Efficacy of transjugular intrahepatic portosystemic shunts in treating cirrhotic esophageal-gastric variceal bleeding

BACKGROUND Esophageal-gastric variceal bleeding(EGVB)represents a severe complication among patients with cirrhosis and often culminates in fatal outcomes.Interven-tional therapy,a rapidly developing treatment modality over the past few years,has found widespread application in clinical practice due to its minimally inva-sive characteristics.However,whether transjugular intrahepatic portosystemic shunt(TIPS)treatment has an impact on patient prognosis remains controversial.METHODS A retrospective study was conducted on ninety-two patients presenting with cirrhotic EGVB who were admitted to our hospital between September 2020 and September 2022.Based on the different modes of treatment,the patients were assigned to the study group(TIPS received,n=50)or the control group(per-cutaneous transhepatic varices embolization received,n=42).Comparative ana-lyses were performed between the two groups preoperatively and one month postoperatively for the following parameters:Varicosity status;hemodynamic parameters[portal vein flow velocity(PVV)and portal vein diameter(PVD);platelet count(PLT);red blood cell count;white blood cell count(WBC);and hepatic function[albumin(ALB),total bilirubin(TBIL),and aspartate transaminase(AST)].The Generic Quality of Life Inventory-74 was utilized to assess quality of life in the two groups,and the 1-year postoperative rebleeding and survival rates were compared.RESULTS Following surgical intervention,there was an improvement in the incidence of varicosity compared to the preoperative status in both cohorts.Notably,the study group exhibited more pronounced enhancements than did the control group(P<0.05).PVV increased,and PVD decreased compared to the preoperative values,with the study cohort achieving better outcomes(P<0.05).PLT and WBC counts were elevated postoperatively in the two groups,with the study cohort displaying higher PLT and WBC counts(P<0.05).No differences were detected between the two groups in terms of serum ALB,TBIL,or AST levels either preoperatively or postoperatively(P<0.05).Postoperative scores across all dimensions of life quality surpassed preoperative scores,with the study cohort achieving higher scores(P<0.05).At 22.00%,the one-year postoperative rebleeding rate in the study cohort was significantly lower than that in the control group(42.86%;P<0.05);conversely,no marked difference was obser-ved in the 1-year postoperative survival rate between the two cohorts(P>0.05).CONCLUSION TIPS,which has demonstrated robust efficacy in managing cirrhotic EGVB,remarkably alleviates varicosity and improves hemodynamics in patients.This intervention not only results in a safer profile but also contributes significantly to a more favorable prognosis.

Transcatheter Closure of Postoperative Residual Atrial or Ventricular Septal Shunts in Patients with Congenital Heart Disease

Background:Transcatheter closure(TCC)has emerged as the preferred treatment for selected congenital heart disease(CHD).While TCC offers benefits for patients with postoperative residual shunts,understanding its mid-and long-term efficacy and safety remains crucial.Objective:This study aims to assess the mid-and long-term safety and efficacy of TCC for patients with residual atrial or ventricular septal shunts following CHD correction.Methods:In this consecutive retrospective study,we enrolled 35 patients with residual shunt who underwent TCC or surgical repair of CHD between June 2011 to October 2022.TCC candidacy was determined based on established criteria.Echocardiography and electrocardiogram were conducted during the perioperative period and continued as part of long-term follow-up.Results:Among the patients,5(14.3%)exhibited interatrial shunt-ing,while 30(85.7%)had interventricular shunting.TCC was successfully implemented in 33 of 35 patients,with exceptions in two cases of post-ventricular septal defect repair due to anatomical challenges involving the shape and aortic angulation.This resulted in a TCC success rate of 94.3%.Trace residual shunt was detected in two interventricular shunting cases and a mild residual shunt in one interventricular shunting case;all resolved by the three-month follow-up after TCC.Minor complications included one hematoma at the puncture site and one transient junctional rhythm during the perioperative period.During a median follow-up of 73 months,there were no instances of residual shunt,device embolization,occluder displacement,valve insufficiency,malignant arrhythmia,infective endocarditis,death,or other serious complications.Conclusion:TCC is an effective and safe therapy for patients with residual atrial or ventricular septal shunts following CHD correction.Thesefindings support the consideration of TCC as the preferred treatment option for appropriate patient populations.

