Inflow and outflow permeability tests in a very soft clay under low stresses

In situ inflow and outflow permeability tests with the BAT probe at SarapuíII soft clay test site are presented.A description of the BAT permeability test is provided,discussing its advantages and shortcomings,especially in the case of very soft clays under low stresses.Pore pressures were monitored during probe installation and were found to be slightly lower than piezocone u2 pore pressures,consistent with the position of the filter.The role of filter tip saturation was investigated after the usual saturation procedure provided an unsatisfactory pore pressure response during probe installation.Results show that the vacuum saturation procedure provides adequate response during installation and increases the reliability of the coefficient of permeability determination in early measurements.Both inflow and outflow tests yielded similar results,indicating that careful execution of the test can lead to good test repeatability regardless of the loading condition.Various sequences of alternated inflow and outflow tests have yielded similar results,indicating that soil reconsolidation and filter clogging were negligible in the tests performed.Data are presented concerning the relationship between index parameters and the in situ coefficient of permeability for SarapuíII clay,which plot outside the range of existing databases.

Spectroscopic Observations of Ten Galactic Wolf-Rayet Stars at Bosscha Observatory:Determination of Stellar Parameters and Mass-loss Rates

We present optical spectra of 10 Galactic Wolf-Rayet(WR)stars that consist of five WN and five WC stars.The optical observation was conducted using a low-resolution spectrograph NEO-R1000(λ/Δλ~1000)at GAO-ITB RTS(27.94 cm,F/10.0),Bosscha Observatory,Lembang.We implemented stellar atmosphere Postdam Wolf-Rayet(PoWR)grid modeling to derive stellar parameters.The normalized optical spectrum can be used to find the best model from the available PoWR grid,then we could derive stellar temperature and transformation radius.To derive luminosity,stellar radius and color excess,we conducted a Spectral Energy Distribution(SED)analysis with additional data on the near-ultraviolet spectrum from the International Ultraviolet Explorer(IUE)database,and UBV and 2MASS JHK broadband filter data.Additional analysis to derive asymptotic terminal wind velocity was conducted from the P-Cygni profile analysis of the high-resolution IUE ultraviolet spectrum.With previously derived parameters,we could determine the mass loss rate of the WR stars.Furthermore,we compared our results with previous work that used PoWR code and the differences are not more than 20%.We conclude that the PoWR spectral grid is sufficient to derive WR stellar parameters quickly and could provide more accurate initial parameter input to the PoWR program code.

Clinical profile and outcomes of hepatocellular carcinoma in primary Budd-Chiari syndrome

BACKGROUND There is scant literature on hepatocellular carcinoma(HCC)in patients with Budd-Chiari syndrome(BCS).AIM To assess the magnitude,clinical characteristics,feasibility,and outcomes of treatment in BCS-HCC.METHODS A total of 904 BCS patients from New Delhi,India and 1140 from Mumbai,India were included.The prevalence and incidence of HCC were determined,and among patients with BCS-HCC,the viability and outcomes of interventional therapy were evaluated.RESULTS In the New Delhi cohort of 35 BCS-HCC patients,18 had HCC at index presentation(prevalence 1.99%),and 17 developed HCC over a follow-up of 4601 person-years,[incidence 0.36(0.22-0.57)per 100 person-years].BCS-HCC patients were older when compared to patients with BCS alone(P=0.001)and had a higher proportion of inferior vena cava block,cirrhosis,and long-segment vascular obstruction.The median alpha-fetoprotein level was higher in patients with BCS-HCC at first presentation than those who developed HCC at follow-up(13029 ng/mL vs 500 ng/mL,P=0.01).Of the 35 BCS-HCC,26(74.3%)underwent radiological interventions for BCS,and 22(62.8%)patients underwent treatment for HCC[transarterial chemoembolization in 18(81.8%),oral tyrosine kinase inhibitor in 3(13.6%),and transarterial radioembolization in 1(4.5%)].The median survival among patients who underwent interventions for HCC compared with those who did not was 3.5 years vs 3.1 mo(P=0.0001).In contrast to the New Delhi cohort,the Mumbai cohort of BCS-HCC patients were predominantly males,presented with a more advanced HCC[Barcelona Clinic Liver Cancer C and D],and 2 patients underwent liver transplantation.CONCLUSION HCC is not uncommon in patients with BCS.Radiological interventions and liver transplantation are feasible in select primary BCS-HCC patients and may improve outcomes.

