Shear wave elastography prior to transjugular intrahepatic portosystemic shunt may predict the decrease in hepatic vein pressure gradient

Hepatic artery diameter predicts bleeding risk after gastroesophageal varices treatment: a contrast-enhanced CT study

OBJECTIVE

Portal hypertension leads to hepatic artery dilatation and a higher risk of bleeding. We tried to identify the bleeding risk after gastroesophageal varices (GOV) treatment using hepatic artery diameter of contrast-enhanced CT.

METHODS

Retrospective retrieval of 258 patients with cirrhosis who underwent contrast-enhanced CT from January 2022 to May 2023 and endoscopy within one month thereafter at Hainan Affiliated Hospital of Hainan Medical University. Cirrhotic patients before GOV treatment were used as the test cohort (n = 199), and cirrhotic patients after GOV treatment were used as the validation cohort (n = 59). The grading and bleeding risk was classified according to the endoscopic findings. Arterial-phase images of contrast-enhanced CT were used for coronal reconstruction, and the midpoint diameter of the hepatic artery was measured on coronal images. The optimal cutoff value for identifying bleeding risk was analyzed and calculated in the test cohort, and its diagnostic performance was evaluated in the validation cohort.

RESULTS

In the test cohort, hepatic artery diameters were significantly higher in high-risk GOV than in low-risk GOV [4.69 (4.31, 5.56) vs. 3.10 (2.59, 3.77), P < 0.001]. With a hepatic artery diameter cutoff value of 4.06 mm, the optimal area under the operating characteristic curve was 0.940 (95% confidence interval: 0.908-0.972), with a sensitivity of 0.887, a specificity of 0.892, a positive predictive value of 0.904, and a negative predictive value of 0.874 for identifying bleeding risk in the test cohort, while in the validation cohort, the sensitivity was 0.885, specificity was 0.939, positive predictive value was 0.920, and negative predictive value was 0.912.

CONCLUSION

Hepatic artery diameter has high diagnostic performance in identifying bleeding risk after GOV treatment.

Transient elastography (FibroScan) in critical care: Applications and limitations

FibroScan^® is a non-invasive device that assesses the ‘hardness’ (or stiffness) of the liver via the technique of transient elastography. Because fibrous tissue is harder than normal liver, the degree of hepatic fibrosis can be inferred from the liver hardness. This technique is increasingly being employed to diagnose liver fibrosis, even in critically ill patients. It is now being used not only for diagnosis and staging of liver cirrhosis, but also for outcome prognostication. However, the presence of several confounding factors, especially in critically ill patients, may make interpretation of these results unreliable. Through this review we aim to describe the indications and pitfalls of employing FibroScan in patients admitted to intensive care units.

Individualized portal pressure gradient threshold based on liver function categories in preventing rebleeding after TIPS

BACKGROUND

The evidence in Portal pressure gradient (PPG) < 12 mmHg after transjugular intrahepatic portosystemic shunt (TIPS) for preventing rebleeding mostly comes from observations in uncovered stents era. Moreover, association between Child-Pugh classes and post-TIPS hepatic encephalopathy (HE) has indicated that tolerance of PPG reduction depends on liver function. This study aimed to investigate the optimal PPG for covered TIPS and explore the optimal threshold tailored to the Child-Pugh classes to find individualized PPG to balance rebleeding and overt HE.

METHODS

This multicenter retrospective study analyzed rebleeding, OHE, and mortality of patients associated with post-TIPS PPGs (8, 10, 12, and 14 mmHg) in the entire cohort and among different Child-Pugh classes. Propensity score matching (PSM) and competing risk analyses were performed for sensitivity analyses.

RESULTS

We included 2100 consecutively screened patients undergoing TIPS. In all patients, PPG < 12 mmHg reduced rebleeding after TIPS (p = 0.022). In Child-Pugh class A, none of the PPG thresholds were discriminative of clinical outcomes. In Child-Pugh class B, 12 mmHg (p = 0.022) and 14 mmHg (p = 0.037) discriminated rebleeding, but 12 mmHg showed a higher net benefit. In Child-Pugh class C, PPG < 14 mmHg had a lower rebleeding incidence (p = 0.017), and exhibited more net benefit than 12 mmHg.

