Portosystemic Shunt Research Articles

Portocaval shunts' role in gut microbiota and hepatic encephalopathy: The gut-to-brain pathway

I read the study by Zhao et al with great interest. Although the study design was quite complicated, it was successful in raising awareness of science and relevant researchers. Thirty patients with liver cirrhosis and portal hypertension secondary to chronic hepatitis B were included in the study. They were treated for variceal bleeding and underwent trans-jugular intrahepatic portosystemic shunt to prevent the recurrence of variceal bleeding and to reduce portal pressure. The authors evaluated the effects of changes in gut microbiota (GM) on hepatic encephalopathy secondary to portocaval bypass. The GM is greatly affected by local and general factors, including herbal and medical drugs, a person's dietary characteristics (carnivorous, vegan, vegetarian), supplementary foods, drinking water sources, and living in a city center or town. Therefore, I congratulate Zhao et al for their concise and comprehensive study on a multifactorial subject.

Comprehensive approach to esophageal variceal bleeding: From prevention to treatment

Esophageal variceal bleeding is a severe complication often associated with portal hypertension, commonly due to liver cirrhosis. Prevention and treatment of this condition are critical for patient outcomes. Preventive strategies focus on reducing portal hypertension to prevent varices from developing or enlarging. Primary prophylaxis involves the use of non-selective beta-blockers, such as propranolol or nadolol, which lower portal pressure by decreasing cardiac output and thereby reducing blood flow to the varices. Endoscopic variceal ligation (EVL) may also be employed as primary prophylaxis to prevent initial bleeding episodes. Once bleeding occurs, immediate treatment is essential. Initial management includes hemodynamic stabilization followed by pharmacological therapy with vasoactive drugs such as octreotide or terlipressin to control bleeding. Endoscopic intervention is the cornerstone of treatment, with techniques such as EVL or sclerotherapy applied to directly manage the bleeding varices. In cases where bleeding is refractory to endoscopic treatment, transjugular intrahepatic portosystemic shunt may be considered to effectively reduce portal pressure. Long-term management after an acute bleeding episode involves secondary prophylaxis using beta-blockers and repeated EVL sessions to prevent rebleeding, complemented by monitoring and managing liver function to address the underlying disease. In light of new scientific evidence, including the findings of the study by Peng et al , this editorial aims to review available strategies for the prevention and treatment of esophageal varices.

Doppler velocities in patent transjugular intrahepatic portosystemic shunts: an analysis of 10 mm vs. 8 mm shunts

Doppler velocities in patent transjugular intrahepatic portosystemic shunts: an analysis of 10 mm vs. 8 mm shunts

CIRSE Standards of Practice on Transjugular Intrahepatic Portosystemic Shunts.

Proposed in the early 1980s as a solution for managing complications of portal hypertension, the percutaneous creation of transjugular intrahepatic portosystemic shunt has consistently gained a central role. Increasingly lower complication rates have been observed thanks to improvements in both technologies and the skills of interventional radiologists. This document is aimed at interventional radiologists and provides best practice recommendations for transjugular intrahepatic portosystemic shunt creation, describing patient selection, intraprocedural management and follow-up, in addition to recommendations in paediatric settings. The CIRSE Standards of Practice Committee established a writing group consisting of seven European clinicians with recognised expertise in the creation of transjugular intrahepatic portosystemic shunt. The writing group reviewed the existing literature performing a pragmatic evidence search using PubMed to select relevant publications in the English language and involving human subjects, preferably published from 2009 to 2024. The final recommendations were developed by consensus. TIPS creation has an established role in the successful management of portal hypertension and its complications. This Standards of Practice document provides up-to-date recommendations for patient selection, materials, its safe performance, and follow-up with complications management.

Tremors in cats with hepatic encephalopathy-congenital portosystemic shunts or postattenuation neurological syndrome.

