness correlates with liver fibrosis and is helpful in determining the level of fibrosis in the METAVIR scoring system. In patients infected with hepatitis B virus or hepatitis C virus, spleen stiffness increases even when liver elasticity remains unaltered. Furthermore, it is useful in diagnosing portal hypertension or predicting existence of esophageal varices. Moreover, in patients suffering from biliary atresia after Kasai portoenterostomy, spleen sonoelastography may be helpful in selecting patients for liver transplantation as well as for choosing the best strategy for portal vein reconstruction before liver transplantation. In myelofibrosis, spleen stiffness correlates with bone marrow fibrosis and may be used to assess the response to treatment. Spleen sonoelastography is also useful in the monitoring of transjugular intrahepatic portosystemic shunt function.

Comparison between real-time tissue elastography and vibration-controlled transient elastography for the assessment of liver fibrosis and disease progression in patients with primary biliary cholangitis

AIM

Assessing disease progression in patients with primary biliary cholangitis (PBC) is necessary in order to evaluate therapeutic effectiveness. Therefore, the aims of this study were to evaluate both the diagnostic accuracy of both real-time tissue elastography (RTE) and vibration-controlled transient elastography (VCTE), and the usefulness of hepatic and splenic elasticity as predictive markers for the progression of symptomatic PBC.

METHODS

The study participants were 44 patients with PBC. We assessed hepatic and splenic elasticity using RTE and VCTE and measured serum markers related to fibrosis and hepatic and splenic blood flow using Doppler ultrasonography. We then compared RTE and VCTE for diagnostic accuracy. Patients with asymptomatic PBC were followed every 1-3 months.

RESULTS

Both RTE and VCTE performed well and had superior diagnostic accuracy compared with biochemical markers. The areas under the receiver operating characteristic curve for RTE and VCTE were 0.92 and 0.92, 0.95 and 0.91, and 0.97 and 0.91 for F ≥ 2, F ≥ 3, and F = 4, respectively. During follow-up, nine patients (25.0%) developed liver-related symptoms. Multivariate analysis revealed that splenic elasticity assessed using RTE was a significant independent factor for the development of liver-related symptoms (odds ratio, 2.19; P = 0.024).

CONCLUSIONS

Real-time tissue elastography offered better diagnostic accuracy for severe fibrosis and cholangitis than VCTE. Splenic elasticity determined using RTE is a useful parameter for evaluating liver-related symptoms and an effective predictive marker of disease progression in patients with asymptomatic PBC.

Upregulated absorption of dietary palmitic acids with changes in intestinal transporters in non-alcoholic steatohepatitis (NASH)

BACKGROUND

Palmitic acid is an important risk factor for the pathogenesis of non-alcoholic steatohepatitis (NASH), but changes in palmitic acid intestinal absorption in NASH are unclear. The aim of this study was to clarify changes in palmitic acid intestinal absorption and their association with the pathogenesis of NASH.

METHODS

A total of 106 participants were recruited to the study, of whom 33 were control subjects (control group), 32 were patients with NASH Brunt stage 1-2 [early NASH (e-NASH)], and 41 were patients with NASH Brunt stage 3-4 [advanced NASH (a-NASH)]. ¹³C-labeled palmitate was administered directly into the duodenum of all participants by gastrointestinal endoscopy. Breath ¹³CO₂ levels were measured to quantify palmitic acid absorption, and serum Apolipoprotein B-48 (ApoB-48) concentrations were measured after a test meal to quantify absorbed chylomicrons. Expressions of fatty acid (FA) transporters were also examined. The associations of breath ¹³CO₂ levels with hepatic steatosis, fibrosis and insulin resistance was evaluated using laboratory data, elastography results and liver histology findings.

RESULTS

Overall, ¹³CO₂ excretion was significantly higher in e-NASH patients than in the control subjects and a-NASH patients (P < 0.01). e-NASH patients had higher serum ApoB-48 levels, indicating increased palmitic acid transport via chylomicrons in these patients. Jejunal mRNA and protein expressions of microsomal triglyceride transfer protein and cluster of differentiation 36 were also increased in both NASH patient groups. The ¹³CO₂ excretion of e-NASH patients was significantly correlated with the degree of hepatic steatosis, fibrosis and insulin resistance (P = 0.005, P < 0.001, P = 0.019, respectively).

CONCLUSIONS

Significantly upregulated palmitic acid absorption by activation of its transporters was evident in patients with NASH, and clinical progression of NASH was related to palmitic acid absorption. These dietary changes are associated with the onset and progression of NASH.