CONCLUSION

Different PPG standards may be required for patients with different liver function categories. A PPG threshold < 12 mmHg might be suitable for patients in Child-Pugh class B, while < 14 mmHg might be optimal for patients in Child-Pugh class C.

Valsalva Maneuver Decreases Liver and Spleen Stiffness Measured by Time-Harmonic Ultrasound Elastography

Ultrasound elastography quantitatively measures tissue stiffness and is widely used in clinical practice to diagnose various diseases including liver fibrosis and portal hypertension. The stiffness of soft organs has been shown to be sensitive to blood flow and pressure-related diseases such as portal hypertension. Because of the intricate coupling between tissue stiffness of abdominal organs and perfusion-related factors such as vascular stiffness or blood volume, simple breathing maneuvers have altered the results of liver elastography, while other organs such as the spleen are understudied. Therefore, we investigated the effect of a standardized Valsalva maneuver on liver stiffness and, for the first time, on spleen stiffness using time-harmonic elastography (THE). THE acquires full-field-of-view stiffness maps based on shear wave speed (SWS), covers deep tissues, and is potentially sensitive to SWS changes induced by altered abdominal pressure in the hepatosplenic system. SWS of the liver and the spleen was measured in 17 healthy volunteers under baseline conditions and during the Valsalva maneuver. With the Valsalva maneuver, SWS in the liver decreased by 2.2% (from a median of 1.36 m/s to 1.32 m/s; p = 0.021), while SWS in the spleen decreased by 5.2% (from a median of 1.63 m/s to 1.51 m/s; p = 0.00059). Furthermore, we observed that the decrease was more pronounced the higher the baseline SWS values were. In conclusion, the results confirm our hypothesis that the Valsalva maneuver decreases liver and spleen stiffness, showing that THE is sensitive to perfusion pressure-related changes in tissue stiffness. With its extensive organ coverage and high penetration depth, THE may facilitate translation of pressure-sensitive ultrasound elastography into clinical routine.

Diagnostic value of conventional ultrasound and shear wave elastography in detecting transjugular intrahepatic portosystemic shunt dysfunction

BACKGROUND

Transjugular intrahepatic portosystemic shunt (TIPS) dysfunction can cause recurrent portal hypertension (PH)-related complications such as ascites and gastroesophageal variceal bleeding. Portography is invasive and costly limits its use as a screening modality.

PURPOSE

To assess the clinical value of conventional ultrasound in combination with point shear wave elastography (pSWE) to predict TIPS dysfunction.

MATERIAL AND METHODS

A total of 184 patients with cirrhosis scheduled for TIPS implantation were enrolled in this study and evaluated retrospectively. The splenoportal venous blood flow parameter, liver stiffness (LS), and spleen stiffness (SPS) were measured. Outcome measures included differences in portal vein velocity (PVV), splenic vein velocity (SPVV), LS, and SPS. The accuracy of change in PVV (ΔPVV), SPVV (ΔSPVV), and SPS (ΔSPS) to diagnose TIPS dysfunction was investigated.

RESULTS

TIPS dysfunction occurred in 28 of 184 patients (15.2%). Eighteen (64.3%) patients had shunt stenoses and 10 (35.7%) had shunt occlusion. Portal vein diameter (PVD), PVV, splenic vein diameter (SPVD), SPVV, LS, and SPS were not significantly different between the TIPS normal and TIPS dysfunction groups. Compared with the TIPS normal group, PVV and SPVV of the TIPS dysfunction group decreased significantly, whereas SPS increased significantly (P < 0.001). The values of areas under the receiver operating characteristic curves of ΔPVV, ΔSPVV, and ΔSPS for the diagnosis of TIPS dysfunction were 0.97, 0.96, and 0.87, respectively.

