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

The Value of Follow-Up Liver Stiffness Changes Measured by Virtual Touch Quantification Elastography for Predicting Recurrence of Gastroesophageal Varices after Endoscopic Injection Sclerotherapy on Cirrhotic Patients

Background and Aims

Recurrence of gastroesophageal varices (GEVs) after sclerotherapy is a public health problem. However, mass screening of recurrence of GEVs through gastroscopy is a high-cost procedure. We aim to evaluate the changes in liver stiffness (LS) over time after endoscopic injection sclerotherapy (EIS) and determine its value in predicting the recurrence of GEVs.

Methods

One hundred and thirty-five patients with GEVs who underwent EIS treatment were included in this study. The patients were divided into two groups, namely, the nonrecurrence and recurrence groups, based on endoscopic findings at 6 months after discharge. LS measurements were obtained on five occasions. Repeated measure analysis of variance was employed to assess LS differences at different time points and compare them between the two groups.

Results

The LS values during the 6-month postdischarge period were consistently higher than the baseline value (measured on the day of hospitalization). The recurrence group demonstrated sustained elevated LS levels throughout the 6-month follow-up period, while the nonrecurrence group showed a gradual decline in LS. The difference in LS trend between the two groups was statistically significant (P = 0.04). The area under the curve (AUC) values for LS differences were 0.806, with a corresponding 95% confidence interval (CI) of 0.640-0.918 and a cut-off value of 0.556, indicating their potential utility in predicting GEV recurrence.

Conclusions

Longitudinal assessment of LS values in post-EIS patients can provide valuable information for predicting the recurrence of GEVs.

Role of Spleen Stiffness Measurement in the Evaluation of Metabolic Dysfunction-Associated Steatotic Liver Disease

BACKGROUND

Spleen stiffness measurement (SSM) correlates with the severity of portal hypertension.

AIMS

We investigated the utility of SSM in individuals with metabolic dysfunction-associated steatotic liver disease (MASLD) for detecting cirrhosis, esophageal varices (EV), and high-risk EV.

METHODS

154 study participants with MASLD underwent simultaneous liver stiffness measurement (LSM) and SSM. 96 (62%) participants had an upper endoscopy (73 participants, i.e., 47% undergoing within a year). The diagnostic performance of SSM, as well as the BAVENO VII proposed SSM cutoffs (≥ 21 kPa, > 40 kPa, and > 50 kPa), was examined.

RESULTS

The failure rate for SSM was 19% compared to 5% for LSM. An invalid SSM was statistically significantly associated with a higher body mass index, a larger waist circumference, and a lower fibrosis stage. The area under the receiver operating characteristics for SSM to diagnose cirrhosis, EV, and high-risk EV was 0.78 (95% CI 0.70-0.85), 0.74 (95% CI 0.61-0.84), and 0.82 (95% CI 0.75-0.98), respectively. SSM ≥ 21 kPa cutoff had a sensitivity > 96% for all three outcomes, with a positive predictive value (PPV) of 88% for cirrhosis. In contrast, SSM > 40 kPa and SSM > 50 kPa cutoffs had better diagnostic abilities for identifying EV, particularly high-risk EV (sensitivity of 100% and 93% with NPV of 100% and 96%, respectively).

CONCLUSION

SSM has a higher failure rate in individuals who are non-cirrhotic or have a higher BMI, or larger waist circumference. Although useful for diagnosing NASH cirrhosis, SSM is most reliable in excluding EV and high-risk EV.

Spleen Stiffness-Based Algorithms Are Superior to Baveno VI Criteria to Rule Out Varices Needing Treatment in Patients With Advanced Chronic Liver Disease

INTRODUCTION

The Baveno VI criteria have set the stage for noninvasive assessment of compensated advanced chronic liver disease (ACLD). The algorithm combining liver stiffness measurement (LSM, <20 kPa) and platelet count (>150,000/μL) safely avoids screening endoscopy for varices needing treatment (VNT) but identifies only a relatively low number of patients. We aimed to evaluate the value of spleen stiffness measurement (SSM) using spleen-dedicated elastography in ruling out VNT.

METHODS

In this real-life multicenter retrospective derivation-validation cohort, all consecutive patients with ACLD (defined by LSM ≥10 kPa) with available upper endoscopy, laboratory results, spleen diameter, LSM, and SSM measured with spleen-dedicated transient elastography were included. VNT were defined as medium-to-large varices or small varices with red spots.

RESULTS

In the derivation cohort (n = 201, 11.9% VNT), SSM demonstrated excellent capability at identifying VNT (area under the receiver operating characteristic curve [AUROC] 0.88), outperforming LSM (AUROC 0.77, P = 0.03) and platelets (AUROC 0.73, P = 0.002). In comparison with Baveno VI criteria (33.8% spared endoscopies), the sequential Baveno VI plus SSM and a novel spleen size and stiffness model were able to increase the number of patients avoiding endoscopy (66.2% and 71.1%, respectively) without missing more than 5% of VNT. These findings were confirmed in an external validation cohort of patients with more advanced liver disease (n = 176, 34.7% VNT) in which the number of spared endoscopies tripled (27.3% and 31.3% for SSM-based algorithms) compared with Baveno VI criteria (8.5%).

DISCUSSION

Spleen stiffness-based algorithms are superior to Baveno VI criteria in ruling out VNT in patients with ACLD and double the number of patients avoiding screening endoscopy.

Portal hypertension in patients with nonalcoholic fatty liver disease: Current knowledge and challenges

Portal hypertension (PH) has traditionally been observed as a consequence of significant fibrosis and cirrhosis in advanced non-alcoholic fatty liver disease (NAFLD). However, recent studies have provided evidence that PH may develop in earlier stages of NAFLD, suggesting that there are additional pathogenetic mechanisms at work in addition to liver fibrosis. The early development of PH in NAFLD is associated with hepatocellular lipid accumulation and ballooning, leading to the compression of liver sinusoids. External compression and intra-luminal obstacles cause mechanical forces such as strain, shear stress and elevated hydrostatic pressure that in turn activate mechanotransduction pathways, resulting in endothelial dysfunction and the development of fibrosis. The spatial distribution of histological and functional changes in the periportal and perisinusoidal areas of the liver lobule are considered responsible for the pre-sinusoidal component of PH in patients with NAFLD. Thus, current diagnostic methods such as hepatic venous pressure gradient (HVPG) measurement tend to underestimate portal pressure (PP) in NAFLD patients, who might decompensate below the HVPG threshold of 10 mmHg, which is traditionally considered the most relevant indicator of clinically significant portal hypertension (CSPH). This creates further challenges in finding a reliable diagnostic method to stratify the prognostic risk in this population of patients. In theory, the measurement of the portal pressure gradient guided by endoscopic ultrasound might overcome the limitations of HVPG measurement by avoiding the influence of the pre-sinusoidal component, but more investigations are needed to test its clinical utility for this indication. Liver and spleen stiffness measurement in combination with platelet count is currently the best-validated non-invasive approach for diagnosing CSPH and varices needing treatment. Lifestyle change remains the cornerstone of the treatment of PH in NAFLD, together with correcting the components of metabolic syndrome, using nonselective beta blockers, whereas emerging candidate drugs require more robust confirmation from clinical trials.