Nonalcoholic fatty liver with a hepatic arterial buffer response strongly associated with future metabolic disease

A change in hepatic blood flow caused by the hepatic arterial buffer response (HABR) occurs as fatty liver disease progress. The aim of this longitudinal cohort study was to investigate whether fatty liver with the HABR induces metabolic disorders. In 2009 and 2010, 494 (89.5%) participants were enrolled. The median follow‐up duration was 5.0 (interquartile range, 3.9‐6.0) years. The hazard ratios of fatty liver with the HABR for incident metabolic disorders were assessed by Cox proportional hazard models. A non–fatty liver group (non‐FL group, hepatorenal echo intensity ratio <1.12), a fatty liver without portal hypertension (FL group, hepatorenal echo intensity ratio ≥1.12 and ratio of the maximal blood velocity in the right hepatic artery to maximal blood velocity in the right portal vein <3.1) group, and a fatty liver with portal hypertension (FL‐HABR group, hepatorenal echo intensity ratio ≥1.12 and ratio of the maximal blood velocity in the right hepatic artery to maximal blood velocity in the right portal vein ≥3.1) group were defined based on echo intensity and Doppler ultrasonography. Fatty liver with and without the HABR was significantly associated with the incidence of diabetes on multivariate analysis (non‐FL versus FL group, hazard ratio, 3.36; 95% confidence interval, 1.05‐12.85; FL versus FL with the HABR group, HR, 2.68; 95% confidence interval, 1.28‐6.04). With respect to the incidence of hypertension and dyslipidemia, only FL with the HABR was a significant factor (hypertension, non‐FL versus FL, P = 0.874, FL versus FL‐HABR, P = 0.016, non‐FL versus FL‐HABR, P = 0.023; dyslipidemia, non‐FL versus FL, P = 0.311, FL versus FL‐HABR, P = 0.194, non‐FL versus FL‐HABR, P = 0.038). Conclusion: Fatty liver with the HABR is a high‐risk condition for metabolic diseases. (Hepatology Communications 2017;1:623–633)

Time-Harmonic Elastography of the Liver is Sensitive to Intrahepatic Pressure Gradient and Liver Decompression after Transjugular Intrahepatic Portosystemic Shunt (TIPS) Implantation

We investigated the correlation between hepatic venous pressure gradient (HVPG) and liver shear wave speed (SWS) measured by multi-frequency time-harmonic ultrasound elastography (THE) before and after transjugular intrahepatic portosystemic shunt (TIPS) implantation. Ten patients with ascites, cirrhotic liver disease and portal hypertension were prospectively examined with invasive HVPG measurement and THE before and after TIPS implantation. HVPG and SWS decreased after TIPS placement from 20.4 ± 2.2 mmHg to 9.8 ± 4.1 mmHg (mean ± standard deviation) and from 3.87 ± 0.54 m/s to 3.27 ± 0.44 m/s. Mean reduction HVPG was -10.6 ± 3.7 mmHg, p < 0.001; mean reduction SWS was -0.60 ± 0.29 m/s, p < 0.001. A linear correlation was observed between HVPG and SWS (R = 0.59, p = 0.0061). THE-measured SWS is a first potential direct ultrasound marker for liver decompression following TIPS in ascites-associated cirrhotic liver disease and therefore might be suitable to non-invasively detect portal hypertension.

Role of spleen elastography in patients with chronic liver diseases

The development of liver cirrhosis and portal hypertension (PH), one of its major complications, are structural and functional alterations of the liver, occurring in many patients with chronic liver diseases (CLD). Actually the progressive deposition of hepatic fibrosis has a key role in the prognosis of CLD patients. The subsequent development of PH leads to its major complications, such as ascites, hepatic encephalopathy, variceal bleeding and decompensation. Liver biopsy is still considered the reference standard for the assessment of hepatic fibrosis, whereas the measurement of hepatic vein pressure gradient is the standard to ascertain the presence of PH and upper endoscopy is the method of choice to detect the presence of oesophageal varices. However, several non-invasive tests, including elastographic techniques, are currently used to evaluate the severity of liver disease and predict its prognosis. More recently, the measurement of the spleen stiffness has become particularly attractive to assess, considering the relevant role accomplished by the spleen in splanchnic circulation in the course of liver cirrhosis and in the PH. Moreover, spleen stiffness as compared with liver stiffness better represents the dynamic changes occurring in the advanced stages of cirrhosis and shows higher diagnostic performance in detecting esophageal varices. The aim of this review is to provide an exhaustive overview of the actual role of spleen stiffness measurement as assessed by several elastographic techniques in evaluating both liver disease severity and the development of cirrhosis complications, such as PH and to highlight its potential and possible limitations.

