Postoperative complications in patients with portal vein thrombosis after liver transplantation:Evaluation with Doppler ultrasonography

AIM： To study the postoperative complications in patients with preoperative portal vein thrombosis （PVT） undergoing liver transplantation （LT） and to evaluate the complications with Doppler ultrasonography.METHODS： Retrospective studies were performed on 284 patients undergoing LT （286 LT） with respect to pre- and postoperative clinical data and Doppler ultrasonography. According to the presence and grade of preoperative PVT, 286 LTs were divided into three groups： complete PVT （c-PVT）, partial PVT （p-PVT） and non-PVT, with 22, 30 and 234 LTs, respectively. Analyses were carried out to compare the incidence of early postoperative complications.RESULTS： PVT, inferior vena cava （IVC） thrombosis, hepatic artery thrombosis （HAT） and biliary complications were found postoperatively. All complications were detected by routine Doppler ultrasonography and diagnoses made by ultrasound were confirmed by clinical data or/and other imaging studies. Nine out of 286 LTs had postoperative PVT. The incidence of the c-Pv-r group was 22.7%, which was higher than that of the p-Pv-r group （3.3%, P 〈 0.05） and non- PVT group （1.3%, P 〈 0.005）. No difference was found between the p-PVT and non-PVT groups （P 〉 0.25）. Of the 9 cases with postoperative PVT, recanalizations were achieved in 7 cases after anticoagulation under the guidance of ultrasound, 1 case received portal vein thrombectomy and 1 case died of acute injection. Ten LTs had postoperative 1VC thrombosis. The c-PVT group had a higher incidence of IVC thrombosis than the non- PVT group （9.1% vs 2.6%, P 〈 0.05）; no significant difference was found between either the c-PV-T and p-PVT groups （9.1% vs 6.7%, P 〉 0.5） or between the p-PVT and non-PVT groups （P 〉 0.25）. Nine cases with IVC thrombosis were cured by anticoagulation under the guidance of ultrasound, and 1 case gained natural cure without any medical treatment after 2 mo. HAT was found in 2 non-PVT cases, giving a rate of 0.7% among 286 LTs. Biliary complications were seen in 12 LTs. The incidence of biliary complications in the c-PVT, p-PVT and non-PVT groups was 9.1%, 3.3% and 4.3%, respectively （P 〉 0.25 for all）, among which 2 stenosis led retransplantations and others were controlled by relative therapy.CONCLUSION： C-PVT patients tend to have a higher incidence of PVT and IVC thrombosis than non- PVT patients after LT. The incidence of postoperative complications in p-PVT patients does not differ from that of non-PVT patients, A relatively low incidence of HAT was seen in our study, Doppler ultrasonography is a convenient and efficient method for detecting posttransplant complications and plays an important role in guiding treatment.

Vascular complications after adult living donor liver transplantation:Evaluation with ultrasonography

Living donor liver transplantation(LDLT) has beenwidely used to treat end-stage liver disease with improvement in surgical technology and the application of new immunosuppressants. Vascular complications after liver transplantation remain a major threat to the survival of recipients. LDLT recipients are more likely to develop vascular complications because of their complex vascular reconstruction and the slender vessels. Early diagnosis and treatment are critical for the survival of graft and recipients. As a non-invasive, cost-effective and non-radioactive method with bedside availability, conventional gray-scale and Doppler ultrasonography play important roles in identifying vascular complications in the early postoperative period and during the follow-up. Recently, with the detailed vascular tracing and perfusion visualization, contrastenhanced ultrasound(CEUS) has significantly improved the diagnosis of postoperative vascular complications. This review focuses on the role of conventional grayscale ultrasound, Doppler ultrasound and CEUS for early diagnosis of vascular complications after adult LDLT.

