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

Episodic overt hepatic encephalopathy after transjugular intrahepatic portosystemic shunt does not increase mortality in patients with cirrhosis

Background & Aims: Overt hepatic encephalopathy (OHE) is a major complication of transjugular intrahepatic portosystemic shunt (TIPS) placement, given its high incidence and possibility of refractoriness to medical treatment. Nevertheless, the impact of post-TIPS OHE on mortality has not been investigated in a large population. Methods: We designed a multicenter, non-inferiority, observational study to evaluate the mortality rate at 30 months in patients with and without OHE after TIPS. We analyzed a database of 614 patients who underwent TIPS in three Italian centers and estimated the cumulative incidence of OHE and mortality with competitive risk analyses, setting the non-inferiority limit at 0.12. Results: During a median follow-up of 30 months (IQR 12-30), 293 patients developed at least one episode of OHE. Twenty-seven (9.2%) of them experienced recurrent/persistent OHE. Patients with OHE were older (64 [57-71] vs. 59 [50-67] years, p <0.001), had lower albumin (3.1 [2.8-3.5] vs. 3.25 [2.9-3.6] g/dl, p = 0.023), and had a higher prevalence of pre-TIPS OHE (15.4% vs. 9.0%, p = 0.023). Child-Pugh and MELD scores were similar. The 30-month difference in mortality between patients with and without post-TIPS OHE was 0.03 (95% CI -0.042 to 0.102). Multivariable analysis showed that age (subdistribution hazard ratio 1.04, 95% CI 1.02–1.05, p <0.001) and MELD score (subdistribution hazard ratio 1.09, 95% CI 1.05–1.13, p <0.001), but not post-TIPS OHE, were associated with a higher mortality rate. Similar results were obtained when patients undergoing TIPS for variceal re-bleeding prophylaxis (n = 356) or refractory ascites (n = 258) were analyzed separately. The proportion of patients with persistent OHE after TIPS was significantly higher in the group of patients who died. The robustness of these results was increased following propensity score matching. Conclusion: Episodic OHE after TIPS is not associated with mortality in patients undergoing TIPS, regardless of the indication. Impact and implications: Overt hepatic encephalopathy (OHE) is a common complication in patients with advanced liver disease and it is particularly frequent following transjugular intrahepatic portosystemic shunt (TIPS) placement. In patients with cirrhosis outside the setting of TIPS, the development of OHE negatively impacts survival, regardless of the severity of cirrhosis or the presence of acute-on-chronic liver failure. In this multicenter, non-inferiority, observational study we demonstrated that post-TIPS OHE does not increase the risk of mortality in patients undergoing TIPS, irrespective of the indication. This finding alleviates concerns regarding the weight of this complication after TIPS. Intensive research to improve patient selection and risk stratification remains crucial to enhance the quality of life of patients and caregivers and to avoid undermining the positive effects of TIPS on survival

Assessment of portal hypertension severity using machine learning models in patients with compensated cirrhosis

Background & Aims: In individuals with compensated advanced chronic liver disease (cACLD), the severity of portal hypertension (PH) determines the risk of decompensation. Invasive measurement of the hepatic venous pressure gradient (HVPG) is the diagnostic gold standard for PH. We evaluated the utility of machine learning models (MLMs) based on standard laboratory parameters to predict the severity of PH in individuals with cACLD. Methods: A detailed laboratory workup of individuals with cACLD recruited from the Vienna cohort (NCT03267615) was utilised to predict clinically significant portal hypertension (CSPH, i.e., HVPG ≥10 mmHg) and severe PH (i.e., HVPG ≥16 mmHg). The MLMs were then evaluated in individual external datasets and optimised in the merged cohort. Results: Among 1,232 participants with cACLD, the prevalence of CSPH/severe PH was similar in the Vienna (n = 163, 67.4%/35.0%) and validation (n = 1,069, 70.3%/34.7%) cohorts. The MLMs were based on 3 (3P: platelet count, bilirubin, international normalised ratio) or 5 (5P: +cholinesterase, +gamma-glutamyl transferase, +activated partial thromboplastin time replacing international normalised ratio) laboratory parameters. The MLMs performed robustly in the Vienna cohort. 5P-MLM had the best AUCs for CSPH (0.813) and severe PH (0.887) and compared favourably to liver stiffness measurement (AUC: 0.808). Their performance in external validation datasets was heterogeneous (AUCs: 0.589-0.887). Training on the merged cohort optimised model performance for CSPH (AUCs for 3P and 5P: 0.775 and 0.789, respectively) and severe PH (0.737 and 0.828, respectively). Conclusions: Internally trained MLMs reliably predicted PH severity in the Vienna cACLD cohort but exhibited heterogeneous results on external validation. The proposed 3P/5P online tool can reliably identify individuals with CSPH or severe PH, who are thus at risk of hepatic decompensation. Impact and implications: We used machine learning models based on widely available laboratory parameters to develop a non-invasive model to predict the severity of portal hypertension in individuals with compensated cirrhosis, who currently require invasive measurement of hepatic venous pressure gradient. We validated our findings in a large multicentre cohort of individuals with advanced chronic liver disease (cACLD) of any cause. Finally, we provide a readily available online calculator, based on 3 (platelet count, bilirubin, international normalised ratio) or 5 (platelet count, bilirubin, activated partial thromboplastin time, gamma-glutamyltransferase, choline-esterase) widely available laboratory parameters, that clinicians can use to predict the likelihood of their patients with cACLD having clinically significant or severe portal hypertension