Research status and hotspots in transjugular intrahepatic portosystemic shunts based on CiteSpace bibliometric analysis

BACKGROUND The transjugular intrahepatic portosystemic shunt(TIPS)is an important technique for treating complications related to portal hypertension in patients with cirrhosis,and the number of publications in the TIPS field continues to rise.AIM To facilitate an understanding of the research status and hotspots in the field of TIPS using CiteSpace bibliometric analysis.METHODS CiteSpace is a software that depicts the strength of relationships through graphics and connections with diverse functionalities and can be used to analyze the status and hotspots of areas of research.Articles on TIPS in the Web of Science Core Collection were retrieved,and CiteSpace software was used to visualize and analyze the number of publications,journals,countries,institutions,authors,keywords,and citations.RESULTS A total of 985 relevant documents were included in the analysis.From January 2013 to December 2022,the number of publications increased annually.The journal,institution,and author with the greatest number of publications in the field of TIPS are the Journal of Vascular and Interventional Radiology,the University of Bonn,and Jonel Trebicka,respectively.The main keywords used in this field are“transjugular intrahepatic portosystemic shunt”,“portal hypertension”,“cirrhosis”,“management”,“stent”,“hepatic encephalopathy”,“refractory ascite”,“survival”,“risk”,and“variceal bleeding”.The greatest obstacle to TIPS placement is currently the occurrence of hepatic encephalopathy.The research hotspots are the mechanism,risk factors,management,and control of hepatic encephalopathy.CONCLUSION This bibliometric analysis reported the research status and hotspots of TIPS.Research on postoperative hepatic encephalopathy is the research hotspot in this field.

Development of a new Cox model for predicting long-term survival in hepatitis cirrhosis patients underwent transjugular intrahepatic portosystemic shunts

BACKGROUND Transjugular intrahepatic portosystemic shunt(TIPS)placement is a procedure that can effectively treat complications of portal hypertension,such as variceal bleeding and refractory ascites.However,there have been no specific studies on predicting long-term survival after TIPS placement.AIM To establish a model to predict long-term survival in patients with hepatitis cirrhosis after TIPS.METHODS A retrospective analysis was conducted on a cohort of 224 patients who un-derwent TIPS implantation.Through univariate and multivariate Cox regression analyses,various factors were examined for their ability to predict survival at 6 years after TIPS.Consequently,a composite score was formulated,encompassing the indication,shunt reasonability,portal venous pressure gradient(PPG)after TIPS,percentage decrease in portal venous pressure(PVP),indocyanine green retention rate at 15 min(ICGR15)and total bilirubin(Tbil)level.Furthermore,the performance of the newly developed Cox(NDC)model was evaluated in an in-ternal validation cohort and compared with that of a series of existing models.RESULTS The indication(variceal bleeding or ascites),shunt reasonability(reasonable or unreasonable),ICGR15,post-operative PPG,percentage of PVP decrease and Tbil were found to be independent factors affecting long-term survival after TIPS placement.The NDC model incorporated these parameters and successfully identified patients at high risk,exhibiting a notably elevated mortality rate following the TIPS procedure,as observed in both the training and validation cohorts.Additionally,in terms of predicting the long-term survival rate,the performance of the NDC model was significantly better than that of the other four models[Child-Pugh,model for end-stage liver disease(MELD),MELD-sodium and the Freiburg index of post-TIPS survival].CONCLUSION The NDC model can accurately predict long-term survival after the TIPS procedure in patients with hepatitis cirrhosis,help identify high-risk patients and guide follow-up management after TIPS implantation.