The value of color Doppler ultrasonography in monitoring normal orthotopic liver transplantation and postoperative complications

OBJECTIVE: To assess the value of color Doppler ultrasonography in monitoring normal orthotopic liver transplantation and postoperative complications. METHODS: Forty-one patients after orthotopic liver transplantation were examined by using color Doppler flow imaging to observe the hepatic blood flow and change of ultrasonography of the hepatic parenchyma and bile duct. The measured indexes included maximum blood flow velocity, time-average blood flow velocity (TAV), resistance index (RI) and diameter of the bile duct. RESULTS: Among 41 patients, 17 (41.5%) suffered from liver transplant rejection. Of the 17 patients, 13 (76.4%) showed decrease of TAV of the portal vein, 15 (88.25%) low-amplitude single-phase serrated wave or negative biphasic wave of the hepatic vein, 9 (52.9%) increased hepatic arterial RI, and 5 (29.4%) slightly dilated bile duct. Sonography showed disappearance of the hepatic artery blood flow around the portal vein in 5 (12.2%) of the 41 patients with hepatic artery thrombosis in the postoperative period. Slight dilatation of the intrahepatic bile duct was found in 3 (7.3%) of the 41 patients in the early postoperational period and it normalized within 2 weeks. Ultrasonography of 20 patients (48.8%) revealed a visible dilatation of the intrahepatic bile duct, which was worsening gradually. The causes of bile duct dilatation included biliary stricture in 2 patients (10%), stone in 15 patients (75%) and others in 3 patients (15%). CONCLUSIONS: Color Doppler ultrasonography is valuable for monitoring normal liver transplantation and postoperative complications.

Doppler ultrasonography in living donor liver transplantation recipients: Intra- and post-operative vascular complications

Living-donor liver transplantation has provided a solution to the severe lack of cadaver grafts for the replacement of liver afflicted with end-stage cirrhosis, fulminant disease, or inborn errors of metabolism. Vascular complications remain the most serious complications and a common cause for graft failure after hepatic transplantation. Doppler ultrasound remains the primary radiological imaging modality for the diagnosis of such complications. This article presents a brief review of intra- and post-operative living donor liver transplantation anatomy and a synopsis of the role of ultrasonography and color Doppler in evaluating the graft vascular haemodynamics both during surgery and post-operatively in accurately defining the early vascular complications. Intra-operative ultrasonography of the liver graft provides the surgeon with useful real-time diagnostic and staging information that may result in an alteration in the planned surgical approach and corrections of surgical complications during the procedure of vascular anastomoses. The relevant intraoperative anatomy and the spectrum of normal and abnormal findings are described. Ultrasonography and color Doppler also provides the clinicians and surgeons early post-operative potential developmental complications that may occur during hospital stay. Early detection and thus early problem solving can make the difference between graft survival and failure.

Comparison of different preoperative objective nutritional indices for evaluating 30-d mortality and complications after liver transplantation

BACKGROUND The nutritional status is closely related to the prognosis of liver transplant re-cipients,but few studies have reported the role of preoperative objective nutri-tional indices in predicting liver transplant outcomes.AIM To compare the predictive value of various preoperative objective nutritional indicators for determining 30-d mortality and complications following liver transplantation(LT).METHODS A retrospective analysis was conducted on 162 recipients who underwent LT at our institution from December 2019 to June 2022.RESULTS This study identified several independent risk factors associated with 30-d mor-tality,including blood loss,the prognostic nutritional index(PNI),the nutritional risk index(NRI),and the control nutritional status.The 30-d mortality rate was 8.6%.Blood loss,the NRI,and the PNI were found to be independent risk factors for the occurrence of severe postoperative complications.The NRI achieved the highest prediction values for 30-d mortality[area under the curve(AUC)=0.861,P<0.001]and severe complications(AUC=0.643,P=0.011).Compared to those in the high NRI group,the low patients in the NRI group had lower preoperative body mass index and prealbumin and albumin levels,as well as higher alanine aminotransferase and total bilirubin levels,Model for End-stage Liver Disease scores and prothrombin time(P<0.05).Furthermore,the group with a low NRI exhibited significantly greater incidences of intraabdominal bleeding,primary graft nonfunction,and mortality.CONCLUSION The NRI has good predictive value for 30-d mortality and severe complications following LT.The NRI could be an effective tool for transplant surgeons to evaluate perioperative nutritional risk and develop relevant nutritional therapy.