Prediction of esophageal varices in cirrhotic patients with apparent diffusion coefficient of the spleen

PURPOSE

To predict esophageal varices in cirrhotic patients with apparent diffusion coefficient (ADC) of the spleen and to correlate the ADC with clinical and laboratory biomarkers of esophageal varices.

MATERIALS AND METHODS

This study was conducted upon 40 patients (28 male, 12 female; age ranged 19-45 years; mean age = 33 years) with biopsy-proven cirrhotic liver. Twenty age- and sex-matched healthy volunteers were included as a control group. Patients with varices (n = 15) and without varices (n = 25) and volunteers underwent echo-planar diffusion-weighted MR imaging of the abdomen with b factors of 0, 400, and 800 s/mm(2). The ADC maps of the abdomen were reconstructed. The ADC values of the spleen were calculated and correlated with the Child score, platelet count, and prothrombin time.

RESULTS

The mean ADC value of the spleen in cirrhotic patients (1.34 ± 0.05 × 10(-3) mm(2)/s) was significantly different (P = 0.001) from that of volunteers (0.87 ± 0.04 × 10(-3) mm(2)/s). The ADC of the spleen in cirrhotic patients with varices (1.49 ± 0.05 × 10(-3) mm(2)/s) was significantly different (P = 0.001) from that of patients without varices (1.11 ± 0.06 × 10(-3) mm(2)/s). The cut-off ADC value of the spleen used for prediction of cirrhosis and varices was 1.15 and 1.29 × 10(-3) mm(2)/s with areas under the curve were 0.872 and 0.889, respectively. The ADC value of the spleen was correlated with the splenic volume (r = 0.862; P = 0.001), Child score (r = 0.742; P = 0.001), platelet count (r = -0.698; P = 0.01), and prothrombin time (r = 0.684; P = 0.01).

CONCLUSION

The ADC value of the spleen can predict esophageal varices in cirrhotic patients and is well correlated with the clinical and laboratory biomarkers of esophageal varices.

Shear Wave Elastography of the Spleen for Monitoring Transjugular Intrahepatic Portosystemic Shunt Function: A Pilot Study

OBJECTIVES

To assess the feasibility of splenic shear wave elastography in monitoring transjugular intrahepatic portosystemic shunt (TIPS) function.

METHODS

We measured splenic shear wave velocity (SWV), main portal vein velocity (PVV), and splenic vein velocity (SVV) in 33 patients 1 day before and 3 days to 12 months after TIPS placement. We also measured PVV, SVV, and SWV in 10 of 33 patients with TIPS dysfunction 1 day before and 3 to 6 days after TIPS revision. Analyses included differences in portosystemic pressure gradient (PPG), PVV, SVV, and mean SWV before and after TIPS procedures; comparison of median SWV before and after TIPS procedures; differences in PVV, SVV, and SWV before and at different times up to 12 months after TIPS placement; accuracy of PVV, SVV, and SWV in determining TIPS dysfunction; and correlation between PPG and SWV.

RESULTS

During 12 months of follow-up, 23 of 33 patients had functioning TIPS, and 10 had TIPS dysfunction. The median SWV was significantly different before and after primary TIPS placement (3.60 versus 3.05 m/s; P = .005), as well as before and after revision (3.73 versus 3.06 m/s; P = .003). The PPG, PVV, and SVV were also significantly different before and after TIPS placement and revision (P < .001). The PPG and SWV decreased, whereas PVV and SVV increased, after successful TIPS procedures. A positive correlation was observed between PPG and SWV (r = 0.70; P < .001), and a negative correlation was observed between PPG and PVV and SVV (r = -0.65; P < .001). The areas under the receiver operating characteristic curve for PVV, SVV, and SWV in determining TIPS dysfunction were 0.82, 0.84, and 0.81, respectively.

CONCLUSIONS

Splenic SWV is compatible with splenoportal venous velocity in quantitatively monitoring TIPS function and determining TIPS dysfunction.

Acoustic radiation force impulse quantification of spleen elasticity for assessing liver fibrosis

PURPOSE

The purpose of this study is to assess the correlation between liver fibrosis and spleen stiffness measured by ARFI in patients with chronic viral hepatitis (B or C) and to explore the possible complementary role of spleen and liver ARFI in grading liver fibrosis.