Transjugular intrahepatic portosystemic shunts and portal hypertension-related complications

Portal hypertension(PH)plays an important role in the natural history of cirrhosis,and is associated with several clinical consequences.The introduction of transjugular intrahepatic portosystemic shunts(TIPS)in the 1980s has been regarded as a major technical advance in the management of the PH-related complications.At present,polytetrafluoroethylene-covered stents are the preferred option over traditional bare metal stents.TIPS is currently indicated as a salvage therapy in patients with bleeding esophageal varices who fail standard treatment.Recently,applying TIPS early(within 72 h after admission)has been shown to be an effective and life-saving treatment in those with high-risk variceal bleeding.In addition,TIPS is recommended as the second-line treatment for secondary prophylaxis.For bleeding gastric varices,applying TIPS was able to achieve hemostasis in more than 90%of patients.More trials are needed to clarify the efficacy of TIPS compared with other treatment modalities,including cyanoacrylate injection and balloon retrograde transvenous obliteration of gastric varices.TIPS should also be considered in bleeding ectopic varices and refractory portal hypertensive gastropathy.In patients with refractory ascites,there is growing evidence that TIPS not only results in better control of ascites,but also improves long-term survivalin appropriately selected candidates.In addition,TIPS is a promising treatment for refractory hepatic hydrothorax.However,the role of TIPS in the treatment of hepatorenal and hepatopulmonary syndrome is not well defined.The advantage of TIPS is offset by a risk of developing hepatic encephalopathy,the most relevant postprocedural complication.Emerging data are addressing the determination the optimal time and patient selection for TIPS placement aiming at improving long-term treatment outcome.This review is aimed at summarizing the published data regarding the application of TIPS in the management of complications related to PH.

Spontaneous porto-systemic shunts in liver cirrhosis:Clinical and therapeutical aspects

Spontaneous porto-systemic shunts(SPSS)are frequent in liver cirrhosis and their prevalence increases as liver function deteriorates,probably as a consequence of worsening portal hypertension,but without achieving an effective protection against cirrhosis'complications.Several types of SPSS have been described in the literature,each one associated with different clinical manifestations.In particular,recurrent or persistent hepatic encephalopathy is more frequent in patients with splenorenal shunt,while the presence of gastric varices and consequently the incidence of variceal bleeding is more common in gastrorenal shunt.In the advanced stage,the presence of large SPSS can lead to the so called“portosystemic shunt syndrome”,characterized by a progressive deterioration of hepatic function,hepatic encephalopathy and,sometimes,portal vein thrombosis.The detection of SPSS in patients with liver cirrhosis is recommended in order to prevent or treat recurrent hepatic encephalopathy or variceal bleeding.

Passive expansion of sub-maximally dilated transjugular intrahepatic portosystemic shunts and assessment of clinical outcomes

AIM To assess for passive expansion of sub-maximally dilated transjugular intrahepatic portosystemic shunts(TIPS) and compare outcomes with maximally dilated TIPS.METHODS Polytetrafluoroethylene covered TIPS(Viatorr) from July 2002 to December 2013 were retrospectively reviewed at two hospitals in a single institution. Two hundred and thirty patients had TIPS maximally dilated to 10 mm(m TIPS), while 43 patients who were at increased risk for hepatic encephalopathy(HE), based on clinical evaluation or low pre-TIPS portosystemic gradient(PSG), had 10 mm TIPS sub-maximally dilated to 8 mm(sm TIPS). Group characteristics(age, gender, Model for End-Stage Liver Disease score, post-TIPS PSG and clinical outcomes were compared between groups, including clinical success(ascites or varices), primary patency,primary assisted patency, and severe post-TIPS HE. A subset of fourteen patients with sm TIPS underwent follow-up computed tomography imaging after TIPS creation, and were grouped based on time of imaging(< 6 mo and > 6 mo). Change in diameter and crosssectional area were measured with 3D imaging software to evaluate for passive expansion.RESULTS Patient characteristics were similar between the sm TIPS and m TIPS groups, except for pre-TIPS portosystemic gradient, which was lower in the sm TIPS group(19.4 mm Hg ± 6.8 vs 22.4 mm Hg ± 7.1, P = 0.01). Primary patency and primary assisted patency between sm TIPS and m TIPS was not significantly different(P = 0.64 and 0.55, respectively). Four of the 55 patients(7%) with sm TIPS required TIPS reduction for severe refractory HE, while this occurred in 6 of the 218 patients(3%) with m TIPS(P = 0.12). For the 14 patients with follow-up computed tomography(CT) imaging, the median imaging follow-up was 373 d. There was an increase in median TIPS diameter, median percent diameter change, median area, and median percent area change in patients with CT follow-up greater than 6 mo after TIPS placement compared to follow-up within 6 mo(8.45 mm, 5.58%, 56.04 mm^2, and 11.48%, respectively, P = 0.01).CONCLUSION Passive expansion of sm TIPS does occur but clinical outcomes of sm TIPS and m TIPS were similar. Sub-maximal dilation can prevent complications related to overshunting in select patients.

