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.

Analysis of the Effects of Preoperative Hepatic Artery Chemoembolization and Quality Nursing Intervention on the Perioperative Safety and Short-term Prognosis of Liver Transplantation in Patients with Hepatocellular Carcinoma

Objective: To investigate the effects of preoperative hepatic artery chemoembolization (TACE) and quality nursing interventions on the perioperative safety and short-term prognosis in patients with hepatocellular carcinoma undergoing liver transplantation. Methods: The study period spanned from January 2021 to December 2023, and 125 patients with hepatocellular carcinoma admitted to our hospital were selected, all of whom underwent liver transplantation. They were randomly divided into an observation group (n = 63) and a control group (n = 62). The patients in the control group did not undergo TACE before the operation, and the patients in the observation group underwent TACE and quality nursing intervention before the operation. The operation time, intraoperative blood loss, length of hospitalization, liver- free period, complication rate, short-term prognosis, and liver function indexes between the two groups were compared. Results: There was no significant difference in operation time, intraoperative blood loss, and length of hospitalization between the two groups (P < 0.05). The liver-free period of patients in the observation group was longer than that of the control group (P < 0.05). The two groups had no significant difference in the incidence of biliary complications, vascular complications, and postoperative infections (P > 0.05). The rate of immune reactive complications in the observation group was lower than that of the control group (P < 0.05). There was no significant difference in the perioperative mortality rate, 1-year postoperative survival rate, and 2-year postoperative survival rate (P > 0.05). The two groups had no significant difference in postoperative liver function indexes (P > 0.05). Conclusion: Preoperative TACE and high-quality nursing intervention in patients with hepatocellular carcinoma had no adverse effect on the perioperative safety and short-term prognosis, prolonged the liver-free time, and reduced the incidence of immune-reactive complications.

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.

Prevention and treatment of hepatic artery thrombosis after liver transplantation

BACKGROUND: Hepatic artery thrombosis (HAT) which is a serious complication after orthotopic liver transplanta- tion (OLT) remains a significant cause of graft loss. The purpose of this study was to sum up our experiences in the prevention, diagnosis and management of HAT after liver transplantation. METHODS: From April 1993 to September 2003, a total of 198 patients underwent OLT at our hospital. The hepatic artery was anastomosed using 7/0 prolane with running continuous suture in 96 patients (group 1) and with inter- rupted suture in 102 (group 2). Ultrasonography was per- formed every day in two weeks after operation and selec- tively afterwards. RESULTS: HAT occurred in 6 patients (6.3%, 6/96) of group 1, and in 1 (1%, 1/102) of group 2 (x2=4.027, P= 0.045). Six patients received emergency thrombectomy, and 1 conservative therapy but died from tumor recurrence eventually. Biliary complication developed in 3 patients af- ter thrombectomy of whom 2 died of liver failure and one waited for retransplantation. In the other 3 patients after thrombectomy, 1 died of renal failure, and 2 survived. The mortality of patients with HAT was 57.1% (4/7). CONCLUSIONS: The technique of hepatic arterial anasto- mosis is the key factor for the prevention of HAT. Routine ultrasonography is very important in early detection of HAT after OLT. Biliary complication is a severe outcome secondary to HAT.

Asymptomatic process of hepatic artery thrombosis in a patient after orthotopic liver transplantation