Tremors have been reported as a neurological sign in cats with hepatic encephalopathy due to congenital portosystemic shunts (HE-CPSS) or postattenuation neurological syndrome (PANS). The clinical records of cats diagnosed with HE-CPSS and manifesting tremors between 2003 and 2023 were retrospectively reviewed to characterise the clinical features of the tremors. Nineteen cats with HE-CPSS were included, of which 17 manifested tremors at admission and two had PANS. Domestic shorthair was the most common breed (12/19). Tremors were the only neurological sign in six of the 19 cats. Tremor localisation was generalised (10/19) or focal to the head (8/19) or a limb (1/19). Most tremors were episodic and non-intentional (15/19), occurring usually at rest with occasional intentional features (4/19). Of the 14 cats for which 1-month follow-up was available, tremors discontinued in nine after surgical or medical management. The limitations of this study included its retrospective nature and the lack of video recordings, brain magnetic resonance imaging and electrophysiological evaluation of tremors in all cases. A diagnosis of HE-CPSS or PANS should be considered in cats with generalised or focal tremors.

Post-TIPS Right Atrial Pressure and Left Atrial Volume Index Predict Heart Failure and Mortality: Dual Center Experience

Background: Heart failure (HF) after Transjugular Intrahepatic Portosystemic Shunt (TIPS) placement affects up to 20% of patients. Understanding factors associated with post-TIPS HF is critical. Cirrhotic Cardiomyopathy (CCM) is associated with adverse clinical outcomes. Aims: We aim to evaluate whether hemodynamic measurements and echocardiographic markers of CCM pre- and post-TIPS can predict post-TIPS HF and death. Methods: We performed a retrospective study of cirrhotic patients who underwent TIPS between 2010 and 2015 at two centers. Patients with cardiomyopathies other than CCM were excluded. A multivariable-adjusted time-to-event analysis assessed associations of clinical, hemodynamic, and echocardiographic parameters with post-TIPS HF and death during 2 years of follow-up. 180-day landmark analysis was used to assess association of echocardiographic changes with outcomes. Results: 360 patients met study criteria. 32 developed HF post-TIPS (8.8%). Right atrial pressure (RAP) measured intraprocedurally post-TIPS insertion was associated with increased risk for HF (adjusted HR 1.10 [1.04-1.17]), with a cut off of 22mm Hg associated with highest risk (multivariable HR 2.71, [1.22-6.02]. 92 patients died (25.5%). An increase in left atrial volume index (LAVI) within 180 days post-TIPS was associated with increased mortality (HR 1.08 [1.01-1.15]). Other echocardiographic CCM markers were not associated with HF or death. Conclusion: Increases in RAP and LAVI post-TIPS, but not CCM status, predict post-TIPS HF and death, respectively. Surveillance echocardiography may play a role in identifying those at highest risk of decompensation post-TIPS. Further prospective study of CCM and its markers in relation to TIPS outcomes is warranted.

TIPS, a Trick for Transcaval TEVAR Access.

We described an alternative access for thoracic endovascular aortic repair (TEVAR) deployment using a transjugular intrahepatic portosystemic shunt (TIPS) needle for gaining transcaval access to the abdominal aorta. A 63-year-old man presented with a penetrating atherosclerotic ulcer in the descending aorta. Traditional transfemoral and transaxillary access were not possible. A transcaval access was established using a TIPS needle to puncture from the caval vein to the aorta. Next, the access was gradually upsized until a 22 french large-bore transcaval access was achieved. Afterwards the thoracic endograft was positioned and deployed accustomed. The infrarenal aortocaval fistula was closed with a covered stent. When classic TEVAR access is not possible, transcaval access is a valuable and minimally invasive alternative access. We prefer the use of a TIPS needle for gaining access and use a covered stent for closing the aortic access site when possible instead of using electrified wires nor a transseptal occluder device. Preoperative planning remains key. We discribe a transcaval access with a TIPS needle and closing of the aortocaval fistula with a covered stent. We are one of fiew reports of transcaval puncturing instead of using an electrified wire and the first using a TIPS needle for gaining transcaval access. We hope this case and our comments help other surgeons, radiologists and patients when they are in need of a transcaval access and contribute to a successful procedure.