Novel procedure for hepatic venous outflow block after liver resection:A case report

BACKGROUND Postoperative complications like remnant hepatic vein(HV)outflow block and liver torsion can occur after right hepatectomy.Hepatic falciform ligament fixation is typically used to prevent liver torsion.We report a novel procedure to manage outflow block.CASE SUMMARY An 80-year-old man developed HV outflow block after remnant right hepatectomy,despite liver fixation and intraoperative HV flow check.He had a history of cholangiocellular carcinoma and had undergone posterior segmentectomy and choledojejunostomy.The falciform ligament fixation was inadequate to maintain liver position.Emergency surgery was performed,using an omental flap and mobilized right side colon with ileocecal region to prevent liver dislocation due to intraabdominal adhesion.His postoperative course was uneventful.CONCLUSION This is the first report providing a novel surgical procedure when the falciform ligament is insufficient for remnant liver fixation.

ASYMPTOTIC STABILITY OF SHOCK WAVES FOR THE OUTFLOW PROBLEM OF A HEAT-CONDUCTIVE IDEAL GAS WITHOUT VISCOSITY

This paper is concerned with an ideal polytropic model of non-viscous and heatconductive gas in a one-dimensional half space. We focus our attention on the outflow problem when the flow velocity on the boundary is negative and we prove the stability of the viscous shock wave and its superposition with the boundary layer under some smallness conditions.Our waves occur in the subsonic area. The intrinsic properties of our system are more challenging in mathematical analysis, however, in the subsonic area, the lack of a boundary condition on the density provides us with a special manner for defining the shift for the viscous shock wave, and helps us to construct the asymptotic profiles successfully. New weighted energy estimates are introduced and the perturbations on the boundary are handled by some subtle estimates.

Large-scale inverted-V channels of upflowing oxygen ions pumped by Alfvén waves

Large-scale inverted-V channels of upflowing oxygen ions are frequently identified in data collected by Cluster,at all local times,near the open-closed field line boundary over Earth’s high-latitude ionosphere-occur with downward propagating MHD Alfvén waves which have cascaded into kinetic regimes of plasma.The transverse acceleration of the oxygen ions in the center of these structures is interpreted as the integrated energization by these waves along the channels.Also observed within the channels are upward parallel electric fields,a key characteristic of kinetic Alfvén waves,which may contribute not only to lifting the ions but also to precipitating aurora electrons that might initiate ion upflow in the ionosphere below.Statistics on five-year observations of Cluster show that the channels typically form during geomagnetic perturbations,particularly when solar-wind dynamic pressure is high or highly fluctuated.Near the open-closed field line boundary,the stronger the wave power,the higher the upward oxygen flux and the higher the beam energy,indicating that these waves provide a simple but efficient way to drive oxygen upflows.

“I Dread the Heart Surgery but it Keeps My Child Alive”—Experiences of Parents of Children with Right Ventricular Outflow Tract Anomalies during the Assessment for Cardiac Reoperation

Background:Parents of children with complex right ventricular outflow tract(RVOT)anomalies are confronted with their child’s need for heart surgery early in life and repeated reoperations later on.Preoperative assessment needs to be performed whenever an indication for reoperation is suspected.The aim was to illuminate the experiences of parents of children diagnosed with RVOT anomalies,in particular,how they experience their child’s heart disease and everyday life during the assessment and after the decision on whether to perform a reoperation.Method:Individual interviews(n=27)were conducted with nine parents on three occasions between 2014 and 2016 and analyzed using reflexive thematic analysis.Results:The analysis resulted in the following five main coexisting themes:The heart surgery keeps my child alive illuminates parents’experiences during and after the assessment and emphasizes that heart surgery,although dreaded,is central for their child’s survival;Everyday struggles illuminates the different struggles parents had to face to ensure that their child would be in the best possible condition;the remaining three themes,Unconditional love,Trust in life,and Togetherness,illuminate the ways in which the parents gained inner strength and confidence in their everyday lives.Conclusion:Although the parents were grateful for the assessment and had learned to navigate among the fears it aroused,they experienced several distressing situations during the assessment process that should be addressed.By inviting both the parents and their child to participate in the child’s care,individualized support can take into account the needs of both parents and child.

