Discrepancy Between Endoscopic Ultrasound-Guided Elastography and Transient Elastrography in Assessing Liver Stiffness of Morbidly Obese Patients

Aims Transient Elastography (TE), is one of the most extensively studied, non-invasive tests (NITs) for liver stiffness measurement (LSM). However, a recent study from our group showed a poor correlation between LSM measured by TE and histology-proven liver fibrosis in obese population due to impeding thicker visceral fat and abdominal wall. Endoscopic ultrasound elastography (EUS-E), a novel adjunct to pre-operative endoscopic evaluation, has advantages to overcome these limitations since the probe can be pressed against the liver capsule transgastrically. This study aimed to assess the correlation between conventional TE and EUS-E in severely obese population.

Methods LSM from EUS-E and TE in patients with class 2 and 3 obesity undergoing pre-operative endoscopic evaluation were collected and analyzed. The correlations between EUS-E and TE (FibroScan) were assessed using Spearman's rank correlation coefficient.

Results 116 LSM (58 EUS-E and 58 TE) from patients with obesity class 2 and 3 were analyzed (mean BMI 45.20±11.16, range 38.60 – 60.05). Overall, there was weak correlation between EUS-E and TE (R=0.282, P=0.01). LSM from TE was significantly higher than EUS-E (15.69±12.73 vs 9.58±5.91; p<0.001). EUS-E had stronger agreement with APRI and FIB4 scores compared to TE [(K=0.037) vs (K=0); EUS-E and TE, respectively]. Despite high grade fibrosis from TE, no patients demonstrated endosonographic signs of cirrhotic morphology or portal hypertension. Among patients without significant fibrosis (n=4), strong correlation of EUS-E and TE was observed only when EUS-E confidence interval cut-off was over 73.5% (AUC=0.672(0.462-0.881), sensitivity=75%, specificity=60%, PPV=67.1%, NPV=68.9%, accuracy=67.8%.

Conclusions LSM from TE in severely obese patients does not correlate well with other NITs and may overestimate true fibrosis. EUS-E offers another mean of LSM that can mitigate the limitation of shear wave propagation in this unique population where an accurate liver assessment is essential pre-operatively. When EUS-E is performed, a confidence interval cut-off of at least 73.5% should be obtained. Further validation against histology-proven fibrosis is warranted. [1] [2] [3] [4]

Conflicts of interest

Authors do not have any conflict of interest to disclose.

• References

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• 2 Ozturk A. et al. &quot;Liver fibrosis assessment: MR and US elastography.&quot;. Abdominal Radiology 2022; 1-14
• 3 Song JE, Lee DW, Kim EY.. &quot;Endoscopic ultrasound real-time elastography in liver disease.&quot;. Clinical endoscopy 2018; 51 (02) 118-119
• 4 Siddiqui MS, Vuppalanchi R, Van Natta ML, Hallinan E, Kowdley KV, Abdelmalek M, Neuschwander-Tetri BA, Loomba R, Dasarathy S, Brandman D, Doo E, Tonascia JA, Kleiner DE, Chalasani N, Sanyal AJ. NASH Clinical Research Network. Vibration-Controlled Transient Elastography to Assess Fibrosis and Steatosis in Patients With Nonalcoholic Fatty Liver Disease. Clin Gastroenterol Hepatol 2019; 17 (01) 156-163.e2

Publication History

Article published online:
15 April 2024