Psoas muscle index in sarcopenia following transjugular intrahepatic portosystemic shunt: A multicenter, retrospective study

AbstractAimsAlthough the skeletal muscle index at the third lumbar vertebra (L3‐SMI) is commonly utilized for the diagnosis of sarcopenia, the psoas muscle index at L3 (L3‐PMI) may serve as a reliable alternative indicator. This study aims to investigate the application of the PMI in patients who have undergone transjugular intrahepatic portosystemic shunt (TIPS).MethodsThis study included a cohort of 406 patients with cirrhosis who underwent TIPS between February 2016 and July 2022 across three medical centers in China. Clinical and imaging data, specifically L3‐SMI and L3‐PMI, were collected for these patients. The prognosis of the patients was assessed through re‐examinations and telephone follow‐ups, which extended up to 5 years. The diagnostic thresholds for sarcopenia, as defined by L3‐PMI and L3‐SMI, were established at 6.36 or 42.00 cm²/m² for males and 3.92 or 38.00 cm²/m² for females, respectively. Cox proportional hazards and Kaplan–Meier (K‐M) analyses were employed to evaluate patient survival.ResultsThe findings indicated that both L3‐PMI and L3‐SMI before TIPS were independent risk factors for mortality. The results of the paired t‐test demonstrated a significant increase in L3‐PMI 1 month post‐TIPS (5.11 ± 1.81 vs. 5.71 ± 1.90 cm²/m², p < 0.001), whereas L3‐SMI did not exhibit a significant increase until 6 months post‐TIPS (45.45 ± 9.41 vs. 48.59 ± 10.38 cm²/m², p < 0.001). Among these patients, 191 (47.0%) and 159 (39.2%) were diagnosed with sarcopenia according to the L3‐PMI and L3‐SMI models, respectively. Patients identified as sarcopenic by both indicators demonstrated a significantly lower survival rate (L3‐SMI model: hazard ratio [HR], 1.913; 95% confidence interval [CI], 1.094–3.410; log‐rank p = 0.020; L3‐PMI model: HR, 1.867; 95% CI, 1.059–3.290; log‐rank p = 0.030). In sarcopenic patients, the reversal of sarcopenia associated with improved survival occurred 1 month after TIPS in the L3‐PMI model (HR, 2.675; 95% CI, 1.245–5.735; log‐rank p = 0.012), while a similar effect was not observed until 6 months post‐TIPS in the L3‐SMI model (HR, 3.342; 95% CI, 1.477–7.560; log‐rank p = 0.004).ConclusionsL3‐PMI and L3‐SMI demonstrate comparable efficacy in diagnosing cirrhosis‐related sarcopenia. Furthermore, L3‐PMI has the capacity to identify improvements in sarcopenia as early as 1 month following TIPS, thereby providing earlier insights into patient survival outcomes.

Recompensation of Liver Cirrhosis by TIPS Reduces Epithelial Cell Death Markers, Translating Into Improved Clinical Outcome.