超声评估左室流出道梗阻在肥厚型心肌病的临床意义

目的确定左室流出道梗阻(left ventricular outflow tract obstruction,LVOTO)在肥厚型心肌病(hypertrophic cardiomyopathy,HCM)的临床意义。方法用超声检查了52例HCM患者的压力阶差,以30 mmHg为界限值分为有梗阻组和无梗阻组,在平均随访(5.9±5.7)年后,用生存分析比较了两组患者的死亡率和发病率并确定了压力阶差与临床终末事件的关系。结果与无梗阻的患者相比,有梗阻组的患者猝死的风险是4.6倍(相对危险度4.6;P=0.047),发展为心力衰竭和中风的风险是3.2倍(相对危险度3.2;P=0.049)。校正年龄后的多变量Cox比例风险回归模型显示LVOTO是进入模型的唯一危险因素(猝死,相对危险度4.1,P=0.084;发展为心力衰竭和中风,相对危险度5.2,P=0.040)。结论 LVOTO是HCM患者猝死及发展为心力衰竭与中风的一个唯一的、独立的、较强的危险因素。压力阶差≥30 mmHg在HCM临床治疗决策中有重要意义。

LAMOST光谱J152238.11+333136.1 P-Cygni轮廓分析

LAMOST一期巡天成功获取河外星系光谱超过150 000条,大样本光谱数据为探索奇异、稀有的天体从而完善现有的天体演化理论提供了必要的数据条件;而先进的信息技术为从海量的数据中挖掘这些珍稀样本提供了有效途径。针对采用基于DoPS的数据挖掘方法,从LAMOST DR5星系光谱数据获得的离群数据挖掘结果中,呈现出疑似P-Cygni轮廓特征的光谱J152238.11+333136.1进行了深入讨论。首先针对该光谱的基本信息、疑似P-Cygni轮廓特征以及相应的离群数据挖掘方法进行了简要表述,光谱在Hβ和[OⅢ]λ4860处呈现P-Cygni轮廓,在NeⅢλ3869和HeⅠλ5874处呈现反P-Cygni轮廓;其次,对该特征的真实性及其生成机制从以下4个角度展开讨论。(1)交叉同源观测。Sloan巡天2004年(相差11年)的同源观测,其光谱上并未呈现对应的特征,据推测可能是正在进行的演化活动或者光纤定位误差所致;(2)通过分析光谱质量、减天光残差等方法,分析P-Cygni特征是否为观测或数据处理所致。NeⅢλ3869和HeⅠλ5874处呈现反P-Cygni轮廓可信度较低;同时,通过比较目标光谱与超级天光,以及相邻光纤观测到的光谱在对应波长处的光谱特征,说明存在P-Cygni轮廓为减天光过程导致的可能性;(3)光谱子型差异。IRAS和WISE等近红外同源观测,显示其为Seyfert 2型星系,光学波段发射线强比[NⅡ]/Hα,[OⅢ]/Hβ显示其为HⅡ区,结合光学、红外测光图像特征,推测目标可能是两个星系进行并合活动;(4)从导致P-Cygni轮廓的物理机制的角度,分析了由星系并合触发外流、由恒星形成(爆发)电离气体触发的外流以及由Wolf-Rayet特征星系的超星风等原因引起的可能性。

WJC 6~th Anniversary Special Issues(3):Cardiomyopathy Hypertrophic cardiomyopathy in 2013:Current speculations and future perspectives

Hypertrophic cardiomyopathy(HCM),the most variable cardiac disease in terms of phenotypic presentation and clinical outcome,represents the most common inherited cardiomyopathic process with an autosomal dominant trait of inheritance.To date,more than 1400 mutations of myofilament proteins associated with the disease have been identified,most of them "private" ones.This striking allelic and locus heterogeneity of the disease certainly complicates the establishment of phenotype-genotype correlations.Additionally,topics pertaining to patients' everyday lives,such as sudden cardiac death(SCD)risk stratification and prevention,along with disease prognosis,are grossly related to the genetic variation of HCM.This review incorporates contemporary research findings and addresses major aspects of HCM,including preclinical diagnosis,genetic analysis,left ventricular outflow tract obstruction and SCD.More specifically,the spectrum of genetic analysis,the selection of the best method for obstruction alleviation and the need for a unique and accuratefactor for SCD risk stratification are only some of the controversial HCM issues discussed.Additionally,future perspectives concerning HCM and myocardial ischemia,as well as atrial fibrillation,are discussed.Rather than enumerating clinical studies and guidelines,challenging problems concerning the disease are critically appraised by this review,highlighting current speculations and recommending future directions.

