When the spleen gets tough, the varices get going

Non-invasive tools for compensated advanced chronic liver disease and portal hypertension after Baveno VII - an update

Non-invasive tests (NITs) and liver stiffness measurement (LSM) in particular, have entered clinical practice over 20 years ago as point-of-care tests to diagnose liver fibrosis in patients with compensated chronic liver disease. Since then, NITs use has evolved thanks to a large number of studies in all major etiologies of liver disease, and they have become important tools to stratify the risk of portal hypertension and liver-related events. The Baveno VII consensus workshop provided several novel recommendations regarding the use of well-established and novel NITs in the specific setting of portal hypertension screening, diagnosis and follow-up. The Baveno VII expert panels paid special attention to summarizing the existing data into simple clinical rules able to guide clinicians in their practice. The "rule of five" for LSM is a tool to stratify the risk of liver-related events, and LSM alone or in combination with platelet count, can be used now to rule-in and rule-out compensated advanced chronic liver disease (cACLD) and clinically significant portal hypertension, as well as to rule-out high-risk varices. Use of NITs in obese subjects with non-alcoholic fatty liver disease (NAFLD) and patients with viral hepatitis C that has been successfully treated, require specific knowledge. This review will update the reader on these aspects.

The Past, Present, and Future of Noninvasive Test in Chronic Liver Diseases

Chronic liver disease is a major global health threat and is the 11th leading cause of death globally. A liver biopsy is frequently required in assessing the degree of steatosis and fibrosis, information that is important in diagnosis, management, and prognostication. However, liver biopsies have limitations and carry a considerable risk, leading to the development of various modalities of noninvasive testing tools. These tools have been developed in recent years and have improved markedly in diagnostic accuracy. Moving forward, they may change the practice of hepatology.

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).

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.

Multicenter Retrospective Risk Assessment of Esophageal Variceal Bleeding in Patients with Cirrhosis: An Acoustic Radiation Force Impulse Elastography-Based Prediction Model

BACKGROUND/AIMS

Acoustic radiation force impulse (ARFI) elastography predicts the presence of esophageal varices (EVs). We investigated whether an ARFI-based prediction model can assess EV bleeding (EVB) risk in patients with cirrhosis.

METHODS

The records of 262 patients with cirrhosis who underwent ARFI elastography and endoscopic surveillance at two institutions in 2008 to 2013 were retrospectively reviewed, and ARFI-spleen diameter-to-platelet ratio scores (ASPS) were calculated.

RESULTS

The median patient age (165 men, 97 women) was 56 years. The median ARFI velocity, spleen diameter, platelet count, and ASPS were 1.7 m/sec, 10.1 cm, 145×109/L, and 1.16, respectively. During the median 38-month follow-up, 61 patients experienced EVB. Among all patients (179 without EVs and 83 with EVs), the cutoff value that maximized the sum of the sensitivity (73.1%) and specificity (78.4%) (area under receiver operating characteristic curve [AUROC], 0.824) for predicting EVB was 2.60. The cumulative EVB incidence was significantly higher in patients with ASPS ≥2.60 than in those with ASPS <2.60 (p<0.001). Among patients with EVs (n=83), 49 had high-risk EVs (HEVs), and 22 had EVB. The cumulative EVB incidence was significantly higher in HEV patients than in low-risk EV patients (p=0.037). At an ASPS of 4.50 (sensitivity, 66.7%; specificity, 70.6%; AUROC, 0.691), the cumulative EVB incidence was significantly higher in patients with a high ASPS than in those with a low ASPS (p=0.045). A higher ASPS independently predicted EVB (hazard ratio, 4.072; p=0.047).

CONCLUSIONS

ASPS can assess EVB risk in patients with cirrhosis. Prophylactic management should be considered for patients with HEVs and ASPS ≥4.50.

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.

Evaluation of Splenic Stiffness in Patients of Extrahepatic Portal Vein Obstruction Using 2D Shear Wave Elastography: Comparison with Intra-Operative Portal Pressure

BACKGROUND/AIMS

To compare splenic stiffness (SS) with intra-operative portal pressures (PPs) in patients of extrahepatic portal vein obstruction (EHPVO).

METHODS

Twenty-one patients (14 males; 7 females) of mean age 20.4 years with clinical and sonographic diagnosis of EHPVO were included in this approved prospective study. Endoscopy for esophageal varices (EV) was done in all patients followed by ultrasonographic 2D shear wave elastography (SWE) of spleen. Three values were taken at different areas of spleen avoiding major vessels and mean was calculated. Intra-operative PP was measured from an omental vein during proximal spleno-renal shunt surgery. The PP was compared and correlated with SS along with other parameters.