Portal hypertension is the main pathophysiological driver of decompensation in patients with liver cirrhosis. Epithelial cell death markers, m30 and m65, correlate with hepatic injury and predict outcomes across various stages of liver disease. We aim (i) to evaluate whether portal hypertension itself contributes to liver outcome-relevant epithelial injury, and (ii) to analyse the capacity of m30/m65 to predict outcome in patients receiving a transjugular intrahepatic portosystemic shunt (TIPS) for refractory ascites. Sixty-six patients undergoing TIPS placement for refractory ascites and 20 patients with compensated cirrhosis as controls were prospectively enrolled in this monocentric cohort study. Epithelial cell death markers were analysed pre-TIPS, as well as 1-3 and 6-9 months post-TIPS. The capacity of baseline levels of m30/m65 in predicting six-month transplant-free survival rates was analysed by multivariable Cox proportional hazards regression. Levels of m30 and m65 were higher in patients with decompensated cirrhosis (pre-TIPS) compared with compensated cirrhosis (controls). Following correction of portal hypertension by TIPS and recompensation, both markers decreased over time, reaching levels comparable to patients with compensated cirrhosis. On multivariable analysis, pre-TIPS baseline levels of m30 and m65 were not predictive for six-month survival. Correction of portal hypertension via TIPS reduces levels of epithelial cell death markers, indicating that portal hypertension is a driver of outcome-relevant, hepatic cell death in patients with decompensated cirrhosis. Baseline m30/m65 values do not affect six-month survival rates, which suggests that TIPS placement overcomes the unfavourable spontaneous prognosis otherwise indicated by elevated baseline m30/65 levels.

Cholate Shunt, Oral Cholate Challenge and Endoscopic Lesions of Portal Hypertension: The SHUNT-V Study.

The accuracy of current criteria for ruling out large oesophageal varices (LEV) and other endoscopic lesions of portal hypertension (PH) may be compromised by obesity and MASLD/MASH. In the US multicentre SHUNT-V study, we evaluated the disease severity index (DSI) for detecting LEV and other lesions of PH at endoscopy. Subjects were adults with compensated cirrhosis scheduled for endoscopy to screen for varices. DSI was calculated from clearances of labelled cholates after oral and intravenous administration. DSI ≤ 18.3 was evaluated as a cut-off for ruling out LEV with acceptance criteria of negative likelihood ratio < 0.52 and sensitivity > 85%. SHUNT-V enrolled 306 subjects; 275 had both DSI and endoscopy, and 238 had Child-Pugh A cirrhosis (52.1% MASLD/MASH, 25.2% chronic hepatitis C and 15.6% alcoholic liver disease; 87% were overweight, 64% were obese and 54% had diabetes). AUROCs for DSI ranged from 0.81 to 0.82 for LEV and 0.79 to 0.80 for all significant PH lesions. DSI 18.3 had sensitivity 96.3%-100% for LEV and 97.3%-100% for all significant PH lesions. If DSI ≤ 18.3 were used as the sole determinant to defer EGD, 27%-35% of EGDs could have been avoided with 0%-3.7% of LEV and 0%-2.7% of all significant PH lesions missed. HepQuant DSI predicts the likelihood of LEV and significant PH lesions across a spectrum of patient characteristics and disease aetiologies. DSI, based on liver function and portal-systemic shunting, can aid in the decision to defer endoscopy for varices in patients with Child-Pugh A cirrhosis. The SHUNT-V study was registered at ClinicalTrials.gov (NCT03583996).

Optimal threshold of portal pressure gradient for patients with ascites after covered TIPS: a multicentre cohort study.

Transjugular intrahepatic portosystemic shunt (TIPS) is recommended for treating recurrent and refractory ascites. However, determining the target portal pressure gradient (PPG) has been inconclusive. This multicentre cohort study explored the post-TIPS PPG potential range associated with improving survival. The study enrolled 276 patients, all of whom underwent covered TIPS for ascites treatment across four medical centers. The cumulative incidences of clinical outcomes were compared among groups categorized by potential PPG thresholds. During the whole follow-up period with a medium follow-up of 21.6 (7.5, 41.6) months, 122 (44.2%) experienced liver-related death, and 73 (26.4%) patients experienced a recurrence of ascites. Multivariable analysis revealed PPG < 7mmHg (p = 0.007) and the recurrence of ascites (p = 0.033) are independent risk factors for survival, while the PPG ≥ 11mmHg was an independent risk factor for the recurrence of ascites (p = 0.012). Patients with ≥ 7mmHg had a lower rate of liver-related death than patients with post-TIPS PPG < 7mmHg (51.0% vs 66.6%, p = 0.004), while those with post-TIPS PPG ≥ 11mmHg exhibited a higher cumulative incidence of ascites compared to those with post-TIPS PPG < 11mmHg (44.6% vs 33.7%, p = 0.023). The robustness of the results was confirmed. Our study highlighted the existence of an optimal post-TIPS PPG range in patients with recurrent and refractory ascites. Patients may experience improved survival and ascites control with a post-TIPS PPG of 7-11mmHg.