Budd-Chiari syndrome in children: Radiological intervention and role of shear wave elastography in monitoring response

OBJECTIVES

Radiological intervention (RI) is the preferred treatment in children with Budd-Chiari syndrome (BCS). We studied the comparative long-term outcome of BCS children, with and without RI and utility of liver and splenic stiffness measurement (LSM, SSM) by 2-dimensional shear wave elastography (2D-SWE) in assessing response.

METHODS

Sixty children (40 boys, median age 10.5 [6.5-15.25] years) with BCS (29 newly diagnosed, 31 follow-up) were evaluated. LSM and SSM by 2D-SWE and vascular patency were monitored pre- and postprocedure (≥ 6 months postprocedure) in those undergoing RI. Medical therapy without anticoagulation and monitoring was done in subjects without RI. The RI and no-RI groups were compared.

RESULTS

Ascites (54,90%), hepatomegaly (56,93%) and prominent abdominal-veins (42,70%), were the commonest features. The majority (46,78%) had isolated hepatic vein block. 44 (73%) cases underwent RI, while 16 (27%) were managed conservatively. Both groups were similar at baseline. Post-RI subjects showed significant improvement in clinical findings, liver functions and portal hypertension. LSM [33 (32-34.5) to 19.2 (18-20.67) kPa] and SSM [54.5 (52.3-57.6) to 28.9 (27.6-30.25) kPa] showed a significant decline from baseline value over a follow-up of 12 (6-13) months. Gradual reduction occurred in the LSM and SSM over 1-5 years, with near-normal LSM [10.2 (9.2-11.5) kPa] and SSM [22.3 (20.5-24.3) kPa] values in patients (n-16) with > 5 years follow-up. Patients without RI showed worsening in LSM and SSM. Hepatopulmonary syndrome and hepatocellular carcinoma developed in 4 (8%) and 1 (1.7%) cases respectively.

CONCLUSION

RI leads to clinical recovery and reduction with near normalization of LSM and SSM over long-term follow-up in children with BCS. 2D-SWE is a promising tool to monitor outcomes.

Spleen stiffness determined by spleen-dedicated device accurately predicted esophageal varices in cirrhosis patients

Background

The advantages of spleen stiffness in prediction of high-risk varices (HRV) in cirrhosis patients have been confirmed. Recently, a new device utilizing a 100 Hz probe dedicated to spleen stiffness measurement (SSM) was developed.

Objectives

To validate the clinical applicability of SSM@100 Hz in predicting HRV by comparing it with other non-invasive tests (NITs).

Design

A prospective cohort study.

Methods

A total of 171 cirrhosis patients who underwent esophagogastroduodenoscopy (EGD) examination were included in this study. SSM using a 100 Hz probe and liver stiffness measurement using a 50 Hz probe were performed. Additionally, 22 healthy controls underwent spleen stiffness evaluation using the 100 Hz probe.

Results

The failure rates of spleen stiffness examination in patients with cirrhosis and in healthy controls were 2.9% and 4.5%, respectively. The means of SSM values were 56.4 ± 21.6 and 13.8 ± 6.7 kPa in cirrhosis and controls. SSM increased proportionally with the severity of esophageal varices. The area under receiver operating characteristic (ROC) for spleen stiffness in predicting HRV was 0.881 (95% confidence interval 0.829-0.934), with a cutoff value of 43.4 kPa. The accuracy, false negative rate and EGD spare rate were 86.5%, 2.5% and 24.3%, respectively. For HRV prediction, SSM was comparable to expanded Baveno VI and VII and superior to other NITs. As to viral versus non-viral cirrhosis and compensated versus decompensated cirrhosis, the cut-off and performance of SSM were different.

Conclusion

SSM@100 Hz demonstrates high accuracy in predicting HRV with a low missed HRV rate. Our findings suggest that SSM@100 Hz can be used independently due to its simplicity and effectiveness. However, further studies are needed to determine appropriate cutoff values based on the cause of cirrhosis and liver function.

Trail Registration

ChiCTR2300070270.

Accuracy of spleen stiffness measurement for the diagnosis of clinically significant portal hypertension in patients with compensated advanced chronic liver disease: a systematic review and individual patient data meta-analysis

BACKGROUND

The diagnosis of clinically significant portal hypertension is crucial for prognosis and treatment guidance in patients with compensated advanced chronic liver disease (ACLD). Spleen stiffness measurement (SSM) might improve the non-invasive diagnosis of clinically significant portal hypertension, but previous studies have reported heterogeneous SSM cutoffs. We aimed to evaluate the accuracy of SSM and SSM-based algorithms in this setting.

METHODS

In this systematic review and individual patient data meta-analysis, we searched PubMed, Embase, Scopus, Web of Science, and the Cochrane Library from database inception to Dec 31, 2022, for articles, abstracts, and letters, with no restrictions on language. Cross-sectional studies reporting hepatic venous pressure gradient and SSM by different techniques (transient elastography; two-dimensional shear-wave elastography [2D-SWE]; point shear-wave elastography [p-SWE]) in adults (≥18 years) with compensated ACLD were eligible for inclusion. The main outcome was the diagnostic performance of two SSM-based algorithms, with the Baveno VII model as a reference, evaluating sensitivity and specificity, as well as summary negative predictive values (NPVs) and positive predictive values (PPVs). In the Baveno VII model, clinically significant portal hypertension was ruled out if patients had a liver stiffness measurement (LSM) of 15 kPa or less and a platelet count of 150 × 109 platelets per L or higher and ruled in if they had an LSM of greater than 25 kPa. The two SSM-based models combined these same cutoffs with additional criteria. In the Baveno VII-SSM single cutoff model, clinically significant portal hypertension was ruled out if at least two of the following were present: LSM of 15 kPa or less, platelet count of 150 × 109 platelets per L or higher, and SSM of 40 kPa or less; and ruled in if at least two were present: LSM of greater than 25 kPa, platelet count of less than 150 × 109 platelets per L, and SSM of greater than 40 kPa. The Baveno VII-SSM dual cutoff model used the same criteria, but with a cutoff of SSM of less than 21 kPa to rule out, and greater than 50 kPa to rule in, clinically significant portal hypertension. This study is registered with PROSPERO, CRD42019127164.

FINDINGS

Of the 44 records assessed for eligibility, 17 studies (with 1245 patients) were included in the meta-analysis. In the transient elastography cohort (n=600), the Baveno VII algorithm was validated for both ruling out (NPV 100%, 95% CI 64-100; sensitivity 100%, 95% CI 70-100) and ruling in (PPV 95%, 85-98; specificity 94%, 95% CI 87-97) clinically significant portal hypertension, but the proportion of patients with indeterminate results (grey zone) was 48% (95% CI 44-52); 57% (95% CI 52-62) of patients with clinically significant portal hypertension were included in the rule-in zone. The Baveno VII-SSM dual cutoff model had adequate NPV (98%, 95% CI 58-100; sensitivity 100%, 95% CI 91-100) and PPV (93%, 95% CI 84-97; specificity 89%, 95% CI 84-93), with 32% (95% CI 28-36) of patients in the grey zone; 76% (95% CI 72-80) of the patients with clinically significant portal hypertension were in the rule-in zone. The Baveno VII-SSM single cutoff model had a sensitivity of 93% (95% CI 85-97) and a NPV of 85% (95% CI 60-96) for ruling out, and a specificity of 86% (95% CI 80-91) and a PPV of 92% (95% CI 83-95) for ruling in, clinically significant portal hypertension. 88% (95% CI 84-91) of patients with clinically significant portal hypertension were included in the rule-in zone and 9% (95% CI 7-12) of patients were in the grey zone. In the 2D-SWE cohort (n=225), all three algorithms could safely rule in clinically significant portal hypertension with adequate PPV (≥90%), but NPV was inadequate for ruling out clinically significant portal hypertension. Insufficient data were available to evaluate the performance of SSM assessed by p-SWE. Heterogeneity was low (I2<25%) for most estimates.