RESULTS

The mean SS was 46.04 ± 8.0 kPa and the mean PP was 33.29 ± 4.1 mmHg. There was no significant correlation between PP and SS (P = 0.61) and between grades of EV and SS (P = 0.38). Significant correlation was seen between grades of EV and PP (0.04). SS also did not show significant correlation with splenic size or duration of disease.

CONCLUSION

SS measured by 2D SWE did not correlate with PP and thus may not help in predicting gastrointestinal bleed in patients of EHPVO.

A combined model based on spleen stiffness measurement and Baveno VI criteria to rule out high-risk varices in advanced chronic liver disease

BACKGROUND & AIMS

Recently, Baveno VI guidelines suggested that esophagogastroduodenoscopy (EGD) can be avoided in patients with compensated advanced chronic liver disease (cACLD) who have a liver stiffness measurement (LSM) <20 kPa and platelet count >150,000/mm³. We aimed to: assess the performance of spleen stiffness measurement (SSM) in ruling out patients with high-risk varices (HRV); validate Baveno VI criteria in a large population and assess how the sequential use of Baveno VI criteria and SSM could safely avoid the need for endoscopy.

METHODS

We retrospectively analyzed 498 patients with cACLD who had undergone LSM/SSM by transient elastography (TE) (FibroScan®), platelet count and EGDs from 2012 to 2016 referred to our tertiary centre. The new combined model was validated internally by a split-validation method, and externally in a prospective multicentre cohort of 115 patients.

RESULTS

SSM, LSM, platelet count and Child-Pugh-B were independent predictors of HRV. Applying the newly identified SSM cut-off (≤46 kPa) or Baveno VI criteria, 35.8% and 21.7% of patients in the internal validation cohort could have avoided EGD, with only 2% of HRVs being missed with either model. The combination of SSM with Baveno VI criteria would have avoided an additional 22.5% of EGDs, reaching a final value of 43.8% spared EGDs, with <5% missed HRVs. Results were confirmed in the prospective external validation cohort, as the combined Baveno VI/SSM ≤46 model would have safely spared (0 HRV missed) 37.4% of EGDs, compared to 16.5% when using the Baveno VI criteria alone.

CONCLUSIONS

A non-invasive prediction model combining SSM with Baveno VI criteria may be useful to rule out HRV and could make it possible to avoid a significantly larger number of unnecessary EGDs compared to Baveno VI criteria only.

LAY SUMMARY

Spleen stiffness measurement assessed by transient elastography, the most widely used elastography technique, is a non-invasive technique that can help the physician to better stratify the degree of portal hypertension and the risk of esophageal varices in patients with compensated advanced chronic liver disease. Performing spleen stiffness measurement together with liver stiffness measurement during the same examination is simple and fast and this sequential model can identify a greater number of patients that can safely avoid endoscopy, which is an invasive and expensive examination.

A Novel FibroScan Examination Dedicated to Spleen Stiffness Measurement

Esophageal varices (EVs) are among the most severe complications of cirrhosis, with a prevalence of 50% to 60% among cirrhotic patients. International guidelines therefore recommend that cirrhotic patients should be screened for the presence of EVs. The main objective of this study was to introduce a new spleen-dedicated FibroScan (Echosens, Paris, France) examination and to assess its performance in detecting large EVs (grade 2 and 3). This novel examination has been validated in simulation and phantom studies and has been used in a population of patients with chronic liver disease. The study described here suggests that the novel spleen-dedicated FibroScan examination performs better than the standard FibroScan for the detection of large EVs (area under the curve = 0.70 for the standard examination and 0.79 [p <0.01] for the spleen examination), but further clinical studies are needed to investigate the role of spleen stiffness in the management of cirrhotic patients.

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.

Spleen stiffness is positively correlated with HVPG and decreases significantly after TIPS implantation

BACKGROUND

Transjugular intrahepatic portosystemic shunt (TIPS) is indicated in patients with decompensated portal hypertension (PH). Hepatic venous pressure gradient (HVPG) is considered gold standard for assessment of PH. Because HVPG measurement is invasive, non-invasive methods for evaluating severity of PH are warranted.