The Management of Shunt Dysfunction Caused by Stent Deviation During Transjugular Intrahepatic Portosystemic Shunt (TIPS) Surgery for Esophageal and Gastric Varices Bleeding.

The Management of Shunt Dysfunction Caused by Stent Deviation During Transjugular Intrahepatic Portosystemic Shunt (TIPS) Surgery for Esophageal and Gastric Varices Bleeding.

Portal Hypertensive Gastropathy and MELD-Na Score Predict Recurrent Gastrointestinal Bleeding After TIPSS: An ALTA Group Study.

Transjugular intrahepatic portosystemic shunt (TIPSS) is highly effective for treatment of variceal bleeding; however, factors contributing to rebleeding complications remain unclear. In this study, we aim to determine risk factors for recurrent portal hypertensive gastrointestinal bleeding following TIPSS. Utilising the Advancing Liver Therapeutic Approaches multicentre database, we retrospectively identified adult patients who underwent TIPSS for secondary prophylaxis of variceal bleeding and had a gastrointestinal rebleeding event within 1 year. We developed multivariable logistic regression models to identify clinical/procedural characteristics associated with rebleeding. We identified 476 patients, predominately middle-aged (mean age 57), male (62%) and White (65%), with mean MELD-Na 16. 16% (n = 77) had a rebleeding event; these patients were more likely to be male (p = 0.016), with higher serum creatinine (p = 0.005), MELD-Na (p = 0.0002), portal hypertensive gastropathy on pre-TIPSS upper endoscopy (p = 0.000) and with higher incidence of TIPSS revision (p = 0.000). There were no significant differences in type of TIPSS endoprosthesis, concurrent embolotherapy, and post-TIPSS pressure gradients between those who experienced rebleeding and those who did not. After adjusting for TIPSS revision, multivariable analysis revealed MELD-Na and presence of portal hypertensive gastropathy on pre-TIPSS endoscopy were independently associated with rebleeding. In this retrospective analysis of a multicentre, nationally representative database, we found that apart from TIPSS-related factors, high MELD-Na and portal hypertensive gastropathy on pre-TIPSS endoscopy were independent predictors of rebleeding within 1 year following TIPSS. These variables may be used to identify high-risk patients who may require additional monitoring following TIPSS.

Clinical Outcomes of Transjugular Intrahepatic Portosystemic Shunt Among Cirrhosis Patients With Recurrent Esophageal Variceal Bleeding

Clinical Outcomes of Transjugular Intrahepatic Portosystemic Shunt Among Cirrhosis Patients With Recurrent Esophageal Variceal Bleeding

Percutaneous thermal ablation in hepatocellular carcinoma patients with and without TIPS.