BACKGROUND: Hepatic artery thrombosis is one of the serious complications after liver transplantation. It wil mostly cause a failure of the transplantation. This case o hepatic artery thrombosis showed a stable clinical course and minimal histological change, and now has been survi ving for 4 years with normal liver function. We investigated the possible causes for asymptomatic hepatic artery throm bosis in one patient after orthotopic liver transplantation ( OLT) and discussed the diagnosis of ischemia of OLT pathologically and clinically. METHODS: Liver function test, color Doppler ultrasono graphy, and hepatic arteriography were performed during the development of hepatic arteriothrombosis. Possible fac- tors for the asymptomatic process of the thrombosis were analyzed. RESULTS: On the 4th postoperative day, thrombosis form ed at the anastomotic stoma of the hepatic artery, and on the 11th postoperative day, the artery was completely oc- cluded. Serial liver biopsies revealed intrahepatic cholesta- sis, hydropic degeneration of hepatocytes, atrophy of the biliary epithelium, and fibrosis in the portal area. Monitor- ing of liver function showed nothing abnormal except ele- vation of γ-GT and ALP levels. On the 71st day after OLT, arteriography demonstrated that the hepatic artery re- mained completely occluded in addition to the establish- ment of collateral circulation and compensation of the por- tal vein. The patient didn' t show any symptoms of arterial thrombosis. CONCLUSION: Collateral circulation and compensation o the portal vein are beneficial to allograft survival and avoidence of retransplantation after thrombosis of the he- patic artery. Color Doppler ultrasonography within 2 weeks after OLT is helpful to the early diagnosis of hepatic arterio- thrombosis.

Anticoagulation and antiplatelets as prophylaxis for hepatic artery thrombosis after liver transplantation

Hepatic artery thrombosis(HAT) is the most serious vascular complication after liver transplantation. Multiple risk factors have been identified to impact its development. Changes in haemostasis associated with end stage liver disease and the disturbance of the coagulation and anticoagulation cascades play an important role in development of this lethal complication. Early recognition and therapeutic intervention is mandatory to avoid its consequences. Pharmacological prophylaxis, by the use of antiplatelet or anticoagulant agents, is an important tool to reduce its incidence and prevent graft loss. Only a few studies have shown a clear benefit of antiplatelet agents in reducing HAT occurrence, however, these studies are limited by being retrospective and by inhomogeneous populations. The use of anticoagulants such as heparin is associated with an improvement in the outcomes mainly when used for a high-risk patients like living related liver recipients. The major concern when using these agents is the tendency to increase bleeding complications in a setting of already unstable haemostasis. Hence, monitoring of their administration and careful selection of patients to be treated are of great importance. Well-designed clinical studies are still needed to further explore their effects and to formulate proper protocols that can be implemented safely.

Arcuate ligament syndrome inducing hepatic artery thrombosis after liver transplantation

BACKGROUND: Hepatic artery thrombosis (HAT) is a frequent complication following liver transplantation, but it is rarely caused by arcuate ligament compression of the celiac artery. This article mainly describes our experience in managing a patient with celiac artery stenosis and HAT after liver transplantation. METHODS: A 44-year-old man with a 15-year history of hepatitis B was admitted to our hospital for hepatocellular carcinoma. Before the operatiori, he received transarterial chemoembolization once, and pretransplant MR angiography indicated a suspected stenosis at the initiation of the celiac artery, while color Doppler showed normal blood flow in the arterial system. In this case, orthotopic liver transplantation was performed for radical cure of hepatocellular carcinoma. However, B-ultrasonography detected poor blood flow in the intra- and extra-hepatic artery on the first posttransplant day, and during exploratory laparotomy a thrombus was found in the hepatic artery. Thus, re-transplantation was conducted with a bypass between the graft hepatic artery and the recipient abdominal aorta with the donor's splenic artery. RESULTS: The patient made an uneventful recovery and color Doppler showed good blood flow in the artery and portal system. Histology confirmed extensive thrombosis in the left and right hepatic artery of the explanted graft, indicating HAT. CONCLUSIONS: Although HAT caused by celiac trunk compression is rarely reported in liver transplantation, the diagnosis should be considered in patients with pretransplant hepatic artery stenosis on angiography and abnormal blood flow on B-ultrasonography. Once HAT is formed, treatment such as thrombectomy or retransplantation should be performed as early as possible.