INTERPRETATION

Algorithms combining Baveno VII criteria with SSM showed good performance and reduced the diagnostic grey zone for clinically significant portal hypertension compared with Baveno VII criteria alone. Future studies should evaluate whether SSM-based diagnosis allows for the identification of patients who would benefit from non-selective β-blocker treatment.

FUNDING

None.

Use of Sound Touch Elastography and Sound Touch Quantification for the Noninvasive Evaluation of Portal Hypertension in a Rat Model

OBJECTIVES

In this study, we used the recently developed ultrasound elastography techniques sound touch elastography (STE) and sound touch quantification (STQ) to quantify portal hypertension (PHT) severity in a rat model of carbon tetrachloride (CCl₄ )-induced cirrhotic PHT.

METHODS

In total, 60 rats were used. Various degrees of PHT were established. Liver and spleen stiffness were measured by STE (L-STE and S-STE, respectively) and STQ (L-STQ and S-STQ, respectively). We measured portal pressure (PP) after ultrasonographic examination. The performance of the STE and STQ parameters in the identification of PHT was evaluated using receiver operating characteristic (ROC) analyses.

RESULTS

Liver and spleen stiffness measurements obtained with STE and STQ correlated positively with the PP (r = 0.566-0.882, all P < .001). The areas under ROC curves for L-STE, S-STE, L-STQ, and S-STQ values were 0.931 (95% confidence interval [CI], 0.847-1.000), 0.982 (95% CI, 0.956-1.000), 0.796 (95% CI, 0.680-0.912), and 0.925 (95% CI, 0.858-0.993), respectively, for PP ≥5 mmHg; 0.937 (95% CI, 0.865-1.000), 0.938 (95% CI, 0.864-1.000), 0.967 (95% CI, 0.923-1.000), and 0.960 (95% CI, 0.897-1.000), respectively, for PP ≥10 mmHg; and 0.954 (95% CI, 0.897-1.000), 0.790 (95% CI, 0.652-0.928), 0.808 (95% CI, 0.680-0.935), and 0.740 (95% CI, 0.595-0.885), respectively, for PP ≥12 mmHg.

CONCLUSIONS

STE and STQ are reliable noninvasive tools for the assessment of PHT severity, especially for PP ≥10 mmHg, in a rat model of CCl₄ -induced cirrhotic PHT.

Spleen Stiffness Measurement Across the Spectrum of Liver Disease Patients in Real-World Practice

Objectives

Spleen stiffness measurement (SSM) provides a non-invasive surrogate marker for clinical significant portal hypertension (CSPH). Results obtained in highly selected populations were promising but require validation across the spectrum of liver disease. We aimed to investigate the clinical applicability of SSM in a real-world setting.

Methods

We prospectively enrolled patients referred for liver ultrasound (January-May 2021). Patients with a portosystemic shunt, liver transplant, or extrahepatic etiology of portal hypertension were excluded. We performed liver ultrasound, liver stiffness measurement (LSM) and SSM (dedicated software, 100 Hz-probe). Probable CSPH was established if ≥1 of the following items occurred: ascites, varices, encephalopathy, splenomegaly, recanalized umbilical vein, collaterals, dilated portal veins, hypertensive gastropathy, or LSM ≥25 kPa.

Results

We enrolled 185 patients (53% male; age 53years [37-64], 33% viral hepatitis, 21% fatty liver disease). Of them, 31% of patients had cirrhosis (68% Child-Pugh A) and 38% of patients had signs of portal hypertension. SSM (23.8 kPa [16.2-42.3]) and LSM (6.7 kPa [4.6-12.0]) were successful and met reliability criteria in 70% and 95%, respectively. Spleen size was inversely associated with SSM failure (odds ratio: 0.66 increment/cm, 95% confidence interval: 0.52-0.82). Optimal spleen stiffness cut-off to detect probable CSPH was >26.5 kPa (likelihood ratio: 4.5, sensitivity: 83%; specificity: 82%). Spleen stiffness did not outperform liver stiffness in detecting probable CSPH (P = 1.0).

Conclusions

In real-world practice, reliable SSM were obtained in 70% and could potentially stratify patients between high- and low-risk of probable CSPH. However, cut-offs for CSPH might be substantially lower than previously reported. Future studies validating these results are required.

Clinical trial number

Netherlands Trial Register (Registration number: NL9369).

The rationale and study design of two phase II trials examining the effects of BI 685,509, a soluble guanylyl cyclase activator, on clinically significant portal hypertension in patients with compensated cirrhosis

BACKGROUND

Clinically significant portal hypertension (CSPH) drives cirrhosis-related complications (i.e. hepatic decompensation). Impaired nitric oxide (NO) bioavailability promotes sinusoidal vasoconstriction, which is the initial pathomechanism of CSPH development. Activation of soluble guanylyl cyclase (sGC), a key downstream effector of NO, facilitates sinusoidal vasodilation, which in turn may improve CSPH. Two phase II studies are being conducted to assess the efficacy of the NO-independent sGC activator BI 685,509 in patients with CSPH due to various cirrhosis aetiologies.

METHODS

The 1366.0021 trial (NCT05161481) is a randomised, placebo-controlled, exploratory study that will assess BI 685,509 (moderate or high dose) for 24 weeks in patients with CSPH due to alcohol-related liver disease. The 1366.0029 trial (NCT05282121) is a randomised, open-label, parallel-group, exploratory study that will assess BI 685,509 (high dose) alone in patients with hepatitis B or C virus infection or non-alcoholic steatohepatitis (NASH) and in combination with 10 mg empagliflozin in patients with NASH and type 2 diabetes mellitus for 8 weeks. The 1366.0021 trial will enrol 105 patients, and the 1366.0029 trial will enrol 80 patients. In both studies, the primary endpoint is the change from baseline in hepatic venous pressure gradient (HVPG) until the end of treatment (24 or 8 weeks, respectively). Secondary endpoints include the proportion of patients with an HVPG reduction of > 10% from baseline, the development of decompensation events and the change from baseline in HVPG after 8 weeks in the 1366.0021 trial. In addition, the trials will assess changes in liver and spleen stiffness by transient elastography, changes in hepatic and renal function and the tolerability of BI 685,509.

