How to assess splenic stiffness in a patient with fatty liver disease?

Assessment of Splenic Stiffness in Fatty Liver Disease

Splenic stiffness should be measured using vibration-controlled transient elastography (VCTE) with a spleen-dedicated 100 Hz module, which provides high accuracy for assessing portal hypertension in patients with fatty liver disease. 1

Primary Assessment Method

Use VCTE with the spleen-dedicated 100 Hz module as the preferred technique for measuring splenic stiffness in fatty liver patients, as this method demonstrates:

• High diagnostic accuracy with an area under the curve of 0.95 for detecting clinically significant portal hypertension (CSPH) in metabolic-associated fatty liver disease (MAFLD) patients 1
• Excellent reproducibility with interobserver agreement ICC of 0.90 and intraobserver agreement ICC ranging from 0.91 to 0.96 2
• Low failure rate of only 3.2% across diverse patient populations 2
• Strong correlation with hepatic venous pressure gradient (HVPG), the gold standard for portal hypertension assessment (r = 0.74, p < 0.0001 in MAFLD patients) 1

Clinical Context and Timing

Before measuring splenic stiffness, first assess liver fibrosis stage using the standard two-tier approach for fatty liver disease:

• Calculate FIB-4 score initially (cutoff <1.3 to exclude advanced fibrosis, >2.67 for high risk) 3
• Perform liver stiffness measurement by VCTE for intermediate FIB-4 scores (1.3-2.67) 3
• Consider splenic stiffness measurement when liver stiffness is >8.0 kPa, as this indicates clinically significant fibrosis and potential portal hypertension risk 3

Diagnostic Cutoff Values

Apply these specific cutoff values for splenic stiffness in MAFLD patients:

• **<40.9 kPa: Rules out CSPH** with high negative predictive value (>90%) 1
• >49.9 kPa: Rules in CSPH with high positive predictive value (>90%) 1
• Values between 40.9-49.9 kPa represent an indeterminate zone requiring additional assessment 1

For comparison, normal healthy volunteers have median splenic stiffness of 16.1 kPa (IQR 14.6-18.7), while patients with chronic liver disease show median values of 26.5 kPa (IQR 20.0-42.3) 2

Technical Requirements for Valid Measurement

Ensure these quality criteria are met during splenic stiffness measurement:

• Obtain at least 10 successful measurements 3
• Achieve success rate of at least 60% 3
• Maintain interquartile range less than 30% of median value 3
• Use ultrasound guidance to locate the spleen, as splenic stiffness cannot be measured by VCTE without a separate ultrasound exam 3

Integration with Other Noninvasive Parameters

Combine splenic stiffness with the LSPS score (liver stiffness × spleen diameter / platelet count) for enhanced diagnostic accuracy:

• The LSPS score >2.06 is 90% specific for ruling in CSPH with positive predictive value >90% 3
• Adding splenic stiffness cutoffs to Baveno VII criteria (liver stiffness <20 kPa and platelet count >150,000/mm³) significantly reduces the grey zone from 60% to 15-20% while maintaining adequate predictive values 1
• This sequential approach outperforms using individual parameters alone 1

Alternative Techniques

If VCTE with spleen-dedicated module is unavailable, consider these alternatives:

• Acoustic radiation force impulse (ARFI) imaging can assess splenic stiffness and correlates with esophageal varices grade, with accuracy for cirrhosis exceeding 90% 3
• Supersonic shear wave elastography shows promising results with area under the curve of 0.80 for detecting esophageal varices, though it has higher failure rates (29.2%) compared to VCTE 4

However, the American Association for the Study of Liver Diseases notes that splenic stiffness measurements by standard VCTE cannot be recommended in clinical practice because they require a separate ultrasound exam and cannot be measured if the spleen is not significantly enlarged 3

Important Caveats

Be aware of these limitations when interpreting splenic stiffness:

• Reproducibility is lower in patients without splenomegaly (ICC 0.87 vs 0.91 with splenomegaly) and without cirrhosis (ICC 0.84 vs 0.90 with cirrhosis) 2
• Overweight status may slightly reduce interobserver agreement, though not significantly 2
• The European Association for the Study of the Liver recommends splenic stiffness only as an additional tool to refine risk of high-risk varices in compensated advanced chronic liver disease, not as a standalone test 3
• Splenomegaly alone is a sensitive but nonspecific sign of portal hypertension and should be routinely reported when combined with platelet count and liver stiffness 3

Clinical Decision Algorithm

Follow this sequential approach for comprehensive assessment:

1. Calculate FIB-4 score in all fatty liver patients 3
2. If FIB-4 is intermediate (1.3-2.67), perform liver stiffness by VCTE 3
3. If liver stiffness >8.0 kPa, measure splenic stiffness using 100 Hz module 1
4. Apply cutoffs: <40.9 kPa rules out CSPH, >49.9 kPa rules in CSPH 1
5. For indeterminate values (40.9-49.9 kPa), calculate LSPS score and consider referral to hepatology 1
6. If splenic stiffness >49.9 kPa or liver stiffness >12.0 kPa, refer to hepatology for consideration of endoscopy to assess for varices 3