Managing hepatocellular carcinoma (HCC) in patients with a transjugular intrahepatic portosystemic shunt (TIPS) is becoming increasingly common. This study aimed to evaluate the safety and efficacy of percutaneous thermal ablation for treating HCC in patients with TIPS. This retrospective longitudinal study was conducted at Nantes University Hospital. The main inclusion criteria were patients undergoing percutaneous thermal ablation for HCC. Patients with a pre-existing TIPS were included in the 'TIPS group'. A 1:1 control group without TIPS, the 'n-TIPS group', was created for this case-control study. The primary endpoints were overall survival and progression-free survival over 12 months. Safety was assessed by comparing complications between the groups. Between 2008 and 2020, 371 patients underwent percutaneous thermal ablation for HCC. The 'TIPS group' included 34 patients (66 nodules), while 34 patients (84 nodules) were randomly assigned to the 'n-TIPS group.' Overall survival rates at 1 year were 97% and 94% respectively (p = 0.52). The progression-free survival rate was 68% and 57% respectively (p = 0.35). No deaths occurred within 30 days post-procedure. There were 3 immediate complications in the TIPS group and 4 in the n-TIPS group (p = 1), none of which were related to the TIPS, including thrombosis. Percutaneous thermal ablation for HCC in patients with TIPS appears to be as safe and effective as in TIPS-naïve patients. These results suggest that the presence of a TIPS should not be considered a contraindication for percutaneous thermal ablation in treating HCC.

Imaging of the Inferior Mesenteric Vasculature.

The inferior mesenteric artery (IMA) and inferior mesenteric vein (IMV) supply and drain blood from the distal colon and rectum, respectively. Routinely imaged at cross-sectional imaging of the abdomen and pelvis, these vessels play a vital role in gastrointestinal tract health but may be neglected due to their diminutive caliber relative to other mesenteric vessels and potential lack of inclusion in routine search patterns. The authors describe and illustrate normal and abnormal appearances of the IMA and IMV and findings that are diagnostic of primary vascular abnormalities or can offer diagnostic clues. After the embryologic features, normal anatomy, and anatomic variants of the IMA and IMV are reviewed, various manifestations of IMA and IMV abnormalities, such as aneurysm and pseudoaneurysm, stenosis, occlusion, dissection, hemorrhage, arteriovenous malformations and fistulas, tumoral invasion, vasculitis, and perivascular lymphatic dilatation, are explored with use of case examples. The role of the IMA and IMV as collateral vasculature, including the clinical scenarios of superior mesenteric arterial occlusion, aortic endoleak, and portosystemic venous shunt, are discussed. Finally, diagnostic clues that the inferior mesenteric vessels and adjacent soft tissues can provide, including mesenteric venous gas, compression or displacement from bowel volvulus or internal hernias, lymphadenopathy, and venous flow artifacts, are highlighted. The authors provide a comprehensive reference for radiologists who evaluate the IMA and IMV on cross-sectional images and shine a spotlight on these neglected but important vessels. ©RSNA, 2024 Supplemental material is available for this article.

A Comparative Analysis of the Efficacy of Parallel Stent Versus Conventional Stent Repair in Addressing Dysfunction in Transjugular Intrahepatic Portosystemic Shunt Treatment

A Comparative Analysis of the Efficacy of Parallel Stent Versus Conventional Stent Repair in Addressing Dysfunction in Transjugular Intrahepatic Portosystemic Shunt Treatment

The primary cause of markedly elevated aminotransferases in hospitalized patients with cirrhosis in ischemic hepatitis.

Marked elevation in aminotransferases (≥1000 IU/l) is typically associated with acute liver injury. Here, we hypothesized that the cause of elevation in aminotransferases ≥1000 in patients with cirrhosis is likely due to a limited number of disorders and may be associated with poor outcomes. We aimed to investigate the most common etiologies of acute elevations in aminotransferases in patients with cirrhosis, and to examine their associated outcomes. From May 2012 to December 2022, all hospitalized patients with cirrhosis and an aspartate aminotransferase or alanine aminotransferase ≥ 1000 IU/l were identified through Medical University of South Carolina's Clinical Data Warehouse. Complete clinical data were abstracted for each patient, and in-hospital mortality was examined. The cohort was made up of 152 patients, who were 57 ± 12 years old, with 51 (34%) women. Underlying liver disease included mainly hepatitis C cirrhosis, alcohol-related cirrhosis, metabolic dysfunction-associated steatohepatitis cirrhosis, autoimmune cirrhosis, primary sclerosing cholangitis cirrhosis, and cryptogenic cirrhosis. The most common cause of marked elevation in aminotransferases in cirrhotic patients was ischemic hepatitis (71%), followed by chemoembolization (7%), autoimmune hepatitis (6%), drug-induced liver injury (3%), post-transjugular intrahepatic portosystemic shunt placement (3%), rhabdomyolysis (3%), and hepatitis C (2%). During hospitalization and over a 1-month follow-up period, the mortality rate in patients with ischemic hepatitis was 73% (79/108), while that for other causes of liver injury was 20% (9/44). Ischemic hepatitis is the leading cause of marked elevation of aminotransferases in patients with cirrhosis, with distinctive clinical characteristics than other etiologies, and significantly poorer outcomes.