Analysis of the Structure and Propagation of a Simulated Squall Line on 14 June 2009

A squall line on 14 June 2009 in the provinces of Jiangsu and Anhui was well simulated using the Advanced Regional Prediction System （ARPS） model. Based on high resolution spatial and temporal data, a detailed analysis of the structural features and propagation mechanisms of the squall line was conducted. The dynamic and thermodynamic structural charac- teristics and their causes were analyzed in detail. Unbalanced flows were found to play a key role in initiating gravity waves during the squall line＇s development. The spread and development of the gravity waves were sustained by convection in the wave-CISK process. The squall line＇s propagation and development mainly relied on the combined effect of gravity waves at the midlevel and cold outflow along the gust front. New cells were continuously forced by the cold pool outflow and were enhanced and lifted by the intense upward motion. At a particular phase, the new cells merged with the updraft of the gravity waves, leading to an intense updraft that strengthened the squall line.

CFD Simulation and Experimental Validation of Fluid Flow in Pre-distributor

Liquid distributor is a very import intemal for distillation columns. Pre-distributor is usually set on the top of distributor for initial distribution. Fluid flow in pre-distributor is a complex system of variable mass flow with many orifices and sub-branches. Consequently, the two phase modeling of pre-distributors was carried out andthe homogeneous model with free surface model was applied. The numerical method was validated by comparing with experimental data. Using the simulated results for different pre-distributors, the impacts of inflow rate, location and orientation uoon the outflow distribution were investigated. Furthermore, influences of the outflow distribution for pre-distributor on liquid uniformity in trough were also analyzed, The conclusions can De aaoptea for me structural design of liquid distributor and pre-distributor of large scale.

Cross-sectional and longitudinal studies on interaction between bladder compliance and outflow obstruction in men with benign prostatic hyperplasia

Aim： To explore the interaction between bladder compliance （BC） and bladder outflow obstruction （BOO） in men with benign prostatic hyperplasia （BPH） using cross-sectional and longitudinal studies. Methods： A total of 181 men with BPH were recruited, and 100 of them were followed for one year. Cystometry was performed in a standing or a sitting position with 30 mL/min infusion. BC was manually corrected and defined. Obstruction coefficient （OCO）, linear passive urethral resistance relation and international continence society （ICS） nomogram were used to diagnose BOO. The obstructed parameters were compared between the reduced BC group and the non-reduced group. BC was compared between the first investigation at the beginning of study and the second investigation at the end of study during the one-year follow-up period. Results： The group with reduced BC had increased OCO and linear passive urethral resistance relation. BC was significantly lower in the obstructed group （55.7 mL/cm water） than that in unobstructed and equivocal one （74.9 mL/cm water, P 〈 0.01）. BC gradually reduced with the increased obstructed grade. There was a significantly weak negative correlation between BC and OCO （r = - 0.132, P 〈 0.01）. Over the one-year follow-up period in the longitudinal study, BC for all men changed from 54.4 to 48.8 mL/cm water （P 〉 0.05）, and BC for the group with BOO fell from 58.4 ± 70.1 to 46.5 ± 38.7 mL/cm water （P 〉 0.05）. Conclusion： In men with BPH, a significant systematic decrease occurred in BC in the obstructed group and a significant systematic increase with urethral resistance occurred in the low BC group. A longitudinal study of the tendency of BC reduction in a group with BOO is necessary in the future.

Liver cirrhosis in hepatic vena cava syndrome(or membranous obstruction of inferior vena cava)

Hepatic vena cava syndrome(HVCS) also known as membranous obstruction of inferior vena cava reported mainly from Asia and Africa is an important cause of hepatic venous outflow obstruction(HVOO) that is complicated by high incidence of liver cirrhosis(LC) and moderate to high incidence of hepatocellular carcinoma(HCC). In the past the disease was considered congenital and was included under Budd-Chiari syndrome(BCS). HVCS is a chronic disease common in developing countries, the onset of which is related to poor hygienic living condition. The initial lesion in the disease is a bacterial infection induced localized thrombophlebitis in hepatic portion of inferior vena cava at the site where hepatic veins open which on resolution transforms into stenosis, membrane or thick obstruction,and is followed by development of cavo-caval collateral anastomosis. The disease is characterized by long asymptomatic period and recurrent acute exacerbations(AE) precipitated by clinical or subclinical bacterial infection. AE is managed with prolonged oral antibiotic. Development of LC and HCC in HVCS is related to the severity and frequency of AEs and not to the duration of the disease or the type or severity of the caval obstruction. HVOO that develops during severe acute stage or AE is a pre-cirrhotic condition. Primary BCS on the other hand is a rare disease related to prothrombotic disorders reported mainly among Caucasians that clinically manifest as acute, subacute disease or as fulminant hepatic failure; and is managed with life-long anticoagulation, portosystemic shunt/endovascular angioplasty and stent or liver transplantation. As epidemiology, etiology and natural history of HVCS are different from classical BCS, it is here, recognized as a separate disease entity, a third primary cause of HVOO after sinusoidal obstruction syndrome and BCS. Understanding of the natural history has made early diagnosis of HVCS possible. This paper describes epidemiology, natural history and diagnosis of HVCS and discusses the pathogenesis of LC in the disease and mentions distinctive clinical features of HVCS related LC.

