Short- and long-term evolution of the endoluminal diameter of underdilated stents in transjugular intrahepatic portosystemic shunt

Milestones to optimize of transjugular intrahepatic portosystemic shunt technique as a method for the treatment of portal hypertension complications

This editorial describes the milestones to optimize of transjugular intrahepatic portosystemic shunt (TIPS) technique, which have made it one of the main methods for the treatment of portal hypertension complications worldwide. Innovative ideas, subsequent experimental studies and preliminary experience of use in cirrhotic patients contributed to the introduction of TIPS into clinical practice. At the moment, the main achievement in optimize of TIPS technique is progress in the qualitative characteristics of stents. The transition from bare metal stents to extended polytetrafluoroethylene-covered stent grafts made it possible to significantly prevent shunt dysfunction. However, the question of its preferred diameter, which contributes to an optimal reduction of portal pressure without the risk of developing post-TIPS hepatic encephalopathy, remains relevant. Currently, hepatic encephalopathy is one of the most common complications of TIPS, significantly affecting its effectiveness and prognosis. Careful selection of patients based on cognitive indicators, nutritional status, assessment of liver function, etc., will reduce the incidence of post-TIPS hepatic encephalopathy and improve treatment results. Optimize of TIPS technique has significantly expanded the indications for its use and made it one of the main methods for the treatment of portal hypertension complications. At the same time, there are a number of limitations and unresolved issues that require further randomized controlled trials involving a large cohort of patients.

Effectiveness and prognosis of covered stents with different diameters in transjugular intrahepatic portosystemic shunt: a meta-analysis

PURPOSE

This meta-analysis was designed to evaluate the clinical outcomes of transjugular intrahepatic portosystemic shunt (TIPS) conducted utilizing stents of different diameters, thus providing recommendations for more logical selections of covered stents for patients with portal hypertension, in particular for the Asian population.

MATERIALS AND METHODS

Web of Science, PubMed, Embase, Cochrane Library, Chinese National Knowledge Infrastructure and Wan Fang were searched for randomized controlled trials and cohort studies from inception until February 2023. The meta-analysis was carried out using Revman 5.4 Software. Heterogeneity between researches was assessed by the χ2 test and I2 index. The outcomes evaluated were the incidence of post-TIPS hepatic encephalopathy (HE), variceal rebleeding, shunt dysfunction, 1-year overall survival and decrease in portal pressure gradient (PPG).

RESULTS

Eight appropriate clinical trials with 1246 patients were selected (638 and 608 patients in the experimental and control groups, respectively). In regards to preoperative PPG reduction, there was no discernible difference between the two groups [mean difference = 1.15, 95% confidence interval (CI) = -0.29-2.58, P = 0.12]. The rate of post-TIPS HE was significantly higher in patients in the 8 mm stent group than in the 6-7 mm stent group [odds ratio (OR) = 0.54, 95% CI = 0.42-0.70, P < 0.00001, I2 = 46%]. There were no significant differences in the rates of variceal rebleeding (OR = 1.05, 95% CI = 0.67-1.65, P = 0.84, I2 = 0%), shunt dysfunction (OR = 0.88, 95% CI = 0.53-1.47, P = 0.64, I2 = 0%) and 1-year overall survival (OR = 0.86, 95% CI = 0.50-1.50, P = 0.61, I2 = 0%).

CONCLUSION

Asian populations with portal hypertension may benefit more from TIPS with 6-7 mm covered stents because they can reduce the risk of postoperative HE while offering similar efficacy when compared to 8 mm covered stents.

Transjugular Intrahepatic Portosystemic Shunt: Devices Evolution, Technical Tips and Future Perspectives

Portal hypertension (PH) constitutes a pivotal factor in the progression of cirrhosis, giving rise to severe complications and a diminished survival rate. The transjugular intrahepatic portosystemic shunt (TIPS) procedure has undergone significant evolution, with advancements in stent technology assuming a central role in managing PH-related complications. This review aims to outline the progression of TIPS and emphasizes the significant influence of stent advancement on its effectiveness. Initially, the use of bare metal stents (BMSs) was limited due to frequent dysfunction. However, the advent of expanding polytetrafluoroethylene-covered stent grafts (ePTFE-SGs) heralded a transformative era, greatly enhancing patency rates. Further innovation culminated in the creation of ePTFE-SGs with controlled expansion, enabling precise adjustment of TIPS diameters. Comparative analyses demonstrated the superiority of ePTFE-SGs over BMSs, resulting in improved patency, fewer complications, and higher survival rates. Additional technical findings highlight the importance of central stent placement and adequate stent length, as well as the use of smaller calibers to reduce the risk of shunt-related complications. However, improving TIPS through technical means alone is inadequate for optimizing patient outcomes. An extensive understanding of hemodynamic, cardiac, and systemic factors is required to predict outcomes and tailor a personalized approach. Looking forward, the ongoing progress in SG technology, paired with the control of clinical factors that can impact outcomes, holds the promise of reshaping the management of PH-related complications in cirrhosis.