Prognostic value of ultrasound in early arterial complications post liver transplant

Liver transplantation is the primary therapeutic intervention for end-stage liver disease.However,vascular complications,particularly those involving the hepatic artery,pose significant risks to patients.The clinical manifestations associated with early arterial complications following liver transplantation are often non-specific.Without timely intervention,these complications can result in graft fai-lure or patient mortality.Therefore,early diagnosis and the formulation of an op-timal treatment plan are imperative.Ultrasound examination remains the pre-dominant imaging modality for detecting complications post liver transplan-tation.This article comprehensively reviews common causes and clinical present-ations of early hepatic artery complications in the post-transplantation period and delineates abnormal sonographic findings for accurate diagnosis of these con-ditions.Overall,ultrasound offers the advantages of convenience,safety,effect-iveness,and non-invasiveness.It enables real-time,dynamic,and precise evalua-tion,making it the preferred diagnostic method for post-liver transplantation assessments.INTRODUCTION Liver transplantation stands as the primary therapeutic approach for end-stage liver disease.Continuous advancements in surgical techniques and the application of novel immunosuppressive agents contribute to ongoing improvements in the success rate and overall survival in patients undergoing liver transplantation procedures.Despite these advan-cements,vascular complications,particularly those involving the hepatic artery,pose significant risks to patients.During the early stages following liver transplantation(within the first 30 d),proper hepatic artery function is crucial for hepatic arterial blood flow.During later stages,collateral circulation,including arteries such as the phrenic artery,right gastric artery,and gastroduodenal artery,becomes important for maintaining hepatic blood supply.It is now understood that the establishment of effective collateral circulation is pivotal for determining the prognosis of hepatic artery complic-ations.The clinical manifestations of these complications are closely linked to factors such as timing,severity,and the specific type of onset.Insufficient hepatic arterial blood flow can lead to abnormal liver function,hepatic infarction,and the formation of hepatic abscesses.Additionally,since the hepatic artery is the sole blood supply to the biliary tract,hepatic artery-related ischemia may result in biliary stricture,obstruction,and the formation of bile ducts.Ultrasound examination remains the primary imaging modality for diagnosing complications post liver transplantation.This article comprehensively reviews common causes and clinical presentations of early hepatic artery complications in the post-transplantation period and outlines abnormal sonographic findings for accurately diagnosing these conditions.NORMAL HEPATIC ARTERY During the intraoperative phase,an ultrasound examination is typically conducted to evaluate the hepatic artery anas-tomosis.The normal internal diameter of the hepatic artery typically ranges from 2 to 5 mm.Two strong echo points are typically identified near the anastomosis.To assess blood flow dynamics,peak systolic velocity,end-diastolic velocity,and resistance index are measured at the donor and recipient sides of the anastomosis following angle correction.Anastomotic stenosis presence and severity can be evaluated by comparing the velocity at the anastomotic site with that at the recipient side.Postoperatively,direct visualization of the anastomosis site through gray ultrasound scans is often challenging.The surgical approach has a significant impact on the proper hepatic artery’s position,resulting in a lower overall success rate of continuous visualization.Color Doppler ultrasound is primarily employed to trace the artery’s path,and spectral measurements are taken at the brightest position of the Color Doppler blood flow signal,primarily used to identify the presence of high-speed turbulence.Hepatic artery spectrum examination plays a crucial role,as a favorable arterial spectral waveform and appropriate hepatic artery flow velocity typically indicate a successful anastomosis,even in cases where the hepatic artery anastomosis cannot be directly visualized by ultrasound.The hepatic artery runs alongside the portal vein,often selected as a reference due to its larger inner diameter.A normal hepatic artery spectrum displays a regular pulsation pattern with a rapid rise in systole and a slow decline in diastole.Parameters for assessing hepatic artery resistance include a resistance index between 0.5 to 0.8 and an artery systolic acceleration of less than 80 ms.Instantaneous increases in the resistance index(RI>0.8)often occur within 2 d after surgery,followed by a subsequent return to normal hepatic arterial parameters.It has been established that the maximum blood flow velocity during systole in the hepatic artery should not exceed 200 cm/s[1].