PATIENTS AND METHODS

We retrospectively correlated spleen stiffness as measured by FibroScan with HVPG in patients who underwent TIPS. Twenty-four patients with spleen stiffness measurement (SSM) one day before (D-1), one day after (D+1) and 28 days after TIPS (D+28) were included.

RESULTS

SSM was positively correlated with pre-TIPS HVPG (HVPG <13mmHg, median SSM: 19.7±8.6kPa; HVPG 13-24mmHg, median SSM: 45.0±15.7kPa; HVPG >24mmHg, median SSM: 75.0±6.2kPa; p<0.05]; r²=0.72; p<0.001) and decreased significantly after TIPS implantation (D-1, median SSM: 67.1±17.3kPa; D+1, median SSM: 44.7±18.5kPa; D+28, median SSM: 35.6±17.0kPa; p<0.05), while liver stiffness measurement decrease was not statistically significant.

CONCLUSIONS

Our study highlights the utility of SSM as non-invasive tool in patients with chronic liver disease in evaluating degree of PH potentially offering a confirmable additional parameter in surveillance of patients undergoing TIPS procedure.

Diagnostic accuracy of transient elastography (FibroScan) in detection of esophageal varices in patients with cirrhosis: A meta-analysis

AIM

To investigate the diagnostic accuracy of FibroScan (FS) in detecting esophageal varices (EV) in cirrhotic patients.

METHODS

Through a systemic literature search of multiple databases, we reviewed 15 studies using endoscopy as a reference standard, with the data necessary to calculate pooled sensitivity (SEN) and specificity (SPE), positive and negative LR, diagnostic odds ratio (DOR) and area under receiver operating characteristics (AUROC). The quality of the studies was rated by the Quality Assessment of Diagnostic Accuracy studies-2 tool. Clinical utility of FS for EV was evaluated by a Fagan plot. Heterogeneity was explored using meta-regression and subgroup analysis. All statistical analyses were conducted via Stata12.0, MetaDisc1.4 and RevMan5.

RESULTS

In 15 studies (n = 2697), FS detected the presence of EV with the summary sensitivities of 84% (95%CI: 81.0%-86.0%), specificities of 62% (95%CI: 58.0%- 66.0%), a positive LR of 2.3 (95%CI: 1.81-2.94), a negative LR of 0.26 (95%CI: 0.19-0.35), a DOR of 9.33 (95%CI: 5.84-14.92) and an AUROC of 0.8262. FS diagnosed the presence of large EV with the pooled SEN of 0.78 (95%CI: 75.0%-81.0%), SPE of 0.76 (95%CI: 73.0%-78.0%), a positive and negative LR of 3.03 (95%CI: 2.38-3.86) and 0.30 (95%CI: 0.23-0.39) respectively, a summary diagnostic OR of 10.69 (95%CI: 6.81-16.78), and an AUROC of 0.8321. A meta-regression and subgroup analysis indicated different etiology could serve as a potential source of heterogeneity in the diagnosis of the presence of EV group. A Deek’s funnel plot suggested a low probability for publication bias.

CONCLUSION

Using FS to measure liver stiffness cannot provide high accuracy for the size of EV due to the various cutoff and different etiologies. These limitations preclude widespread use in clinical practice at this time; therefore, the results should be interpreted cautiously given its SEN and SPE.

Diagnosis and quantification of fibrosis, steatosis, and hepatic siderosis through multiparametric magnetic resonance imaging

BACKGROUND

The presence of liver fibrosis is the common denominator in numerous chronic liver diseases that can progress to fibrosis and hepatocellular carcinoma. Most important, with respect to frequency, are viral hepatitis and non-alcoholic fatty liver disease, the prevalence of which is increasing in epidemic proportions. Liver biopsy, albeit imperfect, continues to be the criterion standard, but in many clinical situations tends to be replaced with noninvasive imaging methods.

OBJECTIVES

The aim of the present article was to describe our imaging department experience with magnetic resonance elastography and to analyze and discuss recently published results in gastroenterology, hepatology, and radiology from other authors in the literature, complemented with a PubMed search covering the last 10 years.

RESULTS AND CONCLUSIONS

Magnetic resonance elastography is an efficacious, noninvasive method with results that are concordant with liver biopsy. It is superior to ultrasound elastography because it evaluates a much greater volume of hepatic tissue and shows the often heterogeneous lesion distribution. The greatest advantage of the magnetic resonance protocol described is the fact that it quantifies fibrosis, fat content, and iron content in the same 25min examination specifically directed for that purpose, resulting in a favorable cost-benefit ratio for the patient and/or institution.