How Controlled is the Expansion of VIATORR CX?

PURPOSE

To investigate and compare the physical properties of the new generation Gore VIATORR-Controlled Expansion Endoprosthesis (VCX) to those of the predecessor VIATORR stent in an in vitro experimental setup.

MATERIALS AND METHODS

A total of 12 stents (8 VCX; 4 VIATORR; GORE, USA) were examined. Radial resistive force (RRF) and chronic outward force (COF) were assessed using a radial force testing machine (RX-650, Machine Solutions Inc., USA). To assess the radial forces of the VCX above 8 mm, balloon expansion was performed between cycles.

RESULTS

All VCX stents show an abrupt decrease in COF at an external diameter of 8.3 mm; RRF decreases likewise at an external diameter of 8.5 mm. The predecessor VIATORR stent without the "controlled expansion" feature shows linear radial force reduction until full expansion at a diameter of 10 mm. The physical properties of the VCX can be altered by balloon modulation. Point of COF (RRF) reduction shifts to 8.5 mm (8.6 mm), 8.6 mm (8.8 mm) and 9.3 mm (9.6 mm) following modulation with a 8 mm, 9 mm and 10 mm balloon.

CONCLUSIONS

The VCX shows an abrupt and disproportionate decrease in COF and RRF at an external diameter of 8.3 mm, thus passive expansion to its nominal diameter of 10 mm is not to be expected. By means of balloon dilatation the physical properties of the stent can be altered, enabling customized TIPS creation. The previous VIATORR stent shows continuous COF and RRF until total expansion.

The role of transjugular intrahepatic portosystemic shunt in patients with cirrhosis and ascites: Recent evolution and open questions

In selected patients with cirrhosis and ascites, transjugular intrahepatic portosystemic shunt (TIPS) placement improves control of ascites and may reduce mortality. In this review, we summarize the current knowledge concerning the use of TIPS for the treatment of ascites in patients with cirrhosis, from pathophysiology of ascites formation to hemodynamic consequences, patient selection, and technical issues of TIPS insertion. The combination of these factors is important to guide clinical decision-making and identify the best strategy for each individual patient. There is still a need to identify the best timing for TIPS placement in the natural history of ascites (recurrent vs. refractory) as well as which type and level of renal dysfunction is acceptable when TIPS is proposed for the treatment of ascites in cirrhosis. Future studies are needed to define the optimal stent diameter according to patient characteristics and individual risk of shunt-related side effects, particularly hepatic encephalopathy and insufficient cardiac response to hemodynamic consequences of TIPS insertion.

Comparison of the Covered Self-Expandable Viatorr CX Stent with the Covered Balloon-Expandable BeGraft Peripheral Stent for Transjugular Intrahepatic Portosystemic Shunt (TIPS) Creation: a Single-Centre Retrospective Study in Patients with Variceal Bleeding

PURPOSE

This study compares the safety and efficacy of the ePTFE-covered self-expansible nitinol stent (VIATORR® Controlled Expansion, Gore, Flagstaff, USA) with the ePTFE-covered, balloon-expandable, metallic stent (BeGraft peripheral, Bentley, Hechingen, Germany) for the creation of the transjugular intrahepatic portosystemic shunt (TIPS).

MATERIAL AND METHODS

From September 2016 to December 2020, 72 consecutive patients receiving TIPS for acute variceal bleeding (rescue and early TIPS, n = 15) or for prophylaxis of variceal rebleeding (n = 57) were enrolled. The main contraindications were patients with vascular liver disease (portal vein thrombosis and Budd-Chiari syndrome). Forty patients (55.6%) received a Viatorr CX stent and 32 patients (44.4%) a BeGraft peripheral stent. Safety endpoints were technical and clinical adverse events and early deaths within 30 days after TIPS implantation. Efficacy endpoints were rebleeding rates, recurrence of large varices requiring endoscopic band ligation, or TIPS revision.