DISCUSSION

These trials will enable the assessment of the short-term (8 weeks) and longer-term (24 weeks) effects and safety of sGC activation by BI 685,509 on CSPH due to various cirrhosis aetiologies. The trials will use central readings of the diagnostic gold standard HVPG for the primary endpoint, as well as changes in established non-invasive biomarkers, such as liver and spleen stiffness. Ultimately, these trials will provide key information for developing future phase III trials.

TRIAL REGISTRATION

1366.0021: EudraCT no. 2021-001,285-38; ClinicalTrials.gov NCT05161481. Registered on 17 December 2021, https://www.

CLINICALTRIALS

gov/ct2/show/NCT05161481 . 1366.0029: EudraCT no. 2021-005,171-40; ClinicalTrials.gov NCT05282121. Registered on 16 March 2022, https://www.

CLINICALTRIALS

gov/ct2/show/NCT05282121 .

Splenic Stiffness Is the Best Predictor of Clinically Significant Varices in Children With Portal Hypertension

BACKGROUND AND AIMS

We studied splenic stiffness measurement (SSM) by transient elastography (TE) and portal hemodynamics parameters (PHDp) on Doppler as predictors of clinically significant varices (CSV) in children.

METHODS

All children of 6 months to 18 years of age with portal hypertension (PHT) (chronic liver disease, CLD and non-cirrhotic portal hypertension, NCPH) were enrolled. TE for spleen (SSM) and liver (liver stiffness measurement, LSM) and PHDp by Doppler ultrasonography were measured. Noninvasive indices for PHT were calculated. CSV were defined as esophageal varices ≥grade 2 and/or gastric varix. Binary logistic regression analysis (LRA) and receiver operating characteristic statistics were applied.

RESULTS

A total of 150 (120 CLD and 30 NCPH) children formed the study cohort. Prevalence of CSV was higher in NCPH than CLD [73.3% vs 53.3%, Odd's ratio (OR) 2.369, P = 0.04]. On LRA, SSM was found to be the only independent predictor of CSV in children with CLD [OR 1.19 (95% Confidence Interval (CI) 1.018-1.16), P = 0.000] as well as in NCPH [OR 1.088 (95% CI 1.018-1.16), P = 0.013]. This model improved prediction of CSV in CLD from 52.5% to 83.9% and in NCPH from 73.3% to 86.7%. In children with CLD, SSM at a cut-off ≥27.6 kPa and in NCPH, SSM at a cut-off ≥29.5 kPa predicted CSV. In children with CLD, SSM correlated with LSM ( R = 0.610, P <0.001) and with noninvasive PHT indices except aspartate aminotransferase-to-platelet ratio index.

CONCLUSION

SSM is the best noninvasive predictor of CSV in childhood CLD and NCPH and can be used as screening test for endoscopy in children with PHT.

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.

A Combined Baveno VII and Spleen Stiffness Algorithm to Improve the Noninvasive Diagnosis of Clinically Significant Portal Hypertension in Patients With Compensated Advanced Chronic Liver Disease

INTRODUCTION

A noninvasive diagnosis of clinically significant portal hypertension (CSPH) has important prognostic and therapeutic implications for patients with compensated advanced chronic liver disease. We aimed to validate and improve the available algorithms for the CSPH diagnosis by evaluating spleen stiffness measurement (SSM) in patients with compensated advanced chronic liver disease.

METHODS

This is a retrospective study including patients with liver stiffness measurement (LSM) ≥10 kPa, no previous decompensation, and available measurements of hepatic venous pressure gradient, LSM, and SSM by transient elastography referring to our center in Bologna. The diagnostic algorithms were adequate if negative and positive predictive values were >90% when ruling out and ruling in CSPH, respectively; these models were validated in a cohort from Verona. The 5-year decompensation rate was reported.

RESULTS

One hundred fourteen patients were included in the derivation cohort. The Baveno VII diagnostic algorithm (LSM ≤15 kPa + platelet count ≥150 × 10 9 /L to rule out CSPH and LSM >25 kPa to rule in CSPH) was validated; however, 40%-60% of the patients remained in the gray zone. The addition of SSM (40 kPa) to the model significantly reduced the gray zone to 7%-15%, maintaining adequate negative and positive predictive values. The diagnostic algorithms were validated in a cohort of 81 patients from Verona. All first decompensation events occurred in the "rule-in" zone of the model including SSM.

DISCUSSION

The addition of SSM significantly improves the clinical applicability of the algorithm based on LSM and platelet count for CSPH diagnosis. Our models can be used to noninvasively identify candidates for nonselective beta-blocker treatment and patients at a high risk of decompensation.

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.

High reproducibility of spleen stiffness measurement by vibration-controlled transient elastography with a spleen-dedicated module

Spleen stiffness measurement (SSM) by vibration-controlled transient elastography (VCTE) is a noninvasive technique for estimating portal hypertension in patients with chronic liver disease (CLD), with its reproducibility yet to be established and its feasibility still unknown beyond CLD. We have studied 420 participants from two tertiary referral centers for liver diseases (Novara, Milan): 297 patients with CLD (32% with cirrhosis) of different etiology (Group A), 63 Philadelphia-negative myeloproliferative neoplasms (Group B), and 60 heathy volunteers (Group C). All underwent SSM by VCTE with a spleen-dedicated module (SSM@100 Hz) and liver stiffness measurement (LSM), blindly performed by 2 different operators. In total, 1680 VCTE examinations for SSM were performed (1000 in Novara, 680 in Milan), with an overall 3.2% failure rate. Median SSM was 26.5 kPa (interquartile range [IQR] 20.0-42.3) in Group A, 26.3 kPa (IQR 22.3-33.6) in Group B, and 16.1 kPa (IQR 14.6-18.7) in Group C. In Group A, the median LSM was 6.8 kPa (IQR 4.9-11.3) in Novara and 8.3 kPa (IQR 7.1-10.8) in Milan, the proportion of patients with cirrhosis being 34% in Novara and 31% in Milan. The Group A interobserver agreement ICC was 0.90 (0.88-0.92), significantly lower in the absence of splenomegaly (ICC 0.87 vs. 0.91) and in absence of cirrhosis (ICC 0.84 vs. 0.90); overweight slightly, but not significantly reduced the interobserveragreement. The intra-observer agreement ICC ranged from 0.91 to 0.96 for the four operators. The Group B interobserver agreement ICC was 0.90 (0.83-0.94). In conclusion, SSM measured by the new spleen-dedicated VCTE module is a feasible, reliable, and highly reproducible tool in patients with CLD and hematological disorders, and in healthy volunteers.

Spleen Transient Elastography and Damping Index Identify a Subgroup of Patients Without an Acute or Chronic Response to Beta-Blockers

Background and Aims

Monitoring of acute or chronic response to beta-blockers in patients with liver cirrhosis is based on the measurement of the HVPG. Our aim was to evaluate the response to beta-blockers with non-invasive techniques.

Patients and Methods

This is a prospective observational study. Consecutive patients with an indication of primary or secondary prophylaxis of variceal bleeding who did not meet exclusion criteria were included. Acute response and chronic response were evaluated. Baseline and after acute and chronic response hepatosplenic measurements of TE and ARFI were obtained. Contrast-enhanced Doppler ultrasound was performed before and after acute and chronic responses.