Esophagogastric junction outflow obstruction: Where are we now in diagnosis and management?

Esophagogastric junction outflow obstruction(EGJOO) is a major motility disorder based on the Chicago Classification of esophageal motility disorders.This entity involves a heterogenous group of underlying etiologies. The diagnosis is reached by performing high-resolution manometry. This reveals evidence of obstruction at the esophagogastric junction, manifested by an elevated integrated relaxation pressure(IRP) above a cutoff value(IRP threshold varies by the manometric technology and catheter used), with preserved peristalsis. Further tests like endoscopy, timed barium esophagram, and cross-sectional imaging can help further elucidate the underlying etiology and rule out mechanical causes.Treatment is tailored to the underlying cause. Similar to achalasia, treatment targeting lower esophageal sphincter disruption like pneumatic dilation, peroral endoscopic myotomy, and botulinum injection are used in patients with functional EGJOO and persistent symptoms.

Redefining Budd-Chiari syndrome:A systematic review

AIM:To re-examine whether hepatic vein thrombosis(HVT)(classical Budd-Chiari syndrome)and hepatic vena cava-Budd Chiari syndrome(HVC-BCS)are the same disorder.METHODS:A systematic review of observational studies conducted in adult subjects with primary BCS,hepatic vein outflow tract obstruction,membranous obstruction of the inferior vena cava(IVC),obliterative hepatocavopathy,or HVT during the period of January2000 until February 2015 was conducted using the following databases:Cochrane Library,CINAHL,MEDLINE,Pub Med and Scopus.RESULTS:Of 1299 articles identified,26 were included in this study.Classical BCS is more common in women with a pure hepatic vein obstruction(49%-74%).HVCBCS is more common in men with the obstruction often located in both the inferior vena cava and hepatic veins(14%-84%).Classical BCS presents with acute abdominal pain,ascites,and hepatomegaly.HVC-BCS presents with chronic abdominal pain and abdominalwall varices.Myeloproliferative neoplasms(MPN)are the most common etiology of classical BCS(16%-62%)with the JAK2V617-F mutation found in 26%-52%.In HVCBCS,MPN are found in 4%-5%,and the JAK2V617-F mutation in 2%-5%.Classical BCS responds well to medical management alone and 1st line management of HVC-BCS involves percutaneous recanalization,with few managed with medical management alone.CONCLUSION:Systematic review of recent data suggests that classical BCS and HVC-BCS may be two clinically different disorders that involve the disruption of hepatic venous outflow.

Effect of iron overload on electrophysiology of slow reaction autorhythmic cells of left ventricular outflow tract in guinea pigs

Objective: To investigate the electrophysiology effects and mechanism of iron overload on the slow response autorhythmic cells in the left ventricular outflow tract of guinea pigs.Methods: Standard microelectrode cell recording techniques were adopted to observe the electrophysiological effects of different concentrations of Fe^(2+)(100 μmol/L, 200 μmol/L) on the left ventricular outflow tract autorhythmic cells.Heart tissues were perfused with FeSO_4(200 μmol/L) combing with CaCl_2(4.2 mmol/L), Verapamil,(1 μmol/L), and nickel chloride(200μmol/L) respectively to observe the influences of these contents on electrophysiology of FeSO_4(200μmol/L) on the left ventricular outflow tract autorhythmic cells.Results: Fe^(2+)at both 100 μmol/L and 200 μmol/L could change the electrophysiological parameters of the slow response autorhythmic cells of the left ventricular outflow tract in a concentrationdependent manner resulting into decrease in Vmax, APA and MDP, slower RPF and VDD, and prolonged APD_(50) and APD_(90)(P all <0.05).Besides, perfusion of increased Ca^(2+) concentration could partially offset the electrophysiological effects of Fe^(2+)(200 μmol/L).The L-type calcium channel(LTCC) blocker Verapamil(1 μmol/L) could block the electrophysiological effects of Fe^(2+)(200 μmol/L).But the T-type calcium channel(TTCC) blocker nickel chloride(NiCl_2, 200 μmol/L) could not block the electrophysiological effects of Fe^(2+)(200 μmol/L).Conclusions: Fe^(2+) can directly change the electrophysiological characteristics of the slow response autorhythmic cells of the left ventricular outflow tract probably through the L-type calcium channel.