RESULTS

Groups receiving the Viatorr CX or BeGraft peripheral stent were comparable in all respects except the TIPS indication for acute variceal bleeding (5% vs. 25%, p = 0.015). All patients had a successful intervention, and the physical variables of stent implantation (intervention and fluoroscopy time, reduction of the portosystemic pressure gradient) as well as adjunctive embolization of varices were similar in both groups. Severe clinical complications (Viatorr CX: 5% vs. BeGraft peripheral: 3.1%, p = 0.692), post-TIPS hepatic encephalopathy (12.5% vs. 18.8%, p = 0.743) and death (5% vs. 0%, p = 0.793) were not different between Viatorr CX and BeGraft peripheral groups. With respect to efficacy, freedom from rebleeding and from variceal band ligation during follow-up (100% vs. 100%, p = 1.0), as well as the need for shunt revision (10.5% vs. 18.8%, p = 0.327), was comparable.

CONCLUSION

Compared to the present gold standard, the Viatorr CX stent, the balloon-expandable BeGraft peripheral stent, showed similar results with respect to safety and efficacy.

Potential Benefits of Underdilation of 8-mm Covered Stent in Transjugular Intrahepatic Portosystemic Shunt Creation

INTRODUCTION

Hepatic encephalopathy (HE) is a major complication of transjugular intrahepatic portosystemic shunt (TIPS) creation. This study was aimed to determine whether underdilated TIPS with 8-mm polytetrafluoroethylene-covered stents could reduce the risk of HE and liver damage yet maintain clinical and hemodynamic efficacy.

METHODS

This retrospective case-controlled study included 134 patients treated with TIPS from March 2017 to November 2019. All the TIPS procedures were created using 8-mm covered stents, and according to the diameter of expansion balloon catheters, the patients were divided into 2 groups, an underdilated group (6-mm balloon catheter, n = 73) and a control group (8-mm balloon catheter, n = 61).

RESULTS

The Kaplan-Meier analysis indicated that the cumulative incidence of overt HE in the underdilated group was significantly lower than that in the control group (11.0% vs 29.5%, log rank P = 0.007), but no statistical differences were found toward variceal rebleeding, shunt dysfunction, and survival between groups. In multivariate analysis, the independent risk factors for overt HE were identified as age (hazard ratio [HR] = 1.036, 95% confidence interval [CI] = 1.003-1.069, P = 0.032), Child-Pugh score (HR = 1.519, 95% CI = 1.212-1.905, P < 0.001), and group assignment (HR = 0.291, 95% CI = 0.125-0.674, P = 0.004).

DISCUSSION

Underdilated TIPS with 8-mm polytetrafluoroethylene-covered stents could reduce the risk of HE and liver function impairment compared with completely dilated TIPS, but not increase the risk of variceal rebleeding, shunt dysfunction, and death.

Transjugular Intrahepatic Portosystemic Shunt Placement for Portal Hypertension: Meta-Analysis of Safety and Efficacy of 8 mm vs. 10 mm Stents

Introduction

Hepatic encephalopathy (HE) following transjugular intrahepatic portosystemic shunt (TIPS) placement remains a leading adverse event. Controversy remains regarding the optimal stent diameter given that smaller stents may decrease the amount of shunted blood and decrease the risk of HE, but stent patency and/or clinical adequacy of portal decompression may also be affected. We aim to provide meta-analysis-based evidence regarding the safety and efficacy of 8 mm vs. 10 mm stents during TIPS placement.

Methods

PubMed, Embase, Cochrane Library, and Web of Science were searched for studies comparing 8 mm and 10 mm stents during TIPS placement for portal hypertension decompression in cirrhotic patients. Randomized controlled trials and cohort studies were prioritized for inclusion. Overall evaluation of quality and bias for each study was performed. The outcomes assessed were the prevalence of HE, rebleeding or failure to control refractory ascites, and overall survival. Subgroup analysis based on TIPS indication was conducted.

Results

Five studies with a total number of 489 cirrhotic patients were identified. The pooled hazard ratio (HR) of post-TIPS HE was significantly lower in patients in the 8 mm stent group than in the 10 mm stent group (HR: 0.68, 95% CI: 0.51~0.92, p value < 0.0001). The combined HR of post-TIPS rebleeding/the need for paracentesis was significantly higher in patients in the 8 mm stent group than in the 10 mm stent group (HR: 1.76, 95% CI: 1.22~2.55, p value < 0.0001). There was no statistically significant difference in the overall survival between the 8 mm and 10 mm stent groups. The combined risk of HE in the variceal bleeding subgroup was statistically lower (HR: 0.52, CI: 0.34-0.80) with an 8 mm stent compared with a 10 mm stent. The combined risk of both rebleeding/paracentesis and survival was not statistically significant between 8 mm and 10 mm stent use in subgroup analysis.