Clinical role of non-invasive assessment of portal hypertension

Measurement of portal pressure is pivotal in the evaluation of patients with liver cirrhosis. The measurement of the hepatic venous pressure gradient represents the reference method by which portal pressure is estimated. However, it is an invasive procedure that requires significant hospital resources, including experienced staff, and is associated with considerable cost. Non-invasive methods that can be reliably used to estimate the presence and the degree of portal hypertension are urgently needed in clinical practice. Biochemical and morphological parameters have been proposed for this purpose, but have shown disappointing results overall. Splanchnic Doppler ultrasonography and the analysis of microbubble contrast agent kinetics with contrast-enhanced ultrasonography have shown better accuracy for the evaluation of patients with portal hypertension. A key advancement in the non-invasive evaluation of portal hypertension has been the introduction in clinical practice of methods able to measure stiffness in the liver, as well as stiffness/congestion in the spleen. According to the data published to date, it appears to be possible to rule out clinically significant portal hypertension in patients with cirrhosis (i.e., hepatic venous pressure gradient ≥ 10 mmHg) with a level of clinically-acceptable accuracy by combining measurements of liver stiffness and spleen stiffness along with Doppler ultrasound evaluation. It is probable that the combination of these methods may also allow for the identification of patients with the most serious degree of portal hypertension, and ongoing research is helping to ensure progress in this field.

Virtual touch quantification (VTq) elastography for non-invasive assessment of liver disease and its complications: what the clinician needs to know

Liver stiffness measurement (LSM) is the most widely used non-invasive alternative to biopsy for assessing liver fibrosis in the UK. Virtual touch quantification (VTq, also known as acoustic radiation force impulse) is the principal available alternative to transient elastography (Fibroscan) and is delivered via software enhancements to standard ultrasound (US) machines. It has recently been endorsed by National Institute for Health and Care Excellence in terms of both accuracy and cost-effectiveness for use in viral hepatitis. However, while an increasing proportion of radiologists use VTq, familiarity among gastroenterologists and trainees with LSM techniques is variable and implementation is patchy. This review considers the background, evidence for and practical use of VTq elastography in clinical practice in the UK. Potential future developments in this rapidly evolving field are also highlighted.

Noninvasive tools and risk of clinically significant portal hypertension and varices in compensated cirrhosis: The "Anticipate" study

In patients with compensated advanced chronic liver disease (cACLD), the presence of clinically significant portal hypertension (CSPH) and varices needing treatment (VNT) bears prognostic and therapeutic implications. Our aim was to develop noninvasive tests-based risk prediction models to provide a point-of-care risk assessment of cACLD patients. We analyzed 518 patients with cACLD from five centers in Europe/Canada with paired noninvasive tests (liver stiffness measurement [LSM] by transient elastography, platelet count, and spleen diameter with calculation of liver stiffness to spleen/platelet score [LSPS] score and platelet-spleen ratio [PSR]) and endoscopy/hepatic venous pressure gradient measurement. Risk of CSPH, varices, and VNT was modeled with logistic regression. All noninvasive tests reliably identified patients with high risk of CSPH, and LSPS had the highest discrimination. LSPS values above 2.65 were associated with risks of CSPH above 80%. None of the tests identified patients with very low risk of all-size varices, but both LSPS and a model combining TE and platelet count identified patients with very low risk (<5%) risk of VNT, suggesting that they could be used to triage patients requiring screening endoscopy. LSPS values of <1.33 were associated with a <5% risk of VNT, and 26% of patients had values below this threshold. LSM combined with platelet count predicted a risk <5% of VNT in 30% of the patients. Nomograms were developed to facilitate point-of-care risk assessment.

CONCLUSION

A significant proportion of patients with a very high risk of CSPH, and a population with a very low risk of VNT can be identified with simple, noninvasive tests, suggesting that these can be used to individualize medical care. (Hepatology 2016;64:2173-2184).

Liver and Spleen Stiffness Measurements by Point Shear Wave Elastography via Acoustic Radiation Force Impulse: Intraobserver and Interobserver Variability and Predictors of Variability in a US Population

OBJECTIVES

Measurements of liver stiffness and spleen stiffness are useful noninvasive ways to assess fibrosis and portal hypertension in patients with chronic liver disease. One method for assessing stiffness is by point shear wave elastography via acoustic radiation force impulse imaging (ARFI). Its advantage is that sites where stiffness is measured are visualized sonographically. However, its reliability has not been well established, and all studies done to date evaluating the use of ARFI in chronic liver disease have been performed outside the United States. We aimed to characterize the intraobserver and interobserver variability of ARFI-measured liver and spleen stiffness.