Electrophysiological changes of autonomic cells in left ventricular outflow tract in guinea pigs with iron deficiency anemia complicated with chronic heart failure

Objective: To investigate the electrophysiological changes of autonomic cells in left ventricular outflow tract in guinea pigs with iron deficiency anemia complicated with chronic heart failure.Methods: Guinea pigs model of iron deficiency anemia complicated with chronic heart failure in 10 guinea pigs of the experimental group was made by feeding a low iron diet,pure water and subcutaneous injection of isoproterenol. The control group consisting of 11 guinea pigs was given normal food, normal water and injected with normal saline. The left ventricular outflow tract model specimen was also prepared. The standard microelectrode technique was used to observe electrophysiological changes of autonomic cells in the outflow tract of left ventricular heart failure complicated with iron deficiency anemia in guinea pig model. The indicators of observation were maximal diastolic potential, action potential amplitude, 0 phase maximal depolarization velocity, 4 phase automatic depolarization velocity, repolarization 50% and 90%, and spontaneous discharge frequency.Results: Compared with the control group, 4 phase automatic depolarization velocity,spontaneous discharge frequency and 0 phase maximal depolarization velocity decreased significantly(P < 0.01) and action potential amplitude reduced(P < 0.01) in model group. Moreover, repolarization 50% and 90% increased(P < 0.01).Conclusions: There are electrophysiological abnormalities of the left ventricular outflow tract in guinea pigs with iron deficiency anemia complicated with heart failure.

THE STABILITY OF STATIONARY SOLUTION FOR OUTFLOW PROBLEM ON THE NAVIER-STOKES-POISSON SYSTEM

In this article, we are concerned with the stability of stationary solution for outflow problem on the Navier-Stokes-Poisson system. We obtain the unique existence and the asymptotic stability of stationary solution. Moreover, the convergence rate of solution towards stationary solution is obtained. Precisely, if an initial perturbation decays with the algebraic or the exponential rate in space, the solution converges to the corresponding stationary solution as time tends to infinity with the algebraic or the exponential rate in time. The proof is based on the weighted energy method by taking into account the effect of the self-consistent electric field on the viscous compressible fluid.

Balloon dilatation for treatment of hepatic venous outflow obstruction following pediatric liver transplantation

AIM To assess the efficacy and safety of balloon dilatation for the treatment of hepatic venous outflow obstruction(HVOO) following pediatric liver transplantation.METHODS A total of 246 pediatric patients underwent liver transplantation at our hospital between June 2013 and September 2016. Among these patients, five were ultimately diagnosed with HVOO. Seven procedures(two patients underwent two balloon dilatation procedures) were included in this analysis. The demographic data,types of donor and liver transplant, interventional examination and therapeutic outcomes of these five children were analyzed. The median interval time between pediatric liver transplantation and balloon dilatation procedures was 9.8 mo(range: 1-32).RESULTS Five children with HVOO were successfully treated by balloon angioplasty without stent placement, with seven procedures performed for six stenotic lesions. All children underwent successful percutaneous intervention. Among these five patients, four were treated by single balloon angioplasty, and these patients did not develop recurrent stenosis. In seven episodes of balloon angioplasty across the stenosis, the pressure gradient was 12.0 ± 8.8 mm Hg before balloon dilatation and 1.1 ± 1.5 mm Hg after the procedures, which revealed a statistically significant reduction(P < 0.05). The overall technical success rate among these seven procedures was 100%(7/7), and clinical success was achieved in all five patients(100%). The patients were followed for 4-33 mo(median: 15 mo). No significant procedural complications or procedurerelated deaths occurred.CONCLUSION Balloon dilatation is an effective and safe therapeutic option for HVOO in children undergoing pediatric liver transplantation. Venous angioplasty is also recommended in cases with recurrent HVOO.