Biliary complications after liver transplantation:A computed tomography and magnetic resonance imaging pictorial review

Biliary complications are the most common complications after liver transplantation.Computed tomography(CT)and magnetic resonance imaging(MRI)are cornerstones for timely diagnosis of biliary complications after liver transplantation.The diagnosis of these complications by CT and MRI requires expertise,mainly with respect to identifying subtle early signs to avoid missed or incorrect diagnoses.For example,biliary strictures may be misdiagnosed on MRI due to size mismatch of the common ducts of the donor and recipient,postoperative edema,pneumobilia,or susceptibility artifacts caused by surgical clips.Proper and prompt diagnosis of biliary complications after transplantation allows the timely initiation of appropriate management.The aim of this pictorial review is to illustrate various CT and MRI findings related to biliary complications after liver transplantation,based on time of presentation after surgery and frequency of occurrence.

Influence of donor age on liver transplantation outcomes: A multivariate analysis and comparative study

BACKGROUND The growing disparity between the rising demand for liver transplantation(LT)and the limited availability of donor organs has prompted a greater reliance on older liver grafts.Traditionally,utilizing livers from elderly donors has been associated with outcomes inferior to those achieved with grafts from younger donors.By accounting for additional risk factors,we hypothesize that the utili-zation of older liver grafts has a relatively minor impact on both patient survival and graft viability.AIM To evaluate the impact of donor age on LT outcomes using multivariate analysis and comparing young and elderly donor groups.METHODS In the period from April 2013 to December 2018,656 adult liver transplants were performed at the University Hospital Merkur.Several multivariate Cox propor-tional hazards models were developed to independently assess the significance of donor age.Donor age was treated as a continuous variable.The approach involved univariate and multivariate analysis,including variable selection and assessment of interactions and transformations.Additionally,to exemplify the similarity of using young and old donor liver grafts,the group of 87 recipients of elderly donor liver grafts(≥75 years)was compared to a group of 124 recipients of young liver grafts(≤45 years)from the dataset.Survival rates of the two groups were estimated using the Kaplan-Meier method and the log-rank test was used to test the differences between groups.RESULTS Using multivariate Cox analysis,we found no statistical significance in the role of donor age within the constructed models.Even when retained during the entire model development,the donor age's impact on survival remained insignificant and transformations and interactions yielded no substantial effects on survival.Consistent insigni-ficance and low coefficient values suggest that donor age does not impact patient survival in our dataset.Notably,there was no statistical evidence that the five developed models did not adhere to the proportional hazards assumption.When comparing donor age groups,transplantation using elderly grafts showed similar early graft function,similar graft(P=0.92),and patient survival rates(P=0.86),and no significant difference in the incidence of postoperative complications.CONCLUSION Our center's experience indicates that donor age does not play a significant role in patient survival,with elderly livers performing comparably to younger grafts when accounting for other risk factors.

Improving the radiological diagnosis of hepatic artery thrombosis after liver transplantation: Current approaches and future challenges

Hepatic artery thrombosis(HAT)is a devastating vascular complication following liver transplantation,requiring prompt diagnosis and rapid revascularization treatment to prevent graft loss.At present,imaging modalities such as ultrasound,computed tomography,and magnetic resonance play crucial roles in diagnosing HAT.Although imaging techniques have improved sensitivity and specificity for HAT diagnosis,they have limitations that hinder the timely diagnosis of this complication.In this sense,the emergence of artificial intelligence(AI)presents a transformative opportunity to address these diagnostic limitations.The development of machine learning algorithms and deep neural networks has demonstrated the potential to enhance the precision diagnosis of liver transplant complications,enabling quicker and more accurate detection of HAT.This article examines the current landscape of imaging diagnostic techniques for HAT and explores the emerging role of AI in addressing future challenges in the diagnosis of HAT after liver transplant.

Prediction of hepatic artery occlusion after liver transplantation by ultrasound characteristics and clinical risk factors