CONCLUSION

pSWE showed a diagnostic efficacy comparable to conventional ultrasound for diagnosing TIPS dysfunction and can be used routinely after TIPS procedures.

Clinical efficacy of transjugular intrahepatic portosystemic shunt created through left or right branches of the portal vein: A meta-analysis

Background and aim

Transjugular intrahepatic portosystemic shunt (TIPS) is a technique successfully used to treat portal hypertension and its complications. However, the choice of the branch, left (L) or right (R), of the portal vein resulting in a better outcome is still under debate. Therefore, this meta-analysis aims to evaluate which branch has a better curative effect on patients treated with TIPS.

Methods

PubMed, EMBASE, Web of science, Cochrane Library databases, Wanfang database and CBM were used for our search in October 2019 and updated in June 2021. The following parameters were used in evaluation: overall mortality, hepatic encephalopathy, shunt dysfunction, variceal rebleeding and rate of postoperative ascites.

Results

There were seven studies included. The sample size was 1940. A lower risk of mortality was observed in TIPS-L-treated patients compared with TIPS-R-treated ones (OR ​= ​0.65, 95% CI ​= ​0.50–0.85, p ​= ​0.002). A lower risk of shunt dysfunction was observed in TIPS-L-treated patients compared with TIPS-R-treated ones (OR ​= ​0.53, 95% CI ​= ​0.33–0.87, p ​= ​0.01). And the TIPS-L group had a significantly higher hepatic encephalopathy-free rate than the TIPS-R group (OR ​= ​0.59, 95% CI ​= ​0.44–0.78, p ​= ​0.0002). However, the rate of rebleeding (OR ​= ​0.75, 95% CI ​= ​0.55–1.03, p ​= ​0.07) and incidence of postoperative ascites (OR ​= ​1.14, 95% CI ​= ​0.86–1.51, p ​= ​0.38) was not statistically significant between the two groups.

Conclusions

Based on the currently available evidence, the technique of TIPS through the left branch of the portal vein can significantly reduce the occurrence of overall postoperative mortality, hepatic encephalopathy and shunt dysfunction.

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 Spleen and Liver Elastography and Color-Doppler Ultrasound in the Assessment of Transjugular Intrahepatic Portosystemic Shunt Function

The reference standard for assessing transjugular intrahepatic portosystemic shunt (TIPS) function is venography with portosystemic pressure gradient (PPG) measurement. This procedure is invasive and expensive; thus, we assessed the feasibility, reproducibility and diagnostic accuracy of color-Doppler ultrasound (CDUS) and spleen and liver stiffness (LS) measurements for identifying TIPS dysfunction. Twenty-four patients (15 undergoing TIPS placement and nine undergoing TIPS revision) consecutively underwent CDUS examination and LS and spleen stiffness (SS) determination by transient elastography (TE) and point shear-wave elastography (pSWE). All parameters were taken before TIPS placement/revision (1-15 d before) and 24 h after, just before revision by venography. pSWE inter-observer agreement was assessed by intra-class correlation coefficient (ICC). CDUS and elastographic data were correlated (Pearson coefficient) with pressure gradients (hepatic venous pressure gradient [HVPG], PPG). Main determinants of TIPS dysfunction were investigated by linear regression. Forty-nine paired examinations were performed in total: 49 (100%) SS reliable measurements by pSWE and 38 (88%) by TE. The ICC for pSWE values was 0.90 (95% confidence interval [CI] 0.81‒0.94). SS values significantly correlated with HVPG and PPG (R = 0.51, p = 0.01). The area under the Receiver-Operating Characteristic (AUROC) curve of SS for diagnosing TIPS dysfunction was 0.86 (95% CI 0.70‒0.96) using a 25 kPa cutoff. At multivariate analysis, the flow direction of the intrahepatic portal vein branches and SS values were independently associated to TIPS dysfunction. The intrahepatic portal vein branches flow direction and SS value are two simple, highly sensitive parameters accurately excluding TIPS dysfunction. SS measurement by pSWE is feasible, reproducible and both positively and significantly correlates with HVPG and PPG values.