Assessing liver fibrosis – the many different techniques

13th March 2023, NIA Diagnostic Imaging

liver fibrosis

Over the last few weeks, we have explored the many issues relating to metabolic dysfunction associated fatty liver disease (MAFLD). We looked at what else we need to do after you diagnosed MALFD. In particular, we highlighted the need to assess the degree of fibrosis in each patient with MAFLD. With the continuous advances in technology, a wide range of new techniques and imaging modalities have emerged, thus allowing for improved diagnosis of various diseases and pathologies. Such advancements can be seen especially in the assessment and staging of liver fibrosis.

LIVER BIOPSY
According to Sande, et al. (2017), percutaneous liver biopsy is the current gold standard for the assessment and staging of liver fibrosis. In comparison to other techniques available, liver biopsy offers the lowest percentage of error (Berger, et al., 2019).
There are, however, many disadvantages that come with this procedure including:
• It is not suitable for screening purposes and early diagnosis.
• Higher risk of complications involved due to its invasive nature.
• Only a certain type of the liver parenchyma can be evaluated (Sande, et al, 2017)

FIBROSCAN

Fibroscan is a non-invasive, quick technique used to measure liver stiffness. A graphical result is displayed on the screen (Kemp & Roberts 2013). This technique is used in medical centres and hospital departments.
Disadvantages:
• Cannot be used with patients with ascites, pleural effusion, or morbidly obese patients – produces unreliable results.
• Cannot visualise areas being sampled

SHEAR WAVE ELASTOGRAPHY (SWE)
Shear wave elastography is a sonographic technique which evaluates the change in liver stiffness. By quantifying this stiffness, we can use this technology to assess, stage and manage liver fibrosis.
Shear wave elastography has many advantages over the previously mentioned methods:
• Non-invasive
• Low-cost
• Readily available
• Allows the examination of any area within the liver
• Can be performed easily in conjunction with a routine abdominal ultrasound scan.
• Real B-mode visualisation of the sampled areas thus avoid ascites and pleural effusion.
• Larger sample areas compared to Fibroscan which only samples at midaxillary region.
• Scan in real-time
• Has higher specificity and sensitivity than Fibroscan (Osman, shimmy & Aziz 2020).

At NIA Diagnostic Imaging, we use the latest technology with LOGIQ E10 series ultrasound system to stage fibrosis in the liver.

How shear wave elastography works
• Fibrosis is commonly graded using Metavir scores. This is acquired by sampling an area of the liver using Shear Wave Elastography and here, the stiffness of the liver parenchyma is measured and quantified.
• The acquired measurements will provide a median score in m/s units, and a Metavir score can be determined which aides in the staging of liver fibrosis.

REFERENCES

Afdhal N. H. (2012). Fibroscan (transient elastography) for the measurement of liver fibrosis. Gastroenterology & hepatology, 8(9), 605–607.
Berger, D., Desai, V., & Janardhan, S., Con: Liver Biopsy remains the Gold Standard to Evaluate Fibrosis in Patients With Nonalcoholic Fattu Liver Disease’, Clinical Live Disease, vol 13, issue 4, p 114-116, doi: https://doi.org/10.1002/cld.740
Kemp, W., Roberts, S., (2013) ‘FibroScan and transient elastography’, Australian Family Physician, vol 42, issue 7, https://www.racgp.org.au/afp/2013/july/fibroscan
Osman, A. M., El Shimy, A., & Abd El Aziz, M. M. (2020). 2D shear wave elastography (SWE) performance versus vibration-controlled transient elastography (VCTE/fibroscan) in the assessment of liver stiffness in chronic hepatitis. Insights into imaging, 11(1), 38. https://doi.org/10.1186/s13244-020-0839-y
Sande, J, Verjee, S, Vinayak, S, Amersi F & Gheani, M 2017, ‘Ultrasound shear wave elastography and liver fibrosis: A Prospective Multicentre Study’, World Journal of Hepatology, vol 9, no. 1, pp. 38-47, doi: 10.4254/wjh.v9.i1.38
https://ge-ultrasound.eu/wp-content/uploads/2021/02/1.-LOGIQ-E9-LOGIQ-E10-LOGIQ-E10s_Shear-Wave-Whitepaper_2020_JB29031XX.pdf
https://gpvoice.com.au/index.php/2022/06/12/nafld-the-many-treatment-options-in-the-pipeline/
https://gpvoice.com.au/index.php/2018/01/31/non-invasive-prenatal-testing-what-gps-need-to-know/

PFO Closure

Furlan AJ, Reisman M, Massaro J, et al. Closure or medical therapy for cryptogenic stroke with patent foramen ovale. N Engl J Med 2012; 366: 991–

A multicenter, randomized, open-label trial of closure with a percutaneous device, as compared with medical therapy alone, in patients between 18 and 60 years of age who presented with a cryptogenic stroke or transient ischemic attack (TIA) and had a patent foramen ovale. The primary end point was a composite of stroke or transient ischemic attack during 2 years of follow-up, death from any cause during the first 30 days, or death from neurologic causes between 31 days and 2 years.

