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.

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.

Microsurgical reconstruction of hepatic artery in A-A LDLT:124 consecutive cases without HAT

AIM:To retrospectively investigate microsurgical hepatic artery(HA) reconstruction and management of hepatic thrombosis in adult-to-adult living donor liver transplantation(A-A LDLT).METHODS:From January 2001 to September 2009,182 recipients with end-stage liver disease underwent A-A LDLT.Ten of these patients received dual grafts.The 157 men and 25 women had an age range of 18 to 68 years(mean age,42 years).Microsurgical techniques and running sutures with back-wall first techniques were performed in all arterial reconstructions under surgical loupes(3.5 ×) by a group of vascular surgeons.Intimal dissections were resolved by interposition of the great saphenous vein(GSV) between the donor right hepatic artery(RHA) and recipient common HA(3 cases) or abdominal aorta(AA)(2 cases),by interposition of cryopreserved iliac vessels between the donor RHA and recipient AA(2 cases).RESULTS:In the 58 incipient patients in this series,hepatic arterial thrombosis(HAT) was encountered in 4 patients,and was not observed in 124 consecutive cases(total 192 grafts,major incidence,2.08%).All cases of HAT were suspected by routine color Doppler ultrasonographic examination and confirmed by contrast-enhanced ultrasound and hepatic angiography.Of these cases of HAT,two occurred on the 1st and 7th d,respectively,following A-A LDLT,and were immediately revascularized with GSV between the graft and recipient AA.HAT in one patient occurred on the 46th postoperative day with no symptoms,and the remaining case of HAT occurred on the 3rd d following A-A LDLT,and was cured by thrombolytic therapy combined with an anticoagulant but died of multiorgan failure on the 36th d after A-A LDLT.No deaths were related to HAT.CONCLUSION:Applying microsurgical techniques and selecting an appropriate anastomotic artery for HA reconstruction are crucial in reducing the high risk of HAT during A-A LDLT.

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.

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.

Hepatic arterial infusion chemotherapy in hepatocellular carcinoma with portal vein tumor thrombosis

AIM: To evaluate the prognostic factors and efficacy of hepatic arterial infusion chemotherapy in hepatocellular carcinoma with portal vein tumor thrombosis. METHODS: Fifty hepatocellular carcinoma (HCC) patients with portal vein tumor thrombosis (PVTT) were treated using hepatic arterial infusion chemotherapy (HAIC) via a subcutaneously implanted port. The epirubicin-cisplatin-5-fluorouracil (ECF) chemotherapeutic regimen consisted of 35 mg/m 2 epirubicin on day 1, 60 mg/m 2 cisplatin for 2 h on day 2, and 500 mg/m 2 5-fluorouracil for 5 h on days 1-3. The treatments were repeated every 3 or 4 wk. RESULTS: Three (6%) of the 50 patients achieved a complete response (CR), 13 (26%) showed partial responses (PR), and 22 (44%) had stable disease (SD).The median survival and time to progression were 7 and 2 mo, respectively. After 2 cycles of HAIC, CR was achieved in 1 patient (2%), PR in 10 patients (20%) and SD in 26 patients (52%). Significant pre-treatment prognostic factors were a tumor volume of < 400 cm 3 (P = 0.01) and normal levels of protein induced by vitamin K absence or antagonist (PIVKA)-Ⅱ (P = 0.022). After 2 cycles of treatment, disease control (CR + PR + SD) (P = 0.001), PVTT response (P = 0.003) and α-fetoprotein reduction of over 50% (P = 0.02) were independent factors for survival. Objective response (CR + PR), disease control, PVTT response, and combination therapy during the HAIC were also significant prognostic factors. Adverse events were tolerable and successfully managed. CONCLUSION: HAIC may be an effective treatment modality for advanced HCC with PVTT in patients with tumors < 400 cm 3 and good prognostic factors.

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.

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.

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.