BACKGROUND Hepatic artery occlusion(HAO)after liver transplantation(LT)is a devastating complication,resulting in early graft loss and reduced overall survival.Ultra-sound is an established assessment method for HAO in patients following LT,especially those with complex hepatic artery reconstruction.METHODS We retrospectively analyzed the ultrasound characteristics and the clinic risk factors associated with HAO in 400 adult LT patients who were enrolled and treated at the Third People's Hospital of Shenzhen between November 2016 and July 2022.Fourteen patients diagnosed with acute HAO(A-HAO)by surgery and fifteen diagnosed with chronic HAO(C-HAO)were included.A control group of 33 patients without HAO complications during the same period were randomly selected using a random number table.All patients underwent an ultrasono-graphy examination.Parameters including resistance index(RI),peak systolic velocity(PSV),and portal vein velocity(PVV)were compared across the groups.Additionally,basic clinical data were collected for all patients,including gender,age,primary diagnosis,D-dimer concentration,total operation time,cold ischemia time,hot ischemia time,intraoperative blood loss and transfusion,intraoperative urine volume,infusion,model for end-stage liver disease(MELD)score,and whether complex hepatic artery reconstructions were performed.Furthermore,risk factors influencing HAO formation after LT were analyzed.RESULTS Compared to the non-HAO group,PVV and RI were higher in the A-HAO group,while PSV was lower.Conversely,both PSV and RI were lower in the C-HAO group compared to the non-HAO group.The proportion of patients undergoing complex hepatic artery reconstructions and the gamma-glutamyltransferase(GGT)level before occlusion were significantly higher in the A-HAO group compared to the non-HAO group.However,there were no distinct differences between the two groups in D-dimer,MELD score,pre-occlusion alanine transaminase and aspartate transaminase levels,or intraoperative conditions.CONCLUSION Ultrasound features of the hepatic artery before occlusion are significantly associated with postoperative HAO development.Additionally,complex hepatic artery reconstructions,defined as revascularization of the graft requiring additional anastomosis between donor hepatic arteries,constitute a risk factor for A-HAO.Besides,abnormal pre-occlusion GGT elevation is an important biochemical indicator.Therefore,ultrasound examination serves as an important tool for screening HAO,especially in patients with the identified risk factors.

Tacrolimus-induced posterior reversible encephalopathy syndrome following liver transplantation

In this editorial,we talk about a compelling case focusing on posterior reversible encephalopathy syndrome(PRES)as a complication in patients undergoing liver transplantation and treated with Tacrolimus.Tacrolimus(FK 506),derived from Streptomyces tsukubaensis,is a potent immunosuppressive macrolide.It inhibits Tcell transcription by binding to FK-binding protein,and is able to amplify glucocorticoid and progesterone effects.Tacrolimus effectively prevents allograft rejection in transplant patients but has adverse effects such as Tacrolimus-related PRES.PRES presents with various neurological symptoms alongside elevated blood pressure,and is primarily characterized by vasogenic edema on neuroimaging.While computed tomography detects initial lesions,magnetic resonance imaging,especially the Fluid-Attenuated Inversion Recovery sequence,is superior for diagnosing cortical and subcortical edema.Our discussion centers on the incidence of PRES in solid organ transplant recipients,which ranges between 0.5 to 5+ACU-,with varying presentations,from seizures to visual disturbances.The case of a 66-year-old male status post liver transplantation highlights the diagnostic and management challenges associated with Tacrolimus-related PRES.Radiographically evident in the parietal and occipital lobes,PRES underlines the need for heightened vigilance among healthcare providers.This editorial emphasizes the importance of early recognition,accurate diagnosis,and effective management of PRES to optimize outcomes in liver transplant patients.The case further explores the balance between the efficacy of immunosuppression with Tacrolimus and its potential neurological risks,underlining the necessity for careful monitoring and intervention strategies in this patient population.

Impact of cirrhosis-related complications on posttransplant survival in patients with acute-on-chronic liver failure