Staging of portal hypertension and portosystemic shunts using dynamic nuclear medicine investigations

AIM： To explore portal hypertension and portosystemic shunts and to stage chronic liver disease （CLD） based on the pathophysiology of portal hemodynamics. METHODS： Per-rectal portal scintigraphy （PRPS） was performed on 312 patients with CLD and liver angioscintigraphy （LAS） on 231 of them. The control group included 25 healthy subjects. We developed a new model of PRPS interpretation by introducing two new parameters, the liver transit time （LTT） and the circu-lation time between right heart and liver （RHLT）. LTT for each lobe was used to evaluate the early portal hypertension. RHLT is useful in cirrhosis to detect liver areas missing portal inflow. We calculated the classical per-rectal portal shunt index （PRSI） at PRPS and the hepatic perfusion index （HPI） at LAS. RESULTS： The normal LTT value was 24 ± 1 s. Abnormal LTT had PPV = 100% for CLD. Twenty-seven noncirrhotic patients had LTT increased up to 35 s （median 27 s）. RHLT （42 ± 1 s） was not related to liver disease. Cirrhosis could be excluded in all patients with PRSI 〈 5% （P 〈 0.01）. PRSI 〉 30% had PPV = 100% for cirrhosis. Based on PRPS and LAS we propose the classification of CLD in 5 hemodynamic stages. Stage 0 is normal （LTT = 24 s, PRSI 〈 5%）. In stage 1, LTT is increased, while PRSI remains normal. In stage 2, LTT is decreased between 16 s and 23 s, whereas PRSI is increased between 5% and 10%. In stage 3, PRSI is increased to 10%-30%, and LTT becomes undetectable by PRPS due to the portosystemic shunts. Stage 4 includes the patients with PRSI 〉 30%. RHLT and HPI were used to subtype stage 4. In our study stage 0 had NPV = 100% for CLD, stage 1 had PPV = 100% for non-cirrhotic CLD, stages 2 and 3 represented the transition from chronic hepatitis to cirrhosis, stage 4 had PPV = 100% for cirrhosis. CONCLUSION： LTT allows the detection of early portal hypertension and of opening of transhepatic shunts. PRSI is useful in CLD with extrahepatic portosystemic shunts. Our hemodynamic model stages the evolution of portal hypertension and portosystemic shunts. It may be of use in the selection of patients for interferon therapy.

Unsatisfactory outcomes of prolonged ischemic priapism without early surgical^shunts： our clinical experience and a review of the literature

Ischemic priapism is a rare occurrence which can cause severe erectile dysfunction （ED） without timely treatment. This retrospective study reports our experience in treating prolonged ischemic priapism and proposes our further considerations. In this paper, a total of nine patients with prolonged ischemic priapism underwent one to three types of surgical shunts, including nine Winter shunts, two AI-Ghorab shunts and one Grayhack shunt. During the follow-up visit （after a mean of 21.11 months）, all patients＇ postoperative characters were recorded, except one patient lost for death. Six postoperative patients accepted a 25-mg oral administration of sildenafil citrate. The erectile function of the patients was evaluated by their postoperative 5-item version of International Index of Erectile Function Questionnaire （IIEF-5）, which were later compared with their premorbid scores. All patients had complete resolutions, and none relapsed. The resolution rate was 100%. Seven patients were resolved with Winter shunts, one with an AI-Ghorab shunt and one with a Grayhack shunt. The mean hospital stay was 8.22 days. There was only one urethral fistula, and the incidence of postoperative ED was 66.67%. Four patients with more than a 72-h duration of priapism had no response to the long-term phosphodiesterase type 5 （PDE-5） inhibitor treatment. These results suggest that surgical shunts are an efficient approach to make the penis flaccid after prolonged priapism. However, the severe ED caused by prolonged duration is irreversible, and long-term PDE-5 inhibitor treatments are ineffective. Thus, we recommend early penile prosthesis surgeries for these patients.