Efficacy of 5-Fluorouracil and High-Concentration Cisplatin Suspended in Lipiodol by Short-Term Hepatic Arterial Infusion Chemotherapy for Advanced Hepatocellular Carcinoma with Portal Vein Tumor Thrombosis

Background: Since advanced hepatocellular carcinoma (HCC) is potentially fatal, and patients’ quality of life (QOL) often deteriorates during their treatment, improving the prognosis and QOL of patients given chemotherapy is very important. In addition, cost-effective treatments are highly desirable when chemotherapy must be given repeatedly. The aim of this study was to evaluate the efficacy and usefulness of 5-fluorouracil (5-FU) and high-concentration cisplatin by short-term hepatic arterial infusion chemotherapy (3-day FPL) in advanced HCC patients. Methods: Thirty patients with unresectable advanced HCC were enrolled. The patients underwent hepatic arterial infusion chemotherapy via the implanted port system with 5-FU on days 1 - 3 and a fine-powder formulation of cisplatin in suspended pre-warmed lipiodol on day 2 every 4 to 10 weeks. Tumor response was assessed one month later with CT. Results: All patients had evidence of portal vein invasion (Vp2-4). Four patients achieved a complete response (CR), 8 patients achieved a partial response (PR), and 7 patients had stable disease (SD). The median progression-free survival (PFS) and overall survival (OS) were 198 days and 452 days, respectively. The OS was significantly longer in the successful disease control group (CR, PR, and SD) than in the progressive disease group (P < 0.005). Conclusions: Three-day FPL was effective and tolerable in advanced HCC patients due to its shorter time of administration than conventional FP therapy. Therefore, repetitive 3-day FPL appears useful and contributes to improving the prognosis and QOL of patients with advanced HCC. In addition, this protocol is a cost-effective treatment.

间歇式充气压力泵联合踝泵运动对肝动脉灌注化疗患者的影响

目的探讨间歇式充气压力泵联合踝泵运动对肝动脉灌注化疗患者下肢深静脉血栓(DVT)的预防效果。方法选取2021年3月至2023年3月该院收治的120例肝动脉灌注化疗患者,采取随机数字表法分为对照组(60例)和观察组(60例)。对照组实施常规护理,观察组实施间歇式充气压力泵联合踝泵运动,比较2组D二聚体(DD)、纤维蛋白原(FIB)、纤维蛋白原降解产物(FDP)水平等。结果干预前,2组DD、FIB、FDP水平比较,差异无统计学意义(P>0.05)。干预后,观察组DD、FIB、FDP水平低于对照组,差异有统计学意义(P<0.05)。观察组下肢肿胀情况、下床活动时间、住院时间优于对照组,差异有统计学意义(P<0.05)。观察组下肢DVT发生率为15.00%(9/60),高于对照组的3.33%(2/60),差异有统计学意义(P=0.027)。观察组护理满意度[95.00%(57/60)]高于对照组[78.33%(47/60)],差异有统计学意义(P<0.05)。结论间歇式充气压力泵联合踝泵运动能有效改善肝动脉灌注化疗患者凝血功能,缩短下床活动时间、住院时间,降低下肢DVT发生率,提高护理满意度。

预见性护理预防肝动脉化疗栓塞术后深静脉血栓形成的效果分析

目的:分析预见性护理预防肝动脉化疗栓塞术(TACE)后深静脉血栓形成(DVT)的效果。方法:选取2022年1月—2023年5月复旦大学附属中山医院青浦分院收治的拟行TACE治疗的原发性肝癌患者82例作为研究对象,采用随机数字表法分为对照组与试验组,各41例。对照组开展常规围术期护理,试验组在对照组基础上开展预见性护理干预。比较两组心理状况、疼痛程度及DVT发生情况。结果:术后1 d,两组汉密尔顿焦虑量表(HAMA)评分比较,差异无统计学意义(P>0.05);术后3 d,两组HAMA评分低于术后1 d,且试验组低于对照组,差异有统计学意义(P<0.001)。术后1 d,两组视觉模拟评分法(VAS)评分比较,差异无统计学意义(P>0.05);术后2 d、3 d,两组VAS评分低于术后1 d,且试验组低于对照组,差异有统计学意义(P<0.05)。试验组DVT发生率低于对照组,差异有统计学意义(P=0.040)。结论:预见性护理应用于TACE围术期护理中可缓解患者焦虑情绪,减轻疼痛,降低DVT发生率。

Risk factors associated with early and late HAT after adult liver transplantation