METHODS

Two hepatologists evaluated unselected hepatology outpatients with ARFI. Exclusions were hepatocellular carcinoma, ascites, a surgical shunt or transjugular intrahepatic portosystemic shunt, portal thrombosis, and cholestatic disease. Each operator obtained 20 measurements from the right liver lobe and spleen. Intraclass correlation coefficients (ICC) were calculated.

RESULTS

A total of 177 patients were included: median age, 61 years; 85% male; and 43% obese. Intraobserver ICCs were the same for both observers for liver stiffness (0.89; 95% confidence interval [CI], 0.85-0.92) and spleen stiffness (0.72; 95% CI, 0.61-0.80). Interobserver agreement was excellent for liver stiffness (ICC, 0.85; 95% CI, 0.76-0.90) but not as good for spleen stiffness (ICC, 0.73; 95% CI, 0.60-0.83). A body mass index of 30 kg/m² or greater, waist circumference of greater than 105 cm, and skin-to-capsule distance of 2 cm or greater negatively affected the ICC for liver stiffness; small spleen size negatively affected the ICC for spleen stiffness.

CONCLUSIONS

To our knowledge, this article is the first report of ARFI findings in a US population with chronic liver disease. Liver stiffness reproducibility was excellent, particularly in nonobese patients. Spleen stiffness reproducibility was excellent in those with larger spleens and therefore may be most useful in patients with cirrhosis and 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.

Development of hyperdynamic circulation and response to β-blockers in compensated cirrhosis with portal hypertension

Nonselective β-blockers are useful to prevent bleeding in patients with cirrhosis and large varices but not to prevent the development of varices in those with compensated cirrhosis and portal hypertension (PHT). This suggests that the evolutionary stage of PHT may influence the response to β-blockers. To characterize the hemodynamic profile of each stage of PHT in compensated cirrhosis and the response to β-blockers according to stage, we performed a prospective, multicenter (tertiary care setting), cross-sectional study. Hepatic venous pressure gradient (HVPG) and systemic hemodynamic were measured in 273 patients with compensated cirrhosis before and after intravenous propranolol (0.15 mg/kg): 194 patients had an HVPG ≥10 mm Hg (clinically significant PHT [CSPH]), with either no varices (n = 80) or small varices (n = 114), and 79 had an HVPG >5 and <10 mm Hg (subclinical PHT). Patients with CSPH had higher liver stiffness (P < 0.001), worse Model for End-Stage Liver Disease score (P < 0.001), more portosystemic collaterals (P = 0.01) and splenomegaly (P = 0.01) on ultrasound, and lower platelet count (P < 0.001) than those with subclinical PHT. Patients with CSPH had lower systemic vascular resistance (1336 ± 423 versus 1469 ± 335 dyne · s · cm(-5) , P < 0.05) and higher cardiac index (3.3 ± 0.9 versus 2.8 ± 0.4 L/min/m(2) , P < 0.01). After propranolol, the HVPG decreased significantly in both groups, although the reduction was greater in those with CSPH (-16 ± 12% versus -8 ± 9%, P < 0.01). The HVPG decreased ≥10% from baseline in 69% of patients with CSPH versus 35% with subclinical PHT (P < 0.001) and decreased ≥20% in 40% versus 13%, respectively (P = 0.001).

CONCLUSION

Patients with subclinical PHT have less hyperdynamic circulation and significantly lower portal pressure reduction after acute β-blockade than those with CSPH, suggesting that β-blockers are more suitable to prevent decompensation of cirrhosis in patients with CSPH than in earlier stages.

Simultaneous measurement of hepatic and splenic stiffness using MR elastography: preliminary experience

PURPOSE

To compare MR elastography (MRE) using a single and a dual driver excitation for the quantification of hepatic and splenic stiffness (HS and SS), and to investigate the performance of HS and SS measured with single or dual driver excitation for the detection of liver cirrhosis in subjects with liver disease.