METHODS

84 subjects (51 patients, 33 healthy volunteers) were enrolled. ARFI of the spleen and the liver was performed. Patients subsequently underwent liver biopsy for grading liver fibrosis according to Knodell scoring system. Multivariate logistic regression and decision tree analysis were adopted to test the relationship between spleen and liver stiffness (independent variables) and liver fibrosis (F1< vs. ≥F3). Leave-One-Out Cross-Validation was used for validating the predictive classification models. Area under the ROC curve (AUROCC) was used as accuracy metric.

RESULTS

Spleen ARFI was able to discriminate early (F1) from severe (≥F3) liver fibrosis with an optimal cut-off of 3.05 m/s: AUROCC 0.807, cross-validated AUROCC 0.614. Liver ARFI was superior to spleen ARFI, using a cut-off of 2.11 m/s: AUROCC 0.879, cross-validated AUROCC 0.672. Neither spleen nor liver ARFI was able to differentiate healthy volunteers from F1 patients. Odds ratios derived from logistic regression were 23.1 and 9.9 for liver and spleen ARFI, respectively; resulting AUROCC was 0.905 (cross-validated 0.848). A decision tree considering the sequential use of liver and spleen ARFI with cut-off of 2.14 and 3.39 m/s, respectively, resulted in AUROCC of 0.903 (cross-validated 0.7).

CONCLUSIONS

Spleen ARFI has the potential to discriminate early from severe liver fibrosis. Spleen and liver ARFI, when combined, show a better discriminative power than liver ARFI alone.

In vivo abdominal magnetic resonance elastography for the assessment of portal hypertension before and after transjugular intrahepatic portosystemic shunt implantation

OBJECTIVE

The objective of this study was to investigate the correlation between hepatic venous pressure gradient (HVPG) and in vivo viscoelasticity of the liver and spleen before and after transjugular intrahepatic portosystemic shunt (TIPS) implantation.

MATERIALS AND METHODS

Ten patients with portal hypertension were examined twice by 3-dimensional multifrequency magnetic resonance elastography as well as prior and subsequent TIPS intervention; HVPG was also measured during TIPS placement. Five harmonic vibrations (25-60 Hz) were transferred to the abdominal region and recorded for the reconstruction of 2 viscoelastic constants, |G*| and φ, corresponding to the magnitude and the phase angle of the complex shear modulus G* of the liver and spleen.

RESULTS

All patients had cirrhosis, yielding high |G*| values in the liver (8.34 ± 2.18 kPa) and spleen (8.44 ± 1.36 kPa). In both organs, a decrease of |G*| after TIPS placement was observed (liver: 8.34 ± 2.18 kPa vs 7.02 ± 1.46 kPa, P = 0.01; spleen: 8.44 ± 1.36 kPa vs 7.06 ± 1.32 kPa, P = 0.01), whereas φ was insensitive to TIPS. Relative changes in |G*| of the spleen were correlated with the relative change of HVPG (R² = 0.659, P = 0.013).

CONCLUSIONS

The observed linear correlation between spleen viscoelasticity HVPG raises the prospect of an image-based noninvasive assessment of portal pressure by magnetic resonance elastography in the follow-up of TIPS placements.

Portal Hypertension in Patients with Liver Cirrhosis: Diagnostic Accuracy of Spleen Stiffness

PURPOSE

To evaluate the accuracy of spleen stiffness (SS) and liver stiffness (LS) measured by using acoustic radiation force impulse imaging in the diagnosis of portal hypertension in patients with liver cirrhosis, with the hepatic venous pressure gradient (HVPG) as a reference standard.

MATERIALS AND METHODS

Institutional review board approval and informed consent were obtained for this prospective single-center study. From February 2012 to August 2013, 60 patients with liver cirrhosis (mean age, 70.8 years; age range, 34-88 years; 34 men, 26 women) with HVPG, LS, and SS measurements and gastrointestinal endoscopy and laboratory data were included if they met the following criteria: no recent episodes of gastrointestinal bleeding, no history of splenectomy, no history of partial splenic embolization, no history of β-blocker therapy, and absence of portal thrombosis. The efficacy of the parameters for the evaluation of portal hypertension was analyzed by using the Spearman rank-order correlation coefficient and receiver operating characteristic (ROC) curve analysis.