Intra-arterial thrombolysis for early hepatic artery thrombosis after liver transplantation

BACKGROUND Early hepatic artery thrombosis(E-HAT)is a serious complication after liver transplantation(LT),which often results in graft failure and can lead to patient deaths.Treatments such as re-transplantation and re-anastomosis are conventional therapeutic methods which are restricted by the shortage of donors and the patient’s postoperative intolerance to re-laparotomy.Due to the advances in interventional techniques and thrombolytics,endovascular treatments are increasingly being selected by more and more centers.This study reviews and reports our single-center experience with intra-arterial thrombolysis as the first choice therapy for E-HAT after deceased donor LT.AIM To evaluate the feasibility and reasonability of intra-arterial thrombolysis for EHAT after deceased donor LT.METHODS A total of 147 patients who underwent deceased donor LT were retrospectively reviewed in our hospital between September 2011 and December 2016.Four patients were diagnosed with E-HAT.All of these patients underwent intraarterial thrombolysis with alteplase as the first choice therapy after LT.The method of arterial anastomosis and details of the diagnosis and treatment of EHAT were collated.The long-term prognosis of E-HAT patients was also recorded.The median follow-up period was 26 mo(range:23 to 30 mo).RESULTS The incidence of E-HAT was 2.7%(4/147).E-HAT was considered when Doppler ultrasonography showed no blood flow signals and a definite diagnosis was confirmed by immediate hepatic arterial angiography when complete occlusion of the hepatic artery was observed.The patients were given temporary thrombolytics(mainly alteplase)via a 5-Fr catheter which was placed in the proximal part of the thrombosed hepatic artery followed by continuous alteplase using an infusion pump.Alteplase dose was adjusted according to activated clotting time.The recanalization rate of intra-arterial thrombolysis in our study was 100%(4/4)and no thrombolysis-related mortality was observed.During the follow-up period,patient survival rate was 75%(3/4),and biliary complications were present in 50%of patients(2/4).CONCLUSION Intra-arterial thrombolysis can be considered first-line treatment for E-HAT after deceased donor LT.Early diagnosis of E-HAT is important and follow-up is necessary even if recanalization is successful.

Microsurgical reconstruction of hepatic artery in living donor liver transplantation:experiences and lessons

BACKGROUND: Hepatic artery (HA) reconstruction is one of the key steps for living donor liver transplantation (LDLT). The incidence of HA thrombosis has been reduced by the introduction of nucrosurgical techniques under a high resolution microscope or loupe. METHODS: We report our experience in 101 cases of HA reconstruction in LDLTs using the graft-artery-undamp and posterior-wall-first technique. The reconstructions were completed by either a plastic surgeon or a transplant surgeon. RESULTS: The rate of HA thrombosis was 2% (2/101). The risk factors for failed procedures appeared to be reduced by participation of the transplant surgeon compared with the plastic surgeon. For a graft with duplicate arteries, we considered no branches should be discarded even with a positive clamping test. CONCLUSIONS: HA reconstruction without clamping the graft artery is a feasible and simplified technique, which can be mastered by transplant surgeons with considerable microsurgical training.

Safety and efficacy of an integrated endovascular treatment strategy for early hepatic artery occlusion after liver transplantation