AIM: To identify risk factors that might contribute to hepatic artery thrombosis (HAT) after liver transplantation (LT). METHODS: The perioperative and follow-up data of a total of 744 liver transplants, performed from February 1999 to July 2010, were retrospectively reviewed. HAT developed in 20 patients (2.7%). HAT was classified as early (occurring in fewer than 30 d post LT) or late (occurring more than 30 d post LT). Early HAT devel-oped in 14 patients (1.9%). Late HAT developed in 6 patients (0.8%). Risk factors associated with HAT were analysed using the chi(2) test for univariate analysis and logistic regression for multivariate analysis. RESULTS: Lack of ABO compatibility, recipient/donor weight ratio >= 1.15, complex arterial reconstruction, duration time of hepatic artery anastomosis > 80 min, duration time of operation > 10 h, dual grafts, number of units of blood received intraoperatively >= 7, number of units of fresh frozen plasma (FFP) received intraoperatively >= 6, postoperative blood transfusion and postoperative FFP use were significantly associated with early HAT in the univariate analysis (P < 0.1). After logistic regression, independent risk factors associated with early HAT were recipient/donor weight ratio >= 1.15 (OR = 4.499), duration of hepatic artery anastomosis > 80 min (OR = 5.429), number of units of blood received intraoperatively >= 7 (OR = 4.059) and postoperative blood transfusion (OR = 6.898). Graft type (whole/living-donor/split), duration of operation > 10 h, retransplantation, rejection reaction, recipients with diabetes preoperatively and recipients with a high level of blood glucose or diabetes postoperatively were significantly associated with late HAT in the univariate analysis (P < 0.1). After logistic regression, the independent risk factors associated with early HAT were duration of operation > 10 h (OR = 6.394), retransplantation (OR = 21.793) and rejection reactions (OR = 16.936). CONCLUSION: Early detection of these risk factors, strict surveillance protocols by Doppler ultrasound and prophylactic anticoagulation for recipients at risk might be determined prospectively. (C) 2014 Baishideng Publishing Group Inc. All rights reserved.

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.

Treatment of hepatocellular carcinoma with portal venous tumor thrombosis: A comprehensive review

The natural history of hepatocellular carcinoma(HCC)with portal vein tumor thrombosis(PVTT)is dismal(approximately 2-4 mo),and PVTT is reportedly found in 10%-40%of HCC patients at diagnosis.According to the Barcelona Clinic Liver Cancer(BCLC)Staging System(which is the most widely adopted HCC management guideline),sorafenib is the standard of care for advanced HCC(i.e.,BCLC stage C)and the presence of PVTT is included in this category.However,sorafenib treatment only marginally prolongs patient survival and,notably,its therapeutic efficacy is reduced in patients with PVTT.In this context,there have been diverse efforts to develop alternatives to current standard systemic chemotherapies or combination treatment options.To date,many studies on transarterial chemoembolization,3-dimensional conformal radiotherapy,hepatic arterial chemotherapy,and transarterial radioembolization report better overall survival than sorafenib therapy alone,but their outcomes need to be verified in future prospective,randomized controlled studies in order to be incorporated into current treatment guidelines.Additionally,combination strategies have been applied to treat HCC patients with PVTT,with the hope that the possible synergistic actions among different treatment modalities would provide promising results.This narrative review describes the current status of the management options for HCC with PVTT,with a focus on overall survival.

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.

Treatment of Hepatocellular Carcinoma with Portal Vein Tumor Thrombosis

The prognosis of hepatocellular carcinoma (HCC) with portal vein tumor thrombosis (PVTT) is very poor although sorafenib is recommended as the first-line treatment. Therefore, an effective treatment regime is needed for treating HCC with PVTT. This review summarized seven potential treatment regimes which including transarterial chemoembolization (TACE), TACE combined with sorafenib, TACE combined with radiotherapy (RT), hepatectomy, hepatic arterial infusion chemotherapy (HAIC), HAIC combined with sorafenib and HAIC combined with RT in the treatment of HCC with PVTT. In conclusion, hepatectomy or the combination of HAIC and sorafenib may be a more effective modality in the treatment of HCC patients with type I - II PVTT. HAIC combined with or without sorafenib/RT or the combination of RT and TACE is an alternative treatment choice for HCC patients with type III - IV PVTT. Further randomized controlled studies are warranted.