Background:Acute-on-chronic liver failure(ACLF)is a life-threatening syndrome defined as acute decompensation in patients with chronic liver disease.Liver transplantation(LT)is the most effective treatment.We aimed to assess the impact of cirrhosis-related complications pre-LT on the posttransplant prognosis of patients with ACLF.Methods:This was an observational cohort study conducted between January 2018 and December 2020.Clinical characteristics,cirrhosis-related complications at LT and patient survival post-LT were collected.All liver recipients with ACLF were followed for 1 year post-LT.Results:A total of 212 LT recipients with ACLF were enrolled,including 75(35.4%)patients with ACLF-1,64(30.2%)with ACLF-2,and 73(34.4%)with ACLF-3.The median waiting time for LT was 11(4-24)days.The most prevalent cirrhosis-related complication was ascites(78.8%),followed by hepatic encephalopathy(57.1%),bacterial infections(48.1%),hepatorenal syndrome(22.2%)and gastrointestinal bleeding(11.3%).Survival analyses showed that patients with complications at LT had a significantly lower survival probability at both 3 months and 1 year after LT than those without complications(all P<0.05).A simplified model was developed by assigning one point to each complication:transplantation for ACLF with cirrhosis-related complication(TACC)model.Risk stratification of TACC model identified 3 strata(≥4,=3,and≤2)with high,median and low risk of death after LT(P<0.001).Moreover,the TACC model showed a comparable ability for predicting the outcome post-LT to the other four prognostic models(chronic liver failure-consortium ACLF score,Chinese Group on the Study of Severe Hepatitis B-ACLF score,model for end-stage liver disease score and Child-Turcotte-Pugh score).Conclusions:The presence of cirrhosis-related complications pre-LT increases the risk of death post-LT in patients with ACLF.The TACC model based on the number of cirrhosis-related complications pre-LT could stratify posttransplant survival,which might help to determine transplant timing for ACLF.

Gastroduodenal artery disconnection during liver transplantation decreases non-anastomotic stricture incidence

Background:The hepatic artery is the only blood source nourishing the biliary duct and associated with biliary complication after liver transplantation(LT).Gastroduodenal artery(GDA)disconnection increased proper hepatic artery flow.Whether this procedure attenuates biliary non-anastomotic stricture(NAS)is not clear.Methods:A total of 241 patients with LT were retrospectively analyzed.The patients were divided into the GDA disconnection(GDA-)and GDA preservation(GDA+)groups.Propensity score matching(PSM)was administrated to reduce bias.Logistic regression was conducted to analyze risk factors for biliary NAS before and after PSM.Postoperative complications were compared.Kaplan-Meier survival analysis and log-rank tests were performed to compare overall survival.Results:In all,99 patients(41.1%)underwent GDA disconnection,and 49(20.3%)developed NAS.Multivariate logistic regression revealed that GDA preservation(OR=2.24,95%CI:1.11-4.53;P=0.025)and model for end-stage liver disease(MELD)score>15(OR=2.14,95%CI:1.12-4.11;P=0.022)were risk factors for biliary NAS.PSM provided 66 pairs using 1:2 matching method,including 66 GDA disconnection and 99 GDA preservation patients.Multivariate logistic regression after PSM also showed that GDA preservation(OR=3.15,95%CI:1.26-7.89;P=0.014)and MELD score>15(OR=2.41,95%CI:1.08-5.36;P=0.031)were risk factors for NAS.When comparing complications between the two groups,GDA preservation was associated with a higher incidence of biliary NAS before and after PSM(P=0.031 and 0.017,respectively).In contrast,other complications including early allograft dysfunction(P=0.620),small-for-size graft syndrome(P=0.441),abdominal hemorrhage(P=1.000),major complications(Clavien-Dindo grade≥3,P=0.318),and overall survival(P=0.088)were not significantly different between the two groups.Conclusions:GDA disconnection during LT ameliorates biliary NAS incidence and may be recommended for application in clinical practice.

Biliary complications following liver transplantation

Biliary tract complications are the most common complications after liver transplantation.These complications are encountered more commonly as a result of increased number of liver transplantations and the prolonged survival of transplant patients.Biliary complications remain a major source of morbidity in liver transplant patients,with an incidence of 5%-32%.Post liver transplantation biliary complications include strictures(anastomotic and non-anastomotic),leaks,stones,sphincter of Oddi dysfunction,and recurrence of primary biliary disease such as primary sclerosing cholangitis and primary biliary cirrhosis.The risk of occurrence of a specific biliary complication is related to the type of biliary reconstruction performed at the time of liver transplantation.In this article we seek to review the major biliary complications and their relation to the type of biliary reconstruction performed at the time of liver tranplantation.