Background:Hepatic artery occlusion(HAO)after liver transplantation(LT)is typically comprised of hepatic artery thrombosis(HAT)and stenosis(HAS),both of which are severe complications that coexist and interdependent.This study aimed to evaluate an integrated endovascular treatment(EVT)strategy for the resolution of early HAO and identify the risk factors associated with early HAO as well as the procedural challenge encountered in the treatment strategy.Methods:Consecutive orthotopic LT recipients(n=366)who underwent transplantation between June 2017 and December 2018 were retrospectively investigated.EVT was performed using an integrated strategy that involved thrombolytic therapy,shunt artery embolization plus vasodilator therapy,percutaneous transluminal angioplasty,and/or stent placement.Simple EVT was defined as the clinical resolution of HAO by one round of EVT with thrombolytic therapy and/or shunt artery embolization plus vasodilator therapy.Otherwise,it was defined as complex EVT.Results:Twenty-six patients(median age 52 years)underwent EVT for early HAO that occurred within 30 days post-LT.The median interval from LT to EVT was 7(6–16)days.Revascularization time(OR=1.027;95%CI:1.005–1.050;P=0.018)and the need for conduit(OR=3.558;95%CI:1.241–10.203,P=0.018)were independent predictors for early HAO.HAT was diagnosed in eight patients,and four out of those presented with concomitant HAS.We achieved 100%technical success and recanalization by performing simple EVT in 19 patients(3 HAT+/HAS-and 16 HAT-/HAS+)and by performing complex EVT in seven patients(1 HAT+/HAS-,4 HAT+/HAS+,and 2 HAT-/HAS+),without major complications.The primary assisted patency rates at 1,6,and 12 months were all 100%.The cumulative overall survival rates at 1,6,and 12 months were 88.5%,88.5%,and 80.8%,respectively.Autologous transfusion<600 mL(94.74%vs.42.86%,P=0.010)and interrupted suture for hepatic artery anastomosis(78.95%vs.14.29%,P=0.005)were more prevalent in simple EVT.Conclusions:The integrated EVT strategy was a feasible approach providing effective resolution with excellent safety for early HAO after LT.Appropriate autologous transfusion and interrupted suture technique helped simplify EVT.

Interventional treatment of acute hepatic artery occlusion after liver transplantation

BACKGROUND: With the development of the associated technology, interventional treatment has become an important method for the treatment of hepatic artery occlusion in some countries. This study was undertaken to evaluate the role of interventional methods in the diagnosis and treatment of acute hepatic artery occlusion after liver transplantation. METHODS: The diagnosis and treatment of 9 cases of acute hepatic artery occlusion after liver transplantation were retrospectively analyzed. RESULTS: In 109 cases of liver transplantation, 9 were diagnosed by angiography. Among them, 7 were diagnosed by Doppler ultrasound. After transcatheter thrombolysis, the hepatic arteries were partially or totally patent again in 6 cases of hepatic artery occlusion after liver transplantation, and stent placements in the hepatic artery were performed in 5 cases. All stents proved patent and no patient required another liver transplantation. CONCLUSIONS: Angiography plays an important role in diagnosing hepatic artery complications after liver transplantation. Interventional therapy is a valuable method in the treatment of acute hepatic artery occlusion after liver transplantation.

Management of early hepatic artery occlusion after liver transplantation with failed rescue

Hepatic artery thrombosis is a serious complication after liver transplantation which often results in biliary complications, early graft loss, and patient death. It is generally thought that early hepatic artery thrombosis without urgent re-vascularization or retransplantation almost always leads to mortality, especially if the hepatic artery thrombosis occurs within a few days after transplantation. This series presents 3 cases of early hepatic artery thrombosis after living donor liver transplantation, in which surgical or endovascular attempts at arterial re-vascularization failed. Unexpectedly, these 3 patients survived with acceptable graft function after 32 mo, 11 mo, and 4 mo follow-up, respectively. The literatures on factors affecting this devastating complication were reviewed from an anatomical perspective. The collective evidence from survivors indicated that modified nonsurgical management after liver transplantation with failed revascularization may be sufficient to prevent mortality from early hepatic artery occlusion. Re-transplantation may be reserved for selected patients with unrecovered graft function.

The effects of ischemia-reperfusion injury and hepatic artery ischemia on CD14 expression in canine auto-transplantation livers

Objective： To study the effect of ischemia-reperfusion injury（IRI） and hepatic artery ischemia（HAI） on CD14 expression in canine auto-transplantation livers. Methods：Liver orthotopic auto-transplantation models were applied with 30 healthy male Xi＇ an canines which were randomly divided into a control group, simultaneous reperfusion（SR） group and HAI group, CD14 protein expression, Malonaldehyde （MDA） Contents in hepatic tissues and ALT values in serum were detected, and the pathological changes of hepatic tissues was investigated under the light microscopy. Results：The level of CD14 protein expression in SR and HAI group tended to be time-dependent and both higher than controls with statistical significance（P 〈 0.01）; The peak values of these two groups both occurred at 4 h, but the level in HAI group （11.94 ± 0.43） was evidently higher than that in SR group（3.04 ± 0.34）. MDA contents in liver tissue, ALT values in serum and pathological changes showed the same changing tendency as CD 14 expression. Conclusion：（1） Up-regulation of CD14 expression may be the receptor-mechanism of Kupffer cells（KCs） activation in liver transplantation. （2） HAI can upregulate CD14 expression after portal vein reperfusion, improve the activity of KCs further more, increase OFRs production and cooperate with portal reperfusion, and finally aggravate the grafts injury.