RESULTS

The correlation coefficient between SS and HVPG (r = 0.876) was significantly better than that between LS and HVPG (r = 0.609, P < .0001). The areas under the ROC curve of SS for the identification of clinically important portal hypertension (HVPG ≥ 10 mm Hg), severe portal hypertension (HVPG ≥ 12 mm Hg), esophageal varices (EVs), and high-risk EVs were significantly higher (0.943, 0.963, 0.937, and 0.955, respectively) than those of LS, spleen diameter, platelet count, and platelet count to spleen diameter ratio (P < .05 for all). SS could be used to accurately rule out the presence of clinically important portal hypertension, severe portal hypertension, EVs, and high-risk EVs (negative likelihood ratios, 0.051, 0.056, 0.054, and 0.074, respectively).

CONCLUSION

SS is reliable and has better diagnostic performance than LS for identifying portal hypertension in liver cirrhosis.

The Role of Spleen Stiffness in Determining the Severity and Bleeding Risk of Esophageal Varices in Cirrhotic Patients

Esophageal varix and its hemorrhage are serious complications of liver cirrhosis. Recent studies have focused on noninvasive prediction of esophageal varices. We attempted to evaluate the association of liver and spleen stiffness (LS and SS) as measured by acoustic radiation force impulse imaging, with the presence and severity of esophageal varices and variceal hemorrhage in cirrhotic patients. We measured LS and SS, along with endoscopic examination of esophageal varices for a total of 125 cirrhotic patients at a single referral hospital in this prospective observational study. The diagnostic utility of noninvasive methods for identifying varices and their bleeding risk was compared, including LS, SS, spleen length, Child-Pugh score, and various serum fibrosis indices. Esophageal varices were present in 77 patients (61.6%). SS was significantly higher in patients with varices than in those without varices (3.58 ± 0.47 vs 3.02 ± 0.49; P < 0.001). A tendency toward increasing SS levels was observed with increasing severity of varices (no varix, 3.02 ± 0.49; F1, 3.39 ± 0.51; F2, 3.60 ± 0.42; F3, 3.85 ± 0.37; P < 0.001). SS was significantly higher in patients who experienced variceal hemorrhage than in those who did not (3.80 ± 0.36 vs 3.20 ± 0.51; P = 0.002). An optimal cut-off value of SS for high-risk varices (≥ F2) or variceal hemorrhage was 3.40 m/s. SS was significantly correlated with the presence, severity, and bleeding risk of esophageal varices. Prompt endoscopic evaluation of variceal status and prophylactic measures based on the SS may be warranted for cirrhotic patients.

Liver stiffness measured by acoustic radiation force impulse elastography reflects the severity of liver damage and prognosis in patients with acute liver failure

AIM

We measured liver stiffness (LS) in patients with acute liver failure (ALF) using acoustic radiation force impulse (ARFI) elastography and investigated the usefulness of measuring LS for predicting the prognosis of ALF patients.

METHODS

From April 2010 to December 2013, we evaluated 63 patients with acute liver disease. The subjects included 41 patients with acute hepatitis (AH), 16 patients with severe AH (SAH), who had no hepatic encephalopathy despite plasma prothrombin time of 40% or less, and six patients with fulminant hepatitis (FH) diagnosed according to the criteria of the Japanese Study Group. The relationships among shear wave velocity (SWV), clinical diagnosis, liver function tests and prognosis were evaluated. Receiver-operator curve (ROC) analysis was performed to investigate whether ARFI elastography exhibits potential usefulness for the prediction of FH.

RESULTS

The mean SWV on admission were 1.98 ± 0.55, 2.61 ± 0.58 and 3.66 ± 0.86 m/s in the AH, SAH and FH groups, respectively. The SWV was significantly higher in the FH group than in the other groups (P < 0.001), and in the SAH group than in the AH group (P = 0.002). The area under the ROC for predicting FH was 0.924 (sensitivity, 83.3%; specificity, 93.0%). The SWV was significantly increased in non-survivors, while remaining decreased in survivors (P = 0.002).

CONCLUSION

The SWV measured by ARFI elastography reflects severity of liver damage, and serial changes in SWV predict the prognosis of ALF patients. The SWV is an early and precise biomarker of FH.

Spleen stiffness can non-invasively assess resolution of portal hypertension after liver transplantation

BACKGROUND & AIMS

Spleen stiffness can be measured by transient elastography. Recent studies have shown that spleen stiffness correlates with hepatic venous pressure gradient and can predict oesophageal varices. Elevated spleen stiffness in cirrhosis has been attributed to splenic tissue hyperplasia and fibrosis, portal hypertension and its consequent hyperdynamic circulation. The aim of this study was to investigate changes to spleen stiffness after orthotopic liver transplantation (OLT) when portal hypertension resolves.