Conclusion

8 mm stents during TIPS placement are associated with a significant lower risk of HE compared to 10 mm stents (32% decreased risk), as well as a 76% increased risk of rebleeding/paracentesis. Meta-analysis results suggest that there is not one superior stent choice for all clinical scenarios and that the TIPS indication of variceal bleeding or refractory ascites might have different appropriate selection of the shunt diameter.

Persistence of gastric or esophageal varices on final angiography increases transjugular intrahepatic portosystemic shunt revision rate after polytetrafluoroethylene-covered stent shunt creation

Background

To assess the association between final polytetrafluoroethylene (PTFE)-covered stent transjugular intrahepatic portosystemic shunt (TIPS) angiographic parameters and free shunt revision survey.

Methods

Series of two comparison groups were generated with persistence of varices or not, the 25^th, 50^th, and 75^th percentile as cutoff for each angle and a 15-mm distance as cutoff for distance D. Kaplan Meier free shunt revision curves were then created and compared with Log Rank test.

Results

Mean follow-up was 455 days. Thirteen (19.4%) patients had shunt revision. Significant free shunt revision survey difference was found between post-procedural angiographic persistent varices group and the group without varices (P=0.0001). Shunt revision rate at 3, 12 and 24 months was respectively 13%, 29%, and 39% in the group with varices versus 0%, 2.7% and 2.7% in the group without. No difference was found between groups for angles A, B, C and distance D.

Conclusions

Persistence of gastric or esophageal varices on final trans-TIPS angiography increases TIPS revision rate after PTFE-covered stent shunt creation whereas geometric parameters have no influence.

Incrementally Expandable Transjugular Intrahepatic Portosystemic Shunts: Single-Center Experience

OBJECTIVE

The purpose of this study is to investigate the long-term safety and efficacy of a small-diameter expandable transjugular intrahepatic portosystemic shunt (TIPS) in the management of portal hypertension.

MATERIALS AND METHODS

This single-center retrospective study included 28 patients (12 women and 16 men; mean age, 56.9 years) who underwent small-diameter expandable TIPS creation between 2008 and 2010 for refractory ascites (n = 15; mean [± SD] model for end-stage liver disease [MELD] score, 15.5 ± 5.3) or gastrointestinal variceal bleeding (n = 13; mean MELD score, 15.2 ± 8.4). An expandable TIPS was created by deploying a covered stent inside a balloon expandable stent. For patients with recurrent symptoms, TIPS adjustment was made by balloon expandable stent balloon dilation. The TIPS diameter was defined as the diameter of the final angioplasty balloon. TIPS patency and efficacy and the rate of post-TIPS hepatic encephalopathy were evaluated.

RESULTS

The median diameter of the initial TIPS was 8 mm in the group with variceal bleeding compared with 6 mm in the group with ascites (p = 0.003). The primary patency rate at 1 and 5 years was 90.8% and 73.3%, respectively. Eighty percent of patients with ascites required no or less-frequent large-volume paracentesis. The clinical success rate for patients with acute variceal bleeding was 92.3%. Six patients with ascites (initial TIPS diameter, 6 mm) and two patients with variceal bleeding (initial diameter, 6 mm and 8 mm) required subsequent TIPS adjustment. Of the 22 patients with no prior history of enecphalophy, seven patients (31.8%) experienced new hepatic encephalopathy within 90 days.

CONCLUSION

A small-diameter expandable TIPS is technically feasible and safe, with efficacy falling within the range of that of conventional TIPS. This technique offers the possibility of individualizing the degree of portal decompression.

Recent advances in hepatic encephalopathy

Hepatic encephalopathy describes the array of neurological alterations that occur during acute liver failure or chronic liver injury. While key players in the pathogenesis of hepatic encephalopathy, such as increases in brain ammonia, alterations in neurosteroid levels, and neuroinflammation, have been identified, there is still a paucity in our knowledge of the precise pathogenic mechanism. This review gives a brief overview of our understanding of the pathogenesis of hepatic encephalopathy and then summarizes the significant recent advances made in clinical and basic research contributing to our understanding, diagnosis, and possible treatment of hepatic encephalopathy. A literature search using the PubMed database was conducted in May 2017 using "hepatic encephalopathy" as a keyword, and selected manuscripts were limited to those research articles published since May 2014. While the authors acknowledge that many significant advances have been made in the understanding of hepatic encephalopathy prior to May 2014, we have limited the scope of this review to the previous three years only.