Portal vein thrombosis and arterioportal shunts:Effects on tumor response after chemoembolization of hepatocellular carcinoma

AIM: To evaluate the effect of portal vein thrombosis and arterioportal shunts on local tumor response in advanced cases of unresectable hepatocellular carcinoma treated by transarterial chemoembolization. METHODS: A retrospective study included 39 patients (mean age: 66.4 years, range: 45-79 years, SD: 7) with unresectable hepatocellular carcinoma (HCC) who were treated with repetitive transarterial chemoembolization (TACE) in the period between March 2006 and October 2009. The effect of portal vein thrombosis (PVT) (in 19 out of 39 patients), the presence of arterioportal shunt (APS) (in 7 out of 39), the underlying liver pathology,Child-Pugh score, initial tumor volume, number of tumors and tumor margin definition on imaging were correlated with the local tumor response after TACE. The initial and end therapy local tumor responses were evaluated according to the response evaluation criteria in solid tumors (RECIST) and magnetic resonance imaging volumetric measurements. RESULTS: The treatment protocols were well tolerated by all patients with no major complications. Local tumor response for all patients according to RECIST criteria were partial response in one patient (2.6%), stable disease in 34 patients (87.1%), and progressive disease in 4 patients (10.2%). The MR volumetric measurements showed that the PVT, APS, underlying liver pathology and tumor margin definition were statistically significant prognostic factors for the local tumor response (P = 0.018, P = 0.008, P = 0.034 and P = 0.001, respectively). The overall 6-, 12- and 18-mo survival rates from the initial TACE were 79.5%, 37.5% and 21%, respectively. CONCLUSION: TACE may be exploited safely for palliative tumor control in patients with advanced unresectable HCC; however, tumor response is significantly affected by the presence or absence of PVT and APS.

Is percutaneous endoscopic gastrostomy tube placement safe in patients with ventriculoperitoneal shunts?

AIM:To investigate whether percutaneous endoscopic gastrostomy (PEG) tube placement is safe in patients with ventriculoperitoneal (VP) shunts.METHODS: This was a retrospective study of all patients undergoing PEG insertion at our institution between June 1999 and June 2006. Post-PEG complications were compared between two groups according to the presence or absence of VP shunts. VP shunt infection rates, the interval between PEG placement and VP shunt catheter insertion, and long-term follow-up were also investigated.RESULTS: Fifty-five patients qualified for the study. Seven patients (12.7%) had pre-existing VP shunts. All patients received prophylactic antibiotics. The complication rate did not differ between VP shunt patients undergoing PEG (PEG/VP group) and non-VP shunt patients undergoing PEG (control group) [1 (14.3%) vs 6 (12.5%), P=1.000]. All patients in the PEG/VP group had undergone VP shunt insertion prior to PEG placement. The mean interval between VP shunt insertion and PEG placement was 308.7 d (range, 65-831 d). The mean follow-up duration in the PEG/VP group was 6.4 mo (range, 1-15 mo). There were no VP shunt infections, although one patient in the PEG/VP group developed a minor peristomal infection during follow-up.CONCLUSION: Complications following PEG placement in patients with VP shunts were infrequent in this study.

Side effects of budesonide in liver cirrhosis due to chronic autoimmune hepatitis: Influence of hepatic metabolism versus portosystemic shunts on a patient complicated with HCC

AIM:To investigate the systemic availability of budesonide in a patient with Child A cirrhosis due to autoimmune hepatitis (AIH) and primary hepatocellular carcinoma,who developed serious side effects. METHODS:Serum levels of budesonide,6β-OH-budesonide and 16α-OH-prednisolon were measured by HPLC/MS/MS; portosystemic shunt-index (SI) was determined by 99mTc nuclear imaging.All values were compared with a matched control patient without side effects. RESULTS:Serum levels of budesonide were 13-fold increased in the index patient.The ratio between serum levels of the metabolites 6β-OH-budesonide and 16α-OH- prednisolone,respectively,and serum levels of budesonide was diminished (1.0 vs.4.0 for 6β-OH-budesonide,4.2 vs. 10.7 for 16α-OH-prednisolone).Both patients had portosystemic SI (5.7 % and 3.1%) within the range of healthy subjects.CONCLUSION:Serum levels of budesonide Vary uP to 13-fold in AIH Patients with Child A eirrhosis in the absenee ofrelevant Portosystemic shunting.Redueed hePatiemetabolism,as indicated by redueed metabolite-to-drugratio,rather than Portosystemie shunting may explainsystemic side effects of this drug in cirrhosis