METHODS

Twenty-one patients awaiting OLT were studied prospectively, while 11 post-transplant patients were recruited as controls. Spleen and liver stiffness were measured with Fibroscan before and at 2-8 weeks after OLT. Criteria applied for spleen stiffness measurement were similar to liver stiffness (≥10 measurements; ≥60% success rate; interquartile range, IQR <30% of median).

RESULTS

Spleen stiffness was significantly higher before OLT compared to post-transplant patients [75.0 (63.9-75.0) kPa vs. 28.4 (22.0-37.5) kPa; P < 0.0001]. For patients awaiting OLT, 90% (19/21) had oesophageal varices (endoscopically or radiologically). In patients who underwent liver transplantation, spleen stiffness decreased significantly from a median of 75.0 (62.0-75.0) kPa before OLT, to 41.9 (27.0-47.4) kPa at 2 weeks after transplant and 32.9 (29.1-38.0) kPa in the subsequent 4-8 weeks after OLT (P < 0.0001). As expected, liver stiffness measurements reduced from 39.3 (24.9-75.0) kPa to 8.6 (6.8-11.8) kPa in patients receiving OLT (P = 0.0004).

CONCLUSIONS

Spleen stiffness can non-invasively assess changes in portal pressure after liver transplantation and decreases significantly when portal hypertension resolves.

Clinically severe portal hypertension: role of multi-detector row CT features in diagnosis

BACKGROUND AND AIM

To explore the CT signs which permit estimation of clinically severe portal hypertension (PH) [≥ 12 of hepatic vein pressure gradient (HVPG)].

METHODS

One-hundred and seven consecutive patients who underwent HVPG measurement in the PH group and 52 controls were included. The diameters of main portal vein (øMPV), superior mesenteric vein (øSMV), splenic vein (øSV), and left gastric vein, øMPV/øSV, øSMV/øSV, as well as estimated spleen volumes were evaluated on the CT scan. The grade of varix and ascites were also evaluated semi-quantitatively. We explored the statistically significant CT features related to severe PH and performed a logistic regression analysis for an estimation model for severe PH.

RESULTS

øMPV/øSV and øSMV/øSV tended to gradually increase as the PH became severer, and the difference between severe and not severe groups was statistically significant (p = 0.015 and 0.038, respectively). According to the regression analysis, øSMV/øSV and the grade of esophageal varix and ascites were finally included as related variables for predicting severe PH. The odds ratio (OR) of øSMV/øSV was 4.596, and large esophageal varix (OR 4.135) and mild (OR 3.051) and large amount of ascites (OR 21.781) were statistically significantly related to severe PH.

CONCLUSION

Changing diameters of portal system, the grades of esophageal varices and ascites on multi-detector row computed tomography might be indicative features for clinically severe PH.

Accuracy of spleen stiffness measurement in detection of esophageal varices in patients with chronic liver disease: systematic review and meta-analysis

BACKGROUND & AIMS

Spleen stiffness measurement (SSM) is a promising noninvasive alternative to esophagogastroduodenoscopy (EGD) that could be used in the diagnosis of esophageal varices (EV) in patients with cirrhosis. However, its overall diagnostic accuracy in various clinical settings is unknown. We conducted a systematic review and meta-analysis of studies that compared the accuracy of SSM with that of EGD in detecting EV in patients with chronic liver disease.

METHODS

Through a systematic search of bibliographic databases and conference proceedings, and contact with authors, we identified 12 studies that reported the accuracy of SSM, compared with EGD, in the diagnosis of any and/or clinically significant EV in adults with chronic liver disease. In a meta-analysis, we combined measures of test performance of individual studies.

RESULTS

Based on pooled estimates, SSM detected the presence of any EV with 78% sensitivity (95% confidence interval [CI], 75%-81%), 76% specificity (95% CI, 72%-79%), a positive likelihood ratio (LR) of 3.4 (95% CI, 2.3-4.9), a negative LR of 0.2 (95% CI, 0.1-0.4), and a diagnostic odds ratio of 19.3 (95% CI, 7.5-49.8). In a meta-analysis of 9 studies, SSM detected the presence of clinically significant EV with 81% sensitivity (95% CI, 76%-86%), 66% specificity (95% CI, 61%-69%), a positive LR of 2.5 (95% CI, 1.7-3.9), a negative LR of 0.2 (95% CI, 0.1-0.5), and a diagnostic odds ratio of 12.6 (95% CI, 5.5-28.7). There was significant heterogeneity among studies owing to differences in elastography techniques and study locations. The included studies that were at risk for spectrum bias, review bias, and disease progression bias.