Results

From June 2015 to May 2018, 55 patients (14 with exclusion criteria) were included. We analyzed 41 patients, mean age 57 (SD: 8), 82.9% men, alcohol 43.9%, children A/B/C 78%/17.1%/4.9%, and 87.8% on primary prophylaxis. In all, the acute response was performed and was positive in 68.3% (CI 95: 55–85%). The chronic response was performed in 30 (73.2%) and was positive in 36.7% (CI 95: 18–55%). Basal measurements significantly related to acute response were spleen TE [responders 58.4 (SD: 23.0) KPa vs. non-responders 75 (SD: 0) KPa; p = 0.02] and damping index [non-responders 0.96 (0.8) vs. responders 0.44 (0.4), p = 0.01], and with chronic response, the spleen TE [responders 58.1 (SD: 21.4) KPa vs. non-responders 73.2 (SD: 5.5) KPa; p = 0.02], and damping index [non-chronic responders 0.8 (0.7) vs. chronic responders 0.4 (0.4), p = 0.04]. A spleen TE ≥ 74 KPa had a high sensitivity of 100% and specificity of 60% and a high NPV100% for predicting poor acute response to beta-blockers. The damping index > 0.6 showed moderate sensitivity of 67% and specificity of 69% with a high NPV of 82% for predicting poor acute response to beta-blockers. The combination of both measurements for predicting poor acute response to beta-blockers had an AUC of 0.8 (CI 95: 0.5–0.9). A spleen TE ≥ 74 KPa had a high sensitivity of 87% and specificity of 71% with a high NPV of 71% for predicting poor chronic response to beta-blockers. A damping index > 0.6 had moderate sensitivity of 60%, specificity of 82%, and NPV of 56% for predicting poor chronic response to beta-blockers. The combination of both measurements for predicting poor chronic response to beta-blockers had an AUC of 0.8 (CI 95: 0.7–0.9).

Conclusion

Spleen TE and damping index can identify a subgroup of patients with poor acute or chronic response to beta-blockers.

Can Location of Stiffness Measurement Impact Spleen 2-Dimensional Shear Wave Elastography Measurement?

ABSTRACT

Ultrasound-based spleen elastography is a promising surrogate to predict portal hypertension noninvasively. In contrast to defined standards for liver stiffness measurement, the standardized examination procedures for 2-dimensional (2D) shear wave elastography spleen elastography have not been established yet. The aim was to investigate the impact of location of stiffness measurement on 2D shear wave elastography spleen stiffness measurement (SSM). Patients with splenomegaly were enrolled. Both B-mode ultrasound and elastography of spleen were performed. For SSM, 3 regions were chosen for spleen measurement: lower pole region, central region, and the region between lower pole and center. Mean SSM value, success rate, and reliability predicators (standard deviation, standard deviation/mean, size of region of interest) were assessed. A total of 124 patients were included. For mean SSM value, there were no significant differences among 3 regions. Spleen stiffness measurement success rate in lower pole region, central region, and the region between them was 63.7% (79), 91.1% (113), and 78.2% (97), respectively. The success rate in the central region was significantly higher than that in the other 2 regions (P < 0.05). Reliability in the central region was also highest among the 3 regions. Location of stiffness measurement has a limited effect on SSM. Changing location of measurement will not influence mean stiffness value in spleen.

The Value of Liver and Spleen Stiffness for Evaluation of Portal Hypertension in Compensated Cirrhosis

Patients with compensated advanced chronic liver disease who develop clinically significant portal hypertension (CSPH) are at high risk for hepatic decompensation and mortality if left untreated. Liver biopsy and hepatic venous pressure gradient (HVPG) measurements are the current gold standard procedures for determining fibrosis severity and diagnosing CSPH, respectively; however, both are invasive, limiting their use in clinical practice and larger trials of novel agents. As such, there is an unmet clinical need for reliable, validated, noninvasive measures to detect CSPH and to further assess portal hypertension (PH) severity. Alterations in the biomechanical properties of the liver or spleen in patients with cirrhosis can be quantified by tissue elastography, which examines the elastic behavior of tissue after a force has been applied. A variety of methods are available, including magnetic resonance elastography, shear-wave elastography, and the most thoroughly investigated measure, vibration-controlled transient elastography. Liver stiffness (LS) and spleen stiffness (SS) measurements offer valuable alternatives to detect and monitor CSPH. Both LS and SS correlate well with HVPG, with thresholds of LS >20-25 kPa and SS >40-45 kPa indicating a high likelihood of CSPH. Because SS is a direct and dynamic surrogate of portal pressure, it has the potential to monitor PH severity and assess PH improvement as a surrogate marker for clinical outcomes. Importantly, SS seems to be superior to LS for monitoring treatment response in clinical trials focusing on reducing PH.

Comparison between spleen and liver stiffness measurements by sound touch elastography for diagnosing cirrhosis at different aminotransferase levels: a prospective multicenter study

OBJECTIVES

To compare the performance of spleen stiffness measurement (SSM) and liver stiffness measurement (LSM) by sound touch elastography (STE) for the diagnosis of cirrhosis at different alanine aminotransferase (ALT) levels, and to compare the applicability and repeatability of SSM with LSM performed by STE, a new two-dimensional shear wave elastography technology.

METHODS

This prospective multicenter study included 25 centers and recruited chronic hepatitis B (CHB) patients with liver biopsy between May 2018 and November 2019. All patients underwent LSM and SSM by STE. Success and reliability rates were calculated and compared. Intra-observer agreement was assessed using intraclass correlation coefficients (ICCs). Differences between areas under the receiver operating characteristic curves (AUCs) of LSMs and SSMs at different ALT levels were compared using the Delong test.

RESULTS

Among 603 CHB patients, the success and reliability rates of SSM were 94.53% (570/603) and 85.74% (517/603), respectively, which were similar to those of LSM (p > 0.05), respectively. The ICC for intra-observer agreements of SSM was 0.964 (p < 0.001). In the total cohort, ALT ≤ 2 × upper limit of normal (ULN) group, and A0-1 group, the AUCs of SSMs were significantly lower than those of LSMs for the diagnosis of cirrhosis (p < 0.001). In the ALT > 2 × ULN group and A2-3 group, the AUC of SSM improved and was not significantly different from that of LSM (p = 0.342, p = 0.510, respectively).

CONCLUSIONS

SSM by STE achieved applicability and repeatability equivalent to those of LSM. SSM might be a good substitute to LSM in patients with high ALT levels.

KEY POINTS

• Spleen stiffness measurement performed by sound touch elastography was proven to have similar applicability and repeatability to liver stiffness measurement in this prospective multicenter study. • Spleen stiffness measurement demonstrated a poorer diagnostic performance for cirrhosis compared with liver stiffness measurement in the total cohort and low ALT level group, yet it showed a similar diagnostic performance to liver stiffness measurement in patients with high ALT levels.

Effect of a 12-week home-based exercise training program on aerobic capacity, muscle mass, liver and spleen stiffness, and quality of life in cirrhotic patients: a randomized controlled clinical trial

Background

Physical inactivity and sarcopenia are two important predictors associated with increased morbidity and mortality in patients with cirrhosis. At present, the benefit of a home-based exercise training program is not well established in cirrhotic patients. The main objective of this study was to evaluate the effect of a 12-week home-based exercise training program on aerobic capacity in cirrhotic patients.