PATIENTS AND METHODS

This prospective HIPAA compliant and IRB approved study involved 49 subjects who underwent MRE at 3.0T, comparing three different acquisition methods (single driver on the liver, single driver on the spleen and dual driver acoustic excitation). A Mann-Whitney test was used to assess changes in stiffness values. Bland-Altman analysis was used to compare single and dual driver configurations for each organ. Performance for detection of liver cirrhosis was assessed using ROC analysis. Pearson correlation was used to estimate the dependence of HS and SS on spleen size.

RESULTS

There were 40 noncirrhotic and 9 cirrhotic patients. There was good agreement between stiffness values measured with a single or a dual driver (Bland-Altman limits of agreement -14.3 % to 18.9 % and -18.1 % to 29.7 %, CV 6.4 % and 9.4 %, for HS and SS. respectively). HS and SS were higher in subjects with liver cirrhosis (p < 0.001), with excellent detection performance (AUROC range 0.87-0.93). SS correlated strongly with spleen size (r = 0.69, p < 0.001), while HS showed weak correlation (r = 0.38, p = 0.006).

CONCLUSION

Using a dual acoustic driver configuration, hepatic and splenic stiffness can be simultaneously estimated with good concordance with single driver measurement.

Liver and spleen elastography using supersonic shear imaging for the non-invasive diagnosis of cirrhosis severity and oesophageal varices

BACKGROUND

Elastography is a promising non-invasive approach for assessing liver fibrosis. We assessed diagnostic performances of liver and spleen stiffness using supersonic shear imaging for diagnosing cirrhosis severity and oesophageal varices.

METHODS

401 consecutive cirrhotic patients were prospectively enrolled from November 2012 to March 2014. All patients underwent liver and spleen stiffness measurement with supersonic shear imaging and Fibroscan.

RESULTS

Failures of measurement were 6.2% and 29.2% for liver and spleen stiffness (supersonic shear imaging), and 18.4% for liver stiffness (Fibroscan). Liver and spleen stiffness were correlated with severity of cirrhosis, with values increasing according to Child-Pugh subclasses and presence of complications. With a negative predictive value ≥90%, liver stiffness cut-offs for high-risk oesophageal varices, history of ascites, Child-Pugh B/C, variceal bleeding and clinical decompensation were 12.8, 19, 21.4, 30.5, and 39.4 kPa, respectively. Areas under the curve of spleen and liver stiffness (supersonic shear imaging), and liver stiffness (Fibroscan) were 0.80, 0.77 and 0.73 respectively for detection of oesophageal varices.

CONCLUSION

Liver stiffness using supersonic shear imaging is a relevant diagnostic tool for assessing cirrhosis severity and its complications. Spleen stiffness shows promising results for the detection of oesophageal varices but is not yet sufficiently robust for clinical practice owing to high failure rates.

A novel model to predict esophageal varices in patients with compensated cirrhosis using acoustic radiation force impulse elastography

BACKGROUND & AIMS

Few noninvasive methods can accurately identify esophageal varices (EVs) in patients with compensated cirrhosis. We developed and validated a novel, acoustic radiation force impulse (ARFI) elastography-based prediction model for high-risk EVs (HEVs) in patients with compensated cirrhosis.

METHODS

A total of 143 patients with compensated cirrhosis between February, 2010 and February, 2013 (training set) and 148 between June, 2010 and May, 2013 (validation set) who underwent ARFI elastography and endoscopy were prospectively recruited. Independent predictors of HEVs were used to construct a prediction model.

RESULTS

Based on multivariate analysis, we developed two new statistical models, a varices risk score and ARFI-spleen diameter-to-platelet ratio score (ASPS), the latter of which was calculated as ARFI velocity × spleen diameter/platelet count. The area under receiver operating characteristic curve (AUROC) of the varices risk score and ASPS to predict HEVs were 0.935 (95% confidence interval [CI] 0.882-0.970) and 0.946 (95% CI 0.895-0.977), respectively. When ASPS, a simpler model with a higher AUROC, was applied in the validation set, acceptable diagnostic accuracy for HEVs was observed (AUROC = 0.814 [95% CI 0.743-0.885]). To detect HEVs, a negative predictive value of 98.3% was achieved at ASPS <2.83, whereas a positive predictive value of 100% was achieved at ASPS >5.28.

CONCLUSIONS

ASPS, a novel noninvasive ARFI-based prediction model, can accurately identify HEVs in patients with compensated cirrhosis. ASPS <2.83 may safely rule out the presence of HEVs, whereas patients with ASPS >5.28 should be considered for endoscopic examinations or appropriate prophylactic treatment.

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.