Lumboperitoneal shunts for the treatment of post-traumatic hydrocephalus

Objective: To assess the effectiveness and safety of lumboperitoneal shunt for treatment of post-traumatic hydrocephalus(PTH).Methods: A retrospective analysis of medical records of patients with lumboperitoneal shunts admitted in Shanghai Tenth People's Hospital from January 2014 to March 2017 was done.Experience with lumboperitoneal shunt placement for PTH was reviewed.The diagnosis of PTH was based on ventricular enlargement with the Evans' index(EI>0.3) before shunt implantation.Patients were evaluated for improvements in Glasgow Coma Scale(GCS), Glasgow Outcome Scale(GOS), and EI after shunt placement.Results: Totally, the study included 34 PTH patients with the average age of 49.32 years(range: 9–67 years).The average follow-up period was(3.9±3.5) months.Before lumboperitoneal shunt, the GOS score was(4±1), the GCS score was(8.53±3.38), and the EI score was(0.40±0.08).After shunt implantation, the GOS score was(3±1), the GCS score was(10.29±3.15), and the EI score was(0.34±0.13), respectively(P<0.05).Before lumboperitoneal shunt, 24(70.58%) patients had a GOS score of 4(vegetative state), and 10(29.42%) patients had a GOS score of 3(severe disabled).After lumboperitoneal shunt, 18(52.94%) patients had improvement in GOS(11 patients improve from GOS 4 to GOS 3, 5 patients from GOS 3 to GOS 2 and 2 patients from GOS 3 to GOS 1), 22(64.71%) patients achieved improvement in their GCS(14 patients GCS improvements ≥2 and 8 patients GCS improvement=1), 21(61.76%) patients had EI improvement(18 patients with EI<0.3).There was no complication in this study.Conclusion: Lumboperitoneal shunt placement is safe and effective for PTH, and serious complications are not observed.

Novel Technique of Multislice CT Angiography for Diagnosis of Portosystemic Shunts in Sedated Dogs

Diagnosing portosystemic shunts (PSS) can be challenging in veterinary patients. Multiple imaging techniques have been described to diagnose PSS. The aim of the study was to investigate whether a novel multi-slice computed tomography (CT) angiographic protocol could be used for diagnosis of PSS in dogs utilizing only patient sedation and without the need of test injection. Independent, blinded reviewers evaluated CT studies in a randomized order for study quality, shunt presence, number, and location of shunt origin and termination. Twenty two confirmed dogs were included in the study including 16 dogs with single extrahepatic congenital PSS, one dog with single intrahepatic congenital PSS, and two dogs with multiple acquired PSS. Three of the dogs (3/22) were surgically and histologically confirmed free of shunts. Final diagnosis was confirmed by surgery or necropsy. The new CT angiography protocol was shown to be diagnostic in dogs with PSS with no need for general anesthesia, test injections, delay times or timing determinations. Specificity and sensitivity were good (100%). The quality of the studies was considered good in the majority of cases (20/22). The amount of motion artifact in the CT scans was minimal, and had no effect on the diagnostic quality. The CT protocol was found to be a useful, fast, and accurate tool for diagnosing portosystemic shunts with a 16-slice system.

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.