Methods

This is a randomized controlled study. Patients with compensated cirrhosis were randomized by a block of 4 with concealed allocation to the home-based exercise training (n = 20) or control (n = 20). Both groups received protein supplementation (9 g/day) for 12 weeks. The home-based exercise training program included several aerobic/isotonic moderate-intensity continuous training exercises for 40 min per session, at least four times a week, with a total duration of 12 weeks. The heart rate was continuously monitored using a Garmin® watch. In the control group, patients received exercise instruction without active encouragement and continuous monitoring. The primary outcome was a change in the 6-min walk test from baseline. Secondary outcomes were the difference in thigh muscle thickness, liver stiffness, spleen stiffness, and quality of life.

Results

A total of 40 patients were enrolled prospectively. The mean age was 56.3 ± 7.8 years, with a male predominance of 65%. The mean body mass index was 25.23 ± 3.0 kg/m², and all were Child–Pugh A. Chronic hepatitis B or C was the primary cause of cirrhosis. The baseline values were a 6-min walk test of 475 ± 70 m, liver stiffness of 15.3 ± 9.3 kPa, spleen stiffness of 29.8 ± 21.7 kPa, and thigh muscle thickness (average compression index) of 0.64 ± 0.2 cm/m². All baseline characteristics between the two groups were not different except the mean muscle mass which was significantly higher in the home-based exercise training group (p = 0.03, 95% CI 0.01 to 0.17). At the end of the study, no significant difference in the 6-min walk test was observed (p = 0.36, 95% CI −15.5 to 41.7). Liver stiffness measurement significantly improved in both groups, but no significant difference between groups was demonstrated (p = 0.77, 95% CI −1.3 to 1.8). Thigh muscle thickness was not different between groups. The fatigue domain of the quality of life index was significantly improved in the home-based exercise training group compared with the control group (p = 0.05, 95% CI 0.00 to 0.67). No adverse events occurred in a home-based exercise training program.

Conclusions

A 12-week moderate-intensity home-based exercise training program in compensated cirrhotic patients significantly improved the fatigue domain of the quality of life index without an increase in adverse events. However, no benefit in terms of aerobic capacity, thigh muscle mass, liver stiffness, and spleen stiffness was demonstrated.

Trial registration: Thai Clinical Trials Registry number TCTR20190926002, 26/09/2019 (Retrospectively registered).

Supplementary Information

The online version contains supplementary material available at 10.1186/s12876-022-02147-7.

Comparison of point and two-dimensional shear wave elastography of the spleen in healthy subjects

BACKGROUND

Few systematic comparative studies of the different methods of physical elastography of the spleen are currently available.

AIM

To compare point shear wave and two-dimensional elastography of the spleen considering the anatomical location (upper, hilar, and lower pole).

METHODS

As part of a prospective clinical study, healthy volunteers were examined for splenic elasticity using four different ultrasound devices between May 2015 and April 2017. The devices used for point shear wave elastography were from Siemens (S 3000) and Philips (Epiq 7), and those used for two-dimensional shear wave elastography were from GE (Logiq E9) and Toshiba (Aplio 500). In addition, two different software versions (5.0 and 6.0) were evaluated for the Toshiba ultrasound device (Aplio 500). The study consisted of three arms: A, B, and C.

RESULTS

In study arm A, 200 subjects were evaluated (78 males and 122 females, mean age 27.9 ± 8.1 years). In study arm B, 113 subjects were evaluated (38 men and 75 women, mean age 26.0 ± 6.3 years). In study arm C, 44 subjects were enrolled. A significant correlation of the shear wave velocities at the upper third of the spleen (r = 0.33088, P < 0.0001) was demonstrated only for the Philips Epiq 7 device compared to the Siemens Acuson S 3000. In comparisons of the other ultrasound devices (GE, Siemens, Toshiba), no comparable results could be obtained for any anatomical position of the spleen. The influencing factors age, gender, and body mass index did not show a clear correlation with the measured shear wave velocities.

CONCLUSION

The absolute values of the shear wave elastography measurements of the spleen and the two different elastography methods are not comparable between different manufacturers or models.

Noninvasive Detection of Clinically Significant Portal Hypertension in Compensated Advanced Chronic Liver Disease

Patients with compensated advanced chronic liver disease have different prognoses depending on the presence of portal hypertension. Current non-invasive diagnostic methods allow identification of clinically significant portal hypertension. Portosystemic collaterals on imaging or liver stiffness of more than 20 to 25 kPa by using transient elastography identifies patients with clinically significant portal hypertension. Patients with liver stiffness of less than 20 kPa and platelet count of greater than 150 g/L can avoid endoscopy. This rule could be expanded using spleen stiffness. Methods to risk stratify for portal hypertension in compensated advanced chronic liver disease and successfully treated chronic hepatitis C and B are subject of research.

The role of liver and spleen elastography in advanced chronic liver disease

Portal hypertension is the main driver of complications in patients with advanced chronic liver disease (ACLD). In the last decade, many non-invasive tests, such us liver and spleen elastography, have been proposed and validated for the identification of patients with clinically significant portal hypertension (CSPH) and its complications, mainly hepatic decompensation and liver-related morbidity and mortality. Moreover, elastography accurately stratifies for the risk of HCC development, HCC recurrence and decompensation after liver surgery. Recent studies suggest a role of SSM in monitoring response to treatments and interventions in ACLD, such as viral eradication, non-selective beta-blockers and transjugular intrahepatic portosystemic shunt placement. However, one of the most indications to perform elastography in ACLD still remains the screening for esophageal varices. In fact, according to the Baveno VI consensus, liver stiffness measurement (LSM) <20 kPa and platelet count >150,000/mm³ can safely identify patients at low risk of varices requiring treatment (VNT) and could therefore avoid invasive upper invasive endoscopy; LSM>20-25 kPa can accurately rule-in CSPH in patients with viral etiology. Spleen stiffness measurement (SSM) is a direct surrogate of portal hypertension and has been demonstrated more accurate in predicting portal hypertension severity and VNT. A combined model including Baveno VI Criteria and SSM (≤46 kPa) can significantly increase the number of spared endoscopies (>40-50%), maintaining a low (<5%) of missed VNT.

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.

Spleen Stiffness for Predicting Varices Needing Treatment: Comparison between Two Different Elastography Techniques (Point vs. 2D-SWE)

The study aimed to establish the benefits of using spleen stiffness values measured by two elastography techniques as noninvasive markers for predicting varices needing treatment and comparing their performances. A prospective study was performed, including 107 subjects with compensated liver cirrhosis, who underwent upper digestive endoscopy, as well as spleen stiffness measurements by means of two elastography techniques: pSWE (point shear wave elastography using Virtual Touch Quantification-Siemens Acuson S2000) and 2D-SWE (2D-shear wave elastography-LOGIQ E9, General Electric). Reliable spleen stiffness measurements were obtained in 96.2% (103/107) patients by means of 2D-SWE and in 94.4% (101/107) subjects with pSWE; therefore, 98 subjects were included in the final analysis, of which 40.8% (40/98) had varices needing treatment. The optimal spleen stiffness cut-off value by 2D-SWE for predicting varices needing treatment was 13.2 kPa (AUROC 0.84), while for pSWE, it was 2.91 m/s (AUROC 0.90). Based on AUROC comparison, no difference between the performance of the two techniques for predicting varices needing treatment was found (p=0.1606). In conclusion, spleen stiffness measured by either 2D-SWE or pSWE is a reliable surrogate marker, with good feasibility, applicability, and predictive accuracy for varices needing treatment, with no significant difference between techniques.