Hepatic artery reconstruction in pediatric liver transplantation:Experience from a single group

Background:The reconstruction of hepatic artery is a challenging part of the pediatric liver transplantation procedure.Hepatic artery thrombosis(HAT)and stenosis are complications which may result in ischemic biliary injury,causing early graft lost and even death.Methods:Two hundred and fifty-nine patients underwent liver transplantation in 2017 in a single liver transplantation group.Among them,225 patients were living donor liver transplantation(LDLT)and 34 deceased donor liver transplantation(DDLT).Results:In LDLT all reconstructions of hepatic artery were microsurgical,while in DDLT either microsurgical reconstruction or traditional continuous suture technique was done depending on different conditions.There were five(1.9%)HATs:four(4/34,11.8%)in DDLT(all whole liver grafts)and one(1/225,0.4%)in LDLT(P=0.001).Four HATs were managed conservatively using anticoagulation,and 1 accepted salvage surgery with re-anastomosis.Until now,3 HAT patients remain in good condition,whereas two developed biliary complications.One of them needed to be re-transplanted,and the other patient died due to biliary complications.Conclusions:Microsurgical technique significantly improves the reconstruction of hepatic artery in pediatric liver transplantation.The risk for arterial complications is higher in DDLT.Conservative therapy can achieve good outcome in selected HAT cases.

Diagnosis and outcomes of collateral arterial formation after irreversible early hepatic artery thrombosis in pediatric liver recipients

BACKGROUND： Early hepatic artery thrombosis （eHAT） has been recognized as an important cause of graft loss and mortality. However, the incidence, etiology and outcome are not dear, especially for children. The present study was to investigate the formation of collateral artery flow after irreversible eHAT and its impact on patient＇s prognosis. METHODS： We analyzed eHAT after liver transplantation in children from October 2006 to April 2015 in our center, illustrated the formation of collateral hepatic artery flow after irreversible eHAT and explored the diagnosis, complications, treatment and prognosis. The basic and follow-up ultrasonographic images were also compared. RESULTS： Of the 330 pediatric liver recipients, 22 （6.67%） de- veloped eHAT within 1 month. Revascularization attempts in- duding surgical thrombectomy, interventional radiology and conservational treatment （thrombolysis） were successful in 5 patients. Among the 17 patients who had irreversible eHAT, follow-up ultrasonography revealed that collateral artery flow was developed as early as 2 weeks after eHAT. Liver abscess and bile duct complication occurred secondary to eHAT in variable time. CONCLUSIONS： Collateral arterial formation is a compensatory adaptation to eHAT to supply blood to liver grafts. However, the severe bile duct damage secondary to eHAT is irreversible and retransplantation is unavoidable.

Diagnosis and management of hepatic artery in-stent restenosis after liver transplantation by optical coherence tomography:A case report