A Linearized Branch Flow Model Considering Line Shunts for Radial Distribution Systems and Its Application in Volt/VAr Control

When urban distribution systems are gradually modernized,the overhead lines are replaced by underground cables,whose shunt admittances can not be ignored.Traditional power flow(PF)model withπequivalent circuit shows non-convexity and long computing time,and most recently proposed linear PF models assume zero shunt elements.All of them are not suitable for fast calculation and optimization problems of modern distribution systems with non-negligible line shunts.Therefore,this paper proposes a linearized branch flow model considering line shunt(LBFS).The strength of LBFS lies in maintaining the linear structure and the convex nature after appropriately modeling theπequivalent circuit for network equipment like transformers.Simulation results show that the calculation accuracy in nodal voltage and branch current magnitudes is improved by considering shunt admittances.We show the application scope of LBFS by controlling the network voltages through a two-stage stochastic Volt/VAr control(VVC)problem with the uncertain active power output from renewable energy sources(RESs).Since LBFS results in a linear VVC program,the global solution is guaranteed.Case study exhibits that VVC framework can optimally dispatch the discrete control devices,viz.substation transformers and shunt capacitors,and also optimize the decision rules for real-time reactive power control of RES.Moreover,the computing efficiency is significantly improved compared with that of traditional VVC methods.

Can a laparoscopic surgery be an alternative to transjugular intrahepatic portosystemic shunts (TIPS) for the treatment of portal hypertensive bleeding?

We read with great confusion the guidance written by Garcia-Tsao et al.(1).In the practice guidance developed by the American Association for the Study of Liver Diseases(AASLD),there is no trail of surgical operation for the treatment of portal hypertensive bleeding in cirrhosis at all.However,it is well known that surgical shunts played an important role in this setting before the emergence of transjugular intrahepatic portosystemic shunts(TIPS),existing studies have shown that surgical shunt still has better long-term patency and survival than TIPS(2),and surgical portoazygous devascularization is still considered as the most direct and effective way of hemostasis in some countries(3).

Transjugular intrahepatic portosystemic shunt for esophagogastric variceal bleeding in patients with hepatocellular carcinoma and portal vein tumor thrombus

BACKGROUND Whether hepatocellular carcinoma(HCC)with portal vein tumor thrombus(PVTT)and acute esophagogastric variceal bleeding(EGVB)can improve the success rate of endoscopic hemostasis and overall survival(OS)from transjugular intrahepatic portosystemic shunt(TIPS)remains controversial.AIM To compare the clinical outcomes between TIPS and standard treatment for such HCC patients.METHODS This monocenter,retrospective cohort study included patients diagnosed as HCC with PVTT and upper gastrointestinal bleeding.Patients were grouped by the treatment(TIPS or standard conservative treatment).The success rate of en-doscopic hemostasis,OS,rebleeding rates,and main causes of death were ana-lyzed.RESULTS Between July 2015 and September 2021,a total of 77 patients(29 with TIPS and 48 with standard treatment)were included.The success rate of endoscopic hemostasis was 96.6%in the TIPS group and 95.8%in the standard treatment group.All the 29 patients in TIPS group successful underwent TIPS procedure and had a better OS compared with standard treatment within the first 160 days after treatment(68 days vs 43 days,P=0.022),but shorter OS after 160 days(298 days vs 472 days, P = 0.022). Cheng’s Classification of PVTT, total bilirubin and Child-Pugh class wereindependently negative associated with OS (all P < 0.05). The main causes of death were liver failure or hepaticencephalopathy (75.9%) in the TIPS group and rebleeding (68.8%) in the standard treatment.CONCLUSIONTIPS could reduce the risk of early death due to rebleeding and prolong short-term survival in HCC patients withPVTT and acute EGVB, which deserves further investigation.

Portal vein arterialization in 25 liver transplant recipients:A Latin American single-center experience

BACKGROUND Portal vein arterialization(PVA)has been used in liver transplantation(LT)to maximize oxygen delivery when arterial circulation is compromised or has been used as an alternative reperfusion technique for complex portal vein thrombosis(PVT).The effect of PVA on portal perfusion and primary graft dysfunction(PGD)has not been assessed.All patients receiving PVA and LT at the Fundacion Santa Fe de Bogota between 2011 and 2022 were analyzed.To account for the time-sensitive effects of graft perfusion,patients were classified into two groups:prereperfusion(pre-PVA),if the arterioportal anastomosis was performed before graft revascularization,and postreperfusion(post-PVA),if PVA was performed afterward.The pre-PVA rationale contemplated poor portal hemodynamics,severe vascular steal,or PVT.Post-PVA was considered if graft hypoperfusion became evident.Conservative interventions were attempted before PVA.