Spleen stiffness measurement by shear wave elastography using acoustic radiation force impulse in predicting the etiology of splenomegaly

PURPOSE

To measure spleen stiffness by shear wave elastography (SWE) using acoustic radiation force impulse (ARFI) in patients with splenomegaly and to evaluate utility of elastography technique in identifying etiology of splenomegaly.

METHODS

Sixty-one treatment-naïve patients with splenomegaly were enrolled. The control group consisted of 20 healthy subjects without history of any disease including diabetes and hypertension, alcohol consumption, or biochemical or ultrasonographic findings indicating hepatic and renal diseases. B-mode ultrasonography and elastographic examinations were performed by a radiologist blinded to the participants. Spleen stiffness was measured by SWE using ARFI. Shear wave velocity (SWV) values were given in m/s.

RESULTS

Splenomegaly patients were assigned into three groups according to their etiologies as hepatoportal (n = 21), myeloproliferative (n = 23), and infectious (n = 17). Splenomegaly groups and control group were comparable regarding age and sex. Spleen size was higher in the splenomegaly groups than in the controls. Median SWV was significantly higher in the hepatoportal (3.85 m/s) and myeloproliferative (3.42 m/s) groups than in the infectious (2.66 m/s) and control (2.22 m/s) groups. The correlation between SWV and spleen size was not significant in any of the groups. The cut-off value was 3.42 (sensitivity 80.9%, specificity 56.5%) in distinguishing hepatoportal from myeloproliferative etiology; 3.02 (sensitivity 100%, specificity 100%) in distinguishing hepatoportal from infectious etiology; and 2.84 (sensitivity 91.3%, specificity 88.2%) in distinguishing myeloproliferative from infectious etiology.

CONCLUSION

Spleen stiffness measured by elastographic techniques in splenomegaly patients was higher than that in healthy subjects. SWV appeared to be beneficial in predicting the etiology of splenomegaly.

Spleen and Liver Stiffness for Predicting High-Risk Varices in Patients with Compensated Liver Cirrhosis

The study evaluates the utility of spleen (SS) and liver stiffness (LS) associated with spleen size (SSZ) as non-invasive markers for predicting high-risk varices (HRV). One hundred thirty-two patients with compensated liver cirrhosis who underwent abdominal ultrasound SS (SSM) and LS measurements (LSM) using a 2-D shear wave elastography (2-D-SWE) technique from General Electric and upper endoscopy were included. Similar rates of reliable SSM and LSM were obtained (95.4% and 97.7% respectively); therefore, 124 patients were included in the final analysis. The optimal cutoff values for SS, LS and SSZ for predicting HRV were 13.2 kPa (area under the receiver operating characteristic curve [AUROC] = 0.84), 12.1 kPa (AUROC = 0.86) and 12.9 cm (AUROC = 0.71), respectively. Including these factors in multiple regression analysis, we obtained the scores for predicting HRV: 0.053 × SS + 0.054 × LS + 0.059 × SSZ - 1.84. The score's optimal cutoff value for predicting HRV was >0.34 (AUROC = 0.93). By comparing the AUROC's, the score including SSZ, SSM and LSM performed better than each independent factor for predicting HRV (p = 0.0091; p = 0.0341; p < 0.0001).

MR Elastography of the Abdomen: Basic Concepts

Magnetic resonance elastography (MRE) is an emerging imaging modality that maps the elastic properties of tissue such as the shear modulus. It allows for noninvasive assessment of stiffness, which is a surrogate for fibrosis. MRE has been shown to accurately distinguish absent or low stage fibrosis from high stage fibrosis, primarily in the liver. Like other elasticity imaging modalities, it follows the general steps of elastography: (1) apply a known cyclic mechanical vibration to the tissue; (2) measure the internal tissue displacements caused by the mechanical wave using magnetic resonance phase encoding method; and (3) infer the mechanical properties from the measured mechanical response (displacement), by generating a simplified displacement map. The generated map is called an elastogram.While the key interest of MRE has traditionally been in its application to liver, where in humans it is FDA approved and commercially available for clinical use to noninvasively assess degree of fibrosis, this is an area of active research and there are novel upcoming applications in brain, kidney, pancreas, spleen, heart, lungs, and so on. A detailed review of all the efforts is beyond the scope of this chapter, but a few specific examples are provided. Recent application of MRE for noninvasive evaluation of renal fibrosis has great potential for noninvasive assessment in patients with chronic kidney diseases. Development and applications of MRE in preclinical models is necessary primarily to validate the measurement against "gold-standard" invasive methods, to better understand physiology and pathophysiology, and to evaluate novel interventions. Application of MRE acquisitions in preclinical settings involves challenges in terms of available hardware, logistics, and data acquisition. This chapter will introduce the concepts of MRE and provide some illustrative applications.This publication is based upon work from the COST Action PARENCHIMA, a community-driven network funded by the European Cooperation in Science and Technology (COST) program of the European Union, which aims to improve the reproducibility and standardization of renal MRI biomarkers. This introduction chapter is complemented by another separate chapter describing the experimental protocol and data analysis.

Spleen Stiffness Predicts Survival after Transjugular Intrahepatic Portosystemic Shunt in Cirrhotic Patients

Objectives

Transjugular intrahepatic portosystemic shunt (TIPS) is an effective intervention for portal hypertensive complications. Little is known about the ability of spleen stiffness (SS) for predicting the survival of cirrhotic patients undergoing TIPS. This study is to evaluate the influence of SS detected by point shear wave elastography (pSWE) in predicting survival after TIPS.

Methods

This retrospective cohort study screened consecutive patients who underwent TIPS and reliable pSWE measurement between October 2014 and September 2017 from our prospectively maintained database. SS values were measured before TIPS. The primary endpoint was the overall survival after TIPS. The Cox regression analysis model was used for univariate and multivariate analyses. A receiver operating characteristic (ROC) curve analysis was performed to calculate the sensitivity, specificity, and positive and negative predictive values.

Results

A total of 89 patients were involved in the final analysis. 24 patients (27.0%) died during a median follow-up time of 31 m. Multivariable Cox regression analysis confirmed that higher SS value (P < 0.001), LS value (P = 0.008), diameter of shunt (P = 0.001), and older age (P < 0.001) were independent prognostic factors of survival after TIPS. The risk of death rose 57.440-fold for each SS unit (m/s) increase. SS was also correlated with liver failure after TIPS. ROC analysis showed that the best SS cutoff value was 3.60 m/s for predicting survival, with a sensitivity of 54.2% and specificity of 90.8%.