BACKGROUNDPercutaneous transluminal angioplasty and stenting represent an effectivetreatment for hepatic artery stenosis after liver transplantation. In the first yearafter stenting, approximately 22% of patients experience in-stent restenosis,increasing the risk of artery thrombosis and related complications, and 50%experience liver failure. Although angiography is an important tool for diagnosisand the planning of therapeutic interventions, it may raise doubts, especially insmall-diameter arteries, and it provides low resolution rates compared withnewer intravascular imaging methods, such as optical coherence tomography(OCT).CASE SUMMARYA 64-year-old male developed hepatic artery stenosis one year after orthotropicliver transplantation and was successfully treated with percutaneous transluminalangioplasty with stenting. Five months later, the Doppler ultrasound resultsindicated restenosis. Visceral arteriography confirmed hepatic artery tortuositybut was doubtful for significant in-stent restenosis (ISR) and intrahepatic flowreduction. To confirm ISR, identify the etiology and guide treatment, OCT wasperformed. OCT showed severe stenosis due to four mechanisms: Focal andpartial stent fracture, late stent malapposition, in-stent neointimal hyperplasia,and neoatherosclerosis.CONCLUSIONIntravascular diagnostic methods can be useful in evaluating cases in which initialangiography results are not sufficient to provide a proper diagnosis of significantstenosis, especially with regard to ISR. A wide range of diagnoses are provided byOCT, resulting in different treatment options. Interventional radiologists shouldconsider intravascular diagnostic methods as additional tools for evaluatingpatients when visceral angiography results are unclear.

Thrombosis prophylaxis in pediatric liver transplantation: A systematic review

AIM To review current literature of thrombosis prophylaxis in pediatric liver transplantation(PLT) as thrombosis remains a critical complication.METHODS Studies were identified by electronic search of MEDLINE, EMBASE and Cochrane Library(CENTRAL) databases until March 2018. The search was supplemented by manually reviewing the references of included studies and the references of the main published systematic reviews on thrombosis and PLT. We excluded from this review case report, small case series, commentaries, conference abstracts, papers which describing less than 10 pediatric liver transplants/year and articles published before 1990. Two reviewers performed study selection independently, with disagreements solved through discussion and by the opinion of a third reviewer when necessary.RESULTS Nine retrospective studies were included in this review. The overall quality of studies was poor. A pooled analysis of results from studies was not possible due to the retrospective design and heterogeneity of included studies. We found an incidence of portal vein thrombosis(PVT) ranging from 2% to 10% in pediatric living donorliver transplantation(LDLT) and from 4% to 33% in pediatric deceased donor liver transplantation(DDLT). Hepatic artery thrombosis(HAT) was observed mostly in mixed LDLT and DDLT pediatric population with an incidence ranging from 0% to 29%. In most of the studies Doppler ultrasonography was used as a first line diagnostic screening for thrombosis. Four different surgical techniques for portal vein anastomosis were reported with similar efficacy in terms of PVT reduction. Reduced size liver transplant was associated with a low risk of both PVT(incidence 4%) and HAT(incidence 0%, P < 0.05). Similarly, aortic arterial anastomosis without graft interposition and microsurgical hepatic arterial reconstruction were associated with a significant reduced HAT incidence(6% and 0%, respectively). According to our inclusion and exclusion criteria, we did not find eligible studies that evaluated pharmacological prevention of thrombosis. CONCLUSION Poor quality retrospective studies show the use of tailored surgical strategies might be useful to reduce HAT and PVT after PLT; prospective studies are urgently needed.

Intraoperative thromboelastography as a tool to predict postoperative thrombosis during liver transplantation