Photoperiod Influences Growth and mll (Mixed-Lineage Leukaemia) Expression in Atlantic Cod

Photoperiod is associated to phenotypic plasticity of somatic growth in several teleost species. However, the molecular mechanisms underlying this phenomenon are currently unknown but it is likely that epigenetic regulation by methyltransferases is involved. The MLL (mixed-lineage leukaemia) family comprises histone methyltransferases that play a critical role in regulating gene expression during early development in mammals. So far, these genes have received scant attention in teleost fish. In the present study, the mean weight of Atlantic cod juveniles reared under continuous illumination was found to be 13% greater than those kept under natural photoperiod conditions for 120 days. We newly determined cDNA sequences of five mll (mll1, mll2, mll3a, mll4b and mll5) and two setd1 (setd1a and setd1ba) paralogues from Atlantic cod. Phylogenetic analysis revealed that the cod genes clustered within the appropriate mll clade and comparative mapping of mll paralogues showed that these genes lie within a region of conserved synteny among teleosts. All mll and setd1 genes were highly expressed in gonads and fast muscle of adult cod, albeit at different levels, and they were differentially regulated with photoperiod in muscle of juvenile fish. Following only one day of exposure to constant light, mll1, mll4b and setd1a were up to 57% lower in these fish compared to the natural photoperiod group. In addition, mRNA expression of myogenic regulatory factors (myog and myf-5) and pax7 in fast muscle was also affected by different photoperiod conditions. Notably, myog was significantly elevated in the continuous illumination group throughout the time course of the experiment. The absence of a day/night cycle is associated with a generalised decrease in mll expression concomitant with an increase in myog transcript levels in fast muscle of Atlantic cod, which may be involved in the observed epigenetic regulation of growth by photoperiod in this species

Association of the interferon-β gene with pericentromeric heterochromatin is dynamically regulated during virus infection through a YY1-dependent mechanism

Nuclear architecture as well as gene nuclear positioning can modulate gene expression. In this work, we have analyzed the nuclear position of the interferon-β (IFN-β) locus, responsible for the establishment of the innate antiviral response, with respect to pericentromeric heterochromatin (PCH) in correlation with virus-induced IFN-β gene expression. Experiments were carried out in two different cell types either non-infected (NI) or during the time course of three different viral infections. In NI cells, we showed a monoallelic IFN-β promoter association with PCH that strongly decreased after viral infection. Dissociation of the IFN-β locus away from these repressive regions preceded strong promoter transcriptional activation and was reversible within 12 h after infection. No dissociation was observed after infection with a virus that abnormally maintained the IFN-β gene in a repressed state. Dissociation induced after virus infection specifically targeted the IFN-β locus without affecting the general structure and nuclear distribution of PCH clusters. Using cell lines stably transfected with wild-type or mutated IFN-β promoters, we identified the proximal region of the IFN-β promoter containing YY1 DNA-binding sites as the region regulating IFN-β promoter association with PCH before as well as during virus infection

Acute and chronic ozone exposure temporarily affects seed germination in alpine plants

10This study was the first to investigate the direct effects of anomalous concentrations of ozone mediated by summer heat waves on seed germination in alpine plants. During germination, the seeds were exposed to three peaks of O3 concentration (125 ppb for 5 and 10 days; 185 ppb for 5 days), derived from measurements taken close to the species growing site. High O3 concentration delayed the first germination time, increased the mean germination time, and reduced the germination percentage during and immediately after the treatment, but, in most cases, effects were weak and had almost vanished three weeks after the treatments. In few cases, chronic exposure to O3 (125 for 10 days’ treatment) enhanced seed germination compared to the control, suggesting that ozone may induce antioxidant and DNA-repair mechanisms or dormancy-breaking effects in hydrated seeds. Although seed mortality increased during O3 treatments in four species, the effect of O3 on seed germination is mostly limited to the period of exposure, indicating that it is unlikely to produce permanent negative effects on seeds, during the germination phase. Our results show that the direct effect of O3 on seeds of alpine plants may have minor impacts on plant reproductive performance during seed germination.partially_openembargoed_20170518ABELI, THOMAS; Guasconi, D. B.; MONDONI, ANDREA; DONDI, DANIELE; BENTIVOGLIO, ANTONIO; BUTTAFAVA, ARMANDO; Cristofanelli, P.; Bonasoni, P.; ROSSI, GRAZIANO; Orsenigo, S.Abeli, Thomas; Guasconi, D. B.; Mondoni, Andrea; Dondi, Daniele; Bentivoglio, Antonio; Buttafava, Armando; Cristofanelli, P.; Bonasoni, P.; Rossi, Graziano; Orsenigo, S