Conclusions

The SS value determined by pSWE in cirrhotic patients was an independent predictive factor for survival after TIPS.

Spleen volumetry and liver transient elastography: Predictors of persistent posthepatectomy decompensation in patients with hepatocellular carcinoma

BACKGROUND

Posthepatectomy decompensation remains a frequent and poor outcome after hepatectomy, but its prediction is still inaccurate. Liver stiffness measurement can predict posthepatectomy decompensation, but there is a so-called "gray zone" that requires another predictor. Because splenomegaly is an objective sign of portal hypertension, we hypothesized that spleen volumetry could improve the identification of patients at risk.

METHODS

Patients with hepatocellular carcinoma who underwent hepatectomy in our tertiary center between August 2014 and December 2017 were reviewed. The primary endpoint was to determine if the spleen volumetry and liver stiffness measurement were independent predictors of posthepatectomy decompensation, and secondarily, to determine if they were synergistic through a theoretic predictive model.

RESULTS

One hundred and seven patients were included. The median follow-up time was 3 months (3-5). Postoperative 90-day mortality was 4.7%. By multivariate analysis, liver stiffness measurement and spleen volumetry predicted posthepatectomy decompensation. The liver stiffness measurement had a cutoff point of 11.6 kPa (area under receiver operating curve = 0.71 confidence interval 95% 0.71-0.88, sensitivity: 89%, specificity: 47%). The spleen volumetry cutoff point was 381.1 cm³ (area under receiver operating curve = 0.78, 95% confidence interval 0.77-0.93, sensitivity: 55%, specificity: 91%). The spleen volumetry improved prediction of posthepatectomy decompensation, because use of the spleen volumetry increased sensitivity (from 62% to 97%) and the negative predictive value (from 96% to 100%) along with a negligible decrease in specificity (from 96.7 to 93.4) and positive predictive value (from 64% to 59%) (P = .003).

CONCLUSION

Spleen volumetry (>380 cm³) and liver stiffness measurement (>12 kPa) are non-invasive, independent, and synergistic tools that appear to be able to predict posthepatectomy decompensation. The importance of this finding is that these measurements may help to anticipate posthepatectomy decompensation and may possibly be used to direct alternative treatments to resection.

Diagnostic accuracy of non-invasive methods detecting clinically significant portal hypertension in liver cirrhosis: a systematic review and meta-analysis

INTRODUCTION

We attempted to investigate non-invasive techniques and their diagnostic performances for evaluating clinically significant portal hypertension.

EVIDENCE ACQUISITION

The systematic search was performed on PubMed, Embase, Scopus, and Web of Science TM core index databases before 13 December 2018 restricted to English language and human studies.

EVIDENCE SYNTHESIS

Thirty-two studies were included, with total populations of 3,987. The overall pooled analysis was performed by bivariate random effect model, which revealed significantly higher sensitivity and specificity of 77.1% (95% confidence interval, 76.8-78.5%) and 80.1% (95% confidence interval, 78.2-81.9%), respectively; positive likelihood ratio (3.67), negative likelihood ratio (0.26); and diagnostic odd ratio (16.24). Additionally, the area under curve exhibited significant diagnostic accuracy of 0.871. However, notable heterogeneity existed in between studies (I2=87.1%), therefore, further subgroup analysis was performed. It demonstrated ultrasonography, elastography, biomarker, and computed tomography scan had a significant overall summary sensitivity (specificity) of 89.6% (78.9%), 81.7% (83.2%), 72.2% (76.8%), and 77.2% (81.2%), respectively. Moreover, the areas under curve values were significantly higher in elastography (0.906), followed by computed tomography scan (0.847), biomarker (0.825), and ultrasonography (0.803).

CONCLUSIONS

In future, non-invasive techniques could be the future choice of investigations for screening and diagnosis of clinically significant portal hypertension in cirrhosis. However, standardization of diagnostic indices and their cut-off values in each non-invasive method needs to be addressed.

Portal pressure monitoring-state-of-the-art and future perspective

Portal hypertension is a serious symptom of chronic liver diseases, which can lead to many critical complications, such as the formation of varices related to upper digestive bleeding, ascites, infection, hepatic encephalopathy, renal failure, and even death. As a result, portal pressure monitoring has important prognostic and clinical implications. The hepatic venous pressure gradient measurement, a gold-standard method applied to monitor portal pressure, is invasive and only available in experienced centers. Over the past decade, noninvasive methods aimed at monitoring the portal pressure have been increasingly investigated, including serum markers, radiological features, ultrasound elastography, doppler and contrast-enhanced ultrasonography. In this study, we focused on both invasive and noninvasive methods for portal pressure monitoring and explored their roles in clinical setting. The advantages and limitations of various techniques for future research are also discussed.

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.

Emerging non-invasive approaches for diagnosis and monitoring of portal hypertension

Clinically significant portal hypertension is associated with an increased risk of developing gastro-oesophageal varices and hepatic decompensation. Hepatic venous pressure gradient measurement and oesophagogastroduodenoscopy are the gold-standard methods for assessing clinically significant portal hypertension (hepatic venous pressure gradient ≥10 mm Hg) and gastro-oesophageal varices, respectively. However, invasiveness, cost, and feasibility limit their widespread use, especially if repeated and serial evaluations are required to assess the efficacy of pharmacotherapy. Although new techniques for non-invasive portal pressure measurement have been pursued for many decades, only recently have new tools been assessed and validated for larger clinical application. This Review focuses on the recent advances in non-invasive approaches for the diagnosis and serial monitoring of portal hypertension and varices for clinical practice.

Liver and Spleen Stiffness Measurements for Assessment of Portal Hypertension Severity in Patients with Budd Chiari Syndrome

AIMS

Budd-Chiari Syndrome (BCS) is a rare vascular disease of the liver caused by the obstruction of the hepatic venous outflow located from the small hepatic venules up to the entrance of the inferior vena cava (IVC) into the right atrium. Current prognostic indexes are suboptimal for an individual prognostic assessment and subsequent management of patients with BCS. Liver (LSM) and spleen (SSM) stiffness measurements are widely validated prognostic tools in hepatology, but the evidence in patients with BCS is limited. This paper describes LSM and SSM in patients with BCS and their correlation with clinical, biochemical, and ultrasound findings from the same patients.

METHODS

We investigated a case series of seven patients with BCS diagnosis and available LSM and SSM evaluated by transient elastography (TE). Biochemical, imaging, and endoscopic findings nearest to the TE evaluation were recorded. Clinical outcomes and BCS evolution were described for each patient. When available, repeated TE assessments were also recorded.

RESULTS

Patients with acute nonfulminant manifestation of BCS presented near-the-upper-limit values (75 kPa) of LSM and SSM, which often persist until the placement of a transjugular intrahepatic portosystemic shunt (TIPS). On the other hand, TE values were markedly lower in patients with compensated BCS. In some patients with repeated TE measurement years after TIPS placement, LSM had decreased to values of <10 kPa years. SSM changes in these patients were, however, less evident.

CONCLUSIONS

Extremely elevated values of LSM and SSM are suggestive of BCS. The evaluation of both LSM and SSM by TE could help clinicians in the initial evaluation, risk stratification, and therapy response monitoring of patients with BCS.