Results:

Primary end point was 5.5% in the closure group as compared with 6.8% in the medical-therapy group (adjusted hazard ratio, 0.78; 95% confidence interval, 0.45 to 1.35; P = 0.37)

Conclusion:

“In patients with cryptogenic stroke or TIA who had a patent foramen ovale, closure

with a device did not offer a greater benefit than medical therapy alone for the

prevention of recurrent stroke or TIA”

2 Saver JL, Carroll JD, Thaler DE, et al. Long-term outcomes of patent foramen ovale closure or medical therapy after stroke. N Engl J Med 2017; 377: 1022–

A multicenter, randomised, open-label trial ,randomly assigned patients 18 to 60 years of age who had a patent foramen ovale (PFO) and had had a cryptogenic ischemic stroke to undergo closure of the PFO (PFO closure group) or to receive medical therapy alone (aspirin, warfarin, clopidogrel, or aspirin combined with extended-release dipyridamole; medical-therapy group). The primary efficacy end point was a composite of recurrent nonfatal ischemic stroke, fatal ischemic stroke, or early death after randomisation.

Results:

Recurrent ischemic stroke occurred in 18 patients in the PFO closure group and in 28 patients in the medical-therapy group, resulting in rates of 0.58 events per 100 patient-years and 1.07 events per 100 patient years, respectively (hazard ratio 0.55; 0.31 – 0.999; P = 0.046)

Conclusion:

“Among adults who had had a cryptogenic ischemic stroke, closure of a PFO was associated with a lower rate of recurrent ischemic strokes than medical therapy alone during extended follow-up.”

Meier B, Kalesan B, Mattle HP, et al. Percutaneous closure of patent foramen ovale in cryptogenic embolism. N Engl J Med 2013; 368: 1083–

A prospective, multicenter, randomised, event-driven trial, randomly assigned patients to medical therapy alone (anti-platelet or warfarin therapy) or closure of the patent foramen ovale.

Results:

9 patients in the closure group and 16 in the medical-therapy group had a recurrence of stroke (hazard ratio with closure, 0.49; 0.22 – 1.11; P = 0.08). The primary analysis of the intentionto- treat cohort showed a nominal 51% hazard rate reduction with closure, but the reduction did not reach significance.

Conclusions:

” …there was no significant benefit associated with closure of a patent foramen ovale in adults who had had a cryptogenic ischaemic stroke.”

Sondergaard L, Kasner SE, Rhodes JF, et al. Patent foramen ovale closure or antiplatelet therapy for cryptogenic stroke. N Engl J Med 2017; 377: 1033–

Multinational trial involving patients with a PFO who had had a cryptogenic stroke, randomly assigned patients to undergo PFO closure plus antiplatelet therapy or to receive antiplatelet therapy alone.

Results:

During a median follow-up of 3.2 years, clinical ischemic stroke occurred in 6 of 441 patients (1.4%) in the PFO closure group and in 12 of 223 patients (5.4%) in the antiplatelet-only group (hazard ratio, 0.23; 0.09 to 0.62; P=0.002).

Conclusions:

“Among patients with a PFO who had had a cryptogenic stroke, the risk of subsequent ischemic stroke was lower among those assigned to PFO closure combined with antiplatelet therapy than among those assigned to antiplatelet therapy alone; however, PFO closure was associated with higher rates of device complications and atrial fibrillation.”

Mas JL, Derumeaux G, Guillon B, et al. Patent foramen ovale closure or anticoagulation vs. antiplatelets after stroke. N Engl J Med 2017; 377: 1011–

In a multicenter, randomised, open-label trial patients 16-60 years of age who had had a recent stroke attributed to PFO, to transcatheter PFO closure plus long-term antiplatelet therapy, antiplatelet therapy alone or oral anticoagulation.

Results:

No stroke occurred among patients in the PFO closure group, whereas stroke occurred in 14 of the 235 patients in the antiplatelet- only group (hazard ratio, 0.03; 0 to 0.26; P<0.001). Large number of patients discontinued anti-coagulation in the anti-coagulant group and statistical significance was not analysed because the study was not adequately powered to compare outcomes.

Conclusion:

“Among patients who had had a recent cryptogenic stroke attributed to PFO with an associated atrial septal aneurysm or large interatrial shunt, the rate of stroke recurrence was lower among those assigned to PFO closure combined with antiplatelet therapy than among those assigned to antiplatelet therapy alone. PFO closure was associated with an increased risk of atrial fibrillation.”

Lee PH, Song J-K, Kim JS, et al. Cryptogenic stroke and high-risk patent foramen ovale: the DEFENSE-PFO Trial. J Am Coll Cardiol 2018; 71: 2335–

Patients with cryptogenic stroke and high-risk PFO were divided between a transcatheter PFO closure and a medication-only group.

Results:

No events occurred in the PFO closure group. 12.9% of patients in the medication group had an event (p= 0.023).

Conclusion:

“PFO closure in patients with high-risk PFO characteristics resulted in a lower rate of the primary endpoint as well as stroke recurrence”