CONCLUSIONS

Based on a meta-analysis, current techniques for measuring spleen stiffness are limited in their accuracy of EV diagnosis; these limitations preclude widespread use in clinical practice at this time.

Assessment of portal hypertension and high-risk oesophageal varices with liver and spleen three-dimensional multifrequency MR elastography in liver cirrhosis

OBJECTIVE

To assess the value of the liver and spleen viscoelastic parameters at multifrequency MR elastography to determine the degree of portal hypertension and presence of high-risk oesophageal varices in patients with cirrhosis.

METHODS

From January to September 2012, 36 consecutive patients with cirrhosis evaluated for transplantation were prospectively included. All patients underwent hepatic venous pressure gradient (HVPG) measurements and endoscopy to assess oesophageal varices. Multifrequency MR elastography was performed within the liver and spleen. The shear, storage and loss moduli were calculated and compared to the HVPG with Spearman coefficients and multiple regressions. Patients with and without severe portal hypertension and high-risk varices were compared with Mann-Whitney tests, logistic regression and ROC analysis.

RESULTS

The liver storage and loss moduli and the spleen shear, storage and loss moduli correlated with the HVPG. At multiple regression, only the liver and the spleen loss modulus correlated with the HVPG (r = 0.44, p = 0.017, and r = 0.57, p = 0.002, respectively). The spleen loss modulus was the best parameter for identifying patients with severe portal hypertension (p = 0.019, AUROC = 0.81) or high-risk varices (p = 0.042, AUROC = 0.93).

CONCLUSIONS

The spleen loss modulus appears to be the best parameter for identifying patients with severe portal hypertension or high-risk varices.

KEY POINTS

1. Noninvasive HVPG assessment can be performed with liver and spleen MR elastography 2. The spleen loss modulus enables the detection of high-risk oesophageal varices 3. The spleen loss modulus enables the detection of severe portal hypertension.

Invasive and non-invasive techniques for detecting portal hypertension and predicting variceal bleeding in cirrhosis: a review

Portal hypertension is a severe syndrome that may derive from pre-sinusoidal, sinusoidal, and post-sinusoidal causes. As a consequence, several complications (i.e. ascites, oesophageal varices) may develop. In sinusoidal portal hypertension, hepatic venous pressure gradient (HVPG) is a reliable method for defining the grade of portal pressure, establishing the effectiveness of the treatment, and predicting the occurrence of complications; however, some questions exist regarding its ability to discriminate bleeding from non-bleeding varices in cirrhotic patients. Other imaging techniques (transient elastography, endoscopy, endosonography, and duplex Doppler sonography) for assessing causes and complications of portal hypertensive syndrome are available and may be valuable for the management of these patients. In this review, we evaluate invasive and non-invasive techniques currently employed to obtain a clinical prediction of deadly complications, such as variceal bleeding in patients affected by sinusoidal portal hypertension, in order to create a diagnostic algorithm to manage them. Again, HVPG appears to be the reference standard to evaluate portal hypertension and monitor the response to treatment, but its ability to predict several complications and support management decisions might be further improved through the diagnostic combination with other imaging techniques.

Association of splenic MR elastographic findings with gastroesophageal varices in patients with chronic liver disease

PURPOSE

To identify magnetic resonance imaging (MRI)-based parameters associated with gastroesophageal varices (GEVs) in patients with chronic liver disease.

MATERIALS AND METHODS

Ninety-three patients were divided into three groups based on endoscopic findings: group 1 with no GEVs (n = 49), group 2 with mild GEVs (n = 30), and group 3 with severe GEVs (n = 14). We used a multivariate logistic regression analysis to assess liver stiffness, aspartate aminotransferase-to-platelet ratio index, spleen stiffness and volume, portal vein velocity, cross-sectional area, and flow volumes potential independent associators of any (mild and severe) GEVs or severe GEVs.

RESULTS

The analysis showed that spleen and liver stiffness and spleen volume were independently associated with any GEVs (spleen stiffness, odds ratio [95% confidence interval], 1.25 [1.04-1.68], P = 0.018; liver stiffness, 1.52 [1.13-2.17], P = 0.006; spleen volume, 1.01 [1.00-1.01], P = 0.016), whereas spleen stiffness was associated with severe GEVs (1.82 [1.25-2.95]; P = 0.005).

CONCLUSION

Liver and spleen stiffness and spleen volume are associated with GEVs in patients with chronic liver disease. Compared with liver stiffness and spleen volume, spleen stiffness is more strongly associated with severe GEVs.