BACKGROUND Thromboembolic complications are relatively common causes of increased morbidity and mortality in the perioperative period in liver transplant patients.Early postoperative portal vein thrombosis(PVT,incidence 2%-2.6%)and early hepatic artery thrombosis(HAT,incidence 3%-5%)have a poor prognosis in transplant patients,having impacts on graft and patient survival.In the present study,we attempted to identify the predictive factors of these complications for early detection and therefore monitor more closely the patients most at risk of thrombotic complications.AIM To investigate whether intraoperative thromboelastography(TEG)is useful in detecting the risk of early postoperative HAT and PVT in patients undergoing liver transplantation(LT).METHODS We retrospectively collected thromboelastographic traces,in addition to known risk factors(cold ischemic time,intraoperative requirement for red blood cells and fresh-frozen plasma transfusion,prolonged operating time),in 27 patients,selected among 530 patients(≥18 years old),who underwent their first LT from January 2002 to January 2015 at the Liver University Transplant Center and developed an early PVT or HAT(case group).Analyses of the TEG traces were performed before anesthesia and 120 min after reperfusion.We retrospectively compared these patients with the same number of nonconsecutive control patients who underwent LT in the same study period without developing these complications(1:1 match)(control group).The chosen matching parameters were:Patient graft and donor characteristics[age,sex,body mass index(BMI)],indication for transplantation,procedure details,United Network for Organ Sharing classification,BMI,warm ischemia time(WIT),cold ischemia time(CIT),the volume of blood products transfused,and conventional laboratory coagulation analysis.Normally distributed continuous data are reported as the mean±SD and compared using one-way Analysis of Variance(ANOVA).Nonnormally distributed continuous data are reported as the median(interquartile range)and compared using the Mann-Whitney test.Categorical variables were analyzed with Chi-square tests with Yates correction or Fisher’s exact test depending on best applicability.IBM SPSS Statistics version 24(SPSS Inc.,Chicago,IL,United States)was employed for statistical analysis.Statistical significance was set at P<0.05.RESULTS Postoperative thrombotic events were identified as early if they occurred within 21 d postoperatively.The incidence of early hepatic artery occlusion was 3.02%,whereas the incidence of PVT was 2.07%.A comparison between the case and control groups showed some differences in the duration of surgery,which was longer in the case group(P=0.032),whereas transfusion of blood products,red blood cells,fresh frozen plasma,and platelets,was similar between the two study groups.Thromboelastographic parameters did not show any statistically significant difference between the two groups,except for the G value measured at basal and 120’postreperfusion time.It was higher,although within the reference range,in the case group than in the control group(P=0.001 and P<0.001,respectively).In addition,clot lysis at 60 min(LY60)measured at 120’postreperfusion time was lower in the case group than in the control group(P=0.035).This parameter is representative of a fibrinolysis shutdown(LY60=0%-0.80%)in 85%of patients who experienced a thrombotic complication,resulting in a statistical correlation with HAT and PVT.CONCLUSION The end of surgery LY60 and G value may identify those recipients at greater risk of developing early HAT or PVT,suggesting that they may benefit from intense surveillance and eventually anticoagulation prophylaxis in order to prevent these serious complications after LT.

Liver transplantation following two conversions in a patient with huge hepatocellular carcinoma and portal vein invasion:A case report

BACKGROUND Surgical resection and liver transplantation(LT)are the most effective curative options for hepatocellular carcinoma(HCC).However,few patients with huge HCC(>10 cm in diameter),especially those with portal vein tumor thrombus(PVTT),can receive these treatments.Selective internal radiation therapy(SIRT)can be used as a conversion therapy for them because it has the dual benefit of shrinking tumors and increasing residual hepatic volume.However,in patients with huge HCC,high lung absorbed dose often prevents them from receiving SIRT.CASE SUMMARY A 35-year-old man was admitted because of emaciation and pain in the hepatic region for about 1 month.The computed tomography scan showed a 20.2 cm×19.8 cm tumor located in the right lobe–left medial lobes with right portal vein and right hepatic vein invasion.After the pathological type of HCC was confirmed by biopsy,two conversions were presented.The first one was drug-eluting bead transarterial chemoembolization plus hepatic arterial infusion chemotherapy and lenvatinib and sintilimab,converted to SIRT,and the second one was sequential SIRT with continued systemic treatment.The tumor size significantly decreased from 20.2 cm×19.8 cm to 16.2 cm×13.8 cm,then sequentially to 7.8 cm×6.8 cm.In the meantime,the ratio of spared volume to total liver volume increased gradually from 34.4%to 55.7%,then to 62.9%.Furthermore,there was visualization of the portal vein,indicating regression of the tumor thrombus.Finally,owing to the new tumor in the left lateral lobe,the patient underwent LT instead of resection without major complications.CONCLUSION Patients with inoperable huge HCC with PVTT could be converted to SIRT first and accept surgery sequentially.

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.