Early respiratory complications after liver transplantation

The poor clinical conditions associated with end-stage cirrhosis,pre-existing pulmonary abnormalities,and high comorbidity rates in patients with high Model for End-Stage Liver Disease scores are all well-recognized factors that increase the risk of pulmonary complications after orthotopic liver transplantation(OLT)surgery.Many intraoperative and postoperative events,such as fluid overload,massive transfusion of blood products,hemodynamic instability,unexpected coagulation abnormalities,renal dysfunction,and serious adverse effects of reperfusion syndrome,are other factors that predispose an individual to postoperative respiratory disorders.Despite advances in surgical techniques and anesthesiological management,the lung may still suffer throughout the perioperative period from various types of injury and ventilatory impairment,with different clinical outcomes.Pulmonary complications after OLT can be classified as infectious or non-infectious.Pleural effusion,atelectasis,pulmonary edema,respiratory distress syndrome,and pneumonia may contribute considerably to early morbidity and mortality in liver transplant patients.It is of paramount importance to accurately identify lung disorders because infectious pulmonary complications warrant speedy and aggressive treatment to prevent diffuse lung injury and the risk of evolution into multisystem organ failure.This review discusses the most common perioperative factors that predispose an individual to postoperative pulmonary complications and these complications’early clinical manifestations after OLT and influence on patient outcome.

Perioperative thrombotic complications in liver transplantation

Although the perioperative bleeding complications and the major side effects of blood transfusion have always been the primary concern in liver transplantation(OLT),the possible cohesion of an underestimated intrinsic hypercoagulative state during and after the transplant procedure may pose a major threat to both patient and graft survival.Thromboembolism during OLT is characterized not only by a complex aetiology,but also by unpredictable onset and evolution of the disease.The initiation of a procoagulant process may be triggered by various factors,such as inflammation,venous stasis,ischemia-reperfusion injury,vascular clamping,anatomical and technical abnormalities,genetic factors,deficiency of profibrinolytic activity,and platelet activation.The involvement of the arterial system,intracardiac thrombosis,pulmonary emboli,portal vein thrombosis,and deep vein thrombosis,are among the most serious thrombotic events in the perioperative period.The rapid detection of occlusive vascular events is of paramount importance as it heavily influences the prognosis,particularly when these events occur intraoperatively or early after OLT.Regardless of the lack of studies and guidelines on anticoagulant prophylaxis in this setting,many institutions recommend such an approach especially in the subset of patients at high risk.However,the decision of when,how and in what doses to use the various chemical anticoagulants is still a difficult task,since there is no common consensus,even for highrisk cases.The risk of postoperative thromboembolism causing severe hemodynamic events,or even loss of graft function,must be weighed and compared with the risk of an important bleeding.In this article we briefly review the risk factors and the possible predictors of major thrombotic complications occurringin the perioperative period,as well as their incidence and clinical features.Moreover,the indications to pharmacological prophylaxis and the current treatment strategies are also summarized.

Vascular complications following liver transplantation:Aliterature review of advances in 2015

Although vascular complications(VCs) following orthotopic liver transplantation(OLT) seldom occur, they are the most feared complications with a high incidence of both graft loss and mortality, as they compromise the blood flow of the transplant(either inflow or outflow). Diagnosis and therapeutic management of VCs constitute a major challenge in terms of increasing the success rate of liver transplantation. While surgical treatment used to be considered the first choice for management, advances in endovascular intervention have increased to make this a viable therapeutic option. Considering VC as a rare but a major and dreadful issue in OLT history, and in view of the continuing and rapid progress in recent years, an update on these uncommon conditions seemed necessary. In this sense, this review comprehensively discusses the important features(epidemiological, clinical, paraclinical, prognostic and therapeutic) of VCs following OLT.

Long-term outcomes of pediatric liver transplantation in acute liver failure vs end-stage chronic liver disease:A retrospective observational study