Transjugular intrahepatic portosystemic shunt for the management of acute variceal hemorrhage

Acute variceal hemorrhage, a life-threatening condition that requires a multidisciplinary approach for effective therapy, is defined as visible bleeding from an esophageal or gastric varix at the time of endoscopy, the presence of large esophageal varices with recent stigmata of bleeding, or fresh blood visible in the stomach with no other source of bleeding identified. Transfusion of blood products, pharmacological treatments and early endoscopic therapy are often effective; however, if primary hemostasis cannot be obtained or if uncontrollable early rebleeding occurs, transjugular intrahepatic portosystemic shunt (TIPS) is recommended as rescue treatment. The TIPS represents a major advance in the treatment of complications of portal hypertension. Acute variceal hemorrhage that is poorly controlled with endoscopic therapy is generally well controlled with TIPS, which has a 90% to 100% success rate. However, TIPS is associated with a mortality of 30% to 50% in such a setting. Emergency TIPS should be considered early in patients with refractory variceal bleeding once medical treatment and endoscopic sclerotherapy failure, before the clinical condition worsens. Furthermore, admission to specialized centers is mandatory in such a setting and regional protocols are essential to be organized effectively. This review article discusses initial management and then focuses on the specific role of TIPS as a primary therapy to control acute variceal hemorrhage, particularly as a rescue therapy following failure of endoscopic approaches.

Noninvasive diagnostic method for idiopathic portal hypertension based on measurements of liver and spleen stiffness by ARFI elastography

BACKGROUND

Acoustic radiation force impulse (ARFI) elastography is an ultrasound technique that is capable of measuring tissue stiffness noninvasively. It is difficult to differentiate idiopathic portal hypertension (IPH) from liver cirrhosis (LC) or chronic hepatitis (CH), and liver biopsy is essential. We investigated whether it would be possible to noninvasively diagnose IPH by measuring the stiffness of the liver and spleen by ARFI.

METHODS

The subjects were 17 IPH patients, 25 LC patients, 20 CH patients, and 20 normal controls (NC). We measured liver stiffness, spleen stiffness, and the spleen/liver stiffness ratio, and plotted ROC curves.

RESULTS

The median value of liver stiffness in the IPH group was lower than that in the LC group (p = 0.00077) and about the same as in the CH group (p = 0.79). The median value of spleen stiffness was highest in the IPH group (IPH vs. LC group, p = 0.003; IPH vs. CH group, p < 0.00001). The spleen/liver stiffness ratio was lower in the LC group and in the CH group, and higher in the IPH group (p < 0.001, respectively). When an ROC curve of spleen/liver stiffness ratios was plotted to differentiate between the IPH group and the combined group of patients with other liver diseases (LC + CH group), when a cutoff value of 1.71 was used, the AUROC was 0.933 sensitivity 0.941, specificity 0.800, and accuracy 0.839.

CONCLUSION

Measuring the spleen/liver stiffness ratio by ARFI made it possible to noninvasively, specifically, and accurately diagnose IPH.

JSUM ultrasound elastography practice guidelines: liver

In diffuse liver disease, it is extremely important to make an accurate diagnosis of liver fibrosis prior to determining indications for therapy or predicting treatment outcome and malignant potential. Although liver biopsy has long been the gold standard in the diagnosis of liver fibrosis, it is still an invasive method. In addition, the sampling error is an intrinsic problem of liver biopsy. Non-invasive serological methods for the diagnosis of liver fibrosis can be affected by factors unrelated to the liver. Recently, after the introduction of FibroScan, it became possible to measure liver fibrosis directly and non-invasively by elastography, which has attracted attention as a non-invasive imaging diagnostic tool for liver fibrosis. In addition, real-time tissue elastography is currently being used to conduct clinical trials at many institutions. Moreover, virtual touch quantification enables the observation of liver stiffness at any location by simply observing B-mode images. Furthermore, the recently developed ShearWave elastography visualizes liver stiffness on a color map. Elastography is thought to be useful for all types of diffuse liver diseases. Because of its association with portal hypertension and liver carcinogenesis, elastography is expected to function as a novel prognostic tool for liver disease. Although various elastographic devices have been developed by multiple companies, each device has its own measurement principle, method, and outcome, creating confusion in clinical settings. Therefore, it is extremely important to understand the characteristics of each device in advance. The objective of this guideline, which describes the characteristics of each device based on the latest knowledge, is for all users to be able to make the correct diagnosis of hepatic fibrosis by ultrasound elastography.