Evidence for preventing EVRB in cirrhotic patients: A systematic review.

Systematic strategies for preventing and treating esophagogastric variceal rebleeding (EVRB) are currently inadequate. This systematic review aimed to update this critical gap by searching contemporary studies from major guideline websites, databases, and professional associations focused on EVRB prevention in cirrhosis patients. Key findings highlight evaluation methods, risk management, preventive measures, health education, and follow-up strategies. Notably, a hepatic venous pressure gradient exceeding 18 mmHg is identified as a reliable predictor of gastroesophageal varices (GOV) rebleeding. Effective management of primary diseases is crucial, with methods including antiviral and anti-fibrotic therapies, alcohol avoidance, vaccination, and careful medication management. The combination of nonselective β-blockers (NSBBs) and endoscopic variceal ligation (EVL) is established as the gold standard for secondary EVRB prevention. For patients experiencing recurrent bleeding despite NSBBs and EVL, transjugular intrahepatic portosystemic shunt (TIPS) therapy is recommended. Surgical options, such as surgical shunt and devascularization, are advised for those unsuitable for endoscopic therapy or TIPS, particularly in Child-Pugh A and B patients unresponsive to treatment. Additionally, traditional Chinese medicine options, such as Fufang Biejia Ruangan Tablets, Fuzheng Huayu Capsules, and Anluo Huaxian Pills, have shown promise in improving hepatic fibrosis and GOV in cirrhotic patients. This review offers a comprehensive overview of current prevention and treatment strategies for EVRB, providing valuable insights for clinicians and healthcare professionals.

Creation of 6-10mm Diameter Transjugular Intrahepatic Portosystemic Shunts Using a Novel TIPS Stent Graft in a Swine Model

PurposeTo assess the delivery, function, and patency of a new expanded polytetrafluoroethylene encapsulated TIPS stent- graft ("Liverty") in an animal model. Materials and MethodsTIPS were created in 2 successive groups: 14 single & 10 overlapping devices, in swine weighing 52-64kg. Explants occurred at 30 (n=10) and 60 (n=14) days. These were evaluated by histomorphometry and histopathologic evaluations, and electron microscopy. ResultsSeven 6mm, five 7mm, and twelve 10mm diameter TIPS were created using varied human TIPS access sets without complications; both sheathed and unsheathed advancement and deployment of the devices within liver tracts. One animal was sacrificed at 35d due to encephalopathy; remainder survived to endpoints. 22/24 TIPS were patent at 30 and 60-day endpoints; Mean stenosis at 30 days was 13.3% +/- 10.1%, and for 60 days was 18.44% ± 5.04%. Two shunts were occluded by tissue overgrowth at unstented native hepatic vein end and downgrowth into TIPS. Histology and electron microscopy showed well-apposed, incorporated devices lined with smooth, uniform neointimal tissue averaging 0.48mm (single devices) and 0.74mm thick (overlapped devices) with minimal adventitial inflammation. ConclusionThe new Liverty TIPS stent graft was straightforward to deploy for TIPS creation and resulted in patent 6,7, and 10mm diameter shunts in both single and overlapping configurations. One- and 2-month histology showed desired tissue healing without in-stent stenosis.