BACKGROUND Children with acute liver failure(ALF)who meet the criteria are eligible for super-urgent transplantation,whereas children with end-stage chronic liver disease(ESCLD)are usually transplanted electively.Pediatric liver transplantation(PLT)in ALF and ESCLD settings has been well described in the literature,but there are no studies comparing the outcomes in these two groups.AIM To determine if there is a difference in post-operative complications and survival outcomes between ALF and ESCLD in PLT.METHODS This was a retrospective observational study of all primary PLTs performed at a single center between 2000 and 2019.ALF and ESCLD groups were compared for pretransplant recipient,donor and operative parameters,and post-operative outcomes including graft and patient survival.RESULTS Over a 20-year study period,232 primary PLTs were performed at our center;195 were transplanted for ESCLD and 37 were transplanted for ALF.The ALF recipients were significantly older(median 8 years vs 5.4 years;P=0.031)and heavier(31 kg vs 21 kg;P=0.011).Living donor grafts were used more in the ESCLD group(34 vs 0;P=0.006).There was no difference between the two groups concerning vascular complications and rejection,but there were more bile leaks in the ESCLD group.Post-transplant patient survival was significantly higher in the ESCLD group:1-,5-,and 10-year survival rates were 97.9%,93.9%,and 89.4%,respectively,compared to 78.3%,78.3%,and 78.3%in the ALF group(P=0.007).However,there was no difference in 1-,5-,and 10-year graft survival between the ESCLD and ALF groups(90.7%,82.9%,77.3%vs 75.6%,72.4%,and 66.9%;P=0.119).CONCLUSION Patient survival is inferior in ALF compared to ESCLD recipients;the main reason is death in the 1st year post-PLT in ALF group.Once the ALF children overcome the 1st year after transplant,their survival stabilizes,and they have good long-term outcomes.

Plasma levels of tumor necrotic factor-alpha and interleukin-6, -8 during orthotopic liver transplantation and their relations to postoperative pulmonary complications

BACKGROUND: Pulmonary complications after orthoto- pic liver transplantation (OLT) include high morbidity and mortality. Experimental data have suggested hepatic ische- mia and reperfusion are induced by pro-inflammatory cyto- kines. The high level of inflammatory cytokines might ad- ditionally influence pulmonary cappillary fluid filtration. The objectives of this study were to measure the concentra- tions of tumor necrotic factor-alpha (TNF-α), interleukin- 6 (IL-6) and interleukin-8 (IL-8) during OLT and to in- vestigate the relationship between these cytokines and post- operative pulmonary complications. METHODS: Twenty-two patients undergoing OLT were divided into two groups according to whether they had postoperative pulmonary complications: group A consis- ting of 8 patients with postoperative pulmonary complica- tions , and group B consisting of 14 patients without post- operative pulmonary complications. Enzyme-linked im- munoassay (ELISA) was used to determine serum TNF-α, IL-6 and IL-8. Blood samples were taken at the beginning of operation (T0 ), clamping and cross-clamping of the in- ferior cava and portal vein (T1, T2 ), 90 minutes and 3 hours after reperfusion (T3 , T4 ) and 24 hours after opera- tion (T5). RESULTS: The level of PaO2/FiO2 in group A was lower than that in group B ( P <0. 05 ). The concentrations of TNF-α, IL-6 and IL-8 in the two groups increased rapidly at T2 , peaked at T3 , decreased rapidly after T3 until 24 hours after operation. The concentrations of TNF-α, IL-6 and IL-8 in group A were higher than those in group B at T2, T3, and T4(P<0.05). CONCLUSION: After un-clamping of the inferior cava and portal vein, the serum concentrations of TNF-α, IL-6 and IL-8 increased may be related to pulmonary injury after he- patic ischemic reperfusion.

Neurologic complications after liver transplantation

Neurologic complications are relatively common after solid organ transplantation and affect 15%-30%of liver transplant recipients.Etiology is often related to immunosuppressant neurotoxicity and opportunistic infections.Most common complications include seizures and encephalopathy,and occurrence of central pontine myelinolysis is relatively specific for liver transplant recipients.Delayed allograft function may precipitate hepatic encephalopathy and neurotoxicity of calcineurin inhibitors typically manifests with tremor,headaches and encephalopathy.Reduction of neurotoxic immunosuppressants or conversion to an alternative medication usually result in clinical improvement.Standard preventive and diagnostic protocols have helped to reduce the prevalence of opportunistic central nervous system(CNS)infections,but viral and fungal CNS infections still affect 1%of liver transplant recipients,and the morbidity and mortality in the affected patients remain fairly high.Critical illness myopathy may also affect up to 7%of liver transplant recipients.Liver insufficiency is also associated with various neurologic disorders which may improve or resolve after successful liver transplantation.Accurate diagnosis and timely intervention are essential to improve outcomes,while advances in clinical management and extended post-transplant survival are increasingly shifting the focus to chronic post-transplant complications which are often encountered in a community hospital and an outpatient setting.